Improvements in Means for Preventing Overwinding and Underwinding Electrically Driven Cranes, Capstans, Lift, and the like.

摘要

17,516. Wardale, H., and Storey, W. R. July 28. Overwinding and overrunning preventing; emergency power cut-off gear. - Comprises a construction of device for preventing overwinding in electric cranes, capstans, lifts, &c. of the type in which a screw and nut is operated from the winding-drum so that, when the rope reaches the desired position in either direction of movement. the nut engages a device to release a switch and break the motor circuit. A striking- plate 4 sliding on guide-rods 5 is carried by a nut 3 on a screwed spindle 1, secured to the axle of the winding-drum. A switch 23, when on, is retained by a spring catch lever 13 which can be released by a lever 6, 7 pivoted to the frame. When the nut reaches the required position in one direction, an adjustable piece 10 on the striking-plate engages the end 7 of the lever, which presses against the catch lever 13 and releases the switch, which is moved to the ' off ' position by a spring 22. At the limiting position in the opposite direction, the striking - plate engages a nut 11 on a rod attached to the end 6 of the lever, and operates the catch lever 13 to release the switch. The controller is reversed by another operator; or the switch 23 may be operated from the controlling-platform by a cord 24.