Abstract:
All embodiments of the present invention relate to a toothbrush to prevent tooth abrasion and gum damage during use. A first embodiment of the invention includes a handle including an open cavity and a neck interconnected to the handle by a pivot. The neck is movable between an aligned first position and a second angled position relative to the handle. A leaf spring is bonded to the end of the neck at a first end, and the second end of the leaf spring engages the handle to provide biasing resistance. The leaf spring is configured such that if pressure to the neck exceeds a threshold limit, there is movement of the neck portion from the first position to a second position. The threshold limit is the pressure just below the pressure at the brush that may cause damage to the hard and soft tissue of the mouth. A protective sheath envelops the junction between the handle member and the neck member to prevent accumulation of unwanted material within the cavity of the handle. A second embodiment is equivalent in structure and components to the first embodiment except that it also includes a manual adjustment of the biasing force of the leaf spring to provide variable pressure and a motor for providing mechanical movement of the brush head. Third and fourth embodiments are equivalent in structure and components of the first and second embodiments, respectively, except that the leaf spring is bonded to the handle instead of the neck.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not Applicable  
       STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT  
       [0002]     Not Applicable  
       BACKGROUND OF THE INVENTION  
       [0003]     The present invention relates generally to a dental hygiene product namely a flexible neck toothbrush. More particularly, the present invention relates to a toothbrush having a handle portion pivotally connected to a neck portion having a dental brush. A leaf spring, interconnected between the handle portion and the neck portion, allows the neck portion to pivot when a threshold pressure is exceeded on the face of the dental brush. The threshold pressure is a pressure upon the dental brush just below that which causes tooth abrasion and gum damage.  
         [0004]     Dental disease is one of the most common human medical afflictions. In an attempt to combat dental disease, the brushing of teeth has become a common daily personal hygiene routine. Many people, however, brush their teeth in an improper fashion by applying excessive pressure to the brush which often damages teeth and gums. Excessive brushing force can cause recession and wear of the gums and other soft oral tissues as well as depletion of hard tissues such as tooth enamel, dentin and cementum. Accordingly, it is desirable to brush the teeth with a light pressure and proper bristle orientation to avoid damage to the hard and soft tissues of the mouth.  
         [0005]     Improper and overzealous oral hygiene often leads to severe tooth root abrasion and gum recession, resulting in a domino effect of sensitive teeth, avoidance of brushing, root caries, gum problems, pulpal trauma, root canal therapy, weakened teeth, tooth breakage and eventual tooth loss. Even standard home oral hygiene recommendations and equipment can lead and often do contribute to tooth and gum trauma because of a toothbrush user&#39;s inability to adapt use of the toothbrush to the arch curvature of the teeth and gums. Most of the focus in the history of tooth brushing has been directed to brush heads, bristles and toothpaste. Recently, the problem with the use of excessive force from the dental brush upon the teeth has been gaining notoriety. While there has been gaining emphasis on improved safety for brushing, prior safety improvements unsatisfactorily added to the cost of the daily dental hygiene, when it is recognized that the average consumer does not typically spend more than a few dollars on a daily use toothbrush. Thus, there is a great need in the art for improved, ergonomic, safer and cost effective brushing devices which allow controlled forces upon the dentition and supporting structures, as well as aiding in the proper orientation of the toothbrush and contacting bristles.  
         [0006]     An acceptable range of pressure used during brushing that is not deleterious to the teeth or gums is known. It is difficult, however, without complex pressure sensing equipment to monitor the pressure applied on the brush against the teeth to stay within the acceptable range of pressure. Prior art devices have attempted to address the use of excessive force and pressure at the brush head by providing pressure-sensing devices. In such devices, when a threshold pressure is reached, an electrical signal is produced and an alarm may sound, a light may flash, a vibration may occur, or the toothbrush neck may disengage. Such pressure sensors and biofeedback systems are typically complex and cannot be produced at a price point level that is acceptable to the average consumer. Another force sensing system such as embodied in U.S. Pat. No. 6,327,734 provides a non-electronic means of feedback by providing a snapping sound when excessive force is applied. The feedback simply provides notice that the safe pressure has been exceeded; however, such feedback may be simply ignored by the user.  
         [0007]     As is known in the art, other devices have attempted to address reduction of pressure upon the teeth by providing spring-like flexion within the toothbrush neck or base immediately adjacent the dental brush. In the known prior art, these devices typically create increasing torque as the neck, brush and head remain virtually the same distance apart from the handle, and there is only a slight flexion which mitigates the forces, but does not alleviate the problem of over-pressurization because the slight flexion exhibits Hookian spring characteristics. Hookian spring characteristics are defined by Hooke&#39;s law of springs which states that the spring force increases in direct proportion to the distance of displacement of the spring.  
         [0008]     Current flexible neck toothbrush designs contribute to tooth abrasion and gum recession because brush head pressure increases directly with handle pressure. Electric toothbrushes were designed to remove more plaque with less force than manual brushes; however, many people utilize automatic toothbrushes just as incorrectly as manual brushes by over pressurization which may have a more deleterious effect than a standard toothbrush because of the added motion or vibration of the brush head.  
