Abstract: A throttle valve has a control member which is angularly positioned by two stepper motors which drive the control member through differential gearing. The drives to the control member are arranged so that a single step displacement of the respective motors in the same direction drives the control member by different amounts in opposite directions, providing a high resolution drive. The control member may be driven at a high speed by reversing one of the motors.

Abstract: A wheel suspension arrangement for a wheel carrier including a suspension spring and a damper has a valve, controlling the damper. A displacement transducer detects the position of the wheel carrier relative to the vehicle body and provides an input to a function generator which produces an output corresponding to the required value of the acceleration of the wheel carrier. A comparator compares the actual acceleration with the desired acceleration and controls the valve accordingly.

Abstract: A gear pump or motor includes a housing having an 8-shaped chamber, a pair of meshed gears in the chamber and a pair of ports opening into the chamber on opposite sides of the zone of mesh of the gears. The teeth of the gears have on their non-working flanks relieved portions adjacent the tip and the root of the tooth which are arranged to leave an unrelieved land across the entire non-working flank.

Abstract: A fuel control system for a gas turbine engine has a pump which delivers fuel to a supply passage. A spill valve downstream of the pump is responsive to a servo pressure signal to spill fuel from the supply passage. A pilot valve is controlled by a torque motor to regulate the servo pressure signal. The torque motor is responsive to an electrical signal dependent on a difference between desired and actual engine speeds.

Abstract: A priming valve for a liquid fuel supply system is arranged in parallel with a fuel metering device and includes a shuttle control element which opens the priming valve during movement, the priming valve being shut at opposite ends of movement of the shuttle. The shuttle is moved by an operating pressure derived from the priming valve inlet via a restrictor and applied to respective ends of the shuttle by a change-over control valve which is operated to deliver a priming charge of fuel.

Abstract: An electromagnetic force applying device comprises a core with an annular air gap, a coil for creating a radial magnetic field in the air gap and an armature ring movable axially in the air gap. The core and the ring are of different magnetic materials with different coefficients of thermal expansion so that the force applied to the ring when a given current flows through the coil varies with temperature.

Abstract: A gear pump or motor includes a housing having an 8-shaped chamber, a pair of meshed gears in the chamber and a pair of ports opening into the chamber on opposite sides of the zone of mesh of the gears. The teeth of the gears have on their non-working flanks relieved portions adjacent the tip and the root of the tooth which are arranged to leave an unrelieved land across the entire non-working flank.

Abstract: A remote-controlled circuit breaker apparatus has a pulse generator operable to provide a single output pulse. A change over switch is operable to select the polarity of the pulse applied to a conductor. A circuit breaker device has two electro-magnets arranged to be responsive to conductor pulses of respective opposite polarities to open and close the circuit breaker device. It is arranged that in the absence of a pulse, and with the circuit breaker device open a constant voltage signal appears on the conductor. A visual indicator is responsive to this signal to provide an open-circuit warning. The circuit breaker device also becomes open circuit in response to thermal overload, thereby causing the visual indicator to be energized.

Abstract: A speed-responsive governor arrangement has a lever which is movable by a governor device. A spring-loaded transmission device is engaged between an arm of the lever and an opposed face of a cam element, so that a torque applied to the lever, opposing that applied by the governor device, is dependent on the positions of the transmission device and the cam element. The cam element has a further face which rests on rollers, so that the position of the cam element may be varied. The positions of the rollers are themselves adjustable.

Abstract: A liquid sprayer for a gas turbine engine comprises a body formed with one or more air passages therein and one or more fuel passages. The fuel passages open into the air passages over portions thereof whose dimensions change smoothly and continuously longitudinally of the passage. Each air passage may be of rectangular cross-section over said portion with the cross-sectional shape thereof changing from one dimension being smaller than the other to said one dimension being greater than the other. The fuel passage opens into the air passage at a location at which the two dimensions are substantially the same.This liquid sprayer device promotes efficient mixing of the fuel with the air.

Abstract: A thrust reversal system for a jet aircraft engine, comprising thrust reverser buckets movable between a stowed and a deployed position, an air motor operable under pilot's control to impart movement to the buckets, a piston movable in a cylinder having restricted outlet orifices for automatically decelerating the motor when the buckets approach both the stowed and the deployed position, a locking mechanism for locking the buckets in the stowed position and a flow control valve for controlling the direction of flow of operating air to the motor, the flow control valve, upon selection of deploy, initially occupying a position corresponding to movement of the motor in the direction to stow the buckets and, after release of the locking mechanism, moving to its alternative position to enable the motor to move the buckets to the deployed position.