Abstract: A vehicle brake control device especially suitable for load carrying vehicles comprises a device for sensing front and rear brake pressure and vehicle deceleration, and a control device for maintaining the relationshipAP.sub.1 -BP.sub.2 +C=Dfwhere P.sub.1 is the front brake pressure, P.sub.2 is the rear brake pressure, f is the sensed deceleration, and A,B,C and D are constants with A greater than B.

Abstract: An anti-skid hydraulic braking system for a vehicle includes a modulator which in response to a skid signal at a skid point is operative to relieve the brake-applying pressure at a braked wheel by displacing fluid from the brake. The modulator includes a brake-application restrictor which is operative to control the rate at which the brake-applying pressure from a source can be re-applied to the brake at the cessation of the skid signal, and a valve assembly is incorporated to by-pass the re-application restrictor. The valve assembly comprising first and second valve members which are relatively movable between a spaced inoperative position in which unrestricted communication is provided between the source and the brake and an operative position in which the valve members are urged into engagement to render the restrictor effective.

Abstract: A fuel injection pump of the rotary distributor type has angularly adjustable stop rings which limit the outward movement of the pumping plungers so as to control the maximum fuel output of the pump. The stop rings have an outwardly extending curved stop surface so that the maximum fuel output can be altered by altering the angular setting of the rings. The latter portion of the stop surface is arranged to curve outwardly at a greater rate so that as the engine speed increases the plungers no longer follow paths determined by said surface so that the maximum fuel delivery of the pump decreases.

Abstract: A brake actuator comprises a piston working in a cylinder with a seal carried by the piston for engagement with the outermost wall of the cylinder and a seal housed in the innermost wall of the cylinder for engagement with the piston. Each seal is of triangular outline and is received in a seal-receiving groove which has first and second relatively inclined end walls with which faces on the seal are in full facial engagement, and a sealing region for engagement with the wall of the cylinder or the piston is defined by and between the third remaining face and the adjacent face of the seal. A space is provided between the second end wall and the third face to accommodate any deformation of the material of the seal which is otherwise confined between the piston and the cylinder.

Abstract: A fuel system for a compression ignition engine comprises a plurality of injection nozzles controlled by electromagnetic devices to deliver fuel in timed relationship to an engine. Fuel for the nozzles is stored under pressure in accumulators which are charged from a source of fuel through small bore pipes so that the recharging of the accumulators after fuel delivery is delayed. Transducers are provided and are responsive to the pressure in the accumulators. The signals provided by the transducers register a pressure drop when fuel flows through the nozzles and the fall in pressure is related to the quantity of fuel supplied through the nozzle.

Abstract: A fuel injection pumping apparatus includes a governor which controls the size of an orifice through which fuel is supplied to an injection pump to determine the amount of fuel supplied by the pump to an associated engine. The governor includes a piston which at one end is subjected to fuel pressure and which bears at its other end against a spring connected in series with a spring. The spring is weaker than the spring so that at idling speed it is the spring which balances the force acting on the piston. Manually operable means is provided to effect movement of an abutment disposed between the springs, the spring acting to determine the maximum speed of the associated engine. When the engine has been started from cold, it is desirable to provide additional fuel to enable the engine to idle properly and for this purpose a device represented by the arrow, moves the end of the spring remote from the spring and this provides a temporary increase in the amount of fuel supplied at idling speeds.

Abstract: A tread brake for braking a wheel (2) of a railway vehicle which is sprung relative to a frame (4) of the vehicle, comprises an actuator (5) suspended from the frame (4) by a swing arm (6), and a rigid link arm (7) fixed to the actuator (5) and connected through a pivot (8) parallel to the wheel axis to a bracket (9) fixedly mounted to a bearing in which the wheel axle is journalled. The link arm (7) adjusts the position of the actuator (5) in response to any movement of the wheel (2) relative to the frame (4) so that the braking element (11) is always applied substantially radially to the wheel, which allows the element to take the form of an elongate rod of friction material. A new handbrake structure is also described.

Abstract: A master cylinder for a hydraulic brake system includes a piston which divides a primary bore into a primary chamber and a secondary chamber. The piston rod sealingly slides in a secondary bore of smaller cross-sectional area than the primary bore. An expander piston sealingly slides in a bore and defines a primary expander chamber and a secondary expander chamber. In use, initial movement of the piston causes fluid to be displaced from the primary chamber to the brake circuit at a rate corresponding to the area of the primary bore. When the pressure in primary chamber becomes sufficiently large the expander piston is moved to the right against the bias of a spring to allow fluid to flow out of primary chamber into primary expander chamber via a passage. An equal volume of fluid is displaced from secondary expander chamber into secondary chamber via a passage.

Abstract: A fuel injection pumping apparatus comprises piston means slidable in a bore from one end of which extends a fuel outlet for connection to a nozzle. A fuel inlet is connected to the one end of the bore and a valve controls flow through the inlet into the bore. The piston means is actuated by liquid under pressure supplied by a plunger actuated by an engine driven cam located in a cylinder. A two way valve is provided to control flow of liquid from the cylinder either to the bore or to a source of liquid, the valve being controlled by an electrically operated actuator. The actuator is controlled by a control circuit which receives a signal from a transducer associated with the piston means.

Abstract: A gas turbine engine fuel control has a main hydromechanical fuel flow control and an electrically operable valve in series with the flow control for speed limitation purposes. The valve is controlled by a signal N.sub.L or N.sub.H derived from an engine speed transducer. A phase advance compensation circuit advances the phase of the transducer signal and its output is applied to an error amplifier which compares it with a datum (which may vary with altitude). The error signal is applied to a non-linear amplifier the amplification factor of which increases when a certain error threshold is exceeded. The combination of phase advance and non-linear amplification ensures rapid limitation of speed without introducing stability problems.

