Abstract:
A dental tool including a dental prophy angle and a dental prophy angle adapter is provided. A dental prophy angle includes a housing and a rotor. The dental prophy angle adapter can include a drive shaft with a tip. The drive shaft of the adapter can be coupled to a gear at the same end of the tip with the rotor of the prophy angle being configured to receive the tip. Further, a slidable sleeve can extend over a portion of the drift shaft so that the slidable sleeve becomes automatically retracted upon engaging a shoulder of the housing resulting in the gear of the drive shaft being positioned beyond the end of the slidable sleeve.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of U.S. application Ser. No. 11/862,628 filed on Sep. 27, 2007, now U.S. Pat. No. 8,123,523, which is a Continuation-In-Part of U.S. application Ser. No. 11/189,193 filed on Jul. 26, 2005, now U.S. Pat. No. 7,422,433 and a Continuation-in-Part of U.S. application Ser. No. 11/682,927 filed on Mar. 7, 2007, now abandoned, all of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The disclosure relates generally to dental instruments and, more specifically, to prophy angles and adapters for use with prophy angles. 
     2. Description of the Related Art 
     Dental prophylaxis angles, generally referred to as “prophy angles,” are commonly used dental instruments for providing rotation for dental tools such as brushes, prophy cups, or other receptacles used in cleaning/polishing teeth. Referring to  FIGS. 1A and 1B , a prophy angle  10  can include an inner housing  16  having an outer housing  18  and a rotor  14  extending at approximately a 90° angle to the neck  18 , which increases the ability of a dentist to reach various surfaces of the teeth of a patient. A drive shaft or rotating member  12  can be located within the housing  16  and attached to a driven gear  20  in the head of the prophy angle. Prophy angles  10  are generally affixed to an adapter (also known as a prophy angle adapter, angle adapter, or dental adapter) or hand piece (not shown), which connects the prophy angle to a drive source (not shown), thereby enabling a rotating motion of the rotating member  12  and driven gear  20  of the prophy angle and any affixed dental tool. 
     Prophy angles  10  are commonly manufactured from lightweight plastic to make them disposable, thereby increasing overall sterility in the dental environment. Being disposable, there is a desire to reduce the cost and/or complexity of assembly of the prophy angle  10  while, at the same time, maintaining the functionality and safety of the prophy angle  10 . 
     One technique to reduce cost is to limit the number of separate pieces in the assembly of the prophy angle  10 . For example, the prophy angle in  FIG. 1B  includes four separate pieces: (i) the rotating member  12 , (ii) the inner housing  16 , (iii) the outer housing  18 , (iv) and the rotor  14 . A reduced number of separate pieces requires less molds to form the separate pieces and less assembly of the pieces. However, by reducing the numbers of separate pieces, each individual and separate piece typically becomes more complex as each piece can take on more functions. 
     One of the issues preventing further reduction in the number of pieces in a disposable prophy angle  10  relates to the ability of the prophy angle  10  to maintain and restrain the position of the rotor  14  within the outer housing  16 . Since the rotor  14  both engages the rotating member  12  and rotates at a head speed, the position of the rotor  14  within the outer housing  16  is critical to maintain a proper engagement between the rotating member and the rotor  14  and to prevent the rotor  14  from being unbalanced during rotation. An improperly positioned and/or restrained rotor  14  can cause failure of the prophy angle  10  and/or causes damage to the adaptor, the dental professional and/or the patient. There is, therefore, a need for an improved prophy angle that reduces the number of pieces in the prophy angle yet while maintaining the positional stability of the rotor within the outer housing. 
     BRIEF SUMMARY OF THE INVENTION 
     Embodiments of the invention provide a novel and non-obvious dental tool. The dental tool can include a (dental) prophy angle and a (dental) prophy angle adapter). The dental prophy angle includes a housing and a rotor. The prophy angle adapter can include a drive shaft comprising a tip at a distal end of the drive shaft and a gear proximal to the tip on the drive shaft and can be configured to receive the prophy angle. In addition, the rotor of the prophy angle can be configured to receive the tip. The prophy angle adapter can further include a slidable sleeve extending over at least a portion of the drive shaft. The slidable sleeve can become automatically retracted upon engaging a shoulder of the housing resulting in the gear of the drive shaft being positioned beyond the end of the slidable sleeve. 
