Methods for the production of ammonia from urea and/or biuret, and uses for NOx and/or particulate matter removal

US 7,220,395 Term ended

Overview Sources & methods

Term ended Aug 23, 2018 · From the USPTO record

Computed 20-year base term

Named at grant EC&C Technologies, Inc. · find this owner

Filed Sep 15, 2003 as application 10/662,762 · Granted May 22, 2007

Base term plus 520 days of patent term adjustment (USPTO delay)

Today

20 years from filing

Term ended Aug 23, 2018

1997 2026

Clock starts
Mar 21, 1997

Term ended
Aug 23, 2018

Granted
May 22, 2007

base term patent term adjustment after the term ends 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

520

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 2

Maintenance fees paid

Two maintenance fees can end this term early, the ones due 3.5 and 7.5 years from grant; the third one's grace period runs past the term end. 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 Mar 21, 1997, when the earliest non-provisional application in its chain was filed (this one was filed Sep 15, 2003)	Mar 21, 2017	High confidence
Continuity chain	Every parent in the chain resolved	no change	High confidence
Patent term adjustment	+520 days, USPTO patent term adjustment record	Aug 23, 2018	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	2 of 2 maintenance fees paid	term ended	High confidence
Computed term end	The steps above, in order	Aug 23, 2018	From the USPTO record

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.

Methods for the production of ammonia from urea and/or biuret, and uses for NOx and/or particulate matter removal

Term ended Aug 23, 2018 · From the USPTO record

20-year base term ended Mar 21, 2017

How we calculated this date

Sources