Patent Publication Number: US-6991084-B2

Title: Handrail-drive for escalator or moving walk

Description:
The present invention relates to an escalator or a moving walk consisting of a balustrade, a balustrade base, steps or pallets for the transportation of persons and objects and, arranged on the balustrade, a handrail construction with a handrail for the safety of persons which, in a reversing zone of the balustrade, can be reversed by means of a drivable reversing sheave. 
   BACKGROUND OF THE INVENTION 
   From patent specification U.S. Pat. No. 2,373,764 an escalator has become known in which the handrail is guided over an upper reversing-wheel which drives the handrail and over a lower, free-running reversing-wheel. The upper reversing-wheel has a pulley which is coaxial with the reversing-wheel and drivable by means of a chain, the chain being drivable by means of a pulley of the step-chain reversing-wheel. The driving energy for the step-chain is provided by an electric motor and gearbox. 
   A disadvantage of such a device is that the handrail-drive can only be used with encapsulated or enclosed reversing-wheels. The centrally arranged pulley with the driving chain must be covered in all situations for reasons of safety. 
   BRIEF DESCRIPTION OF THE INVENTION 
   The present invention avoids the disadvantages of the prior art and provides a handrail-drive that offers safety for the drive, and allows the drive to be used with narrow profile balustrades, such as glass balustrades. 
   In accordance with the invention, an escalator or moving walk includes a handrail-drive which drives a reversing sheave peripherally, and preferably in the balustrade. A drive-wheel has a friction wheel or gear wheel that engages the handrail. 
   The advantages achieved by the invention are to be seen essentially in that in the case of escalators or moving walks with an elegant balustrade, the supporting structure, which takes the form of a truss, can be built narrowly. Furthermore, thanks to the handrail-drive acting directly on the reversing-wheel, guidance of the handrail can be simplified and reverse bending of the handrail minimized. Also advantageous is that the reversing zones can be built as narrow as the balustrades, and that the designer has more freedom in the design of the reversing zones. The width of the truss can be reduced, and the length of the handrail shortened. The handrail no longer crosses the step-chain. The handrail layshaft and chain lubrication equipment are obviated. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in more detail by reference to the following preferred but, nonetheless, illustrative embodiments, as further set forth in the annexed drawings, wherein: 
       FIG. 1  is a side view of a reversing zone of an escalator employing the invention; 
       FIG. 2  is a cross-section view along line A—A of the reversing zone shown in  FIG. 1 ; 
       FIG. 3  is a side view of the reversing zone of the escalator showing the handrail-drive; 
       FIG. 4  is a cross-section view along line B—B of the reversing zone shown in  FIG. 3 ; 
       FIG. 5  is a side view of a first variant embodiment of the handrail drive of the invention utilizing a layshaft; 
       FIG. 6  is a side view of a second variant embodiment thereof; 
       FIG. 7  is a third variant embodiment of the handrail drive of the invention, without a layshaft; and 
       FIGS. 8 ,  9  and  10  each present an alternative construction for the engagement of the handrail drive and the handrail, as denoted at C of  FIG. 4 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In  FIGS. 1 to 10 ,  1  indicates a reversing zone of an escalator or moving walk, which essentially comprises a balustrade base  2 , a balustrade  3 , and a handrail  4 . For the transportation of persons and objects, provided on an escalator are steps  5  or, on a moving walk, pallets  5 , each of which extends on the cheek side to the balustrade base  2 . The step-side or pallet-side of the balustrade  3  (the transporting side) is indicated by reference  6 , and the outside of the balustrade  3  by reference  7 . 
   On escalators and moving walks today, the balustrade  3  consists of, for example, glass with a wall thickness of about 10 mm, which gives the escalator or moving walk a slim, light, elegant appearance. 
     FIG. 1  shows a reversal of the direction of travel handrail  4  by means of a reversing sheave  10  which rotates about an axle  9  and is, for example, transparent, with a wall-thickness which is approximately the same as the wall-thickness of the balustrade  3 . The axle  9  is connected by at least one, for example transparent, supporting cheek  11  which is connected, for example by means of a welded joint  12 , to the supporting construction of the handrail  4  and/or, for example, by means of a screwed or riveted connection  13 , to the balustrade  3 . 
