CA1078032A - Recoverable sleeve with frangible restraining means - Google Patents
Recoverable sleeve with frangible restraining meansInfo
- Publication number
- CA1078032A CA1078032A CA255,015A CA255015A CA1078032A CA 1078032 A CA1078032 A CA 1078032A CA 255015 A CA255015 A CA 255015A CA 1078032 A CA1078032 A CA 1078032A
- Authority
- CA
- Canada
- Prior art keywords
- restraining means
- article
- bond
- recoverable
- recoverable member
- 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
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- 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
- H02G15/182—Cable junctions protected by sleeves, e.g. for communication cable held in expanded condition in radial direction prior to installation
- H02G15/1826—Cable junctions protected by sleeves, e.g. for communication cable held in expanded condition in radial direction prior to installation on a removable hollow core, e.g. a tube
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- 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
-
- 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
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S174/00—Electricity: conductors and insulators
- Y10S174/08—Shrinkable tubes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S411/00—Expanded, threaded, driven, headed, tool-deformed, or locked-threaded fastener
- Y10S411/909—Fastener or fastener element composed of thermo-responsive memory material
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
- Y10T156/11—Methods of delaminating, per se; i.e., separating at bonding face
- Y10T156/1142—Changing dimension during delaminating [e.g., crushing, expanding, warping, etc.]
- Y10T156/1147—Using shrinking or swelling agent during delaminating
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/4981—Utilizing transitory attached element or associated separate material
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49826—Assembling or joining
- Y10T29/49863—Assembling or joining with prestressing of part
- Y10T29/4987—Elastic joining of parts
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/53—Means to assemble or disassemble
- Y10T29/53657—Means to assemble or disassemble to apply or remove a resilient article [e.g., tube, sleeve, etc.]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T403/00—Joints and connections
- Y10T403/48—Shrunk fit
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T403/00—Joints and connections
- Y10T403/57—Distinct end coupler
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
- Y10T428/1328—Shrinkable or shrunk [e.g., due to heat, solvent, volatile agent, restraint removal, etc.]
Abstract
Astract of the Disclosure An article which comprises a hollow, radially recoverable member having at least one open end and held in a radially extended condition by a second member outside the recoverable member, by means of a bond between the outer surface of the recoverable member and the inner surface of the second member. In a preferred article, both members are sleeves. The bond is capable of being sufficiently weakened by the application of solvent thereto to allow the recoverable member to pull away from the second member and shrink radially. The second member preferably has apertures to allow radial access of the solvent to the bond and, moreover, is preferably frangible. It may comprise a plastics or metallic material having weakened portions to enable it to be removed from about the recoverable member after the latter has pulled away. The article is useful for protecting other articles and, may, when it is of an electrical insulating material, act as an insulator.
Description
~ his invention relates to reco~erable articles and to the use and manu~acture thereo~.
Heat recoverable sleeves have iound wide utility in many applications. Thus, heat recoverable sleeves are uæed as insulators for electrical conductors, particularly at areas where splices are formed in the electrical conductors. The slee~es haYe been particularly succe~sful because they allow rapid and uniform application o~ an insulating covering. ~gpically, an electrical conductor which i8 to be spliced or repaired ~irst has/heat recoverable sleeve placed o~er the cond~ctorO ~he repair is then made and the sleeve is put in place over the splice and iR radially reco~ered by the application of heat. Such methods have proved to be quicker, more convenient, and more reliable than prior methods ~uch as taping and ~ulcanizlng.
A aisad~antage Or the use Or heat reco~erable sleeves is that a heat source is necessary ior the recoverg. Suitable heat sources include torches and hot air guns. In some ¢ases, for example in mines, it is undesirable to use torches because o~ the danger of ~ire being started bg the naked ~lame. In other situations, working conditions are so cramp~d or other~lise dif~icult that it is not conYenient to place a heat source such as a torch or hot a~r gun close to the sleeve which is to be recovered. ~e use o~ heat-recoverable slee~es may also be undesirable where the substrate on ~hich the sleeve is to be shrunk is temperature sensitive.
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" 1078032 Various sleeves which can be rccovered without the applicat~on of heat have been propo~ed. In particular there have been disclo~ed various types of expanded sleeve with internal restraining means positioned ~nternally of the in-terior surface of thc sleeve and which hold the sleeve in the expanded condition. One such sleeve comprise~ an expanded sleeve held in the expanded state ~y a cylinder of ice as disclosed in U.S. Patent No. 3,319,328 issued 16th May, 1967 to J. H. Finger et al. ~n actuality, such a sleeve is also a heat-recoverable sleeve because ~t requires à small amount of heat to melt the ice and allou thc ~leeve to recover. How-ever, the amount of heat neces~ary iJ somsmall that ~uch a sleeve i8 not normally considered to be a ~leeve requiring application of an outside heat ~ource. Another type of sleeve havin~ an internal r-~traint i~ de~crib-d in U.S. :-~
Patent No. 3,515,798 is~ucd 2nd June, 1970 to J. A. Sievert wherein a rigid removable mec~anical insert holds the sleove in the expanded conditlon unt~l the ~nsert is removed In general, all of the propo~al~ for making recoverable ves whtoh do not require heat have involved the use of ~ntornal restraining means which place a restraint bet~een tho substrate to be covered and the internal sur~ace of the sleeve or involve contacting the ~nternal ~ur~ace of the sleeve with ~ome fore~gn manter~al. Such re~trainin~ means pres-nt var~ou~ problems. For example, it ~ 9 frequently de~ired to coat tho ~nner ~urface of a recoverable ~leeve with a sealant or adhesive mater~al. Recoverable ~lee~es ~th internal restra~nin~ means often make t~e use of such ~3- -~
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a coating difficult or impossible. ~urthermore, the presence o~ an internal restraining means between the sleeve and substrate may make ~itting o* the sleeve o~er the substrate dif~icult and reduces the range o~ substrate sizes over which the sleeve can be iitted.
According to the present invention ther~ is provided an article comprising a hollow, radially recoverable member ha~ing at least one open end and held in a radially extended condition by restraining means arranged e2ternally of the member by means o~ a bond between the outer surface o~ the member and the inner surface oi the restraining means, which bond i8 capable of being sui~iciently weakened by the applic-ation oi solvent thereto to allow the recoverable member to pull away irom the restraining means and shrink radially.
In a pre~erred embodiment the radially recoverable member and the e~ternal restraining means are tubular ~nd are o~
substantially oircular cro~-se¢tion.
The recoverable member is pre~erably made o~ an elastomeri¢ material. Eowe~er, recoverable members oi other materials, ~or example metallic split cylinaers in -radial tension, may be used. An elastomeric member must be ¢apable o~ be~ng extended radially to a condition ~rom which the member can recover upon removal of the restraining means holding it in the extended condition.
AB elastomeric materials9 virtually any desired material possess~ng elastomeric recovery properties may be used. ~he elastomeric ma~erial should be on~ ~hich does not exhibit j...
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a substantial permanent set or decrease in recovery on storage. Bxamples o~ ~uitable elastomers are natural and synthetic polyisopreneæ, polybutadienes, ~or example cis-polybutadienes, styrene-butadiene rubbers (SBR), butadiene-acrylonitrile rubbers, polychloroprenes (Neoprenes), butyl rubbers, polysulfides, silicone rubbers, urethane rubbers, polyacrylateæ, epichlorohydrin homo and copolymers, propylene oxide rubbers, iluorosilicone rubberæ, fluorocarbon rubber~, chlorosulfonated polyethylenes, chlorinated polyethylene~, ethylenepropylene rubbers, nitrose rubberæ and phosphonitrilic rubbersO Other properties o~ the recoverable member æhould be compatible with the intended u~e of the recoverable member. ~hus, ii the recoverable member is to be uæed ior electrical insulation purposeæ, itæ electrical properties will be of primary importance. On the other hand, ii it i9 likely to be subjected to much phyæical abuse, it may be necessary to pro~ide a recoverable member which has toughne~s~ good ilame reæistance, good æolvent resi~tance, ete. ~or high voltage uses, it may be desirable to have a recoverable member which has been made semi-conducti~e by aispersing in its material o~ construction large amounts of ~uitable ~illers or conducti~e particles or which possesses re~istance to tracking and~or erosion.
To some extent, the nature o~ the recoverable member i~ dependent upon the nature o~ the restraining means a~
will be readily apparent. Thus, the ~orce oi reco~er~ exerted by the expanded reco~erable member must not e~ceed either the ` 107803Z
strength of the restraining means or o~ the bond between the member and the restraining meansO Further, it is necessary to choose a recoverable member which is compatible with the re.~.training mean.Y. to the e~tent that it can be bonded to the restraining means.
The restra?n;ng means is preferably a tube having a circular cross section. However, any member at least a portion o~ which is preferably closed in cross section, may be employed.
- The restraining means may be made o~, ~or esample, a rigid polymeric mater'al, a metal, a cera~ic, especially a porous ceramic, wood or wood products, ~or example paper or resin rein~orced or impregnated paperO In general, the only reauirement of the restraining means is that it has ;
suf~icient strength to hold the recoverable member in its .
extended condition without being de~ormed or collapsed.
