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Publication numberUS20020124353 A1
Publication typeApplication
Application numberUS 09/963,330
Publication date12 Sep 2002
Filing date25 Sep 2001
Priority date25 Jan 2000
Also published asDE10190197D2, DE50110213D1, EP1163088A1, EP1163088B1, WO2001054866A1
Publication number09963330, 963330, US 2002/0124353 A1, US 2002/124353 A1, US 20020124353 A1, US 20020124353A1, US 2002124353 A1, US 2002124353A1, US-A1-20020124353, US-A1-2002124353, US2002/0124353A1, US2002/124353A1, US20020124353 A1, US20020124353A1, US2002124353 A1, US2002124353A1
InventorsH. Holland-Letz
Original AssigneeHolland-Letz H. W.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Handle for a hand tool
US 20020124353 A1
Abstract
The invention provides a handle (38) for hand and garden tools which causes a preferred coupling position of an assigned group of hands when the respective tool is used. The handle (38) contains a first section for contacting the palm and a second section that is intended for being encompassed by the fingers. The first section contains a distal part (50) that is intended for being encompassed by the thumb bridge, a proximal part (54) that is intended for contacting the ball of the hand root and a center part (52) that lies between the two aforementioned parts and has a pronounced radially outward directed curvature that extends over at least part of its circumference and is intended for snugly adjoining the inner surface of the hand. The distance of this curvature from the longitudinal axis (39) is at its greatest in a maximum (59) that lies in a central region of the curvature and distinctly decreases from this location to the distal and the proximal part (50, 54). According to the invention, a length (L0.1) of the center part (52) amounts to 45-55% of the hand width of the assigned group of hands and has a curvature—if viewed in a longitudinal section that contains the longitudinal axis (39)—with a curvature radius (R2.1) of 50-120 mm in the maximum (59). The invention also provides handle sets, hand or garden tools and hand or garden tool sets containing handles of this type (FIG. 5).
Images(61)
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Claims(38)
What is claimed is:
1. Handle for hand and garden tools which causes a preferred coupling position of an assigned group of hands when the respective tool is used, with a first section (42, 162) that is essentially intended for contacting the palm (33), and with a second section (43, 163) that is essentially intended for being encompassed by the finger joints, wherein the two sections (42, 162; 43, 163) respectively lie on one side of an imaginary longitudinal axis (39, 164), wherein the first section (42, 162) contains a distal part (50, 168) that is intended for being encompassed by the thumb bridge (26) between the thumb (20) and the index finger and assigned to a handle beginning, a proximal part (54, 170) that is intended for contacting the ball of the hand root (29) and assigned to a handle end, and a center part (52, 169) that lies between the distal part and the proximal part (50, 168; 54, 170), wherein said center part has a pronounced radially outward directed curvature (57, 171) that extends over at least part of its circumference and is intended for snugly adjoining the palm (33), and wherein said curvature has a surface, the distance of which from the longitudinal axis (39, 164) is at its greatest in a maximum (59, 178) that is situated in a central region of the curvature (57, 171) and distinctly decreases from this maximum to the distal and proximal parts (50, 168; 54, 170), characterized by the fact that a length (L0.1) of the center part (52, 169) amounts to between 45% and 55% of the hand width (B) of the assigned group of hands (19), and by the fact that the curvature (57, 171) has—if viewed in a longitudinal section that contains the longitudinal axis (39, 164)—a curvature radius (R2.1) of 60-120 mm in the maximum (59, 178).
2. Handle according to claim 1, characterized by the fact that the first section (42, 162) lies above an imaginary central plane (yz-plane) that includes the longitudinal axis (39, 164), with the second section (43, 163) lying below this imaginary central plane.
3. Handle according to claim 2, characterized by the fact that the maximum (59, 178) lies in a plane (xz-plane) that extends perpendicular to the central plane and includes the longitudinal axis (59, 164).
4. Handle according to claim 2, characterized by the fact that the maximum (point 137) lies in a plane that is arranged perpendicular to the central plane (xz-plane) and spaced apart from the longitudinal axis.
5. Handle according to one of claims 1-4, characterized by the fact that the surface of the curvature (57, 171) contains a generatrix that extends from the distal to the proximal part (50, 168; 54, 170), with said generatrix representing the geometric location of all points that have the greatest distance from the longitudinal axis (39, 164) in the center part (52, 169) in all cross sections (B-B) along the longitudinal axis.
6. Handle according to claim 5, characterized by the fact that the generatrix is a plane curve.
7. Handle according to claim 5, characterized by the fact that the generatrix is a three-dimensional curve (155, 156).
8. Handle according to claim 7, characterized by the fact that the points (133-143) of the three-dimensional curve (155, 156) partially lie on one side of a plane that extends perpendicular to the central plane (xz-plane) and includes the longitudinal axis, with part of the aforementioned points lying on the other side of said plane.
9. Handle according to one of claims 1-8, characterized by the fact that all generatrices of the surface of the curvature (57, 171) have a convex progression.
10. Handle according to one of claims 1-9, characterized by the fact that the proximal part has a surface contour that continuously decreases from the center part to the proximal end.
11. Handle according to one of claims 1-9, characterized by the fact that the proximal part (54, 170) has a continuously concave surface contour from the center part (52, 169) to the proximal end.
12. Handle according to claim 10 or 11, characterized by the fact that a length LIII. 1 which is measured between the maximum (59, 178) and a proximal end (46) amounts to 50-55% of the hand width (B) of the assigned group of hands.
13. Handle according to claim 10 or 11, characterized by the fact that a length LII.1 which is measured between the maximum (59, 178) and the minimum (61, 180) or a central region of the proximal part (54, 170), respectively, approximately amounts to 33-37% of the hand width (B) of the assigned group of hands.
14. Handle according to one of claims 1-13, characterized by the fact that the distal part (50, 168) has a continuously concave surface structure from the center part (52, 169) to the distal end.
15. Handle according to one of claims 1-14, characterized by the fact that the center part (52, 169) has—if viewed in the form of longitudinal sections—gradually decreasing curvature radii (R2.3, R2.4) on both sides of an imaginary plane that extends through the maximum (59, 178) and includes the longitudinal axis (39, 164).
16. Handle according to one of claims 1-15, characterized by the fact that at least one of the lengths (L0.1, LI.1, LII.1 and/or LIII.1) is realized in accordance with one of the tables shown in FIGS. 93a-96 c.
17. Handle according to one of claims 1-16, characterized by the fact that at least one additional dimension (LI.2-LIII.4, A1A-A3D, R1.1-R3.4, R1.10-R3.13) is realized in accordance with one of the tables shown in FIGS. 93a-96 c.
18. Handle according to one of claims 1-17, characterized by the fact that it essentially has a continuously egg-shaped, oval or elliptical cross sections in the longitudinal direction.
19. Handle according to one of claims 1-18, characterized by the fact that the handle is realized in one piece, and by the fact that the first section (42) is integrally connected to the second section (43) by an inner section (44).
20. Handle according to one of claims 1-18, characterized by the fact that the handle consists of two pieces, wherein the first section and the second section (162, 163) respectively form part of a separate handle part, and wherein the two handle parts are separated by an intermediate space.
21. Handle according to claim 20 for pliers, characterized by the fact that the curvature is realized such that its maximum lies closer to the proximal part than to the distal part.
22. Handle according to claim 20 or 21, characterized by the fact that the first section (162) and the second section (163) are essentially realized identically and in a laterally reversed symmetric fashion referred to a central plane (yz-plane).
23. Handle according to one of claims 20-22, characterized by the fact that it has continuously elliptical, oval or egg-shaped cross sections if imaginary surfaces along the longitudinal axis (164) which connect lateral regions of the sections (162, 163) are included.
24. Handle according to one of claims 1-23, characterized by the fact that it is assigned to a group of small hands and its dimensions are at least partially realized in accordance with one of the tables shown in FIGS. 93a-96 c.
25. Handle according to one of claims 1-23, characterized by the fact that it is assigned to a group of large hands and its dimensions are at least partially realized in accordance with one of the tables shown in FIGS. 93a-96 c.
26. Handle according to one of claims 1-25, characterized by the fact that it is assigned to a group of medium hands and its dimensions at least partially have values that lie between those for the groups according to claims 24 and 25.
27. Handle according to one of claims 1-26, characterized by the fact that the curvature (57, 171) extends in at least two directions that lie perpendicular to one another and is essentially defined with respect to its three-dimensional shape and size by a combination of the surface contour with the radius R2.1 which extends in an xz-plane at least over the length (L0.1) in the upper section (42, 162) of the center part (52, 169), the surface contour with the radius R2.3 and/or R2.4 which extends in a yz-plane, the radii 2.10 and R2.13 and/or R2.14 which define the cross-sectional contour in the maximum (59, 178) of the center part (52, 169) and the eccentricities AII.1 and AII.3 and/or AII.1 and AII.4.
28. Handle according to claims 1-19, characterized by the fact that it has, in the region of the center part (52, 169), the curvature radii R2.2 and R2.5 of 60-150 mm, respectively in a plane 2 of 90 relative to the plane with the curvature radius R2.1 and in a plane 5 of 45 relative to the plane with the curvature radius R2.1.
29. Handle according to one of claims 1-28, characterized by the fact that it contains a thumb support on the upper side of the distal region, wherein said thumb support is realized in the form of a trough or flattening (83, 87) that extends parallel or slightly oblique referred to the yz-plane and/or a lateral trough or flattening (101) that extends slightly oblique referred to the xz-plane.
30. Handle according to one of claims 1-29, characterized by the fact that, in two-part handles, the region of the lower section (185) which is intended for supporting the fingers is largely realized cylindrically and only has a slight curvature in the direction of the longitudinal axis, wherein the upper section (184) has the pronounced concave-convex-concave curvature that extends in the direction of the xz-plane and in the direction of the yz-plane.
31. Handle according to one of claims 1-30, characterized by the fact that a handle for left-handed users is realized in a laterally reversed fashion referred to a handle for right-handed users.
32. Handle according to one of claims 1-31, characterized by the fact that its cross-sectional surfaces are defined by radii RA.10-RC.14, wherein the radii R.10 and R.12 lie between 12 mm and 30 mm, and wherein the radii R.11 and R.13 lie between 15 mm and 30 mm.
33. Handle according to one of claims 1-32, characterized by the fact that the handle has an asymmetric shape for right-handed users and for left-handed users.
34. Handle set for a hand and garden tool which causes a preferred coupling position of the hand when the tool is used, characterized by the fact that the set contains a preselected number of handles (38, 78, 86, 106, 160) according to one or more of claims 1-32, wherein the shape and/or size of each handle (38, 78, 86, 106, 160) predetermines the preferred coupling positions of the hands of a different group of hand sizes and/or hand shapes.
35. Handle set according to claim 34, characterized by the fact that it contains at least two handles with different sizes.
36. Hand or garden tool with a functional part and a handle, characterized by the fact that the handle (38, 78, 86, 106, 160) is realized in accordance with at least one of claims 133.
37. Hand or garden tool set, characterized by the fact that it contains a series of hand or garden tools with one and the same functional part (64, 105, 108), but different handles (38, 78, 86, 106, 160), wherein the shape and/or size of each handle (38, 78, 86, 106, 160) predetermines a preferred coupling position of the hands of a different group of hands.
