US3851798A

US3851798A - Automatic colorant dispenser

Info

Publication number: US3851798A
Application number: US00305255A
Authority: US
Inventors: H Miller
Original assignee: Miller Manufacturing Co
Current assignee: MILLER PAINT EQUIPMENT LP; Northern Trust Co
Priority date: 1972-11-10
Filing date: 1972-11-10
Publication date: 1974-12-03
Anticipated expiration: 1991-12-03

Abstract

An automatic colorant dispenser for paint and the like comprises apparatus including a plurality of reservoirs each holding a supply of colorant, a dispenser nozzle for discharging said colorant into a can or other receptacle having base liquid therein, a metering pump for each colorant having a pair of bellows type positive displacement pumps having different displacement volumes and a pair of independent drive mechanisms for selectively interconnecting said pumps with a common rotary drive shaft for reciprocally activating each pump to a selected number of displacement cycles.

Description

`.m United States aient 1191 1111 3,851,798 mer [45] Dec. 3, 1974 [54] AUTOMATIC COLORANT DiSPENSER 2,923,438 2/1960 Logan e1 a1. 222/135 x 3,465,915 9/1969 D H d [75l Inventor: Herbert L- Mm, Roselle L 3,738,230 6/1973 Cnsi 417/429 x [73] Assignee: Miller Mfg. Co. 0f Schiller` Park,

inc., Addison, lll. Primary Examiner-Stanley H. Tollberg Assistant Examiner-John P. Shannon [22] Flled: Nov. l0, 1972 [21] Appl. No.: 305,255 [57] ABSTRACT An automatic colorant dispenser for paint and the like [52] U.s. c1 222/135, 222/1445, 222/149, comprises apparatus including a plurality cf rcscrvcirs 222/255 each holding a supply of colorant, a dispenser nozzle [51] 1m. c1' 36711 s/52 for discharging said cclcrant intc a can cr cihcr rcccp- [58] Field of Search 222/135, 144.5, 255, 132, taclc having base liquid therein, a metering pump for 222/148, 149, 151; 417/473, 429; 141/351, each colorant having a pair of bellows type positive 3,6() 362 104 .displacement pumps having different displacement volumes and a pair of independent drive mechanisms 56] References Cited for selectively interconnecting said pumps with a com UNITED STATES PATENTS mon rotary drive shaft for reciprocally activating each pump to a selected number of displacement cycles. 2,614,885 10/1952 Roell etal. 222/149 X 2,848,019 8/1958 Corbin et al 141/351 X 14 Claims, 24 Drawing Figures PMENH; sie 31974 snmanra PATENTEu UIC 3 |974 SHEH sur a zig@ 2,563@

PATENTE, BEC 3 i974 SHEEY 8 UF 8 AUTOMATIC COLORANT DISPENSER J' The present invention relates to a new and improved automatic colorant dispenser for paint and the like which is adapted to formulate any one of a wide variety of colors in a color system wherein a relatively small number of colorant liquids, for example, twelve, are used in various formulations with a number of different bases to provide a wide variety range of color hues and shades. It is an object of the present invention to provide a new and improved automatic colorant dispenser which is capable of providing and accurately duplicating, in quart or gallon quantities, a wide range of colors, hues and shades of paint based on formulations provided on machine readable cards.

Another object of the present invention is to provide a new and improved automatic colorant dispenser which is simple in operation so that relatively unskilled sales personnel in a paint department can produce the desired color of paint and the desired quantity with little chance of error.

Another object of the present invention is to provide a new and improved colorant dispenser which is operable automatically to provide an extremely wide range of paint colors and hues from a relatively limited number of colorant materials and limited number of base materials.

Another object of the present invention is to provide a new and improved apparatus of the character described wherein the amount of colorant added to the base liquid is extremely accurately measured although the quantities dispensed may vary from as little as l/lth ofa fluid ounce to as high as 10 ounces per gallon of paint produced.

Another object of the present invention is to provide a new and improved colorant dispensing apparatus wherein there is very little variation in the quantity of colorant dispensed and in relation to the precise amount required by the formulation cards.

Another object of the present invention is to provide a new and improved automatic colorant dispenser having means for sensing when the quantity of any colorant is at a low level and preventing an operation of a dispense cycle for the particular formulation until more colorant is added.

Another object of the present invention is to provide a new and improved automatic colorant dispensing apparatus having novel metering pumps for precisely measuring the quantity of colorant dispensed over an extremely wide range of values from a fraction of an ounce to as high as ounces pergallon of liquid paint produced.

Another object of the present invention is to provide a new and improved automatic colorant'dispensing apparatus of the character described which is formulated to dispense quantities of a colorant for a selected volume of material` such as a quart` and which is automatically operable to provide the same formulation when larger quantities are produced, such as a gallon.

Another object of the present invention is to provide a new and improved automatic colorant dispenser having an independent metering pump for each of the colorants, said pumps not requiring any pistonsor moving seals. l

Another object of the present invention is to provide a new and improved highly accurate metering pump 2 having a pair of positive displacement pumping chambers without moving seals therein.

Another object of the present invention is to provide a new and improved automatic colorant dispensing apparatus having a pair of positive displacement pumping chambers of different displacement volumes each of which is independently programmed for a desired number of displacement strokes in accordance with the quantity of fluid required.

Another object of the present invention is to provide a new and improved automatic colorant dispensing device having an automatic dispensing nozzle for simultaneously dispensing metered quantities of colorant into an awaiting container of base material.

Still another object of the present invention is to provide a new and improved automatic colorant dispensing device having means for automatically dispensing simultaneously metered quantities of colorant materials to an awaiting container of base material.

Another object of the present invention is to provide a new and improved automatic colorant dispenser device having means for cleaning out dispensing orifices after periods of inactivity so that plugging-up or inaccurate quantities of colorant are not dispensed.

Another object of the present invention is to provide a new and'improved automatic colorant dispenser device of the character described wherein the largest quantity of colorant material for a given paint formulation determines the length of time interval that the metering pumps are operated.

The foregoing and other objects of the present invention are accomplished in an illustrative embodiment which includes new and improved apparatus for the precise dispensing of measured volumes of liquid for intermixing with a base material comprising a reservoir for holding a supply of different colorant liquids.

A multiple orifice dispenser nozzle is provided for dispensing simultaneously metered quantities of different colorant liquids into an awaiting can of base material. A plurality of metering pumps are drivingly interconnected and said metering pumps are adapted to accurately meter the required formula volumes of liquid selected from any of the colorant reservoirs in accordance with the formulation read by a card reader.

Each of the metering pumps includes a pair of positive displacement pumping chambers having no moving seals orpistons therein and having different displacement volumes. A pair of independent drive mechanisms for selectively interconnecting the pumping chamber of each pump with a complement rotary drive shaft are provided for reciprocally activating the pumping chambers through a selected number of'displacement cycles to accurately dispense the desired quantities of colorant.

The apparatus includes a can-size sensing switch which determines whether the dispensing cycle will be rerun for larger volumes. The system also includes a low colorant safety system which prevents a dispensing operation from being initiated whenever one or more of the colorants to be dispensed is at or below a low level in its reservoir.

The apparatus also includes novel means for unpluggingv any colorant material which might accumulate in oneor more of the nozzle orifices after a period of inactivity and for simultaneously agitating the colorant in the reservoirs while disabling'the device from dispensing during the interval wherein the nozzle orifices are being cleaned out.

