Abstract: An engine control system utilizes a vortex whistle for producing an acoustic signal the frequency of which varies with the rate of flow of air passing through the inlet manifold of the engine, and a control device for controlling an engine characteristic, such as the rate at which fuel is injected into the manifold, in accordance with the frequency of this acoustic signal.

Abstract: A roller clutch assembly for use in an internal combustion engine starter motor. The assembly includes a clutch outer member which is arranged to be driven and a clutch inner member which carries a pinion gear wheel. The clutch inner member and the pinion gear wheel are arranged as parts of a common member having a radial shoulder between the inner member and the gear wheel. A plurality of rollers lie between the inner and outer clutch members and a plurality of compression springs each urge a respective roller in a circumferential direction. An annular washer is carried by the outer clutch member and abuts the shoulder to prevent disengagement of the clutch inner member from the clutch outer member. The washer is formed in at least two parts and the parts defining the washer are so shaped that the abutting edges of the parts are disposed other than parallel to the convolusions of the springs.

Abstract: In a spark ignition system it is possible for a vehicle to stall with the contact breaker closed, and for a transistor or other device in series with the ignition coil to conduct heavily. This problem is overcome by limiting the time for which the ignition coil can be energised.

Abstract: A road vehicle battery charging system includes an alternator and a rectifier assembly connected to apply d.c. to the battery. A further rectifier provides d.c. to a separate line from which current is drawn for the field coil under the control of a voltage regulator. The line is connected via a series circuit including a resistor and the vehicle ignition switch to one side of the battery, this resistor forming part of a switching circuit which operates a warning lamp whenever the voltage on the separate line is substantially less than voltage on said one side of the battery.

Abstract: An engine starting system particularly but not exclusively for use in a road vehicle, the system including a manually operable switch controlling energisation of a solenoid winding. The solenoid winding when energised causes movement of a pinion of a starter motor to an operative position. There is provided a thermally operable snap-action switch, the heater of which is energised by way of said manually operable switch. The snap-action switch controls energisation of a relay, and the relay in turn controls energisation of the starter motor. The operating time of the thermally operable switch provides a delay between movement of the pinion to its operative position, and energisation of the starter motor, after operation of the manually operable switch.

Abstract: A face commutator for a dynamo electric machine comprises a body carrying a plurality of conductive segments. The segments are arranged in a circle with each segment extending radially. The rear face of each segment includes a channel the radially outermost wall of which is defined by a pair of rearwardly extending circumferentially divergent integral projections which key the outer end of the segment into the body. The other wall of the channel of each segment is defined by a rearwardly extending lug adjacent the radially inner end of the segment, the face of the lug presented to the pair of projections being undercut and so providing keying to the body at the radially innermost end of the segment.

Abstract: A motor vehicle rear lighting system comprises first and second lamp filaments in a single bulb envelope, the first lamp filament having a greater resistance than that of the second lamp filament. One or more electrical switches are operable, in one position, to connect the lamp filaments in series with a battery, and, in another position, to complete the circuit from the battery to the second lamp filament without the first lamp filament in series therewith. The arrangement is such that, in said one position of the one or more switches, the first lamp filament becomes luminous and, in said another position of the switch means, the second lamp filament becomes luminous. In one embodiment, a first lamp filament by-pass is provided and, in said another position of the electrical switch, the circuit to the second lamp filament is completed via the by-pass. In another embodiment, the electrical switches are arranged to connect the lamp filaments in parallel when the switches are in their said another position.

Abstract: A device for changing the amount of linear movement in a linkage system, preferably for reducing the movement, consists of a hollow body into opposite ends of which a tube and a co-axial rod extend. Attached to the inner end of the rod is a pair of flanges which extend through slots in the tube. A compression spring is lodged in the body between the flanges and an end of the body and a further compression spring is lodged between the flanges and an abutment on the tube at the opposite end of the body. Preferably, the rod passes with clearance through a sleeve forming an extension of the body and a viscous material is provided in the sleeve around the rod to act as a damper to short term movements of the rod.

Abstract: A starter motor for an internal combustion engine including a pinion gear wheel assembly movable between a rest position and an operative position. The pinion gear wheel assembly is movable by a solenoid the armature of the solenoid being coupled to the pinion gear wheel assembly by way of a lever pivoted on the starter motor casing. The lever is in the form of a pair of resilient elements. The first resilient element is weaker than the resilient means which urges the armature towards its rest position, so that should the pinion gear wheel assembly be held in its operative position when the electromagnet is de-energised then the armature can be returned to its rest position flexing the first element. The second element supports the first element during movement of the lever assembly to push the pinion gear wheel assembly to its operative position.

Abstract: The motor vehicle is provided with headlamps mounted on a common cross rod which is angularly sprung by means of a tilting system including a lever secured to the cross rod. The headlamps are normally urged into an extreme downwardly tilted position by means of a manually operable device. In one form, the manually operable device takes the form of a solenoid having an operating rod which engages lever attached to the cross rod. The solenoid is electrically connected with a manually operable headlamp lighting switch. The arrangement is such that when the solenoid is de-energised, the operating rod thereof urges the lever into an extreme position in which the headlamps are tilted downwardly. When the headlamp lighting switch is operated to illuminate the headlamps, the solenoid attracts the rod and so releases the lever secured to the cross rod so that tilting of the headlamps can be effected by the headlamp tilting mechanism.

