OA11888A

OA11888A - Toothbrush with eccentric drive.

Info

Publication number: OA11888A
Application number: OA1200200026A
Authority: OA
Inventors: Gerhard Kienzler; Martmut Muller; Arthur Pfeifle
Original assignee: Moser Elektrogerate Gmbh
Priority date: 1999-07-28
Filing date: 2000-07-27
Publication date: 2006-03-28
Also published as: IS6214A; EA200200140A1; SK1432002A3; EE200200024A; NZ516663A; AR027180A1; AP2002002403A0; EA200200083A1; JP2004500157A; AU6438400A; NO20020332L; EA003018B1; ES2233428T3; NO20020405D0; TR200200202T2; BG106357A; EA003107B1; JP3463248B2; IL147846A0; IL147653A0

Abstract

The invention relates to a toothbrush with a brush head (1) that is supported by a brush body (10) and that is provided with a bristle support (20) that receives the bristles (22). Said bristle support is rotatably mounted about an axis of rotation on a housing section (30) of a housing and is reversibly driven by an eccentric drive (50, 52). The brush body (10) is additionally mounted on the housing section (30) in such a manner that it can be pivoted within said section.

Description

1 188 8

Toothbrush with Eccentric Drive

The invention relates to a toothbrush with a brush head according to theprearnble of claim 1.

Various designs of toothbrushes of this type are widely commercially available.The toothbrushes typically include an interchangeable brush head having arotationally symmetric brush body that receives the bristles or bundles of bristles.The brush body is rotatably supported in a housing section which is coupled withthe housing of the toothbrush for rotation about a rotation axis and is a driven byan electric motor. Such drive is described, for example, in WO 91/07116.

In this context, eccentric drives are widely used which reversibly drive the brushbody. The brush body performs an alternating rotation motion in both rotationdirections with a rotation angle of, for example, 130°. Eccentric drives of this typeare known, for example, from U.S. 4,845,795, U.S. 5,504,959 or U.S. 5,617,601. WO 96/37 164 discloses another modification of an eccentric drive for atoothbrush. In this modification, the revolving rotation motion of the drive motoris directly transmitted to a drive shaft which extends through the brush body andhas an angled end. The angled end meshes with a corresponding guide channeldisposed on the bristle carrier, thereby causing the bristle carrier to perform areversing rotation motion. This drive is mechanically simple and wear-resistant.The drive has also a small footprint, allowing the housing to be narrow andcompact.

Although such toothbrushes hâve operated satisfactorily in practice, newprogress in dental care calls for additional improvements. In particular, thesimple rotation motion of the brush body is considered to be inadéquate toreliably clean the tooth surfaces.

This prompted the superposition of a different pivoting motion on the rotation 118 8 8 motion. Such designs, which are based on eccentric drives, are described, forexample, in DE 44 33 914 A1 or WO 96/31171.

The cleaning action of such toothbrushes, however, was still not considered to beoptimal. Moreover, such toothbrushes are quite complex and hence difficult to 5 manufacture.

It is therefore an object of the présent invention to provide a toothbrush of theaforedescribed type that has a simple design and provides an improved cleaningaction in comparison to the conventional toothbrushes with a rotating drive.

The problem is solved by a toothbrush having the characterizing features of claim 1. W Advantageous embodiments of the invention are described in the dépendentdaims.

The invention is based on the concept of superimposing an additional pivotingmotion on the reversing rotation motion. In this way, the bristles held in the brushbody are pressed against the tooth surface in a high-frequency pulsating mode. 1S This induces a vibration effect acting essentially perpendicular to the toothsurface, which helps to dislodge deposits, approximately comparable to anultrasound treatment.

This is achieved by supporting the brush body on a housing section not only forrotation, but also for a pivoting motion. 20 In a first preferred embodiment, the pivoting motion that is superimposed on therotation motion can be produced by engagement of a drive pin of the eccentricdrive with the brush body in a circumferential and axial direction.

Alternatively, according to a second embodiment of the invention, the pivotingmotion that is superimposed on the rotation motion can be produced by 25 operatively connecting a bearing journal attached to a section of the toothbrushhousing with the brush body in the circumferential and axial direction. 3 118 8 8

The superimposed motion can be easily implemented through these simplemeasures.

According to a third preferred embodiment, the eccentric drive has an eccentricshaft that rotâtes in one direction and is oriented perpendicular to the rotationaxis of the bristle carrier and extends through the center of the brush body. Thedrive pin is supported by an end face of the rotating eccentric shaft. This designmakes the device mechanically simple and wear-resistant. The drive also takesup little space, making the housing narrow and compact.

In according to a fourth preferred embodiment, the brush body executes a tiltingmotion that revolves with the rotation motion. In this case, the brush body can besupported by a bearing journal that is axially offset and attached to a housingsection of the housing. The end face of the brush body facing away from thebristles has a corresponding conical recess extending in the axial direction andpointing inwardly. The bearing journal hence supports the brush body in the axialdirection. The conical shape of the recess enables the pivoting or tilting motionproduced by the eccentric drive. The cône angle has to be designed to be largeenough to allow an unobstructed pivoting motion. The bearing journal is thenable to absorb the produced axial forces in any angular position of the brushbody.

