Abstract:
An apparatus is comprised of an applicator for selectively applying a hydrostatic force on a work material contained within the applicator, a tip coupled to the applicator for conducting the work material to a distal end of the tip, and a one-way, pressure-controlled valve defined into the distal end of the tip to selectively open the valve upon application of pressure on the work material supplied to the tip from the applicator and to selectively close the valve and prevent withdrawal or pull back of the work material back into the tip when the pressure on the work material supplied to the tip from the applicator falls below a predetermined value.

Description:
RELATED APPLICATIONS  
       [0001]     The present application is related to U.S. Provisional Patent Application Ser. No. 60/586,801, filed on Jul. 7, 2004, which is incorporated herein by reference and to which priority is claimed pursuant to 35 USC 119. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates to the field of dental apparatus and more particularly to a tip used on a dental syringe for applying dental resin or adhesive.  
         [0004]     2. Description of the Prior Art  
         [0005]     Dental resin or adhesive, and more generally, any work material expressed from a cartridge is generally forced by pressure by a syringe or piston of some type through an applicator tip in which an orifice is defined. The work material is extruded under applied pressure through the orifice and continues to be extruded as long as the pressure applied by the syringe is sufficient to overcome the cumulative resistive forces and friction of the work material within the syringe and tip. Typically, when pressure is removed or at least reduced below a threshold, the work material will cease being extruded from the orifice and in fact will be pulled back into the tip thereby removing some of the work material which has just been applied to the work site, or pulling the work material away from the work site, making it difficult to leave the work material where desired. This problem particularly arises if one applies the adhesive to a “slippery” surface, which makes it difficult to leave only the desired amount on the site. The dispensed work material is in fact still attached to the work material in the reservoir or carpule, and relies on more adhesion with the dispensed work material than the reservoir work material to “break” loose.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     The illustrated embodiment of the invention is an apparatus comprising an applicator for selectively applying a hydrostatic force on a work material contained within the applicator, a tip coupled to the applicator for conducting the work material to a distal end of the tip, and a one-way, pressure-controlled valve defined into the distal end of the tip to selectively open the valve upon application of pressure on the work material supplied to the tip from the applicator and to selectively close the valve and prevent withdrawal of the work material back into the tip when the pressure on the work material supplied to the tip from the applicator falls below a predetermined value. The tip may be composed of material that is made of various kinds on nonstick materials or coated with Teflon® or similar coatings to facilitate nonadhesion of the work material to the tip.  
         [0007]     The work material comprises a dental material, such as a dental resin or dental adhesive.  
         [0008]     The tip is composed of material with a predetermined degree of flexibility and resiliency, and the one-way, pressure-controlled valve comprises a rounded distal end of the tip with a pattern of slits defined through the rounded distal tip. The predetermined degree of flexibility and resiliency is selected so that when the valve is selectively closed no appreciable amount of work material which has been disposed from the distal end of the tip is pulled back into the distal end of the tip. The closure of the tip by the valve cuts the connection between the reservoir work material still in the tip or carpule and the applied work material disposed on the work site, thereby allowing the applied work material to stay where it has been applied. What constitutes an appreciable amount is determined by the context of the application, which in the dental field would be a removal of an amount of the dental material such that in normal practice a reapplication of work material would be called for or prudent to an ordinary dental practitioner to replace that which was just removed. The valve tends to pinch off the work material being expressed through it.  
         [0009]     In the preferred embodiment the slits form an X-shaped pattern through the distal end of the tip. However, it must be understood that other patterns may be employed, including a single straight or curved slit. Where the X-shaped pattern is formed, two straight slits are defined which are orthogonally oriented with respect to each other.  
         [0010]     The tip is comprised of a tip body and a valve body in which the pattern of slits are defined. The valve body is angled with respect to the tip body, and the tip body coupling to the applicator.  
         [0011]     The invention also contemplates providing a kit comprised of a plurality of tips, each with a different geometric configuration and/or corresponding different one-way, pressure-controlled valve adapted to operate with different work materials.  
         [0012]     In one embodiment the dental applicator comprises a plunger within a syringe and where the plunger has indents defined thereon to measure the amount of work material expressed from the valve.  
         [0013]     The invention also includes the method of using the above apparatus. Namely, the illustrated invention includes a method comprising the steps of selectively applying a hydrostatic force on a work material contained within an applicator, forcing the work material through a tip coupled to the applicator to a distal end of the tip, selectively opening a one-way, pressure-controlled valve defined into the distal end of the tip upon application of pressure on the work material supplied to the tip from the applicator, and selectively closing the valve in a manner to prevent withdrawal of the work material back into the tip when the pressure on the work material supplied to the tip from the applicator falls below a predetermined value.  
         [0014]     While the apparatus and method has or will be described for the sake of grammatical fluidity with functional explanations, it is to be expressly understood that the claims, unless expressly formulated under 35 USC 112, are not to be construed as necessarily limited in any way by the construction of “means” or “steps” limitations, but are to be accorded the full scope of the meaning and equivalents of the definition provided by the claims under the judicial doctrine of equivalents, and in the case where the claims are expressly formulated under 35 USC 112 are to be accorded full statutory equivalents under 35 USC 112. The invention can be better visualized by turning now to the following drawings wherein like elements are referenced by like numerals. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a side view of a dental applicator or syringe fitted with the tip of the invention.  
         [0016]      FIG. 2  is side view of a carpule fitted with a tip of the illustrated embodiment.  
         [0017]      FIG. 3  is an end view of the illustrated embodiment of  FIG. 2 . 
