HK1238620B - Elevator tension member - Google Patents

Description

Elevator tension members

Background Art

The subject matter disclosed herein relates to tension members for suspending and/or driving elevator cars and/or counterweights, such as those used in elevator systems.

Traction-drive elevator belts are typically constructed using tension members such as steel cables. Recent developments in the field of composite materials include the use of continuous synthetic fibers, such as carbon fiber, glass fiber, and/or organic aramid or polyimide fibers, to provide a greater strength-to-weight ratio than steel. While belts with continuous carbon fiber and thermosetting resins offer improved strength-to-weight advantages compared to steel cable belts, significant performance and durability challenges remain. For example, rigid structures contradict the desire in the art for flexible belts capable of undergoing thousands of bending cycles without brittleness and fatigue failure.

Summary of the Invention

In one embodiment, a belt for suspending and/or driving an elevator car includes a tension member extending along the length of the belt, the tension member comprising a plurality of fibers bonded in a first polymer matrix, the plurality of fibers extending parallel to the length of the belt and being discontinuous along the length of the belt with one or more longitudinally extending gaps disposed between longitudinally adjacent fibers. A jacket substantially retains the tension member.

Additionally or alternatively, in this or other embodiments, the tension member further comprises a plurality of fiber bundles secured to each other by the second polymer matrix, each fiber bundle comprising a plurality of fibers bonded in the first polymer matrix.

Additionally or alternatively, in this or other embodiments, the second polymer matrix material is different from the first polymer matrix material.

Additionally or alternatively, in this or other embodiments, the tension member has a fiber density of between 30% and 70% by volume.

Additionally or alternatively, in this or other embodiments, the fiber bundle includes fibers having non-uniform cross-sectional size and/or length.

Additionally or alternatively, in this or other embodiments, the tape includes one or more layers of fibers that do not extend parallel to the length of the tape.

Additionally or alternatively, in this or other embodiments, one or more layers are provided at the outermost belt surface.

Additionally or alternatively, in this or other embodiments, the plurality of fibers are formed from one or more of carbon, glass, polyester, nylon, aramid, or other polyimide materials.

Additionally or alternatively, in this or other embodiments, the first polymer matrix is formed from a thermoset material or a thermoplastic material.

Additionally or alternatively, in this or other embodiments, the tape has an aspect ratio of tape width to tape thickness greater than or equal to 3:2, wherein the plurality of tension members are arranged across the tape width.

In another embodiment, an elevator system includes an elevator car, one or more pulleys, and one or more belts operably connected to the car and interacting with the one or more pulleys for suspending and/or driving the elevator car. Each of the one or more belts includes a tension member extending along the length of the belt, the tension member comprising a plurality of fibers bonded in a first polymer matrix. The plurality of fibers extend parallel to the length of the belt and are discontinuous along the length of the belt, with one or more longitudinally extending gaps disposed between longitudinally adjacent fibers. A jacket substantially retains the tension member.

Additionally or alternatively, in this or other embodiments, the tension member further comprises a plurality of fiber bundles secured to each other by the second polymer matrix, each fiber bundle comprising a plurality of fibers bonded in the first polymer matrix.

Additionally or alternatively, in this or other embodiments, the second polymer matrix material is different from the first polymer matrix material.

Additionally or alternatively, in this or other embodiments, the tension member has a fiber density of between 30% and 70% by volume.

Additionally or alternatively, in this or other embodiments, the fiber bundle includes fibers having non-uniform cross-sectional size and/or length.

Additionally or alternatively, in this or other embodiments, the tape includes one or more layers of fibers that do not extend parallel to the length of the tape.

Additionally or alternatively, in this or other embodiments, one or more layers are provided at the outermost belt surface.

Additionally or alternatively, in this or other embodiments, the plurality of fibers are formed from one or more of carbon, glass, polyester, nylon, aramid, or other polyimide materials.