38. Hand or garden tool set according to claim 37, characterized by the fact that at least two handles (38, 78, 86, 106, 160) with different sizes are provided for each functional part (64, 105, 108).
Description
    FIELD OF THE INVENTION
  • [0001]
    The invention pertains to handles for hand and garden tools according to the preamble of claim 1, as well as to handle-and-tool sets containing such handles.
  • BACKGROUND OF THE INVENTION
  • [0002]
    In the context of the present invention, the term handles for hand and garden tools refers to handles that cause a preferred coupling position of the hand when the tool is used, i.e., the user preferably takes hold of and encloses the handles with a specific hand position that depends on the handling of the tool while it is used, wherein this hand position changes only insignificantly while the tool is being used. This pertains, in particular, to handles that are centered in the hand cavity approximately in the center of their longitudinal extent while the tool is used. Until now, handles of this type were manufactured in preselected groups and shapes depending on the intended use of the respective tool, e.g., a handsaw or a file, and designed differently by the various manufacturers. These designs are frequently realized in accordance with given standards. In the product assortment of a manufacturer, only one respective handle is available for a tool of a certain type and size. This applies, in principle, independently of whether the tools have a one-part handle, e.g., for hammers, firmer chisels, files, mason's trowels, saws or the like, or a two-part handle, e.g., for pliers, pruning shears or similar tools of the pliers or scissor family.
  • [0003]
    The design of the handles as a function of the intended use of the respective tool should be done in accordance with ergonomic considerations, particularly if the tools are used professionally. This is the reason why it has already been investigated which coupling position the hands should assume relative to the handles and which dimensions ergonomically favorable handles should have [e.g., “Ergonomic Tool Design, Systematic” (Research Report No. 156), published by the German Federal Institute for Occupational Safety and Accident Research in 1979]. It is surprising that these investigations did not result in handles that sufficiently take into account the anatomical peculiarities of the quite different sizes and/or shapes of the human hand. For example, a barrel shape with a curvature radius of 220 mm for the longitudinal contour is proposed for grab handles (page 253). A curvature radius of 220 mm is also proposed for pliers-like handles. These radii are too large, and do not result in an optimal contact between the handles and the hand. Handles that are known from the prior art and are available on the market also have not undergone additional developments. For example, hammer handles do not fill up the hand cavity, and are even partially shaped in a concave fashion within the contact region such that, in particular, the recoils occurring while hammering are distributed over small and limited zones of the hand. Although saw handles are shaped in a convex fashion in the longitudinal direction, the curvature radii are too large, and possibly-provided depressions for the fingers are not appropriately designed. Although pliers frequently have convex or elliptical handle parts in the longitudinal direction, most handles are too narrow and excessively short such that the outer edges of the palm do not contact the handles, and the inner surface of the hand, as well as the middle joints of the fingers, are subjected to painful pressure in a narrow zone when the pliers are closed. The handles of firmer chisels (wood chisels) usually extend in a continuously conical or even concavely curved fashion in the longitudinal direction. This completely contradicts the anatomy of the encompassing hand. Corresponding and additional deficiencies can also be observed with all the tool handles.
  • [0004]
    Handles of the initially described type are explained in detail in prior applications of the same applicant (PCT/DE 00/00209 of Jan. 25, 2000 and DE 199 02 882.6 of Jan. 25, 1999). Handles of this type should automatically cause a preferred coupling position of the hand while the respective tool is used, and also make it possible to largely standardize the handles in accordance with different handle sizes and/or handle shapes. The essential elements of such handles are the respective center parts, the upper and lateral sections of which are shaped such that they assume a centered position in the hand cavity while the tool is being used, and essentially fit closely against the entire inner surface of the hand. However, the above-mentioned older proposals do not contain any specific information concerning which handles dimensions need to be influenced in order to achieve the desired effect. This also applies to other known handle (PCT-WO 98/29167) which have certain curvatures that fit into the hand cavity and are, in particular, characterized by special support surfaces for the thumb and trough-like receptacles for the remaining four finger. Based on the aforementioned circumstances, the invention aims to further improve handles of the initially described type and to disclose those dimensions of the handles which most easily result in a preferred coupling position of the hand and are suitable for a comprehensive standardization. However, the handles are neither individually adapted to certain hands nor designed for an “average hand.” On the contrary, the invention aims to sort and classify measuring data obtained from hand measurements such that groups of hand sizes can be formed therefrom.
  • SUMMARY OF THE INVENTION
  • [0005]
    This objective is attained with the characteristics disclosed in the characterizing portions of claims 1, 28, 30 and 31. The invention is described in greater detail below with reference to the embodiments that are illustrated in the enclosed figures.
  • BRIEF DESCRIPTION OF THE INVENTION
  • [0006]
    [0006]FIGS. 1 and 2 are a schematic perspective representation and a schematic top view, respectively, of a section of an oval handle known from the prior art, used to explain the terms used in the following description.
  • [0007]
    [0007]FIG. 3 is a schematic representation of the inner surface of a right hand, used to illustrate the hand sections that are important for the invention.
  • [0008]
    [0008]FIG. 4 is a cross sectional view through the hand along the line IV-IV in FIG. 3.
  • [0009]
    [0009]FIG. 5 is a side view of a handle according to the invention for a hand tool in the form of a hammer.
  • [0010]
    [0010]FIG. 6 is a top view of the handle shown in FIG. 5.
  • [0011]
    FIGS. 7-10 are cross sectional views, respectively, through the handle along the lines A-A, B-B, C-C and D-D in FIGS. 5 and 6.
  • [0012]
    [0012]FIG. 11 is a schematic side view of the handle according to FIGS. 5-10 in connection with a hammer, and a hand that encompasses the handle and is situated in a preferred coupling position.
  • [0013]
    [0013]FIGS. 12 and 13 are schematic sectional views along the lines XII-XII and XIII-XIII, respectively, in FIG. 11.
  • [0014]
    FIGS. 14-18 are representations of a second embodiment of a hammer handle according to the invention which correspond to the representations in FIGS. 5-9.
  • [0015]
    FIGS. 19-24 are representations of a handle according to the invention for a hand tool in the form of a mason's trowel which correspond to the representations in FIGS. 5-10.
  • [0016]
    FIGS. 25-30 are representations of a second embodiment of a handle according to the invention for a mason's trowel which correspond to the representations in FIGS. 19-24.
  • [0017]
    [0017]FIGS. 31 and 32 are schematic side views of the handles according to FIGS. 19-24 and FIGS. 25-30, respectively, with a hand that encompasses the handle and is situated in a preferred coupling position.
  • [0018]
    [0018]33 is a schematic side view of a handle according to the invention for a hand tool in the form of a saw.
  • [0019]
    [0019]FIG. 34 is a front view of the handle according to FIG. 33 (viewed from the right in FIG. 33).
  • [0020]
    FIGS. 35-37 are cross sectional views through the handle along the lines A-A through C-C, respectively, in FIG. 33.
  • [0021]
    [0021]FIGS. 38 and 39 are schematic side views of the handle according to FIG. 33 in connection with a hand that encompasses said handle, with the hand still being partially open in FIG. 38 and situated in a preferred coupling position in FIG. 39.
  • [0022]
    FIGS. 40-43 are schematic longitudinal section views through a handle according to the invention that, in particular, is suitable for a mason's trowel, along four different sectional planes that are respectively rotated by 45.
  • [0023]
    [0023]FIGS. 44a and 44 b are cross sectional views through the handle along the lines A through T in FIG. 40.
  • [0024]
    [0024]FIG. 45 is a schematic representation of the position of the x, y and z coordinates of selected points on the surface of the handle according to FIG. 40.
  • [0025]
    [0025]FIG. 46 is a perspective grid representation of a handle that essentially corresponds to FIGS. 40-45.
  • [0026]
    [0026]FIG. 47 is a side view of the handle according to FIG. 46 which corresponds to the side view shown in FIG. 5, in the form of a grid representation.
  • [0027]
    FIGS. 48-50 are a top view, another side view after turning the handle in FIG. 47 by 90 and a bottom view after turning the handle according to FIG. 47 by 180, wherein the handle is rotated against the clockwise direction.
  • [0028]
    [0028]FIG. 51 is a side view of a handle according to the invention for a hand tool in the form of pliers.
  • [0029]
    [0029]FIG. 52 is a top view of the handle according to FIG. 51.
  • [0030]
    FIGS. 53-55 are cross sectional views along the lines A-A through C-C, respectively, in FIG. 51.
  • [0031]
    [0031]FIG. 56 is a schematic representation of the handle according to FIG. 51 in connection with a hand situated in a semi-open position.
  • [0032]
    [0032]FIG. 57 is a representation of a hand, situated in a preferred coupling position, that corresponds to the representation in FIG. 56.
  • [0033]
    [0033]FIG. 58 is a representation of the handle according to FIG. 51, essentially corresponding to the representation in FIG. 13, with a hand that encompasses the handle and is situated in a preferred coupling position.
  • [0034]
    FIGS. 59-63 are representations of a second embodiment of a pliers handle according to the invention that correspond to the representations in FIGS. 51-55.
  • [0035]
    [0035]FIGS. 64 and 65 are representations of a third embodiment of a pliers handle according to the invention that correspond to the representations in FIGS. 51 and 52.
  • [0036]
    FIGS. 66-69 are schematic longitudinal section views through a handle according to the invention which is, in particular, suitable for a hammer, along four different sectional planes that are respectively rotated by 45.
  • [0037]
    [0037]FIG. 70 are cross sectional views through the handle along the lines A through L in FIG. 66.
  • [0038]
    FIGS. 71-73 are grid representations of the handle according to FIGS. 66-70 that correspond to the grid representations in FIGS. 47-50.
  • [0039]
    [0039]FIG. 74 is a perspective dot matrix representation of the handle according to FIG. 71.
  • [0040]
    FIGS. 75-83 are representations of a handle according to the invention that is particularly suitable for a saw, with said representations corresponding to the representations in FIGS. 66-74.
  • [0041]
    FIGS. 84-92 are representations of a section of a handle according to the invention that is suitable for pliers, with said representations corresponding to the representations in FIGS. 66-74.
  • [0042]
    [0042]FIGS. 93a and 93 b are tables with dimensions for a preferred embodiment of the handle according to FIGS. 14-18.
  • [0043]
    [0043]FIGS. 94a and 94 b are tables with dimensions for a preferred embodiment of the handle according to FIGS. 19-24.
  • [0044]
    [0044]FIGS. 95a and 95 b are tables with dimensions for a preferred embodiment of the handle according to FIGS. 34-37.
  • [0045]
    [0045]FIGS. 96a, 96 b and 96 c are tables with dimensions for a preferred embodiment of the handle according to FIGS. 51-55.
  • DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
  • [0046]
    [0046]FIGS. 1 and 2 schematically show, in the form of an enlarged representation, part of a conventional handle 1 that essentially extends in a continuously oval fashion in the longitudinal direction and is, for example, situated on the end of the handle of a hammer. An axis that is respectively defined by the largest diameter in the cross section represents the x-axis, an axis that is respectively defined by the smallest diameter represents the y-axis, and a central axis or longitudinal axis that extends perpendicular to the two aforementioned axes represents the z-axis. In addition, the height of the handle 1 is measured in the direction of the x-axis (dimension H), the thickness of the handle 1 is measured in the direction of the y-axis (dimension D), and the length of the handle 1 is measured in the z-direction (dimension L). It is also assumed that the handle 1 is divided into a first outer handle section 7, a second outer handle section 8 and a third handle section 9 that lies between the two aforementioned handle sections and represents an inner handle section bounded by two imaginary planes 5, 6 that are illustrated with broken lines and, for example, extend parallel to the zy-plane. These three handle sections lie adjacent to one another in the direction of the x-axis. This means that the first handle section 7 has a first outer surface 10 that includes a first zone with small curvature radii, and that the second handle section 8 has a second outer surface 11 that is situated diametrically opposite to the first outer surface and includes a second zone with small curvature radii. By contrast, the third section 9 has two diametrically opposed surfaces, namely third and fourth outer surfaces 12 and 13, with large curvature radii. These surfaces 12 and 13 respectively extend approximately up to the intersection lines with the corresponding boundary planes 5 and 6 that are indicated by the points 14, 15 and 16, 17, and represent continuations of the contours formed by the surfaces 10 and 11. This means that the entire outer surface contour has a continuously elliptical or oval cross section. It is also assumed that the handle section 7 corresponds to the hand cavity of right-handed users, and that the surfaces 10-13 make contact with associated hand and finger regions. The handle 1 is, for example, realized in the form of a one-piece handle and is quite massive, with said handle being suitable, for example, for a hammer, a mason's trowel or the like. In this case, the height of the handle section 9 may approach zero. However, if the handle consists of a handle for pliers, which conventionally comprises two pivoted handle limbs, it can be assumed for the purpose of the invention that one handle limb is essentially realized by the section 7 in FIGS. 1 and 2, and that the other handle limb is essentially realized by the handle section 8, wherein the inner section 9 is in this case omitted. If viewed in the direction of the x-axis, the sections 7 and 8 are spaced apart from one another by a distance that in this situation depends on the type of tool. The height, the thickness and the length of such two-part handles in the x-, y- and z-direction are indicated, analogously to FIGS. 1 and 2, by the dimensions H, D and L, or are determined from distance vectors as described in detail below. In the ensuing figures, the boundary planes that divide the individual sections are at least partially indicated by broken lines, but are not mentioned further in other respects.
  • [0047]
    The parts of a right hand 19 that are important for explaining the invention are illustrated in FIG. 3. According to this figure, the hand 19 contains a thumb 20 with a proximal thumb member 21 near the hand 19 and a distal thumb member 22 that is situated distant from the hand 19, as well as the other four fingers that respectively comprise proximal, central and distal finger members 23, 24 and 25. The hand 19 also comprises a thumb saddle 26 between the thumb 20 and the index finger, an edge of the finger root 27, a ball of the thumb 28, a ball of the hand root 29 and a hand edge 30 with a ball of the hand edge 31. The part at which the fingers begin is referred to as the ball of the finger root 32, and the part circumscribed by the balls 28, 29, 31 and 32, as well as the thumb bridge 26, is referred to as the inner surface of the hand or simply the palm 33. In the preferred coupling position, this palm is deformed into a characteristic hand cavity about a center point 34.
  • [0048]
    According to FIG. 3, the hand width is measured between the hand edge 30 and the diametrically opposite edge of the finger root 27 in the vicinity of the thumb bridge 26, while the hand 19 is stretched out. This dimension is measured transverse to the longitudinal axis of the hand 19 as indicated by a line B in FIG. 3.
  • [0049]
    [0049]FIG. 4 shows a schematic section through the hand surface 33 along the line IV-IV in FIG. 3, with a schematically arranged handle 1 according to FIG. 1. This indicates that conventional oval handles 1 do not fulfill the ergonomic requirements because they only contact the hand in the region of the palm 33 at narrow areas of the thumb bridge 26 or the ball of the thumb 28, and at the ball of the hand edge 31, with the handle not contacting the palm 33 in the regions situated in between.
  • [0050]
    FIGS. 5-10 show a handle 38 according to the invention that is, for example, suitable for a hammer. This handle is largely adapted to the hand 19 according to FIGS. 3 and 4, and is preferably manufactured in one piece. The handle 38 has a longitudinal axis 39 that essentially corresponds to the central axis of the handle 38 in this case. In the that extends perpendicular to the longitudinal axis, the handle has cross-sectional surfaces that are essentially egg-shaped, elliptical or oval at all locations (FIGS. 7-10).
  • [0051]
    The longitudinal axis 39 may, for example, extend through the center points of circular end faces that are arranged on the ends of the handle 38, with the longitudinal axis being arranged coaxial with the central axis of a receptacle opening that is intended to accommodate a tool shaft, or it can be defined in some other way in the central handle region. According to the aforementioned definitions regarding FIGS. 1 and 2, the longitudinal axis forms the z-axis of an imaginary Cartesian coordinate system. In sectional planes that are arranged perpendicular to the longitudinal axis 39 (e.g., FIGS. 7-10), the axes extending through the largest diameter respectively lie parallel to the x-axis, and the axes extending through the smallest diameter lie parallel to the y-axis of the imaginary coordinate system. This also produces the dimensions H and D. The dimensions measured in the direction of the z-axis are referred to in this case as the distances between predetermined cross-sectional planes. The dimensions H and D of the handle 38 have different values along the longitudinal axis 39.
  • [0052]
    In FIGS. 5 and 8, it is assumed that the handle 38 is divided into three sections 42-44 by two planes 40 and 41 that are indicated with broken lines, and each lie on one side of the yz-plane and parallel thereto. The sections 42 and 43 correspond to the sections 7 and 8 in FIGS. 1 and 2 and are referred to as the upper section 42 and the lower section 43 in accordance with their position above and below the yz-plane. However, the section 44 that corresponds to the section 9 in FIGS. 1 and 2 is referred to as the inner section. The handle 38 is also limited on its distal end, is coupled to a functional part of the corresponding tool and lies on the left in FIGS. 5 and 6, as well as on its opposite proximal end, by respective planes 45 and 46 arranged perpendicular to longitudinal axis 39 (FIG. 5), such that the distance between the planes 45, 46 represents the total length of the handle. Between these planes 45, 46 respectively extend one distal end piece 48 that borders on the plane 45 and extends up to a cross-sectional plane 47, a distal part 50 that borders thereon and extends up to a cross-sectional plane 49, a center part 52 that borders thereon and extends up to a cross-sectional plane 51, a proximal part 54 that is situated adjacent thereto and extends up to a cross-sectional plane 53, and ultimately a proximal end piece 55 that borders on the plane 46. It should be clarified that all these parts are assumed to be divided into respective upper, lower and inner or central sections by the planes 40, 41 (FIG. 8), with the respective upper, lower and inner or central sections forming the sections 42-44. Although the handle 38 may also be realized as hollow in its interior, it is preferably solid.
  • [0053]
    The surfaces of the upper, lower and inner sections 42-44 have the contours shown in FIGS. 5 and 6 and the cross-sectional shapes shown in FIGS. 7-10, with the surfaces of the different parts or sections respectively transforming into one another in an essentially smooth fashion. The cross section of the handle 38 has the egg shape shown in FIGS. 7-10. The center part 52 respectively has-if viewed in the form of a longitudinal section-a surface contour that is designed in a more or less convex fashion over at least part of the circumference of the upper section 42. The distal part 50 and the proximal part 54 essentially have a concave surface contour that also extends over at least part of the circumference of the upper section 42. In this embodiment, all surface contours are designed to be convex or concave as can be ascertained, in particular, from a comparison between FIGS. 5 and 6 and FIGS. 7-10. The cross sections in FIGS. 7-10 also indicate that the height H and the thickness D of the handle 1 are greater in the center part 52 than in the distal part and the proximal part 50 and 54. This means that a surface contour that extends in a concave-convex-concave fashion, along the longitudinal direction in the top view according to FIG. 6, results. For example, in a body that is rotationally symmetrical about the longitudinal axis 39, a concave-convex-concave line 56 in FIG. 6 would represent a generatrix of the rotational surface of this body.
  • [0054]
    The distal end piece 48 is realized analogously to conventional collars that prevent the hand from sliding off the handle, and is less important for the purpose of the invention. The distal end piece may also be entirely omitted, with the proximal end piece 55 having the shape of a more or less defined hemispherical cap, and also being less important for the purpose of the invention.
  • [0055]
    In a handle for right-handed users, the center part 52 in the upper section 42 is, according to the invention, realized such that it fits closely against the inner surface 33 of the hand 19 (FIG. 3) of the user while the handle 38 is being used and is situated in the hand cavity. Consequently, the center part 52 in the upper section 42 is provided with a curvature 57 (FIG. 8) that is distinctly directed radially outward and is pronounced in at least two directions that extend perpendicular to one another. This curvature extends over at least part of the circumference of the upper part 42 and is produced due to the convex surface contour. When viewed from the distal end, the curvature of the handle 38 for right-handed users lies on the left side of the xz-plane.
  • [0056]
    The distal part 50 in the upper section 42 is designed to be encompassed by the saddle between the thumb 20 and the index finger (FIG. 3). This is why this region is, analogously to FIG. 5, provided with a concave surface structure that also extends over at least part of the circumference of the upper part 42. By contrast, the proximal part 54 in the upper section 42 is designed to contact the ball of the hand root 29 (FIG. 3). In accordance with FIGS. 5 and 6, this region also is designed in a concave fashion over at least part of the circumference of the upper part 42.
  • [0057]
    The surface contour of the lower section is preferably shaped as required for the encircling by the finger joints which occurs at this location, and for the trapezoidal inner contour of the encircling fingers in a preferred coupling position of the hand.
  • [0058]
    The surfaces of the inner section 44 that correspond to the surfaces 12 and 13 in FIG. 2 serve to connect the sections 42 and 43 as shown in FIGS. 7-10. They may contain corresponding concave and convex surface contours in the longitudinal direction (z-axis) which transform into the contours of the surfaces of the sections 42 and 43 in a smooth fashion.
  • [0059]
    The concave and convex surface contours can be defined by curvature radii R1.1-R3.4 (FIGS. 5 and 6). For the purposes of the present invention, those curvature radii are of particular importance that occur in the upper section of the center part 52 at the maximum or summit 59 of the convex surface contour (sectional plane B-B in FIG. 5), and in the upper sections of the distal and the proximal parts 50, 54 at the respective minimums 60 and 61 of the concave surface contour (sectional planes A-A and C-C in FIG. 5). A comparison between FIGS. 5 and 6 shows that the cross-sectional planes that extend through these maximum 59 and minimums 60, 61 respectively have a different axial position in the upper section 42 than in the lower section 43 (for example, the maximum 62 in FIG. 5).
  • [0060]
    The curvature radii R2.1-R2.4 that are particularly important for the purpose of the invention and would, in FIG. 8 in which they are not shown, lie on the top, the left, the bottom and the right in the coordinate system shown if it were turned to the left by 90, approximately define respective sections of a circular arc that lie in the xz-plane (FIG. 6) in FIGS. 5 and 6. These sections of the circular arc may, viewed in the direction of the z-axis, extend over a longer distance with an essentially constant curvature radius (e.g., R2.1) to both sides of the maximums (e.g., 59) before this curvature radius gradually decreases and the surface contours of the center part 52 ultimately transform into the concave surface contours of the parts 50, 54 at turning points. This not only applies to the four contour lines with the radii R2.1-R2.4 which are shown in FIGS. 5 and 6 and respectively lie in the xz-plane and the yz-plane, but also to the other planes that include the z-axis. For example, the turning points of the contour line extending through the maximum 59 are defined in FIG. 5 by the position of the cross-sectional planes 49 and 51. The transition between the regions identified by the curvature radii R2.1-R2.4 are respectively defined by analogous radii or curves that, depending on practicality, may deviate from the radii R2.1-R2.4. The concave regions with the curvature radii R1.1-R1.4 and R3.1-R3.4 preferably progress accordingly.
