| 摘要 |
<p>1,033,793. Detonators for underwater seismic blasting. IMPERIAL CHEMICAL INDUSTRIES Ltd. May 14, 1965 [June 4, 1964], No. 23225/64. Heading F3A. An electric detonator for underwater use is rendered harmless if not fired within a given time by making a closure plug 17 of waterdestructible material, which resists the ingress of water for a certain period. The material is resilient and water-soluble or water-swellable polymeric material and may be methyl cellulose plasticized with a mixture of glycol and glycerine as in Specification 703,962. The detonator casing 11 of an aluminium/manganese alloy contains a base charge of PETN below a priming charge 13 containing lead azide ignited when a current is passed through a bridge-wire embedded in a match-head composition 15 containing lead styphnate.</p> |
