Abstract:
The present invention is related to a durable foam tipped applicator that can absorb and retain fluids easily. The foam material used to make the applicator tip may be used in both water-based and solvent-based fluids. A wiper insert may be used to remove excess liquid from the applicator during removal from a reservoir of fluid. A lip at the mouth of the wiper insert can redirect excess fluid into the reservoir.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention concerns an improvement to containers used for liquids such as correction fluid and the like. In particular, the improvement provides a durable foam tipped applicator that can be used in either solvent-based fluids or water-based fluids. The foam tipped applicator absorbs and releases correction fluids easily without swelling or losing shape during immersion. The improvement also includes a more efficient container wiper against which an applicator may be wiped to remove excess liquid, thus preventing waste of the liquid and avoiding a common problem in which the container cannot be properly sealed due to excess liquid running onto and drying on the exterior of the container. 
     2. Discussion of the Related Art 
     Liquids and semi-liquids, such as correction fluid, cosmetics, paint, and the like are often stored in containers that include a reservoir for the liquid product and an applicator brush attached to the cap of the container. When the container is closed, the applicator brush is submerged in the reservoir of liquid. Upon removal from the reservoir, liquid product adheres to the applicator brush and is applied to a surface as desired by a user. However, if the amount of liquid withdrawn from the reservoir is not limited in some manner, frequently more liquid adheres to the brush than the user actually needs. As a result, when the user applies the brush to a surface the excess liquid is rapidly transferred to the surface, thereby diminishing the control or precision that can be achieved with the brush and also causing an undesirable build up of material on the coated surface and increased drying time. In circumstances where the desired area to be coated is small, these problems are noticeable even with small amounts of excess liquid. 
     Furthermore, the problems associated with excess liquid on the applicator are compounded when the liquid product is fast-drying. Unused portions of the product will dry-out and become unusable if not promptly returned to the reservoir. The buildup of dried and unusable product on the brush makes future applications less effective. 
     One attempt to solve the problems caused by excess liquid is to utilize a brushless applicator connected to a reservoir of liquid with a regulator to control the flow of fluid to the applicator tip. For example, U.S. Pat. No. 4,923,317 to Bishop et al. depicts a brushless correction fluid applicator having a reservoir of correction fluid permanently connected to a porous regulator of foamed or sponge-like material that controls flow of correction fluid to a flexible but fairly stiff plastic tip. In addition, U.S. Pat. No. 4,974,980 to Gueret describes a flexible, elastically deformable pen for liquid cosmetic products. The tip of the pen is conically shaped but has a cylindrical section at the end of the tip to provide greater precision during application, and is flocked with a fibrous material to hold the fluid to the surface of the tip. 
     The use of foam or sponge-like materials for brushless applicator tips, however, may present problems that do not occur with brushes. For instance, the foam material may not adequately absorb and release the fluid, may not retain its shape over extended periods of immersion or use, or may not recover quickly after drying. Furthermore, molded foam applicators used for application of powdered cosmetics commonly have seams. Such applicators are unsuitable for correction fluids because a seam would not allow the correction fluid to be applied evenly to the desired surface. In addition, because correction fluids may be water-based or solvent-based, foam materials immersed in such fluids may deteriorate rapidly. 
     Other attempts to reduce excess liquid on the applicator involve wiping the applicator and brush during and/or after withdrawal of the brush from the reservoir. The means employed is often in the form of a wiper insert placed in the neck of the container. Such wiper inserts usually are intended to strip the excess liquid from the brush as it is withdrawn from the reservoir. For example, U.S. Pat. No. 5,873,669 to Poore et al. describes a wiper insert having cleaning elements extending toward a reservoir within the container. The cleaning elements define a gap adapted for the frictional passage of the brush applicator. U.S. Pat. No. 4,886,080 to Cole depicts a wiper insert for a cosmetics container that includes at its lower end, near the reservoir, a “wiping orifice” to wipe cosmetics from the shaft and bristles of an applicator brush. In U.S. Pat. No. 4,761,088 to Zubek, a plurality of “tongues” protrude downward from the lower end of a wiper insert to perform the same function. 
