Patent Publication Number: US-2012037666-A1

Title: Anti-Drip Valve for Fluid Dispensers

Description:
TECHNICAL FIELD 
     This disclosure relates generally to fluid dispensers. More specifically, this disclosure relates to mechanisms for preventing or limiting post-dispense dripping of fluids dispensed from such fluid dispensers. 
     DESCRIPTION OF THE RELATED ART 
     Systems for dispensing a plurality of different fluids into a container have been known and used for many years. For example, systems for dispensing paint base materials and colorants into a paint container are known. These paint systems may use twenty or more different colorants to formulate a paint mixture. Each colorant is contained in a separate canister or package and may include its own dispensing pump. The colorants and the respective pumps may be disposed on a turntable or along one or more horizontal rows. In a turntable system, the turntable is rotated so that the colorant to be dispensed is moved to a position above the container being filled. In designs using one or more horizontal rows, the container may be moved laterally to the appropriate colorant/pump. 
     Systems for dispensing large varieties of different fluids are not limited to paints, but also include systems for dispensing pharmaceutical products, hair dye formulas, cosmetics of all kinds, nail polish, beverages, flowable food items, etc. 
     In many fluid dispensing applications, precision is essential as many formulations require the addition of precise amounts of certain ingredients. This is true in the pharmaceutical industry but also in the paint and cosmetic industries as the addition of more or less tints or colorants can result in a visible change in the color of the resulting product. 
     One way in which the precision of dispensing systems is compromised is “dripping.” Specifically, a “leftover” drip may be hanging from a nozzle that was intended to be added to a previous formulation and, with a new container in place under the nozzle, the drop of liquid intended for a previous formulation may be erroneously added to a new formulation. Thus, the previous container may not receive the desired amount of the liquid ingredient and the next container may receive too much. 
     To solve the drip problem, various scraper and wiper designs have been proposed. However, these designs often require one or more different motors to operate the wiper element and are limited to use on dispensing systems where the nozzles are separated or not bundled together in a manifold. 
     Another problem associated with dispensing systems that make use of nozzles lies in the dispensing of relatively viscous liquids such as tints, colorants, base materials for cosmetic products, certain pharmaceutical ingredients or other fluid materials having relatively high viscosities. Specifically, the viscous fluids have a tendency to dry and cake onto the end of the nozzles, thereby requiring frequent cleaning in order for the nozzles to operate effectively. While some mechanical wiping or scrapping devices are available, these devices are not practical for multiple nozzle manifold systems and the scraper or wiper element must be manually cleaned anyway. Further, using a scraper or wiper on a multiple nozzle manifold system creates cross-contamination of materials at the various nozzles. 
     Finally, in terms of paints and other solvent-base materials, there is an increasing trend in regulations at both the state and federal levels limiting the use of volatile organic compounds (VOCs). Low-VOC or no-VOC colorants for paints as well as other low- or no-VOC liquids or slurries may have lower viscosities thereby contributing to the dripping problem described above. 
     SUMMARY OF THE DISCLOSURE 
     An anti-drip valve assembly for a fluid dispenser is disclosed. The disclosed anti-drip valve assembly comprises of a valve block and a cylindrical valve body disposed within the valve block. The cylindrical valve body comprises a recess accommodating a valve element. The recess is in communication with a chamber for accommodating a biasing element for biasing the valve element outward away from the valve body. The recess is in alignment with a dispense port disposed in the valve block. The dispense port is selectively in communication with at least one fluid passageway when the valve body is in a dispense position and the valve element is biased against the dispense port when the valve body is in a closed position. 
     In a refinement, the valve body is moveable between the closed position and at least two dispense positions. In a first dispense position, the dispense port is in communication with a first fluid passageway. In a second dispense position, the dispense port is in communication with a second fluid passageway. 
     In a refinement, the valve element is biased against a portion of the valve block that is not in alignment with the dispense port when the valve body is in either the first or second dispense positions. 
     In a refinement, the valve body is connected to a handle. The handle may be used for selectively moving the valve body between the closed, first dispense position and second dispense position. 
     In a refinement, the valve element is a poppet valve. 
