Brush for a sonic toothbrush with longitudinal axis vibration

Abstract

A brush (10) for a sonic toothbrush with longitudinal axis oscillation, comprising an elongated base body, has a truncated cone-shaped foot (11) with a drive adapter for rotationally fixed coupling to a sonic toothbrush drive with longitudinal axis oscillation, as well as a head (13) with a bristle carrier in which a plurality of bristles are anchored, and an elongated neck (12) connecting the foot (11) and head (13). The base body forms a bend angle such that a geometric longitudinal axis (20) of the foot and a geometric alignment axis of the head enclose an angle γ in the range of 5° to 12°. A geometric bend position (22) in the base body is at least 50% of the total length of the base body away from an end face of the foot (11).A sonic toothbrush with longitudinal axis vibration comprises a brush (10) and a handle with a brush coupling for detachably attaching the brush (10) to the handle, as well as a drive (16) which generates a longitudinal axis vibration at the brush coupling.

Description

Technical field

[0001] The invention relates to a brush for a sonic toothbrush with longitudinal axis vibration, comprising an elongated base body with a foot section and a drive adapter for rotationally fixed coupling to a sonic toothbrush drive with longitudinal axis vibration, wherein the drive adapter defines a geometric longitudinal axis of the brush foot section. The base body further comprises a head section with an <opfteil-Ausrichtungsachse und einen Borstenträger, in welchen eine Vielzahl von Borsten verankert ist, wobei die Borsten im Wesentlichen senkrecht von der I<opfteil-Ausrichtungsachse der Bürste weg ragen. Und schliesslich hat der Grundkörper einen im Vergleich zu Kopfteil und Fussteil querschnittsverjüngten Halsteil, der Fussteil und Kopfteil verbindet. State of the art

[0002] There are different types of electrically powered toothbrushes.

[0003] The principle of a round brush head that can rotate around an axis parallel to the bristle direction and is moved back and forth around this axis is known from patent publications DE 10 2016 011477 (Schiffer), EP 2'454'967 A1 (Braun), WO 2005 046508 A1 (Trisa), and others. The advantage of this arrangement is that the moving part (namely the round brush head) is very small. It requires little drive energy, and the forces (torques) involved tend to be small. The disadvantage of this principle is that the bristle movement depends on the distance from the axis of rotation. The closer the bristles are to the axis of the brush head, the smaller the back-and-forth movement. The movement pattern is therefore very inhomogeneously distributed across the bristle field.

[0004] From the printed materials JP H04-43127 (I <ao), US 2006 168744 A1 (Butler), US 2012 / 0291212 (Montagnino) und anderen ist das Prinzip der Pendelbewegung bekannt. Dabei pendelt die Bürste um eine Pendelachse, die senkrecht zum Handapparat (Antrieb) und zur aufgesetzten Bürste steht und die die Längserstreckungsachse von Handapparat und Bürste am Ort der Kopplung der Bürste an den Handapparat schneidet. Der Vorteil ist, dass die Bewegungsintensität über das ganze Borstenfeld homogen verteilt ist. Alle Borsten haben nämlich mehr oder weniger den gleichen Abstand von der Pendelachse. Der Nachteil besteht allerdings darin, dass relativ grosse Kräfte (Momente) auftreten, weil der Bürstenkopf mit seiner Masse relativ weit von der Pendelachse entfernt ist.

[0005] The principle of housing vibration is known from publications JP 2012-161368 (Sanion), DE 299 13 406 U1 (Rowenta), US 6,766,548 B1 (Rowenta), WO 2005 046508 A1 (Trisa), WO 2013 / 104020 A1 (Erskine), and others. A drive unit in the handle or brush neck generates an unspecified vibration that is transmitted to the bristles. The advantage of this design is that one does not need to concern oneself with the technical details of the motion transmission. The disadvantage, however, is that the entire housing must be vibrated, and therefore more drive energy is required than if only a small part needed to be vibrated. Furthermore, the vibration must not be too strong, as this impairs comfort when holding the handle. Finally, the effective movements of the bristles are unknown, and the effect of cleaning with this type of undefined and uncontrolled vibration is far from optimal.

[0006] Another principle is known from publications WO 2012-151259 A1 (Water Pik), EP 2'548'531 B1 (Trisa), and others. Here, the handpiece has a coupling pin that rotates back and forth around its longitudinal axis. The brush attached to the coupling pin has a straight neck and a bristle plate at the end, from which the bristles are oriented perpendicular to the longitudinal axis of the handpiece or brush neck. The advantage of this geometry is that relatively low forces (moments) occur because the mass (neck, bristle plate) of the brush head is relatively close to the longitudinal axis (center of motion). The intensity of movement is also relatively evenly distributed across the bristle field. However, the disadvantage of this principle is that the bristles only perform a one-dimensional movement (back and forth).Firstly, this results in an unsatisfactory foaming effect for the toothpaste, and secondly, it lacks the advantage of the circular and therefore gentle yet efficient movement, which specialists have been teaching as advantageous in connection with manual toothbrushes for decades.

[0007] With manual toothbrushes, it is well known that the cleaning effect depends on the stiffness of the bristles. Bristles of different stiffness have different cleaning effects and varying potential for damage, depending on their intended use. These effects are well-known in professional circles and are regularly taken into account when advising patients.