Additionally or alternatively, in this or other embodiments, the first polymer matrix is formed from a thermoset material or a thermoplastic material.

Additionally or alternatively, in this or other embodiments, the tape has an aspect ratio of tape width to tape thickness greater than or equal to 3:2, wherein the plurality of tension members are arranged across the tape width.

In yet another embodiment, a method of forming a tension member for an elevator system belt includes arranging a plurality of fibers into a fiber bundle. The plurality of fibers extend parallel to the length of the belt and have one or more longitudinally extending gaps between the longitudinally extending fibers. The plurality of fibers are bonded to a first polymer matrix.

Additionally or alternatively, in this or other embodiments, one or more longitudinally extending gaps are formed by breaking longitudinally adjacent fibers.

Additionally or alternatively, in this or other embodiments, the plurality of fibers are formed from one or more of carbon, glass, polyester, nylon, aramid, or other polyimide materials.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the present disclosure will be apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG1A is a schematic diagram of an exemplary elevator system having a 1:1 roping arrangement;

FIG1B is a schematic diagram of another exemplary elevator system having a different roping arrangement;

FIG1C is a schematic diagram of another exemplary elevator system having a cantilever arrangement;

FIG2 is a longitudinal cross-sectional view of one embodiment of an elevator belt for an elevator system;

FIG3 is a transverse cross-sectional view of one embodiment of an elevator belt for an elevator system;

FIG4 is a longitudinal cross-sectional view of another embodiment of an elevator belt for an elevator system;

FIG5 is a longitudinal cross-sectional view of yet another embodiment of an elevator belt for an elevator system;

FIG6 is a longitudinal cross-sectional view of one embodiment of a tension member for an elevator belt of an elevator system; and

7 is a plan view of one embodiment of a tension member for an elevator belt of an elevator system.

DETAILED DESCRIPTION

FIG1A , FIG1B , and FIG1C illustrate schematic diagrams of an exemplary traction elevator system 10. Features of elevator system 10 that are not required for an understanding of the present invention, such as guide rails, safety features, etc., are not discussed herein. Elevator system 10 includes an elevator car 12 operably suspended or supported within an elevator shaft 14 using one or more belts 16. Belt(s) 16 interact with one or more pulleys 18 to route through various components of elevator system 10. Belt(s) 16 may also be connected to a counterweight 22 that helps balance elevator system 10 and reduce differences in belt tension on either side of a traction sheave during operation.

Each of the pulleys 18 has a diameter 20, which may be the same as or different from the diameter of the other pulleys 18 in the elevator system 10. At least one of the pulleys 18 may be a drive pulley. The drive pulley is driven by the machine 50. The drive pulley, through the movement of the machine 50, drives, moves, and/or propels (via traction) the one or more belts 16 passing over the drive pulley.

At least one of the pulleys 18 may be a diverter, deflector, or idler pulley that is not driven by the machine 50 but helps guide the one or more belts 16 around various components of the elevator system 10.

In many embodiments, the elevator system 10 may utilize multiple belts 16 for suspending and/or driving the elevator car 12. Additionally, the elevator system 10 may have various configurations such that both sides of one or more belts 16 engage one or more pulleys 18 (such as shown in the exemplary elevator systems of FIG. 1A , FIG. 1B , or FIG. 1C ) or only one side of one or more belts 16 engages one or more pulleys 18.

FIG1A provides a 1:1 roping arrangement in which one or more belts 16 terminate at the car 12 and counterweight 22. FIG1B and FIG1C provide different roping arrangements. Specifically, FIG1B and FIG1C illustrate that the car 12 and/or counterweight 22 may have one or more pulleys 18 on which one or more belts 16 engage, with the one or more belts 16 terminating elsewhere, typically at a pair of load-bearing structures within the elevator shaft 14 (such as for an elevator system without a machine room) or at a structure within the machine room (for an elevator system utilizing a machine room). The number of pulleys 18 used in the arrangement determines the specific roping ratio (e.g., a 2:1 roping ratio as shown in FIG1B and FIG1C or a different ratio). FIG1C also provides a so-called backpack or cantilever type elevator. The present invention may be used in elevator systems other than the exemplary types shown in FIG1A, FIG1B, and FIG1C.

