Abstract: An electronically controlled braking system wherein improved braking distribution in a multi-axle vehicle is achieved by making allowance for sources of background braking by assessing through measurement the total background braking force and assigning this in a predetermined proportion between the vehicle axles.

Abstract: A hydraulic master cylinder (1) comprises a body (2) in which conventional output chambers (5,6) are defined. In use, the output chambers are pressurized by a piston (4) which is moved by a combination of mechanical input force applied to an input member (8) and hydraulic pressure within a servo chamber (13) located to the rear of the piston (4). Connection of the servo chamber (13) to a pressure source is controlled by poppet valves (16, 17) which are opened as necessary by ribs (23, 24) of a sleeve (22) mounted on imput member (8). The sleeve (22) is coupled to the piston (4) but free to rotate relative to the input member (8) and is coupled to the input member by means of a helical groove and ball arrangement such that movement of the input member (8) towards the piston (4) causes rotation of the sleeve (22) to open the inlet valve (17), and movement of the input member ( 8) away from the piston (4) causes opposite rotation of the sleeve (22) to close the input valve (17) and open the outlet valve (18).

Abstract: In an hydraulic anti-lock braking system a flow control valve operates with a single-acting solenoid-operated valve (35), and the flow control valve incorporates a spool (17) working in a bore (8) in a housing (7) with the flow directed thorough a passage (20) passing substantially through the centre of the spool (17). 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) and 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).

Abstract: A rotary distributor type fuel pumping apparatus has two pairs of plungers housed in respective diametrical bores which intersect each other. One of the plungers is longer than the remaining plungers conveniently by providing an extension at its inner end. The extension lies in the paths of movement of the remaining plungers so as to minimize the risk of damage to the plungers.

Abstract: A fuel injection pumping apparatus of the rotary distributor type includes a pumping plunger (13) housed in a bore which is completely filled with fuel during the filling stroke of the apparatus. An electromagnetically operable spill valve (22) is provided to control the quantity of fuel supplied by the apparatus during the delivery stroke of the plunger. The spill valve is spring biased to the open position and is closed by an actuating member (42). If the spill valve sticks in the closed position the maximum amount of fuel will be supplied to the associated engine at each delivery stroke. A flow inhibit valve (35) is provided to control fuel flow to the bore. The flow inhibit valve is responsive to the position of the actuating member of the valve and will move to the closed position in the event that the spill valve remains in the closed position.

Abstract: A draw-bar coupling for a vehicle combination incorporates a sensor assembly for sensing the loads acting on the coupling in more than one plane, specifically two or three planes at right angles to each other.

Abstract: A regenerative pump comprises a housing (1), an impeller (5) within the housing (1) having a plurality of vanes (13) spaced angularly around the axis of rotation of the impeller (5) and accommodated within a flow channel (4) within the housing (1) extending between an inlet (19) and an outlet (20), a flow stripper (17) located between the inlet (19) and outlet (20) and through which the vanes (13) pass, a fluid flow loop (27) in the stripper (17) which intersects the path of rotation of the vanes (13), and control means (26) to control the flow of fluid through the loop (27) so as to vary the annular motion transferred to the fluid downstream of the stripper (17), thereby to selectively vary the output of the pump. The flow stripper (17) comprises a land portion (21) upstream of the loop (27) which restricts direct fluid flow through the stripper (17), and the control means (26) comprises valve means which controls a supply of fluid to the upstream end of the loop (27).

Abstract: A solenoid-operated fluid-flow control valve comprises a housing (10) incorporating a solenoid coil (14), a single armature (15) responsive to energization of the coil to determine a pressure differential across a pressure-sensitive member (28, 18) and to open an exhaust port (45), in combination with a valve assembly (13) comprising a hollow valve body (16), and a valve head (19), the valve body being axially movable with respect to the housing in response to the pressure differential acting on the pressure-sensitive member. The valve body and the valve head are relatively movable axially with the valve head being movable with respect to a seating (47) in the housing and a seating (23) on the valve body, whereby to provide selective communication between an inlet port (46), an outlet port (47) and the exhaust port (45).

Abstract: A transformer arrangement is provided which has a primary and at least one secondary winding coupled via a movable armature which is outside of the windings. A second transformer can be provided which has primary and secondary windings coaxial with and surrounding the corresponding windings of the first transformer. The armature is tubular and slidable in the radial clearance defined between the windings of the first transformer and the windings of the second transformer.

Abstract: A fuel system for supplying fuel to a compression ignition engine includes an accumulator in which fuel is stored at high pressure. The fuel being supplied to the accumulator from a high pressure cam actuated pump which includes pumping plungers operable in timed relationship with the associated engine. The apparatus also includes a distributor member having a delivery passage which can register with outlet ports in turn. Valve means is provided and this is operable in a first setting to connect the high pressure pump to the delivery passage so that fuel is supplied at a low rate to the associated engine and a second setting in which the accumulator is connected to the delivery passage to achieve a high rate of fuel delivery to the engine.

