Brush for a sonic toothbrush with longitudinal axis vibration - Patents.com

Abstract

The brush (10) for a sonic toothbrush with longitudinal axis vibration has a longitudinal base body and includes a truncated cone-shaped base part (11) having a drive part adapter that is non-rotatably connected to a sonic toothbrush drive part with longitudinal axis vibration, a head part (13) having a bristle carrier on which a large number of bristles are planted, and a longitudinal neck part (12) that connects the base part (11) and the head part (13). The base body forms a bending angle such that the geometric base longitudinal axis (20) and the geometric head part orientation axis form an angle y within the range of 5° to 12°. The geometric bending position (22) in the base body has a distance of at least 50% of the total length of the base body from the terminal surface of the base part (11). The sonic toothbrush with longitudinal axis vibration comprises a brush (10), a hand-held device having a brush clutch for removably attaching the brush (10) to the hand-held device, and a drive unit (16) for generating longitudinal axis vibration in the brush clutch.

Description

[Technical field]

[0001] The present invention generally relates to a brush for a sonic toothbrush having a longitudinal axis vibration, the brush comprising an elongated substrate having a base portion having a drive adapter for non-rotatably connecting to a sonic toothbrush drive portion having a longitudinal axis vibration. [Background technology]

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

[0003] From publications such as US Pat. No. 5,399,663, US Pat. No. 5,499,813 the principle of a circular brush head that can rotate about an axis parallel to the bristle direction and is reciprocated about this axis is known. The advantage of this assembly is that the part to be moved (i.e. the circular brush head) is very small. This small part does not require much drive energy and the forces (torque) generated tend to be small. The disadvantage of this principle is that the bristle movement depends on the distance to the axis of rotation. The closer the bristles are to the axis of the brush head, the smaller the reciprocating movement. This movement pattern is therefore very unevenly distributed over the bristle area.

[0004] From publications such as US Pat. No. 5,399,663, US Pat. No. 5,499,896 the principle of oscillating movement is known. In this case the brush oscillates about an axis of oscillation, which is perpendicular to the hand-held tool (drive) and the mounted brush and intersects with the longitudinal extension axis of the hand-held tool and the brush at the point where the brush is connected to the hand-held tool. The advantage is that the intensity of movement is uniformly distributed over the entire bristle area. All bristles, i.e., have more or less the same distance from the axis of oscillation. The disadvantage, however, is that the mass of the brush head is relatively far away from the axis of oscillation, which leads to relatively large forces (moments).

[0005] The principle of housing vibration is known from publications such as US Pat. No. 5,399,663, US Pat. No. 5,493,326, US Pat. No. 5,523,611, US Pat. No. 5,523,611. A drive arranged in the handheld tool or in the brush neck generates vibrations that are not specifically defined, which are then transmitted to the bristles. The advantage of this design is that it is not necessary to get bogged down in the technical details of the motion transmission. The disadvantage, however, is that the entire housing must be vibrated, which requires correspondingly more drive energy than if only a small part were to be vibrated. In addition, the vibrations must not be too strong, as this would impair the comfort of holding the handheld tool. In conclusion, the effective movement of the bristles is unknown, and the effect of this type of cleaning with undefined and uncontrolled vibrations is far from optimal.

[0006] Another principle is known from publications such as US Pat. No. 5,999,633, US Pat. No. 5,399,466, and US Pat. No. 5,499,626. Here, the handheld tool has a connecting pin, which rotates back and forth around a longitudinal axis. The brush, which is mounted on the connecting pin, has a straight neck and at the end a bristle plate, from which the bristles stand transversely to the longitudinal axis of the handheld tool or the brush neck. The advantage of this geometry is that the mass of the attachment brush (neck, bristle plate) is relatively close to the longitudinal axis (centre of movement), so that the forces (moments) that arise are relatively small. The strength of movement is also relatively uniformly distributed over the bristle area. The disadvantage of this principle, however, is that the bristles only perform a one-dimensional movement (back and forth). On the one hand, this results in an unsatisfactory foaming effect for the dentifrice, and on the other hand, the advantage of a circular, and therefore gentle but also efficient, movement, which has been recommended by experts for decades in connection with manual toothbrushes, is lost.

[0007] It is known that the cleaning effect of manual toothbrushes depends on the hardness of the bristles. Different bristles have different cleaning effects and different potential harmful effects depending on the intended use. These effects are known to those skilled in the art and are regularly included in the advice given to patients.

[0008] Because electrically powered brushes move much faster than a person can do by hand, sonic toothbrushes are both extremely comfortable for the user and efficient.

[0009] For sonic toothbrushes, the conventional wisdom has been that the higher the motor frequency and the greater the cleaning movement of the bristles, the better the cleaning.

[0010] From patent document 14, a sonic toothbrush with a bent brush head is known. This sonic toothbrush is angled towards the front, which allows better access to various parts of the dentition. In addition, the bending achieves that the filaments of the brush vibrate transversely to the longitudinal axis of the brush with a larger amplitude. The preferred operating frequency is 2000 to 8000 Hz. The frequency can, however, be higher, for example 10 kHz, 50 kHz, or lower, for example 200 Hz or 500 Hz.

[0011] From US Pat. No. 5,399,543 an ultrasonic toothbrush is known which comprises two parallel channels extending transversely to the longitudinal axis of the brush in order to increase the resonant frequency. The frequency is increased in the front-to-back direction when both channels are arranged in the front. The frequency is increased in the lateral direction when the channels are arranged on the left and right of the brush neck.

[0012] Cons: Still, the cleaning behavior of sonic toothbrushes is not fully understood: the insight one has today regarding the cleaning action of a manual toothbrush does not transfer to the highly dynamic situation of a sonic toothbrush. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] DE 10 2016 011477(Schiffer) [Patent Document 2] EP 2 454 967 A1 (Braun) [Patent Document 3] WO 2005 / 046508 (Trisa) [Patent Document 4] JP H04-43127(Kao) [Patent Document 5] U.S. Patent Application Publication No. 2006168744 (Butler) [Patent Document 6] US 2012 / 0291212(Montagnino) [Patent Document 7] JP 2012-161368(Sanion) [Patent Document 8] German Utility Model No. 29913406 (Rowenta) [Patent Document 9] U.S. Patent No. 6,766,548 (Rowenta) [Patent Document 10] WO 2005 / 046508 (Trisa) [Patent Document 11] WO 2013 / 104020 (Erskine) [Patent Document 12] International Publication No. 2012 / 151259 (Water Pik) [Patent Document 13] EP 2548531 (Trisa) [Patent Document 14] WO 2017 / 050612 (Curaden) [Patent Document 15] US Patent Application Publication No. 2012 / 0291212 Summary of the Invention [Problem to be solved by the invention]

[0014] The object of the present invention is to provide a toothbrush for a sonic toothbrush belonging to the technical field mentioned at the beginning, which has a better, in particular gum-friendly, cleaning effect, in particular where a defined and controlled two-dimensional movement of the bristles is generated. [Means for solving the problem]

[0015] According to a first aspect of the invention, the solution is defined by claim 1.

[0016] A brush for a sonic toothbrush having a longitudinal axis vibration includes an elongated base body, the base body having: a) a frusto-conical base portion, the base portion having a drive adapter for non-rotatably connecting to a sonic toothbrush drive portion having a longitudinal axis of vibration, the drive adapter defining a geometrical base longitudinal axis (x) of the brush; b) a head portion, the head portion having a head portion orientation axis and a bristle carrier, a number of bristles being implanted in the bristle carrier; c) and having a neck portion tapered in cross section compared to the base portion, the neck portion joining the base portion and the head portion.

[0017] The substrate has a bend angle such that the geometric base longitudinal axis and the geometric head orientation axis form an angle γ in the range of 5° to 12°, and the geometric bend location within the substrate is spaced from the base end face by at least 50% of the substrate's overall length.

