C21D 9/0043
Muffle furnaces
Official title: {Muffle furnaces; Retort furnaces}
C21D9/0043 (Muffle furnaces) appears on 28 US grants and 31 published applications in this corpus.
Search patents in C21D- Granted patents
- 28
- Published applications
- 31
- Assignees
- 29
- Inventors
- 85
- Latest grant
- 11 Nov 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1979 | 1 | 0 |
| 1980 | 1 | 0 |
| 1981 | 1 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 0 | 0 |
| 1986 | 1 | 0 |
| 1987 | 0 | 0 |
| 1988 | 1 | 0 |
| 1989 | 2 | 0 |
| 1990 | 2 | 0 |
| 1991 | 1 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 1 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 2 | 0 |
| 2001 | 0 | 0 |
| 2002 | 1 | 1 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 1 |
| 2008 | 0 | 0 |
| 2009 | 1 | 0 |
| 2010 | 0 | 1 |
| 2011 | 0 | 1 |
| 2012 | 0 | 0 |
| 2013 | 0 | 3 |
| 2014 | 0 | 1 |
| 2015 | 2 | 1 |
| 2016 | 2 | 3 |
| 2017 | 0 | 3 |
| 2018 | 1 | 0 |
| 2019 | 2 | 2 |
| 2020 | 1 | 0 |
| 2021 | 1 | 1 |
| 2022 | 1 | 4 |
| 2023 | 0 | 2 |
| 2024 | 1 | 3 |
| 2025 | 2 | 2 |
| 2026 | 0 | 2 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Multiple temperature-control process for workpieces by means of a triplex furnace11 Nov 2025US 12,470,115 B2Hedrich GmbH
- Method for inductively heating steel ingots on a transport shoe and device for carrying out the method15 Apr 2025US 12,276,457 B2SMS group GmbH
- Hot press forming member having excellent resistance to hydrogen embrittlement, and method for manufacturing same28 May 2024US 11,993,825 B2Posco
- Method for hardening a sintered component25 Oct 2022US 11,479,843 B2Miba Sinter Austria GmbH
- Batch furnace for annealing material and method for heat treatment of a furnace material13 Jul 2021US 11,060,793 B2Gautschi Engineering GmbH
- Radiant tube heater and heat treatment furnace19 Mar 2026US 2026/0078461 A1Daido Steel Co., Ltd.
- Method for thermally treating chromium steels12 Feb 2026US 2026/0043122 A1Robert Bosch GmbH
- Method for inductively heating steel ingots on a transport shoe and device for carrying out the method22 May 2025US 2025/0164188 A1SMS group GmbH
- Device for tempering an object6 Feb 2025US 2025/0044030 A1EBNER Industrieofenbau GmbH
- Hot press forming member having excellent resistance to hydrogen embrittlement, and method for manufacturing same5 Sep 2024US 2024/0295003 A1Posco
Most cited
By later US patents
- Heating furnace31US 5,018,707 AGas Research Institute · 1991
- Convective heat transfer within an industrial heat treating furnace25US 4,789,333 AGas Research Institute · 1988
- Precise thermal processing apparatus21US 4,195,820 APyreflex Corporation · 1980
- Convective heat transfer within an industrial heat treating furnace18US 4,854,863 AGas Research Institute · 1989
- Muffle furnace for continuous heat treatment10US 4,568,279 ASociete des Electrodes et Refractaires Savoie · 1986