Abstract: A braking system for a vehicle having primary and secondary braking circuits includes a secondary braking circuit having a secondary source of braking pressure connectable to a braking actuator and including a three-port, two-position, inlet solenoid valve having two inlet ports and one outlet port. One of the inlet ports is connected to an outlet of an inlet solenoid valve of the primary braking circuit and to the inlet of an exhaust solenoid valve of the primary braking circuit. The other inlet is connected to a secondary source of braking pressure. The outlet port is connected to the braking actuator. The inlet solenoid valve is movable by an output signal from an electronic control unit.

Abstract: A vibrating sensor comprises an elongated element arranged to vibrate at a frequency dependent upon an external stress applied to the sensor, and an optical fiber for coupling light into an end of the element to excite it into vibration. A light-absorbing layer is provided on a longitudinal surface of the element such that the element will change its configuration, e.g. by bending, as the layer absorbs light and heats that side of the element, this alteration in configuration causing a reduction of radiation which is absorbed so that the element restores. The element may define a Fabry-Perot interferometer between its opposite ends.

Abstract: A unit injector for supplying fuel to an internal combustion engine has a bore (21) in which is mounted a pair of plungers (22) extending from the opposite ends of the bore. The plungers are actuated by cams (26) which are mounted on a pair of cam shafts of the engine.

Abstract: In a motor vehicle brake system, a force increase gradient (Fv ped) at the brake pedal is determined and, in response thereto, the brake pressure is boosted in a manner which provides for successively associating respective threshold values (Fv max) with respective instantaneous force increase gradients (Fv ped) at the brake pedal during a braking operation. The instantaneous actual value of the force increase gradient (Fv ped) is compared with the respective threshold value (Fv max), and the brake pressure booster is controlled in response to the result of this comparison.

Abstract: A series of engine speed changes is analysed in order to detect a sequence of speed changes characteristic of a misfire having occurred. An embodiment of the invention generates a first mask in response to speed increases and a second mask in response to speed decreases. A misfire can only be signalled when both masks are at a PASS state and misfire detector detects a misfire.

Abstract: A fuel system for an engine (10) has a transducer (16) which supplies an input signal to an electronic fuel control system (15) representing driven demand. A variable gain amplifier (19) modifies the signal applied to the control system and is controlled by a load sensor (20) which detects when a suddenly applied load is placed on the engine such as when an air conditioning compressor (18) is brought into operation or when the power output of the alternator (17) is suddenly increased.

Abstract: An optical displacement sensor suitable for use in drowned environments where the refractive index of a medium in the optical path may vary, comprises a light source emitting first to fourth wavelengths. The first and second wavelengths are within the infrared region of the spectrum, whereas the third and fourth wavelengths are in the visible region of the spectrum. A zone plate focuses the first and second wavelengths to respective positions substantially at the extremes of movement of a reflective element whose position is to be measured. The zone plate also focuses the third and fourth wavelengths to respective positions. A cold mirror is interposed between the zone plate and the reflective element and is arranged to transmit the first and second wavelengths and to reflect the third and fourth wavelengths. The ratio of the intensities of the light reflected from the cold mirror gives information about the refractive index of the medium in the optical path.

Abstract: A fuel pumping apparatus of the rotary distributor type includes a fluid pressure actuable spill valve member operable to terminate delivery of fuel through an outlet from a bore containing the pumping plungers. The valve member is moved to the open position by an actuating piston. One end of the cylinder containing the actuating piston is connected to a low pressure source of fuel by way of a non-return valve and the same end of the cylinder can be connected by a control valve to a high pressure source of fuel when spillage of fuel is required. Associated with the piston is a balance piston and the two pistons define a flow path for fuel from the one end of the cylinder to the bore to ensure that the bore is completely full of fuel prior to the next delivery of fuel through an outlet.

Abstract: A front housing part (20) of a brake pressure booster (12) carries two hollow inner threaded members (26) which each engage in a hole (68) formed in a flange (70) of a master cylinder (14) and each support the head (52) of a bolt (50). Each one of the bolts (50) extends through the associated inner threaded member (26) and through the booster (12) and has a threaded portion (56) which projects rearwardly out of the booster to be screwed into a threaded sleeve (18) at a dividing wall (16) of a motor vehicle. The flange (70) of the master cylinder (14) is clamped between the inner threaded members (26) and outer threaded members (60) which likewise are hollow and have inner diameters greater than the head (52) of the corresponding bolt (50). The outer threaded members (60) each include a sleeve-like extension (62) engaging in the corresponding hole (68) of the flange (70) and being screw connected to the inner threaded member (26) received in said hole.

Abstract: An internal shoe-drum type brake has a pair of shoes separable by an actuator into braking engagement with a brake drum. An automatic adjuster includes a two-part strut extending between the shoes, the first strut part being pivotally mounted on the second strut part and cooperating with the latter via teeth on the second part, such that the first strut part is separated from the teeth when excessive shoe separation occurs upon brake actuation and is moved angularly to a new position of adjustment upon brake release. The first strut part is provided with a number of peripheral projections engagable by an external tool to disengage the first part from the teeth of the second part when it is desired to de-adjust the adjuster in order to facilitate drum removal.