Abstract: A torsional vibration damper comprising an input member for connection with a vehicle engine and an output member for connection with a vehicle transmission, the members being mounted for limited relative rotation about a common axis against a damping means comprising one or more circumferentially acting compression springs. Each spring acts between a first abutment formed as an integral part of the input member and a second abutment formed as an integral part of the output member. The damper may also include one or more elastomeric springs or blocks which are subjected to compression in end zones of the relative rotation of the input and output members. Other inventive features of the damper include support members for avoiding fouling of the elastomeric springs or blocks by the compression springs and the use of cantilevered pivot pins for the connection of bob-weight connecting linkages connected between the input and output members.

Abstract: A drum brake backplate assembly including a wheel cylinder (30) having a tubular body (31) having an axially extending bore (32) within which two brake shoe operating pistons (33) are in sealed sliding contact to define a working chamber (48) therebetween. The pistons are displaceable away from each other along the bore on pressurisation of the working chamber and the body located on an associated brake-backplate (44) by quick-attach means (46).

Abstract: A friction damping device (50) capable of generating friction torque for controlling the relative rotation of a first and a second flywheel mass of the twin mass flywheel (10), the friction damping device comprising a first (62) and a second (51) friction member operatively connected with one flywheel mass (12) via a common drive formation (cdf) which forms part of the second friction member. A third friction member (56) is sandwiched between the first and second friction members and is operatively connected with the other flywheel mass (11), and actuating means (61, 67) is operative to axially displace the first and second friction members relative to each other to modify the friction generated by the device upon rotation of the third friction member relative to the first or second friction members resulting from relative rotation of the flywheel masses.

Abstract: A twin mass flywheel for a vehicle comprising two coaxially arranged relatively rotatable masses interconnected by a plurality of pivotal linkages. Each linkage comprises a first link pivotally connected to one flywheel mass, a second link pivotally connected to the other flywheel mass and a pivot joining the links to move radially outwardly. A resilient torque member in each common pivot operable after a predetermined rotation between the flywheel masses to resist said relative rotation. A variable hysteresis friction damping assembly, whose resistance to relative rotation changes as the relative angle of rotation is altered, acts between the flywheel masses. The damping assembly can be provided by two friction damping plates which operate at different stages of rotation. The relative rotation may be limited by a stop member on at least one of the flywheel masses which abuts an abutment surface on the other flywheel mass. The abutment surface can be resilient for cushioning abutment by the stop member.

Abstract: A twin mass flywheel (10) having a friction damper (50) and a friction plate (55) with a shaped radially outer (55a) or radially inner first periphery which cooperates with a similarly shaped first periphery of a further component (54) of the damper to transfer torque between the friction plate (55) and the further component, the first periphery of the friction plate comprising a plurality of drive surfaces (55B), at least one of which is substantially tangential or chordal to the friction plate (55). The friction plate (55) may additionally have a second periphery with second drive surfaces tangential or chordal to the friction plate or it may additionally have drive formations formed as axially projecting lugs on an axially orientated surface of the friction plate. The friction plate (55) may be manufactured by sintering techniques or may have a sintered coating applied to its friction surface.

Abstract: A friction clutch having a clutch cover assembly (20) including a cover (21) attached to a flywheel (11) with at least one spring (12) acting on a pressure plate (13) to force a driven plate (15) into frictional engagement with the flywheel. The clutch also includes a number of lift straps (14) acting to move the pressure plate (13) away from the driven plate (15) when the clutch is disengaged and also includes at least one constant lift mechanism (50) which ensures that the pressure plate moves away from the driven plate by substantially the same amount during each full disengagement operation of the clutch. The constant lift mechanism includes a sensing device (55) acting to sense wear of the driven plate (15) by contact with the flywheel (11), a pin (51) fixed relative to the pressure plate (13), a stop device (56) acting to restrict the lift movement of the pressure plate, and a one-way locking device (60) acting on the pin which allows one way movement of the stop device when driven plate wear occurs.

Abstract: A power transmitting arrangement comprising a fluid coupling and, connected in parallel with the fluid coupling, a series arrangement of a clutch and at least one linkage arrangement (40), and upon engagement of the clutch the series arrangement directly connecting the fluid coupling input to the fluid coupling output. The linkage arrangement comprising at least an anchor link (42) mounted via a pivot (50) to the linkage arrangement input, a main link (41) mounted via a pivot to the linkage arrangement output (70). The anchor link and main link being connected together via a pivot so (60) that the linkage arrangement controls the relative rotation of the input and output of the power transmitting arrangement, when the clutch is engaged, as a result of centripetal forces acting on the links.

