(19)

(11)

EP 0 486 503 A1

(12)

(43) Date of publication: 27.05.1992 Bulletin 1992/22 (21) Application number: 90909764.0 (22) Date of filing: 05.07.1990

(51) International Patent Classification (IPC):  G01C 19/ 14( . ) G01P 9/ 00( . ) G01P 3/ 26( . ) (86) International application number: PCT/GB1990/001035 (87) International publication number: WO 1991/001008 (24.01.1991 Gazette 1991/03)

(84) Designated Contracting States: DE FR GB IT SE (30) Priority: 07.07.1989 GB 19890015673 (71) Applicant: DWYER, Douglas Frank George Devon EX19 8QP (GB)	(72) Inventor: DWYER, Douglas Frank George Devon EX19 8QP (GB) (74) Representative: Gee, David William  Farmhouse Court Marston Nr. Sutton Coldfield West Midlands B76 0DW Marston Nr. Sutton Coldfield West Midlands B76 0DW (GB)