Also listed on Willfire HC, LLC, an earlier holder on the record. The recorded assignments below show how it moved.

Term ends no later than Aug 24, 2028 · Low confidence

Computed 20-year base term

Grace period ended Nov 11, 2026 · no payment on record as of the Nov 10, 2026 fee file · lapse expected

Held by Tyco Fire Products LP

Filed Jan 25, 2008 as application 11/989,406 · Granted Nov 11, 2014

Base term plus 1116 days of patent term adjustment (USPTO delay)

Today

20 years from filing

Ends no later than Aug 24, 2028

2005 2028

Clock starts
Aug 4, 2005

Ends no later than
Aug 24, 2028

Granted
Nov 11, 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

1,116

Days of term adjustment

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

Unresolved

Terminal disclaimer

On file, reference document not resolved, so the date above is an upper bound. We do not guess the cap.

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.

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 1116 days past its 20-year base term on prosecution delay. A terminal disclaimer is on file with no resolved reference, so no cap is applied and none is guessed. 2 of 3 maintenance fees are paid so far. Confidence: Low: the grace period for its third maintenance fee ended Nov 11, 2026 with no payment on record. 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, 2005, when application 11/196,882, the earliest non-provisional in its chain, was filed (this one was filed Jan 25, 2008)	Aug 4, 2025	High confidence
Continuity chain	Every parent in the chain resolved	no change	High confidence
Patent term adjustment	+1116 days, USPTO patent term adjustment record	Aug 24, 2028	High confidence
Terminal disclaimer cap	Disclaimer on file (approved), reference document not resolved	no cap applied, and none guessed	Medium confidence
Patent term extension	None on file	no change	High confidence
Fee events	The grace period ended with no payment on record in the fee file	grace period ended Nov 11, 2026	Low confidence
Computed term end	The steps above, in order	no later than Aug 24, 2028	Low confidence

This family

US 8,424,612	Lapsed on the fee record Apr 2025	Apr 2025
US 8,881,839	this patent no later than Aug 2028	no later than Aug 2028
US 8,689,896	Term ended Aug 2025	Aug 2025

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
Nov 3, 2011 Reel 27171, frame 542	Williams Fire and Hazard Control, Inc.	Willfire HC, LLC	Assignment of Assignor's Interest
Oct 15, 2013 Reel 31407, frame 511	Willfire HC, LLC	Tyco Fire & Security GmbH	Assignment of Assignor's Interest
Sep 27, 2018 Reel 47158, frame 767	Tyco Fire & Security GmbH	Tyco Fire Products LP	Assignment 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.

Free plan: 3 watched companies. Pro: unlimited.

Alerts on its grants, lapses and transfers.

What's changing

Nov 11

Grace period ended Nov 11, 2026 with no payment on record. The term ends early once USPTO posts the lapse

Aug 2028

Term ends no later than Aug 24, 2028.

Note

A terminal disclaimer is on file and its reference is not resolved. No cap is applied and none is guessed

Note

The 1116 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us

Open question

A terminal disclaimer is on file (approved) and its reference document is not resolved. A disclaimer would cap the term earlier than Aug 24, 2028. We will not guess the cap.

Citations

later US patents cite this one

That is below the median 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

This computed term ends no later than the date shown; an unresolved terminal disclaimer may end it earlier. 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.

Methods for Treating "Plunge Zone," Heavy Liquid, Large Tank, Structural Impediment and Timing Issues, When Extinguishing Tank Fires