Title (en)

DRILL BIT

Publication

EP 0044817 A3 19820825 (FR)

Application

EP 81810301 A 19810722

Priority

CH 563280 A 19800723

Abstract (en)

[origin: EP0044817A2] The drill-bit body (2) is fastened to the lower end of a set of rods engaged in the borehole (1). The boss (4) projecting into the spherical cavity (3) supports the shaft (6) carrying the rotary element (11) of spherical shape held in place by the nut (7). The outer surface of the element (11) is covered with hard particles, for example grains of hard metal or diamond elements. As a result of the drive of the drill-bit body (2) about its axis and the friction of the surface (18), the rotary element (11) necessarily rotates on the shaft (6), with the result that the entire inner face of the hole (1) is attacked by abrasion. <IMAGE>

IPC 1-7

E21B 10/08; E21B 10/26; E21B 10/50

IPC 8 full level

E21B 10/08 (2006.01); E21B 10/26 (2006.01); E21B 10/50 (2006.01)

CPC (source: EP US)

E21B 10/083 (2013.01 - EP); E21B 10/26 (2013.01 - EP US); E21B 10/50 (2013.01 - EP)

Citation (search report)

• [XD] US 4203496 A 19800520 - BAKER WILLIAM III [US], et al
• [XD] US 2013839 A 19350910 - PICKIN ROWLAND O
• [Y] US 2025258 A 19351224 - ZUBLIN JOHN A
• [Y] US 2009742 A 19350730 - MITCHELL WILLIAM J
• [Y] US 3695370 A 19721003 - JONES KENNETH W
• [X] DE 1224229 B 19660908 - ROBERT HOCHSTRASSER
• [A] US 2597669 A 19520520 - PILON JOSEPH L, et al
• [A] US 3385683 A 19680528 - WILLIAMS JR EDWARD B
• [A] US 1974756 A 19340925 - SEIFERT WILLIAM V
• [A] US 2667334 A 19540126 - ORTLOFF JOHN E
• [A] FR 2196428 A1 19740315 - ERAP [FR]
• [A] US 2833520 A 19580506 - OWEN ROBERT G
• [A] US 3318399 A 19670509 - GARNER NORMAN E
• [A] FR 1025745 A 19530420 - HUGHES TOOL CO

Designated contracting state (EPC)

AT CH DE FR IT LI SE

DOCDB simple family (publication)

EP 0044817 A2 19820127; EP 0044817 A3 19820825

DOCDB simple family (application)

EP 81810301 A 19810722