FIELD OF THE INVENTION

The present invention relates to the field of heads for oral hygiene devices.

The present invention furthermore relates to the field of oral hygiene devices having a brush head.

BACKGROUND OF THE INVENTION

It is known that some oral hygiene devices, in particular toothbrushes, provide at least one cleaning element attached to a carrier. The cleaning element may be formed by an elastic filament which during operation of the oral hygiene device is bent away from its rest state extension. Due to its elastic properties, the cleaning element may return after bending into its initial position and shape.

If the cleaning element has a symmetric cross section, the flexural strength of the cleaning elements may approximately be isotropic. Thus, bending of a cleaning element requires equal forces irrespective of the direction into which the cleaning element is bent or deflected from its initial position.

However, when cleaning the oral cavity different bending properties of the cleaning element in different directions may be desirable.

Thus, it is an object of this invention to provide a head for an oral hygiene device with at least one cleaning element, which has different bending properties in different directions.

SUMMARY OF THE INVENTION

In some embodiments there is provided a head for an oral hygiene device having a carrier, and at least one elastic cleaning element attached to the carrier, and wherein the carrier is structured such that it provides the cleaning element with a first bending property in a first direction and a second bending property different to the first bending property in a second direction, wherein the first direction and the second direction are different from each other. BRIEF DESCRIPTION OF THE DRAWINGS

This present disclosure is further elucidated by means of figures, wherein

Figure 1 shows a cross-sectional view of an embodiment of a head in accordance with the present disclosure,

Figure 2 shows a cross-sectional view of the embodiment of a head of figure 1 without bristles,

Figure 3 shows a top view onto the head of figures 1 and 2,

Figure 4 shows a perspective top view onto another embodiment of a head,

Figure 5 is a cross-sectional view through the head of figure 4, and

Figure 6 shows a schematic view of an oral hygiene device in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the accompanying figures identical elements have been denoted by identical reference numbers. While the embodiments depicted in the figures are described with respect to the particular configurations that are shown, the shown embodiments are only given as examples.

A head for an oral hygiene device (e.g. a manual or an electric toothbrush) in accordance with the present description has at least one elastic cleaning element that is attached to a carrier. Here, "attached" means that the cleaning element may be mounted inside of the carrier, in particular that a portion of the cleaning element is accommodated in a mounting hole of the carrier or that the cleaning element is attached to a surface of the carrier (e.g. glued to the surface or injection molded in a way that the material of the cleaning element and the carrier engage in a material bond). The carrier is structured in a way that it provides the cleaning element with at least two different bending properties in at least two different directions. This may in particular be achieved by a first bending stop that limits the bendable length of the cleaning element in a first direction in contrast to a larger bendable length of the cleaning element present in a second direction different to the first direction. In some embodiments, the first and the second direction may be opposite to each other. The bending direction is determined by a vector arrow that originates in a central point of the cleaning element, which extends in a plane that is perpendicular to a longitudinal extension direction of the cleaning element and that has an angular value in a range from 0 degrees to 360 degrees measured with respect to a reference direction. The first bending stop (likewise as a second bending stop or any further bending stop that may be present on the carrier) may be formed by a protruding element, e.g. a wall-like element, which protruding element may in particular abut the cleaning element over a portion of its longitudinal length. Measured from a central point of the cleaning element, the bending stop may extend over an angular range of about 180 degrees or less.

In some embodiments, a first bending stop may be present that determines a bendable length of the cleaning element as a multi-step function or continuous function of the bending direction for at least a first angular range of bending directions, e.g. in case that the first bending stop is realized by a protruding element, the protruding element may be formed like a curved wall segment having different height in different directions.

The carrier according to an embodiment of the invention is structured such that it provides for different bending properties of at least one cleaning element in different directions. A bending property may the stiffness or rigidity of the cleaning element when the cleaning element is being bent. In some embodiments, at least one further cleaning element may be attached to the carrier and the carrier is structured such that this at least one further cleaning element has identical bending properties in all directions. As a result an arrangement is provided, wherein different forces have to be applied in different directions to the at least one cleaning element in order to bent the cleaning element.

In some embodiments, at least one cleaning element may be realized as a single filament formed of an elastic plastic material, e.g. a bristle or an elastomeric "finger". In other embodiments, at least one cleaning element may be realized as a bristle tuft comprising a plurality of bristles. In another embodiment, at least one cleaning element may be formed as an elastomeric element that may in particular have a larger longitudinal extension than its diameter. While any suitable material may be utilized, one example for a plastic material suitable for forming a cleaning element may be polyamide, another example is natural or synthetic rubber.

In some embodiments, a plurality of cleaning elements is arranged on the carrier of the head.

In some embodiments, the carrier has at least one bending stop for the at least one cleaning element, the bending stop being arranged such that it influences the bending properties of the cleaning element in at least one direction. In some embodiments, the bending stop party envelopes the cleaning element.