FIG2 provides a schematic longitudinal cross-sectional view of an exemplary tape 16 construction or design. The tape 16 includes a plurality of fibers 24. The fibers 24 are discontinuous across the tape length 26, having a plurality of breaks or gaps 28 between the fibers 24 along the tape length 26. The plurality of fibers 24 may be arranged or stacked along a tape width 30 and/or a tape thickness 32, generally oriented such that the fiber lengths 34 are directed along the tape length 26. The fibers 24 are bonded to a polymer matrix 36 to form tension members 38 for the tape 16. One or more of these tension members 38 may be enclosed in a polymer jacket 40 to form the tape 16. For example, in the embodiment shown in FIG3 , the tape 16 includes three tension members 38 enclosed in a jacket 40.

The fibers 24 can be formed from one or more of a variety of materials, such as carbon, glass, polyester, nylon, aramid, or other polyimide materials. Furthermore, the fibers 24 can be organized into groups, such as spun yarn. The matrix 36 can be formed from, for example, a thermoset or thermoplastic material, while the jacket 40 can be formed from an elastomeric material, such as thermoplastic polyurethane (TPU). The tension member 38 is further configured to have a fiber 24 density of 30% to 70% fibers 24 per unit volume. In some embodiments, the size, length, or circumference of the fibers 24 can vary and can further be intentionally varied to provide a selected maximum fiber 24 density.

Referring again to FIG. 2 , when arranging the fibers 24, the fibers 24 are staggered so that the gaps 28 do not extend continuously across the entire ribbon thickness 32 or the entire ribbon width 30. Thus, the ribbon maintains desired longitudinal strength even though the fibers 24 are discontinuous along the ribbon length 26. Furthermore, the ribbon 16 having discontinuous fibers 24 has reduced bending stiffness along the longitudinal direction, resulting in improved ribbon flexibility and improved damping characteristics compared to ribbons having continuous fibers. Damping is improved by stress concentration at the numerous fiber ends 42 and, consequently, increased hysteretic energy losses in the gaps 28 and regions between the fibers 24. The improved damping characteristics improve elevator ride comfort, particularly in high-rise installations.

Another embodiment is shown in FIG4 . In this embodiment, the fibers 24 are arranged into bundles 44 comprising multiple layers of fibers 24. The bundles 44 can be arranged or stacked along the tape length 26 , along the tape width 30 , or along the tape thickness 32 . The bundles 44 are formed by bonding the fibers 24 with a first polymer matrix 26 a. The bundles 44 can then be formed into the tension member 38 by arranging the fiber bundles 44 into a selected configuration and then bonding the bundles 44 into the tension member 38 using a second polymer matrix 26 b. In some embodiments, the first polymer matrix 26 a and the second polymer matrix 26 b are the same material, while in other embodiments, the first polymer matrix 26 a and the second polymer matrix 26 b are different materials to achieve selected properties of the tension member 38. In other embodiments, as shown in FIG5 , the discontinuous fibers 24 can be mixed with a plurality of continuous fibers 46 to form a hybrid tension member 38.

In some embodiments, the fibers 24 are discontinuous when bonded to the first polymer matrix 26, while in other embodiments, continuous fibers are fed into the production machine and after impregnation and/or partial curing (cooling) of the matrix, the fibers are then broken into short fibers 24 prior to final curing (or solidification).

6 and 7 , the belt 16 or tension member 38 may include one or more layers 48 of randomly oriented fibers 24, wherein at least a portion of the fibers are oriented in a direction other than along the belt length 26. The random or off-longitudinal orientation of the fibers 24 increases the belt strength across the belt width 30. The layers 48 may be the outermost portions of the tension member 38 as shown in FIG6 , or alternatively, one or more layers 48 may be embedded within the interior of the tension member 38. Furthermore, the fibers 24 of the layers 48 may be formed from the same material as the fibers 24 of the remainder of the tension member 38, or may be formed from a different material. The layers 48 may be continuous or discontinuous, or a combination of both.

