Also listed on Nippon Steel & Sumitomo Metal Corporation, an earlier holder on the record. The recorded assignments below show how it moved.
Term ended Oct 20, 2026 · High confidence
20-year base term ended Aug 19, 2024
Held by Nippon Steel Corporation
Filed Feb 16, 2006 as application 10/568,997 · Granted Jul 23, 2013
Base term plus 792 days of patent term adjustment (USPTO delay)
Today
Term ended Oct 20, 2026
2004
2026
Clock starts
Aug 19, 2004
Aug 19, 2004
Term ended
Oct 20, 2026
Oct 20, 2026
Granted
Jul 23, 2013
Jul 23, 2013
base term
patent term adjustment
after the term ends
fee events
Updated Nov 15, 2026 · includes USPTO assignment & status data published Nov 15, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
792
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 792 days past its 20-year base term on prosecution delay. All three maintenance fees were paid, so no fee lapse ended it. 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 19, 2004, when application PCT/JP2004/012223, the earliest non-provisional in its chain, was filed (this one was filed Feb 16, 2006) | Aug 19, 2024 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +792 days, USPTO patent term adjustment record | Oct 20, 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 | term ended | High confidence |
| Computed term end | The steps above, in order | Oct 20, 2026 | High confidence |
This family
| US 8,491,734 | this patent Oct 2026 | Oct 2026 |
1 of 2 applications in this family shown, earliest filings first. 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 |
|---|---|---|---|
| Feb 16, 2006 Reel 17610, frame 346 | Honda, Kazuhiko; Tanaka, Koki | Nippon Steel Corporation; Usinor | Assignment of Assignor's Interest |
| Feb 16, 2006 reel/frame not recorded | Honda, Kazuhiko; Tanaka, Koki | Nippon Steel Corporation | Assignment of Assignor's Interest |
| Feb 16, 2006 reel/frame not recorded | Honda, Kazuhiko; Tanaka, Koki | Usinor | Assignment of Assignor's Interest |
| Feb 25, 2013 Reel 29866, frame 762 | Nippon Steel Corporation | Nippon Steel & Sumitomo Metal Corporation | Merger |
| May 14, 2019 Reel 49257, frame 828 | Nippon Steel & Sumitomo Metal Corporation | Nippon Steel Corporation | Change of Name |
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
Note
The 792 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
16
later US patents cite this one
That is above the median of utility patents granted in 2013 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.