IllllllllllllllllIllllllllilllllllllllllllllllllllli||||l|||||H|l|l||l||||
`U5005143257A
`
`United States Patent
`
`[19]
`
`[11] Patent Number:
`
`5,143,257
`
`Austin et a1.
`
`[45] Date of Patent:
`
`Sep. 1, 1992
`
`[54]
`
`[751
`
`[731
`
`[21]
`
`[221
`
`[5 11
`[52]
`
`[58]
`
`[56]
`
`SYSTEM FOR PROPORTIONED LIQUID
`DISPENSING
`
`Inventors: Mickey D. Austin, Duncanville;
`Richard .1. Keller, Mesquite, both of
`Tex.
`
`Assignee: Kelrus Corp., Mesquite, Tex.
`
`Appl. No.: 621,773
`
`Filed:
`
`Dec. 4, 1990
`
`Int. Cl.5 ............................................... B67D 5/00
`US. Cl. ................................... 222/57; 222/ 129.2;
`222/650; 119/72; 137/98; 137/101.21
`Field of Search ................ 222/57, 71, 650, 129.2,
`222/52; 119/72, 72.5, 74; 137/3, 98, 101.21,
`101.31
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`3,002,384 10/1961 MacDonald et al.
`................. 73/231
`9/1962 Waugh .................. 73/231
`3,053,087
`
`8/1963 Pavone ................... 73/231
`3,101,615
`l/1967 Walch, Jr. et a].
`..... 73/231
`3,301,053
`
`2/1967 Purdy ........................ 119/56
`3,306,261
`
`3,437,075 4/1969 Hawes, Jr. et a1.
`..... 119/72
`
`7/1969 Flynn ................
`. 222/57 X
`3,455,321
`
`7/1970 Russell ........... 222/57
`3,520,448
`
`......... 48/195
`3,634,053
`1/1972 Klass et a1.
`
`....... 204/195 P
`3,700,579 10/1972 Clifton et a1.
`
`3,783,248
`1/1974 Sugden .........
`235/92 FL
`
`............. 48/195
`3,854,894 12/1974 Klass et a1.
`
`3/1980 Purdy ............. 222/57
`4,193,515
`3/1980 Purdy .................................... 222/57
`4,193,516
`
`
`7/1981 Ambler .............. 222/57X
`4,276,997
`
`7/1982 Myers etal.
`......... 137/3
`4,337,786
`1/ 1983 Tavor ............... 222/57 X
`4,369,805
`
`..
`4,554,939 11/1985 Kern et a1.
`137/101.21 X
`
`......... 137/3 X
`4,642,222
`2/1987 Brazelton
`5/1989 Finnell .................................. 222/57
`4,830,220
`
`FOREIGN PATENT DOCUMENTS
`
`3/1981 Canada ........................... 137/101.21
`1097184
`1498449 3/ 1969 Fed. Rep. of Germany ........ 222/57
`1088313 10/ 1967 United Kingdom .................. 222/57
`
`Primary Examiner—Michael S. Huppert
`Assistant Examiner—Anthoula Pomrening
`Attorney, Agent, or Firm—Daniel Rubin
`
`[57]
`
`ABSTRACT
`
`A system for proportional liquid dispensing of two
`liquids, the first of which can comprise the main flow _
`drinking water supplied to livestock or poultry and the
`second of which can comprise controlled quantities of
`medication or nutrient to be introduced into the drink-
`
`ing water. Comprising the system is a solenoid operated
`pump for discharging controlled quantities of the sec-
`ond liquid into the main flow. A flow meter emits an
`electrical signal of the main flow rate at any given time
`while an optical pressure sensor emits an electrical sig-
`nal indicative of the static pressure of the main flow.
`Logic circuits combine the flow rate and pressure sig-
`nals for varying pump operation to controllably main-
`tain a predetermined mixture ratio of the two liquids.
