Patent ES-8502625-A1 (ES)
Title: Drip feed irrigation head
IPC: A01G25/02
Filed: 1984-02-21
Abstract: The irrigation distributor head has inlet and outlet ports, each with a seat for a plug movable between them under the effect of a current of liquid. The plug is held against the inlet port seat when the pressure upstream falls below a predetermined value. - The plug is a round body, whose largest-diameter portion has peripheral teeth. The latter pass the irrigation liquid, while retaining particles above a predetermined size, when the plug is bearing against the outlet port seat. The particles are expelled from the drip-feed head, when the plug moves from the outlet port seat against the inlet port seat and vice versa.  (0/6) EPAB- EP-119181 B Distributor or dripper for the micro-irrigation of soils comprising a housing (1,3) provided with an inlet (4) (to be connected to a conduit of an irrigation liquid under pressure) and with an outlet (24) of this liquid; a closing body of revolution (11) having a conical or frustoconical part (35), which is contained in said housing (1,3) and is movable under the influence of the movement of the irrigation liquid in said housing (1,3) between a seat (14) formed in the housing (1,3) and adjacent to the inlet (4) and a seat (20') formed in the housing (1,3) and adjacent to the outlet (24), this last seat (20') having a frusto-conical form and being coaxial to the conical or frusto-conical part (35) of the closing body (11). - An annular passage (32) defined by the opposite faces of the housing (1,3) and of the closing body (11) and extending from the inlet (4) to the outlet (24) of the housing, this annular passage allowing the rinsing of the dripper or distributor during the movement of the closing body (11), in said housing (1,3) from the seat (20') adjacent to the outlet (24) toward the seat (14) adjacent to the inlet (4) and vice-versa, and means (44) for retracting the closing body (11) onto its seat (14) adjacent to the inlet (4), when the pressure of said irrigation liquid falls below a predetermined value characterized in that it comprises in one of the opposite faces defining said annular passage (32), a circular array of notches (30) which are capable of filtrating the irrigation liquid by retaining particles (31) of determined size contained in said liquid, while the concial or frusto-conical part (35) of the closing body is applied on the frustoconical seat (20') adjacent to the outlet (24) of the housing (1,3).  (21pp) USAB- US4623094 A The micro-irrigation distributor comprises a closure which may reciprocate in a chamber between an inlet and an outlet. The closure carries an elastic membrane provided with peripheral notches acting to filter the irrigating liquid before the liquid reaches a sinuous groove downstream of the membrane. Elastic radial arms attached to the closure urge the closure toward a seat adjacent to the inlet when the pressure applied to the irrigating liquid becomes  lower than a predetermined value. - When the pressure applied to the liquid is higher than the predetermined value, the closure is moved toward a seat adjacent to the outlet. During the movements of the closure between the seats, the dripper is flushed and the particles retained by the filter during the operation of the dripper are ejected.