GB2333532A

GB2333532A - Tear webbing

Info

Publication number: GB2333532A
Application number: GB9801116A
Authority: GB
Inventors: Mark Bellhouse; Kevin Holroyd
Original assignee: MARLING LEEK Ltd
Current assignee: MARLING LEEK Ltd
Priority date: 1998-01-21
Filing date: 1998-01-21
Publication date: 1999-07-28
Also published as: GB9801116D0

Abstract

Tear webbing 14 for absorbing shocks, e.g. in a safety harness for workmen, comprises two layers woven simultaneously with breakable binding threads on a needle loom which may be computer controlled. The webbing may be formed with a pattern of spaced pockets between the layers. The webbing may be incorporated within a fold 16 of outer webbing 12 and may have a cover formed by shrink-wrapping.

Description

TEAR WEBBING This invention relates to a method of making tear webbing, to tear webbing, and also to shock absorbing arrangements.

Tear webbing comprises two layers of webbing joined together in a specific manner so that the two layers tear apart at a predetermined force, thus creating a shock absorber whereby the force inflicted upon the wearer in the event of a fall is reduced. Such webbing is therefore often used in conjunction with safety harnesses for persons working at heights.

According to the present invention there is provided a method of manufacturing tear webbing, the method comprising weaving a first length of webbing onto a second length of webbing with a binder thread with a predetermined breaking force, the weaving being carried out using a needle loom.

The lengths of webbing are preferably woven together with binder threads. The needle loom is preferably computer controlled.

The lengths of webbing are preferably woven together for a first longitudinal extent, then the lengths left apart for a second longitudinal extent to form a pocket, and the pattern of weaving together and then leaving apart is then repeated.

For the second longitudinal extent the binder threads are preferably each woven only into a respective different one of the two lengths of webbing.

The weaving of the binder threads preferably comprises a mixture of standard two/two and one/one.

The lengths of webbing are preferably simultaneously formed by weaving and also woven together with the binder thread.

The invention also provides tear webbing made by a method according to any of the preceding six paragraphs.

The invention further comprises a shock absorbing arrangement comprising a length of such tear webbing.

The arrangement preferably comprises a single length of webbing with the shock absorbing arrangement mounted across a fold in the single length.

Cover means may be provided for the tear webbing which means break or are automatically shedded upon the lengths of webbing separating. The cover means may be produced by shrink wrapping.

Mounting means are preferably provided on each end of the single length.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings in which: Fig. 1 is a diagrarnmatic perspective view of a shock absorbing arrangement according to the present invention; and Fig. 2 is a further diagrammatic perspective view of the arrangement of Fig. 1, but with the cover removed.

The drawing shows a shock absorbing arrangement 10 suitable for use for example in connecting a person's safety harness to a safety line or other fixture, such that in the event of a fall the arrangement 10 will absorb the shock of the fall thereby greatly reducing the chance of the fall causing injury to the person. The arrangement 10 comprises a single length of webbing 12. The length 12 is folded back over itself for part 16 of its length. A length of tear webbing 14 according to the invention is mounted across the folded part 16.

The folded part 16 and tear webbing 14 are located within a cover 20 formed by shrink wrapping, and may be folded therein.

The ends of the webbing 12 are formed into loops 22 by folding back onto itself and sewing with a strength rated stitch pattern 24. The loops 22 accept conventional karabiners 26. The karabiners 26 permit normal mounting onto a harness at one end and to a structure, safety rope etc. at the other end.

The tear webbing 14 is formed by simultaneously weaving two layers of webbing using a computer controlled needle loom such as a Muller (trade mark) NFRE (Q) 2/84 Mutronic Machine. The two layers are woven together for predetermined lengths with binder threads. A pocket is then left between the two layers by the binding threads weaving respectively into each of the layers.

The two layers are then woven together again for a predetermined length and the pattern repeated. The end of the webbing 14 at the open end of the part 16 is cut at the end of a pocket to provide two flaps 18. The flaps 18 are heat sealed to prevent unravelling, and sewn to respective sides of the opening of the part 16 with stitch patterns 20.

In use, with the karabiners 26 connecting a wearer via their harness to a safety line or other fixture, if a fall occurs the shock of the fall will be absorbed by the binder thread breaking. If all of the binder thread breaks the two layers of webbing will separate and the webbing 12 will be pulled to its full length to restrain a fall. The cover 20 is arranged to automatically break or pull off upon breaking of the tear webbing 14.

There is thus described a safety arrangement and tear webbing, and method of making the same, which provides for considerable advantages. For instance, such tear webbing can be accurately and relatively quickly manufactured.

Various modifications may be made without departing from the scope of the invention. For example, the webbing could be initially manufactured and then subsequently formed into the tear webbing. A different needle loom machine could be used.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

CLUMS:- 1. A method of manufacturing tear webbing, the method comprising weaving a first length of webbing onto a second length of webbing with a binder thread with a predetermined breaking force, the weaving being carried out using a needle loom.
2. A method according to claim 1, wherein the lengths of webbing are woven together with binder threads.
3. A method according to claims 1 or 2, wherein the needle loom is computer controlled.
4. A method according to any of claims 1 to 3, wherein the lengths of webbing are woven together for a first longitudinal extent, then the lengths left apart for a second longitudinal extent to form a pocket, and the pattern of weaving together and then leaving apart is then repeated.
5. A method according to claim 4, wherein for the second longitudinal extent the or each binder thread is woven only into a respective different one of the two lengths of webbing.
6. A method according to claim 5, wherein the weaving of the or each binder thread comprises a mixture of standard two/two and one/one.
7. A method according to any of the preceding claims, wherein the lengths of webbing are simultaneously formed by weaving.
8. A method according to claim 7, wherein the lengths of webbing are also woven together with the binder thread.
9. Tear webbing made by a method according to any of the preceding claims.
10. A shock absorbing arrangement comprising a length of tear webbing according to claim 9.
11. A shock absorbing arrangement according to claim 10, wherein the arrangement comprises a single length of webbing with the shock absorbing arrangement mounted across a fold in the single length.
12. A shock absorbing arrangement according to claims 10 or 11, wherein cover means are provided for the tear webbing.
13. A shock absorbing arrangement according to claim 12, wherein the cover means break upon the lengths of webbing separating.
14. A shock absorbing arrangement according to claim 12, wherein the cover means are automatically shedded upon the lengths of webbing separating.
15. A shock absorbing arrangement according to any of claims 12 to 14, wherein the cover means are produced by shrink wrapping.
16. A shock absorbing arrangement according to any of claims II to I wherein mounting means are provided on each end of the single length.
17. Shock absorbing arrangement substantially as hereinbefore described with reference to the accompanying drawings.
18. A method of manufacturing tear webbing, the method being substantially as hereinbefore described with reference to the accompanying drawings.
19. Tear webbing substantially as hereinbefore described with reference to the accompanying drawings.
20. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.