Pneumatically operated stapling apparatus and method

Abstract

A pneumatically operated stapling apparatus and method for driving a staple into a workpiece whenever the workpiece is moved into a stapling position between a staple driver and a backing member. The method and apparatus are particularly suited for stapling difficult to handle workpieces of the type including a panel and a sheet of flexible material to be mounted thereon, and the method and apparatus are able to advantageously use a pneumatic stapling gun of a known type having a staple driving mechanism controlled by a valve plunger positionable either to advance the staple driver toward the backing member, or to retract the staple driver. A trigger element is positioned to be depressed by the workpiece as it is placed in the stapling position, and a pneumatic control means, actuated by depressing the trigger element, first positions the stapler control valve to cause the staple driver to advance and insert a staple into the workpiece and then, while the trigger element remains depressed, automatically changes the position of the stapler control valve to retract the staple driver away from the workpiece to thereby permit the workpiece to be removed from the stapling position to release the trigger element. The pneumatically operated stapling apparatus frees the hands for manipulation of the workpiece, e.g., for accurate placement of a sheet of material on a mounting panel, and allows a known reliable type of pneumatic stapler to be inexpensively adapted to perform a valuable new function. The pneumatic control means in the stapling apparatus and method comprises a pneumatic reservoir, a pneumatic actuator coupled to the stapler control valve to control the positioning thereof, and a valve connected to the trigger element. The valve connects the pneumatic air supply to the pneumatic reservoir when the trigger element is not depressed, and then connects the pneumatic reservoir, with its stored charge of compressed air, to the pneumatic actuator when the trigger element is depressed. The pneumatic circuit formed by the pneumatic reservoir and pneumatic actuator includes leakage means for reducing the pressure therein to restore the pneumatic actuator to its initial position to thereby revert the stapler control valve to its initial position for retraction of the staple driver. The pneumatic control means may include means to adjust the storage volume of the reservoir, and means to adjust the rate of leakage therefrom.

Dependencies are inferred from the claim text.