  • [0061]
    The egg-shaped cross-sectional surfaces in FIGS. 7-10 can be defined by radii RA.10-RC.13. The curvature radii RA.10, RB.10 and RC.10 which respectively occur in the region of the sectional planes A-A through C-C, as well as in the maximum 59 and in the minimums 60, 61 in the upper sections, are of particular importance for the purpose of the present invention. In addition, the radii RA.10-RA.13, RB.10-RB.13, etc, according to FIGS. 7-10 respectively lie in planes that extend parallel to the xy-plane, if turned to the left by respective angles of 90 in the imaginary coordinate system. In this case, the letters A, B, and C etc., indicate the sectional planes A-A, B-B, C,-C etc., in FIG. 5. Consequently, the aforementioned radii define sections of the circular arc which lie in these planes. Analogously to the radii R1.1-R3.4, the sections of a circular arc which belong to the radii RA.10-RC.13 may, when viewed in the planes that lie parallel to the xy-plane, extend over longer arc sections with essentially constant curvature radii on both sides of the maximums and minimums (e.g., 59 in FIG. 8). The transitions between the regions identified by these radii are respectively defined by analogous radii or curves that, depending on practicality, may also deviate from the radii RA.10-RC.13. Similar observations can be made in an arbitrary number of additional cross-sectional planes along the longitudinal axis 39.
  • [0062]
    In the longitudinal direction, the distances L0.1, LI.1, LII.1 and LIII.1, which are shown in FIG. 5 and are described in greater detail below, are of particular importance for the handle 38. The reference plane for these dimensions is the sectional plane B-B that extends through the upper maximum 59 that lies in the xz-plane and otherwise lies parallel to the xy-plane, i.e., the maximum 59 on the upper side of the upper section 42 unequivocally defines the position of the reference plane 63. Its distance from the planes that extend through the minimums 60, 61 is defined, respectively, by the dimensions LI.1 and LII.1, wherein LIII.1 represents the distance of the reference plane 63 from the proximal end of the proximal part 54 (plane 53) of the handle 38. Corresponding dimensions LI.2-LI.4, LII.2-LII.4 and LIII.2-LIII.4 can be used to indicate the distances of the reference plane 63 from other minimums that, for example, are associated with the radii R1.2-R1.4 and R3.1-R3.4 in FIGS. 5 and 6 (for example, see LI.4 and LII.4 in FIG. 6). A dimension LIV.2 indicates, for example, the distance of the maximum 62 from the reference plane, wherein this distance may also be equal to zero, namely if the maximum 62 also lies in the reference plane 63.
  • [0063]
    The lengths of the distal and proximal parts 50, 54, as well as of the center part 52, cannot be precisely defined because this definition is arbitrary. For the purpose of the invention, a length L0.1 of the center part 52 in the upper section 42 is defined by the turning points in which the convex curve section that lies in the xz-plane and contains the maximum 59 transforms into the adjacent concavely curved section that also lies in the xz-plane and contains the minimums 60, 61. In this case, the distal and proximal parts 50, 54 extend from this point to the respective end pieces 48, 55. The position of the turning points is defined in FIG. 1 by the position of the cross-sectional planes 49 and 51 such that the length L0.1 of the center part 52 of the first section 42 is equal to the distance between the planes 49, 51. The same distance or a different distance can be used for the longitudinal dimension of the center part of the lower section 43.
  • [0064]
    In addition, variables A1A-A4A are obtained from FIG. 7 (if turned to the left in the xy-coordinate system). These variables are referred to as distance vectors below because they indicate the distances of the minimums (in this case, for example, 60) from the longitudinal axis 39. In this case, these distances may be identical to one another or differ from one another. The sum of the dimensions A1A and A3A results in the height H, and the sum of the dimensions A2A and A4A results in the thickness D of the handle 38, in the sense of the definition according to FIG. 2, in the respective cross section A-A. Corresponding distance vectors A1B-A4B and A1C-A4C are obtained for the sectional planes B-B and C-C, wherein the distance vectors A1B and A2B represent the most important distance vectors because they define the shape of the handle 38 in the region that contains the curvature 57 and is encompassed by the palm 33 and the fingers that originate at the palm. The letters A-C, etc., also identify the respective sectional planes according to FIGS. 7-9 in this case.
  • [0065]
    The previous description indicates that the aforementioned values (for example, R2.1, L0.1, RB.10, A1B, etc.) are all referred to points in two selected planes that correspond to longitudinal sections through the handle 38 in the xz-plane and the yz-plane The main reason for this can be seen in the fact that the point 59, which is of particular importance for achieving a preferred coupling position and has the greatest absolute distance from the z-axis, lies, in accordance with this definition, in the xz-plane. It should be clarified that, in addition to the longitudinal sections shown in FIG. 5, other longitudinal sections or additional longitudinal sections that lie between the xz-plane and the yz-plane and also contain the z axis can be used for describing the outer surface area of the handle 38. This primarily pertains to the longitudinal sections in the three-dimensional sector of the upper section 42 that contains the surface area section with the curvature 57 (FIG. 8), and extends over an angular range between approximately 90 and 135 beginning at the yz-plane.
  • [0066]
    The arrangement shown represents an optimally designed handle for a right-handed user. An optimally designed handle for a left-handed user would have a shape that, by comparison to the described handle 38, extends in a laterally reversed fashion referred to the xz-plane. For right-handed users and left-handed users, the handle would be designed symmetrically, referred to the xz-plane. This arrangement does not provide an equally superior contact area for the fingers, as does the asymmetrically designed handle 38. However, the design for right-handed users already provides left-handed users with a superior contact area for the hand, by comparison to handles currently available on the market. If a handle for right-handed users and left-handed users, respectively, should be provided, it may also be practical to arrange asymmetric sections, in particular, in the region of the distance vectors A2A, A4A, A2B, A4B, etc.
  • [0067]
    The handle 38 described above with reference to FIGS. 5-10 is centered in the hand cavity approximately in the center of its longitudinal extent. The ball of the hand root and the ball of the hand edge respectively contact the upper sections of the distal and the proximal parts. Handles of this type are primarily suitable for light hammers, small mason's trowels and similar hand and garden tools. An imaginary longitudinal axis of the hand assumes a very steep or nearly a right angle, referred to the longitudinal axis 39 of the respective handle 38, in the preferred coupling position. All these handles are realized in the form of one-piece handles.
  • [0068]
    FIGS. 11-13 indicate how the handle 38 is, when using, for example, a hammer 64, initially taken hold of by the human hand 19, from the side of the upper section 42, and subsequently encompassed. FIGS. 11-13 show the position for a right-handed user, with FIG. 11 showing the preferred coupling position of the hand while using the hammer 42. A broken line 65 indicates the approximate position that the convex curvature 57 shown in FIG. 8 assumes in the hand 19. FIGS. 12 and 13 schematically show two hand positions in the form of sections viewed from the distal end, in a position that is, referred to FIG. 8, turned by approximately 180 about the z-axis, and show the trapezoidal shape of the index finger joints 23, 24 and 25, shown in FIG. 3, in connection with the position of the thumb 20.
  • [0069]
    Conventional handles according to the prior art do not fill the cavity of the hand encompassing the handle, and do not sufficiently support the hand, such that the muscles of the fingers and the hand are highly strained. The handle according to the invention is, by contrast, shaped such that a nearly complete support and a very uniform pressure distribution are achieved, and that the handle “snugly” fits against the respective hand regions at all locations. Practically, the hand encompassing the handle should automatically assume a predetermined coupling position that is perceived as comfortable and favorable by the user, and is referred to as the “preferred coupling position” in this context. However, the handles are neither individually adapted to a particular hand nor designed for an “average hand,” but rather are dimensioned in accordance with “groups of hand sizes” that are obtained from hand measurement data, as well as by sensible sorting and classification thereof.
  • [0070]
    According to the invention, these dimensions and shapes of the handles are adapted to one another in such a way that the resulting handle shape and handle size automatically predetermine a preferred coupling position of the hand for the entire associated group of hands, and that the handle is perceived as lying comfortably in the hand by users of this group when the respective tool is used, and also when higher forces are introduced or when the tool is subjected to use for a long duration, due to the uniform pressure distribution. This invention is, in particular, intended for professional use of the respective tool by craftsmen and causes, if at all, the least possible fatigue and pain in the hand or the arm. Among other things, this is achieved due to the fact that, according to FIG. 4, the dimensions L0.1, LI.1, LII.1 and LIII.1 that are shown in this figure and are described above with reference to FIGS. 5 and 6, as well as the corresponding dimensions that lie in other sectional planes, are essentially realized in accordance with the shape of the hand. In this case, the dimension L0.1 is essentially defined by turning points in which the concave hand cavity transforms into the convex curvatures of the thumb bridge 26 on one side and the ball of the hand edge 31 on the other side. The dimension LI.1 is defined by the distance between the center of the hand cavity and the highest region of the thumb bridge 26, and the dimension LII.1 is defined by the distance between the center of the hand cavity and the highest region of the ball of the hand edge 31. The dimension LIII.1 of the handle is defined by the distance between the center of the hand cavity and the hand edge 30 that needs to be supported on the proximal part in FIGS. 5-10.
  • [0071]
    [0071]FIG. 12 shows a highly abstract section through the handle 38 and the hand 19, of a right-handed user, which encompasses said handle. The contact region between the palm 33 and the fingers and the circumference of the handle 38 is illustrated in the form of sectors in a left-rotating angular coordinate system. The angular coordinate plane of 0-180 corresponds to the xz-plane and the angular plane of 90-270 corresponds to the yz-plane of the Cartesian coordinate system in FIGS. 5 and 6. In this case, the longitudinal axis 39, or the z-axis of the handle 38 according to FIGS. 5 and 6, extends through the point Z.
  • [0072]
    [0072]FIGS. 12 and 13 also show that the fingers that encompass the handle 38 laterally and on the underside press in the direction of the palm 33, as well as in the direction of the inner side of the ball of the thumb 28. The balls of the hand edge 31 laterally adjoin the proximal part 54 of the handle 38. The inner side of the ball of the thumb 28 lies approximately along an angular range of 315-0, as is schematically illustrated in FIG. 12 by a segment 67 that represents the contact surface and is illustrated on an excessively large scale. The palm 33 adjoins the handle along an angular range of approximately 0-135, which is indicated in the form of a segment 68, with the middle finger shown in FIG. 12 adjoining the handle 38 along an angular range of 135 up to slightly more than 270 (segment 69) analogously to the ring finger and the little finger. For a left-handed user, the angular ranges would extend in the opposite direction of rotation.
