Abstract: A switching system for sequential connection of a plurality of loads to an alternating current supply comprises a computer for generating switch selection data in the form of serial bits along a single line to a distributor arrangement which decodes the selection data and provides control signals to switch devices which connect the loads to the supply. The distributor arrangement includes a circuit for inhibiting supply of the control signals to the respective switch devices unless the voltage of the supply phase connected by the device is substantially zero. Additionally the control signals are time-advanced with respect to the zero voltage conditions so that the switch devices can be placed in states in which they can connect a load before disconnection of a preceding load.

Abstract: A battery powered electric vehicle d.c. motor control includes a first potentiometer actuable by an accelerator pedal and a second potentiometer actuable by a brake pedal. The motor current is controlled in accordance with the signals at the sliders of these potentiometers and contactors determine the connection mode of the motor under the control of a comparator which is sensitive to the signal at the slider of the first potentiometer only. This causes braking mode to be selected except when the accelerator pedal is depressed. A resistor is connected in series with the second potentiometer to ensure that a minimum braking demand signal is always present, but means is provided for cancelling this minimum braking demand signal in certain vehicle operating conditions and further means is connected to the comparator for overridingly selecting motoring mode in these conditions.

Abstract: In a dual hydraulic braking system in which brakes on opposite sides of a vehicle can be applied simultaneously for retarding or independently for steering the vehicle, a dual control valve assembly ensures that the brakes on one side cannot be applied before the brakes on the opposite side. When the brakes on one side are to be applied independently, a stem carrying inlet and exhaust valve heads moves with a pedal-operated piston so that the exhaust valve head engages with a valve spool to close an exhaust passage. The spool moves with the piston and head until it is arrested by a stop face, whereafter a seating on the piston moves away from the inlet valve head to allow pressurized fluid to be supplied to the outlet for the brakes. When the brakes are to be applied simultaneously, a volume of fluid trapped in a transfer connection between the exhaust valve heads arrests movement of the spools to ensure that the inlet valves open simultaneously.

Abstract: An hydraulic braking system for vehicles comprises a single pedal-operated master cylinder, a selector valve assembly and a double-acting valve incorporated into a common housing, and an actuator for a brake on either side of the vehicle. A lever acts to close a diverter valve to cut-off the supply of fluid to the actuator on one side when the brake on the other side is to be applied, so that one brake is applied independently of the brake on the other side. Each actuator comprises a differential piston which works in a stepped bore to apply the brake, and when one of the valves closes, the lever simultaneously acts on the double-acting valve to increase the effective area of the actuator for the applied brake. A greater output torque is therefore obtained from the brake on one side when the brake on that side is applied independently than when the brakes on both sides are applied simultaneously.

Abstract: A fuel injection pumping apparatus includes a rotary distributor member having a transverse bore containing a pumping plunger, a single passage is formed in the distributor member and extends from the bore to the periphery of the distributor member, inlet passages and outlets are formed in the body part and break out into the periphery of the distributor member in a common radial plane. The inlet passages and outlets are alternately positioned around the axis of rotation.

Abstract: A fuel system includes a known hydromechanical governor fuel control, which has an electromechanical trim device. The trim device is controlled by a circuit which includes an error signal generating means for producing an error signal representing the difference between the desired and actual values of an engine parameter a proportional-plus-integral controller circuit, a trim datum signal generator and a differentiator which connects the generator to the integrator of the controller, so that in transient conditions the integrator output will ramp to a new value required for a new steady state condition.

Abstract: A pressed, secondary zinc electrode has dispersed therein particulate carbon in an amount between 1 and 50% by weight of the total weight of zinc and carbon and an organic binder in an amount between 0.5 and 10% by weight of the total weight of zinc and carbon.

Abstract: An air mass flow measuring system for measuring flow into an internal combustion engine comprises a throttle angle transducer and further transducers measuring ambient air temperature and pressure as well as the pressure drop across the throttle valve. The signals from these transducers are supplied to calculating circuit which carries out the calculation M=K.sqroot.P.multidot..DELTA.P/T. The values of the coefficient K used in this calculation are derived from an empirically programmed read only memory incorporated in the calculating circuit, such memory storing empirically determined values of K for each combination of a plurality of values of throttle angle and a plurality of values of .sqroot. P.multidot..DELTA.P/T.

Abstract: A two speed governor for a fuel pumping apparatus which supplies fuel to an internal combustion engine comprises a source of fuel under pressure which varies in accordance with the speed of the engine. Fuel is supplied through a first orifice and a second orifice in series from the source. The second orifice is defined by a port the size of which is controlled by a manually operable rod while the first orifice is defined by a port the size of which is controlled by a spool responsive to the pressure of the source. The port closes at the maximum allowed engine speed. A third orifice defined by a port is also controlled by the spool and is connected in parallel with the second orifice. The port is closed at speeds above the idling speed of the engine. In the intermediate speed range the engine is controlled by the rod.

