| 摘要 |
A flexible plastics hose or tube 17 having drip outlet members 16 at spaced points along its length, is formed by extruding the flexible hose or tube 17 from an inclined extrusion head 2 through which the members 16 (gravitationally) are fed, via a hopper 3 and an automatic level sensor actuated, vibratory feeder 5, into said hose 17 as it is formed, said members 16 being withdrawn from the head 2 by the flow of the extruding plastics material of the hose 17, and said members 16 being (gravitationally) delivered by way of said head 2 at a rate corresponding to a predetermined spacing of the drip outlet members 16 along the length of the tube 17. The inclined head 2 includes an axially movable heat insulating cylinder of p.t.f.e., which functions as a mandrel of the head and for feeding the members 16. The members 16 each comprise external threads 18 defining channels 19 for the flow of irrigant to a decompression chamber 20, communicating with diametrically opposed drip outlets 22 from the hose which have been formed by cutting off projections of the hose wall and members 16. <IMAGE> |
