Abstract: In a friction buffer stop, each side wall of the buffer structure has at its lowermost edge mutually spaced slots extending parallel to the adjacent rail, each slot being directly opposite to and of the same length as a slot in the other side wall. Pairs of transversely spaced two-part clamps detachably secure each side wall to the rails. Each clamp comprises a pair of side plates clamped on opposite sides of the rail by a clamping bolt passing through one of the mutually spaced slots. The slots engaged by the bolts of each pair of clamps are identical in length; and the slots engaged by the bolts of each pair of clamps, except the first pair of clamps, are longer than slots engaged by the bolts of an adjacent upstream pair of clamps.

Abstract: A simple and inexpensive mineral insulated cable termination comprises a flexible plastics tube which at one end fits over the cut-back sheath of the cable and which at the other end is closed by an end wall spaced from the surface of the cable, each cable conductor passing through one of a plurality of throughbores in the end wall and, filling the space within the tube, waterproof electrically insulating compound. At a first position around the circumferential wall of the tube, the wall is slit throughout its length and radial thickness and at one position or at each of two positions circumferentially spaced from said first position the wall is adapted to constitute a hinge extending throughout the length of the wall. The abutting longitudinally extending parts of the wall at said first position are so shaped one effects a snap-fit with the other throughout the length of the tube.

Abstract: A residual current detector capable of detecting an earth leakage current, e.g. for use in a circuit breaker, includes a toroidal core through which passes the live and neutral wires of an electrical installation, to form the primary windings of a differential transformer. At least one secondary winding is wound on to the core and driven with an alternating voltage by a generator. A phase sensitive detector identifies a residual current by detecting the change in phase of the voltage across the at least one secondary winding. The secondary winding may comprise two coils, a first coil driven by the generator and a second coil adapted to pick up an induced voltage from the toroidal core. The phase sensitive detector, which may form part of a phase locked loop, compares the phase of the signal from the second coil with that of the alternating voltage of the generator.