Patent Application
20120037666
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.
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.
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.
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:
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.
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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.
