Air-safed underwater fuze system for launched munitions

A fuze system for munitions that are to be launch-deployed and water-detonated, comprising:

• a housing defining a first bore and a second bore contiguous with said first bore, said housing further defining at least one radial port allowing an environment about said housing to communicate with said first bore;
• a first piston slidably mounted in said first bore;
• a second piston slidably mounted in said second bore and positioned flush with said first bore;
• a mechanical loading mechanism coupled between said munitions and said first piston that, prior to launch, positions said first piston in a first position defined by said first piston sealing off said at least one radial port while being spaced apart from said second piston wherein a chamber in said first bore is defined between said first piston and said second piston, and that at launch, positions said first piston in a second position wherein said chamber is expanded so that said at least one radial port is in communication with said chamber so that water fills said chamber when said housing is submerged therein, said first piston having a potential energy bias towards said second piston when in said second position;
• a lock and release mechanism coupled to said mechanical loading mechanism for restraining said mechanical loading mechanism when said first piston achieves said second position and for releasing said mechanical loading mechanism after a specified period of time wherein said potential energy bias causes said first piston to move towards said first position wherein, after said first piston seals off said at least one radial port, said first piston pressurizes said water in said chamber to drive said second piston along said second bore as actuating movement;
• and
• a firing mechanism in communication with said second bore and coupled to said munitions, said firing mechanism being responsive to said actuating movement to generate detonation energy for said munitions.