EP1329413B1

EP1329413B1 - Hoisting rope

Info

Publication number: EP1329413B1
Application number: EP00953527A
Authority: EP
Inventors: Takenobu Mitsubishi Denki Kabushiki Kaisha HONDA
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2000-08-21
Filing date: 2000-08-21
Publication date: 2011-01-12
Anticipated expiration: 2020-08-21
Also published as: EP1329413A1; WO2002016248A1; KR100475330B1; JP4777597B2; EP1329413A4; KR20020035891A; DE60045525D1; CN1379730A

Abstract

A strand (7) is formed by parallelly collecting together a number of fine lines of high strength synthetic resin fiber. And a plurality of such strands (7) are bundled and a surface covering layer (8) of wear-resistant synthetic resin is formed to cover the outer peripheral surface thereof, thereby constituting a hoisting rope (2). The hoisting rope (2) of such arrangement is used to suspend objects (3, 4) and hoist them up through a driving sheave (1). This reduces the tendency of the hoisting rope (2) from losing its shape, making it possible to maintain strength and improve suspension reliability.

Description

TECHNICAL FIELD

The present invention relates to a hoist rope which is formed from a synthetic fiber rope, the rope being made by means of bundling a plurality of strands, and which tows a member to be suspended.

BACKGROUND ART

Figs. 2 and 3 are illustrations of a related-art hoist rope described in, e.g., Japanese Patent Application Laid-Open No. 267534/1995 ( US-A-5,566,786 ). Fig. 2 is a conceptual elevation view of an elevator, showing a suspending status of a hoist rope. Fig. 3 is an enlarged transverse cross-sectional view of the hoist rope shown in Fig. 2.
In drawings, reference numeral 1 designates a driving sheave provided on a hoisting machine of the elevator; and 2 designates a hoist rope which is wound around the driving sheave 1 and is made of a synthetic fiber rope. A first member to be suspended 3 made up of an elevator car is coupled to one end of the hoist rope 2, and a second member to be suspended 4 made of a counterweight is coupled to the other end of the rope.
Reference numeral 5 designates a strand constituting a primary strength member of the hoist rope 2. The strand is made by means of plaiting a plurality of wires of high-strength synthetic resin fiber having a diameter of several microns, and bundling in parallel the wires by means of adhesive means.
Reference numeral 6 designates cladding material made of synthetic resin such as urethane or polyethylene. The cladding material is provided for maintaining a form in which a plurality of the strands 5 are bundled. In order to prevent abrasion of the wires of high-strength synthetic resin fiber, which would otherwise arise in outer circumferential surfaces of the strands 5 when the hoist rope 2 is subjected to repeated bending and stretching as a result of running of the elevator, the cladding material is provided so as to cover outer circumferences of the bundled strands 5.
The hoist rope constituted as mentioned above suffers problems; that is, a problem of the bundled form of the strands 5 being deformed as a result of occurrence of slippage between the cladding material 6 and the strands 5 for reasons of insufficient contact between the cladding material 6 with the outer circumferences of the bundled strands 5; and a problem of a drop in the strength of the hoist rope as a result of abrasion of the cladding material for reason of occurrence of micro-slippage between the strands 5 and the cladding material 6.
WO 98/16681 A2 discloses a hoist rope comprising strands formed by bundling yarns of high-strength synthetic fiber in parallel and a surface cladding layer formed by a combination of synthetic resin and reinforcing fibers.

DISCLOSURE OF THE INVENTION

The present invention relates to a hoist rope, wherein a plurality of strands are each formed by means of bundling a plurality of wires of high-strength synthetic fiber in parallel, and wherein outer circumferences of the bundled strands are sheathed with a surface cladding layer of wear-and-abrasion-resistant synthetic resin material and reinforcing fiber.
The hoist rope comprises outer- layer strength members which are each made from wires having a diameter of several microns and are interposed between the strands and the surface cladding layer, the wires being formed from the same high-strength synthetic resin as that from which the strands are formed or from synthetic resin material categorized in the same family in which the high-strength synthetic resin is categorized. As a result, the strength of the hoist rope is enhanced by means of the strength members along with the strands.
The outer-layer strength members are bundled in parallel by means of adhesive means made from material having a fusing point characteristic lower than that of the surface cladding layer. As a result, adhesive strength between the surface cladding layer and the outer-layer strength members can be improved. A bundled form of a plurality of strands of a hoist rope can be maintained; namely, deformation of the bundled strands can be prevented. Hence, shortening the life of the hoist rope can be prevented, thus improving the suspension reliability of the rope.
In a preferred embodiment the rope has a surface cladding layer formed by mixture of high-strength fiber. As a result, the strength of the surface cladding layer is improved, thus enhancing the strength of the hoist rope.
The rope may have a surface cladding layer formed by means of mixture of high-strength fiber, the fiber being made from the same high-strength synthetic fiber as that from which the strands are formed. As a result, the strength of the surface cladding layer is improved, thus enhancing the strength of the hoist rope.
The rope may have a surface cladding layer formed by means of mixture of high-strength metal fiber. As a result, the strength of the surface cladding layer is improved, thus enhancing the strength of the hoist rope.
The rope may have a surface cladding layer formed by means of high-strength fiber having been integrally braided into a mesh pattern. As a result, the strength of the surface cladding layer is improved, thus enhancing the strength of the hoist rope. Further, the elongation characteristic of the surface cladding layer and that of the strands can be made uniform. Further, the hoist rope is improved in wear-and-abrasion-resistance, whereby the life of the rope can be prolonged and suspension reliability of the rope can be improved.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Fig. 1 is a transverse cross-sectional view of a preferable hoist rope according to the present invention;
Fig. 2 is a conceptual elevation view of an elevator, showing a suspending state of a related-art hoist rope; and
Fig. 3 is an enlarged transverse cross-sectional view of the hoist rope shown in Fig. 2.

