Abstract:
A disposable extension member for joining a dental handtool to a disposable, hollow, dental tip. The dental handtool includes a chuck for releasably retaining the extension member. The extension member has at least one fluid-tight passageway extending through its body for fluid flow from the dental handpiece to the dental tip. The extension member includes an adaptive releasable locking member having an internally threaded, cuplike end portion dimensioned for releasable threading engagement with the dental tip. The chuck provides easy and efficient clamping means to secure the extension member within the handtool.

Description:
RELATED APPLICATIONS 
   This application claims the benefit of provisional patent application Ser. No. 60/592,722 filed 30 Jul. 2004. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to dental syringe adaptors, and more specifically to disposable dental syringe adaptors capable of providing both air and water and that may be quickly inserted or removed from a dental tool. 
   Dental syringes are widely used by dentists, dental assistants, dental hygienists and similar personnel. The syringes are generally handheld devices that deliver air and water to a patient&#39;s mouth during dental procedures. Examples of such syringes are found in U.S. Pat. Nos. 5,378,149 and 4,248,589. The devices generally selectively deliver the air and water at a predetermined pressure. Valves in the dental instrument allow for selective control of the water or air discharge. 
   Cross contamination is a principal concern with dental syringes and dental procedures, in general. Because it is not desirous to transmit or pass bacteria and/or viruses from one patient to another, syringes, tips, and extension pieces have been developed that are autoclavable. Specifically, these devices are made of stainless steel, which can become quite expensive. Extension members, in particular, are expensive, especially if the extension members are designed for a single style of handpiece, such as an air/water syringe or just a water syringe. A disposable extension member would significantly reduce the costs of dental procedures. 
   U.S. Pat. No. 5,049,071, discloses a plastic dental syringe that is adaptable to a handheld dental tool. The syringe may be used as an air/water syringe. However, the design of the syringe does not allow adaptation between different styles or types of dental tips. The syringe is designed for a single type of use. Thus, the disclosed syringe may be not necessarily be used for different procedures that require different dental tips, and the utility of the syringe is limited. 
   Furthermore, it is desirous for dental tools and dental tips to adapt easily to each other. Such results may be achieved by using a locking device for syringes and adaptors that quickly and easily join the dental tools to the dental tips. It would be further desirous to develop a disposable extension member for releasably receiving and connecting with syringe tips that provides for expanded use of such locking devices and for quick exchange of dental accessories. 
   SUMMARY OF THE INVENTION 
   The present invention provides an adaptor assembly for connecting a dental tip to a dental handpiece. More specifically, the present invention provides a disposable extension member for connecting a dental tip to a dental handpiece. The extension member has a first end portion that will be releasably retained within a head portion of the dental handpiece by a chuck assembly. A second end portion has an internally threaded cuplike member that allows the dental tip to be threaded onto the extension member. The extension member is ideal for use with threadable dental tips, such as LUER-LOK® style dental tips. The extension member has a through passageway, which allows fluid to pass from the dental handpiece to the dental tip. The arrangement of the first end portion with the chuck and the second end portion with the cuplike member provides a fluid tight seal for the extension member. 
   Because the extension member is disposable, the member significantly reduces the costs of dental procedures. Also, time is reduced, since the extension member does not need to be autoclaved, but may be thrown out after use. Furthermore, the extension member can be designed to work with a handpiece that delivers water, air, or both, which will further reduce costs in that several different autoclavable extension members may be replaced with the present invention. 
   The present invention is also advantageous in that it can be used with a wide variety of adaptor assemblies, which also have novel features that will described in further detail with following specification and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a dental handpiece used for aspiration of air and/or water and including an adaptor assembly according to the present invention. 
       FIG. 2  is an exploded view of the adaptor assembly shown in  FIG. 1 . 
       FIG. 3  is a partially cut-away side view taken along line  3 - 3  of  FIG. 1  showing operating components of the dental handpiece and in operating connection with the adaptor assembly fabricated according to the present invention. 
       FIG. 4  is an exploded view of an extension member and a connectable dental tip according to the teachings of the present invention. 
       FIG. 5  is cut-away perspective view of an end of an adaptor body according to teachings of the present invention. 
       FIG. 6  is a cut-away perspective view of an end of an alternative embodiment of an extension member according to the present invention. 
       FIG. 7  is a partially cut-away side view of the dental handpiece shown in  FIG. 3  and further showing an alternative adaptor assembly for receiving the extension member. 
       FIG. 8  is a partially cut-away side view of the dental handpiece shown in  FIG. 3  and further showing another alternative adaptor assembly for receiving the extension member. 
       FIG. 9  is a partially cut-away side view of the dental handpiece shown in  FIG. 3  and further showing yet another alternative adaptor assembly for the extension member. 
