Pneumatic check valve having hollow cylindrical piston - with enclosed air forming vibration-damping resilient buffer

摘要

A pneumatic check valve, partic. for use in air-jet looms, has a circular inlet port closed by a cylindrical piston housed in a barrel formed in the lid of the valve whose diameter corresponds to the inside diameter of the valve seat. The body of the piston is hollow, with a wall thickness between 0.1 and 1 mm, the air within it forming a resilient buffer to damp the opening movement of the piston. The underside of the lid forms a stop for the top end of the piston, and has a bleed hole connecting the air buffer to atmos. The valve is intended to equalise the jet pressure across the loom by preventing the loss of air between impulses. The valve operates quietly, without vibration, and with little wear.