In addition to the previously mentioned reduced bending stiffness resulting in greater ribbon flexibility, and in addition to the better damping properties of the ribbon 16 having discontinuous fibers 24, the ribbon 16 improves repairability because fiber continuity does not need to be maintained when making repairs.

Although the present disclosure has been described in detail with reference to only a limited number of embodiments, it should be readily understood that the present invention is not limited to these disclosed embodiments. Rather, the present disclosure may be modified to incorporate any number of variations, alternatives, replacements, or equivalent arrangements not previously described but consistent with the spirit and scope of the present invention. Additionally, while various embodiments of the present disclosure have been described, it should be understood that various aspects of the present disclosure may include only some of the described embodiments. Accordingly, the present disclosure should not be construed as limited by the foregoing description, but is limited only by the scope of the appended claims.

Claims (13)

1. A belt for suspending and/or driving an elevator car, comprising: A tension member extending along the length of the strip, the tension member comprising a plurality of fibers bonded in a first polymer matrix, the plurality of fibers extending parallel to the length of the strip and discontinuous along the length of the strip, and having one or more longitudinally extending gaps arranged between longitudinally adjacent fibers; and A jacket, which substantially holds the tension member; The fibers are interlaced so that one or more longitudinally extending gaps do not extend continuously across the entire belt thickness; and The fibers are arranged as bundles comprising multiple layers of fibers, wherein the bundles are stacked along the thickness of the strip, and wherein the bundles are formed into the tension member by bonding the bundles to the tension member using a second polymer matrix. 2. The tape of claim 1, wherein the second polymer matrix material is different from the first polymer matrix material. 3. The belt as claimed in claim 1 or 2, wherein the tension member has a fiber density between 30% and 70% by volume. 4. The belt as claimed in claim 1 or 2, wherein the fiber bundle comprises fibers having a non-uniform size. 5. The belt as claimed in claim 1 or 2, wherein the belt comprises one or more layers of fibers that do not extend parallel to the length of the belt. 6. The strip as claimed in claim 5, wherein one or more layers are disposed on the outermost strip surface. 7. The belt as claimed in claim 1 or 2, wherein the plurality of fibers are formed from one or more of carbon, glass, polyester, nylon, aramid, or other polyimide materials. 8. The tape as claimed in claim 1 or 2, wherein the first polymer matrix is formed of a thermosetting material or a thermoplastic material. 9. The belt as claimed in claim 1 or 2, wherein the belt has a width-to-thickness ratio greater than or equal to 3:2, wherein a plurality of tension members are arranged across the width of the belt. 10. An elevator system comprising: Elevator car; One or more pulleys; and One or more belts, said one or more belts being operatively connected to the car and interacting with said one or more pulleys for suspending and/or driving the elevator car, each of said one or more belts being a belt as described in any one of claims 1-9. 11. A method of forming a belt for suspending and/or driving an elevator car, the method comprising forming a tension member by means of the following steps: Multiple fibers are arranged in multiple fiber bundles, the multiple fibers extending parallel to the length of the belt and having one or more longitudinally extending gaps between the longitudinally extending fibers; Bonding the plurality of fibers in the fiber bundle to a first polymer matrix; and The plurality of fiber bundles are fixed to each other using a second polymer matrix to form the tension member; the method further includes the following steps: The tension member is substantially held within the jacket. 12. The method of claim 11, further comprising forming the one or more longitudinally extending gaps by breaking longitudinally adjacent fibers. 13. The method of claim 11 or 12, wherein the plurality of fibers are formed from one or more of carbon, glass, polyester, nylon, aramid, or other polyimide materials.