Abstract:
The present invention is a delivery tip for flowable materials with bristles or fibers extending therefrom. The tip is a cannula with a tapered outlet and features a bristle or fiber bundle with a binding restriction member that interfaces with the cannula at some point within the cannula but has a smaller cross-sectional area for flow passage than the cannula at that point. The bristle or fiber bundle extends out of the tapered outlet. The delivery tip is provided means to connect to a material reservoir with flowable material. When positive pressure is applied to the reservoir, material then will flow through the cannula, around the restriction member, into the bristles or fibers and out the outlet for distribution to a desired surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. patent application Ser. No. 11/743,115, filed May 1, 2007, now U.S. Pat. No. ______, which is a continuation in part of U.S. patent application Ser. No. 11/567,367, filed Dec. 6, 2006, the entirety of each being incorporated herein by reference. 
     
    
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention relates to the field of devices used to dispense flowable materials and, more particularly, to the field of flowable material delivery tools and components thereof having brush tips to aid in dispensing such flowable materials. 
       BACKGROUND OF THE INVENTION 
       [0003]    Brush tips for dispensing material, particularly in medical and dental fields, are known in the prior art. Usually such tips provide a flocked spreading means or some form of bristling for application of the material as dispensing occurs. The prior art demonstrates that such means are mounted on the external surface of the syringe, tools, or other apparatus used to dispense or distribute the material. Unfortunately, these prior methods have a number of difficulties. The first is the potentially meticulous process of mounting the flocked and fibrous spreading means. The second is the potential for a weaker hold of the device on such means while in use, i.e. shedding. The third is the potential for clogging the external fibrous spreading means, which usually accompanies more secure binding of the fibrous spreading means. Therefore, prior art devices have had to strike a balance between acceptable shedding and acceptable flow. 
         [0004]    The present invention is a delivery tip mountable upon a material containment or dispensing means which contains bristles internally in a bundle. The bristles are bound by a restriction member that is inserted and resides within a narrowing cannula. The restriction member is positioned within the cannula at a point where a major axis of the member matches a major axis of the cannula, but where a minor axis of the member is smaller than a corresponding minor axis of the cannula. The bristles extend from the restriction member out of a narrow tip of the cannula while the opposing end of the cannula is configured to attach to and engage a containment structure. The present invention represents a departure from the prior art in that the bristled delivery tip allows for more secure bundling of the bristles while simultaneously allowing for effective and accurate distribution of the flowable material. 
       SUMMARY OF THE INVENTION 
       [0005]    In view of the foregoing disadvantages inherent in the known types of delivery means, this invention provides an improved bristled delivery means for fluidic materials. As such, the present invention&#39;s general purpose is to provide a new and improved delivery tip that is readily attachable to known and later developed containment structures and that provides secure hold of fiber bundles while not hindering fluidic discharge of material. 
         [0006]    To accomplish these objectives, the delivery tip comprises a cannula with a delivery tip, a bundle of fibers disposed within the cannula and extending from the delivery tip, and a restriction member not having the same cross-section as the cannula while binding the bundle of fibers. The relationship between the restriction member and the cannula is such that at some point along the body of the cannula the restriction member is engaged with the cannula and has a cross sectional surface area less than the cross sectional area of the cannula at the point of engagement. Attachment means to a source or reservoir of flowable or fluidic material should also be provided, but those exact means will be dependent upon the means used on the reservoir (e.g. mating threaded means, leur lock, snap-fit, etc.). 
         [0007]    Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a transparent side plan view of one embodiment of the present invention, using a luer lock connection means. 
           [0009]      FIG. 2  is a real plan view of the embodiment depicted in  FIG. 1 ; 
           [0010]      FIG. 3  is an end view of the bristled fiber bundled tip of the embodiment depicted in  FIG. 1 ; 
           [0011]      FIG. 4  is a transparent perspective view of the invention utilizing a square binding restriction member; 
           [0012]      FIG. 5  is a perspective view of the invention installed on a syringe; 
           [0013]      FIG. 6  is a perspective view of the invention installed on a reservoir bag; 
           [0014]      FIG. 7  is a perspective view of the invention installed on a bottle; 
           [0015]      FIGS. 8   a - 8   h  are top plan views of example restriction members of varying shapes; 
           [0016]      FIGS. 9   a - 9   f  are top plan views of example restriction members having various internal passages. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    With reference now to the drawings, various embodiments of the inventive delivery tip are herein described. With reference to  FIG. 1 , a brush tip  100  according to the present invention is illustrated having a cannula  101  of varying cross-sectional dimension and a luer lock  102  disposed at a first end  120  configured to attach to and engage a containment structure (not illustrated). The cannula  101  exhibits varying cross section along its length, starting with a first opening proximate the first end  120  and decreasing to a small opening relative to the first opening proximate a second or outlet end  104 . The cannula  101  includes an interior bulk portion  105  proximate the first end  120  and a graded interior portion  106  that extends from the bulk portion  105  to the second or outlet end  104 ; the graded interior portion  106  varies in cross section along an arc length from the bulk interior portion  105  to the second or outlet end  104 . 