It is ~urther desirable that the re.?.training means ;
be capable o~ bein~ bonded to the recoverable sleeve 50 .
bhat it will hold the recoverable sleeve in its extended condition until recover~ oi that .Y.leeve is desired. The bond may be ~ormed by adhe.3 on directly between the reco~erable member and the restraining means or by bondin~
the recoverable member and restraining means with a~ adhesi~e.
~ xamples of suitable rigid polymeric materials are rigid thermoplaætics, ~or example polyvinyl chloride copolymers of vi~y~ chloride with, ~or example, vinyl acetate, polyethylene, polystyrene, copolymers o~ ~.tyrene, ~or e~ample . ~
~.
- . . . .. . .
: . -. ' , ,-~ ' - .
.', ' - , , . ., ' : ''' . ' . ,: -. . , . : . ,, . , , . , .. ~,: . - -copolymers of styrene and acrylonitrile, ABS polymer, at least some of which thermoplastics may, as is known, be cross-linked.
In accordance with this invention, rapid attack and destruction of the bond between the re~training means and the recoverable member is accomplished by means of a solvent which will destroy the bond. Thus, it may be desirable for the restraining means to have holes or pores to allow direct contact of the solvent uit~ the bond at many locations. For this purpose it is adv ntageous to use a porous ceramic outer restraining mean~.
In many applications, it ~ould be undesirable to have the restraining mean- present a~ter the recoverable member has been recovered. Thu~, the restrainng means i8 preferably removable after the recoverable member ha~ been recovered.
This ~ay be achieved b~, for example using a re~training means made of a frang~ble material which can be b~oken by shattering it, for example by impact, b~ using metallic or rigid plastîcs re~tra~ning mean~ having wea~ened portion~, for example ~erration~ or 8core9, b~ ënable the restraining means to be removed ~rom about t~e recoveraDle ~ember a~ter the latter has pulled away ~rom tho re~tra nt, for example to enable the restraining mean8 to be peeled aw~y a~ter shrinkage of the recoverable member, or ~i8801ving the restraining mean~ in a ~uitable solvent.
A particularly convenient remoYable restraining means is one comprisin~ polyvn~1 chloride that which will ~racture ~0~78032 when given a sharp ~low. Thus, after the recoverable mem~er has peeled away from the restraining means and has recovered to its final position on the substrate, the polyvinyl chloride restraining means can simply be given a blow with a hammer to C~ 1' ~.:
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shatter it. Alternatively, such a restraining means may be cracked be~ore shrinkage o~ the recoverable memberO ~hen, the recoverable member will shrink upon the application -of solvent and the restraining means will then ~all away irom about the recoverable member.
~ he bond between the recoverable member and the onter restraining means should be ~u~ficiently strong that the bond will prevent separation o~ the expanded recoverable member from the restraining means under normal condition~
of storage and handling over a long period oi time. On the other hand,the bond must be al~ceptible to being weakened (thus allowing the recoverable member to peel a~ay from the restraining ~eans) on the application of a solvent to `s the bond line.
The bond may be iormed simply by adhesion o~ the ~leeve to the restraining means without the use of any additional bonding agent. 3uch adhesion may occur when two polymeric material~ are ~oined together, particularly at an ele~ated temperature at whi¢h they are both tacky. For example, when usine a polyvinyl chloride re~tra~ni~ means for a neoprene reco~erable member, it has been ~ound con~enient to injection mould the polyvingl chloride around the neoprene member. ~t typical in~ection moulding temperatures, a bond 1~ ~ormed betMeen the polyvinyl chloride restraining meanQ and the neoprene member.
It i~ frequently desirakle to use adhe~ives to in~ure a suitable bond between the recoverable member and the ... . ,, , . . . ,., ~ ........................ . .
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1~7803Z
restraining means. Any adhesive which will provide a strong enough bond to prevent premature recovery of the recoverable member and yet will permit peeling away of the recoverable member from the restraining means upon the application of a solvent to the bond line may be used.
In general, hot melt adhesives are preferred. The hot melt adhesive may be applied by coating the outer surface of the recoverable member and/or the inner surface of the restraining means with a solution of the a & esive, allowing the solvent for the adhesive to evaporate and then bringing the surfaces together under the application of heat and/or pressure.
A preferred hot melt adhesive for a neoprene-PVC
system is a multisegmented block copolymer comprising units of polytetramethyleneether and polytetramethyleneteraphthalate.
A polymer of this type is sold by Du Pont under the trade mark HYTREL. This adhesive forms a strong bond between Neoprene and polyvinylchloride and yet can be readily weakened by application of a number of solvents, for exa~ple acetone, chloroform or trichloroethylene.
Various copolymers may be used as adhesives, for example copolymers of ethylenevinylacetate, e.g., ELV~X (trade mark) from Du Pont or copolymers of ethylene with ethylacrylate.
Terpolymers, for example terpolymers of ethylene, vinyl acetate, and methacrylic acid may, alternatively be used. These adhesives may be used alone or with tackifiers.
Other suitable hot melt adhesives are polyamide resin adhesives. Exemplary of such adhesives are those availa~le .; '.
s l07ao32 .
irom General Mills under the trade name VERSAIOl~, polyester adhe~ives ~see elg., Du Pont ~echnical Bulletin NoO 17--"Polyester Adhesives") and the wide variety oi polyvinyl, polybutene and polyacrylate adhesi~esO -Various rubber based adhesi~es, ior example thosebased upon silicones, nitriles, and neoprene may be used.
In general, any adhesive is suitable if it has good a~finity for the inner surface of the restraining mean~ and the outer suriace of the recoverable member and is resistant to creep under loadO Further, the bond must ha~e susceptibility to ~olvent attack so that upon the application oi solvent to a bond line between the restraining means and the recoverabl~ member, the bond weakens su~iiciently so that the recoverable member peels away ~rom the restraining meansO
Pre~erably the adhesive 1B thermOP~aBtiC SO that it will soften on heating to ~10~J and ultimately wet those suriaces of the restraining means and the recoverable memberO
Ang suitable method of applying the adhe~i~e to the appropriate sur~ace `of the recoverable member and/or oi the restraining means may be employed~ One suitable method o ~ pplication iB to apply the adhesive from solution to one or both surfaces and allow the sol~ent ior the adhesi~e to evaporate, bringing the suriaces together u~der the application of pressure and, if desired, heat to form a strong bond.
In a prefe~red method of manuiacturing an a~ticle of the in~ention, the outer restraining means is in~ectio~
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molded around the recoverable member. In that case, the adhesive is applied to the surface of the elastomeric member prior to the injection moulding step. In ge~eral, it is desired that the peel strength of the adhesive bond be greater than 10 pounds per inch (1.8 kg/cm) and preferablg that the peel strength be greater th~n 20 pounds per inch (3.6 kg/cm)O ~owever, there i~ no absolute requirement with regard to peel ætrength. Thu~, the important consideration i8 whether thepond or peel strength is su~icient to prevent the reco~erable member ~rom peeling away ~rom the restraining means during storage or at any time prior to the time when it is desired to shrink the member down about the substrate.
course a re~training core, e.g., a cardboard tube may be ;
pro~ided internally of the recoverable member to prevent premature reco~ery thereo~ the ~orce tending to cause the recoverable member to shrink and peel away ~rom the restraining mean~ i~ not great, a high bond or poel strengh i~ not so necessary. On the other hand, i~ a recoverable member having an extrèmely high retractive ~orce is employed, lt ie necessary to use an adhesi~e which will ~orm a bond ha~ing a high bond or peel strength.
When it is desired to cause shrinking oi the recoverable member, the bond between the recoverable member and the restraining mean~ is weakened or destroyed by the application o~ ~olvent at the bond line. ~ny solvent which will su~iciently weaken the bond to allow the recoverable member to peel away ~rom the restraining means and shrin~ o~er a substrate -.-.
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may be used. Examples of solvents which may be used arechloroform, methylenechloride, N, N-dimethylformamide, ethylacetate, acetone, ethylene glycol monobutyl ether methylethyketone and trichloroethylene.
Other solvents may be used depending upon the nature of the adhesive used. It should be realized that the term "solvent" does not necessarily indicate that the solvent will dissolve the bond, for example the adhesive material. Rather, "solvent" is used to indicate any material which will destroy or weaken the bond between recoverable member and the restraining means. Thus, for example, acetone which is not a solvent for HYTREL will weaken the HYTREL bond between a neoprene sleeve and a polyvinyl chloride restraint S times faster than will chloroform which is a solvent for HXTREL.
Any desired method of applying the solvent to the bond line may be employed. A convenient method of applying the solvent is simply to spray it from a nozzle along the edge of the article. As the recoverable member peels away fro~ the restraining means the nozzle can be directed to apply solvent along the remaining bond line. As previously indicated, a porous outer restraining means comprising a material such as ceramic may be used. An advantage of such a porous restraining means is that solvent can be applied to the outer surface of the re~training means so that it will travel through the pores and contact substantially all parts . .
of the bond simultan~ously. Another method of obtaining rapid and complete contact of the bond line with solvent comprises using a restraining means havin~ a series of holes extending from the outer surface of the restraint to the bond between the restraining means and the recoverable member. Solvent applied to the outer surface of the re-ætraining means will pass through these holes and quickly contact and weaken the bond. A similar result can be achieved by fracturing a frangible restraining means and allow the solvent to penetrate to the bond line through the fractures.
