(19)

(11)

EP 0 335 893 A1

(12)

(43) Date of publication: 11.10.1989 Bulletin 1989/41 (21) Application number: 88900250.0 (22) Date of filing: 11.12.1987

(51) International Patent Classification (IPC):  B24B 31/ 02( . ) (86) International application number: PCT/IT1987/000100 (87) International publication number: WO 1988/004595 (30.06.1988 Gazette 1988/14)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 19.12.1986 IT 19860024156 (71) Applicant: PREMRU, Edo I-20080 Carpiano (Milan) (IT)	(72) Inventor: PREMRU, Edo I-20080 Carpiano (Milan) (IT) (74) Representative: Dr. Ing. A. Racheli & C. S.r.l.  Viale San Michele del Carso, 4 I-20144 Milano I-20144 Milano (IT)