(19)

(11)

EP 0 811 108 A2

(12)

(43) Date of publication: 10.12.1997 Bulletin 1997/50 (21) Application number: 96905563.0 (22) Date of filing: 21.02.1996

(51) International Patent Classification (IPC):  B65G 1/ 08( . ) E21B 19/ 15( . ) E21B 19/ 14( . ) (86) International application number: PCT/US1996/002354 (87) International publication number: WO 1996/026349 (29.08.1996 Gazette 1996/39)

(84) Designated Contracting States: DE FR GB (30) Priority: 22.02.1995 US 19950392072 22.09.1995 US 19950532354 (71) Applicant: THE CHARLES MACHINE WORKS INC Perry, Oklahoma 73077 (US)	(72) Inventors: SPARKS, Darrel, W. Perry, OK 73077 (US) MCEWEN, Richard, W. Coyle, OK 73027 (US) DEKEN, Arthur, D. Perry, OK 73077 (US) SEWELL, Cody, L. Perry, OK 73077 (US) FRAZIER, Ronald, A. Perry, OK 73077 (US) FRANKLIN, James, E. Perry, OK 73077 (US) (74) Representative: Baillie, Iain Cameron, et al  Ladas & Parry, Altheimer Eck 2 80331 München 80331 München (DE)