Patent attributes
Pneumatic machining device includes a fixing plate, a hollow piston shell, a piston group, a machining tool, a first sealing group, and a second sealing group. The piston shell is fixed to the fixing plate and coupled to a first external pressure source and second external pressure source to feed gas into the piston shell to drive the piston group and the machining tool, respectively. The piston group and the first and second sealing groups are received inside the piston shell. The piston group is driven by the first external pressure source to move away from the fixing plate. The first and second sealing groups divide the piston shell into a number of chambers for controlling a gas pressure. The machining tool is coupled to the piston group and extends out of the piston shell to machine a workpiece as the piston group moves away from the fixing plate.