US Patent 7246383 Fit adjustment mechanism for helmets

A fit adjustment mechanism for the headband of a helmet including a bridge and a buckle. The bridge has ratchet teeth extending from the exterior surface. Each of the ratchet teeth has a tapered surface, a top land, and a retention surface with an undercut face beneath the top land. Substantially flat valleys are formed on the exterior surface between each of the ratchet teeth. The buckle includes a clasp that is resiliently and integrally formed on the exterior surface of the base. The clasp has a pawl having an engagement surface so formed to engage the undercut face of the ratchet teeth retention surfaces.