Patent Application
20050053416
1. Technical Field
A substitute for a mechanical valve with moving parts for fluid dispensing instruments such as writing instruments and painting instruments is disclosed. More specifically, instead of a mechanical valve such as a ball valve, needle valve, or duck bill valve, a combination of filters is substituted for a mechanical valve. Still more specifically, a combination of hydrophobic and hydrophilic filters are used to control the flow of ink, paint correction fluid or any other water based fluids from a flexible barrel reservoir to the tip, brush or applicator of the instrument. Still more specifically, a hydrophobic filter media is disposed between the fluid supply and a hydrophilic filter media. The hydrophilic filter media is disposed between the brush tuft, pen tip or applicator tip and the hydrophobic filter media. Manual pressure applied to the flexible barrel holding the fluid will force the fluid through the hydrophobic filter media and to the hydrophilic filter media. The hydrophilic filter media will deliver a controlled flow of fluid to the applicator tip.
2. Background of the Related Art
In fluid dispensing instruments such as ink pens, gravitational and capillary forces are the two principal means for migrating ink from the reservoir to the tip are employed. In one system, the ink is stored in a narrow tubular reservoir that is connected to a tip. Ink flows from the reservoir through the tip by way of the capillary and gravitational forces.
Another system includes storing the ink in a fiber structure often referred to as a reservoir. The fiber reservoir is saturated with ink which flows from the fiber reservoir to the tip by way of both capillary and gravitational forces. The tip may be an extension of the fiber reservoir or may be a separate member with a collection tube or other structure that is embedded in the fiber reservoir.
Some instruments similar to writing instruments, require the application of pressure by way of the user's hand onto a flexible barrel containing the fluid to be dispensed in order to deliver the fluid through the tip. Specifically, instruments containing correction fluid are now offered in a “pen-shape” form which requires the user to apply pressure to the flexible barrel or reservoir in order to deliver correction fluid through the ball point tip. In contrast, fountain pens include a tip that is directly coupled to a liquid reservoir of ink and both capillary and gravitational forces deliver the ink to the fountain tip.
Further, more exotic writing instruments may include valve systems such as check valves or duckbill valves to help control the flow of ink or writing fluid to the tip. Such mechanical valve systems in writing instruments can be very costly due to the small size of such writing instruments. Further, mechanical valves can be unreliable due to the very nature of a writing instrument which is small, prone to be dropped or handled roughly and used in a wide range of ambient temperatures.
Thus, while writing instruments and correction fluid instruments may come in a variety of forms, none of the fluid delivery mechanisms are without their deficiencies. For example, while the capillary action of a ball point pen is dependable and long lasting, ball point pen apply a very thin coated of ink to the paper and are not preferred writing instruments by consumers for looking for bolder lines. On the other hand, felt tip pens provide a bolder, darker line but are prone to inconsistent ink delivery and premature drying out. Other roller-type pens that attempt to serve as a hybrid between a fountain pen and a ball point pen are prone to premature failure. Further, inexpensive pens that depend on gravity for ink flow will not work properly when the pen tip is disposed vertically above the ink reservoir.
Currently available correction fluid instruments that require the user to squeeze the barrel to apply the fluid operate inconsistently and are awkward to use due to the large amount of force required to be imposed upon the barrel in order to create the desired correction fluid flow. Any writing instrument with a mechanical valve disposed between the ink reservoir and the tip is expensive to manufacture and prone to failure for the reasons set forth above.
Therefore, there is a need for an improved fluid control system between an ink, paint, correction fluid or other liquid reservoir and a writing tip, brush or applicator tip.
Further, in the field of artist supplies, and more specifically, paint, an artist typically uses numerous brushes along with a pallet on which a variety of paint colors is disposed. While this system has been utilized for centuries, there is a demand for paint brushes that include their own reservoir of paint or ink which would eliminate the need for a separate pallet and, in the case of water colors, separate jars or bowls of water for the purpose of cleaning and wetting the brushes. Specifically, there is a demand for individual water color brushes which include a reservoir of water color connected to the brush. However, there currently is no satisfactory fluid control system for controlling the flow of water color from the reservoir to the brush tip. Thus, there is also a need for an improved control system for controlling fluid flow between a barrel reservoir and a brush tip of a water color paint brush applicator.
In satisfaction of the aforenoted needs, a “chemical” valve system between a barrel reservoir and an applicator tip such as a pen tip, brush or fluid applicator, is disclosed.
In an embodiment, the valve or control system comprises two filters including a hydrophobic filter and a hydrophilic filter. In an embodiment, the hydrophobic is disposed between the hydrophilic filter and the barrel reservoir. Further, in an embodiment, the barrel reservoir includes a flexible shell which permits the user to generate pressure in the reservoir by squeezing the barrel. Upon squeezing the barrel, fluid pressure is generated in the reservoir and fluid is forced through the hydrophobic filter towards the hydrophilic filter. Then, the fluid is drawn through the hydrophilic filter in a controlled manner to the writing tip, brush, applicator tip or applicator brush.
