BATTERY CALL TELEPHONE
MINING PATTERN - NO BELL
Primarily designed for use in atmospheres containing methane, but is suitable for use in other situations where robustness of design is necessary, such as railway yards of traction routes, provided no dangerous atmosphere exists other than methane.
Certificate of intrinsic safety for methane No. T/TEL 11B. certified by the Ministry of Power.
The case is cast iron, the front secured to the body by screws having special shaped heads which can only be removed by a key provided for this purpose. A loudspeaking receiver is mounted inside the case and operates via a flexible metallic tube to an acoustic ear-piece. The inset transmitter is waterproof and protected by a metal grid.
Ringing and speaking is controlled by a substantial two-position non-locking switch located on the right hand side of the case. The coils and wiring are specially treated to prevent the detrimental effects of moisture and gases. An external bell and external ringing and speaking batteries are required. Suitable bells are the L 4225 or L 4229 types. For ringing battery the BA 4900 type is approved.
Dimensions in brackets are the equivalent in cm.
Height - 9 inches (22.86cm)
Width - 9 inches (22.86cm)
Depth - 6 inches (15.24cm)
See also K8095
Found in the 1932 and 1935 Catalogues