(19)

(11)

EP 0 020 709 A1

(12)

(43) Date of publication: 07.01.1981 Bulletin 1981/01 (21) Application number: 80900105.0 (22) Date of filing: 30.11.1979

(51) International Patent Classification (IPC):  A47L 15/ 44( . ) B08B 13/ 00( . ) C11D 17/ 04( . ) D06F 39/ 02( . ) B01F 1/ 00( . ) C11D 17/ 00( . ) D06F 39/ 00( . ) (86) International application number: PCT/US1979/001026 (87) International publication number: WO 1980/001160 (12.06.1980 Gazette 1980/13)

(84) Designated Contracting States: AT CH DE FR LU NL SE (30) Priority: 05.12.1978 US 19780966620 (71) Applicant: ECONOMICS LABORATORY, INC. Saint Paul, MN 55102 (US)	(72) Inventors: COPELAND, James Lee Richfield MN 55423 (US) FERNHOLZ, Peter James Burnsville, MN55337 (US) LARSON, Spencer Brian Newport, MN 55055 (US) SALMONSON, Duane Leroy Cottage Grove, MN 55016 (US) WEICK, Michael D. Eden Prairie, MN 55343 (US) (74) Representative: Redies, Franz  (deceased) 02.05.1985 02.05.1985 (DE)