Toothbrush head or brush carrier

Abstract

To provide a method for manufacturing a toothbrush head or a brush carrier including an advanced tuft.SOLUTION: At least one carrier element and at least one shape shift tuft 100 fitted onto the carrier element are provided. The shape shift tuft has: a first cross section which is fitted to rise toward a free end of the shape shift tuft along an extension direction from a fitting end on a fitting surface of the carrier element and has a first cross-sectional area and shape in a first length along the extension direction; and a second cross section having a second cross-sectional area and shape in a second length along the extension direction. In a toothbrush head or a brush carrier, the first cross-sectional area and the second cross-sectional area are virtually identical; the first cross-sectional shape differs from the second cross-sectional shape; and the first cross-sectional shape does not conform to the second cross-sectional shape independent of an angle at which the first cross-sectional shape rotates and independent of displacement of the first cross-sectional shape.SELECTED DRAWING: Figure 4B

Description

[Technical Field]

[0001] The present disclosure relates to toothbrush heads or brush carriers with tufts having two cross sections along their length that do not align when stacked. The present disclosure also relates to methods of manufacturing such toothbrush heads. [Background technology]

[0002] A head for an oral care device can include an attachment surface and at least one twisted tuft including a plurality of fibers and having a base attached to the attachment surface, the twisted tuft having an outer lateral surface, a longitudinal axis, a lower cross-sectional area extending in a plane perpendicular to the longitudinal axis and located at the base, and an upper cross-sectional area extending in a plane perpendicular to the longitudinal axis and located at a free end of the twisted tuft, the lower cross-sectional area and the upper cross-sectional area having substantially the same shape and size, the fibers forming at least the outer lateral surface being each substantially straight and all being inclined either clockwise or counterclockwise with respect to the longitudinal axis, the upper cross-sectional area being twisted relative to the lower cross-sectional area by a twist angle α, and the upper cross-sectional area not coinciding with the lower cross-sectional area when projected orthogonally relative to each other along the longitudinal axis. Such a head for an oral care device is generally disclosed in EP 2910143(B1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] European Patent No. 2910143(B1) Summary of the Invention [Problem to be solved by the invention]

[0004] There is an interest in toothbrushes that include tufts that are shaped in an even more versatile manner to allow for the design of more advanced toothbrush heads or brush carriers or toothbrushes that meet the advanced needs of the toothbrush heads or brush carriers or toothbrushes, respectively. Further, there is a need to provide methods for manufacturing such advanced tufts and toothbrush heads or brush carriers that include such advanced tufts. [Means for solving the problem]

[0005] According to one aspect, a toothbrush head or brush carrier includes at least one carrier element; and at least one shape-shifting tuft attached to the carrier element, the shape-shifting tuft attached so as to rise from an attachment end on a mounting surface of the carrier element generally along an extension direction toward a free end of the shape-shifting tuft, the shape-shifting tuft having a length from an attachment base to the free end, the shape-shifting tuft including a plurality of fibers, the shape-shifting tuft having a first cross-section along a first length along the extension direction, the first cross-section having a first cross-sectional area and shape, and a second cross-section along a second length along the extension direction, the second cross-section having a second cross-sectional area and shape. , the planes in which the cross sections are taken are parallel to one another, preferably the plane in the first length coincides with the attachment surface or is at least as close to the attachment surface as possible without the first cross section intersecting the attachment surface, and more preferably the plane in the second length coincides with the free end or is at least as close to the free end as possible so that the second cross section still intersects all fibers that also intersect the first cross section, the first and second cross-sectional areas are substantially identical, and the first and second cross-sectional shapes are different so that the first cross-sectional shape does not match the second cross-sectional shape independently of the angle by which the first cross-sectional shape is rotated and independently of the displacement of the first cross-sectional shape.

[0006] According to one aspect, there is provided a toothbrush comprising such a toothbrush head or brush carrier.

[0007] According to one aspect, a method of manufacturing a toothbrush head includes the steps of: providing a mold insert having at least one cavity for defining a shape-shifting tuft, the cavity having a length and extending from a first side of the mold insert along an extension direction to a second side of the mold insert opposite the first side; the cavity has a first cross-section having a first cross-sectional shape and area along a first length and a second cross-section having a second cross-sectional shape and area along a second length; the planes in which the cross sections are taken are parallel to one another, preferably the plane on the first length coincides with the first side or is at least as close to the first side as possible without the first cross section crossing the first side, and more preferably the plane on the second length coincides with the second side or is at least as close to the second side as possible; the first cross-sectional area and the second cross-sectional area are substantially identical, and the first cross-sectional shape and the second cross-sectional shape are different, so that the first cross-sectional shape does not align with the second cross-sectional shape independently of the angle by which the first cross-sectional shape is rotated and independently of the displacement of the first cross-sectional shape; and introducing a plurality of fibers into the cavity, each fiber having a first end and a second end, the second ends of the fibers remaining outside the mold insert; at least one of fusing second ends of the fibers together to form joined ends of a plurality of fibers, or bonding the second ends of the fibers by applying a bonding material, such as an adhesive, to form joined ends of a plurality of fibers, in either case the plurality of fibers and joined ends form shape-shifting tufts; - coupling the joining end with the carrier element, preferably by injection molding the carrier element around the joining end; and removing the plurality of fibers from the cavity. [Brief explanation of the drawings]

