INTERLOCK DEVICE FOR SPEED BOX

摘要

A transmission shiftable to change transmission ratios by the operation of a member whose effectiveness depends upon a pressure fluid, e.g. through a valve communicating the fluid to actuators of the gear-change system, has a clutch connecting the output shaft of a prime mover as an internal-combustion engine with the input shaft of the transmission. According to the invention, the clutch-operating cylinder is connected by an entraining device with a valve controlling the pressure fluid. A lost motion may be provided between the operating member of the cylinder and the valve seats to ensure full opening of the clutch before operation of the transmission is enabled.