`
`13 Claims, 5 Drawing Sheets
`
`3
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`0 ® llOVAC
`69
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`Micro Motion 1022
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`1
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`Micro Motion 1022
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`

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`U.S. Patent
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`Sep. 1, 1992
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`Sheet 1 of 5
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`5,143,257
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`2
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`US. Patent
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`Sep. 1, 1992
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`Sheet 2 of 5
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`5,143,257
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`44
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`US. Patent
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`Sep. 1, 1992
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`Sheet 3 of 5
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`5,143,257
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`4
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`US. Patent
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`Sep. 1, 1992
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`Sheet 4 of 5
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`5,143,257
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`27
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`39
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`FIG. 6
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`FIG. 7
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`US. Patent
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`Sep. 1, 1992
`
`Sheet 5 of 5
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`5,143,257
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`muml
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`I-E'i'i—KLEIN
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`6
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`

`

`1
`
`SYSTEM FOR PROPORTIONED LIQUID
`DISPENSING
`
`5,143,257
`
`2
`It is yet a further object of the invention to provide a
`novel pressure sensing device for use in the system of
`the previous objects for contributing to the maintained
`level of accuracy which the system achieves.
`SUMMARY OF THE INVENTION
`
`FIELD OF THE INVENTION
`The field of art to which the invention relates com-
`prises the art of dispensing medication and or nutrients
`to the drinking water of livestock and poultry.
`BACKGROUND OF THE INVENTION
`
`The growing out of livestock and/or poultry is a
`major industry. To insure their good health at maturity,
`the growing-out thereof commonly includes the adding
`of medication, nutrients or other additives to their food
`stuff or water supply. In this manner, the livestock and
`or poultry more readily avoid the common ailments that
`could otherwise tend to stunt development and or cause
`premature death.
`Not only is such development essential for the com-
`mercial well being of the farmer, but good health is also
`essential for the ultimate consumer to whom the end
`result represents an edible food product. For these rea-
`sons, it has been common industry practice to mix medi-
`cation and or nutrients such as an antibiotic or vitamins
`dispensed in controlled dosages to the feed stuff or
`drinking water supply provided to the various animals.
`Critical to such a system is the accuracy of control in
`dispensing the medication and/or nutrient in order to
`insure adequate doses while avoiding overdoses which
`could eventually be passed on to the consumer in the
`ultimate food product with potentially adverse effects.
`BACKGROUND OF THE PRIOR ART
`
`Liquid proportioning devices for dispensing medica-
`tion or nutrients to the drinking water of livestock and
`poultry are available from a variety of commercial
`sources. Exemplifying such devices are the disclosures
`of US. Pat. Nos. 4,193,515; 4,193,516 and 4,830,220.
`In each of the foregoing patents, the proportioner
`utilizes a flexible bladder positioned within a tank that
`provides a concentrate reservoir. Within the tank,
`water diluent is supplied to portions of the tank sur-
`rounding the concentrate reservoir which constitute the
`diluent reservoir. A mixing chamber is connected to the
`concentrate reservoir and to the diluent reservoir by an
`orifice system that is used to meter the liquids in a pre-
`determined ratio. In the ’220 patent there is also dis-
`closed apparatus useful when the concentrates contain
`suspended solids that otherwise could tend to clog the
`orifices.
`
`Characteristically lacking in devices of the type de-
`scribed is the ability to proportion medication and/or
`nutrients being dispensed into the water supply with a
`high order of selected accuracy.
`OBJECTS OF THE INVENTION
`
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`The invention relates to a dispensing system for liquid
`proportioning a controlled ratio between liquids to be
`mixed. More specifically, the invention relates to such a
`system suitable for supplying medication and or nutri-
`ents to the drinking water of livestock and poultry that
`is capable of being selectively preset for maintaining a
`desired mixing ratio with unprecedented accuracy.
`To achieve the foregoing, the system hereof includes
`a solenoid injection type pump that functions to inject
`the liquid medication and/or nutrient into the main flow
`of water. A pressure sensing device connected to the
`main water flow emits a signal indicative of pressure
`changes thereat while a water meter emits a signal in-
`dicative of flow rate of the main water flow. The com-
`
`bined signals from the water meter and pressure sensor
`through associated electronics regulate operation of the .
