CA1091881A - Heat recoverable sleeve having a dimensionally heat stable portion - Google Patents
Heat recoverable sleeve having a dimensionally heat stable portionInfo
- Publication number
- CA1091881A CA1091881A CA277,317A CA277317A CA1091881A CA 1091881 A CA1091881 A CA 1091881A CA 277317 A CA277317 A CA 277317A CA 1091881 A CA1091881 A CA 1091881A
- Authority
- CA
- Canada
- Prior art keywords
- sleeve
- heat
- circumferential wall
- recoverable
- dimensionally
- 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.)
- Expired
Links
Classifications
-
- 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
- H02G15/00—Cable fittings
- H02G15/08—Cable junctions
- H02G15/18—Cable junctions protected by sleeves, e.g. for communication cable
- H02G15/1806—Heat shrinkable sleeves
-
- 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
- B29C61/0608—Making preforms having internal stresses, e.g. plastic memory characterised by the configuration or structure of the preforms
-
- 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
- B29C61/08—Making preforms having internal stresses, e.g. plastic memory by stretching tubes
Landscapes
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
- Manufacturing Of Electrical Connectors (AREA)
- Cable Accessories (AREA)
- Laminated Bodies (AREA)
Abstract
A B S T R A C T
A heat recoverable sleeve having an appendage mounted therein in a portion of the circumferential wall of the sleeve that is dimensionally heat stable or is subject to significantly less dimensional change than elsewhere on the circumferential wall on recovery thereof.
A heat recoverable sleeve having an appendage mounted therein in a portion of the circumferential wall of the sleeve that is dimensionally heat stable or is subject to significantly less dimensional change than elsewhere on the circumferential wall on recovery thereof.
Description
This invention relates to a heat-recoverable article, more e~pecially to such an article for use in covering a splice in an electric cable.
The u~e of heat-recoverable articleY for covering junction~ or splice~ in electric cables i~ known. The article is usually a heat-skrinkable sleeve, which may either be tubular or in ~heet form 80 that the sleeve may be wrapped around the cable splice after it has been made. The sleeve usually ha~ a layer of sealan~ or adhe~ive, e.g., a ma~tic or hot melt adhesive, applied to its inner surface. Such sleeve3 are described in U.S. Patent No. 3,297,819 granted on 10th January, 1967 to J.D. Wetmore and suitable means for joining opposite edges of a wrap-around sleeve are described in U.S. Patent ~o. 3,455,336 granted 15th July, t96g to R.H. Ellis.
Such articles may be rendered heat-recoverable by heating to or above a certain temperature, expansion, and cooling while retaining an expanded fonm: one method for achieving this ie described in U.SO Patent No. 3,086,242 to P.M. Cook et al, issued 29th March, 1966.
Many electrical cables are nowadays maintained under internal pressure, to reduce the pos~ibility of moisture penetrating the cable jacket, especially at splices, and damaging the materials or cau~ing short-circuits. The excess pressure inside the cable may be achieved and maintained by pump~, which are connected to the cables through a valve. It would be convenient to position the
The u~e of heat-recoverable articleY for covering junction~ or splice~ in electric cables i~ known. The article is usually a heat-skrinkable sleeve, which may either be tubular or in ~heet form 80 that the sleeve may be wrapped around the cable splice after it has been made. The sleeve usually ha~ a layer of sealan~ or adhe~ive, e.g., a ma~tic or hot melt adhesive, applied to its inner surface. Such sleeve3 are described in U.S. Patent No. 3,297,819 granted on 10th January, 1967 to J.D. Wetmore and suitable means for joining opposite edges of a wrap-around sleeve are described in U.S. Patent ~o. 3,455,336 granted 15th July, t96g to R.H. Ellis.
Such articles may be rendered heat-recoverable by heating to or above a certain temperature, expansion, and cooling while retaining an expanded fonm: one method for achieving this ie described in U.SO Patent No. 3,086,242 to P.M. Cook et al, issued 29th March, 1966.
Many electrical cables are nowadays maintained under internal pressure, to reduce the pos~ibility of moisture penetrating the cable jacket, especially at splices, and damaging the materials or cau~ing short-circuits. The excess pressure inside the cable may be achieved and maintained by pump~, which are connected to the cables through a valve. It would be convenient to position the
- 2 -' ' " ' ' ~091~81 valve in the wall of a heat-recoverable sleeve which may be in-~talled e.g., over an aperture in the jacket of the ~leeve, 80 that the site of the sleeve could be used to pre~surize the cable. Further, such a valved sleeve may be used as a site for te~ting the pressure inside a cable.
