Methods or machines specially adapted for the production of tubular articles

Introduced: September 1968

Last revised: January 2006

Classification Context

Section:: PERFORMING OPERATIONS; TRANSPORTING
Class:: WORKING CEMENT, CLAY, OR STONE
Subclass:: SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER

Filing statistics

IPC B28B 21/00 belongs to the parent subclass B28B, which recorded 124,681 patent applications worldwide between 2013 and 2023. Annual filings grew from 4,345 in 2013 to 15,254 in 2023 (+251%), peaking at 18,524 applications in 2020. The most active applicants in class B28 are MITSUBOSHI DIAMOND INDUSTRIAL COMPANY (868 applications), QINGDAO GAOCE TECHNOLOGY COMPANY (678 applications) and DISCO CORPORATION (500 applications).

Source: EPO PATSTAT, worldwide filings

Related Keywords

moulding CONCRETE pipesmaking clay PIPE(S)making concrete PIPE(S)moulding TUBE(S) from clay or other ceramic compositions or cementitious material

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 21/7 by building-up from preformed elements
B28B 21/76 Moulds
B28B 21/86 Cores
B28B 21/9 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

MITSUBOSHI DIAMOND INDUSTRIAL COMPANY 868
QINGDAO GAOCE TECHNOLOGY COMPANY 678
DISCO CORPORATION JP 500
ZHOU ZHAODI 500
MITSUBOSHI DIAMOND INDUSTRIAL COMPANY JP 456
HILTI LI 455
CORNING US 407
UNITED STATES GYPSUM COMPANY US 375
ZHENGZHOU YUAN DONG REFRACTORIES COMPANY 370
HUNAN SANY KUAIERJU RESIDENTIAL INDUSTRY COMPANY 351