GB1524895A - Firing mechanism for percussion caps - Google Patents

Abstract

1524895 Generating combustion products under pressure WALLOP INDUSTRIES Ltd 23 Feb 1977 [4 March 1976] 08791/76 Heading F1L [Also in Division F3] A firing mechanism for firing a percussion cap 4 comprises a leaf-spring 5 fixed at one end at 6 and carrying on its underside at or near the other end a firing pin 8, and a manually operable engagement device which can be raised to stress and subsequently release the spring to cause the pin 8 to strike the cap 4. In one embodiment Fig. 2 the engagement device comprises a pivoted lever 9 having a base cut-out through which the other end of the spring 5 protrudes to rest on a lip 24. As the lever 9 is raised the lip 24 causes the spring 5 to be flexed until a position is reached at which the spring 5 clears the lip 24 and is released. A weight 25 can be mounted on the spring above the firing pin 8. In another embodiment Fig. 7 the lever 9 is double-armed and has a catch 11 at one end which normally engages beneath the spring's free end. Pressure in the appropriate sense on an extension arm 12 of the lever 9 causes the catch 11, and hence the spring's full end, to be raised, flexing the spring, until at the release position, the catch and spring automatically disengage. In a further embodiment Fig. 8 the engagement device comprises a flexible plastics strip 14 extending transverse to the spring and secured at one end 15. An edge margin 18 of the strip 14 engages beneath the spring's free end so that, on raising the strip's free end 16 the spring is raised and flexed and eventually released. Applications mentioned are activation of a fire extinguisher, pressure inflator and, specifically, a pyrotechnic device comprising a charge 20 (Fig. 2).