FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to the field dental instruments, and more particularly to a system for marking dental instruments by means of color codes.  
       BACKGROUND OF THE INVENTION  
       [0002]     While performing a typical dental procedure, a dentist or her assistant often utilizes a number of hand held instruments or tools. As dental technology has progressed, the number of such instruments has increased. A given procedure may require an array of instruments varying in shape, length and diameter. A common practice is to collect those instruments pertaining to a specific procedure and place them in a tray dedicated to that particular use. The variety of instruments, trays and dentists present in a dental office has prompted the use of color coding of both trays and instruments to correspond to a given procedure and for use by a specific practitioner. One method commonly used to identify a particular dental instrument is to form a colored ring, sleeve or disc on the handle of the instrument. An example of a dental instrument color coding scheme is disclosed in U.S. Pat. No. 4,882,867, entitled DENTAL INSTRUMENT HAVING IDENTIFICATION MARKINGS, issued on Nov. 28, 1989 to Linden. The Linden method is to permanently mold the colored sleeve, ring or disc into the handle, thereby enhancing the durability of the markings. The use of such a molded component is not entirely practical insofar as the color coded region may be raised with respect to the remainder of the handle surface, thereby interfering with the normal manipulation of the handle. Further, the molding process necessarily requires that the instrument handle be formed of a composite material which is inherently unsuited for repeated use in a sterilized environment.  
         [0003]     In a sterilized environment where the dental tools have metallic handles, a different solution must be found. When using scalers and curettes, for example, the manufacturer typically applies a number to the handle of the instrument indicating the appropriate region of use. There is a conventional numbering system known as the Gracey System in which low numbers (less than five) designate anterior teeth and high numbers (greater than ten) designate the posterior bicuspid and molars. Since the numbers are stamped or etched directly into the handle they are necessarily small and have poor contrast. An effort to address this problem is disclosed in U.S. Pat. No. 4,988,295, entitled IDENTIFICATION MARKING SYSTEM FOR DENTAL INSTRUMENTS, issued on Jan. 29, 1991 to Kline. The instruments proposed by Kline contain a series of annular rings or grooves formed near one end of the handle, the number of rings and spacing indicating the area of use and general size of teeth or roots for which the given instrument has been manufactured. While the rings are certainly more visible than a stamped numeral, they are still relatively small marks which lack a contrasting color.  
         [0004]     An effort to combine the advantages of a color coded handle with the durability of a stainless steel instrument is disclosed in U.S. Pat. No. 5,816,806, entitled DENTAL INSTRUMENTS WITH LARGE MOLDED HANDLES, issued on Oct. 6, 1998 to Herbst et al. The Herbst et al. device requires that the color coded indicator be integrally formed with the handle during the molding process.  
         [0005]     Endodontic instruments are standardized by the International Standard Organization (ISO) Standard 3630, which defines the shape, length, size and handle color. Endodontic files and reamers can have sizes of between “10” and “150”, corresponding to standardized diameters. However, only six handle colors are utilized in the ISO identification scheme which is intended to apply to at least twenty different file sizes. This abbreviated color scheme requires the periodic repetition of the handle color, sometimes leading to confusion. In an effort to more precisely identify each endodontic file, a solution is proposed in U.S. Pat. No. 5,498,158, entitled COLOR-CODED ENDODONTIC CUTTING INSTRUMENTS AND COLOR-CODE SYSTEM AND METHOD, issued on Mar. 12, 1996 to Wong. The Wong device utilizes a two color scheme in which the grasping end of the file is integrally formed to include a first region having the first standardized color corresponding to the first smaller standard size and a second region having the second standardized color corresponding to the second larger standard size.  
         [0006]     In an effort to avoid the limitation imposed by an integrally formed color coded handle, a removable ring is proposed in U.S. Pat. No. 6,193,515, entitled CODED DENTAL HANDLE, issued on Feb. 27, 2001 to Rahman. The Rahman device uses a color coded elastomeric ring that is located adjacent to a receiving port for a tool insert or point.  
