Abstract:
The invention is directed to a toothbrush head of an electric toothbrush, which comprises a handpiece equipped with a drive, a brush head carrier that is connectible to the handpiece, and several bristle supports that carry a respective bristle set, are movably mounted on the brush head carrier and drivable in an oscillatory manner by the drive, each of the bristle supports being adapted to be coupled to a translator element of the drive by means of a respective drive coupling. According to the invention the bristle supports each have drive coupling means enabling them to be coupled to eccentric drivers of the drive translator element which is adapted to be driven for rotation about a longitudinal axis. Owing to the arrangement of two separately mounted bristle supports which are driven by a common drive translator element about various axes of motion, it is possible to achieve an improved cleaning effect by simple means. The relative movement of the bristle sets that are mounted on the bristle supports assists the cleaning motion so that the cleaning effect is not obtained solely by the operator&#39;s movement.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. application Ser. No. 10/535,163, filed May 16, 2005, the contents of which are incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a toothbrush head of an electric toothbrush, which comprises a handpiece equipped with a drive, a brush head carrier that is connectible to the handpiece, and several bristle supports that carry a respective bristle set, are movably mounted on the brush head carrier and drivable in an oscillatory manner by the drive, with each bristle support being adapted to be coupled to a translator element of the drive by means of a respective drive coupling. Furthermore, the invention relates to a toothbrush with such a toothbrush head. 
       BACKGROUND OF THE INVENTION 
       [0003]    From U.S. Pat. No. 5,524,312 there is known an electric toothbrush on whose brush head provision is made for two separate brush holders which are driven by a common transmission rod. The one brush holder performs an oscillating rotary motion about an axis perpendicular to the brush neck. The other brush holder is pivoted back and forth about an axis parallel to the brush neck. This arrangement of brush holders brings about an active relative movement between the tufts of bristles but is disadvantageous inasmuch as it is restricted to a special drive mechanism. The additional brush holder arranged further to the rear of the handle requires a cylindrical bottom side with a special, curved guide groove in which an engaging projection of the transmission rod, which oscillates in longitudinal direction, engages. Furthermore, the configuration of the tufts of bristles arranged on the two brush holders is hardly suitable for the efficient cleaning of interproximal spaces. 
       SUMMARY OF THE INVENTION 
       [0004]    It is therefore an object of the present invention to provide an improved toothbrush head and a corresponding improved toothbrush which avoid the disadvantages of the prior art and develop it further in advantageous manner. An improved cleaning of the teeth is to be achieved preferably by using a simple, effective drive of the two bristle supports. 
         [0005]    This object is accomplished according to the invention by a toothbrush head in accordance with claim  1  and by a toothbrush according to claim  23 . Preferred embodiments of the invention are the subject of the dependent claims. 
         [0006]    According to the invention the bristle supports each have drive coupling means enabling the bristle supports to be coupled to one or more eccentric drivers of the drive translator element which is adapted to be driven for rotation about a longitudinal axis. Owing to the arrangement of two separately mounted bristle supports which are driven by a common drive translator element about various axes of motion, it is possible to achieve an improved cleaning effect by simple means. The relative movement of the bristle sets that are mounted on the bristle supports assists the cleaning motion so that the cleaning effect is not obtained solely by the operator&#39;s movement. 
         [0007]    The eccentric drivers of the translator element for driving the bristle supports may be variously constructed. According to one embodiment of the invention the bristle supports are adapted to be coupled to a common driver pin, which describes a cylindrical or conical orbit relative to the rotation axis of the translator element and is assigned preferably to the handpiece of the toothbrush. Alternatively each bristle support could be provided with its own driver pin on the translator element, the one being able to describe a conical orbit and the other a cylindrical orbit. However, provision is made preferably for only one common driver pin for both bristle supports, with said pin describing preferably a cylindrical drive motion. 
         [0008]    The driver pin is preferably driven to oscillate so that only a partial orbit is described, which may be in the shape of a cylinder segment or a cone segment. It is thus easily possible to obtain a corresponding oscillating motion of the two bristle supports. However, the driver pin could also describe a continuous, complete orbit in the manner of a crank, which like a crank drive brings about an oscillating motion of the bristle supports. It is preferred, however, for the translator element to oscillate with its eccentric drivers within an angle segment of ±90° or less. 
         [0009]    In a further aspect of the invention the translator element is permanently assigned to the toothbrush head and mounted on the brush head carrier for rotation about its longitudinal axis in the interior of the brush head carrier. To be able to remove the toothbrush head from the handpiece of the toothbrush, the translator element may have on its end close to the handpiece a coupling section that forms a releasable rotary coupling for the non-rotatable coupling to a drive element at the handpiece end. The brush head carrier, which forms a brush tube, has on its end remote from the bristle supports releasable fastening means for its attachment to the handpiece of the toothbrush. When the brush head carrier is seated on the handpiece of the toothbrush, the drive translator element provided in the brush head carrier and the drive element at the handpiece end are coupled to each other at the same time. 