For better understanding of the invention. reference should be had to the following detailed description taken in conjunction with the drawings in which:

FIG. 1 is a front, elevational view of a new and improved automatic colorant dispensing apparatus in accordance with the features of the present invention;

FIG. 2 is a side, elevational view of the automatic co1- orant dispenser;

FIG. 3 is an enlarged panel of the device;

FIG. 4 is a View of a typical color formulation card used in the apparatus in accordance with the present invention;

FIG. 5 is a horizontal, cross-sectional view taken substantially along line 5-5 of FIG. I;

FIG. 6 is a vertical, sectional view ltaken substantially along line 6-6 of FIG. 2',

FIG. 7 is a horizontal, sectional view taken substantially along line 7-7 of FIG. 2 showing an agitator mechanism of one of the colorant reservoirs;

FIG.` 8 is an elevational view of the lower end ofa colorant reservoir and agitator system;

FIG. 9 is a vertical, cross-sectional view taken substantially along line 9-9 of FIG. 7 illustrating the low colorant sensing system in accordance with the present invention;

FIG. l0 is a vertical, cross-sectional view illustrating one of the colorant metering pumps in accordance with the features of the present invention;

FIG. 1l is a vertical, cross-sectional view taken substantially along line 11-11 of FIG. 10;

FIG. l2 is a top plane view of a colorant metering Pump? FIG. 13 is a fragmentary', cross-sectional view taken substantially along line 13-13 of FIG. 10;

FIG. 14 is a fragmentary vertical, cross-sectional view illustrating the same mechanism as the lower portion of FIG. 1l, but showing the clutch mechanism in the engaged position;

FIG. 1S is a horizontal, cross-sectional view taken substantially along line 15-15 of FIG. l0;

FIG. 16 is a vertical, cross-sectional view taken substantially along line 16-16 of FIG. 15;

FIG. 17 is a vertical, cross-sectional view taken substantially along line 17-17 of FIG. 15;

FIG. 18 is an enlarged, vertical, cross-sectional view illustrating an inlet check valve in accordance with the features of the present invention;

FIG. 19 is an enlarged, vertical, cross-sectional view of an outlet check valve in accordance with the features of the present invention;

FIG. 20 is a vertical, cross-sectional view of a colorant dispensing nozzle assembly in accordance with the features of the present invention;

FIG. 21 is a vertical cross-sectional view taken substantially along line 2l-21 of FIG. 20;

FIG. 22 is a horizontal` cross-sectional view taken substantially along line 22-22 of FIG. 2l',

FIG. 23 is a vertical, cross-sectional view taken substantially along line 23-23 of FIG. 22; and

FIG. 24 is a schematic diagram of a logic circuit for the colorant dispenser in accordance with the present invention.

Referring now more particularly to the drawings` therein is illustrated a new and improved automatic view of the operator control colorant dispensing apparatus for use in formulating a wide variety of colors. hues and tints of paints or other liquid material. The dispensing apparatus is referred to generally in FIGS. 1 and 2 by the reference numeral 30 and is especially adapted for use in dispensing liquid colorant to formulate a large number of different colors or hues of paint as set up in programmed paint formulation cards 32 (FIG. 4). The automatic colorant dispenser 30 includes an upstanding cabinet 34 having a base portion 36 and an upper portion 38 extending upwardly from a horizontal workshelf 4t) hingedly attached along its rearward edge as at 42 and liftable upwardly to provide access to the interior of the base section 36 from the upper end thereof.

The upper portion of the cabinet 34 is adapted to contain a plurality of multi-sided card holders 44 each mounted for rotation on a central support axle 46. As illustrated in FIG. l, three card holders 44 are mounted in a recess on the Iefthand side of the upper housing section 38 and another three card holders are mounted in a recess on the righthand side, the recesses being separated by a center section 48. At the upper end of the center section 4S there is provided an operator control panel S0 and immediatelyl below the control panel S0 the apparatus includes a multiple orifice dispensing nozzle assembly 52 shown in more detail in FIGS. 2G through 23 of the drawing.

The lower edge of the dispenser assembly 52 is spaced above the upper level of the workshelf 40 so that a quart size can 54 or a gallon size can 56 may be positioned below the dispenser nozzle assembly to receive precise amounts and formulations of colorants discharged therefrom.

The card holders 44 are polygonal in cross-section including a plurality of angular divergent outer side surfaces on which are provided a plurality of vertical spaced card receiving pockets. The card receiving pockets are spaced to permit an upper portion 32a on each formulation card 32 to be displaced to the operator and the portion .32a is provided with an appropriate numerical index and a color chip indicating the color to be produced by the card to facilitate an operator in picking a desired card to activate the dispenser assembly.

In one embodiment in accordance with the present invention` fifty card pockets were provided in each side of the six-sided card holders 44 and six of the card holders were provided making possible a total of 1800 different formulations which could be produced automatically' in quarts or gallons by the apparatus 30.

As illustrated in FIG. 4, each card has space for twelve vertical columns and for ten horizontal rows for a matrix of selected punched holes. Each of the twelve columns stands for a particular one of twelve colorants carried by the machine and each hole in a horizontal row represents a quantity (for example l/96 of a fluid ounce) of the colorant to be provided. Preferably, the cards are made of durable plastic such as that used for credit cards and are punched with a key-punch device with the formulations based on a quart volume basis.

When a quart can 54 is placed on the shelf 4() in position ready for dispensing, a can sensing switch S8 is activated; and if a gallon of paint is to be produced, a larger gallon can S6 placed on the shelf will activate both the lower quart can sensing switch 58 as well as an upper gallon can sensing device 60, which presets a dispense Cycle counter (FIG. 24) to operate the dispensing mechanism through four complete cycles so as to dispense the proper amounts of colorant for the preparation of a gallon of paint. When both the

switches

58 and 60 are activated, the dispenser will discharge four times of the amounts called for by the quart formulation card into the awaiting gallon can.

In addition to the wide variety of colorant formulations available, various different types of base material may be supplied in the receiving cans 54 or 56 giving the dispenser 30 an almost unlimited capability of available colors.

In accordance with the present invention, once the desired color formulation represented on a card 32 is selected by aid of color chip and coding on the top margin portion 32a and the particular color number as shown in FIG. 4, the card is inserted into a receiving slot 62 on the lower portion of the operator control panel 50 with the notched corner of the card to the left side as indicated by the lettering on the panel. When the card is fully inserted into the slot, it is received in a card reader (not shown) such as that manufactured by Amp, Incorporated of Harrisburg, Pennsylvania, and sold as Model No. 26l Catalog No. 42693 8-3. The data presented by the card is transferred from the card into an input register shown in FIG. l24. The dispenser 30 will not begin to dispense colorant, however until a can 54 or 56 is positioned below the dispenser nozzle assembly 52 and has activated at least the can sensing switch 58. Moreover, dispensing will not begin until power has been supplied to the unit as indicated by a power on pilot light 64 and until a start or dispense" push button 68 (FIGS. 3 and 24) has been actuated to reset the control logic shown in FIG. 24 thereby initiating a dispensing cycle.

If one of the colorant materials as required by the formulation card 32 inserted into the card reader is at a level which is so low that a proper formulation could not be furnished in a dispensing cycle called for, the system will be disabledand no dispense will be possible until the particular colorant is refilled. Should this condition occur, a colorant low" indicator light 66 will illuminate. With a cap 54 or 56 in receiving position, electrical power on and no colorant low indicating light indicated, a dispensing cycle can be commenced by an operator pressing the dispense button 68. In case of an overflow or other emergency condition,` dispensing may be stopped immediately by pressing an emergency stop button 70.

After a dispensing cycle has been completed and liquid colorant delivered to the awaiting canthe formulation card 32 may be ejected from the receiving slot 62 of the card reader by pressing downwardly a card eject" lever 72.

