EP4147605A1 - Brush for a sonic toothbrush with longitudinal axis vibration - Google Patents

Abstract

A brush (10) for a sonic toothbrush with longitudinal axis vibration has an elongate base body which has a foot part (11) with a drive adapter (14) for non-rotatably coupling to a sonic toothbrush drive with longitudinal axis vibration, the drive adapter (14) defining a geometric longitudinal axis of the brush. The body further has a head portion (13) having a head orientation axis (21) and a bristle carrier in which a plurality of bristles are anchored, the bristles extending substantially perpendicularly from the head orientation axis (21) of the brush (10). protrude. The base also has an elongated neck part (12) which connects the foot part (11) and the head part (13). The base body forms a kink angle such that the geometric foot part longitudinal axis (20) and a geometric head part alignment axis (21) enclose an angle γ (gamma) in the range of 8° to 15°. The base body has a load-bearing material with a modulus of elasticity of not more than 6000 MPa and not less than 2000 MPa. A sonic toothbrush with longitudinal axis vibration comprises a brush (10) and a handset with a brush coupling for detachably attaching the brush (10) to the handset, and a drive (16) which generates longitudinal axis vibrations on the brush coupling. The sonic toothbrush achieves a better cleaning effect, which is particularly gentle on the gums. In particular, a defined and controlled two-dimensional movement of the bristles is generated.

Description

technical field

The invention relates to a brush for a sonic toothbrush with longitudinal axis vibration with an elongate base body which has a base part with a drive adapter for non-rotatable coupling to a sonic toothbrush drive with longitudinal axis vibration, the drive adapter defining a geometric base part longitudinal axis of the brush. The body further has a head portion having a head orientation axis and a bristle base in which a plurality of bristles are anchored, the bristles projecting substantially perpendicularly from the head orientation axis of the brush. And finally, the base body has a neck part that has a narrower cross-section than the head part and foot part, which connects the foot part and head part.

State of the art

There are different types of electric toothbrushes.

From the pamphlets DE 10 2016 011477 (shipper ), EP 2'454'967 A1 (Brown ), WO 2005 046508 A1 (Trisa ) and others, the principle of the round brush head is known, which can rotate about an axis parallel to the direction of the bristles and is moved back and forth about this axis. The advantage of this arrangement is that the moving part (namely the round brush head) is very small. It does not require much drive energy and the forces (torques) that occur tend to be small. The disadvantage of this principle is that the movement of the bristles depends on the distance from the axis of rotation. The closer the bristles are to the axis of the brush head, the less back and forth movement. The movement pattern is thus very inhomogeneously distributed over the bristle field.

From the pamphlets JP H04-43127 (Kao ), US 2006 168744 A1 (Butler ), US 2012/0291212 (Montagnino ) and others are familiar with the principle of pendulum motion. The brush oscillates about a pendulum axis which is perpendicular to the handset (drive) and to the attached brush and which intersects the longitudinal axis of the handset and brush at the point where the brush is coupled to the handset. The advantage is that the intensity of movement is distributed homogeneously over the entire field of bristles. All bristles are more or less the same distance from the pendulum axis. The disadvantage, however, is that relatively large forces (moments) occur because the mass of the brush head is relatively far away from the pendulum axis.

From the pamphlets 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 are aware of the principle of case vibration. A drive in the handset or in the brush neck generates an unspecified vibration that is transmitted to the bristles. The advantage of this construction is that you don't have to deal with the technical details of the movement transmission. The disadvantage, however, is that you have to vibrate the entire housing and that accordingly more drive energy is required than if only a small part has to be vibrated. In addition, the vibration must not be too strong, as this affects the comfort of holding the handset. Finally, the effective movements of the bristles are not known and the effect of cleaning this type of undefined and uncontrolled vibration is far from optimal.

Another principle is from the pamphlets WO 2012-151259 A1 (Water Pic ), EP 2'548'531 B1 (Trisa) and others. Here the handset has a docking pin that rotates back and forth about the longitudinal axis. The brush placed on the coupling pin has a straight neck and at the end a bristle plate from which the bristles are transverse to the longitudinal axis of the handset or the brush neck. The advantage of this geometry is that relatively low forces (moments) occur because the mass (neck, bristle plate) of the brush attachment is relatively close to the longitudinal axis (center of movement). The intensity of movement is also distributed relatively evenly over the bristle field. The disadvantage of this principle, however, is that the bristles are only one perform one-dimensional movement (back and forth). On the one hand, the foaming effect for the toothpaste is unsatisfactory and, on the other hand, the advantage of the circular and therefore gentle and at the same time efficient movement, which has been taught by specialists in connection with manual toothbrushes as advantageous for decades, is missing.

