Abstract 915,540. Fire-extinguishers. GRAVINER MANUFACTURING CO. Ltd., and WILKINSON SWORD Ltd. Sept. 22, 1961 [Oct. 7, 1960], No. 34373/60. Class 47. [Also in Group XXIX] An electrical actuator, e.g. for a fire-extinguisher comprises a movable member 12, a glass member 13 normally preventing movement of the member 12, and an electrical resistance wire 14, the arrangement being such that the passage of a predetermined current through the wire fractures the glass by thermal shock, thereby freeing the member 12. As shown, the neck of a fire-extinguisher 10 is closed by a diaphragm 11 which is supported by the piston 12. Fracture of the glass tube 13 allows the piston 12 to move. The fluid pressure in the fire-extinguisher ruptures the diaphragm 11 and the contents thereof (powder or fluid) escape through the outlet 10a. According to the Provisional Specification, the wire 14 may be surrounded by a solid oxidizing agent or a pre-mix gas or alternatively a spark gap may be provided to ignite an explosive air/gas mixture.
IN AN ELECTRICAL ACTUATOR FOR CONTROLLING THE MOVEMENT OF A MOVABLE MEMBER, A GLASS MEMBER, SAID GLASS MEMBER ENGAGING SAID MOVABLE FOR PREVENTING MOVEMENT THEREOF, AN ELECTRICAL RESISTANCE WIRE POSITIONED IN CLOSE PROXIMITY TO SAID GLASS MEMBER, SAID WIRE BEING OF A MATERIAL WHICH WHEN HEATED TO A PREDETERMINED TEMPERATURE BY THE PASSAGE OF AN ELECTRIC CURRENT THROUGH SAID WIRE UNDERGOES AN EXOTHERMIC REACTION WHICH RAISES IT TO A SECOND TEMPERATURE GREATLY IN EXCESS OF SAID PREDETERMINED TEMPERATURE, THE INTENSITY OF SAID SECOND TEMPERATURE BEING SUFFICIENT IN RELATION TO THE STRENGH OF THE GLASS MEMBER AS TO FRACTURE SAID GLASS MEMBER BY THERMAL SHOCK THEREBY FREEING SAID MOVABLE MEMBER.
Claim 2
Dependent Claim
109 words
IN AN ELECTRICAL ACTUATOR FOR CONTROLLING THE MOVEMENT OF A MOVABLE MEMBER, A GLASS MEMBER, SAID GLASS MEMBER ENGAGING SAID MOVABLE FOR PREVENTING MOVEMENT THEREOF, AN ELECTRICAL RESISTANCE WIRE POSITIONED IN CLOSE PROXIMITY TO SAID GLASS MEMBER, SAID WIRE BEING OF A MATERIAL WHICH WHEN HEATED TO A PREDETERMINED TEMPERATURE BY THE PASSAGE OF AN ELECTRIC CURRENT THROUGH SAID WIRE UNDERGOES AN EXOTHERMIC REACTION WHICH RAISES IT TO A SECOND TEMPERATURE GREATLY IN EXCESS OF SAID PREDETERMINED TEMPERATURE, THE INTENSITY OF SAID SECOND TEMPERATURE BEING SUFFICIENT IN RELATION TO THE STRENGH OF THE GLASS MEMBER AS TO FRACTURE SAID GLASS MEMBER BY THERMAL SHOCK THEREBY FREEING SAID MOVABLE MEMBER.