  • [0073]
    [0073]FIG. 13 shows that the handle 38 adjoins the inner side of the fingers with its lower section 43 that has a comparatively small curvature radius (e.g., RB.12 in FIG. 8), wherein said fingers form an approximately trapezoidal inner line with their members in the encompassing position. This figure also shows that the thumb 20 adjoins, below its middle joint, one side of the handle 38, and that the index finger adjoins the handle 38, on the other side, with its inner side below the first joint. Both fingers laterally exert pressure upon the handle in the contact regions such that the handle is guided by the fingers. The contact regions subjected to pressure are illustrated in FIG. 13 in the form of hatched segments 70, 71. The thumb bridge 26 exerts only a little pressure upon the handle 38, and merely adjoins the handle with its thin tissue 72 such that no tension in the bridge tissue occurs. However, this region of the hand is still in adequate contact with the handle 38. A broken line 73 in FIG. 13 indicates an invisible part of the handle 38 within the region of the greatest height and thickness (curvature 57 in FIG. 8).
  • [0074]
    Tests on the pressure resistance of the hand surface demonstrated that a “soft” spot lies in the boundary region between the ball of the thumb 28 and the palm 33. At a uniform specific pressure, this region will yield more than the palm 33. Consequently, the curvature 57 (FIG. 8) is at its greatest at this point in an ergonomically correct handle, in order to achieve a uniform load distribution over the entire surface of the hand curvature.
  • [0075]
    According to the invention, the handle shapes and handle sizes are based on the notion that, in particular, the dimensions L0.1, LI.1, LII.1 and LIII.1 according to FIG. 5, and the analogous dimensions in the other longitudinal sectional planes, are important for achieving an appropriate “fit” and the preferred coupling position. This applies, in particular, to the contact region of the ball of the thumb 28 and the hand cavity that lies between approximately 315-135 in the angular coordinate system according to FIG. 12. This concept is taken into account in the form of the distinct curvature 57 in the center part 52 of the upper section 42 of the handle 38 in at least two planes that extend perpendicular to one another, i.e., in the angular range between 0 and 90 referred to FIG. 12. The progression of the curved surfaces of this curvature 57 in the longitudinal direction and the circumferential direction as they are approximately defined by the radii RB.10 and RB.11 (FIG. 8) is also important. In addition, the lengths of the respective distance vectors beginning at the point Z of the respective cross sections are also important, with the lengths of said distance vectors being defined, for example, by the values A1B and A2B in FIG. 8.
  • [0076]
    The radius in the lower section 43 of the handle 38 that is adjoined by the fingers is also important for achieving a comfortable feel of the handle. The fingers that adjoin the handle and are bent at the joints form a trapezoidal contour on their inner surface. The radius or the arc of the handle cross section in this region needs to be dimensioned such that it is tangent to the trapezoidal contour over the longest distance possible, and the contact pressure is distributed over the largest possible surface of the fingers. This requirement should also apply if the position of the finger joints changes slightly, for example, due to changes in the hand position, or with hands that have fingers of different length. The proximal finger joints that adjoin the lower side of the handle form a slightly curved contour that extends in the transverse direction of the hand when it encompasses the handle. Accordingly, the curvature on the lower side of the handle that is identified by the radius R2.3 is only slightly curved, i.e., it has a large radius. The central and distal finger joints adjoin the outer side of the handle in the region of the lower handle part 43 and part of the central handle part 44. The inner contour of these finger joints is also slightly curved in the transverse direction of the hand on this side, as indicated by the radius R2.4 in FIG. 6, if the handle has an optimal ergonomic design. However, the handles could also be shaped such that a compromise between the optimal design for right-handed users and a relatively adequate shape for left-handed users is achieved. In this case, the radius R2.4 is smaller, i.e., the side is curved more strongly. In any case, the curvature is smaller than the curvature on the opposite side that is defined by the radius R2.2, and is smaller than the curvature on the upper side that is defined by the radius R2.1.
  • [0077]
    For the purpose of the invention, existing anthropometric investigations, as they are published on page 231 of Research Report 156 by the German Federal Institute for Occupational Safety and Accident Research of 1979, were used as the basis for deriving the dimensions L0, LI, LII and LIII. Initially, three groups of hand sizes were specified: “S”=“small,”“M”=“medium” and “L”=“large.” Hand sizes up to the 20th percentile were categorized as “small,” hand sizes between the 20th and the 75th percentile were categorized as “medium,” and hand sizes up to the 100th percentile were categorized as “large.” According to the invention, it was determined that the dimension L0.1 according to FIG. 5 should approximately amount to 50%, preferably 45%-55%, of the average hand width according to dimension B in FIG. 3. In addition, the dimension LII.1 according to FIG. 5 should approximately amount to 33%-37% of the average hand width B and the dimension LIII.1 should approximately amount to 50%-55% of the average hand width B. This results in a LIII.1 value of approximately 47 mm-60 mm for the hand sizes “S” through “L.” If this is weighted with the hand widths found in the cited investigation, the length L0.1 amounts to approximately 43 mm for small hands (S), approximately 46 mm for average hands (M), and approximately 48 mm for large hands (L). Based on these core measurements, the remaining measurements of the handles were determined empirically based on models and group tests, wherein the desire for standardization was also taken into account. Different finger lengths as they were found on hands of identical width were consequently not taken into consideration in the design and the dimensions of the handles.
  • [0078]
    The handle size essentially is adapted to the various hand sizes within the dimensional ranges LI and LII, wherein the total length of the handles preferably remains the same. The distal and the proximal end pieces 48, 55 are adapted in the form of continuous progressions that extend up to the handle ends in the cross sections occurring in the end points of the handle 38. In handles that contain a thumb support in the distal region, the total length of the handle is preferably also changed in order to adapt the handle to the hand size.
  • [0079]
    Surprisingly, it was determined that handles with the above-described characteristics and dimensions are suitable for various tools. Depending on the respective function, only comparatively slight changes in the basic shapes are required. This means that at least the center parts 52 of the upper sections 42 are realized very similarly with respect to their size and shape. Depending on the intended use of the respective tool, different shapes are, in particular, practical in the region of the distal end pieces 48 of the handles 38. In certain respects, this also applies to the proximal end pieces 55. Depending on the type and size of the tool on which the handles 38 are used, it is practical to vary the height H and the thickness D or the length of the distance vectors. However, the contour that adjoins the hand is very similar in handles 38 that are used for various tools.
  • [0080]
    In order to achieve a superior fit of the handle 38 in the hand cavity or a shape that is largely adapted to the hand cavity, the parts 50, 52 and 54 in the upper section 42 are, according to the invention, considered to be particularly important as described explicitly with reference to FIGS. 11-13 (the adjacent sides of the section 44 are also considered to be important, but this section is omitted in this case because the entire upper part of the handle is assigned to the section 42 and the entire lower part of the handle is assigned to the section 43). Consequently, the shapes and dimensions are adapted at these locations in such a way that the preferred coupling position is assumed almost automatically by all hands of the respective group of hands, due practically only to the upper section 42.
  • [0081]
    The surfaces of the inner section 44 (FIG. 8) of the handle 38 are also curved convexly outward in this embodiment (FIGS. 7-10) in order also to provide a superior support surface for the hand in this region. In addition, the surfaces of the sections 42 and 43 are realized continuously, i.e., the transitions between the various surfaces of the sections 42, 43 and 44 are preferably continuous and smooth, such that the convexly curved center part 52 gradually transforms into the parts 50 and 54 that are curved concavely inward.
  • [0082]
    In this embodiment, the lower section 43, which is situated diametrically opposite to the upper section 42 and lies below an imaginary central plane (=yz-plane) of the handle 38 in FIG. 5, is shaped and dimensioned similarly to the upper section 42. This lower section is rounded, in particular, in the shape of an egg, and contains no corners or edges that press against the fingers (FIGS. 7-10).
  • [0083]
    In order that the preferred coupling position of the hands of an associated group of hands is not only automatically assumed, but practically becomes mandatory due to the design of the handle, selected dimensions of the handle 38 can be further defined based on experience and investigations as deemed practical for a coupling position, in particular when handling a hammer. For example, the parts 50 and 54 may ascend less concavely than in FIG. 5 from the minimums 60, 61 (FIG. 5) in the proximal and in the distal direction, or even be flat or plane. In this case, the minimums 60, 61 are those points that have the greatest distance from a chord drawn through the end points of the parts 50 and 54. However, a continuously concave progression of the parts 50 and 54 and the corresponding parts in the remaining handle sections provides the significant advantage that the handle 38 fits the hand in an almost positive fashion, such that its tendency to slide in the direction of the longitudinal axis 39 is reduced when using the tool.
  • [0084]
    Other important dimensions for the purpose of the invention are the curvature radii, in particular, the radius R2.1 and R2.2 (FIG. 5) which, depending on the hand size, lies between 50 mm and 120 mm. These dimensions essentially define the convex curvature in the longitudinal direction. Another important dimension is the radius R22 in the yz-plane. This radius defines part of the longitudinally extending curvature in the second direction. This applies analogously to the longitudinally extending radii in the transitions between the xz-plane and the yz-plane, for example, the radius R2.5.
  • [0085]
    Other important dimensions are the radii RA.10-RA.13, RB.10-RB.13 etc. and, in particular, the radius RB.10 and RB.11. This radius defines the progression of the curvature 57 (FIG. 8) in a second direction (y-axis and yz-plane, respectively) such that the curvature 57 is pronounced in two directions that extend perpendicular to one another. In a handle 38 for left-handed users, the radius RB.13 would have to be dimensioned accordingly in order to make the curvature more distinctly pronounced toward the right side in FIG. 8.
  • [0086]
    In addition, the total thickness D and the total height H of the handle 38 are naturally important in this context. FIGS. 7-9 indicate that the distance vectors A1A-A4A, A1B-A4B etc. may respectively be identical or different in the x-direction and the y-direction.
  • [0087]
    In handles 38 that are realized symmetrically referred to the xz-plane and/or the xy-plane, the corresponding values A1A-A4C may be identical (e.g., A1B=A3B and/or A2B=A4B), and can consequently be replaced with the dimensions H and D. It is also preferred to predetermine identical values at least for the dimensions L0.1 of the handles for a preselected group of hands, with the dimensions R2.1 lying close to one another. It is preferred to carry out a weighting in such a way that, for example, the different dimensions of the distal part 50 are defined in order to realize the preferred coupling position in accordance with the above-described dimensions, with the dimensions of the proximal part 54 and, if applicable, the proximal end piece 55 being of lesser importance in this case.
  • [0088]
    With respect to the dimensions LI.1 and LII.1, it may be advantageous to choose approximately identical values for these dimensions for most handles, i.e., the maximums 59 are arranged in the xz-plane in the center between the corresponding minimums 60 and 61. However, there may also be instances in which the maximums 59 are not arranged exactly in the center, but rather are offset toward the distal end or the proximal end. In addition, the distal and proximal parts 50, 54 of the handles 38 usually have approximately the same length so that the center parts 52 lie essentially in the center between the two adjacent distal and proximal parts 50, 54.
  • [0089]
    It is also important for the invention to standardize a series of the above-described dimensions R, L, A, H and D, and to predetermine essentially identical values for a series of hand and garden tools. This is based on the idea that handles of the described type are realized very similarly with respect to size and shape, not only in the central part 52, but also the distal part 50. In such instances, it is merely required to adapt a few of the indicated dimensions, e.g., the distance vectors, as well as the proximal parts 54 and/or the proximal end pieces 55, to the given application (tool type) with respect to their size and shape. This provides the user, particularly the professional user, with the advantage that various types of tools will have handles of the same basic size and shape, so that the user will easily be able to select suitably fitting handles.