In accordance with the present invention if the dispensing apparatus 30 remains inactive for a period of time, liquid colorant may plug the orifices of the dis-` penser nozzle assembly 52 andin order to remove the dried colorant material to provide for accurate dispensing, the apparatus includes a nozzle cleaning assembly generally indicated by the reference numeral 74 and shown in detail in FIGS. through 23. The nozzle cleaning assembly 74 includes a U-shaped handle 76 having downwardly depending legeA pivotally supportedv on an axle 78 which extends horizontally through a box-like enclosure or housing 80 which encloses the nozzle structure. As best shown in FIG. 20 the handle 76 is movable from a rearward position (dotted lines) to a forward position (solid lines), and a stop 82 is engageable with the top wall of the housing to limit the angular movement of the activating handle 76 as illustrated. Within the housing there is provided an actuating arm 84 secured to the axle 78 for rotation therewith and a roller 86 is mounted adjacent an outer end of the arm for engagement with a pusher plate 88 adapted to bias a plurality of cleanout pins or plungers 90 which are coaxially aligned with respective discharge passages 92 formed in a lower nozzle forming member 94 of the dispensing nozzle assembly. As best shown in FIGS. 22

the passages 92 are vertical and are arranged in a circle around a centering pin 96 having a biasing spring 98 on the upper portion thereof for normally biasing the cleanout plungers 90 into the upper retracted position as shown in FIG. 23. When the handle 76 is moved forward to the position shown in solid lines in FIG. 20 the roller 86 moves downwardly and urges the pusher plate 88 downwardly to force the cleanout pins 90 into the lower or (dotted) cleanout-position (FIG. 23) to remove any material which might be plugging up the discharge passages 92 in the bottom nozzle structure 94. Simultaneously the roller 86 on the arm 84 engages a switch 100 for activating coloring agitator motors 102 mounted at the bottom of the colorant holding reservoirs generally indicated by the reference numerals 104. Activation of the switch 100 also energizes a colorant mixing light 106 for indicating to the operator that the colorant material in the reservoirs 104 is being mixed and agitated in preparation for delivery. The switch 100 is also operable to disable the dispensing system so that a dispensing cycle may not be commensed while the discharge orifices 92 are vplugged by the cleanout pins 90.

As shown in FIG. 23 at the bottom each orifice 92 in the nozzle bottom plate 94 is provided with an enlarged recess and a replaceable annular nozzle insert 108 is inserted therein. The lower end portion of the cleanout plunger 90 is provided with a resilient O-

ring

11,0 adjacent the end for pumping out the passage 92 and nozzle inserts 108 without scoring or grooving the same if precisional alignment is not provided between the pins and respective discharge opening.

The nozzle structure of the discharge nozzle assembly 52 includes the bottom member 94/and a pair of identical middle and upper members 112 which are keyed together as shown in FIG. 23 to provide precise alignment for the bores receiving the centering pin 96 and the cleanout plungers 90.

As best shown in FIG. 22, the individual discharge passages 92 in the bottom member 94 are supplied with e liquid colorant through the upper passages 114 terminating in openings at the rearward end of the nozzle structure. The intermediate and upper nozzle members 112 may be identical for cost reduction and the passages 114 in the upper nozzle member 122 may not be used. In this instance, the rearward open ends of the passages are plugged and suitable sealing bushings 116 (FIG. 23) are provided to seal between the members l 12 around the cleanout plungers 90. The upper nozzle member 112 is also provided with suitable sealing bushing assemblies 118 for guiding each cleanout plunger 90 at two points along its length as it is reciprocally moved into and out of the cleanout engagement with the nozzle passages 92 and annular nozzle members 104 in the lower nozzle member 94. Thecentering pin 96 is mounted` for sliding movement within a vertical bore 120 formed in the

nozzle members

94 and 112 and the biasing spring 98 biases the upper end portion of the centering pin upwardly by engagement with a retraction plate 122 having a plurality of openings formed adjacent the outer edge for receiving the upper ends of the cleanout pins 90. The centering pin 96 includes a shoulder adjacent the upper end and a projecting portion extends upwardly through a center opening in the retraction plate 122. The pin is staked over as at 96A (FIG. 23) to secure the pin and retraction plate in place. When the handle 76 is returned to the rearward position the biasing spring 98 urges the retraction plate 122 upwardly to retract the pins 90, and the nozzle assembly 52 is then ready for dispensing liquid colorants The upper ends of the cleanout pins 90 project through circular openings in the pusher plate 88 and retaining C-ring type washers 124 are provided in grooves adjacent the upper end of the pins between the pusher plate 88 and retraction plate 122 as best shown in FIG. 23. This arrangement permits some lost motion between the pins and the retraction or pusher plate and facilitates a smooth operation of the cleanout and unpiugging of the passages.

In accordance with the present invention, liquid colorant is supplied to the rearward end of each of the colorant passages 114 in the nozzle member 112 through a colorant supply line 126 connected to the output side of an individual metering pump assembly 128. The inlet side of each metering pump assembly 128 is supplied with colorant liquid from one of the reservoirs 104 via an inlet line 130 connected to the lower end of the reservoir. Colorant liquid from one or more selected reservoirs 104 is thus directed into the inlet side of its respective metering pump assembly 128 and in accordance with the present invention, the metering pump assembly is operated to precisely meter the formulated amount of liquid coloring agent to the outlet passages 92 in the dispenser nozzle assembly as set up by the formula card 32 inserted into the card reader.

In accordance with the present invention, it is determined by the data input to the system from a selected formulation card 32 which of the one or more metering pump assemblies 128 is to be operated during a dispensing cycle after initiation to dispense a precisely metered quantity of liquid colorant Vinto an awaiting can placed on the hinged work table 40.

In accordance with the present invention a total of 12 reservoirs 104 for colorant are -provided and accordingly 12 metering pump assemblies 128 are utilized and the pump assemblies are aligned side by side in a single row as best shown in FIGS. l and 5.

In accordance with the present invention each of the metering pump assemblies 128 includes a rotary drive shaft 132 supported adjacent opposite end portions in bearings 134 seated in a pair of upright structural members 136. The upright members 136 are formed of substantially thick aluminum plate or the like and are secured to a base member 138. The pumps are positioned in a row along the lower end portion and to the rear of the lower cabinet section 36 so that when the back access panel of the cabinet. is removed the pumps are available for ready removal and/or maintenance. The rotary shafts 132 of each pump are driven by a cornmon drive motor and gear reduction unit 140 through a drive system best shown in FIGS. 1, and 6. The drive motor and gear reduction unit 140 are controlled by a MOTOR RUN LATCH or flip-flop which is shown as a block element in FIG. 24. When the pump drive gear motor is energized, rotary output from the motor shaft is coupled via a pair of shaft couplings 142 and shaft 144 to the rotary shat 132 of an end positioned metering pump assembly 128 as best shown in FIG. 5. The shaft 144 is Jiournalled in suitable bearings (not shown) mounted in an elongated bearing support structure 146. At spaced intervals along the support structure 146 coincident with the spacing betwen the rotary shafts 132 of the respective metering pump assemblies 128 there is provided a plurality of shafts 148 mounted in suitable bearings (not shown). The shafts 148 are coupled to the shafts 132 of the respective metering pump assemblies 128 by suitable coupling assemblies 142 and are driven in synchronism with the shaft 144 by means ofa roller chain or toothed belt 150 entrained around sprockets 152 carried on the shafts. In order to insure that positive driving synchronization is provided between all of the shafts 148 and the main shaft 144, the chain or belt is biased to provide the proper tension by means of idler gears 154 carried on shafts 156, suitable bearing means therefor being also mounted on the bearing support structure 146. Whenever the gear motor 140 is energized to rotate, all of the shafts 132 of the respective metering pump assemblies 128 are synchronously rotated through the drive system as described. In order to count the revolutions of the shafts 132 of the metering pump assemblies 128 during energization ofthe gear motor 140, one of the shafts 148 is provided with a counting drum wheel 158 having permanent magnets mounted around the periphery thereof at 90 intervals. A pickup coil or magnetic emitter 162 is mounted at a fixed location adjacent the periphery ofthe counter drum 158 so that on each revolution of the pump assembly shafts 132` four electrical counting pulses will be provided by the pickup coil or magnetic emitter as the magnets 160 pass the same (FIG, 1). These counting pulses are amplified by the magnetic emitter amplifier shown in FEG. 24 and are used to synchronize operation of the metering pump assemblies 128. Timing signals O-Time` l- Time, 2-Time. and 3-Time are generated in FIG. 24 in synchronism with successive counting pulses and may be counted to indicate the number of shaft revolutions which have occurred. As will be explained, the quantity of colorant dispensed is proportional to the number of shaft revolutions.

