(19)

(11)

EP 0 157 766 A1

(12)

(43) Date of publication: 16.10.1985 Bulletin 1985/42 (21) Application number: 83903281.0 (22) Date of filing: 26.09.1983

(51) International Patent Classification (IPC):  E21B 47/ 18( . ) H04J 3/ 16( . ) G08C 19/ 24( . ) (86) International application number: PCT/US1983/001493 (87) International publication number: WO 1985/001585 (11.04.1985 Gazette 1985/09)

(84) Designated Contracting States: DE FR GB (71) Applicant: EXPLORATION LOGGING, INC. Sacramento, CA 95815 (US)	(72) Inventor: TROY, George, White Citrus Heights, CA 95610 (US) (74) Representative: Patentanwälte Grünecker, Kinkeldey, Stockmair & Partner  Maximilianstrasse 58 D-80538 München D-80538 München (DE)