Abstract: A brake booster having a fluid actuated piston in the form of a diaphragm (5) to which the supply of fluid is controlled by a valve mechanism (8A, 14A, 17), actuated by a driver-operated force input member (16) which acts via a reaction element (19) on an output member (10) providing power assisted input to a master cylinder. The booster includes a force transmission assembly (14,8) providing surfaces through which force is transmitted between the input and output members (16,10). A spring (24) is arranged to yield under a predetermined force to permit relative movement between parts (14) and (8) such as to change the ratio of the operative surface areas and thereby increase the boost ratio.

Abstract: An electrical switch is described which comprises a housing, an operating member mounted on the housing for movement from a rest position in at least three directions relative to the housing, and at least three sets of electrical contacts, a respective set of contacts being operable by movement of said operating member away from the rest position in a respective one of said three directions. Each of the sets of contacts comprises a fixed contact and a movable contact, each of the movable contacts being carried by a common resilient annulus.

Abstract: For the purpose of routing an electric cable through the movable wall of the two pneumatic working chambers of an electronically controllable bake booster, comprising a first pneumatic working chamber and a second pneumatic working chamber which are separated by a movable wall, where a simple assembly and a high functional reliability are to be ensured, a cable feed-through for at least one electric cable penetrating the movable wall is provided, with a portion of the cable-feed through penetrating the movable wall, and a holder which limits the movability of the cable feed-through at least in its longitudinal direction, and a seal surrounding the cable feed-through in the area of the movable wall.

Abstract: A solenoid-operated flow control valve is disclosed which comprises a housing having a bore, a solenoid coil, an armature, an inlet and an outlet, a permanent communication between an inlet and an outlet comprising a first and a second flow path connected in parallel between the inlet and the outlet, the first flow path being closable and the second flow path providing permanent communication between the outlet, an exhaust, a seating and a valve assembly including a hollow valve body working in the bore, the armature being responsive to the coil to open the exhaust to determine a pressure differential across the valve body, the pressure differential in turn causing the valve body to move in the bore so as to co-operate with the seating, whereby the valve body provides selective communication between the inlet, outlet and exhaust, and whereby upon deenergisation of the coil the flow control valve controls the rate of reapplication of pressure to the outlet.

Abstract: A position sensor for monitoring the position of the valve element of a valve is described. The sensor comprises reflector means associated with the valve element and arranged to reflect energy, for example visible light, from a suitable source such that when the valve element is in a first position the reflected energy is incident upon a detector. Movement of the valve element away from the first position results in the reflected light no longer being incident upon the detector. The invention further relates to a valve including such a position sensor.

Abstract: The invention relates to a pneumatic brake booster comprising a housing (10) which is divided into a vacuum chamber (14) and a working chamber (12), in which a dual valve arrangement (20) having a first valve (24, 26) between the vacuum chamber (14) and the working chamber (12) and a second valve (24', 26') between the ambient atmosphere (A) and the working chamber (12) is arranged at the housing (10), in which the valve arrangement (20), in an inoperative position, allows having pressure levels in the vacuum chamber (14) and in the working chamber (12) which are different from the ambient atmospheric pressure (A), and in an operative position, keeps the vacuum chamber (14) sealed off and allows communication between the ambient atmosphere (A) and the working chamber (12), wherein, in normal operation, the first valve (24, 26) and the second valve (24', 26') are actuatable by a common actuating rod, and, in a controlled operation, an electromagnetic actuator (40, 46) which is independent of the actuating rod

Abstract: A method for preventing the driven wheels of an automotive vehicle from spinning provides that whenever one of two driven wheels of one axle of the vehicle has a lower friction coefficient with the road surface than the other wheel of said axle and the one wheel shows a spinning tendency, brake pressure is built up at said wheel, with the rotational speed of the other wheel being measured, and whenever the rotational speed exceeds a specified value with respect to a vehicle reference speed, the brake pressure at the one wheel is reduced or maintained constant.

Abstract: A filter system forming part of the fuel system of a compression ignition engine includes a housing which carries a filter element. The housing has a first inlet which opens into a chamber defined between the housing and chamber the first inlet being connected to a fuel tank, and a first outlet for fuel which has passed through the element and which is connected to a fuel injection pump. The housing has a second inlet which is connected to the chamber and receives heated fuel from the fuel pump and a second outlet which is connected to the chamber through a port. The second outlet is connected to the fuel tank. A third outlet is connected to the second inlet and is connected to a flame type starting aid of the engine. Valve means responsive to the temperature of the fuel in the chamber controls fuel flow through said port.

Abstract: In a control system, for instance forming part of a vehicle anti-lock brake system, a plurality of control processors provides similar or identical control signals of the system in response to a shared transducer input. An independent data correlation processor compares data generated in the control processors for correlation and, in the absence of proper correlation, provides an indication which may be used to disable anti-lock operation of the brake system. In preferred embodiments, a four wheel vehicle with an anti-lock brake system is monitored by dual microprocessors. Each wheel has a speed sensor which supplies an input to each microprocessor. The data correlation processor compares the outputs of the microprocessors for each wheel and sends and alarm or disables the anti-lock brake system if the difference in the microprocessors output is beyond a limit amount.

Abstract: A method of testing a fuel system of an internal combustion engine comprises measuring the instantaneous speed of a component of a pumping apparatus of the system this speed decreasing as fuel is pressurised to achieve fuel delivery to the engine as compared with the nominal engine speed due to "wind up" in the drive to the engine. The speed profiles obtained as fuel is supplied to each injection nozzle and compared to determine if the injection nozzles are working correctly.

