Abstract: A shunting device used on railroad maintenance vehicles, such as pickup trucks and other maintenance vehicles, for transmitting electrical signal through railroad tracks for operating signalling devices and notification to the dispatcher. The shunting device consists of a backing plate for attaching the device to the vehicle, an insulator block to electrically isolate the shunting device from the vehicle, a mounting plate for attaching the shunting device to the insulator block and providing height adjustment, a shock tube attached to the mounting plate, a brush support slidable within the shock tube, a biasing mechanism to provide an outward bias to the brush support, a clamping device attached to the brush support, a brush make with a plurality of wire cable secured and held in position within the clamping device, and an electrical connection on the brush support for electrically connecting the shunting device to a signal generator.

Abstract: A constant current wire crossing apparatus for overhead electrically operated vehicles, wherein wires of opposite polarity are connected by insulators to a crossing unit, including a conducting strip disposed on each insulator and appropriate switching circuitry such that a continuous source of power of correct polarity is available to a passing vehicle in any direction.