You can freely build on How the Koosh Ball's Design Makes It Easy to Catch
This patent expired in 2007. 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
OddzOn Products Inc
Patent granted
1988
Expired
2007
Forward citations
62
What this patent covers
The device uses a dense, spherical arrangement of thin, floppy elastomeric filaments radiating from a central core. When the ball hits a hand, the filaments collapse and absorb the kinetic energy, which prevents the ball from bouncing away. Because the filaments are thin and flexible, they thread between the fingers of the person catching it, creating a secure grip. This design specifically targets the difficulty children have in coordinating the timing and grip required to catch a traditional, rigid ball.
What is now free to use
All 0 claims of US 4756529 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 balls made of solid or rigid materials that do not collapse on impact.
Does not cover spherical objects that lack the specific 'threading' capability between fingers.
Does not cover non-spherical amusement devices, even if they use similar rubbery filaments.
Who is building on this today
The original design was commercialized by OddzOn Products, which was later acquired by Hasbro. Today, the design language of the Koosh ball is widely used in the sensory toy market by various manufacturers focusing on tactile and therapeutic play.
Products built on expired version of this technology
The original Koosh ball
Various tactile sensory balls used in occupational therapy
How to cite this patent in your documentation
OddzOn Products Inc. US Patent 4756529. Generally spherical object with floppy filaments to promote sure capture. Granted 1988, expired 2007. 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.