PASSENGER CONVEYOR HANDRAIL WITH A UNIQUE SLIDING LAYER

1. Field of the Invention

[oooi] This invention generally relates to passenger conveyors. More particularly, this invention relates to a sliding layer for use on a handrail of a passenger conveyor.

2. Description of the Related Art

[ooo2] Passenger conveyors such as escalators and moving walkways typically include moving steps or a moving belt for carrying passengers between landings at opposite ends of the conveyor. Handrails travel with the steps or belt to provide a surface for passengers to stabilize themselves while riding on a conveyor. Typical handrail construction includes a rubber or flexible thermoplastic body that provides the gripping surface for passengers. An underside of the body typically is coated with a sliding fabric such as cotton or polyester. The sliding fabric facilitates the handrail sliding along a guidance.

[0003] Ideally, a sliding fabric layer would have a surface characteristic that provides a low co-efficient of friction between the sliding layer and the guidance. Conventional handrail drive assemblies have limited the ability to utilize a low friction sliding layer on a handrail. Conventional handrail drive assemblies use friction and pinching rollers to engage both sides of a handrail to propel it in unison with the steps or moving belt so that the handrail moves along with passengers riding on the conveyor. The requirement for sufficient friction between the handrail drive mechanism and the handrail cannot be achieved if the sliding fabric layer is too slippery. The need for a low coefficient of friction while the sliding layer rides on the guidance and the need for a high coefficient of friction as the sliding layer is engaged by the drive mechanism has limited the choice of fabrics that are useful as a sliding fabric layer.

[0004] Another consideration in the choice of a sliding fabric is ensuring good bonding between the fabric and the material used to establish the body of the handrail.

[0005] One alternative proposal is shown in U.S. Patent No. 3,633,725 where a fabric sliding layer is used on a "cover" for a handrail that is made of a thermoplastic material. That patent includes an arrangement where the thermoplastic material, itself, slides along a guidance. That arrangement is not typically found in existing handrails in use today.

[0006] Wear of a sliding fabric layer is a major contributor to the need to repair or replace passenger conveyor handrails. There is a need for an improved arrangement that reduces the amount of wear to provide extended handrail life and associated cost savings. This invention addresses those needs.

SUMMARY OF THE INVENTION

[0007] An exemplary passenger conveyor handrail includes a body portion comprising a first polymer material having a first thickness that establishes a gripping surface. A non-woven sliding layer having a second, substantially smaller thickness opposite the gripping surface comprises a second polymer material.

[0008] In one example, the non-woven slider layer is constructed as a sufficiently thin film to provide flexibility required to allow bending of the handrail.

[0009] In one example, the non-woven sliding layer is molded and secured to the body portion. [oooio] In one example, the non-woven sliding layer covers only selected portions of the surface of the body portion facing opposite the gripping surface.

[oooii] In some examples, the non-woven sliding layer comprises one of a fluoropolymer-impregnated thermoplastic polyurethane, a polyoxymethylene material or nylon. [oooi2] Another exemplary passenger handrail comprises a body portion having a first polymer material having a first thickness that establishes a gripping surface. A non-fabric sliding layer having a second, substantially smaller thickness is opposite the gripping surface and comprises a second polymer material.

[oooi3] In one example, the non-fabric sliding layer comprises a thin film. [oooi4] An exemplary method of making a passenger conveyor handrail comprises establishing a gripping surface on one side of a body portion using a first polymer material. A sliding surface that is at least one of non-woven or non-fabric is

provided on at least a portion of an opposite side of the body portion. The sliding surface comprises a second, different polymer material.

[oooi5] The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[oooiδ] Figure 1 diagrammatically illustrates an example passenger conveyor incorporating a handrail designed according to an embodiment of this invention. [oooi7] Figure 2 is a cross-sectional illustration of an example handrail taken along the lines 2-2 in Figure 1.

[00018] Figure 3 schematically shows selected features of a portion of the embodiment of Figure 2.

[oooi9] Figure 4 is a cross-sectional illustration of another example embodiment from the same perspective as shown in Figure 2.