         [0010]    In a further aspect of the invention the bristle supports are all mounted on the brush head carrier for movement about or along an axis of motion transverse to the longitudinal direction of the toothbrush, whereby each bristle support has its own axis of motion which are arranged in spaced relationship to each other. Hence it is a characteristic of the toothbrush head that two bristle supports mounted for movement about separate transverse axes are driven by a common drive translator element. Irrespective of the concrete construction of the drive translator element, such a toothbrush head configuration affords particular advantages for the effective cleaning of the teeth. 
         [0011]    In particular it is possible to provide for two bristle supports. One main bristle support, which may be arranged on the end of the brush head carrier remote from the handpiece of the toothbrush, is preferably mounted for rotation about an axis of rotation essentially perpendicular to the longitudinal direction of the toothbrush and essentially parallel to the main direction of the bristles provided on the main bristle support, and is adapted to be driven in oscillatory manner by the eccentric driver of the drive axis. The main bristle support may be essentially constructed in plate shape and have a circular contour. Preferably it is drivable in oscillating rotational manner about its axis of symmetry. As the case may be, a poking motion along the axis of rotation of the main bristle support can be superimposed on the rotational oscillating drive motion in order to obtain a more thorough cleaning of the interproximal spaces. For this purpose the main bristle support may be displaceably mounted on the brush head carrier in the direction of its axis of rotation. 
         [0012]    Provided adjacent to the main bristle support is preferably an auxiliary bristle support that is arranged in direct proximity behind the main bristle support, meaning closer to the handpiece of the toothbrush. The auxiliary bristle support may have various axes of motion. According to a preferred embodiment of the invention the auxiliary bristle support is pivotally mounted about a pivot axis arranged essentially perpendicular to the longitudinal direction of the toothbrush, and may be driven in oscillatory manner by the drive translator element, which also drives the main bristle support. 
         [0013]    According to an embodiment of the invention the pivot axis is arranged in off-center position relative to the auxiliary bristle support or the bristle set arranged on it in order to obtain a larger movement on a section of the bristle support opposite the pivot axis. The pivot axis of the auxiliary bristle support may be arranged approximately parallel to the main direction of the bristles and hence parallel to the axis of rotation of the main bristle support. If the axis is arranged in longitudinal direction of the toothbrush on an edge section of the auxiliary bristle support, the opposite edge section of the auxiliary bristle support performs a reciprocating motion in transverse direction. Basically it would also be possible to arrange the pivot axis in center position relative to the auxiliary bristle support such that the latter rotates about its own center like the main bristle support. Preferable, however, is the previously described arrangement of the pivot axis in particular on the end of the auxiliary bristle support close to the main bristle support so that the bristles anchored to the auxiliary bristle support closer to the handpiece may move transversely in a reciprocating motion and wipe the interproximal spaces clear. 
         [0014]    In an alternative further aspect of the invention the pivot axis of the bristle support may lie essentially in the plane defined by the auxiliary bristle support and extend perpendicular to the longitudinal direction of the toothbrush. Accordingly, the auxiliary bristle support performs an up and down rocking motion such that its tufts of bristles move up and down in a poking action. This rocking axis of the auxiliary bristle support may extend, relative to the longitudinal dimension of the auxiliary bristle support, approximately centrally in longitudinal direction of the toothbrush, such that the rear end and the front end of the auxiliary bristle support rock up and down in counter sequence. In an alternative embodiment of the invention the rocking axis of the auxiliary bristle support may also be displaced towards one end of the auxiliary bristle support. In particular the auxiliary bristle support may be mounted on the brush head carrier for rocking motion about its end close to the handpiece, with the result that the tufts of bristles anchored in the auxiliary bristle support adjacent to the main bristle support perform an up and down poking motion. The interproximal spaces adjacent to the tooth flanks worked by the bristle set of the main bristle support can thus be cleaned particularly effectively. 
         [0015]    However, it is not compulsory for the auxiliary bristle support to be pivotally mounted. According to a preferred embodiment of the invention it is possible to provide for the auxiliary bristle support to be mounted on the brush head carrier for translational displacement along a motion axis. The corresponding sliding guide of the auxiliary bristle support preferably has a degree of freedom in a direction transverse to the longitudinal direction of the toothbrush. 
         [0016]    To enable the bristles arranged on the auxiliary bristle support to perform a poking motion in longitudinal direction of the bristles, the translational motion axis of the auxiliary bristle support may lie essentially perpendicular to the plane defined by the auxiliary bristle support, i.e., essentially parallel to the main bristle direction defined by the bristles. Alternatively, the axis of motion transverse to the longitudinal direction of the toothbrush may lie in the plane defined by the auxiliary bristle support, thus enabling the auxiliary bristle support to be moved back and forth transversely. This enables the bristles arranged on the auxiliary bristle support to be moved in the direction of the interproximal spaces, wiping them clear. 
         [0017]    The drive couplings between the two bristle supports and the eccentric driver of the drive shaft are preferably constructed as flexible couplings, each having a joint axis transverse to the longitudinal direction of the toothbrush. Insofar as the bristle supports do not make a translational reciprocating motion but a pivoting motion at their coupling points with the driver pin that maintains its spatial orientation, the corresponding angle offset may be compensated by the flexible coupling between the bristle supports and the eccentric driver. 