In accordance with the present invention each metering pump assembly 128 includes a large volume positive displacement pumping chamber 164 and a small volume positive displacement pump chamber 166. The large and small pumping chambers are connected to operate in parallel and are independently controlled s0 either one of the two or both of the pumping chambers may be operated while the shaft 132 is rotating The large volume pumping chamber 164 includes a relatively large diameter bellows chamber having a thin wall of stainless steel and indicated by the reference numeral 168, as best shown in FIG. 10. The lower end of the bellows chamber 168 is permanently connected to a circular closure member 170 having a cylindrical projection on the center thereof extending downwardly for alignment and seating within a recess in the upper end of a reciprocating thrust pin 172. The upper end of the bellows 168 is connected to a fixed annular upper end ring member 174 having a shouldered upper end portion seated in the lower end of an inlet bore having stepped diameters and formed in a valve housing member 178 secured between the upstanding side members 136 by suitable fastening means, as best illustrated in FIGS. 10 and 15. The lower end closure 170 of the large pumping chamber 164 is biased downwardly away from the fixedly positioned upper ring member 174 by means of a concentric coil spring 180 normally under compression and held between upper and lower retaining washers 182 seated within grooves in the

respective members

174 and 170. The small volume pumping chamber 166 includes Aa smaller diameter stainless steel thin walled bellows 184 closed at its lower end by a generally cylindrical lower closure member 186. The lower end closure 186 includes a downwardly projecting cylindrical boss for centering engagement within the recess in the upper end of a reciprocating thrust pin 188. The upper end of the bellows 184 is sealed against the lower end of an annular upper end ring member 90 having its upper end seated and sealed within the lower end of a stepped diameter inlet bore 192 formed in the `valve housing member 178. The lower closure 186 is similarly biased downwardly away from the upper end member 190 by a coaxial spring 194 retained under slight compression by means of a pair of upper and lower retaining rings 196 seated in grooves provided in the

respective members

190 and 186. The large and small positive displacement variable

volume pumping chambers

164 and 166 defined by the respective large and

small bellows

168 and 184 provide for the delivery of precisely meteredquantities ofliquid colorants to the dispensing nozzle assembly 52 in response to the reciprocation of the thrust pins 172 and 188 which are independently and selectively drivingly interconnected with the rotating shaft 132.

The thrust pins 172 and 188 are supported in bearing sleeves 198 seated in parallel vertical passages provided in a bearing support block 200 extending transversely between the pump frame uprights 136 and secured thereto by suitable fasteners. The thrust pins 172 and 188 are provided with 'internally threaded axial bores open at the lower end, and the thrust pin 178 is drivingly interconnected to the rotary shaft 132 by means of an adjustable thrust linkage member 202 having a bifurcated lower end portion in which is mounted a cam follower roller 204 carried on a shaft 206 projecting outwardly to the left as seen in FIG. l0. The link member 202 includes an upwardly extending threaded shank which is engaged within the internally threaded axial bore in the lower end of the thrust pin 172. The

threaded shank is formed with a groove having a fiber ring 203 therein for compressive engagement with the threads to prevent backlash. Adjustment between member 202 and the thrust pin 12 is obtained by relative rotation of the two members and a lock nut 208 is provided to positively secure the

members

172 and 202 in a selected adjustment.

In order to prevent rotation of the shaft 206 about a shaped annular collar 218 mounted for free rotation on the rotary shaft 132. Thecircular cam 216 is eccentric with respect tothe axis of the shaft 132 and the amount of eccentricity determines the length of stroke of the thrust pin 172 and consequently the displacement of the large volume pumping chamber 164 each time the cam completes one revolution.

In order to drivingly interconnect the cam 216 with the rotating shaft 132 to reciprocate the thrust pin 172 for any selected number of reciprocal cycles, the metering pump system 128 is provided with a large pump clutch assembly generally indicated by the reference numeral 220. The clutch assembly includes a coil spring 222 wound from square cross section spring wire with an internal diameter slightly smaller than the diameter of the rotating shaft 132 when no torsional forces are applied tending to uncoil the springs. The spring is mounted on the rotary shaft 122 with one end adjacent and secured against an annular ring 224 on one side of the cam 216 by means of a set screw 226 carried in a radial bore provided in a first annular clutch collar 228 mounted on a right hand half or portion of the coil spring 222 around the shaft 132. The clutch assembly 220 also includes a second annular clutch collar 230 around the opposite or left portion of the internal coil spring 222 having a radial groove 230a formed in the outside face for receiving a radial tang 222a on the outer coil of the spring.

As best shown in FIGS. 11 and 14 the clutch rings 228 and 230 are shaped with radial detent faces 232 adapted to be engaged by the outer end of a pivotally movably latch member 234. As viewed in FIGS. 11, 13 and 14 the rotary shaft 132 is driven in a counterclockwise direction indicated by the arrow and when the detent faces on the clutch rings 228 and 230 are held in aligned position with the latch 234 in the engaged position as shown in FIG. 11, the clutch spring 222 is slightly unwound so that its internal diameter is large enough to permit the shaft 132 to rotate therein. When the latch 234 is moved out of the latch position, the coil spring 222 tends to tightly coil around the shaft and the clutch ring 230 rotates relative to the adjacent ring 228 by an angular increment presented by the numeral A in FIG. 14. Because the coils of the spring 222 are formed of rectangular square cross section spring wire a substantial surface'on the interior of the coils engages and grips the shaft when the latch 234 is moved out of engagement with the clutch rings 228 and 230 permitting the ring to coil tightly around the shaft. As this occurs the clutch engages the shaft to drive the eccentric cam 216 until such time as the latch 234 is returned to a normal upward or latching position as shown in FIG. 11 wherein the detent faces 232 are again aligned and the coil spring 222 is slightly unwound to permit free rotation of the shaft 132 within the interior of the spring coil.

A small pump clutch assembly 220 identical to the large pump clutch assembly is provided with a similar cam and follower mechanism connected to the thrust rod 188 for activating the small pump bellows 184of the small pump chamber 166. As viewed in FIG. 10 the left hand and right hand clutch assemblies 220 for activating the respective small and large

volume pumping chambers

166 and 164 respectively, are independent of one another in that the latch members 234 for each clutch assembly are independently activated. The follower linkages 202 for both large and small pumps are identical and in FlG. for the small pump linkage the compressible fiber washer 203 is shown in the sectional view illustrating the threaded shank 205 of the follower mechanism 202 extending upwardly into the internal bore of the thrust pin 188.

