(19)

(11)

EP 0 592 543 A1

(12)

(43) Date of publication: 20.04.1994 Bulletin 1994/16 (21) Application number: 92914664.0 (22) Date of filing: 06.07.1992

(51) International Patent Classification (IPC):  E02D 31/ 10( . ) E04G 9/ 10( . ) F16L 5/ 00( . ) E04G 9/ 08( . ) E04G 15/ 06( . ) (86) International application number: PCT/GB1992/001217 (87) International publication number: WO 1993/001440 (21.01.1993 Gazette 1993/03)

(84) Designated Contracting States: GB (30) Priority: 04.07.1991 GB 19910014499 28.01.1992 GB 19920001772 (71) Applicant: DUFAYLITE DEVELOPMENTS LIMITED St. Neots Cambridgeshire PE19 1QW (GB)	(72) Inventors: KACZMAREK, Peter Antony Crewe, Cheshire CW1 1YB (GB) KAY, Thomas Nr. Tarporley, Cheshire CW6 9RB (GB) (74) Representative: Maguire, Peter Albert, et al  Maguire & Co. 5 Crown Street St. Ives, Cambridgeshire PE17 4EB St. Ives, Cambridgeshire PE17 4EB (GB)