     In another embodiment of the invention, a method for revealing a gear in a prophy angle adapter is provided. The method can include inserting a slidable sleeve positioned at least partially over a drive shaft of the prophy angle adapter into a housing of a prophy angle and engaging a shoulder of the housing of the prophy angle. The method can further include retracting automatically the slidable sleeve so the gear coupled to the drive shaft upon engaging the shoulder of the housing is positioned beyond an end of the slidable sleeve. 
     In yet another embodiment of the invention, a method for revealing a gear in a prophy angle adapter is provided The method can include connecting a slidable sleeve to a spring of the prophy angle adapter and retracting the slidable sleeve upon compressing the spring so the gear coupled to a drive shaft of the prophy angle adapter is positioned beyond an end of the slidable sleeve when inserting the prophy angle adapter into a housing of a prophy angle. The method can further include biasing the slidable sleeve into an extended position resulting in the gear not being exposed upon removing the slidable sleeve from the housing of the prophy angle. 
     Additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention. The embodiments illustrated herein are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein: 
         FIGS. 1A and 1B  are, respectively, a perspective view and a side cross-sectional view of a prophy angle; 
         FIGS. 2A and 2B  are, respectively, side and cross-sectional side views of the rotor; 
         FIG. 3  is a cross-sectional side view of a drive shaft engaging the rotor, in accordance with the inventive arrangements; 
         FIGS. 4A ,  4 B, and  4 C are, respectively, cross-sectional side, rear, and top views of the housing; 
         FIGS. 5A and 5B  are, respectively, exploded and assembled cross-sectional side views of a housing and a rotor in accordance with the inventive arrangements; 
         FIGS. 6A and 6B  are, respectively, exploded and assembled cross-sectional views of a prophy angle and adapter in accordance with the inventive arrangements; 
         FIGS. 7A and 7B  are cross-sectional side views of the adapter with a sleeve, respectively, in extended and retracted positions, in accordance with the inventive arrangements; and 
         FIG. 8  is a cross-sectional side view of a portion of the adapter and the drive shaft. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 5A-5B  and  6 A- 6 B, a prophy angle  100  and adaptor  400  are disclosed. The prophy angle  100  includes a rotor  200  positioned within a housing  110 . The prophy angle  100  is adapted to fit over a drive shaft  350  and engage the adaptor  400 , and in certain aspects, the drive shaft  350  is part of the adaptor  400 . In operation, the prophy angle  100  may be inserted onto and removed from the adaptor  400  so as to be considered disposable. 
     Referring to  FIGS. 2A and 2B , the rotor  200  includes an attachment device  210  to which an attachment, such as a prophy cup (not shown), can be attached. Many types of attachment devices  210  are known as capable of connecting an attachment to a rotor  200 , and the rotor  200  is not limited as to a particular type of attachment device  210  so capable. For example, the attachment device  210  may be a button. Although the button is not limited as to a specific shape or orientation, the button  210  may include additional protrusions  215  to accommodate a specific prophy cup. Another example of an attachment device  210  is a prophy cup with a threaded post molded inside. 
     The rotor  200  may include a radially-extending flange  220 . In certain aspects of the rotor  200 , the radially-extending flange  220  is sized to extend beyond an opening within the housing  110  (see  FIG. 5B ). The flange  220  of the rotor  200  may also be positioned over the opening to the second bore  114 . In so doing, the flange  220  reduces the incidence of debris from the prophy cup or other attachment from entering the interior of the housing  110 , which could potentially interfere with the subsequent operation of the prophy angle  100 . 
     The rotor  200 , while positioned within the second bore  114  (see  FIGS. 5A and 5B ), creates a seal  280  between the rotor  200  and an inner surface  134  of the second bore  114 . Creating a seal between two surfaces is well known in the art, and any manner of creating a seal is acceptable for use with the prophy angle  100 . However, in certain aspects of the prophy angle  100 , one of the rotor  200  and the inner surface  134  of the second bore  114  includes an annular extension  282  and the other of the rotor  200  and the inner surface  134  includes an annular groove  182 . Upon the rotor  200  being positioned within the second bore  114 , the rotor  200  and/or the housing  110  deforms so as to permit the annular extension  282  to be inserted into the annular groove  182  and create the seal  280 . The seal  280  also acts to restrain linear movement of the rotor  200  relative to the housing  110 . Although not limited in this manner, upon the assembly of the rotor  200  with the housing  110 , a lubricant may be added to ease the positioning of the rotor  200  within the housing  110  and/or reduce friction upon the rotor  200  rotating within the housing  110  during operation. 