         [0009]     Other prior art devices additionally include elastomer or other rubber like substances sandwiched between links in the brush neck. Many such prior art devices that utilize very soft elastomer aid in reducing brushing trauma but such devices deform too quickly, and take a significant amount of time (minutes to hours) to reset back to normal. Such brushes can be frustrating to the user because during the proper two-minute brushing interval, such brushes can quickly become deformed out of the ideal shape for proper usage. Other types of toothbrush components employing stiffer elastomers result in increasing torque and increasing force consistent with Hookian principles.  
         [0010]     Other prior art devices employ biofeedback, which users often ignore, and such devices involve very complicated sliders, pivots and springs to aid in maintaining consistent force. Such devices, however, appear to be valid only over a very small range of motion and further appear to be too complex for simple daily use. Other prior art devices snap out of place at a predetermined threshold force. It appears that such prior art devices might be clumsy and frustrating to use and users may encounter problems if the devices snap back into place.  
         [0011]     In each of the prior toothbrushes, the mechanical attempts to mitigate the excessive force of the brush on the teeth fail for the following reasons, among others: 1). The Hookian spring action of “flexible” toothbrush necks causes increasing brush head force with increasing handle force; 2). Inadequate range of motion wherein the neck flexibly occurs over so small a range of motion as to be easily overruled by excessive handle force and improper brushing motions; 3). Excessive flexibility and poor resetting characteristics which allow the brushes to quickly and progressively bend out of shape while taking minutes or hours for resetting; and/or 4). Poor ergonomics which leads to instability, poor gripping, improper brushing, and tissue damage. Thus, there is a great need in the art for a toothbrush which will automatically maintain a physiologically healthy constant brush head force despite widely varying brush handle forces, positions and motions. Further, there is a great need in the art for a toothbrush that can automatically accommodate variations in dental arch structure and curve alignment as well as variations in manual dexterity without the need for complex sensors and biofeedback mechanisms. There is also a great need in the art for a toothbrush which can provide a constant light pressure on the teeth for people with sensitive gums, gum surgery, oral wounds or other oral maladies. There is also a great need in the art for a user-adjustable variable pressure setting that allows one brush to be multifunctional from ultra soft, to soft, to medium, over an infinite range, or with discrete digital increments between to endpoint settings such that one brush can be used for multiple purposes with a single brush accommodating all types of users. Also needed is a brush that is ergonomic and easy to manipulate and orient properly against dental structures. Consumers would thus benefit from the simplicity of a single brush for use over a wide range of pressures to avoid confusion in the shopping experience and to further avoid the clutter and expense of multiple brushes.  
       BRIEF SUMMARY OF THE INVENTION  
       [0012]     The present invention relates to an ergonomic toothbrush having a flexible neck and adaptively designed handle to prevent tooth abrasion and gum damage during use. A first embodiment of the present invention includes a handle member including an open cavity defining an interior surface. A neck member is interconnected to the handle member via a pivot, wherein the neck member is movable between a first position wherein the handle member and neck member are substantially aligned, and a second position wherein the neck member is angularly offset relative to the handle member. The angle offset can range anywhere from one to forty-five degrees. A leaf spring is bonded at a first end to the end of the neck member, and the second end of the leaf spring engages the interior surface of the handle member to provide biasing resistance. Thus, movement of the neck relative to the handle member about the pivot causes the leaf spring to engage the interior surface of the handle member providing biasing resistance against further pivotal movement. The leaf spring is operative to normally bias the neck member to the first position in substantial alignment with the handle member and is configured such that the application of pressure to the neck portion beyond a prescribed threshold limit causes movement of the neck portion from the first position toward a second position. The neck member is therefore movable between an aligned first position and a second offset position relative to the handle member when a threshold pressure is exceeded. Thus, when the threshold pressure is reached, the biasing member deflects allowing the neck member to move toward a position that is safer or unusable for the user. The threshold pressure is the pressure just below the pressure upon the brush that may cause damage to the soft and hard tissues of the mouth. A protective sheath envelops the junction between the handle member and the neck member to prevent accumulation of unwanted material within the cavity of the handle.  
         [0013]     A second embodiment of the present invention includes all of the components of the first embodiment, but additionally includes a power source and motor to provide vibrational movement to the brush head. Further, the second embodiment includes a manual adjustment that engages the leaf spring at various points along the leaf spring body or incrementally deflects the leaf spring body to provide a variable threshold pressure. Accordingly, a user can adjust the threshold pressure at which the leaf spring gives and moves the neck toward a second position. The neck member is movable between an aligned first position and a second offset position relative to the handle member when a threshold pressure is exceeded. It is additionally contemplated that the handle cavity may be completely or partially filled with a rheostatic fluid or sponge that can affect the degree of flexion of the leaf spring when an electromagnetic force causes the fluid to stiffen by varying degrees.  
         [0014]     A third embodiment of the present invention includes all of the components of the first embodiment, but differs insofar as the leaf spring is mounted to the toothbrush handle, and the leaf spring operatively engages the end of the toothbrush neck to provide a biasing force. As with the first embodiment, the leaf spring resistance is such that once a threshold pressure is reached the leaf spring deflects and allows movement of the neck toward a second non-aligned position. The neck member is movable between an aligned first position and a second offset position relative to the handle member when a threshold pressure is exceeded.  