Abstract: A rotary distributor fuel injection pump includes a pumping plunger housed in a bore and has a spill valve member integrally formed with an actuator piston contained in a cylinder. High pressure fuel from the bore can be admitted to the one end of the cylinder to move the actuator piston and valve member away from the seating by opening an on/off valve. When the spilled fuel has been returned to the bore further fuel flows to the bore by way of the on/off valve and this fuel flows to the on/off valve through a non-return valve from a source of fuel under pressure.

Abstract: In a hydraulic anti-lock braking system a flow control valve operates with a single-acting solenoid operated valve (35) and the flew control valve incorporates a spool (17) working in a bore (8) in a housing (7) with the flow directed through a passage (20) passing substantially through the center of the spool (7). A fixed orifice (21) is located at the one end of the spool which defines a chamber (19) for a control spring (18), and a variable orifice is defined between a port (33) in the housing (7) end a metering edge on the input side of an annular groove (24) in the spool (17) and which communicates with the passage (20) in the spool (17). A chamber containing the spring (18) being of a larger bore than the bore containing the spool (17).

Abstract: A lever 22, which comprises a slot 28 and an abutment 30, is supported on a housing 18 so as to pivot about a pivot axis A. A cable 40, which is supported against the abutment 30 via an enlarged butt end 42, is placed in position in the slot 28, such that the lever 22 can be pivoted by a pulling force C of the cable. The lever 22 comprises a projection 34 which, in extension of the cable 40 and defining an intermediate space 32, is disposed opposite the abutment 30. The end 42 is accommodated in the intermediate space 32 and is supported against the projection 34 for transmitting a pushing force D of the cable. The projection is provided, at its side facing away from the abutment 30, with a ramp 38, on to which ramp the end 42 of the cable 40 is adapted to be placed, when the cable is inserted in the slot, and from which ramp the end 42 slides downward into the intermediate space 32 when a pulling force C is exerted on the cable.

Abstract: A two part pressure unloading delivery valve for a fuel injection pump comprises an annular valve member within which is slidable a plunger. The valve member is biased into engagement with a valve seat by means of a spring and is lifted from the seat by fuel under pressure supplied by the pump. The spring biases the plunger in the direction away from the seat and following closure of the valve member the plunger is moved in the direction towards the seat to allow relief of fuel under pressure from the pipeline connecting the valve with a fuel injection nozzle. After a predetermined movement of the plunger against the spring, damping means in part defined by a piston on the plunger, acts to damp the further movement of the plunger.

Abstract: A method of detecting when a moving component of an electromagnetically operable device attains a final position after de-energizing a winding of the device comprises allowing the energizing current to fall to zero and prior to the component reaching its final position, connecting a sensing circuit in parallel with the winding, the current flow in the sensing circuit increasing from the instant of connections and decreasing when the component reaches its final position, said sensing circuit detecting the change in current flow.

Abstract: A fuel supply apparatus is disclosed which includes a distributor comprising a distributor member rotatable within a bore provided in a sleeve. The sleeve is provided with a plurality of feed ports and a plurality of delivery ports, fewer feed ports being provided than delivery ports. The distributor member is provided with a delivery passage registrable with the delivery ports, in turn, and a plurality of feed passages registrable with the feed ports. The feed and delivery passages communicate with one another. The feed and delivery passages are located so that when the delivery passage registers with one of the delivery ports, one or more of the feed passages register with respective feed ports.

Abstract: A winding support for a rotary electrical component has axially extending poles and a plurality of windings which are wound on the poles so as to project beyond axial ends of the poles spaced apart in the direction of an axis of rotation of the rotary electrical component. The winding support comprises a first part formed from insulative material having spaced apart fingers to be positioned in respective spaces between the windings projecting beyond an axial end of one said pole and a second part arranged to be fastened to the first part for holding the windings in place relative to the first part. The first part preferably comprises a separator member having the spaced apart fingers thereon and a support member for the separator member arranged outboard of and formed of a different material from the separator member.

Abstract: A fuel filter element includes an annular filter medium which is supported on a lower support plate. Fuel flows downwardly through the medium and then through apertures at the outer periphery of the support plate. The support plate is provided with depending annular baffles, the outer one being adjacent the apertures but inwardly thereof. The baffles and support plate form an air collection chamber from which air escapes at a controlled rate through an orifice into a central outlet tube.

Abstract: A fuel injection nozzle of the outwardly opening type has a valve member movable outwardly by the fuel pressure within a bore in a nozzle body. The member is biased to the closed position by an elastic member in the form of a rod. At its end remote from the valve head, the rod engages a collar between which and an adjacent part of the valve body is a shim. The thickness of the shim is selected so that the tension force in the rod is higher than is required to give the desired nozzle opening pressure and this is adjusted to the desired value by compressing a portion of the nozzle body using a cap nut which secures the nozzle body to a supporting part.

Abstract: A control system comprises a controller for controlling an actuator, for instance of an electrically power assisted vehicle steering system. An unstable circuit, such as first and second cascade connected integrators has an input connected to the controller and an output connected to a detector, which signals an error when the output signal of the unstable circuit is outside an acceptable range. During normal operation, the controller supplies a signal to the unstable circuit such that its output signal remains within the acceptable range. The error signal may be used to disable the actuator, for instance so as to remove power assistance from steering system.