Abstract:
A dental piezoelectric ultrasonic magnetic switching scaler handpiece is activated by magnetic means. The dental piezoelectric scaler handpiece includes a housing that contains a fixed magnet and a magnetically activated switch. An activation magnet longitudinally slides along the outside of the housing from a de-energized position to an energized position. The activation magnet is biased to the de-energized position by the fixed magnet. When a user moves the activation magnet away from the fixed magnet and toward the magnetically activated switch, the magnetic field of the activation magnet activates the magnetically activated switch and turns the dental scaler handpiece on.

Description:
TECHNICAL FIELD 
       [0001]    The present invention pertains generally to dental tools, and more particularly to a dental piezoelectric ultrasonic magnetic switching scaler handpiece that is activated by an activation magnet that externally surrounds the handpiece housing. The activation magnet is positionable to de-energized and energized positions along the longitudinal axis of the handpiece housing. 
       BACKGROUND OF THE INVENTION 
       [0002]    Power driven dental tools are well known in the art. One such tool is an ultrasonic dental scaler that has a tip that vibrates at a high frequency in order to remove both plaque and calculus from teeth. Two types are available for producing the ultrasonic vibration: magnetostrictive and piezoelectric. The magnetostrictive type creates a pulsing magnetic field that is applied to a metal stack that flexes to move the tip. The piezoelectric type uses pulsing voltage that is applied to ceramic crystal that moves the tip. 
         [0003]    Ultrasonic scalers are typically controlled through a foot control pedal system that activates or deactivates the handpiece unit. Current models of ultrasonic scalers require the use of the foot switch to control handpiece operation. When the user presses the foot pedal, the ultrasonic scaler is switched on. When the user removes his/her foot from the foot pedal, the ultrasonic scaler is turned off. 
         [0004]    Ultrasonic scalers with hand controlled rather than foot controlled switches have been developed. However, hand controlled switches are not popular due to the limitations of ergonomics, the inability to be sterilized (autoclaved), and controllability. For example, during normal operation of a typical ultrasonic scaling unit, it is necessary for the dentist or dental professional to have the ability to rotate the handpiece in a manner that allows full access to the oral cavity. A hand activated switch has the disadvantage that the switch is not accessible at all times as the handpiece is being manipulated during the course of a dental procedure. 
         [0005]    Foot controlled switches also have drawbacks in a clinical setting. A foot switch occupies space on the floor of a dental office that may be already occupied by several other related dental equipment units such as intraoral camera foot controls, laser foot controls, high speed and low speed handpiece foot controls, etc. A clinic floor with several competing devices for floor space is not an efficient approach to efficient clinic operation. Moreover, a foot switch occupies a fixed location and thus must be manually placed in an ergonomic position depending on the user&#39;s left foot or right foot preference. Also, the foot switch must be manually moved whenever the dental chair or the dentist changes location. Foot pedals can also interfere with general cleaning routines of the dental office floor, as the foot pedals must be moved off the office floor to effect cleaning. Further, foot switches require a cable connected from the dental tool such as a scaler to the foot switch. The cable can potentially tangle with the user during normal clinical procedures. The constant risk of wire damage to the foot switch cable can make foot switch pedals a solution that is not optimal. Even wireless foot switches have problems with interference that make them not a viable option in the marketplace. Issues such as floor placement and positioning are still not resolved with wireless foot pedals. 
         [0006]    Further, dental ultrasonic scaler handpieces are required to be autoclaved after every patient treatment procedure. Autoclaving involves high pressure and temperatures in order to achieve hygienic standards set by law. A hermetically sealed handpiece is thus required for the current design of handpiece units. 
         [0007]    In view of the above, it would be advantageous to have a dental scaling handpiece with the following properties: 
         [0008]    1. no need to use a hardwired or wireless foot switch; 
         [0009]    2. 360° accessibility of the handpiece switch at any angle or position of the handpiece; 
         [0010]    3. no interference with the ultrasonic properties of the handpiece from a cable that passes from outside through a hermetic seal into the inside; 
         [0011]    4. no interference from the water line located inside the handpiece unit; and, 
         [0012]    5. a handpiece that can be easily detached for autoclaving and cleaning. 
       BRIEF SUMMARY OF THE INVENTION 
       [0013]    The present invention is directed to a dental piezoelectric ultrasonic magnetic switching scaler handpiece that is magnetically controlled. it does not apply to the magnetostrictive type of handpiece because of the magnetic interference that is inherent in this type. The dental scaler handpiece is used by dentists and hygienists. The dental scaler handpiece utilizes a suspended movable activation magnet and a magnetically activated switch to turn the device on and off. The sliding activation magnet is biased to a de-energized position by a fixed magnet. When the activation magnet is physically moved to an energized position by the user, the magnetically activated switch is activated and the dental scaler handpiece is turned, on. There is no need for a foot control. The sliding external activation magnet does not require a spring return, and does not interfere with the vibration or water flow of the dental scaler handpiece. The sliding activation magnet is 360° accessible to the user regardless of the relative position of the user&#39;s hands or the angle of the handpiece, and applies equally well to both left handed and right handed users. 
