US3688889A

US3688889A - Driven handrail system

Info

Publication number: US3688889A
Application number: US63672A
Authority: US
Inventors: Ernst Koch; Hans Bachmann
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-08-14
Filing date: 1970-08-14
Publication date: 1972-09-05
Anticipated expiration: 1989-09-05

Abstract

A movable handrail comprising interfitting links secured so as to prevent undesirable lateral movement but to ensure longitudinal expansion without undue checking of the handrail and having depending teeth and guide channels. The handrail is driven by toothed gears along a guiding frame so as to travel with reduced friction, noise, maintenance, and power consumption.

Description

United States Patent Koch et al. Sept. 5, 1972 [54] DRIVEN HANDRAIL SYSTEM 1,101,209 6/1914 Pitt ..I98/ 16 Inventors: Ernst Kmh Unterbrunnen Champney f q Bachmflnn, FOREIGN PATENTS OR APPLICATIONS gItabrIng 5, Zug, both of SwItzerland 391,440 4/1933 Great Bntam ..198/16 [22] Filed: 1970 Primary Examiner-Richard E. Aegerter [21] Appl. No.: 63,672 Att0rneyPlumley and Tyner Related us. Application Data 57 ABSTRACT [63] Continuation-impart of Ser. No. 788,233, Dec. A movable handrail comprising interfitting links 31, 1968, abandoned. secured so as to prevent undesirable lateral movement but to ensure longitudinal expansion without undue [52] US. Cl ..l98/16, 198/195 checking of the handrail and having depending teeth [51] Int. Cl. ..B66b 9/12 and guide channels. The handrail is driven By toothed [58] Field of Search ..198/16-18, 193, gears along a guiding frame so as to travel with 198/ 137, 184, 195, 189; 74/235-238 reduced friction, noise, maintenance, and power consumption. f C'ted [56] Re erences I I 25 C 2 UNITED STATES PATENTS 853,129 5/1907 Simpson ..l98/ 195 PATENTEDSEP 5 I972 SHEET 6 [IF 9 DRIVEN HANDRAIL SYSTEM This application is a continuation-in-part of our prior copending case Serial No. 788,233, filed Dec. 31, 1968, now abandoned.

This invention broadly relates to a handrail for moving stairways especially escalators. More particularly, the invention relates to use of such a handrail which comprises interlinked sections secured together in an improved manner and having interengaging driving and guiding members for the handrail assembly.

Endless conveyors employing belts or link chains have been used in manufacturing, assembling, and packaging lines for many years. The known chains, which include belts such as V-belts, generally do not directly carry articles but merely drive a member which carries the articles. Even those chains which may directly carry articles and those used as handrails have been subject to many disadvantages.

A primary disadvantage of previously used handrails which are driven by either frictional engagement or by toothed gears which mesh with the rail is the tendency of the chain to wear due to the friction generated between links and between the chain and the driving member. This wear can produce slippage as well as fatigue and breakage. Slippage will cause the handrail to be out of synchronization with the stairs and stretching requires compensating tensioning means or periodic refitting. Additionally, handrails which are used in environments subject to temperature, humidity, and pressure changes, particularly those used outdoors, are subject to the danger of freezing or icing resulting in stoppage of the conveyor system or in slippage when moisture, etc., accumulates between the rail and the driving member.

The disadvantages of slippage and wear were overcome in part by use of flexible endless handrails which generally are one-piece rubber members (see e.g. Flohr, German Pat. No. 577,801 and Pitt, US. Pat. No. 1,101,209).

However, these systems tend to exhibit fatigue resulting in stretching and/or breaking. Thus elaborate ten sioning devices were used to compensate for stretching. A stretched or broken rail, however, will ultimately require that individual sections must be removed. When this is done, the resulting rail no longer meshes exactly with the gear teeth in such systems and this means of connection can only be used sparingly. Breakage and stretching generally involve considerable down time for repairs and thereby considerably increasing the cost of production.

Still another disadvantage of the previously used devices is found in the relatively high noise level encountered during operation. The high noise level renders conveyors unfit'for use in certain installations, for example in hospitals.

