You can freely build on How the Aqua-Lung Scuba Regulator Works
This patent expired in 1967. 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
1949
Expired
1967
Forward citations
12
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.
What is now free to use
All 0 claims of US 2485039 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 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.
Who is building on this today
Major manufacturers like Aqua Lung (founded by the inventors), Scubapro, and Mares continue to refine the basic demand-valve architecture established in this patent.
Products built on expired version of this technology
Modern open-circuit scuba regulators
Recreational diving equipment
Underwater research gear
How to cite this patent in your documentation
Individual. US Patent 2485039. Diving unit. 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.