Electric igniter with covered fuse head - has wires running to fuse head completely covered by gaine physically and chemically inert to it

摘要

In an electric igniter, the fuse lead is buried in any kind of explosive in a container. It has a sealed passage across the container wall and ignition wires in the head to go through the passage. There is also an insulated sheath with a single opening sealed to the passage. The sheath completely covers the fuse head, giving electrical insulation and protection against physical and chemical damage inside it and also the explosive. The explosive in contact with the fuse is chemically and physically inert relative to the fuse head material.