[0008] Sonic toothbrushes are very convenient for the user and are also considered efficient because the electrically powered brush makes the movements much faster than you can do by hand.

[0009] With sonic toothbrushes, it has been assumed so far that the cleaning is better the higher the frequency of the motor and the greater the cleaning movement of the bristles.

[0010] From WO 2017 / 050612 A1 (Curaden), a sonic toothbrush with an angled brush head is known. The forward angle of the sonic toothbrush improves access to different areas of the mouth. Furthermore, the angle causes the brush filaments to vibrate with a greater amplitude perpendicular to the brush's longitudinal axis. The preferred operating frequency is between 2000 and 8000 Hz. However, the frequencies can also be higher, for example at 10 kHz or 50 kHz, or lower, for example at 200 Hz or 500 Hz.

[0011] US Patent 2012 / 0291212 A1 discloses an ultrasonic toothbrush which has two parallel channels running perpendicular to the longitudinal axis of the brush to increase the resonant frequency. The frequency is increased in the forward-backward direction when the two channels are located at the front. If the channels are located on the left and right sides of the brush neck, the frequency increases in the lateral direction. Disadvantages:

[0012] There is still a lack of sufficient understanding of the cleaning behavior of sonic toothbrushes. Current knowledge regarding the cleaning effectiveness of manual toothbrushes cannot be applied to the highly dynamic situation of a sonic toothbrush. Description of the invention

[0013] The object of the invention is to create a toothbrush for sonic toothbrushes belonging to the aforementioned technical field, which has a better cleaning effect, particularly one that is gentler on the gums. In particular, a defined and controlled two-dimensional movement of the bristles is to be generated.

[0014] The solution is defined by claim 1. The brush body has a bend angle such that the geometric longitudinal axis of the foot section and a geometric I <opfteil-Ausrichtungsachse einen Winkel γ (gamma) im Bereich von 8° bis 15° einschliessen. Als zweites wichtiges Merkmal kommt hinzu, dass der Grundkörper ein tragendes Material mit einem E-Modul von nicht mehr als 6000 MPa und nicht weniger als 2000 MPa aufweist (MPa = Megapascale).

[0015] The sonic toothbrush according to the invention essentially generates a vibration of the brush head around its longitudinal axis, i.e., around the longitudinal axis of the base (defined here as the x-axis). The bristles primarily perform a wiping motion perpendicular to this longitudinal axis (defined here as the y-axis). A particular advantage of the brush according to the invention lies in the fact that, due to the selected material parameters, it possesses a certain elasticity and therefore, at the intended vibration frequency, also vibrates in the direction of the longitudinal movement (x-axis). This results in a movement that can be described as a figure-eight motion. The bristles move synchronously in the x- and y-directions, following a figure-eight pattern. Such a movement is particularly advantageous for dental care in several respects.

[0016] The combination of a sufficiently large bending angle of at least 8° and a modulus of elasticity that provides sufficient (but not excessive) flexibility results in a two-dimensional movement of the brush head. This movement at the anchored end of the bristles controls the movement of the bristles at their cleaning end (free end of the bristles). The upper limit of the bending angle and the lower limit of the modulus of elasticity ensure that the brush head remains sufficiently stable so that the undesirable "flapping" movement (in the longitudinal direction of the bristles – i.e., along the z-axis) does not occur to an excessively high (and potentially harmful) degree.

[0017] However, it is definitely an advantage of the present brush design that the brush performs a slight "tilting" motion in the direction of the bristles (defined here as the z-direction), because this essentially propels the mixture of saliva and toothpaste "forward" into the interdental spaces. This is particularly important for single-tufted toothbrushes, which are specifically designed for improved interdental cleaning.

[0018] The invention is based on the following fundamental features: a) The brush has a base to which an adapter for the handle, a so-called drive adapter, is attached. The adapter is geometrically designed to be connected to a coupling element (e.g., a pin) of the sonic toothbrush drive in a rotationally fixed (but replaceable) manner. The sonic toothbrush drive generates a longitudinal axis vibration that is transmitted to the brush. The drive adapter defines a geometric longitudinal axis (x) of the brush base. This longitudinal axis is normally the direction in which the brush can be attached to the handle. b) Furthermore, the brush has a head with a bristle holder in which a multitude of bristles are anchored (bristle field). The head is essentially the upper end of the brush (whereas the base forms the lower end). The head defines an <opfteil-Ausrichtungsachse. Die im Kopf verankerten Borsten ragen z.B. quer zur I<opfteil-Ausrichtungsachse weg.Typically, but not necessarily, the bristles are perpendicular to the I <opfteil-Ausrichtungsachse. c) Zwischen Fussteil und Kopfteil hat der Grundkörper ein Halsteil. Der Halsteil verbindet also Fussteil und Kopfteil miteinander. Er ist im Vergleich zum Fussteil querschnittsverjüngt. Das heisst, wenn man den Fussteil im Querschnitt (bezogen auf die Fussteil-Längsachse) betrachtet, dann sind die Abmessungen in x- oder y-Richtung kleiner als beim Querschnitt des Halsteils (also quer zur Halsteil-Längsachse). Dabei ist querschnittsverjüngt auf die Querschnittsfläche zu beziehen. Es ist also nicht zwingend, dass die Abmessungen in x-Richtung und y-Richtung geringer sind. .