         [0018]    In a further aspect of the invention the flexible couplings between the drive translator element and the bristle supports have at least one further degree of freedom in addition to their flexibility. On the one hand the drive coupling of one bristle support, particularly of the auxiliary bristle support, may be constructed such that only forces and movements transverse to the longitudinal direction of the toothbrush are transmitted. No forces are transmitted in the longitudinal direction of the toothbrush. This advantageously enables compensation of the relative movement developing between the driver pin and the bristle support in the longitudinal direction of the toothbrush. 
         [0019]    To transmit the cylindrical or conical drive motion of the driver pin only partly to the bristle supports, the flexible coupling between the driver pin and the bristle supports may also have a degree of freedom transverse to the longitudinal direction of the toothbrush. In particular the connection between the eccentric driver and the auxiliary bristle support and/or the main bristle support may be constructed to be free-moving in a direction transverse to the plane of motion in which the respective bristle support is to move. The driver pin moving on a cylindrical or conical path thus transmits only one component of its oscillatory orbital motion to the respective bristle support. If, for example, the auxiliary bristle support is to be pivoted about an axis perpendicular to the auxiliary bristle support, i.e., parallel to the bristles, then the eccentric driver may sit in a longitudinal slot parallel to the direction of the bristles in the auxiliary bristle support. The motion component transverse to the longitudinal direction of the bristles is transmitted to the bristle support whereas the motion component of the driver pin parallel to the longitudinal direction of the bristles is not transmitted. If, by contrast, the auxiliary bristle support is to be rocked up and down, then the driver pin may sit in a transverse slot parallel to the bristle support plane, as the result of which the corresponding section is moved up and down while however the transversely reciprocating motion is not transmitted. 
         [0020]    However, the driver pin does not have to sit in a slot-shaped recess in the auxiliary bristle support. Alternatively, the auxiliary bristle support may have as drive coupling a sliding surface that extends transverse to the longitudinal direction of the toothbrush and on which the driver pin slides. In this case it is possible to provide preferably a biasing device in the form of a spring, for example, which urges the auxiliary bristle support with its sliding surface into contact with the driver and holds it engaged therewith. However, under certain circumstances it is also possible to dispense with such a biasing device because the auxiliary bristle support is automatically urged into engagement with the driver by the reaction forces from cleaning the teeth, as is the case, for example, when the auxiliary bristle support is to be rocked up and down with a poking motion. 
         [0021]    In this arrangement the amplitude of the stroke of the bristle support can be influenced by the shape of the sliding surface. In a simple further aspect of the invention the engaging sliding surface of the auxiliary bristle support may be of an essentially plane configuration. The drive motion of the eccentric driver has two components acting perpendicularly to each other, with the result that the driver slides back and forth on the sliding surface while simultaneously acting in perpendicular direction upon the sliding surface and moving the bristle support accordingly. The stroke of the bristle support then corresponds to the motion component of the driver perpendicular to the sliding surface. 
         [0022]    If, on the other hand, a bigger—or smaller—stroking motion of the bristle support is desired, then the sliding surface may have a cam-shaped curvature transverse to the longitudinal axis of the translator element. When the eccentric driver moves back and forth over the sliding surface, the cam-shaped curvature generates the desired additional motion perpendicular to the back and forth motion. 
         [0023]    In a further aspect of the invention, the drive coupling means of one of the bristle supports, particularly the main bristle support, transmit forces both in the longitudinal direction of the toothbrush and in a direction transverse to the longitudinal direction of the toothbrush, with the corresponding driver being mounted on the translator element for displacement in the longitudinal direction of the toothbrush and being preferably elastically biased. In particular the driver pin and the main bristle support may be biased against each other and/or against the tubular brush head carrier. The advantage thereby achieved is that no free movements and no rattling noises can arise in spite of the flexibility and in spite of the degrees of freedom of the drive coupling. The drive runs quietly. 
         [0024]    In a further aspect of the invention the translator element, which may be constructed as a plastic injection molding, has an eccentric bearing bore in which the driver pin, which is constructed preferably as a metal pin, is mounted for longitudinal displacement and for rotation about its longitudinal axis. To bias the driver pin against the bristle support a spring may sit on the driver pin and take support upon the translator element. 
         [0025]    To make better use of the driven motion of the two bristle supports or the bristle sets arranged on them and to make the cleaning of the teeth even more effective, several clusters of bristle tufts tilted in varying orientations may be fastened to the main bristle support and/or the auxiliary bristle support. In this arrangement the clusters of bristle tufts tilted in varying orientations may be of varying cross sections and/or be constructed with various properties such as a different level of rigidity, length of bristle, height of bristle and the like. Preferably the bristle tufts arranged on the main bristle support are tilted in directions different from the bristle tufts on the auxiliary bristle support. According to an embodiment of the invention, bristle tufts tilted at varying angles may be provided on each bristle support. 
         [0026]    It has proven expedient to provide not only bristle tufts with a circular cross section but also bristle tufts with a non-circular cross section, in particular an elongated, oval or rectangular cross section. 
         [0027]    To be better able to penetrate the interproximal spaces, bristle tufts whose free working ends lie at various heights above the bristle supports may be provided on the main bristle support and/or on the auxiliary bristle support. 
