US 5,421,473 AGranted

Heat resistant plastics container closure

AssigneeRadley Valley Pty Ltd.

InventorPeter C. McCrossen

Life of this patent

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Abstract

A plastics container (10) for hermetically sealed unrefrigerated storage of perishable food that is capable of retaining the hermetic seal during steam retort cooking and sterilizing at temperatures up to 130.degree. C. The container has a body (12) and cover (16) of a lightweight, disposable nature made from thermoformable plastics barrier sheet capable of prolonged resistance to transmission of oxygen, other gases and water vapor. The container and lid have flange portions (14, 18) that are retained in contact by an injection moulded thermoplastics reinforcing clamp ring in two pieces, a plug half (24) and a socket half (26) that twist-to-lock together in screw thread manner. The clamp ring parts are preferably of polypropylene and moulded with structural cross-sectional thicknesses (t1, t2FIGS. 4, 5) at least twice the thickness of that of the body sheet.

Claims23

Dependent claims

A disaposable packaging container said container comprising:

(a) a body, which has been transformed from a thermoplastics barrier sheet and and which has an open top and a radially outwardly flanged lip circumferentially defining said open top;
(b) a cover having a peripherally and radially outwardly extending flange portion adapted to mate in face-to-face relationship with said outwardly flanged lip of the body, said cover having an inwardly directed step radially inwardly of the flange portion, and
(c) a reclosable reinforcing clamp ring comprising a plug half portion and a mating socket half portion wherein one said half portion is adapted to house and retain the flange portion of the body and the other half portion is adapted to house and retain at least the flange portion of the cover, the socket half portion having a wedge shaped portion engaging the inwardly directed step, effective to compress the cover in a radially outward direction against the receptacle lip, and said half portions being provided with mating engagement means adapted to tighten said flange portions of the body and cover into hermetic sealing contact upon axial rotation of one half portion of the clamp ring with respect to the other.

Dependencies are inferred from the claim text.

Facts

Application: 08/185,840Filed 24 Jan 1994
Granted: 6 Jun 1995
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

B65D 45/305
Annular members, e.g. with snap-over action or screw-threaded: screw-threaded or bayonet-type annular members cooperating with an intermediate ring
B65D 81/34
Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for…: for…
B65D 2401/50
Tamper-indicating means: tamper-band co-operating with intermediate ring connected to the container
Y10T 292/205
Clamps: ring