       FIG. 10  is a perspective exploded view of an adaptor body as shown in  FIG. 4  in arrangement with an alternate dental tip. 
       FIG. 11  is a perspective exploded view of an adaptor body as shown in  FIG. 4  in arrangement with another alternate dental tip. 
       FIG. 12  is a perspective exploded view of an adaptor body as shown in  FIG. 4  in arrangement with a further alternate dental tip. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. 
     FIG. 1  shows a perspective view of a dental handpiece  10  including an adaptor assembly  20 . The adaptor assembly  20  includes a chuck  21  and an elongate extension member  22 . The dental handpiece  10  has a head portion  12  with a reentrant socket  14  (see  FIG. 3 ) located within the head portion  12 . The socket  14  is arranged to receive an inwardly extending portion of the chuck  21  and the extension member  22  so that the extension member  22  will be fittingly secured to the dental handpiece  10 . The handpiece  10  has a through passageway  16  (see  FIG. 3 ) that is in fluid communication with the extension member  22 . The head portion  12  includes finger valves  18   a  and  18   b  for control of air and water flow, respectively. While the dental handpiece  10  is arranged to receive both water and air, the present invention will work with handpieces that deliver only water or air, or other possible fluids. As will be evident with reference to the further drawings and description of the application, the extension member  22  may be easily removed from the handpiece  10  when necessary. The extension member  22  preferably comprises an elongated body having a first end portion  24  that interacts with the socket  14  and the chuck  21 , and a second end portion  26  that allows a dental tip or needle  28  to be attached to the extension member  22 . As will be discussed in more detail with respect to  FIG. 8 , the extension member  22  is arranged so that a disposable dental tip  28  may be removably attached to the second end portion  26  of the extension member  22 . 
     FIG. 2  shows an exploded view of the adaptor assembly  20 . The adaptor assembly  20  comprises the chuck  21  and an annular collet  30 . The chuck  21  includes a plurality of circumferentially spaced, externally tapered jaws  34 , which will allow the extension member  22  to be clamped within the chuck  21 . The collet  30  and the jaws  34  are preferably designed of a resilient plastic so that they will grasp the extension member  22  securely and with enough resistance to firmly retain the extension member  22  within the chuck  21 , without damaging the extension member  22 . A first O-ring  36  sits between the chuck  21  and an externally threaded coupling member  38  to provide a fluid sealing connection between the chuck  21  and the threaded section  38 . Any suitable sealing means may be used in place of the first O-ring  36  that allows a fluid tight connection between the externally threaded coupling member  38  and the chuck  21 . The externally threaded coupling member  38  will sit within a second O-ring  40  located within the socket  14  to provide a fluid tight throughbore between the dental tool  10  and the externally threaded coupling member  38 . 
     FIG. 3  is a partially cut-away view of the socket  14  of the dental handpiece  10  housing the chuck  21 . As previously noted, the chuck  21  is arranged to securely retain the extension member  22  within the socket  14 . The adaptor provides fluid communication from the fluid source through the passageway  16  located within the handpiece  10  to the extension member  22  by way of a throughbore or through passageway  42  located in the threaded externally threaded coupling member  38 . A secondary passageway  17  is also located within the handpiece  10 . The passageway  17  would be utilized if the handpiece  10  used for delivering a second fluid, such as air. The throughbore  42  is in communication with a passageway  44  located in the extension member  22 . As shown in  FIG. 3 , a secondary throughbore  42   a,  and a secondary passageway  44   a  are in communication as well. The secondary throughbore  42   a  and passageway  44   a  may be used to deliver an air flow to the dental tip. They are not necessary for the present invention, but show that the extension member  22  may be used and adapted for a dental tool having any number of fluid passageways and arrangements. 
   Still referring to  FIG. 3 , the first end  24  of the extension member  22  is inserted into the chuck  21  until it rests firmly upon an extending edge  46  of the coupling member  38 . Once fully inserted, a threaded section  48  of the collet  30  will be threaded onto the externally threaded coupling member  38 . The collet  30 , which has an internal tapered surface  50 , will compress the tapered jaws  34  of the chuck  21  to thereby firmly retain the extension member  22 . The abutment of the first end  24  of the extension member  22  with the extending edge  46  will form a tight seal, but the first O-ring  36  is preferably used to further maintain the fluid tight seal between the extension member  22  and the chuck  21 . 
   It should be understood that  FIG. 3  is merely exemplary of adaptor arrangements and should not be considered limiting. The disposable extension member  22  is designed to provide a sealing arrangement with different dental handpieces and further allow connection to a dental tip in an efficient manner, and should include similarly arranged designs that will provide a fluid tight arrangement with a disposable extension member. 