         [0015]     A fourth embodiment of the present invention includes all of the components of the third embodiment of the present invention, except that the fourth embodiment includes a power source and a motor for providing vibrational movement to the brush head. Furthermore, the fourth embodiment includes a manual adjustment for engaging the leaf spring at various points along the leaf spring body or incrementally deflects the leaf spring body to aid a user in providing variable threshold pressure. It is additionally contemplated that the handle cavity may be completely or partially filled with a rheostatic fluid or sponge that can affect the degree of flexion of the leaf spring when an electromagnetic force causes the fluid to stiffen by varying degrees. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     Features of the present invention will become more apparent upon reference to the drawings wherein:  
         [0017]      FIG. 1  is an external view of a first embodiment of the present invention showing movement of the toothbrush neck;  
         [0018]      FIG. 2  is an exploded view of a first embodiment of the present invention showing the components of the invention;  
         [0019]      FIG. 3  is an exploded view of a first embodiment of the present showing the attachment of the neck portion and the biasing member;  
         [0020]      FIG. 4  is a cross sectional view of the a first embodiment of the present invention showing the internal components of the invention and movement of the toothbrush neck shown in phantom;  
         [0021]      FIG. 5  is a cut away view of a first embodiment of the present invention showing the pivot connection between the handle and neck member of the toothbrush.  
         [0022]      FIGS. 6   a - 6   e  is a graphical representation of the movement of the neck member in combination with the biasing member at various points of flexion for the first and second embodiments of the present invention;  
         [0023]      FIG. 7  is a chart plotting a comparison of flexing angles in relation to pressure of the present invention verses a convention toothbrush;  
         [0024]      FIG. 8  is an external view of a second embodiment of the present invention showing internal power components shown in phantom, and a variable pressure adjustment mechanism;  
         [0025]      FIG. 9  is an exploded view of a second embodiment of the present invention showing the components of the invention;  
         [0026]      FIG. 10  is an exploded view of a second embodiment of the present showing the attachment of the neck portion and the biasing member;  
         [0027]      FIG. 11  is a cross sectional view of the a second embodiment of the present invention showing the internal components of the invention and movement of the toothbrush neck shown in phantom;  
         [0028]      FIG. 12  is a cut away view of a second embodiment of the present invention showing the pivot connection between the handle and neck member of the toothbrush;  
         [0029]      FIG. 13  is an external view of a third embodiment of the present invention showing movement of the toothbrush neck;  
         [0030]      FIG. 14  is an exploded view of a third embodiment of the present invention showing the components of the invention;  
         [0031]      FIG. 15  is an exploded view of a third embodiment of the present showing the attachment of the handle portion and the biasing member;  
         [0032]      FIG. 16  is a cross sectional view of the a third embodiment of the present invention showing the internal components of the invention and movement of the toothbrush neck shown in phantom;  
         [0033]      FIGS. 17   a - 17   e  is a graphical representation of the movement of the neck member in combination with the biasing member at various points of flexion for the third and fourth embodiments of the present invention;  
         [0034]      FIG. 18  is an external view of a fourth embodiment of the present invention showing internal power components shown in phantom, and a variable pressure adjustment mechanism;  
         [0035]      FIG. 19  is an exploded view of a fourth embodiment of the present invention showing the components of the invention;  
         [0036]      FIG. 20  is an exploded view of a fourth embodiment of the present showing the attachment of the handle portion and the biasing member; and  
         [0037]      FIG. 21  is a cross sectional view of the fourth embodiment of the present invention showing the internal components of the invention and movement of the toothbrush neck shown in phantom.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0038]     The detailed description as set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of the present invention, and does not represent the only embodiment of the present invention. It is understood that various modifications to the invention may be comprised by different embodiments and are also encompassed within the spirit and scope of the present invention.  
         [0039]     Referring to the drawings, wherein like reference numerals refer to the same or similar elements among  FIGS. 1 through 5 , there is shown a toothbrush  10  in accordance with a first embodiment of the present invention. Toothbrush  10  contains a neck member  12  and a handle member  14 . Toothbrush  10  additionally includes a head section  16  having brush bristles  18 . The head  16  is connected to the neck member  12  by a frictional fit as best illustrated in  FIG. 4  wherein the neck member  12  is inserted within an aperture (not shown) of the head member  16 . The head member  16  may be secured by an inert epoxy or otherwise fixed to the neck member  12 . It is contemplated in this embodiment, as well as all embodiments as set forth herein, that the connection between the neck member  12  and the head member  16  may additionally include an elastomer coupler. The elastomer coupler may be provided as a movable joint that provides additional flexibility in the head member  16  relative to the neck member  12 .  
         [0040]     The handle member  14 , the neck member  12  and the head member  16  are preferably molded of a relatively rigid plastic such as polypropylene or polyethylene terephthalate or other suitable polyester. Conventional uses of polypropylene and polyester molded plastics used in toothbrush configurations may be found in U.S. Pat. No. 6,502,272, the substance of which is incorporated herein by reference. In addition, any elastomer couplers utilized in any of the embodiments of the present invention can be molded of thermal plastic elastomer or combination thereof, including a thermal plastic vulcanite (TPV). Brand names of such TPV material is Santoprene (brand), Vyram (brand) as commercially available from Advanced Elastomer Systems LP, Akron, Ohio. Another preferred elastomer is Dynaflex G6713 (brand) a thermal plastic elastomer marketed by GLS Corp. of Cary, Ill. Such elastomers are described in more detail in U.S. Pat. No. 6,502,272, the substance of which is incorporated herein by reference.  