[0018] The sonic toothbrush according to the invention essentially generates a vibration of the brush about its longitudinal axis, i.e. the longitudinal axis of the base (defined here as the x-axis). The bristles thereby primarily perform a wiping movement transverse to said longitudinal axis. One particular advantage of the brush according to the invention is that the brush has bending angular positions which result in a sufficiently large deflection (also called eccentricity) of the head part, so that it also performs a defined vibration in the direction of the longitudinal axis. As a result, a two-dimensional movement is produced which can be called a "figure-of-eight" movement. Such a movement is particularly advantageous in several respects.

[0019] The combination of the specific bend angle, which is neither too small nor too large according to the present invention, and the bend angle position according to the present invention, which is not too close to the base, creates a deflection (or eccentricity with respect to the longitudinal axis of the base) and a leverage effect that facilitates a tilting movement of the brush head during operation of the toothbrush, which creates the above-mentioned two-dimensional "8"-shaped movement of the bristles.

[0020] However, one advantage of the present brush design is that the brush also performs a small "tilting motion" in the direction of the bristles, which propels the mixture of saliva and dentifrice "forward" between the teeth. This is particularly important with single-tufted toothbrushes, which are particularly suitable for better interdental cleaning.

[0021] The invention otherwise proceeds from the following basic features: a) The brush comprises a base part in which an adapter to a handheld instrument, the so-called drive adapter, is formed. The adapter is designed in geometric terms to be rotationally (but exchangeably) coupled to a connecting member (e.g. a pin) of the sonic toothbrush drive. The sonic toothbrush drive generates longitudinal axis vibrations which are to be transmitted to the brush. The drive adapter defines the geometrical base longitudinal axis (x) of the brush. This longitudinal axis is normally the direction in which the brush can be inserted onto the handheld instrument. b) The brush further comprises a head part with a bristle carrier in which a number of bristles are planted (bristle region). The head part is in this principle the upper end of the brush (whereas the base part forms the lower end). The head part defines a head part orientation axis. The bristles planted in the head project, for example transversely to the head part orientation axis. Typically, but not necessarily, the bristles are perpendicular to the head part orientation axis. c) Between the base and the head, the substrate has a neck, i.e. the neck joins the base and the head together. The neck is cross-sectionally tapered in comparison to the base, i.e. the base is viewed in cross-section (relative to the longitudinal axis of the base) with a smaller dimension in the x or y direction than the neck is viewed in cross-section (i.e. transverse to the longitudinal axis of the neck). Cross-sectional taper then refers to the cross-sectional area, i.e. not necessarily the smaller dimension in the x and y directions.

[0022] In a first variation, the bristle carrier has multiple tufts, each having multiple bristles, and in a second variation, the bristle carrier has exactly one tuft having multiple bristles (the one-tuft variation).

[0023] The bristles may, however, be indirectly attached to the surface of the bristle carrier, particularly if the brush is designed as an interdental brush. In a third variant, the bristle carrier has twisted or twisted wire loops on the surface of the bristle carrier, with the bristles sandwiched and fixed between the strands. In this case, the head orientation axis is preferably oriented perpendicular to the wire orientation.

[0024] The geometric bending position is defined by the intersection between the geometric base longitudinal axis and the geometric head orientation axis. The geometric bending position does not necessarily have to involve a bending (or elbow) change in the direction of the base body. Preferably, the geometric bending position is located within the base body. The shape of the base body does not necessarily have to have a visible bending, but may be formed, for example, in the shape of an arch. In a variant, the geometric bending position may also be located outside the base body. Further variations are clear to the person skilled in the art.

[0025] The distance between the end face of the base and the bend location is measured along the longitudinal axis of the base, and the overall length of the substrate is also measured along the longitudinal axis of the base.

[0026] The geometrical bending position has a relatively large distance from the head in order to achieve a particularly optimal vibration behavior for teeth cleaning in conjunction with an angle γ (gamma) between the geometrical base longitudinal axis and the geometrical head orientation axis of 5° to 12° according to the invention. The larger the angle is selected, the stronger the deflection (eccentricity) of the head from the base longitudinal axis. Likewise, the further the bending position is moved away from the head, the greater the eccentricity. However, it has been found that both parameters (bending position and angle) do not affect the vibration behavior to the same extent and in the same way, so that, in terms of the cleaning action, for example, an increased angle cannot be directly compensated for by a smaller distance between the bending position and the head, since the two-dimensional or three-dimensional vibration pattern of the head reacts differently to both parameters.

[0027] The distance of the geometric bending position to the end face of the base part is preferably at least 60% of the total length of the base body. This defines a particularly optimal range for the geometric bending position, which experimentally leads to a particularly advantageous two-dimensional or three-dimensional vibration pattern. This allows a particularly effective and at the same time gentle cleaning of the teeth to be achieved.

[0028] In a variant, the distance of the geometric bend position relative to the terminal face of the base portion may be 50% to 60% of the total length of the substrate.

[0029] According to a particular embodiment, the distance of the geometric bending position to the end face of the base is at most 75% of the total length (L) of the base body. Within this upper limit range, a sufficiently strong "8" movement is achieved with a bending angle according to the invention of 5° to 12° and with a large constructional margin for the geometric dimensions of the neck and head.

[0030] According to one particular embodiment, the head is plate-shaped and the neck is rod-shaped. The head is thus wider in one direction (e.g. y-direction) than in the other direction (e.g. z-direction) in the transverse plane (i.e. in a plane perpendicular to the head orientation axis). The shape of the transverse cross section may be, for example, rectangular, trapezoidal or oval.

[0031] The neck portion may be, for example, circular, oval, rectangular, hexagonal, octagonal, trapezoidal in cross section, or a geometric approximation or modification of such shapes. The cross-sectional shape need not be rotationally symmetric.

[0032] According to a first particular embodiment, the head portion is at least approximately twice as wide as the neck portion.

[0033] According to a second special embodiment, the head portion is at most about 1.5 times as long as the neck portion, which may be combined with the previous embodiment.

[0034] According to a third particular embodiment, the head portion is, in the cross section defined by the longitudinal axis of the brush and the head orientation axis, approximately the same thickness as the neck portion, i.e. when the head portion is plate-shaped, the neck portion is approximately the same thickness as the head plate.

[0035] In one embodiment, the head is at least about twice as wide and at most about 1.5 times as long as the neck. Particularly preferably, the head is 2 to 3 times as wide and preferably 0.5 to 1.5 times as long as the neck. Due to the relatively slender neck compared to the head, a particularly good vibration behavior and thus an optimal cleaning of the teeth is achieved.

[0036] In variations, the head portion may be less than twice as wide and more than 1.5 times as long as the neck portion.

[0037] In a particular embodiment, the head has a mass that is greater than the mass of the neck, in particular the head preferably has a mass that is more than 30% greater than the mass of the neck, particularly preferably more than 50% greater, This mass distribution is achieved by corresponding geometric dimensions or by different materials or both.

[0038] The relatively large mass of the head compared to the neck has the effect that the easy tilting movement (movement in z-direction) of the brush head can be optimized during operation of the toothbrush. The larger mass allows the impulse of the tilting movement to be magnified, which in turn allows for a stronger two-dimensional "8" movement, which in turn allows for a better interdental approach. This is a great advantage, especially but not limited to one-tuft variations or interdental brushes.

[0039] In a variant, the head portion may have a mass that is less than 30% greater than the mass of the neck portion, and in particular the masses of the head portion and the neck portion may be approximately the same, for example when the head portion is the same thickness as the neck portion, the neck portion is three times longer than the head portion, and the head portion is three times wider than the neck portion.

[0040] Preferably, the base is approximately the same length as the head, so that the base is large enough to achieve stable attachment to the sonic toothbrush actuator (e.g., having a long adapter channel for a correspondingly long pin on a handheld instrument), such that vibrations, and therefore kinetic energy, of the actuator are efficiently transferred to the head via the neck.