         [0007]     The Rahman device, as well as the schemes disclosed in the previously cited patents share a common construction characteristic insofar as the color coded portion or device cannot be relocated by the end user along the length of the instrument handle. Second, the color coding mechanism is not quickly and easily removed by hand should a change in the color coding change be desired. Third, the identification scheme is not universally applicable to a wide variety of existing dental instruments regardless of manufacturer. Fourth, the identifier is limited to the diameter of the handle itself, thereby limiting visibility. Fifth, the use of multiple identifiers at handle locations infinitely selectable by the end user is not possible.  
         [0008]     Additional problems encountered in a real world dental practice include the cost of special identification schemes, incompatibility between systems obtained from different manufacturers, a lack of compatibility with other marking schemes such as colored tape and a lack of a sufficiently large number of available colors to create a unique color coding scheme for each possible scenario of unique types of procedures, unique steps to be performed as part of a given procedure, and a multiplicity of unique end users within a single dental office.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention is a color coded marking system for use in a dental office or similar setting where a plurality of different hand tools having dedicated uses and users are present. The present system includes a color coded ring that may be attached to the cylindrical handle of a dental instrument. The color coded ring is liquid injected molded with a silicone material. The rings are formed in interconnected batches from which an individual ring or rings may be removed as needed.  
         [0010]     The molded rings are housed in a clip or dispenser having male and female halves which surround each batch of clips and protects the individual rings from accidental separation from the batch. A pair of covers may also be attached to the dispenser to provide further protection from accidental ring removal and to provide a relatively cleaner storage environment. The clip permits the marking of instruments without the need to directly handle the coded ring. Rather, the instrument may be inserted through the coded ring while still in the clip, thereby greatly reducing the possibility that the person applying the coded ring will be cut or impaled by the instrument.  
         [0011]     The present invention also includes a dispenser stand or dispenser holder which is also adapted to housing colored tapes. The colored tapes are contained in individual dispensers and are used to mark instruments or items which are not readily adapted to receiving a code ring. The dispenser stand facilitates identifying and retrieving the code rings and tape dispensers in a manner that permits rapid identification of the colors available while maintaining stand portability and safety.  
         [0012]     The molded color coded rings may be readily removed by an end user of the instrument in order to avoid interference with the use and manipulation of the instrument. The coded rings are contoured, durable, and pliable, and may safely continue to reside on the instrument during the cleaning and sterilization process. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a pictorial view of a code ring dispenser constructed according to the principles of the present invention;  
         [0014]      FIG. 2  is pictorial view of a code ring assembly removed from the dispenser shown in  FIG. 1 ;  
         [0015]      FIG. 3  is a side view of the code ring assembly depicted in  FIG. 2 ;  
         [0016]      FIG. 4  is a sectional view of the code ring assembly taken along line  4 - 4  as shown in  FIG. 3 ;  
         [0017]      FIG. 5  is a sectional view of the code ring assembly taken along lines  5 - 5  as shown in  FIG. 3 ;  
         [0018]      FIG. 6  is a detail of the code ring assembly taken from region  43  as identified in  FIG. 4 ;  
         [0019]      FIG. 7  is a pictorial view of a code ring and tape dispenser stand constructed according to the principles of the present invention;  
         [0020]      FIG. 8  is a truncated perspective view of the stand depicted in  FIG. 7  showing the code ring dispenser of  FIG. 1  housed therein;  
