US 3414109 A
Description (OCR text may contain errors)
Dec. 3, 968 M. A. CLARK 3,414,109
TRANSPORTATION DEVICES HAVING MOVABLE HANDRAILS Filed Dem-2, 1965 5 Sheets-Sheet 1 WITNESSES INVENTOR Mi 61M Myron A. Clark ATTORNEY M. A. CLARK Dec. 3, 1968 v TRANSPORTATION DEVICES HAVING MOVABLE HANDRAILS 5 Sheets-Sheet 2 Filed Dec. 2. 1965 M. A. CLARK 3,414,109
TRANSPORTATION DEVICES HAVING MOVABLE HANDRAILS Dec. 3, 1968 s sheets-sheets Filed Dec. 2, 1965 United States Patent 3,414,109 TRANSPORTATION DEVICES HAVING MOVABLE HANDRAILS Myron A. Clark, West Orange, N.J., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Dec. 2, 1965, Ser. No. 511,165 6 Claims. (Cl. 19818) ABSTRACT OF THE DISCLOSURE The return run of a moving handrail engages a plurality of successive traction rollers, each provided with a pressure roller. A cantilever mounting of rollers provides accessibility.
This invention relates to passenger transporting devices employing handrails and it has particular relation to drives for such handrails.
Handrails are employed in various transportation devices for the purpose of facilitating safe movement of passengers between spaced points or landings. As examples of such transportation devices, reference may be made to power-driven moving walks and moving stairways. In a device of this type a balustrade supports an endless flexiible handrail having an upper load run positioned above a conveyor on which a passenger stands, The handrail and the conveyor are driven in synchronism.
In recent years attempts have been made to develop a satisfactory handrail drive which could be located substantially below the space occupied by the balustrade. Such a location is particularly desirable for balustrades of the transparent type. Prior-art drives or handrails which have been located outside the balustrade have been subject to a number of limitations. Among these limitations reference may be made to damage caused by the drive to the surface or interior of the handrail, to the short life of such drives, to the need in many of these drives to locate parts of the handrail at a level below the level of the conveyor where the handrail and the drive are subjected to debris from the conveyor, and to inaccessability of drive components.
In accordance with the invention a handrail drive is constructed to apply a plurality of driving forces acting on spaced points along the return run of the handrail. In a preferred embodiment of the invention a plurality of spaced pairs of rollers are arranged in a compact array along the return run of the handrail. The handrail passes between the rollers of each pair. One of the rollers in each pair is driven and engages the inner surface of the handrail to operate as a traction roller. The remaining roller of each pair preferably is resiliently biased towards its associated traction roller. A cantilever mounting of components assures accessibility of essential parts.
It is therefore an object of the invention to provide an improved transportation device employing a power-driven handrail.
It is another object of the invention to provide an improved handrail drive wherein a plurality of driving forces are applied at spaced points along a run of the handrail.
It is also an object of the invention to provide an improved handrail drive including a plurality of spaced pairs of rollers, each pair comprising a traction roller and a resiliently-biased pressure roller.
It is a further object of the invention to provide an improved handrail drive wherein the handrail and other com ponents are readily accessible for servicing.
Other objects of the invention will be apparent from ice the following description taken in conjunction with the accompanying drawings, in which:
FIGURE 1 is a schematic view in side elevation of a transportation device embodying the invention;
FIG. 2 is a view in side elevation with parts broken away and parts omitted showing the upper portion of the transportation device shown in FIG. 1;
FIG. 3 is a detail view in eleavtion of a handrail drive unit employed in the embodiment of FIG. 2;
FIG. 4 is a view in top plan of the drive unit of FIG. 3; and
IFIG. 5 is a view in end elevation of the drive unit of F G. 3.
Referring to the drawings, FIG. 1 shows a transportation device employing a conveyor 1 for transporting passengers between a first landing 3 and a second landing 5. The conveyor 1 desirably may be of the endless type conventionally employed in moving Stairways or in moving walks. If the conveyor is employed in a moving walk it may take the form of a belt-type treadway or a pallettype treadway. For present purposes, it will be assumed that the conveyor 1 is employed in a moving stairway. The conveyor 1 has an upper load run .la on which passengers stand while being transported between the landings and a lower return run 1b.
Above the conveyor 1 a balustrade is disposed for guiding a handrail 9. The handrail 9 has an upper run 9a positioned to be grasped by passengers as they are transported along the conveyor 1. The handrail has a lower return run 9b.
