Container closure having automatic opening means

Claim 1

In a screw top closure for a container opening defined by a helically threaded neck, a rotatable screw top, carried by said threaded neck, having threads mating with the threads of said neck, to permit movement of said screw top by rotation between an outward position and an inward position on said neck, and a sealing partition positioned across the opening of said neck, the improvement comprising, in combination: An aperture defined in said partition, said aperture being positioned in off-center relation to the rotational axis of said screw top; an upstanding sealing cap member with a rupturable seal positioned across said aperture on the side of said partition facing said screw top, and a projection defined on the side of said screw top facing the partition, said projection being positioned to be longitudinally spaced from said sealing cap member when the screw top is in said outward position, and to engage said sealing cap member when the screw top is rotationally advanced more than a complete rotation to said inward position, to rupture the seal between the cap member and the partition, to open said aperture, said partition also defining an upstanding tube passing transversely through said partition, said tube being generally coaxial with the rotational axis of said screw top, said screw top defining a spike member projecting toward said partition, said spike member being also positioned in generally coaxial relationship with said rotational axis, and a diaphragm member positioned to obstruct the bore of said tube, whereby advancement of said screw top by rotation from said outward position to the inward position on said neck causes the spike to rupture said diaphragm.