Abstract: An inflatable head harness for quickly orienting and securing a device, such as a respiratory mask, in position on the head of a user. The harness comprises a loop to fit around the head, the loop having a longitudinally elastically extensible outer tube and a folded, inflatable, substantially inelastic inner tube positioned within the outer. The inner tube has a greater length than the outer tube and is positioned therein in folded or pleated form. The inner tube is enlarged by means of pressurized fluid, causing the outer tube to extend longitudinally to thereby increase the diameter of the loop and enable it to be slipped over the head. When the pressure is released, the elasticity of the outer tube causes it to contract longitudinally so that the loop is in gripping engagement with the head of the user.

Abstract: At least one gas operated cylinder is mounted on the female connector member of the canopy release body, the piston in the cylinder is restrained in a retracted position by a shear pin protruding in the track ahead of the piston; a roll bar transversely extended in the female member has a cutaway portion to permit the insertion of a prong of a male connector member into an intersecting pocket in the female member so that when the roll bar is turned into a corresponding recess in the prong it interlocks the connector members; the free end of the piston engages a shoulder formed in the periphery of the roll bar; the roll bar may be turned manually away from the piston into position to withdraw it from the recess in the prong, but when gas under pressure moves the piston it shears the shear pin and turns the roll bar into the disengaging position wherein the roll bar is withdrawn from said prong recess.