Abstract: The invention proposes a detection device including a selector linkage with a gear change lever, with which are associated a force threshold detector, a first analog position detector connected to gear shift means, and a circuit for firstly activating an automatic clutch actuating system and secondly processing information received by the threshold detecting means and the first detector. A second analog position detector is connected to line selector and is responsive to information applied to the gear change lever, the second detector being connected to the processing and control circuit.

Abstract: A control mechanism for a machine element of the type including a fixed part and a movable part movable between two limit positions, e.g. an automotive vehicle clutch. A spring biasses the movable part to one of its limit positions. The control mechanism comprises a linkage for controlling the displacement of the movable part between its limit positions. A motor drives the linkage, and a resilient device is coupled to the linkage for reducing the force applied by the motor for displacing the movable part between its limit positions.

Abstract: The invention provides a method for controlling a clutch fitted with motorized actuation by means of a pulse-fed direct-current electric motor. According to the invention, the control system of the electric motor comprises a microcomputer associated with a memory, in which values defining the duration of the control pulses of the clutch are stored, and these values can be updated during the operating life to take into account ageing and wear. The invention is particularly suitable for automatic clutch control in an automobile.

Abstract: A control mechanism for a coupling device such as a clutch or variable speed drive or brake comprises an electric motor. A mechanism links the electric motor to an actuator device for the coupling device. A brake device is coupled to this linking mechanism. The brake device is also coupled to the drive shaft and comprises two friction pads at diametrally opposed positions relative to the drive shaft in contact with the drive shaft. A spring urges the pads towards the drive shaft substantially radially. The brake device comprises a casing rotationally immobilized relative to the drive shaft, which passed through the casing, which encloses the two friction pads. The casing has a back wall and one of the pads is disposed between the drive shaft and this wall. The other pad is slidably disposed in the casing and pressed against the drive shaft by the spring, which is prestressed in compression.

Abstract: A device detects forces in a gearbox operating linkage in order to control an automatic clutch operating system for the purpose of changing the gear ratio. The linkage comprises a shaft in the gearbox adapted to rotate between two limiting positions corresponding to selection of respective different gear ratios. It also comprises a deformable linkage element in the force detecting device adapted to move between two limiting positions corresponding to the limiting positions of the shaft. This deformable linkage element comprises two portions coupled together elastically by an elastic return device. The force detecting device comprises a speed parity detector adapted to assume a parity state representing the position of the shaft and varying according to which of its limiting positions the shaft is in.

Abstract: In a method of automatically operating a clutch release bearing to re-engage a friction clutch adapted to transmit between first and second shafts a torque conditioned by the action of the release bearing on a clutch release device associated with the clutch, the clutch release bearing has a predetermined total travel. This extends between a clutch released position in which no torque is transmitted between the shafts and a clutch engaged position in which the shafts are coupled together in rotation. The clutch release bearing is moved according to speed modes selected from a plurality of predetermined speed modes according to the rotation speeds of the first and second shafts or the gear ratio. During a first phase the clutch release bearing is moved in accordance with a first or fast speed modes over at least a predetermined approach travel. Beyond this the changing difference between the rotation speeds of the two shafts is monitored.

Abstract: The wear take-up assembly comprises ratchet engagement device (51) which is interposed between a toothed sector (42) and a lever assembly (19). The toothed sector (42) co-operates with a positioner operating member (20) and resilient force moderator member (21). The lever assembly (19) acts on the clutch by way of the fork (41) and the thrust member (18). The lever assembly (19) advantageously, comprises two levers (49 and 50) so arranged as to amplify the movement of the lever (49) which co-operates with ratchet engagement device (51) so as to permit a fine wear take-up action.

Abstract: The control device comprises an electric motor-gearbox unit (2) acting on the thrust bearing (16) of a clutch (1) and a switching device (3) comprising four transistors adapted to apply the voltage from the battery (30) with either polarity to the motor (20) of the motor-gearbox unit (2) according to whether the output of "AND" gates (41 and 42) is at 1. This occurs, when end of travel switches (28 and 29) are closed, when positive pulses appear at the output (40c) of the microprocessor (40) and according to whether the output (40d) is at "0" or "1". The microprocessor produces pulses of defined duration at its output (40c) with a recurrence frequency which is a direct function of the frequency produced by the sensor (50) responsive to the rotation speed of the motor when above a threshold higher than the idling speed, in the clutch engagement phase, and which is such in the clutch release phase that the pulses are adjacent.

Abstract: A braking system of the kind which comprises, for each front axle and each rear axle, at least one servo-operated control valve actuated by an anti-locking circuit which comprises a monitoring part and a control part, the electrical supply of the former being regulated by a safety switch controlled by the latter.According to the invention, the safety switch linked to the front axle is in series with the safety switch linked to the rear axle and is downstream thereof in relation to the corresponding current source. This de-activates the anti-locking circuit of the front axle in the event of failure of the anti-locking circuit of the rear axle, thus minimizing the possibility of locking of the rear wheels only during braking.