Abstract:
A dental work site illumination system provides illumination directly onto a work site under professional dental care. The illumination emanates from a light source within the swivel coupling, the light source being energized by an electrical generator mounted within the coupling. The generator is driven by a turbine wheel that is caused to rotate by a flow of exhaust fluid, i.e. compressed fluid after having driven a dental tool. The light source transmits illumination to a fiber optic bundle that terminates adjacent to the dental work site.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of dental equipment and more particularly to an apparatus for providing illumination in close proximity to the patient&#39;s teeth. 
     BACKGROUND OF THE INVENTION 
     It has been known that the overhead light used in traditional dental practice has inherent problems. The dentist works for periods of time with the dentist&#39;s hands, and possibly head, partially preventing the light from illuminating the work site inside of the patient&#39;s mouth. One improvement on this overhead lighting system that has been in use for several years is a light that is strapped to the dentist&#39;s forehead. While this “headlight” does bring the light closer to the work area and avoids interference by the dentist&#39;s head, the dentist&#39;s hands continue to block the light at the work site. 
     Pursuant to the development of fiber optic filaments for the transmission of light, a remote light source was introduced to bring illumination to the tip of the dental handpiece, improving visibility in the work area. This system uses a light source that is typically located in the dental chair or an instrument panel. The entry end of the fiber optic bundle is positioned adjacent to the light source and the fiber optic filaments travel through the supply hose through a swivel coupling to bring light into the handpiece at a point that is close to the drill bit. In an alternate design, the light source is located in the swivel coupling with electric current being supplied from the dental chair or instrument panel through a set of wires enclosed in the supply hose. This newer system is quite effective in providing illumination at the work site with virtually no blockage by the dentist&#39;s head or hands. However, the need for long fiber optic filaments or electric wires and their associated weight as well as a control box/transformer and access to electricity makes this lighting system expensive and cumbersome. Furthermore, installing and servicing this existing lighting system requires significant expertise and time. 
     Most rotary dental apparatus is driven by a flow of compressed air that travels through the supply hose and through the swivel coupling to the handpiece. The swivel coupling serves to connect the supply hose to the handpiece, transmitting compressed air and water while allowing the handpiece to be rotated to access various surfaces of the patient&#39;s teeth. After the compressed air passes through the handpiece, the air is discharged. 
     SUMMARY OF THE INVENTION 
     The present invention provides a unique dental work site illumination system that overcomes the drawbacks of the previously known dental lighting systems. A turbine wheel mounted within the swivel coupling is driven by the compressed air after driving the dental tool. The driven turbine wheel rotates a miniature generator to create an electric current that is connected to a light source located adjacent to the distal end of the swivel coupling. A receptor end of a fiber optic bundle housed within the handpiece is positioned adjacent to the light source, the delivery end of the fiber optic bundle being positioned adjacent to the drill bit. The light transmitted along the fiber optic bundle illuminates the dental work site at close range. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is best understood in conjunction with the accompanying drawing figures in which like elements are identified by similar reference numerals and wherein: 
         FIG. 1  is a perspective view of a dental handpiece mounted to a swivel coupling at the end of a supply hose, the dental handpiece incorporating a fiber optic lens with a light beam emanating therefrom. 
         FIG. 2  is a schematic cross sectional view of the swivel coupling according to the invention with a proximal end of a dental handpiece positioned for attachment to the swivel coupling. 
         FIG. 3  is a schematic cross sectional view taken in the direction of line  3 - 3  of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , a dental handpiece  10  is illustrated in schematic perspective view as being mounted to a coupling component  20  that is fixedly connected to a flexible supply hose  24 , dental handpiece  10  being positioned adjacent to a set of teeth T. As used herein, the term “dental work site” is defined to identify an area of the patient&#39;s teeth being professionally treated. Coupling component  20  is preferably configured to swivel, allowing the dentist or dental technician using the dental equipment to rotate handpiece  10  in the direction indicated by arrow A for greater control and comfort. Handpiece  10  is easily mounted to or removed from swivel coupling  20  through a snap connector, as is known. Handpiece  10  has a chuck  12  at a distal end thereof with a drill bit  14  mounted in chuck  12 . A lens  16  is mounted adjacent to chuck  12  and drill bit  14 . Lens  16  is the light delivery end of a fiber optic bundle (not visible) contained within handpiece  10 . A light beam  18  is directed from lens  16  to illuminate a work site area on the surface of teeth T. 
     Continuing with reference to  FIG. 1 , swivel coupling  20  is assembled to the output end of supply hose  24 . Supply hose  24  is a highly flexible conduit including a pressurized supply tube  28  for delivery of compressed air or another compressed fluid that is used to drive drill bit  14  at a high rate of speed. In addition, a water tube  32  and a chip air tube  34  are contained in supply hose  24 . Water tube  32  provides cooling water to protect drill bit  14 , and chip air tube  34  atomizes the water flowing from water tube  32 , as is known. It is particularly noted that there is no fiber optic bundle or electric wires included in supply hose  24 . 
