| 摘要 |
1,017,516. Electric detonators. H. SCHAFFLER-GLOSSL, and J. SCHAFFLER-GLOSSL, [trading as SCHAFFLER & CO.]. June 7, 1963 [Feb. 28, 1963], No. 22777/63. Heading F3A. An electric detonator has means for preventing premature ignition by stray currents and/or static charges comprising an inner sleeve 10 of insulating material which extends forwardly as a shield for an igniting head 5, 6 and which, together with a sealing plug 4, defines a spark gap between bare foils 7 connected to leg wires 8 and the detonator casing 1. In the embodiment shown the sleeve 10 is made separately from the sealing plug 4 and is distanced therefrom by a transverse rib 13. Alternatively the sleeve may be distanced by a plurality of projections formed either on the sleeve or the plug and the sleeve may have an internal partition wall 14 which forms a seating and prevents rotation of the igniting head, Figs. 4- 7 (not shown). In the embodiment of Fig. 9 (not shown), a sleeve 17 is formed integral with a sealing plug 4. This sleeve has an elliptical cross-section, Fig. 10 (not shown), and is deformable for entry into the detonator casing. Apertures 18 register with foils 7. If the sleeve is separate from the sealing plug it may be made from a hard synthetic resin or ceramic material and if integral with the plug may be made from a resilient synthetic resin, rubber, buna or neoprene. |
