B28B 21/00
Methods or machines specially adapted for the production of tubular articles
B28B21/00 (Methods or machines specially adapted for the production of tubular articles) appears on 349 US grants and 182 published applications in this corpus.
Search patents in B28B- Granted patents
- 349
- Published applications
- 182
- Assignees
- 204
- Inventors
- 547
- Latest grant
- 19 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 17 | 0 |
| 1977 | 16 | 0 |
| 1978 | 14 | 0 |
| 1979 | 5 | 0 |
| 1980 | 6 | 0 |
| 1981 | 8 | 0 |
| 1982 | 10 | 0 |
| 1983 | 9 | 0 |
| 1984 | 8 | 0 |
| 1985 | 11 | 0 |
| 1986 | 13 | 0 |
| 1987 | 15 | 0 |
| 1988 | 7 | 0 |
| 1989 | 5 | 0 |
| 1990 | 6 | 0 |
| 1991 | 11 | 0 |
| 1992 | 7 | 0 |
| 1993 | 16 | 0 |
| 1994 | 9 | 0 |
| 1995 | 7 | 0 |
| 1996 | 3 | 0 |
| 1997 | 4 | 0 |
| 1998 | 5 | 0 |
| 1999 | 5 | 0 |
| 2000 | 4 | 0 |
| 2001 | 2 | 0 |
| 2002 | 4 | 5 |
| 2003 | 1 | 11 |
| 2004 | 5 | 7 |
| 2005 | 4 | 8 |
| 2006 | 5 | 6 |
| 2007 | 4 | 5 |
| 2008 | 1 | 3 |
| 2009 | 0 | 7 |
| 2010 | 4 | 9 |
| 2011 | 4 | 10 |
| 2012 | 4 | 8 |
| 2013 | 8 | 6 |
| 2014 | 7 | 9 |
| 2015 | 4 | 11 |
| 2016 | 15 | 6 |
| 2017 | 8 | 7 |
| 2018 | 3 | 10 |
| 2019 | 7 | 8 |
| 2020 | 8 | 2 |
| 2021 | 2 | 6 |
| 2022 | 4 | 7 |
| 2023 | 4 | 5 |
| 2024 | 6 | 10 |
| 2025 | 9 | 9 |
| 2026 | 5 | 7 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- B28B 21/02Methods or machines specially adapted for the production of tubular articles: by126
- B28B 21/56Incorporating reinforcements or inserts91
- B28B 21/76Moulds68
- B28B 21/42Methods or machines specially adapted for the production of tubular articles: by53
- B28B 21/92Methods or apparatus for treating or reshaping35
- B28B 21/86Cores34
- B28B 21/90Methods or apparatus for demoulding or discharging after shaping21
- B28B 21/70Methods or machines specially adapted for the production of tubular articles: by16
All 9 subgroupsShow fewer
Recent patents
- Support structure and method of forming a support structure19 May 2026US 12,631,013 B2HC Properties Inc.
- Targeted ceramic casting core inhomogeneity12 May 2026US 12,623,373 B2Rtx Corporation
- Multi-mandrel braiding process3 Mar 2026US 12,565,451 B2Rtx Corporation
- Precast column and method of manufacturing the same3 Feb 2026US 12,540,473 B2Ruentex Engineering & Construction Co., Ltd.
- Methods for complex geometry mandrel removal of ceramic matrix composite components20 Jan 2026US 12,528,228 B2Rtx Corporation
- Methods and systems for commercially producing tubular solid oxide fuel cells1 Oct 2026US 2026/0302269 A1WATT Fuel Cell Corp.
- Method for cmc airfoil using core tube of rigidized ceramic fabric10 Sep 2026US 2026/0264289 A1Rtx Corporation
- Targeted Ceramic Casting Core Inhomogeneity6 Aug 2026US 2026/0225282 A1Rtx Corporation
- Adjustable Magnetic Support Stand for Pallet16 Jul 2026US 2026/0200131 A1Hawkeyepedershaab Concrete Technologies, Inc.
- Core wall-thinning design method for prestressed high-performance concrete cylinder pipe22 Jan 2026US 2026/0022072 A1Zhengzhou University
Most cited
By later US patents
- Process for slip casting textured tubular structures50US 6,335,065 B12002
- Method of making a molded-joint assembly47US 4,410,479 ABattenfeld Maschinenfabriken GmbH · 1983
- Method of forming lined pipe39US 5,028,368 AInternational Pipe Machinery Corporation · 1991
- Method of producing patterned shaped article34US 5,445,772 ACCA Inc. · 1995
- Method of installing manhole safety steps and plugs therefor31US 4,241,543 A1980