You can freely build on How Earl Tupper Invented the Airtight Plastic Food Container

What this patent covers

The patent describes a container made of flexible plastic with a groove around the rim. The lid is designed with a matching ridge. When the user presses the center of the lid, it forces the air out and creates a vacuum-like seal against the container wall. This mechanism allows for a secure closure without needing complex mechanical latches or snaps.

What is now free to use

All 0 claims of US 2487400 are in the public domain. Specifically:

The 0 dependent claims add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• Does not cover rigid glass or metal containers that cannot flex to form a seal.

• Does not cover lids that require mechanical hinges or external clamps to stay closed.

• Does not cover containers made of non-polyethylene materials that lack the necessary flexibility.

Who is building on this today

Tupperware Brands Corporation continues to iterate on this original design. Many consumer goods companies, such as Rubbermaid and OXO, have developed variations of this flexible-seal technology for modern kitchen storage.

Products built on expired version of this technology

How to cite this patent in your documentation

Individual. US Patent 2487400. Open mouth container and nonsnap type of closure therefor. Granted 1949, expired 1967. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.