| 摘要 |
<p>991,442. Irrigation; watering plants. MACPENNYS MIST PROPAGATION Ltd. Feb. 20, 1964 [March 2, 1963], No. 8452/63. Headings A1B and A1E. [Also in Division F2] Apparatus for periodic irrigation or watering of plants comprises an outer tank 1 containing a siphon tank 2 positioned above a balance tank 3 carried by a balance arm 4 pivoted at 5 to an adjustable drip feed device 10 continually fed from a water supply pipe 8 which also passes through a valve 9. The balance arm 4 carries a counter weight 13 which engages and closes a bleed orifice 14 which communicates, with valve 9 and outlet pipe 15 the arrangement being such that when tank 3 receives a discharge of water from tank 2 the additional weight of water in tank 3 causes arm 4 to pivot, weight 13 to be lifted from orifice 14 thereby causing the valve 9 to open so that water flows between pipes 8 and 15. The device 10 comprises a porous pad 36 or a column of pads adjustably compressible by screw control 37, 38 to vary the rate of drip into tank 2. The balance tank 3 has an outlet 11 which may be controlled by a needle valve. Instead of valve 9 the balance arm 4 may operate a hydraulic servo valve or an electrical relay arranged to operate a valve controlling the flow of water between pipes 8 and 15.</p> |