With manual toothbrushes it is known that the cleaning effect depends on the hardness of the bristles. Bristles of different hardnesses have different cleaning effects and different damage potentials depending on the application. These effects are well known in specialist circles and are regularly included in the advice given to patients.

The sonic toothbrushes are very convenient for the user and are also considered to be efficient because the electrically powered brush makes the movements much faster than you can do it by hand.

In the case of sonic toothbrushes, it has hitherto been based on the fact that the higher the frequency of the motor and the greater the cleaning movement of the bristles, the better the cleaning.

From the WO 2017/050612 A1 (Curaden ) a sonic toothbrush is known which has an angled brush head. Because the sonic toothbrush is angled forward, the various parts of the teeth are more accessible. In addition, the kink means that the filaments of the brushes oscillate with greater amplitude transversely to the longitudinal axis of the brush. The preferred frequency of operation is 2000 to 8000 Hertz. However, the frequencies can also be higher, for example at 10 kHz, 50 kHz, or lower, for example at 200 Hz or 500 Hz.

From the U.S. 2012/0291212 A1 an ultrasonic toothbrush is known which, in order to increase the resonance frequency, has two parallel channels running transversely to the longitudinal axis of the brush. The frequency is increased in the forward-backward direction when the two channels are placed in the front. If the channels are provided on the left and right of the brush neck, the frequency increases in the lateral direction.

Disadvantages:

There is still a lack of sufficient understanding of the cleaning behavior of sonic toothbrushes. The knowledge that is available today with regard to the cleaning effect of manual toothbrushes cannot be transferred to the highly dynamic situation of a sonic toothbrush.

Presentation of the invention

The object of the invention is to create a toothbrush for sonic toothbrushes that belongs to the technical field mentioned at the outset, which has a better cleaning effect that is gentle on the gums in particular. In particular, a defined and controlled two-dimensional movement of the bristles should be generated.

The solution is defined by claim 1. The main body of the brush has a kink angle such that the geometric longitudinal axis of the foot part and a geometric axis of orientation of the head part enclose an angle γ (gamma) in the range of 8° to 15°. The second important feature is that the base body has a load-bearing material with a modulus of elasticity of no more than 6000 MPa and no less than 2000 MPa (MPa = megapascale).

The sonic toothbrush according to the invention basically generates an oscillation of the brush around the longitudinal axis, ie around the longitudinal axis of the foot part (which is defined here as the x-axis). As a result, the bristles primarily perform a wiping movement transversely to the longitudinal axis (which is defined here as the y-axis). A particular advantage of the brush according to the invention is that it has a certain elasticity due to the selected material parameters and therefore also oscillates in the direction of the longitudinal movement (x-axis) at the envisaged oscillation frequency. A movement results which can be referred to as an "8" movement. The bristles are moved synchronously in the x and y directions and follow a line in the shape of an "8". Such a movement is particularly advantageous in dental care in several respects.

The combination of a sufficiently large kink angle of at least 8 and an E-module that provides a sufficient (but not too large) degree of flexibility poses, leads to a two-dimensional movement of the 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 is still held sufficiently stable so that the unwanted "slapping" movement (in the longitudinal direction of the bristles - i.e. in the direction of the z-axis) is not too high (harmful) extent occurs.

However, it is definitely an advantage of the present brush design that the brush performs a small "nodding movement" in the direction of the bristles (defined here as the z-direction), because this drives the mixture of saliva and toothpaste "forward" into the interdental spaces. This is particularly important with single tuft toothbrushes that are specifically designed for better interdental cleaning.

1. a) Die Bürste hat ein Fussteil, an welchem ein Adapter zum Handapparat, ein sogenannter Antriebsadapter ausgebildet ist. Der Adapter ist in geometrischer Hinsicht darauf ausgelegt, mit einem Kopplungsteil (z.B. Stift) des Schallzahnbürstenantriebs drehfest (aber auswechselbar) verbunden zu werden. Der Schallzahnbürstenantrieb erzeugt eine Längsachsenschwingung, die auf die Bürste zu übertragen ist. Der Antriebsadapter definiert eine geometrische Fussteil-Längsachse (x) der Bürste. Diese Längsachse ist im Normalfall die Richtung, in welcher man die Bürste auf den Handapparat aufstecken kann.
2. b) Weiter hat die Bürste einen Kopfteil mit einem Borstenträger, in welchen eine Vielzahl von Borsten verankert ist (Borstenfeld). Der Kopfteil ist im Prinzip das obere Ende der Bürste (wohingegen der Fussteil das untere Ende bildet). Der Kopfteil definiert eine Kopfteil-Ausrichtungsachse. Die im Kopf verankerten Borsten ragen z.B. quer zur Kopfteil-Ausrichtungsachse weg. Typischerweise, aber nicht zwingend, stehen die Borsten senkrecht zur Kopfteil-Ausrichtungsachse.
3. 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.

