How the Aqua-Lung Scuba Regulator Works
The foundational 1947 patent by Jacques Cousteau and Emile Gagnan for the automatic demand regulator that allows divers to breathe compressed air underwater.
Original patent title: “Diving unit”
The foundational 1947 patent by Jacques Cousteau and Emile Gagnan for the automatic demand regulator that allows divers to breathe compressed air underwater. Granted to Individual in 1949 with 12 forward citations, and it is now in the public domain.
Coverage
What does this patent actually cover?
This patent describes a two-stage demand regulator that automatically supplies air to a diver only when they inhale. It uses a flexible diaphragm that reacts to the pressure difference between the surrounding water and the air inside the regulator. When the diver inhales, the diaphragm moves, opening a valve to release air from the tank at the exact pressure needed for the depth. This mechanism ensures the diver does not waste air and can breathe naturally regardless of their orientation in the water.
The gap
What does this patent NOT cover?
- Does not cover rebreather systems that recycle exhaled air.
- Does not cover surface-supplied diving equipment where air is pumped from a boat.
- Does not cover the design of the high-pressure air cylinders themselves.
- Does not cover mixed-gas diving systems used for deep technical diving.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The invention uses the ambient water pressure to balance the air delivery, meaning the regulator automatically adjusts to the diver's depth without manual intervention.
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
Modern open-circuit scuba regulators
Recreational diving equipment
Underwater research gear
Why it matters
The bigger picture
This invention effectively created the modern sport of scuba diving. By enabling safe, portable, and autonomous underwater breathing, it transformed ocean exploration from a dangerous professional task into a widely accessible activity.
Filed
March 10, 1947
Granted
October 18, 1949
Market context
Who's building on this
Companies in this space
Major manufacturers like Aqua Lung (founded by the inventors), Scubapro, and Mares continue to refine the basic demand-valve architecture established in this patent.
Market impact
This patent enabled the birth of the global recreational diving industry. It standardized the 'demand' delivery method, which remains the safety and functional benchmark for all scuba equipment used today.
Claim 1 — Plain English
What this patent covers
This patent describes a two-stage demand regulator that automatically supplies air to a diver only when they inhale. It uses a flexible diaphragm that reacts to the pressure difference between the surrounding water and the air inside the regulator. When the diver inhales, the diaphragm moves, opening a valve to release air from the tank at the exact pressure needed for the depth. This mechanism ensures the diver does not waste air and can breathe naturally regardless of their orientation in the water.
The clever bit
The invention uses the ambient water pressure to balance the air delivery, meaning the regulator automatically adjusts to the diver's depth without manual intervention.
What it does not cover
- Does not cover rebreather systems that recycle exhaled air.
- Does not cover surface-supplied diving equipment where air is pumped from a boat.
- Does not cover the design of the high-pressure air cylinders themselves.
- Does not cover mixed-gas diving systems used for deep technical diving.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
This patent is in the public domain
See the Freedom to Build guide — what is free to use, what is not, and how to cite this patent.
PatentBrief Score
Impact Score
Early stage
Citation count
22/40
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
$4K – $14K
Midpoint $9K · expired or expiring · industry ×0.9
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
Concepts involved
Citations
Patent lineage
Cite this patent
Emile, G., & Yves, C. J. (1949). How the Aqua-Lung Scuba Regulator Works (U.S. Patent No. 2,485,039). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/2485039/aqualung-scuba-cousteau-gagnan
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 Aqua-Lung Scuba Regulator Works cover?
The foundational 1947 patent by Jacques Cousteau and Emile Gagnan for the automatic demand regulator that allows divers to breathe compressed air underwater.
Who owns patent US 2485039?
Individual owns this patent, granted in 1949.
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 2485039 cited by?
This patent has been cited by 12 later patents that build on its ideas.
What problem does this patent solve?
This invention effectively created the modern sport of scuba diving. By enabling safe, portable, and autonomous underwater breathing, it transformed ocean exploration from a dangerous professional task into a widely accessible activity.
What does this patent NOT cover?
Does not cover rebreather systems that recycle exhaled air.
Same assignee
More from Individual
Patent monitoring