Term ends Nov 21, 2026 · High confidence
20-year base term ended Sep 29, 2025
Held by Caterpillar Inc.
Filed Sep 29, 2005 as application 11/238,933 · Granted Apr 14, 2009
Base term plus 418 days of patent term adjustment (USPTO delay)
Today
2005
2026
Clock starts
Sep 29, 2005
Sep 29, 2005
Term ends
Nov 21, 2026
Nov 21, 2026
Granted
Apr 14, 2009
Apr 14, 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
418
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.
2
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 418 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 Sep 29, 2005, when this application, 11/238,933, was filed | Sep 29, 2025 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +418 days, USPTO patent term adjustment record | Nov 21, 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 | Nov 21, 2026 | High confidence |
This family
| US 7,519,462 | this patent Nov 2026 | Nov 2026 |
| Application PCT/US2006/020050 | PCT application no patent term | no patent term |
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 |
|---|---|---|---|
| Sep 29, 2005 Reel 17053, frame 968 | Brown, Bryan; Akasam, Sivaprasad; Hoff, Brian D.; Khalil, Rabie E. | Caterpillar Inc. | Assignment of Assignor's Interest |
| Jul 31, 2006 Reel 18172, frame 750 | University Of Chicago, The | Energy, United States Department Of | Confirmatory License |
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
Nov 2026
Term ends Nov 21, 2026. No further fees fall due before then
Note
The 418 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
22
later US patents cite this one
That is above 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.