(19)

(11)

EP 0 057 711 A1

(12)

(43) Date of publication: 18.08.1982 Bulletin 1982/33 (21) Application number: 81902282.0 (22) Date of filing: 11.08.1981

(51) International Patent Classification (IPC):  E21C 27/ 34( . ) E21C 29/ 02( . ) E21C 41/ 00( . ) E21C 27/ 02( . ) E21C 29/ 10( . ) (86) International application number: PCT/GB1981/000161 (87) International publication number: WO 1982/000680 (04.03.1982 Gazette 1982/07)

(84) Designated Contracting States: DE FR GB (30) Priority: 13.08.1980 GB 19800026374 (71) Applicant: BARRY, Michael John Pontefract, West Yorkshire (GB)	(72) Inventor: BARRY, Michael John Pontefract, West Yorkshire (GB) (74) Representative: Long, Edward Anthony, et al  Hulse & Co. Eagle Star House, Carver Street Sheffield S1 4FP Sheffield S1 4FP (GB)