~ he bond line attacked by the solvent may be the adhesive itself, the adhesive recoverable member interface, the adhesive restraining means interface, or all of these bond areas. Thus, when weakening of the bond line is referred !-to, it simply means that the adherence between the recoverable member and the restraining means is weakened, in some manner, to the extent that the sleeve will pesl away from the re-straining means.
The recoverable member may be coated on its internal ~urface with various materials, fpr example to enhance the bond between the recoverable member and the substrate to be covered and/or to act as a sealant. For example an adhesive such as a contact adhesive or a mastic may be applied to the int0rior surface of the recoverable member so that the member will form a bond with a substrate. Because the re-coverable member does not require heat for its recovery, it is preferred to employ an adhesive which does not require ;
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. - ~ : . ' : : ' the application of heat to form a strong bond with the sub-strate. In this regard, various contact or pressure sensitive adhesives may be employed As alternatives to adhesives, various other materials may be employed on the internal surface of the recoverable member.
For example, materials of the type described in U.S. Patent No. 3,396,460 issued 13th August, 1968 to J.D. Wetmore may be used. In many instances, it is desirable to coat the inside of the recoverable member with materials which will flow under the application of pressure at the temperature of application.
Preferably, these materials will adhere to both the re-coverable member and the substrate. Particularly suitable materials for this application are pressure sensitive adhesives and mastic and mastic-like materials.
The present invention also provides a method of covering a substra'e comprising positioning over the substrate an a~ticle comprising a hollow, radially recoverable member having at lea~t one open end and held in a radially extended condition by restraining means arranged externally of the member by means of a bond between-the outer surface of the member and the inner surface of the restraining means, which bond is capable of being sufficiently weakened by the applica-tion of solvent thereto to allow the recoverable member to pull away from the restraining means and shrink radially and weakening or breaking the bond between the recoverable member and the restraining means by the application of a solvent to the bond so that the recoverable member shrinks radially into .*
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. , .: .' -. ' ' :- , ' : ' ;' , ~ 078032 contact with the substrate. Advantageously, after the re-coverable member has shrunk down onto the substrate, the restraining means i~ removed from about the substrate.
The restraining means may, for example, comprise plastics material and have weakened portions, the method also co~pris-ing breaking the means along the weakened portions, and re-movîng the restraining means from about the recoverable member after the latter has pulled away ~rom the restraint.
The articles of the present invention have a wide range of applications. Thus, they can be used in many applications in ~hich heat recoverable ~leeves are normally u~ed. For example, ~here the re¢overable ~smber io of electrically in-sulating aaterial, they can be used in the insulation o~
splices in electrical conductors in botn low and high voltage applications. They ~ay be u~ed for covering repairs of joints in electron~c equip~ent and are particularly suitable ~or use in covering splices ~nd repairs in telephone ca~es and bable TV lines.
An area ~here heat recoverable ~leeves have had a great deal of use in recent years i8 for repairing splices in electrical cabl-~ used in mines. The articles of the -14a~
present invention are particularl~ suitable for such mine cable splices because they do not require the application o~ hcat which is usually accomplished by the use of a torch. This may be a major advantage, particularly in gassy mines where the use o~ torches i~ likely to be dangerous.
A number o~ methods are a~ailable for manu~acturing the articles o~ this in~ent~on. ~mply stated, the articles can be ~ormed by bonding the reco~erable member in the extended state, to an outer restraining means. One convenient method o ~ccomplishing this is to ~orm an outer restraining means and an inner member o~ the desired ~inal (i.e~ recovered) diameterO Then , the inner sur~ace of the restraining meana and/or the outer sur~ace of the inner member is coated with a su~table adhesive and the inner member is expanded into contact with the restraining meanc~ ~or example by internal air pressure or by using a mandrel. The e~panded member i8 held in contact with the re~training means ior a period o~ time suiiicient for a bond to be ~ormed between the member and the restraining means whereupon the mandrel or internal pressure is rem~ved.
A pre~erred technique ~or ~orming the article comprises ~ir~t form~ng the recoverable member and then injection molding the outer restr~n~ng means around the memberO In this method, ~he reco~erable member i~ first coated with adhesi~e. ~hen, the outer restra~ning means mater~al i~ injection molded around the reco~erable member.
_ 15 _ - . , .
- .... ..
,~ .- ., ~ . . ~ , -. . .
The two layers may also be formed by dual extrusion. Before the restraining means has hardened, the restraining means and recoverable memker are expanded by a mandrel or co~pressed air ' to give the desired expansion and desired final inside diameter to the recoverable member. While the recoverable member is in the expanded condition, the restraining means is cooled and hardened and upon removal of the~mandrel or release of the air pressure, the recoverable member remains bonded to the re-straining means and is thus held in the expanded condition.
The injection molding process described above has been found to be particularly suitable for use with a combination of a neoprene recoverable member, a HYTREL adhesive, and a polyvinyl chloride restraining means. However, it will be obvious that the process can be carried out using a wide range of suitable materials.
The present invention also provides a method o- ~aking an article which comprises moulding around the outer surface f an clastomeric m~r a restraining means comprising a poly-meric material which is radially rigid when at room temperature, radially expanding the elastomeric member and the res~raining means at a temperature at which the restraining means is plastic, and cooling the article or allowing it to cool whilst maintaining the article in its radially expanded condition, thereby to form an elastomeric member held in a radially expanded condition by the rigid restraining means.
As indicated herein, a wide variety of materials may bé used to manufacture an article of the prese~t invention .
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.
- . -. . .
~078032 depending upon the desired properties of the article. In the case of mine splices, it is necessary to provide a recoverable member which has great strength and abrasion resistance in the recovered state. These requirements are dictated by the mechanical abuse which mine cables must survive. Typically, mine cables are wound on and off cable reels in the mines, are pulled over sharp rock surfaces, and are frequently exposed to impact against sharp edges. Thus, properties such as tensil strength, elongation, flame resistance or retardance, ,, .
,_ .
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.
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abrasion resis~ance, and dielectric strength are all important considerations ~or such me~bers. Additionally, it is important th~t the recovered member can resist peeling or creeping away from the splice which they :
cover.
It has been found that a combination of materials used in accordance with this invention will provide a recoverable article having properties suf~icient for use in extremely demanding environments of mines. In particular, a recoverable elastomeric mine sleeve requires an extremely high recovery force and thus it has been nece~sary to provide a Jestraining means and adhesive which will provide a strong bond bet~een the restraining means and the recoverable ~ember to mainta~n the member in the desired extended condition until recovery is desired.
According to the present invent~on, an elastomeric sleo~ehhaving a good combination o~ propert~es and being suitable ~or use a~ a m~ne ~pl~ce ~leeve oompri~es a neoprene sleeve having the iollo~ing composition:
TABLE I
art~ By ~eight Com~onent A B
Nooprene Rubber 100 100 Phen~l-alpha-napt~lamine 2 2 Hagnesium Ox~de Stoaric aci~ 0.5 0.5 HAF Carbon Black 5 ~ydrated alumina 10 10 Precip~tatod Sil~ca lS 15 .
~0'7803Z
Antimony oxide 15 15 Tri (2-ethylhexyl) phosphate 4 4 Zinc oxide 5 5 N-Cyclohexyl~2-benzothiazole sulfenamide 1 0.75 A treated arnine sold by Du Pont as TA-11 2 ---Tetramethyl thiourea --- 0.75 When cured at 350F (175C) for 15 minutes, a slab .075 in.
thick (O.18 cm) and a tube having an inside diameter of 0.75 in. (1.8 cm) and an outside diameter of 1.0 in. (2.5 cm)., both made from these compositions, were found to have the following properties:
TABLE II
SL~B PROPERTIES A B
.
Tensile Strength, psi(and Kg cm 2) 4400 (308) 300;7 (210~ -Ultimate~Elongation,% 7?0 (4~.7~ 550 (45.5) Tensile Stress at:
100% Elong. p~i(and Kgcm 2) 290 (20.3) 260 (18.2) 200/o Elong. psi(and Kgcm 2) 650 (45.5) 385 (26.5 300YO Elong. psi(and Kgcm 2) 1150 (80.5) 610 (42.7) TUBE PROPERTIES
Tensile Strength, p~3i(and Kgcm 2) 1990 (139) 970 (67.9) Ultimate Elongation,% _ 5~0 (31.7) 430 (30.1 ) .
5.
- .. . .
, . . .- . . . . . ~............. . . - -.. . . . ~ . .
- . , - . , - - . .. .
, . . . . . . . : .
- - . ; , . ~ ,. -. . : -: .
- , .
. ~ . , . . . - . ....
- 1078~32 Tensile Stress at: 3 10~/o Elong., psi(and Kgcm 2) 250 (17.5) 230 (16.1) 20~/o Elong., psi(and Kgcm 2) 460 (32.2) 330 (23.1) 30~/0 Elong., psi(and Kgcm 2) 850 (59.5) 500 (35.0) !