         [0014]    In an embodiment, a dental scaler handpiece includes a housing that has a longitudinal axis. A fixed magnet is disposed within the housing. A magnetically activated switch is also disposed within the housing. The magnetically activated switch is spaced apart from the fixed magnet along the longitudinal axis so that it is not activated by the fixed magnet. An external activation magnet has an aperture that is shaped and dimensioned to receive the housing. The activation magnet is positionable along the longitudinal axis (1) to a de-energized position away from the magnetically activated switch, and (2) to an energized position toward the magnetically activated switch. The fixed magnet urges the activation magnet to the de-energizing position. When the activation magnet is manually moved to the energized position, the magnetically activated switch is activated. 
         [0015]    In accordance with another embodiment, the housing has a de-energized stop that limits movement of the activation magnet in the de-energized position, and the housing has an energized stop that limits movement of the activation magnet in the energized position. 
         [0016]    In accordance with another embodiment, the housing has a perimeter, and the activation magnet is accessible 360° around the perimeter of the housing. 
         [0017]    In accordance with another embodiment, the housing, the activation magnet, and the aperture are all circular. 
         [0018]    In accordance with another embodiment, the activation magnet slides along the housing without any physical connection therebetween. 
         [0019]    In accordance with another embodiment, the activation magnet is urged by the magnetic attraction of the fixed magnet to the de-energized position without the need for a spring member. 
         [0020]    In accordance with another embodiment, no wires connect the activation magnet and the magnetically activated switch. 
         [0021]    In accordance with another embodiment, the activation magnet moves along the longitudinal axis between about 2 millimeters (mm) and about 12 mm from the de-energized position to the energized position. 
         [0022]    In accordance with another embodiment, the activation magnet moves along the longitudinal axis about 3 mm. 
         [0023]    Other embodiments, in addition to the embodiments enumerated above, will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, that illustrate, by way of example, the principles of the dental scaler handpiece and method of use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  is a reduced exploded view of a dental piezoelectric ultrasonic magnetic switching scaler handpiece; 
           [0025]      FIG. 2  is a side elevation view of the dental scaler handpiece in a de-energized state; 
           [0026]      FIG. 3  is a cutaway side elevation view of the dental scaler handpiece in the de energized state; 
           [0027]      FIG. 4  is a side elevation view of the dental scaler handpiece in an energized state; 
           [0028]      FIG. 5  is a cutaway side elevation view of the dental scaler handpiece in the energized state; 
           [0029]      FIG. 6  is an enlarged cross sectional view along line  6 - 6  of  FIG. 2  showing the dental scaler handpiece in the de-energized state; 
           [0030]      FIG. 7  is an enlarged cross sectional view along line  7 - 7  of  FIG. 4  showing the dental scaler handpiece in the energized state; 
           [0031]      FIG. 8  is an enlarged cross sectional view along the line  8 - 8  of  FIG. 2 ; 
           [0032]      FIG. 9  is an enlarged perspective view of a fixed magnet, an activation magnet; and a magnetically activated switch in the de-energized position; 
           [0033]      FIG. 10  is an enlarged perspective view of the fixed magnet, the activation magnet, and the magnetically activated switch in the energized position; and, 
           [0034]      FIG. 11  is a perspective view of the dental scaler handpiece being held by a user. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0035]    Referring initially to  FIGS. 1-3 , there are illustrated reduced exploded, side elevation, and cutaway side elevation views, respectively, of a dental piezoelectric ultrasonic magnetic switching scaler handpiece in a de-energized state, the dental scaler handpiece generally designated as  20 . Dental scaler handpiece  20  includes a housing that has a longitudinal axis  25 . In the shown embodiment, the housing comprises a front housing  22 , a main housing  23 , and a rear housing  24 . An ultrasonic piezoelectric transducer  27  is located inside main housing  23 . Front housing  22  receives a dental tool  26  that is coupled to the ultrasonic piezoelectric transducer  27 . Rear housing  24  connects to an external power supply in a handpiece controller  28  (refer also to  FIGS. 6 and 7 ). A fixed magnet  30  is disposed within the main housing  23 . In the shown embodiment, fixed magnet  30  is surrounded by a fixed magnet housing  32 . Magnetically activated switch  34  is spaced apart from fixed magnet  30  along longitudinal axis  25 . In the shown embodiment, magnetically activated switch  34  is a reed switch such as Type No. SWR-1010 sold by Jin Zon Enterprise Co. Ltd. of Taipei, Taiwan, Republic of China. 
         [0036]    An activation magnet  36  has an aperture  38  that is shaped and dimensioned to receive the main housing  23  in the shown embodiment so that activation magnet  36  is positionable along longitudinal axis  25  (1) to a de-energized position away from magnetically activated switch  34 , and (2) to an energized position toward magnetically activated switch  34  (also refer to  FIGS. 6-10 ). in  FIGS. 1 and 2 , activation magnet  36  is shown in dashed lines, and is housed within an activation magnet housing  40 . Activation magnet housing  40  closely receives the main housing  23 , so that activation magnet housing  40  and activation magnet  36  may he manually slid along the main housing  23  from the de-energized position to the energized position. Fixed magnet  30  magnetically attracts activation magnet  36  to the de-energizing position in the direction of arrow  37  (refer also to  FIG. 6 ). Referring also to  FIG. 7 , when activation magnet  36  is manually moved to the energized position, magnetically activated switch  34  is activated. That is, when activation magnet  36  is moved toward magnetically activated switch  34  in the direction of arrow  39 , the magnetic field  50  of activation magnet  36  causes magnetically activated switch  34  to close, Also shown in  FIG. 1  are water and electrical female connector  29  and water and electrical male connector  31 . 