         [0000]    Additional advantages, application possibilities and advantageous features of this invention will become apparent from the subsequent description of embodiments of the invention, which are depicted in the Figures of the accompanying drawings. In this context, all features described or depicted, whether individually or in any combination, constitute the subject-matter of this invention, irrespective of their summary in the claims or the cross references of the latter and irrespective of their wording and representation in the description and the drawings, respectively. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]      FIG. 1  is a top plan view of the replaceable toothbrush head of an electric toothbrush according to a first preferred embodiment of the invention, showing two movably mounted bristle supports, each mounted and adapted to be driven for pivotal motion about a pivot axis parallel to the main direction of the bristles; 
           [0029]      FIG. 2  is a vertical longitudinal section taken along the line B-B of the toothbrush head of  FIG. 1 , showing the mounting of the drive translator element which drives the two bristle supports; 
           [0030]      FIG. 3  is a horizontal longitudinal section taken along the line D-D of the toothbrush head of  FIG. 2 , showing the drive mechanism and in particular the coupling of the two bristle supports to an eccentric driver pin of the drive translator element; 
           [0031]      FIG. 4  is a longitudinal section of the drive translator element mounting the eccentric driver pin from the preceding Figures; 
           [0032]      FIG. 5  is a fragmentary perspective view of a toothbrush head with two movably mounted bristle supports according to a further embodiment of the invention, in which the rear auxiliary bristle support is mounted and adapted to be driven for an up and down rocking motion about a transverse axis at its rear end section; 
           [0033]      FIG. 6  is a fragmentary perspective view of the toothbrush head of  FIG. 5  as seen looking in a different direction, showing the drive mechanism for the two bristle supports and in particular the coupling of the rear auxiliary bristle support to a driver; 
           [0034]      FIG. 7  is a fragmentary perspective view of a toothbrush head with two movably mounted bristle supports according to an alternative embodiment of the invention, in which the rear auxiliary bristle support is mounted approximately centrally for rocking motion about a transverse axis; 
           [0035]      FIG. 8  is a fragmentary perspective view of the toothbrush head of  FIG. 7  as seen looking in a different direction, showing the drive mechanism for the two bristle supports and in particular the coupling of the rear auxiliary bristle support to the drivers of the drive mechanism; 
           [0036]      FIG. 9  is a fragmentary perspective view of a toothbrush head with two movably mounted bristle supports according to an alternative embodiment of the invention, in which the rear auxiliary bristle support is mounted for a raising and lowering motion about a translational motion axis essentially parallel to the main direction of the bristles; 
           [0037]      FIG. 10  is a fragmentary perspective view of the toothbrush head of  FIG. 9  as seen looking in a different direction, showing the drive mechanism for the two bristle supports and in particular the coupling of the rear auxiliary bristle support to the drivers of the drive mechanism; 
           [0038]      FIG. 11  a fragmentary perspective view of a toothbrush head with two movably mounted bristle supports according to a further embodiment of the invention, in which the rear auxiliary bristle support is mounted for a reciprocating motion about a translational motion axis transverse to the longitudinal direction of the toothbrush and transverse to the main direction of the bristles; 
           [0039]      FIG. 12  is a fragmentary perspective view of the toothbrush head of  FIG. 11 , showing the drive mechanism for the two bristle supports and in particular the coupling of the rear auxiliary bristle support to the drivers; and 
           [0040]      FIG. 13  is a perspective view of a toothbrush head of the toothbrush of  FIG. 1 , showing the arrangement of the bristle tufts on the two bristle supports. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0041]    The toothbrush head  2  shown in  FIG. 1  comprises a brush tube  11  which forms a brush head carrier and is attachable with an end thereof to a handpiece, not shown in detail, of an electric toothbrush. The handpiece includes in known manner a toothbrush housing in which a battery holding compartment and a drive motor are axially arranged one behind the other. 
         [0042]    The brush head  2  has two bristle sets, namely a main bristle set  9  lying directly at the head end and a rear auxiliary bristle set  8  that lies in direct proximity of the main bristle set  9  at its end close to the handpiece. 
         [0043]    As  FIG. 2  shows, the bristle set  9  lying at the head end is carried by a main bristle support  10  which in the direction of the bristle set is constructed roughly like a circular plate and is fastened to a head section of the brush head carrier  11 . As  FIGS. 1 and 2  show, the bristle support  10  is rotatably seated on a spindle  12  which is anchored in the brush head carrier  11  and extends perpendicular to the longitudinal axis of the toothbrush roughly parallel to the main bristle direction of the bristle set  9 . The spindle  12  defines the axis of symmetry of the plate-shaped bristle support  10 . 
         [0044]    The bristle support  10  is driven in an oscillatory rotary movement about the axis of rotation  12  by the motor, employing a translator element  14  in the form of a drive shaft  15 . The drive shaft  15  is a plastic injection molding and is carried in the brush tube  11  in a bearing  16  which may be formed by a metal pin having its one end seated in a bearing section of the brush head carrier  11  and its other end in the drive shaft  15  in the longitudinal direction of the toothbrush. The bearing  16  permits the drive shaft  15  to rotate about its longitudinal axis extending parallel to the longitudinal axis of the toothbrush. The drive shaft  15  is powered by a rotationally oscillating drive element which is connected by gearing to the motor shaft which extends in the longitudinal direction of the toothbrush. The drive shaft  15  performs an oscillating rotary motion. At its end close to the handpiece the drive shaft has a coupling section  1  enabling it to be plugged on a drive element on the handpiece in a manner preventing relative rotation. 
