FLOW RESTRICTOR FOR IRRIGATION SYSTEMS
1509294 Irrigation apparatus LEGO M LEMELSHTRICH Ltd 26 March 1975 [26 March 1974] 12794/75 Heading AID The flow rate of a trickle irrigation system is restricted by passing water through a meandering conduit which contains obstructions along its length. The conduit may be formed by a rectangular plate, 1, Fig. 1, having channels b and ridges a matingly engaged with another plate 2, Fig. 2; having channels c, d and ridges e. Water from a pressurised supply enters via a port 4 and emerges from outlet 8. In an alternative embodiment, Fig. 8, two circular discs having serpentine channels are snap-fitted at their peripheries to trap a membrane so that the spiral conduits 21 formed in each disc can be serially connected via a central aperture in the membrane. Water enters at a lower peripheral inlet 19 and emerges from an upper peripheral outlet after flowing through the lower conduit, the central aperture, and the upper conduit.