[0008] The present disclosure will be further clarified by reference to the detailed description of the exemplary embodiments and drawings. [Figure 1A] 1 is a first exemplary embodiment of an exemplary shape-shifting tuft according to the present disclosure. [Figure 1B] 1B is a schematic diagram of the cross-sectional shapes of the first and second cross sections of the shape-shifting tuft shown in FIG. 1A, the cross sections being taken in a plane coincident with the attached end and free end of the tuft. [Figure 2A] 1 is a second exemplary embodiment of an exemplary shape-shifting tuft according to the present disclosure. [Figure 2B] 2B is a schematic diagram of the cross-sectional shapes of the first cross section and the second cross section of the shape-shifting tuft shown in FIG. 2A. [Figure 3A] 10 is a third exemplary embodiment of an exemplary shape-shifting tuft according to the present disclosure. [Figure 3B] 3B is a schematic diagram of the cross-sectional shapes of the first cross section and the second cross section of the shape-shifting tuft shown in FIG. 3A. [Figure 4A] 1 is a side view of an exemplary brush carrier for a brush head according to the present disclosure, with three shape-shifting tufts mounted on the carrier element. FIG. [Figure 4B] FIG. 4B is a plan view of the brush carrier shown in FIG. 4A. [Figure 5] FIG. 10 is a top view of a carrier element with shape-shifting tufts removed. [Figure 6A] 4B is a plan view of a cross section through the brush carrier shown in FIG. 4A taken at plane AA shown in FIG. 4A. [Figure 6B] 4B is a plan view of a cross section through the brush carrier shown in FIG. 4A taken at plane BB shown in FIG. 4A. [Figure 6C] 4B is a plan view of a cross section through the brush carrier shown in FIG. 4A taken at plane CC shown in FIG. 4A. [Figure 7] 1 is a depiction of a toothbrush comprising a toothbrush head according to the present disclosure. [Figure 8]FIG. 1 is a flow diagram of a manufacturing process for making a toothbrush head or brush carrier according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] In this disclosure, a novel type or class of tufts is discussed, which type of tufts will be referred to herein as "shape-shifting tufts" to distinguish the proposed novel class of tufts from other tuft types. Thus, the term "tufts" alone includes all possible kinds of tufts, including shape-shifting tufts.

[0010] A tuft is understood to typically, but not necessarily, comprise a plurality of fibers, e.g., 10, 47, 98, or any other number, joined in some manner, such as by fusing the bottom ends of the fibers together or by bonding the bottom ends together using a bonding material, such as an adhesive or thermoplastic material. The joined fiber ends are referred to as the bottom ends, while the opposing top ends of the fibers are referred to as the free ends, since they are unbonded and intended to individually contact the tooth surface during tooth cleaning. Fibers can be made by cutting natural or synthetic filaments to the desired length. Synthetic filaments can be made from a variety of plastic materials, such as nylon (polyamides such as PA 6, PA 6.6, PA 6.10, PA 6.12, or PA 12), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene (PP), low-density polyethylene (LDPE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), or any other suitable material. The filaments can have any suitable diameter, such as 0.075 mm (often referred to as approximately 3 mils, where 1 mil is 0.0254 mm) to 0.5 mm, preferably 0.1 mm to 0.3 mm, e.g., 0.1 mm, 0.125 mm, 0.15 mm, 0.175 mm, 0.2 mm, 0.25 mm, or 0.3 mm. The artificial filaments can have various cross-sectional shapes, such as round, oval, X-shaped, or star-shaped. The filaments can be coextruded from two or more materials that differ in at least one material parameter, such as a colorant additive, and can have a sheath-core or islands-in-the-sea structure. The filaments can contain any suitable additive, such as colorants, abrasives, antimicrobial materials, or active agents, such as sodium fluoride (NaF). The filaments can be twisted or include notches along their length. Filaments for use in oral hygiene products such as toothbrushes are available from a variety of suppliers, such as Pedex GmbH (Wald-Michelbach, Germany) or Dupont (Wilmington, Delaware, USA).

[0011] Shape-shifting tufts are characterized as follows: -Contains multiple fibers. - extending from the mounting base towards the free end along the extension direction, the mounting base coinciding with the mounting surface of the carrier element to which the shape-shifting tuft is attached; -having a length measured from the mounting base along the extension direction towards the free end. - a first cross-section taken at a first length and a second cross-section taken at a second length different from the first length, the cross-sections each being taken in a plane, the two planes being parallel to each other. The first cross-section has a first cross-sectional area and a first cross-sectional shape, and the second cross-section has a second cross-sectional area that is essentially the same as the first cross-sectional area and a second cross-sectional shape that is different from the first cross-sectional shape and cannot be aligned with the first cross-sectional shape by rotation and / or translation.