`pump to controllably maintain an accurate mixing ratio
`sought to be achieved.
`Included in the various operating functions of the
`system is a display of cumulative water totals in the
`course of flow allowing easy recognition of water com-
`sumption during any 24 hour period. It is also operative
`to indicate water totals during any selective time period
`required for the grow-out of a poultry flock. A second
`operating function is to provide injection from a stock
`solution of liquid medication or nutrient into the main
`water flow based on a selected ratio to be maintained
`and controlled through sensing both mainline flow rate
`and mainline pressure in a manner as to control the rate
`of injection.
`A third operating function is provided in the form of
`display indicators identifying the mode of operation and
`current status of the system during use at any point in
`time. By means of the various operating components,
`the foregoing can be operated at a selected high level of
`accuracy, as for example maintaining an injection level
`of medication into a mainline water flow at the ratio of
`
`1:128. (one ounce of medication per gallon of flow) Any
`desired change in the selected ratio can conveniently be
`reset by means of an adjustment setting of a timing
`potentiometer.
`Also included is a novel air ventilation system for
`disposing of naturally occurring effervescence which
`occurs in some medications such as Genital Violet and
`Potassium Chloride, that if left to themselves could
`result in an erratic supply of stock solution to the pump.
`The above noted features and advantages of the in-
`vention as well as other superior aspects thereof will be
`further appreciated by those skilled in the art upon
`reading the detailed description which follows in con-
`junction with the drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`It is therefore an object of the invention to provide a
`novel liquid proportioning system for ratio mixing of
`liquids with unprecedented accuracy.
`It is the further object of the invention to effect the
`FIG. LA is a diagrammatic illustration of the liquid
`proportioning system of the invention as utilized in a
`previous object with a system that is presettably adjust-
`bypass arrangement;
`able to a selected ratio mixture throughout a wide range
`FIG. l-B is a diagrammatic illustration of the system
`of operation.
`It is a still further object of the invention to utilize the 65 of the liquid proportioning system of the invention as
`utilized in a direct inline arrangement;
`'
`system of the previous objects for the dispensing of
`medication and/or nutrients into the drinking water
`FIG. 2 is longitudinal cross sectional view of the
`supply to livestock and/or poultry.
`injection pump hereof;
`
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`3
`FIG. 3 is a performance curve for the pump of FIG.
`
`2;
`
`FIGS. 4 A,B,C and D are schematic representations
`of the various flow modes of the system;
`FIG. 5 is an elevation view of the air ventilation
`device for the medication feed;
`FIG. 6 is a sectional view taken substantially along
`the lines 6—6 of FIG. 5;
`FIG. 7 is a plan View of the intake plate of FIG. 5;
`and
`
`FIG. 8 is a schematic electrical diagram for the sys-
`tem hereof.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`like parts are
`In the description which follows,
`marked throughout the specification and drawings with
`the same reference numerals respectively. The drawing
`figures are not necessarily to scale and in certain views
`parts may have been exaggerated for purposes of clar-
`ity.
`Referring now to the drawings, there is illustrated in
`FIG. LA the system hereof designated 10 including a
`commercial grade flow meter 12, having a Hall effect
`switch 13, and a dispenser unit 14 powered from a 110
`volt AC source designated 16. Water to the system
`enters the pipe inlet 18 to flow toward outlet 19 to flow
`in the direction indicated by the arrows in main line 21
`through a pressure regulator 20 and a strainer 22.
`In this arrangement, dispensing unit 14 is positioned
`in a bypass 24 and is supplied with medication/nutrient
`26 from a liquid source 28. Comprising source 28 is a
`reservoir 29 receiving dispensing unit conduit 37 termi-
`nating within the reservoir in a conical container 39 of
`the air ventilation system 33 to be described. The direct
`line embodiment of FIG. l-B is similar absent the bypass
`24 and its use is optional with the farmer-purchaser.