Tensile Strength at 150C,psi 370 (25.9) 280 (19.6) Ultimate Elongation at 150C,% 200 (14.0) 150 (10.5) Tear Strength (DieC),pli 370 215 Tear Strength (DieC) at:
150C, pli 90 80 Tape Abrasion (1/4"(0.63cm) strip, 250"tape, 2 lb.(0.9Kg) wt., 1504 Grid, mil) 35 36 ~ensile Set (20~/~ elong. at RT) After 24 hrs., % 1 2 After 7 day~, % 6 10 U~ing the compositions of Table I, tubes of neoprene ha~ing an i.d. of 0.75 in. (1.8cm) and an o.d. of 1.0 in.
(2.5cm) were molded. ~he neoprene tubes were placed in an injection mold and a polyvinylchloride cornposition as set forth below in Table III was injected around it. Two suitable polyvinylchloride compositions are as follows:
TABLE III
Component ~ _ A B
Po1yvinylchloride 100 100 , ... ,, . ~ . . . . . .
., , , , . ~ : .
:
:107803Z
An organotin stabilizer sold by M & T Chemicals 3 3 A cycloali~atic epoxy sold by Ciba-Geigy . 4 4 Low molecular weight polyethylene 2 2Low molecular weight nitrile rubber 10 Prior to the injection of the polyvinylchloride, the outer surface of the neoprene sleeve was abraded and coated with a 5% solution of HYIREL in chloroform and dried. Prior to injection molding, the tubes were preheated to soften the adhesive. Injection molding was carri:ed out using the conditions set forth in Table IV, below:
TABLE IV
Machine Temperature Noz-~le heat, 390F (197& ) Front heat, 375F ~188C) Center heat, 365F (183C3 Rear heat, 300F (147C) ~.
Mold Temperature Manifold, 275F (~34C) .Front plate, 175F ( 78& ) f Back plate, 200F ( g2C) Machine Settinas -- ¦
Injection time, seconds . ~5 - . . .
. . ~ , ~ .
', ' ' . ~ , ' ' ': ' . ' '" .: ' ' . ' : ' .' .
" 107803Z
Cooling time, seconds 15 Total cycle time, seconds 60-90 The resulting tubular article was expanded by pre-heating the tube and expanding 100 to 20~/o using air pressure to expand the tube into a cold expansion mold. The peel strength was found to be about 40 lb/in. (7.2Kg/cm) between the polyvinylchloride restraint and the Neoprene ~leeve.
A similar tube was recovered by spraying solvent onto the bo'nd line at the end of the article. A suitable solvent is 3~/~ chloroform or acetone and 7~/0 Freon 12. The use of between 45 and 75 grams of solvent resulted in recovery of the Neoprene sleeve by ~mplete peeling away from the restraining, means in about 5 minutes. The restraining means was then fractured with a hammer and removed.
The tubular articles of this invention may be expanded using conventional apparatus and methods, for example by means of màndrels or using hydraulic pressure.
Preferred forms of articles of the invention will now be de~cribed ~y way of Example only, with refersnce to the ¦ -accompanying drawings in which:-Figure 1 is a perspective view of an article of the invention, in position around a substrate, in which the bond between the recoverable member and the restraining means can be weakened or broken by application of a solvent to the bond, Figure 2 is a perspective view of the article of Figure , . ~
: ' . . ; :.
107803Z `
6, the recoverable member of which has partially recovered onto the substrate, Figure 3 ~ a perspective view of the recoverable member of the article of Figure 1 after it has been re-covered onto the substrate and after having shattered the restraining means but before the restraining means~has been removed.
Figure 4 is a perspective view of the recovered member on the substrate after the restraining means has been removed, Figure 5 i9 a perspective view of another solvent- ¦
shrinkable article of the invention showing an alternative form of removable restraining means .
and `
Figure 6 i9 a perspective view of another solvent-shrinkable article of the invention having yet - a further different restraining means. :
Referriny t~ drawings in Figure 1 an outer re- :
Btraining means made of a frangible material, for example polyvinyl chloride, i~ bonded to an inner sleeve 2 made, for example, of neoprene, 6 or a bond 6. ~he article is shown in .
position over a substrate 3 to`be covered. me bond 6 may be .
de8troyed or weakened by application thereto of a solvent 5 issuing from a nozzle 4. Upon.application of the solvent, the ..
81eeve 2 pulls away from the restraining means 1 and shrin~s ..
: into contact with the substrate 3 tsee Figure 2).
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The restraint 1 may then be removed from about the ..
Heat recoverable sleeves have iound wide utility in many applications. Thus, heat recoverable sleeves are uæed as insulators for electrical conductors, particularly at areas where splices are formed in the electrical conductors. The slee~es haYe been particularly succe~sful because they allow rapid and uniform application o~ an insulating covering. ~gpically, an electrical conductor which i8 to be spliced or repaired ~irst has/heat recoverable sleeve placed o~er the cond~ctorO ~he repair is then made and the sleeve is put in place over the splice and iR radially reco~ered by the application of heat. Such methods have proved to be quicker, more convenient, and more reliable than prior methods ~uch as taping and ~ulcanizlng.
A aisad~antage Or the use Or heat reco~erable sleeves is that a heat source is necessary ior the recoverg. Suitable heat sources include torches and hot air guns. In some ¢ases, for example in mines, it is undesirable to use torches because o~ the danger of ~ire being started bg the naked ~lame. In other situations, working conditions are so cramp~d or other~lise dif~icult that it is not conYenient to place a heat source such as a torch or hot a~r gun close to the sleeve which is to be recovered. ~e use o~ heat-recoverable slee~es may also be undesirable where the substrate on ~hich the sleeve is to be shrunk is temperature sensitive.
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" 1078032 Various sleeves which can be rccovered without the applicat~on of heat have been propo~ed. In particular there have been disclo~ed various types of expanded sleeve with internal restraining means positioned ~nternally of the in-terior surface of thc sleeve and which hold the sleeve in the expanded condition. One such sleeve comprise~ an expanded sleeve held in the expanded state ~y a cylinder of ice as disclosed in U.S. Patent No. 3,319,328 issued 16th May, 1967 to J. H. Finger et al. ~n actuality, such a sleeve is also a heat-recoverable sleeve because ~t requires à small amount of heat to melt the ice and allou thc ~leeve to recover. How-ever, the amount of heat neces~ary iJ somsmall that ~uch a sleeve i8 not normally considered to be a ~leeve requiring application of an outside heat ~ource. Another type of sleeve havin~ an internal r-~traint i~ de~crib-d in U.S. :-~
Patent No. 3,515,798 is~ucd 2nd June, 1970 to J. A. Sievert wherein a rigid removable mec~anical insert holds the sleove in the expanded conditlon unt~l the ~nsert is removed In general, all of the propo~al~ for making recoverable ves whtoh do not require heat have involved the use of ~ntornal restraining means which place a restraint bet~een tho substrate to be covered and the internal sur~ace of the sleeve or involve contacting the ~nternal ~ur~ace of the sleeve with ~ome fore~gn manter~al. Such re~trainin~ means pres-nt var~ou~ problems. For example, it ~ 9 frequently de~ired to coat tho ~nner ~urface of a recoverable ~leeve with a sealant or adhesive mater~al. Recoverable ~lee~es ~th internal restra~nin~ means often make t~e use of such ~3- -~
.
a coating difficult or impossible. ~urthermore, the presence o~ an internal restraining means between the sleeve and substrate may make ~itting o* the sleeve o~er the substrate dif~icult and reduces the range o~ substrate sizes over which the sleeve can be iitted.
According to the present invention ther~ is provided an article comprising a hollow, radially recoverable member ha~ing at least one open end and held in a radially extended condition by restraining means arranged e2ternally of the member by means o~ a bond between the outer surface o~ the member and the inner surface oi the restraining means, which bond i8 capable of being sui~iciently weakened by the applic-ation oi solvent thereto to allow the recoverable member to pull away irom the restraining means and shrink radially.
In a pre~erred embodiment the radially recoverable member and the e~ternal restraining means are tubular ~nd are o~
substantially oircular cro~-se¢tion.
The recoverable member is pre~erably made o~ an elastomeri¢ material. Eowe~er, recoverable members oi other materials, ~or example metallic split cylinaers in -radial tension, may be used. An elastomeric member must be ¢apable o~ be~ng extended radially to a condition ~rom which the member can recover upon removal of the restraining means holding it in the extended condition.
AB elastomeric materials9 virtually any desired material possess~ng elastomeric recovery properties may be used. ~he elastomeric ma~erial should be on~ ~hich does not exhibit j...