[0019] Preferably, the modulus of elasticity is at least 2500 MPa, and particularly at least 3000 MPa. This ensures a base body that is sufficiently rigid to optimally transmit longitudinal axis vibrations.

[0020] In certain variants of the invention (e.g., with rather small bending angles in the range of 8°), the modulus of elasticity can tend to be lower (e.g., 2000 MPa to 3000 MPa) than with large bending angles (e.g., at 15°).

[0021] Another special design is characterized by the fact that the modulus of elasticity of the load-bearing material (or materials) of the base body is in the range of 4000 MPa to 6000 MPa.

[0022] If the mass of the head section is relatively large in relation to the cross-section of the neck section, then an E-modulus in the range of 5000 MPa to 6000 MPa is advantageous.

[0023] According to a particular design, the neck part is curved in a longitudinal arc, thereby creating the angle between the longitudinal axis of the foot part and the I <opfteil-Ausrichtungsachse. Mit anderen Worten: Fussteil und Kopfteil sind in sich geradlinig. Nur der Halsteil ist gekrümmt. Dies hat den Vorteil, dass sich die bei der Längsachsenschwingung auftretenden Kräfte auf den Halsteil verteilen und nicht konzentriert an einer Stelle auftreten.

[0024] According to a particular embodiment, the neck section is a slender segment of the base body between the head and foot sections. The foot section typically has the largest cross-section at the drive adapter (foot end) and the smallest cross-section at the transition to the neck section.

[0025] The head section is essentially defined by the fact that it forms the anchoring point for the bristles.

[0026] Preferably, the head section is plate-shaped and the neck section is rod-shaped. The head section is therefore flat in cross-section (i.e., in the plane perpendicular to the I). <opfteil-Ausrichtungsachse) in der einen Richtung (z.B. y-Richtung) breiter als in der anderen Richtung (z.B. z-Richtung). Die Form des Querschnitts kann beispielsweise rechteckig, trapezförmig oder oval sein.

[0027] The neck section, for example, can be circular, oval, square, hexagonal, octagonal, trapezoidal, or a geometric approximation or variation of such a shape in cross-section. The cross-sectional shape does not have to be rotationally symmetrical.

[0028] According to a first particular embodiment, the head part is at least about twice as wide as the neck part.

[0029] According to a second particular embodiment, the head section is at most approximately 1.5 times as long as the neck section. This can also be combined with the previously mentioned embodiment.

[0030] According to a third particular embodiment, the head part is spanned in a cross-section through the longitudinal axis of the brush and the I <opfausrichtungsachse etwa gleich dick wie der Halsteil.

[0031] The head section is preferably two to three times wider and 0.5 to 1.5 times longer than the neck section. The relatively slim neck section, compared to the head section, allows for particularly good vibration and thus optimal cleaning of the teeth.

[0032] According to the above dimensions, the head section thus forms a kind of momentum mass and the neck section a kind of (slender) elastic rod.

[0033] In some variations, the head section can be less than twice as wide and more than 1.5 times as long as the neck section.

[0034] According to a preferred embodiment, the head part is spanned in a cross-section through the longitudinal axis (x) and the I <opfausrichtungsachse etwa gleich dick wie der Halsteil. Ist der Kopfteil plattenförmig, dann ist also der Halsteil etwas gleich dick wie die I<opfteilplatte.

[0035] In a particular embodiment, the head section has a mass (i.e., inertial mass) that is greater than the mass of the neck section; in particular, the head section has a mass that is preferably more than 30%, and more preferably more than 50%, greater than the mass of the neck section. This mass distribution can be achieved either by appropriate geometric dimensions, by using different materials, or by both.

[0036] The relatively large mass of the head compared to the neck section optimizes the nodding motion of the brush head during use. This greater mass amplifies the momentum of the nodding motion, thereby intensifying the two-dimensional figure-eight movement and improving access to the interdental spaces. This is particularly advantageous, but not exclusively, for single-tufted brushes and interdental cleaning.

[0037] In one variation, the headpiece can also have a mass that is less than 30% greater than the mass of the neck piece; in particular, the masses of the headpiece and the neck piece can also be approximately the same. This is the case, for example, if the headpiece is the same thickness as the neck piece, and if the neck piece is three times as long as the headpiece and three times as wide as the neck piece.

[0038] Preferably, the base is approximately the same length as the head. This ensures the base is large enough to achieve a stable attachment to the sonic toothbrush drive (e.g., with a long adapter channel for a correspondingly long handle). The vibration, and thus the kinetic energy of the drive, will be efficiently transferred to the head via the neck section.

[0039] In one particular design, the base is shorter than the head, specifically about half the length of the head. This allows for more design freedom in the neck section. Furthermore, if, in this design, the drive adapter is a slim pin on the brush head that is inserted into an adapter channel in the handle, then the secure attachment to the sonic toothbrush drive is concealed.

[0040] In some variations, the foot section can also be longer than the head section.

[0041] Preferably, the neck section has a transverse dimension that is no more than one-quarter of the length of the neck section. The transverse dimension is understood to be a diameter perpendicular to the geometric axis of orientation or perpendicular to the longitudinal axis of the foot section. Where the neck section joins the head section, the I <opfteil-Ausrichtungsachse massgeblich und dort, wo der Halsteil an den Fussteil anschliesst, ist die Fussteil-Längsachse massgeblich. Der Halsteil wird damit bewusst schlank gehalten, so dass damit das Schwingungsverhalten des Kopfteils unterstützt werden kann, insbesondere das Schwingungsverhalten in der Ebene (die "8"-Bewegung) und die Nickbewegung.

