(19)

(11)

EP 0 471 757 A1

(12)

(43) Date of publication: 26.02.1992 Bulletin 1992/09 (21) Application number: 90907721.0 (22) Date of filing: 30.04.1990

(51) International Patent Classification (IPC):  B22D 11/ 10( . ) B22D 41/ 52( . ) B22D 41/ 50( . ) B22D 41/ 58( . ) (86) International application number: PCT/US1990/002331 (87) International publication number: WO 1990/013379 (15.11.1990 Gazette 1990/26)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 01.05.1989 US 19890346397 (71) Applicant: FERRO CORPORATION Cleveland Ohio 44114-1183 (US)	(72) Inventors: DUNWORTH, Bruce Tyler, TX 75703 (US) McCORKLE, Gary 5621 Old Bullard Road Tyler, TX 75703 (US) (74) Representative: Thomas, Roger Tamlyn, et al  D. Young & Co. 21 New Fetter Lane London EC4A 1DA London EC4A 1DA (GB)