         [0021]      FIG. 9  is an isometric view of the dispenser depicted in  FIG. 7 ;  
         [0022]      FIG. 10  is a plan view of the stand depicted in  FIG. 7  shown with a code ring assembly, a code ring dispenser and a plurality of tape dispensers residing therein;  
         [0023]      FIG. 11  is a sectional view taken along line  76 - 76  as shown in  FIG. 10 ;  
         [0024]      FIG. 12  is a side elevation view of the stand depicted in  FIG. 10 ;  
         [0025]      FIG. 13  is a rear elevation of the stand depicted in  FIG. 12 ;  
         [0026]      FIG. 14  is a detailed front elevation of the region  72  identified in  FIG. 13 ;  
         [0027]      FIG. 15  is a pictorial view of the dispenser depicted in  FIG. 1  shown with both of the protective covers removed;  
         [0028]      FIG. 16  is a pictorial view of the dispenser depicted in  FIG. 1  shown with one of the protective covers removed;  
         [0029]      FIG. 17  is a pictorial view of the code ring assembly mounted within the female half of the dispenser and without the male half of the dispenser shown in  FIG. 1 ;  
         [0030]      FIG. 18  is a pictorial view of dental instruments marked with color coded rings according to the principles of the present invention; and  
         [0031]      FIG. 19  is a pictorial view of dental instruments marked with color coded tape according to the principles of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0032]      FIG. 18  illustrates a tray  1  which serves as a supporting surface for a dental tool or instrument holder  2 . Residing within the holder  2  is a number of individual dental tools such as tools  3 ,  4  and  5 , for example. Tool  3  is typical of many dental tools and has a shaft portion  6  that is intended to be grasped by a dental practitioner while using the instrument  3 . Tool  3  is marked with a first code ring  7  and a second code ring  8 . The first code ring  7  has a counterpart ring  9 ,  10 ,  11 ,  12 ,  13 ,  14  and  15  appearing on each of the remaining instruments residing in the holder  2 . The first code ring  7  is of a first color which can be used to distinguish some characteristic of the tool, such as the particular procedure for which the tool is to be used. The rings  7  and  9 - 15  are arranged in unique positions along the shaft of each dental tool signifying the order in which each tool is to be used when performing the procedure. In the present example, the instrument  16  is intended to be used first, the tool  17  is to be used second and the tool  3  is intended to be used last while performing the procedure. A second set of individual code rings  8 ,  18 ,  19 ,  20 ,  21 ,  22 ,  23  and  24  are also affixed to the shaft of the dental instruments. The code rings  8  and  18 - 24  are of a second color and are used to signify a second characteristic of the instruments, such as the individual practitioner who is designated to utilize this particular set of tools.  
         [0033]     In some situations the use of a code ring  7  is not practical due to the size or shape of the dental tool. As depicted in  FIG. 19 , some dental tools such as files  25  and reamers  26 . The tools  25  and  26  are shown housed in a tray  27  which partially conceals the shaft  28  of each instrument  29 . A transparent cover  30  can be used to protect the instruments from dust while housed in the tray  27 . The shafts  28  are too small or too obstructed to permit the use of a ring  7 , and so a piece of tape  31  is used to either mark or even join adjacent instruments  32  and  33  which are to be used for a particular procedure or by a specific practitioner.  
         [0034]     The placing of the code rings  7  or tape  31  on dental instruments is inherently problematical. The sterile end  34  of a typical dental instrument is often dangerously sharp, pointed or abrasive and in any event must be kept clean even if the tip  34  is relatively blunt or dull. Placing an individual ring  7  on an instrument shaft  6  invites the opportunity to puncture or prick the hand or finger of the person attempting to place and position the ring  7 , and increases the probability that the hand will contaminate the sterile portion  34  the tool.  