[0012] With regard to the feature "not aligned," it should be understood that this refers to the fact that the second cross section is a parallel projection from the plane in which it is taken onto the parallel plane in which the first cross section is taken, and in this case, it is not possible to align the first and second cross sections by displacement and rotation within this joint plane, i.e., the first and second cross sections cannot be made to coincide by displacement and rotation operations.

[0013] The shape-shifting tuft may have an outer surface extending between the first length and the second length, and this outer surface may be defined by straight lines connecting each point on the outer edge of the first cross section with one point on the outer edge of the second cross section, such that every point on one edge has a unique connecting partner on the other edge.

[0014] As described in more detail below with respect to the method of manufacturing the shape-shifting tufts, the shape-shifting tufts may include bonded ends that can be bonded to the carrier element, where the bonded ends cannot extend beyond the attachment surface; for example, the bonded ends may be molten masses of fibrous material created by heating each end of the shape-shifting tuft so that the fibrous material melts and forms an essentially homogeneous mass of material upon cooling and solidification.

[0015] The shape-shifting tufts are coupled to a carrier element having an attachment surface from which a visible portion of the shape-shifting tuft rises, from an attachment end coincident with the attachment surface to a free end of the shape-shifting tuft. The shape-shifting tufts generally extend along an extension direction. The attachment surface may be planar or curved (i.e., have a three-dimensional topography), or even stepped, i.e., the attachment surface may include at least one step that essentially provides a discontinuity in the surface.

[0016] A circular tuft cut at two separate lengths by parallel planes will have the same cross-section at the two cut planes, and the cross-sectional area and shape will always be the same. This is regardless of the angle of the cut plane relative to the extension direction of the circular tuft. The same applies to any other tuft with an invariant cross-section. Therefore, the angle of the cut plane relative to the extension direction is not important, as a shape-shifting tuft will always have two inconsistent cross-sectional shapes at the two separate cut planes. Thus, the precise definition of the extension direction of the tuft is not important. However, the extension direction can be defined as follows: the shape-shifting tuft is cut by two parallel planes at a distance such that the first and second planes traverse the same number of fibers. The area center of each cross section is then identified. A line drawn connecting the two area center points can then be said to be the extension direction starting from the attached end and passing through the free end. The relationship between the extension direction and the cutting plane may not be important for defining the shape-shifting tufts, but nevertheless the planes in which the cross section is taken may be selected to be, for example, essentially perpendicular to the extension direction of the shape-shifting tufts, or they may be parallel to the flat mounting surface of the carrier element, or they may be parallel to the flat free ends of the shape-shifting tufts.

[0017] As noted above, the free ends of a shape-shifting tuft may be planar, i.e., the free ends of all of the fibers forming the shape-shifting tuft terminate in a single plane, but this does not exclude the free ends of a shape-shifting tuft from having a non-planar topology, where the free ends of the fibers forming the shape-shifting tuft terminate on a three-dimensional surface, or where the free ends of the fibers forming the shape-shifting tuft terminate irregularly.

[0018] As described above, the shape-shifting tuft has two cross-sections with two different cross-sectional shapes at two distinct length values ​​along the extension direction. The cross-sectional shape of the shape-shifting tuft may preferably smoothly transition from the first cross-sectional shape to the second cross-sectional shape, i.e., multiple cross-sections may be taken in multiple planes parallel to the first and second cross-sectional planes, with the difference between the cross-sectional shapes becoming smaller as the parallel planes approach along the extension direction. This means that the change in cross-sectional shape occurs without any steps or abrupt changes, i.e., the transition occurs smoothly. In some embodiments, straight lines can be drawn from each point on the edge of the first cross-section to a point on the second cross-section, and each point on each of the two edges has a unique counterpart on the other edge of the two edges. The multiple straight lines then determine the contour of the shape-shifting tuft between at least the two planes on which the first and second cross-sections are taken.

[0019] According to some embodiments, at least one of the cross-sectional shapes has at least one concave surface, and preferably at least the second cross-sectional shape has a concave surface. A free tuft end including a concave surface can support good cleaning of the tooth surface because debris can collect within the concave surface. The first cross-sectional shape may not include a concave surface, for example, it may be round or have no concave surface, and the attached end of the shape-shifting tuft can benefit from a more stable structure that cannot be provided by a cross-sectional shape with a concave surface. This is because the fibers around the concave surface can bend more easily, i.e., under lower applied force, and therefore may provide a less pronounced cleaning effect. Thus, the shape-shifting tuft can balance good bending stability with good cleaning properties. However, this should be understood as merely one example. In another example, multiple shape-shifting tufts can be arranged on a carrier element, so that their attached bases can be optimally held by the carrier element due to their compressed shape, but the free ends of the tufts can have an elongated and / or concave shape.