         [0037]      FIGS. 4 and 5  are side elevation and cutaway side elevation views, respectively, of dental scaler handpiece  20  in the energized state. Shown are front housing  22 , main housing  23 , rear housing  24 , fixed magnet  30 , magnetically activated switch  34 , activation magnet  36 , and activation magnet housing  40 . In the shown energized position, activation magnet housing  40  and activation magnet  36  have been manually pushed in the direction of arrow  39  to the energized position. In doing so, the user must overcome the magnetic attraction between fixed magnet  30  and activation magnet  36 . FIG,  6  is an enlarged cross sectional view along line  6 - 6  of  FIG. 2  showing the dental scaler handpiece in the de-energized state.  FIG. 7  is an enlarged cross sectional view along line  7 - 7  of  FIG. 4  showing the dental sealer handpiece  20  in the energized state. It is noted that in  FIG. 6 , activation magnet  36  is urged in direction  37  by the magnetic attraction of magnet  30  to the de-energized position without the need for a spring member. Front housing  22  has a de-energized stop  42  or shoulder that limits movement of activation magnet  36  and activation magnet housing  40  in the de-energized position. Similarly, main housing  23  has an energized stop  44  or shoulder that limits movement of activation magnet  36  and activation magnet housing  40  in the energized position. It is noted that activation magnet  36  and activation magnet housing  40  slide along the main housing  23  without any physical connection therebetween. It is also noted that no wires connect activation magnet  36  and magnetically activated switch  34 . In other words, the activation of magnetically activated switch  36  is effected only by magnetic means. 
         [0038]    Several parameters combine to make operation of dental scaler handpiece  20  possible. The relative physical placement of fixed magnet  30 , activation magnet  36 , and magnetically activated switch  34  must be considered. Also important are the distance of movement of activation magnet  36  from the de-energized position to the energized position, the magnetic strengths of fixed magnet  30  and activation magnet  36 , and the magnetic sensitivity of magnetically activated switch  34 . These parameters must be selected so that when activation magnet  36  is in the de-energized position ( FIG. 6 ), magnetically activated switch  34  will not energize, and when activation magnet  36  is moved to the energized position ( FIG. 7 ), the magnetic field  50  of activation magnet  36  will cause magnetically activated switch  34  to activate or close. In the embodiment shown in  FIG. 6 , activation magnet  36  moves along longitudinal axis  25  a distance D that is between about 2 mm and about 12 mm from the de-energized position to the energized position. That is, activation magnet housing  40  is free to move between de-energized shoulder  42  and energized shoulder  44  a distance D. In one embodiment, distance D is about 3 mm which provides enough proximity for effective triggering of the magnetically activated switch  34  while maintaining operator comfort and control. 
         [0039]    Magnetically activated switch  34  is electrically connected to handpiece controller  28  that is remotely located from dental scaler handpiece  20 . Handpiece controller  28  receives the switch closure from magnetically activated switch  34  and uses that closure to activate dental scaler handpiece  20 . In one mode of handpiece controller  28  operation, dental scaler handpiece  20  is activated when activation magnet  36  is in the energized position, and deactivated When activation magnet  36  is in the de-energized position. That is, activation magnet  36  must be held in the energized position in order for dental scaler handpiece  20  to be activated. In a second mode of handpiece controller  28  operation, dental scaler handpiece  20  is activated when activation magnet  36  is moved to the energized position and remains activated even if activation magnet  36  is released to return to the de-energized position. The dental scaler handpiece  20  is then de-activated by again moving activation magnet  36  to the energized position and releasing the activation magnet  36  which causes dental scaler handpiece  20  to de-energize. These modes of operation are programmed into handpiece controller  28  with firmware. 
         [0040]      FIG. 8  is an enlarged cross sectional view along the line  8 - 8  of  FIG. 2 , showing fixed magnet  30 , magnetically activated switch  34 , activation magnet  36 , aperture  38 , activation magnet housing  40 , and main housing  23 . It is noted that main housing  23  has a perimeter P and that activation magnet  36  is accessible  360 ° around perimeter P of the housing. It is further noted that main housing  23 , activation magnet  36 , activation magnet housing  40 , and aperture  38  are all circular. 
         [0041]      FIG. 9  is an enlarged perspective view of fixed magnet  30 , activation magnet  36 , and magnetically activated switch  34  in the de-energized position.  FIG. 10  is an enlarged perspective view of fixed magnet  30 , activation magnet  36 , and magnetically activated switch  34  in the energized position. It is noted that activation magnet  36  is generally disposed between fixed magnet  30  and magnetically activated switch  34 , and that in the shown embodiment, fixed magnet  30  and activation magnet  36  are ring shaped. Various types of magnets could be used for this purpose. Fixed magnet  30  is preferably a bonded neodymium, iron, boron permanent magnet having a 10.4 mm outer diameter, an 8.1 mm inner diameter, and a 3.55 mm length producing 2700 gauss. Activation magnet  36  is preferable of the same material having a 20 mm outer diameter, an 18 mm inner diameter, and a 6 mm length. producing 1400 gauss. 
         [0042]      FIG. 11  is an enlarged perspective view of dental scaler handpiece  20  being held by a user. The user can hold. dental scaler handpiece  20  like a pencil and use the thumb and index finger as preferred digits to move activation magnet housing  40  with activation. magnet  36  away from fixed magnet  30  and toward magnetically activated switch  34  (refer to  FIGS. 6  and 
         [0043]    In terms of use, a method for a user to use a dental scaler handpiece includes (refer to  FIGS. 1-11 ): 
         [0044]    (a) providing a dental piezoelectric scaler handpiece  20  including;
       a housing ( 22 ,  23 ,  24 ) having a longitudinal axis  25 ;   a fixed magnet  30  disposed within the housing;   a magnetically activated switch  34  disposed within the housing, magnetically activated switch  34  spaced apart from fixed magnet  30  along longitudinal axis  25 ;   an activation magnet  36  having an aperture  38  that is shaped and dimensioned to receive the housing so that activation magnet  36  is positionable along longitudinal axis  25  (1) to a de-energized position away from magnetically activated switch  34 , and (2) to an energized position toward magnetically activated switch  34 ; and,   fixed magnet  30  urging activation magnet  36  to the de-energizing position; and,       
 
