Abstract:
An automatic colorant dispenser having a compact modular design incorporating simply installed, precision stepper-motor driven, colorant pump modules, specifically designed to provide maximum abrasion resistance using advanced aerospace technologies plus exceptional operational life utilizing high quality, high precision and high reliability mechanical and electrical components. By employing advanced performance materials and space saving, compact geometric and ergonomic design methodology in the fully modular automatic colorant dispenser, up to sixteen space saving, two gallon colorant canister modules are efficiently grouped and directly connected to their respective energy-saving colorant pump modules. All component modules have been ergonomically located behind large open access panels to ultimately maintain the system with maximum convenience and simplicity. Built-in retractable production shelves provide maximum operational versatility but retract into a compact 2′×4′ footprint weighing only 440 pounds. Stainless steel used on all working surfaces and advanced twin epoxy powder paint protects the modular cabinet.

Description:
FIELD OF THE INVENTION 
     This invention relates to the field of colorant pumps and, in particular, to a modular automatic colorant dispenser. 
     BACKGROUND OF THE INVENTION 
     Automatic Colorant Dispensers are well known in the art. Generally, colorants dispensed by these dispensers contain various abrasive and corrosive components including water. The prior art pumps used to dispense these colorants are of a lower quality, generic, single impeller “oil-pump” type usually produced from cast iron and are continuously exposed to the abrasive, oxidizing materials. These operating conditions cause dramatic wear to critical internal metering components in the generic prior art pumps resulting in their eminent failure usually within the first three months of normal system usage. These prior art pumps are very inconvenient to replace in existing prior art automatic colorant dispensers because of antiquated drive methods employed. These pumps are also very expensively priced and including the required qualified service technician labor, pump replacement can initially cost up as much as one tenth of the total system price. 
     Prior art pumps were never originally designed to pump colorants. Prior art pumps handled many different types of oils. These oils provided the much needed shaft lubrication. 
     Because pumped colorants do not provide any lubrication, constant colorant abrasion under pressure attacks the solid cylindrical bearings needed to maintain the proper pump shaft rotational geometry in all prior art pumps. The prior art pump drive system torque requirements are extremely demanding, highly inefficient and drive up the overall electrical power requirements of the entire automatic colorant dispenser. A single prior art pump cannot be rotated manually indicating the extremely inefficient method of pump shaft bearing design. 
     Attempting to protect and to reduce the internal wear and damage caused by the hardened foreign matter in colorants, generic prior art pumps employ a ceramic plastic impeller. This material has proven to be a poor design choice for the application. Broken or chipped impeller teeth cause severe loss of calibration and reduce the pump output dramatically. 
     Prior art automatic dispenser manufacturers have also implemented individual colorant filters or strainer units attempting to protect their pumps from the foreign materials in the colorants. Because of the wide viscosity ranges of many popular colorants, the filters or strainers almost immediately clog up and starve their pumps of colorant. Because precise, repeatable metering is needed to deliver each colorant to achieve the desired color formula or recipe, the clogging causes the product to be mis-tinted and ultimately rejected. 
     Prior art dispensers usually contain from ten to sixteen colorant circuits each including one storage canister and one pump per colorant circuit. Prior art pumps are driven by either one of two ways. 
     The first method employs a large length of roller chain, associated idler sprockets to maintain chain positioning through the dispenser and a large horsepower motor with a gear reduction unit that provides the needed output power. 
     The second method is employing an individual motor of significant fractional horsepower with a combined gear reducer to an individual prior art pump with horizontal shaft rotation. The majority of prior art automatic dispenser manufacturers all have chosen the single roller chain driven approach over of the large expense of multiple drive motor/gear reducers. Both of these drive approaches sacrifice individual precision metering because the prior art pumps were never designed to deliver dispense accuracies greater than {fraction (1/128)} of an ounce. 
     Replacement of pumps in the prior art has been difficult due to the pump locations and the critical realignment of these drive components must be completed in cramped confined space which is very time consuming. This intentionally reinforces that prior art pumps should only be replaced by factory approved service technicians. 
     Canisters of the prior art automatic dispensers have been produced from stainless steel tube with welded bottom plates. Each colorant canister in a system contributes significant weight to the system. In configuring prior art automatic dispensers to dispense water-based colorants for architectural paints and coatings, stainless steel canisters provide no significant structural advantages and could actually be replaced with other equally compatible canister materials such as PVC (polyvinylchloride) that are lighter and more easily machined. 
     Automatic dispensers in the prior art utilize a discharge nozzle component that allows each individual colorant circuit to come together in a small diameter. The prior art nozzles have many mechanical joints where components must be connected at mating surfaces. O-rings are needed to seal each joint. Every joint is a potential location for colorant to leak between individual circuits causing cross contamination of all of the colorants. 
     Automatic Dispensers in the prior art have been manufactured for over forty years using large, space consuming cabinets weighing in excess of a half ton with bulky roller conveyors attached to the front sections. Prior art cabinets were never efficiently designed for functional usage in providing adequate service access openings to critical internal components. Prior art dispenser manufacturers physically buried computers inside prior art cabinets eliminating the possibility of quick access or even simple upgrading of the operating PC system. For these types of customer service, an authorized factory service technician would be required to perform these tasks. 
     For many years, the Paint and Coatings market has been requesting smaller, more compact cabinets to fit the constantly shrinking floor space availability faced by paint retailers and manufacturers. Prior art manufacturers have responded to these requests only with automatic dispenser designs that suffer decreased performance and reliability to insure that their customer service departments maximized profitability. 
     Automatic dispensers in the prior art have always required the refilling of each of the colorant canisters. Prior art manufacturers have made the colorant refilling process a difficult task by placing certain canisters in extremely hard to reach locations. In some models, half of the colorant canisters used are at the rear of the dispenser making access to those canisters impossible. Prior art dispensers have been poorly designed with the addition of heavy, hard to move roller conveyors that span the entire front of the dispenser cabinets. 