- .: ' . . . : . , -. , - ',' . :, ~ ' .' : ' .... . ' ~'" "~' ' ', ' ' ' ;' -, ~.
a substantial permanent set or decrease in recovery on storage. Bxamples o~ ~uitable elastomers are natural and synthetic polyisopreneæ, polybutadienes, ~or example cis-polybutadienes, styrene-butadiene rubbers (SBR), butadiene-acrylonitrile rubbers, polychloroprenes (Neoprenes), butyl rubbers, polysulfides, silicone rubbers, urethane rubbers, polyacrylateæ, epichlorohydrin homo and copolymers, propylene oxide rubbers, iluorosilicone rubberæ, fluorocarbon rubber~, chlorosulfonated polyethylenes, chlorinated polyethylene~, ethylenepropylene rubbers, nitrose rubberæ and phosphonitrilic rubbersO Other properties o~ the recoverable member æhould be compatible with the intended u~e of the recoverable member. ~hus, ii the recoverable member is to be uæed ior electrical insulation purposeæ, itæ electrical properties will be of primary importance. On the other hand, ii it i9 likely to be subjected to much phyæical abuse, it may be necessary to pro~ide a recoverable member which has toughne~s~ good ilame reæistance, good æolvent resi~tance, ete. ~or high voltage uses, it may be desirable to have a recoverable member which has been made semi-conducti~e by aispersing in its material o~ construction large amounts of ~uitable ~illers or conducti~e particles or which possesses re~istance to tracking and~or erosion.
To some extent, the nature o~ the recoverable member i~ dependent upon the nature o~ the restraining means a~
will be readily apparent. Thus, the ~orce oi reco~er~ exerted by the expanded reco~erable member must not e~ceed either the ` 107803Z
strength of the restraining means or o~ the bond between the member and the restraining meansO Further, it is necessary to choose a recoverable member which is compatible with the re.~.training mean.Y. to the e~tent that it can be bonded to the restraining means.
The restra?n;ng means is preferably a tube having a circular cross section. However, any member at least a portion o~ which is preferably closed in cross section, may be employed.
- The restraining means may be made o~, ~or esample, a rigid polymeric mater'al, a metal, a cera~ic, especially a porous ceramic, wood or wood products, ~or example paper or resin rein~orced or impregnated paperO In general, the only reauirement of the restraining means is that it has ;
suf~icient strength to hold the recoverable member in its .
extended condition without being de~ormed or collapsed.
It is ~urther desirable that the re.?.training means ;
be capable o~ bein~ bonded to the recoverable sleeve 50 .
bhat it will hold the recoverable sleeve in its extended condition until recover~ oi that .Y.leeve is desired. The bond may be ~ormed by adhe.3 on directly between the reco~erable member and the restraining means or by bondin~
the recoverable member and restraining means with a~ adhesi~e.
~ xamples of suitable rigid polymeric materials are rigid thermoplaætics, ~or example polyvinyl chloride copolymers of vi~y~ chloride with, ~or example, vinyl acetate, polyethylene, polystyrene, copolymers o~ ~.tyrene, ~or e~ample . ~
~.
- . . . .. . .
: . -. ' , ,-~ ' - .
.', ' - , , . ., ' : ''' . ' . ,: -. . , . : . ,, . , , . , .. ~,: . - -copolymers of styrene and acrylonitrile, ABS polymer, at least some of which thermoplastics may, as is known, be cross-linked.
In accordance with this invention, rapid attack and destruction of the bond between the re~training means and the recoverable member is accomplished by means of a solvent which will destroy the bond. Thus, it may be desirable for the restraining means to have holes or pores to allow direct contact of the solvent uit~ the bond at many locations. For this purpose it is adv ntageous to use a porous ceramic outer restraining mean~.
In many applications, it ~ould be undesirable to have the restraining mean- present a~ter the recoverable member has been recovered. Thu~, the restrainng means i8 preferably removable after the recoverable member ha~ been recovered.
This ~ay be achieved b~, for example using a re~training means made of a frang~ble material which can be b~oken by shattering it, for example by impact, b~ using metallic or rigid plastîcs re~tra~ning mean~ having wea~ened portion~, for example ~erration~ or 8core9, b~ ënable the restraining means to be removed ~rom about t~e recoveraDle ~ember a~ter the latter has pulled away ~rom tho re~tra nt, for example to enable the restraining mean8 to be peeled aw~y a~ter shrinkage of the recoverable member, or ~i8801ving the restraining mean~ in a ~uitable solvent.
A particularly convenient remoYable restraining means is one comprisin~ polyvn~1 chloride that which will ~racture ~0~78032 when given a sharp ~low. Thus, after the recoverable mem~er has peeled away from the restraining means and has recovered to its final position on the substrate, the polyvinyl chloride restraining means can simply be given a blow with a hammer to C~ 1' ~.:
. , , .. . . . . .
. : . . . .
, . . , ', , . ., ~ , . --.: -.: : . , - - - .
shatter it. Alternatively, such a restraining means may be cracked be~ore shrinkage o~ the recoverable memberO ~hen, the recoverable member will shrink upon the application -of solvent and the restraining means will then ~all away irom about the recoverable member.
~ he bond between the recoverable member and the onter restraining means should be ~u~ficiently strong that the bond will prevent separation o~ the expanded recoverable member from the restraining means under normal condition~
of storage and handling over a long period oi time. On the other hand,the bond must be al~ceptible to being weakened (thus allowing the recoverable member to peel a~ay from the restraining ~eans) on the application of a solvent to `s the bond line.
The bond may be iormed simply by adhesion o~ the ~leeve to the restraining means without the use of any additional bonding agent. 3uch adhesion may occur when two polymeric material~ are ~oined together, particularly at an ele~ated temperature at whi¢h they are both tacky. For example, when usine a polyvinyl chloride re~tra~ni~ means for a neoprene reco~erable member, it has been ~ound con~enient to injection mould the polyvingl chloride around the neoprene member. ~t typical in~ection moulding temperatures, a bond 1~ ~ormed betMeen the polyvinyl chloride restraining meanQ and the neoprene member.
It i~ frequently desirakle to use adhe~ives to in~ure a suitable bond between the recoverable member and the ... . ,, , . . . ,., ~ ........................ . .
: ... . . -- ; , . . . - . ~ . - . , .. :
1~7803Z
restraining means. Any adhesive which will provide a strong enough bond to prevent premature recovery of the recoverable member and yet will permit peeling away of the recoverable member from the restraining means upon the application of a solvent to the bond line may be used.
In general, hot melt adhesives are preferred. The hot melt adhesive may be applied by coating the outer surface of the recoverable member and/or the inner surface of the restraining means with a solution of the a & esive, allowing the solvent for the adhesive to evaporate and then bringing the surfaces together under the application of heat and/or pressure.
A preferred hot melt adhesive for a neoprene-PVC
system is a multisegmented block copolymer comprising units of polytetramethyleneether and polytetramethyleneteraphthalate.
A polymer of this type is sold by Du Pont under the trade mark HYTREL. This adhesive forms a strong bond between Neoprene and polyvinylchloride and yet can be readily weakened by application of a number of solvents, for exa~ple acetone, chloroform or trichloroethylene.
Various copolymers may be used as adhesives, for example copolymers of ethylenevinylacetate, e.g., ELV~X (trade mark) from Du Pont or copolymers of ethylene with ethylacrylate.
Terpolymers, for example terpolymers of ethylene, vinyl acetate, and methacrylic acid may, alternatively be used. These adhesives may be used alone or with tackifiers.
Other suitable hot melt adhesives are polyamide resin adhesives. Exemplary of such adhesives are those availa~le .; '.
s l07ao32 .
irom General Mills under the trade name VERSAIOl~, polyester adhe~ives ~see elg., Du Pont ~echnical Bulletin NoO 17--"Polyester Adhesives") and the wide variety oi polyvinyl, polybutene and polyacrylate adhesi~esO -Various rubber based adhesi~es, ior example thosebased upon silicones, nitriles, and neoprene may be used.
In general, any adhesive is suitable if it has good a~finity for the inner surface of the restraining mean~ and the outer suriace of the recoverable member and is resistant to creep under loadO Further, the bond must ha~e susceptibility to ~olvent attack so that upon the application oi solvent to a bond line between the restraining means and the recoverabl~ member, the bond weakens su~iiciently so that the recoverable member peels away ~rom the restraining meansO
Pre~erably the adhesive 1B thermOP~aBtiC SO that it will soften on heating to ~10~J and ultimately wet those suriaces of the restraining means and the recoverable memberO
Ang suitable method of applying the adhe~i~e to the appropriate sur~ace `of the recoverable member and/or oi the restraining means may be employed~ One suitable method o ~ pplication iB to apply the adhesive from solution to one or both surfaces and allow the sol~ent ior the adhesi~e to evaporate, bringing the suriaces together u~der the application of pressure and, if desired, heat to form a strong bond.
In a prefe~red method of manuiacturing an a~ticle of the in~ention, the outer restraining means is in~ectio~
: - 10-- :
- -.. . . .
:. . - - .
., ~ , .
.: , . : :~ , - . ' 107803Z ~
molded around the recoverable member. In that case, the adhesive is applied to the surface of the elastomeric member prior to the injection moulding step. In ge~eral, it is desired that the peel strength of the adhesive bond be greater than 10 pounds per inch (1.8 kg/cm) and preferablg that the peel strength be greater th~n 20 pounds per inch (3.6 kg/cm)O ~owever, there i~ no absolute requirement with regard to peel ætrength. Thu~, the important consideration i8 whether thepond or peel strength is su~icient to prevent the reco~erable member ~rom peeling away ~rom the restraining means during storage or at any time prior to the time when it is desired to shrink the member down about the substrate.
course a re~training core, e.g., a cardboard tube may be ;
pro~ided internally of the recoverable member to prevent premature reco~ery thereo~ the ~orce tending to cause the recoverable member to shrink and peel away ~rom the restraining mean~ i~ not great, a high bond or poel strengh i~ not so necessary. On the other hand, i~ a recoverable member having an extrèmely high retractive ~orce is employed, lt ie necessary to use an adhesi~e which will ~orm a bond ha~ing a high bond or peel strength.
