Abstract: An inductive displacement transducer is described in which the magnitude of the phase difference between A.C. current and voltage in a coil is dependent upon the axial displacement of a monitored object. The phase difference depends upon the axial position relative to the coil of a short-circuit turn which moves with the monitored object. A magnetic flux concentrator, which may be combined with the short circuit turn, enhances the flux linkage between the short-circuit turn and the coil. In order to sense the height of a vehicle suspension strut, the coil is mounted on a plastics dirt shield, the short-circuit turn is provided by a sleeve plated with an electrically conductive metal and secured to the strut cylinder. Various circuits are described for monitoring the height signals produced by the different suspension struts of a vehicle.

Abstract: A d.c. motor control system, intended primarily for use in battery powered vehicles, includes a control switch (RL2a, RL2b) for varying the connections of the motor field winding (24) to determine the mode of operation of the motor and speed interlock means for preventing said control switch being operated to change the motor mode while the motor is actually running. Instead of using a mechanical speed transducer the speed interlock means includes means for supplying current to the motor field winding (24) when current would not otherwise be flowing therethrough and means (BR1, T.sub.1, P.sub.16 etc.) connected to detect the voltage across the armature which occurs in these circumstances if the motor is in motion.

Abstract: An internal shoe drum brake incorporates an automatic adjuster which includes and adjuster element carried by one of the brake shoes, a strut extending between the shoes and engaged by the adjuster element and a rotary adjuster cam mounted on the same shoe as the adjuster element, or a parking brake lever pivoted on the shoe, the cam engaging the adjuster element in a non-rotatable manner. When the shoes are separated for braking, excess shoe separation causes the adjuster element to be disengaged from the cam so that the cam is rotated by a spring to re-engage the adjuster element and thereby establish a retracted position of the shoes.

Abstract: A secondary zinc electrode, for example, for a nickel/zinc cell has an electrically conductive support onto each major surface of which is pressed an active zinc material. A grid structure defining a plurality of compartments is pressed into the material on each major surface of the support so as to separate the active material into a plurality of physically separate areas. Such an arrangement mitigates the shape change problem to which secondary zinc electrodes are prone in service.

Abstract: In a vehicle braking system of the kind in which brakes mounted on opposite sides of the vehicle are associated with respective pedals (1) and can be operated together for normal vehicle retardation or independently to assist vehicle steering, the brakes are connected to respective chambers (14, 15) of a tandem master cylinder (5) through respective control devices (7) which are actuated by the pedals (1) and control communication between the respective chambers (14, 15) and a reservoir.

Abstract: The present specification describes and claims a spot-type disc brake comprising a caliper and a torque taking member, a pair of abutment members being mounted on the torque taking member to form guides for an inboard friction pad assembly, one abutment member being secured in a fixed position and the other abutment member being adjustable in position to a limited extent. This arrangement is particularly applicable to twin-pin sliding caliper disc brakes wherein the same pinch bolts secure both the abutment members and the pins upon which the caliper is slidably mounted, to the torque taking member.

Abstract: A resistance bridge circuit is temperature compensated, for both zero error and sensitivity, over a predetermined temperature range by connecting a first compensating resistance in series with one resistor of the bridge, and a second compensating resistance in parallel with the same or an adjacent resistor of the bridge, to reduce zero error, the positions and values of the first and second resistances being determined from measurements, at a plurality of temperature levels, of the voltage levels and resistance values of the bridge, and on the arrangement of proposed external connections to the bridge. Third and fourth compensating resistances are connected in series and parallel respectively with the bridge as a whole, the values of the third and fourth resistances being dependent on measurements as aforesaid and on the proposed external connections. The four compensating resistances are the only compensating elements required to provide a predetermined zero error and sensitivity.

Abstract: A master cylinder assembly comprising two separate master cylinders is disclosed. Pressure spaces of the master cylinders are interconnected through outlet passages and a transfer passage, and a transfer valve is housed within each outlet passage. When the master cylinders are inoperative both transfer valves are retained by yieldable spacers in intermediate positions in which a limited flow can take place through both valves in both directions. This prevents hydraulic fluid from being trapped in the transfer passage which otherwise might cause a fracture to occur upon expansion with temperature of the fluid. Each transfer valve comprises a valve member which is engageable with a seating. The yieldable spacers by which the valve members may be held away from the seatings may be the thickness of a film of hydraulic fluid therebetween.

Abstract: A live axle is combined with a brake which is disposed outboard of bearings on which a hub is journalled for rotation. The bearings are mounted on a relatively stationary axle tube, and a drive shaft is mounted within the axle tube for limited movement in an axial direction in order to transmit a brake-applying force to the brake from an actuator housed within a relatively stationary part of the axle.

