The Patent Finder
US

Engine systems and methods of operating an engine

US 9,118,048 In force
OverviewSources & methods

Term ends Feb 24, 2032 · Medium confidence

Why Medium: A parent in the chain could not be resolved.

Held by Rolls-Royce PLC
Filed Jun 30, 2011 as application 13/174,706 · Granted Aug 25, 2015
Base term plus 903 days of patent term adjustment (USPTO delay)
Today
20 years from filing
2009 2032
Clock starts
Sep 4, 2009
Term ends
Feb 24, 2032
Granted
Aug 25, 2015
base term patent term adjustment 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
903
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 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.

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 filingClock starts Sep 4, 2009, when the earliest non-provisional application in its chain was filed (this one was filed Jun 30, 2011); a parent in its chain could not be resolved (the next row)Sep 4, 2029High confidence
Continuity chainA parent in the chain could not be resolveddated from this application's own claimMedium confidence
Patent term adjustment+903 days, USPTO patent term adjustment recordFeb 24, 2032High confidence
Terminal disclaimer capNone on recordno cap appliedHigh confidence
Patent term extensionNone on fileno changeHigh confidence
Fee events2 of 3 maintenance fees paidIn forceHigh confidence
Computed term endThe steps above, in orderFeb 24, 2032Medium confidence

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.

Not on this page: the patent's family, its recorded assignments and its citation count. USPTO's assignment records, linked above, list every recorded assignment.

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.

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