When it is desired to cause shrinking oi the recoverable member, the bond between the recoverable member and the restraining mean~ is weakened or destroyed by the application o~ ~olvent at the bond line. ~ny solvent which will su~iciently weaken the bond to allow the recoverable member to peel away ~rom the restraining means and shrin~ o~er a substrate -.-.
.
.~ , . . .
may be used. Examples of solvents which may be used arechloroform, methylenechloride, N, N-dimethylformamide, ethylacetate, acetone, ethylene glycol monobutyl ether methylethyketone and trichloroethylene.
Other solvents may be used depending upon the nature of the adhesive used. It should be realized that the term "solvent" does not necessarily indicate that the solvent will dissolve the bond, for example the adhesive material. Rather, "solvent" is used to indicate any material which will destroy or weaken the bond between recoverable member and the restraining means. Thus, for example, acetone which is not a solvent for HYTREL will weaken the HYTREL bond between a neoprene sleeve and a polyvinyl chloride restraint S times faster than will chloroform which is a solvent for HXTREL.
Any desired method of applying the solvent to the bond line may be employed. A convenient method of applying the solvent is simply to spray it from a nozzle along the edge of the article. As the recoverable member peels away fro~ the restraining means the nozzle can be directed to apply solvent along the remaining bond line. As previously indicated, a porous outer restraining means comprising a material such as ceramic may be used. An advantage of such a porous restraining means is that solvent can be applied to the outer surface of the re~training means so that it will travel through the pores and contact substantially all parts . .
of the bond simultan~ously. Another method of obtaining rapid and complete contact of the bond line with solvent comprises using a restraining means havin~ a series of holes extending from the outer surface of the restraint to the bond between the restraining means and the recoverable member. Solvent applied to the outer surface of the re-ætraining means will pass through these holes and quickly contact and weaken the bond. A similar result can be achieved by fracturing a frangible restraining means and allow the solvent to penetrate to the bond line through the fractures.
~ he bond line attacked by the solvent may be the adhesive itself, the adhesive recoverable member interface, the adhesive restraining means interface, or all of these bond areas. Thus, when weakening of the bond line is referred !-to, it simply means that the adherence between the recoverable member and the restraining means is weakened, in some manner, to the extent that the sleeve will pesl away from the re-straining means.
The recoverable member may be coated on its internal ~urface with various materials, fpr example to enhance the bond between the recoverable member and the substrate to be covered and/or to act as a sealant. For example an adhesive such as a contact adhesive or a mastic may be applied to the int0rior surface of the recoverable member so that the member will form a bond with a substrate. Because the re-coverable member does not require heat for its recovery, it is preferred to employ an adhesive which does not require ;
.. . .. . . .
. - ~ : . ' : : ' the application of heat to form a strong bond with the sub-strate. In this regard, various contact or pressure sensitive adhesives may be employed As alternatives to adhesives, various other materials may be employed on the internal surface of the recoverable member.
For example, materials of the type described in U.S. Patent No. 3,396,460 issued 13th August, 1968 to J.D. Wetmore may be used. In many instances, it is desirable to coat the inside of the recoverable member with materials which will flow under the application of pressure at the temperature of application.
Preferably, these materials will adhere to both the re-coverable member and the substrate. Particularly suitable materials for this application are pressure sensitive adhesives and mastic and mastic-like materials.
The present invention also provides a method of covering a substra'e comprising positioning over the substrate an a~ticle comprising a hollow, radially recoverable member having at lea~t one open end and held in a radially extended condition by restraining means arranged externally of the member by means of a bond between-the outer surface of the member and the inner surface of the restraining means, which bond is capable of being sufficiently weakened by the applica-tion of solvent thereto to allow the recoverable member to pull away from the restraining means and shrink radially and weakening or breaking the bond between the recoverable member and the restraining means by the application of a solvent to the bond so that the recoverable member shrinks radially into .*
C - 14 - ¦
- ~ - -- . . - . :
.
. , .: .' -. ' ' :- , ' : ' ;' , ~ 078032 contact with the substrate. Advantageously, after the re-coverable member has shrunk down onto the substrate, the restraining means i~ removed from about the substrate.
The restraining means may, for example, comprise plastics material and have weakened portions, the method also co~pris-ing breaking the means along the weakened portions, and re-movîng the restraining means from about the recoverable member after the latter has pulled away ~rom the restraint.
The articles of the present invention have a wide range of applications. Thus, they can be used in many applications in ~hich heat recoverable ~leeves are normally u~ed. For example, ~here the re¢overable ~smber io of electrically in-sulating aaterial, they can be used in the insulation o~
splices in electrical conductors in botn low and high voltage applications. They ~ay be u~ed for covering repairs of joints in electron~c equip~ent and are particularly suitable ~or use in covering splices ~nd repairs in telephone ca~es and bable TV lines.
An area ~here heat recoverable ~leeves have had a great deal of use in recent years i8 for repairing splices in electrical cabl-~ used in mines. The articles of the -14a~
present invention are particularl~ suitable for such mine cable splices because they do not require the application o~ hcat which is usually accomplished by the use of a torch. This may be a major advantage, particularly in gassy mines where the use o~ torches i~ likely to be dangerous.
A number o~ methods are a~ailable for manu~acturing the articles o~ this in~ent~on. ~mply stated, the articles can be ~ormed by bonding the reco~erable member in the extended state, to an outer restraining means. One convenient method o ~ccomplishing this is to ~orm an outer restraining means and an inner member o~ the desired ~inal (i.e~ recovered) diameterO Then , the inner sur~ace of the restraining meana and/or the outer sur~ace of the inner member is coated with a su~table adhesive and the inner member is expanded into contact with the restraining meanc~ ~or example by internal air pressure or by using a mandrel. The e~panded member i8 held in contact with the re~training means ior a period o~ time suiiicient for a bond to be ~ormed between the member and the restraining means whereupon the mandrel or internal pressure is rem~ved.
A pre~erred technique ~or ~orming the article comprises ~ir~t form~ng the recoverable member and then injection molding the outer restr~n~ng means around the memberO In this method, ~he reco~erable member i~ first coated with adhesi~e. ~hen, the outer restra~ning means mater~al i~ injection molded around the reco~erable member.
_ 15 _ - . , .
- .... ..
,~ .- ., ~ . . ~ , -. . .
The two layers may also be formed by dual extrusion. Before the restraining means has hardened, the restraining means and recoverable memker are expanded by a mandrel or co~pressed air ' to give the desired expansion and desired final inside diameter to the recoverable member. While the recoverable member is in the expanded condition, the restraining means is cooled and hardened and upon removal of the~mandrel or release of the air pressure, the recoverable member remains bonded to the re-straining means and is thus held in the expanded condition.
The injection molding process described above has been found to be particularly suitable for use with a combination of a neoprene recoverable member, a HYTREL adhesive, and a polyvinyl chloride restraining means. However, it will be obvious that the process can be carried out using a wide range of suitable materials.
The present invention also provides a method o- ~aking an article which comprises moulding around the outer surface f an clastomeric m~r a restraining means comprising a poly-meric material which is radially rigid when at room temperature, radially expanding the elastomeric member and the res~raining means at a temperature at which the restraining means is plastic, and cooling the article or allowing it to cool whilst maintaining the article in its radially expanded condition, thereby to form an elastomeric member held in a radially expanded condition by the rigid restraining means.
As indicated herein, a wide variety of materials may bé used to manufacture an article of the prese~t invention .
' -~ ~ 16 ~
,,~,;,,r ;.~ . , -, ., .' ' ' '' ..
.
- . -. . .
~078032 depending upon the desired properties of the article. In the case of mine splices, it is necessary to provide a recoverable member which has great strength and abrasion resistance in the recovered state. These requirements are dictated by the mechanical abuse which mine cables must survive. Typically, mine cables are wound on and off cable reels in the mines, are pulled over sharp rock surfaces, and are frequently exposed to impact against sharp edges. Thus, properties such as tensil strength, elongation, flame resistance or retardance, ,, .
,_ .
- 16a-r~
.
. -' ' :' . - - --' . ' . .
'' : .
.,- : , ,, , ::
.. . . . . . . . . . . .
abrasion resis~ance, and dielectric strength are all important considerations ~or such me~bers. Additionally, it is important th~t the recovered member can resist peeling or creeping away from the splice which they :
cover.
It has been found that a combination of materials used in accordance with this invention will provide a recoverable article having properties suf~icient for use in extremely demanding environments of mines. In particular, a recoverable elastomeric mine sleeve requires an extremely high recovery force and thus it has been nece~sary to provide a Jestraining means and adhesive which will provide a strong bond bet~een the restraining means and the recoverable ~ember to mainta~n the member in the desired extended condition until recovery is desired.
