Improvements in or relating to control devices for flame or temperature operated electric switches

摘要

513,920. Thermal switches. GRAVINER MANUFACTURING CO., Ltd., MATHISEN, A., and SALMOND, H. M. April 21, 1938, No. 11987. [Class 38 (v)] A flame-actuated device for operating electric switches comprises a bolt 1 biassed upwards by a spring 26, but prevented from moving by engaging a flange 16 having a tubular extension 17 which abuts against an upper flange 19 and coaxial tubular part 20. The flange 19 is retained by the engagement of its bevelled edge 21 engaging an aperture in a nut 23 secured to a part 12 soldered to a fixed part 11. The tubular parts 17, 20 and also channels 18 and chamber 15 are filled with gun powder and closed by a solid primary head 33. An inflammable strip 36 and inflammable disc 35 are provided to catch fire at once in the presence of flame. This ignites the head 33 which by way of the tubes 20, 17 and channels 18 ignites the main charge in chamber 15. The force of the explosion forces flange 19 free from nut 23 and allows flange 16 to be moved upwards by bolt 1. A cover 30 retains the parts after explosion. On a general rise in temperature, the soldered connection between parts 11 and 12 is broken allowing the bolt 1 to be moved upwards. In the embodiment of Fig. 1, the movement of bolt 1 closes a circuit between contact springs 3, 4. In a modification, the parts are held by screw threads which are adapted to be stripped by the force of the explosion. Specification 514,086, [Group XXI], is referred to.