It has been found, however, that despite the use of many different valve mountings, inadequate sealing between the valve and the sleeve ha3 caused leakage, and this problem has inhibited the use of valved sleeves in pressurized cable splicing.
It is also possible to instal a valve in a sleeve over a splice, as an example of a splice in electrical conduits which it would be desirable to pressurize, there may be mentioned that described in ~.V. Raychem S.A.'s British Patent No. 1,431,167.
The pre3ent intention provides a heat-recoverable, preferably a heat-shrinkable, sleeve having an appendage, preferably a valve mounted therein in a portion of the sleeve that is dimensionally heat stable, or i~ subject to significantly les~ dimensional change than elsewhere in the ~leeve on recovery.
The sleeve may have one or two open ends, and is preferably tubular. If the sleeve has one closed end, it is to be understood that the valve is not mounted in the end wall, but is mounted in the circumferential wall, i.e., in the ca~e of a tubular sleeve closed at one end, in the tubular wall.
Although the description will refer more especially to a valve installation, the invention i~ applicable to .,
It has been found, however, that despite the use of many different valve mountings, inadequate sealing between the valve and the sleeve ha3 caused leakage, and this problem has inhibited the use of valved sleeves in pressurized cable splicing.
It is also possible to instal a valve in a sleeve over a splice, as an example of a splice in electrical conduits which it would be desirable to pressurize, there may be mentioned that described in ~.V. Raychem S.A.'s British Patent No. 1,431,167.
The pre3ent intention provides a heat-recoverable, preferably a heat-shrinkable, sleeve having an appendage, preferably a valve mounted therein in a portion of the sleeve that is dimensionally heat stable, or i~ subject to significantly les~ dimensional change than elsewhere in the ~leeve on recovery.
The sleeve may have one or two open ends, and is preferably tubular. If the sleeve has one closed end, it is to be understood that the valve is not mounted in the end wall, but is mounted in the circumferential wall, i.e., in the ca~e of a tubular sleeve closed at one end, in the tubular wall.
Although the description will refer more especially to a valve installation, the invention i~ applicable to .,
- 3 -l~gl881 all sleeves having devices mounted in their circumferential wall, or having aperture~ in the wall to allow, for example, an elongate ~tructure to be po~itioned therethrough. A~
examples, there may be mentioned an applicator for injection of foamable material into the ~pace enclosed by the sleeve, a pres~ure indicating or sensing device or an electrical conductor or conductors leading to, for example, a piezo electric device, for ~en~ing pre~sure or other chan~e~, or leading to mean~ for measuring temperature at point~ within the space enclo~.ed by the sleeve, e.g., the interface between the internal wall of the sleeve and a substrate enclosed thereby.
The portion of the Rleeve may be of a small area, e.g., a disk in the sleeve, it may extend the whole length of the sleeve as a longitudinal band, or it may be, although le~ de~irably, a circumferential band, the shape and size of the portion depending on the intended use of the ~.leeve and o~ the processes u~ed in its manufacture.
The portion may result from expansion of the whole sleeve and controlled re-shrinkage in the desired area, but advantageously result3 from expan~ion of the remainder of the sleeve only, and prevention or control of expan~ion of the portion during manufacture.
For example, if a tube i~ expanded by pas~ing through a heating mean~ while it i~ subjected to exces~ internal pre~ure heat may be prevented from reaching a portion of the circumference of the tube by an in~ulating or blocking 1~9~881 device, resulting in a longitudinal band of non-shrinkable or less ~hrinkable material extending the length of the tube, the band appearing a~ a portion of greater wall thickness. The tube may then be cut into ~leeves of appropriate length, an aperture made in the band, and a valve mounted in the aperture. Another possible method compri~es positioning a ~uitably ~haped member, e.g., a disk or rectangle of suitable material, e.g., aluminium, at intervals on a tube to be expanded, whereby heat may be prevented from reaching the tube at the regions under the member, and expansion restricted, for example becau~e the member acts as a heat sink.
