Patent ID: 7930971

Claim:
A rotary actuator comprising: (a) a housing defining a cylindrical bore; (b) a spool member rotatably mounted within the cylindrical bore in the housing, (c) a vane attached to the spool member and projecting radially outward therefrom; (d) a stop member attached to the housing within the bore and projecting radially inward toward the spool member, the stop member having first and second end surfaces circumferentially spaced from one another defining a gap through which the vane is free to travel, the stop member including first and second passageways for hydraulic fluid, each leading from an inlet port to an outlet port where the outlet ports are on respective ones of the first and second end surfaces; and (e) a hydraulically-actuated, spring-biased friction brake mechanism operatively deployed between the housing and the spool member for preventing rotation of the spool member relative to the housing whenever hydraulic fluid pressure is being applied to an inlet port below a predetermined value.