[0042] In some variations, the cross dimension can also be more than a quarter of the length of the neck section. This can be useful, for example, if a particularly flexible or elastic material is used for the neck section.

[0043] Preferably, the base body consists essentially of a single piece of a load-bearing material. This achieves, on the one hand, a particularly cost-effective manufacturing of the base body. On the other hand, it also enables particularly optimal vibration behavior, since no interfaces between different materials disrupt the vibration behavior, especially 2-dimensional or 3-dimensional vibration behavior, where such an interface would be distorted by the vibration pattern in different directions.

[0044] Within the scope of the invention, a one-piece base body made of a load-bearing material is also referred to even if the surface of the brush is coated or encased by a non-load-bearing material. For example, in the case of a one-piece base body, areas made of a material with increased roughness or surface grip can be provided on the foot section, so that the brush can be more easily removed from the drive pin with the fingers.

[0045] According to a particular embodiment, the base body is essentially formed by two material parts bonded together. For example, if the foot section is injection-molded from a different plastic than the neck and head of the brush, then a very rigid plastic (with a high modulus of elasticity) can be used to ensure that the coupling to the drive pin on the handle optimally transmits the drive's movement to the brush. At the same time, the neck can be designed with sufficient elasticity using a less rigid material (the modulus of elasticity of the neck material is lower than that of the foot section).

[0046] Another special design is characterized by the fact that the main body is essentially formed from three load-bearing material parts bonded together. For example, the main body can consist of two material parts of different strengths bonded together lengthwise. Furthermore, it is conceivable that the head section, neck section, and foot section are each made of different materials. The requirements for the head section differ from those for the foot section, which can be optimized through the choice of material.

[0047] A basic body made of two or three load-bearing materials bonded together can be produced, for example, using modern plastic injection molding processes with two or three materials.

[0048] Even on the main body with the two or three load-bearing material parts, non-load-bearing (e.g. soft) sheath layers may still be present to achieve certain functions (e.g. protection when the back of the brush comes into contact with the teeth).

[0049] Preferably, the brush head has a deflection of 10%–20% relative to the brush length. Here, deflection is defined as the ratio of the distance of a center point (center of gravity) of the brush head to the adapter's longitudinal axis, divided by the total length L (in the x-direction) of the base body. The deflection can be considered the "eccentricity of the brush head with respect to the adapter's longitudinal axis." The deflection is crucial for the vibration pattern: it has been observed that with a deflection of 10%–20%, the figure-eight motion is particularly pronounced.

[0050] The deflection can also be less than 10% or greater than 20%. For brushes with a short overall length, the deflection is preferably chosen to be in the range of 20% so that the "imbalance" of the head does not become too small. For brushes intended for high operating frequencies (e.g., above 240 Hz), the deflection is more likely to be in the range of 10%, because at higher frequencies the "imbalance" of the head could otherwise become too large.

[0051] According to a particular design, the bristles protrude essentially perpendicularly from the I <opfteil-Ausrichtungsachse der Bürste weg. Der Winkel zwischen der Fussteil-Längsachse und der Borstenrichtung beträgt dann 90° minus Knickwinkel γ (gamma). Bei einem Knickwinkel von beispielsweise γ = 11° ergibt sich 90° - 11° = 79°.

[0052] The bristles are anchored, for example, on the main surface of the plate-shaped head. However, in the case of a single-tuft brush, the head can also be rod-shaped, with the single tuft anchored in a cylindrical recess (e.g., a blind hole).

[0053] The distance between the geometric bending position and the end surface of the base is preferably at least 50% of the length of the base body. This, in conjunction with the inventive range of the Young's modulus, defines a particularly optimal range for the geometric bending position, which, according to experiments, leads to particularly advantageous 2-dimensional and 3-dimensional vibration patterns. This enables particularly effective and gentle tooth cleaning.

[0054] The geometric bending position is determined by an intersection point between the geometric longitudinal axis of the foot section and the geometric I <opfteil-Ausrichtungsachse definiert. An der geometrischen Knickposition muss also nicht zwingend eine knickartige (oder knieartige) Richtungsänderung des Grundkörpers vorhanden sein. Vorzugsweise befindet sich die geometrische Knickposition innerhalb des Grundkörpers. Die Form des Grundkörpers muss nicht zwingend einen optisch erkennbaren Knick umfassen, sondern kann zum Beispiel bogenförmig ausgebildet sein. In Varianten kann weiter die geometrische Knickposition auch ausserhalb des Grundkörpers liegen. Dem Fachmann sind weitere Variationen bekannt.

[0055] The distance between the end face of the foot section and the bending point is measured along the longitudinal axis of the foot section. Similarly, the total length of the base body is measured along the longitudinal axis of the foot section.