     The rotor  200  includes a gearing system  230  to drive the rotation of the rotor  200  within the housing  110 . Many types of gearing systems  230  are known capable of driving the rotation of the rotor  200  within the housing  110 , and the rotor  200  is not limited as to a particular type of gearing system  230  so capable. However, in certain aspects of the rotor  200 , the gearing system  230  includes one gear of a bevel gear set. As will be described in more detail below, the other gear  352  of the bevel gear set is attached to the drive shaft  350  (see  FIG. 3 ) and is positionable within the housing  110 . 
     The rotor  200  also includes a lock  240 . The lock  240  interacts with a lock receiver  120  (see  FIGS. 4A-4C ) of the housing  110  to restrain linear movement of the rotor  200  within the housing  110  yet allow rotation of the rotor  200  within the housing  110 . In particular, the lock receiver  120  can restrain linear movement in a direction substantially parallel to a rotational axis of the rotor  200 . In certain aspects of the lock  240 , the lock  240  has a partially-curved outer profile  242 . Also, portions of the lock  240  may have a substantially spherical profile  242  taken along a cross-section perpendicular to a longitudinal axis of the rotor  200 . In so doing, the lock  240  interacts with the lock receiver  120  of the housing  110  to allow rotation of the rotor  200  within the housing  110 . 
     The rotor  200  may also include a rotor conduit  260  having an inlet  265  and an outlet  270 , and the prophy angle  100  is not limited as to the particular use of the rotor conduit  260 . For example, the rotor conduit  260  may be used to transfer materials (e.g., dentifrice, water) to a working area of the prophy angle  100 . Alternatively, the rotor conduit  260  may be used as part of a system to provide suction to the working area of the prophy angle  100 . 
     Referring to  FIG. 3 , in certain aspects of the rotor  200 , the lock  240  includes a recessed lock channel  250  for receiving a tip  355  extending from a distal end of a drive shaft  350 . Upon the drive shaft  350  being engaged within the lock  240 , the tip  355  is positioned within the lock channel  250 . While so positioned, engagement between the tip  355  and upper and lower portions  255 U,  255 L of the lock  240  can restrict movement of the lock  240 , respectively, in a downward direction and an upward direction. Moreover, a width of the lock channel  250  between the upper and lower portions  255 ,U  255 L can be dimensioned slightly greater than a diameter of the tip  355  to further restrict movement of the lock  240  relative to the tip  355  and vice versa. 
     Although the lock  240  is illustrated as having both an upper portion  255 U and a lower portion  255 L, the lock  240  is not limited in this manner. For example, the lock  240  may only include the lower portion  250 L, which would restrain movement of the lock  240  in the upward direction. The drive shaft  350  also restricts movement of the lock  240  in a direction towards the drive shaft  350 . 
     In certain aspects of the rotor  200 , however, the lock  240  includes both an upper portion  255 U and a lower portion  255 L. These two portions  255 U,  255 L, acting together, can restrain rotation of the drive shaft  350  about a specified axis of rotation and position the draft shaft  350  within the specified axis of rotation. The drive shaft  350  typically rotates at a high speed, and any imbalance of the drive shaft  350  can cause the drive shaft  350  to wobble during rotation, which can damage the drive shaft  350  and/or prophy angle  100  and/or cause poor engagement between the drive shaft  350  and the gearing system  230 . However, by constraining the distal end (i.e., the tip  355 ) of the drive shaft  350  with the upper and lower portions  255 U,  255 L of the lock  240 , this wobble, if present, can be reduced. 
     A further discussion of engagement of the rotor  200  and the drive shaft  350  and between the rotor and the housing  110  and the configurations thereof is found in related U.S. application Ser. No. 11/189,193, filed on Jul. 26, 2005, incorporated herein by reference in its entirety. 
