GB495791A - Improvements in and relating to electric motors - Google Patents

Abstract

495,791. A.C. commutator motors. CROCKER-WHEELER ELECTRIC MANUFACTURING CO. May 20, 1937, No. 14041. Convention date, May 23, 1396. [Class 35] The armature of a commutator motor is energized from an adjustable transformer the primary winding of which is connected across one phase of a three phase supply a field winding being connected between a tapping on the transformer and the third line terminal of the supply, a winding on the motor stator being supplied by the transformer and partly or wholly energizing the armature by induction. In the form shown, the field winding 2 is connected between the supply terminal C and a tapping 14 on the primary of a transformer 30 connected to the supply terminals A and B. The armature is energized partly by induction from the stator winding 3 supplied by the transformer primary and partly directly from the secondary winding 32. If desired, the armature may be wholly energized by induction, in which case the brushes are short-circuited and an autotransformer is used. The Specification as open to inspection under Sect. 91 comprises also an arrangement, Fig. 3 (Cancelled), wherein the armature is wholly energized from the transformer secondary winding 22, the stator winding 3 being short-circuited. This subject-matter does not appear in the Specification as accepted.