Sensitive air supply control valve - has pressure and weight balanced double poppet valve

摘要

A very light action control valve for pneumatically powered machines, primarily for small bore ( 4mm) has two poppet valves (6, 7) on the same shaft (13) so as to engage seats (4, 5) at either end of a cylinder fed with air. The valves are orientated in the same direction and one seat (4) on the outside of the input cylinder so that balance with respect to air pressure is achieved. The input cylinder is clamped between two other cylinders (2, 3) which are connected to discharge ducts. Small diameter rods or cables (14, 17) are attached to and in line with the valves and pass through the end flanges (8, 9) of the outer cylinders (2, 3). The upper rod is connected to a pivoting actuator arm (13) having a spring (20) to compensate its weight. A light spring (15) connected to the other rod (14) ensures that the valves re-seat when the actuator rod is released.