(19)

(11)

EP 0 078 261 A1

(12)

(43) Date of publication: 11.05.1983 Bulletin 1983/19 (21) Application number: 81902063.0 (22) Date of filing: 01.05.1981

(51) International Patent Classification (IPC):  E21B 33/ 035( . ) G05B 19/ 46( . ) E21B 34/ 16( . ) (86) International application number: PCT/US1981/000583 (87) International publication number: WO 1982/003887 (11.11.1982 Gazette 1982/27)

(84) Designated Contracting States: FR GB (71) Applicant: VETCO OFFSHORE, INC. Ventura, CA 93001 (US)	(72) Inventors: HURTA, Gary Lee Houston, TX 77079 (US) MILBERGER, Lionel John Houston, TX 77040 (US) WILLIAMS, Alfred M. Houston, TX 77040 (US) SALINGER, Kenneth C. De Soto, TX 75117 (US) (74) Representative: Gross, Gernot K.  Kleiberweg 5 D-65207 Wiesbaden D-65207 Wiesbaden (DE)