Patent ID: 7018378
Filing Date: 2006-03-28
Classification: A61B

Abstract:
1. A device comprising: a shank; a holding component for engaging and holding a rod, the holding component comprising a recess having two legs, a U-shaped cross-section for accommodating the rod, an open end for receiving the rod into the U-shaped cross-section between the legs, and an inner thread on the legs; and a screw, which cooperates with the inner thread of said legs and acts on the rod when positioned in the recess, the screw having a central axis; wherein the inner thread comprises an inner thread base, first and second partial flanks adjacent to one another, and an internal thread edge between the first and second partial flanks said second partial flanks facing away from said open end; wherein the screw has an outer thread for engagement with the inner thread of said legs, the outer thread comprising an outer thread base, third and fourth partial flanks adjacent to one another, and an external thread edge between the third and fourth partial flanks said third partial flanks facing toward the open end; the second and third partial flanks have a negative angle β the first and fourth partial flanks have a positive angle β wherein a first radius (r when the screw and legs of the holding component are brought into engagement without load, the first and fourth partial flanks are in contact with one another, and a gap is provided between the second and third partial flanks wherein during the tightening of the screw into the holding component, a force between said legs and outer thread draws the legs inwards to prevent loosening of the connection between said rod and said screw.