     Prior art manufacturers have not addressed the serious ergonomic needs of the operator for the safe operation and maintenance of prior art automatic dispensers. Operators place themselves in potentially harmful physical positions when attempting to reach the inaccessible rear mounted canisters. Operators must straddle the bulky, front mounted roller conveyor in the refilling process while pouring heavy containers of colorant at arms length. 
     Addressing the electrical requirements and associated electronics of existing automatic dispensers in the prior art have basically operated in the very same way for as long as they have been manufactured. Presently offered systems operate using inefficient large horsepower motors to handle the demanding torque requirements of each out of date pump. Safety is an issue when trying to replace or repair a component that may be near any one of unguarded exposed roller chain paths. It is important to note that these systems have not improved with modern cutting edge technology, either in mechanical advances or in innovative electronics. 
     SUMMARY OF THE INVENTION 
     The present invention includes a specifically designed pump module, containing a precision dual bearing housing with two pairs of precision needle bearings, hardened dual shafts and impellers, an abrasion resistant, hard-coated pump chamber, twin Viton cartridge seals, an abrasion resistant, hard-coated lower cover plate and premium quality, quick disconnect fittings at inlet and outlet of pump chamber. 
     The present invention incorporates the pump, mounted on a pump drive bracket with power provided to the main pump shaft by a precisely controlled stepper motor. The stepper motor is directly connected to the driven pump shaft with a zero backlash coupling of solid design. The stepper motor is mounted to the top surface of the pump drive bracket providing simple but precise alignment of all three components. The pump module is physically attached to the base of the modular cabinet with a new 3M product that provides easy attachment, but this 3M foam adhesive product also cushions and eliminates vibrations and provides absolute silence during operation. 
     Therefore, it is an aspect of the invention to provide an efficient colorant pump with repeatable high accuracy. 
     It is another aspect of the invention to provide a colorant pump that delivers superior extended life. 
     It is still another aspect of the invention to provide a colorant pump that requires minimal torque to rotate. 
     It is a further aspect of the invention to provide a precisely supported bearing shaft geometry that will not fail under constant colorant pressure or contamination. 
     It is yet another aspect of the invention to provide an automatic colorant dispenser that has maximized modular design geometry and provides efficient, simplified repair or replacement of all critical parts. 
     It is still another aspect of the invention to provide an automatic colorant dispenser that operates quietly. 
     The present invention also incorporates a specifically designed canister module that is mounted in an ergonomic space-saving cabinet. The modular automatic colorant dispenser includes mounting provisions for up to sixteen canister modules. The canister modules are produced from PVC and have a lower plate and upper cover also fabricated from PVC. Each canister module is directly mounted to the top mounting plate surface in the new modular cabinet. Each pump module is directly positioned under each canister module to optimize the input connection tubing geometry between pump and canister. No colorant filters or strainers are required or used in the present invention. 
     Each canister module includes a built-in colorant agitator motion system. An individual agitator motor is connected to the bottom plate of each canister. A center pipe is threaded into the canister bottom plate with a Viton o-ring sealing the threaded pipe connection. The center pipe is fitted with small bearings at the top and bottom of the pipe. The agitator shaft rotates inside the center pipe and directly connects to the agitator motor output shaft. 
     The specifically designed ladder fin agitator provides slow, gentle agitation of all colorants and is fully programmable to handle even the most demanding colorants. The canister module has been designed to allow simplified replacement by removing four screws in the top mounting plate and disconnecting the inlet, outlet lines and unplugging the electrical connection to the agitator drive motor. 
     The present invention also incorporates each component module into a specifically designed modular automatic dispenser cabinet. The modular cabinet has been designed to efficiently house all automatic dispenser component modules. Up to sixteen colorant canister positions have been arranged in twin hexoidal canister patterns to reduce total cabinet space. Easy access to all system components modules has been provided through four (4) full width panels. One panel each on the left and right sides and two panels at the rear allow maximum open access of all dispensing components. Each panel is the same physical size and is fitted with a keyed lock. 
     The present invention incorporates additional features into the modular automatic dispenser cabinet that provide safety to the operator. Two hinged top panels provide full open access to all colorant canisters for easy refilling of colorants. Both left and right side panels are equipped with air dampened shock cylinders to eliminate any possibility of premature panel closing. Both panels will safely remain in a vertical position until the operator physically closes the top panels. 
     The present invention incorporates a centrally located compartment that houses up to sixteen individual solenoid valves. The forward, upper central cabinet location for these valves is critical in maintaining a minimal length of output tubing between each colorant circuit solenoid valve and their corresponding discharge nozzle connection. 
     The modular automatic dispenser cabinet has been designed with a small cabinet protrusion at the upper front center area that houses a discharge nozzle module of compact geometry. All required colorants to produce a specific paint formula can be simultaneously dispensed from this compact discharge nozzle module without any opportunity of colorant contamination between colorant circuits. 
     Each colorant circuit in the discharge nozzle module is equipped with a quick disconnect fitting allowing direct connection to each solenoid valve with an absolute minimal length of tubing. The modular automatic colorant dispenser cabinet provides a removable discharge nozzle module cover for full access to this modular component. A flush mounted upper cover is also provided for full access to the complete solenoid valve array and the associated colorant circuit tube piping. 
     It is another aspect of the invention to provide an automatic colorant dispenser with a nozzle that does not leak or drip. 
     The present invention incorporates two built-in retractable, stainless steel shelves for simplified dispensing of colorants into both one (1) gallon containers and also five (5) gallon buckets. When retracted, both shelves are flush to the front surface of the modular cabinet. The five gallon shelf has been designed into a flush mounted opening is the full width of the cabinet. 
