Abstract: An electronically controllable braking system for ground vehicles, comprising a cylinder/piston arrangement (6) which is able to introduce friction forces (F.sub.akt) into a friction element (8) which is coupled with a vehicle wheel by subjecting a hydraulic chamber (4) of the cylinder/piston arrangement (6) with hydraulic fluid, is developed further in that an electrically actuatable displacement element (12) projects into the hydraulic chamber (4) of the cylinder/piston arrangement (6) which is actuatable as a function of control signals from an electronic controller (22) for increasing or decreasing the pressure acting on the hydraulic fluid in the hydraulic chamber (4) in order to increase or decrease, respectively, the friction forces (F.sub.akt) which, during a braking operation, are introduced into the friction element (8).

Abstract: A governor mechanism for use with a fuel pumping apparatus includes a centrifugal weight mechanism which is coupled to an output member the latter being coupled to a fuel control member so that with increasing speed the quantity of fuel supplied by the apparatus is reduced. A governor spring opposes the movement of the output member but in addition a leaf spring is provided to supplement the action of the governor spring. The leaf spring is formed by one end of a torsion spring which is wound about a cylindrical member. The cylindrical member and the torsion spring are axially movable relative to each other to alter the effective number of turns of the torsion spring connected in series with the leaf spring.

Abstract: A brake booster with a master cylinder (10) comprises: a primary piston (12) and a secondary piston (14), with the secondary piston (14) being limited in its axial movability by a stop pin (25) being accepted transversely to a longitudinal axis (L) of the master cylinder (10) in a hole (24), and a reservoir (16) for brake fluid, comprising a connection (17) via which the reservoir (16) is connected with the master cylinder (10), with the connection (17) being arranged in the radial extension of the stop pin (25), with the connection (17) comprising a transverse web (28) in its flow cross sectional area which covers the hole 24 at least partially.

Abstract: An improved torque sensor, or relative angular movement sensor, comprises an input member, an output member, LED light sources, a pair of photodetector units adapted to receive light from the LED light sources, and signal processing means, in which said signal processing means is adapted to receive output signals from the photodetector units, the output signals of the photodetector units being dependent upon the light signals which they receive, and the signal processing means being adapted to process the output signals from the photodetector units so as to produce a modified output signal indicative of the relative angular displacement between, or torque applied between, the input and output member. The improvement comprises the provision of diagnostic means which continuously monitors a sum signal, .SIGMA., which comprises the sum of the output signals from the photodetector units, and which detects any variation in the sum signal due to failure of the sensor.

Abstract: An electric-powered vehicle having a drive system which includes at least one electric motor which is controlled and monitored by an electric control system for driving at least one vehicle wheel in a traction mode of the motor and also for selectively providing a contribution to overall braking torque when operated in a braking mode, and which also provides a hydraulic braking system which is actuated by the vehicle driver and which operates on at least the front wheels of the vehicle. The hydraulic braking torque produced by the driver by way of the hydraulic braking system, is adjusted in such a manner that, for the purpose of modulating the overall braking torque effective at the vehicle wheels the variation of the electric torque is arranged to stay within the "regenerative range" of operation of the electric motor, at least under predetermined operating conditions of the vehicle.

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 torque limiter comprises input and output shafts connected together by a clutch which disengages to prevent excessive torque from being applied to the output shaft and to allow the input shaft to rotate freely. As the clutch disengages, a brake is applied to the output shaft to prevent it from rotating. When the brake is applied, a latch holds the brake on. The clutch comprises balls which are held in clutch plate recesses to transmit torque but which ride out of the recesses and fall into pockets so that the clutch becomes permanently disengaged.

Abstract: A fuel system for an engine (10) includes a fuel pump (13), a controller (14) which controls the operation of the fuel pump so that fuel is delivered to the engine at the required time and in the desired quantity, and a transducer (15) for supplying a demand signal to the controller. The system also includes a transducer (16) which provides signals in response to the passage of indicia on a wheel (12) driven by the engine. The system further comprises means for determining the indicia spacing errors and further means responsive to the generally sinusoidal fluctuation of engine speed which corrects the determined spacing. errors.

Abstract: A switch assembly having a relatively fixed component, a first switch operating member rotatable relative to the fixed component between first and second stable positions, a second switch operating member rotatable with respect to the fixed component between first and second stable positions, switch contacts associated with each of the switch operating members in order to control the operation of respective electrical circuits, and a latch member responsive to the first operating member occupying its first position for applying a moment to the second operating member to restore it to its first position.

Abstract: A fuel system for an internal combustion engine comprises a plurality of pump/injectors each of which comprises a housing within which is provided a plunger-type fuel pump, a spill valve, an injector and a non-return valve. The pump is arranged to supply fuel at high pressure to the injector and to a port of the spill valve. The other port of the spill valve is connected to a source of fuel through a non-return valve, and also to the spring chamber of the injector through the non-return valve. The spring chamber communicates through a restrictor with a common passage the pressure within which is controlled by a valve.