[0041] In a particular embodiment, the base is shorter than the head, in particular the base is about half as long as the head, which provides more constructional room for the neck. In one such embodiment, the drive adapter is additionally formed as a slender pin on the brush, which, when introduced into an adapter channel in the handheld device, provides a stable attachment to the sonic toothbrush drive.

[0042] In a variation, the base portion may be longer than the head portion.

[0043] Preferably, the neck has a lateral dimension which is less than or equal to a quarter of its length. A lateral dimension is to be understood as a diameter perpendicular to the geometric orientation axis or perpendicular to the longitudinal axis of the base. Where the neck connects to the head, the head orientation axis is the reference, and where the neck connects to the base, the longitudinal axis of the base is the reference. The neck is thereby deliberately kept slender, so that the vibration behavior of the head, in particular in the plane (figure-of-eight movement) and the tilting movement, can be supported.

[0044] In a variant, the lateral dimension may be greater than one-quarter of the length of the neck, which may be of value, for example, when a particularly soft or elastic material is used for the neck.

[0045] Preferably, the substrate comprises a material assuming the supporting function with an elastic modulus of less than 8000 MPa, in particular in the range of 2000 MPa to 6000 MPa, which results in a substrate that is sufficiently elastic for optimal transmission of vibrations and, on the other hand, is also sufficiently stable.

[0046] Preferably, the elastic modulus is at least 2500 MPa, in particular at least 3000 MPa, which ensures a substrate that is sufficiently rigid to optimally transmit longitudinal axis vibrations.

[0047] At certain variants of the invention (at rather small bending angles, for example in the range of 8°), the modulus of elasticity may tend to be lower (for example 2000 MPa to 3000 MPa) than at larger bending angles (for example 15°).

[0048] Another particular embodiment is characterized in that the elastic modulus of the material (or materials) performing the supporting function of the substrate is in the range of 4000 MPa to 6000 MPa.

[0049] When the mass of the head portion is relatively large compared to the cross section of the neck portion, a modulus of elasticity in the range of 5000 MPa to 6000 MPa is advantageous.

[0050] Preferably, the base body is made essentially in one piece of one material. On the one hand, this allows a particularly low-cost production of the base body. On the other hand, this also allows a particularly optimal vibration behavior, since there are no transition interfaces of different materials that would interfere with the vibration behavior, in particular the two- or three-dimensional vibration behavior. In the vibration behavior, such transition interfaces would be bent in different directions due to the vibration pattern.

[0051] Within the scope of the present invention, the brush surface may be coated or covered with a material that does not perform a supporting function, but is still considered to be a one-piece substrate made of one material performing the supporting function. For example, the base of the one-piece substrate may be provided with areas made of a material that increases roughness or surface grip, so that the brush can be more easily picked up and removed from the drive pin by the fingers.

[0052] According to a particular embodiment, the base body is formed by two material parts that are substantially bonded together. For example, if the base part is injection-molded from a different plastic than the neck and head of the brush, a very stiff (high elastic modulus) plastic can ensure that the connection to the drive pin on the hand-held tool optimally transmits the movement of the drive to the brush. Nevertheless, the neck can be made sufficiently elastic by a less stiff material (the elastic modulus of the material of the neck part is lower than that of the base part).

[0053] Another particular embodiment is characterized in that the base body is essentially formed from three material parts which are materially joined together. Thus, the base body may consist of two material parts which are materially joined together, for example in the longitudinal direction, with different strengths. Furthermore, it is possible for the head part, the neck part and the base part to be formed from different materials. The requirements for the head part are different from those for the base part, which can be optimized by the selection of materials.

[0054] Substrates made of two or three material combinations are produced, for example, by modern two- or three-material plastic injection molding processes.

[0055] Even in a substrate having two or three material parts performing a supporting function, there may be further present a (e.g. soft) covering layer that does not perform a supporting function, thereby achieving a specific function (e.g. protection of the back surface of the brush when it comes into contact with the teeth).

[0056] Preferably, the head has a run-out of 10% to 20% with respect to the length of the brush. Run-out is understood here as the ratio of the distance of the center (centre of gravity) of the head to the longitudinal axis of the adapter divided by the total length L (in the x-direction) of the base body. The run-out can be considered as the "eccentricity of the head with respect to the longitudinal axis of the adapter". The run-out is important in the vibration pattern, and it has been found that with a run-out of 10% to 20% the "8" movement is particularly pronounced.

[0057] The runout may be less than 10% or more than 20%. In the case of brushes with a small overall length, the runout is preferably selected in the range of 20%, so that the "unbalance" of the head does not become too small. In the case of brushes specified for high operating frequencies (e.g. above 240 Hz), the runout is rather selected in the range of 10%, since at relatively high frequencies the "unbalance" of the head may otherwise become too large.

[0058] According to a particular embodiment, the bristles project substantially perpendicularly from the head orientation axis of the brush. The angle between the base longitudinal axis and the bristles direction is then 90° minus the bending angle γ (gamma). When the bending angle is, for example, γ=9°, then 90°-9°=81°.

[0059] The bristles are arranged on the main surface of the head, which may be formed, for example, in the shape of a plate, or in the case of a one-tuft brush, the head may be rod-shaped, with a single tuft arranged in a cylindrical cavity (e.g. a blind hole).

[0060] Preferably, the geometrical base longitudinal axis and the geometrical head orientation axis form an angle γ (gamma) in the range of 7° to 10°. This angle range has proven to be particularly advantageous in experiments, so that a particularly ideal vibration pattern for teeth cleaning can be achieved. Experiments have shown that this results in a particularly advantageously sharp vibration pattern, in particular a "figure of eight" movement, so that teeth cleaning with the brush can be performed particularly gently. This angle range has also proven to be particularly advantageous in conjunction with a runout or eccentricity of the head with respect to the overall length of the brush of 10% to 20%, and likewise leads to particularly good cleaning results with optimal ergonomics.

[0061] An angle range of 7°-10°, in combination with a deflection of 10%-20%, leads to good inherent dynamics of the brush head vibration in the desired "figure eight" sense.

[0062] In one particular embodiment, the neck portion is cross-sectionally tapered compared to the head portion, i.e., the head portion has a greater width and / or thickness (viewed perpendicular to the head portion orientation axis) than the neck portion, which makes the neck portion mechanically less stiff than the head portion (when the substrate is made from one material or from multiple materials having approximately the same elastic modulus).

[0063] The sonic toothbrush according to the invention with longitudinal axis vibration comprises a brush according to the invention, a hand-held device with a brush clutch for removably mounting the brush to the hand-held device, and a drive for generating longitudinal axis vibration in the brush clutch. The drive may comprise, for example, a piezoelectric drive, an electromagnetic drive and / or an electric rotary drive. Particularly preferably, a piezoelectric drive is used due to its particularly simple construction, particularly compact design form and fine controllability.

[0064] Preferably, the drive is designed to generate a frequency of longitudinal axis vibration in the range of 150 Hz to 400 Hz. Since a two-dimensional or three-dimensional movement pattern is generated by the brush, the frequency of longitudinal axis vibration is set relatively low, so that more time is provided for performing multiple direction changes per vibration, for example during a "figure of eight" movement. The frequency of longitudinal axis vibration is advantageously less than or equal to 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. Internal twisting movements can occur, which lead to the head performing, for example, only every other vibration.

[0065] The frequency of the longitudinal axis vibration may be less than 150 Hz, for example 120 Hz.

[0066] Preferably, the drive is formed to generate longitudinal axis vibrations with an amplitude (deflection with respect to the resting position) of less than 3°, in particular in the range of 1° to 3°. That is, the base is periodically rotated (reciprocated) around the longitudinal axis of the base by the above-mentioned angle. In a variant, the amplitude may be greater than 3°.

[0067] According to a second aspect of the invention, which can be observed independently of the first aspect of the invention, the solution is defined by claim 19.