[00020] Figure 5 is another example embodiment shown in cross-section from the same perspective as Figures 2 and 4.

[00021] Figure 6 is another example embodiment shown in cross-section.

[00022] Figure 7 schematically shows an example embodiment of a sliding layer.

[00023] Figure 8 is an illustration of another example embodiment of a sliding layer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [00024] Figure 1 shows an example passenger conveyor 20. A plurality of steps 22 move between landings 24 and 26 to carry passengers in a desired direction.

A handrail 30 follows a path along a guidance (not illustrated) to provide a surface for a passenger to hold onto as they ride the conveyor 20.

[00025] Figure 2 shows one example handrail configuration where the handrail 30 includes a body 32 comprising a rubber or flexible thermoplastic material, for example. The body 32 establishes a gripping surface 34 that faces in a direction to be grasped by an individual riding on the conveyor 20, for example.

[00026] An oppositely facing surface 38 of the handrail body 32 has a sliding layer 40 secured in place. The sliding layer 40 is exposed to directly contact and slide along a conventional guidance (not illustrated) as the handrail moves in a known manner. [00027] As can be appreciated from the illustration, the example sliding layer

40 is substantially thinner than the body 32 (e.g., the body 32 has a first thickness and the sliding layer 40 has a second, substantially smaller thickness). One example includes a thin film as the sliding layer 40. Using a thin sliding layer 40 allows the example handrail 30 to bend as needed. The first thickness in some examples is between twice and ten times as thick as the second thickness.

[00028] In the illustration of Figure 2, a portion of the surface 38 is not covered by the sliding layer 40. In this example, the uncovered portion of the surface 38 provides a surface for a conventional handrail drive mechanism to engage the handrail 30 in a known manner. The uncovered material and the surface 38 that does not include a sliding layer 40 has sufficient friction characteristics to achieve the necessary traction with a conventional pinching roller style handrail drive.

[00029] The sliding layer 40 in one example comprises a fluoropolymer- impregnated thermoplastic urethane. In one example, the fluoropolymer comprises polytetrafluoroethylene (i.e., TEFLON®). In another example, the sliding layer 40 comprises a polyoxymethylene material. In still another example, the sliding layer 40 comprises nylon. Any one of these examples may also comprise a lubricant to further reduce a friction characteristic of the sliding layer 40.

[00030] A unique aspect of the example sliding layer 40 is that it is composed or constructed of at least one of a non-woven or a non-fabric sliding layer. Conventional arrangements relied upon a woven fabric layer such as cotton or polyester to establish a sliding layer. The disclosed example embodiments of this invention differ from the conventional approach in that the sliding layer 40 is not a fabric in some examples and is not woven in other examples. Unique sliding layer formations are used to provide enhanced handrail service life and better performance characteristics.

[00031] In one example, the sliding layer 40 is molded and secured onto the body portion 32 of the handrail 30 using an appropriate adhesive, given the polymer

materials selected to establish the body portion 32 and the sliding layer 40. In one example, the sliding layer 40 is co-extruded at the time of forming the body portion 32. In such an example, a first polymer material is used to establish the body portion 32 and a second, different polymer material is used to establish the sliding layer 40. [00032] In another example, the sliding layer 40 is overmolded onto a preformed body portion 32. Example overmolding techniques include placing the body portion 32 within a mold that is then used to form the sliding layer 40 and applying the sliding layer 40 material onto the desired portions of the surface 38 of the body portion 32. Example application techniques include brushing on, rolling on, spraying on or pouring on the material used to form the sliding layer 40.

