Patent ID: 8166904

Claim:
A payload delivery unit for protecting and delivering a payload submerged in a submersion medium, the payload delivery unit comprising a container including: a pressure resistant shell defining a containment chamber and including first and second shell members having opposed first and second sealing faces, respectively; and a resilient seal device engaging and interposed between the first and second sealing faces; wherein the container is configured and constructed such that: when the submersion medium applies an exterior pressure to the first and second shell members such that a shell pressure differential, defined as the exterior pressure less an interior pressure of the containment chamber, exceeds a prescribed pressure, the first and second shell members compressively load and deform the seal device to effect a seal between the first and second shell members that prevents ingress of the submersion medium into the containment chamber, wherein the compressively loaded and deformed seal device operates as a biasing device tending to mechanically force the first and second shell members apart from one another; and when the shell pressure differential is less than the prescribed pressure, the seal device elastically rebounds to automatically mechanically force or assist in automatically mechanically forcing the first and second shell members apart from one another to permit ingress of the submersion medium into the containment chamber.