Abstract: A vehicle gas suspension system consists of a suspension unit, a high pressure reservoir, a low pressure reservoir and an electrically driven pump. Control valves are disposed in connection lines between the unit and the reservoirs for respectively controlling the flow of gas to and from the suspension unit so as to maintain the ride height of the vehicle at a suitably adjusted attitude irrespective of vehicle loading. The pump comprises a tubular barrel, a valve at one end of the barrel, and a piston and flexible seal which reciprocate in the barrel reservoirs. A vacuum relief valve in the wall of the low pressure reservoir allows air to be drawn into the reservoir from the atmosphere, and a dump valve opens to allow gas to flow from the high pressure reservoir to the low pressure reservoir when a maximum permitted pressure is reached in the high pressure reservoir.

Abstract: A fuel injection pumping apparatus comprises a rotary distributor member which is also axially slidable within a fixed sleeve. The distributor member is provided with a recess which communicates with a bore containing the pumping plungers. The recess is provided with mutually inclined leading and trailing edges which cover and uncover inlet ports and outlet ports as the member rotates. While an inlet port is in communication with the recess fuel is allowed to flow to the bore and when the inlet ports are covered and outlet port is uncovered to the recess fuel flows from the bore to the uncovered outlet port. The fuel quantity is varied by altering the axial position of the distributor member.

Abstract: A corona-discharge type gas flow meter includes a discharge electrode, and a split collecting electrode, the collecting electrodes are connected to input amplifiers which act as current-to-voltage converters receiving a reference signal from an integrator acting to integrate the sum of the outputs of the input amplifiers. The output of the integrator is used to control an EHT supply for the discharge. An output amplifier provides a flow signal by running the signal from one input amplifier, from a variable offset nulling signal derived via an amplifier from the integrator and a fixed offset nulling signal from a potentiometer.

Abstract: A fuel injection pumping apparatus of the rotary distributor type has a distributor member which is also axially movable to determine the allowed outward movement of the pumping plungers and hence the amount of fuel supplied to the associated engine. The extent of outward movement is determined by inclined stop surfaces which co-operate with complementary surfaces on shoes associated with the plungers. In order to minimize axial movement of the distributor member when the shoes engage the stop surfaces a chamber to which liquid is supplied to vary the axial setting of the distributor member, is locked off from fluid supply and drain passages, by a servo valve 41 when the correct position of the distributor member is obtained. A hydraulic lock is thus created in the chamber.

Abstract: A friction lining wear indicator for shoe-drum brakes comprising a sensor mounted on a brake shoe, which actuates an indicator when the thickness of a friction lining carried by a platform of the shoe for engagement with a drum is less than a predetermined value. In order to locate the sensor at the most effective position without machining the lining or fastening the sensor permanently to the shoe, the sensor is located by a mounting device located in a depression in an edge of the platform, and co-operates with the shoe to retain the sensor adjacent the lining. The mounting device comprises a plastics plug, or a resilient clip, and the retaining device is releasable. The sensor comprises a wire loop or a pressed insulation-coated metal strip, and may be integral with the mounting device. The sensor and the drum are connected in a circuit with the indicator which is actuated when the sensor touches the drum.

Abstract: In a fluid-pressure-operable relay valve a control piston works in a bore in the valve housing to control sequential communication between an inlet port and an outlet port, and between the outlet port and an exhaust port. An exhaust valve seating on the control piston is engageable with an exhaust valve member coupled to one end of a lever pivotally mounted in the housing, and a spring acts on the exhaust member to urge an inlet valve member towards an inlet seating surrounding the inlet port. Since the spring acts in opposition to fluid pressure at the inlet port, a relatively small `cracking force` is required to the urge the inlet member away from the inlet seating to open the inlet valve.In alternative constructions the inlet and exhaust members are combined into a single valve member which is urged directly by the spring towards the inlet seating.

Abstract: In an hydraulic power booster a boost piston working in a bore in a housing is of stepped outline having at least three axially spaced portions of at least two different diameters. The two end portions carry seals having slidable sealing engagements with complementary portions of the bore, and a stationary seal is fixed in the housing. An intermediate portion of the piston disposed between the end portions and of smallest diameter has a slidable engagement in the stationary seal.

Abstract: A vehicle brake actuator has a piston (23) within a cylinder (22) for urging friction pad assemblies (19, 20) into braking engagement with a brake disc (21). The actuator incorporates a pressure accumulator (3) and an electrical valve (9) operable to supply pressure from the accumulator to the cylinder in response to the action of a brake pedal or other control device. The actuator may also incorporate a pump (1) for charging the accumulator, together with other equipment such as skid control device. A braking system incorporates one or more of the actuators and device for producing an electrical output in response to displacement of the brake control device for supply to the valve.

Abstract: An apportioning valve for controlling the pressure applied to the rear brakes of a vehicle comprises an inlet to receive actuating fluid and an outlet for connection to the rear brakes. The inlet and outlet are normally connected via an inlet chamber, and an auxiliary chamber is connected to the inlet chamber via a throttle and to a vent valve seat. A pendulum is biased against the valve seat during deceleration and thus closes the valve seat and allows pressure to build up in auxiliary chamber. When pressure in the auxiliary chamber is sufficiently high control pistons move to isolate the inlet from the outlet.

