Lapsed Sep 2, 2020 on the fee record · High confidence
20-year base term ended Oct 16, 2025
Third maintenance fee unpaid; grace period ended.
Held by BT Wearables LLC
Filed Oct 16, 2005 as application 11/252,279 · Granted Sep 2, 2008
Base term, 20 years from filing, plus 198 days of patent term adjustment (USPTO delay)
Today
Lapsed Sep 2, 2020
2005
2026
Clock starts
Oct 16, 2005
Oct 16, 2005
No longer in force
Sep 2, 2020
Sep 2, 2020
Granted
Sep 2, 2008
Sep 2, 2008
Term would have run to
May 2, 2026
May 2, 2026
base term
patent term adjustment
after the term ends
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
198
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.
26
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 2, 2026: its 20-year base term plus 198 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.
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts Oct 16, 2005, when this application, 11/252,279, was filed | Oct 16, 2025 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +198 days, USPTO patent term adjustment record | May 2, 2026 | 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 3 maintenance fees paid | lapsed Sep 2, 2020 | High confidence |
| Computed term end | The steps above, in order | Sep 2, 2020 | High confidence |
This family
| Application 90/016,611 | Pending not computed | not computed |
| US 7,420,472 | this patent Sep 2020 | Sep 2020 |
| US 7,733,224 | In force Oct 2027 | Oct 2027 |
| US 8,647,268 | Lapsed on the fee record Feb 2022 | Feb 2022 |
| US 8,525,673 | Lapsed on the fee record Sep 2025 | Sep 2025 |
| US 8,680,991 | In force no later than Jun 2027 | no later than Jun 2027 |
| US 8,531,291 | Lapsed on the fee record Sep 2025 | Sep 2025 |
| US 8,461,988 | Term ended no later than Nov 2025 | no later than Nov 2025 |
8 of 26 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 |
|---|---|---|---|
| May 28, 2015 Reel 35734, frame 53 | Tran, Bao | Empire IP LLC | Assignment of Assignor's Interest |
| Apr 26, 2023 Reel 63452, frame 334 | Empire IP LLC | BT Wearables LLC | Assignment of Assignor's Interest |
| Apr 2, 2024 Reel 66986, frame 239 | Empire IP | BT Wearables LLC | Corrective Assignment to Correct the Removing 6 Patent Numbers 7733224, 8525673,8680991, 8461988, 8531291, 9351640 Previously Recorded at Reel: 63452 Frame: 334. Assignor(S) Hereby Confirms the Assignment. |
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
Note
The 198 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
412
later US patents cite this one
That is top 1% of utility patents granted in 2008 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
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.