Propulsion system, opposing grains rocket engine, and method for controlling the burn rate of solid propellant grains
US 8,051,640 Lapsed on the fee recordLapsed Nov 8, 2015 on the fee record · From the USPTO record
20-year base term ends May 9, 2028
First maintenance fee unpaid; grace period ended.
May 9, 2008
Nov 8, 2015
Nov 8, 2011
Jun 19, 2030
How we calculated this date
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts May 9, 2008, when this application, 12/151,900, was filed | May 9, 2028 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +771 days, USPTO patent term adjustment record | Jun 19, 2030 | 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 | 0 of 3 maintenance fees paid | lapsed Nov 8, 2015 | High confidence |
| Computed term end | The steps above, in order | Nov 8, 2015 | 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.