  • [0090]
    On the distal and/or proximal end of the handle 38, the end pieces 48 and/or 55 are preferably designed in the form of a bulge. This is realized by dimensioning their cross sections to be greater than in the region of the sections A-A and C-C in FIGS. 7 and 9. In the preferred coupling position of the hand, the outer sides of the finger joints of the index finger and the little finger and, if applicable, the hand edge 30 and the ball of the hand edge 31 are supported on these end pieces 48, 55.
  • [0091]
    According to FIGS. 6 and 10, the handle 38 may also be provided with a support surface 74 for the thumb 20. This support surface 74 preferably lies on the upper side of the distal end piece 48 and a region of the distal part 50 situated adjacent thereto. FIG. 10, in particular, shows that this support surface may consist of a trough or flattening that extends parallel or slightly oblique relative to the yz-axis.
  • [0092]
    Another preferred embodiment of a handle 78 is shown in FIGS. 14-18. This handle 78 essentially differs from the handle 38 only in that a support surface 80 is arranged on the surface of the center part 79. Specifically, the cross section in FIG. 17 indicates that this support surface is arranged on the side of the xz-plane which faces away from a curvature 81, wherein the curvature 81 corresponds to the curvature 57 in FIG. 8. According to FIGS. 14 and 15, the support surface 80 may also extend over a larger region or even the entire region of the center part 79 in the direction of the longitudinal axis 82 of the handle 78. In other respects, the support surface 80, like the support surface 83 for the thumb, is essentially realized to be flat or slightly concave, i.e., in the form of a groove or trough that extends in the direction of the longitudinal axis 82. This support surface is provided in addition to or instead of the support surface 83. The support surface 80 advantageously serves for supporting the ball of the thumb 28 in order to achieve an even better adaptation to the hand and an even more comfortable coupling position.
  • [0093]
    The most important dimensions for a preferred embodiment of the handle 78 according to the invention are indicated in the tables shown in FIGS. 93a and 93 b. The dimensions listed in these tables indicate in two columns [sic] the dimensions specified for a given group of small, medium and large hands. The dimensions for a medium hand “M” fall between the values for “S” and “L,” wherein intermediate sizes may also be provided if so required. According to the invention, a total of three groups, namely, “small,” “medium” and “large,” is considered sufficient. A more detailed explanation of FIGS. 93a and 93 b is provided below.
  • [0094]
    In the embodiment according to FIGS. 19-24, the handle 86 is intended for a tool in the form of a mason's trowel, which is not illustrated in these figures. The handle 86 essentially corresponds to the handle 38 according to FIGS. 5-10, where said handle a support surface 87 for the thumb, as in FIGS. 6 and 10. A distal handle end lies in a plane 89 that extends perpendicular to a longitudinal axis 88 of the handle 86, with the distal end piece 90 ending in the aforementioned plane. As in the previous description, one respective distal part 91, one center part 92, one proximal part 93 and one proximal end piece 94 are situated adjacent to this end piece 90.
  • [0095]
    The values for the various dimensions are chosen so that the handle 86 is also suitable for other tools besides mason's trowels, e.g., heavy hammers, roofing hammers, sledge hammers, axes and, in an analogous two-part design, for garden and pruning shears. The important dimensions for a preferred embodiment of the handle 86 are indicated in the tables according to FIGS. 94a and 94 b. This applies, in particular, to the length L0.1 of the center part 92 arranged between the two cross-sectional planes 95, 96 which is measured in an upper section and approximately corresponds to 50% of the hand width of the assigned group of hands, as well as to the dimensions LI.1 and LII.1 that define the position of the minimums 97, 98 of the upper surface contour in the distal and the proximal part 91 and 93. The position of a reference plane 95 is defined by the maximum 100 of the center part 92 in FIG. 5. In other respects, the handle is designed essentially identically to the handle according to FIGS. 5-10.
  • [0096]
    FIGS. 25-30 show a second embodiment of the handle 86 according to FIGS. 19-24, wherein the same reference symbols were used for designating identical components. In addition to the support surface 87 provided on the upper side of the upper section, a second lateral support surface 101 for the thumb 20 is provided in this case. This second support surface lies in the distal part 91 of the handle 86 analogous to the support surface 87 and preferably extends into the distal end piece 90. The cross sections in FIGS. 27 and 30, in particular, indicate that the support surface 101 is arranged on the side of the xz-plane which faces away from the curvature 102, where said curvature 102 corresponds to the curvature 57 in FIG. 8. The support surfaces 87 and 101 may essentially be realized flat or slightly concave so that they are adapted to the shape of the thumb. FIGS. 27 and 29 show that the support surface 101 may extend from an upper section 103 of the handle 86 into an adjacent inner or central section 104 that can also be assumed to be omitted in its entirety. The lateral support surface serves for achieving an additional lateral guidance of the handle. A similar lateral support surface may also be provided on the handles for hammers which are shown in FIGS. 5-6 and FIGS. 10-18. In other respects, the handle is designed essentially identically to the handle according to FIGS. 19-24.
  • [0097]
    [0097]FIG. 31 shows the handle 86 in connection with a mason's trowel 105, namely in the position in which it is grasped by the hand 19 of a right-handed user in a first preferred coupling position. In this case, the thumb 20 rests on the upper support surface 87. FIG. 32, in contrast, shows the handle 86 of the mason's trowel 105 in the position in which it is held by a right-handed user in a second preferred coupling position. In this case, the thumb 20 adjoins the lateral support surface 101, which is not visible in FIG. 32.
  • [0098]
    The handles 38, 78 and 86 according to FIGS. 5-32 are particularly suitable for tools 64, 103 in which the hand encloses the handle from the top in the preferred coupling position. FIGS. 33-37 show a handle 106 for a tool that is pushed and pulled, i.e., a saw 107 or, for example, a hand plane, a firmer chisel (wood chisel) or the like. According to FIGS. 33-37, the handle 106 of the saw 107 is mounted on a functional part 108 by means of screws or the like. The handle 106 is provided with a central opening 109 as is customary, for example, with straight-back handsaws with open handles. This handle is provided with an upper section 110 (on the right in FIG. 36) that contains support surfaces for the inner side of the hand on the side of the handle 106 which faces away from the functional part 108 or the opening 109, namely analogous to FIGS. 1, 2 and 5-32. A lower section 111 of the handle 106 (on the left in FIG. 36) which faces the opening 109 is provided with support surfaces for the fingers. The sections 110, 111 and a section 112 (FIG. 17) situated between the two aforementioned sections correspond to the sections 7, 8 and 9 in FIGS. 1 and 2. A handle for a bow saw or the like may be realized accordingly.
  • [0099]
    A comparison between FIGS. 5-9 and FIGS. 33-37 shows that the surface contours of the sections 110, 111, as well as of the inner section 112 (FIG. 36) that connects the two aforementioned sections, are realized largely identically to the sections 42-44. In addition, the handles 38, 78, and 86 each comprise a distal end piece 114, a distal part 115, a center part 116, a proximal part 117, and the proximal end piece 118, which are arranged one behind the other in the direction of the longitudinal axis 119 (FIG. 34), analogously to the handle 106. The cross-sectional plane B-B which extends through a summit or maximum 120 of the surface contour of the center part 116 in the upper section 110 again serves as the reference plane. The length of the convex center part 116 is defined by the position of the turning points to the adjacent concave parts 115, 117 and by cross-sectional planes 121, 122 that extend through these turning points, with the length of the convex center part being dimensioned at approximately 50% of the hand width B (FIG. 3) of the average user of the assigned group. The position of concave minimums 123, 124 of the distal and the proximal part 115, 117 is respectively defined by the dimensions LI.1 and LII. 1, with the values of these dimensions being identical to those in FIGS. 5-10.
  • [0100]
    In other respects, the previous explanations regarding the handles 38, 78, and 86 also apply in this case, with the various dimensions being indicated in the tables according to FIGS. 95a and 95 b. In addition, FIGS. 38 and 39 indicate how the handle 106 is initially taken hold of from the rear and then enclosed with the human hand 19 while the saw 107 is used. The position for a right-handed user is illustrated in FIGS. 38, 39, with this position simultaneously representing the preferred coupling position of the hand while using the saw 107.
  • [0101]
    The handles 38, 78, 86 and 106 described thus far are explained in greater detail by means of side views and top views, as well as a few cross sections that extend perpendicular to their longitudinal axes (e.g., FIGS. 27-30). In this case, the side views and top views respectively show an outer contour in the upper end of the lower region which has the shape of a concave-convex-concave curve 127, 128 (FIG. 25) and 129, 130 (FIGS. 26). This outer contour would also result if a longitudinal section that contains the z-axis and lies in the xz-plane would be illustrated in FIG. 25 instead of the side view shown, and if a corresponding longitudinal section that lies in the yz-plane would be illustrated in FIG. 26. Consequently, each of these curves 127-130 represents a (usually different) generatrix of the surface area of the handle body, wherein the handle body would represent a body of revolution with the z-axis as the axis of rotation if all curves 127-130 were identical. For example, FIGS. 25 and 26 show that one particularity of the invention can be seen in the fact that the curves 127-130 may have entirely different progressions because the handles designed in accordance with ergonomic requirements largely have an asymmetric shape.
  • [0102]
    In the previous description, it was assumed that the cross sections, e.g., according to FIGS. 27-30, are essentially egg-shaped or oval or elliptical, except for possibly provided support surfaces 87, 99 in order to simplify the illustrations. In this case, the respectively largest diameter lies, according to FIGS. 1 and 2, on a line that extends parallel to the x-axis, with the respectively smallest diameter lying on a line that extends parallel to the y-axis. Consequently, the described maximums and minimums (e.g., 97, 98, 100 and FIG. 25) lie in the xz-plane. This means that the curve 127 extends in one plane. This applies accordingly to the curves 128-130, wherein the curves 129, 130 lie, however, in the yz-plane. In addition, it was assumed in the previous description that the maximums (e.g., 100 in FIG. 25, but also 59 and 120 in FIGS. 5 and 33) define the point on the surface area of the handle body which has the greatest absolute distance from the respective z-axis (e.g., the dimension A1B in FIG. 22). This is the reason the curve 127 represents the geometric locus of all points on the surface area of the handle body which respectively are the greatest distance from the z-axis along the latter, and thus forms a generatrix of the surface area which always has a convex progression in the region of the curvature 102 and, according to the invention, respectively lies in the upper section 42 or 102.
  • [0103]
    Except for the position of the curvature 102 in the upper section 42 or 102, these prerequisites are neither absolutely imperative nor always advantageous with respect to ergonomic aspects. It may, in particular, be practical to shift the point that has the greatest distance from the z-axis into a plane which is arranged parallel to the xz-plane that always represents the central plane in this case. This, among other things, makes it possible to achieve an improved adaptation of the handle 86 to the cavity of the hand 19, in particular, due to a more pronounced lateral excursion of the curve 102 (FIG. 28). For reasons of simplicity, it may also be specified in this case that the curve containing the absolute maximum represents a curve that lies in a plane that extends parallel to the xz-plane. It would, in contrast, also be possible for the curve containing the absolute maximum to represent the geometric locus of all points that are the greatest distance from the z-axis along the latter. This means that this curve may also represent a three-dimensional curve that only lies on one side of the xz-plane or contains points that lie on both sides of this plane. This is described in greater detail below with reference to FIGS. 40-45.
