Improvements in or relating to detectors for fire alarm systems

摘要

738,991. Thermal switches. WILSON, E., and WHITE, W. Nov. 24, 1953 [Jan. 22, 1953], No. 1853/53. Class 38 (5). A fire detector comprises a brass spindle B biased upwards by a spring G but normally retained in the position shown, with an insulating portion H breaking the circuit between two spring balls E, by being soldered to a ferrule K. In the event of fire, the solder melts and the spindle is forced upwards so that the balls E engage a recess T in the spindle so as to complete an alarm circuit and to retain the spindle in its operated position.