CPC Main Group
B28B 21/00 Methods or machines specially adapted for the production of tubular articles
Filing statistics
CPC B28B 21/00 belongs to the parent subclass B28B, which recorded 57,301 patent applications worldwide between 2013 and 2023. Annual filings grew from 2,365 in 2013 to 5,105 in 2023 (+116%), peaking at 7,697 applications in 2020. The most active applicants in class B28 are DISCO CORPORATION (1,471 applications), HILTI (575 applications) and CORNING (544 applications).
Source: EPO PATSTAT, worldwide filings
9 direct subcodes
Child Classifications
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- B28B 21/02 by casting into moulds
- B28B 21/42 by shaping on or against mandrels or like moulding surfaces
- B28B 21/52 by extruding
- B28B 21/56 incorporating reinforcements
- B28B 21/70 by building-up from preformed elements
- B28B 21/76 Moulds
- B28B 21/86 Cores (in general B28B7/00)
- B28B 21/90 Methods or apparatus for discharging after shaping
- B28B 21/92 Methods or apparatus for treating or reshaping
Top Applicants
Top 10 applicants by patent filingsfor class B28, 2013–2023, worldwide · Source: EPO PATSTAT
- DISCO CORPORATION JP 1,471
- HILTI LI 575
- CORNING US 544
- MITSUBOSHI DIAMOND INDUSTRIAL COMPANY JP 518
- UNITED STATES GYPSUM COMPANY US 485
- DISCO ABRASIVE SYSTEM 459
- GE (GENERAL ELECTRIC COMPANY) US 454
- MITSUBOSHI DIAMOND INDUSTRIAL COMPANY 439
- DISCO CORPORATION 403
- NGK INSULATORS JP 308