US3905315A

US3905315A - Synchronous drive system and embroidering machine employing the same

Info

Publication number: US3905315A
Application number: US503904A
Authority: US
Inventors: Hiroshi Sasaki
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-09-20
Filing date: 1974-09-06
Publication date: 1975-09-16
Anticipated expiration: 1992-09-16
Also published as: DE2444915B2; JPS5341587B2; JPS5055444A; DE2444915A1

Abstract

There is provided a synchronous drive system which employs, in place of conventional mechanical elements, a pair of belt-driven unit mechanisms: The unit mechanism essentially comprises a pair of stationary shafts arranged at a predetermined interval, a slider means movably disposed between the stationary shafts, and a belt member trained around the pulleys of the stationary shafts and slider means. The synchronous system thus features its unique power conversion from rotatative movement into linear movement. There are further provided an X- and Y- axis directional drive system and a multiple-head embroidering machine both utilizing this synchronous drive system.

Description

United States Patent Sasaki 1 1 Sept. 16, 1975 SYNCHRONOUS DRIVE SYSTEM AND 2,760,454 8/1956 Lambach 112/90 EMBROIDERING MACHINE EMPLOYING 3,456,608 7/1969 Marcus 1 12/102 3,468,268 9/1969 Rolaulfs 112/86 THE SAME Inventor: Hiroshi Sasaki, No. 48-14, 2-chome, Denenchohu, Ota-ku, Tokyo, Japan Filed: Sept. 6, 1974 Appl. No.1 503,904

[30] Foreign Application Priority Data Sept. 20, 1973 Japan 48-106677 [52] US. Cl. .1 112/86; 112/102; 112/103 [51] Int. Cl. D05C 3/04 [58] Field of Search 112/102, 103, 83, 86, 9O

[56} References Cited UNITED STATES PATENTS 1,154,871 9/1915 Marschalek 112/83 1,274,119 7/1918 Wetter 112/83 2,030,495 2/1936 Bretschneider" 112/86 2,091,727 8/1937 Bohmann et a]. 1. 112/102 2,709,976 6/1955 Lambach 112/90 Primary Examiner-Alfred R. Guest Attorney, Agent, or FirmWilliam Anthony Drucker [S 7 1 ABSTRACT There is provided a synchronous drive system which employs, in place of conventional mechanical elements, a pair of belt-driven unit mechanisms:

The unit mechanism essentially comprises a pair of stationary shafts arranged at a predetermined interval, a slider means movably disposed between the stationary shafts, and a belt member trained around the pulleys of the stationary shafts and slider means. The synchronous system thus features its unique power conversion from rotatative movement into linear movement. There are further provided an X- and Y- axis directional drive system and a multiple-head embroidering machine both utilizing this synchronous drive system.

5 Claims, 16 Drawing Figures PATENTEB SEP 1 6 m5 SHEET PATENTED W5 3. 905.3 1 5 SHEET 5 F|G.7 (a) PATENTEB l W5 (if Ou Ei m Est SYNCI-IRONOUS DRIVE SYSTEM AND EMBROIDERING MACHINE EMPIJOYING THE SAIME BACKGROUND OF THE INVENTION This invention relates to a synchronous drive system which is capable of causing a plurality of moving elements to make linear motions in synchronism with one another by means of rotary driving, and also to an automatic multiple-head embroidering machine adapted for industrial use and controlled by numerical system or the like which employs said synchronous drive system for effecting its embroidering movements in X- and Y- axis or longitudinal and transverse directions.

Conventionally typical drive systems which are used to change rotary movement into linear movement mainly include mechanisms which employ assemblies of rack and pinion, and of screw and nut or the like. These systems have widely been utilized from old times. However, they have the disadvantage that with these systems structurally it is difficult to completely eliminate backlash between the individual parts and abrasion of some of the parts, however precise these parts are made. As a consequence, if these mechanisms are directly applied to a synchronous drive system, the system will have a deal of difficulties due to such disadvantage. Further, the conventional systems of this kind are generally complicated in structure, are large in scale enough to be high in moment of inertia, and are easily influenced by any errors in positioning or assembling of the surrounding parts or elements, thus resulting in difficulty in their designing, high manufacturing costs, and hard maintenance, etc. The result of embroidery by an automatic embroidering machine is influenced by the accuracy of movement of a material to be embroidered on such as cloths with respect to the machine body. Further, in an industrial-use embroidering machine which is enquipped with a plurality of arm beds for making embroidery on their respective frames simultaneously, it is required to equalize the displacements of the individual cloths to one another, but with the embroidering machine having the conventional type of synchronous drive system it is extremely difiicult to maintain above the level the accuracy of the displacements of the cloths to be embroidered on.