  • [0104]
    FIGS. 40-43 show longitudinal sections through a handle 131, the outer contour of which essentially corresponds to the previous description. FIG. 40 shows a longitudinal section in the xz-plane which contains the z-axis such that the contours essentially correspond, for example, to those in FIG. 19 and/or 25. FIG. 41 also shows a longitudinal section that contains the z-axis, but this longitudinal section corresponds to a sectional plane that extends from 45 to 225 in the angular coordinate system shown in FIG. 12. FIG. 42 shows a longitudinal section in the 90-270 position according to FIG. 12, and FIG. 43 shows a longitudinal section that contains the z-axis, analogously to the remaining longitudinal sections and extends from 135 to 315 in FIG. 12. The three longitudinal sections shown in FIGS. 41-43 can also be assumed to be generated by incrementally turning the handle 131 by 45, starting from the position shown in FIG. 40 and then sectioning the handle parallel to the plane of projection.
  • [0105]
    [0105]FIG. 44, based on FIG. 40, shows a total of 20 cross sections that extend perpendicular to the z-axis. This means that the x-axis of the imaginary coordinate system points vertically upward in all sections. If all sections shown in FIG. 44 are arranged one behind the other on the z-axis at the distances indicated in FIG. 40, their circumferential lines 132 (see cross section A in FIG. 44a) very closely represent the surface contour of the complete surface area of the handle 131 when connecting all circumferential lines 132 to one another over the shortest possible distance by means of conical surfaces. The accuracy of the thereby obtained surface area is improved as the number of cross sections used increases.
  • [0106]
    According to the present invention, it is important that the upper section that contains the curvature and that is identified by reference symbol 103, analogously to FIG. 28 (see cross section A in FIG. 44a), contain not only points that lie in the xz-plane but also points 133-143 that are the greatest distance from the z-axis in the respective cross section and at least partially do not lie in the xz-plane. The distance vectors 144-154 which lead to these points 133-143 are respectively indicated in FIGS. 44a and 44 b in the form of arrows. This indicates that the radius vectors 144-154 partially extend on the right side of the xz-plane and partially on the left side of this plane similar to spatial vectors. In this case, the angles a (see cross section H) formed in connection with the xz-plane precisely indicate in which longitudinal sectional plane that is formed as in FIGS. 40-43 and includes the z-axis the points 133-143 lie. Here, all points 133-143 theoretically may lie on different longitudinal sections.
  • [0107]
    The radius vector 147 in the cross section K has the absolute greatest length of all radius vectors that are shown in FIG. 44 and that lie within the region assigned to the central part (see, for example, the cross sections H-R). Consequently, the point 136 defined by this radius vector has the greatest distance from the z-axis within the central part in the upper handle section, with this point corresponding, for example, to the maximum 100 in the illustration of FIG. 25. In addition, FIG. 45 shows that the points 133-143 which are connected by the curves 155 and 156 have partially positive and negative y-values in the xyz-coordinate system shown in FIG. 12. However, all x-values are positive and have their minimum in the cross section L such that they lie on a three-dimensional curve.
  • [0108]
    In contrast to FIGS. 40-44, it is also possible to locate the points 133-143 so that they all lie on the same side of the xz-plane, but at a certain distance from this plane. The shape selected for an individual instance largely depends on the location at which the different maxima and curvatures lie and how pronounced these maxima and curvatures should be.
  • [0109]
    With respect to the dimensions L0.1, LI.1, LII.1 and LIII.1 that were described with reference to FIG. 5, only a few modifications were made in the arrangement according to FIGS. 40-45. If the points that have the greatest distances from the z-axis lie on a curve that is located in a plane that includes the z-axis, the xyz-coordinate system is simply turned about the z-axis by such an angle that the xz-plane corresponds to the plane containing the plane curve. The new coordinate system obtained thereby is then used for defining the various dimensions analogous to the previously described coordinate system, with a reference plane that corresponds to the reference plane 63 (FIG. 5) and is arranged perpendicular to the z-axis being located, in particular, through the point with the greatest absolute distance from the z-axis. Consequently, the only difference can be seen in the fact that the new xyz-coordinate system assumes a different position in space than the coordinate system in FIG. 5.
  • [0110]
    If the points 133-143 in FIGS. 44 and 45 would lie in one plane and this plane would not contain the z-axis, but is, for example, arranged parallel to the xz-plane, the coordinate system according to the previous description may be turned in a such a way that the point 136 with the greatest absolute distance from the z-axis lies in the turned xz-plane. When using the aforementioned definitions for the dimensions L0.1, LI.1, LII.1, LIII.1 etc., slightly different values than those determined in the plane that contains all points 133-143 would be obtained. This applies correspondingly if the points 133-143 do not lie on a plane curve, but rather on a three-dimensional curve analogous to FIGS. 44, 45, and if a plane that contains the z-axis and the point 136 is used as the new xz-plane. In such instances, the positions of the maxima and minima determined in accordance with FIGS. 5-10 and the values for the dimensions L, R, A etc. slightly deviate from the actual values. However, the deviations become smaller as the distance of the maximum 136 from the xz-plane decreases (see, for example, FIG. 45) such that the definitions outlined above with reference to FIGS. 5-10 can be used here for achieving a superior approximation. This is the reason the, value ranges indicated in the tables according to FIG. 93a-FIG. 96c also include handles in which the maximum (e.g., 59 in FIG. 5) lies on a three-dimensional curve and/or not in the described xz-plane. In other respects, the cross section K in FIG. 44a schematically indicates in which sectional planes of the longitudinal sections according to FIGS. 40-43 appear. In this case, a longitudinal section L1 is referred to as a section in the xz-plane (α=0), and a longitudinal section L2 is referred to as a section in the yz-plane (α=90). Accordingly, L3, L4 and L5 refer to longitudinal sections with the angles α=180, α=270 and α=45 which include the z-axis, namely viewed in the directions of the respective arrows. These longitudinal sections L1-L5 are also indicated in the table.
  • [0111]
    The tables according to FIGS. 94a, 94 b contain numerical values in millimeters for a handle that is designed in accordance with FIGS. 40-45 and FIGS. 19-24, wherein the longitudinal sections L1-L5 in column 1 of FIG. 94a correspond to the longitudinal sections at angles of 0, 90, 180, 270 and 45 in accordance with the representation in section K of FIG. 44. Column 2 contains the three selected groups of hands, column 3 contains the corresponding hand widths B, and column 4 contains the handle lengths, for example, between the planes 45 and 46 in FIG. 5. The lengths and radii according to the definitions indicated in FIG. 5 are contained in columns L0-LIII and R1-R3, wherein, for example, the dimension of 41 mm (handle size “M”) that is formed by the combination of L2 (column 1) and LII (column 7) means that this length LII is contained in the longitudinal sectional plane L2 and corresponds to the dimension LII.2 in FIG. 5, although in the corresponding sectional plane. In this case, the value formed from L1 and LII corresponds to the value LII.1 drawn in the xz-plane in FIG. 5. This means that all important dimensions for the handle according to FIGS. 40-45 can be obtained from the tables. Accordingly, the dimension R2 (next to the last column in FIG. 94a) indicates, for example, in connection with L2 that this pertains to the radius R2.2 in FIG. 5.
  • [0112]
    Corresponding dimensions for the radii R10-R13 are indicated in FIG. 94b, wherein R10 in column K corresponds, for example, to the radius RB.10 in FIG. 8 because it lies at the maximum (see cross section K in FIG. 44a). Accordingly, the dimension A2 in the sectional plane K represents the dimension A2B in FIG. 8.
  • [0113]
    FIGS. 46-50 show grid representations of a handle 157 in which the points with the greatest distance from the z-axis lie on a three-dimensional curve that extends in the longitudinal direction of the handle 157 analogous to FIGS. 40-44. In this case, the distal end is respectively arranged on the left and the proximal end is respectively arranged on the right. The handle 157 in FIG. 46 is illustrated in the form of a perspective presentation, with FIG. 47 showing a side view analogous to the illustrations in FIGS. 5, 14 and 19, namely a view from the right side—looking from the distal end—of the handle 157. FIG. 48 shows a top view, FIG. 49 shows a side view from the opposite side, and FIG. 50 shows a bottom view of the handle, with these views resulting by respectively turning the handle 157 90 about a longitudinal axis 158 starting with FIG. 47. In the preferred instance, the left side again represents the side that is provided with a pronounced curvature 159 that extends in at least two directions.
  • [0114]
    The handles (e.g., 38) described thus far are respectively realized in one piece, wherein the first sections (e.g., 42) are integrally connected to the second sections (e.g., 43) by means of adapted inner sections (e.g., 44). However, the invention is not limited to handles of this type, but may be analogously realized in two-part handles with arms that can be moved relative to one another, e.g., handles for pliers, scissors or the like. As in FIGS. 1 and 2, in the following description, one of the two handle arms is referred to as the first section and the other as the second section, with the two arms or sections being separated from one another by an intermediate space, in contrast, for example, to FIGS. 5-10, so that the two arms or sections are not physically connected to one another.
  • [0115]
    When designing handles for pliers, it is important that all four distal finger joints 25 (FIG. 3) adjoin the surface of the second, lower section as uniformly as possible when the pliers are in the open position, e.g., before cutting a wire or before surrounding an object with the serrated jaws of universal pliers, in order to be able to exert a sufficient force. However, the surfaces of this section should adjoin the central finger joints 23 when the pliers are closed.
  • [0116]
    FIGS. 51-55 show a handle 160 according to the invention, which, for example, is intended for adjustable gripping pliers. In this case, a handle arm or upper section 162 is realized analogously to the first or upper section of the handles described thus far (e.g., 42 of 38) on its outer surface, with the other handle arm or lower section 163 being realized analogously to the second or lower section of the handles described thus far (e.g., 43 of 38) on its other surface. The two sections 162 and 163 are realized on both sides of a central plane (yz-plane) that extends through a longitudinal axis 164. In order to make it possible to selectively use the pliers in two positions that are turned about the longitudinal axis 164 by 180 and to achieve approximately the same preferred coupling position relative to the hand cavity and the ball of the thumb, the lower side of the lower section 163 in FIG. 51 is realized with the same shape as the upper side of the upper section 162, but in a laterally reversed fashion relative to a central plane (xy-plane). Thus, the underside of the section 163 or 162 which respectively lies on the bottom when the given tool is used does not provide optimal contact surface for the fingers. Since the upper sides of both sections 162, 163 which are of particular importance for the invention have identical shapes, only the design of the upper section 162 in accordance with the invention is described in greater detail below. In this case, the central plane is preferably placed so that it contains a not-shown rotational axis that connects the two arms of the pliers to one another, with this rotational axis extending perpendicular to plane of projection in FIG. 51 and consequently parallel to the y-axis in the sense of the definitions used thus far.
