(19)

(11)

EP 0 469 073 A1

(12)

(43) Date of publication: 05.02.1992 Bulletin 1992/06 (21) Application number: 90907846.0 (22) Date of filing: 13.04.1990

(51) International Patent Classification (IPC):  C01G 1/ 00( . ) G21B 3/ 00( . ) (86) International application number: PCT/US1990/001998 (87) International publication number: WO 1990/013126 (01.11.1990 Gazette 1990/25)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 21.04.1989 US 19890341733 28.04.1989 US 19890345628 (71) Applicant: Mills, Randell L. Cochranville, PA 19330 (US)	(72) Inventor: Mills, Randell L. Cochranville, PA 19330 (US) (74) Representative: Patentanwälte Beetz - Timpe - Siegfried Schmitt-Fumian - Mayr  Steinsdorfstrasse 10 D-80538 München D-80538 München (DE)