BRIEF SUMMARY OF THE INVENTION The present invention has been devised in order to eliminate the above-mentioned weekpoints possessed by the conventional synchronous drive system and the automatic embroidering machine, and therefore it is a primary object of the invention to provide a synchronous drive system which is intended to cause a plurality of moving elements to make linear motions in synchronism with one another by means of rotary driving, and is characterised not only by its highly accurate driving ability enough to ensure highly synchronized motions of the moving elements, but also by its wide application and simple construction.

A second object of the invention is to provide a X- and Y axis directional synchronous drive system which is particularly adapted for use with an automatic embroidering machine in which it is used to move given moving elements in X- and Y- axis directions, i.e.. in longitudinal and transverse directions, and is characterised by its highly accurate driving ability, wide application and simple construction.

A third object of the invention is to provide an automatic multiple-head embroidering machine adapted for industrial use and capable of being numerically controlled, which employs said X- and Y- axis directional drive system, and is able to produce very nicely finished embroideries.

A fourth object of the invention is to provide an automatic multiple-head embroidering machine adapted for industrial use and numerically controllable, employing said X- and Y- axis directional drive system which comprises pairs of rotary drive mechanisms, one of each pair being exclusively used for the X-axis directional motion, and the other for the Y-axis directional motion.

A fifth object of the invention is to provide a cloth supporting frame adapted for use with the abovementioned embroidering machines, which is characterised by that it is light in weight, easy to move, and convenient for cloth to be applied to or removed from while it is simple in structure, free from trouble, and may be manufactured at low costs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view, partly broken away to show a unit mechanism which constitutes an essential part of the X- and Y- axis directional drive system to be equipped on an embroidering machine according to the present invention;

FIG. 2 is a sectional view taken on line II II of FIG.

FIG. 3 is a sectional view taken on line III III of FIG. 1;

FIG. 4 is a schematic view showing belt members trained around pulleys;

FIG. 5 is a schematic view showing a pair of unit mechanisms connected to each other to be used for the X-axis drive.

FIG. 6 is a top plan view of the same mechanisms of FIG. 5;

FIG. 7a is a front view showing a rotary drive mechanism used in the present invention;

FIG. 7b is a top plan view, partly broken away, to show the same mechanism of FIG. 7a;

FIG. 8 is a schematic view showing belt members trained around pulleys in the rotary drive mechanism;

FIG. 9 is a schematic bottom plan view showing the relationship between three movable shafts and a moving plate,

FIG. 10 is a rear view showing an embroidering machine according to the invention;

FIG. 11 is a schematic sectional view showing the same embroidering machine of FIG. 10',

FIG. 12 is a top plan view showing a cloth supporting frame according to the invention;

FIG. 13 is an enlarged sectional view taken on line II II of FIG. 12;

FIG. 14 is an enlarged sectional view taken on line III III of FIG. 12; and

FIG. [5 is an enlarged sectional view showing cloth to be embroidered on in engagement with fastening plnS.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIGS. 1 4, numeral 1 designates a frame, 2 and 3 represent stationary shafts vertically fixed on the right and left ends of the frame 1 respectively, and 4, 5 and 6, 7 indicate pairs of pulleys mounted on the

stationary shafts

2 and 3 respectively, each pair of pulleys being rotatably disposed one above the other. At the both upper and lower ends of each of the pulleys 4 7 are respectively formed two guide grooves a, b.

Numerals

8 and 9 are a guide shaft and a guide rail respectively, which are arranged parallel with each other, extending between the

fixed shafts

2, 3 of the frame I. Numeral I designates a slider which is slidably mounted on the guide shaft 8 through a ball bush (linear ball bearing) I2 with its sliding groove II slidably receiving the guide rail 9. A movable shaft 13 is vertically mounted on the slider 10 and positioned on a line extending between the

fixed shafts

2 and 3. Independently rotatably fitted on the movable shaft I3 are pulleys l4, l5, and 16 which are arranged one above another, and are each provided with two guide grooves a, b at its upper and lower ends as is the case with the pulleys 4 7. The grooves a and b of each pulley are integrally formed so that they are necessarily rotated in the same direction. Belts such as wires l7, 18 are trained around these pulleys (These belts l7, 18 are omitted from FIGS. 1, 2, and 3), and have their ends secured to the frame 1 by means of fastening means 19, 20 fixed on the frame. 21 and 22 are guide pulleys.