         [0045]    As  FIG. 4  shows, provision is made in the drive shaft  15  for a passage hole extending approximately parallel to and at a distance from its longitudinal axis, in which a driver pin  50  is accommodated for rotation and longitudinal displacement. On its front end the driver pin  50  has a stud-shaped pickup  51  which extends at roughly right angles to the driver pin  50  and may be rigidly connected thereto, for example by welding. 
         [0046]    The driver  50  performs a rotational orbital movement on a path shaped like a cylinder segment about the longitudinal and rotation axis of the drive shaft  15 , with the plane of symmetry of the oscillating pivoting motion from which the driver is displaced to the right and left forming the plane of longitudinal symmetry of the toothbrush head  2 . 
         [0047]    The end of the driver pin  5 , or the pickup  51  fastened thereto, close to the bristle support  10  sits in a blind-hole-shaped recess  18  in the bristle support  10 , said recess being constructed in a segment of the bristle support  10  close to the handpiece  1  and extending essentially parallel to the axis of rotation  12  (cf.  FIG. 3 ). On account of the blind-hole-shaped recess only the component of the drive motion of the driver  50  transverse to the axis of rotation  12  is transmitted onto the bristle support  10 . The up and down motion, i.e., the component of the orbital drive motion parallel to the axis of rotation  12 , is not transmitted because the pickup  51  in the recess  18  is free-moving, i.e., longitudinally displaceable, parallel to the axis of rotation  12 . Furthermore the mount of the pickup  51  in the recess  18  forms a rotary joint in order to compensate the oscillating angle offset between the bristle support  10  and the driver  50 . 
         [0048]    As  FIG. 4  shows, the end of the driver pin  50  remote from the pickup  51  projects out of the passage hole in the drive shaft  15 , protruding by some length beyond an edge of the drive shaft  15 . A helical compression spring  52  is mounted on the driver pin  50  in the region of the projecting length. The free end of the driver pin  50  is compressed and flattened, forming a radial enlargement  55 . The helical spring  52  thus rests against the enlargement and is held by it. Furthermore the helical compression spring  52  bears with its other end against the edge of the drive shaft  15 . The helical compression spring  52  thus biases the driver pin  50  axially against the bristle support  10  in order to prevent rattling noises during use. Considering that the pickup  51  is seated in the blind-hole-shaped recess  18  in the bristle support  10 , the pickup  51  performs an oscillating motion in a circular path about the axis of rotation  12  of the bristle support  10 . The driver pin  50  is accordingly displaced in axially oscillating manner in the passage hole in the drive shaft  15 , with the helical compression spring  52  being alternately compressed and extended in the process. 
         [0049]    As  FIGS. 1 and 2  show, the rear bristle set  8  near the handpiece  8  is carried by a roughly plate-shaped auxiliary bristle support  13  which like the main bristle support  10  is movably mounted on the brush head carrier  11  independently of the drive translator element  15 . As  FIG. 2  shows, the auxiliary bristle support  13  has its forward edge portion at the end close to the main bristle support  10  pivotally mounted about a pivot axis  19  that extends essentially perpendicular to the longitudinal direction of the toothbrush and perpendicular to the plane defined by the auxiliary bristle support  13 . Hence the auxiliary bristle support  13 , in particular its portion at the end remote from the main bristle support  10 , is able to pivot transversely back and forth as indicated by the arrow  20 . It will be understood, of course, that it is not only possible for the bristle support  13  to be pivoted in the previously mentioned plane but that it is also possible for the bristle support  13  to be pivoted on the arc of a circle that is arranged congruently to the circular arc of the eccentric driver pin  50 . As such, only one additional degree of freedom of motion relative to the pivot axis  19  needs to be provided for the bristle support  13 . 
