Abstract: A compound disc brake comprises a pair of pressure plates with a ball and ramp camming mechanism, one of the plates comprises a driven plate keyed to a rotating axle shaft to be braked, and the other plate comprises an input plate carried from the driven plate by the camming mechanism. The input plate is of larger diameter than the driven plate with its radially outer region comprising a torque-transmitting mechanism which transmits torque applied to that region by primary braking device, which can be a spot brake, to the central region of the input plate. Retardation of the input plate by the primary braking device causes the pressure plates to separate axially and move into engagement with relatively stationary braking surfaces in a brake housing whereafter servo braking occurs. Various multi-plate embodiments are disclosed, including embodiments in which the torque-transmitting mechanism is a separate annular disc keyed to the outer peripheral edge of the servo plate.

Abstract: A circuit for processing a high frequency output signal from a variable reluctance transducer, this signal including an unwanted low frequency component, comprises a comparator having a first input receiving the transducer signal and a second input receiving the same transducer signal but via a low pass filter. The comparator therefore provides an output representing the high frequency variations in the transducer signal and substantially unaffected by the low frequency component. Alternatively, the transducer signal may be applied to a circuit providing a first output signal varying as the low frequency component and also providing a second output signal varying as the high frequency variations in the received transducer signal, the first output signal being used as a feedback control which tends to render the second output signal free of low frequency variations.

Abstract: A disc assembly for a vehicle disc brake has a rotor with a pair of opposite faces from which are mounted annular braking discs. Each disc is mounted for limited radial movement on a carrier device by fasteners located outside the braking area of the disc; and the disc and the carrier device have complementary radial abutment faces, the carrier device being mounted on the rotor by connectors. The brake torque is transmitted from the discs to the carrier device by the abutment faces and then to the rotor by the connectors. This provides a simple construction which reduces stress on the discs and permits and guides radial expansion of the discs during braking.

Abstract: A line driver is provided for driving a twisted pair of lines with complementary data signals. The driver comprises NPN and PNP transistors arranged as complementary emitter followers with their emitters connected to a biasing resistor network to provide an arrangement capable of being used as a "wired-or" output.

Abstract: An improved manufacturing method produces small orifices in a succession of work pieces according to a desired flow specification. After the work pieces are subjected to one or more preliminary processing steps, an apparatus, preferably an electro discharge machine, is used to produce a small orifice in each work piece. A gas, preferably nitrogen, is flowed through the orifice produced in a work piece, and the pressure drop of the gas flowing through the orifice is measured, preferably by a pressure gauge capable of providing both a visual display for a human operator and an electrical signal for a microprocessor. The pressure drop is compared to a correlation of pressure drop and the desired flow specification. The results of the comparison are used to determine whether an adjustment is needed to the apparatus and/or one of the preliminary processing steps.

Abstract: A depowering apparatus for controlling selection and deselection of devices, such as a pair of torque motors, comprises two channels. Each channel has a normally open switch in series with a normally closed switch connecting a power supply line to the torque motor. A control circuit in each channel closes the normally open switch of that channel and opens the normally closed switch of the other channel in response to a channel select signal so as to ensure that each of the torque motors can be depowered to allow the other to take control.

Abstract: A geared rotary actuator comprises at least two axially aligned compound epicyclic gear trains driven by an input shaft so that output ring gears in each train rotate relatively. Sun gears in adjacent gear trains are drivingly coupled to the input shaft through a differential device which permits limited rotational displacement between the sun gears. An element, for example an aircraft lift control surface, may be mounted on one set of the ring gears by means of spindles which extend normally of a plane which includes the axes of the ring gears, so that as a result of stresses therein the element may tilt locally about the spindles.

Abstract: A vehicle dual wheel braking system of the type in which a respective electronically controlled pressure adjustment channel is provided for each of the wheels at the opposite ends of an axle of the vehicle for setting the braking pressures individually for each wheel in dependence upon a common electrical signal representative of the braking demand level set by a driver of the vehicle, each channel comprising a pressure control loop containing a pressure controller, a pressure control valve which adjusts the supply of fluid from a reservoir to the brake actuators for applying and releasing the brakes by solenoid control of the inlet and exhaust functions of the pressure control valve, and a feedback transducer which supplies a signal representative of the pressure in the pressure control valve.

Abstract: A vehicle braking system wherein, for avoiding serious brake unbalance under fault conditions which would cause either loss of braking or excessive braking at one wheel, a small bore link pipe is arranged to connect the pressure control elements, for example solenoid actuated relay valves, of respective brake circuits associated with the two wheels at opposite ends of an axle whereby the pressure control elements in each electronically controlled pressure adjustment channel are influenced in such a manner that a correctly functioning channel attempts to influence a faulty channel in such a direction as to reduce the pressure unbalance.

