Abstract: A parachute release mechanism is provided which is compact, lightweight, and free from external wire harnesses. The release mechanism includes a passage connected between a source of pressurized gas and a piston chamber having a piston disposed therein. A shear pin is disposed in an opening in the piston and in the piston chamber. Activation of the source of pressurized gas causes the piston to move forward shearing the shear pin and either deploying or releasing a parachute.

Abstract: An explosively operated, confined linear explosive separation joint. The joint features a one-piece female member of a clevis type shape with shear lip grooves located on the outside surface of the clevis generally aligned with the fillet formed between the sidewall and the bottom of the opening in the clevis. The explosive means is contained in the bottom of the clevis portion with the male portion of the joint slideably nested in the clevis opening abutting the explosive. Shear lip groove alignment with the corner radius or fillet formed at the bottom of the clevis and the stiffer structure adjacent to the break point combine to ensure optimum use of the explosive energy and produce a joint which fails primarily in shear rather than tension, taking advantage of the materials weakest property.