Abstract: The present invention relates to a sealing device for the driver member of a pneumatically operated driving tool for fasteners. It comprises a working cylinder, a working piston slidably arranged in said working cylinder for movement between an upper and a lower dead center, a resilient stop member defining the lower dead center of the working piston movement, a driving member secured to said working piston and extending through an opening of said stop member, a control valve actuated by a trigger to alternatively connect a cylinder space above said working piston with a source of compressed air and to atmosphere, and a piston return space in communication with a cylinder space below said working piston.

Abstract: The present invention relates to a valve control apparatus for operating a working piston, comprising a main valve spool including a smaller piston face subjected to compressed air from a reservoir and a larger piston face facing a main control space, further comprising an auxiliary valve spool having a first effective area which can be connected by a trigger valve to atmosphere or to a compressed air reservoir to displace the main control spool into an open position, and having a second effective area which is connected to a piston stroke chamber for displacing the main valve spool into a closed position, wherein the auxiliary valve spool is returned when the pressure acting on its second effective area falls below a predetermined value, wherein this effective area is connected to a shift valve which communicates with atmosphere when the trigger is not actuated and which is closed when being actuated and wherein the trigger is provided to move a first length of travel and a second length of travel to actuate