         [0035]     In order to increase the safety and simplicity of applying a ring  7  to a shaft  6 , the rings are formed integrally as a set of multiple rings as shown in  FIG. 2 . Each ring  7  is formed by liquid injection molding silicone rubber to produce a structure  35  that includes twenty five individual rings  7  each joined to a central trunk  36  by means of branches  37 . Referring also to  FIG. 3 , the characteristics of the structure  35  are important in permitting a user to readily remove a ring  7  for use. Since the present invention may be used to accommodate differing tool shaft diameters and shapes, the ring  7  is preferably manufactured in multiple sizes. In the case of a relatively small ring  7 , the dimension  38  is approximately 0.051 inch, while for a relatively large ring the dimension  38  is approximately 0.021 inch. Each branch  37  tapers to a break point  39  at which the ring  7  may be readily separated from the branch  37 . The dimension  40  corresponding to the longitudinal width of the break point  39  is approximately 0.020 inch for the smaller ring  7  and is approximately 0.019 inch for the larger ring  7 . As best seen in  FIG. 5 , the lateral width  53  of the break point  39  is approximately 0.63 inch. The attachment point  42  which joins the branch  37  to the trunk  36  is necessarily larger in cross section than the diameter  40  in order to insure that the ring  7  separates from the structure  35  at the break point  39  when a force is applied to the ring  7 . The overall length  41  of the structure  35  is approximately 3.446 inches for the smaller ring  7  and is approximately 3.476 inches for the larger ring  7 . The overall height  54  of structure  35  is approximately 0.730 inch for the smaller ring  7  and 0.760 inch for the larger ring  7 .  
         [0036]     Referring also to  FIG. 4 , the height  44  of the ring  7  is 0.140 inch. The diameter  45  of the smaller ring  7  is 0.230 inch and the diameter  45  of the larger ring  7  is 0.260 inch. As best seen in  FIG. 6 , each ring  7  has a beveled or tapered interior surface  47 . The angle  46  of the bevel  47  is approximately ten degrees. Further, the ring  7  has a curved edge  48  having a radius  49  of 0.017 inch. The curved edge  48  joins the beveled surface  47  at line  50 . The smallest inner diameter  51  has a value of 0.140 inch for the smaller ring  7  and a value of 0.170 inch for the larger ring  7 . The diameter  52  of the inscribed circle formed by the line  50  is equal to 0.150 inch for the smaller ring  7  and 0.180 inch for the larger ring  7 . The tapered interior surface  47  causes the ring  7  to present a varying inside diameter to the instrument shaft  6 , simplifying insertion of the ring onto the shaft. The ring  7  is composed of a resilient silicon rubber material that deforms sufficiently to cause substantially all of the interior surface  47  to abut the instrument shaft  6  once the ring assumes a final mounting position on the shaft.  
         [0037]     The structure  35  is composed of a silicone rubber material and is relative pliable. In other words, the trunk  36  and branches  37  lack sufficient stiffness to maintain the shape shown in  FIG. 2  without substantial deformation. In order to permit the rings  7  to be safely and accurately applied to a dental instrument the structure  35  must be externally supported.  
         [0038]     Referring to  FIG. 17 , the structure  35  is shown residing in a first clip  55 . Referring also to  FIG. 15 , the first clip  55  is seen to be the female half which is adapted to join a second clip  56  to form a complete clip assembly  57 . A series of sockets  58 ,  59 ,  60  and  61 , for example, are formed in the first clip  55  and are adapted to receive an aligned pin, wedge or other fastener formed within the second clip  56 . The completed clip assembly  57  creates a series of scalloped edges  62  which expose each of the rings  7  of the structure  35 . Each clip assembly half  55  and  56  includes a handle or grip portion  63  that is suitably dimensioned to permit grasping the handle  63  between, for example, a thumb and index finger. When a practitioner desires to place a ring  7  on a dental instrument shaft, the practitioner grasps the clip handle  63  with one hand and, using the other hand, inserts the dental instrument shaft through the aperture  64  formed by each ring  7 . By applying a slight relative twisting and pulling motion between the shaft  6  of the dental instrument and the clip assembly  57 , the ring  7  will separate from the structure  35  at the break point  39 . The ring  7  is thus securely surrounding the shaft  6  and may then be safely repositioned on the shaft, if necessary, by finger manipulation.  
         [0039]     In order to preserve the sanitary condition of each ring  7  prior to use some form of protection must be provided. Referring to  FIG. 16 , the clip assembly  57  is provided with a removable first cover  65 . The cover  65  is preferably composed of a transparent material which permits a user to determine the color of the rings  7 , the quantity of rings available within the clip assembly  57  and the location of each remaining ring. As shown in  FIG. 1 , a second transparent cover  66  encloses the remaining exposed portion of the structure  35 . The covers  65  and  66  are substantially identical and interchangeable. The covers  65  and  66  are composed of a material that is capable of slight deformation, thereby permitting the edges  86  of each cover to abut and grip a series of bosses  87  extending from the clip assembly  57 .  