Abstract: A fuel system for an internal combustion engine includes a small accumulator in which fuel is stored, a fuel injection nozzle including an electrically operated means which controls fuel flow through the nozzle from the accumulator, and a transducer for providing a signal representing the accumulator pressure. An electrically operated valve is provided to control the flow of fuel from a pump to the accumulator and the system includes a control circuit for the valve. The control circuit is supplied with the signal provided by the transducer and also with a desired pressure signal which conveniently is obtained from a pressure map to which a signal representative of an engine operating parameter is supplied.

Abstract: A pair of brushes respectively slidably engage radially outer surfaces of first and second electrically conductive rings which are disposed co-axially and are rotatable about their common axis. The first ring surrounds an axial portion of the second ring and is electrically insulated therefrom by a thin layer of insulating material, while the second ring is mounted on a rotary shaft and is electrically insulated therefrom similarly by a thin layer of insulating material. The second ring may be axially stepped so that it has a smaller diameter portion which is surrounded by the first ring and a larger diameter portion which is engaged by the respective brush.

Abstract: A control system for a vehicle hydraulic suspension arrangement which has damping control valves for regulating fluid flow between parts of the suspension, comprises means for generating an electrical signal corresponding to the range of an obstacle in the vehicle path, and means responsive to that signal for shutting a selected damping control valve so as to resist upward movement, relative to the vehicle body, of wheels carried by a part of the suspension which includes the selected valve, whereby the ground clearance of at least the part of the body carried by those wheels is increased.

Abstract: A liquid fuel injection pumping apparatus of the rotary distributor type has two forms of cam lobe on its cam ring. The first form of cam lobe is a pumping lobe which can effect inward movement of a plunger to achieve pumping of fuel and after the crest of the lobe has been passed allows outward movement of the plunger to lower the fuel pressure in the various passages in the apparatus. The other form of lobe is a holding lobe which while one plunger is being moved inwardly holds another plunger against movement. When the crest of the holding lobe is reached the associated plunger is allowed to move outwardly and this movement is arranged to take place shortly before the end of the inward movement of the plunger associated with a pumping lobe. The effect is to reduce the period towards the end of fuel delivery at which fuel is supplied at a reducing rate.

Abstract: In an anti-skid braking system a supply of operating fluid from a master cylinder to a vehicle brake is modulated in accordance with skid signals from a skid sensing mechanism. The system incorporates an hydraulic pump of the double-acting type having a plunger working in a bore and a working chamber which is in communication with a modulator assembly adapted to control brake application following skid correction.

Abstract: The present specification discloses a pin slider disc brake comprising a torque-taking member and a caliper member, the members being slidable relative to one another by at least one pin connection. Each pin connection comprises an elongate, preferably cylindrical, pin guide which can be made of a corrosion-resistant material, the pin guide being detachably secured to, for example, the torque-taking member. The pin guide has a blind bore extending therethrough, in which a pin secured to the caliper member can freely slide, and the pin guide is so mounted to present an external surface which acts as a friction pad support surface. Thus, the pin guide can be relatively cheaply manufactured of corrosion-resistant material and simply replaced in the event of damage or wear.

Abstract: A suspension unit for a power tool comprises a pair of telescopically engaged members and a spring unit acting between the members to draw one member within the other. The member is provided with a support bracket whereby it can be hung from a support in use and the member is adapted to support the power tool. Means in the form of a lateral peg mounted upon a movable guide block to which the member is secured, and a slot through which the peg extends, acts to prevent relative rotation of the members. In this way any reaction torque developed on the power tool will be transmitted to and resisted by the support.

Abstract: A friction pad assembly comprises a backing plate having friction material secured thereto, and an anti-rattle spring having a bent portion intermediate its ends, the bent portion seating in a recess in the backing plate. To avoid problems caused by heat when the spring is held in place in the recess by the friction material and located before heat bonding of the friction material, the recess is accessible to secure the spring to the backing plate after the friction material is secured to the backing plate. The bent portion is preferably retained in position in the recess by its own resilience.

Abstract: A fuel injection pumping apparatus comprises an axially movable distributor member the axial setting of which determines the amount of fuel supplied by the apparatus at each pumping stroke. The distributor member is biassed by a spring in one axial direction and is movable in the opposite direction by varying the fluid pressure in a chamber through a port. The port is formed in a sleeve which is coupled to the distributor member by means of a lever and a rod member is axially movable within the sleeve. The axial position of the rod member can be varied to alter the effective size of the port and the distributor member and sleeve move because of the change in pressure in the space. A new equilibrium position is thus established with the distributor member following the movement of the rod member.