The handrail may be of the conventional construction employing a C-shaped cross section as shown in FIG. 5. This cross section has a flat central portion having legs 9d and 9e projecting therefrom. The handrail is constructed of an elastomer such as rubber in which reinforcing materials such as cotton fabric or canvas 9 is embedded. In addition, relatively inextensible members such as steel ribbon or steel wires 9g are also embedded in the elastomer to minimize stretching of the resultant handrail. The handrail generally is constructed as an elongated strip and its ends thereafter are spliced and vulcanized to produce an endless or a closed loop.
The balustrade 7 is assumed to be of the transparent type and the handrail 9 is guided around the balustrade in a conventional manner. Thus, as shown in FIG. 2, a conventional T-shaped guide 11 is located within the cross section of the handrail 9 to serve as a guide means. Because of the increased friction presented to movement of the guide rail around the ends of the balustrade 7, it is common practice to replace the guide 11 by guide rollers 13 at these ends. Each of these rollers rotates about an axis transverse to the direction of movement of the handrail and has a portion projecting into the interior of the C- shaped cross section to carry the handrail with a minimum of friction.
As shown in FIG. 5, the C-shaped cross section of the handrail opens upwardly at any point along the return run of a handrail. For the upper run the C-shaped cross section opens downwardly and the outer surface of the handrail is presented to be grasped by passengers moving along the conveyor.
Some of the steps 10 forming part of the conveyor 1 are illustrated in FIG. 1. These steps move in a closed path which extends around sprocket wheels 15 and 17 in a conventional manner. The upper sprocket wheel 17 may be rotated by an electric motor 18 through suitable driving mechanism 19.
By inspection of FIG. 2 it will be noted that the return run of the handrail is guided by idler rollers 21 and passes between a plurality of pairs of rollers which are utilized in driving the handrail. Although the number of pairs of rollers is determined by factors such as roller load and handrail delaminating pressure limits, friction in path, etc., seven pairs 23, 24, 25, 26, 27, 28 and 29 are illustrated in FIG. 2. Inasmuch as the pairs of rollers may be of similar construction a detailed description of the pair 29 will suffice.
As shown in FIG. 5, the pair 29 includes a drive or traction roller 33 which is mounted for rotation about an axis transverse to the direction of movement of the handrail return run. The rim of the drive roller 33 projects within the C-shaped cross section of the handrail to engage the inner surface of the handrail. The roller may be constructed of a rigid material such as steel coated with a high friction outside surface. In a preferred embodiment of the invention the roller has a steel hub 33a provided with an elastomer or rubber tire 33b.
A pressure roller 35 is mounted for rotation about an axis parallel to the axis of the drive roller 33 and engages the outer surface of the handrail to urge the handrail towards the drive rollers 33. The roller 35 may be constructed of a rigid material or an elastomer. It is assumed for present purposes that the roller 35 is constructed with a steel hub 35:: and a rubber tire 35b. The drive rollers are mounted on a plate 37 which may be secured to the supporting structure or truss of the conveyor in any suitable manner. The drive roller 33 has its hub, 33a, releasably secured to a steel sleeve, 33A which rotates on a stub shaft 330. The stub shaft 330 is releasably secured to the plate 37 as by a screw-threaded connection. Preferably the sleeve 33A is mounted for rotation relative to the stub shaft 33c by means of conventional ball or roller bearings which preferably are of a self-lubricating type. This cantilever mounting of the drive rollers appreciably facilitate assembly and servicing operations.
Each of the drive rollers is positively driven through a sprocket wheel 33d concentric with and secured to the sleeve 33A. The sprocket wheels of the drive rollers are coupled by a sprocket chain 39 (FIG. 2) to a sprocket wheel 41 mounted for rotation with the main sprocket wheel 17. Idler sprocket wheels 43 and 45 assist in guiding the sprocket chain 39 through a suitable path. As clearly shown in FIG. 2 the sprocket chain 39 passes around a substantial part of the periphery of the sprocket wheels associated with the drive rollers of the pairs 23 and 29. However the sprocket chain engages only small portions of the upper parts of the sprocket wheels associated with the drive rollers of the pairs 24 to 28, inclusive. A guide bar 47 is located slightly above the desired path of the sprocket chain as it passes over the sprocket wheels. The guide bar is constructed of material having low friction such as steel. In a preferred embodiment of the invention the guide bar is constructed of nylon. The guide bar is held in position above the sprocket chain by means of brackets 49 which are secured to the guide bar and to the plate 37 in any suitable manner such as by machine screws.
The sprocket wheel 33d for the traction rollers 33 of the end pairs 23 and 29 may have teeth of any suitable conventional form. Preferably the sprocket wheels for the intermediate pairs 24 to 28 have teeth designed with a zero pressure angle to minimize the components of force urging the sprocket chain towards the guide bar 47.
