Stroke control device for an actuator rod of a linear actuator

Claim 1

In a linear actuator having an actuating rod threaded with a rotating drive screw shaft and movable back and forth along the rotating drive screw shaft, a stroke control device for controlling a stroke of the actuating rod, said stroke control device comprising in combination: a worm formed on an outer peripheral surface of the rotating drive screw shaft, a worm gear externally meshing with said worm and having a vertical worm gear shaft projecting into a limit switch box, a cam plate mounting shaft rotatably supported within said limit switch box for rotation about a substantially horizontal axis, a plurality of limit-switch actuating cam plates rotatably and adjustably mounted on an outer peripheral surface of said cam-plate mounting shaft for adjustment of the back and forth movement stroke of the actuating rod, a second worm gear fixed to said cam-plate mounting shaft, speed reducing means drivingly engaging said worm gear shaft and said second worm gear to transmit rotation of said worm gear shaft to said cam plate mounting shaft, and a plurality of limit switches mounted within said limit switch box in locations corresponding to each respective limit-switch actuating cam plate.