     Referring to  FIGS. 4A-4C  and  5 A- 5 B, the housing  110  is illustrated. The housing  110  includes a first bore  112  and a second bore  114 . The first bore  112  extends along a longitudinal length of the of housing  110  and is configured to receive the drive shaft  350  (see  FIG. 6B ). The second bore  114  communicates with and extends substantially perpendicular from the first bore  112 . The second bore  114  is also configured to receive the rotor  200 . Although not limited in this manner, the housing  110  can be constructed from a variety of available plastics having sufficient rigidity to apply pressure to a patient&#39;s teeth, while remaining flexible enough to receive the internal components of the prophy angle. 
     The first bore  112  may also be configured to receive the adapter  400  (see  FIG. 6B ). Although not limited in this manner, the inner surface  116  of the first bore  112  may define a first shoulder  118  that limits movement of a portion of the adapter  400  past the shoulder  118 . The adapter  400  engaging the first shoulder  118  may also be used to specifically position the adapter  400  and, thus, the drive shaft  350 , within the housing  110 . Other features capable of specifically positioning the adapter  400  within the housing  110  are known and can be used with the present adapter  400  and housing  110 . 
     Positioned within the second bore  114  is a lock receiver  120 . The lock receiver  120  receives the lock  240  of the rotor  200  and acts to restrain linear movement of the rotor  200  within the housing  110  yet allow rotation of the rotor  200  within the housing  110 . In certain aspects, the lock receiver  120  includes a plurality of bearing arms  122  positioned within the second bore  114 . The bearing arms  122  may include an upper bearing surface  124  and also a recess  126  on a radially inward-facing surface of the bearing arm  122 . The recess  126  may have a profile configured to receive the lock  240  of the rotor  200 . 
     The housing  110  may also include a housing conduit  128  having an outlet  130  that releaseably connects with the inlet  265  of the rotor conduit  260 . The housing conduit  128  also includes an inlet  132  that is configured to be releaseably connected to the adapter  400 . 
     Referring specifically to  FIGS. 5A and 5B , the prophy angle  100  is assembled by inserting the rotor  200  into the second bore  114 . Upon the rotor  200  being positioned within the second bore  114  of the housing  110 , the lock  140  of the rotor  200  is nested within the lock receiver  120  of the housing  110 . As previously described, upon the lock  140  being nested within the lock receiver  120 , movement of the rotor  200  out of the second bore  114  is restrained. Also, upon insertion of the rotor  200  within the second bore  114 , the seal  280  between the rotor  200  and the inner surface  134  of the second bore  114  engages, which can further restrain movement of the rotor  200  out of the second bore  114 . By restraining movement of the rotor  200  out of the second bore  114 , a user can handle/manipulate the prophy angle  100  with reduced fear that the prophy angle  100  will become unintentionally disassembled. 
     Referring to  FIGS. 6A and 6B , the prophy angle  100  is shown being assembled with an adapter  400 , and  FIGS. 7A and 7B  illustrate the adaptor  400 . The adapter  400 , directly or indirectly, provides the rotational movement to the gearing system  230  of the rotor (see  FIG. 3 ), and any adapter  400  so capable is acceptable for use with the prophy angle  100 . The adaptor  400  includes a body  410  and a nose  412 , and the nose  412  may be removably attachable to the body  410 . Alternatively, the nose  412  may be integral with the body  410 . The adapter  400  includes a shaft  418  that is connected to a drive shaft  350  via a coupler  435 . The adaptor  400  may also include a supply conduit  430  (see  FIGS. 7A and 7B ) that is releaseably connectable to the inlet  132  of the housing conduit  128 . 
     An outer portion of the nose  412  may be shaped to mate with the prophy angle  10 . As is known in the art, many types of different types of prophy angles  100  exist that have different mating profiles, and the present adaptor  400  is not limited as to a particular shape of the nose  412  and as to a particular profile of prophy angle  100  with which the nose  412  can mate. However, in a current aspect of the adapter  400 , the nose  412  is a configured as a doriot-style adapter. Depending upon the type of prophy angle  100 , other type of connections devices include, but are not limited to, latch type, 3-ball chuck, attachment ring, push chuck, quick-connect collars, autochucks, E-type (i.e., ISO 3964), DIN 13940, ISO 1797, U-type, NSK type, and Midwest type. 
