Fitting for detachable connecting structural parts

A fitting for detachably connecting two abutting structural parts, said fitting comprising (a) a connecting member operable for insertion in a bore hole of a first of said structural parts, said connecting member comprising an expandable sleeve and a bolt-shaped expansion member, said bolt-shaped expansion member being disposed in said sleeve for axial displacement therein, one end of said expansion member defining a widening conical section operable to expand said sleeve upon displacement and a second end defining an engagement surface;

• and (b) a cylindrical locking element operable to be rotatably disposed in a second of said structural parts and to communicate with the engagement surface of said expansion member when said first and second structural parts are in abutting relationship, said locking element comprising (i) a first eccentric surface defining a first recess in said locking element, said eccentric surface being developed about the axis of rotation of said locking element and being operable to engage the engagement surface on said bolt-shaped expansion member at the point on said surface at maximal radial distance from the axis of rotation and upon rotation of said locking element in a first direction, to effect displacement of said bolt-shaped expansion member relative to said first structural part, and (ii) an abutment surface operable to restrain said expandable sleeve, the distance between said eccentric surface and the axis of rotation decreasing and the distance between said eccentric surface and said abutment surface increasing upon rotation of said locking member in said first direction.