| 摘要 |
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. |