     A specifically designed spring loaded, locking latch mechanism is centrally located below the five gallon shelf The two-piece locking arm is fabricated from multiple laminated steel plates for maximum strength. The locking latch design provides positive locking of the shelf in the operating position and can withstand four times the actual load. 
     The simple lifting of the shelf allows the spring-loaded detent to release the shelf for flush mounted storage. This detent is automatically reset when the shelf is lowered, allowing the next locking motion to occur. 
     The stainless steel working surface of the five (5) gallon shelf has been formed with three full width horizontal ribs to assist in the movement of five (5) gallon pails and totally eliminates the need of bulky, space consuming conveyor rollers. When placed in the appropriate dispense position on this shelf, with the filler cap or “bung hole” opened, a five (5) gallon pail will maintain precise alignment to simultaneously receive the required colorants. 
     The one (1) gallon shelf is located above the five (5) gallon shelf and flips down to provide a solid stainless steel work surface for processing up to three one (1) gallon containers. When this shelf is flipped up, the shelf becomes flush to the cabinet front surface. When placed in the appropriate dispense position on this shelf, with the can lid removed, a one (1) gallon can will maintain precise alignment to simultaneously receive the required colorants. 
     It is another aspect of the invention to provide an apparatus for connecting a support shelf to a work surface that maintains space efficiency. 
     The present invention also incorporates a flush mounted access panel cover located between the one (1) gallon shelf and the cabinet mounted discharge nozzle module. This front access panel may be removed to access the entirely self-contained electronics bay. 
     The flush mounted electronics bay is a steel fabrication that houses all of the electronic components that provide signals and power to each internal module. This includes a compactly designed printed circuit board rack with individual printed circuit cards controlling internal processing, power management and digital switching functions. This electronics bay also houses up to sixteen stepper motor controller cards that individually control each stepper-motor driven pump module. 
     The electronics bay has also been designed to fully comply with all applicable emission regulation and safety compliance guidelines and to provide the required airflow ventilation needed to maintain the appropriate electrical component environment. The electronics bay access cover is secured with six hex flathead fasteners. 
     The present invention also incorporates heavy-duty swivel casters at each corner of the modular automatic colorant dispenser cabinet for easy positioning. Two heavy-duty levelers are provided, one at each side near the front edge of the modular cabinet to maintain maximum stability of the modular automatic colorant dispenser after proper positioning has taken place. 
     The present invention incorporates the stepper-motor driven pump modules, the colorant conditioning canister modules, the solenoid valve array module and discharge nozzle module into a compact, space saving 24″×48″ footprint that weighs approximately half of all prior art systems. Each individual sub-system module can be easily accessed for inspection or replacement with ultimate simplicity. 
     The present invention incorporates a low-profile computer tray that glides from left to right over each of the upper cabinet top panels. The computer tray is fabricated from lightweight aluminum and contains eight (8) miniature rollers that allow effortless movement of the personal computer (PC), monitor, keyboard, mouse and other peripherals. A rear mounted tethered cable limits the overall travel of the computer tray. The tray provides full access to either of the two top panels for colorant refilling procedures but does not use valuable space inside the modular automatic dispenser cabinet. 
     It is another aspect of the invention to provide a cabinet for a modular automatic dispenser that is space and weight efficient. 
     The operating sequence for this system occurs as follows. The external PC communicates to the internal digital controller via standard RS-232C communications protocol and instructs the automatic colorant dispenser as to which colorants and in what amounts are to be delivered for each dispensing cycle. When the container is placed in the appropriate position on the appropriate shelf, the operator presses the dispense button on the keyboard. The digital controller activates each of the required colorant circuit valves and each of the required stepper-driven colorant pumps to simultaneously dispense all colorants into the container. Depending on the specific formula and container size, new FlowMaster pumps accurately and repeatabily dispense formulas in as little as five seconds up. The tinted container is then removed from the shelf, re-sealed or re-capped and then thoroughly mixed. 
     Colorants are automatically recirculated throughout each colorant canister circuit by programming into the pc, a specific amount of appropriate recirculation. The pump modules are gravity fed colorant from each canister module and if a specific colorant has not been chosen for a considerable amount of time, the pump module will activate and pump the respective colorant through the pump, up to the respective solenoid valve, and back to the upper return fitting of each canister. 
     For normal periods of inactivity, each colorant canister will engage the agitator drive that is built into each canister. The agitator drive provides a gentle six (6) rpm stirring motion to the colorant and the specially designed ladder fins rotationally raise the heavier materials, which want to settle to the bottom of the canister. This gentle motion is also programmably controlled. For extended periods of inactivity, a discharge nozzle cover or cap is provided to seal off air from each individual colorant circuit in the discharge nozzle module. 
     It is another aspect of the invention to provide an automatic colorant dispenser that efficiently operates all sub-systems using low voltage D.C. power components for maximum energy efficiency. 
     These aspects of the invention are not meant to be exclusive and other features, aspects, and advantages of the present invention will be readily apparent to those of ordinary skill in the art when read in conjunction with the appended claims and accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of the modular automatic colorant dispenser according to the present invention. 
     FIG. 2 is a cross-sectional view of the preferred embodiment of the colorant pump used in the modular automatic colorant dispenser shown in FIG.  1 . 
     FIG. 3 is an isometric view of the twin impellers located inside the pump module. 
     FIG. 4 is a cut away view of the pump module, as it would appear inside the cabinet. 
     FIG. 5 is an inside view of the arrangement of the pump modules inside the cabinet. 
     FIG. 6 is a bottom view of the preferred embodiment of the discharge nozzle module used in the modular automatic colorant dispenser of FIG.  1 . 
