(19)

(11)

EP 0 535 054 A1

(12)

(43) Date of publication: 07.04.1993 Bulletin 1993/14 (21) Application number: 91911103.0 (22) Date of filing: 13.06.1991

(51) International Patent Classification (IPC):  C23C 14/ 35( . ) C23C 14/ 56( . ) C23C 14/ 34( . ) H01J 37/ 34( . ) (86) International application number: PCT/GB1991/000955 (87) International publication number: WO 1991/020091 (26.12.1991 Gazette 1991/29)

(84) Designated Contracting States: CH DE FR GB IT LI NL SE (30) Priority: 16.06.1990 GB 19900013498 24.08.1990 GB 19900018624 (71) Applicant: GENERAL VACUUM EQUIPMENT LIMITED Rochdale OL11 3EX (GB)	(72) Inventors: CASEY, Frank Rochdale Lancashire OL11 5HZ (GB) DOWNING, Paul, Alexander Bury Lancashire BL8 2JW (GB) ELLIS, Graham, Harold Bolton Lancashire BL5 2SL (GB) (74) Representative: Low, Peter John, et al  Wilson, Gunn, M'Caw & Co., 41-51 Royal Exchange, Cross Street Manchester, M2 7BD Manchester, M2 7BD (GB)