[0068] A brush for a sonic toothbrush having a longitudinal axis vibration includes an elongated base body, the base body having: a) a sonic toothbrush having a base portion, the base portion having a drive adapter for non-rotatably connecting to a sonic toothbrush drive having a longitudinal axis of vibration, the drive adapter defining a geometrical base longitudinal axis (x) of the brush; b) a head portion, the head portion having a head portion orientation axis and a bristle carrier, a number of bristles being implanted in the bristle carrier; c) and having a neck portion tapered in cross section compared to the base portion, the neck portion joining the base portion and the head portion.

[0069] The brush substrate has a bending angle such that the geometric base longitudinal axis and the geometric head orientation axis form an angle γ (gamma) in the range of 8° to 15°. A second important feature is added that the substrate comprises a material performing a supporting function having an elastic modulus of less than 6000 MPa and more than 2000 MPa (MPa = megapascals).

[0070] The sonic toothbrush according to the invention essentially generates a vibration of the brush around a longitudinal axis, i.e. the longitudinal axis of the base (here designated x-axis). The bristles thereby primarily perform a wiping movement transverse to said longitudinal axis (here designated y-axis). One particular advantage of the brush according to the invention is that the brush has a certain elasticity based on the selected material parameters and therefore also performs a vibration in the direction of the longitudinal movement (x-axis) at the predetermined vibration frequency. As a result, a movement that can be called an "8" movement is generated. 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 several respects during dental care.

[0071] The combination of a sufficiently large bending angle of at least 8 and a modulus of elasticity that provides a sufficient (but not too large) degree of flexibility leads to a two-dimensional movement of the head. This movement at the planted end of the bristles controls the movement of the bristles at the cleaning end of the bristles (the free ends of the bristles). The upper limit of the bending angle and the lower limit of the modulus of elasticity ensure that the brush head still remains sufficiently stable so that undesirable "striking" movements (movements in the longitudinal direction of the bristles, i.e. in the direction of the z-axis) do not occur at too high (harmful) a magnitude.

[0072] But in particular one advantage of the present brush design is that the brush performs a small "tilting movement" in the direction of the bristles (defined here as the z-direction), since this propels the mixture of saliva and dentifrice "forward", so to speak, between the teeth. This is particularly important in the case of single-tufted toothbrushes, which are particularly suitable for better interdental cleaning.

[0073] The invention otherwise proceeds from the following basic features: d) The brush comprises a base part in which an adapter to a handheld instrument, the so-called drive adapter, is formed. The adapter is designed in geometric terms to be rotationally (but exchangeably) coupled to a connecting member (e.g. a pin) of the sonic toothbrush drive. The sonic toothbrush drive generates longitudinal axis vibrations which are to be transmitted to the brush. The drive adapter defines the geometrical base longitudinal axis (x) of the brush. This longitudinal axis is normally the direction in which the brush can be inserted onto the handheld instrument. e) The brush further comprises a head part with a bristle carrier in which a number of bristles are planted (bristle region). The head part is in this principle the upper end of the brush (whereas the base part forms the lower end). The head part defines a head part orientation axis. The bristles planted in the head project, for example transversely to the head part orientation axis. Typically, but not necessarily, the bristles are perpendicular to the head part orientation axis. f) Between the base and the head, the substrate has a neck, i.e. the neck joins the base and the head together. The neck is cross-sectionally tapered in comparison to the base, i.e. the base is viewed in cross-section (relative to the longitudinal axis of the base) with a smaller dimension in the x or y direction than the neck is viewed in cross-section (i.e. transverse to the longitudinal axis of the neck). Cross-sectional taper then refers to the cross-sectional area, i.e. not necessarily the smaller dimension in the x and y directions.

[0074] Preferably, the elastic modulus is at least 2500 MPa, in particular at least 3000 MPa, which ensures a substrate that is sufficiently rigid to optimally transmit longitudinal axis vibrations.

[0075] At certain variants of the invention (at rather small bending angles, for example in the range of 8°), the modulus of elasticity may tend to be lower (for example 2000 MPa to 3000 MPa) than at larger bending angles (for example 15°).

[0076] Another particular embodiment is characterized in that the elastic modulus of the material (or materials) performing the supporting function of the substrate is in the range of 4000 MPa to 6000 MPa.

[0077] When the mass of the head portion is relatively large compared to the cross section of the neck portion, a modulus of elasticity in the range of 5000 MPa to 6000 MPa is advantageous.

[0078] According to one particular embodiment, the neck is curved in the longitudinal direction in an arc, which creates an angle between the longitudinal axis of the base and the orientation axis of the head. In other words, the base and the head themselves are straight. Only the neck is curved. This has the advantage that the forces occurring during longitudinal vibration are distributed over the neck and not concentrated in one place.

[0079] According to one particular embodiment, the neck portion is a slender section of the substrate between the head portion and the base portion, the base portion typically having a largest cross-section at the drive adapter (base end) and a smallest cross-section near the transition to the neck portion.

[0080] The head portion is substantially defined by forming a bristle implant.

[0081] Preferably, the head is plate-shaped and the neck is rod-shaped. The head is thus wider in one direction (e.g., y-direction) than in the other direction (e.g., z-direction) in a transverse plane (i.e., in a plane perpendicular to the head orientation axis). The shape of the transverse cross section may be, for example, rectangular, trapezoidal or oval.

[0082] The neck portion may be, for example, circular, oval, rectangular, hexagonal, octagonal, trapezoidal in cross section, or a geometric approximation or modification of such shapes. The cross-sectional shape need not be rotationally symmetric.

[0083] According to a first particular embodiment, the head portion is at least approximately twice as wide as the neck portion.

[0084] According to a second special embodiment, the head portion is at most about 1.5 times as long as the neck portion, which may be combined with the previous embodiment.

[0085] According to a third particular embodiment, the head portion is approximately the same thickness as the neck portion in a cross section defined by the longitudinal axis of the brush and the head orientation axis.

[0086] Particularly preferably, the head is 2 to 3 times as wide as the neck and preferably 0.5 to 1.5 times as long. Due to the relatively slender neck compared to the head, a particularly good vibration behavior and thus an optimal cleaning of the teeth is achieved.

[0087] The head part, according to the above dimensions, thus forms a kind of spring mass, and the neck part forms a kind of (slender) elastic rod.

[0088] In variations, the head portion may be less than twice as wide and more than 1.5 times as long as the neck portion.

[0089] According to one preferred embodiment, the head portion is about the same thickness as the neck portion in the cross section defined by the longitudinal axis (x) and the head orientation axis, i.e. when the head portion is plate-shaped, the neck portion is about the same thickness as the head plate.

[0090] In a particular embodiment, the head has a mass (i.e. inertial mass) that is greater than the mass of the neck, in particular the head preferably has a mass that is more than 30% greater, particularly preferably more than 50% greater than the mass of the neck, This mass distribution is achieved by corresponding geometric dimensions or by different materials or both.

[0091] The relatively large mass of the head compared to the neck has the effect that the tilting motion of the brush head can be optimized during operation of the toothbrush. The larger mass allows the impulse of the tilting motion to be magnified, which in turn allows for a stronger two-dimensional "eight" motion, which in turn allows for a better interdental approach. This is of great advantage, particularly but not exclusively in one-tuft variations or interdental cleaning.

[0092] In one variant, the head portion may have a mass that is less than 30% greater than the mass of the neck portion, and in particular the masses of the head portion and the neck portion may be approximately the same, for example when the head portion is the same thickness as the neck portion, the neck portion is three times longer than the head portion, and the head portion is three times wider than the neck portion.

[0093] Preferably, the base is approximately the same length as the head, so that the base is large enough to achieve stable attachment to the sonic toothbrush actuator (e.g., having a long adapter channel for a correspondingly long pin on a handheld instrument), such that vibrations, and therefore kinetic energy, of the actuator are efficiently transferred to the head via the neck.

[0094] In a particular embodiment, the base is shorter than the head, in particular the base is about half as long as the head, which provides more constructional room for the neck. In one such embodiment, the drive adapter is additionally formed as a slender pin on the brush, which, when introduced into an adapter channel in the handheld device, provides a stable attachment to the sonic toothbrush drive.

