D21F 1/02
Head boxes of fourdrinier machines
Official title: Head boxes of Fourdrinier machines
D21F1/02 (Head boxes of fourdrinier machines) appears on 427 US grants and 160 published applications in this corpus.
Search patents in D21F- Granted patents
- 427
- Published applications
- 160
- Assignees
- 137
- Inventors
- 585
- Latest grant
- 4 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 15 | 0 |
| 1977 | 4 | 0 |
| 1978 | 10 | 0 |
| 1979 | 10 | 0 |
| 1980 | 8 | 0 |
| 1981 | 6 | 0 |
| 1982 | 7 | 0 |
| 1983 | 13 | 0 |
| 1984 | 7 | 0 |
| 1985 | 16 | 0 |
| 1986 | 8 | 0 |
| 1987 | 9 | 0 |
| 1988 | 11 | 0 |
| 1989 | 14 | 0 |
| 1990 | 17 | 0 |
| 1991 | 14 | 0 |
| 1992 | 17 | 0 |
| 1993 | 3 | 0 |
| 1994 | 7 | 0 |
| 1995 | 8 | 0 |
| 1996 | 13 | 0 |
| 1997 | 14 | 0 |
| 1998 | 19 | 0 |
| 1999 | 13 | 0 |
| 2000 | 17 | 0 |
| 2001 | 19 | 4 |
| 2002 | 20 | 10 |
| 2003 | 6 | 13 |
| 2004 | 9 | 6 |
| 2005 | 8 | 6 |
| 2006 | 2 | 3 |
| 2007 | 2 | 6 |
| 2008 | 3 | 8 |
| 2009 | 6 | 4 |
| 2010 | 5 | 5 |
| 2011 | 5 | 8 |
| 2012 | 8 | 11 |
| 2013 | 2 | 5 |
| 2014 | 3 | 2 |
| 2015 | 2 | 0 |
| 2016 | 1 | 1 |
| 2017 | 0 | 0 |
| 2018 | 1 | 4 |
| 2019 | 1 | 5 |
| 2020 | 5 | 11 |
| 2021 | 2 | 8 |
| 2022 | 12 | 3 |
| 2023 | 5 | 13 |
| 2024 | 7 | 12 |
| 2025 | 7 | 6 |
| 2026 | 6 | 6 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Sheet manufacturing apparatus4 Aug 2026US 12,698,592 B2Seiko Epson Corporation
- Flow-optimized edge treatment30 Jun 2026US 12,668,921 B2Voith Patent GmbH
- Apparatus for forming a substrate2 Jun 2026US 12,644,211 B2Kimberly-Clark Worldwide, Inc.
- Headbox for manufacturing a substrate21 Apr 2026US 12,606,956 B2Kimberly-Clark Worldwide, Inc.
- Foam-based manufacturing system and process14 Apr 2026US 12,601,113 B2Kimberly-Clark Worldwide, Inc.
- Method and device for producing a fibrous web17 Sep 2026US 2026/0275634 A1Andritz Kuesters GmbH
- Apparatus for forming a substrate10 Sep 2026US 2026/0265971 A1Kimberly-Clark Worldwide, Inc.
- Foam-Based Manufacturing System and Process6 Aug 2026US 2026/0226679 A1Kimberly-Clark Worldwide, Inc.
- Foam-Based Manufacturing System and Process23 Jul 2026US 2026/0210038 A1Kimberly-Clark Worldwide, Inc.
- Device for producing a fibrous web16 Jul 2026US 2026/0201640 A1Andritz Kuesters GmbH
Most cited
By later US patents
- Extended flexible headbox slice with parallel flexible lip extensions and extended internal dividers194US 5,129,988 AKimberly-Clark Corporation · 1992
- Method of making ply-separable paper128US 4,225,382 AThe Procter & Gamble Company · 1980
- Multilayer headbox41US 5,645,689 AVoith Sulzer Papiermachinen GmbH · 1997
- Headbox apparatus with stock dilution conduits for basis weight control39US 5,196,091 ABeloit Technologies, Inc. · 1993
- Apparatus for forming a multilayer jet of paper making stock37US 4,445,974 AAktiebolaget Karlstads Mekaniska Werkstad · 1984