GB2043729A - Improvements in or relating to covers formed of heat-unstable material - Google Patents

Improvements in or relating to covers formed of heat-unstable material Download PDF

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Publication number
GB2043729A
GB2043729A GB7906772A GB7906772A GB2043729A GB 2043729 A GB2043729 A GB 2043729A GB 7906772 A GB7906772 A GB 7906772A GB 7906772 A GB7906772 A GB 7906772A GB 2043729 A GB2043729 A GB 2043729A
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GB
United Kingdom
Prior art keywords
sheet
cover
sleeve
edge
edge portions
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB7906772A
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GB2043729B (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Post Office
Original Assignee
Post Office
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Post Office filed Critical Post Office
Priority to GB7906772A priority Critical patent/GB2043729B/en
Publication of GB2043729A publication Critical patent/GB2043729A/en
Application granted granted Critical
Publication of GB2043729B publication Critical patent/GB2043729B/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C61/00—Shaping by liberation of internal stresses; Making preforms having internal stresses; Apparatus therefor
    • B29C61/06—Making preforms having internal stresses, e.g. plastic memory
    • B29C61/10—Making preforms having internal stresses, e.g. plastic memory by bending plates or sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/66—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by liberation of internal stresses, e.g. shrinking of one of the parts to be joined
    • B29C65/68—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by liberation of internal stresses, e.g. shrinking of one of the parts to be joined using auxiliary shrinkable elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B7/00—Insulated conductors or cables characterised by their form
    • H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
    • H01B7/18—Protection against damage caused by wear, mechanical force or pressure; Sheaths; Armouring
    • H01B7/24—Devices affording localised protection against mechanical force or pressure
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
    • H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
    • H02G1/16—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for repairing insulation or armouring of cables

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Cable Accessories (AREA)

Abstract

A cover for forming a sleeve around a body, e.g. a cable, to be protected comprises a sheet 10 formed from dimensionally heat unstable material. Opposite edge portions 14, 15 of the sheet have attached thereto respective components 16, 22 of a burr type fastener. When the sheet is wrapped around a cable the components 16 and 22 engage to provide a fastening which is resistant to sliding movement due to tangential forces. <IMAGE>

