You can freely build on Boosting Fuel Cell Power for Vehicles Using Oxygen Injection
This patent expired in 2012. 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
Energy Partners Inc
Patent granted
1994
Expired
2012
Forward citations
90
What this patent covers
This patent describes a way to make hydrogen fuel cells more powerful for vehicles by dynamically changing the air they breathe. Under normal driving, the fuel cell uses regular air as an oxidant. When the vehicle demands high power, such as during acceleration, the system detects the increased amperage and automatically opens a valve to inject pure oxygen into the air intake. This enriches the oxygen content to between 30% and 60%, allowing the fuel cell to generate more power without needing a massive, heavy fuel cell stack.
What is now free to use
All 0 claims of US 5346778 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 fuel cell systems that operate at temperatures above the boiling point of water.
Does not cover systems that enrich oxygen to levels higher than 60% by volume.
Does not cover fuel cells that operate at pressures significantly higher than 30 psig above atmospheric pressure.
Does not cover systems that lack a mechanism to sense amperage output to trigger oxygen injection.
Who is building on this today
The core concepts of fuel cell load management are now standard in the R&D labs of major automotive manufacturers like Toyota, Hyundai, and Honda. These companies focus on optimizing air management systems to improve the power density of their commercial fuel cell stacks.
Products built on expired version of this technology
Experimental hydrogen fuel cell prototype vehicles from the 1990s
High-performance hydrogen fuel cell power modules
Stationary fuel cell systems with peak-load management
How to cite this patent in your documentation
Energy Partners Inc. US Patent 5346778. Electrochemical load management system for transportation applications. Granted 1994, expired 2012. 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.