[00033] As can be appreciated from Figure 2, this example embodiment includes a sliding layer 40 over a substantial amount of the surface 38 of the handrail 30. A portion 42 of the sliding layer covers the so-called lip area of the surface 38. To facilitate the handrail bending around the turnarounds at each end of the conveyor travel, for example, the at least the portion 42 of the sliding layer 40 includes a plurality of slots 44 shown in Figure 3 that are transverse to the direction of travel of the handrail during the passenger conveyor movement. In this example, the slots 44 facilitate a relatively harder material of the sliding layer 40 bending around the turnarounds as needed for a particular situation. The desire to provide a longer-lasting sliding layer 40 and desirable friction characteristics may require using relatively harder materials compared to those typically used to establish the body portion 32 or the gripping surface 34 of a handrail. The example of Figure 3 includes the slots 44 to accommodate such materials and conventional handrail travel.

[00034] In this example, the slots 44 extend from an edge 46 of the sliding layer 40 at least along the portion 42 where the sliding layer 40 covers the lip area of the surface 38. Interrupting the sliding layer 40 with slots 44 as shown in Figure 3 would not hinder the ability of the sliding layer 40 to provide a desired coefficient of friction for interaction between the handrail 30 and the guidance or other portion of the conveyor structure along which the handrail travels during normal operation because the exposed polymer of the surface 38 at the slots 44 will not contact a guidance. The sliding layer 40 in this example has a thickness that effectively separates the exposed surface 38 within the slots 44 from a guidance.

[00035] Figure 4 shows another example embodiment of a handrail 30 that includes a plurality of drive teeth 50 on the surface 38 of the handrail. The example teeth 50 are transverse to the direction of handrail movement. In this example, the sliding layer 40 extends along lateral portions of the surface 38 and is on the outermost edge of the teeth 50 to facilitate the teeth 50 sliding along an appropriately designed guidance. At the same time, the drive-engaging surfaces of the teeth 50 can be kept free of the material of the sliding layer 40 to have appropriate friction or traction characteristics associated with driving the handrail to propel it in the desired direction. [00036] Figure 5 shows another example embodiment of a handrail 30 that includes longitudinally arranged grooves 52 and teeth 54. In this example, the outer edges of the teeth 54 are at least partially covered with the material of the sliding layer 40 to facilitate the teeth sliding along a guidance during handrail movement.

[00037] Figure 6 shows another example handrail 30 where the sliding layer 40 comprises a plurality of laterally spaced portions selectively positioned on the surface 38. In such an arrangement, the sliding layer 40 effectively elevates the surface 38 away from a guidance surface so that desired, low friction engagement between a guidance and the sliding layer 40 can be accomplished. One advantage to an arrangement as shown in Figure 6 is that less sliding layer 40 material may be used while still achieving the benefits of an embodiment of this invention.

[00038] In one example, the sliding layer 40 comprises laterally spaced longitudinally extending strips of the material of the sliding layer 40. The strips in one example are molded. In another example, the strips comprise threads. This is shown in Figure 7, for example. In another example shown in Figure 8, a plurality of drops or beads of the material used to establish the sliding layer 40 are longitudinally spaced and laterally spaced in a desired pattern on the surface 38.

[00039] Some examples will include combinations of the different formations of the sliding layer 40 shown in the various illustrated examples. Given this description, those skilled in the art will realize what combination and what material selection will best meet the needs of their particular situation.

[00040] The disclosed examples have a variety of advantages compared to previous handrail designs. Using a low-friction material for the sliding 40 reduces the

coefficient of friction as the handrail slides along a guidance. This provides extended handrail life. As the coefficient of friction is a dominant factor influencing a handrail's service life, reducing the coefficient of friction using an example embodiment of this invention extends that life and provides significant cost savings. Another advantage to the disclosed examples is they allow for reduced power consumption for moving the handrail. A lower coefficient of friction allows for using less power to move the handrail as desired. Another advantage is that there is less heat generation at the sliding surface, which provides better temperature control over the handrail and may allow for using less expensive materials in some instances. [ooo4i] Another advantage includes reducing the complexity of a handrail guidance arrangement. Many conventional systems include rollers associated with newels to reduce factional force at the location of the newels. Adding such rollers increases the complexity and expense of the passenger conveyor assembly. Reducing a coefficient of friction using one of the example sliding layers 40 allows for eliminating such rollers without any adverse effects, which provides cost savings from a material and installation standpoint.

[00042] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.