         [0018]    Still referring to  FIG. 1 , a fiber bundle  109  is threaded through the graded interior portion  106  of the cannula  101  and extends just outside the second or outlet end  104 . The fiber bundle  109  is inserted through and bound within an interior region  108  of a restriction member  107 . The restriction member  107  is inserted into the interior bulk portion  105  and urged against an interior portion of the cannula  101  where a major axis  122  of the restriction member  107  matches a major axis  124  of the interior surface of the cannula  101 , but where a minor axis  126  of the restriction member  107  is smaller than a corresponding minor axis of the cannula  101 ; if the bulk portion  105  has a circular cross section, the minor axis of the cannula  101  will be equal in length to the corresponding major axis  124  of the cannula  101 . The diameter  128  of the fiber bundle  109  is smaller than the inner diameter  130  of the second or outlet end  104  and extends beyond the outlet  104  a length L. In one embodiment, the length L of the fiber bundle  109  extending from the outlet  104  is equal to or greater than 0.5 mm, although any length is possible depending on the requirements of the desired use. 
         [0019]    Referring now to  FIGS. 1 and 2 , an end view of the invented tip  200  illustrates a wall surface  201  of the interior bulk portion  105  which defines an open space  202  inside the cannula  201 . A luer lock thread  203  is positioned proximate the first end  120  of the cannula  101 . The restriction member, here illustrated in the form of an elliptical disk  204 , engages the wall surface  201  of cannula  101  with the fiber bundle  206  (denoted  107  in  FIG. 1 ) inserted into a hole  205 . The major axis  222  of the elliptical disk  204 , at the point of engagement, matches, or is slightly larger than, the major axis  224  of the wall surface  201  of the cannula  101 , while the minor axis  230  is smaller than the corresponding minor axis  232  of the cannula  101 . The wall surface  201  of the cannula  101  may be circular, as depicted in the figures, or may, alternatively, be of any other shape, so long as the relation required between the wall surface  201  of the cannula  101  and the restriction member  107 —e.g., the elliptical disk  204 —holds true—i.e., the restriction member has a smaller cross-sectional area than the cross sectional area defined by the wall surface  201  of the cannula  101 , but simultaneously has a means to interface with or engage the wall surface  201  of the cannula  101 . 
         [0020]    The diameter of fiber bundle  206  is slightly larger than the diameter of the hole  205  in the restriction member. Thus, the fiber bundle  206  is securely fixed or engaged with the restriction member—e.g., the elliptical disk  204 . The restriction member—e.g., the elliptical disk  204 —is typically inserted into the bulk portion  105  of the cannula  101  to a point where the major axis  224  of the restriction member engages—e.g., through friction fit—with the corresponding major axis  222  of the bulk portion  105  of the cannula  101 . It is noted here, that while engagement of the restriction member with the cannula is preferably accomplished through a friction fit, other means of engagement, such as, for example, adhesive or welding, are suitable for purposes of the present invention. Once engaged by whatever means, the fiber bundle  206  threads through the second or outlet end  104  of the cannula  101 . 
         [0021]    As stated previously, the restriction member  107 —e.g., the elliptical disk  204 —has a smaller cross sectional area that the corresponding cross sectional area of the bulk portion  105  where the restriction member  107  engages the surface wall  201  of the cannula  101 . An elliptical disk, for example, permits the flowable material to flow around the disk in the regions of the minor axis  230  of the disk with little or no hindrance. Depending on the viscosity of the flowable material, the relative cross sectional areas of the bulk portion  105  and the restriction member  107  may be advantageously selected. 
         [0022]    It should be noted that the luer lock depicted is only an example as other connection means may be used, such as a threaded interface, a snap-fitting interface, or any other interface known or later conceived in the art, without departing from the scope of the invention. It should also be noted that the restriction member—e.g., the elliptical disk—disk may be of any shape that lends itself to interfacing with the wall surface of the cannula while having a smaller cross-sectional area, such as the square member  401  illustrated in  FIG. 4 . All that is required is that the restriction member must make contact with the surface wall of the cannula at a given point so to be secured or engaged in place while simultaneously having a smaller cross-sectional area than the cannula at that point. As such, the term restriction member should not be seen as limited to a round or elliptical shape.  FIGS. 8   a  through  8   h  illustrate four different possible shapes (a triangle, a square, a five-pointed star, and an eight-pointed star, a hexagon, a pentagon, a rounded rectangle and a clover-like shape respectively), though any shape that meets the above referenced requirements, be they ellipses, polygons (like  FIG. 8   a ,  8   b ,  8   e , or  8   f ), star shapes (like  FIGS. 8   c  and  8   d ) or other free-form shapes (like shown in  FIGS. 8   g  and  8   h ) will suffice. 