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 transmission system comprises an engine (10) which drives a propeller shaft (14) through continuously variable gearing (CVG) (11), split path gearing (12), and a disconnector device (13). The gear ratio of the CVG (11) is controlled by an actuator (24). The input and output shaft speeds of the CVG (11) are sensed by transducers (25, 26) and the propeller shaft speed is sensed by a pair of transducers (27, 28). The system is responsive to an accelerator pedal (22) and a selector switch (23), and controls a throttle (19) via an electric motor (20).In normal operation, with the selector switch (23) in the drive position (D) or the reverse position (R), two signal generators (41, 42) calculate a target throttle position and a target engine speed and the motor (20) and actuator (24) adjust the throttle (19) and CVG (11) accordingly.When the switch (23) is in the neutral position (N) or the park position (P), the disconnector device (13) receives the drive from the propeller shaft (14). The speed (N.sub.

Abstract: An assembly of a metal tube and a flange body having an opening therein through which the tube is passed during assembly and a method of making it, comprising, deforming the flange resiliently to enlarge the opening to allow passage of the tube, inserting and passing the tube through the opening to the desired position, allowing the flange to resiliently recover toward its condition prior to deformation thereby being urged into engagement with the tube at the opening. In another form of the method, the tube opening is large enough to permit passage of the tube and the flange is subsequently deformed inwardly onto the tube. The flange is finally secured to the tube by laser or electron beam welding.

Abstract: An ultra lightweight, thin link for a windscreen wiper mechanism is formed of a strip which is of U-shaped section for most of its length and which has end portions in which integral bush bearings are provided by plunged holes in the strip. The strip is very thin, e.g. about 0.5 mm, and is formed of non-alloy steel having nitrogen diffused through substantially the whole of the section thereof.The nitrogen is in solid solution in a ferritic matrix. Such a structure is obtained by heat treatment in a nitrogen containing atmosphere followed by oil quenching. The strip also has an epsilon iron nitride surface layer thereon in a portion 19b of which oil is absorbed to impart self lubricating properties to the bearings.

Abstract: An adjuster for a shoe drum brake has a variable length strut for maintaining a predetermined maximum shoe to drum clearance. A thermally responsive body of shape memory effect material (SME material as defined in the Specification) is arranged to move the brake shoes outwardly by extending the strut to compensate for drum expansion during excessive temperature conditions. Alternative arrangements are described using a body of (SME) material to disable the adjuster during excessive temperature conditions.

Abstract: A fuel control system for a gas turbine engine comprises a variable metering device and a flow limiting valve arranged in series. The limiting valve is servo pressure operated to reduce fuel flow in response to unacceptably high levels of certain engine operating conditions and is additionally movable to a fully shut condition when the engine is stopped. The servo operating pressure is controlled by an electrically actuated pilot valve which can be energized to a first level to provide flow limitation, and to a second, higher level to effect shut down. The pilot valve can also be energized in a reverse direction to open the limiting valve when starting the engine.

Abstract: A fuel injection pumping apparatus of the rotary distributor type has pumping plungers located in a bore in the distributor member. A cup shaped member surrounds the distributor member and has slots in which are located cam followers. The cup shaped member is connected to a drive shaft as also is the distributor member. Slidable within the cup shaped member is an annular member which has a tapered internal surface which can register with complementary surfaces on the followers or on the plungers to limit the outward movement of the plungers.

Abstract: A control circuit for an electromagnet includes a main current control element in series with the electromagnet winding and controlled so as to switch on and pass a "pull-in" current for an initial period and to control the current to a lower "hold" level during a subsequent period. A capacitor is connected in series with a diode and a transistor across the winding and the transistor is controlled to switch on during the change from "pull-in" to "hold" so that the capacitor is charged up during this change. A second transistor is connected in series with a second diode to permit reverse current flow from the capacitor to the winding during switch-off to hasten collapse of the flux in the winding and overcome the drop-out delaying effect of eddy currents in the electromagnet core.

Abstract: A permanent magnet dynamo electric machine is provided with a shield of high saturation flux density at the weaker or lower flux tip or edge of a permanent magnet pole face to prevent both circumferential and axial demagnetization of that portion of the pole face. The shield resides in a recess in the pole face so as to maintain a constant width air gap between the rotor and stator and has a thickness in the range of 5-15% of the overall thickness of the shield and pole combined. The shield and its pole face extend axially at least over the entire axial dimension of the area swept by the rotor.

Abstract: A transducer includes a winding in a magnetic circuit including a magnet, a pole-piece and a disc which has pairs of protuberances in its periphery, each pair being connected by a web of lesser radial distance from the disc axis than the peaks of the protuberances. The winding is connected in a discriminating circuit including an integrator which integrates the winding output, and a zero crossing detector. An output circuit receives signals from the integrator and the zero crossing detector and produces an output signal for the whole period during which the web between two protuberances is passing the pole piece.