An example of engagement of the

belts

17, 18 around the pulleys is shown in FIG. 4. In this drawing, one belt 17 with its one end secured to the fastening means 19 is first trained around the pulley 14 in the guide groove b thereof to then pass over the guide groove a of the pulley 4, and further travels over pulleys in the order of 1515, 50, 16b, and guide pulley 21, while another belt 18 with its one end secured to the fastening means 20 passes over pulleys in the order of 14a, 6a, 150, 7a, 160 and guide pulley 22. With this arrangement, the guide grooves b of the pulleys 4 7 are not in use. Further, all the pulleys need not have guide grooves.

One set of said unit mechanism is used for X-axis drive, and two sets, A and B for Y-axis drive. An example of the Y-axis drive is shown in FIGS. and 6 in which the unit mechanisms A and B are connected to each other by means of belts I7, 18 which run in connection with both the unit mechanisms A, B in a fashion that they have their respective free ends integrally tied together at the intersecting point between the unit mechanisms. Provided between the two unit mechanisms in engagement with the belt 17 is a rotary drive means 23 which serves to move the belt 17 backward or forward. In FIG. 6, if the rotary drive means 23 is rotated clockwise, the belt 18 of the unit mechanism A is pulled by the means 23 toward the unit mechanism B, thus to downwardly drive the movable shaft 13. This movement of the movable shaft 13 causes the belt 17 of the unit mechanism B to be pulled toward the unit mechanism A so that also the movable shaft 13 of the unit mechanism B is driven downward. In this case, the displacements of both the movable shafts 13, I3 are equal to each other. If the rotary drive means 23 rotates counterclockwise, both the movable shafts l3, 13 are upwardly driven by the same displacement, for the same reason as mentioned above.

In FIGS. 70, 7b, and 8, numeral 24 designates a driving wheel adapted to be rotated by drive motor 53 (FIG. 25 a driven wheel, 26 a guide pulley, 27 an endless loop of driving belt aroung the drive pulley 24, the driven pulley 25, and the

guide pulley

26, 28, 30 rotary pulleys both provided with respective four guide grooves c, d, e, f, 29 a pulley having upper and lower guide grooves g, h, and 3], 32, 33, 34 guide pulleys for the

belts

17, 18, the guide pulleys 3] and 34 being provided with guide grooves, i, j at the upper and lower ends thereof respectively. Numeral 35 is a brake means for braking the rotation of the

pulley

29, and 36 and 37 clutch means for transmitting the rotation of the driven pulley 29 to the rotary pulleys 28, 30. Said rotary drive means 23 are used for both the X- and Y- axis drives (one is shown in FIG. 7), as designated respectively by 23X and 23Y in FIG. 10. In the embodiment of FIG. 10 the rotary drive means 23X and 23Y are driven by a single driving source, but may be driven by separate driving sources, if desired.

FIG. 9 is a bottom plan view schematically showing the relationship between three movable shafts 13 of the X- and Y-axis drive means and the moving plate 38 adapted to be moved in the longitudinal, transverse, or diagonal directions by means of said movable shafts. In this drawing, l3Y represents a movable shaft adapted to move the moving plate 38 in the Y-axis directions (i.e., in the upward and downward directions), and 13X a movable shaft adapted to move the same plate 38 in the X-axis directions, both the movable shafts being fitted in guide rails 39( and 39X respectively. 40 is a ball bearing mounted on the, movable shaft 13 for smoothing the movement of the movable shaft 13 with respect to the guide rail 39.

The relationship between the movable shaft 13 and the moving plate 38 is shown in FIGS. 2 and 3. This moving plate 38 is used for moving a cloth supporting frame 4] over which the cloth to be embroidered on is applied in a supported manner. In FIG. 3, numeral 42 denotes a hook joint secured to the moving plate 38 through a screw means 43, 44 a thumb screw for fixing the cloth supporting frame to the moving plate 38 through the hook joint 42, and 45 a bearing ball secured to the underside of the cloth supporting frame 41 for smoothing the movement of the frame 4! with respect to a base plate 46.

FIG. 10 is a rear view showing an embroidering machine according to the invention which is provided with the above-mentioned X- and Y- axis directional drive systems, and FIG. 11 is a sectional schematic view of the same. In these views, numeral 47 represents a plurality of machine bodies arranged side by side over the base plate 46, 48 a support bar of tubular structure spanning between support frames 49a, 4% which are erected on the right and left ends of the

base plate

46, 50 an elongate angled member of L-shaped cross section, which is bridged between the support frames 49a, 49b in parallel relation with the

support bar

48, 51 and 52 members of channel-like sections integrally secured to the outer surfaces of an angled member 50 at right angles to each other, 56 a drive shaft for vertically reciprocating a needle, and 57 a drive shaft for moving a thread take-up lever, said

drive shafts

56, 57 being bridged between the support frames 49a, 49b to be actuated by a given drive means accomodated within the support frames. The above-described machine bodies inclusive of their drive means may be of a conventional type or the like.