         [0023]    Referring now to  FIGS. 1-3 , a front plan view of the tip  300  of the cannula  101  at the second or outlet end  104  is illustrated. The fiber bundle  109  is illustrated in cross sectional view against the wall  301  of the tip  300 , and is comprised of several strands or fibers  303  as illustrated. An open space(s)  304  occurs within the fiber bundle  109  as the overall diameter of fiber bundle  109  is smaller than inside diameter of the wall  301 . The material will pass through the fiber bundle  109  through the space(s)  304 . The total number of strands or fibers  303  of given individual diameter  310  will determine the strand density of the fiber bundle  109  and, hence, the density or average size of the space(s)  304 . Therefore, by controlling the total number of fibers of given diameter  310  or variety of diameters in the bundle, the flow of the material through the cannula  101  and the tip  300  can be controlled. 
         [0024]    When the above described tip is attached to a syringe or other delivery device containing flowable material, for example a syringe  501 , reservoir bag  601 , or bottle  701  as depicted in  FIGS. 5-7 , a positive pressure on the flowable material relative to the external pressure at the tip outlet will cause the material to flow from the delivery device—e.g., the syringe  501 —through the cannula  101 , about the restriction member  107 , through the fiber bundle  109  and, finally, through the outlet end  104  of the tip. Because the space(s)  304  in the fiber bundle  109  exist at the outlet end  104 , the flowable material is permitted to flow through the outlet end  104 , yet the fiber bundle  109  maintains its position within the tip and also its structural integrity. The extended length L of the fiber bundle  109  then acts as a brush which is used to spread or otherwise distribute the flowable material to the application surface. 
         [0025]    Dynamics of the material flow through the cannula  101  as described—e.g., flow rate—is affected by the relative cross-sectional areas of the restriction member and the interior wall surfaces of the cannula, including the surface at the point of engagement of the restriction member  107  with the bulk portion  105  of the cannula  101 , the relative dimensions of the graded portion  106  of the cannula  101  and the relative size of the space(s)  304  and the cross sectional area of the outlet end  104 . The relative sizing of these various configurations of the tip may be altered for different intentions and purposes—e.g., for handling flowable materials of different viscosities. In one embodiment, it is sufficient to characterize operation of the invention as requiring, for example, a larger ratio of cross sectional area of the wall surface of the bulk portion at the point of engagement to the cross sectional area of the restriction member for flowable materials having greater viscosity than other materials. In similar characterization, a more viscous flowable material will require a larger ratio of total collective space(s) between the fibers at the tip outlet to the cross sectional area of the tip at the outlet than would a material having less viscosity. 
         [0026]    Various further embodiments of the inventive tip are illustrated in  FIGS. 9   a - e.  These embodiments comprise restriction members  920 - 924  having generally circular outer boundaries  901  (excluding the boundary illustrated in  FIG. 9   f ). The circular outer boundaries  901  are configured to engage a corresponding circular inner wall surface  201  of the bulk portion  105  of the cannula  101 . Various shaped passages  903 - 907  are cut out of the interior of the restriction members  920 - 924  to accommodate passage of the flowable material through the restriction member rather than around the outer boundary of the restriction member. In this fashion, accommodation of varying viscosities can better be had by varying the cross sectional area of the restriction members through varying the relative size of the passages  903 - 907  with respect to the cross sectional size of the restriction member. Indeed, in one embodiment, one or more combinations of restriction members and attached bundles of fibers are configured for removal and replacement in the tip to accommodate usages having different viscosities so that the entire tip assembly need not be disposed of following use. Referring also to  FIG. 9   f , an embodiment combining the above disclosure is illustrated. In this embodiment, a restriction member  930  comprise an outer boundary  932  having cutout portions  934  and interior passages  936  for accommodating passage of the flowable material. As with the embodiments previously described, the cutout portions  934  and interior passages  936  are sized for particular viscosities of flowable material. 
         [0027]    While certain embodiments and details have been included herein and in the attached invention disclosure for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes in the methods and apparatuses disclosed herein may be made without departing form the scope of the invention, which is defined in the appended claims.