Sonobuoy float inflation and depth selection initiators

摘要

A shape-memory alloy initially configured to have engaging potential for a lance, guillotine or pin connected thereto is wrapped in a heating element powered by current from a water activated battery. When the alloy reaches a specific temperature it silently reverts to a predetermined shape. The reversion force is used to displace a lance to pierce a gas cylinder seal to allow inflation of a float and to cut a retaining loop or withdraw a pin to payout a preset length of hydrophone suspension cable.