   Referring to  FIG. 4 , a cut-away exploded perspective view of the extension member  22  and the dental tip  28  is shown. The second end portion  26  of the extension member  22  includes an adaptive releasable locking member, which includes a cuplike portion  52  having an internally threaded surface  54  comprising a raceway  55 . The cuplike member  52  should be considered to include any structure that will provide an internal threaded surface that will allow mating with the dental tip  28  and should not be limited to the presently shown design. The threaded surface  54  interacts with a pair of diametrically opposed extending tabs or tab portions  56  radially extending from a flange  58  located on the dental tip  28 . The threaded surface  54  and the raceway  55  may be arranged to receive a single tab  56 , but preferably it will receive two tabs  56 . As the dental tip  28  is threaded into the cuplike member  52 , the tabs  56  are compressed against the threaded surface  54  to form a fluid tight fitting between the passageway  44  and the interior of the dental tip  58  (see  FIG. 1 ). When the dental tip  28  is threaded into the cuplike member  52 , the taper of the dental tip  28  allows for the passageway  44  to be sealed against the inside of the dental tip  28  without necessarily employing other sealing means. Though not necessary, the passageway  44  is shown extending outwardly of the cuplike member  52 . The depicted design allows for a shallow cuplike member, since there is less needed length when threading the dental tip  28 . The tabs  56  of the dental tip  28  only need to be threaded a few rotations within the raceway  55  to form a fluid tight seal between the passageway  44  and the dental tip  28 . However, the passageway  44  may terminate inwardly of the cuplike member  52 , or possibly flush with cuplike member  52 . The dental tips  28  are generally considered LUER-LOK®-style dental tips. Thus, the present invention provides an efficient, inexpensive device that will allow adaptation between dental handpieces and LUER-LOK®-style dental tips. Provided the dental tip  28  and the extension member  22  are capable of sealing engagement, the design will fall within the scope of the present invention. 
     FIG. 4  also shows fins  60  extending along the length of the extension member  22 . The fins  60  provide support means for the cuplike member  52  and the extension member  22 . The fins  60  reduce twisting of the extension member  22  and potential snapping of the extension member  22  when the dental tip  28  is inserted and secured within the cuplike member  52 . It should be understood that the support means could take different shapes and forms than the fins  60  shown, provided they reinforce and strengthen the arrangement of the extension member  22 . For instance, the support means could be a solid structure encircling the extension member  22 , rather than separate fins. Likewise, more or fewer fins than shown could be used with the extension member  22 . 
     FIGS. 5 and 6  show partial perspective views of the first end  24  of different embodiments of the extension member  22  used in the present invention.  FIG. 5  shows the extension member  22  having the single passageway  44 , while  FIG. 6  shows extension member  22  having the passageway  44  surrounded by a plurality of the secondary passageways  44   a.  For instance the secondary passageways  44   a  would allow for mating with the secondary passageway  17  of the handpiece  10  (see  FIG. 3 ). As previously noted, the extension member  22  is not limited to either embodiment, and may also include other potential passageway designs. Whereas the prior art would require many different extension sections or possibly not allow adaptation between different needle or dental tip arrangements, the present invention allows a single extension member to be used for several different dental devices and tips. Furthermore, because the present invention is disposable, using an adaptor to convert between an air/water syringe an air syringe or water syringe is much more economical for many practitioners. 
     FIG. 7  is a partially cut-away side view of an alternative adaptor assembly  120  for receiving the extension member  22 . The adaptor assembly  120  comprises a chuck  121  and a threaded coupling member  138 . The chuck  121  comprises a plurality of locking fingers  122  that provide the clamping means needed to retain the extension member  22 . Preferably the locking fingers  122  are circumferentially spaced. The coupling member  138  has an externally threaded surface  140  that mates with the chuck  121  and the locking fingers  122  similarly to the first adaptor assembly  20  and chuck  21 . The coupling member  138  has distal end  142  that tapers outwardly from the interior of the coupling member  138 . The fingers  122  have an inwardly extending ridge  144  that forms a cavity  146 . As the chuck  121  is threaded onto the coupling member  138 , the distal end  142  of the coupling member  138  will mate with the cavity  146  of the chuck  121 . As the chuck  121  is threaded further onto the coupling member  138 , the ridges  144  of the fingers  122  come into contact with the sloped or tapered surface of the distal end  142 . The ridge  144  will slide inwardly, thereby gripping and retaining the extension member  22 . The chuck  121  may be formed out of a resilient material, such as a resilient plastic material, that will allow the chuck  121  to sufficiently grasp the extension member  22  and release it, when necessary. However, other materials may be used to form the chuck  121 , as well. 
