An apparatus for forming a weld between a first portion of a biocompatible conductive thermoplastic material and a second portion of a biocompatible conductive thermoplastic material comprises a first electrode, a second electrode, and a structure for holding said first and second electrodes in opposition to one other with a space therebetween for receiving said first portion and said second portion in contact with one another. The structure is electrically non-conductive and an electrical circuit comprising a power source and a switch arranged such that closure of said switch applies a voltage potential across said first electrode and said second electrode so as to generate heat via electrical resistance, the heat being sufficient to melt regions of said first and second portions.

A resistance welding apparatus can employ a modular power supply system with multiple power supply modules and leads for electrically connecting the modular power supply system to a welding resistor. The resistance welding apparatus is selectively configurable in at least three of (i) a first configuration in which the leads connect the first power supply module to the resistor and the second power supply module is disconnected from the resistor; (ii) a second configuration in which the leads connect the second power supply module to the resistor and the first power supply module is disconnected from the resistor; (iii) a third configuration in which the leads connect the first and second power supply modules to the resistor in series; and (iv) a fourth configuration in which the leads connect the first and second power supply modules to the resistor in parallel.

Disclosed is a method of resistance welding between composite articles. A conductive element is provided between faying surfaces, having a plurality of lower resistivity electrode portions spaced apart along the length of the contact area between the composite articles. The electrode portions can be used to spot weld across the electrode portions, and along a longitudinal portion of the conductive element between the electrode portions by application of an electrical current. Also disclosed are apparatus for use in the resistance welding methods and composite articles and structures and elements incorporating the conductive element.

The electrofusion joint includes a tubular main body, a stopper portion, a first heat generating section, and a second heat generating section. The tubular main body includes a joint receiving portion. The stopper portion projects inward on the inner surface of the main body. The first heat generating section includes a heating wire wound and arranged at the joint receiving portion. The second heat generating section includes a heating wire wound so that wound parts are adjacent to each other and the heating wire is disposed in the stopper portion. The first heat generating section includes at least one heat generating portion in which the heating wire is wound so that the wound parts are adjacent to each other.

Electrofusion tape and method for the production thereof for welding together with plastics pipes in particular for use in a fixed-point fastening, consisting of a jacket element preferably of an electrically insulating plastics material, at least one heating element of electrically conductive plastics material and at least two contact elements for supplying electricity to the heating element, wherein the jacket element and the heating element take the form of tapes, wherein the jacket element surrounds the heating element at least in part, wherein the contact elements are arranged in the mutually opposing marginal regions of the heating element and extend parallel to one another along the heating element.

A method of securing a first component part and a second component part together, the method comprising providing an electrically conductive member between a first surface of the first component part and a facing first surface of the second component part and securing the first and second components together by passing a current through the electrically conductive member. The electrically conductive member is distributed across at least 50% of the surface area of the first surface of the first component part.

Disclosed is a method of resistance welding between composite articles. A conductive element is provided between faying surfaces, having a plurality of lower resistivity electrode portions spaced apart along the length of the contact area between the composite articles. The electrode portions can be used to spot weld across the electrode portions, and along a longitudinal portion of the conductive element between the electrode portions by application of an electrical current. Also disclosed are apparatus for use in the resistance welding methods and composite articles and structures and elements incorporating the conductive element.

A resistance spot welding system can join two polymeric workpieces and includes a power supply. The power supply has a positive terminal and a negative terminal. The resistance spot welding system further includes a welding electrode assembly electrically connected to the power supply. The welding electrode assembly includes a housing, a first electrically conductive pin and a second electrically conductive pin. The first and second electrically conductive pins both protrude from the housing. The first electrically conductive pin is electrically connected to the positive terminal of the power supply, and the second electrically conductive pin is electrically connected to the negative terminal of the power supply. The second electrically conductive material is electrically insulated from the first electrically conductive pin. The first and second electrically conductive pins are at least partly made of a material having a hardness ranging between 50 HRC and 70 HRC.

A system for coupling pipes includes a first pipe having a tapered, spigot end; a second pipe having a tapered, spigot end; a coupler having two tapered socket ends adapted to internally receive the respective tapered, spigot ends of the first pipe and the second pipe; and a resistive element. The first pipe, the second pipe, and the coupler are made from a reinforced thermosetting resin (RTR). The resistive element includes a first layer and a second layer of thermoplastic material; and an electrically conducting resistive heating element with positive and negative terminals for connecting electrical power. The electrically conducting resistive heating element is sandwiched by the first layer and the second layer of thermoplastic material. The resistive element is disposed between an interior of the coupler and at least one of: an exterior of the first pipe and an exterior of the second pipe. Upon application of electrical power to the positive and negative terminals of the resistive element, the electrically conducting resistive heating element generates heat sufficient to melt the thermoplastic material such that, when the heat is removed, the hardened thermoplastic material seals the first pipe and/or the second pipe to the coupler.

A process, for joining workpieces using hybrid mechanical connector-resistance welding. The process in some embodiments includes introducing a conductive fluid to an interface between the workpieces. The process also includes inserting at least one mechanical conductive connector into at least one of the workpieces so that the connector reaches the interface having the conductive fluid therein. The process in some embodiments includes further applying energy for welding to the at least one mechanical conductive connector so that the energy passes, through the connector, to the conductive fluid and heat is generated in the workpieces at the interface, thereby melting the workpieces and forming a weld joint connecting the workpieces.