Next, description is made of an embroidering cloth support frame over which embroidering cloth is to be applied. If the cloth to be embroidered on is loosened or has some folds, precise finish may never be expected, no matter how excellent the drive mechan'um may be. For this reason, improvements have been made to the cloth support frame by the present inventor. In the following will be described details of the improvements with reference to FIGS. I2, l3, l4 and 15.

In these drawings, numeral 101 represents a frame body made of a thin metal plate such as duralumin, which has right and left side edge portions 102 inwardly folded into channel-like shapes, and front and rear end edges I03 inwardly folded to form erect portions 104 and sloped portions extending from the erect portions. These folded side edges 102, erect portions 104 (shown in F IG. I 3 and sloped end edges 103 serve to enhance the rigidity of the frame body I] and prevent deformation of the same body. Numeral I designates a number of first fastening pins closely planted over base members 106 made of relatively thick cloth orthe like and applied on the upper surfaces of the sloped portions 103. Each pin 105 has its top end fonned as a sharp blade 105a and has its upper portion of approximately one third of its whole length upwardly bent (see FIG. I5).

The support frame, with the above-described structure, permits embroidering cloth to be applied thereover with much easiness.

Numeral 108 designates two elongated foundation plates secured to the frame body 101 near the opposite side edges thereof by butterfly nuts.

Along each foundation plate 108 are erected in a line a plurality of second fastening pins 110 which are adapted to penetrate through an end portion of the cloth 107 to secure it to the foundation plate 108 (See FIG. 14).

Numeral 111 represents a caster provided under the frame body 101, 112 a screw fixing the base member to the sloped

edge portion

103, 1 13 a table, 1 14 a connector connecting the cloth supporting frame 101 to a drive means 115 (Only a part is shown, and its type and structure are optional), 116 a setscrew, 117 a recess formed by folding the sloped edge portion 103 which permits insertion of a finger thereinto thus to facilitate engagement and disengagement of the cloth with respect to the

pins

105, and 118 an opening.

FIGS. 13 and 14 show an example of application of embroidering cloth with respect to the present cloth frame 101. To engage the cloth 107 with the pins 105, first the cloth 107 is applied over the blades 1050 of the pins 105, and then is forced in the direction of bending of the blades (i.e., in the arrow A direction of FIG. 15) to be followed by pulling it backward or in the opposite direction to that of bending of the blades (In practice, the cloth need not be so strongly pulled, since it moves backward by itself by force of its restitution). Thus, the pins have been thrusted through the cloth, as shown by B. Positive thrusting of fastening pins with respect to cloth may be ensured by the provision of blades 1050 at the tops of the pins 105.

Further, the sloped edge portions I03 have elasticity enough to effectively serve to ensure the positive engagement of the cloth 107 by the pins 105, particularly with uniform tension applied over the whole cloth. This engagement will be effectively enhanced by clamping together the mutually coupled cloth and fastening pins and the sloped edge portion with a clip. The cloth 107 may be easily disengaged from the pins 105 merely by separating the cloth from the pins in a peeling manner.

The embroidering machine and embroidering cloth frame according to the invention are of the aforedescribed constructions. As described, the movement of the movable shafts 13 for moving the moving plate 38 is effected by traction of the belts l7, 18, which traction power is generated by actuation of the drive wheel 24 and the clutch means 36, 37. That is, when the drive wheel 24 is actuated, the driven

wheels

25, 25 are rotated via the driving belt 27, but since in a normal condition the clutch means 36, 37 are not in action, power is not transmitted to the rotary pulleys 28, 30 and therefore the joined

belts

17, 18 are not tracted. If in FIGS. 7a, 7b the drive wheel 24 is supposed to rotate clockwise and in FIG. 8 the clutch means 36 is actuated, the rotary pulley 28 is rotated to move the belts from the guide pulley 31 toward the guide pulley 34. Inversely, if the clutch means 37 is actuated, the rotary pulley 30 .is rotated to move the belts from the guide pulley 34 toward the guide pulley 31. In this arrangement, the brake means 35 is utilized to instantly stop the belts. In this example, the clutch means 36, 37 and the brake means 35 are numerically controlled. For this purpose, a linear scale is provided right under the guide shaft 8, which scale is read by a censor to determine the difference between a directive value and an actual value, and compensation is made for the difference thus obtained.

