US3749224A

US3749224A - Handrail drive arrangement for escalators and human conveyor bands

Info

Publication number: US3749224A
Application number: US00226120A
Authority: US
Inventors: K Engeler
Original assignee: Inventio AG
Current assignee: Inventio AG
Priority date: 1971-02-24
Filing date: 1972-02-14
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31
Also published as: GB1354255A; AT315736B; DE2208694A1; CH517044A; FR2126203A1; FR2126203B1; IT947836B; SE371415B; DE2208694C2

Abstract

A handrail drive arrangement for personnel transport means, especially escalators and human conveyor bands or belts wherein power transmission is carried out by means of an entrainment mechanism which engages with a toothed arrangement located at the underside of a flexible handrail. According to the invention the entrainment mechanism positively couples the advancing run and the return run of the handrail with one another and simultaneously transmits the driving force or motive power to the advancing run and the return run.

Description

mite States Patent 1 Engeier [451 July 31,1973

Inventor:

Karl Engeier, Schlieren, Switzerland lnventio Aktiengesellschaft, i-iergiswil N.W., Switzerland Filed: Feb. 14, 1972 Appl. No.: 226,120

Assignee:

Foreign Application Priority Data Feb. 24, 1971 Switzerland 2699/71 US. Cl 198/16, 198/203, 198/208 Int. Cl 1166b 9/12 Field of Search 198/16, 203, 208

[56] Reierences Cited UNITED STATES PATENTS 2,885,057 5/1959 Hansen 198/16 Primary ExaminerRichard E. Aegerter Assistant Examiner-Joseph E. Valenza Attorney-Werner W. Kleeman [57] ABSTRACT A handrail drive arrangement for personnel transport means, especially escalators and human conveyor bands or belts wherein power transmission is carried out by means of an entrainment mechanism which engages with a toothed arrangement located at the underside of a flexible handrail. According to the invention the entrainment mechanism positively couples the advancing run and the return run of the handrail with one another and simultaneously transmits the driving force or motive power to the advancing run and the return run.

4 Claims, 4 Drawing Figures 1a a e PATENIEU JUL3 1 I975 same 0F 5 1 HANDRAIL DRIVE ARRANGEMENT FOR ESCALATORS AND HUMAN CONVEYOR BANDS BACKGROUND OF THE INVENTION The present invention broadly relates to the field of transport mechanisms and, in particular, concerns a new and improved handrail driv-e arrangement for escalators and human conveyor bands or the like, wherein the transmission of force or power is undertaken by an entrainment mechanism which engages with a toothed arrangement located at the underside of a flexible handrail.

The purpose of such type drive systems is to drive the handrail arranged to both sides of and along the conveying path at the balustrades with the speed and direction of movement of the conveyor means. It is extremely important that the handrail revolves absolutely synchronously with the escalator stair-type belt or the human conveyor band, as the case may be, so as to afford positive support for the traveller during the personnel conveying operation.

The state-of-the-art handrail drive arrangements transmit the drive force or motive power either in a force-locking manner or a positiveor formlocking manner. Belonging to the first classification are those drive systems which transmit the drive force by friction. With such type drives the handrail is trained about the deflection locations at the balustrade and, in the event that the drive action does not take place at a deflection location, then such handrail is trained or wrapped about a drive gear or wheel housed at the base or pedestal of the escalator. With this arrangement the wrapping angle of the handrail about the drive gear or wheel must be as large as possible in order to attain really good power transmission. However, the resultant bending loads with the simultaneous effect of relatively large tension loads, on the one hand produced by virtue of the pre-loading or pre-stress required for friction drives and, on the other hand, by virtue of the load which prevails owing to the bearing forces of the travelling public, result in damage to and premature wear of the handrail.

With friction drives working with counter-pressure rollers there is not present the tension load resulting from preloading. However, there is present a squeezing action which likewise can considerably impair the longevity of the handrail. The most prominent disadvantage of friction drives, however, is predicated upon the fact that owing to aging of the material of the handrail as well as the reduction in the contact pressure and the pre-loading'it is possible for slippage to arise, the handrail then no longer travelling synchronously with the escalator or the like.