Abstract: A charging circuit charges a first capacitor to a first voltage and a second capacitor, via a potential divider to a second voltage smaller than the first voltage. A trigger circuit repeatedly triggers a thyristor which discharges the second capacitor into the primary winding of a pulse transformer whose secondary winding is connected across a diode in series with the first capacitor between output terminals.

Abstract: An accumulator type fuel injection system has a cam actuated plunger pump for charging an accumulator chamber with fuel under pressure and valve means which in one position connects the accumulator chamber with a fuel delivery passage to cause delivery of fuel and in its other position to connect the delivery passage to a drain channel to terminate delivery of fuel. The drain channel includes a restrictor. The system includes a piston slidable in a cylinder having one end connected to the plunger pump through a valve and to the outlet of a low pressure pump. The other end of the cylinder is connected to the drain channel upstream of the restrictor. The piston acts to displace fuel in the one end of the cylinder to the plunger pump when the valve means is moved to its second position.

Abstract: A fuel injection nozzle includes a fuel pressure actuated valve member of the inwardly opening type which is movable by the action of fuel under pressure away from a seating to allow fuel flow from a nozzle inlet through an outlet. Mounted on the nozzle body is a spill valve which when operated allows fuel to escape from the nozzle inlet so as to lower the fuel pressure applied to the nozzle valve member. The spill valve is actuated by hydraulic means.

Abstract: An anti-lock ABS braking system for a road vehicle includes a respective dump valve for each brake actuator which enables pressure to be selectively dumped from that actuator to release the braking action of the relevant rear wheel. Whether a given rear wheel of the vehicle is still operating in a stable condition is established, as is the aggregate dump valve time of the rear wheel opposite to that under consideration. The brake pressure at the still stable rear wheel is allowed to continue to rise for a prescribed period and then its dump valve is actuated for a period corresponding to the measured aggregate dump time of the opposite rear wheel.

Abstract: A variable rate pump including a distributor member rotatable within a sleeve. The distributor member is provided with a bore within which a pumping plunger is reciprocable under the influence of a first cam lobe and a second cam lobe. A valve is provided for selecting whether fuel is supplied due to the motion of the plunger under the influence of the first cam lobe or the second cam lobe. An arrangement is also provided in which the distributor member carries first and second plungers each reciprocable under the influence of respective cam lobes. A valve is provided for selecting whether the fuel is supplied by the first plunger or by the second plunger.

Abstract: A pneumatic brake booster with a booster housing part includes a vacuum chamber and a working chamber separated therefrom by a movable wall, and a valve body part including a control valve assembly and an electromagnet assembly. The control valve assembly can be actuated both by an actuation rod as well as by the electromagnet assembly, in order to make connections between the vacuum chamber and the working chamber, or between the working chamber and the ambient atmosphere. To improve the heat dissipation and to simplify the assembly the valve body part comprises several separate portions at least the first portion of the valve body part being at least partially designed as a magnetic return of the electromagnet assembly and is coupled with the second portion of the valve body part.

Abstract: An optical torque sensor for incorporation in a vehicle steering system comprises a light-emitting diode (LED) 1, a light sensor 2 which receives a light signal, a signal processor for receiving output signals from the light sensor 2, and a light-transmitting medium which alters the direction of propagation of light propagating through the medium to an extent which is dependent on the torque applied to the medium. The medium is defined by a generally cylindrical body 5 which is attached to input and output ends 7 and 8 of a torsion bar 10. In one construction, the body is formed of a plurality of optical fibres 6 or a plastics material having polarised strata along the length of the cylinder. In an alternative construction, the medium is a material having a refractive index which is dependent on the torque applied to the medium.

Abstract: An arrangement for torque measurements in motor vehicles includes a measuring hub which has first and second peripheral zones, a first adapter fastened to the first peripheral zone and adapted to be mounted on a vehicle hub, and a second adapter which is fastened to the second peripheral zone of the measuring hub and on which a wheel body can be mounted. The wheel body belongs to a test wheel and has an inner diameter which is greater than the outer diameter of the vehicle hub. The test wheel includes a rim which corresponds to the rim of a vehicle wheel normally mounted on the vehicle hub. The measuring hub is arranged essentially radially within the wheel body of the test wheel.

Abstract: The operation of a catalyst can be monitored using a two part test. An engine management system is arranged to perturb the oxygen concentration of the exhaust gas of an internal combustion engine such that an oxygen concentration of the gas entering the catalyst varies between oxygen rich and oxygen deficient. A first test involves counting the number of transitions of the gas leaving the catalyst between two predetermined oxygen concentrations in response to a predetermined number of transitions of the gas entering the catalyst. A second test is performed if the first test indicates the catalyst to be faulty. The second test involves forming an integral of the oxygen concentration of the gas leaving the catalyst and correcting the integral for gas flow through the catalyst.

Abstract: A rotary distributor pump for supplying fuel to a six cylinder engine is adapted to supply fuel to a three cylinder engine by connecting its three inactive outlet ports to chambers and by arranging that no fuel is supplied to its pumping chamber prior to registration of its delivery passage with an inactive outlet port. In order to minimise the risk of cavitation of the fuel within the chambers they are vented to a low pressure source of fuel just before the delivery passage registers with an inactive outlet port.