The rotating motion of the eccentric shaft can be readily transferred to the brushhead if the brush body has a radially inwardly extending conical recess, in whichthe drive pin of the eccentric shaft is directly inserted. In this case, the rotationaxis of the brush body and eccentric shaft intersect each other perpendicularly.

According to a fifth embodiment, the pivoting or tilting motion of the brush bodydoes not revolve, but is performed about a defined axis. With this arrangement,for example, an oscillating linear motion can be combined with the reversingrotation motion.

The brush body preferably has a guide channel extending in the axial direction 4 118 8 8 for guiding the drive pin of the eccentric shaft. The pivoting motion is producedby having the guide pin traverse a guide channel, making contact at the end ofthe guide channel and thereby entraining the brush body in the axial direction.Unlike the fourth embodiment, the brush body is engaged during the rotation 5 motion of the drive pin only along predetermined angular sectors. The length ofthe guide channel therefore détermines the excursion of the brush body in theaxial direction.

The guide channel can also be formed directly in the région of the peripheralsurface of the brush body. This can be accomplished in a number of ways,which will now be described with reference to certain examples.

Preferably, the guide channel is formed directly in the bristle carrier. The drivepin hereby engages directly in the guide channel, moving back and forth betweena front reversing point and a rear reversing point. The force to reversibly drive thebristle carrier is transmitted by the sides of the guide channel that extend in theaxial direction.

This design requires only a small number of movable components, runs thereforevery quiet and is suitable in particular for high-frequency applications, alsoreferred to as fast-running toothbrushes.

Preferably, the guide channel forms a part of a siiding block that is inserted in the 20 brush body. The siiding block can be inserted in an axially extending recess inthe brush body either directly or through a support, which simplifies assemblyand reduces the cost. The siiding block has the advantage over a directly built-inchannel that it can be exchanged when worn. In particular, the material can beselected independently of the material of the brush body, so that the design canbe optimally adapted to the wear characteristics.

According to another embodiment, a siiding block is axially displaceable in theguide channel, with the siiding block having a drive-pin bore adapted to engagewith the guide pin. Advantageously, with a support of this type the brush head 5 1188 8 does not follow the entire motion of the eccentric pin in the axial direction duringa révolution of the eccentric pin, but for example, is engaged only immediatelybefore the respective reversing points. The axial component responsible for thepivoting motion can thereby be arbitrarily "apportioned."

With ail the latter embodiments described above, the design of the sliding blockand the corresponding recess and/or guide channel disposed on the bristlecarrier enable a rotation and/or pivoting motion of the sliding block in a directionthat opposes the rotation motion performed by the bristle body. The drive pinengaging in the sliding block is then not subjected to bending stress.

The sliding blocks typically hâve a cylindrical shape to provide a reliable supportin the recess and/or guide channel. In another preferred embodiment, the slidingblock has a spherical shape. This arrangement advantageously minimizes thefriction forces produced between the sliding block and the recess and/or guidechannel.

The aforedescribed pivoting or tilting axis is defined, for example, by two bearingjournals that project radially outwardly and are disposed on the housing sectionof the brush head. The bearing journals engage with corresponding bearingchannels which are disposed along the circumference of the brush body. Tosimplify manufacture, the bearing channel can extend around the circumference;alternatively, bearing channels can be provided that are associated with arespective bearing journal and hâve a limited extent along the circumference.

The length along the circumference should be great enough so as not to obstructthe rotation motion of the brush body.

Accordjfig to a particularly simple design of the invention, a pivoting motion canbe produced by providing the brush body with a V- or U-shaped bearing channeldisposed opposite the eccentric shaft, wherein the bearing channel is attached tothe brush body in the axial direction along a circumferential section, essentiallymirror-symmetrically to the symmetry plane of the brush body. Moreover, at leastone bearing journal is disposed on the housing section and is guided by this bearing channel.

According to the invention, the cleaning power of a toothbrush of this type canalso be further enhanced by having the brush head perform an up-and-downmotion in addition to the reversing rotation motion and the positively guidedpivoting motion. Such a motion is akin a nutating or wobbie motion.

According to the invention, the up-and-down motion of the brush head that is partof the nutating motion, is produced by supporting the bristle carrier for axialdisplacement on the housing section and providing on the bristle carrier at leastone bearing channel that is disposed on the bristle carrier along a circumferentialsection and exhibits a pitch in the axial direction. At least.one bearing journal isdisposed on the housing section and engages in the bearing channel. Thepositively coupled bristle carrier follows the corresponding motion of the drive pinbetween the two reversing points in the axial direction and hereby produces theaxial displacement of the bristle carrier.

It should be noted, that the placement of a drive pin/bearing journal with respectto the guide/bearing channels can be reversed. In other words, the bearingjournals can also be placed on the brush head, and the corresponding channelsplaced on the housing section. Without diminishing the performance, the guidepin can also be placed on the brush head and a corresponding bore can beprovided on the eccentric shaft.