     As explained in Poore et al., even after being wiped against the lower end of the wiper insert, usually more than enough liquid for the present application still adheres to the applicator. In such an event, the user typically wipes superfluous amounts of liquid off against the inside of the upper edge of the container opening. This can, however, lead to another problem if some of the liquid runs onto the exterior of the container. Most wiper inserts known in the art are not effective in preventing the liquid from running over when the brush is wiped against the upper edge of the wiper insert. When liquid runs over the upper edge of the wiper insert, it tends to run onto the closure threads of the container with which the container cap must interact to create a proper seal when the container is closed. If not removed, the liquid dries in place. Over time, the buildup of excess liquid will preclude proper closure of the container, thus allowing the liquid in the reservoir to dry-out or to spill if the container is tipped over. Even if the dried excess liquid does not preclude proper closure, it generally cannot be reclaimed, thus causing additional waste. 
     Another disadvantage inherent in most prior art wiper inserts is that users must exercise caution while re-inserting an applicator lest he or she accidentally brush liquid onto the exterior of the insert or neck of the container and cause additional buildup of product on the closure threads. This problem occurs because the inner diameter of the upper edge of most prior art wiper inserts is often no greater than the inner diameter of the central portion, and therefore only slightly greater than the diameter of the applicator brush used with the container. 
     Yet another problem inherent in most prior art wipers is that they frictionally engage with the applicator at all times. Such wiper inserts would be unsuitable for use with a foam applicator, however, because the wiper elements may cut or tear the applicator material or cause the material to wear out prematurely. These problems may be compounded if the wiper elements engage with the foam applicator at an obtuse angle. 
     There is thus a need in the art for a brushless applicator that is compatible with both solvent-based and water-based liquids, absorbs and releases fluids easily, retains its shape, and recovers quickly after drying. In addition, there is a need in the art for additional means with which to remove excess liquid from a brushless applicator in order to further preclude the accumulation of dried liquid product on the exterior of the container, and to provide facile re-insertion of the applicator into the container. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a brushless applicator suitable for use with correction fluids and a container insert for wiping excess liquid from a brushless applicator in such a manner as to avoid damaging the applicator, to prevent spillover of the liquid onto the exterior of the container, and to promote flow of excess liquid wiped from the applicator back into a container reservoir. 
     One embodiment of the invention is a container having a reservoir portion for containing correction fluid, a neck portion having an opening formed around a central axis and an applicator having a foam tip made of a material that is chemically inert in both water-based and solvent-based solutions. The foam tip material has a density from about 4 to about 7 pounds per cubic foot and has a porosity of from about 80 to about 130 pores per inch. 
     Another embodiment includes the neck portion of the container has a wiper insert around the neck portion of the opening of the container. The upper portion of the insert defines the inner diameter of the opening to the container and slopes inward and downward to a second inner diameter that is smaller than the first. The upper portion of the insert has a wiping lip that is shaped to direct excess fluid back into the container as it is removed from the applicator, while the lower portion of the insert has an annular wall for removing excess liquid from the applicator as it is removed from the container. In a preferred embodiment, the annular wall extends inward and downward until terminating at a rounded edge. 
     In another embodiment, the inner portion of the insert has at least one cleaning element that wipes excess fluid off the applicator as it is removed from the container. In yet another embodiment, the cleaning elements have the shape of prongs that extend toward the applicator to form an open and broken circle about the applicator. The diameter of the open and broken circle formed by the cleaning elements may be larger than the diameter of the applicator such that the cleaning elements do not contact the applicator during storage. In one embodiment, the cleaning elements are less than about 0.5 mm from the surface of the applicator. In another embodiment, the cleaning elements are approximately orthogonal to the axis of the applicator. The prong-shaped cleaning elements also may be separated from each other by sectional apertures. The cleaning elements also may flex or bend as the applicator is removed or inserted into the container. 
     In one embodiment of the invention, the foam tip is made of material having a density of from about 5.4 pounds per cubic foot to about 6.6 pounds per cubic foot. In yet another embodiment, the material for the foam tip has a porosity from about 85 to about 120 pores per inch. In another embodiment the material has a porosity of about 110 pores per inch. The material for the foam tip in another embodiment has a tensile strength of at least 20 psi. In yet another embodiment the material has a minimum elongation of 180 percent. In a preferred embodiment the material for the foam tip is polyester polyurethane. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become more readily apparent from the following detailed description, which should be read in conjunction with the accompanying drawings, in which: 
     FIG. 1 depicts a partial cross section of a container, in an open configuration with a brushless applicator and a wiper insert for a brushless applicator inside the container in accordance with the present invention. 
     FIG. 2 depicts a partial cross section of a container in a closed configuration with a brushless applicator immersed in the reservoir of fluid and a wiper insert in accordance with the present invention. 
