GB1252116A - - Google Patents

Abstract

1,252,116. Irrigation pipes. IMPERIAL CHEMICAL INDUSTRIES OF AUSTRALIA & NEW ZEALAND Ltd. 9 April, 1970 [28 April, 1969; 10 July, 1969; 28 July, 1969 (2)], No. 16973/70. Heading A1B. [Also in Division F2] An irrigation system comprises a resilient rain pipe 1 with flexible tributary pipes 4 interference fitted in the main pipe wall, and a resilient cover 2, attached to the main pipe throughout its length, extending over the tributary pipes and having a continuous slot 3 of less width than the diameter of the tributary pipes. The tributary pipes 4 are capillary tubes, and the pipes 1, 4 are of natural rubber, P.V.C., or polyethylene. In operation, the tributary pipes 4 are located completely inside the cover 2, wherein plugs of adhesive filler divide the cover into compartments each containing a tributary pipe, the compartments preferably being filled with a water permeable filler, e.g. sand, powdered cork, or polyurethane foam. Alternatively, the tributary pipes 4 protrude from the cover 2, wherein, during transport of the system, the pipes 4 are pushed into the cover so that only a small length of pipe protrudes from the cover, Fig. 2 (not shown). The main pipe 1, and cover 2 are extruded as a single extrusion of 8 cross-sectional profile, and the extrusion is drawn longitudinally for a predetermined distance past a knife which cuts the slot 3 and the slot is temporarily widened by a shoe adjacent the knife. At the end of the travel, a solid punch passes through the opened out slot 3 and pierces the main pipe wall. Then a hollow punch temporarily opens out the newly formed hole, and injects the end of a tributary pipe 4, inside the punch, into the hole. The punch is retracted and then a guide pushes the pipe 4 into the cover 2, and a knife cuts the tributary pipe, during insertion of the pipe.