You can freely build on How Early Vehicle Airbag Safety Systems Work
This patent expired in 1988. 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
Eaton Yale and Towne Inc
Patent granted
1971
Expired
1988
Forward citations
26
What this patent covers
The device functions as an occupant restraint system that remains collapsed during normal operation. Upon detecting an accident, it triggers an expansion process to deploy a confinement, which acts as a cushion. The patent details two primary methods for inflation: using a fluid reservoir with a zero-reaction diffuser to direct gas flow, or utilizing gas-generating chemical materials that ignite to fill the confinement instantly.
What is now free to use
All 0 claims of US 3552770 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 electronic crash sensors or modern accelerometer-based deployment logic
Does not cover multi-stage inflation systems that adjust pressure based on occupant size
Does not cover side-curtain or knee-based airbag configurations
Who is building on this today
Major automotive suppliers like Autoliv, ZF Friedrichshafen, and Joyson Safety Systems continue to refine the chemical and mechanical principles of rapid gas inflation established in early patents like this one.
Products built on expired version of this technology
Early automotive supplemental restraint systems (SRS)
Experimental 1970s vehicle safety prototypes
How to cite this patent in your documentation
Eaton Yale and Towne Inc. US Patent 3552770. Safety device. Granted 1971, expired 1988. 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.