     FIG. 7 is a cut away view of the discharge nozzle module tube arrangement used in the modular automatic colorant dispenser of FIG.  1 . 
     FIG. 8 is an elevated view of the preferred embodiment of the modular cabinet, with a cut away view of the inside of the cabinet. 
     FIG. 9 is a cross sectional view of the locking latch mechanism used in the retractable, flush mounted, pull-up production shelf. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first to FIG. 1, a schematic of the present invention is shown. For illustration purposes only, FIG. 1 represents a schematic of one component of the modular automatic colorant dispenser  10 , equipped with only one pump module  12 . However, in the preferred embodiment, and other embodiments, the modular automatic colorant dispenser system  10  is configured with multiple pump modules  12 . Therefore, FIG. 1 serves only for illustration and explanation purposes. 
     The modular automatic colorant dispenser system  10  in FIG. 1 is one pump module  12 . The pump module is driven by a stepper motor  14 . The stepper motor is positioned directly above the pump module  12  by a bracket  16  and is directly coupled to the pump body  18  by a zero backlash shaft coupling  20 . The rotational accuracy of the stepper motor  14  allows the pump module  12  to precisely meter on the order of {fraction (1/512)} of an ounce. The pump module  12  pumps average viscosity colorant at approximate rates up to 40 ounces per minute. 
     Referring now to FIG. 2, a cross section of the pump module  12  is shown. The pump body  18  includes twin impellers  22 . Twin impellers  22  are preferably made from air hardened tool steel that receive an extremely hard, heat treating process. This hardened material process assists the twin impellers  22  in pulverizing any foreign materials passing through the pump chamber  24  with the colorant. Filters or strainers are used in the prior art in order to remove the “bead-milling” spheres used in the milling and blending procedures performed by the colorants manufactures. 
     Traditional bearing assemblies used in prior art pumps are made of solid bronze in a cylindrical type form having marginally short operational life, especially in hostile and abrasive colorant environments. 
     In the pump module  12 , the precision needle bearings  28  and needle thrust bearings  27  will operate at or less than 170 rpm, ensuring that the needle bearings  28  and needle thrust bearings  27  will far outlast the pump module  12 . The twin needle roller bearings,  27  and  28  provide superior shaft positioning accuracy and dramatically reduce the rotational friction and torque requirement over traditional bearing geometries employed in prior art pumps. Needle roller thrust bearings  27  and needle roller bearings  28  remain fully lubricated due to the bearing bore provisions provided in the bearing housing  29 . In the preferred embodiment of the pump module  18 , fully lubricated needle roller bearing units  27  and  28  will satisfactorily maintain the proper lubrication function when operating at the extremely low rotational requirements of the pump. 
     To prevent colorant leakage and contamination from entering the bearing housing  29  from the pump chamber  24 , a shaft seal  30  is positioned on each shaft between these two pump components. The seal is a cartridge type which is well known in the art. The twin seal cartridges can be easily replaced with standard tools. Each of the two shaft seals  30  are made of Viton and incorporates a miniature spring reinforcing ring that maintains lip sealing geometry. 
     An inlet fitting  32  is connected to the pump body  18  and the inlet line  34  attaches to the pump module  12 . The inlet fitting  32  and the inlet line  34  are preferably oversized to reduce flow restrictions entering the pump module  12 . 
     However, these bead mill spheres and other foreign material present in the colorants when pumped through prior art pumps cause severe damage to internal pump components. Thus, filters and strainers were added in the prior art to remove these harmful particles. However, the filters and strainers soon become clogged, reducing or totally blocking the required flow of colorant, which in turn ultimately destroys the important calibration value. Thus, in the present invention, the twin hardened impellers  22  pulverize all foreign materials, including bead mill particles. The design features of the pump, in the present invention, totally eliminate clogged or restricted colorant flow with absolutely no damage to internal pump components. The twin impeller pump of the present invention delivers extended repeatable calibration stability, significantly extending pump life. 
     The stepper motor  14  as shown in FIG. 1 is rotationally connected to the bearing shaft  26  with a zero backlash solid shaft coupling  20 . The bearing shaft  26  is in turn rotationally connected to the twin impellers  22 , allowing the pump module to dispense precise measures of colorant. 
     The driven bearing shaft  26  and secondary idler shaft include twin needle bearings  28  to maintain precise rotational shaft positioning of both impellers. The driven bearing shaft  26  and secondary idler shaft further include twin needle thrust bearings  27  to maintain precise internal clearances between the twin impellers  22  and the pump body  18  and the lower pump cover plate  19 . 
     Prior art needle bearing units have been shown to operate at 35,000 rpm in aerospace applications and have an extended lifetime compared to traditional bearing assemblies. 
     Similarly, the outlet fitting  36  is connected to the pump body  18  and the outlet line  38  exits the pump module  12 . Both the inlet fitting  32  and the outlet fitting  36  have been designed to provide maximum sealing protection from colorant leakage at the pump body  18 . 
     In the preferred embodiment, the inlet line  34  is made from oversized heavy wall Tygon extruded tubing that allows maximum unrestricted colorant flow using gravity feed into inlet fitting  32  of the pump module  12 . High-density, hard walled polyethylene tubing of standard size commonly known and available in the art is used in all other tubing locations of the present invention. 
     The outlet line  38  is critical to the precise metering and repeatable delivery of colorants in the present invention. When the colorant leaves the pump module  12 , the colorant is under significant pressure and therefore, the outlet line must withstand these pressures without deforming. In the present embodiment, the outlet line  38  utilizes this tough, hard walled, high-density polyethylene tubing to prevent any internal deformation or other physical diameter changes in the tube. 
