Abstract: Synchronizing device (1) of a gear changing transmission for a vehicle. The synchronizing device includes an inner synchronizer ring (2), a middle synchronizer ring (3) and an outer synchronizer ring (4), wherein in the operating mode the outer synchronizer ring (4). The inner synchronizer ring (2) includes a first conical inner ring body (201) with a first inner surface of the inner ring (2011) and a first outer surface of the inner ring (2012), which each bound the first inner ring body (201) in a radial direction extending to an axial ring axis (8), wherein the first inner surface of the inner ring (2011) extends at a first inner angle (?2011) of the inner ring and the first outer surface of the inner ring (2012) at a first outer angle (?2012) of the inner ring to the ring axis (8). In order to further increase the synchronizing moment to be transmitted the first inner angle (?2011) of the inner ring is smaller than the first outer angle (?2012) of the inner ring according to the invention.

Abstract: A shift device has thrust pieces to change force in a radial direction to thrust when they swing relative to and contact with a hub. The thrust pieces respectively are fixed with holders each containing a ball and a spring. The springs elastically press the balls outwardly in the radial direction against the groove of the shift sleeve, pressing the radially inner surfaces of the thrust pieces on the guide surfaces of the hub through the holders to be configured in such a way that a clearance between the radially outer surfaces of the thrust pieces and the inner surface of the shift sleeve is ensured and the thrust pieces can swing being guided along the guide surfaces.

Abstract: A shift device includes a shaft, a hub, a sleeve, a pair of speed gears sandwiching the hub, a first synchronizer ring, a second synchronizer ring, a plurality of thrust pieces disposed in cut-off portions of the hub and a pair of springs pushing the thrust pieces outwardly in a radial direction toward the sleeve. The thrust pieces move together with the sleeve when the sleeve is moved toward the one of the speed gears, while the thrust pieces moves inwardly in the radial direction against the first and second springs when the sleeve is moved halfway toward the other of the speed gears so that the thrust pieces move in an axial direction and swing to provide different self-servo functions according to the above shift directions when they contact with the hub.

Abstract: A power transmission apparatus includes a first power transmitting member, a second power transmitting member, a synchronizer ring, arranged between the first power transmitting member and the second power transmitting member, a sleeve held at the first power transmitting member, a synchronizer key arranged between the first power transmitting member and the sleeve, and a drag restricting member arranged between the first power transmitting member and the sleeve. A synchronizer ring engaging portion is formed at a side of the drag restricting member facing the second power transmitting member so as to protrude in the radially inward direction, and a drag restricting engagement portion is formed at the outer circumferential surface of the synchronizer ring at a side thereof facing the first power transmitting member, the drag restricting engagement portion being engageable with the synchronizer ring engaging portion.

Abstract: A gear has a hub with cut-off portions and outer splines as one unit. Thrust pieces are inserted in the cut-off portions for transmitting thrust between a shift sleeve and a synchronizer ring. The gear has a flange portion formed with supporting holes corresponding to the cut-off portions provided with a force-amplifying slope at synchronized member sides thereof. First end portions of the thrust pieces are inserted in the supporting holes. Second end portions thereof are formed with a side end surface for receiving friction torque from the synchronizer ring and with a pressure-receiving slope for transmitting the friction torque to the force-amplifying slope. The thrust pieces swing around centers in the supporting holes so that the second end portions swing in a rotational direction to contact the pressure-receiving slopes with the force-amplifying slopes to change the friction torque to the thrust acting on the synchronizer ring.

Abstract: A shift device includes a hub, a sleeve splined with the hub, and a pair of speed gears sandwiching the hub. Thrust pieces are respectively inserted in the concave portions of the sleeve and movable in the notches of the hub in an axial direction, and formed with slanted surfaces on their outer circumference for contacting with slanted surfaces of the sleeve, and contact with projections of synchronizer rings so that the thrust pieces can move around the projections and push the projections in the axial direction. The thrust pieces are also formed with projecting portions at their four edges, seen from an outside of the hub in a radial direction, the projecting portions being formed with slanted surfaces corresponding to the slanted surfaces of the hub.

Abstract: The object of the present invention is to provide a synchro-spring to be used in a synchronizing mechanism having insert-shifting keys. Said synchro-spring is characterized by shaping convex forms in the portions which come into contact with said insert-shifting keys, and when this synchronizing mechanism is used for an automobile transmission, an enough capacity of the synchronizer ring can be ensured without increasing the size of the synchronizing mechanism, and smooth gear shifting is attained, and then excellent operability can be acquired.

Abstract: A power transmission system is provided which can prevent a feeling of inertia travel due to torque transmission interruption occurring when a dog clutch is engaged to shift the speed position, without increasing the axial length of a transmission. An input shaft is connected to a prime mover via a main clutch. Gear pairs are formed by input and output gears arranged on the input shaft and output shafts, respectively. A dog clutch connects one of the gear pairs to the input or output shaft. An auxiliary shaft is connected to the prime mover. Transmission paths are formed on the auxiliary shaft for transmitting the driving force of the prime mover to the output shaft at different gear ratios. In shifting the speed position, an assist clutch supplies the driving force to the output shaft via the auxiliary shaft and a selected transmission path.

Abstract: The object of the present invention is to provide a synchro-spring to be used in a synchronizing mechanism having insert-shifting keys. Said synchro-spring is characterized by shaping convex forms in the portions which come into contact with said insert-shifting keys, and when this synchronizing mechanism is used for an automobile transmission, an enough capacity of the synchronizer ring can be ensured without increasing the size of the synchronizing mechanism, and smooth gear shifting is attained, and then excellent operability can be acquired.

Abstract: A dual synchronization system of a manual transmission constructed in the dual set of a plurality of keys to be attached to the internal side of a synchronizer sleeve by a synchronizer ring, first and second key sets being positioned apart at a predetermined degree of angle along the circumferential direction of a synchronizer ring, wherein the first key set attaching the synchronizer ring close to a clutch gear at the initiation of synchronization and the second key set pushing the synchronizer ring close to the clutch gear after the completion of synchronization, thereby continuously maintaining the frictional force between the synchronizer ring and the clutch gear to achieve stable shifting feelings.

Abstract: A dual synchronization system of a manual transmission constructed in the dual set of a plurality of keys to be attached to the internal side of a synchronizer sleeve by a synchronizer ring, first and second key sets being positioned apart at a predetermined degree of angle along the circumferential direction of a synchronizer ring, wherein the first key set attaching the synchronizer ring close to a clutch gear at the initiation of synchronization and the second key set pushing the synchronizer ring close to the clutch gear after the completion of synchronization, thereby continuously maintaining the frictional force between the synchronizer ring and the clutch gear to achieve stable shifting feelings.

Abstract: Disclosed herein is a manual transmission synchronizer for automobiles. The manual transmission synchronizer is operated in such a way that a sleeve engaged with a clutch hub is moved in the direction of the manipulation of a gearshift lever by the manipulation of the gearshift lever, synchronizer keys push a synchronizer ring due to the movement of the sleeve, the synchronizer ring is brought into tight contact with and synchronized with the cone portion of a clutch gear by the pushing of the synchronizer ring, and the gear portions of the synchronizer ring and the clutch gear are moved into and engaged with the inner gear portion of the sleeve, thereby performing the shifting of gears.