Abstract: A planet gear (9) connected to the input shaft (2a) and a planet carrier (13) connected to the output shaft (18) can be coupled by a clutch (18) operated in clamping by fly weights (29) and a spring (34) to bring about direct engagement. If clamping is insufficient for torque to be transmitted, the crown wheel (8) slows down and is then immobilized by the free wheel (16). The device then acts as a reduction gear, with a piston (44) acting on the housing (2) in the direction which will release the clutch (18) and applying a brake (43) preventing the crown wheel (8) from rotating even in the direction normally permitted by the free wheel (16). Narrow bleed ducts (151, 172) of a chamber (40) associated with a piston (44) and a damping chamber (171) prevent sudden variations in the state of the clutch (18).

Abstract: The coupling device, such as a clutch, comprises an alternation of first discs (22) made from hardened steel and having teeth (25) for rotational coupling with a first member of the clutch, and second discs (19) having teeth (15) for rotational coupling with a second member of the clutch.The discs (19) are made of carbon fibres embedded in a carbon former, with no support inside the disc.Use for improving the stability and progressive nature of the functioning of the clutch, and the longevity of the discs.

Abstract: Volumetric coupling (38) having multiple hydraulic pumps, controlled by a ring (40) which links the discharge side directly to the suction side for each pump when the coupling is uncoupled, and seals the discharge side when the coupling is coupled.

Abstract: A transmission apparatus in which a differential-type transmission device has rotating elements with intermeshing teeth, one of which elements is connected to an input shaft and the other to an output shaft. One of the rotating elements is a reaction element, and the transmission apparatus has a selective locking mechanism mounted operatively between the reaction element and a housing of the transmission apparatus. The selective locking mechanism has a free-wheel for enabling the reaction element to rotate in the same direction as the input shaft and the output shaft when a selective connection device connects the rotating elements of said differential mechanism in order to cause direct drive operation. When the freewheel is locked, the reaction element is integral in rotation with a rotor of a brake which is able to be selectively released in order to release the rotor and the reaction element in relation to said housing.

Abstract: A transmission device including a planetary gear train with a ring gear connected to the input, and a sun wheel counter-rotationally locked by a free-wheel. A planet carrier is connected to the output shaft. The ring gear and the planet pinion carrier my be coupled via a clutch which is compression-actuated by fly-weights to ensure direct drive. When the clutch is released by an axial thrust caused by the helical gearing and countering that of the fly-weights, the sun-wheel is immobilized by the free-wheel and the device operates as a reducing mechanism. The planetary gear train is arranged as an oil pump delivering through a duct and through the stack of clutch discs. When the clutch is actuated by the fly-weights, the delivery path is closed off, and the meshing motion between the gears forming the oil pump tends to be eliminated as a result. Therefore, the frictional process of the discs need only immobilize the gears to achieve direct drive.

Abstract: The transmission apparatus comprises serially mounted two-speeds modules. Each module is responsive to speed and torque for shifting up when speed is relatively high and/or torque relatively low, and for shifting down in the contrary case. Speed sensitivity is provided by flyweights tending to engage a direct drive clutch. Torque sensitivity for shifting down is provided by the clutch having a limited torque capability, depending upon the force produced by the flyweights. Torque sensitivity for shifting up is provided by the helical gear teeth inducing an axial thrust which is able, or not, to oppose engagement of the clutch by the flyweights. Such a transmission apparatus can dispense with a centralized control.

Abstract: An epicyclic train operates as a speed reducer between an input and an output when a clutch is released, and as a direct drive connection in the contrary case. The selective clamping is obtained by centrifugal weights, counter to biasing springs and to an helical teeth reaction force, which is proportional to the torque transmitted during speed-reducing operation. The reaction force promotes speed-reducing operation when the torque to be transmitted is high. Means are provided for applying a force pulse to the weights when the driver depresses the accelerator pedal. Since, upon a ratio change, the reaction force and the friction forces in the clutch vary so as to stabilize the newly created transmission ratio, a force pulse is enough for initiating a ratio change which will then be stabilized by a spontaneous variation of the reaction force and the friction forces.

Abstract: Four elements (9a, 9b, 11a, 11b) are mutually articulated as a parallelogram deformable according to four parallel axes (A1, . . . A4). A crank (31) causes a circular motion of a first co-ordination axis (K1) connected to one (9a) of the elements. Another element (11b) is articulated to the frame along a second co-ordination axis (K2). A variable volume chamber (17) is defined between the cylindrical surfaces (S1, . . . S4) whose axes (C1, . . . C4) intersect the longitudinal axes (Da, Db) of the first elements (9a, 9b). Distribution orifices (19, 21) are selectively open and obturated by the elements as a function of the angular position of the crank (31). A sparking-plug is provided. Each first element (9a, 9b) carries two cylindrical convex surfaces (S1, S2; S3, S4) the rigidely interconnected. Each cylindrical surface is in dynamic sealing relationship with a cylindrical surface belonging to the other element and whose axis (C1, . . .

Abstract: The speed-responsive clutch has axle-free rocking flyweights which are rockingly mounted in correspondingly shaped recesses of a cage. The rocking movement of the flyweights corresponds to a substantially radial movement of the center of gravity of the flyweights and to a substantially axial movement of an actuator portion of the flyweights for variably pressing friction disks of the clutch.

Abstract: A differential pinion shaft is coupled to the input shaft. A crown is coupled to the output shaft. The mechanical resistance of a compensated sub-assembly, multiplied by a gear, is transmitted to a planet wheel. The speed of rotation of the planet stabilizes and, as a result, the transmission ratio between the input shaft and the output shaft stabilizes when the two forces acting on the periphery of the pinion are equal, although they then correspond to a torque much larger on the output shaft than on the planet wheel, the couple on the planet wheel being greater than that on the shaft of the compensator sub-assembly. The sub-assembly comprises an inertial load and a consuming load the joint behavior of which, depending on the speed of rotation and on the acceleration, resembles, on a smaller scale, that of the vehicle.

Abstract: A multi-speed mechanical automatic transmission has two planetary gear trains, each including a sun gear, planet gears mounted in a planet carrier, and a ring gear. The first planetary gear train provides low gear and direct drive; the second train modifies low gear operation of the first train to provide an intermediate gear operation. The first sun gear is fixed to an input shaft, and the first planet carrier drives an output shaft. The second planet carrier is coupled to rotate the first ring gear in one direction, and free wheels or selectively actuated friction brakes prevent rotation of the first and second ring gears in the opposite direction. The first planetary train has helical gears, and a direct drive clutch selectively couples the first ring gear to the first planet carrier.

Abstract: A transmission (1) has an input (2) connected to an engine (3). At a speed above idling, a centrifugal clutch (9) connects the engine to a pump (8) of a torque converter (7) and also to a sun gear (14) of a planetary gear train (13). A turbine (11) of the torque converter is connected to a ring gear (16) of the planetary gear train, and a planet carrier (18) is connected to an output (4) of the transmission. A free wheel (22) mounted between the ring gear and a stationary housing prevents reverse rotation of the ring gear. At low engine speeds, the power passes via the sun and planet gears through the planet carrier to the output, while reaction torque exerted by the planet gears on the ring gear is greater than forward torque transmitted through the torque converter, so that the ring gear is held stationary by the free wheel. In this condition, the planetary gear train acts as a mechanical speed reducer.