You can freely build on How the Modern Frisbee Design Works
This patent expired in 1985. Every claim — 1 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
Wham O Manufacturing Co
Patent granted
1967
Expired
1985
Forward citations
137
What this patent covers
The patent defines the geometry of a flying disc, specifically focusing on the transition from a flat center to a curved rim. It describes an upper convex surface and a lower concave surface that create lift during flight. A critical feature is the inclusion of 'air flow spoiling means,' which are concentric raised ribs on the top surface. These ribs disrupt the airflow to prevent the disc from stalling or wobbling, ensuring a more stable flight path.
What is now free to use
All 1 claims of US 3359678 are in the public domain. Specifically:
Claim 1: AN AERODYNAMIC TOY — 4 specific elements
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 discs without the specific concentric raised ribs on the top surface.
Does not cover non-circular aerodynamic toys.
Does not cover discs that lack the defined downward curvature from the central area to the rim.
Who is building on this today
Wham-O remains the primary entity associated with the Frisbee brand, though various sports equipment manufacturers now produce high-performance discs for Ultimate and disc golf that refine these original aerodynamic principles.
Products built on expired version of this technology
Wham-O Frisbee
Professional Ultimate Frisbee discs
Recreational plastic flying discs
How to cite this patent in your documentation
Wham O Manufacturing Co. US Patent 3359678. Flying saucer. Granted 1967, expired 1985. 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.