| 摘要 |
A hill holder cooperates with a countershaft in a vehicle transmission to permit rotational movement thereof in one direction while preventing rotational movement thereof in an opposite direction. The hill holder includes a cylindrical housing which is supported on a rear wall of a bell housing of the transmission in co-axial relationship with the countershaft. A clutch assembly is provided in the hill holder for selectively connecting the countershaft to the housing to prevent rotation thereof in one rotational direction. The clutch assembly includes a hub member which is secured to the countershaft for rotation therewith. The clutch assembly further includes a reaction member which is axially movable relative to the housing, but is restrained from rotating relative thereto. Mating ramp-shaped teeth are formed on adjacent end faces of the hub member and the reaction member. A fluid actuated piston is provided for moving the reaction member between a disengaged position, wherein the teeth are not engaged and the countershaft is free to rotate in either direction, to an engaged position, wherein the teeth are engaged and the countershaft is free to rotate in only one direction. |
