Lampchanger

Abstract

A lampchanger preferably for use in a railroad signal lantern having a focusing lens which includes a horizontally rotatable turret adapted to support a plurality of lamps for indexing one of the lamps to the focal point of the lens. The turret includes a plurality of bayonet sockets for holding a lamp in which the sockets have resilient sides which taper inwardly away from the turret body for accurately securing the lamp in position. The turret includes a contact insulator having a radially extending slot adjacent each of the sockets with a power contact positioned in each of the slots. Each power contact includes a circular ridge for engaging the bottom of a lamp positioned in a socket for cleaning and making a good contact with the lamp. A power brush engages the rotatable turret and is positioned to engage the power contact and engages the slot of the insulator positioned in lamp operating position for mechanically holding the turret in position. A light detector is directed at the lamp in position in the focal point for detecting whether the lamp is lighted. And motor means is connected to the turret for rotating the turret when the light detector detects a burned out lamp. The control circuit includes means for preventing rotation of the turret in the event of failure of the light detector and includes a binary counter for actuating the motor with a gated oscillator clocking the counter and a capacitor large enough to charge the circuit in the hold state if power is lost.