GB271855A - Improvements in or relating to tap-changing mechanism for electrical transformers - Google Patents

Abstract

271,855. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of Hill, L. H., and Dann, W. M.). May 27, 1926, [Convention date]. Regulating transformers.- Relates to tap changing mechanism for variable ratio transformers, and comprises a main driving shaft 1 arranged to operate circuit breakers 39 forming part of the tap changing system and arranged to be selectively driven through reducing gear 6 either by a motor 2 or by a hand wheel 17. Provision is made for interrupting the motor control circuit, which comprises a pilot switch system not described, releasing the motor brake 8, and bringing into operation means for locking the shaft 1 against rotation at positions corresponding to the tap switches. The manual operating means is carried on a lever 19 pivoted at 18 and is adapted for engagement with the shaft 5 at 15. The lever 19 is provided with an extension 21 engaging a stop device 22 and has a pointer for indicating when the manual means is in operation. The lever 19 is also provided with a rearward extension pivotally connected to a crank arm 26 so that movement of the manual operating gear into engagement causes a partial rotation of a shaft 27 which is communicated to a shaft 29 carrying an arm 30 adapted to break the motor control circuit at 32 and to release the brake 8. At the same time a member 43 carried by a bracket 42 pivoted on the shaft 29 and normally held in a raised position by a bracket 41 fixed to the shaft 29, is allowed to fall into engagement with a ring 36 carried by the driving shaft 1 and having notches 37 corresponding to the tapping positions. Rotation of the shaft 1 is arrested by engagement of the device 43 with one of the notches 37, further rotation being effected when desired by raising the device 43 in opposition to springs 44 connecting the brackets 41, 42.