Detachable quarter-turn blind hole fastener

Abstract

A detachable blind hole quarter-turn fastener for securing a panel to a frame in which means are provided for detachably securing the fastener to the panel in response to a quarter-turn of the fastener cross pin stud in one direction and for detachably securing the panel to the frame in response to a quarter-turn of the cross pin stud in the other direction.

Having thus described my invention, what I claim is: 
     
       1. An assembly of a fastener and a panel and a frame including in combination, a panel formed with an opening having a major diametral dimension and a minor dimetral dimension, a frame formed with an opening having a major diametral dimension and a minor diametral dimension, said frame opening major and minor dimensions extending respectively generally in the directions of the panel minor and major dimensions, a fastener formed with .Iadd.a bushing having .Iaddend.a shoulder adapted to engage the outside of said panel around said opening, a stud mounted in said bushing for rotary and for limited axial movement, a cross pin on said stud adjacent to the inside of said panel, said cross pin having a length less than said major diametral dimensions and greater than said minor diametral dimensions, means for biasing said stud for axial movement of said cross pin toward said bushing, means forming spaced locking elements on said bushing over which said cross pin moves in response to rotary movement of said stud in one direction and concomitant axial movement against the action of said biasing means to align said cross pin with the minor dimension of said panel releasably to retain said fastener on said panel, and stops on said bushing angularly disposed between said locking elements, said stops extending axially for a distance greater than said limited axial movement of said stud to prevent rotary movement of said stud beyond the point at which the cross pin engages the stops, said cross pin riding over said locking elements and into alignment with the minor dimension of said frame in response to rotary movement of said stud in the other direction to engage the inner surface of said frame releasably to secure the panel to the frame. 
     
     
       2. An assembly as in claim 1 in which said bushing comprises bosses for engaging the edge of the panel hole in the region of the ends of its major dimension. 
     
     
       3. An assembly as in claim 2 in which said locking elements and said stops form respective pairs of diametral recesses, the recesses of one pair being deeper than the recesses of the other pair, said deeper recesses being generally perpendicular to said bosses. 
     
     
       4. A fastener assembly including in combination, a bushing having a bore therein, a stud mounted in said bushing for rotary and for limited axial movement, means forming a pair of circumferentially spaced axially extending locking elements on the underside of said bushing, means forming respective axially extending stops on the underside of said bushing between said locking elements to provide respective pairs of diametrically opposite recesses, the recesses of one pair being deeper than the recesses of the other pair, a crosspin carried by said stud below the underside of said bushing, means for urging said stud in an axial direction to move said cross pin toward said recesses and means for limiting the axial movement of said stud to a distance less than the axial extent of said stops from the underside of said bushing.