Abstract: A booster for a vehicle braking system has an input piston, a boost piston and an output piston working a bore, the boost piston being advanced in the bore in response to pressure fluid from a source pressurizing a boost chamber under control of a valve.The operation of the valve is dependent on the pressure in the system, and the valve has a valve mechanism working in a bore in the boost piston of which one part has a pressure-responsive face, the valve being operative, on initial movement of the input piston to cause pressurization of the braking system to the threshold level, and application of pressure fluid to the pressure-responsive face to move the part relative to the input piston to place the boost chamber in communication with the pressure source. Threshold pressurization of the braking system may be achieved by pressurization of the boost chamber, or an auxiliary chamber forward of the boost piston to a predetermined level.

Abstract: A microprocessor based electric vehicle traction battery monitoring system evaluates the state of charge, interfaces with a traction motor control system, and controls recharging. The state of charge is evaluated during the first part of discharge by integrating the current after compensating it for rate of discharge and during the last part of discharge by dividing the battery into sub-packs and evaluating the state of charge from the lowest sub-pack voltage compensated for polarization voltage. The charge storage capacity is also calculated from the lowest sub-pack voltage. The maximum traction motor current is progressively limited during the last part of discharge. During charging, the charge withdrawn is replaced while progressively reducing the charging current and the battery is then charged at a constant current until the rate of rise of the lowest sub-pack voltage falls below a fixed level.

Abstract: A mechanical brake actuator has rotatable and non-rotatable cam components provided with confronting helical grooves between which ball bearings are arranged to form a helical thrust bearing. A push rod, connecting rod or the like acts generally tangentially on a lever arm on the rotatable cam component for turning the latter. The lateral reaction arising from the lateral force due to the push rod is transferred from the rotatable cam component to the non-rotatable cam component by the helical thrust bearing, thereby avoiding the need to provide a separate journal bearing for the rotatable cam component. The rotatable cam component acts on a tappet member via an axial thrust bearing and an automatic adjuster mechanism.

Abstract: In a method of producing a lead-acid battery plate, a lead oxide-containing paste is supplied to a carrier and the exposed surface of the paste on the carrier is contacted with a layer of fibrous material. Vibrational energy is then supplied to the fibrous layer so as to cause the paste to impregnate the fibrous layer and thereby secure the fibrous layer to the plate.

Abstract: Apparatus is disclosed for bonding a plurality of cores of a multi-core ribbon electric cable in side-by-side relationship by heating the insulation of the cores to bond together the insulation of adjacent cores. Instead of continuously bonding the cores together along their entire length, the apparatus is designed to interrupt the bonding at predetermined intervals so that when the cable is cut at a sectional interval it is not necessary to separate the insulation of one core from the next.

Abstract: An apparatus for providing an indication of a change in the dielectric constant of a fluid comprises a pair of electrodes at least one of which in use is surrounded by the fluid, an oscillator operable to charge and discharge the capacitors formed by the electrodes, the frequency of oscillation of the oscillator being dependent upon the voltage developed across one of the capacitors, and means responsive to the difference in the voltages developed across the capacitors.

Abstract: An anti-skid braking for a vehicle comprises a wheel having an hydraulic brake applicable by supplying thereto fluid under pressure from a master cylinder, a sensor to sense the presence of skid conditions at the wheel during braking and thereupon to produce a skid signal, a dump valve operative to cause fluid to be displaced from the brake in response to a skid signal so as to relieve the brake pressure, and a flow-control regulator valve arranged to regulate flow of fluid to the brake so as to re-apply the brake pressure at a controlled rate. The flow-control valve comprises a first restriction of predetermined size connected in series with a second restrictor defined between two relatively movable members and located upstream of the first restriction. The first restriction is defined at least in part by the member of which that member is biassed by a valve spring against the action of the pressure difference across the first restriction.

Abstract: A liquid fuel pumping apparatus for supplying fuel to a multi-cylinder engine has a plurality of outlets for connection to the injection nozzles of the engine. The apparatus includes a spill passage and a spill control valve which is electrically controlled. The valve is closed to cause fuel from a high pressure pump to be delivered through the outlets, fuel being supplied by the high pressure pump to the outlets in turn. A pressure transducer provides signals indicative of the pressures attained in the various outlets during delivery of fuel therethrough. One of the pressure signals serves as a standard and the other signals are compared with this signal to produce correction signals which vary the time the spill valve is closed when fuel is supplied to those outlets to which the other signals pertain.

Abstract: A liquid level indicator which includes a plurality of pairs of optical fibers and a common carrier supporting at least an end portion of each fiber. The carrier is formed with an elongated passage into which, in use, liquid flows to a height dependent on the liquid level to be monitored. The end portions of each pair of fibers are separated by the passage and have their axes generally coextensive, while the end portions of adjacent pairs of fibers are spaced apart along the passage. The end surfaces of end portions of each pair of fibers are inclined at an acute angle to the axis of the fibers such that transmission of light from one fiber to the other is substantially prevented if the liquid does not fill the region of the passage between the fibers, while light is transmitted between the fibers if the region of the passage is filled with the liquid.

Abstract: A variable reluctance transducer includes a C-shaped assembly defining a magnetic circuit, one limb of the C being longer than the other. The assembly is arranged with its limbs on opposite sides of a movable member. A winding linked to the magnetic circuit is connected to a discriminating circuit including an integrator having a variable bias circuit which ensures that the peaks of the integrator output are in a predetermined relationship to a reference voltage. A comparator compares the integrator output with the reference voltage.

Abstract: A pipe coupling includes a nut in which a collet, a back-up member and an anti-extrusion washer are retained by means of an axially split ring which is detachably engageable in a peripheral groove in the back-up member and engaged in a recess in the nut. The anti-extrusion washer has an extrusion press fitted into the member. This construction permits the various parts to be easily assembled into the nut without the risk of damaging the ring or the screw-threading in the nut.