Making by using a driving shield

Introduced: July 1974

Last revised: January 2006

Full Title

Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries > Making by using a driving shield

Classification Context

Section:: FIXED CONSTRUCTIONS
Class:: EARTH OR ROCK DRILLING; MINING
Subclass:: SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS

Filing statistics

IPC E21D 9/06 belongs to the parent subclass E21D, which recorded 106,833 patent applications worldwide between 2013 and 2023. Annual filings grew from 4,236 in 2013 to 15,272 in 2023 (+261%). The most active applicants in class E21 are HALLIBURTON ENERGY SERVICES GROUP (26,607 applications), PETROCHINA COMPANY (14,382 applications) and SINOPEC (CHINA PETROCHEMICAL CORPORATION) (10,137 applications).

Source: EPO PATSTAT, worldwide filings

Related Keywords

advancing SHIELD(S) for tunnelling

2 direct subcodes

Child Classifications

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E21D 9/08 with additional boring or cutting means
E21D 9/093 Control of the driving shield

Top Applicants

Top 10 applicants by patent filingsfor class E21, 2013–2023, worldwide · Source: EPO PATSTAT

HALLIBURTON ENERGY SERVICES GROUP US 26,607
PETROCHINA COMPANY 14,382
SINOPEC (CHINA PETROCHEMICAL CORPORATION) 10,137
CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 6,517
BAKER HUGHES US 6,269
SCHLUMBERGER TECHNOLOGY US 5,929
SAUDI ARABIAN OIL COMPANY SA 5,880
SOUTHWEST PETROLEUM UNIVERSITY 4,477
CHINA UNIVERSITY OF MINING AND TECHNOLOGY 4,357
SCHLUMBERGER TECHNOLOGY NL 4,219