     FIG. 3A is a longitudinal cross-section of one embodiment of a wiper for a brushless applicator in accordance with the present invention. 
     FIG. 3B is a magnified view of the lip at the upper end of the embodiment featured in dotted circled in FIGS. 3A and 7. 
     FIG. 4A is a longitudinal cross-section of an alternative embodiment of a wiper insert for a brushless applicator in, accordance with the present invention. 
     FIG. 4B is a magnified view of the lip at the upper end of the alternative embodiment featured in dotted circles in FIG.  4 A. 
     FIG. 5 is a longitudinal cross section of one embodiment of a brushless applicator in accordance with the present invention. 
     FIG. 6 is a longitudinal cross section of an alternative embodiment of a brushless applicator in accordance with the present invention. 
     FIG. 7 is a longitudinal cross-section of one embodiment of a wiper for a brushless applicator in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following embodiments will be described in the context of a correction fluid container. Those skilled in the art, however, will recognize that the disclosed structures are readily adaptable for broader applications. Note that whenever the same reference numeral is repeated with respect to different figures, it refers to the corresponding structure in each figure. 
     FIG. 1 illustrates an embodiment of brushless applicator tip  26  and wiper insert  100  situated securely in place in the neck  4  of container  2 . Wiper insert  100  is formed of an elastic material, such as polyethylene or the like, and is generally cylindrical in shape. The lower portion of container  2  forms reservoir  8 , in which correction fluid  10  is stored. Applicator  20  is affixed to container cap  22  and comprises shaft  24  and applicator tip  26 . 
     Applicator tip  26  is formed from a foam or sponge-like material that is substantially inert in both water-based and solvent-based solutions, i.e., any chemical activity between the material and the solution is minimal and does not adversely affect the solution or prematurely deteriorate the foam tip. For use in correction fluids, it is preferred that the foam or sponge-like material have a pore size from about 80 pores per inch to about 130 pores per inch, more preferably from about 85 pores per inch to about 120 pores per inch, and most preferably about 110 pores per inch. One skilled in the art, however, would recognize that the appropriate porosity of the applicator tip material will vary according to the physical properties and desired amount of the fluid to be applied. Suitable materials for use in forming an applicator tip for use in correction fluids may include polyurethane polymers, polystyrene, polyamide, polyester, polyether cellulose, phenolic, epoxy, polyolefin materials having a density from about 1 to about 10 pounds per cubic foot, more preferably having a density from about 4 to about 7 pounds per cubic foot, most preferably having a density from about 5.4 to about 6.6 pounds per cubic foot. A material with too low a density may lack sufficient structural integrity for the intended application, whereas a material with too high density may have no ability to hold or apply the fluid. 
     For correction fluids, it is preferred that brushless applicator tip  26  is formed of polyester polyurethane material. In a preferred embodiment, brushless applicator tip  26  is formed from a material sold under the trademark “Ultra Fine 2,” which can be obtained from FOAMEX, located at 1500 East Second Street, Eddystone, Pa. 19018. In an alternative embodiment, brushless applicator tip  26  is formed from a material sold under the trademark “Ultra Fine 6,” which is also available from FOAMEX. 
     For use in correction fluids, applicator tip  26  may have a wedge shape. Preferably, the width of base  28  of wedge-shaped applicator tip  26  (FIGS.  5  and  6 ), is from about ¼ to about ½ of the altitude, h, of the wedge, more preferably from about ¼ to about ⅓ of the altitude of the wedge. The sides  30  of the wedge-shaped applicator tip  26  that are used to apply correction fluid (see FIGS. 5 and 6) may be straight or curved to provide increased durability, more uniform coverage of liquid and/or greater precision for the user. In one preferred embodiment, the sides  30  are slightly convex (FIG.  6 ). 
     The base  28  of applicator tip  26  is preferably affixed to shaft  24  by thermal melt fusion, although one skilled in the art would appreciate that other bonding methods, such as adhesive bonding, solvent bonding and other welding methods may also be suitable. 
     When container  2  is closed, as depicted in FIG. 2, brushless applicator  26  is immersed in correction fluid  10  and cap  22  releasably interlocks with threads  6  on the exterior of neck  4 . 
     With reference now to FIGS. 3A,  3 B and  3 C, it can be seen that wiper insert  100  is generally cylindrical in shape about a central axis A. Wall  102  is substantially parallel to axis A along a central portion of wiper insert  100 . 
