Plastics component screw connection - uses screw with non-round flange engaging with mating portion of one component

摘要

The screw connection is for use between plastics components. Its shank is designed to screw into one of them, while its head has on the side towards the shank a protruding flange engaging with the other. The flange of the screw is non-round, and engages with a portion (17) of the second component (15) whose mating face (24) is at a distance (x) from the screw axis (18) roughly equal to the minimum radius of the flange. The latter can be of elliptical section, or alternatively polygonal with rounded corners. The design prevents the screw working loose after tightening.