As illustrated in FIG. 11 when the clutch assemblies 220 are disengaged with the latch member 234 in the upward or latched position with the detent surfaces 232 on adjacent

clutch collars

228 and 230, the respective cams 216- are positioned approximately 45 or oneeighth of a revolution above bottom dead center. Accordingly when one or both latch members 234 is retracted, the clutch assemblies 220 become engaged to drive one or both of the

respective thrust members

188 and 172. As the thrust members initially move downwardly the bellows 168 and/or 184 expand in volume until bottom dead center is reached after approximately one quarter ofa revolution. If only a single cycle of displacement is required from either of both of the pumps, as soon as the detent faces 232 move past the latching edge of the latch members 234, the latch members are released and biased upwardly against the sur face of the

clutch collars

228 and 230 by means of latch springs 236. The latch members 234 are pivotally supported at the upper end of L-shaped brackets 238 and the springs 236 normally cause the latch members to tilt up as shown in FIG4 1l and engage the detent faces 232.

In order to release the faces and engage the clutch the large bellows pumping clutch assembly 220 is provided with a solenoid coil 240L which is controlled by a clutch drive latch or flip-flop that is shown as part of the clutch drive latches" element of FlG. 24. The small bellows latch assembly is provided with a similar or identical solenoid coil indicated by the number 2408 which is controlled by a separate clutch drive latch. lf a solenoid coil is energized, its latch member 234 is pulled down and out of the latch up condition as shown in the FIG. 14 and the respective clutch assembly 220 controlled thereby is then engaged to rotate its cam 216 along with the shaft 132 and reciprocate the respective` thrust pins 172 and 188. When a

solenoid coil

240L or 2405 is de-energized, its spring 236 causes the respective latch member 234 to pivot upwardly' and engage the detent face 232 of the

clutch collars

228 and 230 thus unwinding the coil spring 222 slightly and permitting the shaft 132 to rotate freely withinthe enlarged coils ofthe springs. ln these clutch disengaging conditions the cams 216 cease to rotateA ln accordance with the present invention, it has been found that by starting the pumping cycle of a bellows at a point 45 above a bottom dead center position, surges or excess volume of liquid on the initial engagement of the clutch is eliminated substantially from that encountered if the cycle is started from precisely a bottom dead center position. lt has been found in tests that if only a single cycle is to be provided the volumetric accuracy of pumping cycle decreases substantially when the cycle starts from a bottom dead center condition wherein the bellows has a maximum volume when compared to a cycle wherein the starting point is above bottom dead center and initially the bellows expands as the thrust pin is moved downwardly toward bottom dead center` The problem does not seem to occur on subsequent cycles of pumping after the initial or first one. However, in formulating accurate colors it is extremely important to provide accurate volumetric dispensing of even a single displacement cycle especially wherein small amounts of colorant in the order of l/96th of an ounce are provided in a quart of base material,

As viewed in FlG. itl a spacer bushing 212 is provided for the clutch assembly 220 ofthe small volume pump 166 between the collar 230 and the adjacent upright frame member 136. A pair of C-ring type retaining washers 2114 are provided adjacent opposite ends of the shaft 132 inside the bearings 134 to secure the shaft against axial displacement as it rotates.

In order to provide braking action on the collars 218 and their associated cams 216 so that the cams will come to substantially the same stopping position after latchup of the clutch members 234 occurs by deenergizing either or both of the solenoids SM05 or 240L, there is provided a pair of brake assemblies best shown in FIG. 13, including upstanding brake blocks 246 formed of "Nylon" Phenolic resin, grade c, or other suitable plastic material. Each block is provided with a semi-cylindrical braking surface Zda (FIG. 13,1` adapted to brakingly engage the outer periphery of the collar ZES. The brake block 246 is provided with a horizontal slot 2466' intermediate its ends and terminating at a blind end as shown in FIG. 13. A threaded bore 246C is formed to extend partway into the slot 246b and a slightly tapered threaded set screw 248 is provided for adjusting the brake pressure by tightening or loosening the set screw with the bore. The action of the braking surface 246e against the collars 218 prevents backlash from occurring as the clutch assemblies are engaged and disengaged and provides for precise driving rotation of the respective cam members 216 without backlash at the beginning or end ofa rotative cycle.

As previously' indicated on each complete revolution of the shaft 132 while the clutch mechanisms 220 are engaged, the cams 216 rotate from a starting position approximately 30 of cam rotation above bottom dead center. Because the cams start at a position intermediate bottom and top dead center. the acceleration forces on the

thrust rods

172 and 188 on stopping and starting are considerably smaller than ifthe starting or stopping was at the end of a stroke or at the beginning of stroke reversal where acceleration forces are at a maximum. After bottom dead center is passed, the rotating cams begin to elevate the link assemblies 202 upwardly causing compression of the respective large and

small pumping chambers

164 and 166 until top dead center position is reached. At this point the link assemblies begin to move downwardly and if only a single cycle of rotation is provided the clutch assemblies are disengaged by deenergizing one or both of the solenoid coils 2408 and 240L so that the latch members 234 are biased upwardly by the springs 236 and engage the stop surfaces 232 on the

clutch collars

228 and 230. When this occurs the coil spring 222 is unwound slightly to permit the rotary' shaft 132 to rotate within the turns of the coil. Action of the brake blocks 246 and the surfaces thereof 246g of the cam collars 218 prevents oscillation and backlash of the cams 216 as rotation is stopped and latchup occurs,

In a working embodiment of the pump assemblies 128 constructed in accordance with the features of the present invention, the circular cams 216 were positioned to be approximately one eighth inch eccentric of the axis of rotation of the shaft 132 so that the length of stroke between bottom and top dead center is approximately one quarter inch. The

bellows structures

168 and 184 are in the range of 2 to 21/2 inches long so that the amount of compression on the bellows is a relative low percentage of the total bellows length and the stress involved is minor resulting in extremely long life and low stress on associated equipment. Because there are no moving seals with a bellows arrangement as shown, there is no possibility for colorant leakage around a sliding piston or the like, a difficulty that has characterized many of the prior art pumping devices.

Preferably the respective large and

small pumping assemblies

164 and 166 are dimensioned with different displacement volumes so that the displacement volume of the small bellows is a fractional portion of the displacement volume of the large bellows. For example, if the displacement volume of the small bellows 184 is dimensioned to provide l/lth of a fluid ounce on a reciprocal stroke, the displacement volume of the larger bellows 168 may be set up to'be ten or eight times as large with a volume of l/lOth or 1/ath of a fluid ounce. Accordingly, if it is desired to dispense l/lOth or 1/fsth of an ounce of colorant the clutch assembly 220 for the large volume displacement pump 164 may be engaged for one shaft revolution or, in thealternative, the clutch assembly 220 for the small volume pumping assembly 166 may be engaged for a total of ten or eight shaft revolutions providing eight pumping strokes for the small bellows assembly 184 to provide l/lOth or 1sth of a fluid ounce. Because the large volume and small volume pumping assemblies are operating in parallel it is possible to provide for precisely metered values of dis= pensing volumes over a wide range by selectively and independently engaging the two clutch assemblies 220 with the coils 240S and/or 2401.. The biasing springs 180 and 194 continuously bias the rollers 204 of the cam follower linkage assemblies 202 against the circular cams 216 and cams having different eccentricity in relation with the shaft 132 may be provided to change the displacement volume of the respective large and small pumping chambers as desired.