`Water meter 12 is of a type providing an external
`output signal continuously indicative of the encoun-
`tered flow rate. In a preferred embodiment, the meter
`includes a spinning magnet capable of being read by a
`Hall effect switch 13. Such meters are available from a
`variety of commercial sources such as the Sentry II
`water meter from Sensus Technologies of Uniontown,
`PA.
`
`Comprising dispensing unit 14 is an exterior cabinet
`30 in which the various operating components are en-
`closed. About the front face of the cabinet are windows
`32 and 34 for providing water flow data for cumulative
`or a selected time period and functional signal lights
`84,86,88,90 and 92 providing operational status of vari-
`ous operational modes. Specifically, the signal lights
`include float active 84, prime active 86, medicate active
`88, pump active 90 and backflush active 92 as will be
`understood. Push buttons 31, 35 and 36 respectively
`afford start, 24 hour flow reset‘and grow-out reset.
`Within cabinet 30 there is included a solenoid actu-
`ated reciprocally operative injection pump 38 (FIG. 2)
`of a type manufactured by Fluid-O-Tech of Italy and
`available from domestic distributors. The pump when
`actuated has a normal discharge rate of 0.3 cc per stroke
`and is able to produce pressures on the order of 110 psig
`when pumping against conventionally maintained mu-
`nicipal line water pressures. Any pump for this purpose
`is of course selected to be compatible without damage
`to internal components for the chemicals with which it
`is used for the selected applications. Suitable for such
`use herein in addition to the above, is a pump capable of
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`5,143,257
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`4
`being controlled by either a timing pulse or by a wave
`clipping of the power source. A pneumatic piston could
`be substituted if accompanied by auxiliary equipment
`enabling it to operate in the manner to be described.
`Briefly, pump 38 as shown in FIG. 2 is comprised of
`a housing defining a central flow passage 40 extending
`between an inlet 42 and an outlet 44. An inlet check 46
`
`is biased against an inlet aperture 48 via a compressed
`spring 50 which in turn acts against a compressed spring
`52. The latter is positioned in the flow passage at the
`backside of a reciprocally operable tubular piston 54. At
`the outlet end of the piston there is provided an internal
`dynamic ball check 56 biased rearwardly by a com-
`pressed spring 58. An exhaust ball check 60 is biased
`against a seat 62 by means of spring 64.
`Surrounding the pump is an electromagnetic coil 66
`controllably energized via leads 68 connected to the
`circuit illustrated in FIG. 8. Rear core 70 and front core
`72 are separated by a core break 74 and surround the
`piston cylinder in order, when energized and deener-
`gized, to effect reciprocal actuation of piston 54. Perfor-
`mance operation of pump 38 can be understood by
`reference to the performance chart of FIG. 3 whereby
`the pump can be operated at an output of about 0.5
`gallons per hour at a 100 psig. Curve “A” is indicative
`of a low pressure version while curve “B” represents
`the high pressure version utilized herein.
`Also contained within cabinet 30 for operation in
`conjunction with solenoid pump 38 is a solenoid valve
`76 (FIGS. 4 A,B,C, & D) connected in a looped ar-
`rangement about the pump and a pressure sensing as-
`sembly designated 77. The latter includes a Bourdon
`tube 78 having an inlet socket 80 connected to the main
`water line 21. Positioned opposite the displacement end
`is an optical sensor 82 to be described. The basic ar-
`rangement of components within cabinet 30 is as illus-
`trated schematically in FIG. 4 A in which cabinet 30
`has been outlined in phantom. The flow path for ar-
`rangements during the sequentially changing operating
`cycles, include the prime flow illustrated in FIG. 4B;
`the medication flow illustrated in 4 C and the backflush
`flow as illustrated in FIG. 4 D.
