GB174922A - Improvements in controlling devices for the motors of electrically driven vehicles - Google Patents

Abstract

174,922. Krupp Akt.-Ges., F. Feb. 4, 1921, [Convention date]. Controllers with auxiliary switches.-Motor controllers are provided with an electromagnetic cut out, the releasing coil of which is energized by the closure of auxiliary switches actuated by movements of the controller drum. The object is to remove sparking from the controller fingers. In the construction shown in the drawings, a brush a<53>, Fig. 2 is attached to the actuating- spindle a<56> of a resistance and series-parallel drum controller A which has auxiliary segmental contacts a<47>, a<48>, a<49>. The brush and segmental contacts form a two-way switch in series with the releasing coil G<2> of the electromagnetic cutout. By means of a lost-motion connection between the spindle a<56> and the drum, the twoway switch changes over when the direction of movement of the controller actuating spindle is reversed, the effect being to connect the releasing coil in a low resistance path across the mains. Appropriate connections for preparing the releasing circuit are formed by a two-way switch M adapted to be changed over by cam action when the controller is passing through its neutral position. The cut-out after it has been opened by the releasing coil is maintained open by a reduced current flowing through a resistance in series with the motor armatures. In order to reclose the cut-out the controller is brought back to the neutral position, in which the switch M is changed over so as to break the existing circuit of the releasing coil and simultaneously prepare for subsequent completion as described above. Series-parallel systems.-Provision is also made for temporarily opening the cut-out during the transition from series to parallel running. Controllers, actuating and interlocking.-The controller drum A is geared by a Geneva stop mechanism, Figs. 3 and 4, to a reversing and braking drum B. Both drums are actuated by a remote hand wheel N, Fig. 5, through pulley and wire-cable transmissions Q, R. S. T. Rotary movements of the hand wheel act only upon a pulley Q connected to the drum A. Longitudinal movements of the hand wheel axle, which are permitted when the controller drum is in the neutral position, act only upon a pulley R connected to the drum B and effect the reversal of the motor connections. A bevel gear drive between the drum B and its actuating spindle b<42>, Fig. 3, allows the reversal to be effected withoute interfering with the Geneva stop drive from the controller drum A.