[0056] According to the invention, the geometric bending position has a relatively large distance from the headboard in order to be in relation to the angle γ (gamma) between the geometric longitudinal axis of the footboard and the geometric I <opfteil-Ausrichtungsachse von 8° bis 15° einen besonders gutes Schwingungsverhalten zur Reinigung der Zähne zu erreichen. Je grösser der Winkel gewählt wird, desto stärker wird die Auslenkung des Kopfteils von der Fussteil-Längsachse (Exzentrizität). Ebenso wird die Exzentrizität grösser, wenn die Knickposition weiter von dem Kopfteil entfernt wird. Es hat sich aber gezeigt, dass die beiden Parameter (Knickposition und Winkel) das Schwingungsverhalten nicht in demselben Masse und in derselben Art und Weise beeinflussen, so dass hinsichtlich der Reinigungswirkung z.B.An increase in the angle cannot be directly compensated for by a smaller distance between the bending position and the headboard, since the 2-dimensional and 3-dimensional vibration pattern of the headboard react differently to the two parameters.

[0057] In some variations, the distance between the geometric bending position and the end surface of the foot section can also be less than 50% of the length of the base body, e.g., at least 35%.

[0058] Preferably, a geometric longitudinal axis of the foot section and a geometric I <opfteil-Ausrichtungsachse einen Winkel γ (gamma) im Bereich von 10° bis 14° ein. Dieser Winkelbereich hat sich bei Experimenten als besonders vorteilhaft erwiesen, so dass damit für die Zahnreinigung ein besonders ideales Schwingungsbild erreicht werden kann. Experimente haben gezeigt, dass damit das Schwingungsbild, insbesondere die "8" Bewegung besonders vorteilhaft ausgeprägt ist, womit die Zahnreinigung mit der Bürste besonders schonend durchgeführt werden kann. Der Winkelbereich hat sich weiter im Zusammenhang mit der Auslenkung bzw. Exzentrizität des Kopfteils bezogen auf die Gesamtlänge der Bürste zwischen 10% und 20% als besonders vorteilhaft erwiesen und ebenfalls zu besonders guten Reinigungsergebnissen bei optimaler Ergonomie geführt.

[0059] The angle range of 10°–14°, combined with a bend at mid-length of the brush, results in good deflection (eccentricity) of the brush head. This achieves good inherent dynamics of the brush head's oscillation, in line with the desired figure-eight motion.

[0060] In a particular design, the neck section is tapered in cross-section compared to the head section. This means that the head section is wider and / or thicker (perpendicular to the I). <opfteil-Ausrichtungsachse betrachtet) als der Halsteil. Damit wird der Halsteil mechanisch weniger steif als der Kopfteil (sofern der Grundkörper aus einem oder mehreren Materialien mit ungefähr gleichem E-Modul gefertigt ist).

[0061] In another embodiment of the invention, the distance (K) of the geometric bending position to the end surface of the foot part is at least 60% of the total length (L) of the base body.

[0062] According to a particular embodiment, the distance between the geometric bending position and the end surface of the foot section is at most 75% of the total length (L) of the base body. Within this upper limit, a sufficiently pronounced figure-eight motion can be achieved with the bending angle according to the invention, ranging from 8° to 15°, while allowing considerable design freedom with regard to the geometric dimensions of the neck and head sections.

[0063] An inventive sonic toothbrush with longitudinal axis vibration comprises an inventive brush and a handle with a brush coupling for detachably attaching the brush to the handle and with a drive that generates a longitudinal axis vibration at the brush coupling. The drive can, for example, be a piezoelectric drive, a magnetic drive, and / or an electric rotary drive. A piezoelectric drive is particularly preferred, especially due to its simple design, particularly compact construction, and precise controllability.

[0064] Preferably, the drive is designed to generate a longitudinal axis vibration frequency in the range of 150 Hz to 400 Hz. Since the brush produces a two-dimensional or three-dimensional motion pattern, the longitudinal axis vibration frequency is set relatively low, allowing more time for multiple changes of direction per oscillation, e.g., during a figure-eight motion. The longitudinal axis vibration frequency is advantageously not higher than 300 Hz. If the frequency is too high, the base body can no longer transmit the longitudinal axis vibration generated by the drive to the brush head. This can lead to internal torsional movements, causing the head to, for example, only complete every other oscillation.

[0065] The longitudinal axis oscillation frequency can also be less than 150 Hz, e.g. 120 Hz.

[0066] Preferably, the drive is designed to generate a longitudinal axis oscillation with an amplitude of no more than 3°, particularly in the range of 1° to 3°. This means that the foot section is periodically rotated (moved back and forth) around its longitudinal axis. In some variations, the amplitude can also be greater than 3°.

[0067] Further advantageous embodiments and combinations of features of the invention can be derived from the following detailed description and the entirety of the patent claims. Brief description of the drawings

[0068] The drawings used to illustrate the exemplary embodiment show: Fig. 1 a schematic top view of a brush; Fig. 2 a schematic side view of the brush; Fig. 3 a schematic back view of the brush; Fig. 4 a schematic top view of a sonic toothbrush comprising the brush; Fig. 5a a schematic side view and a top view of a sonic toothbrush; Fig. 6 a schematic side view of a sonic toothbrush with exactly one tuft; Fig. 7 a schematic representation of the "8" movement according to the invention; Fig. 8 a schematic representation of the angular amplitude of the longitudinal axis oscillation; Fig. 9 an embodiment with an oval brush head; Fig. 10 an embodiment of a single-tuft brush with a rear bristle field; Fig. 11 an embodiment of a single-tuft brush with a front bristle field.