- 4a -As a further method, the tube may be ~ubjected to uniform heating superimpo~ed on which i~ a ~elective cooling of one position to prevent or reduce expansion.
It will be apparent as indicated above that the invention may be employed where other appendages, e.g., device~ other than valves, are to be incorporated into heat-recoverable articles and i8 useful in all in~tances where proper functioning is dependent to some extent on proper attachment of the device to the article.
Two forms of article constructed in accordance with the invention will now be described in greater detail by way of example with reference to the accompanying drawings, in which FIG. 1 is a perspective view of a valved heat-shrinkable sleeve having a longitudinal band of non-8hrinkable màterial, and FIG. 2 i~ a cro~s-section through a valved heat-shrinkable sleeve having a valve mounted in a non-shrinkable zone.
Referring to Fig. 1., a sleeve indicated generally by the reference numeral 1 is generally heat-shrinkable with a longitudinal band 2 being les~ shrinkable or dimensionally heat ~table. Mounted in the band 2 i8 a valve 3. On recovery of the sleeve, the wall thicknes~ of the band 2 will remain substantially constant, while the remainder of the ~leeve will contract radially with re~ulting wall thickne~ increase.
~Ogl88~
Figure 2 illustrate~ a cross-section of sleeve 1 having a diqk 4 of unexpanded material, the valve 3 being centered in the disk.
examples, there may be mentioned an applicator for injection of foamable material into the ~pace enclosed by the sleeve, a pres~ure indicating or sensing device or an electrical conductor or conductors leading to, for example, a piezo electric device, for ~en~ing pre~sure or other chan~e~, or leading to mean~ for measuring temperature at point~ within the space enclo~.ed by the sleeve, e.g., the interface between the internal wall of the sleeve and a substrate enclosed thereby.
The portion of the Rleeve may be of a small area, e.g., a disk in the sleeve, it may extend the whole length of the sleeve as a longitudinal band, or it may be, although le~ de~irably, a circumferential band, the shape and size of the portion depending on the intended use of the ~.leeve and o~ the processes u~ed in its manufacture.
The portion may result from expansion of the whole sleeve and controlled re-shrinkage in the desired area, but advantageously result3 from expan~ion of the remainder of the sleeve only, and prevention or control of expan~ion of the portion during manufacture.
For example, if a tube i~ expanded by pas~ing through a heating mean~ while it i~ subjected to exces~ internal pre~ure heat may be prevented from reaching a portion of the circumference of the tube by an in~ulating or blocking 1~9~881 device, resulting in a longitudinal band of non-shrinkable or less ~hrinkable material extending the length of the tube, the band appearing a~ a portion of greater wall thickness. The tube may then be cut into ~leeves of appropriate length, an aperture made in the band, and a valve mounted in the aperture. Another possible method compri~es positioning a ~uitably ~haped member, e.g., a disk or rectangle of suitable material, e.g., aluminium, at intervals on a tube to be expanded, whereby heat may be prevented from reaching the tube at the regions under the member, and expansion restricted, for example becau~e the member acts as a heat sink.
- 4a -As a further method, the tube may be ~ubjected to uniform heating superimpo~ed on which i~ a ~elective cooling of one position to prevent or reduce expansion.
It will be apparent as indicated above that the invention may be employed where other appendages, e.g., device~ other than valves, are to be incorporated into heat-recoverable articles and i8 useful in all in~tances where proper functioning is dependent to some extent on proper attachment of the device to the article.
Two forms of article constructed in accordance with the invention will now be described in greater detail by way of example with reference to the accompanying drawings, in which FIG. 1 is a perspective view of a valved heat-shrinkable sleeve having a longitudinal band of non-8hrinkable màterial, and FIG. 2 i~ a cro~s-section through a valved heat-shrinkable sleeve having a valve mounted in a non-shrinkable zone.
Referring to Fig. 1., a sleeve indicated generally by the reference numeral 1 is generally heat-shrinkable with a longitudinal band 2 being les~ shrinkable or dimensionally heat ~table. Mounted in the band 2 i8 a valve 3. On recovery of the sleeve, the wall thicknes~ of the band 2 will remain substantially constant, while the remainder of the ~leeve will contract radially with re~ulting wall thickne~ increase.
~Ogl88~
Figure 2 illustrate~ a cross-section of sleeve 1 having a diqk 4 of unexpanded material, the valve 3 being centered in the disk.