The invention is also based on the following basic features:

1. a) The brush has a base on which an adapter for the handset, a so-called drive adapter, is formed. In terms of geometry, the adapter is designed to be non-rotatably (but interchangeably) connected to a coupling part (eg pin) of the sonic toothbrush drive. The sonic toothbrush drive generates a longitudinal axis vibration that is to be transmitted to the brush. The drive adapter defines a geometric base part longitudinal axis (x) of the brush. This longitudinal axis is normally the direction in which you can attach the brush to the handset.
2. b) The brush also has a head part with a bristle carrier, in which a large number of bristles are anchored (bristle field). The head section is essentially the top of the brush (whereas the foot section is the bottom). The header defines a header alignment axis. The bristles anchored in the head protrude, for example, transversely to the axis of alignment of the head part. Typically, but not necessarily, the bristles are perpendicular to the headpiece orientation axis.
3. c) The base body has a neck part between the foot part and the head part. The neck part thus connects the foot part and the head part to one another. Its cross-section is tapered compared to the foot part. That is, if you look at the foot part in cross section (based on the foot part longitudinal axis), then the dimensions in the x or y direction are smaller than in the cross section of the neck part (i.e. transverse to the neck part longitudinal axis). In this case, cross-section tapered refers to the cross-sectional area. So it is not mandatory that the dimensions in the x-direction and y-direction are smaller.

The modulus of elasticity is preferably at least 2500 MPa, in particular at least 3000 MPa. This ensures a base body that is sufficiently strong to optimally transmit the vibrations along the longitudinal axis.

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°).

Another special embodiment is characterized in that the modulus of elasticity of the supporting material (or the supporting materials) of the base body is in the range of 4000 MPa to 6000 MPa.

If the mass of the head part is relatively large in relation to the cross section of the neck part, then a modulus of elasticity in the range from 5000 MPa to 6000 MPa is advantageous.

According to a particular embodiment, the neck portion is arcuately curved in the longitudinal direction, thereby creating the angle between the longitudinal axis of the foot portion and the axis of orientation of the head portion. In other words: footboard and headboard are linear in themselves. Only the neck part is curved. This has the advantage that the forces occurring during the vibration along the longitudinal axis are distributed over the neck part and are not concentrated at one point.

According to a special embodiment, the neck part is a slim section of the base body between the head part and the foot part. The foot part typically has the largest cross-section at the drive adapter (foot end) and the smallest cross-section at the transition to the neck part.

The head part is essentially defined by the fact that it forms the anchorage of the bristles.

The head part is preferably plate-shaped and the neck part is rod-shaped. The head part is therefore wider in cross-section (i.e. in the plane perpendicular to the head part alignment axis) in one direction (e.g. y-direction) than in the other direction (e.g. z-direction). The shape of the cross section can be, for example, rectangular, trapezoidal or oval.

For example, the neck portion is circular, oval, square, hexagonal, octagonal, trapezoidal in cross-section, or a geometric approximation or modification of such a shape. The cross-sectional shape does not have to be rotationally symmetrical.

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

According to a second particular embodiment, the head portion is at most about 1.5 times as long as the neck portion. This can also be combined with the aforementioned embodiment.

According to a third particular embodiment, the head part has approximately the same thickness as the neck part in a cross-section spanned by the longitudinal axis of the brush and the head alignment axis.

More preferably, the head portion is between 2 and 3 times as wide and preferably between 0.5 and 1.5 times as long as the neck portion. With the neck part, which is relatively slim compared to the head part, a particularly good vibration behavior is achieved and thus an optimal cleaning of the teeth is achieved.

According to the above dimensioning, the head part thus forms a kind of centrifugal mass and the neck part forms a kind of (slender) elastic rod.

In variants, the head part can also be less than twice as wide and more than 1.5 times as long as the neck part.

According to a preferred embodiment, the head part has approximately the same thickness as the neck part in a cross section spanned by the longitudinal axis (x) and the head alignment axis. If the head part is plate-shaped, then the neck part is approximately the same thickness as the head part plate.

In a particular embodiment, the head portion has a mass (i.e., inertial mass) greater than a mass of the neck portion, in particular the head portion has a mass preferably greater than 30%, more preferably greater than 50% greater than the mass of the neck portion . This mass distribution can be achieved either through appropriate geometric dimensions or through different materials or through both.

