Linear actuator.

摘要

A power operated linear actuator for remote operation of a machine comprises a cylinder frame 17 containing a reversible motor 20 and a step-down gear train 21, a push-pull rod 11 connected with a threaded nut 36 movable along a high-pitch screw threaded shaft 31 in the cylinder frame and an electromagnet clutch 24 between the gear train and the screw shaft. When the clutch 24 is energised the push-pull rod 11 and hence a machine control (14) (Fig 1, not shown) are movable or held by the rotating or stationary motor 20: when the clutch is not energised the nut is rotatable freely by movement of the central (14) and push-pull rod 11.