H01H 33/55
Oil reservoirs or tanks
Official title: Oil reservoirs or tanks; Lowering means therefor (associated with withdrawal mechanism for isolation of switch H02B11/08)
H01H33/55 (Oil reservoirs or tanks) appears on 25 US grants and 27 published applications in this corpus.
Search patents in H01H- Granted patents
- 25
- Published applications
- 27
- Assignees
- 20
- Inventors
- 69
- Latest grant
- 9 Dec 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 1 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 1 | 0 |
| 1986 | 1 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 1 | 0 |
| 2000 | 0 | 0 |
| 2001 | 1 | 0 |
| 2002 | 1 | 1 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 1 |
| 2007 | 1 | 1 |
| 2008 | 0 | 2 |
| 2009 | 1 | 0 |
| 2010 | 1 | 4 |
| 2011 | 0 | 0 |
| 2012 | 2 | 3 |
| 2013 | 1 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 2 |
| 2016 | 0 | 2 |
| 2017 | 4 | 4 |
| 2018 | 2 | 0 |
| 2019 | 1 | 0 |
| 2020 | 0 | 0 |
| 2021 | 0 | 1 |
| 2022 | 1 | 1 |
| 2023 | 1 | 0 |
| 2024 | 1 | 3 |
| 2025 | 2 | 1 |
| 2026 | 0 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Contactor and general switching device comprised thereof9 Dec 2025US 12,494,332 B2
- Subsea substation system with one enclosure having separate thermal zones13 May 2025US 12,300,978 B2ABB Schweiz AG
- Tap changer assembly and a transformer tank assembly29 Oct 2024US 12,131,857 B2Hitachi Energy Ltd
- Arc extinguishing systems5 Dec 2023US 11,837,420 B2Siemens Aktiengesellschaft
- Expandable turret for electrical equipment11 Oct 2022US 11,469,039 B2Hitachi Energy Switzerland AG
- Driving mechanism and operating device for an electrical switch2 Apr 2026US 2026/0094774 A1Eaton Intelligent Power Limited
- Contactor27 Mar 2025US 2025/0104943 A1
- Subsea substation system19 Dec 2024US 2024/0421568 A1ABB Schweiz AG
- Arc extinguishing chamber, vacuum circuit breaker, and method of assembling arc extinguishing chamber22 Aug 2024US 2024/0283228 A1Mitsubishi Electric Corporation
- A tap changer assembly and a transformer tank assembly6 Jun 2024US 2024/0186050 A1Hitachi Energy Ltd
Most cited
By later US patents
- Low oil trip and/or lockout apparatus15US 4,591,816 ARTE Corporation · 1986
- Monitoring of decomposition gases in transformers by referencing volume or pressure to temperature10US 5,900,538 A1999
- Circuit breaker for disconnecting an electrical apparatus from electrical network8US 6,479,780 B2ABB AB · 2002
- Sudden pressure relay having seismic protection6US 4,001,644 AWestinghouse Electric Corp. · 1977
- Distribution transformer having a primary disconnect switch4US 4,324,961 AWestinghouse Electric Corp. · 1982