Quick release fastener

A fastener assembly for use in the blind fastening together of first and second parts having aligned apertures extending therethrough with the aperture in the second part being larger than the aperture in the first part, said fastener assembly comprising:

• a stud member having a head and a relatively reduced threaded shank adapted to be projected through said aligned apertures with the head being positioned on the outer side of first part and being larger than the aperture therein;
• a nut having a threaded aperture therethrough for interengagement with the threaded shank to permit relative rotation therebetween, the nut having a nose portion on its outer surface tapered toward the first part, and the nut having a smaller outer diameter than the aperture in the second part so that it can be projected therethrough with the nut located on the opposite side of the second part from the first part;
• a first helical spring having a normal outer diameter larger than the aperture in the first part and smaller than the aperture in the second part assembled around said stud in engagement with the nut and the spring being expandible to have a larger outer diameter than the diameter of the aperture in the second part, the first helical spring being wound in a first direction;
• a surface on the end portion of the nut facing the first and second parts adapted to receive one end of a second helical spring, the other end of the second helical spring bearing against the first part, the second spring being assembled around said stud and under compression when the fastener assembly is inserted into the first part so as to exert a constant axial force on the nut to facilitate rotation of the threaded stud with respect to the nut, the second helical spring being wound in a second direction and being wound with end projections so that the ends can bite into both the nut and the first part to facilitate prevention of rotation of the nut when the stud is rotated, the second helical spring being formed with respect to the first helical spring so that relative rotation between the nut and shank to compress the springs will place a greater load on the second helical spring than the first helical spring to further facilitate retention of the nut against rotation when the stud is rotated;
• the first and second springs biasing the nut in a direction away from the first and second parts so that when the assembled shank portion of the stud and the spring and nut are inserted through the aperture in the second part with the springs extending under partial compression between the first part and the nut is restrained from rotation by the combined biasing forces of the springs, it will move axially toward the head of the stud to expand the first helical spring into engagement with the second part and retain the second part in fixed relationship with respect to the first part.