The relatively large mass of the head part compared to the neck part has the effect that a nodding movement of the brush head can be optimized during operation of the toothbrush. Due to the greater mass, the momentum of the nodding movement can be increased, which means that the two-dimensional "8" movement can be intensified and, in turn, the spaces between the teeth can be reached better. This is particularly, but not only, of great advantage with the single-tufted variant or with interdental cleaning.

In a variant, the head part can also have a mass which is less than 30% greater than the mass of the neck part; in particular, the masses of the head part and the neck part can also be approximately the same. For example, if the head is the same thickness as the neck, and if the neck is three times as long as the head and the head is three times as wide as the neck.

The foot part is preferably approximately the same length as the head part. This means that the foot section is large enough to ensure stable attachment to the sonic toothbrush drive (e.g. with a long adapter channel for a correspondingly long handheld pin). The vibration and thus the kinetic energy of the drive is efficiently transmitted to the head part via the neck part.

In a special embodiment, the foot part is shorter than the head part, in particular the foot part is about half as long as the head part. This creates more design freedom for the neck part. If, in such an embodiment, the drive adapter is also designed as a slim pin on the brush, which is inserted into an adapter channel in the handset, then the stable attachment to the sonic toothbrush drive is hidden.

In variants, the foot part can also be longer than the head part.

Preferably, the neck portion has a transverse dimension which is no more than a quarter of a length of the neck portion. The transverse dimension is to be understood as a diameter perpendicular to the geometric alignment axis or perpendicular to the longitudinal axis of the foot part. Where the neck part connects to the head part, the head part alignment axis is decisive and where the neck part connects to the foot part, the foot part longitudinal axis is decisive. The neck part is deliberately kept slim so that the vibration behavior of the head part can be supported, in particular the vibration behavior in the plane (the "8" movement) and the pitching movement.

In variants, the transverse dimension can also be more than a quarter of a length of the neck part. This can be useful if, for example, a particularly flexible or elastic material is used for the neck part.

The base body preferably consists essentially in one piece of a load-bearing material. In this way, on the one hand, a particularly cost-effective production of the base body is achieved. On the other hand, a particularly optimal vibration behavior is also made possible because no border crossings of different materials disturb the vibration behavior, in particular a 2-dimensional or 3-dimensional vibration behavior in which such a border crossing is bent in different directions by the vibration pattern.

Within the scope of the invention, a one-piece base body made of a load-bearing material is also spoken of when 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 part, so that the brush can be better removed from the drive pin with the fingers.

According to a special embodiment, the basic body is essentially formed by two material parts connected by a material bond. If, for example, the foot part is molded from a different plastic than the neck and head of the brush, a very rigid plastic (with a high modulus of elasticity) can be used to ensure that the coupling to the drive pin on the handset optimally supports the movement of the drive the brush transmits. Nevertheless, the neck can be made sufficiently elastic with a less rigid material (modulus of elasticity of the material of the neck part is lower than modulus of elasticity of the foot part).

A further special type of embodiment is characterized in that the basic body is essentially formed by three integrally connected load-bearing material parts. For example, the base body can consist of two materially bonded material parts of different strengths in the longitudinal direction. It is also conceivable that the head part, neck part and foot part are each made of different materials. The requirements for the headboard are different from those for the footboard, which can be optimized with the choice of material.

A base body made of two or three materially bonded load-bearing materials is the result, for example, of modern plastic injection molding processes with two or three materials.

The base body with the two or three load-bearing material parts can also have non-load-bearing (e.g. soft) coating layers in order to achieve certain functions (e.g. protection when the back of the brush comes into contact with the teeth).

The head part preferably has a deflection of 10%-20% in relation to a length of the brush. In the present case, the deflection is understood to mean a ratio between the distance between a center (centre of gravity) of the head part and the longitudinal axis of the adapter, divided by the total length L (in the x-direction) of the base body. The deflection can be viewed as "eccentricity of the head part with respect to the longitudinal axis of the adapter". The deflection is decisive for the oscillation pattern: it was found that the "8" movement is particularly pronounced with a deflection of 10% - 20%.

The deflection can also be less than 10% or greater than 20%. In the case of brushes that are short overall, the deflection is preferably chosen in the range of 20% so that the "imbalance" of the head is not too small. In the case of brushes that are intended for high operating frequencies (eg above 240 Hz), the deflection should be chosen in the range of 10%, because at higher frequencies the "imbalance" of the head could otherwise become too great.

According to a particular embodiment, the bristles project substantially perpendicularly to the axis of orientation of the head of the brush. The angle between the longitudinal axis of the foot part and the direction of the bristles is then 90° minus the bending angle γ (gamma). With a kink angle of γ=11°, for example, the result is 90°−11°=79°.

