VACUUM CLUTCH ACTUATOR

A vacuum clutch actuating mechanism including a member responsive to vacuum encircling a driven shaft and defining a closed space. One wall of the member is flexible and moves in response to vacuum supplied to the closed space. A leaf spring is attached to the moving wall and extends radially outwardly to engage a driven member mounted for radially outward movement and engage a driving member when the vacuum is supplied to the closed space moving the flexible wall. A two way overrunning clutch can be provided between the outer periphery of the driven member and an inwardly facing peripheral surface of the driving member. The radially outward movement of the spring is sufficient to initially lock up the overrunning clutch when the flexible wall moves in response to vacuum.