GB836420A - Improvements in or relating to electric current-collecting brushes - Google Patents

Abstract

836,420. Brushes for electric machines. MORGAN CRUCIBLE CO. Ltd. July 1, 1957 [July 9, 1956], No. 21259/56. Class 35. In an electric current-collecting brush cornprising a succession of at least two separatelymade brush parts to collect and transmit current in respective parallel paths between the surface 1 of an electric commutator or slip-ring a terminal connection, not shown, a brush part or parts has at least one slot disposed generally transversely to the longitudinal axis of the brush to create a greater total electrical resistance in one or more of the parallel paths than in another. The sandwich brush shown in Figs. 1 and 2 comprises two parts 11, 12 bonded together with an intervening layer of electrical insulation one, 11, of which parts is slotted while to the other, 12, is attached by a rivet 7 a flexible lead 31; in another embodiment for reversible machines there is also a slotted part on the opposite face of the part 12. The split tandem brush shown in Fig. 4 has two transverse slots defining a tortuous current path in one part 19 and both parts 18, 19 have respective leads 32, 33, spring fingers 42, 43 bearing on the top of the brush. In another embodiment the slot is tapered. The differential resistance may be achieved by the slots in combination with the means disclosed in Specification 832,903, which is referred to.