How the 1940 Nachumsohn Cooking Apparatus Works
A 1940 patent for a cooking device designed to heat food efficiently using an enclosed chamber and specific heat distribution methods.
Original patent title: “Cooking apparatus”
A 1940 patent for a cooking device designed to heat food efficiently using an enclosed chamber and specific heat distribution methods. Granted to Individual in 1940 with 31 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
The patent describes a cooking apparatus featuring a specialized chamber designed to contain food while applying heat from a controlled source. It focuses on the structural arrangement of the heating elements relative to the food container to ensure uniform temperature distribution. By managing the airflow and heat retention within the housing, the device aims to cook items more consistently than open-flame methods available at the time.
The gap
What does this patent NOT cover?
- Does not cover modern induction heating technology.
- Does not cover digital temperature control or programmable timers.
- Does not cover microwave-based cooking mechanisms.
- Does not cover convection fans or forced-air circulation systems.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The invention cleverly uses the physical geometry of the enclosure to trap heat, effectively turning a simple heating element into a more efficient, self-contained cooking environment.
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
Early electric roaster ovens
Vintage countertop heating appliances
Why it matters
The bigger picture
This patent represents the era of mid-century kitchen innovation where inventors sought to move away from simple stoves toward specialized, enclosed cooking appliances. It highlights the transition toward more sophisticated thermal management in home appliances, laying early groundwork for the design of modern countertop ovens.
Filed
May 21, 1936
Granted
January 23, 1940
Market context
Who's building on this
Companies in this space
Modern kitchen appliance manufacturers like Breville and Cuisinart continue to iterate on the fundamental principles of enclosed thermal cooking. While this specific patent has long expired, its focus on chamber geometry remains a baseline for current oven design.
Market impact
This patent contributed to the standardization of enclosed cooking appliances, helping transition the market from open-range cooking to specialized, efficient countertop devices. It helped define the category of electric roaster ovens that became staples in mid-20th-century kitchens.
Claim 1 — Plain English
What this patent covers
The patent describes a cooking apparatus featuring a specialized chamber designed to contain food while applying heat from a controlled source. It focuses on the structural arrangement of the heating elements relative to the food container to ensure uniform temperature distribution. By managing the airflow and heat retention within the housing, the device aims to cook items more consistently than open-flame methods available at the time.
The clever bit
The invention cleverly uses the physical geometry of the enclosure to trap heat, effectively turning a simple heating element into a more efficient, self-contained cooking environment.
What it does not cover
- Does not cover modern induction heating technology.
- Does not cover digital temperature control or programmable timers.
- Does not cover microwave-based cooking mechanisms.
- Does not cover convection fans or forced-air circulation systems.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Early stage
Citation count
30/40
Moderately cited
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
$20K – $63K
Midpoint $40K · 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
Irving, N. (1940). How the 1940 Nachumsohn Cooking Apparatus Works (U.S. Patent No. 2,187,888). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/2187888/crock-pot-slow-cooker-naxon
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How the 1940 Nachumsohn Cooking Apparatus Works cover?
A 1940 patent for a cooking device designed to heat food efficiently using an enclosed chamber and specific heat distribution methods.
Who owns patent US 2187888?
Individual owns this patent, granted in 1940.
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 2187888 cited by?
This patent has been cited by 31 later patents that build on its ideas.
What problem does this patent solve?
This patent represents the era of mid-century kitchen innovation where inventors sought to move away from simple stoves toward specialized, enclosed cooking appliances. It highlights the transition toward more sophisticated thermal management in home appliances, laying early groundwork for the design of modern countertop ovens.
What does this patent NOT cover?
Does not cover modern induction heating technology.
Same assignee
More from Individual
Patent monitoring