Abstract: A hydraulic rotary actuator assembly includes a rotatable drive assembly disposed about and rotatable about a longitudinal axis of the actuator and a stator assembly disposed about the rotatable drive assembly. The rotatable drive assembly includes an output shaft having a coupling end for rotatably engaging a workpiece, and a rotor disposed concentrically about the longitudinal axis and rotatable to drive rotation of the output shaft. The rotor has an outside radial surface that includes at least one radially protruding flange or rotor vane. The stator assembly is disposed concentrically about and generally radially spaced from the rotor and has at least one radially movable stator vane that is sealingly engageable with the outside radial surface of the rotor.

Abstract: A personnel monitoring and locating system is disclosed that is particularly well suited for monitoring and/or locating underground miners. A plurality of remote terminals having transceivers associated therewith are positioned in a mine and periodically are caused to transmit interrogation signals. Each miner to be monitored is equipped with a transponder that replies to the interrogation signal with the reply signal being timewise delayed by a predetermined amount of time that is different for each of the transponders in use so that the reply from each transponder is timewise spaced from every other interrogated transponder. A host computer at the surface is linked to each remote terminal for transmission of information with information from the remote terminal being indicative of the location of each transponder equipped miner.