You can freely build on How the Modern Three-Point Car Seatbelt Works
This patent expired in 1979. 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
Volvo AB
Patent granted
1962
Expired
1979
Forward citations
17
What this patent covers
This patent describes a restraint system that uses a single continuous strap to form both a lap belt and a diagonal shoulder belt. The system anchors at three specific points: two on the floor and one on the door pillar. By pulling the strap across the chest and hips, it distributes the force of a sudden stop across the strongest parts of the human body, such as the pelvis and ribcage, rather than focusing pressure on the soft abdomen.
What is now free to use
All 0 claims of US 3043625 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 two-point lap-only belts common in early aviation or older cars.
Does not cover automatic motorized seatbelt systems that move along a track.
Does not cover airbag deployment systems or their integration with belts.
Does not cover child-specific restraint systems like five-point harnesses.
Who is building on this today
Every major automotive manufacturer, including Toyota, Ford, and Volkswagen, builds upon this design. It remains the baseline safety requirement for all road-legal passenger vehicles worldwide.
Products built on expired version of this technology
Standard seatbelts in almost every passenger vehicle produced since the 1960s.
How to cite this patent in your documentation
Volvo AB. US Patent 3043625. Safety belt. Granted 1962, expired 1979. 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.