Internal fuel staging for improved fuel cell performance
US 6,852,442 Lapsed on the fee recordLapsed Feb 8, 2017 on the fee record · From the USPTO record
20-year base term ended Jul 18, 2020
Third maintenance fee unpaid; grace period ended.
Jul 18, 2000
Feb 8, 2017
Feb 8, 2005
Sep 1, 2021
How we calculated this date
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts Jul 18, 2000, when the earliest non-provisional application in its chain was filed (this one was filed Jan 22, 2002) | Jul 18, 2020 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +410 days, USPTO patent term adjustment record | Sep 1, 2021 | 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 8, 2017 | High confidence |
| Computed term end | The steps above, in order | Feb 8, 2017 | 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
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.