According to the present invent~on, an elastomeric sleo~ehhaving a good combination o~ propert~es and being suitable ~or use a~ a m~ne ~pl~ce ~leeve oompri~es a neoprene sleeve having the iollo~ing composition:
TABLE I
art~ By ~eight Com~onent A B
Nooprene Rubber 100 100 Phen~l-alpha-napt~lamine 2 2 Hagnesium Ox~de Stoaric aci~ 0.5 0.5 HAF Carbon Black 5 ~ydrated alumina 10 10 Precip~tatod Sil~ca lS 15 .
~0'7803Z
Antimony oxide 15 15 Tri (2-ethylhexyl) phosphate 4 4 Zinc oxide 5 5 N-Cyclohexyl~2-benzothiazole sulfenamide 1 0.75 A treated arnine sold by Du Pont as TA-11 2 ---Tetramethyl thiourea --- 0.75 When cured at 350F (175C) for 15 minutes, a slab .075 in.
thick (O.18 cm) and a tube having an inside diameter of 0.75 in. (1.8 cm) and an outside diameter of 1.0 in. (2.5 cm)., both made from these compositions, were found to have the following properties:
TABLE II
SL~B PROPERTIES A B
.
Tensile Strength, psi(and Kg cm 2) 4400 (308) 300;7 (210~ -Ultimate~Elongation,% 7?0 (4~.7~ 550 (45.5) Tensile Stress at:
100% Elong. p~i(and Kgcm 2) 290 (20.3) 260 (18.2) 200/o Elong. psi(and Kgcm 2) 650 (45.5) 385 (26.5 300YO Elong. psi(and Kgcm 2) 1150 (80.5) 610 (42.7) TUBE PROPERTIES
Tensile Strength, p~3i(and Kgcm 2) 1990 (139) 970 (67.9) Ultimate Elongation,% _ 5~0 (31.7) 430 (30.1 ) .
5.
- .. . .
, . . .- . . . . . ~............. . . - -.. . . . ~ . .
- . , - . , - - . .. .
, . . . . . . . : .
- - . ; , . ~ ,. -. . : -: .
- , .
. ~ . , . . . - . ....
- 1078~32 Tensile Stress at: 3 10~/o Elong., psi(and Kgcm 2) 250 (17.5) 230 (16.1) 20~/o Elong., psi(and Kgcm 2) 460 (32.2) 330 (23.1) 30~/0 Elong., psi(and Kgcm 2) 850 (59.5) 500 (35.0) !
Tensile Strength at 150C,psi 370 (25.9) 280 (19.6) Ultimate Elongation at 150C,% 200 (14.0) 150 (10.5) Tear Strength (DieC),pli 370 215 Tear Strength (DieC) at:
150C, pli 90 80 Tape Abrasion (1/4"(0.63cm) strip, 250"tape, 2 lb.(0.9Kg) wt., 1504 Grid, mil) 35 36 ~ensile Set (20~/~ elong. at RT) After 24 hrs., % 1 2 After 7 day~, % 6 10 U~ing the compositions of Table I, tubes of neoprene ha~ing an i.d. of 0.75 in. (1.8cm) and an o.d. of 1.0 in.
(2.5cm) were molded. ~he neoprene tubes were placed in an injection mold and a polyvinylchloride cornposition as set forth below in Table III was injected around it. Two suitable polyvinylchloride compositions are as follows:
TABLE III
Component ~ _ A B
Po1yvinylchloride 100 100 , ... ,, . ~ . . . . . .
., , , , . ~ : .
:
:107803Z
An organotin stabilizer sold by M & T Chemicals 3 3 A cycloali~atic epoxy sold by Ciba-Geigy . 4 4 Low molecular weight polyethylene 2 2Low molecular weight nitrile rubber 10 Prior to the injection of the polyvinylchloride, the outer surface of the neoprene sleeve was abraded and coated with a 5% solution of HYIREL in chloroform and dried. Prior to injection molding, the tubes were preheated to soften the adhesive. Injection molding was carri:ed out using the conditions set forth in Table IV, below:
TABLE IV
Machine Temperature Noz-~le heat, 390F (197& ) Front heat, 375F ~188C) Center heat, 365F (183C3 Rear heat, 300F (147C) ~.
Mold Temperature Manifold, 275F (~34C) .Front plate, 175F ( 78& ) f Back plate, 200F ( g2C) Machine Settinas -- ¦
Injection time, seconds . ~5 - . . .
. . ~ , ~ .
', ' ' . ~ , ' ' ': ' . ' '" .: ' ' . ' : ' .' .
" 107803Z
Cooling time, seconds 15 Total cycle time, seconds 60-90 The resulting tubular article was expanded by pre-heating the tube and expanding 100 to 20~/o using air pressure to expand the tube into a cold expansion mold. The peel strength was found to be about 40 lb/in. (7.2Kg/cm) between the polyvinylchloride restraint and the Neoprene ~leeve.
A similar tube was recovered by spraying solvent onto the bo'nd line at the end of the article. A suitable solvent is 3~/~ chloroform or acetone and 7~/0 Freon 12. The use of between 45 and 75 grams of solvent resulted in recovery of the Neoprene sleeve by ~mplete peeling away from the restraining, means in about 5 minutes. The restraining means was then fractured with a hammer and removed.
The tubular articles of this invention may be expanded using conventional apparatus and methods, for example by means of màndrels or using hydraulic pressure.
Preferred forms of articles of the invention will now be de~cribed ~y way of Example only, with refersnce to the ¦ -accompanying drawings in which:-Figure 1 is a perspective view of an article of the invention, in position around a substrate, in which the bond between the recoverable member and the restraining means can be weakened or broken by application of a solvent to the bond, Figure 2 is a perspective view of the article of Figure , . ~
: ' . . ; :.
107803Z `
6, the recoverable member of which has partially recovered onto the substrate, Figure 3 ~ a perspective view of the recoverable member of the article of Figure 1 after it has been re-covered onto the substrate and after having shattered the restraining means but before the restraining means~has been removed.
Figure 4 is a perspective view of the recovered member on the substrate after the restraining means has been removed, Figure 5 i9 a perspective view of another solvent- ¦
shrinkable article of the invention showing an alternative form of removable restraining means .
and `
Figure 6 i9 a perspective view of another solvent-shrinkable article of the invention having yet - a further different restraining means. :
Referriny t~ drawings in Figure 1 an outer re- :
Btraining means made of a frangible material, for example polyvinyl chloride, i~ bonded to an inner sleeve 2 made, for example, of neoprene, 6 or a bond 6. ~he article is shown in .
position over a substrate 3 to`be covered. me bond 6 may be .
de8troyed or weakened by application thereto of a solvent 5 issuing from a nozzle 4. Upon.application of the solvent, the ..
81eeve 2 pulls away from the restraining means 1 and shrin~s ..
: into contact with the substrate 3 tsee Figure 2).
.~ ~
The restraint 1 may then be removed from about the ..
2 2 -- !
~:' ' ' i covered substrate 3 by striking the restraint 1 whereupon it cracks along lines 7 and the resulting segments 8 fall ¦-away (see Figures 3 and 4).
In Figure 5 there is shown a restraining means compris- ¦
ing a metallic tube having a helical score line 9. After solvent shrinking of the sleeve 2, restraining means 1 may be removed from about the covered substrate 3 by severing the restraint 1 along the ~core line 9 by pulling the pull ring attached to the restraint 1.
In Figure 6 there is shown an outer restraining means 1 which is provided with a plurality of apertures 11 which enable the solvent to attach the bond between the sleeve 2 and the outer restraining means 1 simultaneously at a number of locations. -- 22a -' . `
~,, ,' ,', .
~:' ' ' i covered substrate 3 by striking the restraint 1 whereupon it cracks along lines 7 and the resulting segments 8 fall ¦-away (see Figures 3 and 4).
In Figure 5 there is shown a restraining means compris- ¦
ing a metallic tube having a helical score line 9. After solvent shrinking of the sleeve 2, restraining means 1 may be removed from about the covered substrate 3 by severing the restraint 1 along the ~core line 9 by pulling the pull ring attached to the restraint 1.
In Figure 6 there is shown an outer restraining means 1 which is provided with a plurality of apertures 11 which enable the solvent to attach the bond between the sleeve 2 and the outer restraining means 1 simultaneously at a number of locations. -- 22a -' . `
~,, ,' ,', .
Claims (34)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An article comprising a hollow, radially recoverable member having at least one open end and held in a radially extended condition by restraining means arranged externally of the member by means of a bond between the outer surface of the member and the inner surface of the restraining means, which bond is capable of being sufficiently weakened by the application of solvent thereto to allow the recoverable member to pull away from the restraining means and shrink radially.
2. An article as claimed in claim 1 wherein the restraining means comprises apertures to allow radial access of the solvent to the bond.
3. An article a claimed in claim 1 or claim 2 wherein the restraining means is frangible.
4. An article as claimed in claim 1, wherein the restraining means comprises a plastics or metallic material and has weakened portions to enable the restraining means to be removed from about the recoverable member after the latter has pulled away from the restraint.