     Prior art colorant dispensers that do not use this type of hard-walled tubing experience certain cross-sectional tube deformation of the outlet tubes. Maintaining the inside diameter of the tubing is critical in holding the constant calibration value of each colorant pump. Prior art dispensers fail to maintain calibration due to usage of improperly specified tubing. 
     The present invention does not have a pressure differential rate, therefore, possesses a constant efficient fluidity because of the oversized, unrestricted inlet tubing  34  and the hard-walled, internal diameter maintained outlet tubing  38  pump connections. Therefore the present invention has superior calibration consistency. 
     Referring next to FIG. 3, the twin impellers  22  are shown engaged inside the pump body  18 . The manufacturing tolerances of the twin impellers  22  and the pump body  18  are within +/−0.002 inches and are therefore dimensioned to leave only minimal gaps between the twin impellers  22 , the pump body  18  and the pump bottom cover plate  19 . Both pump body  18  and pump bottom cover  19  are made of 6061-T6 Aluminum Alloy. The internal machined surface clearance dimensions allow the pump body  18  and the pump bottom cover  19  to be processed with an aerospace developed, state-of-the-art, hard coat process that produces a built-up, uniform, hardened surface that provides maximized abrasion resistance against all known abrasive colorants. The process is known as Magnaplate HCR and is provided by General Magnaplate Corporation in Linden, N.J. This tough, durable process dramatically extends the life of the pump module. 
     Referring next to FIG. 4, the pump module  12  is shown in its preferred embodiment. As depicted here, the pump module  12  is directly connected to the colorant canister  44  by the inlet line  34 . The pump module  12  is connected to the remainder of the modular automatic colorant dispenser system by the outlet line  38 . The present invention has modular capabilities in part because of the pump module  12 . 
     Building the multiple embodiments of the modular automatic colorant dispenser system entails placing as many pump modules  12  as colorant varieties desired and connecting each pump modules  12  to a respective colorant canister  44 . 
     The pump body  18  and the stepper motor  14  are connected to the bracket  16 . When placing the pump module  12  into a modular automatic dispenser cabinet  50  (as shown in FIG.  8 ), the bracket  16  is attached to the cabinet. 
     The number of pump modules  12  placed into a cabinet varies according to individual preference, giving the present invention the capability of adapting to various individual and industrial needs. It is this feature of the present invention that makes the automatic colorant dispenser modular in nature. 
     Referring next to FIG. 5, a multitude of the pump modules  12  are mounted inside the cabinet  50 . The pump modules  12  are attached to the bracket  16  (as shown in FIG. 4) and then the bracket  16  (as shown in FIG. 4) is attached to the pad  42 . The bracket  16  is then mounted into the cabinet  50  using the pad  42 . The pad  42 , in the preferred embodiment, is a foam structured, double backed adhesive mounting tape. The pad  42  not only firmly attaches the bracket onto the cabinet  50 , but in addition, provides excellent vibration isolation and noise isolation. 
     The pad  42  creates a ⅛ of an inch gap between the bracket  16  and the cabinet  50 , which channels out all of the harmonics. Additionally, the pad  42  allows pump module  12  to operate more accurately. In alternative embodiments of the present invention, the bracket  16  is mounted into the cabinet  50  using mechanical fasteners commonly used in the art. 
     Because each pump module  12  contains its own stepper motor  14 , no driving mechanism or roller chain drive network is needed to connect all of the pumps, allowing the inside of the cabinet  50  to remain relatively open. The canisters  44  are suspended entirely from the top mounting surface of the cabinet  50 , eliminating the need for canister supports, and this farther opens up the inside of the cabinet  50 . The canisters  44  hold the individual colorants and are preferably made of PVC plastic or a similar compatible material. In the preferred embodiment, the canisters  44  have a capacity of 9 quarts. 
     This is an additional design feature of the invention allowing a standard colorant filling capacity of 8 quarts. With the additional quart of colorant provided to each pump, the system always is primed and ready, without allowing a total depletion of colorant in the pumps. As shown in FIG. 1, the canister  44  supplies colorant to the pump module  12  through the inlet line  34 . Flow restriction between the canister  44  and the pump module  12  has been eliminated due to the absence of in-line filters or strainers as in prior art dispensers. As shown in FIG. 2, an oversized inlet fitting  32  and an oversized inlet line  34  have been employed to maintain maximized gravity fed colorant flow. 
     Referring again to FIG. 1, in practice, the modular automatic colorant dispenser system performs as follows. Each canister  44  includes an agitator  48  to stir the contained colorant. The agitator  48  is driven by an agitator drive module  52  located underneath the canister  44  and is preferably rotationally driven at approximately 6 rpm. The agitator drive module  52 , in the preferred embodiment combines a small, low voltage, fractional horsepower synchronous motor with an integral gear reducer combined into a single compact housing that deliver the needed output speed with additional reserve torque for more demanding colorants. The agitator  48  includes multiply placed ladder fins  54 . 
     Each ladder fin  54  serves to break-up potential air-dried colorant that may form a skin at the top surface of the colorant when the agitator drive  52  is activated providing rotation to the agitator  48 . The precise angular positioning of each ladder fin  54  on the agitator  48  provides gentle upward guidance of the colorant insuring the proper recombining of settling colorant pigments. 
     The top section of the agitator  48  in the preferred embodiment provides attached tabs that serve as a can rest. These agitator  48  attachments have been specifically designed to aid in the refilling of colorant by safely suspending an opened quart can of colorant in the inverted, colorant refilling position. By resting an opened can of colorant on the provided can rest attachments  49 , all colorant can be efficiently drained from each colorant container, thus maximizing the removal of colorant into each colorant canister  44 . In the preferred embodiment, the ladder fins  54  are fabricated of stainless steel, because of the highly corrosive and staining characteristics of the colorants. 
