Automatic lamp bulb changer for signal lamps

摘要

In order to provide for automatic replacement of lamp bulbs (lamps) when they fail to illuminate and to enhance the reliability of signal lamps, such as those which signal oncoming trains as they move along railway tracks, a plurality of lamps are disposed angularly spaced from each other on one side of a turntable which is rotatable under spring bias to bring the lamps successively into positions in alignment with the lens of the signal lamp. A latching mechanism having a latch member incorporated into the turntable and a detent member operated by a solenoid provides for releasable engagement of the turntable so as to enable it to move between the successive positions. The primary one of the lamps is wired directly into the signaling system while the secondary lamp or lamps is wired to be operated by a circuit responsive to the illumination of the lamp which is in alignment with the lens and which controls actuation of the solenoid and release of the turntable as well as switching of power to the secondary lamp or lamps.