BEST MODES FOR IMPLEMENTING THE INVENTION

In order to describe a first embodiment of the present invention in more detail, the embodiment will be described by reference to the accompanying drawings. As shown in Fig. 1, reference numeral 7 designates a strand constituting a primary strength member of a hoist rope 2 made from a synthetic fiber rope, and the strand is made by bundling a plurality of wires having a diameter of several microns formed from high-strength synthetic resin fiber with adhesive means.
Reference numeral 8 designates a surface cladding layer which is made of wear-and-abrasion-resistant synthetic resin and is arranged so as to cover outer circumferential surfaces of the plurality of strands 7. The surface cladding layer 8 is formed from the same high-strength synthetic resin as that from which the strands 7 are formed or from synthetic resin belonging to the same family as that to which the high-strength synthetic resin belongs.
The strength of the surface cladding layer 8 is enhanced by mixture of high-strength fiber 9 made of PBO resin; aramid, e.g. KEVLAR®; carbon; or XYRON®. High-strength metal fiber, such as a wire formed from carbon steel by means of hardening, or a monocrystal material such as a whisker, can be employed as an alternative to the high-strength fiber 9.
If the high- strength fiber 9 mixed into the surface cladding layer 8 differs in elongation characteristic from high-strength synthetic fiber from which the stands 7 are formed, the high-strength fiber 9 to be mixed integrally into the surface cladding layer 8 is plaited into a mesh pattern. By means of a mesh structure of the thus-plaited fiber, the elongation characteristic of the surface cladding layer 8 and that of the strands 7 can be made uniform, and the life of the rope can be prolonged, thus improving the suspension characteristic of the rope.
If the high-strength fiber 9 to be mixed into the surface cladding layer 8 is formed from the same high-strength synthetic resin fiber as that from which the strands 7 are formed or if an improvement in the strength of the rope is expected by virtue of mixture of the high-strength fiber 9, the strands 7 and the high-strength fiber 9 are arranged linearly in parallel with each other in the longitudinal direction of the hoist rope 2, whereby integration of the strands 7 with the high-strength fiber 9 and an improvement in the strength of the rope can be achieved.
Further, if the high-strength fiber 9 to be mixed into the surface cladding layer 8 is made of a material differing from the high-strength synthetic resin fiber constituting the strands 7 or if an improvement in wear-and-abrasion resistance of the rope is expected by virtue of mixture of the high-strength fiber 9, the high-strength fiber 9 is plaited into a mesh pattern, whereby integration of the strands 7 with the high-strength fiber 9 and an improvement in the wear-and-abrasion resistance of the rope can be achieved.
Outer-layer strength members are formed between the strands 7 and the surface cladding layer 8. Each of the outer-layer strength members is formed by means of bundling wires having a diameter of several microns, the wires being formed from the same high-strength synthetic resin as that from which the strands are formed or from synthetic resin material categorized in the same family in which the high-strength synthetic resin is categorized. The outer-layer strength member is formed by means of bundling the wires in parallel with adhesive means. The outer-layer strength members are formed so as to enclose the outer circumferential surfaces of the plurality of strands 7. Thus, the strength of the hoist rope 2 can be enhanced by means of the strength member along with the strands 7.
The outer-layer strength members are bundled in parallel with each other by means of adhesive means made from material having a fusing point characteristic lower than that of the surface cladding layer 8. As a result, adhesive strength between the surface cladding layer 8 and the outer-layer strength members can be improved when the outer-layer strength members are sheathed with the surface cladding layer 8 through fused coating. An improvement in adhesive strength between the surface cladding layer 8 and the outer-layer strength members enables preservation of a bundled form of the plurality of strands 7 of the hoist rope 2; namely, deformation of the bundled strands can be prevented. Hence, shortening of the life of the hoist rope can be prevented.