         [0041]     The neck member  12  is pivotally connected to the handle member by a pivot mechanism comprising the combination of a male component in the form of a pivot bar  20  formed on the proximal end of the neck member  12  and a pivot slot  22  formed in the distal end of the handle member  14 . The pivot mechanism  20 ,  22  forms the junction between the neck member  12  and handle member  14 . Pivot bar  20  extends through the neck member  12  and interfaces with the distal end of the handle member  14  as pivot slot  22 . The pivot bar  20  is received within the pivot slot  22  to allow pivotal movement of the neck member  12  relative the handle member  14 . A cavity  26  is formed in the handle member  14 .  
         [0042]     A leaf spring  24  is embedded into the proximal end of the neck member  12 . The leaf spring  24  is inserted into the handle cavity  26  when the pivot bar  20  engages the pivot slot  22 . The leaf spring  24  engages the interior surface of the cavity  26  to provide a biasing force when pressure is applied to the toothbrush head  16 . Protective sheath  25  envelops the junction between the distal end of the handle member  14  and the proximal end of the neck member  12 . Leaf spring  24  for purposes of this first embodiment, as well as each embodiment described herein is comprised of a high-grade plastic having appropriate spring-like characteristics. In this regard, it may be formed in each of the embodiments from a fiber-reinforced plastic, wherein such fibers may be made of glass or carbon fibers. The leaf spring  24  can be separately injected molded and then inserted or injection mold integrated into the neck member  12 . It is additionally contemplated by all embodiments of the present invention that the leaf spring  24  while shown as being flat can have a polygonal, round, oval, U, T, or I cross-section. Also, it is contemplated that the leaf spring  24  may be formed as a metallic leaf spring that is either injected molded into the plastic of the neck member  12  or otherwise embedded within a preformed slot  28  in the proximal end of the neck member  12 . In this regard, the leaf spring  24  is configured with materials and dimensions such that it holds the neck member  12  and handle member  14  in substantial alignment when no pressure is applied or when a pressure is applied that is less than the threshold pressure. When a force is applied to the head of the brush  16  that exceeds a threshold pressure, the leaf spring  24  deflects and allows movement of the neck member  12  toward an offset position. The neck member  12  is movable between an aligned first position and a second offset position relative to the handle member  14  when a threshold pressure is exceeded. The threshold pressure is the pressure upon the brush head  16  just before the pressure level that may cause damage to the hard and soft tissues of the mouth. Once deflected, the neck cannot impart increasing pressure upon the dental structures, and with ever-increasing handle force, the angle of displacement may become great enough to discourage the user from continuing to brush with the toothbrush  10  in the furthest deflected state. Once the pressure is released to zero or reduced to below the threshold level the leaf spring  24  immediately begins resetting toward the original aligned position. The angle of displacement only becomes discouraging to the user if far too much force is applied. Once threshold pressure is exceeded, the neck moves unimpeded out of alignment. This unimpeded movement allows users with limited time, poor dexterity, or low cognition to brush improperly without causing damage to the oral tissues. The unimpeded movement once the threshold pressure is exceeded also allows the neck to quickly and easily displace and reset around obstacles, irregularities and curvatures of the mouth, thus avoiding unwanted oral trauma.  
         [0043]     Referring particularly to  FIG. 4 , there is shown a cross-sectional view of the first embodiment of the present invention. The leaf spring  24  engages the interior surface  30  of the cavity  26  in the handle member  14 . The toothbrush is shown with the neck in a first position, and toothbrush  10  will remain in this position so long as a safe threshold pressure is applied at the toothbrush head  16 . When the safe threshold pressure is exceeded, the leaf spring deflects as shown in the phantom leaf spring  32  and the phantom neck member  34  toward a second offset position at the exceeded threshold pressure. In the embodiments of the present invention, the neck  12  does not immediately move or snap out to a second position after a threshold pressure is exceeded. During use, after the threshold pressure is reached, no increasing pressure can be applied to the oral tissue, and any attempt to increase pressure by the user results in unimpeded movement of the neck  12  as it rotates about the pivot mechanism  20 ,  22  toward the maximum rotation point. Because of the elastic nature of the leaf spring  24  and the arrangement of the leaf spring  24  in cooperation with the neck  12  and handle  14  members, the brush  10  always instantaneously attempts to reset toward the aligned position as soon as the pressure is reduced. Unlike brushes with elastomeric flexibility features, the toothbrush  10  of the present invention does not suffer from temporary extended deformation before resetting. Thus, the brush  10  adapts to the curvature of the dental arch even during normal brushing, and immediately resets toward a normal position.  
         [0044]     Referring particularly to  FIGS. 6   a  through  6   e , there is shown a graphical representation of the toothbrush  10  device of the first embodiment of the present invention.  FIG. 6   a  shows the neck member  12  in combination with the leaf spring  24  in a normal position when no pressure is being applied.  FIG. 6   b  represents the toothbrush when a safe pressure is being applied, and the neck  12  and leaf spring  24  remain in a first position. When the safe pressure is exceeded, the leaf spring  24  deflects allowing movement of the neck member  12  as shown in  FIGS. 6   c - 6   e  in varying degrees.  FIGS. 6   d  and  6   e  represent the toothbrush wherein the leaf spring  24  has deflected to its maximum amount limited by the pivot bar  20  and pivot slot  22  as shown more particularly in  FIG. 5 .  
