AU595409B2

AU595409B2 - Branch seal

Info

Publication number: AU595409B2
Application number: AU82826/87A
Authority: AU
Inventors: Raymond Charles Foss; Michael John Sleeman
Original assignee: Bowthorpe Hellerman Ltd
Current assignee: Bowthorpe Hellerman Ltd
Priority date: 1986-12-20
Filing date: 1987-12-18
Publication date: 1990-03-29
Anticipated expiration: 2007-12-18
Also published as: DE8716722U1; GB2199201A; AU8282687A; GB8729200D0; GB2199201B

Description

COLLISON for and on behalf of the Applicant).

Davies Collison, Melbourne and Canberra.

I II ~i mill OF AUSTRALIA

COMMONWEALTH

PATENT ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE CLASS INT. CLASS Application Number: Lodged: Complete Specification Lodged: Accepted: Published: 59#5 i^ Priority: Related Art-: tv S S 0* S

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S S r F, 'l r t lH.' in i Ij,'tee ttnll I" lio.r is C r f1' J1, 10-1) :"NAME OF APPLICANT: BOWTHORPE-HELLERMANN LTD

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5 S ADDRESS OF APPLICANT: Crawley, West SUssex, RH10 2RZ, England.

0e NAME(S) OF INVENTOR(S) Raymond Charles FOSS S"Michael John SLEEMAN

S.

S.*

ADDRESS FOR SERVICE: DAVIES COLLISON, Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED.

"BRANCH SEAL" The following statement is a full description of this invention, including the best method of performing it known to us -1- BRANCH SEAL 0e *9 This invention relates to a branch seal or sealed closure particularly for branched telecommunications or power cables and more particularly to a method of forming such a branch seal.

It is known to form a branch seal or sealed closure around branched cables by disposing a heat recoverable sleeve around the branched cable and then applying heat to cause the sleeve to shrink about the cables. Various techniques have been proposed for sealing the end of the sleeve between the 'fe* branched cables, including the technique of applying a clip between the branched cables in order to bring the opposite sides of the sleeve together before effecting heat recovery.

We have now devised an improved method for forming a branch seal.

In accordance with this invention, there is provided a method of forming a sealed closure around branched elements which are disposed generally parallel to each other, comprising disposing a. heat-recoverable sleeve around said elements, applying heat to cause the sleeve to shrink about said elements and then, whilst the sleeve is hot, applying tongs across an open end of the sleeve between adjacent said elements so as to engage opposed portions of the sleeve and operating said tongs to urge said opposed portions of the sleeve into face to face contact between said elements.

This method results in the opposed portions of the sleeve adhering together face-to-face over the areas which have been urged together by the tongs, ensuring that the sleeve seals around both of the branched elements. A clip may be applied subsequently as an additional safeguard ensuring that the two sides of the sleeve will remain together.

We have found that it is preferable for the tongs which are used have jaws movable towards and away from each other substantially linearly such that elongate co-operating oortions of the jaws come together whilst remaining parallel to each other in their longitudinal direction. These tongs give a good seal which is easy to produce and reliable. Preferably the elongate co-operating portions of the jaws comprise flat rectangular metal plates or plate-like elements which come together face-to-face or edge-to-edge over a rectangular area between the adjacent branched elements.

Embodiments of this invention will now be described by way of example only and with reference to the accompanying drawings, in which: FIGURE 1 is a section through a closure being formed around branched cables; FIGURE 2 is a side view of the jaws of cne •embodiment of tongs used in forming the closure; FIGURE 3 gives a side view of an end view of the same embodiment of tongs but with modified jaws; FIGURE 4 is a side view of another embodiment of tongs in detail; and FIGURE 5 gives a side view and an end view of the tongs of Figure 4 but having modified jaws.

Referring to Figure 1, a heat-recoverable sleeve preferably having a coating of adhesive on its inner 4/ O_ 3 surface, is positioned around branched cables 12, 14. Then heat is applied to the sleeve to cause it to shrink but, whilst it is still hot, tongs are applied to the end of the sleeve, between the cables, and used to urge the two opposite side portions 10a, lOb, together (as indicated by the arrows). These sleeve portions become firmly adhered together face-to-face and the sleeve seals to the cables around the full circumference of each of these.

Referring to Figure 2, in one embodiment the tongs have a pair of jaws 20, 22 and include linkage such that when a pair of hand-grips of the tongs are urged together, the jaws move towards each other along a straight line A-A'.

A pair of rectangular plates 24, 26 are welded or otherwise :se. secured to the jaws, these plates being of equal size and 15 arranged face-to-face in parallel planes. Thus in use of these tongs, rectangular areas of the sleeve are brought S"together between the branched cables, which areas corress°o° pond to the rectangular metal plates of the tongs.

