Abstract: An apparatus for providing an indication of the level of smoke in an engine exhaust includes a radiation sensor which is mounted in a combustion chamber of the engine. The signal produced by the sensor during combustion of fuel is processed to produce a signal representing the period of combustion of fuel in the cylinder and this signal is applied to a map which contains recorded data showing the relationship between the combustion period and the level of smoke. From the map the level of smoke can be obtained.

Abstract: In a power assistance system for a vehicle steering mechanism fluid pressure providing the assistance is supplied from a pump driven intermittently by an infinitely-variable electric motor. For a rack and pinion mechanism fluid pressure chambers are formed by sealing boots at each end of the rack, and are connected through the pump, which is operative to create a pressure differential between the chambers, and thus across the rack to provide power assistance. The electric motor is energized as required to drive the pump in the appropriate direction, and when the motor and pump are inoperative fluid is allowed to flow freely between the chambers to accommodate fluid displacement as a result of unassisted operation of the steering. The pump is preferably a turbine pump, which allows fluid flow when inoperative. The system provides power assistance efficiently, and relatively cheaply.

Abstract: A brake actuator has a body containing a pair of brake-applying members which may be actuated hydraulically to separate the friction elements of a brake into engagement with a rotatable braking surface. The members are interconnected by a mechanism in the form of a shaft of which respective end portions are provided with reversible threaded portions of opposite hand which engage corresponding threads within the members, the shaft being constrained against axial movement between bearings. Any excess movement of one of the members relative to the other is transmitted to that other member such as to cause an opposite and proportional force on the other member to substantially equalize the wear rates on the friction elements.

Abstract: A fuel injection nozzle of the inwardly opening type including a valve member surrounded by a sleeve, the valve member and sleeve both being movable by fuel under pressure supplied to an inlet. The valve member is biased into engagement with a seating by the action of a spring which acts on the valve member through a spring abutment. The sleeve acts on the spring abutment through an annular intermediate member. The extent of movement of the sleeve is limited by the engagement of the intermediate member with a stop surface and the extent of movement of the valve member is limited by the engagement of a step on the valve member with the intermediate member.

Abstract: A fuel reservoir comprises a tank having a base wall and side walls. In order to minimize the accumulation of water in the tank two pick-up pipes, are provided which are connected together to an outlet pipe. The first pick-up pipe extends to adjacent the base wall of the tank and the second pick-up pipe to some distance above the base wall. In use fuel and water will be drawn through the outlet pipe and in the event that the water in the tank freezes fuel can be drawn through the second pick-up pipe.

Abstract: A residual pressure control valve which is interposed between a fuel injection pump and a nozzle includes an annular valve element which is biased by a spring into contact with a seating surrounding a port connected to the pump. Slidable in the valve element is a piston which is resiliently biased away from the seating. The piston has a groove communicating with the port and the valve element has a port which is uncovered to the groove upon movement of the piston relative to the valve element against the action of its resilient loading.

Abstract: The invention provides an ammunition feed for an automatic weapon in a helicopter gun turret which is capable of flexing in two planes to accommodate movement of the weapon and rapidly and reliably delivering loosely held rounds. The feed comprises a stranded wire belt, having spindles crimped onto it, which moves in a guide chute. Transverse inverted Vee shape members forming cradles are secured at their midpoints to rollers on the spindles and rounds are trapped and transported between adjacent cradles. The cradles are sufficiently flexible to hold the rounds in position during sharp changes in direction of the feed. A transfer wheel delivers rounds to the breech, the drive for the transfer wheel also driving the cable drive, means being provided to ensure positive drive transmission during gun recoil and further means to stop the feed when firing ceases.

Abstract: A master cylinder reservoir is provided with flexible arms adapted to snap-engage with a retaining formation on a pressure cylinder, the arms lying generally parallel to a spigot of the reservoir received within a socket of the cylinder. A seal is provided between opposed surfaces of the spigot and socket.

Abstract: A fuel injection nozzle includes a fuel pressure actuated valve member which is biased into contact with a seating by resilient means. The nozzle also includes a spill valve member having a head which is biased into contact with a seating by the resilient means. The head of the spill valve is lifted from the seating by the application of fuel under pressure to a piston portion of the spill valve member. When the head of the spill valve is lifted from the seating fuel is spilled from the nozzle inlet to a drain.

Abstract: A beacon lamp comprising a base, a support member fixed in relation to the base and a reflector carrier rotatably mounted on said support member for rotation relative thereto about a first axis. A drive motor carrier is resiliently supported by said support member such that in a rest position the principal axis of the motor carrier is disposed at a small angle to said first axis. An electric motor is supported by said drive motor carrier, and has its output member engaging a cylindrical wall of said reflector carrier, said motor carrier being deflected during positioning of said motor such that said principal axis is rendered substantially parallel with said first axis and said carrier resiliently biases the motor output member against said cylindrical wall of said reflector carrier.