Although the aforedescribed concepts can be applied to toothbrushes in general,they are suited in particular for fast-running toothbrushes, which are also referredto as ultrasonic toothbrushes. The eccentric shaft of these toothbrushes rotâteswith a rotation speed in the range between approximately 15,000 and 25,000rpm. Such a high rotation speed places a high load on the components, inparticular due to the continuing reversai of the rotation direction of the brushbody. For these reasons, the drive should be constructed as simply as possible,which is optimally achieved by the aforedescribed measures. 1138 8

The invention will now be described with reference to the embodiments illustratedin the drawings. There is shown in:

Fig. 1 an axial cross-section of a brush head according to a first embodiment,with the brush body in a first position,

Fig. 2 the brush head according to Fig. 1, with the brush body in a secondposition,

Fig. 3 a top view of the brush head according to Fig. 1, with the brush body ina third position,

Fig. 4 an axial cross-section of a brush head according to a secondembodiment,

Fig. 5 a top view of the brush head according to Fig. 4,

Fig. 6 a brush head according to a third embodiment ("nutating head toothbrush"), a) view from below, b) view from the right, \, c) front view,

d) cross-sectional view of along A-A

Fig. 7 a brush head according to a fourth embodiment ("nutating headtoothbrush"), a) view from below, b) view from the right, c) front view, 118 8 8

d) cross-sectional view of along A-A

Fig. 8 a perspective view of the brush head according to Fig. 6,

Fig. 9 an exploded view of a toothbrush with the brush head of Fig. 6,

Fig. 10 a longitudinal cross-section of the toothbrush with the brush head of

Fig. 6 - sectional plane = mirror-symmetry plane,

Fig. 11 an axial bearing journal for the brush head of Fig. 6 and Fig. 7,

Fig. 12 a cross-sectional view of a drive according to a fifth embodiment,

Fig. 13 a cross-sectional view of a drive according to a sixth embodiment,

Fig. 14 a cross-sectional view of a drive according to a seventh embodiment. A first embodiment of a toothbrush according to the invention is illustrated in Fig. 1 to Fig. 3.

The brush head 1 has a brush body 10, with a bristle carrier 20 having bristles 22attached to one end face of the brush body 10. A conical recess 14 extending inthe axial direction and projecting inwardly is machined in the end face facingaway from the bristles 22. A corresponding bearing journal 34 projecting perpendicularly thereto andengaging with the conical recess 14 is disposed on a housing section 30. Thebrush body 10 also has a conical recess 18 which extends inwardly in a radialdirection r, with a drive pin 52 of an eccentric shaft 50 inserted into the recess 18.This results in the subsequently described mechanical movement of the brushbody 10.

The eccentric shaft 50 is driven for continuous rotation by a drive motor (notshown). The eccentric pin 52 executes a circular rotation motion U, whereby thebrush body 10 simultaneously performs a reversing rotation motion R and apivoting motion with respect to the stationary axis G. In the position illustrated in 9 1188 8

Fig. 1, the eccentric pin 52 is at the left reversai point, so that the brush body 10is tilted upwardly by the tilt angle K. Fig. 2 shows the opposite position, in whichthe brush body 10 is tilted downwardly by the tilt angle K. During a complétérévolution U of a eccentric shaft 50, the brush body 10 executes a pivotingmotion, starting from the position illustrated in Fig. 1 and continuing to theposition illustrated in Fig. 2, finally returning to the initial position of Fig. 1. Theentire tilt angle is therefore equal to 2K.

As seen with particularity from Fig. 3, the tilt motion is positively coupled with therotation motion, so that the brush body 10 is always tilted by the tilt angle K withrespect to the stationary axis G, thereby performing a sort of nutating motion.

The mechanical movement of the second embodiment depicted in Fig. 4 and Fig.5 is different from that of the first embodiment. A brush head 100 with a brushbody 110 is again provided. A bristle carrier 120 receiving bristles 122 isattached to the end face of the brush body 110. A conical axial recess 114 islocated on the opposite side. The brush body 110 is supported by the axialrecess 114 on a bearing journal 34 which is disposed on a housing section 30and projects perpendicularly therefrom.

Also provided is an eccentric shaft 50 with a drive pin 52 that can be rotatablydriven. So far, this embodiment is identical to the previously describedembodiment.

Unlike the previously described embodiment, however, two bearing journals 38are provided that project outwardly in a radial direction and engage in a bearingchannel 118 extending around the peripheral surface 116.

Also provided on the brush body 110 is a receiving opening 124 in which a sidingblock 130 is inserted that is secured to a support 134. The siding block 130 isprovided with a guide channel 132 in which the guide pin 52 engages. Thisresults in the following motion:

The bearing journals 38 allow a pivoting motion of the brush body 110 about the

JO 118 8 8 stationary axis G only in the plane depicted in Fig. 4, but not in the bisectingplane depicted in Fig. 5.

