F27D 21/02
Observation or illuminating devices
F27D21/02 (Observation or illuminating devices) appears on 215 US grants and 224 published applications in this corpus.
Search patents in F27D- Granted patents
- 215
- Published applications
- 224
- Assignees
- 201
- Inventors
- 691
- Latest grant
- 18 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 2 | 0 |
| 1978 | 2 | 0 |
| 1979 | 2 | 0 |
| 1980 | 2 | 0 |
| 1981 | 1 | 0 |
| 1982 | 1 | 0 |
| 1983 | 1 | 0 |
| 1984 | 3 | 0 |
| 1985 | 2 | 0 |
| 1986 | 1 | 0 |
| 1987 | 1 | 0 |
| 1988 | 2 | 0 |
| 1989 | 1 | 0 |
| 1990 | 6 | 0 |
| 1991 | 2 | 0 |
| 1992 | 2 | 0 |
| 1993 | 2 | 0 |
| 1994 | 3 | 0 |
| 1995 | 2 | 0 |
| 1996 | 2 | 0 |
| 1997 | 2 | 0 |
| 1998 | 3 | 0 |
| 1999 | 2 | 0 |
| 2000 | 6 | 0 |
| 2001 | 4 | 3 |
| 2002 | 2 | 2 |
| 2003 | 4 | 2 |
| 2004 | 2 | 7 |
| 2005 | 4 | 4 |
| 2006 | 3 | 3 |
| 2007 | 1 | 3 |
| 2008 | 4 | 1 |
| 2009 | 1 | 8 |
| 2010 | 0 | 7 |
| 2011 | 5 | 3 |
| 2012 | 4 | 1 |
| 2013 | 3 | 2 |
| 2014 | 1 | 3 |
| 2015 | 3 | 14 |
| 2016 | 3 | 4 |
| 2017 | 9 | 8 |
| 2018 | 5 | 11 |
| 2019 | 9 | 18 |
| 2020 | 17 | 26 |
| 2021 | 8 | 18 |
| 2022 | 16 | 23 |
| 2023 | 14 | 9 |
| 2024 | 15 | 17 |
| 2025 | 13 | 14 |
| 2026 | 10 | 13 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Manufacturing device for manufacturing a dental object18 Aug 2026US 12,708,495 B2Ivoclar Vivadent AG
- Instrumented plate for oven11 Aug 2026US 12,704,327 B2Saint-Gobain Centre De Recherches Et D ' Etudes Europeen
- Inspection apparatus for melting furnaces that can be used in the steel industry and method14 Jul 2026US 12,680,759 B2Danieli Automation S.P.A.
- Device for monitoring an apparatus for induction heating of a metal material, method for automatic loading and control system9 Jun 2026US 12,650,264 B2Otto Junker GmbH
- Liquid level detection method and detection apparatus for the same, molten material liquid level detection method and detection apparatus for the same, and method for operating vertical furnace24 Mar 2026US 12,584,690 B2Jfe Steel Corporation
- Apparatus and method for refining liquid metal24 Sep 2026US 2026/0284739 A1Danieli & C. Officine Meccaniche SpA
- Device for Monitoring an Apparatus for Induction Heating of a Metal Material, Method for Automatic Loading and Control System17 Sep 2026US 2026/0276308 A1Otto Junker GmbH
- Inspection assembly for a furnace environment3 Sep 2026US 2026/0259007 A1Tallman Technologies Inc.
- Furnace environment inspection system and method27 Aug 2026US 2026/0251396 A1Tallman Technologies Inc.
- Method for measuring molten material level in blast furnace, device for measuring molten material level in blast furnace, and blast furnace operation method30 Jul 2026US 2026/0218322 A1Jfe Steel Corporation
Most cited
By later US patents
- Coal charging car for charging chambers in a coke-oven battery114US 6,152,668 AThyssen Krupp Encoke GmbH · 2000
- Apparatus for monitoring wall surface55US 6,002,993 ANippon Steel Corporation · 1999
- Pressurized housing for surveillance camera40US 5,852,754 AVideolarm, Inc. · 1998
- Repairing apparatus for furnace wall38US 4,649,858 ASumitomo Metal Industries, Ltd. · 1987
- Apparatus for observing the interior of a hot furnace31US 5,162,906 AShinagawa Refractories Co., Ltd. · 1992