INDUSTRIAL APPLICABILITY

As has been described, a hoist rope according to the present invention is provided with a plurality of strands which are each formed by means of bundling a plurality of wires of high-strength synthetic fiber in parallel, and a surface cladding layer of wear-and-abrasion-resistant synthetic resin sheathing outer circumferences of the bundled strands.
In relation to the hoist rope according to the present invention, outer-layer strength members are each made from wires having a diameter of several microns and are interposed between a plurality of bundled strands and a surface cladding layer, wherein the wires are formed from the same high-strength synthetic resin as that from which the strands are formed or from synthetic resin material categorized in the same family in which the high-strength synthetic resin is categorized. As a result, the strength of the hoist rope is enhanced by means of the strength members along with the strands, and the hoist rope is useful for towing a member to be suspended by way of a driving sheave. Further, desired strength is readily obtained, and a suspension reliability of the rope can be improved. Hence, the rope is suitable for towing the member.
The hoist rope according to the present invention is provided with the outer-layer strength members which are bundled in parallel by means of adhesive means made from material having a fusing point characteristic lower than that of the surface cladding layer. As a result, adhesive strength between the surface cladding layer and the outer-layer strength members is improved, and the rope is useful for towing a member to be suspended by way of a driving sheave. Preservation of a bundled form of a plurality of strands of a hoist rope; namely, prevention of deformation of the bundled strands, can be achieved. Hence, shortening of the life of the hoist rope can be prevented, thus improving the suspension reliability of the rope. For this reason, the rope is suitable for towing the member.
The hoist rope may be provided with a surface cladding layer formed by mixture of high-strength fiber. As a result, the strength of the surface cladding layer is improved, and the rope is useful for towing a member to be suspended by way of a driving sheave. Since desired strength is readily obtained and the suspension reliability of the rope can be improved, the rope is suitable for towing the member.
The hoist rope may be provided with a surface cladding layer formed by means of mixture of high-strength fiber, the fiber being made from the same high-strength synthetic fiber as that from which the strands are formed. As a result, the strength of the surface cladding layer is enhanced, and the rope is useful for towing a member to be suspended by way of a driving sheave. Since desired strength is readily obtained, and the suspension reliability of the rope can be improved. Hence, the rope is suitable for towing the member.
The hoist rope may be provided with a surface cladding layer formed by means of mixture of high-strength metal fiber. As a result, the strength of the surface cladding layer is enhanced, and the rope is useful for towing a member to be suspended by way of a driving sheave. Since desired strength is readily obtained, the suspension reliability of the rope can be improved. Hence, the rope is suitable for towing the member.
Further, the hoist rope may be provided with a surface cladding layer formed by means of high-strength fiber having been integrally braided into a mesh pattern. As a result, the strength of the surface cladding layer is enhanced, and the rope is useful for towing a member to be suspended by way of a driving sheave. Desired strength is readily obtained, and the elongation characteristic of the surface cladding layer and that of the strands can be made uniform. In addition, the wear-and-abrasion-resistance of the hoist rope is improved, whereby the life of the rope can be prolonged and suspension reliability of the rope can be improved. Hence, the rope is suitable for towing the member.

Claims

A hoist rope comprising:
a plurality of strands (7) which are each formed by means of bundling a plurality of wires of high-strength synthetic fiber in parallel; and

a surface cladding layer (8) formed by a combination of wear-and-abrasion-resistant synthetic resin material and reinforcing fiber (9) so as to cover outer circumferential surfaces of the bundled strands; characterized by

outer-layer strength members which are formed from wires having a diameter of several microns, the wires being formed from the same high-strength synthetic resin as that from which the strands (7) are formed or from synthetic resin material categorized in the same family in which the high-strength synthetic resin is categorized, and which are interposed between the strands (7) and the surface cladding layer (8); and

by the outer-layer strength members being formed by bundling the wires in parallel with each other by means of adhesive means made from material having a fusing point characteristic lower than that of the surface cladding layer (8).
The hoist rope according to claim 1, wherein the surface cladding layer is formed by mixture of the wear-and-abrasion-resistant synthetic resin material and high-strength fiber as the reinforcing fiber (9).
The hoist rope according to claim 2, wherein the high-strength fiber is the same high-strength synthetic fiber as that from which the strands (7) are formed.
The hoist rope according to claim 2, wherein the high-strength fiber is a high-strength metal fiber.
The hoist rope according to claim 2 or 4, wherein the high-strength fiber is plaited into a mesh pattern integrally with the surface cladding layer (8).