[0069] Basically, identical parts in the figures are marked with the same reference symbols. Ways to implement the invention

[0070] The Figure 1 Figure 1 shows a schematic top view of a brush 10. The brush 10 comprises a frustoconical base 11, a rod-shaped neck 12 adjoining the frustoconical base 11, and finally a plate-shaped head 13 adjoining the neck 12. These three parts form the basic body of the brush.

[0071] The frustoconical base 11 includes a drive adapter. In this case, this is essentially formed by a channel-shaped receptacle 14 into which a pin of the sonic toothbrush handle can be inserted and locked (see below). Figure 4The brush 10 has a foot section longitudinal axis 20, which is aligned coaxially with the mount 14 and, during operation of the sonic toothbrush, coaxially with the stem. This longitudinal axis defines the x-axis of the xyz coordinate system used here. In other words, the drive adapter defines the geometric foot section longitudinal axis (x) of the brush.

[0072] In the Figure 1 The bristle field 17 of the head part 13 is also visible, which in this case has several (e.g. 20 - 40) tufts, each with a large number (e.g. 100 - 200) of bristles.

[0073] According to a preferred embodiment, the head section 13 is teardrop-shaped in the front view. That is, its shape widens—starting at the transition to the neck section—gradually almost to the upper end of the head section, where it terminates in a rounded end contour. With this shape, the center of gravity of the head section 13 is closer to the end of the brush (given a specific length of the bristle field in the x-direction). This can enhance the eccentric effect at the specified operating frequency and thus also the figure-eight motion.

[0074] The main surface of the plate-shaped head section 13 extends essentially transversely across the x-axis in the y-direction.

[0075] On the bristle field 17, a "8" lying in the y-direction is further depicted with the reference symbol 23. The "8" illustrates the movement which results from the selected material property (modulus of elasticity), the angle between the geometric longitudinal axis 20 of the foot section and the geometric I <opfteil-Ausrichtungsachse (siehe weiter unten) und der Knickposition im Betrieb in der Ebene ausgeführt wird.

[0076] In addition to the "8", the brush also performs a small nodding movement with the head 13 – this movement is essentially perpendicular to the "8", i.e., essentially in the z-direction. In a preferred embodiment, the bristles are thus moved in three dimensions (x, y, z).

[0077] The Figure 2 shows a schematic representation of a side view of the brush 10. In this figure, in addition to the geometric longitudinal axis 20 of the foot section, the geometric I is also shown. <opfteil-Ausrichtungsachse 21 ersichtlich. In der Darstellung gemäss Figure 1 are the longitudinal axis of the foot section 20 and the I <opfteil-Ausrichtungsachse 21 hintereinander. Die I<opfteil-Ausrichtungsachse 21 ist im Wesentlichen die Längsachse des Kopfteils. Die beiden Achsen schneiden sich in der geometrischen Knickposition 22. In der vorliegenden Ausführungsform schliessen die geometrische Fussteil-Längsachse 20 und die geometrische I<opfteil-Ausrichtungsachse 21 einen Winkel γ (gamma) von 10° ein. Die geometrische Knickposition 22 weist vorliegend einen Abstand K zu der Endfläche des Fussteils 11 von 50% der Gesamtlänge L der Bürste 10 auf. In dieser Kombination des Winkels zur Knickposition 22 wird eine Bürste 10 geschaffen, mit welcher eine besonders effektive und zahnfleisch-schonende Reinigung der Zähne möglich ist.

[0078] As a result of the combination of Figures 1 and 2As can be seen, in the present embodiment the head part 13 is plate-shaped and the neck part 12 is rod-shaped. In the projection of the base body onto the xz-plane, the head part 13 and the neck part 12 have the same transverse dimension (i.e., the same thickness). In the projection onto the xy-plane (front view according to...) Figure 1 The headpiece 13 is approximately three times as wide (y-direction) as the neckpiece 12. The length (x-direction) of the headpiece is about one-third greater than its width (y-direction). The neckpiece 11, for example, is one-third as wide and 1.5 times as long as the headpiece 13.

[0079] The neck section 12 is tapered compared to the head section 13 and the foot section 11. In the present example, the neck section 12 is tapered in at least one of the side views (here in the z-direction according to Figure 1 (considered) less wide than the headboard 13.

[0080] In the present example, the base body of the brush 10 has as its supporting material a glass fiber reinforced polypropylene Borealis GB311U with an E-modulus of approximately 3500 MPa (Tensile Strength at yield = 97 MPa; Elongation at Yield = 2.8%; E-modulus = Tensile Strength at Yield / Elongation at Yield).

[0081] The deflection is determined by the ratio of distance A to length L of the brush. Distance A corresponds to the distance from the front center of the head (which here corresponds to the center of the bristle field 17) to the longitudinal axis 20 of the foot (see Figure 2 ). In the present example, the deflection is 14%.

[0082] The bristles are arranged in several tufts and project perpendicularly from the main surface of the plate-shaped head. In this case, they are perpendicular to the y-direction and run in the xz-plane. In this embodiment, the bristles are attached to the front of the head (or the front 27 of the brush), meaning they point slightly downwards towards the adapter surface (yz-plane) of the base.