     The lower end of wiper insert  100  includes the bottom of wall  102 , which is marked by first bevel  104 . In a preferred embodiment, bevel  104  extends inward and downward until terminating at a rounded edge  106  (FIG.  7 ). The lower end of insert  100  also may include a plurality of, illustratively four, prong-shaped cleaning elements  120 , arranged about central axis A, and made of a flexible and resilient material such as, for example, polyethylene. Prongs  120  are connected to and dependent from the interior of wall  102  and extend obliquely inward and downward from wall  102  toward axis A for a distance of from about 1 mm to about 5 mm, preferably about 2 mm. The lower end of prongs  120  are turned, marked as second bevel  108 , so that prongs  120  extend toward axis A, preferably in a plane approximately orthogonal to axis A. The prongs  120  terminate short of axis A. Lower end  122  of prongs  120 , in one illustrative embodiment, do not connect to each other, but instead form a broken ring to define a circular gap  124  through which applicator  20  passes (best shown in FIG.  3 C). It will be understood by one of skill in the art that gap  124  may be other than circular in appearance, depending upon the cross-sectional shape of applicator  20  and/or the pattern in which excess correction fluid is to be wiped from the applicator. 
     Gap  124  allows passage of applicator tip  26  and shaft  24  of applicator  20 . During insertion and removal of applicator  20 , it is preferred that prongs  120  flex about first bevel  104  and second bevel  108  in a direction radially outward and away from axis A upon contact with shaft  24  or applicator tip  26 . When applicator  20  is withdrawn from reservoir  8 , shaft  24  and applicator tip  26  necessarily wipe against prongs  120 , thus removing an initial amount of excess liquid. Although prongs  120  may be configured to frictionally contact shaft  24  and applicator tip  26  at all times when applicator  20  is within container  2 , it is preferred that prongs  120  are configured to be less than about 0.5 mm from shaft  24 , thereby reducing potential tearing of applicator tip during use but nevertheless allowing excess fluid may to be wiped from shaft  24  and applicator tip  26 . Between prongs  120  are open spaces  126  through which excess liquid may drain into reservoir  8  (best shown in FIG.  3 C). Spaces  126  are wedge-like in shape when viewed from above, wider at second bevel  108  and tapering as prongs  120  converge toward axis A. Thus, prongs  120  form an open and broken circle about the central axis and are separated from each other by sectional apertures formed by spaces  126 . As described below, when additional fluid is wiped off applicator  20  against the upper end of wiper insert  100 , the excess fluid flows down wall  102  through spaces  126  and returns to reservoir  8 . 
     The upper portion of insert  100  forms peripheral annular flange  110  which engages and seats against the top of neck  4  of container  2 , as shown in FIGS. 1 and 2. Lip  112  is in the form of a protruding structure extending upward from flange  110 , preferably either substantially parallel to or angled away from central axis A. In an illustrative embodiment, depicted in FIGS. 3A and 3B, lip  112  is substantially perpendicular to flange  110  or parallel to central axis A. In an alternative embodiment, depicted in FIGS. 4A and 4B, lip  112  extends curvedly upward and outward from axis A at approximately a 45° angle. As may be appreciated with reference to FIG. 4B, the curved upward and outward shape of lip  112  causes at least a portion of the outer surface of flange  110  to be substantially concave. 
     Even after scraping against cleaning prongs  120 , as it is withdrawn from reservoir  8 , applicator  20  may contain more correction fluid than the user needs. The purpose of lip  112  is to provide an edge against which applicator  20  can be wiped to remove this excess fluid. Lip  112  directs the wiped off fluid toward the interior of insert  100  rather than allowing it to spill over to container threads  6 . 
     Inwardly sloping inner circumference  114  slopes from a wider dimension proximate to lip  112  toward a narrower dimension where it meets the interior of wall  102 . Circumference  114  defines the inner circumference of flange  110  and directs excess liquid from lip  112  toward the central portion of insert  100  and reservoir  8 . The inner diameters of lip  112  and the top of circumference  114  are greater than the inner diameter of the central portion of insert  100 . In an illustrative embodiment, circumference  114  presents a convex appearance when viewed cross-sectionally. Thus, upon re-insertion of applicator  20  into container  2 , the applicator is guided toward central axis A and wall  102  by circumference  114 , then, at wall  102 , downward and substantially parallel to central axis A, until it passes between prongs  120 . 
     The above description is intended to be illustrative, not limitive. Thus, it will be apparent to those skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.