Patent Publication Number: US-6655401-B2

Title: Multiple chemical product eductive dispenser

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to dispensers and more particularly to a chemical product selection and venturi eductor device for selectively dispensing and mixing, at a corresponding dilution ratio and total fluid flow rate, one of a plurality of fluids with another fluid. 
     2. Prior Art 
     Selector valves typically allow an operator to select and dispense one particular chemical fluid at a time, while closing off access to all of the other fluid sources available for selection. One such prior selector valve typically includes a static body having several inlet ports and one outlet port and a rotatable valve core with passages to allow selective connection of a selected inlet port with the outlet port. Sealing of the non-selected inlet ports is provided by a spring loaded, O-ring sealed plunger carried in the rotatable core and bearing against the face of the static body. While selector valves of this type allow for selective connection and dispensing of a plurality of fluids, they have several inherent disadvantages. 
     One problem associated with selector valves of this type is the ability to efficiently change over from one selected input chemical fluid to another. A residual volume of the prior chemical in many systems of this type must be purged prior to inputting a second selected chemical fluid. Purging the system is very detrimental in that it requires delays in the operation and diminishes the accuracy of the volume and timing of the mixing of the fluids. Because of the distance and the geometry of the path the selected fluid must travel within the selector valve system, the system may contain a significant amount of residual chemical after the user has selected a new inlet port, thereby requiring the user to spend time purging the line. 
     A contributing factor to the problem of residual fluids in the selector valve is turbulent flow of the fluids through the selector valve. Specifically, the cause of turbulent flow in the selected fluid flow path is commonly stagnation points or blind spots which are typically found at the juncture between mating components. These areas create turbulent flow of the fluid through the selector valve and minimize the ability to effectively purge the valve and flush the residual chemicals. Additionally, turbulent flow through the selector valve retards the fluid flow and requires greater pressures and timing problems for the selected input fluid sources and responsiveness of the selector valve and connected system components. 
     Two solutions to some of these identified problems are disclosed in U.S. Pat. Nos. 5,377,718 and 5,653,261 which are assigned to the assignee of the present invention. The systems of these patents reduce the amount of carry-over, or residual fluid, retained in the selector valve between dispensing selections by streamlining and reducing the volume of passages that retain residual fluid. Thus, in the illustrative embodiments contained therein, carry-over of less than 0.4 cc and less than 0.1 cc, respectively, are achieved. 
     While the systems disclosed in U.S. Pat. Nos. 5,377,718 and 5,653,261 solved a number of problems associated with prior selector valves, the systems were directed to reducing the amount of carry-over, and not to eliminating carry-over in the system. While many applications benefitted from the relatively small amount of carry-over, other applications were not suitable. 
     One specific prior art system avoiding chemical carryover is shown in FIG.  1 . The dispensing system  10  uses two ball valves  12 ,  14 , each directing a motive fluid, typically received from a pressurized water supply at a water inlet  16 , to a respective eductor  18 ,  20 . Thus, each selector valve  12 ,  14  does not direct or retain a chemical fluid. Instead, each chemical fluid is eductively drawn from a respective chemical fluid reservoir  22 ,  24  into the corresponding eductor  18 ,  20  downstream of the selector valve  12 ,  14 , respectively, in response to the motive fluid. Mixed fluid from each eductor  18 ,  20  is dispensed from a common outlet  26 . A third ball valve  28  supplies bypass water directly to the outlet  26  for purposes such as achieving a greater dilution, rinsing a hose (not shown) connected to the outlet  26 , and rinsing articles (not shown). 
     While the dispensing system  10  efficiently mixes a number of chemical fluids for use from a single dispenser, further improvements are desired. For example, selecting a particular mixture requires positioning one or more of several different levers increases the opportunity for human error. In another example, use of several ball valves  12 ,  14 ,  28  increases the cost for selecting a chemical fluid, as compared to selector valves, such as disclosed in the above-referenced patents. In addition, a dispensing device be of a large size to position each ball valve and their levers. 
     Consequently, a significant need exists for a device for selectively mixing one or more of a chemical fluid with a motive fluid that is economic and smaller, yet does not carry-over chemical fluid between dispensing. 
     SUMMARY OF THE INVENTION 
     In accordance with principles of the present invention, in a preferred embodiment of the invention, a single selection member diverts a motive fluid to separate channels formed in an eductor body, at least one channel and preferably others being selectively and operatively associated with an eductor for drawing a chemical fluid. Thus, a single device is capable of selecting different mixed fluids without retaining a volume of residual fluid, or carry-over. A dispenser using the device can thus be smaller and more economically manufactured. 
