Isolation member with improved static discharge barrier and non-electric detonator cap including the same

摘要

An isolation member (34) for use in a non-electric detonator cap (10) is of substantially cylindrical shape and has an interior passageway (40) extending therethrough and defining a positioning region (44) and a discharge port (56). The positioning region (44) is dimensioned and configured to snugly receive and seat therein a signal transmission line or shock tube (30) and to orient the signal-emitting end (30a) thereof to aim along the longitudinal axis of cap (10) through a rupturable diaphragm (42) at the target provided by receptor charge (14). The isolation member is positioned between and spaces the signal-emitting end (30a) of the signal transmission line (30) from the receptor charge (14) contained in the detonator cap (10). The diaphragm (42) is formed with centrally intersecting score lines (42a, 42b) that facilitate rupturing of the diaphragm by the signal. The diaphragm (42) may have a circular or polygonal, e.g., rectangular, periphery. The isolation member is preferably made of a semi-conductive material to bleed off to the shell (12) any static electricity charges transmitted through the signal transmission line (shock tube 30) so as to prevent static discharge initiation of the charge.