Abstract: A liquid fuel pumping apparatus for supplying fuel to an internal combustion engine includes a member which is movable against the action of a spring system by means of centrifugally operable weights. The member is coupled to a fuel control rod of the pumping apparatus, and the spring system includes first and second springs. The first spring is preloaded so as to be deflected by the weights only when the speed of the engine attains a predetermined value. The other spring is deflected by the weights at lower engine speeds and also acts to transmit the force exerted by the weights to the first spring.

Abstract: A fuel system for an engine has a pump which supplies fuel to the engine and an actuator for controlling the pump output. The actuator is controlled by a control circuit to which are fed electrical signals representing demanded engine speed, actual engine speed and pump output. The control circuit sets the slope of the pump output versus speed curves of the engine, and speed-sensitive means operates below a predetermined engine speed for modifying this slope to make it shallower and so produce a smaller change in pump output for a given change in speed.

Abstract: A fuel system for an engine, particularly a compression-ignition engine, has a pump supplying fuel to the engine and a control member for determining the output of the pump, the control member being itself controlled by a control circuit receiving parameters one of which is measured by transducer means. The transducer means is designed so that if it fails, the fuel system fails safe. In another arrangement, in which failure of the transducer means results in an output which would increase fuel, then the failure is detected and action is taken.

Abstract: A fuel pumping apparatus for supplying fuel to an internal combustion engine includes a rotor which acts as a distributor member and has a high pressure passage for registration with an outlet port or ports and low pressure passages for registration with low pressure ports formed in the body part of the apparatus. In order to minimize leakage of the high pressure, the rotor is divided into two parts the part having the low pressure ports being of larger diameter than the part which has the high pressure ports.

Abstract: A frequency to voltage converter includes an operational amplifier having its non inverting input terminal connected to a supply line which has a voltage intermediate a pair of supply terminals for the amplifier, a resistor connected in series with first and second diodes between the inverting input terminal and the line a first capacitor through which the input of the converter is connected to a point intermediate the diode and a second capacitor connected between the junction of the first diode and the resistor and one of the supply lines, a feed back resistor connected between the output terminal of the amplifier and the junction of the first diode and the resistor and a third capacitor connected between the output and inverting input terminals of the amplifier.

Abstract: An electrical inverter comprises positive and negative supply lines across which is connected a first series circuit including the anode-cathode path of a first thyristor and the anode-cathode path of a second thyristor. A second series circuit bridges the supply lines and includes a pair of capacitors. In addition a commutating circuit is provided for the first and second thyristors, and this includes a transformer having a secondary winding connected between a point intermediate the first and second thyristors, and the capacitors of the second series circuit, and the primary winding of the transformer is connected in a series circuit, one end of which is connected to the point intermediate the first and second thyristors. The arrangement is such that when the commutating circuit is operated, current flow in the primary and secondary windings of the transformer acts to reduce the current flowing in the conducting thyristor to zero.

Abstract: A fuel pumping apparatus for supplying fuel to an internal combustion engine includes a body part comprising a generally cup shaped portion which accommodates a first portion of the rotor. The open end of the cup shaped portion is closed by a plug portion which accommodates the second portion of the rotor. The two parts of the rotor are connected to each other so as to rotate together, and the first portion of the rotor together with the cup shaped portion of the body part house the low pressure fuel channels of the apparatus while the plug portion and the second portion of the rotor house the high pressure passages and components of the apparatus.

Abstract: The invention relates to an actuator mechanism for the fuel quantity control member of a fuel injection pump. The mechanism includes an output member which is driven by an electro-magnetic device and the flexible member which is connected to the control member of the injection pump. An arm is angularly movable about the output member and is connected to the link and a helically coiled torsion spring is provided to transmit motion between the output member and the radial arm. The control member mounts an abutment which can be contacted by a lever to move the control member towards the position of minimum fuel irrespective of the setting of the output member. During such movement, the spring is stressed.

Abstract: A variable reluctance electric motor comprises a stator including at least three pairs of pole pieces with windings surrounding at least one of the pole pieces of each pair, and a rotor structure. The rotor structure defines a pair of opposed pole pieces each having circumferentially extending extensions on the opposite sides thereof. The extensions extend at least to the adjacent pair of stator pole pieces when the rotor pole pieces are aligned with stator pole pieces, and be selective energisation of the pairs of stator pole pieces, the rotor can be made to move angularly in either direction.

