Child resistant closure

Claim 1

A child resistant closure assembly for the threaded neck of a container comprising: an internally threaded closure defining an internal thread complementary to the thread of a container neck and an internal upper sealing surface, said closure defining a sidewall providing a radially outwardly extending clutch ring, said clutch ring defining a multiplicity of upwardly facing closure teeth spaced about the periphery of the clutch ring, each said tooth providing a generally vertical leading edge and a substantially inclined trailing edge, an open-topped collar comprising an outer gripping surface and defining an inner recess receiving said clutch ring, and means for defining said recess comprising a lower inwardly projecting retention bead and an upper collar clutch portion, the lower surface of said clutch portion comprising a multiplicity of downwardly facing collar teeth, each said collar tooth defining a generally vertical leading edge and a substantially angled trailing edge, and said collar being movable vertically upwardly with respect to said closure by no more than about twice the distance between the confronting surfaces of said clutch ring and said retention bead, whereby when said collar is rotated in a clockwise direction said generally vertical leading edges engage, and when said collar is rotated in a counterclockwise direction said trailing edges engage and said angled collar trailing edge rides up said inclined trailing edge except when a downward force is exerted against said collar to maintain said trailing edges in engagement.