GB191121800A - Improvements in Controllers for Electric Motors. - Google Patents

Abstract

21,800. Bennitt, W. B. Oct. 3. Controllers, drum; controllers, actuating- mechanism for.-In controllers consisting of a rheostat drum mounted fast on a spindle and a main circuit drum loose on the spindle, the actuating-mechanism for the loose drum consists of a plate 2 attached to it and driven counterclockwise to move the plate and drum by a pawl 5. The pawl is pivoted to a crank extension 6 on the spindle, and is pulled outwardly by a spring 8 passing over a second crank extension 9. During rotation of the spindle, the pawl engages a stop 4 on the plate 2, which rotates until the main circuit is made, a spring latch 14 hooking, in this position, to an extension 16 of the armature 17 of the no-volt magnet 18. The pawl 5 is released from the stop 4 by a roller 12 on an arm 10, which is pivoted at 11 and pulled down by a spring 13. The roller rides up a slot 3 during rotation of the plate. and effects a sufficient inward displacement of the pawl against the spring 8, to cause a release at the moment at which the latch 14 comes into operation. The latch is released from the armature extension 16 (i) by de-energization of the magnet 18, which allows the armature 17 to rise about its pivot 19 and the extension to fall out of the way of the latch, (ii) by the rise of the core 22 of an overload magnet 23, which pulls up the arm 21 of a bell-crank lever pivoted at 20, the end 25 of the other arm pulling back the latch 14, and, (iii) by the return of the spindle by the operator. In this case, the extension 9 strikes a projecting pin 30, which is forced outwards from bearings 27 by a spring 26. In retreating under the stroke of the extension 9, the pin trips the latch 14. In each case, the spindle must be returned to the starting position before the sequence of switching operations can be repeated.