Integral plastic fastener

Claim 1

In a molded plastic article adapted to be attached by an integrally molded resilient plastic fastener to a cooperating part having an aperture for receiving said fastener, the improvement comprising: said plastic article having a first surface, an opposite second surface and a solid central portion; and said fastener comprising an integral lug extending from said first surface outwardly and terminating in a distal end, said lug in cross-section having a circular outside surface of constant diameter along its length, the portion of said first surface which intersects said lug defining a shoulder adapted to surround said aperture, the central portion of said lug having an axial hollow core which in cross-section has a generally polygonal shape, said core being surrounded by a solid wall portion, said hollow core extending from a first end adjacent said distal end to a second end which is located interiorly of the first surface so as at least to extend into said solid central portion of said plastic article, the length of said core being greater than the length of said lug and the average width of said core adjacent said first end being greater than the average width of said core adjacent said second end.