[0020] According to some embodiments, a shape-shifting tuft may have an extension direction that is inclined relative to a normal to the attachment surface at the shape-shifting tuft's attachment base. In the case of two or more shape-shifting tufts, the tufts may have different inclinations, i.e., in the case of two shape-shifting tufts, their extension directions may not be parallel, but they may be inclined toward or away from each other such that the free ends of the tufts may be closer to each other or further from each other than their attached ends.

[0021] As previously mentioned, a brush carrier or toothbrush head may include two or more shape-shifting tufts, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc., shape-shifting tufts, each of which may be essentially identical to the other shape-shifting tufts, or each of which may be different from all other shape-shifting tufts, or at least one subgroup of shape-shifting tufts may have essentially the same shape while at least one other shape-shifting tuft has a different shape. Shape-shifting tufts may be provided together with at least one other tuft, for example, a standard circular tuft or a tuft with a constant cross-sectional shape or a twisted tuft as described in EP 2910143 B1. Instead of one such non-shape-shifting tuft, multiple such non-shape-shifting tufts may be provided. Shape-shifting tufts may be provided in groups, for example, they may be arranged in a ring-like tuft configuration. One exemplary brush carrier or toothbrush head having three shape-shifting tufts and one standard round tuft is discussed in connection with Figures 4A, 4B, 5, 6A, 6B, and 6C.

[0022] According to some embodiments, an exemplary toothbrush head or brush carrier may have at least two shape-shifting tufts, preferably at least three shape-shifting tufts, which are angled so that their free ends are closer to each other than their mounting bases, and preferably the shape-shifting tufts (e.g., their areal center points on the mounting surface) are arranged approximately on a circle, ellipse, or oval, more preferably a straight central tuft is attached to the center of the circle, even more preferably the free ends of the shape-shifting tufts surround the central tuft, and even more preferably each of the three shape-shifting tufts has an elongated first cross-sectional shape and is oriented so that the major axis of the elongated first cross-sectional shape points to the center point of the circle, ellipse, or oval, or is tangent to the circular, elliptical, or oval central region of the circle, ellipse, or oval, and each of the shape-shifting tufts has a second cross-sectional shape at its free end that is curved around the central tuft ("curved" in the sense of partially surrounding it).

[0023] Exemplary Shape-Shifting Tufts Figures 1A, 1B, 2A, 2B, and 3A, 3B show three different exemplary shape-shifting tufts 100, 110, and 120, with Figures 1A, 2A, and 3A showing perspective views of each of shape-shifting tufts 100, 110, and 120. In these examples, the attachment surface is assumed to be flat and the free ends of the shape-shifting tufts are also assumed to be flat, so the first cross section is always taken at the height of the attachment surface, i.e., length value 0, and the second cross section is always taken at the height of the flat free ends, i.e., length value Ls, where Ls is the free length of the shape-shifting tuft.

[0024] Shape-shifting tuft 100 has an attached end 101 and a free end 109, shape-shifting tuft 110 has an attached end 111 and a free end 119, and shape-shifting tuft 120 has an attached end 121 and a free end 129. Attachment ends 101, 111, and 121 are understood to rise from a carrier element, which, as previously mentioned, is assumed herein to have a flat mounting surface. Not shown are any portions of shape-shifting tufts 100, 110, and 120 that may be disposed within or beneath the carrier element (and the carrier element is not explicitly shown). 1B, 2B, and 3B show the outlines of first cross sections 102, 112, and 122, respectively, taken in a first plane coincident with the height of the mounting surface, and the outlines of second cross sections 108, 118, and 128, respectively, taken in a second plane parallel to the first plane and coincident with the heights of free ends 109, 119, and 129, respectively, of shape-shifting tufts 100, 110, and 120. In accordance with the present disclosure, the cross-sectional area of ​​the first cross section in each embodiment is essentially the same as the cross-sectional area of ​​the second cross section of the same embodiment, but the cross-sectional shape of the first cross section in each embodiment is different from the cross-sectional shape of the second cross section of the same embodiment.

[0025] In all three examples, the first cross-section is circular or circular-like (e.g., dodecagonal, as in FIGS. 3A and 3B ), but this should not be understood as limiting, as the first cross-sectional shape can be any practical shape. The first cross-section can preferably be shaped to provide, for example, a higher or lower bending stiffness than the shape-shifting tuft has at its free end. For example, an elongated, V-shaped, or +-shaped free end has a fairly low overall bending stiffness while providing specific cleaning characteristics, such as a debris-collecting concave surface or a wide cleaning edge, which can provide beneficial cleaning effects. This lower bending stiffness can be offset by the cross-sectional shape of the shape-shifting tuft closer to its attachment base, which may be circular or circular-like. However, one skilled in the art may also find advantages in a low bending stiffness at the base and a compressed fiber arrangement at the free end, or an elongated cross-sectional shape at the base and a V-shape at the free end, etc.