Abstract: A twin mass flywheel (10) in which two co-axially arranged flywheel masses (11,12) are mounted for limited angular rotation relative to each other and a plurality of pivotal linkages (40) interconnect the two flywheel masses. Each linkage comprises a first link (41) pivotally connected (43) to one (12) of the flywheel masses, a second link (42) pivotally connected (44) to the other (11) of the flywheel masses, and a pivot (45) for pivotally connecting the first and second links. A resilient member in the form of an elastomeric torsion unit (46) or spring (36) is associated with the pivotal connection (44) of at least one link (42) with its associated flywheel (11) for controlling the relative rotation of said flywheel masses (11, 12).

Abstract: A twin flywheel (210) comprising first (211) and second (212) co-axially arranged flywheel masses which are mounted for limited angular rotation relative to each other. The flywheel masses (211, 212) are interconnected by at least one linkage arrangement (240), comprising a multi-link linkage (240) having two or more circumferentially spaced main links (242, 251) pivotally mounted on the second flywheel masses with the or each circumferentially adjacent pair of main links interconnect via a generally circumferentially extending connecting linkage, and an anchor link (242) which connects the multi-linkage (240) with the first flywheel mass. Relative rotation of the flywheel masses (211, 212) causes the multi-link linkage (240) to be pivoted relative to the second flywheel mass by the anchor link, so that when the twin mass flywheel is rotating, relative rotation of the flywheel masses (211, 212) is resisted by centripetal forces acting on the linkage arrangement.

Abstract: A twin mass flywheel for a vehicle comprising two co-axially arranged relatively rotatable masses interconnected by a plurality of pivotal linkages. Each linkage comprises a first link pivotally connected to one flywheel mass, a second link pivotally connected to the other flywheel mass and a pivot joining the links to move radially outwardly. A resilient torque member in each common pivot operable after a predetermined rotation between the flywheel masses to resist said relative rotation. A variable hysteresis friction damping assembly, whose resistance to relative rotation changes as the relative angle of rotation is altered, acts between the flywheel masses. The damping assembly can be provided by two friction damping plates which operate at different stages of rotation. The relative rotation may be limited by a stop member on at least one of the flywheel masses which abuts an abutment surface on the other flywheel mass. The abutment surface can be resilient for cushioning abutment by the stop member.

Abstract: A clutch control system for the automatic control of a motor vehicle clutch which connects an engine with a gearbox under the control of a driver operated gear ratio selector lever. The control system controls both initial clutch take-up on starting of the vehicle, clutch re-engagement following each ratio change, clutch disengagement on movement of the gear selector lever to change the operative ratio of the gearbox, and clutch disengagement on the coming to rest of the vehicle. The clutch control system also warns the driver if he attempts to drive away in a designated non take-up gear or in any gear in a predetermined abusive manner and may be arranged to promote rapid engagement or disengagement of the clutch in certain abusive conditions to reduce energy generation in the clutch.

Abstract: An automatically adjusting clutch (10) in which a pressure plate (13) is biased axially towards a flywheel (11) by a main clutch engaging spring (12) to clamp a driven plate between the pressure plate and flywheel to engage the clutch. A first part (30) of the pressure plate is moveable by an adjuster relative to a second part in the form of a pivot ring (40) of the pressure plate to increase the effective axial thickness of the pressure plate to compensate for the wear of the driven plate. The adjuster having an array of adjuster teeth (44) which are disposed circumferentially around the pivot ring (40) and one or more pawls (60) which move relative to and in contact with the array as the pressure plate moves relative to the flywheel.

Abstract: A twin mass flywheel comprising two co-axially arranged flywheel masses which are mounted for limited angular rotation in a drive and over-run direction relative to each other, and a plurality of pivotal linkages. Each pivotal linkage comprises a first link pivotally connected to one of the flywheel masses, a second link pivotally connected to the other of the flywheel masses and a pivot pivotally connecting the first and second links. The action of the links controls relative rotation of the flywheel masses, and the controlling action of the links is supplemented by one or more assister springs which operate over a significant proportion of the full drive direction range of relative rotation. The twin mass flywheel may further include end stops to positively limit relative rotation of the flywheel masses in the drive and over-run directions and may additionally include end stop resilient means which cushion the relative rotation of the flywheel masses just prior to contact of the end stops.