`Comprising the air ventilation system 33 of the float
`assembly 28 as best seen in FIGS. 5,6 and 7, is a conical
`shell container 39 which houses the float switch 27 on
`post 41 and the distal open end of medication drop tube
`37. The mouth of cone 39 is covered by a metal disc
`intake plate 96, preferably of brass or stainless steel,
`with a patterned array of four 0.125 inch intake ports 98.
`The intake ports are located so as to draw air bubbles
`generated by the medication in the stock solution 26
`away from the medication drop tube 37 and toward the
`sides of the cone. At that location, the air bubbles are
`directed by surface tension between the material of the
`cone toward exhaust ports 100 (one shown) in the top of
`the cone and through which the air bubbles are eventu-
`ally released to atmosphere. This prevents accumula-
`tion of trapped air around the float switch which could
`otherwise cause premature dropout of the float and
`terminate the medication cycle prior to injecting all
`available medication 26 in the container reservoir 29.
`At the same time, a hammer effect caused by the
`pump turning off on the completion of each pump cycle
`could cause a back pressure in the float switch chamber.
`This hammering tends to induce a coriolis force causing
`any effervescence created in the float switch chamber
`to be spiraled toward the walls of the chamber where
`surface tension will likewise cause the bubbles to adhere
`
`8
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`

`

`5,143,257
`
`5
`and eventually be exhausted to atmosphere. It will be
`appreciated that this system not only prevents damage
`to the pump, but also ensures high accuracy since any
`air that is pumped into the main conduit will reduce the
`amount of medication being pumped by an amount
`which the air has displaced.
`To operate the system 10, as will now be described
`with reference also to the circuit of FIG. 8, dispensing
`unit 14 is installed in a main line water flow in the man-
`ner of FIG. 1 A or 1 B and the unit is connected to a 120
`vac power outlet 16 that is spiked-protected by means
`of a metal-oxide varistor ZNR-l. The power is trans-
`formed thru a 120/6.3 vac transformer T1 and rectified
`by an integrated circuit bridge DB101. The rectified 6.0
`vdc is filtered thru three capacitors C1, C2, C3 and fed
`into a 7805 type 5 vdc voltage regulator 94. This 5 vdc
`power is further filtered by means of a capacitor C4 and
`supplies all necessary voltage and current for the opera-
`tion of both logic and sensing devices in the system, as
`will be understood.
`
`Power is supplied to the Hall effect switch 13 located
`top center within the housing of the water meter 12.
`The Hall effect switch senses the rotation of a spinning
`magnet (not shown) located within the water meter and
`transmits the pulses thru an ohm biasing resistor R15 to
`the binary counting chip U4 located on a circuit board
`(not shown). After the counting chip U4 has counted
`the proper number of pulses (dependent upon type of
`water meter used) it emits an output pulse to chip U1.
`Following reception of this signal by U1 and on the
`subsequent transition of switch 13 from a high state to a
`low state, U1 emits a pulsed output to the LCD dis-
`play/counter modules 32 (LCD-l) and 34 (LCD-2)
`incrementing their number by one. This process contin-
`ues to repeat itself incrementing the LCD display/coun-
`ter modules by one each time and thereby allowing a
`cummulative total of the water flowing thru the meter
`to be displayed. The LCD display/counter modules 32,
`34, may be reset by pushing the reset buttons 35, 36 on
`cabinet 30 and associated with the module being reset.
`Pressing the reset button sends a high signal thru a
`resistor R6 or R7 activating a transistor Q1 or Q2 con-
`figured as a grounded emitter thereby sending a low
`signal
`to the LCD display/counter module causing
`reset to occur. The functions and components associ-
`ated with each LCD module are identical.
`When it is desired to introduce medication, nutrient
`or other liquid stock 26 into the system, that may for
`example be vitamins B12, or B6, ferrous sulfate, potas-
`sium chloride, citric acid, etc. it is first mixed and placed
`in the reservoir container 29 which is open to atmo-
`sphere. The float assembly 28 consisting of the liquid
`float sensor 27 (FS-l), the air ventilation system 33 and
`the medication drop tube 37 are placed to extend below
`liquid level in reservoir 29.
