Abstract: A solenoid having an armature movable with respect to a stator from a rest position to an energized position when a coil is energized. Two return devices, for instance helical compression springs, urge the armature to return to the rest position. Two slidable sleeves are provided between stator and the armature. Ingress of dirt into the armature may jam either sleeve with respect to the stator or the armature without jamming the solenoid, since the other return devices/sleeve combination will still permit movement of the armature.

Abstract: In a method of controlling the brake pressure of a vehicle brake system equipped with anti-lock protection it is provided to measure the slip and/or rotational retardation of a wheel whose brake is applied and to compare each measured value with a given threshold value so as to lower the brake pressure if the threshold value proves to have been surpassed. Undesired pressure reductions can be avoided by increasing the threshold value for given periods of time from a basic value (S.sub.G) and subsequently decreasing it again. At a point in time T.sub.1 at which the rotational retardation of the braked wheel is greater than a value corresponding to a physically feasible slowdown of the vehicle the threshold value is increased abruptly, to be decreased thereafter according to a predetermined function of time. During the lowering of the threshold value the change in speed of the retarded wheel is measured over given intervals of time .DELTA.T and compared with the instantaneous higher threshold value.

Abstract: A fuel pumping apparatus has a fixed body in which is defined bores containing pumping plungers. The plungers are moved inwardly by cam lobes on a rotatable cam ring to displace fuel to an associated engine. The cam ring is provided with an annular extension within which is located a drive shaft. The drive shaft is coupled to the extension of the cam ring by means of a tongue and slot connection. The tongue is carried on a push member mounted in the drive shaft and movable by means of a piston and the tongue and slot are arranged so that as the piston moves, relative angular movement will take place between the drive shaft and cam ring.

Abstract: A method of determining the coefficient of adhesion between a roadway and the wheels of a motorcycle provides for retarding the rear wheel of the motorcycle more strongly than the front wheel for a predetermined period of time and for comparing the rotational speeds or the rotational retardations of the front and rear wheels. Furthermore, the sloping of the motorcycle is measured directly so as to determine both the longitudinal coefficient of adhesion and the lateral coefficient of adhesion from the sloping. The coefficients of adhesion thus obtained serve for adjustment of threshold values for anti-lock braking of the motorcycle.

Abstract: A gear having good fatigue strength and corrosion resistance has a body with gear teeth formed of a hot isostatically pressed alloy powder. The alloy is cobalt based and consists of 10 to 35 wt % Cr, 0-22 wt % Ni, 0-20 wt % W, 0-20 wt % Fe, 0-10 wt % V, 0-10 wt % Mo, 0-6 wt % Nb, 0-3 wt % Si, 0-3 wt % C, 0-3 wt % B and 0-1 wt % Mn, the balance, apart from impurities, being cobalt.

Abstract: In order to detect misfire in an internal combustion engine, engine speed is determined by measuring the time of passage of a crankshaft disc from a first position to a second position during every revolution. A detection circuit takes the reciprocal of the measured times of passage to form a series of engine speeds and forms the difference between consecutive engine speeds. These differences are compared with a threshold to signal a misfire when the threshold is exceeded.

Abstract: A pressure control device for an anti-lock and/or anti-slip system of a motor vehicle comprises a valve casing (10) in which a damping chamber (36) and an expansion chamber (44) are arranged in a common recess (12, 12'), the two chambers having a common axis. A pump is disposed in an adjacent recess having an axis parallel to the common axis of the chambers whereby substantial space is saved over prior arrangements.

Abstract: In a method of controlling the brake pressure in the rear wheel brakes of a double-track vehicle, wherein the rotational speeds at least of the rear wheels are measured and the brake pressure is lowered, kept constant, or raised, depending on the unstable or stable states arising at the individual rear wheels, the pressure in the brake of a stable rear wheel being approximated at least temporarily to the pressure in the brake of an unstable rear wheel, it is provided that, upon initiating a pressure decrease in the brake of an unstable rear wheel, the pressure in the brake of the stable rear wheel is kept constant for a predetermined period of time (.DELTA.t) and then decreased until the pressure in the brake of the unstable wheel is either kept constant or increased. This guarantees shorter stopping distances and at the same time provides a smaller difference in the braking torques at the rear axle, at good stability of the motor vehicle.

Abstract: An internal shoe drum brake having a generally C-shaped shoe return spring of which an intermediate portion is retained on the backplate and respective end portions respectively engage brake shoes. The intermediate portion of the spring is retained by a retention device secured to the brake backplate and has opposed tongues embracing a portion of the spring in such a manner as to retain the spring relative to the backplate in directions generally parallel to the latter. The retention device also retains the spring in a direction perpendicular to the backplate and may be associated with or embody a mounting device for an electrical component.

Abstract: The invention relates to an internal combustion engine comprising an inlet manifold, at least one combustion chamber with at least two inlet valves and at least one outlet valve, a piston reciprocable in the or each chamber to define a variable volume space therein, and means for controlling the timing of the opening and closing of each of two of the inlet valves of the or each chamber independently so that opening of one of the independently controlled inlet valves of the or each chamber occurs during the exhaust stroke of the engine, opening of the other of the independently controlled inlet valves of the or each chamber, at a time when said one of the independently controlled inlet valves is closed, and when pressure in the or each chamber is lower than pressure in said inlet manifold, producing a predetermined pressure differential across said other of the independently controlled inlet valves, creating an in-flow to the or each chamber generating turbulence, at least some of which is present when combust

Abstract: The present specification discloses a clamp member and a torque taking member with the clamp member being slidably mounted on the torque taking member by at least one sliding pin connection, whereby the clamp member can slide relative to the torque taking member to apply a friction pad to each side of a braking disc. The at least one pin connection comprises a pin which engages in a bore with a flexible sleeve located on the pin, the flexible sleeve engaging the wall of the bore. The pin has a two part construction with the flexible sleeve located between said parts, said parts being secured together so as to deform the flexible sleeve radially outwardly into engagement with the wall of the bore.

