BACKGROUND OF THE INVENTION

[0001] The subject matter disclosed herein relates to elevator systems. More specifically, the subject disclosure relates to tension members for elevator suspension and/or driving.

[0002] Elevator systems utilize ropes or belts operably connected to an elevator car, and routed over one or more sheaves, also known as pulleys, to propel the elevator car along a hoistway. Belts in particular typically include a plurality of wires at least partially within a jacket material. The plurality of wires are often arranged into one or more strands and the strands are then arranged into one or more cords.

[0003] In an exemplary belt construction, a plurality of cords are typically arranged equally spaced within a jacket in a longitudinal direction. The cords are typically formed of a plurality of outer strands helically wound around a center strand and each strand is made up of a plurality of wires helically wound around a center wire. Each belt is subject to changes in tension and a plurality of bending cycles over the pulleys as the elevator car travels up and down the hoistway. The individual cords within a belt are also subject to tension variation as they travel over the plurality of traction and deflecting sheaves due to a crown feature of the pulleys to keep the belt centered on the pulley. The tension changes and bending cycles result in relative movement of individual strands in the cord and also of individual wires of the strands. If the wires are not sufficiently held in place a fractured or end wire could move out of its relative position and pierce into and out of the coating jacket or if the wire movement is not sufficiently anchored, a return to the original position could be prohibited or nonreversible, and an accumulation of wire can occur. This excess wire or wires can bundle up in an area causing a bump in the cord or force the wire or wires out of the strand helix. Further, this accumulation of wires may accelerate the fracture of wire(s) which can be then forced out of the cord helix and pierce into and out of the coating jacket. This can cause any of a number of issues such as accelerating other wire fracture, accelerating cord and belt degradation, interfering with degradation detection, interfering with other components of the elevator system and the like. BRIEF DESCRIPTION OF THE INVENTION

[0004] According to one aspect of the invention, a belt for suspending and/or driving an elevator car includes a plurality of wires arranged into a plurality of strands. The plurality of strands includes one or more center elements with a plurality of outer wires arranged around the one or more center elements and includes one or more anchorage features to limit relative movement of the plurality of wires. A jacket substantially retains the plurality of strands.

[0005] Alternatively in this or other aspects of the invention, the one or more anchorage features are one or more scallops in the plurality of outer wires meshable with a complimentary surface of an adjacent outer wire.

[0006] Alternatively in this or other aspects of the invention, the one or more scallops are meshable with a complimentary surface of the one or more center elements.

[0007] Alternatively in this or other aspects of the invention, the one or more anchorage features is a deformed surface of the plurality of outer wires.

[0008] Alternatively in this or other aspects of the invention, the deformed surface is formed by compacting the strand.

[0009] Alternatively in this or other aspects of the invention, the one or more anchorage features is one or more teeth disposed in the plurality of wires interlockable with one or more notches disposed in adjacent wires of the plurality of wires.

[0010] Alternatively in this or other aspects of the invention, the plurality of strands are formed into a plurality of cords.

[0011] Alternatively in this or other aspects of the invention, a strand lay direction and a cord lay direction are substantially opposite.

[0012] Alternatively in this or other aspects of the invention, the one or more anchorage features is a deformed surface formed by compacting a cord of the plurality of cords

[0013] Alternatively in this or other aspects of the invention, the plurality of wires have an increased surface roughness applied thereto.

[0014] Alternatively in this or other aspects of the invention, an adhesive or coating is applied to one or more wires of the plurality of wires.

[0015] According to one aspect of the invention, the belt is utilized in combination with a sheave for engaging the belt.

[0016] Alternatively in this or other aspects of the invention, the sheave has a crown or a grooved surface BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1A is a schematic of an exemplary elevator system having a 1:1 roping arrangement;

[0018] FIG. IB is a schematic of another exemplary elevator system having a 2:1 roping arrangement;

[0019] FIG. 1C is a schematic of another exemplary elevator system having a cantilevered arrangement;

[0020] FIG. 2 is a cross-sectional view of an exemplary elevator belt;

[0021] FIG. 3 is a cross-sectional view of a prior art cord for an elevator belt;

[0022] FIG. 4 is a cross-sectional view of a strand of an elevator belt;

[0023] FIG. 5 is a cross-sectional view of another embodiment of a strand of an elevator belt;

[0024] FIG. 6 is a view of an embodiment of a wire of an elevator belt;

[0025] FIG. 7 is a cross-sectional view of an embodiment of a cord having a coating applied to the wires of the cord;

[0026] FIG. 8 is a cross-sectional view of an embodiment of a cord having a coating applied to strands of the cord.

[0027] FIG. 9 is a cross-sectional view of an embodiment of a cord of an elevator belt; and

[0028] FIG. 10 is a view of an embodiment of a wire interface of an elevator belt.

