Shift device with synchronizer

A shift device with a synchronizer comprising:

• a shaft;
• a hub having a boss portion fixed to the shaft, a flange portion extending from the boss portion outwardly in a radial direction, and an annular portion formed with outer splines on an outer side thereof, the annular portion and the flange portion being formed at two sides of the hub in an axial direction with a plurality of cut-off portions, and the cut-off portions being provided on the two sides in a rotational direction thereof with a first guide surface;
• a shift sleeve that is formed on a circumferential surface thereof with inner splines having slanted surfaces, the inner splines of the shift sleeve being engaged with the outer splines of the hub in such a way that the shift sleeve is movable in the axial direction;
• a pair of speed gears that are arranged at the two sides in the axial direction of the hub to be rotatably supported on the shaft, the speed gears being provided at each hub side thereof with a cone surface and outer splines engageable with the inner splines of the shift sleeve;
• a pair of synchronizer rings that are respectively arranged between the hub and the speed gears, the synchronizer rings being provided with a friction surface capable of being pressed selectively by one of the cone surfaces of the speed gears, and the synchronizer rings being provided at hub sides thereof with a plurality of projections projecting in the axial direction and a plurality of pressure receiving surfaces;
• and
• a plurality of lever members that are arranged at the two sides of the hub among the shift sleeve, the hub and the synchronizer rings, the lever members having a top portion engaged with a corresponding one of the cut-off portions of the hub and contactable with a corresponding one of the slanted surfaces of the shift sleeve to function as a point of effort of leverage, a first portion contactable with the hub functioning as a fulcrum of the leverage, a second portion connectable with the shift sleeve to function as a point of load of the leverage to transmit pressing force from the shift sleeve to a corresponding one of the pressure receiving surfaces in a leverage operation, and the lever members being capable of receiving friction torque from the projections of the synchronizer rings, wherein
• the lever members includes a plurality of first lever members configured to press a first one of the synchronizer rings, and a plurality of second lever members configured to press a second one of the synchronizer rings, and wherein
• the first lever members and the second lever members are alternately arranged at the two sides of the hub with a phase shift between the first lever members and the second lever members in the rotational direction.