Resealable closure for bottles and other containers

Claim 1

A sealing closure for a container havIng a mouth which is enclosed by a lip comprising an elastically yielding sealing member extending at least partially around said lip and locking to said lip by elastic action, a collar flange extending from the lower edge of said sealing member and directed obliquely downwards away from said lip, the collar flange being threaded on the outside with threads having asymmetrical profiles, and a cap having an annular jacket which is threaded on its inside with threads having asymmetrical profiles to cooperate with the corresponding thread on said collar flange so that the threads prevent said cap from being pulled away from said sealing member but do not prevent the unscrewing of said cap from said sealing member, said collar flange having an outer diameter at its free lower edge which is greater than the inner diameter at the open end of said cap prior to compression of said collar by said cap and said collar flange being weakened by a number of axial grooves to facillitate a radial and uniform compression of said collar flange when said cap is pressed down over said collar flange, and at least one small projection from said lip along its surface against which the sealing member engages, said projection cooperating with said sealing member to prevent turning of said sealing member relative to the container when the cap is unscrewed, and an axial sealing ring extending from the engaging portion of said sealing member and forming an opening to the interior of said container, and a cylindrical sealing plug attached to the top end of said cap which is adapted to mate with said sealing ring when said cap is pressed upon said sealing member.