         [0050]    To drive the auxiliary bristle set  8  in an oscillatory rotary movement about the pivot axis  19 , the auxiliary bristle support  13  is coupled to the eccentric driver  50  which also drives the main bristle support  10 . As  FIGS. 2 and 3  show, provision is made on the bottom side of the auxiliary bristle support  13  for a drive coupling  21  which comprises a longitudinal clearance space  22  extending parallel to the pivot axis  19 , in which the driver pin  50  is guided. For this purpose the drive shaft  15  has in the region of the passage hole a recess  53  such that the driver pin  50  lies free (cf.  FIG. 4 ) and the passage hole, in which the driver pin  50  is received, is formed by two aligned passage hole sections. The longitudinal clearance space  22  is defined in the drawn embodiment by two post-shaped projections  23  and  24  between which the driver  50  is guided. The projections  23 ,  24  extend essentially parallel to the pivot axis  19  such that the clearance space or gap defined between the projections  23  and  24  extends likewise parallel to the pivot axis  19 . Accordingly, only one component of the orbital drive motion of the driver  50  is transmitted, namely in the plane parallel to the longitudinal direction of the toothbrush and perpendicular to the pivot axis  19 . The vertical component of the drive motion parallel to the plane of symmetry of the toothbrush is not transmitted because the driver  50  is free to move back and forth in this direction in the longitudinal clearance space  22  between the projections  23  and  24 . In the longitudinal direction of the pin-shaped driver  50  the latter may also move freely back and forth between the projections  23  and  24  in order to permit the longitudinal motion of the driver  50  induced by the pickup  51 . Finally the connection between the projections  23  and  24  and the driver  50  forms a flexible coupling which permits the driver  50  to pivot relative to the auxiliary bristle support  13  about an axis parallel to the pivot axis  19  in order to compensate the oscillating angle offset between the bristle support  13  and the driver  50 . The inner sides of the projections  23  and  24  may be rounded for this purpose. The tubular brush head carrier  11  has underneath the auxiliary bristle support  13  a clearance hole through which the projections  23  and  24  of the auxiliary bristle support  13  extend. 
         [0051]      FIGS. 5 to 12  show alternative bearing arrangements of the auxiliary bristle set  8  or the auxiliary bristle support  13 . The toothbrush heads shown in these Figures are provided likewise for the toothbrush presented in  FIG. 1 , complying otherwise with the previously described toothbrush head, including the construction of the drive translator element  14  and its driver  50 , hence to this extent reference is made to its description and the same reference numerals are used for corresponding components. In the Figures, only the pin-shaped driver  50  of the drive translator element is shown for the sake of simplicity. 
         [0052]    According to  FIG. 5  the auxiliary bristle support  13  is mounted on the brush head carrier  11  for pivotal motion about a pivot axis  25  which extends essentially parallel to the plane defined by the auxiliary bristle support  13  and transverse to the longitudinal direction of the toothbrush. The auxiliary bristle support  13  has its rear end portion or edge, i.e., that close to the handpiece  1 , pivotally mounted, with the result that it can perform an up and down rocking motion about the pivot axis  25 . The portion of the auxiliary bristle support  13  close to the main bristle support  10  is able to rock up and down as per the arrow  26  with the result that the bristles of the auxiliary bristle set  8  perform a poking motion. 
         [0053]    To drive the auxiliary bristle support  13  about the pivot axis  25  in an oscillatory motion, provision is made on its bottom side for an engaging or sliding surface  27  as drive coupling, with which it sits on the driver  15  which also drives the main bristle support  10 . As  FIG. 6  shows, the engaging or sliding surface  27  is formed by the end of an elongated tappet or protuberance  28  which extends transverse to the longitudinal direction of the toothbrush and projects toward the driver  50 . The surface of the tappet  28  may be of an essentially plane configuration. The driver  50  oscillating in an orbital path rides in transverse direction over the sliding surface  27 , with the vertical component of the orbiting crank motion being transmitted to the tappet or protuberance  28 , causing the auxiliary bristle support  13  to rock up and down, while the sliding surface  27  is held in engagement with the driver  50  by the reaction forces from cleaning the teeth, which forces act on the auxiliary bristle set. As the case may be, the auxiliary bristle support may be held biased by a spring, for example, which urges the auxiliary bristle support against the driver  50 . Alternatively it would also be possible to provide instead of the sliding surface  27  a groove-shaped transverse recess in a corresponding section of the auxiliary bristle support  13  in which the driver  50  sits, with the result that the auxiliary bristle support would be urged upwards by the driver and actively drawn down. Such a transverse groove corresponds to the arrangement of two parallel sliding surfaces  27  between which the driver  50  is guided. 
         [0054]    According to  FIGS. 7 and 8  the auxiliary bristle support  13  may also be mounted approximately centrally about a transversely extending pivot axis  29  in the manner of a rocker. As in the embodiment previously described the pivot axis  29  extends transverse to the longitudinal direction of the toothbrush approximately in the plane defined by the auxiliary bristle support  13  or a plane parallel thereto, with the result that a portion of the auxiliary bristle support  13  close to the main bristle support  10  and an opposite portion of the auxiliary bristle support  13  close to the handpiece  1  perform up and down rocking movements in counter sequence. Like the previously described embodiment of  FIGS. 5 and 6 , the drive coupling of the auxiliary bristle support may be formed by a sliding surface  27  provided on a tappet  28 , which slides on the driver  50 . Considering that in this embodiment the reaction forces from cleaning the teeth act on either side of the pivot axis  29 , the provision of a biasing device holding the auxiliary bristle support in engagement with the driver  50  may be useful. As the case may be, it is also possible to provide the previously described positive guidance by means of a transverse groove in which the driver sits. 
         [0055]    According to  FIGS. 9 and 10  the auxiliary bristle support  13  may also be guided for translatory displacement on the brush head carrier  11 . As  FIG. 9  shows, the auxiliary bristle support  13  may be guided along two motion axes  30  which extend essentially perpendicular to the plane defined by the auxiliary bristle support. The sliding guide may be constructed, for example, as a cylindrical stud guide known in the art. The sliding guide axes  30  may be arranged on the longitudinal central plane of the toothbrush in a rear and front edge portion of the auxiliary bristle support  13 , as is shown in  FIG. 9 . The auxiliary bristle support  13  may perform up and down stroke motions in accordance with its translational mobility, so that the auxiliary bristle set  8  on the auxiliary bristle support  13  makes poking movements. 