Preferably a drip pan 51 is provided for collecting drippings such as oil from the sprocket wheels associated with the drive rollers and from the sprocket chain. This drip pan conveniently may be constructed of sheet metal and may be secured to the guide bar 47 in any suitable manner such as by machine screws. The drip pan has a vertical wall with openings permitting passage therethrough of the sleeves carrying the drive rollers. Each opening desirably is provided with a conventional oil seal in sealing engagement with the associated sleeve for the purpose of preventing passage of foreign matter or oil from the associated sprocket wheel towards the associated drive roller. For example the drip pan 51 has an oil seal 33e through which the sleeve 33A passes. A lower portion of the drip pan is formed into a trough configuration 51a for the purpose of collecting drippings and of carrying such drippings away from the vicinity of the drive and pressure rollers.
The seven pressure rollers 35 are mounted in a cage 55 having two vertical side walls 55a and 55b connected by an upper wall 556. The lower edges of the walls 55a and 55b may be turned inwardly to provide additional stiffening for the cage. The upper wall 550 has a separate opening or window through which each of the pressure rollers 35 projects towards its associated drive roller.
Mounting provision is made for adjusting the cage towards and away from the drive rollers. Thus the lefthand end of the plate 37 as viewed in FIG. 3 has an angle 57 secured thereto in a position to underlie the cage 55. The angle is threaded for reception of a bolt 59 which engages a metal strap 61 secured to the lower edges of the cage 55. Consequently by manipulation of the bolt 59 the cage 61 may 'be forced towards the drive rollers. The cage also has secured thereto a bracket 63 which may be secured to the plate 37 by means of a bolt 65. This bolt may pass through an elongated slot in the plate 37 to permit the securing of the cage to the plate in any position to which the cage is adjusted by manipulation of the bolt 59.
The right-hand end of the cage 55 as viewed in FIG. 3 has secured thereto an angle 67 which is threaded for reception of bolts 69. These bolts also pass through the arm 71 of a bracket. This arm is secured to a plate 73 which is secured to a stationary part of the supporting structure of truss of the conveyor by means of bolts passing through elongated openings 75 in the plate. Thus by manipulation of the bolts 69 the cage may be adjusted towards the drive rollers. A machine screw 69A may be in threaded engagement with the angle 67. This screw may be positioned to engage the arm 71 when the parts are in their adjusted positions.
Inasmuch as the pressure rollers 35 are similarly mounted in the cage 55 a description of the mounting of the roller 35 in the pair 29 will suffice. This roller is mounted in a sub-frame 77 of forked configuration formed of sheet steel. The sub-frame 77 has two parallel legs or sides 77a and 77b between which the pressure roller 35 is mounted for rotation. These sides are connected at one end by a generally horizontal web 770.
At their lower right-hand edges as viewed in FIG. 3 the sides 77a and 7712 are provided with semi-circular notches which rest on pins 79 which are secured to the side walls of the cage 55. The sub-frame 77 thus serves as a lever fulcrum'ed on the pins 79.
The web 550 of the cage has secured thereto a stud 81 which projects downwardly through an opening in the sub-frame 77. This stud has slidably mounted thereon two coil-spring seats 83 and 85 between which a coil spring 87 is compressed by a nut 89 in threaded engagement with the stud 81. Consequently when the cage 55 is moved upwardly to compress the handrail between the drive rollers 33 and the pressure rollers 35, each of the pressure rollers pivots its sub-frame 77 about the pins 79 to compress further the associated coil spring 87. In this way, an individual bias is provided for each of the pressure rollers.
If desired a set of idler rollers 22 (FIG. 1) may be provided with an adjustment 91 for taking up excessive slack in the handrail. Preferably this adjustment is not utilized to apply tension to the handrail. For illustration purposes it is assumed that the set of idler rollers 22 engages the inner surface of the handrail and that they are mounted On a bracket 91 which is adjustably secured to the supporting structure by a machine screw 91A.
By dividing the traction forces acting on the handrail among a plurality of rollers the traction force required at any point of the handrail is materially reduced. Furthermore, it will be noted that the handrail passes through the pairs of rollers substantially in a straight line. This line may be slightly curved but the handrail is not required to undergo substantial changes in direction as it passes through the rollers. Each appreciable change of direction of the handrail could result in substantial wear and could contribute to rapid breakdown of splices and to breakage of reinforcements such as the wires 9g. Furthermore, the reduction in pressure minimizes the possibility of damage to the outer surface or internal laminations of the handrail.
It will be noted that the free-running pressure rollers may be made appreciably smaller in diameter than the drive rollers. This coupled with the smaller size of traction rollers permitted by the distribution of driving forces among a plurality of pairs of rollers and the location of each coil spring 87 on one side of its roller 35 result in an extremely compact structure. As shown in FIG. 2, the return run of the handrail and the associated drive and traction rollers may be located essentially above the conveyor. This minimizes the possibility of debris from the conveyor reaching the handrail and its drive.
