H01T 21/00
Apparatus or processes specially adapted for the manufacture or maintenance of spark
Official title: Apparatus or processes specially adapted for the manufacture or maintenance of spark gaps or sparking plugs
H01T21/00 (Apparatus or processes specially adapted for the manufacture or maintenance of spark) appears on 850 US grants and 766 published applications in this corpus.
Search patents in H01T- Granted patents
- 850
- Published applications
- 766
- Assignees
- 154
- Inventors
- 970
- Latest grant
- 8 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 2 | 0 |
| 1978 | 2 | 0 |
| 1979 | 2 | 0 |
| 1980 | 1 | 0 |
| 1981 | 1 | 0 |
| 1982 | 5 | 0 |
| 1983 | 7 | 0 |
| 1984 | 2 | 0 |
| 1985 | 4 | 0 |
| 1986 | 7 | 0 |
| 1987 | 5 | 0 |
| 1988 | 6 | 0 |
| 1989 | 8 | 0 |
| 1990 | 5 | 0 |
| 1991 | 4 | 0 |
| 1992 | 4 | 0 |
| 1993 | 6 | 0 |
| 1994 | 2 | 0 |
| 1995 | 10 | 0 |
| 1996 | 11 | 0 |
| 1997 | 1 | 0 |
| 1998 | 5 | 0 |
| 1999 | 6 | 0 |
| 2000 | 16 | 0 |
| 2001 | 12 | 8 |
| 2002 | 9 | 36 |
| 2003 | 15 | 14 |
| 2004 | 26 | 21 |
| 2005 | 14 | 21 |
| 2006 | 22 | 16 |
| 2007 | 9 | 24 |
| 2008 | 12 | 15 |
| 2009 | 13 | 32 |
| 2010 | 15 | 36 |
| 2011 | 26 | 40 |
| 2012 | 42 | 66 |
| 2013 | 59 | 54 |
| 2014 | 62 | 44 |
| 2015 | 51 | 33 |
| 2016 | 35 | 27 |
| 2017 | 31 | 53 |
| 2018 | 53 | 47 |
| 2019 | 47 | 42 |
| 2020 | 46 | 26 |
| 2021 | 29 | 23 |
| 2022 | 25 | 27 |
| 2023 | 31 | 24 |
| 2024 | 25 | 25 |
| 2025 | 13 | 7 |
| 2026 | 4 | 5 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Tool for removing a seal ring from a spark plug8 Sep 2026US 12,728,506 B2Robert Bosch GmbH
- Spark plug with a sealing earth electrode21 Apr 2026US 12,609,512 B2Robert Bosch GmbH
- Protection device against pulsed currents10 Mar 2026US 12,573,819 B2Citel
- Spark plug electrode having thermally resilient joint and method of manufacturing the same10 Feb 2026US 12,548,984 B2Federal-Mogul Ignition Company
- Spark plug14 Oct 2025US 12,444,909 B2Robert Bosch GmbH
- Spark plug with improved ground electrode27 Aug 2026US 2026/0254204 A1
- Spark plug resistor element arrangement, method for producing same, and spark plug for an internal combustion engine27 Aug 2026US 2026/0254205 A1
- Electrode with elongated elevation or groove, and a spark plug comprising such an electrode as a ground electrode23 Jul 2026US 2026/0213499 A1Robert Bosch GmbH
- Spark plug systems and methods2 Jul 2026US 2026/0188984 A1
- Electrode shape forming method and electrode shape forming device4 Jun 2026US 2026/0155635 A1Subaru Corporation
Most cited
By later US patents
- Spark plug69US 3,958,144 A1976
- Spark plug51US 4,743,793 ANgk Spark Plug Co., Ltd. · 1988
- Spark plug and method for assembling a spark plug45US 5,159,233 A1992
- Spark plug having a noble metallic firing tip bonded to an electric discharge electrode and preferably installed in internal combustion engine44US 6,215,235 B1Denso Corporation · 2001
- Resistor-incorporated spark plug and manufacturing method of resistor-incorporated spark plug41US 6,160,342 ANgk Spark Plug Co., Ltd. · 2000