[n accordance with the invention, liquid colorant flows from the respective reservoirs 104 via the supply lines 130 into an inlet or supply passage 250 provided in a cover member 252 secured to the upper surface of the valve housing 178 of a respective metering pump 128. As best shown in FIGS. l0 and 15 the fluid inlet passage 250 is in communication with the upper ends of the stepped diameter

fluid inlet passages

176 and 192 which are in communication with the upper ends of the respective large and

small bellows

168 and 184. The inlet passage or bore 176 of the large bellows is larger in diameter than the passage 192 which communicates with the small size bellows and as shown in FIG. the upper surface of the housing member 178 is formed with a generally figure 8 shaped groove 254` having a suitably shaped resilient sealing gasket 256 seated therein to provide a seal between the confronting surfaces of the valve housing member 178 and cover member 252 around the inlet passage 250 communicating between the upper ends of the stepped diameter

fluid inlet passages

176 and 192.

In accordance with the present invention, a relatively large size intake check valve 258 is seated in the upper end of the bore 176 to permit fluid to flow downwardly and enter the upper end of the large volume pumping chamber 164. A similar but smaller check valve 260 is seated in the upper end of the inlet bore 192 leading to the small volume pumping chamber 166 to permit incoming fluid colorant to flow from the passage 250 downwardly into the upper end of the small volume pumping chamber. The

check valves

258 and 260 are identical except for size and are illustrated in detail in FIG. 18. The valves include a hollow annular body 262 having a thickened lower end portion 264 extending inwardly and forming an upwardly concave frustoconical valve seating surface 266. A recess is formed adjacent the lower outer end of the valve body to accommodate an O-ring sealing washer 268 which seats in a stepped diameter shoulder portion formed in the bore 176 of the valve housing member 178. A circular valve disk 270 is staked onto the lower end of a reciprocating valve stem 272 for movement toward and away from the concave conical valve seat 266. An O-ring seal 274 is seated in a groove on the upper surface of the valve disk around the periphery thereof for sealing engagement against the conical valve seating surface 266. The valve stem 272 is supported for reciprocation in the central bore ofa'spider 276 having a generally cylindrical central body portion in which the stem bore is defined and an outwardly extending flange 278 formed with a plurality of circumferentially spaced circular fluid passages 280 therein. The O-ring 274 is biased upwardly by the valve disk 270 and stem 272 for sealing engagement against the conical seating surface 266 by means of a bias spring 282 having a lower end coil seated in a recess provided in the central portion of the spider member and an upper end compressed beneath a retaining washer 284 seated in a groove adjacent the upper end of the valve stem.

As best indicated in FIGS. 10, 16 and 18, colorant entering the passage 250 from the supply tube leading to a reservoir 104 may flow freely down the interior of the valve body 260 and through the circular openings 280 and the spider flange 278. Dependent upon the amount of suction below the valve disk 270 caused by a downward stroke of the thrust pin 172 expanding the volume of the large bellows 168, the fluid flows freely past the O-ring 274 into the lower end of the bore 176. The fluid pressure below the valve disk 270 becomes greater than the pressure above when an upward stroke of the thrust pin 172 causing a contraction of the bellows volume is commenced and the O- ring seal 274 is then compressed tightly against the conical valve seat 266 of the check valve so that reverse flow is prevented. The same operation pertainsto the smaller inlet check valve 260 positioned above the small volume pumping chamber 166 in the small inlet passage 192 in the valve housing member 178.

When one or both of the

bellows

168 or 184 is compressed or contracting in volume the fluid trapped below the

check valves

258 and 260 in the

respective passages

176 and 192 is -under increased pressure and is forced out through a pair of transverse flow passages 286 and 288 (FIG. 15) formed in the valve housing member 170 to extend between the lower end of the

inlet passages

176 and 192 respectively and a pair of vertical, outlet or

pressure passages

290 and 292 respective. The vertical outlet or

pressure passages

290 and 292 are formed in the valve housing member 178 of substantially the euqal diameter and are stepped in diameter as best shown in FIG. 16.between a minimum adjacent the lower 4end in communication with the

cross passages

286 and 288. The upper ends of the

vertical outlet passages

290 and 292 are in communication with a common outlet passage 294 formed in the valve housing cover member 252 and having a threaded outlet at one end for receiving 'the threaded end portion of one of the pressure lines 126 leading to the dispenser nozzle assembly 52. Seated in the upper end portion of each

vertical outlet passage

290 and 292 is provided an outlet check valve 296 (FIG. 19) which permits an upward flow of pressurized colorant and prevents back flow in a downward direction As best shown in FIG. 15 a generally figure 8-shaped groove 298 is formed in the upper surface of the valve housing member 178 around the upper end ofthe

vertical outlet passages

290 and 292 in order to accommodate a similarly shaped gasket 300 for sealing in the abutting surfaces of the cover member 252 and the valve housing member 178 around the outlet passage 294 extending between the

vertical passages

290 and 292.

The outlet check valves 296 include a cylindrical annular body 302 having a thickened portion 304 adjacent to the lower end and a shoulder on the outer lower end ofthe body forms a recess for accommodating an O-ring 306 for sealing against an abutting stepped shoulder in one of the

vertical outlet passages

290 and 292. A frustroconical upwardly concave seating surface 308 is defined internally of a thickened lower outer rim portion 304 for sealing engagement with an O-ring 310 carried in a peripheral groove on the lower side of a circular valve disk 312. The valve disk 312 is staked onto the lower end of an axial valve stem 314 which is mounted for reciprocal movement in a central bore defined within a spider assembly 316 having a center portion defining the bore and an outwardly extending flange 318 intermediate its ends having the outer periphery thereof seated within a groove formed in the upper end of the valve body 302. The flange 318 is formed with a plurality of circumferentially spaced circular fluid passages 320 for accommodating an upward flow' of liquid colorant when the pressure below the valve disk 312 is great enough to lift the O-ring 310 ofi` of the vertical valve seating surface 308 on an upward stroke of the

thrust pin

172 or 188 when causing the large and/or

small bellows

168 and 184 to contract in volume. The check valves 296 prevent reverse downward flow of liquid colorant back into the inlet or suction side ofthe system.

From the foregoing it will be seen that the valve housing member 178 and cover member 252 attached threto provide means for directing the fluid flow in accordance with the operation of the large volume and small

volume pumping chambers

164 and 166 of the metering pump assembly 128. lf a formulation card 32 inserted into the card reader of the apparatus 30 calls for a specified quantity of colorant from all of the 12 colorants available in the reservoirs 104, the metering pump assemblies 128 will be activated in accordance with the specific quantities of each colorant specified on the card 32 to pump the colorant out to the dispenser nozzle assembly 52 for discharging the colorant into an awaiting can. The

revolution counter

158, 160, and 162 counts the shaft revolutions of the metering pumps and a compare circuit resets the clutch drive latch for each solenoid 240L and 2405 when the number of revolutions indicated by the

counter

158, 160, 162 equals the number called for by the card 32. The

common pump drive gear motor will be energized long enough to provide the required maximum number of revolutions for the pump shafts 132 to dispense the largest quantity required by the formulation on the card 32. After this has been accomplished the pump motor will be de-energized by the motor run reset logic shown as a block element of FIG. 24 which resets the motor run latch. The solenoid coils 240L ofthe large volume pumping chambers 164 will be selectively energized for the desired number of shaft rotations to provide the quantities of each colorant required in the formulation. Similarly, the solenoids 2408 for the small volume pumping chambers 166 will be selectively and independently energized as required for the desired number of cycles of shaft rotation.

It will be seen, of course, that all of the pumps may be dispensing colorants simultaneously to the dispenser nozzle assembly 52 for discharge into an awaiting can and the dispensing cycle will terminate as soon as the colorant requiring the largest quantity has been dispensed. After the dispensing has been completed the motor 140 will be de-energized and the formulation Card 32 may be removed from the card reader slot 62 by manipulation of the release lever 72. The apparatus is now ready for receiving the next order when a form ulation card 32 is inserted and the dispense button 68 is activated after a can has been placed in position to receive the colorant dispensed.