Now in the case of the positive or form-locking drive systems there is no longer present loading of the handrail owing to the pre-stress and squeezing action, so that eventually there only still appear the loads resulting from the hearing or support forces of the travelling public. Furthermore, the aforementioned slippage problem is no longer possible with such type drive. In a great many instances the handrail is constructed at its underside in a racklike manner or there are connected to the underside of such handrail link chains, flexible perforated steel bands or other suitable means. Power transmission takes place by means of large gear or sprocket wheels forming entrainment mechanisms located at the'deflection locations of the handrail. Ac-

cordingto a different construction of drive system the handrail provided at its underside with teeth is driven at the return run by one or a number of V-belt pulleys in which there is housed an entrainment mechanism consisting of an endless toothed band. Other variants of this type drive employ for power transmission purposes a plurality of gears at the return run and serving as the entrainment mechanisms, or also in order to obtain a greater length of engagement a toothed band guided over two rollers or a link chain.

These drive systems possess the drawback that the load resulting from the bearing forces of the travelling public completely acts upon the advancing or forward run. Consequently, considerable friction and tension loads are present at the linear sections and the deflection locations of the handrail. Such can lead to premature wear of the handrail as well as the guideand deflection devices.

SUMMARY OF THE INVENTION Therefore, with the above discussion in mind it should be apparent that the technology in this art is still in need of a handrail drive arrangement for conveyor mechanisms of the character described, and particularly for escalators and human conveyor belts or bands, which is not associated with the aforementioned limitations and drawbacks of the state-of-the-art constructions. Hence, a primary ojective of this invention is to provide a handrail drive arrangement for such escalators and human conveyor belts or bands which effectively and reliably fulfills the existing need in the art and is not associated with the aforementioned drawbacks and limitations of the heretofore known constructions.

Yet a further equally important and more specific object of the present invention is to provide a handrail drive arrangement capable of taking-up the loads caused by the bearing forces of the travelling public, especially for large-lift escalators and long human eonveyor bands, so that premature wear at the handrails and the guideand deflection devices respectively is prevented, and thus, operation of the personnel escalator or conveyor band can be carried out more economically.

Another significant object of the present invention relates to a new and improved construction of handrail drive for human transport devices which is relatively simple in construction, economical to manufacture, extremely reliable in operation, not readily subject to breakdown and wear, requires a minimum of maintenance and servicing, and affords positive and reliable synchronous travel of the handrail with the transport device proper.

Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the drive arrangement proposed by this invention provides an entrainment mechanism which positively couples the advancing run and the return run of the handrail with one another and simultaneously transmits the drive force to the advancing run and the return run.

In order to be able to effectively unload the deflection or turning locations of the handrail, it is a further aspect of this development to arrange the entrainment mechanism so as to be displaceable, whereby during standstill of the drive there is rendered possible a simultaneous displacement of the advancing run and return run in the sense of increasing the play between the arcuate-shaped individual components of the handrail and the deflection devices.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a schematic illustration, in side view, of a personnel transport device designed according to the teachings of this invention, and here shown by way of illustration in the form of an escalator;

FIG. 2 is an enlarged elevational view of the inventive handrail drive;

FIG. 3 is a cross-sectional view of the handrail drive depicted in FIG. 2, taken substantially along the line A-A thereof; and

FIG. 4 is a schematic view of the handrail drive depicted in FIG. 2 at the region of a deflecting location of the handrail.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Considering now the drawings more specifically, it is here mentioned that while for purposes of illustrative explanation the inventive handrail drive will be considered in conjunction with an escalator for transporting personnel or humans, it is obviously not to be considered as solely limited to this environment of use since it has applicability for other types of personnel transport devices, such as for instance the previously mentioned personnel conveyor belts or bands. A side schematic view of an escalator structure with which the inventive handrail drive arrangement or system has been employed has been illustrated in FIG. 1.