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

The distance from the geometric buckling position to the end face of the foot part is preferably at least 50% of a length of the base body. A particularly optimal range for the geometric kink position is thus defined in connection with the range of the E-modulus according to the invention, which according to the experiments leads to particularly advantageous 2-dimensional or 3-dimensional oscillation patterns. In this way, a particularly effective and also gentle tooth cleaning can be achieved.

The geometric buckling position is defined by an intersection between the geometric foot portion longitudinal axis and the geometric head portion orientation axis. A kinked (or knee-like) change in direction of the base body does not necessarily have to be present at the geometric buckling position. The geometric buckling position is preferably located within the base body. The shape of the base body does not necessarily have to include an optically recognizable kink, but can, for example, be arcuate. In variants, the geometric buckling position can also be outside of the base body. Other variations are known to those skilled in the art.

The distance between the end face of the foot piece and the buckling position is measured along the foot piece longitudinal axis. The total length of the base body is also measured along the longitudinal axis of the foot piece.

According to the invention, the geometric buckling position has a relatively large distance from the head part, in order to, in connection with the angle γ (gamma) between the To achieve a particularly good vibration behavior for cleaning the teeth due to the geometric foot part longitudinal axis and the geometric head part alignment axis of 8° to 15°. The larger the angle selected, the greater the deflection of the head section from the longitudinal axis of the foot section (eccentricity). Also, the eccentricity increases as the buckling position is further away from the head portion. However, it has been shown that the two parameters (buckling position and angle) do not affect the vibration behavior to the same extent and in the same way, so that with regard to the cleaning effect, for example, an increase in the angle cannot be directly influenced by a smaller distance between the folding position and the Headboard can be compensated because the 2-dimensional or 3-dimensional vibration pattern of the headboard reacts differently to the two parameters.

In variants, the distance from the geometric kink position to the end surface of the foot part can also be less than 50% of a length of the base body, for example at least 35%.

A geometric foot part longitudinal axis and a geometric head part alignment axis preferably enclose an angle γ (gamma) in the range of 10° to 14°. Experiments have shown that this angle range is particularly advantageous, so that a particularly ideal vibration pattern can be achieved for tooth cleaning. Experiments have shown that the vibration pattern, in particular the "8" movement, is particularly advantageous, with which tooth cleaning with the brush can be carried out particularly gently. The angular range has also proven to be particularly advantageous in connection with the deflection or eccentricity of the head part in relation to the total length of the brush between 10% and 20% and also led to particularly good cleaning results with optimum ergonomics.

The angle range of 10° - 14° in combination with a bending position halfway along the brush leads to good deflection (eccentricity) of the brush head. Good dynamics of the oscillation of the brush head in the sense of the desired "8" movement are thus achieved.

In a particular embodiment, the neck portion has a reduced cross-section compared to the head portion. That is, the head portion is wider and/or thicker (viewed perpendicular to the head portion orientation axis) than the neck portion. This means that the neck part is mechanically less stiff than the head part (if the base body is made of one or more materials with approximately the same modulus of elasticity).

In a further embodiment of the invention, the distance (K) from the geometric buckling position to the end face of the foot part is at least 60% of the total length (L) of the base body.

According to a special embodiment, the distance from the geometric buckling position to the end face of the foot part is at most 75% of the total length (L) of the base body. In this area, which is limited at the top, a sufficiently strong "8" movement can be achieved with the bending angle of 8° to 15° according to the invention with a great deal of design freedom with regard to the geometric dimensions of the neck part and head part.

A sonic toothbrush according to the invention with longitudinal axis vibration comprises a brush according to the invention and a handset with a brush coupling for detachably attaching the brush to the handset and with a drive which generates longitudinal axis vibrations on the brush coupling. The drive can have, for example, a piezo drive, a magnetic drive and/or an electric rotary drive. A piezo drive is particularly preferably used, in particular because of the simple structure, the particularly compact design and the precise controllability.

The drive is preferably designed to generate a longitudinal axis vibration frequency in the range from 150 Hz to 400 Hz. Since the brush creates a 2-dimensional or 3-dimensional movement pattern, the longitudinal axis oscillation frequency is set relatively low, so that more time is available to carry out several changes of direction per oscillation, eg in an "8" movement. 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 Torsional movements occur which lead to the head, for example, only vibrating every second time.

The longitudinal axis vibration frequency can also be less than 150 Hz, e.g. 120 Hz.

The drive is preferably designed to generate a longitudinal axis vibration with an amplitude of no more than 3°, in particular in the range from 1° to 3°. This means that the foot part is periodically rotated (moved back and forth) around the longitudinal axis of the foot part. In variants, the amplitude can also be greater than 3°.

Further advantageous embodiments and combinations of features of the invention result from the following detailed description and the entirety of the patent claims.

