Connecting device for detachably maintaining flat structures perpendicular to each other

Claim 1

Connecting device for detachably maintaining flat panels perpendicular to each other comprising: a fastener bolt having a head (12) set apart from a shank portion by a reduced cylindrical section (11), said head and said shank portions having the same diameter and said cylindrical section having a substantially smaller diameter than said head and said shank portions, said head (12) of said fastener bolt (10) adjacent said cylindrical section being in the form of a hemispherically shaped cup, the curved side of which forms one side and the stepped transition from said shank portion to said reduced cylindrical section forms the opposite side of an attachment groove; and a cylindrical tightening bolt (20) having cylindrical tightening bore (21) sized for receipt of said fastener bolt head and perpendicular to and extending up to the axis of rotation (25) of said tightening bolt (20) and then merging into a hemispherical cup (28) sized to mate with said hemispherically shaped cup and having tightening slot (22) extending the length of the side wall of said tightening bore (21) up to said hemispherical cup (28) forming a part of said tightening bore (21); said fastener bolt fastening to the first said panel with said shank, said attachment groove and said head protruding therefrom, said tightening bolt rotatably received in a first blind bore provided in the second said panel, said fastener bolt inserted into a second blind bore provided in the second said panel, whereby the axis of rotation of said tightening bolt and the longitudinal axis of said first blind bore receiving said tightening bolt are perpendicular to the longitudinal axes of said fastener bolt and said second blind bore, and are lying in a plane extending through the longitudinal axes of both said fastener bolt and said first blind bore, said tightening bolt operatively engaging said head of said fastener bolt in such a manner that said tightening slot of said tightening bore is engaged in said attachment groove, and as said tightening bolt is rotated, said fastener bolt is pulled along its longitudinal axis into said second blind bore causing the two panels to be firmly joined, said tightening bolt being capable of being rotated up to about 180° from its initial input position.