BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a dental facility, and more particularly to a dental facility having changeable dental tool members.  
           [0003]    2. Description of the Prior Art  
           [0004]    Typical dental facilities comprise such as the dental burs, which includes a bur head or bur tool attached to one end of a handle, for engaging into the mouths of the users and for working onto the teeth. The typical dental facilities may further include a spraying device having a sprayer head attached to one end of a handle, also for engaging into and for spraying water into the mouths of the users, and/or for working onto the teeth of the users. The dental tool members, such as the bur heads or bur tools, or the sprayer heads, are solidly secured to the handle and may not be disengaged from the handle, such that the dental tool members may only be flushed or cleaned with water or detergent after every working or operation.  
           [0005]    However, AIDS has become a serious problem to both the dentists and the patients, because the AIDS viruses may be contaminated or infected via the dental tool members that have not been completely cleaned, and that may not be fully and completely cleaned.  
           [0006]    The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional dental facilities.  
         SUMMARY OF THE INVENTION  
         [0007]    The primary objective of the present invention is to provide a dental facility including a dental tool member that may be easily disengaged or removed from the handle, and that may be discarded after use, and that may be quickly changed with the other ones after use.  
           [0008]    In accordance with one aspect of the invention, there is provided a dental facility comprising a coupler including an upper portion, a latch disposed in the coupler, and including a tongue extendible outward of the coupler, a dental tool member including a barrel engageable onto the upper portion of the coupler, and means for biasing the tongue of the latch to engage with the barrel and to detachably secure the dental tool member to the coupler. The dental tool member is allowed to be detached from the coupler for being changed with the other one after use, and for preventing both the patients and the dentists from being contaminated or infected with various viruses by the dental tool member.  
           [0009]    The coupler includes a shank disposed in the upper portion of the coupler and having an upper portion extended upward beyond the coupler, the shank includes a channel formed therein for receiving the latch.  
           [0010]    The shank includes an aperture formed therein and communicating with the channel of the shank, and a rod engaged through the aperture of the shank and engaged through the latch for pivotally securing the latch to the shank.  
           [0011]    The shank includes a cavity formed therein, the biasing means includes a spring received in the cavity of the shank and engaged with the latch for biasing the tongue of the latch to engage with the barrel of the dental tool member.  
           [0012]    The barrel includes a hole formed therein. A device may further be provided for disengaging the tongue of the latch from the barrel of the dental tool member, and includes a knob slidably engaged in the hole of the barrel and engaged with the latch for depressing the latch against the biasing means and for disengaging the tongue of the latch from the barrel of the dental tool member.  
           [0013]    The knob includes an inner end located with the barrel and having an enlarged head provided thereon for engaging with the barrel and for preventing the knob from being disengaged from the barrel.  
           [0014]    A duct is further provided and secured to the coupler, and a handle is further provided and attached to the duct. The duct includes a bent upper portion secured to the lower portion of the coupler.  
           [0015]    Further objectives and advantages of the present invention will become apparent from a careful reading of a detailed description provided hereinbelow, with appropriate reference to accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a perspective view of a dental facility in accordance with the present invention;  
         [0017]    [0017]FIG. 2 is a cross sectional view taken along lines  2 - 2  of FIG. 1;  
         [0018]    [0018]FIG. 3 is a cross sectional and exploded view of the dental facility; and  
         [0019]    [0019]FIG. 4 is an end view illustrating the coupler of the dental facility for quickly coupling the dental tool member. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]    Referring to the drawings, and initially to FIGS.  1 - 3 , a dental facility in accordance with the present invention comprises a handle  10  including a bore  11  formed therein and including one end, such as the lower end thereof for coupling to the water and/or medicine reservoir, for receiving the water and/or the medicine therefrom. The handle  10  includes an inner thread  12  formed in the other end thereof, such as the upper end thereof.  
         [0021]    A duct  20  includes an outer thread  21  formed or provided on the outer peripheral portion of the lower portion thereof for threading with the inner thread  12  of the handle  10 , and for coupling the duct  20  to the handle  10 . The duct  20  includes a bore  22  formed therein for communicating with the bore  11  of the handle  10  and for receiving the water and/or the medicine from the handle  10 . The duct  20  includes a bent portion  23  formed or provided on the upper portion thereof and having an outer thread  24  formed or provided on the outer peripheral portion thereof.  