     
    
       [0018]     The invention and its various embodiments can now be better understood by turning to the following detailed description of the preferred embodiments which are presented as illustrated examples of the invention defined in the claims. It is expressly understood that the invention as defined by the claims may be broader than the illustrated embodiments described below.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]     The illustrated invention is a tip  10  on a carpule  12  of dental/orthodontic bonding and or adhesive work material  14 , or more generally any dental or oral material  16 . According to the invention a “carpule” or a cartridge  12  of dental anesthetic adhesive or resin is inserted in a syringe  18  as shown in  FIG. 1 . Indents  30  are provided in the plunger  28  of the syringe  18  to measure and control the exact amount of work material expressed through tip  10 , which has not previously been done in dentistry.  
         [0020]     The tip  10  is placed permanently or may be removable from the carpule  12 . It may be made of any flexible material, such as flexible plastics, and may be coated with Teflon® or coating material to prevent the adhesive or resin from binding or sticking to the tip. Tip  10  is comprised in the illustrated embodiment of a cylindrical, bullet-shaped body  10   a  to which a flexible cylinder valve body  10   b  has been attached, which valve body  10   b  extends from tip body  10   a  at a downward angle to provide ease of handling by the dentist in the oral environment. In the illustrated embodiment valve body  10   b  is angled at about 45 degrees from the longitudinal axis of tip body  10   a , which is also aligned with the longitudinal axis of carpule  12 . It is contemplated that a kit is provided according to the invention, including a plurality of tips  10 , each tip  10  providing a valve body  10   b  with a different angular orientation with respect to tip body  10   a.    
         [0021]     In the illustrated embodiment valve  10   b , the distal end  22  of valve body  10   b  is provided with a pair of orthogonal slits  20  which have their intersection on the imaginary plane which bisects valve  10   b . One slit  20  lies in the imaginary plane and the other slit  20  is perpendicular to the imaginary plane. In addition, such a kit is provided according to the invention with a plurality of different valve bodies  10   b  differing in their flexibility and resiliency and/or differing slit patterns to accommodate different dental materials of varying viscosity, consistency and surface tensions.  
         [0022]     In the illustrated embodiment the tip  10  is scored or cut through by slits  20  in an “x” pattern or any other pattern through the entire tip  10 . In the preferred embodiment the slit pattern is such that it tends to form the resin or adhesive which is extruded from the carpule  12  into a predetermined prismatic shape, such as a localized “x” shape, which rounds by the surface tension of the resin into a cylinder or into a flat ribbon or the like. In the illustrated embodiment the slits  20  are defined into the very distal end  22  of the tip  10 . The pattern formed by slits  20  function similarly to a sphincter or a heart valve in the sense that pressure behind slits  20  causes them to open or part, and lack of pressure allows the resiliency of the material of tip  10  to close slits  20 . Slits  20  in tip  10  cooperate to act like a valve that prevents back flow.  
         [0023]     The objective is that when the resin or work material is expressed thru the tip  10  from carpule  12  by means of syringe  18 , or what could be called a dental “caulking gun”  18 , the scored tip  10  flexes open releasing the resin or work material. When the pressure is removed from the resin or work material and no more is expressed through slits  20 , the tip  10  “closes” cutting off the resin or work material. The purpose is to allow the expressed portion to remain at the dental or oral site where it was applied without being pulled back by work material within the tip  10  and/or carpule  12 . In other words, slits  20  in tip  10  are arranged and configured relative to the work material expressed through tip  10  to positively cut off the work material when pressure behind slits  20  is removed or at least reduced below a threshold level. Thus through trial and error by balancing the thickness of the walls of tip  10 , the resiliency of the walls of tip  10 , the geometry of the pattern of slits  20  against the viscosity and stiffness of the work material being express through tip  10 , a positive closure of slits  20  or cutting of the work material is effected, even in cases where there is a negative pressure applied to the work material in carpule  12  or tip  10 . In this manner, the work material which has been expressed onto the teeth or other dental site is not pulled backed off the teeth or other dental site, when application of the work material is terminated. Precise control of the dental material is thus achieved and the dentist or oral surgeon does not need to compensate for work material pullback due to idiosyncronicities of the syringe or applicator.  
         [0024]     In the illustrated embodiment a tip cover may be provided to cover the slits  20  of tip  10  to protect the work material when not used, and a cover to encapsulate and protect the carpule  12  when tip  10  is removed.  
         [0025]     Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the invention as defined by the following invention and its various embodiments.  
         [0026]     For example, the invention may also be used in a construction caulking gun with construction grade caulking material. The advantage is that with the use of the invention one does not need to wipe the tip  10  of the caulking gun to cut off the flow of caulking material and to disconnect the cartridge from the gun tip. The invention closes the tip so it is not necessary to plug the tip hole with a nail or use a cap in an attempt to seal the tip hole. However, the primary application is orthodontic/dental. The invention enables the user to easily apply controlled amounts of work material to a tooth and pull away without the work material coming back with the syringe.  
         [0027]     Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the invention as defined by the following claims. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the invention includes other combinations of fewer, more or different elements, which are disclosed in above even when not initially claimed in such combinations. A teaching that two elements are combined in a claimed combination is further to be understood as also allowing for a claimed combination in which the two elements are not combined with each other, but may be used alone or combined in other combinations. The excision of any disclosed element of the invention is explicitly contemplated as within the scope of the invention.  
         [0028]     The words used in this specification to describe the invention and its various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use in a claim must be understood as being generic to all possible meanings supported by the specification and by the word itself.  
         [0029]     The definitions of the words or elements of the following claims are, therefore, defined in this specification to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the claims below or that a single element may be substituted for two or more elements in a claim. Although elements may be described above as acting in certain combinations and even initially claimed as such, it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination may be directed to a subcombination or variation of a subcombination.  
         [0030]     Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements.  
         [0031]     The claims are thus to be understood to include what is specifically illustrated and described above, what is conceptionally equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the invention.