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.

A differential drag apparatus is disclosed for detecting air pressure forces on a drag-sensing body. The body is movable in response to a predetermined magnitude of air pressure force. A pressure regulator responds to the movement of the body by releasing uniform pressure to an activation system. The activation system in turn releases a trigger provided the air pressure force acting against the drag-sensing body remains above the predetermined magnitude for a predetermined length of time. The trigger upon release may perform any number of activates such as opening or closing an electrical circuit, initiating a mechanical response, i.e. releasing a parachute, or detonating a small munition charge. The detonation of a charge, for example, may in turn ignite a rocket motor, release an explosive, or any other of related activities. The apparatus is insensitive to short duration forces above or below the predetermined magnitude, and radiation as results from proximate nuclear blast. The trigger and regulator are initially primed by a pyro-train fuse; yet, activated only by differential movement of the drag-sensing body for a predetermined length of time.

A releasing device for a parachute which is ready for use and folded and disposed in a receptacle and held together by securing string against the force of an unholding preloaded spring. The release device includes a breaking device for disconnecting the securing string and a control for actuating the breaking device at predetermined conditions. The control actuates the breaking device by an electric control signal derived after an initialization operation and depending on a barametric pressure which is present and further depending on the presence of a given pressure change rate. The breaking device comprises an energy storing device which is releasable by the electric control signal for disconnecting the securing string.

The invention concerns a releasing mechanism for a parachute which is stowed in a container held closed by a safety string against the pulling force of a preloaded spring. This safety string is fixed to a container and can be released by action of an energy storage, e.g. a detonator or a preloaded spring. The energy set free by controlled ignition or triggering can either destroy or release the safety string.

A pressure dependent parachute release device having a primary storage volume, a check valve between the primary storage volume and a secondary storage volume, a pressure operable valve, the outlet of which is connected to the inlet of a flow restrictor, with the outlet of the flow restrictor being connected to a pressure operated actuator. The inlet of the check valve and a primary port of the pressure operable valve are in fluid communication with the primary storage volume, and a secondary port of the pressure operable valve and the outlet of the check valve are in fluid communication with the secondary storage volume. The pressure operable valve is first set to a primary position, blocking communication from the secondary storage volume to the outlet. A pressure differential between the primary and secondary storage volumes shifts the valve to a secondary position allowing fluid communication between the secondary storage volume and the pressure operated actuator via the flow restrictor. The resulting movement of the pressure operated actuator enables release of the parachute. In a preferred embodiment, the pressure dependent parachute release device is used to open the nose section of an air/water rocket.