Term ends May 5, 2028 · Medium confidence
20-year base term ended Dec 29, 2020
Why Medium: A parent in the chain could not be resolved.
Held by Hitachi Energy Ltd.
Filed Jun 15, 2001 as application 09/881,001 · Granted Nov 20, 2018
Base term plus 2684 days of patent term adjustment (USPTO delay)
Today
2000
2028
Clock starts
Dec 29, 2000
Dec 29, 2000
Term ends
May 5, 2028
May 5, 2028
Granted
Nov 20, 2018
Nov 20, 2018
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
2,684
Days of term adjustment
Read from the USPTO patent term adjustment record, not recalculated here.
None
Terminal disclaimer
No disclaimer on this record.
2 of 2
Maintenance fees paid
Two maintenance fees can end this term early, the ones due 3.5 and 7.5 years from grant; the third one's grace period runs past the term end. This counts the ones the record shows paid.
4
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 2684 days past its 20-year base term on prosecution delay. 2 of 2 maintenance fees are paid so far. Confidence: Medium. 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 Dec 29, 2000, when application 09/749,999, the earliest non-provisional in its chain, was filed (this one was filed Jun 15, 2001); a parent in its chain could not be resolved (the next row) | Dec 29, 2020 | High confidence |
| Continuity chain | A parent in the chain could not be resolved | dated from this application's own claim | Medium confidence |
| Patent term adjustment | +2684 days, USPTO patent term adjustment record | May 5, 2028 | 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 2 maintenance fees paid | In force | High confidence |
| Computed term end | The steps above, in order | May 5, 2028 | Medium confidence |
This family
| US 6,512,966 | Term ended Dec 2020 | Dec 2020 |
| US 10,135,253 | this patent May 2028 | May 2028 |
| US 6,671,585 | Term ended Dec 2020 | Dec 2020 |
3 of 4 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 |
|---|---|---|---|
| Sep 5, 2001 Reel 12140, frame 927 | Lof, Per-anders Kristian; Gertmar, Lars Gustaf Ingolf; Andren, Lars Anders Tommy | ABB AB | Assignment of Assignor's Interest |
| Mar 23, 2018 Reel 45713, frame 398 | ABB AB | ABB Schweiz AG | Assignment of Assignor's Interest |
| Mar 6, 2020 Reel 52916, frame 1 | ABB Schweiz AG | ABB Power Grids Switzerland AG | Assignment of Assignor's Interest |
| Dec 31, 2021 Reel 58666, frame 540 | ABB Power Grids Switzerland AG | Hitachi Energy Switzerland AG | Change of Name |
| Nov 13, 2023 Reel 65549, frame 576 | Hitachi Energy Switzerland AG | Hitachi Energy Ltd. | Merger |
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
May 2028
Term ends May 5, 2028. No further fees fall due before then
Note
The 2684 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
173
later US patents cite this one
That is top 1% of utility patents granted in 2018 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.