Agricultural Water Pressure Gauge

The present invention relates to agricultural irrigation. In order to obtain optimum results, the quantity of water delivered to growing crops is carefully controlled. The amount of time that an irrigation system should be operated depends upon a variety of factors, including soil moisture condition as measured by a moisture gauge and water supply pressure. Instruments that are used in the field are ordinarily difficult to maintain in readable operating condition due to the exposure to the elements and the complex nature of certain instruments.

The primary object of the present invention is to provide a water pressure gauge for agricultural use that has no moving parts, that comprises only a few inexpensive parts, that can easily be maintained by the simplest of procedures.

In order to accomplish the foregoing object, I provide a translucent tube of approximately half an inch in diameter closed at one end by a fitting that provides a hollow probe capable of penetrating flexible water conduit for measurement of pressure therein. The other end of the tube is open to atmosphere. Between the probe end of the tube and an intermediate baffle, an outlet opening is provided sized so that the water rises in the tube to a level proportional to the conduit water pressure. Simple indication markings on the tube provide a reading of water pressure.

A detailed description of the invention will be made with reference to the accompanying drawings wherein like numerals designate corresponding parts in the several figures. These drawings, unless described as diagrammatic or unless otherwise indicated, are to scale. p

FIG. 1 is a pictorial view part of a conduit system for drip irrigation, the gauge incorporating the present invention being attached at the valve end of the main trunk supply line.

FIG. 2 is an enlarged axial sectional view of the pressure gauge, and taken along a plane corresponding to lines 2--2 of FIG. 1.

FIG. 3 is a sectional view taken along a plane corresponding to line 3--3 of FIG. 2.

The following detailed description is the best presently contemplated mode of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for purposes of illustrating the general principles of the invention since the scope of the invention is best defined by the appended claims.

In FIG. 1 a system is illustrated including flexible conduit 10 for a drip irrigation. The conduit 10 may be polyvinyl plastic provided with 1/2" hose fittings. The inventive gauge 12 is installed upstream of the valve 13 that controls flow to the trunk part of the conduit 10.

The gauge 12 comprises a translucent plastic vessel or tube 14 closed at one end by a resilent, but relatively rigid plastic plug 16. The tube seats against a shoulder 18 formed at the base of a slightly enlarged outer end 20 of the plug 16. The plug 16 has a hollow prong or probe 22 terminating at a barbed end 24. The prong is sufficiently pointed as to be capable of piercing the wall of the conduit 10 upon exertion of moderate force. The barbed end 24 terminates in a rearwardly facing shoulder 26 over which the wall of the conduit 10 snaps in order to lock the probe in position.

When the gauge is in place, it is maintained substantially in right angle relationship to the conduit 10 by reason of the fact that the shank part of the prong or probe is only slightly greater than the thickness of the conduit. The enlarged end 20 of the plug 16 stabilizes the gauge.

The pressure of water in the conduit sends a small stream through th prong, through the plug 16 and into the hollow interior of the gauge vessel 14. A centrally apertured baffle ring 28 modulates the flow. Water rises above the baffle to the upper part of the gauge. Water exits via an outlet port 30 located near the inner end of the plug 16. The level of water in the gauge reaches an equilibrium point in accordance with water pressure. The higher the pressure, the greater the inflow of water, the higher the water level in the gauge and the higher is the head of water causing flow outwardly of the port. The level of water is measured by side markings 31 etched, printed or attached to the tube. The size of the port 30 is carefully calibrated so that a sufficient restriction is imposed upon the outflow of water. The port 30 must not be so small as to cause the gauge to be completely flooded for wide ranges of water pressure.

The baffle ring 28 is found to be necessary. It may take a variety of forms. In the present instance, the ring 28 is made of rubber like material with an outside diameter slightly greater than the inside diameter of the gauge tube 14 so that it can be positioned fractionally. The baffle ring 28 in the present instance has a neck 29 that surrounds the baffle orifice.

The gauge can easily be pulled outwardly from the conduit. The hole or slit is virtually self-sealing, but a patch can be used if desired. Instead of puncturing the conduit, the gauge can be installed at a T-fitting as by the aid of hose threads 32 formed about the enlarged end 20 of the plug. A hexagonal part 34 is provided at the base of the threads 32 to facilitate installation of the gauge at a T-fitting.

The end of the tube 14 opposite the plug 16 is partially closed by a ported cap 36 that maybe solvent welded in place.