     FIG. 2  shows details of the reversal of the handrail  4 . On the outside  7 , the axle  9  is connected by means of, for example, a screwed or riveted connection  13  to the supporting cheek  11 , which, as is the supporting cheek  11  of the transporting side  6 , connected to a support  14  of the handrail construction by means of the welded joint  12 . In the case of transparent supporting cheeks  11 , in the peripheral zone of the reversing sheave  10  dark tinting can be provided. The supports  14 , which are arranged on both sides of the reversing sheave  10 , each have at one end a gliding surface  15  on which the surface of the handrail  4  glides and is guided. The handrail  4  is supported medially and reversed by the rotating reversing sheave  10 . The reversing sheave  10  is held rotatably by means of a bearing  16  on the axle  9 . 
     FIG. 3  shows the handrail-drive  20  which is integrated with the balustrade base  2  and consists of, for example, an electric motor  21  which, by means of a chain or belt  22  (toothed belt, V-belt, flat belt, studded belt), drives a drive-wheel  23 . The reversing sheave  10  is driven peripherally by the drive-wheel  23 . The handrail  4 , which is guided over a diverter roller  24 , is moved along with the reversing sheave  10  by means of friction. The electric motor  21  can be a torque motor, or synchronized with the step-chain  26 . 1  by means of a control circuit, or synchronized by means of a step-chain motor. 
   The cross-section B—B shown in  FIG. 4  illustrates the arrangement of the handrail-drive  20  in the balustrade base  2  and the peripheral drive at the edge of the reversing sheave  10  by means of the drive-wheel  23 . Also, the step  5 , which is connected to the step-chain  26 . 1  on both sides, is shown with idler wheels  25 ,  26  which roll on a guide  26 . 2  arranged on the truss  27 . 
     FIGS. 5 and 6  show the handrail-drive  20  according to the invention with a layshaft  28 , the layshaft  28  being drivable by means of a main shaft  29  which drives the step-chain. The transmission of force from shaft to shaft and from the layshaft  28  to a reduction wheel  30  takes place by means of chains or belts  31  (toothed belt, V-belt, flat belt, studded belt), the reduction wheel  30  driving the drive-wheel  23 .  FIG. 6  shows the handrail-drive  20  without a reduction wheel  30 , the transmission of force from the layshaft  28  to the drive-wheel  23  taking place directly by means of crossed belts  32 . 
     FIG. 7  shows a variant embodiment of the handrail drive  20  without a layshaft. In this variant, the reduction wheel  30  is driven directly by the main shaft  29  by chain or belt  31 . Elimination of the layshaft  28  is a constructional advantage and reduces the number of components. 
     FIGS. 8 ,  9  and  10  show detail C of  FIG. 4 , which shows in more detail the drive-wheel  23  and the reversing sheave  10  for variants of possible frictional pairs and gearwheel pairs. 
     FIG. 8  shows a drive-wheel  23  with a smooth surface as a friction surface, by means of which the reversing sheave  10  can be driven. The drive-wheel  23  is, for example, arranged on a rocker-arm (not shown) which can have applied to it by means of a spring  34  a spring force, the drive-wheel  23  being thereby pressed against the reversing sheave  10 . The necessary pressure on the friction contact point  33  is produced thereby. The reversing sheave  10 , which may be made, for example, of plastic, aluminum, or safety glass, and the drive-wheel  23  which may be made, for example, of polyurethane, polyamide, or polyvinylidene fluoride, are matched to each other as friction partners, it being possible for the spring force of spring  34  to be, for example, increased or decreased pneumatically or hydraulically. 
     FIG. 9  shows the drive-wheel  23  with a smooth surface as the friction surface and the reversing sheave  10  with a milled, knurled, or cross-knurled surface  35  as its friction surface, the drive-wheel  23  being, for example, a rubberized roller of polyurethane and driving the slimly constructed and therefore extremely light reversing sheave  10  under spring-pressure loading. With this surface of the reversing sheave, friction at the friction contact point  33  is improved and reduces the danger of slipping. 
     FIG. 10  shows the drive-wheel  23  with spur toothing  36 , the reversing sheave  10  also having spur toothing. The contact point  37  is on the gearwheel reference circle and is mechanically engaged. The gearwheels are provided with many small teeth because large teeth would cause damage to the handrail  4 . The inside, or gliding, surface of the handrail  4  is hardly damaged by the small teeth on the large diameter of the reversing sheave  10 . The drive of the handrail  4  takes place in a manner comparable to a multi-stage gearwheel gearbox, the handrail  4  being engaged with the last gearwheel. A fastening angle bracket  38 , which is arranged on the truss  27 , holds the drive-wheel  23  fixed at a certain distance from the reversing sheave  10 , the distance being settable. 
   As set forth in the annexed claims, the term “escalator” is intended to mean and include a moving walk, and the term “steps” thereof is intended to mean and include pallets of a moving walk.