[0029] The detailed description explains the invention, together with advantages and features, by way of examples with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0030] Shown in FIGS. 1A, IB and 1C are schematics of exemplary traction elevator systems 10. Features of the elevator system 10 that are not required for an understanding of the present invention (such as the guide rails, safeties, etc.) are not discussed herein. The elevator system 10 includes an elevator car 12 operatively suspended in a hoistway 14 with one or more belts 16. The one or more belts 16 interact with one or more sheaves 18 to be routed around various components of the elevator system 10. The one or more belts 16 could also be connected to a counterweight 22, which is used to help balance the elevator system 10 and reduce the difference in belt tension on both sides of the traction sheave during operation. Although the exemplary belt 16 shown FIG. 2 has a generally planar exterior surface, other arrangements are possible. As one example, belts with a grooved arrangement could be used. [0031] The sheaves 18 each have a diameter 20, which may be the same or different than the diameters of the other sheaves 18 in the elevator system 10. At least one of the sheaves 18 could be a traction sheave and driven by a machine 50. Movement of the traction sheave by the machine 50 drives (through traction) the one or more belts 16 that are routed around the drive sheave.

[0032] At least one of the sheaves 18 could be a diverter, deflector or idler sheave.

Diverter, deflector or idler sheaves are not driven by a machine 50, but help guide the one or more belts 16 around the various components of the elevator system 10. The shape of the sheave 18 depends on the shape of the belt 16 that it engages. For example, one or more of the sheaves 18 may have a crown (i.e. a convex shape) along its axis of rotation to assist in keeping the one or more belts 16 centered, or in a desired position, along the sheaves 18. While such a shape may be used with the belt 16 shown in FIG. 2, other shapes are possible. As one example, the sheave could have a grooved surface to receive a grooved belt.

[0033] In some embodiments, the elevator system 10 could use two or more belts 16 for suspending and/or driving the elevator car 12. In addition, the elevator system 10 could have various configurations such that either both sides of the one or more belts 16 engage the one or more sheaves 18 (such as shown in the exemplary elevator systems in FIGS. 1A, IB or 1C) or only one side of the one or more belts 16 engages the one or more sheaves 18.

[0034] FIG 1A provides a 1:1 roping arrangement in which the one or more belts 16 terminate at the car 12 and counterweight 22. FIGS. IB and 1C provide different roping arrangements. Specifically, FIGS. IB and 1C show that the car 12 and/or the counterweight 22 can have one or more sheaves 18 thereon engaging the one or more belts 16 and the one or more belts 16 can terminate elsewhere, typically at a structure within the hoistway 14 (such as for a machine-room- less elevator system) or within the machine room (for elevator systems utilizing a machine room. The number of sheaves 18 used in the arrangement determines the specific roping ratio (e.g. the 2:1 roping ratio shown in FIGS. IB and 1C or a different ratio). FIG 1C also provides a so-called rucksack or cantilevered type elevator. The present invention could be used on elevator systems other than the exemplary types shown in FIGS. 1A, IB and 1C.

[0035] FIG. 2 provides a schematic of an exemplary belt construction. Each belt 16 is constructed of one or more cords 24 and a jacket 26. As seen in FIG. 2, the belt 16 has an aspect ratio greater than one (i.e. belt width is greater than belt thickness).

[0036] The belts 16 are constructed to have sufficient flexibility when passing over the one or more sheaves 18 to provide low bending stresses, meet belt life requirements and/or have smooth operation, while also being sufficiently strong to suspend and/or drive the elevator car 12.

[0037] The jacket 26 could be any suitable material, including a single material, multiple materials, two or more layers using the same or dissimilar materials, and/or a film. In one arrangement, the jacket 26 could be a polymer, such as an elastomer, applied to the cords 24 using, for example, an extrusion or a mold wheel process. In another arrangement, the jacket 26 could be a woven fabric that engages and/or integrates the cords 24. As an additional arrangement, the jacket 26 could be one or more of the previously mentioned alternatives in combination.

[0038] The jacket 26 can substantially retain the cords 24 therein. The phrase substantially retain means that the jacket 26 has sufficient engagement with the cords 24 such that the cords 24 do not pull out of, detach from, and/or cut through the jacket 26 during the application on the belt 16 of a load that can be encountered during use in an elevator system 10 with, potentially, an additional factor of safety. In other words, the cords 24 remain at their original positions relative to the jacket 26 during use in an elevator system 10. The jacket 26 could completely envelop the cords 24 (such as shown in FIG. 2), substantially envelop the cords 24, or at least partially envelop the cords 24.

[0039] Referring now to FIG. 3, each cord 24 comprises a plurality of wires 28 in a geometrically stable arrangement. Optionally, some or all of these wires 28 could be formed into strands 30, which are then formed into the cord 24. The phrase geometrically stable arrangement means that the wires 28 (and if used, strands 30) generally remain at their cross sectional theoretical positions in the cord 24 and axial, movement of the wires 28 (and if used, strands 30) relative to each other is reversible or return to their theoretical positions.

