Electrical detonator with externally accessible pole piece - uses metal layer element between latter and conductive housing with additional contact ring

摘要

The detonator comprises a conductive housing (1) containing an insulated pole piece (7), electrically connected to a metal layer element (3) with a metal detonation bridge applied to an aluminium ceramic substrate. A contact element (4) electrically connects the metal layer element (3) with the conductive housing (1) in the radial direction. Pref. the contact element (4) comprises a ring with equally spaced radial projections extending inwards from its inner periphery. It pref. has a gilded surface for enhancing its conductivity it is between 0.05 and 0.3mm thick and it has a hardness of above 350 HV1. The detonator remains intact in spite of temp. extremes.