Patent ID: 6145727
Filing Date: 2000-11-14
Classification: B25C

Abstract:
A pneumatic tool comprising:a housing;a cylinder disposed within said housing;a piston slidably movable within said cylinder, said piston having a driver for driving fasteners, such as nails;an upper piston chamber and a lower piston chamber defined within said cylinder on an upper side and a lower side of said piston, respectively;compressed air supply means;control means for controlling the supply of the compressed air from said compressed air supply means to said upper piston chamber and to said lower piston chamber to drive the fasteners into a workpiece;said control means including a variable pressure chamber and valve means, said variable pressure chamber being always connected to said compressed air supply means, and said valve means being operable to connect and disconnect said variable pressure chamber and said lower piston chamber in response to the position of said piston relative to said cylinder; andmeans for maintaining a predetermined volume in said variable pressure chamber, irrespective of the operation of said control means.