(19)

(11)

EP 0 035 994 A1

(12)

(43) Date of publication: 23.09.1981 Bulletin 1981/38 (21) Application number: 80901047.0 (22) Date of filing: 18.04.1980

(51) International Patent Classification (IPC):  F28D 9/ 04( . ) F28D 21/ 00( . ) (86) International application number: PCT/US1980/000443 (87) International publication number: WO 1981/000760 (19.03.1981 Gazette 1981/07)

(84) Designated Contracting States: DE FR GB NL SE (30) Priority: 10.09.1979 US 19790074020 (71) Applicant: KRAMERT, Arthur R. Roseburg, OR 97470 (US)	(72) Inventor: KRAMERT, Arthur R. Roseburg, OR 97470 (US) (74) Representative: Oliver, Roy Edward, et al  W.P. THOMPSON & CO. Celcon House 289-293 High Holborn London WC1V 7HU London WC1V 7HU (GB)