         [0045]     Referring particularly to  FIG. 7 , a chart is shown representing a comparison of flexing angles versus pressures on the brush head of the various embodiments of the present invention. The present invention is shown in comparison with a standard flexible neck toothbrush. As is evident from the graph, pressure on the standard flexible neck brush continues to increase well beyond the safe threshold level. The device of the present invention maintains the pressure level at the brush well below the safe threshold level.  
         [0046]     Referring to the drawings, namely  FIGS. 8 through 11 , wherein like reference numerals refer to the same or similar elements among the figures, there is shown a toothbrush  36  in accordance with a second embodiment of the present invention. The second embodiment of the present invention is distinguished from the first embodiment of the present invention primarily by the inclusion of power components that allow the toothbrush to operate as an electric toothbrush. In addition, a manual pressure adjustment is provided to provide a variable threshold pressure. Toothbrush  36  contains a neck member  38  and a handle member  40 . Toothbrush  36  additionally includes a head section  42  having brush bristles  44 . The head  42  is connected to the neck member  38  by a frictional fit as best illustrated in  FIG. 11  wherein the neck member  38  is inserted within an aperture (not shown) of the head member  42 . The head member  42  may be secured by an inert epoxy or otherwise fixed to the neck member  38 . It is contemplated in this embodiment, as well as all embodiments as set forth herein, that the connection between the neck member  38  and the head member  42  may additionally include an elastomer coupler. The elastomer coupler may be provided as a movable joint that provides additional flexibility in the head member  42  relative to the neck member  38 . The handle member  40 , the neck member  38  and the head member  42  are preferably molded of a relatively rigid plastic such as polypropylene or polyethylene terephthalate or other suitable polyester.  
         [0047]     The neck member  38  is pivotally connected to the handle member by a pivot mechanism comprising the combination of a male component in the form of a pivot bar  46  formed on the proximal end of the neck member  38  and a pivot slot  48  formed in the distal end of the handle member  40 . The pivot mechanism  46 ,  48  forms the junction between the neck member  38  and handle member  40 . Pivot bar  46  extends through the neck member  38  and interfaces with the distal end of the handle member  40  as pivot slot  48 . The pivot bar  46  is received within the pivot slot  48  to allow pivotal movement of the neck member  38  relative the handle member  40 . A cavity  52  is formed in the handle member  40 .  
         [0048]     A leaf spring  50  is embedded into the proximal end of the neck member  38 . The leaf spring  50  is inserted into the handle cavity  54  when the pivot bar  46  engages the pivot slot  48 . The leaf spring  50  engages the interior surface of the cavity  52  to provide a biasing force when pressure is applied to the toothbrush head  42 . Protective sheath  51  envelops the junction between the distal end of the handle member  40  and the proximal end of the neck member  38 . Leaf spring  50  for purposes of this second embodiment, as well as each embodiment described herein is comprised of a high-grade plastic having appropriate spring-like characteristics. In this regard, it may be formed in each of the embodiments from a fiber-reinforced plastic, wherein such fibers may be made of glass or carbon fibers. The leaf spring  50  can be separately injected molded and then inserted or injection mold integrated into the neck member  38 . It is additionally contemplated by all embodiments of the present invention that the leaf spring  50  while shown as being flat can have a polygonal, round, oval, U, T, or I cross-section. Also, it is contemplated that the leaf spring  50  may be formed as a metallic leaf spring that is either injected molded into the plastic of the neck member  38  or otherwise embedded within a preformed slot  54  in the proximal end of the neck member  38 . In this regard, the leaf spring  50  is configured with materials and dimensions such that it holds the neck member  38  and handle member  40  in substantial alignment when no pressure is applied or when a pressure is applied that is less than the threshold pressure. When a force is applied to the head of the brush  42  that exceeds a selected threshold pressure, the leaf spring  50  deflects and allows movement of the neck member  38  toward an offset position. The neck member  38  is movable between an aligned first position and a second offset position relative to the handle member  40  when a threshold pressure is exceeded. The threshold pressure in this embodiment is a variable that can be set anywhere from just barely above the force required to overcome spring tension and friction to a pressure upon the brush head  42  just before the pressure level that may cause damage to the hard and soft tissues of the mouth. Once deflected, the neck cannot impart increasing pressure upon the dental structures, and with ever-increasing handle force, the angle of displacement can become great enough to discourage the user from continuing to brush with the toothbrush  36  in the furthest deflected state. Once the pressure is released to zero or reduced to below the threshold level the leaf spring  50  immediately attempts resetting to the original aligned position. The angle of displacement only becomes discouraging to the user if far too much force is applied. Once threshold pressure is exceeded, the neck moves unimpeded out of alignment. This unimpeded movement allows users with limited time, poor dexterity, or low cognition to brush improperly without causing damage to the oral tissues. The unimpeded movement once the threshold pressure is exceeded also allows the neck to quickly and easily displace and reset around obstacles, irregularities and curvatures of the mouth, thus avoiding unwanted oral trauma.  
         [0049]     Batteries  68  located in the handle member  40  cavity  52  provide power to a motor  67 . The motor  67  provides vibrational movement to the head  42  through a flexible connector  70 . Buttons  72  provide manual control of the motor  67 .  
