| 摘要 |
A fluid pressure actuator is disclosed of the piston and cylinder type, in which an internally mounted transducer is incorporated for providing an electrical output signal corresponding to the position of the piston in the cylinder. The transducer is disclosed as a rotary potentiometer having a disc or drum element provided with conductive plastic tracks and a rotary wiper element rotated in correspondence with the linear travel of the piston in the cylinder by a connected cam rod slidably mounted within the piston rod and caused to rotate in one embodiment by means of a cam bushing engaging the cam rod, and in other embodiments by three converging spring biased plungers carried in the piston engaging respective sides of a hexagonal shaped cam rod. Other disclosed arrangements include a reduction drive interposed between the cam element and the rotary wiper to enable a multiturn cam element to be employed with a single turn potentiometer disc, and a multi-turn drum potentiometer having a wiper element driven by the cam rod engaging a helical thread form to be axially advanced by the piston motion.
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