NZ207778A - Sling: sheathed endless loop - Google Patents

Description

207778 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL NO: 207778 DATED: 9 April 1984 IMPROVEMENTS IN OR RELATING TO SLINGS WE, JOHN EDWARD BUTLER (NEW ZEALAND) LIMITED, of 80-82 Richmond Road, Grey. Lynn, Auckland, New Zealand, a company incorporated according to the Laws of New Zealand do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: 207778 This invention relates to slings and in particular to a sling adapted to support a load when suspended from a lifting means.

An object of this invention is to provide a sling of simple 5 construction.

According to a first aspect of the invention there is provided a sling comprising an endless loop incorporating a core formed by one or more tendons arranged in a plurality of coils to define the loop, a protective cover about the loop and one or 10 more sleeves provided about a section of the protective cover and slideable therearound.

According to a second broad aspect of the invention there is ; provided a sling as defined in the preceding paragraph wherein two sleeves are provided about the cover disposed at first 15 opposing sections of the loop and two further opposing sections of the loop intermediate the sleeves are located in adjacent relationship to one another by a captivating sleeve such that . an eyelet is formed by the loop at both ends of the captivating sleeve.

In further describing this invention reference is made to the drawings of a preferred embodiment in which: 207:778 Figure 1 is partly schematic part cutaway perspective view, and Figure 2 is a partly schematic perspective view.

A preferred sling 10 comprises an endless loop 12 of resilient material. The loop 12 comprises a core 14 formed by" one or more tendons 14a arranged in a plurality of coils which define the loop 12. It is preferred that one tendon only 14a is provided and which is formed from a material having a high tensile strength such as, for example a suitable synthetics material or a suitable metal. The tendon 14a is preferably arranged in a plurality of coils with the ends of the tendon 14a being attached to one another or each end to an associated section of the tendon 14a to help resist unravelling of the coils.

However, experiment has shown that friction between adjacent coils prevents the coils from unravelling when the tendon 14a ends are unfastened. Alternatively, it will be appreciated that the core 14 can comprise a plurality of tendons 14a forming a plurality of individual coils which will facilitate the strength of the sling 10. In this embodiment, the coils may be loosely bound together and in the event of one or more coils breaking during use, the remaining coils may prevent the sling 10 as a whole from breaking.

A protective cover 16, is provided about the core 14, preferably in the form of a hollow tube with a seamless wall. 207778 The cover 16 is preferably formed from a resilient material such as a suitable nylon webbing to facilitate the strength and resiliency thereof. The cover 16 is preferably adapted to in use, allow for expansion and contraction of the overall 5 length of the sling 10 when stressed during use. The cover 16 may therefore be endless and incorporate an expansion section in the form of a concertina (not depicted). Alternatively, one end 18 of the cover 16 may be telescopically housed within the other end 20 thereof.

One or more slideable sleeves 22 are provided about a section of the cover 16 to provide additional protection therefor. Two sleeves 22 are preferably provided about the cover 16, for example at first opposing sections 12a of loop 12.

Altering; the positions of the sleeves 22 on cover 16, helps 15 to avoid concentrated wearing of the cover 16 which can result during use from chaffing by hooks and alternative couplings (not depicted). The sleeves 22 are preferably formed from a material having the same or similar characteristics as the cover material.

In use, the sling 10 can be disposed with the first opposing sections 12a thereof, each preferably covered by a sleeve 22^ connected to lifting means and with two further opposing sections 12b of loop 12, intermediate the first sections 12a, supporting a load. 207778 A captivating sleeve 24 can be provided to retain the second loop sections 12b in adjacent relationship to one another. The captivating sleeve 24 preferably comprises two integrally formed adjacent and parallelly disposed receptacles one each for the two loop Msections 12b. The first loop sections 12a of sling 10, form eyelets 26, one at each end of the captivating sleeve 24 for connection to hooks or alternative couplings. The captivating sleeve 24 provides reinforcement to, and helps to prevent wearing of the cover 16 to help prevent concentration of wear thereon. It will be appreciated that the captivating sleeve 24 can comprise one receptacle only common to both the loop sections 12b. In an alternative embodiment of the invention, the second loop sections 12b can be twisted about one another for example in a right hand lay to facilitate the strength of the sling 10. The two so twisted sections 12b can be covered by a single moveable captivating sleeve 24 to provide protection for the cover 16. 2G?,:;'73

Claims (7)

WHAT WE CLAIM IS:

1. A sling comprising an endless loop incorporating a core formed by at least one tendon arranged in a plurality of coils to define the loop with a protective cover in the form of a flexible seamless walled hollow tube 5 circumscribingly enveloping about the tendons and at least one seamless sleeve provided about a section of the protective cover and slidable therearound.

2. A sling as in Claim 1 wherein two of the said sleeves are circumjacent to the cover disposed at opposing 10 intermediate sections of the loop being held in juxtaposition by a captivating sleeve such that an eyelet is formed by the loop at each end of the captivating sleeve.

3. A sling as claimed in Claim 1 or Claim 2 wherein an end of the cover is telescopically housed within another end of 15 the cover to in use allow for expansion and contraction of the cover.

4. A sling as claimed in Claim 2 or Claim 3 wherein the captivating sleeve comprises two adjacent integrally formed parallelly disposed receptacles one for each-opposing.. 2 0 section of the loop. 207773 - 7 -

5. A sling as claimed in Claim 2 or Claim 3 wherein the opposing sections of the loop are twisted about one another within the captivating sleeve.

6. A sling as claimed in any one of the preceding claims save Claim 3 wherein the protective cover is endless and incorporates an expansion section.

7. A sling substantially as herein described with reference to the accompanying drawings. JOHN EDWARD BUTLER ■ (NEW ZEALAND) LIMITED By its Attorneys HENRY HUGHES LIMITED s e>\ ?y A 2 OMAR 1937.;! V fh \ - O // //