Abstract: A device for enclosing at least part of an elongate object, for example a pipe line, comprises a dimensionally recoverable cover 21 one surface of which is partly or wholely coated with a closure adhesive 22 and covered by a layer of sealant.The cover is preferably in the form of a continuous sheet which may be cut to the appropriate length. The device may be wrapped around the object and the overlying sealant may then be peeled back or peeled away to expose the closure adhesive. The cover is bonded to itself or to the object to be enclosed by means of the exposed closure adhesive, and the device is then recovered by heating.

Abstract: The invention relates to a novel thermoplastic monoorganopolysiloxane resin comprising units of the formula RSiO.sub.1.5 and R.sub.1 R.sub.2 R.sub.3 SiO.sub.0.5 wherein R,R.sub.1,R.sub.2 and R.sub.3 are hydrogen, or organic groups which may be the same or different, at least 85% of the R groups in the RSiO.sub.1.5 being organic groups, and at least two of the groups R.sub.1, R.sub.2 and R.sub.3 in each R.sub.1 R.sub.2 R.sub.3 SiO.sub.0.5 unit being organic groups, and in which the ratio RSiO.sub.1.5 units to R.sub.1 R.sub.2 R.sub.3 SiO.sub.0.5 units is from 1:0.005 to 1:0.03 on a molar basis. Such resins are useful as electrical insulation material and as hold out agents for heat recoverable materials.

Abstract: The invention relates to a novel process for the production of a thermoplastic, high softening point polysiloxane resin which comprises reacting a solvent-soluble partially condensed organosiloxane with a silane capping agent. The resins so produced are useful as electrical insulator material and also as hold out agents for heat recoverable articles.

Abstract: An enclosure for a shielded cable termination or joint comprises a protective sleeve comprising a conductive outer layer (51), an insulating inner layer (52), advantageously of substantially uniform cross-section for at least a portion of its length, and optionally a stress grading innermost layer (53). At least the insulating layer (52) and/or the stress grading layer (53) overlaps the or each cable shield, in the case of the insulating layer by an amount at least equal to the thickness of the portion of the insulating layer overlapping the cable shield end. Preferably the sleeve is installed by heat recovery.

Abstract: A composition based on epihalohydrin elastomers comprises from 12 to 125 parts, preferably from 25 to 75 parts, of a suitable tackifier, and from 25 to 150 parts, preferably from 30 to 100 parts, of a particulate filler per 100 parts by weight of elastomer. The tackifier contains polar moieties for compatibility with the elastomer and is preferably a phenolic, modified phenolic, coumarone-indene or polyketone resin. The filler is preferably an inorganic material such as alumina trihydrate, silica, or iron oxide. These composition have useful adhesive and surprising stress-grading properties and are thus suitable for use with heat-recoverable articles in the terminatiion, connection, and encapsulation of high voltage electrical apparatus.

Abstract: A recoverable seal for sealing a container, especially an artillery ordinance cannister, comprising a heat-shrinkable continuous annular band having a uniform coat of heat-activatable adhesive on the inwardly-facing surface thereof which has a mean thickness of 0.01 to 1.0 mm and differs from the mean thickness over the surface by at most 25% of the mean thickness. The band may be provided with a tearable region such as a score line to enable it easily to be peeled off the container. After the band has been recovered on the container, the band can be peeled away and a layer of adhesive will remain aiding the ability of the seal to withstand pressurization and depressurization.

Abstract: The invention concerns a novel cladded elongate substrate such as a jacketed cable, the cladding being flame retarded and comprising a vinyl acetate/alkene copolymer composition incorporating a halogen-free inorganic flame retardant. The composition is characterized by a high content of vinyl acetate and/or the presence of a polyalkene or alkene/alkene copolymer blended with the vinyl acetate/alkene copolymer.

Abstract: The substantial change in modulus with temperature of certain materials, especially memory metals, is used to make a novel connector by forcing a band made from such a material in its low modulus state up an external tapered portion of a tubular coupling member so as to deform the band which remains in position about the coupling member. To make a connection one or more substrates is (are) positioned inside the tubular coupling member and the band is brought to its high modulus state whereupon it contracts and deforms the tubular coupling member and forces it into firm connection with the substrate.

Abstract: The invention provides a polymer composition which comprises a crosslinkable or crosslinked blend of an elastomer and a thermoplastic polymer, the elastomer comprising a polymer of ethylene with an ethylenically unsaturated aliphatic ester, and the elastomer and the thermoplastic polymer being substantially free of halogen-containing substituents. The preferred compositions may be used as jacketing materials for wire and cable, as harnessing materials, and in the manufacture of heat recoverable articles having improved oil resistance and thermal ageing properties.

Abstract: The invention relates to novel melt processable polymer compositions which comprise a blend of non-silicone polymer and a monoorganic polysiloxane resin. Such compositions are useful inter alia as flameproof and moisture resistant coating compositions and in the product of heat shrinkable silicone elastomer compositions.