Abstract: A clutch control system for the automatic control of a motor vehicle clutch (14) which connects an engine (10) with a gearbox (12) under the control of a driver-operated gear ratio selector member (24). The control system includes an electric control unit (36) which controls the level of clutch engagement in response to an engine speed error signal (E) derived from a comparison of current engine speed (Ve) and a reference speed signal (Vr) generated by the control unit. A sensing means (19a) is provided to detect a "foot-off" condition of an engine controlling accelerator pedal (19) and to provide and indication of the full range of movement of the accelerator pedal from the "foot-off" condition to the fully depressed position. The electronic control unit (36) responds to an accelerator pedal "foot-off" signal to ensure that the reference speed signal is above the engine idle signal by a predetermined amount to prevent creeping of the associated vehicle due to partial clutch engagement at engine idle.

Abstract: An actuation system for a vehicle in which a pump (10b) draws fluid from a reservoir (10a) to supply one or more first consumers, such as steering valve (50). One of more second consumers, such as a clutch actuator (12), are actuated via a solenoid valve (12a) from an accumulator (10c) charged by the pump. The solenoid valve connects each second actuator (12) to the accumulator or to the reservoir. When the pressure in the accumulator is below a predetermined charge pressure, flow to the first consumer is restricted to a level sufficient to ensure effective operation of the first consumer, while generating a back pressure sufficient to ensure charging of the accumulator. The flow restriction to the first consumer may be achieved by the solenoid valve (12a) or by a separate charging valve (20).

Abstract: A method and apparatus for producing an arcuate brake shoe from a first strip of material which is to provide a web of the shoe and has a plurality of projections extending from one edge and a second strip which has a plurality of corresponding openings to receive the projections and which is to provide the platform of the shoe. The two strips are secured together with projections and openings engaged and formed into an arcuate shape by passage through a roller arrangement.

Abstract: A twin mass flywheel sub-assembly comprising a pair of axially spaced side plates for connection with an associated first flywheel mass, a force transmitting member for connection with an associated second flywheel mass and being disposed at least partially between the side plates. A plurality of linkages connect the side plates and the force transmitting member, each linkage comprising a first link pivotally connected to the side plates, a second link pivotally connected to the force transmitting member, and a pivot for pivotally connecting the first and second links. The linkages being arranged to move in a generally radially outward direction as the sub-assembly rotates thereby controlling relative rotation of the side plates and force transmitting member. One of the flywheel masses may have cushioning springs to engage the other flywheel mass at the limits of relative rotation of the flywheel masses.

Abstract: A clutch control system for the automatic control of a motor vehicle clutch (14) which connects an engine (10) with a gearbox (12) under the control of a driver-operated gear ratio selector lever (24). The control system includes an electronic control unit (36) which controls initial clutch. take-up on starting of the vehicle, clutch re-engagement following each ratio change, disengagement on movement of the gear selector lever (24) to change the operative ratio of the gearbox (12), and clutch disengagement on the coming to rest of the vehicle. The level of clutch engagement is controlled in response to an engine speed error signal (E) derived from a comparison of current engine speed (Ve) and a reference speed signal (Vr) generated by the control unit, the error signal being compared with a current clutch position signal (Vc) to produce a clutch actuation signal (Vce).

Abstract: An operating lever mechanism for a master cylinder which includes a mounting bracket (12) and a lever (23) mounted on the bracket trough a pivot pin (22). The lever is connected to a master cylinder actuating rod (25) and the pivot pin (22) is adjustably mounted on the bracket in slots (27) so that by turning an adjuster wheel (31) the pin (22) is moved in the slots (27) to vary the distance between the pivot axis of the lever and the connection of the lever with the master cylinder actuating rod (25) to adust the operating lever ratio of the mechanism as desired.

Abstract: A clutch control system for the automatic control of a motor vehicle clutch which connects an engine with a gearbox under the control of a driver-operated gear ratio selector lever. The control system includes an electronic control unit which controls initial clutch take-up on starting of the vehicle, clutch re-engagment following each ratio change, clutch disengagment on movement of the gear selector lever to change the operative ratio of the gearbox, and clutch disengagment on the coming to rest, etc. of the vehicle. The control system also incorporates an automatic calibration routine which is invoked on the inital keying-on of the system, said routine comprising a predetermined sequence of events in which the system responds to actions of the operator and at predetermined that the system is ready to proceed to the next stage of the calibration.