Term ends Dec 1, 2026 · High confidence
20-year base term ended Aug 5, 2024
Held by Rolls-Royce PLC
Filed Aug 5, 2004 as application 10/913,057 · Granted Mar 31, 2009
Base term plus 848 days of patent term adjustment (USPTO delay)
Today
2004
2026
Clock starts
Aug 5, 2004
Aug 5, 2004
Term ends
Dec 1, 2026
Dec 1, 2026
Granted
Mar 31, 2009
Mar 31, 2009
base term
patent term adjustment
fee events
Updated Nov 14, 2026 · includes USPTO assignment & status data published Nov 14, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
848
Days of term adjustment
Read from the USPTO patent term adjustment record, not recalculated here.
None
Terminal disclaimer
No disclaimer on this record.
3 of 3
Maintenance fees paid
Three maintenance fees fall due, at 3.5, 7.5 and 11.5 years from grant. This counts the ones the record shows paid.
3
Family applications on record here
Applications sharing this one's continuity chain whose file history this site holds. The family may have others.
This patent's term runs 848 days past its 20-year base term on prosecution delay. All three maintenance fees are recorded paid; no more fees are due. Confidence: High. from the record
How we calculated this date
One row per rule, each showing its own input and what it did to the date. A step we could not verify says so instead of resolving itself.
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts Aug 5, 2004, when this application, 10/913,057, was filed | Aug 5, 2024 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +848 days, USPTO patent term adjustment record | Dec 1, 2026 | 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 | 3 of 3 maintenance fees paid | In force | High confidence |
| Computed term end | The steps above, in order | Dec 1, 2026 | High confidence |
This family
| US 6,949,307 | Term ended Sep 2023 | Sep 2023 |
| US 7,510,793 | this patent Dec 2026 | Dec 2026 |
| US 7,799,451 | Term ended Aug 2024 | Aug 2024 |
The applications whose file history this site holds. The family may have others.
Assignments
Assignment documents as recorded at the USPTO, oldest first, with the reel and frame each was recorded at. A recorded assignment is a filed document, not a statement of current ownership, and the absence of a later one is not evidence that the last one still stands.
| Recorded | Assignor | Assignee | Conveyance |
|---|---|---|---|
| Oct 29, 2004 Reel 15310, frame 580 | Perna, Mark A.; Kantak, Milind V.; Birmingham, Daniel P.; Rush, Gregory C.; Debellis, Crispin L. | Sofco-Efs Holdings, LLC | Assignment of Assignor's Interest |
| Oct 12, 2007 Reel 19943, frame 796 | Sofco-Efs Holdings LLC; McDermott Technology, Inc.; BWX Technologies, Inc. | Rolls-Royce Fuel Cell Systems (USA) Inc. | Assignment of Assignor's Interest |
| Jul 20, 2012 Reel 28604, frame 475 | Sofco-Efs Holdings LLC; McDermott Technology, Inc.; BWX Terchnologies, Inc. | Rolls-Royce Fuel Cell Systems (US) Inc. | Corrective Assignment to Correct the Assignee Name of Rolls-Royce Fuel Cell Systems (USA) Inc. Previously Recorded on Reel 019943 Frame 0796. Assignor(S) Hereby Confirms the Assignee Name Should Be Rolls-Royce Fuel Cell Systems (US) Inc.. |
| Oct 23, 2014 Reel 34035, frame 736 | Rolls-Royce Fuel Cell Systems (USA) Inc. | LG Fuel Cell Systems Inc. | Change of Name |
| Mar 25, 2020 Reel 52223, frame 483 | LG Fuel Cell Systems Inc. | Rolls-Royce PLC | Assignment of Assignor's Interest |
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.
Free plan: 3 watched companies. Pro: unlimited.
Alerts on its grants, lapses and transfers.
What's changing
Dec 2026
Term ends Dec 1, 2026. No further fees fall due before then
Note
The 848 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
1
later US patent cites this one
That is below the median of utility patents granted in 2009 in our data, the only group it is compared against.
How we rank
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.
In force means the term is running and no lapse is on record. It is not a finding that the patent is valid.