Abstract: A vandal resistant light signal unit consisting of a modular integrated circuit arrangement having an insulative circuit board, which has a first broad area layer of conductive material on one side of the circuit board and a second broad area layer on an opposite side of the circuit board. The first layer defines a positive energy plane and the second a negative energy plane. Also, the unit has a plurality of independent series circuits connected in parallel to respective spaced points or nodes on the oppositely located layers of conductive material. Moreover, the broad area layers are connected to opposite sides of a power supply, and these layers constitute an arrangement for resisting vandalism occasioned by projectiles directed at said light signal unit.

Abstract: There is provided an electric motor driven switch machine for positioning a railroad track at a switching point having rail point detection and indication mechanism. In particular, the detection and indication mechanism has a latch out mechanism that identifies a latch out condition when the railroad tracks are not at, or near, their proper positions before or after switching the railroad tracks. The detection and indication mechanism includes a four bar linkage which comprises a point detector bar, two cam followers, and a link arm assembly. The cam followers, supported in part by the link arm assembly, are connected to two point detector switches, so that the switch machine is operating when either one of these switches is closed or the railroad tracks are being switched.

Abstract: A switch machine controller for providing fail safe control of a switch machine, having a motor for actuating the movements of a railroad switch, said motor being a brushless D.C. motor having a permanent magnet structure and a plurality of independent field coils. The controller has control circuitry for energizing and de-energizing field coils of said motor sequentially as the armature rotates. Further the controller, including a motor driver arrangement for switching a first service of power sequentially to said field coil of said motor, switches machine control lines connected to second source of power. Also, an amplifier for controlling timing signals which, in turn, controls the motor driver, thus receiving its power only from said switch machine control lines, and can only generate the proper sequence of signals when the control lines are energized, such that the motor can only run when the control lines are energized.