Also, to give a satisfactory performance, it was necessary to use large driving members which increased the danger of slippage and misalignment. Thus, it is clear that previously used movable handrails have not been satisfactory. While other conveyor systems which use endless belt-type conveyors were known in other arts, the problems unique to handrails have not been solved, since in addition to having an operable system, a handrail used by humans must meet much more stringent requirements of reduced noise, reduced slippage, reduced interplay of parts, etc., in order to enable humans to use it with a feeling of safety.

In view of the recognized disadvantages of prior movable handrails, it is a primary object of the present invention to create a driven handrail which comprises several interconnected links which will show practically no wear or breakdown tendencies, will require no adjustment for stretching, and which will run at a considerably reduced noise level.

Another object is to provide the subject handrail comprising interconnected links which present teeth and longitudinal grooves adapted to be engaged respectively by driving gears and frames.

Another object is to provide a handrail wherein handrail wherein handrail links are removably, but securely engaged by means allowing the rail to be driven over curves of varying radii.

Still another object is to provide the subject handrail wherein the links are arranged so as to protect the driving mechanism from the environment and to insulate the noise generated in the driving mechanism.

A further object is to provide a chain conveyor system wherein the links are connected in such a way as to inspire confidence in its safety by reducing lateral and longitudinal displacement while allowing expansion in a longitudinal direction to compensate for environmental changes.

The above-noted defects are avoided and the objects are achieved in accordance with the present invention by the provision of a driven handrail system utilizing a support frame containing toothed driving gears and an improved sectionalized chain comprising interfitted links wherein each link is adapted to engage adjacent links and wherein a plurality of teeth on each link frictionally engage driving gears and longitudinal grooves on each link slidably engage a frame. Preferred embodiment of the invention relate to special means for connecting individual links and for securing slidable engagement with the frame.

By way of general summary of the invention, the

characteristic feature is to provide a handrail which is formed of interfitted U-shaped links withv depending teeth adapted to be driven by a gear and to be guided in its movement by engagement with lips on a supporting frame. Specific improvements are achieved by interfitting the link by a tongue and groove connection which reduces noise due to clattering together of the elements and which reduces the relative movement between links to present a stable and smoothly operating system. The linkage also provides for only limited longitudinal movement between links to compensate for swelling or contraction due to weather conditions and any pinching of elements experienced when the units are bent at the ends of the handrail track.

A specific means to provide secure interengagement with controlled expansion and contraction is a flexible, preferably natural or synthetic rubber of Shore l-lardness about 60, insert between the tongue and groove connections. Additional stability can be achieved by secondary hooks and grooves to interconnect links besides the tongue and groove primary connections.

Further objects and advantages of the invention become evident from consideration of the description of preferred embodiments which are illustratively shown in the attached drawings. In the drawings, like numerals represent like elements and FIG. 1 is a perspective view, partly in section, of an embodiment of the handrail of this invention showing FIGS. 11-12 the slidable engagement of the support frame and the linked handrail elements.

FIGS. 2-4 are perspective views partly in section of other embodiments of engagement according to this invention.

FIG. 5 is a transverse sectional view showing an embodiment of engagement of elements according to this invention.

FIGS. 6-8 are longitudinal sectional views showing embodiments of interfitting the handrail sections, FIG. 6 representing a sectional view of the embodiment of FIG. 5 taken along lines I-I.

FIGS. 9-10 are longitudinal sectional views showing embodiments of interfitting the handrail sections.

FIGS. ll, 12, 13 and 14 are respectively a front, rear, top and bottom view of a single handrail section.

- FIGS. 15 and 16 are sectional views of the handrail section of FIG. 1 1, taken respectively along lines X-X and XI-XI thereof.

FIGS. 17-18 are details of the handrail section of representing the circled portions thereof.

FIG. 19 is a sectional view of an insert adapted to be used in joining adjacent handrail sections and is also illustrated in FIG. 6.

FIGS. 20-22 are respectively a top, front and sectional view of another embodiment of handrail section, FIG. 22 representing section III-III of FIG. 20.

