Abstract: A valve assembly for controlling the flow of pressurized fluid supplied to an actuating cylinder having a piston driven by the pressurized fluid along a stroke path therewithin, the pressurized fluid being applied to alternative driving sides of the piston. The valve assembly comprises a first and a second valve pistons, which cooperate to block the supply of pressurized fluid to the current driving side of the piston when the piston reaches the end of its stroke path, thereby limiting the pressure of the pressurized fluid supplied to the driving side to a level reduced compared to a pressure level applied to drive said piston. If a leak occurs within the actuating cylinder at the end of the stroke path of the piston, it will be at the reduced pressurized fluid pressure.

Abstract: A valve assembly for controlling the flow of pressurized fluid supplied to an actuating cylinder having a piston driven by the pressurized fluid along a stroke path therewithin, the pressurized fluid being applied to alternative driving sides of the piston. The valve assembly comprises a first and a second valve pistons, which cooperate to block the supply of pressurized fluid to the current driving side of the piston when the piston reaches the end of its stroke path, thereby limiting the pressure of the pressurized fluid supplied to the driving side to a level reduced compared to a pressure level applied to drive said piston. If a leak occurs within the actuating cylinder at the end of the stroke path of the piston, it will be at the reduced pressurized fluid pressure.

Abstract: A multi-stage air pressure cylinder is made of superposed components tightly fastened together wherein additional stages can be added by superposing additional components. The two-stage cylinder comprises two end wall members each having a cylindrical recess facing each other and divided by a fixed partition wall having a perforation therethrough. The partition wall and the end wall members are tightly fastened together. The partition wall subdivides two compression chambers. A piston is located in each compression chamber. One piston has a projection extending outside the cylinder and the other is adapted to exert a mechanical pressure on the first one while fluid pressure is exerted on both pistons.