Now in this Figure reference character 1 designates the pedestal or base of an escalator and at which there is housed a drive 2 of a stepped escalator chain 3. Drive 2 is driven in conventional manner by means of any suitable and therefore not particularly illustrated electric motor. At the lower region of the pedestal 1 of the drive 2 drives a suitable gear arrangement 5 through the agency of a chain 4. A further gear arrangement or transmission 8 is driven via a chain 7 by means of a deflecting gear or wheel 6 located at the upper end of the escalator. At the central region of the escalator the stepped chain 3 drives a gear arrangement 9. The pedestal l carries a balustrade or handrail support 10 about which is trained an elastic flexible endless handrail 11 having at its undcrface the toothed arrangement or gear teeth 11a as shown quite clearly in FIG. 2. Handrail 11 slides upon

guide slide rails

12 and 13 secured to the balustrade 10 and defining guideand deflecting devices or means. A number of drive units 14 housed at the balustrade 10 simultaneously drive the handrail 11 at the advancing or forward moving run 11.1 and the rearward or reverse moving run I 1.2 through the agency of a respective endless doubletooth belt 15, Le, a belt having teeth 15a at both faces as clearly shown in FIG. 2 and defining an entrainment mechanism. As will be explained more fully in conjunction with FIG. 4 the double-toothed belts 15 can be adjusted by tensioning rolls 16 in in such a manner that load-relief or unloading of the handrail 11 at the deflection locations where there is positioned the deflecting means 12 is possible. A chain 17 or equivalent transmits rotational moment from the gear arrangement 5 to the lower drive unit or drive 4 of the handrail 11. On

the other hand the upper drive unit or drive 14 has imparted thereto a rotational moment from the gear arrangement 8 through the agency of a chain 18, whereas the drive unit or drive 14 arranged at the central region of the escalator is driven by the gear arrangement 9 through the agency of the chain 19.

Referring now to FIG. 2 there is illustrated therein, on an enlarged scale, details of a drive unit 14 of the inventive handrail drive arrangement as same is employed in conjunction with the escalator structure of FIG. 1. Thus it will be recognized a drive gear 21 and deflecting gear 22 are rotatably mounted upon a base plate 20 of the drive unit 14. The double-toothed belt 15, defining the entrainment mechanism, is in meshing engagement by means of its tooth or toothed arrangement 15a, on the one hand with the handrail l1, and on the other hand, with the deflection gears or wheels 22 and the drive gear 21. A sprocket wheel or gear 23 is fixedly connected with the drive gear 21. By means of the chain 18 there is delivered to the associated drive unit 14 the rotational moment required for driving the handrail 11.

Reference numerals

12 and 13 again designate the guide slide rails for the handrail 11 and defining the guide and deflecting devices. Supports 24 are secured to the base plate 20 and at which there are threadably connected by means of the nut members 26 one end of the bifurcated threaded bolts 25. At the fork-shaped or bifurcated end of each bifurcated bolt 25 there are rotatably mounted the tensioning rolls 16. Upon loosening the nut members 26 the bifurcated bolts 25 together with the tensioning or tension rolls 16 can be shifted. Owing to this arrangement the possibility exists of accommodating the toothed arrangement 15a of the double-toothed belt 15 to the toothed arrangement 11a of the handrail 11 at the advancing run 11.1 and the return run 11.2 and to tension appropriately the double-toothed belt 15 of each drive unit 14. Additionally, it is possible to improve the load conditions prevailing at the deflection or turning locations formed by the rails 12 of the handrail 11 by displacing the double-toothed belt 15 by means of the tension rolls 16. In this connection attention is invited to FIG. 4.