Brief description of the drawings

Fig. 1

eine schematische Darstellung einer Draufsicht auf eine Bürste;

Fig. 2

eine schematische Darstellung einer Seitenansicht der Bürste;

Fig. 3

eine schematische Darstellung einer Rückenansicht der Bürste;

Fig. 4

eine schematische Darstellung einer Draufsicht auf eine Schallzahnbürste umfassend die Bürste;

Fig. 5a, b

eine schematische Seitenansicht und einer Draufsicht einer Schallzahnbürste;

Fig. 6

eine schematische Darstellung einer Seitenansicht einer Schallzahnbürste mit genau einem Büschel;

Fig. 7

eine schematische Darstellung der erfindungsgemässen "8"-Bewegung;

Fig. 8

eine schematische Darstellung der Winkelamplitude der Längsachsen-Schwingung;

Fig. 9

eine Ausführungsform mit einem ovalen Bürstenkopf;

Fig. 10

eine Ausführungsform einer Einbüschelbürste mit rückseitigem Borstenfeld;

Fig. 11

eine Ausführungsform einer Einbüschelbürste mit vorderseitigem Borstenfeld.

The drawings used to explain the embodiment show:

1

a schematic representation of a plan view of a brush;

2

a schematic representation of a side view of the brush;

3

a schematic representation of a rear view of the brush;

4

a schematic representation of a plan view of a sonic toothbrush comprising the brush;

Fig. 5a, b

a schematic side view and a plan view of a sonic toothbrush;

6

a schematic representation of a side view of a sonic toothbrush with exactly one tuft;

7

a schematic representation of the inventive "8"movement;

8

a schematic representation of the angular amplitude of the longitudinal axis vibration;

9

an embodiment with an oval brush head;

10

an embodiment of a single-tufted brush with a rear bristle field;

11

an embodiment of a single-tufted brush with a front-side bristle field.

In principle, the same parts are provided with the same reference symbols in the figures.

Ways to carry out the invention

The figure 1 shows a schematic representation of a top view of a brush 10. The brush 10 comprises a truncated cone-shaped foot part 11, a rod-shaped neck part 12, which adjoins the truncated cone-shaped foot part 11, and finally a plate-shaped head part 13, which adjoins the neck part 12. The three parts form the main body of the brush.

The frustoconical foot portion 11 includes a drive adapter. In the present case, this is essentially formed by a channel-shaped receptacle 14, into which a pin of the handset of the sonic toothbrush can be inserted and locked (see below figure 4 ). The brush 10 has a foot part longitudinal axis 20 which is aligned coaxially with the receptacle 14 or, when the sonic toothbrush is in operation, coaxially with the pin. This longitudinal axis defines the x-axis of the xyz coordinate system used here. In other words: the drive adapter defines the geometric longitudinal axis (x) of the base part of the brush.

In the figure 1 The bristle field 17 of the head part 13 can also be seen, which in the present case has several (eg 20-40) tufts each with a large number (eg 100-200) of bristles.

According to a preferred embodiment, the head part 13 is teardrop-shaped when viewed from the front. That is, its form expands - beginning with the transition to Neck part - successively to almost the upper end of the head part and ends there in a rounded final contour. In this form (with a given length of the bristle field in the x-direction) the center of gravity of the head part 13 is closer to the end of the brush. This can increase the eccentric effect at the given operating frequency and hence the "8" motion.

The main surface of the plate-shaped head part 13 extends essentially transversely to the x-axis in the y-direction.

An "8" lying in the y-direction is also shown on the bristle field 17 with the reference number 23 . The "8" illustrates the movement, which is carried out during operation in the plane due to the selected material property (E-modulus), the angle between the geometric foot part longitudinal axis 20 and the geometric head part alignment axis (see below) and the buckling position.

In addition to the "8", the brush also performs a small nodding movement with the head part 13 - this movement is directed essentially at right angles to the "8", ie essentially in the z-direction. In terms of a preferred embodiment, the bristles are thus moved in three dimensions (x, y, z).

The figure 2 12 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 part, the geometric axis of alignment of the head part 21 can also be seen. In the representation according to figure 1 the foot part longitudinal axis 20 and the head part alignment axis 21 are in a row. Header alignment axis 21 is essentially the longitudinal axis of the headboard. The two axes intersect in the geometric bending position 22. In the present embodiment, the geometric foot part longitudinal axis 20 and the geometric head part alignment axis 21 enclose an angle γ (gamma) of 10°. In the present case, the geometric bending position 22 has a distance K from the end surface of the foot part 11 of 50% of the total length L of the brush 10 . In this combination of the angle to the bending position 22, a brush 10 is created with which a particularly effective and gum-friendly cleaning of the teeth is possible.

