Press-on twist-off infestation-proof closure for oxygen sensitive products

• US 4,000,825 A
• Filed: 05/22/1974
• Issued: 01/04/1977
• Est. Priority Date: 05/22/1974
• Status: Expired due to Term

• Current Assignee: Continental Can Company Incorporated (Dean Foods Company)
• Original Assignee: Continental Can Company Incorporated (Dean Foods Company)
• Inventors: Westfall, James E.
• Primary Examiner(s): Norton, Donald F.
• Application Number:
  US05/472,137
• Time in Patent Office: 958 Days
• Field of Search: 215/318, 215/327, 215/334, 215/337, 215/341, 215/343, 215/345
• US Class Current: 215/318
• CPC Class Codes: B65D 41/0457 the sealing element covering or co-operating with the screw-thread or the like of a container neck

Abstract

A press-on turn-off closure cap for glass containers which have a top rim sealing finish, a contiguous frusto-conical sealing finish, and on the neck therebelow a circumferential band of thread formations. The closure cap has a cup-shaped shell with a top panel and a two-step depending skirt. The shell is lined at the juncture of the top panel and the upper inner step with an annular gasket formed of solid plastisol or the like which provides hermetic sealing engagement with both the top rim finish and also the contiguous frusto-conical side seal finish. In addition the lower step of the shell is lined with a circumferential gasket which after being pushed down over the band of thread formations takes a cold-flow set so as to form mating thread formations capable of camming the closure cap off the container on relative rotation between the cap and container.

Claims

1. In a press-on turn-off gasket closure cap of the combination top and side seal type for use in establishing and maintaining a hermetic seal on a glass container of the type in which the upper edge of the rim together with a frusto-conical portion of the side surface thereof provide the hermetic sealing finish and the outer surface of the container neck below said frusto-conical finish has a series of thread formations arranged in a circumferential band therearound, said cap comprising (1) a generally cup-shaped integral shell having a top panel portion having an annular margin which provides a gasketed down-turned channel formation registrable with said upper edge finish and having a stepped skirt portion with the upper inner step thereof being gasketed and depending from the outer wall of said channel formation as a continuation thereof and providing a downwardly and outwardly flared frusto-conical skirt portion embracingly registrable with said frusto-conical finish portion and having an inclination steeper than that of said frusto-conical finish portion and the bottom of which frusto-conical skirt portion joins an outwardly flared shoulder portion the bottom outer periphery of which joins the top of a lower outer cylindrical step terminating at the bottom in a bead, and (2) an upper annular sealing gasket formed of a solid plastisol located generally within the circumferential corner portion of said shell formed by said annular margin and said upper inner step of said stepped skirt portion having its upper and radially inner portion located on the underside of said top panel portion and extending inwardly to at least adjacent the bottom of the inner side wall of said channel formation and with its lower radially outer portion terminating adjacent the bottom of said frusto-conical skirt portion, with said upper annular sealing gasket filling said channel formation and having a downwardly and outwardly tapered gasket portion lining said frusto-conical skirt portion and diminishing radially outwardly in horizontal cross-section below said channel formation, said tapered gasket portion being at least several times longer in a vertical direction than the depth of said channel formation, said channel-filling upper gasket portion sealingly engaging said upper edge finish of a container when said closure cap is hermetically sealed thereon with at least the lower part of said tapered gasket portion being appreciably thinned out by compressed sealing engagement between said frusto-conical finish portion and said frusto-conical skirt portion, the improvement in said closure cap, comprising, a lower generally cylindrical gasket formed of a puffed plastisol capable of taking a cold flow set lining said lower outer cylindrical step and compressingly embracing said series of thread formations of said container neck after being pushed downwardly thereover so as to take a set with respect thereto whereby said closure cap may be removed by rotation with respect to said container.