`The injection system is then activated by pressing the
`start button 31 which sends a high signal to a resistor R8
`activating transistor Q3, configured as a grounded emit-
`ter, which in turn sends a low signal to pal chip U1. On
`receipt of this signal, U1 checks the status of the float
`signal FS-l from float sensor 27, generated by means of
`an encapsulated reed switch and floating magnet (not
`shown). This, in turn, activates the triac opto-isolator
`U7 by turning on the LED thru a resistor R16. When
`the LED becomes active the triac output is activated
`sending a float active signal to both pal chips U1 and
`U2. Should U1 detect a float active signal at the same
`time the start signal is active and the unit is not already
`
`6
`in the medication mode, then the “run” output of pa]
`chip U1 is latched on. This output reports to pal chip U2
`activating the medication and backflush cycles. U2 is
`clock-controlled by a timing chip U3 configured as an
`astable multi-vibrator. Two other timing circuits lo—
`cated on the PC board are controlled by separate timing
`chips U5 and U6 both operating in a monostable mode.
`The first of these U5 controls the time “on” of the prim-
`ing system while the second U6 controls the time “on”
`of the injection pump.
`For the priming cycle, pal chip U2 receives a low
`signal at its start input and on the next transition of the
`U2 clock from low to high, U2, thru a latching output,
`outputs a signal which enables the timing chip control-
`ling the prime circuit. At the same time, U2 outputs a
`trigger signal to the prime timer U5 initiating the timing
`sequence of the priming circuit. On receipt of the trig-
`ger signal by the prime timer US, the timer outputs a
`high-level signal activating the priming circuit solid-
`state relay (SSRA-l) thereby supplying power to the
`priming solenoid of valve 76 (ES-1). At this time, the
`function of the start pushbutton 31 is disabled until after
`the medication and backflush cycles have been com-
`pleted.
`Activation of the priming solenoid 76 (ES-l) allows
`water to be diverted from the main flow to be intro-
`duced into the drop tube 37 (FIG. 4 B) to insure there
`is water present from the medication container 29 to the
`pump motor and thereby prevent activation of pump 38
`in a dry condition. On completion of the timing interval,
`the priming timer U5 output changes from high to low
`turning off the priming solid-state relay SSRA-l and
`de-energizing the priming solenoid 76 ES-l
`thereby
`blocking water flow from main 21 into the drop tube 37.
`At this time the priming cycle is completed.
`For the medication cycle, (FIG. 4 C) the priming
`cycle latching output should be high after the priming
`timer US has completed its timing cycle. At the same
`time, the float sensor 27 (FS-l) signals that liquid is
`present in the stock solution reservoir 29. With the next
`transition of the U5 clock from low to high, U2 is
`caused to shift into the medication mode. In this mode,
`the priming cycle latching output is taken low, disabling
`the priming timer U5, and the medication active output
`is latched on, enabling the medication timer chip U6.
`The pump timing chip U6 and R-C network consist of
`a capacitor C8, a resistor R14 and a potentiometer R13
`which sets the basic timing length for fine adjustment of
`the timing cycle. A signal from U1, synchronized to the
`count pulses of the LCD modules 32, 34, is applied to
`the trigger input of the medication timer U6. The basic
`timing interval of chip U6 is established by means of the
`R-C timing network associated with the chip (R13, R14,
`& CS) and is modified by the output of the pressure-
`sensing assembly 77. The Hall effect switch 13 serves to
`increment the LCD counter modules and also provides
`the trigger pulse which fires the pump timer chip U6.
`The pressure-sensing assembly 77 is comprised of a
`Bourdon tube 78 (FIGS. 4A, B, C, & D) rated at 0-100 .