     Once the colorant travels by gravity feed from the canister  44  via the inlet line  34  and through the pump module  12 , the colorant enters the outlet line  36  and travels to the valve  58 . The valve is a solenoid operated 3-way valve of spool type design. Using compact modular design, the valves  58  are conveniently mounted in a modular valve rack allowing easy installation and removal of each required valve. Each valve  58  is provided with three quick disconnect fittings, one to connect the outlet line  38 , one to connect the return line  60  and one to connect the discharge line  62 . Colorant is only dispensed through the solenoid valve to the discharge nozzle  70  when the electrical coil of the valve  58  is energized. The remaining unneeded, metered colorant from outlet line  38  is returned to the canister  44  through return line  60 . 
     In the preferred embodiment of the invention, the valves  58  provide leak proof sealing for maximized performance under safety compliance guidelines for dispensing the more demanding flammable pumped media such as automotive type acrylic lacquer based finished and other similar coatings product in prior art markets. 
     Additionally, each of the solenoid valves  58 , in the preferred embodiment operate on 24 VDC, each of the stepper motors  14  also operate on 24 VDC and the agitator drive motors  52  each operate on 24 VAC. In the preferred embodiment of the invention, a compact power supply has been specifically designed to provide these low voltages requirements. In particular, because of the specific power requirements incorporated in this preferred embodiment, the invention meets or exceeds compliance guidelines set by the National Fire Protection Agency (NFPA) explosion-proof compliance rating. 
     This multiple output power supply is input switchable to accommodate both 120 VAC, 60 Hz operation (used in North America) and 220 VAC, 50/60 Hz operation (used internationally) input voltages. 
     FIG. 6 shows to bottom view of the discharge nozzle assembly  70 . The discharge housing  72  provides positioning and attachment hole for each of the required discharge tubes  74 . As shown in FIG. 1, the discharge nozzle assembly also includes the discharge nozzle cap  76 , which acts as a sealing device to prevent premature drying of the colorants held in the tip of each discharge tube  74 . The discharge nozzle cap  76  employs twin o-ring grooves which position two Viton o-rings. The o-rings seal against the outside diameter of the discharge housing  72  providing a positive internal sealing area for all of the nozzle discharge tubes with frictional fit to maintain a firm holding capability around the discharge housing  72  outside diameter. 
     Colorant is dispensed from the discharge nozzle assembly  70  into the waiting container  80 , through a stream of colorant  78 . The efficient tight geometric grouping arrangement of each required nozzle discharge tube  74  in the nozzle discharge housing insures the safe and complete metered discharge of all required colorants without any cross contamination of colorants. 
     Referring next to FIG. 7, in alternative embodiments, the nozzle discharge tubes  74  are collectively positioned and fitted into the discharge nozzle housing  72 . FIG. 7 demonstrates multiple discharge nozzle tubes  74  affixed to the discharge nozzle housing  72 , penetrate the wall of the cabinet. Strong and durable potting epoxy  73  is used to permanently secure each required discharge nozzle tube  74 . After all tubes have been inserted and correctly positioned, the epoxy is back filled into the provided epoxy well of the discharge nozzle housing  72 . The nozzle discharge tubes  74  are preferably made of stainless steel tubing incorporating a single 90 degree bend to align each nozzle discharge tube with their respective corresponding valve  58  output fitting. A single discharge line  62  is connected between valve  58  and discharge nozzle tube  74 , simplifying assembly of the preferred embodiment of the invention. 
     Returning again to FIG. 1, the modular colorant system  10  also includes a compact, built-in electronics bay in the modular automatic colorant dispenser cabinet  50 . This bay houses the control and diagnostic module  92 . These operating and diagnostic functions are designed into multiple standard euro-card formatted printed circuit boards. 
     These cards are conveniently mounted into a standard EIS printed circuit board rack with a corresponding back plane board to facilitate all incoming and outgoing electrical system connections. 
     These cards are of standard formatted size commonly found in the art. One card controls the power distribution for the system, the second card houses the internal computer control processor, and the third and fourth cards provide the collective switching capabilities that drive the individual components that control the power going to each valve and stepper motor controller card. 
     By removing the six screws that secure the electronics bay front access panel, all printed circuit cards may be easily replaced or swapped in each corresponding track of the card cage. The electronics bay in the modular automatic colorant dispenser cabinet  50  also houses each of the individually required stepper motor drive cards. 
     By incasing the entire modular electronics sub-system in the single, well shielded, well ventilated electronics bay, the preferred embodiment of the invention fully complies with all applicable FCC compliance guidelines addressing both EMI and RFI issues. 
     Referring again to FIG. 1, the computer control module  90  includes a processing unit  94  and a display  96 . The computer control module  90  provides simple, easy upgrade of the standard PC  94 . Calibration and metering values, diagnostic and system data for general operational maintenance may be easily programmed into any future PC upgrade. 
     FIG. 1 shows only one pump module  12 , one canister  44 , one valve  58  and one nozzle  74  for the sake of simplicity in the schematic. However, in practice, multiple pump modules  12 , multiple canisters  44 , multiple valves  58  and multiple nozzle discharge tubes  74  are used, generally one for each desired colorants of that specific colorant system, in the dispenser system. 
     Each of these is referred to as a colorant circuit configuration. Preferred embodiments of the invention dispense in 10, 12, 14 or 16 colorant circuit configurations, and as such, include 10, 12, 14 or 16 of each of the above elements, respectively. However, in alternate embodiments, the number of colorant circuits can be greater to accommodate color system criteria requiring a greater number of colorants. 
     Even with a plurality of colorant pumps, each individual pump is driven by its own stepper motor, which is individually controlled by an individual stepper motor driver control card, individually controlled by the system control module. Therefore, there is no need to connect each pump with a roller driven chain drive, which leaves more free space inside the dispenser cabinet. 