5. An article as claimed in claim 4 wherein the weakened portions comprises one or more score lines.
6. An article as claimed in claim 1 wherein the recoverable member is substantially tubular.
7. An article as claimed in claim 6 wherein the restraining means is substantially tubular.
8. An article as claimed in claim 1 wherein the recoverable member comprises an elastomer.
9. An article as claimed in claim 8 wherein the elastomer is a polychloroprene.
10. An article as claimed in claim 8 wherein the elastomer is an ethylene propylene rubber.
11. An article as claimed in claim 8 wherein the elastomer is silicone rubber.
12. An article as claimed in claim 1 wherein the material of the restraining means comprises polyvinyl chloride.
13. An article as claimed in claim 1 wherein the bond is a direct bond between the material of the recoverable member and the material of the restraining means.
14. An article as claimed in claim 1 wherein the restraining means and the recoverable member are bonded together by an adhesive.
15. An article as claimed in claim 14 wherein the adhesive is a hot melt adhesive.
16. An article as claimed in claim 15 wherein the adhesive is a block copolymer comprising units of polytetra-methyleneether and/or polytetramethylene terephthalate.
17. An article as claimed in claim 14 wherein the bond is breakable at the interface between the recoverable member and the adhesive.
18. An article as claimed in claim 14 wherein the bond is breakable at the interface between the restraining means and the adhesive.
19. An article as claimed in claim 1 which is provided with a removable supporting core positioned internally of, and in contact with, the recoverable member.
20. An article as claimed in claim 1 wherein the recoverable member is of electrically insulating material.
21. An article as claimed in claim 1 wherein at least one part of the innermost surface of the recoverable member is coated with a sealant.
22. An article as claimed in claim 21 wherein the sealant is a contact or pressure sensitive adhesive or a mastic.
23. A method of covering a substrate comprising positioning over the substrate an article comprising a hollow, radially recoverable member having at least one open end and held in a radially extended condition by restraining means arranged externally of the member by means of a bond between the outer surface of the member and the inner surface of the restraining means, which bond is capable of being sufficiently weakened by the application of solvent thereto to allow the recoverable member to pull away from the restraining means and shrink radially, and weakening or breaking the bond between the recoverable member and the restraining means by the application of a solvent to the bond so that the recoverable member shrinks radially into contact with the substrate.
24. A method as claimed in claim 23 wherein the solvent is initially applied to the bond at an edge of the article.
25. A method as claimed in claim 23 wherein the solvent is applied to the outer surface of the restraining means, the restraining means having a plurality of radial apertures therein to allow the solvent to reach the bond.
26. A method as claimed in any one of claims 23 to 25 wherein, after the recoverable member has shrunk down onto the substrate, the restraining means is removed from about the substrate.
27. A method as claimed in claim 23 wherein the restraining means comprises plastics material and has weakened portions, and wherein the method also comprises breaking the means along the weakened portions, and removing the restraining means from about the recoverable member after the latter has pulled away from the restraint.
28. A method of making an article which comprises moulding around the outer surface of an elastomeric member a restraining means comprising a polymeric material which is radially rigid when at room temperature, radially expanding the elastomeric member and the restraining means at a temperature at which the restraining means is plastic, and cooling the article or allowing it to cool whilst maintaining the article in its radially expanded condition, thereby to form an elastomeric member held in a radially expanded condition by the rigid restraining means.
29. A method as claimed in claim 28 wherein the restraint is injection moulded around the elastomeric sleeve.
30. A method as claimed in claim 28 or claim 29 wherein the polymeric material is thermoplastic.
31. A method as claimed in claim 28 or claim 29, wherein the recoverable member comprises polychloroprene and the restraining means comprises polyvinyl chloride.
32. A method as claimed in claim 29 wherein a hot melt adhesive is applied to the outer surface of the recoverable member, to the inner surface of the restraining means, or to both said surfaces, before the injection moulding step.
33. A method as claimed in claim 28 wherein the radial expansion is effected by introducing a gas under pressure into the interior of the elastomeric member.
34. A method as claimed in claim 33, wherein said gas under pressure is compressed air.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/587,267 US4135553A (en) | 1975-06-16 | 1975-06-16 | Recoverable sleeve |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1078032A true CA1078032A (en) | 1980-05-20 |
Family
ID=24349097
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA255,015A Expired CA1078032A (en) | 1975-06-16 | 1976-06-16 | Recoverable sleeve with frangible restraining means |
Country Status (2)
| Country | Link |
|---|---|
| US (2) | US4135553A (en) |
| CA (1) | CA1078032A (en) |
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| PL2608338T3 (en) | 2011-12-21 | 2014-04-30 | 3M Innovative Properties Co | Terminal connection device for a power cable |
| US9926630B2 (en) | 2012-07-13 | 2018-03-27 | Frans Nooren Afdichtingssystemen B.V. | Process for the protection against corrosion of an article in a wet environment and composition therefore |
| US9224522B2 (en) | 2013-02-04 | 2015-12-29 | Tyco Electronics Corporation | Holdout devices and cover assemblies and methods incorporating the same |
| US9178289B2 (en) * | 2013-05-14 | 2015-11-03 | Tyco Electronics Corporation | Joint bodies and methods for covering electrical cables and connections |
| CN105340145B (en) | 2013-06-26 | 2019-06-18 | 3M创新有限公司 | Power cable terminal-connecting means |
| USD841452S1 (en) * | 2016-06-10 | 2019-02-26 | Douglas Swain Conselvan | Tube restoring device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1815706A (en) * | 1928-05-07 | 1931-07-21 | Habirshaw Cable & Wire Corp | Method of impregnating cables |
| US2360925A (en) * | 1940-08-29 | 1944-10-24 | Edwin T Wyman | Process for preventing leakage in rubber articles and the like |
| US2677165A (en) * | 1950-10-27 | 1954-05-04 | Sonoco Products Co | Concrete form and method of molding concrete columns therewith |
| US2670313A (en) * | 1951-01-19 | 1954-02-23 | Richard E Young | Method of making a ring of a length of thermoplastic material |
| GB821863A (en) * | 1956-10-19 | 1959-10-14 | Crane Packing Ltd | Improvements relating to the joining of synthetic plastic materials, such as pipes |
| US3036374A (en) * | 1959-08-10 | 1962-05-29 | Olin Mathieson | Metal forming |
| BE635318A (en) * | 1962-07-23 | |||
| US3319328A (en) * | 1962-09-24 | 1967-05-16 | Millmont Ind Inc | Method of installing a protective cap on an exposed wooden pole |
| US3250050A (en) * | 1963-06-17 | 1966-05-10 | Millmont Ind Inc | Pole cap |
| US3511734A (en) * | 1963-11-01 | 1970-05-12 | Cee Bee Mfg Co Inc | Method of lining concrete pipe |
| US3329174A (en) * | 1964-07-01 | 1967-07-04 | Arrow Tank Company Inc | Lined hollow wood body |
| US3390033A (en) * | 1964-08-13 | 1968-06-25 | Rca Corp | Method of separating frit sealed parts of an electron tube |
| US3415287A (en) * | 1964-08-21 | 1968-12-10 | Raychem Corp | Protective covering and article |
| US3421551A (en) * | 1965-05-21 | 1969-01-14 | Gerald F Currier | Destructible article for reserving a recess in concrete |
| US3411971A (en) * | 1966-09-02 | 1968-11-19 | Sylvania Electric Prod | Method of separating frit-sealed glass bodies |
| US3534465A (en) * | 1968-02-09 | 1970-10-20 | Dow Chemical Co | Method for lining vessels |
| US3898369A (en) * | 1968-02-27 | 1975-08-05 | Robin J T Clabburn | Metal coated heat-recoverable articles |
| US3568311A (en) * | 1968-09-30 | 1971-03-09 | Gen Electric | Insulating and spacing electrically conductive members |
| US3515798A (en) * | 1968-12-06 | 1970-06-02 | Minnesota Mining & Mfg | Elastic cover and removable cone assembly |
| US3669824A (en) * | 1969-05-19 | 1972-06-13 | Raychem Corp | Recoverable article |
| US3674134A (en) * | 1970-03-13 | 1972-07-04 | Kay Laboratories Inc | Rupturable container |
| US3768523A (en) * | 1971-06-09 | 1973-10-30 | C Schroeder | Ducting |
| US3770876A (en) * | 1972-05-08 | 1973-11-06 | Goodyear Tire & Rubber | Elastic cover and method of applying said cover |
| US3827625A (en) * | 1972-06-21 | 1974-08-06 | Reclosable Package Corp | Reclosable package and controlled release paper for use therein |
| US3913444A (en) * | 1972-11-08 | 1975-10-21 | Raychem Corp | Thermally deformable fastening pin |
| US4035534A (en) * | 1972-09-01 | 1977-07-12 | Raychem Corporation | Heat-shrinkable laminate |
-
1975
- 1975-06-16 US US05/587,267 patent/US4135553A/en not_active Expired - Lifetime
-
1976
- 1976-06-16 CA CA255,015A patent/CA1078032A/en not_active Expired
- 1976-09-03 US US05/720,611 patent/US4070746A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US4135553A (en) | 1979-01-23 |
| US4070746A (en) | 1978-01-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |