How the First Automatic Pop-Up Toaster Works
Charles Strite's 1921 patent for the first toaster that automatically pops bread up after a set time, preventing it from burning.
Original patent title: “Bread-toaster”
Charles Strite's 1921 patent for the first toaster that automatically pops bread up after a set time, preventing it from burning. Granted to Individual in 1921 with 2 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
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.
The gap
What does this patent NOT cover?
- 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.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The innovation lies in integrating a mechanical timer with a spring-loaded release, solving the problem of burnt toast by decoupling the heating process from human presence.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Standard household pop-up toasters
Commercial bread toasting equipment
Why it matters
The bigger picture
This invention fundamentally changed breakfast habits by moving bread toasting from a manual, attention-heavy task to an automated one. It established the standard 'pop-up' interaction model used in nearly every household toaster today.
Filed
June 22, 1920
Granted
October 18, 1921
Market context
Who's building on this
Companies in this space
Major appliance manufacturers like Sunbeam, Breville, and KitchenAid continue to refine the basic mechanical pop-up architecture established by Strite.
Market impact
This patent enabled the creation of the modern home appliance market for breakfast toasting. It shifted consumer expectations toward convenience and automation, effectively replacing manual toasting forks and open-flame methods.
Claim 1 — Plain English
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.
The clever bit
The innovation lies in integrating a mechanical timer with a spring-loaded release, solving the problem of burnt toast by decoupling the heating process from human presence.
What it does not cover
- 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.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Limited data
Citation count
10/40
Early citations
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$7K – $21K
Midpoint $13K · expired or expiring · industry ×2.2
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Concepts involved
Citations
Patent lineage
Cite this patent
Strite, C. P. (1921). How the First Automatic Pop-Up Toaster Works (U.S. Patent No. 1,394,450). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/1394450/pop-up-toaster-strite
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="US1394450"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4405829 · 1983
How RSA Public-Key Encryption Keeps Digital Messages Secret
This patent describes the foundational RSA algorithm, a method for securely sending messages where anyone can encrypt a message using a public key, but only the intended recipient can decrypt it using a secret private key.
Massachusetts Institute of Technology
US 4575330 · 1986
How 3D Printers Build Objects Layer by Layer from Liquid
This patent describes the foundational method for 3D printing, where a machine builds a three-dimensional object layer by layer by hardening a liquid material with light or other energy.
UVP Inc
Semantically similar
You might also find these interesting
More to explore
More in Consumer Electronics
US 7657849 · 2010 · Apple Inc
How the iPhone's Slide-to-Unlock Gesture Works
US 7479949 · 2009 · Apple Inc
How Touchscreens Understand Your Finger Swipes and Scrolls
US 4528643 · 1985 · FPDC Inc
How Stores Make Custom Products On-Demand with Remote Approval
US 7469381 · 2008 · Apple Inc
How Touchscreens Show and Snap Back When You Scroll Past an Edge
New to patents?
Common Questions
Frequently Asked Questions
What does How the First Automatic Pop-Up Toaster Works cover?
Charles Strite's 1921 patent for the first toaster that automatically pops bread up after a set time, preventing it from burning.
Who owns patent US 1394450?
Individual owns this patent, granted in 1921.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 1394450 cited by?
This patent has been cited by 2 later patents that build on its ideas.
What problem does this patent solve?
This invention fundamentally changed breakfast habits by moving bread toasting from a manual, attention-heavy task to an automated one. It established the standard 'pop-up' interaction model used in nearly every household toaster today.
What does this patent NOT cover?
Does not cover electronic sensors that detect the color or moisture level of the bread.
Same assignee
More from Individual
Patent monitoring