The Patent Finder
US

Energy Efficient Controlled Magnetic Field Generator Circuit

US 9,590,601 Lapsed on the fee record
OverviewFamilyAssignmentsSources & methods

Lapsed Mar 7, 2021 on the fee record · High confidence

First maintenance fee unpaid; grace period ended.

Filed Apr 7, 2015 as application 14/680,877 · Granted Mar 7, 2017
Base term, 20 years from filing, plus 34 days of patent term adjustment (USPTO delay)
Today
Lapsed Mar 7, 2021
2015 2035
Clock starts
Apr 7, 2015
No longer in force
Mar 7, 2021
Granted
Mar 7, 2017
Term would have run to
May 11, 2035
base term patent term adjustment after the term ends 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
34
Days of term adjustment
Read from the USPTO patent term adjustment record, not recalculated here.
None
Terminal disclaimer
No disclaimer on this record.
0 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.
66
Family applications on record here
Applications sharing this one's continuity chain whose file history this site holds. The family may have others.

Its term would have run to May 11, 2035: its 20-year base term plus 34 days of term adjustment for prosecution delay. 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.
StepInputDate after this stepConfidence
Base term, 20 years from filingClock starts Apr 7, 2015, when this application, 14/680,877, was filedApr 7, 2035High confidence
Continuity chainEvery parent in the chain resolvedno changeHigh confidence
Patent term adjustment+34 days, USPTO patent term adjustment recordMay 11, 2035High confidence
Terminal disclaimer capNone on recordno cap appliedHigh confidence
Patent term extensionNone on fileno changeHigh confidence
Fee events0 of 3 maintenance fees paidlapsed Mar 7, 2021High confidence
Computed term endThe steps above, in orderMar 7, 2021High confidence

This family

US 9,638,821Lapsed on the fee record
May 2025
May 2025
Application PCT/US2015/021093PCT application
no patent term
no patent term
US 9,853,837In force
Apr 2035
Apr 2035
Application PCT/US2015/024265PCT application
no patent term
no patent term
US 9,590,601this patent
Mar 2021
Mar 2021
US 10,168,393In force
Sep 2036
Sep 2036
US 9,614,589Lapsed on the fee record
Apr 2025
Apr 2025
US 9,557,391Lapsed on the fee record
Jan 2021
Jan 2021
8 of 66 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.
RecordedAssignorAssigneeConveyance
May 21, 2015
Reel 35694, frame 193
Krause, James Michael; Mabry, James P.; Pepa, EltonLockheed Martin CorporationAssignment 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.

The Patent Finder CompaniesExpirationsCalculatorWatchlistPricing MethodologyCorrectionsLegalPrivacysupport@thepatentfinder.com Updated Nov 15, 2026 · includes USPTO assignment & status data published Nov 15, 2026 and grant & fee data published Nov 10, 2026 (weekly) Part of 137 Finder · © 2026 137 Finder LLC · Sources cited