FIGS. 23-25 are respectively a top, front and sectional view of still another embodiment of handrail section. FIG.'15 representing section VII-VII of FIG. 13.

Referring more particularly to FIG. 1, there is illustrated a handrail comprising several interconnected links 1, which are securely fixed in relation to each other due to a linkage to be more fully described below. The links 1 comprising the rail are driven by two gears 11 having peripheral gear teeth. Gear 11 is housed in frame and extends through a slot 44 to engage teeth 5 of the rail. It is further seen that longitudinal grooves 6 in links 1 slidably engage out-turned lips of frame 10. Gear 11 is mounted on a shaft, which is attached by suitable means to a conventional driving mechanism (not shown). A worm gear can also be used to drive the rail in which case the gear 11 is replaced by such mechanism.

Link 1 is shown as a generally U-shaped member; however, it can take any desired geometrical shape including embodiments described below wherein no legs 3 are provided or wherein different shapes for legs 3 are provided.

According to a preferred embodiment of the invention, each link 1 has a base 2 and legs 3 that are bent downward to provide the U-shaped cross-section. Legs 3 extend over gear 11 and frame 10, thus making this embodiment particularly useful in handrails on escalators adapted for use outside or in dirty atmospheres wherein the driving gear 11 and frame 10 are to be protected or covered. It will be apparent that covering the driving mechanism reduces noise, reduces the likelihood of freezing or clogging of the gears, and considerably reduces the danger to adjacent objects and personnel. I

At approximately the middle of each link 1 on the inside of base 2, there is provided a flange 4 running parallel to the legs 3. The flange 4 is integrally formed with the base 2 and contains intergral teeth 5. The link 1 can be formed of any metal or non-metal; preferred non-metals are synthetic plastics such as polyamides, acetal resins, ABS plastics, polyethylenes, or the like which should be of relatively high density. The method of forming can be conventional technique used with metals or non-metals: for example, casting, stamping, milling, molding, etc. While the link 1 is preferably manufactured as an integral one-piece unit, it may be desirable in some cases to have link members of different materials or of different colors; thus, separate pieces can be separately formed and then integrally united. For example, the body of the link comprising base 2 and legs 3 may be made of metal, while the teeth may be formed of plastic and bonded by any conventional technique. The tooth configuration can vary from the V-shaped embodiment shown to rectangular, square, or any other configuration and the pitch diameter of the teeth can vary. The determining factor in these instances is the structure of the gear teeth and gear 11. The two should, of course, be mated and the present invention is not limited by the particular configuration. The link 1 can also be modified to carry directional symbols or other printed or embossed symbols. By virtue of the uniting means on link 1, the rail presents a smooth continuous surface.

As further shown in FIG. I, projections 12 can be formed in this embodiment at the juncture of legs 3 and base 2 to define longitudinal grooves 6 adapted to slidably engage lips 15 on sides 19 of frame 10. This insures the precise guidance of the chain and provides additional support. It is possible to dispose teeth 5 sidewise on flange 4 or on legs 3 to engage suitably oriented gear teeth. Also it is possible to vary the positioning of groove 6 depending on the shape of the supporting frame. For example, in FIGS. 2 and 3, groove 6 is on flange 4 and mates with inturned lips (17 and 20-21) of the respective frames and in FIGS. 4 and 5 the groove 6 is seen to be positioned lower on leg 3 than shown in FIG. 1. In FIG. 2 the frame is 18, in FIG. 3 it is 46 and in FIG. 5 it is 50. Also, FIG. 5 shows a special frame or balustrade for handrails wherein guide 19 supports engaging guide member 52 and has spacers 51 to ensure positioning of the link 1 thereon. All of these frames are not critical to the invention so long as some means is provided to engage the grooves 6 and teeth 5 of the assembled handrail.

Referring to the link structure itself, the terminals of link 1 are seen to have interengaging devices which generally comprise tongue and groove connection consisting of a projection 7, a transverse flange 8 which defines a groove for receiving tongue 13 on flange 9 formed on the adjacent link. These flanges interengage so as to prevent pivoting about the axis perpendicular to the longitudinal axis of flange 4. The grooved flange 8 and tongued flange 13 can frictionally engage by snapping together to allow secure connection of the links or as described below an insert can be used to ensure the engagement.