         [0056]    The stroke motion of the auxiliary bristle support  13  is produced in this case too by coupling to the eccentric driver  50 . As  FIG. 10  shows, provision may be made on a bottom side of the auxiliary bristle support  13  for a sliding surface  27  which extends transverse to the longitudinal direction of the toothbrush and is formed by the surface of a tappet  28  projecting towards the driver  50 . Conveniently, the tappet  28  is located approximately centrally underneath the auxiliary bristle set and centrally between the motion axes  30  such that a uniform distribution of force and skew-free motion can be obtained. The reaction forces from cleaning the teeth, which act on the auxiliary bristle set  8 , hold the sliding surface  27  in engagement with the driver  50 . 
         [0057]      FIGS. 11 and 12  show a further possible bearing arrangement of the auxiliary bristle support  13 . In this case too the auxiliary bristle support  13  is mounted on the brush head carrier  11  for translatory displacement, which takes place along two parallel sliding guide axes  31  which extend in the plane defined by the auxiliary bristle support  13  transverse to the longitudinal direction of the toothbrush. As  FIG. 11  shows, a rear end portion close to the handpiece  1  and an end portion of the auxiliary bristle support  13  close to the main bristle support  10  may be mounted by means of said sliding guide. In this case the auxiliary bristle support  13  is able to perform reciprocating movements laterally and transversely, as is indicated by the arrow  32 . 
         [0058]    The translationally oscillating drive motion of the auxiliary bristle support  13  is effected by the driver  50  in this case too. As  FIG. 12  shows, the auxiliary bristle support  13  sits on the driver  15  by means of a transverse guide  33 . Similar to the embodiment of  FIGS. 2 and 3 , the transverse guide  33  is defined by two parallel post-shaped projections  23  and  24  which define between themselves a gap or a longitudinal clearance space  22  extending essentially perpendicular to the plane of the auxiliary bristle support  13 . The driver  50  is free to slide up and down between the two projections  23  and  24  in vertical direction, i.e., in the plane of longitudinal symmetry of the toothbrush. However, in a plane normal thereto, i.e., in a plane parallel to the two sliding guide axes  31 , the drive motion of the driver  50  is transmitted such that the auxiliary bristle support  13  oscillates back and forth in the direction of the sliding guide axes  31 . 
         [0059]    A preferred bristle array of the two bristle supports  10  and  13  is shown in  FIG. 13 . It will be understood that the bristle array of  FIG. 13  may be provided on each of the previously described embodiments of the auxiliary bristle support or its bearing arrangement. 
         [0060]    The main bristle set  9  drivable in an oscillatory rotational motion has an on the whole roughly circular cylindrical contour and is formed by a multiplicity of bristle tufts of various angles of tilt, various heights and various cross sections. 
         [0061]    As  FIG. 13  shows, central first bristle tufts  38  are arranged centrally around the axis of rotation of the main bristle support. They extend perpendicular to the plane defined by the bristle support  10  and have a roughly circular or slightly oval cross section. Four of these first bristle tufts  38  are provided. They lie centrally around the axis of rotation  19 . Adjacent to the first bristle tufts  38  are second bristle tufts  39  which in the non-rotated position of the bristle support  10  lie on the longitudinal central axis of the toothbrush and in longitudinal direction in front of and respectively behind the first bristle tufts  38 . As  FIG. 13  shows, the second bristle tufts  39  have an oval cross section with a longitudinal axis extending transverse to the longitudinal axis of the toothbrush. The second bristle tufts  39  are arranged likewise perpendicular to the plane defined by the bristle support  10 . Their distance from the axis of rotation  19  is larger than that of the first bristle tufts  38 . The ratio of the contour length to the contour width is approximately two. 
         [0062]    The other bristle tufts of the driven bristle set are tilted in varying orientations. The fourth bristle tufts  40 , which are arranged radially outside the first bristle tufts  38 , in a manner of speaking on a second bristle tuft ring, have a roughly circular cross section and are tilted radially outwardly, i.e., their free working ends are further removed from the axis of rotation of the bristle support than their fastening ends anchored in the bristle support  10 . The angle of tilt is acute and amounts to less than 20°. 
         [0063]    The third bristle tufts  41  are likewise tilted in a radially outward direction. However, they have an oval contour or an elongated cross section, the longitudinal axis of the cross section being radially oriented. The cross section of the third bristle tufts is about twice to three times longer than it is wide. The third bristle tufts  41  sit radially outside the first bristle tufts  38  and adjacent to them on a symmetry axis of the bristle set extending transverse to the longitudinal direction of the toothbrush. 
         [0064]    The other bristle tufts of the bristle set  9  are likewise tilted but in circumferential direction around the axis of rotation  12 . They form the outer edge or ring of the bristle set  9 . 
