Abstract: A master cylinder for a dual hydraulic braking system has two pistons arranged end-to-end in respective bore sections, each piston having sealing valves which close off communication between front and rear brake circuits and respective reservoirs when displaced by operation of a brake pedal to cause pressurization of respective compression chambers connected to the brake circuits. This invention provides two seals in the inner piston between the two compression chambers and an auxiliary chamber defined between these seals into which small quantities of brake fluid escape in the event of leakage from either compression chamber to give visual warning of such leakage.

Abstract: An electromagnetic angular speed or angular position transducer comprises a permanent magnet with closely spaced pole faces and a ferromagnetic core magnetically connected to the magnet and carrying a coil. The transducer cooperates with a toothed wheel the teeth of which are moved past the pole faces and the core in such a way that two magnetic circuits are completed by the teeth, one passing through the teeth and the two pole faces, and the other passing through the teeth and the core. The two magnetic circuits are in parallel with one another and the reluctance of each changes as the teeth move therepast. The circuit through the two pole faces ensures that the magnet is operated with a high leakage flux so that small changes in the reluctance cause relatively large flux changes and thus a relatively high electromotive force in the coil wound about the core.

Abstract: An angular velocity transducer assembly for a vehicle wheel, of the type comprising an electromagnetic pick up cooperating with a relatively movable toothed wheel in which the toothed wheel is carried by the vehicle wheel and the electromagnetic pick up is carried by a mounting support on a fixed part of the vehicle to which it is attached by a tie rod in the form of a U-bolt. The mounting support is formed as a shoe having an arcuately curved surface which is adapted to bear on the axle of the vehicle either over substantially the whole of the curved surface or at various different places spaced around the curved surface.

Abstract: A device for cleaning the headlamp glass of an automobile headlamp. The device is formed in two main units, a motor unit and a reduction gear unit, which latter carries a wiper blade which, in use of the device, is moved over the surface of the glass to effect cleaning. The motor is mounted inside the headlamp and the gear unit outside, the two being connected together through a hole in the headlamp glass. A resilient seal is provided to make the joint waterproof and there are various arrangements for ensuring that the assembly is correctly centred within the hole in the glass and oriented properly in an angular sense.

Abstract: The injection timing of a fuel injection pump is controlled by displacement of a helical splined sleeve interconnecting a driving shaft and an injection pump drive shaft to vary the angle between the shafts. According to this invention the displacement of the sleeve is effected by an hydraulic actuator controlled by an electronic circuit which is responsive to a number of engine operating parameters and which receives a feedback signal from a detector, preferably magnetic, of the actual relative angular displacement between the shafts to ensure that the actual angle between the shafts is that required by the operating parameters.

Abstract: A method of attaching terminals to the wires of a cable having a plurality of wires all insulated from one another with separate insulating layers is disclosed, wherein the wires are surrounded, in the region where a terminal is to be connected, by a liquid conductive material. After the outer cover of the cable has been removed (if it has one), a terminal element is positioned in contact with the liquid conductive material adjacent the wires of the cable at the said region. A rising voltage is then applied between the terminal and one end of the wire which is to be connected to the terminal. The voltage continues to rise until the occurrence of dielectric breakdown of the insulation surrounding the wire to be connected allowing a spark to jump from the wire to the terminal and to burn a hole through the insulating layer allowing the liquid conductive material to flow in and make contact with the wire. Subsequent solidification of the liquid conductive material makes the connection permanent.