     Consistent with one aspect of the invention, an apparatus for mixing at least one chemical fluid with a motive fluid has a selector body with a motive fluid passage and an eductor body with at least two fluid channels. Each fluid channel is in fluid communication between the motive fluid passage and a dispensing outlet. At least one fluid channel is an eductor whose venturi creates a low pressure when motive fluid passes through the eductor to draw a chemical fluid. Selecting the mixture of the motive fluid and the chemical fluid is achieved with a selector member that is contained within the motive fluid passage of the selector body to divert motive fluid to one or more of selected fluid channels. The single motive fluid selector member achieves an economy and efficiency over systems requiring a plurality of selector devices. In addition, since the selector member diverts motive fluid rather than a chemical fluid, carry-over of chemical fluids between dispensing selections is avoided. 
     In another aspect of the invention, a dispenser includes an apparatus with two eductors in the eductor body for mixing one of two chemical fluids, each supplied from a respective reservoir with a motive fluid; or alternatively for mixing the source chemical fluid from one or more sources but supplied at different flow rates. Also, different dilution rates may be produced by varying the flow rate of the motive fluid into the eductors. The selector member is positioned to divert motive fluid to at least one of the eductors to dispense the desired mixture. 
     Consistent with yet a further aspect of the invention, a method of mixing chemical fluids into a motive fluid without a carry-over of a previously selected chemical fluid includes the steps of (1) coupling a first supply of a chemical fluid to a venturi of a first eductor, (2) coupling a second supply of a chemical fluid to a venturi of a second eductor, (3) positioning a selector member to first position to divert the motive fluid to an inlet of the first eductor to dispense a first mixture, and (4) positioning the selector member to a second position to divert the motive fluid to an inlet of the second eductor to dispense a second mixture. 
     In short, prior art dispensing apparatus selected chemical sources by valves in the chemical lines. This invention contemplates a plurality of chemical eductors that are operated by a single valve in the motive fluid line diverting motive fluid to a selected eductor. Moreover, the motive fluid passage can be diverted to one or more chemical fluid channels connected to the same source to vary the dilution ratio of mixed fluid to be dispensed. 
     The above and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
     FIG. 1 is a cutaway view of a prior art dispensing system using three ball valves and two separate eductors to select between multiple chemical fluids for mixing. 
     FIG. 2 is a cutaway view of a dispenser consistent with the present invention for selecting between two chemical fluids. 
     FIG. 3 is a perspective view of a first embodiment of the device shown in FIG. 2 for selecting and eductively mixing fluids. 
     FIG. 4 is a cross sectional view along line  4 — 4  of the device of FIG. 3 showing fluid flow through the eductor channels. 
     FIG. 5 is a cross sectional view along line  5 — 5  of the device of FIG. 3 showing fluid flow through the bypass channel. 
     FIG. 6 is a perspective view of a second embodiment of the device shown in FIG. 2 for selecting and eductively mixing fluids with a selector member comprised of concentric rings, the concentric rings removed for clarity. 
     FIG. 7 is a perspective view of the device of FIG. 6 having concentric outer and inner selector rings positioned to select one of four channels. 
     FIG. 8 is a perspective view of the device of FIG. 6 having the concentric outer and inner selector rings positioned to select four of four channels. 
     FIG. 9 is a perspective view of a third embodiment of the device shown in FIG. 1 for individually selecting channels with push buttons for eductive mixing. 
     FIG. 10 is a cutaway view of the device of FIG. 9 showing spools positioned to selectively allow motive fluid to each channel in the eductor body. 
     FIG. 11 is an exploded view, partially in section, of a fourth embodiment of the device shown in FIG. 1 for dialing a selector member comprised of a cylinder for selectively allowing motive fluid to a channel in the eductor body. 
     FIG. 12 is a cutaway view of the device of FIG. 11 showing the diversion channel, particularly in section, in the cylinder aligned with the bypass channel in eductor body. 
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     Turning to the Drawings, wherein like numbers denote like parts throughout the several views, FIG. 2 shows a dispenser  30  and includes a single device  32  for selectively educting one or more chemical fluids for mixing with a motive fluid. Examples of suitable applications for a dispenser  30  include dispensing chemical fluids such as concentrated detergents, glass cleaners, disinfectants, wetting agents, protective polymer polishes, etc., that are diluted to a desired dilution ratio by mixing with a motive fluid of pressurized water. It will be appreciated that other chemical fluids and motive fluids may be used which are consistent with aspects of the invention. 
     The motive fluid is received at an inlet valve  34 , depicted as a ball valve, and passed through a motive fluid conduit  36  to the device  32  for mixing a selected chemical fluid, drawn respectively from chemical fluid reservoirs  38 ,  40  via chemical conduits  42 ,  44 . The reservoirs  38 ,  40  may be mounted and contained within a cabinet  46  of the dispenser  30  or remotely positioned as shown. 