`psi, an infrared optical
`sensor
`transmitter-receiver
`82(Q4 & D1) and the resistors R17, R18, & R19. The
`optical sensor is constructed in such a manner that the
`angle of transmission of the transmitter and the angle of
`reception of the receiver is such that convergence is
`achieved at a distance of about 0.2 inches from the face
`of the sensor. This distance, while not critcal, is desir-
`able since it is the approximate distance the face of the
`Bourdon tube will travel over its rated pressure range.
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`The relationship allows the sensor to receive the widest
`possible change and yet react in the broadest manner to
`changes in pressure as indicated by the change or reduc—
`tion in light received. The end face of the tip of the
`Bourdon tube 78 is preferably covered with a reflective
`tape (not shown) to provide constant reflectivity of the
`infra-red beam from the transmitter D1 to the receiver
`Q4 thus bypassing variations in the construction of the
`Bourdon tube. For the embodiment being described, the
`sensor 82 is located substantially 0.007 inches from and
`parallel to the face of the Bourdon tube. This location is
`essential since it establishes the relationship of changing
`squares which provides linearity to the injection system.
`Power is supplied to the anode of the infrared trans-
`mitter D1 thru a voltage divider network consisting of 15
`resistor R17 to 5 vdc and resistor R18 to ground. The
`cathode of transmitter D1 is connected to logic ground.
`Infrared light produced by the transmitter D1 is re-
`. flected off of the Bourdon tube end face and collected
`by the infrared receiver Q4 that is configured as a
`ground-biased NPN transistor. Thus, the collector is
`connected to 5 vdc while the emitter is connected to
`ground thru a resistor R19 and a fine adjustment scaling
`potentiometer R20 that modifies the timing length
`based on the voltage level present as reported by sensor
`82. In this manner, pressure changes in the main flow
`line connected to inlet socket 80 will cause the Bourdon
`tube end face to be linearly displaced in response to
`pressure changes, in a well known manner. Such dis-
`placement is immediately sensed by reilected light onto
`receiver Q4 that is conducted to pin 4 of chip U6. Volt-
`age at
`this pin causes the timing duration to alter
`whereby as the voltage rises, the timing duration in-
`creases.
`
`10
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`20
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`25
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`30
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`8
`ing chip U6 that is continuous and linear for the pres-
`sure range and flow conditions involved. This allows
`the device to maintain highly accurate injections at the
`selected preset mixing ratio across a broad range of
`main flow pressures and flow rates. An infinite number
`of injection ratios could be achieved in this manner by
`varying the pump timer to produce either a larger or
`smaller timing pulse. In fact, a whole family of curves
`for available injection ratios may be achieved by modi-
`fying the output of the pressure-sensing device 77.
`When the output of the pump timer U6 goes high,
`that signal is applied to U2. U2 then checks the float
`input 27 (FS-l) to verify that liquid 26 is still present in
`the reservoir 29. If both these conditions are met, U2
`then outputs a high signal to the pump solid-state relay
`(SSRA-Z) thereby applying power to the injection
`pump and causing injection of the stock solution 26 into
`the main water flow 21. The medication cycle ends
`when the signal 27 (FS-l) goes from high to low at U2.
`When this event occurs and on the‘next transition of the
`U3 clock from low to high, U2 drops the medication
`latching output and the run latching output of U1.
`Interaction of the above therefore includes the Hall
`effect switch 13 which counts revolutions of the spin-
`ning magnet located within the water meter 12 until 0.1
`gallons of water have flowed thru the meter. The num-
`ber of revolutions counted depends on the water meter
`being used. When 0.1 gallons have passed the meter, the
`counting chip outputs a signal to U1. U1 receives this
`signal and waits until the Hall effect switch has gone
`low again. This wait period allows the counting chip to
`stabilize and verify a correct count value. If the correct
`count value is present and the Hall effect switch has
`gone low then U1 outputs a trigger signal that starts the
`timing sequence of the pump timing chip U6. At the
`same time, a reset signal is sent to the counter chip U4
`to reset the internal registers of U4 to a 0 condition and
`allow a new count sequence to begin. This process
`repeats itself for so long as water flows and power is
`applied to the system. Consequently, a new pump cycle
`is initiated after every 0.1 gallons of flow thru the main
`conduit 21.