Description

SPECIFICATION Improvements in or relating to covers formed of heat-unstable material This invention relates to a cover formed of dimensionally heat-unstable plastics material. The invention is concerned particularly with preformed plastics covers which can be readily disposed about a body to be protected, sealed or closely covered for any other purpose, by drawing edges of the sheet material together and securely fastening them and applying heat to shrink the dimensionally heatunstable material over the body surface.
Such covers made in the configuration of longitudinally split sleeves are especially useful in the repair of polyethylene sheated cable, where, following removal of a section of sheathing, for example, in order to effect conductor maintenance, it is desired to replace the removed sheathing section by sheath material having similar sealing and protecting properties to the original sheath. To ensure such sleeves seal tightly over the original sheath end parts and the exposed cable interior, it is necessary that a closure joining the edges of the split sleeve should not fail during the shrinkdown process.
In one proposal described in U.K. Patent Application No. 2573/76 Serial No. 1545571 a cover is formed from heat shrinkable sheet material having two opposed edge portions one of which defines a sealing flap engageable in overlapping relationship with the other edge portion. Each edge portion has outstanding projections which, when the sheet is formed into a sleeve, abut to produce longitudinally spaced posts. A separate post retaining means is engageable over said posts to prevent movement of the two sets of projections away from each other. To form a cover the sheet is located around a core with the projections abutting. The post retaining means is then located over the posts. The sleeve is then sealed around the core by heat treatment which causes shrinking of the material of the sleeve so that it tightly engages the core.The post retaining means prevents opening of the sleeve during this process.
Generally the sleeve has a thermoactive adhesive on its inner surface, this adhesive being activated during the heat treatment and thus adhering the sleeve to the core.
The present invention provides a cover which does not require separate retaining means during the heat treatment.
According to the present invention there is provided a cover formed from dimensionally heat unstable sheet material which is adapted to be formed into a sleeve, said sheet having two opposed edge portions one of which is engageable in overlapping relationship with the other when formed into said sleeve, one of said edge portions carrying one com ponentof a bur type fastener and the other carrying the other component of a burtypefastener, said components being so positioned that they can engage when the sheet is formed into a sleeve.
Bur type fasteners are resistant to relative sliding movement although they can be pulled directly away from one another. This feature is useful in the present application since when the cover wrapped around a core and then subjected to heat shrinkage the resultant forces are tangential and thus acting to cause sliding of the fasteners.
The bu r fastener may comprise two component strips, one of which extends along an extreme edge of said one edge portion and the other of which extends close to but spaced from the extreme edge of said other edge portion.
The sheet may have a projection extending adjacent to and positioned inwardly of said other strip.
The sheet may be coated with a sealant or adhesive on that surface which is to form the inner surface of the sleeve.
The components of the burtype fastener may be bonded on, struck on or moulded into the sheet.
Said edge portions of the sheet may be formed from unexpanded polymer and the remainder of the sheet from expanded polymer.
The invention will be described now by way of example only with particular reference to the accompanying drawings. In the drawings: Figure 1 shows sheet material for forming a cover in accordance with the invention Figure 2 is a scrap view of part of a cover, and Figure 3 shows the cover located around a cable.
Referring to Figure 1 a cover is adapted to be formed from a sheet 10. The sheet 10 is made of a polymer such as polyethylene. The sheet comprises a main portion 12 and opposite, longitudinally extending edge portions 14, 15. One edge portion 14 carries a strip 16 which constitutes one component of a bur type fastener such as a "Velco" (Registered Trade Mark) fastener. The other edge portion 15 has an outer portion 18 whose thickness is less than that of the remainder of the sheet and an upstanding ridge 20 which extends longitudinally along the sheet at the junction of the main portion 12 with the edge portion 15. The edge portion 15 carries a strip 22 which extends adjacent the ridge 20. The strip 22 constitutes the other component of the bu r fastener.
The strips 16, 22 can be stuck on, stapled on, stitched on or moulded into the polymer. The edge portions 14, 15 of the sheet are formed from unexpanded polymer whilst the main portion 11 is formed from expanded polymer, that is one which has been conditioned to make it dimensionally heat-unstable to such an extent that it will shrink when subjected to heat.
The surface of the sheet opposite that with the ridge is covered with a layer 24 of sealant or adhesive.
In use the sheet is wrapped around, for example, a cable to be covered so that the layer 24 is next to the cable and the edge portion 14 overlaps the edge portion 15 with the strips 16 and 22 in engagement (Figure 2). In Figure 2 the gap between the overlapping portion is exaggerated and in practice the gap will be smaller. The ridge 20 acts as a stop to locate the The drawings originally filed were informal and the print here reproduced is taken from a later filed formal copy.
edge portion 14.
The sleeve is then subjected to heat treatment to cause it to shrink and thus tightly envelop the cable.
At the same time the sealant or adhesive is activated by the heat to cause the join between the sleeve and cable to be sealed.
During the heat treatment the sleeve is prevented from opening by the bur fastener comprising the strips 16, 22. A bur fastener is resistant to sliding movement although it can be opened by pulling the two components directly away from each other.
When the sleeve shrinks the forces acting on the bu r fastener are tangential i.e. tending to cause sliding movement, and thus can be resisted. In this way the use of a separate sleeve retaining member is obviated. The present method of closure also obviates the need to cut away any part of the sleeve when the cable is to be pulled into a pipe or duct. Some prior art sleeves require the removal of shoulders or closure rails prior to their being pulled into a pipe.

