This invention relates to releasable nuts, such as explosive nuts in which a set of threaded segments are driven out of engagement with a bolt by a device actuated by squib-produced gases. More particularly, this invention relates to a releasable nut in which the segments are released and locked out of engagement with the bolt threads in a two-step sequence: first, radial release by longitudinal displacement of an enclosing sleeve structure, and second, by positive outward displacement and lockout by a telescoping cone structure of novel construction.

In a preferred form of the invention, actuation is achieved by an entirely enclosed explosion, and the features of releasability and lockout also act to prevent the escape of explosion gases.

The use of explosion nuts and explosion bolts have experienced vastly increased application in recent years because of their convenience for use in many applications in space technology. For example, upon a signal from the earth or from within the device itself, an orbiting space device can impart electrical ignition to explosive squibs within such nuts, so as to detach an exhausted launching vehicle from the orbiting payload. Astronauts have made quick escapes from a satellite pod, after return to the earth's surface, by exploding bolts or nuts to release a hatch cover. In addition to these widely known applications, variations of the explosive nut or bolt are beginning to be proposed for application in submarine devices, or for devices to be used in environments of high radioactivity.

One of the major objects of the present invention is to vastly increase the possible applications of explosion nuts, and to eliminate many of the objectionable features heretofore associated with them. Thus, the explosion nut of this invention could be used in connection with fire escapes, shipboard hatches, safety devices on construction cranes or high-speed rotating machinery.