Improvements in or relating to fire alarm street boxes or like signalling apparatus

摘要

389,725. Fire-alarm systems. STANDARD TELEPHONES & CABLES, Ltd. and BATES, E. F., Connaught House, Aldwych, London. Aug. 12, 1932, No. 22575. [Class 40 (i).] The pull handle P of a fire-alarm or like signal box co-operates, through the intermediary of a pivoted lever O carrying a latch T, with a pivoted lever S which is adapted to operate the starting lever F of the signal transmitter. When the handle P is pulled the latch T operates lever S to start the transmitter, but after predetermined movement the latch becomes disengaged from the lever S to allow restoration of the levers F, S to normal after the code signal is sent in the event that the handle P is held operated. Thus the arrangement ensures that a normal code signal is transmitted irrespective of whether the pull handle is allowed to restore immediately after operation or is held operated. The pull handle is associated with a glass plate X. In a modification, the operating handle is pivoted on the door of the box and carries a lever adapted to co-operate with a second pivoted lever associated with the starting lever. The arrangement is such that after a predetermined rotation the first lever becomes disengaged from the second lever to permit restoration of the second lever independently of the handle.