Locking toggle bolt

Claim 1

A form-fitting connecting arrangement comprising in combination: a workpiece having an opening therethrough, an article having a cylindrical blind bore being axially aligned with said opening and an undercut surface extending essentially radially outwardly from said blind bore and at a certain distance from the orifice of said bore, and a toggle having an elongated bolt and a toggle body having a diameter corresponding substantially to the diameter of the bore, said opening having a transverse dimension at least as great as said diameter of the bore, said toggle being introducible through the opening into the bore, locking elements mounted on said toggle body and having ends facing the bore orifice, said elements being adapted to be swung from a position lying within the diameter of the bore into a position in which they project at least partially beyond the diameter of the toggle body and engage lockingly the undercut surface of the bore, said toggle body being of relatively low height and being mounted on the bore-internal end of said bolt at the blind end of the bore, said locking elements having bore-internal ends closing together on said bottom piece to form a thick-walled cylindrical sleeve enveloping said bolt, an elongated cylindrical sleeve arranged longitudinally displaceably around said bolt and having an end tapering conically towards the interior of the bore and engaging between the ends of the locking elements facing the bore orifice, so that, upon a displacement of the bottom piece in the direction of the bore orifice, the ends of the locking elements are swung positively radially outwardly, the length of said elongated sleeve equalling substantially said certain distance of said undercut surface from the orifice of said bore plus the thickness of the workpiece at said opening plus the length of said displacement of said bottom piece necessary for swinging said locking elements radially outwardly into locking engagement with said undercut surface, said bolt having on its outer end remote from said blind end of said bore means on said bolt for effecting said displacement and including means for providing a bearing surface with said workpiece.