As described, the automatic embroidering machine according to the invention accomplishes its objects in a fmhion that the rotary drive means 23X, 23Y are actuated to tract the

belts

17, 18 which, in turn, move the

movable shafts

13X, 13! together with the slider, thus to displace the moving plate 38 in frontward or rearward directions and in rightward or leftward directions. In FIG. 9, when the movable shafts l3Y, l3Y move to displace the moving plate 38 in upward or downward directions or Y-axis directions, the movable shaft 13X correspondingly moves within the guide rail 39X in the same directions. When the movable shaft 13X moves to displace the moving plate 38 in rightward or leftward directions (or in X-axis directions), the movable shafts 13Y, I3Y correspondingly move along the

guide rails

39Y, 39Y in the same directions, respectively.

Further, it goes without saying that when the moving plate 38 is to be displaced obliquely, all the

movable shafts

13X, 13Y, 13Y should be moved simultaneously. The present invention has some advantages: first, the displacement of the unit mechanism with respect to the machine for moving the embroidering cloth is only a small percentage of the driving amount of the rotary drive means (The unit mechanism in the drawings has a displacement of one-sixth of the driving amount of therotary drive mechanism. That is, in FIG. 4, if the free end of the belt 18 around the guide pulley 22 is pulled by 6 cm, the

pulleys

14, 15, 16 (of the movable shafts) come nearer to the

pulleys

7, 6 by 1 cm, as a result of the arrangement of three turns of the belt 18 between the pulleys 16, l5, l4 and the

pulleys

7, 6, which means far higher precision of movement of the present embroidering machine than the conventional embroidering machine mechanism employing racks and pinions, or the like. Secondly, in FIG. 6, the belt 17 between the

pulleys

4, 5 and the

pulleys

14, 15, 16 of the unit mechanism A and between the

pulleys

6, 7 and the pulleys 14, I5, 16 of the unit mechanism 8 is, when the brake means is actuated, always under the loaded and strained state irrespective of the direction of rotation of the rotary drive means 23.

While, there may be a slight looseness on the belt 18 depending upon the rotating direction of the rotary drive means 23 (In FIG. 8, when the rotary drive means 23 rotates clockwise, looseness occurs on the belt in the unit mechanism B. But, this looseness is invisibly small and merely latent in the belt). However, the looseness only causes a slight delay in the movement of the slider at the moment the rotary drive means 23 gets reversed in rotation, but never affects the resulting dis placements of the two sliders. Therefore, the synchronization of them is very precise, and the Y-axis drive of the moving plate has all the higher precision. Particularly, unless said Y-axis drive is precise, there will occur considerable discrepancies in the resulting embroideries between the machine bodies on the right and left ends. Thus, the above-mentioned advantage is of much significance. The third advantage is that when one belt is subjected to traction to rotate one pulley, the traction power is transmitted to the other belt which is in connection with said pulley so that there will never occur a partial elongation of only one of the belts, thus ensuring high power transmission speed and high response to result in finer finish of the embroideries. The fourth advantage is that for the X-axis drive, the

guide rails

39Y, 39Y are moved with the movable shafts 13Y, l3Y, thus ensuring rectilinear motion of the moving plate, and the fifth is that because of the arrangement of the rotary drive mans 23X for the X-axis drive and 23Y for the Y-axis drive independently from each other, thus facilitating the designing and working of the machine and enabling reduction in the manufacturing cost. Such arrangement will further lead to easier repair, maintenance, and inspection of the product, since in the event of an accidental cutting of the transmission belt 27, for finding the cause, it will be sufficient to inspect only either of the rotary drive means 23X, 23Y to which the out transmission belt 27 belongs.

A further advantage is that the belts l7, 18 are trained, respectively, around a plurality of grooves (four grooves in the drawings) of the

pulleys

28, 30 in connection with the

clutches

36, 37, thus being free from slipping and consequently precise in movement. As a seventh advantage, the embroidering machine according to the invention is simple in construction, easy to control and inspect, and excellent in endurance en bugh to maintain its precision for a long time. A still further advantage is that the present embroidering machine uses a cloth supporting frame of a seamless solid construction made of a single part which is very lightweight, and may be operated at high speeds. Another feature of the cloth supporting frame is that the side edge portions 102 and the end edge portions 103 are folded as specified hereinbefore, which results in the increased rigidity of the whole frame body and sufficient elasticity of the sloped end portions 103 so that uniform tension are spread over the embroiden'ng cloth applied around the frame, thus preventing partial loosening of the cloth as well as facilitating mountinig or dismounting of the cloth with respect to the frame. Thus, the present cloth frame has excellent working property.

