GB320922A - Improvements in and connected with electric lighting installations for railway and like vehicles - Google Patents

Abstract

320,922. Stone & Co., Ltd., J., and Honey, A. E. July 21, 1928. Supplying consuming devices from variablespeed generators.-Train and like vehicle installations provided with an " on " wire for energizing electromagnetic switches controlling main load circuits and for supplying currents to auxiliary lights under certain conditions, have separate auxiliary switches automatically controlled by the main switches for the prolonged connection of the " on " wire to the auxiliary load circuits. The pull-on winding of the auxiliary switch is energized and its contacts interrupt the pull-on winding of the main switch and connect the on " wire to the auxiliary load. Additional control from a battery changeover switch or from a cut-in switch may be utilized. Retarding devices are provided automatically to prevent closure of the auxiliary switch before complete closure of the main switch. The retarding devices may be mechanical, electrical or electromechanical. As shown, Fig. 1, the lifting coil m of the main lighting switch l is energized by the guard's switch k and connects the positive lighting conductor g by way of conductor r to the coil s of an auxiliary switch P. The coil s may carry only a fraction of the internal lighting current by providing shunts s<1>. The contact brush p of the switch makes contact at v and connects the " on " wire h by way of conductor y with the positive lead a to supply the auxiliary lighting load q'. In the conductor y is located a switch D which controls the auxiliary lights depending upon whether the train is stationary or running above a particular speed. The control switch D can be replaced by a modified battery or cut-in switch. On joining additional coaches to a train, these will be automatically lighted. All lights are extinguished by the guards switch in the position k<2> connecting the " off conductor with the de-magnetizing coils of the switches. In order to prevent the auxiliary switch P from closing before the main switch is fully home, it is provided with several alternative retarding devices. In one arrangement a demagnetizing winding s<2> is provided on the switch P. In another arrangement, Fig. 3, the core t has an extension t' provided with a spherical head t<2> engaging in a recess in a keeper w co-operating with the pole-pieces 10 of an electromagnet 9 energized by the guard's switch k. A slight lost motion takes place between the extension t' and contact brush p. In other arrangements, pot magnets are employed or the retarding device may be a dash-pot, or a combination of electromagnetic and mechanical means can be employed. Specifications 180,049, 245,502, 260,334, and 282,507 are referred to.