Electromechanical primer cap

An electromechanical primer cap, which may be selectively initiated electrically or mechanically, comprising:

• an outer metal cup having a cylindrical sidewall extending in an axial direction and a base having upper and lower major surfaces extending at an angle from the axial direction, the base being provided with a hole therethrough extending in the axial direction through the base from the upper major surface of the base to the lower major surface of the base,
• an electrically conductive pole piece having a portion projecting into the hole in the base of the outer metal cup,
• an explosive mixture provided within the outer metal cup,
• a firing bridge support body made of an electrically insulating material having a ring shape having upper and lower major surfaces extending in a radial direction perpendicular to the axial direction and having a through-bore extending in the axial direction through the firing bridge support body from the upper major surface to the lower major surface, and comprising a firing bridge arranged on the upper major surface of the firing bridge support body, the firing bridge having first and second poles, wherein the pole piece is electrically connected to the second pole of the firing bridge, and the first pole of the firing bridge is electrically connected to the metal cup, and
• a counter surface placed onto the explosive mixture, wherein the counter surface protrudes downwardly in the axial direction such that a lower surface of the counter surface is level with the upper major surface of the firing bridge support body, or into the through-bore of the firing bridge support body or through the through-bore of the firing bridge support body, and continues towards an upper contact surface of the electrically conductive pole piece to provide a spacing between the lower surface of the counter surface and the upper contact surface of the electrically conductive pole piece in which a portion of the explosive mixture is provided contacting the lower surface of the counter surface and the upper contact surface of the electrically conductive pole piece, the spacing being configured to allow mechanical initiation of the explosive mixture.