Abstract: A fuel pumping apparatus of the rotary distributor type has a fluid pressure operable valve which can be opened to terminate delivery of fuel to an associated engine. The operation of the valve is controlled by an axially movable shuttle contained in a cylinder. The shuttle is biased toward one end of the cylinder and is displaced away from the one end of the cylinder by fuel supplied by an auxiliary plunger. The shuttle is angularly movable by an actuating mechanism to vary the extent of movement before operation of the valve. The shuttle is biased to the one end of the cylinder by a shuttle return piston in order to reduce the frictional loads on the actuating mechanism. The cylinder containing the return piston is connected to an accumulator chamber.

Abstract: A screening arrangement is provided for attachment to the rear of a connector having one or more poles for receiving an optical fibre. The screening arrangement comprises a conductive housing and a conductive sleeve for the or each optical fibre. The or each conductive sleeve is electrically connected to the conductive housing and acts as a waveguide attenuator. The conductive housing is closed, for instance by transverse plates, about the conductive sleeve or sleeves so as to form a Faraday cage on the rear of the connector pierced only by the waveguide attenuators.

Abstract: A gas turbine engine fuel control system includes a metering device responsive to an electrical signal for regulating fuel flow from a pump to the engine, a shut-off valve downstream of the metering device and operable by a first servo pressure, a spill valve operable by a second servo pressure for spilling fuel from upstream of the metering device, an electrically operable valve for controlling the first and second servo pressures, and a circuit for supplying electrical signals to the metering device and the electrically operable valve so that during shut down of the system the spill valve and the shut off valve are maintained respectively open and shut before the metering device shuts.

Abstract: A fuel injection nozzle for internal combustion engines has a valve member slidable in a bore within a nozzle body. A first bore portion in which a first valve member portion is a close sliding fit extends from an end face of the body. The first bore portion is connected by an annular recess in the wall of the bore, forming an undercut bore portion, to a second tore portion which surrounds a reduced diameter portion of the valve member, the end of which seats in the closed condition of the nozzle on a valve seat formed in the nozzle body. This prevents the access of fuel from the undercut bore portion via the second bore portion to one or more spray nozzles formed in a tip portion of the nozzle body. A fuel supply passage extends from the end face of the body within the body wall and intersects an eccentric extension extending from the undercut bore portion for the supply of fuel thereto, the intersection including the portion of the eccentric extension closest to the end face.

Abstract: A fuel injection pumping apparatus of the rotary distributor type has a fixed stroke pumping plunger housed in a bore formed in a rotary distributor member. The pumping plunger is actuated by cam lobes formed on a cam ring. A piston housed in a cylinder is provided and one end of the cylinder is connected to the bore. The piston is spring biased towards the one end of the cylinder and the extent of movement of the piston away from the one end of the cylinder is limited by a stop. The piston absorbs the initial volume of fuel delivered by the pumping plunger as the latter is moved inwardly by the cam lobes thereby ensuring that fuel is delivered to an associated engine at a high rate.

Abstract: A rotary distributor fuel pumping apparatus includes a cam actuated pumping plunger which delivers fuel to a plurality of outlets in turn during successive inward movements. A spill valve is provided which can be opened when fluid pressure is applied to a piston to spill fuel from the bore. An auxiliary plunger delivers fluid under pressure which can be applied to the piston through a control valve. The control valve includes an annular spring loaded component which is moved by the fluid pressure and an angularly adjustable rod which is surrounded by the component. The rod is provided with a helical groove and the component with a slot and when these are brought into communication fluid under pressure is applied to the piston.

Abstract: For a given vehicle speed the data in the maps is read out, and combined using weighting factors to determine the merit figure. The merit figures for the different possible gear ratios are compared and the ratio which gives the highest merit figures is selected.

Abstract: A fuel pumping apparatus for supplying fuel to an internal combustion engine has an injection pump supplied with fuel by a low pressure feed pump through an adjustable throttle. A fluid pressure operable piston is movable against the action of a spring to control the timing of delivery of fuel by the injection pump. Fuel under pressure is applied to the piston through a first fixed orifice from the feed pump. A second fixed orifice and a variable orifice are connected in series between a drain and the downstream side of the first fixed orifice. In parallel with the first fixed orifice is a constant pressure drop valve which maintains the pressure drops across the first fixed orifice substantially constant when the pressure drop has risen to a predetermined value.

Abstract: An electrical connector for forming an electrical connection to a pair of electrical terminals comprises first and second electrical connection members each having an eyelet formed with an arcuate, terminal-receiving slot. The connection members are held in fixed relative positions by either mounting them on, or moulding them into, an electrically insulating disc, or by clamping them by means of a clamping bar. In the connected condition of the connector the arcuate, terminal-receiving slots formed in the eyelets span at least opposite quadrants of a circle passing through the electrical terminals.