The transverse groove flange 8 can extend over the same width as projection 7 or over any other width. Added stability is achieved by other interengaging devices in some embodiments. For example as shown in FIg. 4-5 hooks 47 may be provided on flange 8 to engage grooves 48 on flanges 76 at a position which does not interfere with the slidable engagement of grooves 6 and the frame 52. Also some advantages are achieved by providing lips 22 (FIG. 4) on the links which will cover the bottom of the link connection and give a more integral closed rail system. In addition to or instead of the described connection means, the coupling of links can be achieved through conventional techniques such as the use of pins engaging suitable holes in adjacent links.

The linkage is more specifically shown in FIGS. 6-10. In FIGS. 6-8 inserts are used to secure the tongue-groove connection whereas in FIGS. 9-10, frictional engagement without inserts is relied on. As seen in FIG. 6, the insert can be a U-shaped device 45 (illustrated in FIG. 19) and as seen in FIGS. 7-8, the insert can be a cord-

like round device

36 or 40.

The simplest attachment is shown in FIGS. 9-10 wherein tongue 13 on flange 9 frictionally engages groove 8 on flange 7 of the next adjacent link 1. It should be noted that the tongue and groove connection is provided relatively high on the link cross-section, i.e. adjacent the top of link base 2. Since it has been found that this type linkage and its positioning allows too much relative movement between links in some uses, particularly at the corners or turning points of the handrail, other systems of connection have been devised.

Referring to FIG. 6, the end of the links 1 in this embodiment also have flange 7 in which a transverse groove 8 runs across the direction of travel. The opposite end of each link 1 has a connecting flange 9 with tongue 13 adapted to engage groove 8 of an adjacent link. However, insert 45 lines groove 8. Also, the positioning of the connection is relatively low in the crosssection of the link, so it is more adjacent teeth 5 than base 2. Furthermore, it should be noted that the edge of

flanges

7 and 9 overlap and rest on each other to close the connection and give a more secure connection. These overlapping edges are beveled, preferably at about a 30 angle, so it is not possible to pinch ones fingers in the joint and a smooth surface is presented that is easily grasped by a user. The embodiments of FIGS. 7-8 differ in this regard from FIG. 6 in that inserts 36 and 40 are held in

secondary grooves

35 and 41 provided along each side of groove 8 to receive the round cord-like inserts and retain them. The interfitting of flange 22 and groove 26 described above is also illustrated herein.

By assembling the links 1 as described, an endless toothed handrail or a finite length rail may be provided wherein the interaction of tongue 13 on flange 9 with groove 8 on flange 7 insures locking connection between the links. Each of the linking embodiments of the Figure exhibits advantages in different systems.

It will be apparent from consideration of the above description that service and maintenance of the rack chain according to the invention is generally unnecessary when proper materials and design have been achieved. The handrail which is driven by gears 11 through frictional engagement of teeth 5 and the gear teeth can reduce friction when teeth 5 are of synthetic materials. Legs 3 further provide protection from weather and avoid rust entirely when synthetic materials are used. Similarly, icing and freezing are avoided. Additionally, the noise level is remarkably reduced by use of synthetic links 1 and, a lower driving power is required to operate the conveyor due to the lower friction between the links, between the teeth 5 and the gear teeth and between links and guide lugs. Any conventional driving system and motor can be used with the present handrail and by suitably forming teeth 5, the handrail can be easily adapted for use with existing frames and gears. Even if replacement of a link is necessary the structure shown herein allows rapid repair by unsnapping the broken link.

Some specific links to be used according to the invention are illustrated in more detail in FIGS. 11-18 and 20-25. FIGS. 11-18 represent one preferred link which has been illustrated generally in FIGS. 5-6 and FIG. 19 is an insert adapted for use in this embodiment. FIGS. 15-16 are cross-sections of FIG. 11 and show the details adapted for interconnection with adjacent links. The additional connections provided by hooks 47 and grooves 48 are also illustrated as are the overlapping flange edges 9 at the top of the section and 22-26 at the bottom. In this unit, instead of using a connecting

means

8 and 13 which extends continuously along the edge of the link, two sections only are provided which mate as described before. In this regard numeral 76 represents the extension on flange 7 which actually provides groove 8 and numeral 54 represents the extension on flange 9 from which tongues 13 depend.

