Abstract:
A mixing and dispensing apparatus wherein a liquid concentrate is metered into a diluent stream of an eductor in a precise manner. A needle valve is employed in conjunction with a cam member and the cam member includes slopes of varying degrees. In this manner, a wide range of dilution rates can be accomplished with only a single revolution of the needle valve. The apparatus is particularly useful in mixing and dispensing chemical concentrates such as cleaning and sanitizing materials.

Description:
BACKGROUND OF INVENTION 
     1. Technical Field 
     This invention relates generally to liquid mixing and dispensing apparatus and more particularly, to such an apparatus wherein the mixing is conducted at a variable rate and in a precise manner. 
     2. Background Art 
     Mixing and dispensing apparatus of the type which mix a chemical cleaning or sanitizing concentrate with water are well known. The resulting solutions can be filled into suitable containers such as bottles or buckets. They can also be sprayed from the dispensing apparatus. Apparatus of this type are available from Johnson Diversey of Sturtevant, Wis. as the J-FILL dispensing units or Solution Centers. 
     While the previously referred to units afford accurate, reliable and dispensing of solutions, the metering of the concentrate into the diluent water can be a problem. In many instances the metering is accomplished by providing two different concentrate bottles or metering devices placed in the bottle for the concentrate. Accordingly, it would be desirable to be able to vary the amount of concentrate incrementally without the use of different concentrate bottles or metering devices and do so in a precise and efficient manner. 
     Various types of metering valves are available. For example, in U.S. Pat. No. 938,601 a needle valve is disclosed in conjunction with a camming surface. The needle valve is intended for use with a Bunsen burner. U.S. Pat. No. 824,527 also discloses a needle valve in conjunction with a valve slide having an inclined hole. This valve also is intended for use with gas burners. A faucet type valve with a camming surface is disclosed in U.S. Pat. No. 1,423,966. 
     The prior art does not disclose a needle valve for use with a mixing and dispensing apparatus which can precisely measure the amount of concentrate into a diluent stream of water. 
     The objects of the invention therefore are: 
     a. Providing an improved liquid and dispensing apparatus. 
     b. Providing a liquid mixing and dispensing apparatus which allows for a precise metering of diluent. 
     c. Providing a liquid mixing and dispensing apparatus wherein the precise metering of diluent is accomplished in an efficient manner. 
     d. Providing a liquid mixing and dispensing apparatus wherein the precise metering of diluent is accomplished over a wide range of dilution rates. 
     e. Providing a liquid mixing and dispensing apparatus of the foregoing type wherein the precise metering of diluent is accomplished by a single rotation of a needle valve. 
     f. Providing a liquid metering apparatus which can be retrofitted to a liquid mixing and dispensing apparatus. 
     SUMMARY OF INVENTION 
     The foregoing objects are accomplished and the shortcomings of the prior art are accomplished by the precision variable rate dispensing apparatus of this invention which includes a support member and an eductor connected to the support member. The eductor has a liquid inlet, an inlet for liquid concentrate and an outlet for a mixed solution. A needle valve assembly is in fluid communication with the inlet for liquid concentrate, the needle valve assembly including a valve body, and a needle member for reciprocal movement with respect to a passage to vary flow therethrough. A cam follower portion is connected to the needle member and a cam member is positioned between the cam follower portion and the passage. The needle member is constructed and arranged so that when the needle member is turned in one direction with the cam follower portion in contact with the cam member, the needle member will move away from the passage to increase flow through the valve and when the needle portion is turned in the opposite direction the needle member will move in the direction of the passage to reduce flow through the valve. 
     In one aspect, the cam member is constructed and arranged so that a single revolution of the needle portion will cause a full operation of the valve. 
     In a preferred embodiment, the cam member has a cam surface with a first degree slope and a rapidly increasing slope larger than the first, with the rapidly increasing slope of the cam surface terminating in an end wall connected to the first degree slope. 
     In another aspect, the cam follower member is defined by a flange member extending from the needle portion. 
     In another embodiment, the cam member is defined by a one piece, ramped, annular component. 
     In yet another embodiment, the valve body is connected to the eductor at one end of the eductor and the inlet for liquid concentrate is connected to a side of the valve body. 
     These and still other objects and advantages of the invention will be apparent from the description which follows. In the detailed description below a preferred embodiment of the invention will be described in reference to the full scope of the invention. Rather, the invention may be employed in other embodiments. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a back view of a multi-station liquid mixing and dispensing apparatus utilizing the valve assembly of this invention. 
         FIG. 2  is an elevational view showing one embodiment of the valve assembly. 
         FIG. 3  is a view similar to  FIG. 2  showing another embodiment of the valve assembly. 
         FIG. 4  is a sectional view and the valve assembly shown in FIG.  2 . 
         FIG. 5  is a partial sectional view of the valve assembly shown in FIG.  3 . 
         FIG. 6  is an exploded view of the valve assembly shown in FIG.  2 . 
         FIG. 7  is a perspective view of a cam member utilized in the valve assembly. 
         FIG. 8  is a side view of the cam member. 
         FIG. 9  is a bottom view of the cam member. 
         FIG. 10  is a side view of the cam member opposite that of FIG.  8 . 
         FIG. 11  is a top view of the cam member. 