     Referring now to  FIG. 2 , a schematic side cross sectional view of swivel coupling  20  is shown adjacent to an end portion of handpiece  10  that is positioned for being moved in the direction indicated by arrow B to be connected to swivel coupling  20 . Certain mechanical details of swivel coupling  20  that are currently known are not shown for reasons of clarity, particularly the swivel mechanism and the snap connector. The housing of swivel coupling  20  is shown in dashed lines. As illustrated, the right end of swivel coupling  20  is configured for assembly to supply hose  24  (see  FIG. 1 ). A pressurized supply tube  28 , a water tube  32  and a chip air tube  34  are shown at the right end of swivel coupling  20  in positions to engage respective ends of mating tubing within the supply hose. The opposite ends of pressurized supply tube  28 , water tube  32  and chip air tube  34  are located at the left end of swivel coupling  20  for connection to handpiece  10 . A mating set of pressurized supply tube  28 ′, water tube  32 ′ and chip air tube  34 ′ are situated within handpiece  10 . Handpiece  10  is to be moved in the direction indicated by arrow B for connection to swivel coupling  20 . During the use of dental handpiece  10 , compressed air or other pressurized fluid is conveyed through pressurized supply tube  28  in swivel coupling  20  and through pressurized supply tube  28 ′ in handpiece  10  to drive the connected drill bit or other tool. Subsequently the fluid, being somewhat pressure depleted, is conducted away. An exhaust tube  30 ′ is provided within handpiece  10  to conduct used compressed fluid, now at a relatively low pressure, out of handpiece  10 . Exhaust tube  30 ′ connects to exhaust tube  30  within swivel coupling  20 . Pressurized fluid, e.g. pressurized air, flows through supply tubes  28 ,  28 ′ and through exhaust tubes  30 ′,  30  in the directions indicated by flow arrows (not numbered). Near the end of swivel coupling  20  that is assembled to the supply hose, exhaust tube  30  is formed with a bend to direct the exhaust fluid toward a turbine wheel  42 , causing turbine wheel  42  to rotate. The exhaust fluid is discharged to atmosphere or through tubing within supply hose  24  after rotating turbine wheel  42 . 
       FIG. 3  provides a detailed view of turbine wheel  42  taken in the direction of line  3 - 3  of  FIG. 2 . Whereas driving a turbine wheel by the flow of compressed fluid is known, driving the turbine wheel with primary compressed fluid, before driving the rotary dental tool, results in a reduction of the force and effectiveness of tool rotation. Therefore, a preferred embodiment of the invention utilizes the exhaust fluid, i.e. fluid having a lower pressure after having driven the tool. Exhaust fluid is expelled from exhaust tube  30  in the direction indicated by arrow C to rotate turbine wheel  42  in the direction indicated by arrow D. Turbine wheel  42  is configured with a plurality of vanes, preferably oriented at an angle to the radii in order to obtain maximum drive force from the exhaust fluid. Therefore, by driving the turbine wheel with the exhaust fluid subsequent to driving the tool rotation, little or no reduction in tool drive power occurs. The preferred embodiment of the present invention is to rotationally drive the turbine wheel with exhaust fluid, particularly exhaust air. 
     Referring again to  FIG. 2 , turbine wheel  42  is mechanically coupled to an electrical generator  40  in a manner to activate generator  40  to generate an electric current. Electric generator  40  is manufactured of materials adapted to undergo repeated autoclave cycles. The electric current from generator  40  passes through wires  46  that are connected to a light source  44 . Generator  40  is capable of providing sufficient power to drive light source  44 . Generator  40  is sufficiently small and light weight to mount within swivel coupling  20  and sufficiently powerful to illuminate light source  44 . A generator adapted to satisfy the requirements of the present invention is approximately 6.0 mm in diameter by 12.0 mm in length and is capable of producing 20 milliamps at 2.7 volts. According to the preferred embodiment of the invention, light source  44  is an LED light source with a power rating of 0.03-0.05 watts at 2.6-2.7 volts. However, alternate light source types are understood to be within the scope of the present invention. The light emanating from light source  44  is transmitted to a fiber optic bundle  48 ′ positioned in the connective end of handpiece  10  when handpiece  10  is mounted to swivel coupling  20 . Fiber optic bundle  48 ′ transmits illumination to fiber optic lens  16  (see  FIG. 1 ) to be in close proximity and directed to the dental work site for improved visibility by the dentist or technician. 
     While the description above discloses a preferred embodiment of the present invention, it is contemplated that numerous variations and modifications of the invention are possible and are considered to be within the scope of the claims that follow.