CA2504816A1

CA2504816A1 - Improvement to a food container

Info

Publication number: CA2504816A1
Application number: CA002504816A
Authority: CA
Inventors: Winston R. Mackelvie
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-05-13
Filing date: 2005-05-13
Publication date: 2006-11-13

Abstract

This invention is an improvement to food containers where the lid of the food container is provided with a large central hole. Prior to snapping on the lid, a piece of common transparent food film is laid over the top of the container. When the lid is snapped on, the film is trapped therebetween. Thus is provided a clean, clear, bubble-shaped viewing window into the container. Because the film can expand as a bubble through the hole and retract into the container, pressure changes are accommodated which helps prevent food leaks and air ingress which extends food safe storage time. The lid's channel is also maintained in a cleaner condition by eliminating food build-up therein.

Description

BACKGROUND OF THE INVENTION
This invention is in the field of food containers having removable lids.
One objective of the invention is to provide a transparent, leak proof viewing window through the opaque plastic material commonly used for lids.
A second objective of the invention is to provide an variable volume chamber above the food to accommodate pressure changes that cause leakage.
Yet another objective of the invention is to provide cleanliness by preventing food accumulation in the narrow recessed groove of the lid which can sometimes can be difficult to clean and therefore becomes contaminated.
Yet another objective of the present invention is to reduce the amount of material and therefore the cost of the lid.
SUMMARY OF THE INVENTION
The present invention is an improvement to a container, said improvement comprising in combination, a lid for said container having having a large orifice, and a sheet of flexible film, the arrangement being such that said film is secured between said container and said lid.
Transparent plastic food wrap is placed over the top lip of the container. The lid having the large hole of the present invention is snapped (or screwed) onto the container trapping the film. Thus is formed a hygienic, leak-proof viewing window into the container.
Being so trapped, the film also acts as a gasket to seal against leakages, especially if the food is added hot and the container is inadvertently tipped as would happen in its transport as, for example, in a child's lunch box.
When filled hot, rising water vapour naturally displaces the air above the food and raises internal pressure. This will often lift the lid of the container, at least partially, causing leakage. With the present invention, when the food is hot the plastic film expands outwards into a bubble above the lid. This volumetric change neutralizes pressure in the container.
As hot food cools or the container is refrigerated, the moisture laden vapour above the food condenses to liquid reducing the internal pressure. Instead of air slowly leaking into the container to equalize the pressure drop, the present invention allows the same film to be draw down into the container eliminating the pressure differential. This prevents unwanted air above the food intact and so the food stays fresh longer.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig 1 shows an perspective view of a typical plastic food container with a snap-on lid that has a large central opening and, a separate sheet of transparent plastic food wrap;
Fig 2 shows the three components of Fig 1 assembled and showing the bubble that expands upwardly;
Fig 3 shows a top view and where hole may be a knock-out section indicated by circular dashed line;
Fig 4 shows a section at 4-4 in Fig 3 of the same embodiment where cooling has taken place drawing the plastic film wrap into the container.

SPECIFICATIONS
In Figs l and 2, container 4 which may be of any shape (rectangular, round, tub, bottle) has lid 1 with snap-lock groove 7 and large opening 2. As shown in Fig 3, opening 2 (dashed circle) may be provided in the form of a knock-out blank or other means which the owner can remove to effect the present invention. Film 3 is common food wrap film torn from a roll to cover the entire top of container 4. When lid 1 is snapped down over film 3 onto container 4, an unobvious benefit ensues: film 3 is able to expand into a bubble 5, as shown in side view Fig 2, to accommodate any higher internal pressure. By forming bubble 5, the present invention helps to prevent leakage of food A by means of film 3 acting as a seal or gasket in groove 7 between lid 1 and container 4.
Furthermore Fig 3 shows a top view of how bubble 5 provides a clear window to view contents of container 4 and how hole 2 may be in the form of a knock-out disc which the user can decide to remove.
In Fig 4 another advantage of the present invention is shown, where, acting as a gasket, film 3 prevents unhygienic food accumulation in the narrow, hard-to-clean snap groove 7 of lid 1 adding to food safety. Also shown in Fig 4 is yet another advantage where film 3 is drawn down naturally into container 4 as food A cools, thereby neutralizing internal pressure drop (vacuum) and unwanted ingress of air which, in turn, adds to the storage life of food A.

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