Abstract: A polymer composition containing silicon carbide of a critical maximum average particle size can be processed into heat-shrinkable articles possessing nonlinear electrical resistance characteristics. An embodiment of the invention provides a heat-shrinkable article comprising a laminate of a layer of elastomer, including silicon carbide particles, and a layer of a heat-shrinkable polymeric material. The elastomeric layer may be a blend of a rubbery polymer and a low density polyethylene having dispersed therein particulate silicon carbide of particle size finer than about 300 grit.

Abstract: A heat-recoverable article comprises a memory metal member to which has been imparted both thermally-recoverable and resiliently-recoverable strain. The resilient strain is retained by means of a disburdenable keeper, preferably one made from fusible or chemically degradable material, which can be removed, for example, by heating or chemical treatment, to allow resilient recovery. The article is preferably so constructed that it can be heated to obtain both thermal and resilient recovery simultaneously. One preferred form of article is a radially expanded longitudinally split tube, the keeper being positioned in the split. Such an article can be used as a connector to secure an earth lead to the sheath of a mineral-insulated cable.

Abstract: A feedthrough device is provided for sealing a supply line as it passes through an aperture in a wall member such, for example, as the housing of electrical apparatus. The device, which is generally tubular, comprises a first member which is radially inwardly deformable and can be pushed through the aperture and a second member which can telescopically engage the first member so as to co-operate with it to clamp against the wall member and provide a seal whilst at the same time preventing radial inward deformation of the first member. A recoverable sleeve member, which may be provided on, or be integral with, either of the first or second members engages the supply line to effect a seal therewith.

Abstract: A dimensionally-recoverable article comprising a hollow resilient member which has been expanded to a dimensionally unstable configuration in which it is retained by a keeper positioned between and separating two parts of the hollow member away from the path of recovery thereof. The keeper is preferably made from a fusible or chemically degradable material so that it can be removed, for example, by heating or chemical treatment to allow the hollow member to recover towards its original configuration. One preferred form of article is a radially-expanded longitudinally split tube having the keeper positioned within the split. Such an article may be used as a connector to secure an earth lead to the sheath of a mineral-insulated cable.

Abstract: A heat-recoverable article for protecting a conduit, for example, an electric cable, where its conductors pass through an aperture in a bulkhead, in order, for example, to prevent chafing; the article has an inner expansible and an outer shrinkable sleeve, the outer jacket of the cable terminating in an annular space between the sleeves, the space shrinking on heating of the article; one end of the inner sleeve is expansible to grip the bulkhead.

Abstract: Electrical connections to line substrates, such as cables, are made by employing a radially shrinkable coil member which is positioned about the substrate in an expanded form and is then caused or allowed to revert to a smaller radius so that it grips the substrate. In preferred embodiments the coil member is made from a heat-recoverable material or is made from a resilient material which is held in an expanded form by a disburdenable material, e.g. a fusible material such as solder, which is subsequently removed, deformed or destroyed so as to cause connection. The devices are especially suitable for connecting earth leads to the sheaths of mineral insulated cables in the vicinity of terminations and splices thereof.

Abstract: A wiring harness, and a method for making it, which comprises positioning the wires in a desired configuration and applying a bonding agent as a fluid coating. The method is especially suitable for use with wires insulated with crosslinked polymer insulation.

Abstract: The effective transition temperature from martensite to austenite in a dimensionally heat-recoverable memory metal member can be temporarily raised by applying a stress and maintaining the applied stress at a temperature below the raised transition temperature so that the memory metal remains substantially in the martensitic state. When it is desired to utilize the member the stress is removed at a temperature above the original transition temperature. The applied stress is advantageously maintained by a disburdenable keeper. In an especially preferred embodiment the keeper comprises an aluminium tube positioned within a band or tube made from a brass memory alloy, the combined article being suitable as a connector for hydraulic pipes and the like.

Abstract: A hollow structure for use as an electrical insulator or other similar structure having outwardly disposed flanges extending circumferentially thereabout. The hollow structure includes a hollow member of heat recoverable material positionable about a central insulator core, electrical conduit, fuse or other substrate. The outwardly extending flanges are integrally formed with the hollow member and extend radially therefrom in the dimensionally heat stable state. The hollow member is designed to be expanded to a heat recoverable state for later facile positioning about an appropriate substrate. The hollow member may then be heat recovered about the substrate to become securely positioned thereon. Proper selection of the hollow member as to its dimensionally heat stable inner diameter relative to the inner diameter of the substrate results in control of the orientation of the flanges once the hollow structure has been recovered about the substrate.

Abstract: Described herein is a reusable connector which may, for example, find use in making electrical connections. The connector comprises a heat recoverable metallic band disposed about a non-resilient, deformable member, typically a hollow cylinder that has been slotted to form tines, that has been deformed from an original configuration. When it is desired to make a connection, an object member is inserted into the deformable member and the metallic band is caused to shrink and drive the deformable member towards its original configuration thereby engaging the object member. Preferably the object member has an enlarged portion that is positioned so that when the object member is inserted, the enlarged portion passes through the metallic band. Recovery of the metallic band behind the enlarged portion inhibits withdrawal of the object member from the connector.