(19)

(11)

EP 0 681 630 A1

(12)

(43) Date of publication: 15.11.1995 Bulletin 1995/46 (21) Application number: 94907947.0 (22) Date of filing: 02.02.1994

(51) International Patent Classification (IPC):  E02F 9/ 28( . ) (86) International application number: PCT/US1994/001169 (87) International publication number: WO 1994/018401 (18.08.1994 Gazette 1994/19)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI NL PT SE (30) Priority: 02.02.1993 US 19930012467 (71) Applicant: ESCO CORPORATION Portland Oregon 97210 (US)	(72) Inventors: JONES, Larren, F. Aloha, OR 97007 (US) EMRICH, Robert, K. Tigard, OR 97223 (US) (74) Representative: Grünecker, Kinkeldey, Stockmair & Schwanhäusser Anwaltssozietät  Maximilianstrasse 58 D-80538 München D-80538 München (DE)