         [0050]    (b) the user manually moving activation magnet  36  to the energized position, thereby causing magnetically activated switch  34  to activate. 
         [0051]    The method further including:
       in (a), the housing having a dc-energized stop  42  that limits movement of activation magnet  36  in the de-energized position, and the housing having an energized stop  44  that limits movement of activation magnet  36  in the energized position;   in (a), dc-energized stop  42  limiting movement of activation magnet  36  in the de-energized position; and,   in (b), energized stop  44  limiting movement of activation magnet  36  in the energized position.       
 
         [0055]    The method further including:
       in (a), the housing having a perimeter P; and,   in (b), activation magnet  36  being accessible 360° around perimeter P of the housing.       
 
         [0058]    The method further including:
       in (b), activation magnet  36  moving along longitudinal axis  25  between about 2 mm and about 12 mm from the de-energized position to the energized position.       
 
         [0060]    The method further including:
       in (a), activation magnet  36  sliding along the housing without any physical connection therebetween.       
 
         [0062]    The method further including:
       in (a), activation magnet  36  urged by magnetic attraction of fixed magnet  30  to the de-energized position without the need for a spring member.       
 
         [0064]    The method further including:
       in (a), no wires connecting activation magnet  36  and magnetically activated switch  34 .       
 
         [0066]    The user having a thumb and an index finger, the method further including:
       in (b), the user using the thumb and the index finger to move activation magnet  36  to the energized position.       
 
         [0068]    The embodiments of the dental piezoelectric ultrasonic magnetic switching scaler handpiece and method of use described herein are exemplary and numerous modifications, combinations, variations, and rearrangements can be readily envisioned to achieve an equivalent result, all of which are intended to be embraced within the scope of the appended claims. Further, nothing in the above provided discussions of the dental scaler handpiece and method should be construed as limiting the invention to a particular embodiment or combination of embodiments. The scope of the invention is defined by the appended claims.