     Mixed fluids from the device are emitted from the dispenser through an outlet  48  and a hose  50  connected to the outlet  48 . As will be discussed in greater detail below, the device  32  includes a plurality of pathways for selectively mixing the motive fluid with the chemical fluids, and thus applications consistent with the invention may include an outlet  48  divided into separate conduits for each pathway, as would be known to those skilled in the art. 
     The device  32  includes a single selection control, depicted as a lever  52 , for selecting the mixing. Consequently, an operator need only move one control, simplifying use of the dispenser  30  and reducing the likelihood for error. In some applications, the selection control includes a position wherein no mixed fluids are emitted from the outlet  48 , and thus the inlet valve  34  may be omitted or not routinely used. 
     FIGS. 3-5 depict a first embodiment of a selector disk device  60  for the dispenser  30  of FIG.  2 . In particular, the device  60  is integrally formed from separately molded and attached components of a selector body  62 , an eductor body  64 , and an outlet  66 . Between the selector and eductor bodies  62 ,  64 , a selector disk  68  and selector seal  70  are contained. 
     With particular reference to FIG. 3, the selector disk  68  is rotated by an externally exposed lever  72  for angularly positioning a disk orifice  74  in the selector disk  68  to one of a plurality of sealed orifices  76 ,  77 ,  79  under the selector disk  68 , which in turn are respectively registered to one of a plurality of inlets  82 - 84  in the eductor body  64 . The eductor body  64  includes a plurality of fluid channels  88 - 90  that correspond to and include the inlets  82 - 84 . In the illustrative depiction, there is no fourth inlet and no corresponding fluid channel. This allows the selector disk  68  to be positioned to an OFF position at a blind position. 
     With particular reference to FIG. 3, the first fluid channel  88  is illustratively depicted as a first eductor  92  that has a chemical fluid port  94  at the venturi of the eductor  92  for eductively drawing in a first chemical fluid. Typically, a metering tip (not shown) is inserted into the chemical port  94  for controlling the dilution ratio of the first chemical fluid, in coordination with the dimensional sizing of the first eductor  88 . A chemical fluid conduit is connected to the metering tip and is inserted into a reservoir containing the chemical fluid (not shown). Alternatively, the chemical fluid conduit is inserted between the port  94  and the metering tip. 
     Similarly, the second fluid channel  89  is illustratively depicted as a second eductor  96  that has a chemical port  98  at the venturi of the eductor  96  for eductively drawing in a second chemical fluid. Typically, a metering tip (not shown) is inserted into the chemical port  98  for controlling the dilution ratio of the second chemical fluid, in coordination with the dimensional sizing of the second eductor  96 . 
     The third fluid channel  90  advantageously illustrates a motive fluid bypass  100  sized for a desired flow rate of the motive fluid without any chemical fluid. It will be appreciated that the eductor body  64  is illustrative only and that various combinations of eductors and bypasses of various sizes may be selected for a specific application to achieve a desired flow rate, dilution ratio, and number of chemical fluids. 
     With particular reference to FIG. 5, a cross-sectional view of the device  60  of FIG. 3 depicts the fluid flow path with the selector disk  68  blocking motive fluid from entering the eductors  92 ,  96 . With particular reference to FIG. 5, a cross-sectional view of the device  60  of FIG. 3 depicts the fluid flow path with the disk orifice  74  angularly aligned to divert motive fluid through the motive fluid bypass  100 . In FIGS. 4,  5  the flow path through the device  60  begins with motive fluid passing through a motive fluid passage  102  formed in the selector body  62 . The fluid flow is exposed to an upstream face  104  of the selector disk and passes through the disk orifice  74  into the eductor body  64 . More particularly, in the illustrative depiction, the fluid flow passes into the third fluid channel  90 , i.e., the motive fluid bypass  100 . As shown in FIGS. 5 and 6, fluid flow is emitted from the eductor body at outlets  106 - 108 , which are respectively part of the fluid channels  88 - 90 . The emitted fluid flow is collected in the outlet  66  for dispensing through a hose (not shown in FIGS.  3 - 7 ). 
     FIGS. 6-8 depict a second embodiment of a device  120  for the dispenser  30  of FIG. 2 that employs a concentric disk selection member  122  for diverting motive fluid. In the illustrative depiction, an eductor body  124  is similar to the previously described eductor body of FIGS. 3-5, other than having four fluid channels  126 - 129  rather than the previously described three. Thus, the device  120  does not have an OFF position. Instead, the device  120  has a selection member  122  capable of simultaneously selecting one, two, three or four fluid channels  126 - 129 . Thereby, the device  120  is capable of mixing fluids to achieve different dilution ratios of the same chemical fluid or to simultaneously combine two or more chemical fluids with a motive fluid. 