Abstract: A drum brake in a motor vehicle, comprising a parking brake which includes a brake cable connected detachably to a hand brake lever arranged in the drum brake by the brake cable being passed through a retaining member which is connected to the hand brake lever an engaging behind the retaining member by a nipple of larger cross sectional dimensions connected to the corresponding free end of the brake cable is characterized in that the brake cable (6) is passed through a guide tube (7) which is fixed to the anchor plate (1) of the drum brake, is exposed to the outside of the drum brake, and terminates at a distance ahead of the retaining means (8), the inner diameter of the guide tube (7) being somewhat greater than the maximum outer diameter of the nipple (9), in that the retaining member (8) has a guide path (10) for the nipple (9) extending from its front face (11) which faces the guide tube (7) to its rear face (12), and in that rear face ( 12) of the retaining member (8) is provided with a locking member (

Abstract: An electronic braking system for a towing vehicle for towing a standard semi-trailer without such a braking system has a separate pressure control channel for the generation of trailer brake pressure whenever the towing vehicle is braked or if the parking brake of the towing vehicle is applied. The pressure signal level set in the towing vehicle is a function of the driver's electrical demand signal, compensated for trailer load and operating gradient. The compensation for trailer load is evaluated by assessing the total trailer mass from measurements of towing load during acceleration and substracting from this value the portion of the trailer load being supported by the towing vehicle as sensed by vertical force protection means on the towing means.

Abstract: An adaptive control system is provided for an internal combustion engine having at least two control inputs which affect an engine output. The system involves establishing a first base value for a first control input as a function of engine operating conditions and establishing a second base value for a second control input as a function of engine operating conditions. Corrections are applied in accordance with a predetermined control strategy to the first base value and the second base value to obtain a first corrected value for the first control input and a second corrected value for the second control input. A particular control input is periodically perturbed, and the engine output is monitored. The actual slope or differential of the engine output with respect to the particular control input is determined.

Abstract: A system for regulating the idling speed of an internal combustion engine comprises a circuit for generating the ignition spark, when the engine is idling, upon expiry of a predetermined time delay from an initial crankshaft position, which circuit is enabled only after the crankshaft has reached a first limiting position, and enforced when the crankshaft reaches a second limiting position if the time delay has not expired. The spark timing therefore varies smoothly with speed between the first and second limiting positions of the crankshaft, but being retarded to the second limiting position for large over-speed errors or advanced to the first limiting position for large under-speed errors. It also reverts to the second limiting position for speeds below half normal idling speeds (cranking speeds).

Abstract: A vehicle brake has a fixed backplate carrying a pair of friction elements and an actuator operable to urge the elements into braking engagement with a rotary braking surface. An abutment for the elements has a portion which is deflectable by load on the elements arising from braking torque. A radiation input device directs radiation at a surface of the deflectable portion and a device is provided to sense radiation after its impingement on the portion and to transmit the sensed radiation to a device producing a responsive electrical output representing deflections of the portion.

Abstract: A running control for a gas turbine engine includes a fuel control responsive to an input signal which corresponds to a desired rate of change of engine speed. A speed governor circuit generates a first output signal corresponding to a difference between demanded and actual speeds. Limit signal generators provide second and third signals which correspond to permitted acceleration and deceleration respectively. The second and third signals are integrated and a selected one of the first, second or third signals is applied to the fuel control. At least the integrator for the second signal can be reset by a feedback arrangement which modifies the integrator input in accordance with a difference between the desired rate of change of engine speed and the second signal.

Abstract: The present invention provides a friction pad assembly wherein an edge region of the backing plate has two recesses located symmetrically about a center line (11) of the assembly with a resilient leaf spring secured across each recess (13). In use, in a disc brake retaining pins engage against the springs to hold the assembly in position. This pad assembly design thus minimizes the required space by locating the resilient pad anti-rattle springs within the profile and sides of the backing plate, and by using the necessarily relatively short springs, the tendency for the springs (19) to be buckled or distorted, or affected by heat, is minimized.

Abstract: A fuel pumping apparatus for supplying fuel to an internal combustion engine includes a pumping plunger mounted in a bore and movable inwardly by an engine driven cam to displace fuel through an outlet to an injection nozzle. The quantity of fuel supplied to the nozzle is controlled by a spill valve. The apparatus also includes a restricted flow path through which fuel can flow to reduce the initial rate of fuel delivery through the nozzle, the flow path including a valve formed by the plunger and the bore so that fuel can flow through the flow path only during the initial inward movement of the plunger.

Abstract: A clamp for a fuel injection nozzle of an internal combustion engine includes a beam element which is forked at one end for engagement with surfaces on the nozzle and at its other end engages a reaction member. Intermediate its ends the beam element is apertured to receive a threaded member engaged with the cylinder head of the engine whereby the nozzle is clamped in a bore in the cylinder head. The beam element is formed from strip material and is dimensioned so that the force which can be applied to the nozzle is limited by the elastic deformation of the beam element.

Abstract: In an anti-lock brake system (ABS) for a motorcycle the driving stabilty is improved by measuring the position of lateral inclination of the motorcycle and adjusting at least one threshold value for the anti-skid control in response to the measurement. In another embodiment the transverse acceleration of the motor cycle is measured and an ABS threshold value adjusted accordingly.

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.