Claims (13)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A heat recoverable sleeve having an appendage mounted therein in a portion of the circumferential wall of the sleeve that is dimensionally heat stable or is subject to significantly less dimensional change than else-where on the circumferential wall on recovery thereof.
2. A sleeve as claimed in claim 1, wherein the portion of the sleeve extends along the sleeve in a longitudinal band.
3. A sleeve as claimed in claim 1, wherein the portion of the sleeve is circular.
4. A sleeve as claimed in claim 1, wherein the appendage is a valve.
5. A sleeve as claimed in claim 2 or claim 3, wherein the appendage is a valve.
6. A sleeve as claimed in claim 1 which is tubular.
7. A sleeve as claimed in claim 1 which is open at both ends.
8. A sleeve as claimed in claim 1 which is heat-shrinkable.
9. A heat-recoverable sleeve having both ends open, and comprising a dimensionally heat-stable portion and a heat-shrinkabe portion, a valve being mounted in the heat-stable portion.
10. A process for the manufacture of a heat-recoverable sleeve having an appendage mounted therein in a portion of the circumferential wall that is dimensionally stable or is subject to significantly less dimensional change than elsewhere on the circumferential wall on recovery thereof, which comprises forming the sleeve and rendering it heat-recoverable bv heating, deforming and cooling while maintaining it in the deformed configuration, characterized in that deformation of a portion of the circumferential wall of the sleeve is avoided or reduced to a significantly smaller extent than elsewhere on the wall.
11. A process as claimed in claim 10, wherein the sleeve is rendered heat-shrinkable.
12. A process as claimed in claim 10, wherein the portion is a disk or a longitudinal band extending along the length of the sleeve.
13. A process as claimed in any one of the claims 10 to 12, wherein avoidance or reduction of deformation is achieved by preventing heat from reaching the portion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1779776A GB1585154A (en) | 1976-04-30 | 1976-04-30 | Heat recoverable article |
| GB17797/76 | 1976-04-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1091881A true CA1091881A (en) | 1980-12-23 |
Family
ID=10101387
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA277,317A Expired CA1091881A (en) | 1976-04-30 | 1977-04-29 | Heat recoverable sleeve having a dimensionally heat stable portion |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS589490Y2 (en) |
| CA (1) | CA1091881A (en) |
| DE (1) | DE7713578U1 (en) |
| FR (1) | FR2349936A1 (en) |
| GB (1) | GB1585154A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3272049D1 (en) * | 1981-12-15 | 1986-08-21 | Raychem Sa Nv | Support for a closure assembly |
| US4626458A (en) * | 1983-01-06 | 1986-12-02 | Raychem Limited | Recoverable article for encapsulation |
| DE3401928C2 (en) * | 1984-01-20 | 1993-12-23 | Messwandler Bau Gmbh | Casting mold for producing high-voltage sheath insulation |
| DE3518654C2 (en) * | 1985-05-21 | 1994-12-15 | Siemens Ag | Method of assembling a branch sleeve and casting mold to carry out the method |
| DE29511390U1 (en) * | 1995-07-14 | 1995-09-21 | Alcatel Kabel AG & Co., 30179 Hannover | Heat recoverable item made of a plastic material |
| DE29519179U1 (en) * | 1995-12-04 | 1996-02-01 | Alcatel Kabel AG & Co., 30179 Hannover | Arrangement for wrapping a splice connection |
| US7544404B2 (en) * | 2001-12-10 | 2009-06-09 | Raytheon Company | Shape-recovering material |
-
1976
- 1976-04-30 GB GB1779776A patent/GB1585154A/en not_active Expired
-
1977
- 1977-04-28 JP JP5501277U patent/JPS589490Y2/en not_active Expired
- 1977-04-29 CA CA277,317A patent/CA1091881A/en not_active Expired
- 1977-04-29 FR FR7713008A patent/FR2349936A1/en active Granted
- 1977-04-29 DE DE19777713578 patent/DE7713578U1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS52169089U (en) | 1977-12-22 |
| JPS589490Y2 (en) | 1983-02-21 |
| GB1585154A (en) | 1981-02-25 |
| DE7713578U1 (en) | 1977-08-04 |
| FR2349936A1 (en) | 1977-11-25 |
| FR2349936B3 (en) | 1980-02-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |