Abstract:
A cradle switch plug is placed into the cradle of a dental instrument in a dental delivery unit to deactivate the instrument thereby allowing the instrument to remain at the ready without endangering or spraying the user and/or assistants and/or patients. In addition, when an instrument is removed from an air fitting a blind air fitting plug is screwed into the air fitting. The air plug prevents entry of debris into the air fitting and/or air ports thereof. The air plug also enables proper seating of the air fitting within the cradle and, thus, actuation of the cradle switch.

Description:
BACKGROUND AND SUMMARY  
       [0001]     Embodiments of the present invention relate to machines used in dentistry. More specifically, embodiments of the present invention relate to accessories disabling dental air-powered tools, such as drills and the like, without requiring replacement of the tools in their cradles.  
         [0002]     Embodiments relate to improvements in a dental delivery unit. In particular, the present invention provides a cradle switch plug for activating a cradle switch in a dental tool holder. Generally, the cradle switch plug activates the cradle switch to thereby disable an instrument without that instrument being disposed within the cradle, such as an instrument that is only temporarily not being used but which, for a variety of reasons, the user does not wish to return to the cradle. Additionally, embodiments provide a threaded air fitting plug that covers the open end, i.e., the air fitting, of an unused air supply hose and which is configured or shaped to enable (or not interfere with) the proper seating of the air fitting within the cradle and activation of the cradle switch to disconnect the hose from or deactivate the supply of pressurized air to the hose. Alternatively, embodiments can employ a combination of a cradle switch plug and a threaded air fitting plug to provide both functions.  
         [0003]     Typical dental delivery units, such as that shown in U.S. Pat. No. 6,419,487, include a source of motive fluid, such as compressed air, to which at least one hose is attached. The hose leads and provides motive fluid to a tool, such as a turbine drill, that a dentist or assistant uses to work on a patient&#39;s teeth. The hose can also carry exhaust motive fluid, can supply water and air for irrigation and other purposes, and provide a fiber optic conduit, among other items, depending on the particular features desired by the end user. Typically, a switch, such as a foot pedal, enables and controls the amount of power used by the tool. Additionally, a tool holder preferably includes a “kill switch” or cradle switch that shuts off the supply of motive fluid to the tool when it rests in its cradle and activates the switch. A plurality of hoses is included in most dental delivery units, each hose with its own respective cradle and corresponding cradle switch. The cradle “kill switches” allow power to travel to their respective hoses until the hoses are returned to their cradles thereby activating the switch.  
         [0004]     Upon occasion, the user will need to have one tool handy while using a second tool and will set the first tool down. Because the cradle switches allow power to travel to their hoses until they are returned to their cradles, both tools will continue to receive power in this scenario. Thus, when the second tool is used, the first will also be activated, spraying people and objects or worse. Thus, there is a need for a way to readily turn off power to a dental tool without replacing it in its holder.  
         [0005]     The tools on the hoses of a delivery unit are typically interchangeable. When a tool is removed from its hose, the end cap of the hose is exposed, leaving ports in the end cap, such as air supply and exhaust ports, vulnerable to debris and other non-sterile material that could, among other things, infect the patient. Thus, there is a need for an easy way to keep debris and/or other non-sterile material from entering the ports on an end cap of such hoses.  
         [0006]     Embodiments provide a cradle switch plug that fits into a hose cradle, interacting with its kill switch to turn off power to the respective hose. Thus, if the user wants to use a second tool without replacing the first tool in its cradle or removing it from its hose, the user simply places the plug in the cradle to deactivate the tool.  
         [0007]     Embodiments also provide a threaded blind air fitting plug for a dental delivery air hose. When a tool is removed from its hose, the blind plug can be screwed on in its place to prevent material from entering ports in the end of the hose and to enable the air fitting to activate the cradle switch to thereby deactivate the hose.  
         [0008]     Embodiments further provide for a combined cradle switch plug and blind plug in which one end of a cylinder is shaped as the cradle switch plug and the other is threaded to fit on the end of a hose. Alternatively, the cradle switch plug can include threads into which the blind plug can be screwed so that when the user wishes to use the blind plug, he or she unscrews the blind plug from the cradle switch plug, then screws the blind plug onto the air fitting end cap of the hose.  
         [0009]     The above and other features of the present invention, as well as the structure and operation of preferred embodiments of the present invention, are described in detail below with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.  
         [0011]      FIG. 1  shows a typical dental delivery unit with which embodiments can be used.  
         [0012]      FIG. 2  shows a typical dental delivery unit tool support with five cradles with which embodiments can be used.  
         [0013]      FIG. 3  is a schematic diagram showing a cradle switch plug according to embodiments.  
         [0014]      FIG. 4  is a schematic diagram showing a blind air fitting plug according to embodiments.  
         [0015]      FIG. 5  is a schematic plan diagram of an air fitting with which embodiments can be used and showing ports in the end of the fitting.  
         [0016]      FIG. 6  is a schematic diagram of an air fitting and a blind plug according to embodiments, the plug not being screwed onto the air fitting.  
         [0017]      FIG. 7  is a schematic diagram of an air fitting and a blind plug according to embodiments, the plug being screwed onto the air fitting.  
         [0018]      FIG. 8  is a schematic diagram of a dental delivery unit with which embodiments have been employed.  
         [0019]      FIG. 9  is a schematic diagram of a combined cradle switch plug and blind plug according to embodiments. 
     
    
     DESCRIPTION  
       [0020]     While the present invention may be embodied in many different forms, there is described herein in detail an illustrative embodiment with the understanding that the present disclosure is to be considered as an example of the principles of the invention and is not intended to limit the invention to the illustrated embodiment.  
         [0021]     Typical dental delivery units, such as that shown in U.S. Pat. No. 6,419,487, include a source of motive fluid, such as compressed air, to which at least one hose is attached. See  FIG. 1 , which shows a typical delivery unit  10  with a tray  100  supporting a plurality of hoses  110  that end in air fittings  120  to which are attached tools or instruments  130 . Each hose  120  leads and provides motive fluid to a tool  130 , such as a turbine drill, that a dentist or assistant uses to work on a patient&#39;s teeth. The hose can also carry exhaust motive fluid, can supply water and air for irrigation and other purposes, and provide a fiber optic conduit, among other items, depending on the particular features desired by the end user. Typically, a switch (not shown), such as a foot pedal, enables and controls the amount of power used by the tool  130 . Additionally, a tool holder or cradle  200  in the tray  100  preferably includes a “kill switch” (not shown) such that motive fluid is not sent to the tool  130  when it rests in its cradle  200 . Each instrument  130  generally has its own respective cradle  200 . The cradle “kill switches” allow power to travel to their respective tools  130  until they are returned to their cradles  200 .  
         [0022]     To enable a user to have one tool handy while using a second tool without power going to the first tool, embodiments provide a cradle switch plug  210 , as seen in  FIGS. 2, 3 , and  8 . The switch plug  210  fits into a cradle  200 , interacting with its kill switch to turn off power to the respective hose  110  and tool  130 . Thus, if the user wants to use a second tool without replacing the first tool in its cradle or removing it from its hose, the user simply places the switch plug in the cradle to deactivate the tool.  
         [0023]     To ensure proper functioning, the switch plug  210  preferably has a contour substantially identical to that of an air fitting  120  on the hose  110  and to which the tool  130  is attached. Additionally, the switch plug  210  must be of sufficient weight to activate the kill switch of the cradle  200 . Furthermore, the switch plug  210  must be constructed of a material, or with a finish, that is easily cleaned, sterilized, durable, and resistant to corrosion and fluids.  
         [0024]     Preferably, embodiments use stainless steel as the primary material for the switch plug  210 , thus providing adequate weight and substantially eliminating corrosion of the switch plug  210 . Although in the embodiment shown and descried the plug  210  is preferably constructed of stainless steel, it is to be understood that the switch plug  210  of the present invention can be alternately configured and constructed of other suitable materials having the described characteristics, such as, for example, other metals, weighted or heavier plastics, or from any other suitable material or with a finish that is easily cleaned, sterilized, durable, and resistant to corrosion and fluids.  
         [0025]     Yet another alternative is packaging or enclosing the plug  210  in a sterilized package or packaging material that is replaced and/or disposed of after each use.  
         [0026]     The tools on the hoses of a delivery unit are typically interchangeable. When a tool is removed from its hose, the end cap of the hose  130  or its air fitting  120  is exposed. Embodiments contemplate a blind air fitting plug  220  that threads onto the end cap of the hose  130  or its air fitting  120  and has a contour configured that enables (or does not interfere with) proper seating of the hose/air fitting in the cradle and, thus, the activation of the cradle switch by the end cap of the house  130  or its air fitting  120 . The blind air fitting plug  220 , of course, must be of sufficient weight to activate the kill switch of the cradle.  
         [0027]     An example of a fitting plug  220  according to embodiments is shown in  FIGS. 2-4  and  6 - 8 .  FIG. 5  shows an example of an end of a hose  130  or its air fitting  120  including ports, such as air supply and exhaust ports  501 ,  502 , as well as water supply  503 , spray air supply  504 , and fiber optic conduit  505 . As seen in  FIG. 4 , embodiments of the fitting plug  220  preferably include threads  410  and a blank end cap  420  sized to screw into the air fitting  120  or hose  130 . When a tool  130  is removed from its hose  110 , the blind plug  220  can be screwed on in its place thereby preventing material from entering ports in the end of the hose and enabling the air fitting  120  to properly seat within the cradle and actuate the cradle switch.  
         [0028]     Embodiments further provide for a combined cradle switch plug and blind plug, as seen in  FIG. 9 . The combined plug  900  can comprise one end  910  of a cylinder shaped like a cradle switch plug  210  as described above. The other end  920  of the combined plug  900  can have a portion  921  similar to the blind end cap  410  of the blind air fitting plug described above, as well as a threaded portion  922  to fit on the end of a hose  130 . Alternatively, a cradle switch plug  210  can include threads into which the blind plug  220  can be screwed so that when the user wishes to use the blind plug  220 , he or she unscrews the blind plug  220  from the cradle switch plug  210 , then screws the blind plug  220  onto the air fitting end cap of the hose.  
         [0029]     While various illustrative embodiments of the present invention described above have been presented by way of example only, and not limitation, it will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.