As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the spirit and scope of the claims, or equivalence of such spirit and scope are therefore intended to be embraced by the claims.

What I claim is:

l. A synchronous drive system adapted for industrial use, and essentially constituted by first and second unit mechanisms, each comprising:

first and second stationary shafts arranged in spaced relation to each other, each having one or more pulleys arranged one above another and each provided with a plurality guide grooves;

a slider means mainly composed of a movable shaft arranged between said first and second stationary shafts, said movable shaft having a plurality of pulleys which are disposed one above another and are each provided with a plurality of guide grooves;

first and second belt members each having its one end secured to a stationary fastening means, said belt members being in engagement with the pulleys of said first and second stationary shafts and the pulleys of the movable shaft in a fashion trained around the guide grooves thereof, so that each pulley of the movable shaft is in engagement with both the belt members, the slider means thus being adapted to move towards the first or second stationary shafts by traction of the belts, said first and second belt members of the first unit mechanism having the free ends thereof integrally connected, respectively, to the free ends of the first and second belt members of the second unit mechanism, said drive system further including a rotary drive means which engages with either of the first and second belt members to draw the same.

2. An X- and Y-axis drive system comprising a first unit mechanism for X-axis directional drive, second and third unit mechanisms for Y-axis directional drive, each unit mechanism comprising:

first and second stationary shafts arranged in spaced relation to each other, each having one or more pulleys arranged one above another and each provided with a plurality of guide grooves;

a slider means mainly composed of a movable shaft arranged between said first and second stationary shafts, said movable shaft having a plurality of pulleys which are disposed one above another and are each provided with a plurality of guide grooves; and

first and second belt members each having its one end secured to a stationary fastening means, said belt members being in engagement with the pulleys of said first and second stationary shafts and the pulleys of the movable shafl in a fashion trained around the guide grooves thereof, so that each pulley of the movable shaft is in engagement with both the belt members, the slider means thus being adapted to move towards the first or second stationary shafts by the traction of the belt members, the first unit mechanism for X-axis drive having the free ends of the first and second belt members thereof connected to each other, the second unit mechanism for Y-axis having the free ends of the first and second belt members thereof connected to the free ends of the first and second belt members of the third unit mechanism for Y-axis drive.

each said X- and Y- axis drive system further comprising a first rotary drive means which engages with either of the first and second belt members of the first unit mechanism to draw the same, and a second rotary drive means which engages with at least one of the first and second belt members of the second and third unit mechanisms to draw the same.

3. An embroidering machine carrying a plurality of machine bodies and essentially constituted by a plurality of X- and Y- axis drive systems each composed of a first unit mechanism for X-axis directional drive, and second and third unit mechanisms for Y-axis directional drive, each unit mechanisms comprising:

first and second belt members each having its one end secured to a stationary fastening means, said belt members being in engagement with the pulleys of said first and second stationary shafts and the pulleys of the movable shaft in a fashion trained around the guide grooves thereof, so that each pulley of the movable shaft is in engagement with both the belt members, the slider means thus being adapted to move towards the first or second stationary shafts by the traction of the belts, the first unit mechanism having the free ends of the first and second belt members thereof connected to each other, the second unit mechanism having the free ends of the first and second belt members thereof connected to the free ends of the first and second belt members of the third unit mechanism,

each said X- and Y- axis drive system including a first rotary drive means which engages with either of the first and second belt members of the first unit mechanism to draw the same, and a second rotary drive means which engages with at least one of the first and second belt members of the second and third unit mechanism to draw the same;

said embroidering machine further including:

a base plate carrying said machine bodies and on which the unit mechanisms for X- and Y- axis drive are mounted;

a plurality of moving plates each having X- and Y- axis guide rails arranged in engagement with the movable shafts of the unit mechanisms for X- and Y- axis drive in a fashion that each said moving plate is movable in X-, Y- axis and oblique directions in accordance with the movement of the movable shafts; and

a plurality of frames each supporting cloth to be embroidered on by one of said machine bodies.