[0026] In shape-shifting tuft 100 shown in Figures 1A and 1B, the cross-sectional shape of second cross section 108 is essentially V-shaped, in shape-shifting tuft 110 shown in Figures 2A and 2B, the cross-sectional shape of second cross section 118 is shaped like an elongated wedge profile with rounded edges, and in shape-shifting tuft 120 shown in Figures 3A and 3B, the cross-sectional shape of second cross section 128 is +-shaped (i.e., shaped like the mathematical symbol "plus"). It is understood that these cross-sectional shapes as shown can only be approximately achieved using a limited number of fibers per tuft (e.g., less than about 500 fibers, or less than about 350 fibers, or less than about 200 fibers, or less than about 150 fibers, or less than about 100 fibers, preferably 20-500 fibers). It should also be understood that the fibers of the tufts tend to diverge slightly from one another from the attachment base to the free end (so-called "flowering" of the tufts), and therefore the cross-sectional area of ​​the second cross section may in fact be slightly larger than the first cross-sectional area of ​​the first cross section, even if this is not intended.

[0027] In embodiments not shown in Figures 1A, 1B, 2A, 2B, 3A, and 3B, the free ends of the shape-shifting tufts may have a three-dimensional topology, i.e., the free ends of the individual fibers do not terminate in essentially one plane (whether inclined relative to the mounting surface or not), but the free ends of the fibers may terminate in a three-dimensional surface or may terminate irregularly. This means that the individual fibers of the tuft terminate at different lengths. See, for example, Figure 4A, where the central tuft has a convex free end. In such a case, the second cross-section would be taken in a second plane that intersects all fibers that also intersect the first plane, i.e., the second plane would be located immediately below the convex free end.

[0028] For completeness, it is stated that all cross sections taken at intermediate planes parallel to the first plane but closer to the first plane than the second plane will of course also intersect all fibers that intersect the first plane, and the cross-sectional area of ​​each intermediate cross section will be essentially the same as the cross-sectional area of ​​the first cross section or the second cross section. In that case, the cross-sectional shape of intermediate cross sections taken at planes of increasing distance to the first plane will smoothly transform from the first cross-sectional shape to the second cross-sectional shape.

[0029] While the exemplary embodiments shown in FIGS. 1A, 2A, and 3A contemplate a flat mounting surface, it should be understood that the mounting surface may be non-flat (as shown in FIG. 4A), e.g., the mounting surface may be curved or step-like. To the extent this disclosure refers to a normal to the mounting surface, this is understood to mean a normal to the mounting surface smoothly interpolated at the center of the base area of ​​the shape-shifting tuft. The extension direction of the tuft may be tilted relative to such a mounting surface normal. The tufts may be tilted circumferentially, e.g., clockwise or counterclockwise, relative to a center point, such as the actual physical center point of the carrier element, or the tufts may be tilted radially inward or outward. The tufts may, of course, be tilted as appropriate to meet any need. The angle of inclination should not be understood as being limiting, but is often in the range of 0 to 20 degrees, such as 5 degrees, or 7 degrees, or 11 degrees, or 14 degrees, or 15 degrees, or 16 degrees, or 17 degrees, or 18 degrees, or any other value. For curved mounting surfaces, the tufts may be inclined differently relative to the mounting surface normal, but the extension directions of the tufts may still all be parallel to one another.

[0030] Exemplary Toothbrush Heads Including Shape-Shifting Tufts Figures 4A, 4B, 5, 6A, 6B, and 6C all relate to one exemplary brush carrier 11A including three shape-shifting tufts 100A, 110A, and 120A and an additional tuft 130A, all of which are attached to a carrier element 150A including a mounting surface 151A. While only the brush carrier 11A including tufts 100A, 110A, 120A, and 130A and carrier element 150A is shown here, it will be understood that this brush carrier 11A can be attached to a brush housing to form a toothbrush head. While the toothbrush head 10 shown in Figure 7 is mentioned as an example, it will be apparent that the toothbrush head can also be a non-removable part of the toothbrush; for example, the toothbrush head of a manual toothbrush is typically not removable, while the toothbrush head of an electric toothbrush is typically replaceable.