As from the combination of Figures 1 and 2 As 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 (ie the same thickness). In the projection onto the xy plane (front view according to figure 1 ) the head part 13 is about three times as wide (y-direction) as the neck part 12. The length (x-direction) of the head part is about one-third greater than the width (y-direction). The neck part 11 is, for example, one third as wide and 1.5 times as long as the head part 13.

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

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

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

Here, the bristles are arranged in several tufts and protrude perpendicularly from the main surface of the plate-shaped head part. In the present case, they are perpendicular to the y-direction and run in the x-z plane. In the present embodiment, the bristles are attached to the front of the head portion (or the front 27 of the brush), that is, they point slightly downward toward the adapter surface (y-z plane) of the base portion.

The figure 3 shows a schematic representation of a rear view of the brush 10 according to FIGS Figures 1 and 2 . As can be seen from the figures, the base body has a different material on the back 26, which is soft and offers protection (protective layer, protective jacket) when the back of the brush comes into contact with the teeth. This stuff is non-load-bearing and can therefore have a modulus of elasticity outside the modulus of elasticity range of 2000-6000 MPa according to the invention. The supporting material can be seen on the front face 27 and makes up a substantial part of the cross-section of the body.

The figure 4 shows a schematic representation of a top view (z-direction) of a sonic toothbrush comprising the brush 10 and a handset 16 with a pin 15. The brush 10 is attached to the pin 15 so that the brush is detachable, rotationally fixed and fixed axially. The handset 16 rotates the pin 15 back and forth at a frequency of, for example, 180-270Hz 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 handset 16). The brush thus rotates back and forth about the longitudinal axis 20 of the foot part (x-axis).

The Figure 5a shows a schematic representation of a side view of a sonic toothbrush 10. The sonic toothbrush 10 comprises a handset 16 and a brush 10. The drive of the handset 16 is designed as a piezoelectric drive (not shown), which causes the brush 10 to oscillate about the x-axis 20 ( Longitudinal axis of the handset) generated. 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 part 13 according to the invention, an imbalance occurs which has a movement component in the Y-direction 24 and/or in the Z-direction 25 (see below, Figure 5b ) supports. This effect is controlled by the suitably angled kink in the brush neck, the suitably selected modulus of elasticity and can be adjusted by further geometric design features of the brush (such as the kink angle position, deflection, mass distribution and other features according to the particular embodiments of the invention)).

The Figure 5b shows a schematic top view of a personal care appliance according to FIG Figure 5a . The Z-direction 25 can be seen in this illustration. It runs essentially in the direction of the bristles. As can be seen from the figure, the handset is significantly larger than the brush. This is the only way it can generate a longitudinal axis vibration (instead of an undefined or non-directional vibration movement, as is the case with known sonic toothbrushes.

The figure 6 12 shows an embodiment of the sonic toothbrush which comprises exactly one tuft 18 . The tuft 18 is arranged at the rear with respect to the head part 13 . The head part is tilted backwards.

The figure 7 shows a schematic representation of the "8" movement according to the invention. In the present case, the "8" movement has the form of an "8" flattened on one side, 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 handset.

The figure 8 illustrates the amplitude of long-axis vibrational motion. The x-axis is perpendicular to the plane of the drawing. The plate-shaped head part 13 (shown without bristles) pivots about the angle α (alpha) about the x-axis. (The bristles extend in figure 8 in z-direction upwards). The main component of the pivoting movement (and hence the bristle wiping movement) is in the y-direction. The angle α (alpha) is preferably 2°.

The figure 9 shows a brush 10 with a plate-shaped oval head part 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 part 13 is further away from the upper end of the brush 10 than in the case of the teardrop-shaped head part according to FIG figure 1 .

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

The foot part 11 tapers from the end surface 29 to the transition into the neck part 12. The foot part 11 can be, for example, in the shape of a truncated cone or a truncated pyramid, with a longitudinal section having, for example, a concave profile. Thus the center of gravity of the foot part 11 is closer to the end surface 29 than in the case of a comparable foot part with straight profile lines.

The neck portion 12 is approximately half the length (L) of the brush in the illustrated embodiment. As the figure 10 As illustrated, the neck portion 12 need not necessarily have a constant cross section along its entire length. It may well have a changing contour.

The head part 13 is formed by the extension of the neck part 12 . In the present example, the head part 13 has essentially the same transverse dimensions (viewed in a section perpendicular to the head part alignment axis 21) as the neck part 12. The bristle field 17 is placed on the side of the head part 13. The bristles thus protrude perpendicularly to the alignment axis 21 of the head part.

figure 11 shows an embodiment in which the foot part 11 is essentially formed by a pin 30 as a drive adapter. The neck part 12 is in the form of a rod and occupies, for example, 90% of the length of the brush. The head part 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 handset in the x-direction for non-rotatable coupling to a sonic toothbrush drive with longitudinal axis vibration, the drive adapter defining the geometric foot part longitudinal axis (x) of the brush.

