Combustion Cavity Layouts for Fuel Staging in Trapped Vortex Combustors

US 8,689,562 Lapsed on the fee record

Overview Sources & methods

Lapsed Apr 8, 2018 on the fee record · High confidence

Computed 20-year base term

First maintenance fee unpaid; grace period ended.

Held by Lean Flame, Inc.

Filed Nov 30, 2009 as application 12/627,852 · Granted Apr 8, 2014

Base term, 20 years from filing, plus 745 days of patent term adjustment (USPTO delay)

Today

Lapsed Apr 8, 2018

2009 2031

Clock starts
Nov 30, 2009

No longer in force
Apr 8, 2018

Granted
Apr 8, 2014

Term would have run to
Dec 15, 2031

base term patent term adjustment after the term ends 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

745

Days of term adjustment

Read from the USPTO patent term adjustment record, not recalculated here.

No effect

Terminal disclaimer

Resolved from the filed document, referencing US 8,689,561, to Dec 15, 2031. The term already ends on or before that date, so the cap shortened nothing.

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.

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 Nov 30, 2009, when this application, 12/627,852, was filed	Nov 30, 2029	High confidence
Continuity chain	Every parent in the chain resolved	no change	High confidence
Patent term adjustment	+745 days, USPTO patent term adjustment record	Dec 15, 2031	High confidence
Terminal disclaimer cap	Disclaimer resolved from the filed document (refs US 8,689,561)	resolves to Dec 15, 2031, no earlier than this term, so no change	High confidence
Patent term extension	None on file	no change	High confidence
Fee events	0 of 3 maintenance fees paid	lapsed Apr 8, 2018	High confidence
Computed term end	The steps above, in order	Apr 8, 2018	High 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.

Combustion Cavity Layouts for Fuel Staging in Trapped Vortex Combustors

Lapsed Apr 8, 2018 on the fee record · High confidence

20-year base term ends Nov 30, 2029

How we calculated this date

Sources