Abstract: A graphite body comprises aligned graphite flakes bonded with a binder, in which the graphite has an average particle size of >200 ?m. Methods of forming such highly oriented graphite material include:— a) forming a mixture of a mesophase pitch with a graphite powder; b) rolling the mixture to align the graphite powder and to form a body of graphite and pitch; c) carbonising the body; and optionally d) graphitising the body. Pressing rather than rolling may be employed. Such graphite bodies have high thermal conductivity and anisotropy and may be used for thermal management.

Abstract: Disclosed herein is an electrical brush (1) having a brush wear sensor (9) in the form of a loop (10, 11, 13) of insulated electrical conductor having two arms joined by a looped end, the arms leading from an upper surface of the brush to a depth (d) to be equivalent to the point at which brush wear is to be sensed. A pair of fine bores (5, 6) lead from the brush upper surface to meet a transverse hole (8) in a side face of the brush at the wear depth. Each arm of the sensor loop lies in a respective one of the fine bores with the looped end disposed in the transverse hole and joining the respective arms in the fine bores. Assembly preferably is by insertion of the free ends of the arms of the loop of insulated electrical conductor into the transverse hole and then separately into and through respective ones of the fine bores.

Abstract: A wear sensor comprising a pair of outputs for connection to an electrical detection circuit or the like and a link element connected between the outputs and positioned to be worn and broken at a given wear point, and resistor means connected between the outputs to be electrically in parallel with the link element and positioned not to be worn; the resistance of the link element being less than the resistance of the resistor means such that the resistance of the sensor as detected between the outputs will have an initial value, indicating electrical continuity with the sensor, until the sensor is worn to said given wear point and the link broken, and a further, higher value once the link has been broken.

Abstract: An electric traction current-collector has a carbon current-collector block (1) housing a rupturable tubular container (7 l ) for air under pressure applied through a pneumatic control system for a pantograph or other carrier so that loss of air pressure due to rupture of the container causes the current-collector block to be retracted. The container (7) is so thin that, if it is not completely housed and supported, it bursts under the applied air pressure and consequently any defect in the carbon block which spoils complete support of the container causes retraction of the current-collector.