Air starter

Claim 1

A fluid operated pre-engaged starter comprising: a casing containing a fluid operated motor driving a shaft; a starter clutch member rotatably mounted on said casing in driving connection with said motor shaft and slidable axially between a disengaged position and an engaged position with an engine clutch member; a piston slidably mounted in a fluid chamber in said casing and operative in response to the introduction of fluid pressure into said chamber to move from a retracted position to an extended position; said piston being connected to said starter clutch member causing said piston in moving to its extended position to move said starter clutch member toward its engaged position; a fluid supply line for supplying operating fluid to said motor and containing a fluid operated valve for opening and closing said supply line; means for opening said valve to operate said motor in response to the movement of said piston toward its extended position, corresponding to the engaged position of said starter clutch member; and means for maintaining said valve in its fully open position during return movement of said piston and for closing said valve to stop said motor only in response to the arrival of said piston at its retracted position whereby said motor continues to operate until said piston discontinues urging said starter clutch member into engagement with the engine clutch member.