Abstract: A liquid fuel injection pumping apparatus of the rotary distributor type includes a cam ring which is angularly adjustable to vary the timing of delivery of fuel. The setting of the cam ring is determined by a piston in which is located a servo valve. The servo-valve has a land to control fluid flow into a cylinder containing the piston. The servo valve is spring biased and a wedge is provided between a cylindrical member engaged by a spring and the servo-valve, the wedge being movable to alter the distance of the portion of the land which controls fluid flow of the servo valve. The wedge is coupled to the output member of a speed responsive device, the output member also being coupled to a fuel quantity control of the apparatus so that the setting of the cam ring depends upon the amount of fuel delivered by the apparatus.

Abstract: A load conscious control valve arrangement for modifying the pressure applied to the rear hydraulic brake of a motor cycle comprises a control valve rigidly mounted by a bracket on the frame of the motor cycle. The stem of the control valve is connected by a tension spring to an adjustable spring support of a combined spring/damper suspension strut. Deflection of the rear suspension as a result of increased loading causes an increased tension to be applied by the spring and thereby increases rear brake pressure. To compensate against the decrease in tension which would otherwise be applied to the valve stem when the adjustable stop is adjusted but there is no increase in the load on the motor cycle, an eccentric formed on the adjustable stop so that rotation of the stop may be provided to adjust the suspension strut causes a shift in the radial direction of the suspension strut of the point Z at which the spring is connected to the spring support.

Abstract: An hydraulic pressure master cylinder has a cylinder usually of metal, and a separately made plastics reservoir. The reservoir is retained on the cylinder by means of a pair of resilient arms, the internal faces of which are recessed to conform the external surface of the cylinder. The reservoir is fitted to the cylinder by deforming the arms outwardly to enable them to shap-engage around the cylinder so that the latter seats within the recesses. If desired, the free end portions of the arms may be joined by a fixing device such as a rivet.

Abstract: The present invention provides a friction pad assembly comprising a backing plate and a pad of friction material secured thereto, the backing plate having at least one hole offset from the central axis of the assembly, through which a pad support pin passes to engage a wire spring supported on the backing plate and having two generally oppositely directed arms. The arms engage either the pad support pins and/or part of the brake and produce an asymmetric loading of the pad assembly, the spring biassing the friction pad assembly against an abutment face of the brake to thus reduce the possibility of the pad assembly hitting the abutment face to produce disturbing `klonking`.

Abstract: A hose connector has a body having a first portion adapted to receive a flexible hydraulic hose and a second portion adatped for connection to a brake actuator. A bore portion of the second body portion is arranged to provide a space large enough to contain at least a major part of any heated brake fluid returning from the actuator upon brake retraction thereby minimizing the amount of heated fluid reaching the hose.

Abstract: A fuel injection nozzle includes a body defining a bore to which fuel can be supplied. The bore defines a guide portion of reduced diameter at its outer end and the guide portion supports a valve member for axial movement. The valve member has an outlet orifice formed therein. The orifice in the closed position of the valve member is closed by the guide portion and is uncovered to the bore to allow fuel flow as the valve member is moved by fuel under pressure.

Abstract: In an anti-skid vehicle braking system an electronic control unit is arranged to control the operation of an anti-skid valve assembly for modulating the fluid pressure applied to a brake actuator. A wheel speed sensor measures the speed of a braked wheel and produces a signal which is converted into a deceleration signal by a conditioning circuit and a differentiator and compared in a comparator with a deceleration threshold value. A pressure sensor provides a pressure signal corresponding to the current brake actuator pressure and a pressure signal conditioning circuit modifies the pressure signal to take account of a load signal produced by a load sensor which measures the loading of the braked wheel. The deceleration threshold value is produced by modulation of a constant threshold value in a threshold generator circuit and a threshold modulator circuit in response to the modified pressure signal.

Abstract: A temperature measuring system comprises a sensor which is connected to a supply rail through a first lead, and which may be selectively connected by a relay through a second lead or a third lead to the inverting input of an operational amplifier. The leads have different resistance values. The output of the amplifier is connected to its input through a resistor, and its non-inverting input is connected to the rail through a potential divider. The output of the amplifier is connected to a computer through a low pass filter and an A/D converter. In operation, the output voltage of the amplifier is first measured with the second lead connected to its inverting input and then measured again with the third lead connected. From these measurements the resistance of the sensor is calculated after calculating and hence eliminating the resistance of the leads. The sensed temperature can then be calculated from the resistance of the sensor.

Abstract: A fuel injection nozzle for supplying fuel to an internal combustion engine includes a fuel pressure actuated valve member slidable within a bore. The working clearance defined between the co-operating surfaces of the valve member and bore at one end communicates in use with a source of fuel under pressure which may not have adequate lubricity to provide proper lubrication of the surfaces. A groove is defined between the surfaces and communicates with a drain and the other end of the working clearance communicates in use with a source of lubricating medium.

Abstract: A circuit for controlling a plurality of inductive loads, includes a plurality of low voltage transistors controlled by a flip-flop so that only one of the low voltage transistors is on at any given time. These low voltage transistors connected one end of respective ones of the loads to one rail of a supply. Diodes connect the other ends of the loads to a common point which is connected to the other rail of the supply by a single high-voltage transistor. Further diodes connect said one end of the respective loads to said other rail to protect the low voltage transistors from high voltages caused by the interruption of current in the loads.