         [0050]     The manual adjustment of the threshold pressure of the leaf spring  50  is effected through a manual adjustment knob  62 . Rotational movement of the knob  62  translates to rotational movement of a shaft  64  deep within the device  36  structure. A helical structure  66  affixed to the end of the shaft  64  engages the leaf spring  50  to provide variable resistance against the leaf spring  50 , thus modifying the pressure level of the leaf spring  50  deflection. Alternatively, the helical structure  66  could be a coil, polygonal structure or cam structure configured to lift and lower the deflection point. Accordingly, a user can “dial” in a desired pressure for use with the brush  36 . Currently, after mouth surgery or other injury to the mouth, a doctor may recommend use of an ultra soft bristle brush with low brushing pressure, and to graduate to stiffer bristles and increased brushing pressure as the mouth heals. The adjustable nature of the toothbrush  36  of the present invention allows a person to use a single brush to accomplish varying degrees of brushing pressure.  
         [0051]     Referring particularly to  FIG. 11 , there is shown a cross-sectional view of the second embodiment of the present invention. The leaf spring  50  engages the interior surface  56  of the cavity  52  in the handle member  40 . The toothbrush is shown with the neck in a first position, and toothbrush  36  will remain in this position so long as a selected threshold pressure is applied at the toothbrush head  42 . When the selected threshold pressure is exceeded, the leaf spring deflects as shown in the phantom leaf spring  58  and the phantom neck member  60  toward a second offset position at the exceeded threshold pressure. In the embodiments of the present invention the neck  38  does not immediately move or snap out to a second position after a threshold pressure is exceeded; in operation, after the threshold pressure is reached, no increasing pressure can be applied to the oral tissues, and any attempt to increase pressure by the user results in unimpeded movement of the neck  38  as it rotates about the pivot mechanism  46 ,  48  toward the maximum rotation point. Because of the elastic nature of the leaf spring  50  and the arrangement of the leaf spring  50  in cooperation with the neck  38  and handle  40  members, the brush  36  instantaneously attempts to reset toward the aligned position as soon as the pressure is reduced. Unlike brushes with elastomeric flexibility features, the toothbrush  10  of the present invention does not suffer from temporary extended deformation before resetting. Thus the brush  10  adapts to the curvature of the dental arch even during normal brushing, and always immediately attempts resetting toward a normal position.  
         [0052]     Referring to  FIGS. 13 through 16 , wherein like reference numerals refer to the same or similar elements among the drawings, there is shown a toothbrush  74  in accordance with a third embodiment of the present invention. The third embodiment of the present invention is distinguished from the first embodiment of the present invention primarily by the affixation of the leaf spring  88  to the handle member  78  rather than the neck member  76 . Toothbrush  74  contains a neck member  76  and a handle member  78 . Toothbrush  74  additionally includes a head section  80  having brush bristles  82 . The head  80  is connected to the neck member  76  by a frictional fit as best illustrated in  FIG. 16  wherein the neck member  76  is inserted within an aperture (not shown) of the head member  80 . The head member  80  may be secured by an inert epoxy or otherwise fixed to the neck member  76 . It is contemplated in this embodiment, as well as all embodiments as set forth herein, that the connection between the neck member  76  and the head member  80  may additionally include an elastomer coupler. The elastomer coupler may be provided as a movable joint that provides additional flexibility in the head member  80  relative to the neck member  76 . The handle member  78 , the neck member  76  and the head member  80  are preferably molded of a relatively rigid plastic such as polypropylene or polyethylene terephthalate or other suitable polyester.  
         [0053]     The neck member  76  is pivotally connected to the handle member by a pivot mechanism comprising the combination of a male component in the form of a pivot bar  84  formed on the proximal end of the neck member  76  and a pivot slot  86  formed in the distal end of the handle member  78 . The pivot mechanism  84 ,  86  forms the junction between the neck member  76  and handle member  78 . Pivot bar  84  extends through the neck member  76  and interfaces with the distal end of the handle member  78  as pivot slot  86 . The pivot bar  84  is received within the pivot slot  86  to allow pivotal movement of the neck member  76  relative the handle member  78 . A cavity  26  is formed in the handle member  78 .  
         [0054]     A leaf spring  88  is embedded into the distal end of the handle member  78 . The leaf spring  88  engages the proximal end of the neck member  76  when the pivot bar  84  engages the pivot slot  86 . The leaf spring  88  engages the surface the proximal end of he neck member  76  to provide a biasing force when pressure is applied to the toothbrush head  80 . Protective sheath  89  envelops the junction between the distal end of the handle member  78  and the proximal end of the neck member  76 . Leaf spring  88  for purposes of this third embodiment, as well as each embodiment described herein is comprised of a high-grade plastic having appropriate spring-like characteristics. In this regard, it may be formed in each of the embodiments from a fiber-reinforced plastic, wherein such fibers may be made of glass or carbon fibers. The leaf spring  88  can be separately injected molded and then inserted or injection mold integrated into the handle member  78 . It is additionally contemplated by all embodiments of the present invention that the leaf spring  88  while shown as being flat can have a polygonal, round, oval, U, T, or I cross-section. Also, it is contemplated that the leaf spring  88  may be formed as a metallic leaf spring which is either injected molded into the plastic of the handle member  78  or otherwise embedded within a preformed slot  92  formed in the cavity  90  of the handle member  78  as best shown in  FIG. 16 . In this regard, the leaf springs  88  is configured with materials and dimension such that it holds the neck member  76  and handle member  78  in substantial alignment when no pressure is applied or when a pressure is applied that is less than a threshold pressure. When a force is applied to the head of the brush  80  that exceeds the threshold pressure, the leaf spring  88  deflects and allows movement of the neck member  76  toward an offset position. The neck member  76  is movable between an aligned first position and a second offset position relative to the handle member  78  when a threshold pressure is exceeded. The threshold pressure is the pressure upon the brush head  80  just before the pressure level that may cause damage to the hard and soft tissue of the mouth. Once deflected, the neck cannot impart increasing pressure upon the dental structures, and with ever-increasing handle force, the angle of displacement may become great enough to discourage the user from continuing to brush with the toothbrush  74  in the furthest deflected state. Once the pressure is released to zero or reduced to below the threshold level the leaf spring  88  attempts resetting toward the original aligned position. The angle of displacement only becomes discouraging to the user if far too much force is applied. Once threshold pressure is exceeded, the neck moves unimpeded out of alignment. This unimpeded movement allows users with limited time, poor dexterity, or low cognition to brush improperly without causing damage to the oral tissues. The unimpeded movement once the threshold pressure is exceeded also allows the neck to quickly and easily displace and reset around obstacles, irregularities and curvatures of the mouth, thus avoiding unwanted oral trauma.  