For initial startup of the apparatus 30, the required colorant materials are loaded into the reservoirs 104 by pivoting the work table 40 upwardly about the hinge 42 and removing loosely fitting plastic caps or covers 322 (FIG. 2) on the upper end of the colorant reservoirs 104. The metering pump assemblies 128 are operated under a liquid head so that the colorant is drawn through the supply line 130 into the pump valve housings 178 and large and

small pumping chambers

164 and 166 to remove all the air therefrom, Liquid pumped by the metering pump assemblies 128 is then passed upwardly through the pressure lines 126 to the dispensing nozzle assembly 52 until all ofthe air in the system has been removed. The colorant materials used commonly do not dry rapidly and from time to time the supply of colorants in the reservoirs 104 is merely replenished and does not require a complete cleanout of a fluid therein or in the complete liquid flow path from the reservoir to the dispensing nozzle. The cleanout pins of the dispenser nozzle assembly provide for intermittently cleaning out the dispensing passages 92 should the apparatus 30 remain inactive for a period of time, for example over the weekend without use,

Each of the colorant reservoirs 104 includes a tubular cannister-like body 324 preferably formed of stain less steel and provided with a bottom closure assembly adjacent the lower end 326 formed of molded plastic material and adapted to support the agitator motor 102. As best shown in FIGS. 7 and 8 the closure assembly includes a circular bottom wall 328 and an upwardly extending peripheral cylindrical flange 330 having a groove 332 therein for receiving the lower end portion ofthe tubular canister wall 324. At the center, the bottom wall 328 is formed with a circular opening and a downwardly depending cylindrical housing 334 is provided for supporting a vertical, centrally positioned agitator shaft 336 having a propeller type agitating mixer blade 338 carried on the upper end and secured thereto by a cap screw 340. Suitable bearing and sealing means (not shown in detail) are seated within the depending support housing 334 for the agitator shaft 336 and at the lower end the shaft 336 is drivingly connected to the rotor shaft of the agitator drive motor 102. The drive motor 102 is mounted and supported on a base plate 342 which is supported in parallel relation with the circular bottom wall 328 by means of a plurality of downwardly depending integrally formed legs 344 and cap screws 346 (FIG. 8). Colorant from the lower end of the reservoir flows downwardly through a rectangular opening 328a in the bottom wall 328 into an integrally formed sump 348 having an opening at one end for the supply tube 130 which directs the colorant to the inlet side of its respective metering pump assembly 128. .As previously indicated, the agitator motor 120 is energized to rotate the agitator blade 338 only on an intermittent basis as when the nozzle passages 92 are being unplugged at the beginning of a workday or the like by activation of the handle 76 as previously described. The colorant liquid is normally fluid and retains its fluid state without hardening for a long period of time before tending to solidify. Accordingly, the colorant liquid normally flows freely into the integral sump structure 348 through the opening 328:1 and into the delivery tube 130 connected to the pump 128.

In accordance with a feature of the present invention, the automatic dispenser 30 includes a sensing switch 350 supported from the lower closure assembly 326 of each reservoir 104 for responding to a low colorant condition and disabling the control circuit form initiating a dispensing cycle whenever the colorant in any of the reservoirs 104 is at a predetermined low level such that the proper formulation of the colorant dispensed would be in error because of the low quantity of coloram.

The switch 350 is mounted on an L-shaped bracket 352, secured to the underside of a base plate 342 and includes an operator button 350d positioned for actuation by a plunger 354 which is reciprocally mounted in a sleeve 356 having a radial flange 358 at the lower end secured to the underside of the base plate. The upper end of the plunger 354 is connected to a flexible diaphragm 360 which is sensitive to the head or height of liquid colorant in the cannister. The diaphragm 360 is secured to the circular wall 328 to cover a circular opening 328b and is held in place to seal the opening by means of an annular ring 362 and a plurality of lugs 364 and cap screws 366 which are threadedly engaged in downwardly depending short leg members 368 spaced outwardly of the circumference of the opening 328b and integrally formed on the bottom wall 328 as best shown in FIG. 9.

Normally the plunger 354 is biased upwardly along with the diaphragm 360 against the pressure head exerted by the colorant liquid in the cannister by means of a coil spring 370 arranged in coaxial alignment on the upper end of the plunger 354 between the upper end of the sleeve 356 and a bearing washer 372 disposed on the underside of the diaphragm 360. Normally when ample colorant fluid is present in the cannister 324, the head of liquid is sufficient to depress the diaphragm 360 downwardly against the force of the bias spring and thereby engage the operator 350:1 of the switch 350. When the switch 350 is thus engaged it does not interrupt or effect normal dispensing cycles of the dispensing apparatus. ln the event the colorant becomes low and the head or level of liquid above the bottom wall 328 is not sufficient to depress the spring 370 and actuate the switch operator 350a, the switch 350 then interrupts the power to a control circuit so that a new dispensing cycle cannot be commenced. In addition, the switch 350 is also wired to cause the colorant low signal light 66 on the operator control panel 50 to illuminate. Low colorant level on any one of the 12 reservoirs 104 is sufficient to illuminate the low colorant signal light 6'6 and prevent a dispensing cycle from being initiated. After sufficient colorant liquid is added to the reservoir 104 having a low level of colorant therein the switch 350 is activated by the plunger 354 so that dispensing can again be commenced.

Y Referring to FIG. 24 therein is illustrated a block diagram of an electrical schematic control circuit and logic system for operating the dispenser 30 in the manner described. The control circuitry is carried in a panel enclosure 374 (FIG. 2) provided in the upper housing section 38 adjacent the rearward side. The cabinet structure 34 is provided with a removable rear panel so that access may be had to the control circuit panel 374 as well as the metering pump assemblies 128 and the drive assembly therefor.

Referring to FIG.,24 therein is illustrated in schematic block for a control circuit generally indicated by the reference numeral 376 for controlling operation of the dispenser 30 as previously described. After power has been supplied to the circuit and the handle 76 has been pivoted forwardly to clean out the dispensing passages 92 with the cleanout plugs 90, the agitator motors 102 are activated to mix up the colorant by rotation of the agitator blades 338 in each of the colorant reservoirs 104. During this time the switch is engaged by the roller 86 and this removes power from th dispensing control system so that the dispensing cycle cannot be commenced while the cleanout pins 90 are` seated in the dispensing orifices 92. When the handle 76 is moved to the rearwardly sloping position shown in dotted lines (FIG. 20), the switch 100 is deactivated so that the agitation motors 102 in the various reservoirs of colorant 104 no longer are activated and the system is energized ready for a dispensing cycle provided that none of the colorant low level switches have been activated by a condition of low colorant. Once a formulation card 32 is selected and inserted into the slot 62, the data sensed therefrom is fed into the input register and when the dispense button 68 is initiated, the dispensing cycle is commenced so that various selected clutch coil

drive control solenoids

240L and 240S are activated to dispense controlled quantities of colorants. All of the metering pump assemblies 128 are driven from the common drive gear motor which is energized by the motor run latch. Each control solenoid is actuated for a number of revolutions that correspond to the amount of liquid colorant required by the formulation card 32 inserted into the card reader. During the operation of the pump drive motor 140, the counter wheel 158, its four quadrantally spaced permanent magnets 160, and the adjacent impulse coil or magnetic emitter 162 count the revolutions of the pump shafts l32. The compare circuit de-energizes each solenoid 240L and 240S after the proper number of shaft revolutions, as has been explained. After the proper quantities of liquid colorants selected in accordance with the perforations in the card 32 have been dispensed through the operation of the large volume pumping chambers 164 and small volume pumping chambers 166 of the respective metering pump assemblies 128 as controlled by the respective solenoids 240L and 240s, an all bits this revolution latch causes a motor run latch reset to reset the motor run latch so that the common pump drive motor 140 is shut down and the pistons are reset ready for the next dispensing cycle. The card 32 is then removed from the card reader slot 62 by activating the card ejector lever 72.

