Abstract: A microprocessor system having two microprocessors, each of which has its own reset circuit, and a circuit being provided which detects under-voltage in the system supply voltage, each of said microprocessors having circuitry associated with it for inducing a simulated low voltage condition on the reset circuit of the other microprocessor to test said under-voltage detection circuit and to measure the resulting reset period generated.

Abstract: An actuator lock is provided to prevent movement of an actuator until the actuator lock is released. A first member of the lock is movable in response to fluid pressure within a chamber to move from a locked position to an unlocked position allowing the actuator to move. The first member is held at the unlock position by a latching member so that the lock cannot return to the locked position. During testing of the actuator, a test member is operable to reversibly move the first member from the locked position to an unlocked and unlatched position.

Abstract: A brake shoe for an internal shoe drum brake has an arcuate platform carrying a lining of friction material on its outer face. A web extends perpendicularly from the inner face of the platform and provides a shoe tip intended to be supported on an angled surface of the brake abutment. This shoe tip has a pair of differently directed surface portions. The invention also embraces an internal shoe drum brake incorporating a pair of the aforesaid shoes of which the abutment shoe tips are arranged so that the abutment is engaged respectively by non-corresponding ones of the shoe tip surface portions.

Abstract: A multi-lane controller providing redundancy comprises two lanes. Each lane comprises an input/output interface, a data flow controller and a control data processor. Each data flow controller receives input data from and supplies output data to both input/output interfaces. The information exchange between each lane does not rely on the proper operation of either the control data processor or data flow controller of any of the lanes.

Abstract: A lock for an engine thrust reverser comprises a locking member, for example, in the shape of a fork, arranged to engage a locking pin of a thrust reversing member. In use, the thrust reversing member is held in an inoperative position by other locks such that no force is exerted on the locking member by the thrust reversing member. If the other locks fail, the thrust reversing member pushes against the locking member. Under such conditions the lock cannot be unlocked and consequently the thrust reversing member is prevented from being deployed.

Abstract: An hydraulic braking system for a vehicle comprises a pedal-operated combined hydraulic booster and master cylinder assembly (1) for applying a brake (15, 18) on a wheel (16, 19) and having a master cylinder (6) and a servo chamber (7), an auxiliary hydraulic power supply (10) defining a booster pressure in the servo chamber, a flow valve (17, 20) through which fluid is supplied to the brake, and a solenoid-controlled valve (27) for controlling the setting of the flow valve for brake re-application during ABS by the application to it of control fluid from the servo chamber (7) in response to signals from a control module (38).

Abstract: A brake pressure booster for a vehicle brake system comprises a vacuum booster which includes two chambers, the low pressure chamber (16) of which is evacuated during actuation in a brake pressure boosting fashion, while a pressure higher than that in the low pressure chamber is adjustable in the high pressure chamber (14) by means of a control valve (28), the higher pressure exceeding the external atmospheric pressure. That is accomplished by a mechanical regulating valve (12) connected upstream of the control valve (28). Upon connection of a pressure source (18) to the high pressure chamber (14), a valve seat controlling access from the pressure source (18) to the valve opens before another valve seat closes that controls the connection between an inlet (24) into the valve and the high pressure chamber (14).

Abstract: An internal shoe drum brake has a pair of brake shoes mounted on a backplate with one pair of adjacent shoe ends in sliding engagement with an abutment fixed to or integral with the backplate. An actuator disposed between the other pair of adjacent shoe ends is operable to move the shoes, in use, into braking engagement with the braking surface of the rotary brake drum. At least the actuator or abutment is provided with shoe tip engagement surfaces of arcuate form and the respective engaging shoe tips have a generally complementary arcuate form resulting in a generally even wear pattern for the shoes.

Abstract: Disclosed is the backlit display and/or backlit keyboard display which have a controlled level of illumination at the surface thereof. Where such switch and/or display are illuminated by a light emitting diode, the present invention interposes an optical filter between the light emitting diode and the surface of the cover. The optical filter contains a pattern thereon having a variable density distribution of opaque material which in a preferred embodiment is densest in the area closest to the light emitting diode and decreases in density in areas away from the light emitting diode. In a preferred embodiment the optical filter is a "negative" of the illumination without a filter present. The result in both the switch and display embodiments is a substantially constant level of illumination across the surface of the cover. Further disclosed is at least one slot in translucent layers which may be incorporated in a switch or display which reduces "crosstalk" between switches and/or displays.

Abstract: A hot wire flow rate measuring apparatus, having a platinum wire sensor and a thermistor in the upper limbs of a bridge circuit whose lower limbs have resistors. The thermistor, together with a linearising resistor and a scaling resistor, is connected into the bridge circuit via a potential divider. A differential amplifier and a transistor control the supply of power to the bridge circuit so that the platinum wire sensor is maintained at a higher temperature than the thermistor by a fixed temperature difference.

Abstract: Measurements of wheel speed are compared to detect excessive wheel spin. An output of the wheel spin detector is supplied to a drive reducing device for reducing vehicle drive engine output in response to detection of excessive wheel spin. The reduced vehicle drive engine output is compared with a predetermined value by a subtracter. An estimate of surface friction is updated with a value dependent upon the output of the subtracter.