[0040] Referring to FIG. 4, one embodiment of a strand 30 with improved wire 28 anchorage is shown. In this embodiment, outer wires 28b are located around a center wire 28a, or group of center wires (not shown). The outer wires 28b are formed to a selected shape to increase a contact area between adjacent outer wires 28b, and in some embodiments, with the center wire 28a. In the embodiment shown, the outer wires 28b are provided with an anchorage feature, for example a scallop 32 or notch, which engages an adjacent outer wire 28b. The anchorage feature on the outer wire 28b and the adjacent outer wire 28b could have complementary shapes. The term "complementary" does not require the securing feature on the outer wire 28b to perfectly complement the adjacent outer wire 28b. As long as the anchorage feature on the outer wire 28b performs the desired function (reducing relative movement in a radial direction between the wires, but allowing for reversible movement of the wires in an axial direction) when compared to a conventional engagement of two wires (e.g. point contact), then the shapes are "complementary". In the embodiment shown, the scallop 32 abuts a substantially round portion 34 of the adjacent outer wire 28b, but it is to be appreciated that other configurations are contemplated by the present disclosure. Further, though one scallop 32 at each outer wire 28b is shown, additional quantities of such features may be utilized. In some embodiments, additional scallops 32 may be utilized on the outer wire 28b, for example to mesh the outer wires 28b with the center wire 28a. Such anchorage features may be applied along an entire length of the wires 28, or alternatively at selected locations along the length. Further, while anchorage features are shown in the outer wires 28b, such features may be formed into the center wires 28a, or both outer wires 28b and center wires 28a may have the anchorage features.

[0041] Referring now to FIG. 5, the outer wires 28b may be formed or compacted to increase the contact area between adjacent outer wires 28b, and between the outer wires 28b and the center wire 28a. The compacting or forming may be performed on individual outer wires 28b before assembly into the strand 30, and/or may be performed on the strand 30 after assembly of the wires 28 thereinto. Further, compacting or forming may be applied to cords 24 to limit wire 28 movement therein, maintaining cross-section position of the wires 28.

[0042] Referring to FIG. 6, another technique may be utilized to limit relative radial movement of the wires 28 in the strand 30, while promoting reversible movement of the wires 28 in the axial direction. For example, an outer surface 36 of the wire 28 may have its surface roughness increased by, for example, sand blasting. The increased surface roughness increases friction between adjacent wires 28 and adjacent strands 30 to maintain cross- sectional position of the wires 28. Referring to FIGs. 7 and 8, in addition or separately in other embodiments, an adhesive or coating 60 may be applied to the wires 28 to limit relative movement by enhancing binding of the strands 30 to the jacket 26 material and also provide some anchorage feature of the strands 30 to adjacent strands 30. In the embodiment of FIG. 7, each wire 28 has a coating 60 applied to it, while in FIG. 8 each strand 30 has a coating 60 applied to it. It is to be appreciated, however, that the embodiments illustrated are merely exemplary, and other embodiments, such as those where only the outer strands 30 are coated, or just a center strand 30 is coated, are contemplated within the present disclosure.

[0043] In construction of a cord 24, as shown in FIG. 9, the center strand 30b, also known as a king strand, has a lay direction which is either clockwise or counterclockwise, depicted by arrows 48 and 50. Similarly, each outer strand 30a of the cord 24 has an either clockwise or counterclockwise lay direction as depicted by arrows 44 and 46. Finally, .the cord 24 is wound helically in an either clockwise or counterclockwise lay direction as depicted by arrows 40 and 42, respectively. Where wires 28 cross within strands 30a/30b, for example outer wires 28b crossing center wires 28a, and between strands 30a/30b when formed into the cord 24, features may be utilized in the wires 28 to lock or secure the wires 28 to one another. For example, as shown in FIG. 10, a first wire 28 may have a notch 52 which interlocks with a tooth 54 of a second wire 28. These notches 52 and teeth 54 may be located along a length of the wires 28 where desired at locations where wires 28 cross to hold the wires 28 in radial position relative to each other when assembled into the cord 24.

[0044] Further, in some embodiments, certain lay configurations of the cord 24 relative to the outer strands 30a and relative to the king strand 30b are utilized to increased friction between the elements and secure them in relative radial position. An alternating configuration, such as having a clockwise king strand lay direction 48, a counterclockwise outer strand lay direction 46 and a clockwise cord lay direction 40 is preferred as is the opposite alternating configuration of a counterclockwise king strand lay direction 50, a clockwise outer strand lay direction 44 and a counterclockwise cord lay direction 42. Also in some embodiments, it is beneficial to vary a lay length between the king strand 30b and the outer strands 30a. For example, the lay length of the king strand 30b may be shorter than the lay length of the outer strands by about 10% or more.

[0045] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.