INSERT SLEEVE FOR FIXING A SCREW IN AN OBJECT, PARTICULARLY OF A SOFT MATERIAL

摘要

The sleeve is provided with an outer screwthread and an inner screwthread for a screw. The outer screwthread is adapted to the screwthread of a tapped hole in the object. It also comprises an extension adapted to be deformed by a buckling so as to be locked in the screwthread of the hole. The extension has an outer diameter that is less than the minor diameter of the outer screwthread and an inner diameter that is greater than the major diameter of the inner screwthread. The extension has a flange preferably provided with an outer knurling which improves the engagement thereof with the screwthread of the tapped hole when an axial force is applied to the flange to effect outwards buckling of the extension. During disengagement of the sleeve a bolt is threaded into the inner screwthread and jammed therein to effect disengagement of the extension from the hole. The sleeve is replaceable and can be used in particular when the object is made from a soft material whereas the screw is made from a hard material. It may have if desired means for locking the screw against rotation.