(19)

(11)

EP 0 258 225 A1

(12)

(43) Date of publication: 09.03.1988 Bulletin 1988/10 (21) Application number: 86901624.0 (22) Date of filing: 13.02.1986

(51) International Patent Classification (IPC):  G02C 1/ 06( . ) (86) International application number: PCT/US1986/000310 (87) International publication number: WO 1987/005123 (27.08.1987 Gazette 1987/19)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (71) Applicants: WEST, Keith, E. Edina, MN 55424 (US) RICHARDSON, Kenneth L. Staples, MN 56479 (US)	(72) Inventors: WEST, Keith, E. Edina, MN 55424 (US) RICHARDSON, Kenneth L. Staples, MN 56479 (US)