[0031] 4A and 4B show side and top views of an exemplary brush carrier 11A. Three shape-shifting tufts 100A, 110A, and 120A are arranged approximately on a circle 400A around an additional tuft 130A, which may also be referred to as a central tuft 130A due to its location. Tufts 100A, 110A, 120A, and 130A are all mounted on a mounting surface 151A of a carrier element 150A. The three shape-shifting tufts 100A, 110A, and 120A are arranged along circle 400A, each with an equiangular distance of 120 degrees between adjacent tufts. The central tuft 130A is mounted at the center of circle 400A, which is also the center of carrier element 150A. While central tuft 130A is shown herein as a straight, circular tuft, the central tuft may also have many other cross-sectional shapes, such as a triangular shape. Shape-shifting tufts 100A, 110A, and 120A are all identical in shape and all slope toward central tuft 130A. Shape-shifting tuft 100A has an attached end 101A and a free end 109A; shape-shifting tuft 110A has an attached end 111A and a free end 119A; shape-shifting tuft 120A has an attached end 121A and a free end 129A; and central tuft 131A has an attached end 131A and a free end 139A, with free end 139A of central tuft 130A having a non-planar free end topography that is spherical, i.e., the ends of the fibers of central tuft 130A terminate on segments of a sphere. However, this is by way of example only and should not be understood as limiting. Shape-shifting tufts 110A extend generally along extension direction 113A, shape-shifting tufts 120A extend generally along extension direction 123A, and central tufts 130A extend generally along extension direction 133A. Figure 4A shows three parallel planes AA, BB, and CC through which the cross sections shown in Figures 6A, 6B, and 6C are taken.Plane AA is shown herein with a first length along the extension direction, which is closer to attachment surface 151A and therefore closer to attachment ends 101A, 111A, and 121A, and plane CC is shown with a second length along the extension direction, which is closer to free ends 109A, 119A, and 129A of shape-shifting tufts 100A, 110A, and 120A.

[0032] FIG. 5 is a plan view of carrier element 150A with the tufts removed. Tuft holes 200A, 210A, and 220A are all shown as having an elongated diamond shape at attachment surface 151A. Similarly, circular tuft hole 230A for the central tuft is visible. The long axes of diamond-shaped tuft holes 201A, 211A, and 221A are shown in dashed lines, and when these long axes extend beyond their respective tuft holes, they are tangent to circle 401A around the center of carrier element 150A. Comparing with FIG. 4B, it is clear that circle 401A defines a relatively small central region in the center of carrier element 150A. In other embodiments, the long axes of the tuft holes for shape-shifting tufts may point toward the center or another enlarged central region.

[0033] Figures 6A, 6B, and 6C show cross sections through brush carrier 11A taken along parallel planes AA, BB, and CC, respectively, as shown in Figure 4A. Figure 6A shows a cross section taken at plane AA, looking in the direction of the line of sight to carrier element 150A. First cross sections 102A, 112A, and 122A of the three shape-shifting tufts can be seen, with first cross sections 102A, 112A, and 122A all having elongated, generally diamond-like cross-sectional shapes. The central tuft has first cross section 132A having a circular shape. Figure 6C shows a cross section taken at plane CC, looking in the direction of the line of sight to carrier element 150A. The second cross sections 108A, 118A, and 128A of the three shape-shifting tufts are visible, all of which have a curved, bean-like cross-sectional shape, with the concave surface of the bean-like cross-sectional shape partially enveloping the central tuft, which, of course, has a circular cross-sectional shape 138A. These particular second cross-sectional shapes of the shape-shifting tufts allow for a high fiber density in the central free end region of the brush carrier 11A, so that interdental areas, in particular, can be cleaned with a large number of fibers arranged in a fairly small area. FIG. 6B shows a cross section taken on plane BB, looking in the direction of the carrier element 150A. The intermediate cross sections 105A, 115A, and 125A of the three shape-shifting tufts are visible, providing an impression of how the elongated, diamond-shaped first cross-sectional shape transforms into the bean-like second cross-sectional shape. The cross-sectional shape 135A of the central tuft, of course, remains unchanged.

[0034] Exemplary Toothbrush 7 is a depiction of an exemplary toothbrush 1 comprising a handle portion 20 and, here, a toothbrush head 10 according to the present disclosure removably attached to the handle portion 20. The toothbrush head 10 comprises a brush carrier 11 mounted for driving movement relative to a toothbrush head housing 12.

[0035] Method for manufacturing shape-shifting tufts FIG. 8 illustrates process steps for a method of manufacturing a brush carrier or toothbrush head with at least one shape-shifting tuft.

[0036] In step 500, a mold insert is provided having at least one cavity for defining a shape-shifting tuft. The cavity has a length and extends from a first side of the mold insert along an extension direction to a second side of the mold insert opposite the first side. Further, the cavity has a first cross-section having a first cross-sectional shape and area at a first length and a second cross-section having a second cross-sectional shape and area at a second length, the planes in which the cross-sections are taken are parallel to one another, preferably the plane at the first length coincides with the first side or is at least as close to the first side as possible without the first cross-section crossing the first side, and more preferably the plane at the second length coincides with the second side or is at least as close to the second side as possible, the first and second cross-sectional areas are substantially identical, and the first and second cross-sectional shapes are different so that the first cross-sectional shape does not match the second cross-sectional shape independently of the angle by which the first cross-sectional shape is rotated and independently of the displacement of the first cross-sectional shape. The mold insert may have multiple cavities defining either additional shape-shifting tufts or non-shape-shifting tufts, such as circular tufts or other constant or twisted cross-section tufts.

