GB484116A - Improvements in and relating to electric drum switches - Google Patents

Abstract

484,116. Drum controllers. GHAY, W. T., MILLAR, G. H., and METROPOLITANVICKERS ELECTRICAL CO., Ltd. Nov. 2, 1936, No. 29802. [Class 38 (iii)] A drum controller which may be employed in the system described in Specifications 469,958 and 470,065, comprises one or more metal carriers 7, 8, having an outer cylindrical or part -cylindrical surface on which a number of circumferentially extending grooves or ridges 13-21 corresponding respectively with contact fingers are provided, and contact segments 22- 35, provided with base portions engaging the grooves or ridges, are secured to the carrier members and located axially in position. The carrier members 7, 8, are mounted on a cylindrical drum 1 of insulating material which is mounted by means of spider members 4, 5, on an operating shaft. The carrier 7 has rectangular grooves 13-17, and into these grooves fit the base portions 36 of the contact segments, through which pass holding bolts 38. These bolts are asymmetrically arranged with respect to the base portion and the groove so that the contact segment can be mounted only with the off-set contact portion extending to the correct side. One or more grooves may be associated with two contact fingers in which case the contact segments are so formed that by reversal the contact portion is disposed to engage one or the other of the contact fingers. The two carriers 7, 8, are shaped with interfitting adjacent ends at 40-44 so that contact segments on either carrier may co-operate at different times with the same contact finger. Further insulating members 2 and 3 may carry further contact carriers 9-12. A number of contact segments 33-35 may be arranged together to form a single segment of the necessary length or a single long segment such as that shown at 22 may be used. Contact strips 45-47 are secured to ridges 49, 50, 51, where contact is required for a substantial part of the movement. A retaining plate carried by the cylinder 1 may be used for mounting the carriers, the initial establishment and the final disconnection of the circuit may be effected by a contact strip 56 secured to an axially extending lug on the carrier 7, and a similar contact strip 57 may also be provided. Bonds 59 located at the bottom of suitable grooves may connect adjacent carriers at the divisions between the insulating members 1, 2 and 3.