Abstract: A direction indicator control circuit for a road vehicle has a switch means for operating the direction indicator lamps to indicate a turn, and a pulse generator operated by return movement of the steering wheel following completion of a turn, the pulse generator producing a pulse of fixed length which serves to cancel the switch means. A pair of switches are associated with each turning direction, each pair being successively operated by the turning of the steering wheel in one order during the initiation of a turn, and in the reverse order after the completion of the turn. The pulse generator produces the fixed length pulse only when the switches are actuated in the correct order, thereby eliminating erroneous turn indicator information.

Abstract: A lamp reflector comprising a dished body having a reflective inner surface, the body being elliptical in vertical axial section and having a different shape in horizontal axial section, which may be elliptical, arcuate or parabolic. The horizontal width of the body taken in a transverse vertical cross-section is greater than its vertical height.A vehicle lamp assembly comprising a reflector as defined above, a lens receiving light from the reflector, and a mask mounted between the two. The reflector and the mask or the mask alone may be movable relative to the lens.

Abstract: A pulse producing device has an E-shaped core with an input winding and an output winding, so that flow of flux between the limbs of the core produces an output in the windings. The flow of flux is controlled by parts rotating close to the limbs, and these parts are formed on a rotatable plate the periphery of which is split and deformed to provide two rows of tags, one row passing close to the central limb and one of the outer limbs and the other row passing close to the central limb and the other outer limb.

Abstract: To manufacture semi-conductor devices an etchant resistant material is applied to the major surfaces of a semi-conductor wafer having at least one n-type zone and at least one p-type zone. The wafer is then divided into individual devices by sawing or scribing part of the way through the wafer and then cracking the wafer along the grooves defined by the sawing or scribing operation, p-n junctions being exposed at the divided edges of the devices. The devices are then mounted on an etchant resistant, adhesive tape with one major surface of each device being presented to the tape, and the tape, with the devices carried thereby, is immersed in an etchant so that the divided edges of the devices are etched.

Abstract: The motor vehicle comprises a body, a pair of headlamps which are mounted on a common cross rod angularly movable relative to the body, and a headlamp tilting mechanism. The mechanism comprises a tensioned cable secured at one end to an axle housing of the motor vehicle and at its opposite end to a spring arm. An outer sleeve over the cable abuts against the underside of the body. The spring arm is clamped at one of its ends to the cross rod and a further spring arm is also clamped to the cross rod and has its free end urged into abutment with a stop fixed relative to the body. The cable is secured to the end of the spring arm which is remote from cross rod and the cable biases the further arm into engagement with the stop. The provision of the spring arms serves to reduce the amount of angular movement imparted to the cross rod by the cable when changes in the attitude of the vehicle body relative to the wheels occurs under changing conditions of load carried by the body.

Abstract: A lamp assembly comprises a hollow body in which first and second reflectors are mounted. The hollow body is mounted on a support plate through the intermediary of three adjusting screw devices, to enable the body to be tilted relative to the plate. The second reflector is mounted in the body by means of a flexible support and a pair of spaced adjusting screws which enable the second reflector to be selectively adjusted both in the horizontal plane and in the vertical plane relative to the body.

Abstract: The vehicle lamp assembly comprises a housing having a window therein. Disposed within the housing is a first ellipsoidal reflector, a mask, a second ellipsoidal reflector, and a concave mirror. The mask is disposed in the inner focal planes of the respective reflectors and is also disposed at the focal plane of the concave mirror. The second reflector is disposed on the opposite side of the mask to the first reflector and the mask on the side thereof facing the second reflector is silvered. When a filament in the first reflector only is illuminated, a dipped beam pattern is provided. When both of the filaments are illuminated, a full beam pattern is provided because the dipped beam pattern is modified by light from the second reflector being reflected off the mask towards the concave mirror.

Abstract: A fault indicating system in a vehicle includes a d.c. source, a plurality of electrically operated devices operated by the d.c. source and a plurality of fault indicating units, one for each device. Each fault indicating unit is operable by a predetermined address signal, and on being operated produces after a delay an output representative of the operation condition of its device, each fault indicating unit having a different delay. A monitoring unit produces the predetermined address signal and receives the output signals from the fault indicating units. The monitoring unit operates in cycles, in each of which it has a transmission period in which it feeds the address signal to all the fault indicating units, and a plurality of receiving periods during which it receives the output signals from the fault indicating units in turn, warning means being operable by the monitoring unit to indicate a fault in any of the devices.

Abstract: An electrical switch including first and second fixed electrical contacts carried by the body of the switch. Fastened to the body is an L-shaped flexible strip which carries first and second movable contacts, one end of one limb of the L-shaped strip being secured to the body. In order to engage the first movable contact with the first fixed contact the strip is flexed along the length of said one limb, and in order to engage the second movable contact with the second fixed contact the strip is twisted along the length of said one limb.

Abstract: A radiation-sensitive switching circuit includes a light emitting diode which from time to time illuminates a photo-transistor, the photo-transistor serving when its output reaches a predetermined value to operate a trigger circuit. In order to allow for aging of the components, the current flow through the diode is increased when the output from the transistor falls below a known level. Conveniently, this is achieved by having a transistor in parallel with the diode, and turning the transistor off when the output from the photo-transistor becomes too low.