The automatic colorant dispenser in accordance with the present invention thus provides an extremely accurate means of reproducing an extremely wide range of colorants used for tinting and coloring paints or other liquids with accurate results and reproducibility. The automatic system is relatively simple for an unskilled operator to use and prevents normal operator mistakes often caused by carelessness. In the event a can is being overiilled an operator can stop the process by engaging the emergency stop button 70 on the control panel 50. The system includes means for preventing the initiation of a dispensing cycle if any one of the collorant levels is low enough to endanger the proper formulation The cards 32 including the punched formulation information thereon are also provided with marginal portions 32a having a color ship identical or similar to the color of the paint to be produced. The pump assemblies 128 provide for extremely accurate metering of liquid colorant in accurate quantities varying from as low as l/96th of a fluid ounch to as high as ten ounces per quart of base material. The system also provides formulations set up on a standard quart basis with a dispensing cycle repeated four times when a gallon quantity is desired. The dispense cycle may be repeated twenty times for a five-gallon can. The control system 376 also includes means for overriding a gallon measuring system sensed by the sensor 60 so that only a quart formulation will be added to a gallon of base material thus making possible an extremely light tinting of the base material for special use and tones.

Although the present invention has been described with reference to a single illustrative embodiment thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. Apparatus for dispensing precisely measured volumes of liquid for intermixing with a base material comprising reservoir means for holding a supply of said liquid; a dispenser nozzle for discharging said liquid into said base material; metering pump means for pumping an adjustably selected metered volume of liquid from said reservoir means toward said nozzle for dispensing, said pump means including a pair of positive displacement pumping chambers having different displacement volumes; and a pair of independent drive mechanisms for selectively interconnecting and disconnecting said pumping chambers with a common rotary drive shaft for reciprocally activating each of saidY pumping chambers through a selectively adjustable number of displacement cycles.

2. The apparatus of claim l wherein said reservoir means includes a plurality of separate reservoirs for supplying different types of said liquid; said metering pump means including a pump assembly for each of said reservoirs for directing a metered quantity -of liquid to said nozzle, each of said pump assemblies including a pair of said positive displacement pumping charnbers and a pair of said independent drive mechanisms for selective interconnecting the same with said drive shaft.

3. The apparatus of claim 2 including control means responsive to data input for activating one or more of said independent drive mechanisms to interconnect a pumping chamber and said common drive shaft for a number of pumping cycles in response to said data input for simultaneously delivering metered quantities of said liquid from said chambers to said dispenser nozzle during a dispensing operation.

4. The apparatus of claim 3 wherein said control means includes a data reader for receiving input from a selected discrete data source and means for driving said common shaft for a maximum number of revolutions in response to said data source as represented by the highest number of pumping cycles required for any of said pumping chambers.

5. The apparatus of claim l wherein said control means includes sensing means responsive to the absence or presence of a receptacle positioned to receive liquid from Said dispenser nozzle for preventing the initiation of a dispensing cycle of said apparatus.

6. The apparatus of claim 5 including additional sensing means responsive to the size of a receptacle placed in a receiving position for repeating a dispensing cycle in response to the size being sensed.

7. The apparatus of claim 3 wherein said control means includes quantity sensor means for said reservoirs responsive to prevent a dispensing cycle when the liquid level in a reservoir falls below a selected low level.

8. The apparatus of claim 2 wherein said dispenser nozzle includes a discharge outlet for each pump assembly, and extendable cleanout means for simultaneously clearing each of said outlets of any material clogging the same.

9. The apparatus of claim 8 including agitators in each of said reservoirs for stirring said liquid, and control means for energizing said agitators whenever said cleanout means is extended to clear said outlets.

10. The apparatus of claim 9 wherein said control means includes means responsive to data input for activating one or more of said independent drive mechanism to interconnect a pumping chamber and said common drive shaft for a number of pumping cycles in response to said data input for dispensing liquid from said outlets of said dispenser nozzle during a dispensing operation, said control means including means for preventing a dispensing operation from commencing wherever said cleanout means is extended to clear said outlets.

11. A method of coloring paint by discharging one or more different colorants into a receptacle containing base material comprising the steps of sensing the presence of a receptacle of base material in a receiving position below a dispenser nozzle, reading data for a selected colorant formulation for said paint related to the quantities of one or more colorants to be dispensed into said receptacle, activating a common drive system for a plurality of metering pumps for each of said colorants, and selectively drivingly interconnecting and disconnecting one or more of said pumps with said drive system to discharge a volume metered quantity of liqthe chambers in each pair of pumping chambers is expanded and contracted during a pumping cycle for a selected number of cycles independent of the number of cycles of the other one in said pair of chambers.

14. The method of claim lll including the steps 0f sensing the size of a receiving receptacle and repeating the dispensing cycle to correspond to a ratio of the sensed receptacle size to a standard receptacle size.

l I l l

Claims

1. Apparatus for dispensing precisely measured volumes of liquid for intermixing with a base material comprising reservoir means for holding a supply of said liquid; a dispenser nozzle for discharging said liquid into said base material; metering pump means for pumping an adjustably selected metered volume of liquid from said reservoir means toward said nozzle for dispensing, said pump means including a pair of positive displacement pumping chambers having different displacement volumes; and a pair of independent drive mechanisms for selectively interconnecting and disconnecting said pumping chambers with a common rotary drive shaft for reciprocally activating each of said pumping chambers through a selectively adjustable number of displacement cycles.

2. The apparatus of claim 1 wherein said reservoir means includes a plurality of separate reservoirs for supplying different types of said liquid; said metering pump means including a pump assembly for each of said reservoirs for directing a metered quantity of liquid to said nozzle, each of said pump assemblies including a pair of said positive displacement pumping chambers and a pair of said independent drive mechanisms for selective interconnecting the same with said drive shaft.

5. The apparatus of claim 1 wherein said control means includes sensing means responsive to the absence or presence of a receptacle positioned to receive liquid from said dispenser nozzle for preventing the initiation of a dispensing cycle of said apparatus.

11. A method of coloring paint by discharging one or more different colorants into a receptacle containing base material comprising the steps of sensing the presence of a receptacle of base material in a receiving position below a dispenser nozzle, reading data for a selected colorant formulation for said paint related to the quantities of one or more colorants to be dispensed into said receptacle, activating a common drive system for a plurality of metering pumps for each of said colorants, and selectively drivingly interconnecting and disconnecting one or more of said pumps with said drive system to discharge a volume metered quantity of liquid through said dispenser nozzle into said receptacle on a dispensing cycle.

12. The method of claim 11 wherein said discharging of a metered quantity of liquid includes the steps of expanding and contracting one or more of a pair of fluid connected positive displacement metering pump chambers having different displacement volumes for a selected number of pumping cycles corresponding to the quantities required by said formulation data.

13. The method of claim 12 wherein one or more of the chambers in each pair of pumping chambers is expanded and contracted during a pumping cycle for a selected number of cycles independent of the number of cycles of the other one in said pair of chambers.

14. The method of claim 11 including the steps of sensing the size of a receiving receptacle and repeating the dispensing cycle to correspond to a ratio of the sensed receptacle size to a standard receptacle size.