         [0022]    A coupler  30  includes an inner thread  31  formed or provided in the lower portion thereof for threading with the outer thread  24  of the duct  20 , and for attaching the coupler  30  to the duct  20 . Alternatively, the coupler  30  may also be directly secured to the handle  10 , instead of to the duct  20 . The coupler  30  includes a shank  32  secured in the upper portion thereof with such as fasteners, or adhesive materials, or by welding processes. The shank  32  has an upper portion partially extended upward and outward beyond the coupler  30 , and includes one or more passages  33  formed therein (FIG. 4) for communicating with the bores  11 ,  22  of the handle  10  and the duct  20  and for receiving the water and/or the medicine from the duct  20  and the handle  10 .  
         [0023]    The coupler  30  includes a channel  34  formed therein, such as formed in the shank  32 , and an aperture  35  formed in the lower portion of the shank  32  and communicating with the lower portion of the channel  34  thereof for receiving a rod  37  therein, and a cavity  38  formed in the shank  32  and communicating with the upper portion of the channel  34  of the coupler  30  for receiving a spring  39  therein.  
         [0024]    A latch  40  is received in the channel  34  of the coupler  30 , and includes an orifice  41  formed therein, such as formed in the lower portion thereof for receiving the rod  37  and for rotatably securing the lower portion of the latch  40  to the shank  32  or to the coupler  30 . The latch  40  includes a tongue  42  provided or bent or formed on the upper portion thereof and extended away from the shank  32  or the coupler  30 . The spring  39  may engage with the latch  40  and thus may bias the tongue  42  of the latch  40  outward or away from the shank  32  or the coupler  30 .  
         [0025]    A dental tool member  5 , such as a bur head  50 , provided on the upper portion of a barrel  51  for engaging into the mouths of the uses and for working onto the teeth of the users. The barrel  51  includes a bore  52  formed therein for receiving the upper portion of the shank  32  or of the coupler  30 , and includes an opening  53  formed therein for selectively or detachably receiving the tongue  42  of the latch  40  and for detachably securing the barrel  51  and the bur head  50  of the dental tool member  5  to the coupler  30 .  
         [0026]    It is to be noted that the tongue  42  of the latch  40  may be moved inward of the channel  34  of the shank  32  or of the coupler  30  when the upper portion of the shank  32  or of the coupler  30  is engaged into the bore  52  of the barrel  51 , for allowing the tongue  42  of the latch  40  to be biased and engaged into the opening  53  of the barrel  51  when the tongue  42  of the latch  40  is aligned with the opening  53  of the barrel  51 , such that the dental tool member  5  may be easily and quickly secured onto the coupler  30  with the latch  40 .  
         [0027]    The barrel  51  further includes a hole  54  formed therein, such as located below the opening  53  of the barrel  51 . A button or a knob  57  is slidably received in the hole  54  of the barrel  51 , and includes an enlarged head  58  formed on one end thereof, such as the inner end thereof, and received in the barrel  51 , for preventing the knob  57  from being disengaged from the barrel  51 . The inner end of the knob  57  is engaged with the latch  40  for depressing the latch  40  against the spring  39 , and for disengaging the tongue  42  of the latch  40  from the barrel  51 , and for allowing the dental tool member  5  to be easily and quickly disengaged from the coupler  30 , and for allowing the dental tool member  5  to be easily and quickly discarded or replaced with the other ones.  
         [0028]    After each time of use or operation, or after the dental tool member  5  has been engaged into the mouth of a patient, the dental tool member  5  may be easily and quickly disengaged from the coupler  30 , and may thus be discarded after each or every use. The other dental tool members  5  may then be easily and quickly secured or attached onto the coupler  30  for engaging with or for working onto the teeth of the other users. The patients thus will not be infected with the AIDS or the other viruses by the dental tool member  5 .  
         [0029]    Accordingly, the dental facility in accordance with the present invention includes a dental tool member that may be easily disengaged or removed from the handle, and that may be discarded after use, and that may be quickly changed with the other ones after use.  
         [0030]    Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.
A dental facility includes a latch disposed in a coupler and having a tongue extendible outward of the coupler, a dental tool member having a barrel engageable onto the coupler, and a spring for biasing the tongue of the latch to engage with the barrel and to detachably secure the dental tool member to the coupler. The dental tool member may be detached from the coupler for being discarded or changed with the other one after use, and for preventing both the patients and the dentists from being contaminated or infected by the dental tool member.