[0083] The Figure 3 shows a schematic representation of a rear view of brush 10 according to the Figures 1 and 2As can be seen from the figures, the base body has a different, soft material on its back side 26, which provides protection (protective layer, protective coating) when the brush back comes into contact with the teeth. This material is non-load-bearing and can therefore have a modulus of elasticity outside the inventive range of 2000–6000 MPa. The load-bearing material is visible on the front side 27 and constitutes a substantial part of the cross-section of the base body.

[0084] The Figure 4Figure 1 shows a schematic top view (z-direction) of a sonic toothbrush comprising the brush 10 and a handle 16 with a pin 15. The brush 10 is attached to the pin 15 so that it is detachable, rotationally fixed, and axially fixed. The handle 16 rotates the pin 15 back and forth at a frequency of, for example, 180–270 Hz with an amplitude of, for example, 2° (relative to a rest position) about the longitudinal axis of the pin 15 (which corresponds to the longitudinal axis of the handle 16). The brush thus rotates back and forth about the longitudinal axis 20 (x-axis) of the base.

[0085] The Figure 5aFigure 1 shows a schematic side view of a sonic toothbrush 10. The sonic toothbrush 10 comprises a handle 16 and a brush 10. The drive of the handle 16 is designed as a piezoelectric drive (not shown), which generates an oscillation of the brush 10 about the x-axis 20 (longitudinal axis of the handle). Thus, during operation, the brush 10 performs a rotational oscillation about the x-axis 20 relative to the handle. Due to the deflection of the head 13 according to the invention, an imbalance arises, which produces a motion component in the Y-direction 24 and / or in the Z-direction 25 (see below). Figure 5b ) supported. This effect is controlled by the suitably angled bend in the brush neck, the suitably selected modulus of elasticity, and can be adjusted by further geometric design features of the brush (such as bend angle position, deflection, mass distribution, and other features according to the specific embodiments of the invention).

[0086] The Figure 5b shows a schematic top view of a personal care device according to Figure 5a In this illustration, the Z-direction 25 is visible. It runs essentially in the direction of the bristles. As can be seen from the figure, the handle is significantly larger than the brush. This is the only way it can generate a longitudinal axis oscillation (instead of an undefined or undirected vibration, as is the case with known sonic toothbrushes).

[0087] The Figure 6 Figure 1 shows an embodiment of the sonic toothbrush, which comprises exactly one tuft 18. The tuft 18 is arranged at the rear of the head 13. The head is tilted backwards.

[0088] The Figure 7Figure 1 shows a schematic representation of the "8" movement according to the invention. In this case, the "8" movement has the form of a one-sidedly flattened "8", with an axis of symmetry (X-axis) running through the center 27 of the "8". The two loops 28a, 28b of the "8" extend in the y-direction. However, the invention is not limited to exactly this form of the "8" movement; the exact form of the movement ultimately depends on the parameters of the brush head and the vibration generated by the motor of the handheld device.

[0089] The Figure 8 This illustrates the amplitude of the longitudinal axis oscillation. The x-axis is perpendicular to the plane of the drawing. The plate-shaped head 13 (shown without bristles) pivots around the angle α (alpha) about the x-axis. (The bristles extend in Figure 8 (in the z-direction upwards). The main component of the pivoting movement (and thus the bristle wiping movement) is in the y-direction. The angle α (alpha) is preferably 2°.

[0090] The Figure 9 Figure 1 shows a brush 10 with a plate-shaped oval head 13. The longitudinal axis of the oval shape runs essentially in the x-direction and the transverse axis in the y-direction. The center of the head 13 is further away from the upper end of the brush 10 than in the case of the teardrop-shaped head shown in Figure 1. Figure 1 .

[0091] Figure 10 shows a brush with a bending angle γ (gamma) of 14° and a distance K of the geometric bending position 22 to the end surface 29 of the foot part 11 of 75% based on the length L of the brush.

[0092] The foot section 11 tapers from the end surface 29 to the transition into the neck section 12. The foot section 11 can be, for example, truncated cone-shaped or truncated pyramid-shaped, with a concave profile in longitudinal section. This means that the center of gravity of the foot section 11 is closer to the end surface 29 than in a comparable foot section with straight profile lines.

[0093] In the illustrated design, the neck section 12 occupies approximately half the length (L) of the brush. As the Figure 10 To illustrate, the neck section 12 does not necessarily have to have a constant cross-section along its entire length. It can certainly have a changing contour.

[0094] The head section 13 is formed by extending the neck section 12. In the present example, the head section 13 has essentially the same transverse dimensions (in a section perpendicular to the I). <opfteil-Ausrichtungsachse 21 betrachtet) wie der Halsteil 12. Das Borstenfeld 17 ist seitlich am Kopfteil 13 platziert. Die Borsten stehen also senkrecht zur I<opfteil-Ausrichtungsachse 21 ab.

[0095] Figure 11Figure 1 shows an embodiment in which the foot section 11 is essentially formed by a pin 30 as a drive adapter. The neck section 12 is rod-shaped and comprises, for example, 90% of the brush length. The head section 13 is the part in which the bristle field 17, here in the form of a single tuft, is anchored. The pin 30 is inserted into the handle in the x-direction for rotationally fixed coupling to a sonic toothbrush drive with longitudinal axis oscillation, the drive adapter defining the geometric longitudinal axis (x) of the brush foot section.