         [0055]     Referring particularly to  FIG. 16 , there is shown a cross-sectional view of the third embodiment of the present invention. The leaf spring  88  engages the proximal end of the neck member  76 . The neck member  76  has a curved flange  77  for engaging the leaf spring  88 . The toothbrush is shown with the neck in a first position, and toothbrush  74  will remain in this position so long as a safe pressure is applied at the toothbrush head  80 . When the safe pressure is exceeded, the leaf spring deflects as shown in the phantom leaf spring  96  and the phantom neck member  98  toward a second offset position at the exceeded threshold pressure. In the embodiments of the present invention the neck  76  does not immediately move or snap out to a second position after a threshold pressure is exceeded; in operation, after the threshold pressure is reached, no increasing pressure can be applied to the oral tissue, and any attempt to increase pressure by the user results in unimpeded movement of the neck  76  as it rotates about the pivot mechanism  84 ,  86  toward the maximum rotation point. Because of the elastic nature of the leaf spring  88  and the arrangement of the leaf spring  88  in cooperation with the neck  76  and handle  78  members, the brush  74  always instantaneously attempts resetting toward the aligned position as soon as the pressure is reduced. Unlike brushes with elastomeric flexibility features, the toothbrush  74  of the present invention does not suffer from temporary extended deformation before resetting. Thus, the brush  74  adapts to the curvature of the dental arch even during normal brushing, and immediately resets toward a normal position.  
         [0056]     Referring particularly to  FIGS. 17   a  through  17   e , there is shown a graphical representation of the toothbrush  74  device of the third embodiment of the present invention.  FIG. 17   a  shows the neck member  76  in combination with the leaf spring  88  in a normal position when no pressure is being applied.  FIG. 17   b  represents the toothbrush when a safe pressure is being applied, and the neck  76  and leaf spring  88  remain in a first position. When the safe pressure is exceeded, the leaf spring  88  deflects allowing movement of the neck member  76  as shown in  FIGS. 17   c - 17   e  in varying degrees.  FIGS. 17   d  and  17   e  represent the toothbrush wherein the leaf spring  88  has deflected to its maximum amount limited by the pivot bar  84  and pivot slot  86 .  
         [0057]     Referring to the drawings, namely  FIGS. 18 through 21 , wherein like reference numerals refer to the same or similar elements among the figures, there is shown a toothbrush  100  in accordance with a fourth embodiment of the present invention. The fourth embodiment of the present invention is distinguished from the third embodiment of the present invention primarily by the inclusion of power components that allow the toothbrush to operate as an electric toothbrush. In addition, a manual pressure adjustment is provided to provide a variable threshold pressure. Toothbrush  100  contains a neck member  102  and a handle member  104 . Toothbrush  100  additionally includes a head section  106  having brush bristles  108 . The head  106  is connected to the neck member  102  by a frictional fit as best illustrated in  FIG. 21  wherein the neck member  102  is inserted within an aperture (not shown) of the head member  106 . The head member  106  may be secured by an inert epoxy or otherwise fixed to the neck member  102 . It is contemplated in this embodiment, as well as all embodiments as set forth herein, that the connection between the neck member  102  and the head member  106  may additionally include an elastomer coupler. The elastomer coupler may be provided as a movable joint that provides additional flexibility in the head member  106  relative to the neck member  102 . The handle member  104 , the neck member  102  and the head member  106  are preferably molded of a relatively rigid plastic such as polypropylene or polyethylene terephthalate or other suitable polyester.  
         [0058]     The neck member  102  is pivotally connected to the handle member by a pivot mechanism comprising the combination of a male component in the form of a pivot bar  110  formed on the proximal end of the neck member  102  and a pivot slot  112  formed in the distal end of the handle member  104 . The pivot mechanism  110 , 112  forms the junction between the neck member  102  and handle member  104 . Pivot bar  110  extends through the neck member  102  and interfaces with the distal end of the handle member  104  as pivot slot  112 . The pivot bar  110  is received within the pivot slot  112  to allow pivotal movement of the neck member  102  relative the handle member  104 . A cavity  116  is formed in the handle member  104 .  