During a complété révolution U of the eccentric shaft 50, the brush body 110 is moved, starting from the position illustrated in Fig. 4 that is tilted downwardly by5 the tilt angle K, to a position (not shown) that is tilted upwardly by the tilt angle K, and finally returns to the initial position of Fig. 4. Accordingly, only a tilting motion about an axis perpendicular to the drawing plane is executed. The brush body 110 is moved alternatingly, through contact of the guide pin 52 with the respective end of the guide channel 132, so that the maximum displacement pathw and therefore the tilt angle K is determined by the length of the guide channel132 in conjunction with the position of the guide pin 52 relative to the eccentricshaft.

As seen from the foregoing, a combined rotating and tilting motion can beimplemented by using a simple design, which produces an optimal cleaning 15 effect.

The third embodiment of the toothbrush according to the invention is illustrated inFig. 6 as well as in Figs. 8 to 11.

As seen from Fig. 6, a brush head 200 of this type has a brush body 210, towhich a bristle carrier 220 with bristles is attached. The bristles are not shown in 20 the drawing for sake of clarity.

The end face 212 of the brush body 210 has an inwardly pointing recess 214extending in the axial direction. The recess 214 merges into a cône 215, whichis followed by a cavity 213 extending inwardly in the axial direction.

Bearing channels, which in the présent example are referred to as a bearingchannel of the second type 217 and bearing channel of the third type 219, areformed in the peripheral surface 216 of the brush body 210. The bearing channelof the second type 217 is located opposite to a guide channel 232. Twoopposing bearing channels of the third type 219 are located relative to an 118 8 8 imaginary mirror-symmetry plane extending through the bearing channel of thesecond type 217 and the guide channel 232.

The bearing channel of the second type 217 is essentially U-shaped in thedirection of the channel, wherein the two legs of the U-shape are arrangée!mirror-symmetrically with respect to the aforedescribed mirror symmetry plane.The bearing channels of the third type 219 also extend along a circumferentialsegment and are formed with a pitch in relation to the axial direction on the bristlecarrier.

Fig. 7 shows a brush head according to a fourth embodiment, with the Figs. 8, 9,10 and 11, like the illustrations of the third embodiment, depicting embodimentsof the toothbrush of the invention.

The brush head 300 according to Fig. 7 has the following characteristic featureswhich are similar to those of the brush head 200 depicted in Fig. 6:

The brush head 300 has a brush body 310, with an axial recess 314 disposed onthe end face 312 of the brush body 310. The axial recess 314 merges into a cône315, which terminâtes in a cavity 313. Like the brush head 220 of the previousembodiment, the peripheral surface 316 of the brush body 310 has a bearingchannel of the second type 317 and two bearing channels of the third type 319.The bearing channels of the third type 319 are again attached opposite to oneanother, whereas the bearing channel of the second type 317 is located oppositea guide channel 332. As in the previous embodiment, for sake of clarity, thebristle carrier 320 attached to the brush body 310 is shown without the bristles.

As in the previous embodiment, the bearing channel of the second type 317 is U-shaped and extends on the peripheral surface 316 of the brush body 310. As inthe previous example, the bearing channels of the third type 309 hâve pitch inthe axial direction; unlike the previous example, however, the angle of pitchchanges along the circumference.

Fig. 8 shows a perspective view of the brush head according to a third 12 118 8 8 embodiment. The following features can be seen in Fig. 8:

The brush head 400 is based on a brush body 410 and a bristle carrier 420 withbristles 422, the bristle carrier being disposed on the brush body 410. The brushbody 410 has an essentially cylindrical form with an approximately elliptical base.The end face 412 of the brush body 410 has a recess 414 in the axial direction,which in the illustrated example is cylindrical. The cylindrical axial recess 414has an inwardly pointing conical taper. The cône has the reference numéral 415.The cône 415 is merges into a cavity 413.

The "narrow sides" of the cylindrical brush body 410 having an elliptical basehâve a guide channel 432 and a bearing channel of the second type 417 (onlyhinted at in the figure) located opposite of each other. The guide channel 432 isformed as a receiving opening 424 which is conically tapered to the inside and aninwardly expanding cavity 426 subséquent to the receiving opening 424.

The "longitudinal sides" of the cylindrical brush body 410 also hâve two opposingbearing channels of the third type 419 which are constructed in a mannerdescribed above. In the présent example, the bearing channels of the secondand third type 417 and 419 are formed in the cylindrical brush body so as toProject into the cavity 413 which follows the cône 415 and hence the axial recess414.

Fig. 9 shows an exploded view of such a toothbrush with a brush head todemonstrate the insertion of the brush head according to Fig. 6 and Fig. 7 intothe housing of a toothbrush.

The toothbrush is based on a housing 560 shaped as a truncated cône, with apointed end of the housing 560 forming a housing section 562 adapted to receivethe brush head. The exemplary housing section 562 is cylindrical and placed onthe housing in such a way that the cylinder axis of the housing section 562 isessentially perpendicular to the axis of the housing 560 that is shaped as atruncated cône. 13 1188 8

The cylindrica! housing section 562 has a recess (not shown) adapted to receivethe brush body 510. An axial bearing journal 568 can be inserted centrally on thebottom of this recess. The circumference of the cylindrical housing section 562has three bores adapted for insertion in the radial direction of two bearing 5 journals 566 and a bearing journal 564. These bearing journals 564 and 566 andthe bearing journals 568 are adapted to engage with the respective bearingchannels 217, 317, 417 and 219, 319, 419, as well as with the axial recess 214,314, 414.