4. An embroidering machine adapted for industrial use, carrying a plurality of machine bodies and essentially constituted by a plurality of X- and Yaxis direc tional drive system each comprising a first unit mechanism for X-axis directional drive, second and third unit mechanisms for Y-axis directional drive, each unit mechanism comprising:

first and second stationary shafts arranged in spaced 6 relation to each other, each having one or more pulleys arranged one above another and each provided with a plurality of guide grooves;

first and second belt members each having its one end secured to a stationary fastening means, said belt members being in engagement with the pulleys of said first and second stationary shafts and the pulleys of the movable shaft in a fashion trained around the guide grooves thereof, so that each pulleyoof the movable shaft is in engagement with both the belt members, the slider means thus being adapted to move towards the first or second stationary shafts by the traction of the belt members, the first unit mechanism having the free ends of the first and second belt members thereof connected to each other, the second unit mechanism having the free ends of the first and second belt members connected to the first and second belt members of the third unit mechanism,

each said X- and Y-axis drive system further comprising first and second rotary drive means each composed of:

a driving wheel;

first and second driven wheels;

an endless loop of transmission belt trained around said driving wheel and first and second driven wheels in a fashion that said driven wheels are rotated in opposite directions to each other;

first and second rotary pulleys mounted, respectively,

on said first and second driven wheels;

first and second clutch means engaged, respectively, with said first and second driven pulleys, and first and second rotary wheels, said clutch means being actuated to allow the rotary pulleys to be rotated in either directions,

said first rotary means being in engagement with the first unit mechanism in a fashion that said mutually connected free ends of the first and second belt members of the first unit mechanism are trained around said rotary pulleys of the first rotary means, said second rotary means being in engagement with the second and third unit mechanisms in a fashion that the first and second belt members of the second and third unit mechanisms mutually connected to each other at the free ends thereof are trained around said rotary pulleys of the second rotary means,

said embroidering machine further including:

a base plate carrying said machine bodies and on which the unit mechanisms for X- and Y-axis directional drive are mounted;

a plurality of moving plates each having X- and Y- axis guide rails arranged in engagement with the movable shafts of the unit mechanisms for X- and Y-axis directional drive in a fashion that each said moving plate is movable in X-, Y-axis and oblique directions in accordance with the movement of the movable shafts; and

a plurality of cloth frames each supporting cloth to be embroidered on by one of said machine bodies.

5. A cloth supporting frame for use with an embroidering machine according to any of the preceding claims, comprising: a frame body having opposite side edge portions inwardly folded into channel shapes, and

opposite end portions inwardly folded into erect porcloth to be stretched over the frame from said sloped tions and sloped portions extending from the erect poredge portions to the underside of the frame body with tions; and a number of fastening pins closely planted an end of the cloth caught by said fastening pins. over said base members thereby allowing embroidering

Claims

1. A synchronous drive system adapted for industrial use, and essentially constituted by first and second unit mechanisms, each comprising: first and second stationary shafts arranged in spaced relation to each other, each having one or more pulleys arranged one above another and each provided with a plurality guide grooves; a slider means mainly composed of a movable shaft arranged between said first and second stationary shafts, said movable shaft having a plurality of pulleys which are disposed one above another and are each provided with a plurality of guide grooves; first and second belt members each having its one end secured to a stationary fastening means, said belt members being in engagement with the pulleys of said first and second stationary shafts and the pulleys of the movable shaft in a fashion trained around the guide grooves thereof, so that each pulley of the movable shaft is in engagement with both the belt members, the slider means thus being adapted to move towards the first or second stationary shafts by traction of the belts, said first and second belt members of the first unit mechanism having the free ends thereof integrally connected, respectively, to the free ends of the first and second belt members of the second unit mechanism, said drive system further including a rotary drive means which engages with either of the first and second belt members to draw the same.

2. An X- and Y-axis drive system comprising a first unit mechanism for X-axis directional drive, second and third unit mechanisms for Y-axis directional drive, each unit mechanism comprising: first and second stationary shafts arranged in spaced relation to each other, each having one or more pulleys arranged one above another and each provided with a plurality of guide grooves; a slider means mainly composed of a movable shaft arranged between said first and second stationary shafts, said movable shaft having a plurality of pulleys which are disposed one above another and are each provided with a plurality of guide grooves; and first and second belt members each having its one end secured to a stationary fastening means, said belt members being in engagement with the pulleys of said first and second stationary shafts and the pulleys of the movable shaft in a Fashion trained around the guide grooves thereof, so that each pulley of the movable shaft is in engagement with both the belt members, the slider means thus being adapted to move towards the first or second stationary shafts by the traction of the belt members, the first unit mechanism for X-axis drive having the free ends of the first and second belt members thereof connected to each other, the second unit mechanism for Y-axis having the free ends of the first and second belt members thereof connected to the free ends of the first and second belt members of the third unit mechanism for Y-axis drive. each said X- and Y- axis drive system further comprising a first rotary drive means which engages with either of the first and second belt members of the first unit mechanism to draw the same, and a second rotary drive means which engages with at least one of the first and second belt members of the second and third unit mechanisms to draw the same.

