EMI protected water-activated pressurized gas release apparatus

A water-activated pressurized gas release device comprising a first casing of electrically conductive material, a source of pressurized gas connected to said first casing, means for releasing the gas, a single piece second casing of electrically conductive material including bore means for receiving a battery means and further including cavity means, electric circuit means disposed at least partially in said cavity means and connected to said gas release means then to ground, means defining an opening in said second casing to said cavity means providing communication between said first and second casings for connection of said electric circuit means to said gas release means, said first and second casings connected along an interface about the periphery of said opening, one of said casings including a portion which extends along and external of the periphery of the interface and which overlaps the interface and the other of said casings to prevent the entrance of electromagnetic interference radiation between said casings at the interface, passage means interconnecting said bore means and said cavity means, said electric circuit means including an electrically conductive means which extends into said passage means for electrically connecting to one terminal of the battery means, an end cap connectable to said second casing and including means for electrically connecting the other terminal of the battery means to ground upon immersion of the device in water to thereby complete a circuit for supplying electrical energy to said gas release means, and electromagnetic interference filter means having at least one capacitor in said passage means and electrically connected to said conductive means for conducting electromagnetic interference radiation through said at least one capacitor to ground.

Apparatus for supplying electrical energy for firing a primer for release of a pressurized gas when water is detected comprising an electrically conductive casing including a bore means for receiving a battery means, an electric circuit means electrically connectable to one terminal of the battery means and electrically connectable to the primer then to ground, said bore means including a cylindrical outer surface having threads thereon, an end cap of plastic material having threads engageable with said bore means threads for threadedly connecting said end cap to said casing for closing said bore means, an electrically conductive sensor member within said end cap, means for electrically connecting said sensor member to the other terminal of the battery means, passage means in said end cap for flow of water therein to contact said sensor means to thereby complete a circuit upon immersion of the apparatus in water for firing of the primer, said end cap having a cylindrical end portion axially outwardly of said end cap threads, said casing having means defining a shoulder for abutting engagement by said end portion when said end cap is threadedly connected to said casing, an o-ring means, and said end portion and said cylindrical outer surface radially spaced to capture said o-ring means therebetween to seal the connection of said end cap to said casing whereby to reduce the torque required for such sealing.