Abstract: A differential mechanism (10) having two output cam members (16, 17) rotatable about an axis (A) each cam member having an annular cam surface of undulating form comprising pairs of mutually inclined surfaces (24, 25; 26, 27). The inclined surfaces are engaged by end surfaces (29, 30) of cam followers (28) so that relative contra rotation of the output cam members (16, 17) causes the cam followers to slide axially. An input element (11-14) engages and supports the followers (28) and moves the followers circumferentially relative to the output cam members and a component (11, 14) of the differential which rotates during use of the differential drives oil pump means (70) for forcing oil into the differential.

Abstract: A differential mechanism having two output cam members rotatable about an axis (X--X), each cam member having a single annular frustoconical cam surface thereon of undulating form comprising pairs of mutually inclined surfaces and a plurality of cam followers having end surfaces engaging the cam surfaces of the output cam members. Relative contra rotation of the output cam members causes the cam followers to slide axially and an input member engages the followers which are slidably supported by the input member and moves the followers circumferentially relative to the output cam members. A locking means is also provided for locking the output cam members and/or the input member against relative rotation to lock up the differential mechanism.

Abstract: A differential mechanism has two output cam members rotatable about an axis, each cam member having a single annular cam surface of undulating wave form comprising equal numbers of pairs of mutually inclined surfaces. A plurality of cam followers having end surfaces engage the cam surfaces of the output cam members, the arrangement being such that relative contra rotation of the output cam members causes the cam followers to slide axially. At least two different types of cam followers are provided and the number of followers is an integer multiple of the number of pairs of inclined surfaces. An input member slidably supports the followers and moves the followers circumferentially relative to the output cam members. Arrangements are also disclosed for pumping oil into the differential and for locking up the differential.

Abstract: A differential mechanism having two output cam members rotatable about an axis, each cam member having a single annular cam surface of undulating form comprising pairs of mutually inclined surfaces. The inclined surfaces are engaged by end surfaces of followers so that relative contra rotation of the output cam members causes the cam followers to slide axially. An Input element engages and supports the followers and moves the followers circumferentially relative to the output cam members. The input element engages with a radially inner portion of each cam follower to move the follower circumferentially relative to the cam output members, and the cam surfaces are inclined away from the axis of rotation.

Abstract: A differential mechanism having two output cam members, each having a single annular cam surface with pairs of inclined surfaces. Relative contra rotation of the output cam members cause cam followers to slide axially, and a housing engages the cam followers which are slideably supported by the housing moving the followers circumferentially relative to the output cam members. The two cam output members are thrust axially against the housing during drive of the cam output members through the followers and at least one cam output member acts against the housing through a friction thrust washer. This mechanism allows control of the torque ratio between inside and outside output shafts of a vehicle when turning a corner.

Abstract: A motor vehicle has a manually operated change speed gearbox driven by an internal combustion engine through a clutch which is automatically disengageable and re-engageable by operation of a power hydraulic clutch control. The hydraulic control comprises a fluid reservoir connected by a conduit to a control valve connected to the reservoir by a conduit which includes a pump and a one-way valve and a pressure accumulator and a piston and cylinder or fluid pressure operated actuator connected by piping to the control valve. The clutch is operated by the actuator causing disengagement of the clutch when the control valve is operated to relieve fluid pressure in the actuator. The hydraulic control is assembled and filled with hydraulic fluid at some place which can be distant from the vehicle manufacturer's production line. The filled control is transported to where the vehicle is being made and the control is installed in the vehicle; possibly after the filled control has been stored first.

Abstract: The differential comprises a drive input element, two output cam members each rotatable about a common axis, each cam member having a single angular cam surface thereon of undulating form arranged such that the cam surfaces on the cam members converge towards each other and a plurality of cam followers. The followers have cam engaging end surfaces for imparting drive from the input element to the output cam members. Relative contro-rotation of the output cam members causes the cam followers to slide axially. The cam followers are elongate in direction of the common axis and are slidably supported throughout virtually their entire length by the drive input element. The followers may be arranged closely adjacent each other to provide a degree of mutual support.

Abstract: A motor vehicle having a transmission comprising a clutch (14), a clutch control (18, 20) and a change-speed gearbox (12). The gearbox (12) has a plurality of mutually exclusively engageable gear ratios any desired one of which can be engaged by a manually operated gear lever (16) which comprises a shaft (33) pivoted at (34) and a hand knob (42) on a tube (40) rockably pivoted in force relatively to the shaft (33), a signal is sent to the clutch control (18, 20) causing automatic disengagement of the clutch (14). Further manual force on the tube (40) pivots the shaft (33) in direction (A) or (B) to the opposite side of a gear shift pattern. The clutch control (18, 20) receives a signal (54') that a new gear ratio has been engaged and automatically reengages the clutch (14).

Abstract: A transmission comprises first and second input shafts which are drivable respectively from independently operable first and second clutches. Gearing is provided which enables drive to be transmitted from the input shafts to an output via a layshaft. Further gearing is provided on a further layshaft for selection of reverse ratio. In reverse ratio the further gearing is in a drive path which includes the first and second input shafts. The further gearing includes synchronizer means to facilitate selection of reverse ratio.