In a refinement, the hydrophobic and hydrophilic reservoirs are spaced apart and are disposed within a ferrule.
In another refinement, the hydrophobic and hydrophilic reservoirs are in abutting engagement with each other and disposed between the fluid reservoir and the applicator tip.
The above-referenced fluid control system is applicable to ink pens, correction fluid pens and paint brushes, such as self contained water color paint brushes whereby a brush is connected to a barrel reservoir containing water color with the disclosed fluid control system disclosed therebetween. The disclosed fluid control system will also be applicable to the delivery of other water based fluids through a tip, brush or applicator.
The disclosed embodiments are described more or less diagrammatically in the accompanied drawings, wherein:
Turning to
Once such source is Filtrona of Colonial Heights, Va. Hydrophobic reservoirs or filters 11 are typically made from polypropylene or other non-polar polymers with a carbon backbone. Such non-polar polymers, when incorporated into a filter reservoir to form a hydrophobic filter, lack an affinity for water or, in other words, repel water. Suitable hydrophobic filter materials include aromatic polymers and halogenated polymers. Other materials suitable for fabricating the hydrophobic reservoir or filter 11 include but are not limited to: rubber; certain polyesters; polyurethane; polyhydrocarbons like polyethylene and polystyrene; acrylates; carbonates; chlorinated polymers; polyaromatic esters like poly(butylene terephthalate); ethers like polyethersulfone; polyetheretherketone; fluorinated polymers like poly(vinylidene fluoride); methacrylates; polyvinyl chloride; higher vinyl acetates; cellulose-esters; and mixtures of the above. Other suitable materials for fabricating hydrophobic filters or hydrophobic reservoirs shown at 11 in
Conversely, hydrophilic filter or reservoir elements 12 may be fabricated from non-polar polymers, often with hydroxy groups disposed on the polymer backbone. Another suitable polymer component for a hydrophilic filter 12 is polysulfone. Other hydrophilic materials for fabricating the hydrophilic filter or reservoir 12 include: cellulose-based fibers like stem of flax and Hemp, shell of coconut or cotton; protein-based fibers like animal hair, wool or silk; mineral-based like asbestos, chrysotile; nylons; polyamides; glass; metal; and silicate. Still other suitable hydrophilic materials for the filter 12 will be apparent to those skilled in the art.
Though fibers of different materials can be used to render a reservoir hydrophobic, hydrophilic fibers can be rendered hydrophobic by surface modification techniques. These techniques include surface coating and grafting. By the same virtue, a hydrophobic reservoir can be made hydrophilic through plasma treatment or ozonolysis.
As shown in
An analogous embodiment is illustrated in
In addition to using two different filter or reservoir elements 11, 12 that hydrophobic and hydrophilic respectively, other “chemical” type control valves or systems may be employed also based upon the difference in chemical affinity of the fluid being transported and the valve material. Such other systems would include two filter elements with different electrostatic interactions, two filter elements with different acidities or different acid-base reactions, two different filter elements with complimentary and non-complimentary hydrogen bonding, and two different filter elements with different metal-ligand affinities. Some molecules have special affinities towards other molecules. In the metal-ligand interaction, the ligand interacts or binds with a metal center by donating its lone pair of electrons (as in dative bond formation). An example can be using a reservoir with phenolic fiber inside to restrict the flow of a liquid enriched in iron ions. Since there is a strong interaction between phenol and iron ions, the flow of the iron will be slowed down owing to its interaction with the phenolic moieties in the fibers.
Working examples of the hydrophobic/hydrophilic reservoir 11, 12 system as shown in
A hydrophobic reservoir 11 (density=0.4 g/cc, 5.5 OD×3 mm) and a hydrophilic reservoir 12 of various lengths (both are from Filtrona, Colonial Heights, Va.) were connected together using a Tigon tubing. The reservoir 11, 12 combination was connected to the ink barrel 14 of a color brush with the hydrophobic 11 side facing the ink. The force applied onto the barrel body 14 to squeeze the ink out was measured. Table 1 depicts the result of this experiment.
Color brushes 15 incorporating hydrophobic reservoirs 11 (5.5 mm OD×3 mm) of various densities (0.4, 0.344, 0.289 g/cc) were prepared. A hydrophilic reservoir 12 was not included in this test. The force applied onto the barrel body 14 to squeeze the ink out was measured for these color brushes. Table 2 depicts the result of this experiment.
Thus, the layer force required for the structure with the hydrophobic filter element 12 only (i.e., without the hydrophilic element) illustrates the benefit of controlled flow with reduced pressure provided by the hydrophobic/hydrophilic filter combination 11, 12 of this disclosure.
While only certain embodiments have been set forth, alternative embodiments and various 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.
This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application Ser. No. 60/496,301, filed Aug. 19, 2003, the disclosure of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60496301 | Aug 2003 | US |