The area over which the opposite sides of the sleeve are urged together may be relatively wide or relatively narrow, according to the width of the plates of *es the tongs chosen. Figure 3 for example shows a modification in which the jaws of the tongs are provided with plates 24a, 26a which meet along their edges to urge the sleeve sides o. :25 together over a narrow rectangular area. In Figure 3 the plates are elongated in the lengthwise direction of the tongs, but may instead be oriented at right angles to the S, length of the tongs elongated in the direction per- S° pendicular to the paper on which Figure 3 is drawn).

Figure 4 shows another embodiment of tongs in detail. The jaws 30, 32 comprise parallel shafts on which bodies 34, 36 may slide, being fixed in required positions by clamp screws 37. The bodies 34, 36 mount rectangular plates 38, 40 which are arranged edge-to-edge with each other, and extend perpendicular to the length of the tongs.

4 Figure 4 shows two pairs of bodies 34, 36 with their sealing plates, for use on a cable joint having three cables extending from an end of that joint. However, one pair may be removed by loosening the respective clamp screws 37 and sliding the bodies from the shafts 30, 32 once locking screws 39 have also been removed.

The tongs shown in Figure 4 are of the type having a pair of hand-grips 42, 44 and links 46, 48. The link 46 is journalled to the front end of the grips 42, 44 at 41 and 43 respectively and the jaws 30, 32 are mounted to the grip 42 and the link 46 respectively. Link 48 is journalled to grip 44 at 45 and to an adjustment shaft 50 of grip 42 at 47, substantially further away from the jaws than point 1. In operation, when the grips 42, 44 are urged together, .1:5 this causes link 48 to pivot and lie more parallel to the grips, in turn causing grip 44 to move forwardly and rock S link 146 so as to close the jaws 30, 32 together. When the hand-pressure is released from the grips, a return spring S 52 (which is connected between link 46 and grip 42) serves to return the components to their original positions. However, throughout the closing movement of the jaws, the facing edges of the sealing plates 38, 40 remain parallel to each other along their lengths.

Figure 5 shows a modification of the tongs of 0 2.5 Figure 4, the jaw shafts 30, 32 being replaced with jaws 501 52 which are integral with the grip 42 and link 46 respectively and include plate portions arranged edge-to-edge and elongated in the direction perpendicular to the length of the tongs.

In all of the arrangements of tongs which have been described, the jaws include plates which come together whilst their facing edges or surfaces remain parallel to each other at least in their longitudinal direction. We have found that this ensures that the opposite portions of the sleeve are brought together in a manner promoting a reliable seal over the required rectangular area. This contrasts with the use of pliers, in which the co-o,perating surfaces of the jaws are elongated in the lengthwise direction of the pliers and the jaws move together over an arc.

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Claims

1. A method of forming a sealed closure around branched elements which are disposed generally parallel to each other, 7 comprising disposing a heat-recoverable sleeve around said a elements, applying heat to cause the sleeve to shrink about said f elements and then, whilst the sleeve is hot, applying tongs across an open end of the sleeve between adjacent said elements B so as to engage opposed portions of the sleeve and operating 0 said tongs to urge said opposed portions of the sleeve into face-to-face contact between said elements.

2. A method as claimed in claim 1, in which at least w three said elements extend generally parallel tco each other from said one end of the sleeve and, in one application of the tongs, S. said opposed portions of the sleeve are urged into face-to-face D contact between every adjacent pair of said elements at said one B end of the sleeve. B 0 D

3. A method as claimed in claim 1 or 2, in which the tongs comprise jaws with co-operating portions which are a elongate and parallel to each other and the jaws move relative to each other such that the co-operating portions come together whilst remaining parallel to each other in their longitudinal direction. 00.. 0000 S

4. A method as claimed in claim 3, in which said co- operating portiono of the jaws are elongated in the lengthwise *:o.oo direction of the tongs. B

5. A method as claimed in claim 3, in which said co- B operrating portions of the jaws are elongated in a direction B transverse to the length of the tongs.

6. A method as claimed in claim 5, in which the jaws of l 7-1-- L" i" ii,. F 7 the tongs comprise respective elongate elements along which bodies mounting said co-operating portions are slidable.

7. A method as claimed in any preceding claim, in which after said opposed portions of the sleeve have been urged into face-to-face contact between adjacent branched elements using said tongs, a clip is applied to the end of the sleeve between said branched elements for ensuring that said opposed portions of the sleeve remain together.

8. A method of forming a sealed closure around branched elements, said method being substantially as herein described with reference to the accompanying drawings. Dated this 10th day of January 1990 BOWTHORPE-HELLERMANN LTD By its Patent Attorneys Davies Collison S* I- Soo• r