Raychem Limited

Other

Nachum Rosenzweig

Pravin L Soni

Chi-Ming Chan

Manoochehr Mohebban

Pradeep Barma

Eugen L Kurjatko

Ken W Skanderup

An energy absorbing device comprising: an elongate body arranged along a longitudinal axis to receive an axial impact force at a first end thereof; apparatus arranged adjacent a second end of the body for deformation thereof; die apparatus for producing deformation of the body and a ring fixed to the die apparatus and surrounding the body. Also disclosed is a repeatable energy absorption device including crushing apparatus having threaded apparatus on its outside surface. Upon receipt of the axial impact, the first end of the body moves from a first position away from the crushing apparatus to a second position closer to the crushing apparatus. The device additionally includes threaded sleeve apparatus having a first end for supporting the crushing apparatus and for moving the crushing apparatus toward the first end after the axial impact, to return the first end of the body to the first position.

Device and method for absorbing impact energy

Conductive polymer composition

A composition which comprises a matrix polymer and, distributed therein, a particulate conductive filler. At least some of the filler particles are composed of a conductive polymer composition and/or the matrix comprises a sintered polymer. The matrix polymer and the filler particles and the method of distributing the particles are such that the particles maintain their identity in the matrix. For example, the particles are preferably highly cross-linked so that they have a hot modulus of at least 250 psi if the composition is prepared by melt extrusion or another process involving a high degree of shear; or a low-shear process such as sintering can be used. Preferably the matrix polymer is capable of coating the filler particles; for example, the matrix polymer and the filler polymer may be chemically similar. The invention is particularly useful for preparing compositions which have high resistivities, eg. 1000 ohm.cm or more, and which can be prepared with a high degree of reproduceability. The compositions can exhibit PTC, ZTC or NTC behavior, depending on the nature of the conductive filler, and their resistivity is dependent on the electric field. The compositions are particularly useful as resistive materials in sheet heaters and as stress-grading materials for high voltage apparatus.

A method of joining, repairing or reinforcing substrates, particularly polymeric pipes for transporting fluids, e.g. natural gas and water. The method makes use of an article, preferably a heat-recoverable article, which comprises a conductive polymer composition and which is heated to its recovery temperature by passing electrical current through the conductive polymer. Preferably the article is a heat-shrinkable coupler. The coupler may make direct contact with and fuse to the pipes, or there may be an insert between the coupler and the pipes. The article preferably comprises carbon blank dispersed in either a sintered polymer, particularly ultra high molecular weight polyethylene or a very high molecular weight polymer, particularly polyethylene having a molecular weight greater than 150,000.

Heat recoverable article comprising conductive polymer compositions

A coupler for joining polymeric pipes comprises a generally cylindrical radially heat-shrinkable member which is composed of a conductive polymer. To recover the coupler, current is passed axially through the coupler via electrodes. The coupler has a center portion of increased wall thickness and in this way, when there is a gap between the pipes, overheating of the center portion of the coupler is avoided.

Heat-recoverable coupler

A method of joining a substrate, particularly a polymeric pipe for transporting fluids, e.g. natural gas and water, to an article which is not heat-recoverable and which comprises a conductive polymer composition. The article is heated by passing electrical current through the conductive polymer. The heated article makes direct contact with and fuses to the substrate, and is preferably a coupler which is used to join two pipes together. The conductive polymer preferably comprises carbon black dispersed in a sintered polymer, particularly ultra high molecular weight polyethylene, or carbon black dispersed in a very high molecular weight polymer, particularly polyethylene having a molecular weight greater than 150,000.

Method of joining an article comprising a conductive polymer composition

The invention relates to novel bearings and methods for making bearings. The method comprises dimensionally recovering at least one race or rolling or sliding element such that a rolling element is free to roll or slide yet contained within the race.

Method of forming a bearing by dimensional recovery of a race or rolling

Methods of modifying substrates, in particular joining pipes, especially pipes composed of glass fiber-reinforced polymers, make use of heat-recoverable conductive polymer articles. An insert is placed between the substrate and the article, and undergoes a desired chemical and/or physical change when the article is recovered. Preferably the insert is a fiber-reinforced thermosetting polymer which is cured in situ against the substrate. Preferably the conductive polymer is a sintered material or another material having good physical properties above its recovery temperature.

Method of using heat-recoverable articles comprising conductive polymer

A method of joining, repairing or reinforcing substrates, particularly polymeric pipes for transporting fluids, e.g. natural gas and water. The method makes use of an article, preferably a heat-recoverable article, which comprises a conductive polymer composition and which is heated to its recovery temperature by passing electrical current through the conductive polymer. Preferably the article is a heat-shrinkable coupler. The coupler may make direct contact with and fuse to the pipes, or there may be an insert between the coupler and the pipes. The article preferably comprises carbon black dispersed in either a sintered polymer, particularly ultra high molecular weight polyethylene or a very high molecular weight polymer, particularly polyethylene having a molecular weight greater than 150,000.

An assembly which comprises a heat-recoverable article which is adapted to join substrates together and a plug which is in a recess of the article. The plug comprises a first polymer, e.g. nylon, which is opaque at room temperature and transparent at an elevated temperature, and preferably comprises a colored portion beneath the first polymer. When the article is connected to a power supply, it heats and recovers. At the recovery temperature of the substrate, the nylon melts and the colored portion becomes visible, thus indicating to an operator that the article should be disconnected from the power supply.

Temperature indication assembly for use with heat-recoverable articles

A heat-recoverable article which can be connected to a power supply and a switch unit which comprises a thermally-responsive member which can be thermally coupled to the article. The thermally-responsive member, when so coupled, regulates the passage of current through the article. The article heats and recovers and current through the article is regulated automatically.

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Palo Alto, CA, United States of America

Nachum Rosenzweig