Abstract: An electro-hydraulic control system is intended for the kind of automatic power transmission which comprises at least three forward gear ratios and in which ratio changes are effected under power by releasing one clutch interconnecting the transmission input and output through one engaged gearset simultaneously with engaging another clutch interconnecting the input and output through another engaged gearset. The control system comprises hydraulic gear actuators each for engaging and disengaging a separate gearset. Electro-hydraulic valves control the supply of hydraulic fluid to the actuators in response to ratio selection signals derived in an electronic control. One set of electro-hydraulic valve states is arranged to engage first and second gearsets while a second set of electro-hydraulic valve states is arranged to engage both second and third gearsets.

Abstract: A transmission comprises gear trains which provide increasing speed ratios and two clutches which are operable independently to provide alternative paths through the gear trains between an input and an output. The gear trains provide alternate ratios driven respectively through one and the other clutch. The input comprises a first shaft drivable by one clutch and a shaft drivable by the other clutch. A layshaft is provided through which drive in a selected ratio is transmitted from one of the first and second shafts to the other to drive the output which is also a shaft. One of the first and second shafts has a gear thereon which meshes with a gear on the output shaft.

Abstract: Concentric piston and cylinder components of a hydraulic slave cylinder used with a clutch release bearing have their axial movement under a biassing spring limited by latch means in the form of flanges. The flanges each have a radial face and a chamfered face, and one flange is radially deformable, being on a slotted cylindrical extension. The radially deformable flange allows the cylinder to be rapidly assembled without the need for assembly of a separate retaining device.

Abstract: A hydraulic pressure control valve for a fluid pressure operated clutch includes a piston responsive to a pilot control pressure as a proportion of source pressure and feedback pressure indicative of fluid pressure in the clutch to connect the clutch to source pressure whenever pilot pressure exceeds feedback pressure and to connect the clutch to drain whenever feedback pressure exceeds pilot pressure.

Abstract: A rotary transmission is of the dual clutch kind and includes three gear trains through which the clutches providing alternative drive paths between a common input shaft and a common output shaft. One clutch drives the output shaft either through a two-wheel gear train or through a three-wheel train of which the first wheel is a gear wheel driven directly from the input shaft, the second wheel is a gear wheel interengaged with the first wheel and journalled on the output shaft and the third wheel is a sleeve wheel journalled on and engageable with the output shaft so that the second wheel drives the output shaft through the sleeve wheel. The other clutch is arranged to drive the output shaft either through a two-wheel gear train of which the second gear wheel is provided by the sleeve wheel or through a six-wheel gear train of which all the gear wheels are members of the first, second and third mentioned trains.

Abstract: A rotary transmission has an input shaft, an output shaft, two layshafts, two drive clutches and gear trains selectively engageable by dog clutches to transmit drive from the input shaft to the output shaft according to the state of engagement of the drive clutches and dog clutches. A transfer gear train and dog clutch is provided for drive between the layshafts, a further dog clutch being provided between one of the layshafts and the output shaft. The transmission provides six sequential speed ratios with pre-selection of adjacent ratios, alternate speed ratios being driven respectively through one and the other clutch.

Abstract: A rotary power transmission having a series of up to five gear trains and two clutches alternately engagable to provide drive paths through the gear trains in series sequence has control means including a fluid pressure source and three solenoid-operated valves to direct source fluid to two spool valves which provide discrete fluid pressure signals for engagement of gear trains two at a time in progressively over-lapping pairs, the gear trains being for eventual drive according to clutch engagement.

Abstract: An internal drum brake of the kind including a strut between a hand brake lever pivoted on one shoe and the other shoe, has a wear adjuster comprising a pair of screw-threaded members with a pawl and pawl wheel for relative rotation thereof on operation of the service brake system, the axis of the screw-threaded members intercepting the line of action between the shoe and an abutment which limits return movement of the shoe to a brake-released position, one of the members having a spacer between the shoe and the abutment, the spacing effect of the spacer being changed on relative rotation of the screw-threaded members.

Abstract: A vehicle brake system fluid modulating valve has a main piston acted upon by a control spring and master cylinder pressure on one hand and an opposing brake system on the other hand. A slave piston is also acted upon by the master cylinder pressure, and is arranged to control an operating point at which the main piston effects brake pressure modulation. This control is effected by cutting off the master cylinder pressure to the slave piston when the operating point is reached. Electrical transducers sense vehicle load and master cylinder pressure, respectively, and their output signals are processed by a comparator for consequential operation of the valve to cut-off the master cylinder pressure to the slave piston. The operating point is altered by balancing the master cylinder pressure signal in response to changes in the vehicle load signal.

Abstract: A vehicle brake pressure proportioning valve has a stepped proportioning plunger movable by brake pressure against a loading spring. A control plunger subject to pressure from an inlet port co-operates with a metering valve associated with the proportioning plunger. For low inlet pressures both plungers move together and there is no significant pressure drop through the valve but at a particular vehicle deceleration a control mass moves to hydraulically lock the control plunger and allow full operation of the metering valve. A control spring acts on the control mass with a force which, at the time of hydraulic locking, varies according to the distance moved by the control plunger and, by inference, the weight of the vehicle.

Abstract: A transmission comprises gear trains which provide increasing speed ratios and two clutches which are operable independently to provide alternative paths through the gear trains between an input and an output. The gear trains provide alternate ratios driven respectively through one and the other clutch. The input comprises a first shaft drivable by one clutch and a shaft drivable by the other clutch. A layshaft is provided through which drive in a selected ratio is transmitted from one of the first and second shafts to the other to drive the output which is also a shaft. One of the first and second shafts has a gear thereon which meshes with a gear on the output shaft.