The housing 560 of the toothbrush forms a cavity extending in the axial direction.Also depicted in Fig. 9 is the eccentric shaft 550 that can be inserted in thiscavity. A drive pin 552 oriented in the axial direction of the eccentric shaft 550 isdisposed on the end face of the eccentric shaft 550. When the eccentric shaft550 - as intended - is inserted in the cavity of the housing 560, the drive pin 552engages directly with the guide channel 532 of the brush body 510. * Fig. 10 illustrâtes the engagement of the respective bearing pins 664, 668/ guidepins 652 with the respective bearing/guide channels of the brush head 600. Fig.10 shows a longitudinal cross-section of the toothbrush, with the brush head 600and the eccentric shaft 650 of Fig. 6 inserted. The mirror-symmetry plane of thetoothbrush 601 is selected to be the sectional plane. 0 lllustrated is a brush body 610 with a rotation axis oriented essentially perpendicular to the longitudinal axis of the housing 660 of the toothbrush 601.Also illustrated are the guide pins 652 that engage with the guide channel, theaxial bearing journals 668 that engage with the axial recess, and the radialbearing journals 664 that are secured on the housing section 662 and engage 5 with the bearing channel of the second type.

The mechanical movement of the third embodiment and the mechanicalmovement of the fourth embodiment, as illustrated in Figs. 6 to 10, areessentially identical. The following three motions are superimposed to produce anutating motion of a brush head of the electric toothbrush: 14 1. a reversing rotation motion, 2. a pivoting motion, 3. an up-and-down motion.

The reversing rotation motion is produced by the rotation motion of the eccentricshaft 550 and 650, respectively, which moves the drive pin 552 and 652 that is inengagement with the recess 214, 314, 414, back and forth between two reversaipoints. The axial recess 214, 314, 414 is so dimensioned in the axial directionthat the rotation motion of the eccentric shaft 550, 650 transmits only one force,which produces a reversing rotation motion perpendicular to the rotation axis.

The pivoting motion of the brush body 210, 310, 410, 510, 610 is produced bythe fact that the reversing rotation motion is positively guided by the engagementof the radially disposed bearing journal 564 and 664, respectively, with thebearing channel of the second type 217, 317, 417. The radial bearing journal564 and 664, respectively, that moves in a bearing channel of the second type217, 317, 417 causes the brush head to perform a tilting motion about an axislocated in the mirror-symmetry plane of the brush head.

Two bearing journals which are arranged mirror-symmetrically to the aforedescribed mirror-symmetry plane and extend in the radial direction, engageduring the reversing rotation motion with respective bearing channels of the thirdtype 219, 319 and 419 which are arranged in the brush body 210, 310, 410 andwith axial pitch in the circumferential direction, to thereby produce an up-and-down motion of the brush body 210, 310, 410, 510, 610.

The stroke or the up-and-down motion of the brush head is more lesspronounced, depending on the angle of inclination of the bearing channels of thethird type 219, 319 and 419, respectively. With the brush head of the thirdembodiment illustrated in Figs. 6, the up-and-down motion is independent of therotation angle. With the brush head of the fourth embodiment (Fig. 7), the strokeduring the reversing motion is dépendent on the rotation angle bacause the angle 15 118 8 8 of inclination increases in one direction. In the présent example, for a left-handrotation, the brush body initially moves strongly upward starting from the rightlimit stop, whereas the second half of the rotation executes only a very smalllifting stroke. Starting from the left limit stop and for a right-hand rotation of the 5 brush head, the speed of the downward motion of the brush head is exactly theopposite. Such a stroke motion with a different up-and-down velocity of thebrush causes variations in the pressure exerted by the toothbrush on the toothduring the cleaning operation. This feature further improves the cleaning effect ascompared to an embodiment relying on a brush body that executes a reversing 1° pivoting motion. The superposition of these three motions nécessitâtes a sturdydesign as well as an ability of the axial bearing journal 568 and 668, respectively,to absorb the mechanical stress load, since the bearing journal must not onlyenable the brush head to move in ail the above-described directions, must alsobe able to absorb the produced forces.