  • [0117]
    According to FIGS. 51 and 52, the upper section 162 is provided with a surface contour 165 and is divided into a distal part 168, a central part 169 and a proximal part 170 that are arranged one behind the other in the longitudinal direction by means of imaginary planes 166, 167. According to the invention, the section 162 is shaped and dimensioned in such a way that the central part 169 is situated in the hand cavity in the conventional coupling position of the hand for universal pliers, with the distal part 168 being encompassed by the thumb bridge 26 and the proximal part 170 serving as a contact surface for the ball of the hand root 29 and the ball of the hand edge 31. Consequently, the central part 169 has a pronounced convex curvature 171 that is directed outward in the longitudinal direction and in the transverse direction, wherein the distal part 168 is tapered beginning at the center part 169 and continuing to a collar 172 that prevents the hand from sliding off the handle and is arranged on the distal end. The outer contour of the distal part 168 is realized in a lateral region 174 in such a way that it extends with a flat concave arc and with a slight angle of inclination relative to the longitudinal axis 164 in the side view shown in FIG. 52, with said contour also extending in slightly concave fashion along the upper surface 165 shown in FIG. 51, but with a comparatively large angle of inclination relative to the longitudinal axis 164. Similarly, the proximal part 170 extends on the upper surface (FIG. 51) at a comparatively large angle of inclination relative to the longitudinal axis 164, but in essentially concave fashion. In a lateral region 175 (FIG. 52), its surface extends at a comparatively small angle of inclination relative to the longitudinal axis 164 and essentially in slightly descending concave fashion to the proximal end. On the proximal end, the upper section 162 is preferably hemispherical.
  • [0118]
    In other respects, the outer contour of the section 162 is dimensioned and shaped in the longitudinal section and in the cross section, as well as in the direction of the handle height H and in the direction of the handle thickness D, such that the other section 163, if realized identically, is sufficiently well adapted to the trapezoidal inner contours of the enclosing fingers in the preferred coupling position. In this case, the curvature 171 in the section 162 is realized in accordance with a curvature 176 in the section 163 that becomes effective after the pliers are turned by 180 about the longitudinal axis 164.
  • [0119]
    Surfaces 162 a, 163 a of the sections 162, 163 which face one another are not important for the purpose of the invention, and consequently may be conventionally designed with rounded edges. The handle height H at the different locations along the handle 160 (FIGS. 53-55) and, in particular, the curvatures were dimensioned in accordance with the assigned group of hands such that a comfortable preferred coupling position is achieved while taking into account the function of pliers.
  • [0120]
    [0120]FIG. 56 indicates how the handle 160 is encompassed by the human hand 19 when the pliers are used. This figure shows the conventional position for right-handed users, with FIG. 56 showing the initial process of taking hold of the pliers from the rear, FIG. 57 showing the pliers being used in connection with the preferred coupling position of the hand, and FIG. 58 indicating in a section like FIG. 13 how the two sections 162, 163 of the handle 160 are separated from one another and arranged on both sides of the xy-plane in the preferred coupling position of the hand 19. The broken line 177 in FIGS. 56 and 57 also indicates where the curvatures 171 and 176 shown in FIG. 54 are ultimately located on the hand 19.
  • [0121]
    Analogous to the handle 38, the cross-sectional plane B-B in a maximum 178 in the upper section 162 serves as the reference plane for the handle 160, with said maximum lying in a plane that extends parallel to the xy-plane on one hand and in a longitudinal section that lies in the xz-plane on the other hand.
  • [0122]
    The length L0.1 of the convex center part 169 is defined by the position of the turning points to the concave adjacent parts 168, 170 and by the cross-sectional planes 166, 167 that extend through these turning points, respectively. Analogous to one-piece handles, this length amounts to approximately 50%, preferably 45%-55%, of the hand width B (FIG. 3) of the average user of the assigned group. The position of concave minimums 179, 180 of the distal and the proximal part 168, 170 is defined by the dimensions LI.1 and LII.1, wherein these dimensions may have the same values as those in FIGS. 5-10.
  • [0123]
    In other respects, the same explanations as those that refer to the handle 38 apply, with the various dimensions being indicated in the tables according to FIGS. 96a, 96 b.
  • [0124]
    In an embodiment of the pliers handles 183 which are illustrated in FIGS. 59-63, the upper section and the lower section 184, 185 are, relative to the surfaces that come in contact with the hand cavity and the ball of the thumb in the preferred coupling position, also realized asymmetrically, e.g., in accordance with FIGS. 61-63. In particular, the lower surface of the section 185 intended for contact by the fingers is realized in a largely cylindrical fashion, when seen in cross section. However, this lower surface only has a slight curvature in the direction of a longitudinal axis 186 (see R2.2 in FIG. 59). In this case, the radii and the other dimensions in the lower section 185 are chosen so that this section provides a very comfortable contact surface for the fingers that enclose this section. The “trapezoid” (see also FIG. 58) formed by the bent finger joints 23-25 (FIG. 3) and the thumb 20 consequently is practically filled by the handle 183 such that a very uniform pressure distribution is possible. The upper section 184 is realized in accordance with the upper section of the handle 160 in FIGS. 51-55.
  • [0125]
    The pliers illustrated in FIGS. 51-63 contain handles 160, 183 for the right-handed user. If the corresponding handles are designed for the left-handed user, the sections 162, 163 and 184, 185 are realized in a laterally reversed fashion relative to the xz-plane (see 61-63).
  • [0126]
    In other respects, the previous explanations with respect to the handle 160 apply.
  • [0127]
    [0127]FIGS. 64 and 65 show a handle 189 that contains two sections 190, 191 that are realized in a laterally reversed symmetrical fashion on either side of the longitudinal axis 192 and a central plane (yz-plane) containing this longitudinal axis. Both sections 190, 191 have a clearly pronounced curvature 194 in the sense of the other described handles in a central part 193, namely in the x-direction and in the y-direction. Such a handle shape provides optimal properties for right-handed and left-handed users in the upper section 190 (or 191) that cooperates with the hand cavity. In addition, the handles 189 are significantly improved in comparison to pliers handles available on the market within the section 191 (or 190) that is enclosed with the fingers.
  • [0128]
    Most known pliers handles, namely also handles for larger universal pliers or cutting pliers, are simply not sufficiently ergonomic because they do not contain a proximal part with superior ergonomic design or suitable contact surface for the ball of the hand edge. Even the pliers handles of larger pliers are too short or extend up to the proximal end in the form of a continuous arc that lies in one plane such that they are by no means adapted to the hand cavity. The entire compressive force consequently must be exerted by the hand cavity. In order to reduce the specific pressure in this region, the invention proposes to extend at least the handles of larger pliers to such a degree that the ball of the hand edge also adjoins a corresponding proximal part (e.g., 170 in FIG. 51). Thus, the compressive forces exerted by the ball of the hand edge are provided with a longer lever arm such that the compressive forces acting upon the inner surfaces of the hand are additionally reduced. Consequently, the concave-convex-concave surface contour explicitly described above is also effectively realized in pliers handles.
  • [0129]
    Naturally, other types of pliers, e.g., wire strippers, universal pliers, needle-nose pliers and other gripping and cutting pliers, as well as shears, in particular, plate shears, may be equipped with the described pliers handles and other pliers handles.
  • [0130]
    Like FIGS. 40-50, FIGS. 66-74 show longitudinal sections, cross sections and grid or dot matrix representations of a hammer handle, e.g., a hammer handle according to FIGS. 14-18. In this case, longitudinal sections are also illustrated in the four planes 0, 45, 90 and 135 (FIGS. 66-69), with FIG. 70 containing a series of cross sections A-L along the z-axis. Practical dimensions for such a section are indicated in the tables according to FIGS. 93a, 93 b which are structured analogously to the tables according to FIGS. 94a, 94 b.
  • [0131]
    FIGS. 75-83 show representations that correspond to FIGS. 66-74 for a saw handle that is approximately realized in accordance with FIGS. 33-39, and FIGS. 84-92 show corresponding representations for the upper sections of pliers handles, e.g., the pliers according to FIGS. 51-58. With respect to FIGS. 84-87, it must be noted that this pertains to an upper section of pliers according to the section 162 in FIGS. 51-55, and that the position of the longitudinal sections is chosen in accordance with the cross section K in FIG. 88a. In addition, the longitudinal sections, in contrast to the corresponding illustrations (e.g., FIG. 40-43), are respectively illustrated in a position that is turned about the z-axis by 180.
  • [0132]
    The tables according to FIGS. 95a, 95 b and 96 a, 96 b indicate the dimensions for the saw handle according to FIGS. 75-83 and the pliers handle section according to FIGS. 84-89, analogously to FIGS. 94a, 94 b.
  • [0133]
    The invention is not limited to the described embodiments and can be modified in several ways. This applies, in particular, to the individual design of the various handles described with reference to the figures and the dimensions selected for a certain group of hands. An optimal handle for a large hand has a larger total volume than that for a small hand. In addition, other criteria may be used for categorizing the handles into the respective groups, in particular, if dimensions other than those indicated in the figures are deemed practical for ergonomic reasons as the result of a series of tests. With respect to the cross sections, it should be noted that the handles are preferably oval, egg-shaped, circular, elliptical or the like in all regions in which they come in contact with the hand of the user. However, the handles also may have different shapes and, in particular, be provided with conventional finger depressions or the like in the lower sections. In particular, it is possible to select the angular ranges shown in FIG. 12 differently, wherein a range of approximately 315-90 is deemed particularly effective with respect to the angle of the described curvature. However, this does not prevent the handles from containing corners at the locations at which the less-stressed hand sections contact the handle. In addition, the dimensions of the handles in the different groups of hands selected for the purpose of the invention preferably have a ratio of S:M:L=43:46:48. This ratio refers specifically to the dimension L0.1, but other group classifications can also be chosen if so required. It is also practical to incorporate the minimum and maximum values for the curvature contours in the region of the various cross sections into the design. For example, the radii R10, R12 preferably have a length between 10 mm and 30 mm while the radii R11, R13 preferably have a length of approximately 15 mm-30 mm. In this context, it is also advantageous to vary the remaining dimensions of the corresponding handle in the same percentile ratio if the sizes are changed from group to group or even within the same group, e.g., if the length L0.1 is changed. A comparison of tables 93 a-96 c shows that the length of the center part is approximately 50% of the hand width for all described handles. In addition, the curvature radius R2.1 lies between 50 mm and 120 mm and the curvature radii R2.2 and R2.4 lie between 50 mm and 150 mm for all handles. Surprisingly, these dimensions which are particularly important for the coupling position are essentially identical for all handles. The sectional drawings and tables describe examples of several advantageous handle designs. In addition, the scope of the invention not only includes the described handles, but also the tools manufactured with said handles and sets that contain several different handles or tools and that are assigned to the same functional parts. In this case, the sets may, depending on the respective requirements, comprise handles and/or tools provided with handles for right-handed and/or left-handed users, as well as tools other than those described above. It goes without saying that the individual characteristics may also be applied in combinations other than those described above.
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Classifications
U.S. Classification16/430
International ClassificationB25G1/10, A45C13/26
Cooperative ClassificationY10T16/476, B25G1/102
European ClassificationB25G1/10B
Legal Events
DateCodeEventDescription
6 Nov 2000ASAssignment
Owner name: GWW, INC., WISCONSIN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FLYNN, TIMOTHY R.;REEL/FRAME:011092/0682
Effective date: 20001106
25 Feb 2002ASAssignment
Owner name: FELO WERKZEUGFABRIK-HOLLAND-LETZ GMBH, GERMANY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HOLLAND-LETZ, HORST;REEL/FRAME:012630/0432
Effective date: 20011220