Now in FIG. 3 reference numeral 21 again designates the drive gear rigidly connected with the sprocket gear 23 and which is rotatably mounted upon the base plate 20 of the drive unit 14 and receives its driving rotational moment through the agency of the chain 18. Supports 27 which are connected to the base plate 20 carry the guide slide rails 13 for the handrail 11. The guide slide rails 12 are secured in any suitable aNd therefore not particularly illustrated fashion to the balustrade 10 of the escalator. The guide slide rails 13, located between the deflecting gears or sprocket wheels 22 for instance at the upper region of the drive unit 14 of FIG. 2 and also between the deflecting gear 23 and the drive gear 21 at the lower region of such drive unit, insure that the double-toothed belt 15, while taking into account a minimum play 28, remains in meshing engagement with the teeth 11a of the handrail ll. Ribs 13.1 for guiding the handrail 11 are arranged at the guide slide rails 13. For the same purpose the guide slide rails 12 are likewise provided with ribs 12.1 or equivalent structure. The double-toothed belt 15 is provided with steel inserts or reinforcements 15.1 which insure that it is practically free of elongation of stretching.

Now in conjunction with the illustration of FIG. 4 there will be explained the manner in which it is possible by displacing the entrainment mechanism to improve the load conditions at the deflection or turning locations of the handrail 11. If during standstill of a drive unit 14 the tension rolls l6 and therewith the double-toothed belt defining the entrainment mechanism are displaced in the direction of the arrows A, then, the advancing or forward run 11.1 and the return run 11.2 of the handrail 11 are simultaneously transported opposite to such arrow direction, i.e., in the direction of the arrows B. Since the double-toothed belt 15 as a practical matter does not elongate, as explained above, this shifting or displacement is transferred practically without any loss. Hence at the relevant deflection location there is present a play 29 between the substantially arcuate-shaped portions of the handrail 11 and the associated guide slide rail 12. Due to adjustment of this play 29 there prevails at such deflection location a considerable reduction in the friction between the handrail 11 and such guide slide rail 12. Additionally, the tensional load at this section of the handrail 11 is considerably reduced.

The advantages realized with the-practice of the inventive concepts reside in the features that owing to the positive or form-locking connection between the forward or advancing run 11.1 and the return run 11.2 of the handrail 11, brought about by the double-toothed belt 15 there is rendered possible displacement of the handrail 1 1 such that play can be adjusted at the deflection locations. In this manner the friction between the handrail 1 1 and the guide slide rails 12 can be appreciably reduced at the deflection locations and the tensional stress or load at such sections of the handrail is considerably reduced. An increase in the bearing or load-applying forces of the travelling public or users of the personnel conveying system cannot impair the thus obtained favorable wear conditions since, owing to the positive or form-locking connection of the forward handrail run and return handrail run by means of the double-toothed belt 15 which is free of elongation, it is practically impossible to cause any change in this play. The simultaneous drive of the advancing run and the return run produces a low specific surface pressure at the force or power transmission locations so that also in this regard the handrail is effectively protected. A further advantage of the invention resides in the fact that especially in the case of large lift escalators and long personnel conveyor bands or belts the loads caused by the bearing forces of the travellers are takenup by the inventive drive arrangement and distributed in such a manner that at the used section of the handrail there likewise can only arise minimum frictionand tension loads. Hence with the arrangement of handrail drives depicted in FIG. 3 the bearing forces arising along the used portions of the length of the handrail are distributed to the three drive units proposed in this exemplary embodiment. These drive units are preferably arranged at the upper end, the lower end and at the central region of the linear portion of the escalator.

It is within the contemplation of this invention, and depending upon the lift of the escalator or the length of the personnel conveyor band, to employ one or a number of drive units. The desired load conditions of all of the important components of the handrail can be likewise decisive for the selection of the number of drive units. instead of using the tension rolls for adjusting the play at the deflection locations it would be also possible to displaceably arrange the entire drive.- Furthermore, it is possible, instead of employing a drive with an endless double-toothed belt for driving the handrail, to use a displaceably mounted gear which is dimensioned such that it likewise can simultaneously drive the advancing run and the return run of the handrail.

