Patent ID: 6746326
Filing Date: 2004-06-08
Classification: A01D,A01F

Abstract:
A fluid operated actuator comprising a shaft and a housing said shaft being at least partially mounted in the housing for relative rotation between the shaft and the housing, wherein the shaft comprises a substantially central bore in which a first piston is mounted, the shaft including a fluid inlet connectable to supply of pressurised fluid and a fluid outlet, and wherein a conduit is provided for the flow of fluid between the inlet and the outlet, one end of the housing comprising a chamber in which there is mounted a valve assembly comprising a second piston and a valve arranged to selectively open or close an inlet to said chamber, and wherein fluid exiting the outlet opens said valve and exerts a force on the second piston causing movement thereof in a first direction, and wherein upon movement of the first piston towards the second piston, the first piston engages with the valve to open the inlet to said chamber and allow fluid to flow out of said chamber, generating movement of the second piston in a second direction opposite to said first direction.