Method and apparatus for using free radicals to reduce pollutants in the exhaust gases from the combustion of fuel
US 6,029,442 Lapsed on the fee recordLapsed Feb 29, 2012 on the fee record · From the USPTO record
20-year base term ended Oct 7, 2017
Third maintenance fee unpaid; grace period ended.
Oct 7, 1997
Feb 29, 2012
Feb 29, 2000
Oct 7, 2017
How we calculated this date
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts Oct 7, 1997, when this application, 08/947,287, was filed | Oct 7, 2017 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | None on file | no change | High confidence |
| Terminal disclaimer cap | None on record | no cap applied | High confidence |
| Patent term extension | None on file | no change | High confidence |
| Fee events | 2 of 3 maintenance fees paid | lapsed Feb 29, 2012 | High confidence |
| Computed term end | The steps above, in order | Feb 29, 2012 | From the USPTO record |
Sources
Google Patents · The patent document at USPTO · Assignment records at USPTO
USPTO account required: This application in Patent Center · USPTO's maintenance fee lookup
Maintenance fee events come from USPTO's own fee records. Its fee lookup asks for the patent number and the application number.
Not on this page: the patent's family, its recorded assignments and its citation count. USPTO's assignment records, linked above, list every recorded assignment.
Every date shows its work: the base term, any term adjustment or extension, any disclaimer cap, and the maintenance fee record, each with a confidence tier. How this record was built
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