         FIG. 12  is another end view of the cam member. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , the variable rate dispensing apparatus generally  10  includes a needle valve assembly generally  11  in conjunction with a dispensing apparatus generally  12 . Dispensing apparatus  12  without the needle valve assembly  111  is commercially available from Johnson Diversey of Sturtevant, Wis. as Solutions Center Chemicals. It includes a housing member  14  and a rack member  16  for bottles (not shown) of chemical concentrate. There are four valve bodies  18  connected to the housing member. Valve bodies include valves at the opposite side which can control the flow of water therethrough. A supply line  20  is interconnected to the valve bodies which will transport water to the valve bodies  18 . A hose connection  21  is connected to the supply line  20 . The dispensing apparatus  12  also includes the eductors  23  to which are connected liquid supply lines  25 , the supply lines terminating in the caps  27  for connection to bottles of chemical concentrate. When diluent water flows through the supply line  20 , chemical concentrate is siphoned through the liquid supply lines  25  and into the eductors  23  where it is mixed into a mixed solution flowing out of the outlet lines  30  and  31 . A preferred eductor is described in U.S. Pat. No. 5,927,338 assigned to Johnson Diversey, Inc. 
     Referring to  FIGS. 2 and 3 , there are shown two embodiments of the valve assembly  11  and  11 A. The basic difference between the two embodiments is that the  FIG. 10  embodiment includes an elbow  33  with a parallel connection to the eductors  23  whereas the embodiment in  FIG. 10A  includes a transverse connection. Both embodiments are connected to the eductors through the conduits  34  and  35 . In both instances, the valve body  32  is interconnected to the eductor  23  at one end of the eductor and the inlet  38  for liquid concentrate is connected to a side of the valve body. 
     Referring to  FIGS. 4 and 6 , the valve assembly  11  include a valve body  32  to which is attached an intake nozzle member  38  having a barbed section  39  to provide a fluid tight connection of line  25 . Valve body  32  has a component  42  in which is positioned a needle member  44  having a nose section  46  extending therefrom and into passage  47 . Also disposed in compartment  42  is a cam member  50 . There are appropriate seals  54  to seal the needle member  44  against the inner wall of the compartment  42  as well as against the passage  48 . There is a cam follower portion  52  in the form of a flange member connected to the needle member for riding against a cam surface of cam member  50 . Cap  56  closes the compartment  42  and confines the spring  57  to bias it against the contact washer  58  on the needle member  44 . A dial member  60  has a reduced section  61  which extends through the cap  56  and has a cut-out  62  for accommodating connector portion  64  of the needle member  44 . 
     As also seen in  FIG. 4 , the intake nozzle member  38  is connected to valve body  32  by means of the extension  66  disposed between upstanding wall  70  and tubular portion  67 . Extension  66  has a rib  65  for pivotal attachment in the groove  68  in the upstanding wall  70 . A seal  69  affords sealing engagement between the intake nozzle member  38  and the wall  70 . A seal  71  is also provided between conduit  34  and elbow  33 . 
       FIG. 5  further illustrates valve assembly  11 A. It has the same components as valve assembly  11  except for the elimination of elbow conduit  33 . Conduit  34  is connected to valve body  32  and a seal is provided at  71 . 
     The cam member  50  is more particularly described in  FIGS. 7-12 . It includes a one piece, ramped, annular component with a cam track  78  having a first degree slope  80  and a rapidly increasing slope  82 . The first degree slope  80  has a slope in the range of 4° to 8°, whereas the second slope  82  is much larger and is in the range of 8° to 20° A wall  84  connects the first and second degree slopes. An important feature of the invention is the utilization of the two different slopes in the cam track  78  of the needle valve assembly  11  which affords the precision and quick adjustment in the variable rate dispensing apparatus  10 . The small slope  80  on the first 180° of the cam track  78  can allow for dilution rates in the range of 1:512 to 1:256 while the rapidly increasing slope  82  allows for an exponential area changes in the 1:256 to 1:8 range. The 1:512 ratio rate provides a dilution of ¼ oz/gallon whereas the 1:256 ratio rate provides a dilution of ½ oz/gallon. This is a difference of ¼ oz/gallon for the first 180° slope  80 . The final 180° slope  82  provides a dilution of 16 oz/gallon and a difference of 15¾ oz/gallon between the slopes. This wide range of dilution is effected in one revolution turn of the needle. It should be pointed out that the first degree slope is accomplished within 180° of the cam track whereas the larger degree within the final 180°. The first degree slope is indicated between the slope end points  86  and  87  in FIG.  7 . 
     It should be understood that spring pressure holds the cam follower portion  52  in any given position. Nothing stops complete rotation of dial member  60 . If the dial member  60  and cam follower portion  52  are turned too far, it resets back to start after it falls off ramp  82  and along wall  84  with spring  57  pushing back. 
     Referring back to  FIG. 4 , an increase or decrease in flow through the valves  11  and  11 A is effected by a turning dial member  60 . Accordingly, needle member  44  and the nose section  46  move toward and away from passage  47  to regulate the flow of concentrate from the passage  72  and ultimately to the eductor  23  through the conduit  34 . 
     It will thus be seen that there is now provided a precise and variable valve assembly for a dispensing apparatus which provides a wide range of dilutions for a chemical concentrate. This is effected in a rapid manner in that only one revolution of the needle valve dial is required. The needle valve assembly can accommodate a wide variety of various chemical concentrates such as cleaners, sanitizers, strippers and disinfectants. 
     While the variable rate dispensing assembly has been described for use in conjunction with several eductors in a dispensing apparatus, it is obvious that it can be employed with only a single eductor. Further, while a single, larger outlet hose is shown at  31  for filling buckets, it is obvious that more than one could be utilized in place of the shorter hoses  30 . All such and other modifications within the spirit of the invention are meant to be within its scope as defined by the appended claims.