These different motions are made possible by an axial bearing journal 768illustrated in Fig. 11. The bearing journal 768 consists essentially of a cylindricalbody 774, a cylindrical neck 772 that is positioned on the cylindrical body 774and has a smaller cross-sectional area than the body 774, and an essentiallyspherical head 770 disposed on the cylindrical neck 772. 20 The body 774 is adapted to be inserted in a bore disposed on the housing section 662 and 562, respectively. The dimensions of the head 770 are selectedso that the head 770 requires very little clearance for insertion in the cavity 213,313, 413 of the axial recess 214, 314 and 414, respectively. The lengths of theneck 772 and the axial bearing journal 768 are selected so that the up-and-down 25 motion of the brush body 210, 310, 410, 510, 610 produced by the guiding of theradial bearing journal 566 that engages with the bearing channels of the thirdtype 219, 319 and 419, respectively, does not produce a mechanical bendingstress in the bearing journal 768. The cône 215, 315 and 415, respectively, ofthe axial recess 214, 314, 414 in the brush body 210, 310 and 410, respectively, 30 of the brush body 210, 310, 410, 510, 610 then moves between the spherical 16 118 8 8 head 770 and the upper edge of the body 774 along the neck 772 of the axialbearing journal 768.

Figs. 12 to 14 show in cross-section different drives according to additionalembodiments. In particular, these figures are intended to show how a revolvingrotation motion of the eccentric shaft can be transformed into a reversing rotationmotion.

The embodiment of the toothbrush depicted in Fig. 12 illustrâtes how a reversingrotation motion can be produced with the help of a sliding block that is inserted ina guide channel disposed on the brush body.

The toothbrush consists of a handle portion 880 to which a housing 860 with abrush body 810 can be connected. A motor 890 is disposed in the handle portion880, with the motor being connected via a respective gear with an eccentric shaft850 which is guided inside the housing 860. The front section of the housing 860includes a housing section 862 into which the brush head 800 can be inserted.

The brush body 810 is movably supported in the housing section 862 through anaxial bearing journal 868 and a radial bearing journal 864 in a manner describedabove.

The bristle carrier 820 has a guide channel 832 adapted to receive a sliding block830 that can move axially. A drive pin 852 of the eccentric shaft 850 engages ina drive-pin bore 836 disposed on the sliding block 830. In this way, the slidingblock 830 is positively coupled with the drive pin 852 and can move freely in theguide channel 832 back and forth between two reversing points.

The drive-pin bore 836 receives the drive pin 852 essentially without play. Therelative motion of the drive pin 852 in the height direction and in the rotationdirection is substantially unobstructed to minimize friction losses.

As seen with particularity from the enlarged schematic diagram X, the drive pin852 in the selected cross-sectional view is located at the left reversai point. 17 118 8 8

When the rotation begins, the position of the drive pin shifts to the right until thedrive pin reaches its right reversai point. The brush body 810 executes a rotationmotion. Later during the rotation motion, the drive pin 852 returns to its initialposition, whereby the brush carrier 820 moves in the opposite direction. A reliable motion requires that the eccentric pin 852, on one hand, can movefreely in the guide channel 832 between the two reversing points, and on theother hand, is guided laterally with a relatively smal! clearance, so that thereversing motion can be converted essentially without play. In addition, thesliding block 830 has to be supported in the guide channel 832 for rotation aboutits longitudinal axis. The sliding block 830 can then execute a compensatingmotion in a direction opposing the rotation direction of the bristle carrier 820,thereby eliminating bending stress of the engaging drive pin 852. The slidingblock 830 and the guide channel 832 hâve a matching circular cross-sectionwhich allows a compensating motion essentially without play and with reducedfriction. Lastly, the eccentric pin 852 should be long enough to always maintaincontact when following the changing height position of sliding block 830.

The brush head 900 depicted in Fig. 13 is essentially identical to theaforedescribed embodiment.

Once more, a brush head 900 having a bearing journal 968 is provided. Thebristle carrier 920 is supported by an axial recess 914 for (in particular)longitudinal displacement.

The bristle carrier 920 has an axial guide channel 932 in which a sliding block930 is supported for axial displacement. The sliding block 930 has a drive-pinbore 936 in which a drive pin 952 engages on the eccentric shaft 950.

The basic design is so far identical to the embodiment described with referenceto Fig. 12. The différence is, however, that the sliding block 930 has thespherical shape.

The embodiment of a toothbrush with a brush head 1000 illustrated in Fig. 14 is 18 118 8 8 essentially identical to the embodiments described with référencé to Figs. 12 and 13.

Once more, a brush body 1010 with a bristle carrier 1020 is iilustrated whichtogether form a brush head 1000. The bristle carrier 1020 with bristles 1022 is,as in the aforedescribed embodiments, rotatably (and longitudinally displaceably)supported by the bearing journal that coopérâtes with the axial recess 1014. Theaxial recess 1014 consists, as described in detail above, of a cône 1015 and thefollowing cavity 1013. The radial bearing journal 1064 that engages with abearing channel 1017 positively guides the brush body 1010 in the housingsection 1060.

So far, the basic design is essential to the embodiments described with référencéto Figs. 12 and 13. The différence is, however, that the guide pin 1052 whichcan be rotated by a motor operating on the eccentric shaft 1050, engages directlywith a guide channel 1032.