     The combinations are selectable by radially elongated inlets  132 - 135  to the respective fluid channels  126 - 129 . Then, an outer concentric selector disk  138 , rotatably contained within the device  120 , has an angularly elongated orifice  140  that can be angularly positioned to divert motive fluid to one or two inlets  132 - 135 . Simultaneously, an inner concentric selector disk  142 , rotatably constrained with the outer concentric selector disk  138 , has an angularly elongated orifice  144  that can be angularly positioned to divert motive fluids to one or two inlets  132 - 135 . 
     For instance, as illustrated in FIG. 7, each concentric selector disk  138 ,  142  are rotated to only expose one inlet  132 , thus only one fluid channel  126  is selected. By contrast, as illustrated in FIG. 8, outer concentric selector disk  138  is angularly positioned to expose inlets  132 ,  135 , thereby selecting fluid channels  126 ,  129 . Inner concentric disk  142  is angularly positioned to expose inlets  134 ,  133 , thereby selecting fluid channels  128 ,  127 . 
     FIGS. 9,  10  depict a third embodiment of a device  150  for the dispenser  30  of FIG. 2 that uses push button selection member  152  for diverting motive fluid. In the illustrative depiction, an eductor body  154  is similar to the previously described eductor bodies, except having a fluid channel  156  that is surrounded by four other fluid channels  157 - 160 . A selector body  162  includes a motive fluid passage  164  that separates into vertically elongated inlets  166 - 170 , each corresponding and vertically aligned with an assigned fluid channel  156 - 160 . The selection member  152  traverses a plane that intersects or blocks each inlet  166 - 170 . In particular, the selection member  152  includes a plurality of selection spools or lands  172 - 176 , each traversing within a spool cavity  178 - 182 , as shown in FIG.  10 . Each land  172 - 176  includes a recessed portion  184 - 188  registered to align with the respective inlet  166 - 170  as the spool  172 - 176  traverses through the respective spool cavity  178 - 182 . 
     FIGS. 11-12 depict a fourth embodiment of a device  200  for the dispenser  30  of FIG. 2 that uses a cylindrical selection member  202  for diverting motive fluid. In the illustrative depiction, an eductor body  204  is similar to the previously described eductor body of FIGS. 9-10. The selection member  202  differs in that its cylindrical outer diameter  206  is received within a cylindrical cavity  208  in a selection block  210 . Along an inner diameter  212  of the cylindrical cavity  208 , an opening  214  provides motive fluid and a plurality of inlets  216 - 220  direct motive fluid to respective fluid channels  222 - 226 . The cylindrical selection member  202  includes a cylinder passage  228  that communicates between two portions of its outer diameter  206  to put the opening  214  into fluid communication with at least one of the inlets  216 - 220 . For instance, as depicted in FIG. 12, the cylinder passage  228  has an angularly wide portion  230  that allows communication with the opening  214  when the cylindrical selection member  202  is at various angular positions. An angularly narrow portion  232  of the cylinder passage  228  that selectively aligns with one of the inlets  216 - 220 , which are thus angularly spaced in the illustrative embodiment to select one at a time. 
     In use, a dispenser  30  mixes a selected chemical fluid when an operator positions a selection member, such as a selector disk  68 , concentric disk selection member  122 , push button selection member  152 , and a cylindrical selection member  202 . Thereby, the device  32  diverts motive fluid to one or more fluid channels, such as to the first eductor  92  that draws a first chemical fluid for mixing, to the second eductor  96  that draws a second chemical fluid for mixing, or to the motive fluid bypass  100 . The selected fluids are then dispensed through an outlet  48  for uses, such as washing or for filling portable dispensing articles, such as spray bottles. 
     By virtue of the foregoing, a dispenser  30  is provided of reduced volume and reduced number of parts, especially when the plurality of fluid channels are formed within a unitary eductor body  64 . Moreover, since the chemical fluids are eductively drawn, a passive device  30  is achieved that requires no active components to draw the chemical fluids, utilizing instead the motive force form the motive fluid (e.g., pressurized water supply). Also, since gravity is not used to direct the chemical fluids to the dispenser  30 , a more flexible positioning and sizing of chemical fluid reservoirs  38 ,  40  is available. Yet, with the flexibility of chemical fluid selection, the single device  32  does not suffer from carry-over of one chemical fluid when changing selections. 
     While the present invention has been illustrated by a description of various embodiments and while these embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant&#39;s general inventive concept.