Fastener for coupling together two panels in face-to-face relation

Claim 1

A fastener for coupling together two panels in a face-to-face relation to each other comprising a male member to be fitted in one of said panels and a female member to be fitted in the other one of said panels, said male member having a head portion to be fitted in a mounting hole of said one panel and a locking shaft portion depending from the lower surface of said head portion, said female member having a mounting flange for regulating the extent of insertion into a mounting hole in said other panel, a hollow locking body portion depending downwardly from said mounting flange and having a blind space and locking means to lock said female member with respect to said mounting hole, said two members being coupled together to couple together said two panels in the face-to-face relation to each other, said locking means consisting of a plurality of locking pawl portions each being provided like a door on the outer periphery of said locking body portion and extending substanially tangentially from said female body member via a reduced thickness hinge portion extending in the longitudinal direction of said locking body portion outer periphery, each said locking pawl portion having a rectangular portion of predetermined length axially of said female member and a tapered lead-in portion of greater axial extent than said predetermined length extending from a free end portion, said tapered portion including a first portion of shallow taper leading from said end portion and connected by a smooth outwardly concave curve to a more steeply tapered portion extending to said rectangular portion, said rectangular portion having a top engagement edge facing the lower surface of said mounting flange.