[0095] In a variation, the base portion may be longer than the head portion.

[0096] Preferably, the neck has a lateral dimension which is less than or equal to a quarter of its length. A lateral dimension is to be understood as a diameter perpendicular to the geometric orientation axis or perpendicular to the longitudinal axis of the base. Where the neck connects to the head, the head orientation axis is the reference, and where the neck connects to the base, the longitudinal axis of the base is the reference. The neck is thereby deliberately kept slender, so that the vibration behavior of the head, in particular in the plane (figure-of-eight movement) and the tilting movement, can be supported.

[0097] In a variant, the lateral dimension may be greater than one-quarter of the length of the neck, which may be of value, for example, when a particularly soft or elastic material is used for the neck.

[0098] Preferably, the base body is made essentially in one piece of one material which assumes the supporting function. On the one hand, this allows a particularly low-cost production of the base body. On the other hand, this also allows a particularly optimal vibration behavior, since there are no transition interfaces of different materials which would interfere with the vibration behavior, in particular the two- or three-dimensional vibration behavior. In the vibration behavior, such transition interfaces would be bent in different directions due to the vibration pattern.

[0099] Within the scope of the present invention, the brush surface may be coated or covered with a material that does not perform a supporting function, but is still considered to be a one-piece substrate made of one material performing the supporting function. For example, the base of the one-piece substrate may be provided with areas made of a material that increases roughness or surface grip, so that the brush can be more easily picked up and removed from the drive pin by the fingers.

[0100] According to a particular embodiment, the base body is formed by two material parts that are substantially bonded together. For example, if the base part is injection-molded from a different plastic than the neck and head of the brush, a very stiff (high elastic modulus) plastic can ensure that the connection to the drive pin on the hand-held tool optimally transmits the movement of the drive to the brush. Nevertheless, the neck can be made sufficiently elastic by a less stiff material (the elastic modulus of the material of the neck part is lower than that of the base part).

[0101] Another particular embodiment is characterized in that the base body is formed essentially from three material parts which assume the supporting function and are connected in a material-bonding manner. Thus, the base body may consist of two material parts which are connected in a material-bonding manner, for example in the longitudinal direction, with different strengths. Furthermore, it is possible for the head part, the neck part and the base part to be formed from different materials. The requirements for the head part are different from those for the base part, which can be optimized by the selection of materials.

[0102] The base body made of two or three material-bonded materials which assume the supporting function is produced, for example, by a novel two- or three-material plastic injection molding process.

[0103] Even in a substrate having two or three material parts performing a supporting function, there may be further present a (e.g. soft) covering layer that does not perform a supporting function, thereby achieving a specific function (e.g. protection of the back surface of the brush when it comes into contact with the teeth).

[0104] Preferably, the head has a run-out of 10% to 20% with respect to the length of the brush. Run-out is understood here as the ratio of the distance of the center (centre of gravity) of the head to the longitudinal axis of the adapter divided by the total length L (in the x-direction) of the base body. The run-out can be considered as the "eccentricity of the head with respect to the longitudinal axis of the adapter". The run-out is important in the vibration pattern, and it has been found that with a run-out of 10% to 20% the "8" movement is particularly pronounced.

[0105] The runout may be less than 10% or more than 20%. In the case of brushes with a small overall length, the runout is preferably selected in the range of 20%, so that the "unbalance" of the head does not become too small. In the case of brushes specified for high operating frequencies (e.g. above 240 Hz), the runout is rather selected in the range of 10%, since at relatively high frequencies the "unbalance" of the head may otherwise become too large.

[0106] According to a particular embodiment, the bristles project substantially perpendicularly from the head orientation axis of the brush. The angle between the base longitudinal axis and the bristles direction is then 90° minus the bending angle γ (gamma). When the bending angle is, for example, γ=11°, then 90°-11°=79°.

[0107] The bristles are arranged on the main surface of the head, which may be formed, for example, in the shape of a plate, or in the case of a one-tuft brush, the head may be rod-shaped, with a single tuft arranged in a cylindrical cavity (e.g. a blind hole).

[0108] The distance of the geometric bending position to the end face of the base is preferably at least 50% of the length of the base body. This defines a particularly optimal range for the geometric bending position, which in conjunction with the inventive range of elastic modulus leads to a particularly advantageous two-dimensional or three-dimensional vibration pattern according to the experiments. This allows a particularly effective and also gentle cleaning of the teeth to be achieved.

[0109] The geometric bending position is defined by the intersection between the geometric base longitudinal axis and the geometric head orientation axis. The geometric bending position does not necessarily have to involve a bending (or elbow) change in the direction of the base body. Preferably, the geometric bending position is located within the base body. The shape of the base body does not necessarily have to have a visible bending, but may be formed, for example, in the shape of an arch. In a variant, the geometric bending position may also be located outside the base body. Further variations are clear to the person skilled in the art.

[0110] The distance between the end face of the base and the bend location is measured along the longitudinal axis of the base, and the overall length of the substrate is also measured along the longitudinal axis of the base.

[0111] The geometrical bending position has a relatively large distance from the head in order to achieve a particularly good vibration behavior for cleaning teeth in conjunction with an angle γ (gamma) between the geometrical base longitudinal axis and the geometrical head orientation axis of 8° to 15° according to the invention. The larger the angle is selected, the stronger the deflection (eccentricity) of the head from the longitudinal axis of the base. Likewise, the further the bending position is moved away from the head, the greater the eccentricity. However, it has been found that both parameters (bending position and angle) do not affect the vibration behavior to the same extent and in the same way, so that, in terms of the cleaning action, for example, an increased angle cannot be directly compensated for by a smaller distance between the bending position and the head, since the two-dimensional or three-dimensional vibration pattern of the head reacts differently to both parameters.

[0112] In a variant, the distance of the geometric bend position relative to the end face of the base portion may be less than 50% of the length of the substrate, such as at least 35%.

[0113] Preferably, the geometrical base longitudinal axis and the geometrical head orientation axis form an angle γ (gamma) in the range of 10° to 14°. This angle range has proven to be particularly advantageous in experiments, so that a particularly ideal vibration pattern for teeth cleaning can be achieved. Experiments have shown that this results in a particularly advantageously sharp vibration pattern, in particular a "figure of eight" movement, so that teeth cleaning with the brush can be performed particularly gently. This angle range has also proven to be particularly advantageous in conjunction with a runout or eccentricity of the head with respect to the overall length of the brush of 10% to 20%, and likewise leads to particularly good cleaning results with optimal ergonomics.

[0114] The angle range of 10°-14°, in combination with a bending position at half the length of the brush, leads to a good deflection (eccentricity) of the brush head, which achieves a good inherent dynamics of the vibration of the brush head in the desired "figure eight" movement sense.

[0115] In one particular embodiment, the neck portion is cross-sectionally tapered compared to the head portion, i.e., the head portion has a greater width and / or thickness (viewed perpendicular to the head portion orientation axis) than the neck portion, which makes the neck portion mechanically less stiff than the head portion (when the substrate is made from one material or from multiple materials having approximately the same elastic modulus).

[0116] In another embodiment of the invention, the distance (K) of the geometric bend position relative to the end face of the base portion is at least 60% of the total length (L) of the substrate.

[0117] According to a particular embodiment, the distance of the geometric bending position to the end face of the base is at most 75% of the total length (L) of the base body. Within this upper limit range, a sufficiently strong "8" movement is achieved with a bending angle according to the invention of 8°-15° and with a large constructional margin for the geometric dimensions of the neck and head.

[0118] The sonic toothbrush according to the invention with longitudinal axis vibration comprises a brush according to the invention, a hand-held device with a brush clutch for removably mounting the brush to the hand-held device, and a drive for generating longitudinal axis vibration in the brush clutch. The drive may comprise, for example, a piezoelectric drive, an electromagnetic drive and / or an electric rotary drive. Particularly preferably, a piezoelectric drive is used due to its particularly simple construction, particularly compact design form and fine controllability.

