Abstract: A load measuring device is incorporated in a damper or suspension strut of a vehicle. The device comprises an annular plate which is interposed between axially spaced opposite faces of a thrust bearing and an abutment for the adjacent end of the spring, and the plate is supported from the opposite faces at at least three angularly spaced locations of which a location on one side of the plate is disposed substantially at the mid-point in the circumferential length between a pair of locations on the opposite side of the plate. Bending moments in the plate are monitored by thick film technology to give a direct reading of load.

Abstract: A method of monitoring torque in a drive transmission incorporating a friction clutch assembly having a two part rotatable drive transmitting member the two parts of which are relatively movable against the action of damper springs comprising monitoring the extent of the relative movement of said two parts (16, 17) of said drive transmitting member. The invention also resides in a friction clutch assembly having a two part, rotatable, drive transmitting member, the two parts being movable relative to one another against the action of damper springs, the clutch including a plurality of angularly spaced reference teeth on each part of said two part member respectively and a sensor relative to which said two part member rotates, said sensor monitoring said teeth and in use producing, at a plurality of points in each revolution of the two part member, an output representative of the relative positions of said parts of said two part member.

Abstract: A load monitoring arrangement for a vehicle axle comprises a bolt which in use is fixedly mounted on a vehicle body and is connected with a resilient suspension part so that the body is connected with the suspension part through the intermediary of the bolt. A transducer is secured to the bolt so as to monitor the effect of loading forces acting thereon.

Abstract: A tire pressure monitoring system includes a tuned circuit with a pressure sensitive switch which is closed when the tire pressure is normal, connected across it, the tuned circuit and switch being mounted on the vehicle wheel. Mounted on a part of the vehicle is a detector circuit including an oscillator which includes an inductor which is at least intermittently coupled to the inductor of the tuned circuit. When the switch is closed the oscillator runs normally and its output is detected to indicate that all is well. When switch is open, however, the oscillator output is suppressed whenever the inductors are coupled together. The circuit can also be used in other applications where it is required to detect the state of an isolated switch.

Abstract: A load transducer includes a hollow body and a movable control element mounted in the body and extending through the body to an external surface of the body so that an external mechanical load can be applied to the control element to move the control element in one direction. Resilient means separate from the control element urges the control element in the opposite direction such that, in use, the control element is displaced by an amount dependent on the magnitude of the applied load. Coupled to the control element is a variable capacitor including a first electrode supported by a first carrier member in which the first carrier member is mounted so that the carrier members are capable of relative sliding movement in a direction perpendicular to a pair of parallel mutually presented surfaces of the electrodes.

Abstract: A headlamp levelling system for a road vehicle, comprises an electric motor which, in use, drives a member coupled to the headlamp so as to allow the headlamp to be adjusted in a manner to vary the direction of the light beam emitted, in use, by the headlamp. The motor is connected across the terminals of an electrical supply by way of an electrical circuit including switch means and a plurality of spaced pairs of electrical contacts. The switch means has a plurality of switch positions, one for each of said pairs of contacts, and a bridging member is associated with said pairs of contacts. The contacts and the briding member undergo relative movement in response to movement of said driven member so that the bridging member bridges said pairs of contacts, in turn, in respective discrete positions of the driven member and hence of said headlamp.