[0037] In optional step 501, the cavity is either closed on a second side by a closure element that may define a planar or non-planar fiber abutment surface, or the closure element is positioned close to the second side, for example at a distance in the range of 0.01 mm to 10 mm, so that the free ends of the fibers that may be introduced into the cavity from the first side abut against the fiber abutment surface of the closure element that defines the planar or non-planar free ends of the tufts defined by the cavity.

[0038] In step 502, fibers are introduced into the cavity from a first side, each fiber having a first end (which becomes a free end) and a second end, with the second end of the fiber remaining outside the mold insert on the first side. As the fibers are introduced into the cavity, they orient themselves to fit the shape-shifting tuft cavity. Some rocking or vibration of the mold insert may be used to support the fiber placement and prevent individual fibers from being placed with prestress. Due to the shape-shifting configuration of the cavity and potentially due to the topology of the free ends of the tufts defined by the closure elements, the fibers will have different lengths within the cavity, and therefore may extend to the first side at different heights. A cutting step may be applied to cut the fibers to a common length. In the filling step, a high degree of filling of the tuft cavity may be applied; for example, the cavity filling may be greater than 50%, greater than 60%, greater than 65%, greater than 70%, or greater than 75%.

[0039] In step 503, at least one of melting the second ends of the fibers together to form a bonded end of the plurality of fibers or bonding the second ends of the fibers by applying a bonding material, such as an adhesive, to form a bonded end of the plurality of fibers. In either case, the plurality of fibers and the bonded end form a shape-shifting tuft. Ideally, melting the second ends together or bonding the second ends with a bonding material does not introduce any new prestress but rather relieves any prestress that is still present.

[0040] In step 504, the joining ends of the shape-shifting tufts are preferably coupled to the carrier element by injection molding the carrier element around the joining ends. The mold insert may then form the first mold half or may be a component of the first mold half, such that the mold insert and additional mold halves define mold cavities for the carrier elements. Generally, the mold insert may include multiple groups of tuft cavities, each group associated with one carrier element.

[0041] In step 505, the plurality of fibers, i.e., at least one shape-shifting tuft, is removed from the tuft-defining cavity along with the carrier element being released from the molding cavity. The fibers are temporarily bent during the removal process, but due to the fact that the fiber orientation is essentially fixed by the bonded ends, they spring back to the orientation imparted to the plurality of fibers by the cavity after removal. Because the introduction of the fibers and the bonding of the second ends avoids the introduction of any prestress, the shape of the removed shape-shifting tuft will essentially follow the shape defined by the cavity. As mentioned above, some unavoidable blooming may occur, such that the cross-sectional area may increase slightly toward the free end of the shape-shifting tuft. If some prestress is still present on the individual fibers, each fiber may spring back to an unstressed position, such that the shape of the shape-shifting tuft may be slightly deformed, but the described techniques are expected to avoid prestressing for most of the embodiments discussed herein.

[0042] In optional step 510, cavities are formed by wire erosion, in which a thin, straight wire cuts through the material of the mold insert. In this manner, the wire can be moved along the edges of the cross-sectional shape on the first and second sides, so that the shape of the shape-shifting tuft is defined by a straight line, as described in the previous paragraph. Other techniques for forming cavities can be employed as well. For example, the mold insert can be fabricated from thin sheets, and cavities can be formed in each sheet by etching, laser cutting, laser ablation, or other electrical discharge machining (EDM) in addition to wire erosion. Additional techniques that can be used are 3D printing, such as direct metal laser sintering, selective laser sintering, selective laser melting, or electron beam melting. Mold inserts can also be fabricated from ceramic or polymer materials using 3D printing techniques.

[0043] Dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​recited. Instead, unless otherwise indicated, 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."

Claims

1. A toothbrush head or brush carrier, comprising: at least one carrier element; at least one shape-shifting tuft mounted on the carrier element, the shape-shifting tuft being mounted so as to rise from an attachment end on the attachment surface of the carrier element in a generally extending direction toward a free end of the shape-shifting tuft; the shape-shifting tuft has a length from the attachment base to the free end; the shape-shifting tuft comprises a plurality of fibers; The shape-shifting tuft has a first cross-section having a first cross-sectional area and shape at a first length along the elongation direction and a second cross-section having a second cross-sectional area and shape at a second length along the elongation direction. the planes in which the cross sections are taken are parallel to one another, preferably the plane on the first length coincides with the attachment surface or is at least as close as possible to the attachment surface without the first cross section intersecting the attachment surface, and more preferably the plane on the second length coincides with the free end or is at least as close as possible to the free end so that the second cross section still intersects all fibres that also intersect the first cross section; A toothbrush head or brush carrier, wherein the first cross-sectional area and the second cross-sectional area are substantially identical, and the first cross-sectional shape and the second cross-sectional shape are different, such that the first cross-sectional shape does not align with the second cross-sectional shape independently of the angle by which the first cross-sectional shape is rotated and independently of the displacement of the first cross-sectional shape.