In an embodiment, the cleaning element may be attached to a mounting surface of the carrier, e.g. by molding it onto the carrier. In such an embodiment, a bending stop for the cleaning element provided on the carrier on one side of the cleaning element may shorten a bendable length of the cleaning element on this side. Thus in order to achieve similar deflection of the cleaning element from its rest position likely requires different bending forces in different directions. In some embodiments, the bending stop may be formed by a protruding element being arranged on the carrier, wherein the protruding element may in particular abut part of the cleaning element.

Abutment in the sense of the present disclosure means that the protruding element protruding from the carrier is in engagement with the cleaning element when the cleaning element is in its initial rest position. However, abutment also includes configurations, wherein the cleaning element may be brought into engagement with the protruding element only if the cleaning element is deflected from its rest position. In some embodiments, the carrier may have a first bending stop and at least one second bending stop, which are arranged such that a first bendable length of the cleaning element in a first direction is longer than a second bendable length of the cleaning element in a second direction, wherein the first direction and the second direction are different from each other. By providing two different bending stops for differently limiting bending motions of a cleaning element in different directions (i.e. for generating different bendable lengths' in the different directions), different bending properties in different directions are achieved.

In some embodiments, the elastic cleaning element has a mounting section, an operative section and an operative end opposite the mounting section. The mounting section of the cleaning element may be accommodated in the carrier (e.g. the mounting section may be fastened inside a mounting hole provided in the carrier). The carrier may have a first bending stop associated with the operative section of the cleaning element for constricting a bending motion the operative section of the cleaning element in a first direction. Additionally, the carrier may comprise at least a second bending stop associated with the operative section of the cleaning element for constricting a bending motion of the operative section of the cleaning element in a second direction, wherein the second direction is different from the first direction. In the meaning of the present disclosure, the operative end of the cleaning element is the free end intended for engagement with, e.g., the gums and/or teeth to be treated. The operative section of the cleaning element in the meaning of the present disclosure is the part of the cleaning element which is intended to be brought in engagement with the gum and teeth during use of the brush head.

The mounting sections of the bristles may be accommodated in holes in the bristle carrier.

In an embodiment in which the cleaning element is accommodated in holes in the carrier, a first bending stop may be provided by the upper edge of a protruding element arranged in close proximity to the hole such that the cleaning elements abuts the protruding element when it is bent. The protruding element may also be arranged such that it essentially prolongs an inner wall of the hole and thus abuts the cleaning element over part of its longitudinal extension length. A second bending stop may be provided by an upper edge of the hole. A bendable length of the operative section is defined by a distance between an upper edge of a bending stop and the operative end of the cleaning element. In some embodiments, the first bending stop and the second bending stop are arranged such that a first bendable length of the operative section is shorter than a second bendable length of the operative section. In order to achieve an equal deflection of the operative section of the cleaning element for a bending motion in the direction of the first bending stop which is defining a shorter bendable length of the operative section a higher force is required when compared to a bending motion in the direction of the second bending stop providing a longer bendable length of the operative section.

In some embodiments, a second bending stop may be formed by a protruding element being arranged on the carrier, wherein the protruding element abuts part of the operating section of an cleaning element. The protruding element in the embodiments of figures 1 to 3 may be formed by a wall member 5 extending from carrier and above the upper edge of the hole 3. The wall member 5 forming the first bending stop essentially extends parallel to the longitudinal extension direction of the cleaning element and abuts the cleaning element. However, there may be other embodiments, wherein the first bending stop extends under an angle with respect to the bristles.

For example in the embodiments depicted in the figures, the first bending stop may be formed by wall members 5, 105. While the first bending stop of the embodiment of figures 1 to 3 may be an arc shaped wall member, the first bending stop of the embodiment according to figures 4 and 5 may be a H-shaped wall member 105. However, there may be other embodiments, wherein the first bending stop has another shape, e.g. a triangular shape.

In some embodiments, the carrier and the first bending stop may be integrally formed, e.g. by plastic injection molding of the carrier together with the first bending stop.

This may be the case for both embodiments shown in the figures. In the embodiment according to figures 1 to 3, the carrier and the arc-shaped first bending stop 5 may be integrally formed. In the embodiment according to figures 4 and 5, the H-shaped first bending stop 105 may be integrally formed with the bristle carrier 102.

In some embodiments, the carrier and the protruding element may be formed of two separate parts.

In some embodiments, at least two or more cleaning elements may be arranged on the carrier and the first bending stop may be arranged such that it abuts at least two cleaning elements.

In the embodiments depicted in figures 1 to 3, the head 7 comprises a plurality of cleaning elements realized a bristle tufts 8, where each bristle tuft may comprise two or more bristles. In this embodiment, the lateral cross-sectional area of each of the bristle tufts 8 may be circular. However, other examples for the shape of the lateral cross-sectional area of a bristle tuft (or a cleaning element in general) may be rectangular, square, elliptical, or star-like shapes.