     Additionally, as the canisters are fully suspended from the top mounting surfaces of the cabinet, even more space is available inside the cabinet because there are no lower canister supports. As such, embodiments of the present invention can be compact due to the open architecture of the cabinet. Each individual pump module  12  is driven by a separate stepper motor  14 . Each pump module  12  runs only when that specific colorant is needed. This feature is unlike prior arts, where all pumps are connected together by roller drive chain arrangements, requiring all of the pumps to be operated constantly. Therefore the present invention eliminates this requirement, extending the life of each individual pump because each pump module only operates when required to deliver that specific colorant. 
     Referring next to FIG. 8, the preferred embodiment of the modular automatic dispenser cabinet  50  is shown. The cabinet  50  is preferably made of a metal strong enough after forming to support the multiple canisters  44  filled with colorant and suspended from the top surface of the cabinet. 
     Additionally, the cabinet is preferably made of a non-corrosive material. In the preferred embodiment of the invention, the upper section of the cabinet is fabricated from stainless steel, which is inherently stain and corrosion resistant, thereby not damaged by the colorants. But, in the alternate embodiments, the cabinet can be constructed of any material known in the art. 
     The top of the cabinet  50  includes two upper access panels  122 . Each upper access panel  122  is approximately one half the width of the cabinet, and thereby, the cabinet  50  is capable of being divided into two halves. The individual right and left upper access panels provide easy access to all of the colorant canisters  44  specifically the canister lids  98 . These upper access panels  122  allow fill access to the valve array and discharge nozzle section built into the modular cabinet with a large access panel  120 . All solenoid valves  58  in the configured array and discharge nozzle assembly  70  are conveniently positioned under the large centrally located access panel  120 . Each of the two upper access panels  122  are equipped with air cushioned closures  124 , which prevent the top access panels  122  from crashing down against the cabinet  50 . Each half of the cabinet contains one half of the total number of colorant canisters  44 . The computer control module  90  (see FIG. 1) is positioned on a compact low profile moveable platform  100 . In the preferred embodiment of the invention, this computer tray freely rolls with a limited travel from right to left. 
     The moveable computer tray  100  is smaller in width than either of the two top access panels  122 . The moveable computer tray  100  can only travel the safe distance permitted by the small tethered steel cable that attaches at the rear of the moveable computer tray  100  to a central point at the center of the modular cabinet  50 . 
     In the preferred embodiment, the computer control module  90  sits atop the moveable tethered computer tray  100  allowing quick access to either the right or left bank of colorant canisters  44 . In prior art dispensers, large cabinet areas have been solely designed to only house the PC computer and monitor thus wasting significant centrally located internal cabinet area as well as waste valuable floor space and overall foot print. The upper access panels  122  provide adequate internal clearance between the inside of the access panels and the top of the colorant canister lids  98 . 
     The canisters  44  are arranged in a hexoidal pattern mirrored on each side of the modular cabinet  50  taking advantage of ergonomic spacing to reduce overall cabinet size. This spacing arrangement allows for a maximum number of colorant canisters  44  to be placed in a minimum amount of space. As shown in FIG. 8, the preferred embodiment of the cabinet  50  provides 16 spaces to accommodate 16 canisters  44 . 
     FIG. 8 shows the modular cabinet  50  fully loaded to its capacity with 8 canisters  44  per each half of the cabinet  50 . In practice, where less than 16 canisters have been configured for operation, a blank lid  98  will be placed over the unused blank colorant canister locations. When the canister lid  98  is removed from the canister  44 , up to eight quarts of colorant may be poured and emptied into the appropriate canister  44  by resting the opened quart can on the designated attachments of agitator  48  until can is thoroughly emptied out. Like the colorant canisters  44 , the canister lids  98  are also made from PVC. 
     The modular cabinet  50  also includes four lockable access panels  118 . These panels allow for targeted and easy access to particular pump modules  12  or the complete access to all other internal cabinet  50  areas. The lockable feature of the four access panels  118  prevents the impermissible tampering or unauthorized access to or adjustment of any interior component systems including the pump modules  12 . 
     The front side  110  of the modular cabinet  50  includes a small cabinet projection  112  where the discharge nozzle assembly  70  is firmly attached to this projection. This small cabinet projection  112  has been designed to occupy an absolute minimum of exterior space, thereby allowing the cabinet to fit into smaller operating areas. 
     Generally, containers  80  (as shown in FIG. 1) to be tinted with colorants are five (5) gallon containers. The cabinet front  110  of the modular cabinet  50  provides a strong, built-in, pull-up, retractable, five (5) gallon track shelf  114  to accommodate these sized containers  80 . The working surface of this track shelf employs a heavily ribbed stainless steel track shelf  114  surface. There are three equally spaced ribs or rails that are formed into the stainless steel shelf surface that run the complete distance of the shelf Having an approximate length of 45 inches, the five (5) gallon track shelf easily accommodates three containers at a time. 
     The formed stainless steel work surface of the five (5) gallon shelf  114  raise each container up approximately ¼ inch above the shelf surface. Full five (5) gallon containers can weigh from 50 to 60 pounds each and by having that weight distributed on three individual shelf ribs, minimal effort or force is required to slide the canisters in and out of dispensing position and actually maintain that positioning. 
     Frequently, one (1) gallon and one (1) quart cans serve as the container  80 , thus, in alternative embodiments, the container can be any size commonly used in the art. Therefore, to accommodate these smaller container sizes. The cabinet front  110  of the modular cabinet  50  further provides a strong, built-in, retractable one (1) gallon shelf  116 . The pull-down shelf  116  is located directly under the cabinet projection  112  and directly above the five (5) gallon track shelf  114 . The one (1) gallon pull-down shelf  116  is approximately 24 inches in width and provides a stainless steel work surface. The smaller sized containers are placed on the pull-down shelf  116  to receive dispensed colorant at a reduced distance from the discharge nozzle  70 , thus avoiding colorant spatter. When not in use, the one (1) gallon shelf  116  can be easily flipped up to rest flush against the cabinet front  110  of the modular cabinet  50 . 