[0119] Preferably, the drive is designed to generate a frequency of longitudinal axis vibration in the range of 150 Hz to 400 Hz. Since a two-dimensional or three-dimensional movement pattern is generated by the brush, the frequency of longitudinal axis vibration is set relatively low, so that more time is provided for performing multiple direction changes per vibration, for example during a "figure of eight" movement. The frequency of longitudinal axis vibration is advantageously less than or equal to 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. Internal twisting movements can occur, which lead to the head performing, for example, only every other vibration.

[0120] The frequency of the longitudinal axis vibration may be less than 150 Hz, for example 120 Hz.

[0121] Preferably, the drive is configured to generate longitudinal axis vibrations with an amplitude of less than 3°, in particular in the range of 1° to 3°, i.e. the base is periodically rotated (reciprocated) about the longitudinal axis of the base. In a variant, the amplitude may be greater than 3°.

[0122] In one particular embodiment of the invention, the brush includes an RFID chip in the base, which allows the handheld tool to read the data and use it for optimal operation of the brush, for example the optimal drive frequency of the brush can be read and the drive in the handheld tool can be controlled accordingly.

[0123] In another particular embodiment of the invention, the RFID chip is arranged in the longitudinal region of the connecting cavity of the base, which means that the RFID chip is arranged in the vicinity of the hand tool and does not influence the vibration behavior of the brush.

[0124] Further advantageous embodiments and feature combinations of the invention can be seen from the detailed description below and from the claims as a whole.

[0125] The drawings are used to explain the embodiments. [Brief description of the drawings]

[0126] [Figure 1] FIG. 2 is a schematic plan view of a brush. [Diagram 2] FIG. 2 is a schematic side view of a brush. [Diagram 3] FIG. 2 is a schematic rear view of the brush. [Figure 4] FIG. 2 is a schematic plan view of a sonic toothbrush with a brush. [Figure 5a] FIG. 1 is a schematic side view of a sonic toothbrush. [Figure 5b] FIG. 1 is a schematic plan view of a sonic toothbrush. [Figure 6] FIG. 1 is a schematic side view of a sonic toothbrush with exactly one tuft. [Figure 7] FIG. 2 is a schematic diagram of a figure-8 movement according to the present invention. [Figure 8] FIG. 2 is a schematic diagram of the angular amplitude of the longitudinal axis vibration. [Figure 9] FIG. 1 illustrates an embodiment having an oval brush head. [Figure 10] FIG. 1 illustrates an embodiment of a single-tuft brush with a rear bristle region. [Figure 11] FIG. 1 illustrates an embodiment of a single-tuft brush with a front bristle region. [Figure 12a] FIG. 1 illustrates an embodiment having an RFID. [Figure 12b]FIG. 1 illustrates an embodiment having an RFID. [Figure 12c] FIG. 1 illustrates an embodiment having an RFID. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0127] As a general rule, the same components are given the same symbols in the drawings.

[0128] 1 shows a schematic plan view of a brush 10. The brush 10 comprises a frusto-conical base portion 11, a rod-shaped neck portion 12 connected to the frusto-conical base portion 11, and finally a plate-shaped head portion 13 connected to the neck portion 12. These three portions form the substrate of the brush.

[0129] The frustoconical base 11 carries a drive adapter, which here is formed by a substantially channel-shaped receiver 14, into which a pin of a handheld device of the sonic toothbrush can be introduced and locked (see below with reference to FIG. 4). The brush 10 has a base longitudinal axis 20, which is oriented coaxially to the receiver 14 or, during operation of the sonic toothbrush, to the pin. This longitudinal axis defines the x-axis of the xyz coordinate system used here. In other words, the drive adapter defines the geometrical base longitudinal axis (x) of the brush.

[0130] Also visible in Figure 1 is the bristles region 17 of the head portion 13, which here comprises a plurality of tufts (eg 20-40), each having a large number of bristles (eg 100-200).

[0131] According to a preferred embodiment, the head 13 is teardrop-shaped in front view, i.e. the shape of the head 13 starts at the transition to the neck and gradually widens approximately up to the upper end of the head, where it ends with a rounded final contour. With this shape, the center of gravity of the head 13 (for a given length of bristle area in the x-direction) is close to said end of the brush. This can enhance the eccentric effect and thus the "8" motion at a given operating frequency.

[0132] The main surface of the plate-shaped head portion 13 extends in the y direction, substantially transverse to the x axis.

[0133] Further indicated on the bristle region 17 is an "8" laid down in the y-direction by reference numeral 23, which represents the motion that will be performed in this plane during operation based on the selected material properties (elastic modulus), the angle between the geometric base longitudinal axis 20 and the geometric head orientation axis (see further below), and the flexion position.

[0134] In addition to this "8", the brush also performs a small tilting movement by means of the head 13. This movement is oriented substantially perpendicular to the "8", i.e. substantially in the z-direction. In the sense of a preferred embodiment, the bristles are thereby moved in three dimensions (x, y, z).

[0135] FIG. 2 shows a schematic side view of the brush 10. In addition to the geometrical base longitudinal axis 20, the geometrical head orientation axis 21 can also be seen in this view. In the representation shown in FIG. 1, the base longitudinal axis 20 and the head orientation axis 21 are contiguous. The head orientation axis 21 is essentially the longitudinal axis of the head. The two axes intersect at the geometrical bending position 22. In this embodiment, the geometrical base longitudinal axis 20 and the geometrical head orientation axis 21 form an angle γ (gamma) of 10°. The geometrical bending position 22 here has a distance K of 50% of the total length L of the brush 10 relative to the end face of the base 11. This angle in combination with the bending position 22 provides the brush 10 with a particularly effective and gum-friendly cleaning of the teeth.

[0136] As can be seen from the combination of Figures 1 and 2, in this embodiment, the head portion 13 is plate-shaped and the neck portion 12 is rod-shaped. When the substrate is projected onto the xz plane, the head portion 13 and the neck portion 12 have the same lateral dimensions (i.e. the same thickness). When projected onto the xy plane (front view shown in Figure 1), the head portion 13 is about three times as wide (y direction) as the neck portion 12. The length (x direction) of the head portion is about one third greater than its width (y direction). The neck portion 11 is, for example, one third as wide and 1.5 times as long as the head portion 13.

[0137] The neck portion 12 tapers relative to the head portion 13 and the base portion 11. In this example, the neck portion 12 is narrower than the head portion 13 in at least one side view (here, as viewed in the z direction in Figure 1).

[0138] The substrate of the brush 10, in this example, comprises, as a material performing the supporting function, glass fibre reinforced polypropylene Borealis GB311U having an elastic modulus of approximately 3500 MPA (yield tensile strength = 97 MPa; yield elongation = 2.8%; elastic modulus = yield tensile strength / yield elongation).

[0139] The runout is specified by the ratio of the spacing A to the brush length L. The spacing A corresponds to the distance between the center of the front of the head (here corresponding to the center of the bristle region 17) and the longitudinal axis 20 of the base (see FIG. 2). In this example, the runout is 14%.

[0140] The bristles are here arranged in tufts and protrude perpendicularly from the main surface of the plate-shaped head. In this case, the bristles are perpendicular to the y direction and extend in the xz plane. In this embodiment, the bristles are attached to the front surface of the head (or the front surface 27 of the brush), i.e. they point slightly downwards towards the adapter surface of the base (yz plane).

[0141] Figure 3 shows a schematic rear view of the brush 10 shown in figures 1 and 2. As can be seen from these figures, the substrate comprises another material at the rear surface 26, which is soft and provides protection (protective layer, protective coating) when the brush rear surface comes into contact with the teeth. This material does not perform a support function and may therefore have an elastic modulus outside the range of elastic modulus according to the invention, between 2000 and 6000 MPa. The material performing the support function is visible at the front surface 27 and forms the main part of the cross section of the substrate.