         [0040]     In the operatory of a typical dental office, some means must be provided for conveniently storing and providing access to the clip assembly  57 . Referring to  FIG. 7 , a stand  67  is shown that is adapted to house the clip assembly  57  without the cover  65  installed and with the cover  65  installed. Further, the tape  31  is housed in transparent dispensers  68  which may also be securely placed within the stand  67 . Referring also to  FIG. 8 , the clip assembly  57  complete with both covers  65  and  66  in place is shown housed in the stand  67 . A series of bosses or ledges are formed within the sides of the clip retaining groove  69  in order to securely accommodate whatever item may be placed in the groove. The beveled wall  71  is adapted to intercept and retain the exterior surface of lower cover  65 . As best seen in  FIG. 13 , the stand  67  is slightly deformable and sufficiently resilient to grip the lower cover  65  as the covered assembly  57  is place within groove  69 .  
         [0041]     In the case of the assembly  57  with the bottom cover  65  removed, the rings  7  rest slightly above the floor  70  of the groove  69  as depicted in  FIG. 14 . The clips  55  and  63  are retained by the boss  73  formed at the base of the beveled wall  71 . Referring also to  FIG. 9 , each groove  69  is separated from the adjacent groove by a divider  74 .  
         [0042]     The stand  67  is also adapted to house the tape dispenser  68 . As seen in  FIG. 10 , a typical tape dispenser  68  has a depth that is somewhat less than the depth  75  of a clip assembly  57 , complete with the top cover  66  and bottom cover  65  in place, which is approximately 3.814 inches. The rear edge  77  of the tape dispense  68  extends almost to the rear bottom edge  78  of the stand  67 . Referring also to  FIG. 11 , the width  80  of each tape dispenser  68  is approximately 0.3820 inch and the height  82  of each dispenser is approximately 1.7778 inches. The width  81  of each divider  74  is approximately 0.2430 inch. The overall width  79  of a typical stand  67  is approximately 5.25 inches which provides for eight grooves  69  for accommodating various articles. As best viewed in  FIG. 12 , the tape dispenser  68  has a curved perimeter  83  which mates with the indentation  84  visible in  FIG. 8 . The boss  85  extending from the indentation  84  tends to grip and secure the dispenser  68  within the groove  69 .  
         [0043]     From the foregoing one can readily foresee that numerous modifications to the foregoing may be made without departing from the spirit and the scope of the invention. For example, the rings  7  may be any type of fastener or label is capable of being impaled, snagged or gripped by an instrument or tool which is intended to be marked for identification. The clip assembly  57  may be modified as desired to either surround or secure the fastener or label formed on the structure  35  so that the fastener or label is accessible. The stand  67  may be modified as desired to support various embodiments of the clip assembly  57  or other tape dispensers  68 . Further, the dimensions of the rings  7  and the clip assembly  57  may be modified as necessary to accommodate a tool or instrument having a particular size or shape. The claims define the scope of the invention.
A clip assembly ( 57) retains a ring structure ( 35) which contains a plurality of individual color coded rings ( 7). A hand held tool ( 3), such as a dental instrument having a shaft ( 6) may be marked with a colored ring ( 7) by inserting the shaft ( 6) through the aperture ( 64) of the ring and separating the ring from the structure ( 35) by a twisting or pulling motion. The clip assembly ( 57) and the structure ( 35) are protected from contamination by transparent covers ( 65, 66). A stand ( 67) may be used to retain the clip assembly prior to and after use, with or without the presence of the covers ( 65. 66). The stand can also retain a tape dispenser ( 68) which contains colored tape ( 31) as may be needed for marking instruments that are not suitable for labeling with a ring ( 7).