GB190311725A - Improvements in relating to Switching Mechanism for Controlling Alternating-current Electric Motors. - Google Patents

Abstract

11,725. Carolan, E. A., [General Electric Co.]. May 22. Motors, controlling.-To provide in an alternating-current motor for automatically changing from the starting to the running armature windings when the motor speeds up, the motor armature, shown in Fig. 5 as of the closedcircuited type, is provided at one end with a fast switch base-ring A, Figs. 1 and 5, carrying two insulated contacts 10, 11 with which co-operate two connected spring contacts 12, 13 on a pivoted and weighted ring B, Fig. 7. The contacts 11, 10 and the ring B are connected to the separate branches of a star-connected resistance R<1>, R<2>, R<3>, and also to the branches of the armature winding A<1>, A<2>, A<3>. The resistance R<1> &c. is placed at the opposite end of the armature from the switch, and is connected as described above by leads 25, 26, 27 passing through the armature core and a hole 24 in the plate A. The ring B is turned on its pivot 15 by a spring 17, and bears, when the armature is stationary, on a stop 16, the contacts being then disengaged and the resistance R', R<2>, R<3> in the armature circuit. When full speed is attained, the centrifugal effect of the heavy portion 20 of the ring B draws the ring against a second stop 22 with the contacts engaged and the resistance cut out. The contacts 10, 12 and 11, 13 come together with a rubbiug motion, the points at which arcing occurs being well out of contact in the "full on " position.