摘要 |
The fluid actuator comprises a cylindrical body (11) defining an interior chamber (14) within which is located a piston assembly (15). This isolates a fluid outlet (5) at one end (12) of the chamber from a fluid inlet (1,2,3,4) at the other end (13) of the chamber. The piston assembly (15) comprises a central cylindrical piston element (15D) concentrically surrounded by at least one annular piston element (15A, 15B, 15C) and is resiliently urged by spring (16) to seat against the end of the body. Face seals (L, K, M and N) are provided at end (13) for respective piston elements (15A,15B,15C,15D) and individual inlet ports (1,2,3,4) penetrate the seals to provide for fluid delivery against individual piston elements. |