[0142] FIG. 4 shows a schematic plan view (z-direction) of a sonic toothbrush, which comprises a brush 10 and a handheld device 16 with a pin 15. The brush 10 is slipped onto the pin 15, so that the brush is detachably, non-rotatably and axially fixed. At the transition between the brush 10 and the handheld device 16, an adapter plane 33 is defined. The adapter plane 33 is perpendicular to the longitudinal axis of the handheld device and to the longitudinal axis of the brush base. The handheld device 16 rotates the pin 15 back and forth about the longitudinal axis of the pin 15 (corresponding to the longitudinal axis of the handheld device 16) with a frequency of, for example, 180-270 Hz with an amplitude of, for example, 2° (relative to the rest position). The brush thus rotates back and forth about the longitudinal axis 20 of the base (x-axis).

[0143] FIG. 5a shows a schematic side view of a sonic toothbrush 10. The sonic toothbrush 10 comprises a handheld device 16 and a brush 10. The drive of the handheld device 16 is formed as a piezoelectric drive (not shown) and generates a vibration of the brush 10 about the x-axis 20 (longitudinal axis of the handheld device). The brush 10 thus performs a rotational vibration about the x-axis 20 relative to the handgrip during operation. Due to the deflection according to the invention of the head part 13, an unbalance occurs, which assists the movement components in the Y-direction 24 and / or Z-direction 25 (see below, FIG. 5b). This effect is controlled by a suitably angled bend provided in the brush neck, a suitably selected elastic modulus, and can be adjusted by other geometrical constructional features of the brush (e.g. the bend angle position, the deflection, the mass distribution and other features according to the special embodiment of the invention).

[0144] Fig. 5b shows a schematic plan view of the personal care device shown in Fig. 5a. In this view, the Z direction 25 is visible. The Z direction 25 runs substantially in the direction of the bristles. As can be seen from this view, the hand-held tool is clearly larger than the brush. Only then can the hand-held tool generate longitudinal axis vibrations (instead of an undefined or undirected vibration movement, as is present in the case of known sonic toothbrushes).

[0145] Figure 6 shows an embodiment of a sonic toothbrush with exactly one tuft 18. The tuft 18 is arranged rearward with respect to the head part 13. The head part is inclined backwards as it were.

[0146] Figure 7 shows a schematic diagram of the "8" movement according to the invention. The "8" movement here has the shape of a "8" flattened on one side, with an axis of symmetry (X-axis) running through the centre 27 of the "8". Both loops 28a, 28b of the "8" extend in the y-direction. The invention is not however limited to this exact shape of the "8" movement, the exact shape of the movement ultimately depending on the parameters of the brush head and the vibrations generated by the motor of the handheld device.

[0147] Figure 8 shows the amplitude of the longitudinal axis oscillatory motion. The x-axis is perpendicular to the drawing plane. The plate-shaped head portion 13 (bristles not shown) pivots about the x-axis by an angle α (alpha). (The bristles extend upwards in the z-direction as viewed in Figure 8). The main component of the pivoting motion (and therefore the bristles wiping motion) is in the y-direction. The angle α (alpha) is preferably 2°.

[0148] Figure 9 shows a brush 10 with a plate-shaped oval head 13. The longitudinal axis of the oval shape extends substantially in the x-direction and the transverse axis in the y-direction. The centre of the head 13 is here further away from the upper end of the brush 10 compared to the teardrop-shaped head shown in Figure 1.

[0149] FIG. 10 shows a brush with a bending angle γ (gamma) of 14° and a spacing K of the geometric bending position 22 to the terminal face 29 of the base portion 11 of 75% with respect to the length L of the brush.

[0150] Starting from the end face 29, the base 11 tapers up to a transition to the neck 12. The base 11 may for example be frustoconical or frustopyramidal in shape and has for example a concave profile in longitudinal section, so that the centre of gravity of the base 11 is closer to the end face 29 than in the case of a comparable base with a straight profile line.

[0151] The neck 12, in the illustrated embodiment, occupies approximately half of the length (L) of the brush. As Figure 10 shows, the neck 12 does not necessarily have to have a constant cross-section along the entire length of the neck 12. The neck 12 may have a generally varying profile.

[0152] The head portion 13 is formed by the extension of the neck portion 12. In this example, the head portion 13 has substantially the same lateral dimensions (seen in a cross section perpendicular to the head orientation axis 21) as the neck portion 12. The bristles areas 17 are arranged laterally on the head portion 13. The bristles thus extend perpendicular to the head orientation axis 21.

[0153] Figure 11 shows an embodiment in which the base portion 11 is substantially formed as a drive adapter by means of a pin 30. The neck portion 12 is rod-shaped and occupies, for example, 90% of the brush length. The head portion 13 is the part in which the bristle area 17, here in the form of a single tuft, is implanted. The pin 30 is inserted in the handheld device in the x direction for non-rotatable connection to a sonic toothbrush drive having a longitudinal axis of vibration, the drive adapter defining the geometrical base longitudinal axis (x) of the brush.

[0154] The brush shown in Figure 11 is made of a material having an elastic modulus of approximately 4600 MPa, for example, an example of such a material is LNP ULTEM® EXCP0096 Polyetherimide, 30% carbon fiber reinforced, 10% PTFE lubricated (Yield tensile strength = 163 MPa, Yield elongation = 3.5%, Tensile strength / elongation = 4650 MPa).

[0155] Figures 12a-c show an embodiment with an RFID chip 31. Figure 12a shows a longitudinal section of the brush, Figure 12b shows a view of the adapter plane 33 of the brush from below, and Figure 12c shows an enlarged view of an extract from Figure 12a. The RFID chip 31 is housed in a conical base part 32, in particular preferably just above the adapter plane 33 (corresponding to the end face 29 in the preceding embodiment). In this case only a bottom plate 34 is provided between the adapter plane 33 and the RFID chip 31 as protection. The RFID chip 31 can be fixed, for example, in a holder 35, which itself is inserted in the form of a plug into an opening in the base part 32 and anchored there.

[0156] A coupling cavity 36 for a drive pin (not shown) of a hand-held instrument opens into the adapter plane 33. A clamping element 37 is present in the coupling cavity 36, which (detachably) fastens the drive pin of the hand-held instrument in such a way that the oscillating movement of the drive pin is best transmitted to the brush. The coupling cavity 36 with the clamping element 37 is an example of a plug-in connection between the brush and the drive pin of the hand-held instrument.

[0157] The RFID chip 31 is present within the longitudinal area occupied by the connecting cavity 36. Advantageously, this longitudinal area of ​​the connecting cavity is substantially as long as the conical base of the brush.

[0158] 12a-c show an embodiment in which the holder for the RFID chip is inserted from the side (i.e. transversely to the longitudinal axis of the brush), but it is also possible to design the brush in such a way that the holder is inserted from the adapter plane.

[0159] An RFID reader is housed in the handheld tool (not shown), which can read the RFID chip 31. This makes it possible, for example, to control the drive to operate at an optimum frequency for the brush, so that the controlled two-dimensional movement according to the invention is optimally generated. Further data can also be read, which indicates to the user, via an acoustic or optical signal, whether the brush should be replaced.

[0160] Modifications of the embodiment: In an alternative embodiment, not shown, brush 10 includes interdental brushes in place of bristle regions 17 for cleaning between teeth.

[0161] To recap, in summary, the present invention provides a brush for a sonic toothbrush drive which results in particularly advantageous movement of the head for effective and gum-friendly tooth cleaning.

