(19)

(11)

EP 0 536 298 A1

(12)

(43) Date of publication: 14.04.1993 Bulletin 1993/15 (21) Application number: 91913172.0 (22) Date of filing: 26.06.1991

(51) International Patent Classification (IPC):  B24B 31/ 14( . ) (86) International application number: PCT/US1991/004568 (87) International publication number: WO 1992/000162 (09.01.1992 Gazette 1992/02)

(84) Designated Contracting States: BE CH DE ES FR GB IT LI NL (30) Priority: 26.06.1990 US 19900543702 (71) Applicant: HOFFMAN, Steve, E. Englewood Cliffs, NJ 07632 (US)	(72) Inventor: HOFFMAN, Steve, E. Englewood Cliffs, NJ 07632 (US) (74) Representative: Richards, Michèle E. (GB)  Hoechst Aktiengesellschaft Central Patent Department D-65926 Frankfurt am Main D-65926 Frankfurt am Main (DE)