| abstract |
A cylindrical primer cup having a top end which may be sealed so as to safely contain granular or liquid explosive matter is disclosed. A cylindrical conduit extends in a straight path through the cup, providing an opening at either end permitting through-passage of detonating cord or blasting caps. The cylindrical conduit additionally has a fixed diameter throughout, facilitating its travel along a detonating cord. A frustoconical conduit extends well within the primer cup for the placement and frictional retention of blasting caps therein. The sidewalls of the two conduits are relatively thin to provide for easier primer detonation. Symmetrically placed columnar-shaped ribs provide longitudinal structural support for the cylindrical conduit. |