3. An embroidering machine carrying a plurality of machine bodies and essentially constituted by a plurality of X- and Y-axis drive systems each composed of a first unit mechanism for X-axis directional drive, and second and third unit mechanisms for Y-axis directional drive, each unit mechanisms comprising: first and second stationary shafts arranged in spaced relation to each other, each having one or more pulleys arranged one above another and each provided with a plurality of guide grooves; a slider means mainly composed of a movable shaft arranged between said first and second stationary shafts, said movable shaft having a plurality of pulleys which are disposed one above another and are each provided with a plurality of guide grooves; and first and second belt members each having its one end secured to a stationary fastening means, said belt members being in engagement with the pulleys of said first and second stationary shafts and the pulleys of the movable shaft in a fashion trained around the guide grooves thereof, so that each pulley of the movable shaft is in engagement with both the belt members, the slider means thus being adapted to move towards the first or second stationary shafts by the traction of the belts, the first unit mechanism having the free ends of the first and second belt members thereof connected to each other, the second unit mechanism having the free ends of the first and second belt members thereof connected to the free ends of the first and second belt members of the third unit mechanism, each said X- and Y- axis drive system including a first rotary drive means which engages with either of the first and second belt members of the first unit mechanism to draw the same, and a second rotary drive means which engages with at least one of the first and second belt members of the second and third unit mechanism to draw the same; said embroidering machine further including: a base plate carrying said machine bodies and on which the unit mechanisms for X- and Y- axis drive are mounted; a plurality of moving plates each having X- and Y- axis guide rails arranged in engagement with the movable shafts of the unit mechanisms for X- and Y- axis drive in a fashion that each said moving plate is movable in X-, Y- axis and oblique directions in accordance with the movement of the movable shafts; and a plurality of frames each supporting cloth to be embroidered on by one of said machine bodies.

4. An embroidering machine adapted for industrial use, carrying a plurality of machine bodies and essentially constituted by a plurality of X- and Y-axis directional drive system each comprising a first unit mechanism for X-axis directional drive, second and third unit mechanisms for Y-axis directional drive, each unit mechanism comprising: first and second stationary shafts arranged in spaced relation to each other, each having one or more pulleys arranged one above another and each provided with a plurality of guide grooves; a slider means mainly composed of a movable shaft arranged between said first and second stationary shafts, said movable shaft having a plurality of pulleys which are disposed one above another and are each provided with a plurality of guide grooves; and first and second belt members each having its one end secured to a stationary fastening means, said belt members being in engagement with the pulleys of said first and second stationary shafts and the pulleys of the movable shaft in a fashion trained around the guide grooves thereof, so that each pulleyoof the movable shaft is in engagement with both the belt members, the slider means thus being adapted to move towards the first or second stationary shafts by the traction of the belt members, the first unit mechanism having the free ends of the first and second belt members thereof connected to each other, the second unit mechanism having the free ends of the first and second belt members connected to the first and second belt members of the third unit mechanism, each said X- and Y-axis drive system further comprising first and second rotary drive means each composed of: a driving wheel; first and second driven wheels; an endless loop of transmission belt trained around said driving wheel and first and second driven wheels in a fashion that said driven wheels are rotated in opposite directions to each other; first and second rotary pulleys mounted, respectively, on said first and second driven wheels; first and second clutch means engaged, respectively, with said first and second driven pulleys, and first and second rotary wheels, said clutch means being actuated to allow the rotary pulleys to be rotated in either directions, said first rotary means being in engagement with the first unit mechanism in a fashion that said mutually connected free ends of the first and second belt members of the first unit mechanism are trained around said rotary pulleys of the first rotary means, said second rotary means being in engagement with the second and third unit mechanisms in a fashion that the first and second belt members of the second and third unit mechanisms mutually connected to each other at the free ends thereof are trained around said rotary pulleys of the second rotary means, said embroidering machine further including: a base plate carrying said machine bodies and on which the unit mechanisms for X- and Y-axis directional drive are mounted; a plurality of moving plates each having X- and Y-axis guide rails arranged in engagement with the movable shafts of the unit mechanisms for X- and Y-axis directional drive in a fashion that each said moving plate is movable in X-, Y-axis and oblique directions in accordance with the movement of the movable shafts; and a plurality of cloth frames each supporting cloth to be embroidered on by one of said machine bodies.

5. A cloth supporting frame for use with an embroidering machine according to any of the preceding claims, comprising: a frame body having opposite side edge portions inwardly folded into channel shapes, and opposite end portions inwardly folded into erect portions and sloped portions extending from the erect portions; and a number of fastening pins closely planted over said base members thereby allowing embroidering cloth to be stretched over the frame from said sloped edge portions to the underside of the frame body with an end of the cloth caught by said fastening pins.