     In a refinement, the biasing element is a spring for biasing the valve element against the dispense port or valve block. 
     An improved fluid dispenser is also disclosed which comprises a canister of fluid that is coupled to at least two pumps including a first pump and a second pump. Communication between the canister and the pumps is established through a valve block. The valve block accommodates a cylindrical valve body. The cylindrical valve body comprises a recess for accommodating a valve element. The recess is in communication with a chamber for accommodating a biasing element for biasing the valve element outward away from the valve body. The recess is in alignment with a dispense port disposed in the valve block when the fluid dispenser is in a closed position. The dispense port is selectively in communication with a first fluid passageway that is in communication with the first pump when the valve body is in a first dispense position. The dispense port is selectively in communication with a second fluid passageway that is in communication with the second pump when the valve body is in a second dispense position. 
     In a refinement, the valve element is biased against a portion of the valve block that is not in alignment with the dispense port when the valve body is in either the first or second dispense positions. 
     A method for retrofitting a fluid dispenser with an anti-drip valve is also disclosed. The method comprises providing a fluid dispenser that comprises a canister of fluid coupled to at least two pumps including the first pump and the second pump and wherein the communication is established through a valve block. The valve block accommodates the cylindrical valve body. A dispense port in the valve block is selectively in communication with a first fluid passageway that is in communication with the first pump when the valve body is in a first dispense position. The dispense port is in communication with a second fluid passageway that is in communication with the second pump when the valve body is in a second dispense position. The method comprises replacing the cylindrical valve body described above with a new cylindrical valve body comprising a recess for accommodating a valve element. The recess is in communication with a chamber for accommodating a biasing element for biasing the valve element outward away from the new cylindrical valve body. The recess is in alignment with the dispense port disposed in the valve block when the new cylindrical valve body is in the closed position. 
     Other advantages and features will be apparent from the following detailed description when read in conjunction with the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the disclosed methods and apparatuses, reference should be made to the embodiments illustrated in greater detail in the accompanying drawings, wherein: 
         FIG. 1  is a partial perspective view of a fluid dispenser illustrating a single canister, two pumps, a valve and a product receptacle; 
         FIG. 2  is a bottom perspective view of the dispenser illustrated in  FIG. 1 , particularly illustrating the valve in an open position with respect to the large pump and a closed position with respect to the small pump; 
         FIG. 3  is another bottom perspective view of the dispenser illustrated in  FIGS. 1-3 , particularly illustrating the valve body in a closed position with respect to both pumps; 
         FIG. 4  is an exploded view of an improved valve body made in accordance with this disclosure; 
         FIG. 5  is an exploded view of the valve body illustrated in  FIG. 4  and the valve block illustrated in  FIGS. 1-3 ; 
         FIG. 6  is another perspective view of the improved valve body disclosed herein; and 
         FIG. 7  is another perspective view of the improved valve body disclosed herein. 
     
    
    
     It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are sometimes illustrated diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of the disclosed methods and apparatuses or which render other details difficult to perceive may have been omitted. It should be understood, of course, that this disclosure is not limited to the particular embodiments illustrated herein. 
     DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS 
     Turning to  FIG. 1 , a partial view of a dispenser  10  is disclosed which includes a canister  11  disposed on a valve block  12  that accommodates a valve assembly  13 . The dispenser  10  includes two pumps, including a larger pump  14  and a smaller pump  15 . Each pump  14 ,  15  includes a knob or handle  16 ,  17  connected to a piston stem  18 ,  19 . Only one canister/pump  14 /pump 15 /valve block  12 /valve assembly  13  is illustrated in  FIG. 1 . A plurality of such combinations may be typically mounted on the turntable  21 , which may be operated manually or by a suitable motor (not shown). A linear arrangement is also possible. A dispense canister is shown at  22  disposed on a platform  23 . Pump  14  also includes a scale or gage  25  and a similar scale or gage may be employed for the small pump  15 . In one embodiment, the pump  14  is a five fluid ounce pump which is capable of dispensing from less than five fluid ounces in a single stroke of the piston  18  when the pump cylinder  26  is full. The pump  15 , on the other hand, may be a one fluid ounce pump and intended to dispense materials in one fluid ounce increments only (assuming the pump cylinder  27  is full) or in amounts less than one fluid own and therefore a scale or gage for the pump  15  may or may not be necessary for the pump  15 . 