[0096] A brush according to Fig. 11 It is, for example, made of a material with a modulus of elasticity of approximately 4600 MPa. LNP ULTEM® < EXCP0096 Polyetherimide, 30% Carbon Fiber Reinforcement, 10% PTFE Lubricant is given as an example of such a material (Tensile Strength at Yield = 163 MPa, Elongation at Yield = 3.5%, Tensile Strength / Elongation = 4650 MPa). Variations of the exemplary implementations:

[0097] In other embodiments not shown, the brush 10 has an interdental brush for cleaning the spaces between the teeth instead of the bristle field 17.

[0098] In summary, it can be stated that according to the invention a brush for a sonic toothbrush drive is created which leads to a particularly advantageous movement of the head part for effective and gum-friendly cleaning of the teeth.

Claims

1. Brush (10) for a sonic toothbrush with longitudinal axis vibration, comprising an elongated base body, which a) has a foot section (11) with a drive adapter (14) for rotationally fixed coupling to a sonic toothbrush drive with longitudinal axis vibration, wherein the drive adapter (14) defines a geometric foot section longitudinal axis (x) of the brush, b) a head section (13) with an I <opfteil-Ausrichtungsachse (21) und einen Borstenträger hat, in welchen eine Vielzahl von Borsten verankert ist, , c) und der einen im Vergleich zum Fussteil querschnittsverjüngten Halsteil (12) hat, der Fussteil (11) und Kopfteil (13) verbindet, characterized by the fact that d) the base body forms a kink angle such that the geometric longitudinal axis of the foot section (20) and a geometric I <opfteil-Ausrichtungsachse (21) einen Winkel γ im Bereich von 8° bis 15° einschliessen, und e) dass der Grundkörper ein tragendes Material mit einem E-Modul von nicht mehr als 6000 MPa und nicht weniger als 2000 MPa aufweist.

2. Brush (10) according to claim 1, characterized by the fact that the modulus of elasticity is at least 2500 MPa, in particular at least 3000 MPa.

3. Brush (10) according to claim 1 or 2, characterized by the fact that the head section (13) is plate-shaped and the neck section (12) is rod-shaped, wherein preferably a) the head section (13) is at least about twice as wide as the neck section (12) and / or b) the head section (13) is at most about 1.5 times as long as the neck section (12) and / or c) the head section (13) is spanned in a cross-section through the longitudinal axis (x) and the I <opfausrichtungsachse etwa gleich dick wie der Halsteil ist.

4. Brush (10) according to one of claims 1 to 3, characterized by the fact that the head part (13) has a mass that is greater than the mass of the neck part (12), in particular the head part (13) has a mass that is at least 30%, particularly preferably at least 50% greater than the mass of the holding part.

5. Brush (10) according to one of claims 1 to 4, characterized by the fact thatthe foot section (11) is approximately the same length as the head section (13).

6. Brush (10) according to one of claims 1 to 5, characterized by the fact that the neck part (12) has a transverse dimension that is no more than a quarter of the length of the neck part (12).

7. Brush (10) according to one of claims 1 to 6, characterized by the fact that the basic body consists essentially of a single piece made of a load-bearing material.

8. Brush (10) according to one of claims 1 to 6, characterized by the fact that The basic body is essentially formed by two or three material parts joined together by a material bond.

9. Brush (10) according to one of claims 1 to 8, characterized by the fact that the head part (13) has a deflection (A) of 10% - 20% of a length (L) of the brush (10).

10. Brush (10) according to one of claims 1 to 9, characterized by the fact that the bristles essentially perpendicular to the I <opfteil-Ausrichtungsachse (21) der Bürste (10) weg ragen.

11. Brush (10) according to one of the preceding claims, characterized by the fact that the distance of the geometric bending position (22) to the end surface of the foot part (11) is at least 50% of a length (L) of the base body.

12. Brush (10) according to one of the preceding claims, characterized by the fact that the geometric longitudinal axis of the foot section (20) and the geometric alignment axis of the head section (21) enclose an angle γ in the range of 10° to 14°.

13. Brush (10) according to one of claims 1 to 12, characterized by the fact that The neck section (12) is tapered in cross-section compared to the head section.

14. Brush (10) according to any one of claims 1 to 13, characterized by the fact that the distance (K) of the geometric bending position (22) to the end surface of the foot part (11) is at least 60% of the total length (L) of the base body.

15. Brush (10) according to any one of claims 1 to 14, characterized by the fact thatthe distance of the geometric bending position (22) to the end surface of the foot part (11) is at most 75% of the total length (L) of the base body.

16. Sonic toothbrush with longitudinal axis vibration, comprising a) a brush (10) according to one of claims 1 to 15 and b) a hand unit (16) with a brush coupling for detachably attaching the brush (10) to the hand unit (16) and with a drive in the hand unit (16) which generates a longitudinal axis vibration at the brush coupling.

17. Sonic toothbrush according to claim 16, characterized by the fact that the drive in the handset (16) is designed to generate a longitudinal axis vibration frequency in the range of 150 Hz to 400 Hz.

18. Sonic toothbrush according to claim 16 or 17, characterized by the fact that the drive is designed to generate a longitudinal axis oscillation with an amplitude (α) of a maximum of 3°, in particular of at least 1° and not more than 3°.

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