Furthermore, for the purpose of adjusting the engagement of the teeth, at least one of the deflecting gears 22 can be mounted to be displaceable in the direction of the band. Within certain limits it would also be possible to adjust the play at the deflection locations of the handrail 11, even when omitting the tensioning rolls 16, by employing at least two displaceably mounted deflecting gears 22. While for clarity in illustration there has only been considered the handrail at one lengthwise extending edge of the transport device, it should be obvious that normally a similar handrail arrangement of the same construction as disclosed herein would then be provided at the other lengthwise extending side of such transport device.

While there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly,

What is claimed is:

l. A handrail drive arrangement for personnel transport devices, especially escalators and conveyor bands, comprising a flexible handrail provided at its underside with a tooth arrangement, drive means for said handrail, said handrail during its travel defining an advancing run and a return run, said drive means including a toothed belt simultaneously engaging with the toothed arrangement at the underside of both the advancing run and the return run of the flexible handrail, said toothed belt positively interconnecting the advancing run and the return run of the handrail and simultaneously transmitting the drive force to the advancing run and return run, means for displacing said toothed belt, said displacing means comprising support means, a pair of tensioning rolls, a pair of bifurcated means, nut members for displaceably mounting said pair of bifurcated means together with said tensioning rolls at said support means, each of said bifurcated means rotatably mounting one of the pair of tensioning rolls, each tensioning roll being arranged at a part of the toothed belt which extends between the advancing run and the return run of the handrail, said pair of bifurcated means in conjunction with said pair of tensioning rolls simultaneously displacing the toothed belt and the advancing run and return run of the handrail and in the same direction.

2. The handrail drive arrangement as defined in claim 1, wherein the toothed belt comprises an endless, essentially non-elongatable double-toothed belt containing-steel reinforcement means.

3. The handrail drive arrangement as defined in claim 1, wherein said drive means embodies a number of individual drive units which are substantially uniformly arranged over the length of the personnel transport device.

being a drive gear for driving the toothed belt, and guide slide rail means arranged between the deflecting gears at the advancing run and between the deflecting gear and the drive gear at the return run for maintaining in meashing engagement the teeth of the doubletoothed belt with the tooth arrangement of the handrail.

Claims

1. A handrail drive arrangement for personnel transport devices, especially escalators and conveyor bands, comprising a flexible handrail provided at its underside with a tooth arrangement, drive means for said handrail, said handrail during its travel defining an advancing run And a return run, said drive means including a toothed belt simultaneously engaging with the toothed arrangement at the underside of both the advancing run and the return run of the flexible handrail, said toothed belt positively interconnecting the advancing run and the return run of the handrail and simultaneously transmitting the drive force to the advancing run and return run, means for displacing said toothed belt, said displacing means comprising support means, a pair of tensioning rolls, a pair of bifurcated means, nut members for displaceably mounting said pair of bifurcated means together with said tensioning rolls at said support means, each of said bifurcated means rotatably mounting one of the pair of tensioning rolls, each tensioning roll being arranged at a part of the toothed belt which extends between the advancing run and the return run of the handrail, said pair of bifurcated means in conjunction with said pair of tensioning rolls simultaneously displacing the toothed belt and the advancing run and return run of the handrail and in the same direction.

2. The handrail drive arrangement as defined in claim 1, wherein the toothed belt comprises an endless, essentially non-elongatable double-toothed belt containing steel reinforcement means.

4. The handrail drive arrangement as defined in claim 1, wherein said toothed belt is a double-toothed belt, a base plate supporting said pair of tension rolls, at least four further rolls supported by said base plate, two of said further rolls being arranged at the adancing run of the handrail and defining deflecting gears, another two of said further rolls being arranged at the region of the return run of the handrail, one of said two further rolls being a drive gear for driving the toothed belt, and guide slide rail means arranged between the deflecting gears at the advancing run and between the deflecting gear and the drive gear at the return run for maintaining in meshing engagement the teeth of the double-toothed belt with the tooth arrangement of the handrail.