A brush according to 11 is, for example, made of a material with an E module of approx. 4600 MPa. LNP ULTEM ^® EXCP0096 Polyetherimide, 30% Carbon Fiber Reinforcement, 10% PTFE Lubricant is mentioned as an example of such a material (Tensile Strength at Yeald = 163 MPa, Elongation at Yield = 3.5%, Tensil Strength / Elongantion = 4650 MPa).

Modifications of the exemplary embodiments:

In further, non-illustrated embodiments, the brush 10 has an interdental brush for cleaning the interdental spaces instead of the bristle field 17 .

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 cleaning of the teeth that is gentle on the gums.

Claims (18)

Brush (10) for a sonic toothbrush with longitudinal axis vibration with an elongate body, the a) has a foot part (11) with a drive adapter (14) for non-rotatable coupling to a sonic toothbrush drive with longitudinal axis vibration, the drive adapter (14) defining a geometric foot part longitudinal axis (x) of the brush, b) has a head part (13) with a head part alignment axis (21) and a bristle carrier in which a plurality of bristles are anchored, c) and which has a neck part (12) with a narrower cross-section than the foot part, which connects the foot part (11) and the head part (13), characterized in that d) the base body forms a kink angle such that the geometric longitudinal axis (20) of the foot part and a geometric axis of orientation of the head part (21) enclose an angle γ in the range of 8° to 15°, and e) that the base body has a load-bearing material with a modulus of elasticity of no more than 6000 MPa and no less than 2000 MPa. Brush (10) according to Claim 1, characterized in that the modulus of elasticity is at least 2500 MPa, in particular at least 3000 MPa. Brush (10) according to claim 1 or 2, characterized in that the head part (13) is plate-shaped and the neck part (12) is rod-shaped, preferably a) the head part (13) is at least twice as wide as the neck part (12) and/or b) the head part (13) is at most about 1.5 times as long as the neck part (12) and/or c) the head part (13) in a cross-section spanned by the longitudinal axis (x) and the head alignment axis is approximately the same thickness as the neck part. Brush (10) according to one of Claims 1 to 3, characterized in that the head part (13) has a mass which is greater than a mass of the neck part (12), in particular the head part (13) has a mass which is at least 30 %, particularly preferably at least 50%, is greater than the mass of the holding part. Brush (10) according to one of Claims 1 to 4, characterized in that the foot part (11) is approximately the same length as the head part (13). A brush (10) according to any one of claims 1 to 5, characterized in that the neck portion (12) has a transverse dimension which is no more than a quarter of a length of the neck portion (12). Brush (10) according to one of Claims 1 to 6, characterized in that the base body consists essentially of a single piece of a supporting material. Brush (10) according to one of Claims 1 to 6, characterized in that the basic body is formed essentially by two or by three material parts which are materially connected. Brush (10) according to one of Claims 1 to 8, characterized in that the head part (13) has a deflection (A) of 10% - 20% of a length (L) of the brush (10). A brush (10) according to any one of claims 1 to 9, characterized in that the bristles project substantially perpendicularly from the head portion orientation axis (21) of the brush (10). Brush (10) according to one of the preceding claims, characterized in that the distance from 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. Brush (10) according to one of the preceding claims, characterized in that the geometric longitudinal axis (20) of the foot part and the geometric axis of orientation of the head part (21) enclose an angle γ in the range from 10° to 14°. Brush (10) according to one of Claims 1 to 12, characterized in that the neck part (12) has a narrower cross-section than the head part. Brush (10) according to one of Claims 1 to 13, characterized in that the distance (K) from the geometric bending position (22) to the end face of the foot part (11) is at least 60% of the total length (L) of the base body. Brush (10) according to one of Claims 1 to 14, characterized in that the distance from the geometric bending position (22) to the end face of the foot part (11) is at most 75% of the total length (L) of the base body. Long axis vibration sonic toothbrush comprising a) a brush (10) according to any one of claims 1 to 15 and b) a handset (16) with a brush coupling for detachably attaching the brush (10) to the handset (16) and having a drive in the handset (16) which generates longitudinal axis vibration at the brush coupling. Sonic toothbrush according to Claim 16, characterized in that the drive in the handset (16) is designed to generate a longitudinal axis vibration frequency in the range from 150 Hz to 400 Hz. Sonic toothbrush according to Claim 16 or 17, characterized in that the drive is designed to generate a longitudinal axis vibration with an amplitude (α) of at most 3°, in particular at least 1° and not more than 3°.

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