This results in the following to mechanical movement: ^5 The eccentric pin 1052 moves - driven by the motor-driven eccentric shaft 1050 -freely back and forth in the guide channel 1032 between front and rear reversaipoints. A force is transmitted from the drive pin 1052 to the bristle carrier 1020via the sides of the guide channel 1032 which extend in the axial direction of thebrush body 1010. To eliminate bending stress on the guide pin 1052 that 20 engages with the guide channel 1032, the guide channel 1032 has a cavity 1022which extends inwardly in the radial direction. The cavity 1026 receives the freeend of the drive pin 1052 while maintaining a gap from the inner wall of the cavity1026. In addition, the receiving opening 1024 of the guide channel 1032expands conically outwardly in the radial direction. 25 This embodiment advantageously requires only a small number of moveableparts, and hence opérâtes quietly and is particularly appropriate for highfrequency applications, so-called fast-running toothbrushes. These toothbrushes 19 118 8 8 hâve an eccentric shaft rotating with a rotation speed in the range between15,000 and 25,000 rpm. At these high rotation speeds, the componentsexpérience a particularly high stress which is caused mainly by the continuingreversai in the direction of the bristle body. It is therefore désirable to design asimple toothbrush that can be easily operated, which is optimally provided by theaforedescribed measures. 20

List of reference numerals 1 1 A ft 8 1 brush head 10 brush body 12 end face 14 axial recess 16 peripherai surface 18 radial recess 20 bristle carrier 22 bristles 30 housing section 34 axial bearing journal 38 radial bearing journal 50 eccentric shaft 52 drive pin 100 brush head 110 brush body 112 end face 114 axial recess 116 peripherai surface 118 bearing channel of the first type 120 bristle carrier 122 bristles 124 receiving opening 130 sliding block 132 guide channel 134 support 210 brush body 212 end face 213 cavity 214 axial recess 215 cône 216 peripherai surface 217 bearing channel of the second type219 bearing channel of the third type 21 118 8 8 220 brislle carrier 232 guide charinel 310 brush body 312 end face 313 cavity 314 axial recess 315 cône 316 peripheral surface 318 bearing channel of the second type 319 bearing channel of the third type 320 bristle carrier 332 guide channel 410 brush body 412 end face 413 cavity 414 axial recess 415 cône 416 peripheral surface 417 bearing channel of the second type 419 bearing channel of the third type 420 bristle carrier 422 bristles 424 receiving opening 426 cavity 432 guide channel 510 brush body 550 eccentric shaft 552 drive pin 560 housing 562 housing section receiving the brush head 564 radial bearing journal 566 radial bearing journal 568 axial bearing journal 22 610 brush body 601 toothbrush 650 eccentric shaft 652 drive pin 660 housing 662 housing section 664 radial bearing journal 668 axial bearing journal 768 axial bearing journal 770 head 772 neck 774 body 810 brush body 820 bristle carrier 830 sliding block 832 guide channel 836 drive-pin bore 850 eccentric shaft 852 drive pin 860 housing 862 housing section 864 radial bearing journal 868 axial bearing journal 880 handle portion 890 motor 900 brush head 910 brush body 914 axial recess 920 bristle carrier 922 bristles 930 sliding block 932 guide channel 936 drive-pin bore 950 eccentric shaft 118 8 8 23 952 drive pin 1188 8 960 housing 962 housing section 964 radial bearing journal 968 axial bearing journal 1000 brush head 1010 brush body 1013 cavity 1014 axial recess 1015 cône 1017 bearing channel of the second type 1020 bristle carrier 1022 bristles 1024 receiving opening 1026 cavity 1032 guide channel 1050 eccentric shaft 1052 drive pin 1060 housing 1062 housing section 1064 radial bearing journal 1068 axial bearing journal ax axial direction r radial direction u circumferential direction K tilt angle R rotation motion brush body U rotation motion eccentric shaft G rotation axis

