IL45369A - Flowrate control device - Google Patents

Description

4 A flowrate control device VEAVIZAHEI HASHKAYA Aba 43138 2 This Invention relates to a flowrate control device particularly designed to control the rate of liquid flow so as to ensure a substantially constant delivery Such devices are of particular significance irrigation where is desired to ensure a uniform rate and density of for when such a flowrate control device is associated or forms part a rotary water sprinkler of a referred to as rotary water sprinkler of the kind having at least one nozzle radially located with respect to a central supply conduit with which communicates and about which it is rotatably the device ensures that the area sprayed by the sprinkler and the density of spray is substantially uniform from sprinkler to sprinkler and substantially independent of supply pressure It is an object of the present invention to provide a new and improved flowrate control According to the present Invention there is provided a flowrate control device comprising a a housing inlet adapted to be coupled to a liquid flow a housing a housing wall portion defining within said on the one a tubular path which communicatee at the ends thereof respectively with said inlet and on the other a chamber communicating with said inlet and being otherwise closed and being separated from said flowpath by at least flexible wall said housing wall portion being formed with a constricting barrier which tapers substantially uniformly to a minimum adjacent said inlet and outlet so as to constitute a correspondingly tapering constriction in said throughflow the arrangement With such a device the liquid in the chamber acquires the pressure of the supply flowing into the housing On the other and in conformity with the liquid flowing through the throughflow path having a significant velocity of flow is at a pressure which is significantly less than the pressure of the in relatively static flow conditions in the adjacent In view of the fact that the chamber separated from the throughflow path by at least one reslllently flexible wall this wall portion reslllently displaced under the relatively Increased pressure in the chamber the throughflow path thereby reducing the across section of the An equilibrium position achieved corresponding to a constant flowrate through the throughflow path when the forces acting on either of the reslllently flexible wall portion are these forces being the liquid pressure obtaining in the chamber on the one hand and the liquid pressure in the throughflow path together with the restoring forces of the flexible wall portion on the other Embodiments of a flowrate control device in accordance with the present invention will now be described by way of example and with reference to the accompanying drawings in 1 is a perspective view of the respective components of a device in accordance with the present 2 is a longitudinally sectioned side elevation of one of the components shown in 2 taken along the line 3 a perspective view of the device when and 4 shows the incorporation of the device shown 4 As seen 1 to 4 of the drawings the flowrate control device comprises an elongated channel 31 having end walls 32 and An inlet aperture 34 is formed in the end wall 32 and an outlet aperture 35 is formed in the end wall the latter being formed integrally with an annular barrier wall Formed integrally with an opposite surface of the barrier wall 35 is a tubular hub 36 having a tapering outer Projecting from the barrier wall 35 in an opposite direction to the hub 36 and spaced from the channel member 31 is an abutment ridge 37 whilst projecting outwardly from the end wall 32 and flush with upper edge thereof is an abutment ridge Extending upwardly from a base of the channel member 31 is a crescent shaped barrier 39 which rises in a uniform curve from positions adjacent the inlet and outlet 34 and 35 achieving a maximum height at its central location A rectangular flexible rubber strip 41 is shown in adapted to overlie the channel member 31 and is provided with upwardly directed longitudinal ridged edges A rectangular retaining member 43 is formed with a pair of side walls an upper wall 45 in which is formed a rectangular aperture 46 and an end wall 47 in which is formed an aperture The device is assembled with the rubber strip 41 overlying the channel member 31 and retained in position by means of the retaining member 43 which fits over and around the channel member 31 with one edge thereof retained under the abutment ridge 37 and with the abutment ridge 38 passes through the aperture The ridged edges 42 of the strip 41 engage 5 When used with a rotary sprinkler of the kind the assembled device as shown in 4 of the drawings located in the of a supply pipe the tapering edge of the barrier wall 35 being pressed against the of the by an flange of a coupling skirt 52 of a rotary sprinkler the pipe 51 being screw coupled to the skirt As can be seen from 4 of the there defined between the device and the surrounding pipe a chamber 54 in which irrigation liquid is in a substantially condition and at the supply pressure prevailing in the supply pipe The irrigation on the other passes through the device via the inlet 32 over the barrier 39 and out of the outlet 34 into the a consequence of the flow of the liquid at a significant speed through the the liquid pressure in the device falls as compared with the pressure in the The presence of the constricting barrier 39 a graduated constriction in the throughflow results in the speed of throughflow gradually rising and the pressure gradually falling until they reach respective and minimum at the central location The chamber 54 is separated from the location 40 by the rubber strip 41 and as the pressure difference on either side of the strip 41 rises a consequence of increase in supply the strip 41 flexes inwardly towards the location 40 so as to limit the flowpath through the It will be appreciated that the device described above can be used as flowrate control devices with other than rotary water insufficientOCRQuality

Claims (10)

1. 45369/3 CLAIMS - 6 - 1. A flowrate control device comprising a housing, a housing inlet adapted to be coupled to a liquid flow supply, a housing outlet, a housing wall portion defining within said housing, on the one hand, a tubular through flowpath which communicates at the ends thereof respectively with said inlet and outlet, and, on the other hand, a chamber communicating with said inlet and being otherwise closed and being separated from said flowpath by at least one, reslllently, flexible wall portion, said housing wall portion being formed with a constricting barrier which tapers substantially uniformly to a minimum adjacent said inlet and outlet so as to constitute a correspondingly tapering constriction in said throughflow path, the arrangement being such that a portion of said supply is located in said chamber in a substantially no flow condition whilst the remainder of said supply flows through said path*

2. A device according to Claim 1 wherein said flexible wall portion is constituted by a flexible membrane fitted on an apertured wall portion.

3. A device according to Claim 1 wherein said housing wall portion comprises a rigid portion extending across said housing between said inlet and outlet and a tubular portion extending through said partition, one end of said tubular portion adjacent said inlet being apertured and covered with a flexible membrane*

4. A device according to Claim 1 wherein said housing comprises a conduit member having defined therein an elongated aperture, an inlet and an outlet of said conduit member, a flexible membrane sealing said aperture, retaining means for retaining said membrane in said sealing position and a 45369/3 ^ - -

5. A flowrate control device substantially as hereinbefore described by way of example and with reference to the accompanying drawings.

6. A water sprinkler having at least one nozzle radially located with respect to a central supply conduit with which it communicates and about which it Is rotatably displaceable, incorporating a flowrate control device according to any one of the preceding claims.

7. A water sprinkler according to Claim 6 wherein said chamber is defined between said tubular through flowpath and a coupling unit of said sprinkler.

8. * A water sprinkler according to Claim 7 when dependent on Claim 3 wherein said rigid portion is adapted to be held in position in said coupling unit.

9. A water sprinkler according to Claim 8 wherein there is formed integrally with said rigid portion a conduit adapted to be coupled to a rotary sprinkler head.

10. A water sprinkler according to Claim 6 substantially as hereinbefore described by way of example and with reference to the accompanying drawings* For the Applicants DR. REIHHOLD COHN AND PARTNERS IS:cb