| |||||||
MINE TELEPHONES AND SIGNALLING APPARATUS INTER-COMMUNICATION TELEPHONES The components are mounted in black-enamelled stamped-metal cases, and comprise cradle switch, induction coil, buzzer, ebonite terminal strip, 16 calling and ringing buttons with automatic release, and a hand micro-telephone. The maximum capacity is sixteen lines, and calling is effected by removing the hand-set and pressing the button corresponding to the required number. Further pressure actuates the buzzer at the called station. On release, the button remains in the speaking position until restored to normal by replacement of the hand-set in its cradle.
Junction boxes are also used for inter-connecting the multi-wire cables at each junction. They comprise varnished wood cases housing the necessary complement of terminals. T.2246
Taken from the ATM Mine Telephones and Signalling Apparatus Catalogue 1928 |
|||||||
Last revised: October 06, 2012FM2 |