As shown with special clarity in FIGS. 1l-12, the individual links 1 have on the underside of base 2, on both sides of teeth 5, tongues 13 which close over flush with the resilient abutting end 76 of flange 7 which is lined in grooves 8 with a soft elastic insert 45. The inserts 45 shown in FIG. 19 are of such dimensions that when the members are assembled they are held by compression in grooves 8. It is seen that the inserts present a U-shaped cross section with

limbs

28 and 29 of unequal length, which in cross section present the form of a symmetrical truncated pyramid. The zones of thickest measurement are at different levels because of this disposition. Strip 30 which connects the two

limbs

28 and 29 has a thickness about equal to that of the limbs at their thickest part.

On the opposed ends of each tongue 13 there is a resilient clamping hook 47 which is shown on an enlarged scale in FIG. 18. This clamping hook, when the members are assembled, hooks into a recess 48 which is provided on the side surface of each coupling piece 76 to cooperate with the hook. Clamping hooks 47 are so arranged that a shifting crosswise to the direction of circulation of the members is prevented. The clamping hooks are so long that a compression of strip 30 of insert 45 is necessary for engagement of the hook in groove 48, whereby the inserts in the assembled state are compressed on all sides. To facilitate assembly of the links, the edges of coupling pieces 76 which are turned toward tongues 13 are rounded or tapered on the side that cooperates with clamping hooks 47, as shown in FIG. 17 which shows a section through a coupling piece 76 on an enlarged scale. The outside 49 of clamping hook 47 which slides along the slanted surface 31 of the coupling piece 76 in the course of assembly of the members, is also slanted for facilitation of assembly.

The assembled links are held together by elastic stressing by virtue of tongues 13 engaging coupling pieces 76 and by virtue of clamping hooks 47 engaging grooves 48. Additional stability occurs by reason of overlapping

edges

9 and 7 and 22 and 26 and by engagement of frame members such as 10 in the longitudinal grooves 6.

Referring to FIGS. -22 another embodiment of unit 1 is shown. This unit corresponds to FIGS. 11-18 except that in each groove 8 there are secondary grooves 35 parallel to teeth 5 in opposite walls of coupling piece 76, in 35 in soft elastic insert 36 made of round cord is positioned.

When assembled, these inserts 36 are under compression to hold the sides of tongues 13 and thereby prevent a rattling of the members, but because of their additional compressibility, they allow an expansion caused by pressure differences. Grooves. 35 have a width which corresponds to the diameter of inserts 36, or they can be somewhat smaller than this diameter. Inserts 36, after being introduced into grooves 35, will not fall out before the individual members have been assembled. The length of inserts 36 is less than the length of the groove 35, so that there is sufficient space for expansion of an insert in the longitudinal direction when the insert is pinched by longitudinal stress of the handrail.

In the embodiment shown in FIGS. 23-25, there are two rows of teeth 5 near the outer edges on the underside of base 2. In this embodiment only one coupling piece 38 is provided in the middle of the member. Coupling piece 38 extends beyond the link 1 and cooperates with a single tongue 39 of the next member, which is disposed at the end of the respective member that is opposite the coupling piece, and that in the assembled state engages in a groove 38a of the coupling piece.

In groove 38a there are grooves 40 on the opposite walls, which serve to receive soft elastic inserts 41 in the form of round cords which are distinguished from those of FIG. 20 only in length. In the assembled state, two inserts 41 are applied with compression to each piece 39.

In this embodiment also clamp hooks 42 are provided which correspond to clamp books 47 except that they are inturned rather than outturned. These elements, in the assembled state of the members, are hooked into secondary grooves 43 at both ends of each coupling piece 38, to prevent mutual shifting of the members. Otherwise the unit is similar in parts and design to the units of FIGS. 20 and 11.