Claims

24 New Clairns 1188 8

1. Toothbrush with a brush head (1,100, 200, 300, 400, 500, 600, 800, 900, 1000) in which a brush body (10,110, 210, 310, 410, 910, 1010) is rotatablysupported on a housing section (30, 562, 662, 862, 962, 1062) for rotation abouta rotation axis (G) and reversibly driveable by an eccentric drive (50, 52; 550, 5 552; 650, 652; 850, 852; 950, 952; 1050, 1052), the brush body including a bristle carrier (20, 120, 220, 320, 420, 820, 920, 1020) adapted to receive bristles(22, 122, 422, 922, 1022), wherein the brush body (10,110, 210, 310, 410, 910,1010) is also pivotally supported on the housing section (30, 562, 662, 862, 962,1062), and wherein the eccentric drive (50, 52; 550, 552; 650, 652; 850, 852; 10 950, 952; 1050, 1052) has an eccentric shaft (50, 550, 650, 850, 950, 1050) that rotâtes in one direction, with the eccentric shaft arranged so as to beperpendicular to the rotation axis (G) of the bristle carrier (20, 120, 220, 320, 420,820, 920, 1020), characterized in that the eccentric drive (50, 52; 550, 552; 650, 652; 850, 852; 950, 952; 1050,1052) supports on its end face a drive pin (52, 552, 652, 852, 952, 1052)operatively associated with the brush body (10,110, 210, 310, 410, 910, 1010) forurging in the circumferential direction (U), that the brush body (10,110, 210, 310,410, 910, 1010) has a conical recess (14, 114, 214, 314, 414, 914, 1014) that is 20 oriented axially inwardly and disposed on the end face (12, 112, 212, 312, 412)that faces away from the bristles (22, 122, 422, 922, 1022), said recesscooperating with a bearing journal (34, 568, 668, 768, 868, 968, 1068) which isattached to a housing section (30, 562, 662, 862, 962, 1062) and projects axiallytherefrom, so that the brush body is pivotable about a tilt angle (K) relative to the 25 rotation axis (R). 25 113 8 8
2. Toothbrush according to claim 1, characterized in that for producing a pivoting motion that is superimposed to the rotation motion(R), a drive pin (52) of the eccentric drive (50, 52) is operatively connectée! withthe brush body (10,110, 210, 310, 410, 910, 1010) for urging in thecircumferential direction (U) and in the axial direction (ax).
3. Toothbrush according to claim 1 or 2, characterized in that for producing a pivoting motion that is superimposed to the rotation motion(R), a bearing journal (564, 664, 964, 1064) disposed on a housing section (562,662, 862, 962, 1062) is operatively connected with the brush body (10,110, 210,310, 410, 910,1010) in the circumferential direction (U) and in the axial direction(ax).
4. Toothbrush according to one of the daims 1 to 3, 15 characterized in that the eccentric drive (50, 52; 550, 552; 650, 652; 850, 852; 950, 952; 1050,1052) has an eccentric shaft (50, 550, 650, 850, 950, 1050) that rotâtes in onedirection, with the eccentric shaft arranged so as to be perpendicular to therotation axis (G) of the bristle carrier (20, 120, 220, 320, 420, 820, 920, 1020) 20 and aligned with the center of the brush body (10,110, 210, 310, 410, 910, 1010) 26 Μ 8 8 8 and supporting on its end face the drive pin (52, 552, 652, 852, 952, 1052).
5. Toothbrush according to one of the ciaims 1 to 4, characterized in that the brush body (10) has a radially inwardly extending conical recess (18) in5 which the guide pin (52) is inserted.
6. Toothbrush according to one of the ciaims 1 to 4, characterized in that the brush body (110) has a guide channel (132) extending in the axialdirection (ax), in which the drive pin (52) is guided.
7. Toothbrush according to claim 6, characterized in that the guide channel (232, 332, 432, 1032) is formed directly in the brush body(210, 310, 410, 1010).
8. Toothbrush according to claim 6 or 7, ^5 characterized in that the guide channel (132) is - alternative^ or in addition - a component of asliding block (130) which is inserted in the brush body (110). 27 118 8 8
9. Toothbrush according to claim 8, characterized in that the sliding block (130) is fixed on the brush body (110) in the axial direction.
10. Toothbrush according to claim 8, 5 characterized in that a sliding block (830, 930) is supported in the guide channel(832, 932) for axial displacement, and that the sliding block (830, 930) has a drive-pin bore (836, 936)adapter for engagement with the drive pin (852, 852, 952).
11. Toothbrush according to one of the daims 8 to 10, characterized in that the sliding block (830, 930) is shaped as a sphere or a cylinder.
12. Toothbrush according to one of the daims 1 to 11, characterized in 15 that the brush body (110) has two opposing bearing channels of a first type extending in the circumferential direction (U) or a bearing channel (118) of thefirst type that extends at least over most of the circumference, wherein thebearing channels cooperate with corresponding bearing journals (38) which are 28 1188 8 attachée! to the housing section (30) and project radially therefrom.
13. Toothbrush according to one of the daims 1 to 12, characterized in that the brush body (210, 310, 410, 510, 1010) has a bearing5 channel of the second type (217, 317, 417) facing the eccentric shaft (850, 950, 1050), with the bearing channel (217, 317, 417) attached to the brush body (210,310, 410, 910, 1010) along a circumferential section and formed in the shape ofa V or U in the axial direction essentially mirror-symmetrically to the symmetryplane of the brush body, and 1° - that at least one bearing journal (564, 664, 964, 1064) which is guided in the bearing channel of the second type (217, 317, 417), is disposed onthe housing section (562, 662, 862, 962, 1062).
14. Toothbrush according to one of the daims 1 to 13, characterized in - that the bristle carrier (220, 320, 420, 820, 920, 1020) is supportedfor axial displacement on the housing section (560, 660, 860, 960, 1060) and hasat least the bearing channel of the third type (219, 319, 419) which is disposedon the bristle carrier (220, 320, 420, 820, 920, 1020) along a circumferentialsection and having pitch in the axial direction, and 20 that at least one bearing journal (566) which is guided in thebearing channel of the third type (219, 319, 419), is disposed on the a housingsection (562, 662, 862, 962, 1062).
15. Toothbrush according to one of the preceding daims, 29 characterized in 118 8 8 that an enci face of the guide pin (52) is secured on a drive shaft (50) that can bedriven with a rotation speed in a range of 15,000 to 25,000 rpm.