Synthetic fiber rope

• US 7,665,289 B2
• Filed: 12/04/2007
• Issued: 02/23/2010
• Est. Priority Date: 12/04/2006
• Status: Active Grant

• Current Assignee: Inventio AG (Schindler Holding AG)
• Original Assignee: Inventio AG (Schindler Holding AG)
• Inventors: De Angelis, Claudio
• Primary Examiner(s): Hurley; Shaun R
• Application Number:
  US11/999,223
• Publication Number:
  US 20080148704A1
• Time in Patent Office: 812 Days
• Field of Search: 572/23, 572/38, 572/41, 572/44, 572/50
• US Class Current: 57/250
• CPC Class Codes: B66B 7/06 Arrangements of ropes or cables
• CPC Class Codes: B66B 7/1223 by analysing electric variables
• CPC Class Codes: D07B 1/025 comprising high modulus, or high tenacity, polymer filaments or fibres, e.g. liquid-crystal polymers
• CPC Class Codes: D07B 1/145 comprising elements for indicating or detecting the rope or cable status
• CPC Class Codes: D07B 1/24 Ropes or cables with a prematurely failing element
• CPC Class Codes: D07B 2205/205 Aramides
• CPC Class Codes: D07B 2205/3003 Glass
• CPC Class Codes: D07B 2501/2007 Elevators
• CPC Class Codes: D07B 2801/10 Smallest filamentary entity of a rope or strand, i.e. wire, filament, fiber or yarn

Abstract

A synthetic fiber rope can be used to the limit of failure by setting a sensitivity of detection of the state of wear of the rope. Strands of the rope have indicator fibers or indicator yarn that have a high probability of losing electrical conductivity and thereby indicate cable wear. The matrix of the strand with indicator fibers or with at least one indicator yarn has a lower resistance to abrasion than the matrix of the other strands without indicator fibers or indicator yarns.

Claims

1. A synthetic fiber rope having strands that are arranged in at least one strand layer, a strand including twisted yarns of synthetic fibers and a matrix, the synthetic fiber rope comprising:

at least one strand of the at least one strand layer having indicator fibers or at least one indicator yarn, wherein the matrix of the strand with said indicator fibers or with said at least one indicator yarn has a lower resistance to abrasion than the matrix of the other strands of the synthetic fiber rope for monitoring a service life of the synthetic fiber rope.

2. The synthetic fiber rope according to claim 1 wherein the matrix of the strand with said indicator fibers or with said at least one indicator yarn is impregnated with softener.

3. The synthetic fiber rope according to claim 1 wherein the matrix of the strand with said indicator fibers or with said at least one indicator yarn has a lower Shore hardness than a Shore hardness of a matrix of an adjacent strand or another strand of the rope.

4. The synthetic fiber rope according to claim 1 wherein the matrix of the strand with said indicator fibers or with said at least one indicator yarn is degraded by at least one of heat treatment and an addition of molecules of another material.

5. The synthetic fiber rope according to claim 1 wherein a matrix of at least one strands without said indicator fibers or without said at least one indicator yarn is impregnated with an additive that reduces a friction relative to the strands with said indicator fibers or with said at least one indicator yarn.

6. The synthetic fiber rope according to claim 1 wherein said at least one strand with said indicator fibers or with said at least one indicator yarn is positioned in the rope to have a higher load absorption relative to adjacent fibers in the rope.

7. A method for monitoring a rope service life of a synthetic fiber rope according to claim 1 including a step of permanently monitoring the strands utilizing the indicator fibers.

8. The method according to claim 7 including monitoring the indicator fibers by connecting the indicator fibers at one end of the rope to a signal transmitter, connecting the indicator fibers at an opposite end of the rope to a signal receiver, generating a transmission signal from the signal transmitter, monitoring for the transmission signal with the signal receiver, and on the basis of a presence or absence of the transmission signal at the signal receiver evaluating a condition of the indicator fibers.

9. The method according to claim 8 including monitoring of the indicator fibers by generating optical signals or electric signals as the transmission signal.

10. An elevator installation with a synthetic fiber rope according to claim 1 connected to an elevator car.