Abstract: A brushless a.c. synchronous motor comprises a stator assembly having a stator winding which is supplied with power by an invertor. The main input power to the invertor flows through the primary winding of a transformer the secondary winding of which supplies current by way of a rectifier, to a field winding of the rotor assembly of the motor.

Abstract: A direction indicator system for road vehicles, comprises an electrical circuit which is in the form of a single integrated circuit and which includes circuitry means externally connectible in at least two alternative ways to enable the indicator system to operate in any one of at least two different modes.

Abstract: A rotary actuator comprises a stator structure defining a magnetisable pole piece and an angularly movable rotor structure which defines a pole element. The pole piece and pole element form part of a magnetic circuit and a winding is provided about a portion of the magnetic circuit defined by the rotor and stator structures. The faces of the pole piece or pole element which are presented to each other are provided with a slot or a cutaway portion which extends along at least part of the circumferential length of the face whereby a desired torque/angle characteristic is obtained.

Abstract: An engine fuel system, particularly for a compression ignition engine, has a control arrangement for determining the quantity of fuel injected in accordance with the position of a control member such as an accelerator pedal. For part of its movement, the pedal produces an output which is a certain function of the pedal position, and for another part of the movement, an output is produced which is a different function of the pedal position.

Abstract: A hydraulic system comprises an electrically controlled actuator element operable to initiate delivery of liquid. The system also includes a movable member the movement of which is representative of the amount of liquid delivered and sensing means is provided for detecting movement of the member. The sensing means provides a control signal which is arranged to effect a change in the state of the actuator element when the required quantity of liquid has been delivered.

Abstract: A control system for a vehicle having an engine and a gear box includes an electronic fuel control system for controlling the fuel supplied to the engine by means of a pump. The selection of a particular ratio of the gear box is effected by a control circuit which senses the speed of the vehicle by means of a sensor. When a change in gear ratio is effected, the control system for the gear box provides a signal to the electronic fuel control system which produces a reduction in the amount of fuel supplied to the engine during the gear changing process.

Abstract: An electrical inverter comprises first and second supply lines, which in use are connected to the positive and negative terminals of a d.c. supply. An inverting network is connected between the supply lines and has output terminals for connection to the load. A current sensing device is provided in one of the supply lines and is operable when the current flow in the supply line exceeds a predetermined value, to stop current flowing in the load for a predetermined period of time.

Abstract: A fuel pumping apparatus for supplying fuel to an internal combustion engine is provided with a governor mechanism having weights which through linked means effect movement of a control rod to reduce the amount of fuel supplied to the engine. The weights are opposed by a governor spring and a maximum fuel stop is provided to control the normal maximum amount of fuel supplied to the engine. Releasable actuator means is provided to effect movement of the control rod to an excess fuel position, when it is required to start the engine.

Abstract: A d.c. motor control system includes a pair of armature windings mounted on a single rotor or on a pair of mechanically coupled rotors, and a field winding or windings. The system includes switch means operable to effect a change in the electrical connections of the armature windings to a pair of electrical supply terminals and means for effecting variations of the current flowing in the field winding or windings.

Abstract: A fuel pumping apparatus for supplying fuel to an internal combustion engine includes an injection pump which delivers fuel through a delivery passage which includes a spring loaded delivery valve. A vent conduit extends from the delivery passage, and communicates with a vent conduit during a delivery stroke of the injection pump. The vent conduit communicates with the delivery passage intermediate the injection pump and the delivery valve, and the vent passage includes a screwed plug at its end and a valve element which is resiliently loaded into contact with a seating. The seating is positioned adjacent the vent conduit so that the amount of fuel in the conduit during normal operation of the apparatus, is as small as possible.

Abstract: The invention relates to a fuel injection pumping apparatus which includes a feed pump the output pressure of which is controlled by valve. The feed pump supplies fuel to an injection pump under the control of a shuttle which is movable in a bore. The extent of movement of the shuttle determines the amount of fuel supplied by the injection pump to the associated engine. In addition, a fluid pressure operable device is provided to control the timing of injection of fuel to the engine, and the pressure for controlling the device is obtained from a point intermediate a fixed restrictor and a variable restrictor constituted by a groove formed in the shuttle and a port formed in wall of the bore accommodating the shuttle. Fuel from the outlet of the pump flows through the fixed and variable restrictors.