Nippon Piston Ring Co., Ltd.
3 more in force are now held by other companies
Held is read from USPTO's recorded assignments; a transfer never recorded there does not appear.
Recorded under 6 name spellings.
Recorded as renamed to RIKEN NPR Precision (2026)
6
Ending by 2030
May 2029
Next term end
When these terms end
Held patents by the year their term ends
20262027202820292030203120322033203420352036203720382039204020412042204320442045
Fee deadlines
Maintenance fees fall due 3.5, 7.5 and 11.5 years after grant. A missed fee ends a patent at the end of the six month grace period that follows, not on the due date.
- 1 fee due Dec 25, 2026The maintenance fee for Multi-piece oil ring (US 10,330,198) comes due Dec 25, 2026. Unpaid by Jun 25, 2027, it lapses early.
- 2 fees due Jan 4 to 9, 2027 · next Jan 4
- 2 fees due Feb 20 to 28, 2027 · next Feb 20
- 3 fees due Apr 1 to 29, 2027 · next Apr 1
- 3 fees due Jun 19 to 30, 2027 · next Jun 19
- 2 fees due Jul 2 to 16, 2027 · next Jul 2
- 3 fees due Sep 3 to 30, 2027 · next Sep 3
- 2 fees due Oct 2 to 14, 2027 · next Oct 2
Recent changes
Nothing was recorded against this company's patents in the last 90 days.
Patents held now
Soonest term end first. Each date below is computed on that patent's own page, which shows the rule, the adjustments and the fee history it was derived from.
| Patent | Title | Status | Expires | Confidence |
|---|---|---|---|---|
| US 8,381,696 | Cylinder In force · From the USPTO record | In force | From the USPTO record | |
| US 8,733,313 | Iron-based sintered alloy for valve seat, and valve seat for internal combustion engine In force · From the USPTO record | In force | From the USPTO record | |
| US 10,030,772 | Multi-piece oil ring In force · From the USPTO record | In force | From the USPTO record | |
| US 10,330,198 | Multi-piece oil ring In force · From the USPTO record | In force | From the USPTO record | |
| US 10,514,097 | Method for producing piston ring with recess In force · From the USPTO record | In force | From the USPTO record | |
| US 8,592,050 | Piston Ring In force · High confidence | In force | High confidence | |
| US 8,820,750 | Internal combustion engine oil ring In force · From the USPTO record | In force | From the USPTO record | |
| US 9,464,717 | Piston ring In force · From the USPTO record | In force | From the USPTO record | |
| US 10,669,613 | Titanium alloy In force · From the USPTO record | In force | From the USPTO record | |
| US 9,506,138 | Piston ring In force · From the USPTO record | In force | From the USPTO record |
Also on record, not counted in the 40: 3 patents in force now held by others · 30 lapsed for an unpaid fee · 172 ended at full term. List them
Sources and methods
Compiled from the USPTO record, grants, published applications and recorded assignments, not yet reviewed by hand.
How this record was built
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.
Published applications
US patent applications published under this name that have not become patents. An application is published about eighteen months after its earliest filing; one that has not been published is in no public record.
3 pending · 4 abandoned · 29 no status recorded