Gear selector control for manual transmission

Abstract

The gear shift mechanism of a manually operated transmission having multiple forward speed ratios and a reverse drive ratio includes a gear selector shaft under the manual control of the vehicle operator. A selector pin fixed to the selector shaft moves within a system of interconnected slots in a guide plate mounted on the transmission casing. Movement of the gear selector lever causes the selector pin to move within the restricted path defined by the slots. A pawl supported on the surface of the guide plate is mounted pivotably in a slotted hole that permits linear displacement with respect to the pivot pin. A torsion spring continuously applies a resilient force to the pawl tending to restore the pawl to a normal position, where it prevents movement of the selector mechanism from a forward drive position directly to the reverse drive position. The device applies a force to the selector mechanism that resists movement of the selector pin to the reverse drive position but permits the gear shift to be made from the neutral plane into the reverse drive position. The pawl absolutely prevents movement of the selector mechanism from the forward drive position that is in the same plane as the reverse drive position and provides a guided surface along which the selector mechanism moves from the highest forward gear ratio to the lower gear ratios.