Term ends May 23, 2031 · High confidence
20-year base term ends Aug 4, 2029
Held by Liquidpiston, Inc.
Filed Aug 4, 2009 as application 12/535,529 · Granted Oct 21, 2014
Base term plus 657 days of patent term adjustment (USPTO delay)
Today
2009
2031
Clock starts
Aug 4, 2009
Aug 4, 2009
Term ends
May 23, 2031
May 23, 2031
Granted
Oct 21, 2014
Oct 21, 2014
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
657
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.
46
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 657 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 4, 2009, when this application, 12/535,529, was filed | Aug 4, 2029 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +657 days, USPTO patent term adjustment record | May 23, 2031 | 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 | May 23, 2031 | High confidence |
This family
| US 7,191,738 | Term ended Jul 2023 | Jul 2023 |
| Application PCT/US2005/000932 | PCT application no patent term | no patent term |
| US 7,909,013 | In force Oct 2028 | Oct 2028 |
| US 8,365,698 | In force Jul 2029 | Jul 2029 |
| Application 61/085,928 | Provisional application no patent term | no patent term |
| Application 61/149,889 | Provisional application no patent term | no patent term |
| Application 61/154,539 | Provisional application no patent term | no patent term |
| Application 61/184,627 | Provisional application no patent term | no patent term |
8 of 46 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 9, 2009 Reel 23205, frame 406 | Shkolnik, Alexander Cerge; Shkolnik, Nikolay; Nabours, Stephen L.; Nelms, Ryan D. | Liquidpiston, Inc. | Assignment of Assignor's Interest |
| Mar 29, 2010 Reel 24154, frame 875 | Liquidpiston, Inc. | Adams Capital Management IV, L.P. | Security Agreement |
| Dec 16, 2015 Reel 37307, frame 760 | Liquidpiston, Inc. | Adams Capital Management IV, L.P.; Northwater Intellectual Property Fund L.P. 2 | Security Interest |
| Dec 16, 2015 reel/frame not recorded | Liquidpiston, Inc. | Adams Capital Management IV, L.P. | Security Interest |
| Dec 16, 2015 reel/frame not recorded | Liquidpiston, Inc. | Northwater Intellectual Property Fund L.P. 2 | Security Interest |
| Nov 23, 2016 Reel 40410, frame 559 | Adams Capital Management IV, L.P.; Northwater Intellectual Property Fund L.P.2 | Liquidpiston, Inc. | Release of Security 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
May 2031
Term ends May 23, 2031. No further fees fall due before then
Note
The 657 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
43
later US patents cite this one
That is top 25% of utility patents granted in 2014 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.