`
`During the foregoing, optical sensor 82 detects
`changes in the operating pressure of the system almost
`instantly and reports those changes to the pump timing
`chip U6, pin 4. The voltage present on pin 4 of U6 acts
`as a modifier to the basic timing length in a manner that
`as the voltage rises the timing length is increased. This
`action enables the higher operating pressures of the
`system to operate the pump longer in order to inject the
`required amount of chemical 26 into the main flow of
`the system.
`Assuming a static system without water flow and a
`static pressure of 80 PSI, the Hall effect switch has no
`revolutions to count and therefore no pump action is
`required. As demand increases due to increased drink-
`ing by a flock of birds, the water meter begins to spin
`and the Hall effect switch registers the increasing de-
`mand. This initiates pump action on each 0.1 gallons of
`flow. Assuming the flock is composed of one week old
`birds, the demand for water will be light and conse-
`quently the flow rate will remain low (on the order of
`0.25 to 1.25 GPM of consumption). Since static pressure
`in the system decreases as flowlrate increases, the pres-
`sure at these flow rates will be something less than 80
`PSI (typically in the range of about 70 PSI to 75 PSI).
`Since pressure in the main conduit 2] acts as back pres-
`sure on the pump 38, the lower the pressure in the main
`
`The bias voltage afforded by the R17/R18 network
`provides a constant current thru the transmitter of 19.4
`ma and is constructed of 1% precision components to
`provide consistency and longevity to the system. The
`receiver is biased thru the series resistor network to
`provide the proper scaling for the system. For the em-
`bodiment being described, the required range is from
`21.6 mv at -0- pressure to 69.7 mv at -80- PSI. This
`range provides the proper voltage levels to PIN 4 of U6
`(voltage control pin) to provide the necessary timing
`duration to adjust dynamically for changes in pressure.
`Scaling adjustments are necessary to compensate both
`for minute differences in the internal piping of the unit
`and for different sizes of pipe in the field.
`The total system of the pressure sensing assembly 77
`and the pump timing circuit of U6 and the R-C network
`are critical to the operation of the pressure-sensing de-
`vice enabling it to function as a linear modifier into the
`timing circuit. This is based on the premise that pressure
`at the Bourdon tube 78 represents the differential be-
`tween water pressure and atmospheric pressure, which
`is equal to the square of the rate of flow of the water
`thru the pipe 21. Also, since light intensity decreases
`with the square of the distance from its source, there is
`a proportional relationship of squares between the light
`of the infrared transmitter D1, Q4 and the pressure
`detected in the flow pipe. This relationship remains
`effective even though the source, the infrared receiver
`Q4 detects, is not the quantity of infrared directly trans-
`mitted by D1 but rather the reduced quantity of infrared
`light reflected by the end face of Bourdon tube 78.
`The net result of the above and the translation of their
`results into electronic format via U6 and the R-C net-
`work produces a timing pulse output by the pump tim-
`
`35
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`50
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`55
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`60
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`65
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`10
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`10
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`5,143,257
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`10
`to the priming solid»state relay (SSRA~1) is also turned
`off removing power from the priming solenoid 76
`(ES-l) and stopping water discharge through the drop
`tube 37.
`
`Final backflush is effected as the pump output of U2
`goes low. On the next transition of the U3 clock from
`low to high, the pump clean latching output goes low
`and the final backflush-latching output goes high. This
`causes another trigger signal to be sent to the priming
`timer US that is still enabled from the previous cycle.
`On receipt of the trigger signal, the output of the
`priming timer U5 goes high turning on the priming
`solid-state relay (SSRA-l). This energizes the priming
`solenoid 76 for the final sequence and again diverts main
`water flow into the drop tube 37 thus serving to flush
`the-drop tube with clean water and alleviate any partic-
`ulate accumulation.
`,
`When the priming timer U5