         [0059]     A leaf spring  114  is embedded into the distal end of the handle member  104 . The leaf spring  114  engages the proximal end of the neck member  102  when the pivot bar  110  engages the pivot slot  112 . The leaf spring  114  engages the surface the proximal end of he neck member  102  to provide a biasing force when pressure is applied to the toothbrush head  106 . Protective sheath  115  envelops the junction between the distal end of the handle member  104  and the proximal end of the neck member  102 . Leaf spring  114  for purposes of this fourth embodiment, as well as each embodiment described herein is comprised of a high-grade plastic having appropriate spring-like characteristics. In this regard, it may be formed in each of the embodiments from a fiber-reinforced plastic, wherein such fibers may be made of glass or carbon fibers. The leaf spring  114  can be separately injected molded and then inserted or injection mold integrated into the handle member  104 . It is additionally contemplated by all embodiments of the present invention that the leaf spring  114  while shown as being flat can have a polygonal, round, oval, U, T, or I cross-section. Also, it is contemplated that the leaf spring  114  may be formed as a metallic leaf spring that is either injected molded into the plastic of the handle member  104  or otherwise embedded within a preformed slot  118  formed in the cavity  116  of the handle member  104  as best shown in  FIG. 21 . In this regard, the leaf spring  114  is configured with materials and dimensions such that it holds the neck member  102  and handle member  104  in substantial alignment when no pressure is applied or when a pressure is applied that is less than the threshold pressure. When a force is applied to the head of the brush  106  that exceeds a selected threshold pressure, the leaf spring  114  deflects and allows movement of the neck member  102  toward an offset position. The neck member  102  is movable between an aligned first position and a second offset position relative to the handle member  104  when a threshold pressure is exceeded. The threshold pressure in this embodiment is a variable that can be set anywhere form just barely above the force required to overcome spring tension and friction, to a pressure upon the brush head  106  just before the pressure level that may cause damage to the hard and soft tissues of the mouth. Once deflected, the neck cannot impart increasing pressure upon the dental structures, and with ever-increasing handle force, the angle of displacement can become great enough to discourage the user from continuing to brush with the toothbrush  100  in the furthest deflected state. Once the pressure is released to zero or reduced to below the threshold level the leaf spring  114  immediately attempts resetting toward the original aligned position. The angle of displacement only becomes discouraging to the user if far too much force is applied. Once threshold pressure is exceeded, the neck moves unimpeded out of alignment. This unimpeded movement allows users with limited time, poor dexterity, or low cognition to brush improperly without causing damage to the oral tissues. The unimpeded movement once the threshold pressure is exceeded also allows the neck to quickly and easily displace and reset around obstacles, irregularities and curvatures of the mouth, thus avoiding unwanted oral trauma.  
         [0060]     Batteries  132  located in the handle member  104  cavity  116  provide power to a motor  131 . The motor  131  provides vibrational movement to the head  106  through a flexible connector  134 . Buttons  136  provide manual control of the motor  131 .  
         [0061]     The manual adjustment of the threshold pressure of the leaf spring  114  is effected through a manual adjustment knob  126 . Rotational movement of the knob  126  translates to rotational movement of a shaft  128  deep within the device  100  structure. A helical structure  130  affixed to the end of the shaft  128  engages the leaf spring  114  to provide variable resistance against the leaf spring  114 , thus modifying the pressure level of the leaf spring  114  deflection. Alternatively, the helical structure  130  could be a coil, polygonal structure or cam structure configured to lift and lower the deflection point. Accordingly, a user can “dial” in a desired pressure for use with the brush  100 . Currently, after mouth surgery or other injury to the mouth, a doctor may recommend use of an ultra soft bristle brush and/or light brushing pressure, and to graduate to stiffer bristles and/or more pressure as the mouth heals. The adjustable nature of the toothbrush  100  of the present invention allows a person to use a single brush to accomplish varying degrees of stiffness.  
         [0062]     Referring particularly to  FIG. 21 , there is shown a cross-sectional view of the fourth embodiment of the present invention. The leaf spring  114  engages the proximal end of the neck member  102 . The neck member  102  has a curved flange  103  for engaging the leaf spring  114 . The toothbrush is shown with the neck in a first position, and toothbrush  100  will remain in this position so long as a selected threshold pressure is applied at the toothbrush head  106 . When the selected threshold pressure is exceeded, the leaf spring deflects as shown in the phantom leaf spring  122  and the phantom neck member  124  toward a second offset position at the exceeded threshold pressure. In the embodiments of the present invention the neck  102  does not immediately move or snap out to a second position after a threshold pressure is exceeded; in operation, after the threshold pressure is reached, no increasing pressure can be applied to the oral tissue, and any attempt to increase pressure by the user results in unimpeded movement of the neck  102  as it rotates about the pivot mechanism  110 ,  112  toward the maximum rotation point. Because of the elastic nature of the leaf spring  114  and the arrangement of the leaf spring  114  in cooperation with the neck  102  and handle  104  members, the brush  100  instantaneously attempts resetting toward the aligned position as soon as the pressure is reduced. Unlike brushes with elastomeric flexibility features, the toothbrush  100  of the present invention does not suffer from temporary extended deformation before resetting. Thus, the brush  100  adapts to the curvature of the dental arch even during normal brushing, and immediately tries to reset toward a normal position.  
         [0063]     Additional modifications to the method of the present invention and the devices used in accordance with the method will be apparent to those skilled in the art. It is understood that such additional modifications are within the scope and spirit of the present invention.