DRIP IRRIGATION HOSE; OUTLETS FROM REGULATING PASSAGE EACH COMPRISE A SINGLE LONGITUDINAL SLIT, WATER DRIPS FROM OUTLETS WHEN HOSE IS PRESSURISED; METHOD OF MANUFACTURE

摘要

A drip irrigation hose in which the outlets from the regulating passage each comprise a single longitudinal slit (46, 47). The slits are sufficiently long and the film is sufficiently flexible so the water drips from the outlets when the hose is pressurized. The slits are sufficiently short and the film is sufficiently rigid so the outlets close completely when the hose is depressurized, inhibiting clogging. An apparatus for making the hose includes an outlet forming wheel (20) having a knife blade (30) on its periphery, a backing wheel (26) engaging the outlet forming wheel to establish a first nip (28) therebetween and having a circumferential slot (32) into which the knife blade fits at the first nip, and a rib forming wheel (22) having impressions around its periphery that define a desired track pattern for the ribs. The outlet forming wheel and the rib forming wheel are mounted on a common shaft to operate in synchronism.