You can freely build on How the First Automatic Pop-Up Toaster Works
This patent expired in 1940. Every claim — 0 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
Individual
Patent granted
1921
Expired
1940
Forward citations
2
What this patent covers
The patent describes a mechanical toaster featuring a timer mechanism that controls the heating duration and a spring-loaded carriage. Once the timer expires, it triggers a release mechanism that allows the spring to push the bread carriage upward, effectively removing the toast from the heating elements. This design ensures the bread is toasted to a specific degree without requiring manual monitoring or intervention.
What is now free to use
All 0 claims of US 1394450 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 electronic sensors that detect the color or moisture level of the bread.
Does not cover toasters that use conveyor belts for continuous toasting.
Does not cover induction-based heating methods.
Who is building on this today
Major appliance manufacturers like Sunbeam, Breville, and KitchenAid continue to refine the basic mechanical pop-up architecture established by Strite.
Products built on expired version of this technology
Standard household pop-up toasters
Commercial bread toasting equipment
How to cite this patent in your documentation
Individual. US Patent 1394450. Bread-toaster. Granted 1921, expired 1940. 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.