         [0065]    The fifth bristle tufts  42  have an oval contour or an elongated cross section which is oriented roughly tangentially to the edge of the bristle support  10 . In cross section the bristle tufts  42  are about twice to three times longer than they are wide. As  FIG. 1  shows, the fifth bristle tufts  42  are arranged in pairs in the region of the longitudinal axis of the toothbrush when the bristle set  9  is in non-rotated position. They are tilted in pairs towards each other such that their free working ends are closer together than their fastening ends anchored in the bristle support  10 . 
         [0066]    Finally, provision is made for sixth bristle tufts  43  which lie likewise on the outer edge of the bristle set and are tilted in circumferential direction around the axis of rotation  12 . However, they have a roughly circular cross section and are arranged in pairs on either side of the third bristle tufts  41  and tilted towards them likewise in opposite directions. The angles of tilt of the outer lying bristle tufts  43  and  42 , which are inclined in circumferential direction, are likewise acute and amount preferably to less than 20° relative to the perpendicular through the plane defined by the bristle support  10 . 
         [0067]    As  FIGS. 2 and 13  show, the bristle tufts arranged on the movable bristle support  10  have two lengths. The outer positioned fifth bristle tufts  42  lying at the very front and rear in longitudinal direction, whose free ends all lie in one plane, are longer than the remaining bristle tufts. The free ends of the fifth bristle tufts  42  define a plane. The difference in height between the bristle tufts lies in the region from 0.5 mm to 2.5 mm, preferably around 1.0 mm to 1.5 mm 
         [0068]    The bristle tufts of the auxiliary bristle set  8  are likewise of varying cross sections in terms of contour and surface area and are arranged in addition likewise at varying angles of tilt. Also, provision is made for bristle tufts of varying lengths, as will be described in the following. 
         [0069]    As  FIG. 1  shows, provision is made in the auxiliary bristle set  8  roughly speaking for three rows of bristle tufts, all of which extend approximately in the longitudinal direction of the toothbrush. The middle row lies on the longitudinal central axis of the auxiliary bristle support  13  while the two outer rows are spaced therefrom in transverse direction. 
         [0070]    In the middle bristle row all the bristle tufts are tilted toward the main bristle set. The bristle tufts have various cross-sectional areas. A first bristle tuft  44  of the fixed bristle set  8  has an oval cross section, whose longitudinal axis is approximately twice as long as its transverse axis, and sits in the middle row closer to the main bristle set  9  than bristle tufts  45  hereinafter referred to as fourth bristle tufts, which are likewise tilted rearwardly towards the handpiece. The fourth bristle tufts  45  have a round or, as the case may be, slightly oval cross section, but are constructed to be far slimmer and have a smaller cross-sectional area than the first bristle tufts  44 . 
         [0071]    The two outer rows of bristle tufts of the fixed bristle set  8 , which converge slightly towards the handpiece, as is shown in  FIG. 1 , are comprised of second, third, fifth and sixth bristle tufts. Second bristle tufts  46  have an oval cross section with a relatively slim contour. The longitudinal axis of the longitudinal cross-sectional contour amounts roughly to three times the width of the cross-sectional contour. The third bristle tufts  47  have a roughly circular cross section, with the diameter of the cross section amounting roughly to half the longitudinal axis of the cross section of the second bristle tufts  46 . The third bristle tufts are outwardly tilted away from the longitudinal central plane. Fifth bristle tufts  57  are arranged nearest to the handpiece and have a cross section roughly the same as the second bristle tufts  46  but they are inwardly tilted towards the longitudinal central plane (cf.  FIG. 1 ). By contrast, the other bristle tufts of the outer rows are not tilted. The sixth bristle tufts  58  are the thickest bristle tufts and arranged in the outer rows nearest to the main bristle set  9 . They have an elongated cross section with a longitudinal axis that is transverse to slightly oblique in relation to the longitudinal central plane. 
         [0072]    As  FIG. 1  shows, the bristle tufts of the outer two rows are arranged at varying distances to the longitudinal central axis of the brush head  2 . The distance to the longitudinal central axis decreases towards the handpiece  1 . However, the bristle tufts  47  are arranged in a row one behind the other such that their contour lies at least partly roughly behind the contour of the next bristle tufts respectively in the row. 
         [0073]    The bristle tufts of the auxiliary bristle set  8  define two working planes, as  FIG. 2  shows. The circular third bristle tufts  47  and the oval, thick sixth bristle tufts  58  in the outer rows as well as the thicker first bristle tufts  44  and the round bristle tufts  45  in the middle row are shorter, defining with their free working ends a lower plane that coincides with the plane defined by the first, second, third and fourth as well as sixth bristle tufts of the main bristle set  9 . A higher, second plane is defined by contrast by the longer slim oval bristle tufts  46  and  57  in the two outer rows. This higher plane coincides with the plane that is defined by the longer fifth bristle tufts of the main bristle set  9 . Hence in the auxiliary bristle set  8  the slimmer oval bristle tufts are of greater length than the thicker bristle tufts. 
         [0074]    Unlike the main bristle set  9  the auxiliary bristle set  8  has no circular contour but an on the whole elongated contour which at its end close to the rotary bristle set  9  embraces the latter. 
         [0075]    The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.” 
         [0076]    Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
         [0077]    While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.