     Turning to  FIG. 2 , the valve block  12  is in communication with the canister  11  via the passageways  28 ,  29 , shown in phantom. The passageways  28 ,  29  connect the canister  11  to the valve assembly  13 . Referring to  FIGS. 2 and 4 , the valve assembly  13  includes a handle  31  coupled to a collar  32 . The collar  32  is connected to the valve body  33  by the pin  34 . The valve body  33  includes peripheral grooves  35 ,  36  for accommodating the seal elements  37 ,  38 . The first passageway  41  provides communication between the passageway  28  and the dispense port  42  as illustrated in  FIG. 2 . In  FIG. 2 , the handle  31  has been rotated so the dispenser  10  is open with respect to the large pump  14 . Specifically, fluid passes through the passageway  28 , through the first passageway  41  and down through the dispense port  42 . As also seen in  FIG. 2 , the small pump  15  is isolated as no communication exists between the passageway  29  and the dispense port  42  in the position illustrated in  FIG. 2 . 
     Returning to  FIG. 4 , the valve body  33  also includes a second fluid passageway  43  which provides communication between the passageway  29  and the dispense port  42  when the handle  31  has been rotated to a position for dispensing from the small pump  15 . Such a position is not illustrated in the figures as shown but it will be apparent to one skilled in the art that such a position exists between the closed position illustrated in  FIG. 3  and the open position for the large pump  14  illustrated in  FIG. 2 . Referring to  FIG. 4 , the valve body  33  includes a recess  44  and an additional chamber  45 . The recess  44  accommodates the valve element  46  and the chamber  45  accommodates the biasing element  47 . 
     Turning to  FIG. 3 , the handle  31  has been rotated so that both sets of passageways  28 ,  41  and  29 ,  43  are isolated from the dispense port  42 . Thus,  FIG. 3  illustrates the dispenser  10  in the closed position. 
     Referring to  FIGS. 3 and 4 , the means for priming or loading the pumps  14 ,  15  will now be described.  FIGS. 3 and 4  illustrate passageways  51 ,  52  that are connected to transverse slots  53 ,  54 . When the handle  31  is in the closed position as illustrated in  FIG. 3 , the passageways  28 ,  29  that are in communication with the canister  11  are also in communication with the slots  53 ,  54  which, in turn, are coupled to the bottoms  55 ,  56  of the pumps  14 ,  15  which include the piston heads  57 ,  58  which draw fluid into the pump canisters  25 ,  27 . Therefore in the closed position in  FIG. 3 , raising either knob  16 ,  17  draws the piston stems  18 ,  19  and piston heads  57 ,  58  upward to draw fluid through the passageways  28 ,  29  and through the transverse slots  53 ,  54  and into the pump canisters  25 ,  27 , resulting in the priming of the pumps. Fluid may also pass through the passageways  41 ,  43  so that no air bubbles are dispensed through the dispense port  42  when a dispense is carried out as illustrated in  FIG. 2 . 
       FIG. 5  illustrates the insertion of the valve assembly  13  through the cylindrical opening  61  of the valve block  12 . The valve block  12  also includes recesses  62 ,  63  that are in alignment with the piston heads  57 ,  58 . The shorter passageways  64 ,  65  channel the flow in a more direct fashion to the transverse passageways  41 ,  58  during dispensing from the pumps  14 ,  15  respectively.  FIGS. 6 and 7  provide additional views of the valve assembly  13 . 
     It will be noted that valve assembly  13  include proximal and distal ends  67 ,  68  respectively and the distal end  68  includes a key slot  69  to facilitate assembly of the valve assembly  13  into the valve block  12 . 
     While only certain embodiments have been set forth, alternatives and modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit and scope of this disclosure and the appended claims. 
     Thus, an improved valve assembly and an improved semi-manual fluid dispenser are disclosed that eliminate or at least alleviate the dripping problem associated with dispensing low viscosity fluids.