with parts held relatively to each other by friction or gripping

Introduced: September 1968

Title

Titles differ between systems:

IPC: with parts held relatively to each other by friction or gripping, e.g. using wedges

CPC: with parts held relatively to each other by friction or gripping

Full Title

Full titles differ between systems:

IPC:

Props; Chocks > Telescopic props > with parts held relatively to each other by friction or gripping, e.g. using wedges

CPC:

Props (in the building art E04G25/00); Chocks > Telescopic props (general means for fixing telescopic parts together ) > with parts held relatively to each other by friction or gripping

Of 9 combined children, 8 exist in both systems.

1 codes are CPC-only extensions.

3 shared codes have differing titles between IPC and CPC.

Child Classifications

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E21D 15/285 CPC only CPC only
E21D 15/30 by means expanded or contracted by pressure applied through the medium of a fluid or quasi- fluid, e.g. rubber +2 CPC IPC+CPC Available in IPC and CPC
E21D 15/32 by a deformable collar +1 CPC IPC+CPC Available in IPC and CPC
E21D 15/34 by axially- moving balls, rollers, or the like IPC+CPC Available in IPC and CPC
E21D 15/36 by a tiltable collar surrounding one or both parts IPC+CPC Available in IPC and CPC
E21D 15/38 with longitudinally-divided upper or lower prop parts, e.g. interfitting laminations IPC+CPC Available in IPC and CPC
E21D 15/40 Collar or other support gripped to one or both parts by toggle-action, cam, or other member pivoted or similarly mounted IPC+CPC Available in IPC and CPC
E21D 15/42 with special parts to influence the friction IPC+CPC Available in IPC and CPC
E21D 15/43 Details of wedges (friction linings or pads E21D15/42) +1 CPC IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

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

Top Applicants (CPC)

Class E21,2013–2023, worldwide · Source: EPO PATSTAT

HALLIBURTON ENERGY SERVICES GROUP US 27,652
SAUDI ARABIAN OIL COMPANY SA 7,755
PETROCHINA COMPANY 7,025
BAKER HUGHES US 6,589
SCHLUMBERGER TECHNOLOGY US 6,151
SINOPEC (CHINA PETROCHEMICAL CORPORATION) 4,443
SCHLUMBERGER TECHNOLOGY NL 4,255
CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 3,991
SERVICES PETROLIERS SCHLUMBERGER FR 3,300
SCHLUMBERGER CANADA CA 3,086