     Heavy prior art roller conveyors employed at the front of prior art dispensers to easily move processed five gallon containers made the critical 2 inch diameter bung hole alignment in the container  80  virtually impossible. All colorants had to clear the opening in the can top for 100% delivery of all colorant, otherwise the desired formula color could not be attained. 
     In the preferred embodiment of the invention, the modular cabinet  50  has a total weight of approximately 440 pounds. Because of this low weight, the modular cabinet  50  is easier to fabricate, easier to ship, easier to maneuver, and occupies considerably less floor space than other automatic colorant dispensers found in the art. Additionally, because there are many older stores in less populated areas of the country and the world, the floors of these stores can not normally accommodate a very large and heavy automatic colorant dispenser. 
     Thus, with the present invention, these stores can accommodate the modular automatic colorant dispenser. Also, because of the efficient use of space in the cabinet, the modular automatic colorant dispenser occupies an absolute minimum of space, allowing smaller stores to accommodate the present invention. 
     Referring next to FIG. 9, the locking mechanism assembly  150  for the retractable, flush mounted, pull-up five (5) gallon production shelf  114  is shown. Although the locking mechanism assembly  150  is shown in its preferred embodiment, as a pull-up production shelf  114  for the modular automatic colorant dispenser cabinet  50 , this design could be used in any situation where a shelf is required that is pulled up for active use, and then pushed down to save space when not in use. 
     The pull-up five (5) gallon production shelf  114  is mounted onto the modular cabinet  50  into a recessed shelf housing  130  on the cabinet front  110 . When the pull-up shelf  114  is in the resting position (not shown), the lower pivot arm  132  and the upper pivot arm  134  allow the pull-up shelf  114  to retract into the recessed housing  130  and become flush mounted with the cabinet front  110 . 
     In practice, to transition the pull-up shelf  114  from resting position to active position, the user applies an upward force on the pull-up shelf  114  by pulling upward on the shelf handle  138  until a distinct click is heard and felt. The two large shelf pivots  140  allow the shelf to transition from resting to active position. The upward force in raising the shelf  114  causes a cam-type shape on the end of the lower pivot arm  132  to compress the springs of the spring loaded locking pin  136 . The spring force insures positive locking between the upper pivot arm  134  and the lower pivot arm  132 . 
     To transition the pull-up shelf  114  from the active position to the resting position requires a slight upward force of the shelf  114  until a distinct click is heard from the spring loaded detent mechanism, indicating that the shelf may be lowered to its resting position. At a point near the end of the lowering motion, the spring-loaded detent mechanism will reset itself for the next shelf raising motion. Additional strength is provided in the preferred embodiment of the invention by using multiple piece construction or lamination in both the upper pivot arm  134  and the lower pivot arm  132  connection. By utilizing several individual upper and lower pivot arms that are collectively ganged together, the unique spring-loaded mechanism provides maximum strength and durability for many years of faithful service. This design improves upon the basic toggle principle exhibited by prior art mechanisms. In the traditional toggle locking mechanisms, the user would be required be required to release the locking pin manually. However, with the locking exhibited in FIG. 9, using one hand, the user simply pulls the shelf up slightly, then lowers the shelf to the resting position and pulls up on the shelf until it has locked itself into the active position locked position. The unique spring-loaded detent mechanism automatically resets every time the shelf is lowered into the recessed shelf housing  130 . 
     In practice, the modular automatic colorant dispenser system performs as follows. Referring again to FIG. 1, the colorant is stored in the canister  44 , and the agitator  48  conditions the colorant. The colorant then passes from the canisters  44  through the inlet line  34 . The stepper motor  14  then drives the twin impellers, located inside the pump body  18 , to precisely pump and pulverize any particles in the colorant, and then the twin impellers propel the colorant through the pump module  12 . 
     The rotational accuracy of the stepper motor  14  is translated to the pump body  18 , providing extremely accurate metering of precise amounts of colorant. The colorant then exits the pump module  12  through the outlet line  38  and on to the valve  58 . The valve  58  then distributes the precisely metered colorant through the discharge nozzle assembly  70  to the awaiting container  80 , or returns the unused colorant back to the canister  44 . Additionally, the modular automatic colorant dispenser system  10  thoroughly reconditions the colorant by programmed intervals. This efficient reconditioning is accomplished whereby the pump re-circulates colorant at programmed intervals through the return line  60  at the valve  58 . The purpose of controlled reconditioning of colorants is to insure properly conditioned colorant is always ready to dispense from the modular automatic colorant dispenser system  10 . In prior art dispensers, colorants have been damaged from over mixing causing the overheating of the colorants. Manually set timer control methods used in all prior art dispensers can not address the specific needs of each colorant due to their individual specific weights and chemistry. 
     Still referring to FIG. 1, the computer control module  90  allows a user to preprogram the precise amount of each colorant that will be dispensed into the container  80 . Each stepper motor  14  is controlled from the computer control module  90 , thereby controlling the precise amounts of colorant to be dispensed. The computer control module  90  allows the user to pre-program each stepper motor to dispense each colorant. Pre-programmed color formulas provide each individual stepper motor the information to produce the desired color formula. 
     Thousands of industry color system formulations can be stored in the hard drive of the computer control module  90 , with virtually immediate access to the chromatic color values for many thousands of custom designed color formulations. 
     Although the present invention has been described with reference to certain preferred embodiments thereof, other versions are readily apparent to those of ordinary skill in the art. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiments contained herein.