2. The toothbrush head or brush carrier of claim 1 , wherein the free ends of the shape-shifting tufts have a non-planar topology.

3. 3. The toothbrush head or brush carrier of claim 1 or claim 2, wherein the cross-sectional shape of the shape-shifting tufts transitions smoothly from the first length to the second length.

4. A toothbrush head or brush carrier according to any preceding claim, wherein at least the second cross-sectional shape has a concave surface.

5. A toothbrush head or brush carrier according to any one of claims 1 to 4, wherein the extension direction of the shape-shifting tufts is inclined relative to a normal to the mounting surface of the mounting base.

6. A toothbrush head or brush carrier described in any one of claims 1 to 5, wherein when the area center point of the second cross section is projected onto the first cross section along a direction that coincides with the direction determined by the surface normal of the mounting surface at the mounting base of the shape-shifting tuft, the area center point of the second cross section does not coincide with the area center point of the first cross section.

7. A toothbrush head or brush carrier according to any one of claims 1 to 6, wherein the distance between the first length and the second length is greater than or equal to about 50 percent of the total free length of the shape-shifting tufts, preferably greater than or equal to about 60 percent of the total free length of the shape-shifting tufts, more preferably greater than or equal to about 70 percent of the total free length of the shape-shifting tufts, and even more preferably greater than or equal to about 80 percent of the total free length of the shape-shifting tufts.

8. A toothbrush head or brush carrier according to any one of claims 1 to 7, wherein each of the fibers has a base on the mounting surface, a free end, a length measured between the base and the free end, and an inclination angle measured with respect to the extension direction, and the inclination angles of at least two fibers are different.

9. A toothbrush head or brush carrier according to any one of claims 1 to 8, wherein each point on the outer edge of the first cross section can be connected to one point on the outer edge of the second cross section by a straight line that defines the outer lateral shape of the shape-shifting tuft between the first length and the second length.

10. 10. The toothbrush head or brush carrier of any one of claims 1 to 9, comprising at least two shape-shifting tufts, preferably at least three shape-shifting tufts, said shape-shifting tufts being angled so that their free ends are closer to each other than their attachment bases, preferably said shape-shifting tufts being arranged on a circle or an ellipse or an oval, more preferably a straight central tuft attached to the center of the circle, even more preferably said free ends of the shape-shifting tufts surrounding said central tuft, even more preferably each of said three shape-shifting tufts has an elongated first cross-sectional shape and is oriented so that a major axis of said elongated first cross-sectional shape points at a center point of said circle, ellipse or oval, or is tangent to a circular, elliptical or oval central area of ​​said circle, ellipse or oval, and each of said shape-shifting tufts has a second cross-sectional shape at their free end that is curved around the central tuft.

11. A toothbrush comprising a toothbrush head or a brush carrier according to any one of claims 1 to 10.

12. The toothbrush of claim 11 , wherein the toothbrush comprises a repeatedly detachable brush portion, including the toothbrush head or the brush carrier.

13. 1. A method of making a toothbrush head or brush carrier, comprising: providing a mold insert having at least one cavity for defining a shape-shifting tuft, the cavity having a length and extending from a first side of the mold insert along an extension direction to a second side of the mold insert opposite the first side; the cavity has a first cross-section having a first cross-sectional shape and area along a first length and a second cross-section having a second cross-sectional shape and area along a second length; the planes in which the cross sections are taken are parallel to one another, preferably the plane at the first length coincides with the first side or is at least as close to the first side as possible without the first cross section crossing the first side, and more preferably the plane at the second length coincides with the second side or is at least as close to the second side as possible; the first cross-sectional area and the second cross-sectional area are substantially identical, and the first cross-sectional shape and the second cross-sectional shape are different, so that the first cross-sectional shape does not align with the second cross-sectional shape independently of the angle by which the first cross-sectional shape is rotated and independently of the displacement of the first cross-sectional shape; introducing a plurality of fibers into the cavity, each fiber having a first end and a second end, the second ends of the fibers remaining outside the mold insert; at least one of fusing the second ends of the fibers together to form joined ends of the plurality of fibers, or bonding the second ends of the fibers by applying a bonding material such as an adhesive to form joined ends of the plurality of fibers, wherein in either case the plurality of fibers and the joined ends form shape-shifting tufts; - coupling said joining end to said carrier element, preferably by injection molding said carrier element around said joining end; and removing the plurality of fibers from the cavity.

14. The method of claim 13 including forming the cavity by wire erosion.

15. 15. The method of any one of claims 13-14, further comprising either closing a distal end of the cavity open on the second side with a molding element that defines the shape of the free end of the tuft, or providing a molding element that defines the shape of the free end of the tuft proximate the distal end of the cavity.

Images