Abstract: Disclosed is a method and apparatus for controlling operation of an engine whereby there is a known general function relating an engine control input to the engine output. This known control function has a number of structures or method steps which accomplish the following functions. The value of at least one engine output is measured; a base value of at least one engine input is supplied. A value of the engine output is determined based upon a predetermined function of the base value of the supplied engine control input; the measured value of the engine output is compared with the determined value of the engine output; in response to the comparison, base values of the two parameters in the predetermined function are adjusted; and the base value of the engine control input is adjusted based upon the adjustment to the two parameters.

Abstract: An hydraulic pump and motor assembly for a vehicle hydraulic system has a housing accommodating the pump and motor, the pump having one or more spring-loaded pistons working in complementary bores to pump hydaulic fluid from a reservoir port to a delivery port, and the pistons being operated from an eccentric on a rotary output shaft of the motor through a cam bearing assembly. The assembly includes a retaining device for the pistons to limit their radially inwards movement, when the motor output shaft is removed, to an amount which is insufficient to break the hydraulic circuit containing the pistons. This enables the motor to be removed, while ensuring that the pistons are retained in their bores so that the hydraulic circuit remains intact. The cam bearing assembly may be mounted on the shaft without being retained on it, with the engagement between the pistons and the cam bearing assembly arranged so that they are all retained in the housing on withdrawal of the output shaft.

Abstract: The extent to which a throttle can be opened is determined in accordance with a "lowest wins" philosophy. This is achieved by a transmission mechanism disposed between the accelerator pedal and the throttle valve and comprising an interlock collar fast with a rotatable shaft for operating the valve, a spring normally urging the shaft in a direction to open the valve, and first and second input collars rotatably mounted on the shaft and coupled respectively to the pedal and to a motor device operable in response to signals from electronic means in accordance with at least one appropriate parameter. The input collars are arranged to co-operate unit the interlock collar in a manner such that the angular position of the interlock collar is determined by the position of that one input collar what has moved by the smaller distance from a given retracted position.

Abstract: A traction control system for the driven wheels of a road vehicle includes a modulation unit which controls fluid flow from a master cylinder actuated via a servo unit to supply fluid under pressure to a spinning driven wheel in order to reduce the degree of spin and increase the torque transmitted to the other driven wheel. The servo unit is actuatable independently and by itself when spin control is required, by way of a solenoid valve which causes a part of the normal output force of the servo to be applied to the master cylinder for the purpose of spin control.

Abstract: A method of and an apparatus for controlling a brake system in a heavy-duty vehicle provide for continuously measuring parameters which are characteristics of the state of the vehicle, such as the velocity of the vehicle, the inclination of the roadway, the axle load, and the transverse acceleration. Furthermore, the braking capability is being monitored continuously. To that end the temperature of the brakes, their condition of wear, the state of a compressed air reservoir, and the tire pressure are measured. For any given state of the vehicle and brakes it is determined whether or not the stopping distance to be expected will be longer than a predetermined rated stopping distance. If that is so, the driver is warned and/or a reduction of the travelling speed is initiated automatically.

Abstract: A speed measuring apparatus, for instance for measuring the speed of a vehicle over the ground, comprises a plurality of photodetectors arranged to view consecutive regions along parallel light paths. The photodetectors are arranged as two sets of alternating photodetectors whose combined outputs are subtracted to provide a signal whose frequency represents speed and is insensitive to height.

Abstract: A transparency such as an aircraft front window has an electrically conductive metal, e.g. gold, film vacuum deposited thereon for demisting and/or defrosting purposes. To increase the reliability of such metal film, a layer of an oxide of indium, e.g. indium tin oxide, is formed on the metal film by a sputtering operation to a typical thickness of 10 to 200 nm.

Abstract: A disc brake comprises a brake support which is to be mounted on a first side of a brake disc and comprises a bridge portion engaging over onto the other side. Two brake pads are arranged on either side of the brake disc and supported against braking forces on the brake support. For direct actuation of a brake pad an actuator is arranged on the first side of the brake disc. For transmitting actuating forces to the other indirectly actuable brake pad a floating caliper engages over the brake disc. The brake support comprises two arms on the first side of the brake disc. Of the arms, a first arm of lower rigidity is loaded with the braking forces of the directly actuated brake pad. The other arm, which has a greater rigidity carries the bridge member and is loaded with braking forces of the indirectly actuated brake pad.

Abstract: An electromagnetically operable fluid control valve includes a valve member slidable in a bore in a valve body. Resilient means biases the valve member to the open position and an actuator including an armature when energized moves the valve member to the closed position. Stop means formed by a part movable with the armature engages the valve body to limit the movement of the armature and valve member when the actuator is de-energized. Damping means formed by a liquid filled recess in the part acts to damp the aforesaid movement.

Abstract: In an hydraulic anti-skid braking system (FIG. 1), a valve controlling the flow of braking fluid to a brake actuator is actuated by a pulse-driven stepper motor in response to signals emanating from a skid sensor. In a practical arrangement (FIG. 3), a motor under the control of a microprocessor actuates a pressure dump valve via an eccentric mechanism upon the appearance of a skid signal at the sensor, in order to de-pressurize the actuator, and also drives a pump which assists in re-pressurizing the system when the skid signal ceases.