     The shaft  418  is rotated by the drive source  450 . As is known in the art, many different types of drive sources  450  exist and these different drive sources  450  have different configurations for coupling with a rotating member, such as the shaft  418 . In this regard, the present adapter  400  is not limited as to drive source  450  for the adapter  400 . For example, the drive source  450  may be connectable to the adapter  400 . Alternatively, the drive source  450  may be integrated with the adapter  400 . Also, examples of drive sources  450  include electrically-driven and pneumatically-driven motors. A further discussion on adapters  400  and connections between the shaft  418  and either the drive source  450  or between the shaft  418  and the drive shaft  350  (e.g., via the coupler  435 ) is found in related U.S. application Ser. No. 11/682,927 filed on May 7, 2007, incorporated herein by reference in its entirety. 
     As illustrated, the drive shaft  350  is a part of the adaptor  400 . However, the drive shaft  350  is not limited in this manner. For example, the drive shaft  350  may be a portion of the prophy angle  100 . In other aspects, the drive shaft  350  is removably attachable to a collet within the adaptor  400 . In so doing, the drive shaft  350  can be replaceable and/or cleaned. 
     The adaptor  400  may include a retention device  440  for maintaining a position of the prophy angle  100  on the adaptor  400  and any retention device  440  so capable is acceptable for use with the adaptor  400 . In certain aspects of the adaptor  400 , however, the retention device  440  is a locking pin  442  that is positionable within an opening  142  (see  FIGS. 5A-5B ) in the housing  110  of the prophy angle  100 . The locking pin  442  may be resiliently biased such that after the locking pin  442  is depressed, to either allow the prophy angle  100  to be positioned over the adapter  400  or to remove the prophy angle  100  from the adapter  400 , the locking pin  442  returns to an extended position. Upon the locking pin  442  being positioned within the opening  142 , the locking pin  442  prevents removal of the prophy angle  100  from the adaptor  400 . 
     Referring to specifically to  FIGS. 7A and 7B , a slidable sleeve  460  may be positioned over the drive shaft  350 . The slidable sleeve  460  moves from an extended position ( FIG. 7A ), which conceals the gear  352  of the drive shaft  350 , to an retracted position ( FIG. 7B ), which reveals the gear  352  of the drive shaft  350 . The slidable sleeve  460  is not limited in the manner in which the slidable sleeve  460  moves from the extended position to the retracted position and back again. However, in certain aspects, the slidable sleeve  460  engages a second shoulder  144  (see  FIGS. 5A-5B ) of the housing  110  as the slidable sleeve  460  is inserted into the housing  110 , which causes the slidable sleeve  460  to retract relative to the gear  352  of the drive shaft  350 . 
     The slidable sleeve  460  may also be connected to a resilient member  464 , such as a spring, which is compressed upon the slidable sleeve  460  is retracted. Upon the slidable sleeve  460  being removed from the housing  110 , the resilient member  464  biases the slidable sleeve  460  into the extended position. In this manner, upon the adapter  400  being completely removed from the housing  110 , even unintentionally, the gear  352  of the drive shaft  350  is not exposed. 
     Referring to  FIG. 8 , while attached to the adaptor  400 , the drive shaft  350  may be capable of being biased along a line substantially parallel to a longitudinal axis of the drive shaft  350 . Although any technique of enabling the drive shaft  350  to be biased is acceptable for use, similar to the slidable sleeve  460 , the drive shaft  350  may be connected to a second resilient member  468 , such as a spring. 
     Upon being inserted into the housing  110 , the drive shaft  350  engages the gearing system  230 , which biases the drive shaft  350  towards the adaptor  400 . The second resilient member  468 , in turn, pushes back against the drive shaft  350 , which ensures proper engagement of the gear  352  of the drive shaft with the gear system  230  of the rotor  200 . The ability of the drive shaft  350  to be biased along the line substantially parallel to the longitudinal axis of the drive shaft  350  gives the drive shaft  350  linear adjustability relative to the body  410  of the adaptor  400 , and this linear adjustability allows for variations in dimensions in the housing  110 , rotor  200 , drive shaft  350  and/or adaptor  400 .