| abstract |
A shaped charge has provision for bleeding off internal pressure. The shaped charge has a case, a cap, and an O-ring. The case and the cap each have a first end. The case and the cap are assembled together by one of the first ends receiving the other first end. A groove is formed between the case and the cap; the groove receives the O-ring. The groove is provided with a gap on the external pressure side of the O-ring. The gap communicates with the exterior of the shaped charge. When internal pressure is greater than external pressure, the O-ring is deformd and extrudes into the gap, thereby exposing the gap to the internal pressure and allowing the internal pressure to vent out of the shaped charge. The gap is formed either by beveling an edge of the groove or by a borehole extending from a position that communicates with the exterior of the shaped charge to an opening in the groove. |