You can freely build on How the First Aerosol Spray Can Works

What this patent covers

The patent describes a pressurized container that uses a liquefied gas propellant to force a liquid product out through a nozzle. When the valve is opened, the difference in pressure between the inside of the can and the outside causes the liquid and propellant mixture to rush out. As the propellant evaporates, it breaks the liquid into a fine mist or aerosol. This mechanism allowed for the portable, self-contained spraying of insecticides, which was the original intended use during World War II.

What is now free to use

All 0 claims of US 2331117 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 non-pressurized pump-action spray bottles.

• Does not cover systems that use mechanical air pumps instead of liquefied gas propellants.

• Does not cover the chemical composition of the liquid being sprayed.

Who is building on this today

Major consumer goods companies like SC Johnson, Procter & Gamble, and various contract packaging firms continue to refine aerosol delivery systems for household and personal care products.

Products built on expired version of this technology

How to cite this patent in your documentation

CLAUDE R WICKARD. US Patent 2331117. Dispensing apparatus. Granted 1943, expired 1961. 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.