(19)

(11)

EP 0 022 817 A1

(12)

(43) Date of publication: 28.01.1981 Bulletin 1981/04 (21) Application number: 80900203.0 (22) Date of filing: 27.12.1979

(51) International Patent Classification (IPC):  G10B 3/ 12( . ) G10H 1/ 34( . ) (86) International application number: PCT/US1979/001123 (87) International publication number: WO 1980/001427 (10.07.1980 Gazette 1980/15)

(84) Designated Contracting States: FR (30) Priority: 02.01.1979 US 19790000588 27.02.1979 US 19790015729 (71) Applicant: ARP Instruments, Inc. Lexington, MA 02173 (US)	(72) Inventors: DODDS, Philip V. W., Smith, Mark V. Lexington, MA 02173 (US) SMITH, Mark V. ARP Instruments, Inc. Lexington, MA 02173 (US) (74) Representative: Baillie, Iain Cameron, et al  c/o Ladas & Parry Isartorplatz 5 D-8000 München 2 D-8000 München 2 (DE)