When the handrail is to be removed, the pressure rollers and their cage may be removed as a unit. Because of the cantilever mounting of the traction rollers the handrail readily may be moved around the free ends of the traction rollers.
I claim as my invention:
1. In a device for transporting persons between spaced landings, an endless, flexible handrail, a supporting structure for guiding the handrail in a closed elongated loop,
said handrail having a C-shaped cross-section and having an upper run with an outer surface to be grasped by persons to operate as a balustrade and a low return run, and driving means for applying a separate force between the handrail and the structure acting substantially in the same direction at each of a plurality of points spaced between the ends of the loop along the return run of the handrail in the direction of movement of the return run, said driving means comprising a plurality of pairs of rollers spaced along the return run and spaced from the upper run of the handrail, each of the pairs comprising a traction roller and a pressure roller, means mounting each of said rollers relative to the structure for rotation about a separate axis extending transverse to the direction of movement of the handrail, each of said traction rollers having a portion of its periphery positioned to engage a first surface of the handrail, means biasing each of the pressure rollers against the opposite surface of the handrail to urge the handrail against the associated one of the traction rollers, the rollers for each of the pairs being positioned to make the plane containing the axes of the pair substantially transverse to the direction of movement of the handrail between such rollers, and coupling means mechanically coupling the traction rollers together for rotation, said coupling means including driving means coupled to at least one of said traction rollers for rotating the traction rollers to move the handrail, said pressure rollers being smaller in diameter than said traction rollers.
2. A device as claimed in claim 1 wherein said biasing means includes separate spring means for biasing each of the pressure rollers, each of the spring means including a spring spaced from the associated one of the pressure rollers in the direction of the return run.
3. A device as claimed in claim 1 wherein said biasing means includes a separate lever for mounting each of said pressure rollers, each of said levers being mounted for pivotal movement about an axis parallel to the axis of the associated pressure roller and spaced from the axis in the direction of said return run, each of said springs extending between a separate pair of said pressure rollers.
4. A device as claimed in claim 1 wherein the device includes an endless conveyor having an upper load run for conveying persons in the direction of the upper run of said handrail and having a lower return run, said traction rollers being located beneath the balustrade established by said structure at a level above the level of the load run of the conveyor.
5. A device as claimed in claim 1 wherein said coupling means comprises a separate driving sprocket wheel secured to each of the traction rollers for rotation about the same axis, a main power drive sprocket wheel mounted for rotation about its axis, and a flexible endless sprocket chain engaging each of the driving sprocket wheels for rotating each of the driving sprocket wheels in dependence on rotation of the main power drive sprocket wheel, said driving sprocket wheels being mounted in a common plane along a line, said sprocket chain having a portion extending parallel to said line to engage tangentially each of said sprocket wheels, and a guide device having a surface extending parallel to and adjacent said sprocket chain to prevent reaction forces from moving the chain substantially away from said driving sprocket wheels in the direction of the sprocket teeth in engagement with said chain, said driving sprocket wheels including two end sprocket wheels and at least one sprocket wheel intermediate said end sprocket wheels, any of said sprocket wheels located between said end sprocket wheels having substantially zero-pressure-angle sprocket teeth.
6. A device as claimed in claim 1 wherein said first surface is the inner surface of the handrail, the mounting means for each of said traction rollers and its associated driving wheel providing a cantilever support positioned to leave one face of the traction wheel clear of its mounting means, the mounting means for the pressure rollers comprising a sub-frame releasably mounting all of the pressure rollers and the biasing means as a unit assembly to the supporting structure, whereby all of the pressure rollers may be moved as a unit away from the traction rollers, said biasing means including a separate coil spring for each of the pressure rollers, each coil spring being spaced from the associated pressure roller in the direction of the return run, said sprocket wheels including two end sprocket wheels and at least one sprocket wheel intermediate said end sprocket wheels, any of said sprocket wheels located between said end sprocket wheels having substantially zero-pressure-angle sprocket teeth, and a barrier located between any intermediate one of said sprocket wheels and the associated one of the traction rollers, said barrier including a grease seal.
References Cited UNITED STATES PATENTS 1,224,046 4/1917 Turley 22.6-l87 2,304,419 12/1942 Pratt 19820'3 2,413,339 12/1946 Stadelman 198--203 2,609,917 9/1952 Gotthardt 198-127 2,759,596 8/1956 Keller 198203 3,049,213 8/1962 Fabula 19816 3,283,878 11/1966 Rissler 19816 2,973,084 2/1961 Sinden 198208 3,164,246 12./l965 De Good 198-160 RICHARD E. AEGERTER, Primaly Examiner.