GB374216A - Improvements relating to alternating current dynamo electric machines - Google Patents

Abstract

374,216. Controlling induction motors. HOSEASON, D. B., Grimsworth, Groby Road, Bowdon, DALE, S., Heath Cottage, Poplar Grove, Brooklands, both in Cheshire, and ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Crown House, Aldwych, London. April 24, 1931, No. 12200. [Class 35.] In order to connect either of two rotor windings of an alternating- current motor to slip-rings, the ends of the windings are connected to two sets of contacts to each of which sets corresponds a set connected to the slip-rings and by means of a switch member corresponding sets of contacts can be connected. For this purpose, the ends of one winding are connected to contacts S1, S2, S3, comprising springs 5 carried on insulators 8 passing through the sliprings 1, 2, 3 ; the ends of the other windings are connected to contacts R1, R2, R3 comprising springs 25 similarly supported ; the springs 25 are shorter than the springs 5 as shown. Corresponding to the contacts S1, S2, S3 are contacts 11, 12, 13 connected to the slip-rings 1, 2, 3 respectively, and to the contacts R1, R2, R3 contacts 31, 32, 33 also connected to the rings 1, 2, 3. The contacts 11, 12, 13, 31, 32, 33 are constructed and supported in a similar manner to the contacts S1, S2, S3, R1, R2, R3, except that the supporting rods stop at the slip-rings to which the contacts are to be connected. A collar 41 sliding on the shaft carries blades 44 which, when the collar is in the position shown in Fig. 7, connect the contacts S1, S2, S3 to the contacts 11, 12, 13. When the collar 41 is moved into the position shown in Fig. 8 the blades 44 are clear of the springs 5 and blades 45 connect the contacts R1, R2, R3 to the contacts 31, 32, 33 ; at the same time blades 50 connect the contacts S1, S2, S3 to a ring 51, thus short-circuiting the first set of windings.