   Still referring to  FIG. 7 , a sealing mechanism  148  is located within a corresponding annular groove  150 . The sealing mechanism  148  comprises a circumferential resilient flange to provide further sealing means between the extension member  22  and the coupling member  138 . The sealing mechanism  148  also contributes further retention means for the extension member  22  by frictionally engaging the extension member  22  when the extension member  22  is inserted into the coupling member  138 . An O-ring  154  located between the coupling member  138  and the socket  14  provides further sealing means, as well. The extension member  22  is inserted into the socket  14  until it abuts an internal surface  156 , where it will be in fluid communication with the passageway  16 . The overall arrangement provides a fluid-tight arrangement that securely retains the extension member  22 . 
     FIG. 8  provides another embodiment of an adaptor assembly  220 . As with the prior embodiments, a coupling member  238  is threaded into the socket  14 . The coupling member comprises a cylindrical housing  240  with a centrally located throughbore  242  for insertion of the extension member  22 . The housing  240  comprises an annular reentrant cavity  243  that surrounds the extension member  22 . The extension member  22  will abut the internal surface  156 , as was described in  FIG. 7  with respect to the assembly  120 . Likewise, an O-ring  154  sits between the coupling member  238  and the socket, as shown in  FIG. 7 . 
   Still referring to  FIG. 8 , an annular sealing mechanism  244  having a resilient flange  246  that frictionally engages the extension member to provide fluid-tight retention of the extension member  22  is located within the reentrant cavity  243 . A collar  248  is located within the reentrant cavity  243 . The collar  248  is connected to the housing  240  by way of a protrusion  250  that mates with a groove  252  located in the housing  240 . The collar  248  has an internally located channel  254  for receiving and supporting retention means  256 . The retention means  256  preferably comprises a flexible annular disc that surrounds and retains the extension member  22  in frictional engagement. A plunger  258  is retained above the retention means  256  within the reentrant cavity by a lip  260 , which is a portion of the collar  248 . In a normal position, the retention means  256  exerts upward force on the plunger  258  to retain the plunger  258  against the lip  260 . To remove the extension member  22 , the plunger  258  is pressed inwardly toward the head portion  12 , thereby moving the retention means  256  away from the extension member  22  and allowing the extension member  22  to be removed from the throughbore  242 . 
     FIG. 9  shows another embodiment  320  of an adaptor assembly. The extension member  22  mates with the socket  14 , as was shown in  FIGS. 7 and 8 . A coupling member  338  extends within a reentrant chamber  340  located within an annular collet  342 . The collet  342  has a throughbore  344  that surrounds the extension member  22 . The chamber  340  is coaxially and radially spaced from the throughbore  344 . The chamber  340  has an internally threaded portion  346  that is in threading engagement with an internally threaded portion  348  of the coupling member  338 . The coupling member  338  further includes a tapered wall  350 . The tapered wall  350  is engageable with a tapered surface  352  of a rubber compression sleeve  354 . As the collet  342  is threaded onto the coupling member  338 , the compression sleeve  354  is pushed downwardly, which allows the sleeve  354  to slide down the tapered wall  350 . The sleeve  354  also moves inwardly towards the extension member  22  to thereby clamp and retain the extension member  22 . 
   As  FIGS. 7-9  show, the extension member  22  can be used with a variety of adaptor assemblies, which further enhances the utility of the present invention. Further,  FIGS. 7-9  include the secondary passageway  17  within the handpiece  10 . If the extension member was arranged as shown in  FIG. 6 , any of the shown adaptor assemblies would accommodate a secondary fluid through passageway  17 . Thus, the adaptability and interchangeability of the present invention is further exemplified. 
     FIGS. 10-12  show exploded views of the second end portion  26  of the extension member  22  and alternative dental tips,  428  ( FIG. 8 ),  528  ( FIG. 9 ), and  628  ( FIG. 10 ).  FIGS. 8-10  illustrate that the present invention may be used in conjunction with numerous tip designs. For instance the dental tip  628  has the tabs  56  integral with the flange  58  and not as separate protrusions. Provided the mating portions of the dental tips interact with the threaded portion  54  of the cuplike member  52  to form a fluid tight seal, the present invention is useful for different dental tips. The dental tips  428 ,  528 , and  628  are generally considered LUER-LOK®-style dental tips, and, also, dental tips considered to have LUER tapers. Thus, the present invention provides an efficient, inexpensive device that will allow adaptation between dental handpieces and LUER-LOK®-style dental tips or LUER taper style dental tips. 
   The present invention provides an affordable extension member for various dental tips and designs. Because the extension member is disposable, it is inexpensive to design and, also, limits possible contamination, since it may be discarded after a single use. The extension member may be used with many different dental handpieces having different gripping means and adaptor assemblies, which further increases the utility of the instrument. The adaptor assemblies described in the present invention also contain new and novel concepts that enhance the utility of the present invention. 
   The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.