(19)

(11)

EP 0 105 305 A1

(12)

(43) Date of publication: 18.04.1984 Bulletin 1984/16 (21) Application number: 83901208.0 (22) Date of filing: 05.04.1983

(51) International Patent Classification (IPC):  B02C 4/ 08( . ) E21F 13/ 00( . ) B02C 21/ 02( . ) E21F 13/ 02( . ) (86) International application number: PCT/GB1983/000101 (87) International publication number: WO 1983/003444 (13.10.1983 Gazette 1983/24)

(84) Designated Contracting States: BE DE FR GB (30) Priority: 03.04.1982 GB 19820009957 (71) Applicant: MMD DESIGN AND CONSULTANCY LIMITED Somercotes Derbyshire DE55 4NJ (GB)	(72) Inventor: POTTS, Alan Nottingham NG1 9DA (GB) (74) Representative: Dealtry, Brian, et al  Eric Potter & Clarkson St. Mary's Court St. Mary's Gate Nottingham NG1 1LE Nottingham NG1 1LE (GB)