Vacuum sealing closure lid for home canning operations

Claim 1

The combination with an open-rimmed vessel such as a jar or the like adapted to contain a perishable foodstuff, of a closure lid seated on the rim of said vessel, means establishing a seal between said lid and the rim coextensively around the latter, said lid being provided with a vent opening therein, a hollow open-ended tubular nipple formed of yieldable elastomeric material and projecting upwardly from said vent opening and establishing communication between the interior of the jar and the ambient atmosphere, the upper end of said nipple being adapted for connection to a source of sub-atmospheric pressure, whereby the jar may be evacuated, said nipple being formed with an internal frusto-conical valve seat of small slant angle, a valve body in the form of a spherical ball disposed wholly within the vertical confines of the nipple, normally resting loosely, and bearing to a large extent circumferentially against said seat in sealing relationship, whereby the ball will deform the seat and come to rest thereon at different elevations when different degrees of sub-atmospheric pressure are maintained within the vessel, said seat being disposed in a medial region of the nipple, whereby inward pressure which is applied to the nipple at a level below the valve will deform the valve seat, at least partially unseat the ball, and permit air to flow downwardly through the nipple and around the opposite sides of the ball to thus relieve the sub-atmospheric pressure within the jar, and retaining means adjacent the upper end of the nipple for preventing the ball from escaping from the nipple under the influence of air which is drawn upwardly through the nipple, or during handling of the jar lid.