The lateral cross-sectional area of a cleaning element in the meaning of the present disclosure is its cross-sectional area in a direction perpendicular to the longitudinal extension direction. The head 7 may comprise four protruding elements 5, wherein each of the protruding elements 5, 105 may be associated with one cleaning element 8. Each of the protruding elements 5 may be arranged such that it abuts a part of the outer surface of the cleaning element to which it is associated.

In the embodiment of figures 4 and 5, the H-shaped collar 105 as the protruding element forming a first bending stop may be associated with two cleaning elements 108 and thus simultaneously abuts two cleaning elements 108.

In the embodiment depicted in figures 1 to 3, each of the cleaning elements 8 has a circular cross- sectional area and the first bending stops 5 may be formed such that each partly encloses the cleaning element it is associated with. In some embodiments, a plurality of cleaning elements is realized by a plurality of bristle tufts. At least one of the bristle tufts may have a circular cross-sectional area and the first bending stop may form a partial circular arc partly enclosing the circular cross-sectional area of the bristle tuft. In some embodiments, the partial circular arc forming the first bending stop may have an angular extension in a range from about 10° to about 270°, or may have an angular extension in a range from about 50° to about 200°, or to about 180°.

In the embodiment of figures 1 to 3, each of the protruding elements 5 forming a plurality of first bending stops encloses the circular cross-sectional area of the associated cleaning element 8 by a partial circular arc extending over approximately 180° of the cross-sectional area of each of the groups 8.

In the embodiment depicted in figures 4 and 5, the cross-sectional area of the cleaning elements 108 may be approximately rectangular such that the first bending stop 105 formed by an El- shaped collar extends over the narrow side of the rectangle as well as part of the long sides of the rectangle.

In some embodiments, at least a first and a second cleaning element may be arranged on the carrier. A first bending stop for limiting the bending motion of the first cleaning element in a first direction may be associated with the first cleaning element and a second bending stop for limiting the bending motion of the second cleaning element in a second direction may be associated with the second cleaning element. In such embodiments, the first direction and the second direction may be opposite to each other. Figure 3 shows that the head 7 has two cleaning elements 8a, 8b having protruding elements forming bending stops 5 associated therewith. The protruding elements 5 are arranged such that they would complement each other, i.e. together they may cover a full circle of 360°. This configuration may lead to the cleaning element 8a being more rigid under a bending motion towards the left side of figure 3 and the cleaning element 8b being more rigid under a bending motion towards the right side of figure 3. As the head 7 depicted in the examples of figures 1 to 3 may used as a head 7 of an electric oral hygiene device providing a oscillatory rotational motion of the head 7 during operation of a oral hygiene device, the arrangement of cleaning elements 8 of this embodiment may leads to the fact that in both directions of rotation of the head 7, always some of the cleaning elements 8 are more rigid under a bending motion and thus may provide a higher force on the teeth and gum than others.

In the following, the functionality of providing two distinct bending stops for a single cleaning element is described with reference to figure 1. However, the same could be described with respect to the embodiment to figures 4 and 5.

In the embodiment depicted in figures 1 to 3, the second bending stop may be formed by the upper edge 4 of the hole 3 accommodating the mounting sections 6 of the bristles 1. When bending for example the cleaning element 8 a on the left side of figure 1 to the right side of figure 1, the cleaning element will be curved over a bendable length defined as the distance of the operative section 9 of the cleaning element measured between the bending stop 4 formed by the upper edge of the hole 3 and the operative end 10 of the cleaning element. In the embodiment indicated by figures 1 - 3, the cleaning elements 8a, 8b may be realized as bristle tufts that each comprise a plurality of two or more bristles 1. When performing a bending motion of the cleaning element into the opposite direction, i.e. towards the left of the drawing of figure 1, the operative section 9 of the bristle 1 may be bent over a bending length which is determined as the distance between the upper edge 11 of the protruding element 5 forming the first bending stop and the operative end 10 of the bristle 1. The bendable length between the upper edge 11 of the protruding element 5 and the operative end 10 may be shorter than the bendable length of the operative section 9 between the first bending stop 4 and the operative end 10 of the bristle 1. Consequently, when moving the operative end 10 of bristle 1 to the left side of figure 1 , a higher force may be required in order to obtain an identical deflection of the operative end 10 when compared to a bending motion of the operative end 10 to the right of figure 1. This fact may be used in order to enhance the forces applied by the bristle 1 to the gum and teeth to be cleaned in one direction of bending motion when compared to a bending motion in another direction.

Figure 6 shows a schematic view of an oral hygiene device, here realized as an electric toothbrush, having a handle portion 21 and a replaceable part 22 being detachably mounted on the handle portion. The replaceable part may comprise a head according any embodiment of the present disclosure.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

LIST OF REFERENCE CHARACTERS, 101 bristles

, 102 carrier

, 103 hole

, 104 second bending stop

, 105 first bending stop

mounting section of a cleaning element head

, 8a, 8b, 108 cleaning elements

operative section of a cleaning element0 operative end of a cleaning element

1 upper edge