Claims

1. A brush (10) for a sonic toothbrush having longitudinal axis vibration, comprising an elongate base body, said base body being a) having a frustoconical base portion (11), said base portion (11) having a drive unit adapter (14) that is non-rotatably connected to a sonic toothbrush drive unit having longitudinal axis vibration, said drive unit adapter (14) defining the geometric base portion longitudinal axis (x) of said brush, b) having a head portion (13), said head portion (13) having a head portion orientation axis (21) and a hair support, and a plurality of hairs are implanted in said hair support, c) and having a neck portion (12) that is tapered in cross-section compared to said base portion, said neck portion (12) connecting said base portion (11) and said head portion (13), in the brush (10), d) said base body forms a bending angle such that the geometric base portion longitudinal axis (20) and the geometric head portion orientation axis (21) form an angle γ within the range of 5° to 12°, and e) the geometric bending position (22) within said base body has a spacing (K) of at least 50% of the total length (L) of said base body with respect to the end face of said base portion (11), A brush (10) for a sonic toothbrush having longitudinal axis vibration, characterized in that.

2. The spacing (K) of said geometric bending position (22) with respect to the end face of said base portion (11) is at least 60% of the total length (L) of said base body, characterized in that the brush (10) according to claim 1.

3. The spacing of said geometric bending position (22) with respect to the end face of said base portion (11) is at most 75% of the total length (L) of said base body, characterized in that the brush (10) according to claim 1.

4. Said head portion (13) is plate-shaped and said neck portion (12) is rod-shaped, preferably, a) said head portion (13) is at least about twice as wide as said neck portion (12), and / or b) said head portion (13) is at most about 1.5 times as long as said neck portion (12), and / or c) said head portion (13) has approximately the same thickness as said neck portion in a cross-section defined by said longitudinal axis (x) and said head portion orientation axis, A brush (10) according to claim 1, characterized in that.

5. The head part (13) has a mass larger 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% larger than the mass of the neck part (12). The brush (10) according to claim 1, characterized in that.

6. The base part (11) is approximately the same length as the head part (13). The brush (10) according to claim 1, characterized in that.

7. The neck part (12) has a lateral dimension that is ¼ or less of the length of the neck part (12). The brush (10) according to claim 1, characterized in that.

8. The substrate has a support function with a modulus of elasticity that is 6000 MPa or less and 2000 MPa or more. The brush (10) according to claim 1, characterized in that it has a material.

9. The modulus of elasticity is at least 2500 MPa, particularly at least 3000 MPa. The brush (10) according to claim 8, characterized in that.

10. The substrate is substantially integrally made of one material. The brush (10) according to claim 8, characterized in that.

11. The substrate is formed by material parts that are substantially joined in a two- or three-material combination. The brush (10) according to claim 8, characterized in that.

12. The head part (13) has a runout of 10% to 20% with respect to the length of the brush (10). The brush (10) according to claim 1, characterized in that.

13. The bristles project substantially perpendicular to the head part orientation axis (21) of the brush (10). The brush (10) according to claim 1, characterized in that.

14. The geometric base part longitudinal axis (20) and the geometric head part orientation axis (21) form an angle γ within the range of 7° to 10°. The brush (10) according to claim 1, characterized in that.

15. The neck part (12) is tapered in cross-section compared to the head part. The brush (10) according to claim 1, characterized in that.

16. An ultrasonic toothbrush having longitudinal axis vibration, a) the brush (10) according to any one of claims 1 to 9, and b) A hand-held instrument, comprising a brush clutch for removably attaching the brush (10) to the hand-held instrument, and a drive unit (16, inside the hand-held instrument) for generating longitudinal axis vibration in the brush clutch. A sonic toothbrush having longitudinal axis vibration, comprising the above.

17. The sonic toothbrush according to claim 16, wherein the drive unit (16) is configured to generate a longitudinal axis vibration frequency within the range of 150 Hz to 400 Hz.

18. The sonic toothbrush according to claim 16, wherein the drive unit (16) is configured to generate a longitudinal axis vibration having an amplitude of less than 3°, particularly 1° to 3°.

19. A brush (10) for a sonic toothbrush having longitudinal axis vibration, comprising a vertically elongated base body, wherein the base body f) has a base portion (11), and the base portion (11) has a drive unit adapter (14) that is non-rotatably connected to a drive unit of a sonic toothbrush having longitudinal axis vibration. The drive unit adapter (14) defines the longitudinal axis (x) of the geometric base portion of the brush. g) has a head portion (13), and the head portion (13) has a head portion orientation axis (21) and a hair support. A plurality of hairs are implanted in the hair support. h) and has a neck portion (12) that is tapered in cross-section compared to the base portion. The neck portion (12) connects the base portion (11) and the head portion (13). In the brush (10), i) the base body forms a bending angle such that the longitudinal axis (20) of the geometric base portion and the geometric head portion orientation axis (21) form an angle γ within the range of 8° to 15°, and j) the base body has a material that provides a support function and has an elastic modulus of 6000 MPa or less and 2000 MPa or more. A brush (10) for a sonic toothbrush having longitudinal axis vibration, characterized by the above.

20. The brush (10) according to claim 19, wherein the elastic modulus is at least 2500 MPa, particularly at least 3000 MPa.

21. The head portion (13) is plate-shaped, and the neck portion (12) is rod-shaped. Preferably, a) the head portion (13) is at least about twice as wide as the neck portion (12), and / or b) the head part (13) has a length of at most about 1.5 times the length of the neck part (12) and / or c) the head part (13) has approximately the same thickness as the neck part in a cross-section defined by the longitudinal axis (x) and the head part orientation axis, The brush (10) according to claim 19, characterized in that.

22. The head part (13) has a mass greater than the mass of the neck part (12), in particular, the head part (13) has a mass at least 30%, particularly preferably at least 50% greater than the mass of the neck part. The brush (10) according to claim 19, characterized in that.

23. The base part (11) has approximately the same length as the head part (13). The brush (10) according to claim 19, characterized in that.

24. The neck part (12) has a transverse dimension that is at most one quarter of the length of the neck part (12). The brush (10) according to claim 19, characterized in that.

25. The substrate consists essentially of one material that performs a supporting function and is integrally formed. The brush (10) according to claim 19, characterized in that.

26. The substrate is formed by material parts that are substantially joined in a two- or three-material combination manner. The brush (10) according to claim 19, characterized in that.

27. The head part (13) has a runout (A) of 10% to 20% of the length (L) of the brush (10). The brush (10) according to claim 19, characterized in that.

28. The bristles project substantially perpendicular to the head part orientation axis (21) of the brush (10). The brush (10) according to claim 19, characterized in that.

29. The distance of the geometric bending position (22) from the end face of the base part (11) is at least 50% of the length (L) of the substrate. The brush (10) according to claim 19, characterized in that.

30. The geometric base part longitudinal axis (20) and the geometric head part orientation axis (21) form an angle γ in the range of 10° to 14°. The brush (10) according to claim 19, characterized in that.

31. The neck part (12) is tapered in cross-section compared to the head part. The brush (10) according to claim 19, characterized in that.

32. The brush (10) according to claim 19, characterized in that the distance (K) of the geometric bending position (22) from the end face of the base part (11) is at least 60% of the total length (L) of the base body.

33. The brush (10) according to claim 19, characterized in that the distance of the geometric bending position (22) from the end face of the base part (11) is at most 75% of the total length (L) of the base body.

34. A sonic toothbrush having longitudinal axis vibration, c) a brush (10) according to any one of claims 19 to 33, d) a hand-held device (16) having a brush clutch for detachably attaching the brush (10) to the hand-held device (16), and a drive unit provided in the hand-held device (16) for generating longitudinal axis vibration in the brush clutch. A sonic toothbrush having longitudinal axis vibration, comprising the above.

35. The sonic toothbrush according to claim 34, characterized in that the drive unit provided in the hand-held device (16) is configured to generate a vibration frequency of longitudinal axis vibration within the range of 150 Hz to 400 Hz.

36. The sonic toothbrush according to claim 34, characterized in that the drive unit is configured to generate longitudinal axis vibration having an amplitude (α) of at most 3°, particularly at least 1° and 3° or less.

37. The brush according to any one of claims 1 to 15 or 19 to 33, characterized in that it includes an RFID chip (31) in the base part (32).

38. The brush according to claim 37, characterized in that the RFID chip (31) is arranged in the longitudinal region of the connecting hollow chamber (36) of the base part.

Images