GB314576A - Improvements in and relating to brush and terminal contact mechanism of dynamo electric machines - Google Patents

Abstract

314,576. Stone & Co., Ltd., J., and Honey, A. E. March 30, 1928. Dynamos, regulating.-In a dynamo brushrocking and terminal mechanism in which contact arms from the brush-holders extend from the rocker inwardly to the axis of revolution where they make pivotal contact with fixed terminal devices, such as are described in Specifications 114,021; 115,681, [Class 38 (iv), Electric supply and transmission systems &c.], and 118,886 for pole changing in train-lighting machines, the arms on the terminal devices are so mounted as to be capable of yielding flexibly in all directions excepting in the plane of the rocking- Good contact between the arms and terminals is thereby assured and the frictional resistance to the rocking is minimized. In the form shown, Fig. 1, the arms h<1>, h<2> from the mutually insulated brush holder arms f<1>, f<2> on the rocker g terminates in disc-like ends, shown in dotted lines at h<4>, Fig. 2, which are gripped by the fixed terminal brush contact devices j<1>, j<2>. When the rocker changes its position the discs h<4> rotate between the spring jaws of the terminal devices. These devices, as shown in Fig. 3, are secured to the terminal brackets l<2> by bow springs m<2> mounted in planes parallel to the plane of rotation of the rocker and yielding in directions other than in their own plane. They are riveted to the brackets and mav be backed by stiffening plates o. They may be reduced in width at their bends x, Fig. 2, to increase their flexibility and their flexure may be limited bv curved ears n<1>, Fig. 3, on their attachment plates n. Their inward movement may be limited by abutment of the terminal-securing screws r against the inner surfaces and a guard-plate q may be provided to prevent cleaners' cottonwaste &c. from fouling the terminals j<1>, j<2> . The bow springs may be at right angles to the length of the terminal devices instead of collinear therewith as shown, and two superposed bow springs may be employed instead of one for each terminal device. Alternatively, the bows may be formed as bent integral extensions of the terminal devices. The conductivity of the bow springs may be increased by an inner lining of flexible metallic braid.