Having described the invention in non-limiting exemplary terms, what is desired to be protected is defined in the appended claims.

What is claimed is:

1. Handrail for escalators and the like comprising individual members with an essentially U-shaped longitudinal cross section, having on their inside a plurality of teeth longitudinally arranged for transmission of propulsive output and longitudinal grooves adapted to receive a guide profile and having on one longitudinal end surface of each member a profiled flange which projects and overlaps the gap at the joint between two interconnected adjacent members and interfitting means adjacent each longitudinal end of each member adapted to interconnect two adjacent members.

2. Handrail according to claim 1, characterized in that the members at their ends overlap each other with an angle joint.

3. Handrail according to claim 1, characterized in that one end of every member has an outside ledge with a recess and the other end has an inside ledge with an attachment.

4. Handrail according to claim 3, characterized in that the recess has been developed as a groove limited on all sides.

5. Handrail according to claim 3, characterized in that the recess is developed as an open groove running obliquely to the revolving direction of the handrail.

6. Handrail according to claim 1, characterized in that the longitudinal grooves are disposed in the lateral parts of the U-shaped members.

7. Handrail according to claim 1, characterized in that the elements consist of plastic material.

8. Handrail according to claim 1, characterized in that on the inside of the member on both sides along the toothing two hook-like coupling elements opened to the outside and protruding beyond the member are disposed on one end and two parallel bridges pointing inward and running parallel to the teeth are disposed at the other end.

9. Handrail according to claim 8, characterized in that each time two toothed bridges are disposed on the inside of each member and a hook-like coupling element protruding beyond the member has been disposed at one end between the toothed bridges and the bridge running parallel to the teeth has been disposed at the other end, which bridge engages in a recess of a coupling element of the following member, and in that grooves for reception each time of one soft elastic insert have been provided in the coupling element at opposite sides of the recess which elements in an assembled state fit against both sides of each bridge.

10. Handrail according to claim 9, characterized in that the softly elastic insert consists of a loop.

11. Handrail according to claim 10, characterized in that the loop is accommodated in a groove of a member.

12. Handrail according to claim 11, characterized in that the width of the grooves is either equal to or somewhat smaller than the loop of the inserts.

13. Handrail according to claim 12, characterized in that the inserts in their assembled state are under tension.

14. Handrail according to claim 8, characterized in that the bridges support the soft elastic inserts.

15. Handrail according to claim 8, characterized in that the ridges covered with inserts and viewed together with them in the direction of revolution have a somewhat larger dimension than the hook-like aperture of the coupling elements.

16. Handrail according to claim 15, characterized in that the inserts have a U-shaped cross section with embossed legs at the outside surfaces.

17. Handrail according to claim 8, characterized in that the legs of the insert are of unequal length.

18. Handrail according to claim 8, characterized in that the legs of the insert always have the form of a symmetrically developed truncated pyramid in cross section, the base surfaces of which are pointed toward each other.

19. Handrail according to claim 1, characterized in that the members are guided by means of a band shaped gliding guide profile.

20. Handrail according to claim 1, characterized in that a bridge is provided which supports the teeth and in that the longitudinal grooves are provided in the bridge.

21. Handrail according to claim 1, characterized in that the means for the connection of the members comprises interfitting means disposed in a plane level with the plane of the root of the gear teeth and which further comprise soft elastic inserts placed between the interfitting means.

22. Handrail according to claim 21, characterized in that the inserts consist of natural rubber, the hardness of which is about 60 Shore.

Claims

22. Handrail according to claim 21, characterized in that the inserts consist of natural rubber, the hardness of which is about 60* Shore.

23. Handrail according to claim 21, characterized in that the inserts consist of plastic.

24. Handrail according to claim 21, characterized in that at least one resilient clamping hook is provided each time at one end of the bridge which hook is attached to the coupling element of the next member in the assembled state of the members.

25. Handrail according to claim 24, characterized in that the coupling elements have a ledge for the clamping hooks running in the direction of revolution of the member at the lateral surfaces cooperating with the clamping hooks.