Claims (7)

1. A cover formed from dimensionally heat unstable sheet material which is adapted to be formed into a sleeve, said sheet having two opposed edge portions one of which is engageable in overlapping relationship with the-other when formed into said sleeve, one of said edge portions carrying one component of a bur type fastener and the other carrying the other component of a bur type fastener, said components being so positioned that they can engage when the sheet is formed into a sleeve.
2. A cover as claimed in claim 1 wherein the bur fastener comprises two component strips, one of which extends along an extreme edge of said one edge portion and the other of which extends close to but spaced from the extreme edge of said other edge portion.
3. A cover as claimed in claim 2 wherein the sheet has a projection extending adjacent to and positioned inwardly of said other strip.
4. A cover as claimed in any preceding claim wherein the sheet is coated with a sealant or adhesive on that surface which is to form the inner surface of the sleeve.
5. A cover as claimed in any preceding claim wherein the components of the bur type fastener are bonded on, stuck or moulded into the sheet.
6. A cover as claimed in any preceding claim wherein the edge portions of the sheet are formed from unexpanded polymer and the remainder of the sheet from expanded polymer.
7. A cover formed from dimensionally heat unstable sheet material substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
GB7906772A 1979-02-26 1979-02-26 Covers formed of heat-unstable material Expired GB2043729B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB7906772A GB2043729B (en) 1979-02-26 1979-02-26 Covers formed of heat-unstable material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB7906772A GB2043729B (en) 1979-02-26 1979-02-26 Covers formed of heat-unstable material

Publications (2)

Publication Number Publication Date
GB2043729A true GB2043729A (en) 1980-10-08
GB2043729B GB2043729B (en) 1982-11-10

Family

ID=10503439

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7906772A Expired GB2043729B (en) 1979-02-26 1979-02-26 Covers formed of heat-unstable material

Country Status (1)

Country Link
GB (1) GB2043729B (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3043824A1 (en) * 1980-11-20 1982-06-03 Siemens AG, 1000 Berlin und 8000 München Cable junction with end seals - which comprise support ring and shrink-fit sleeve for versatility
EP0056080A1 (en) 1980-12-19 1982-07-21 Siemens Aktiengesellschaft Longitudinally split sleeve of synthetic thermoplastic material with shape memory
US4478252A (en) * 1981-02-05 1984-10-23 Raychem Ltd. Device for enclosing objects
US4581265A (en) * 1983-12-12 1986-04-08 Raychem Corporation Wraparound closure
US4944973A (en) * 1983-12-12 1990-07-31 Raychem Corporation Wraparound article
WO1997049539A1 (en) * 1996-06-27 1997-12-31 Raychem Limited Wraparound heat-shrinkable article
US5958529A (en) * 1996-11-20 1999-09-28 Raychem Corporation Side entry sealing device
US5997967A (en) * 1993-05-07 1999-12-07 Hawkings; Robert Mark Side entry device for sealing wire bundles
US8127405B2 (en) 2003-06-18 2012-03-06 Suburban Machine Co., Inc. Reusable hose bundling sleeve
US10711921B2 (en) 2015-03-13 2020-07-14 Bradley D Barger Reusable hose bundling sleeve

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3043824A1 (en) * 1980-11-20 1982-06-03 Siemens AG, 1000 Berlin und 8000 München Cable junction with end seals - which comprise support ring and shrink-fit sleeve for versatility
EP0056080A1 (en) 1980-12-19 1982-07-21 Siemens Aktiengesellschaft Longitudinally split sleeve of synthetic thermoplastic material with shape memory
US4478252A (en) * 1981-02-05 1984-10-23 Raychem Ltd. Device for enclosing objects
US4581265A (en) * 1983-12-12 1986-04-08 Raychem Corporation Wraparound closure
US4944973A (en) * 1983-12-12 1990-07-31 Raychem Corporation Wraparound article
US5997967A (en) * 1993-05-07 1999-12-07 Hawkings; Robert Mark Side entry device for sealing wire bundles
WO1997049539A1 (en) * 1996-06-27 1997-12-31 Raychem Limited Wraparound heat-shrinkable article
US5958529A (en) * 1996-11-20 1999-09-28 Raychem Corporation Side entry sealing device
US8127405B2 (en) 2003-06-18 2012-03-06 Suburban Machine Co., Inc. Reusable hose bundling sleeve
US8691036B2 (en) 2003-06-18 2014-04-08 Suburban Machine Co., Inc. Method of making a reusable hose bundling sleeve
US10711921B2 (en) 2015-03-13 2020-07-14 Bradley D Barger Reusable hose bundling sleeve

Also Published As

Publication number Publication date
GB2043729B (en) 1982-11-10

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PCNP Patent ceased through non-payment of renewal fee