Abstract: A valve for incorporation between a fuel injection nozzle and the pumping chamber of a spill type fuel injection pump includes a valve member slidable in a cylinder. The ends of the cylinder are connected to the nozzle and pumping chamber respectively and formed in the cylinder is a seating. The valve member is biased by a spring into engagement with the seating and a flow path exists between the end of the cylinder connected to the nozzle and a position in the cylinder upstream of the seating considered in the direction of fuel flow to the nozzle. The valve also includes an orifice interconnecting the ends of the cylinder.

Abstract: A fuel pump for supplying fuel to an engine includes a rotary drive shaft (12) having an enlarged portion (18) through which the rotary part of the pump is driven. The pump also has an annular cam ring (17) which is angularly adjustable within the pump housing to vary the timing of fuel delivery. The pump includes a transducer (31) having pole pieces (33, 34) which are located in close proximity to the elongated portion (18) of the drive shaft. The pole pieces form part of a magnetic circuit including a magnet and the pole piece (33) and the adjacent surface or the portion (18) are shaped so that the flux in the magnetic circuit varies in a cyclic manner as the shaft rotates. The pole pieces and magnet are mounted on the cam ring (17) and the transducer includes a former (37) carried by the housing of the pump and upon which is wound a winding. The former surrounds a part of the magnetic circuit and the former and the part of the magnetic circuit are shaped so as to allow angular movement of the cam ring.

Abstract: A block of monocrystalline silicon oriented so as to have a body surface aligned in a {110} crystallographic plane is selectively etched so as to define a groove for receiving an optical waveguide and a reflecting surface facing the groove. The groove is aligned with a <110> crystallographic axis. The reflecting surface is in a {100} crystallographic plane. Thus, the groove is parallel to the body surface and the reflecting surface is at 45.degree. to the body surface.

Abstract: In an hydraulic braking system for vehicles solenoid-controlled valves are located in brake lines between the master cylinder and brakes on front and rear wheels of the vehicle. The solenoid-controlled valves are adapted to operate independently of each other to achieve independent pressure levels in the front and rear brakes by operation of a motor driven pump in response to signals supplied to an electronic control module from pressure sensing apparatus in each respective brake line.

Abstract: A fuel injector has a circular plate like valve member (31) urged into engagement with an annular seating element (29) formed on the face of a seat member (23) in a closed position. A discharge orifice (28) is formed in the seat member through which fuel can flow when the valve member is lifted from the seating element (29) into an open position by magnetic forces produced by energizing a solenoid winding (17). The valve member is located within an annular spacer member (22) and a recess is formed in the face of the valve member remote from the seating element in which is located one end of a coiled compression spring (33). The base wall (35) of the recess is inclined at an angle between 6.degree. and 16.degree. with respect to the opposite surface of the valve member engageable with the seating element and is engaged by the spring so that a lateral force is applied to the valve member to urge it into engagement with the inner wall of the spacer member.

Abstract: A filter element for liquids has an outer casing within which is located a central tube. A filter medium is located between the casing and the tube. Liquid enters the medium through apertures in an upper end plate and the filtered liquid leaves the medium by way of apertures in a lower end plate. Mounted in the lower portion of the central tube is a further tube through which the filtered liquid can flow into the upper portion of the central tube. The upper end of the further tube is joined by a wall to the central tube and air which passes through the filter medium collects in a dead space defined between the tubes. An air bleed orifice formed in the wall allows the air to pass at a controlled rate into the filtered fuel flowing in the central tube.

Abstract: A thixoformable material and a method for forming it are provided in which the material comprises a series of sequentially deposited layers of substantially metallic material, at least some of the layers having different properties. The layers may be of different materials or the layers may differ in that some are provided with reinforcing material whereas other are not. The reinforcing material may consist of particles of spherical, fiberous or other shapes and may be made of various carbides or other suitable reinforcing materials.The thixoformable material may be formed in sheets, cylindrical forms or any other shape and subsequently cut to the volume and/or shape required for the forming stage.A layered material of this sort offers the advantages of thixoformable materials but with enhanced toughness and damage resistance due to the layered 3-dimensional structure.

Abstract: A fuel system for a multi-cylinder compression ignition engine includes a tubular body (10) having an internal step (11) against which is located a flanged pump barrel (12), a pair of valve blocks (22, 23) mounted in end to end relationship between the barrel (12) and a mounting block (24) secured to the body by bolts (25) which provide a clamping force which ensures a liquid tight seal between the engaging end faces of the blocks and the barrel. A bore (14) in the barrel (12) houses a pumping plunger (15) and the valve blocks house a delivery valve (41) and a spill valve (26), respectively. The spill valve is controlled by an electromagnetic valve (30) mounted on the mounting block.

Abstract: A first difference is formed between the speeds of a front left wheel and a rear right wheel. A second difference is formed between the speeds of a front right wheel and a rear left wheel. The higher of the differences is compared with a threshold from a spin threshold generator to provide an indication of wheel spin, which may be used in a traction controller or in an antilock brake system.