Abstract: A pneumatic cylinder having a cylinder tube with at least one open end coupled to an end cap to close the open end. The pneumatic cylinder includes a piston reciprocally movable in the cylinder and the piston has a first seal to create a substantially fluid-tight seal with the internal surface of the cylinder tube. The piston has a piston spear at the end portion thereof for cooperating with a piston spear receiving space in the end cap. A second seal is provided in the piston spear receiving space for creating a substantially fluid-tight seal between the piston spear and the piston spear receiving space thereby creating a volume chamber between the first and second seals. The volume chamber provides a compressible volume of volume which acts as an air cushion at the end of the piston stroke.

Abstract: A fully programmable servo-pneumatic modular weld gun having closed-loop position and pressure control generally includes a weld gun base module, a pneumatic cylinder with a movable piston having a first welding electrode, a J-shaped gun arm having a first end attached to the base module and a second end having a second welding electrode and a controller for providing closed-loop positioning and pressure control of the first welding electrode. The pneumatic cylinder includes an internal positioning encoder for detecting piston position and transmitting piston position information to the controller to control movement of the piston through a proportional flow control valve and a proportional pressure regulator.

Abstract: A fully programmable servo-pneumatic modular weld gun having closed-loop position and pressure control generally includes a weld gun base module, a pneumatic cylinder with a movable piston having a first welding electrode, a J-shaped gun arm having a first end attached to the base module and a second end having a second welding electrode and a controller for providing closed-loop positioning and pressure control of the first welding electrode. The pneumatic cylinder includes an internal positioning encoder for detecting piston position and transmitting piston position information to the controller to control movement of the piston through a proportional flow control valve and a proportional pressure regulator.