The invention relates to a toothbrush having a head part, a carrier element and a plurality of cutouts, and to a process which is intended for producing such a toothbrush that includes guiding the bristle filaments through the cutouts and connecting the carrier element to the head part. The invention also relates to a head part for a changeable-head toothbrush. The present application claims priority to German Application No. 102 59 723.5 filed Dec. 19, 2002.
Producing toothbrushes by AFT (Anchor Free Tufting) technology has great advantages in relation to the conventional bristle-covering operation, in which bristle filaments bent around anchors or clips are stuffed into the head part of the brush. Because the shape of the clusters of bristles is not predetermined by the size of the corresponding fastening means, more or less any desired bristle arrangements can be realized by means of AFT. In the case of AFT, use is made of a carrier plate with a plurality of cutouts through which clusters of bristle filaments are guided. The rear ends are then melted for permanent connection to the carrier plate. AFT technology is described, for example, in EP-A 0 972 464, EP-A 0 405 204 or EP-A 0 567 672. The bristle covered carrier plate is then connected to the head part of the toothbrush. Ultrasonic welding, which is described for example in DE-U 2000 6311, is preferred.
AFT technology straightforwardly allows the production of different bristle profiles, by the bristle filaments, which are guided loosely through the cutouts, being forced into the desired profile shape, using a template, before the incipient melting. However, the properties of a toothbrush or of its bristle arrangement, such as rigidity, wear and cleaning efficiency, are determined not just by the material selection and the profile shape, but also by the length and the setting angle of the bristles. Up until now, it was not possible for these parameters, in particular the bristle length and profile shape, to be varied independently of one another in order to optimize the cleaning properties further.
WO 94/22346 discloses a toothbrush with an inflection in the bristle-carrying head part, but does not describe the production process. The conventional bristle-covering operation of such a brush involves high outlay because it is only possible to compensate for height differences in the head part by compensating movements of the stopping tool.
The object of the invention is thus to provide a toothbrush which, along with straightforward production, allows the largely free selection of parameters of the bristle arrangement for the purpose of improving the cleaning performance. It is also intended to specify a corresponding production process.
The object is achieved by a toothbrush having a head part, a carrier element and a plurality of cutouts and by a process which is intended for producing such a toothbrush and that includes guiding the bristle filaments through the cutouts and connecting the carrier element to the head part. Advantageous developments of the invention can be gathered from the dependent claims, the description and the drawings.
The invention is based on a toothbrush produced by AFT. This toothbrush has a head part and at least one carrier element which is connected thereto and has a plurality of cutouts through which bristle filaments are guided and, for fastening on the carrier element, are melted by way of their rear ends. The top surface or the top surfaces of the at least one carrier element define a front surface of the finished head part. The front surface is that surface in which the roots of the bristles and of any other cleaning elements are located. According to the invention, this front surface has a non-planar three-dimensional configuration and/or is capable of assuming such a configuration during intended use. A suitable selection of the topography, i.e., of the non-planar shape of the front surface in the rest state and/or under loading, makes it possible to produce a multiplicity of bristle arrangements. In particular, it is easily possible to vary the bristle length and the setting angle relative to the plane of the actual head part.
Toothbrushes with such a static and/or dynamic topography can be realized in different ways according to the invention.
A first possibility is to use a flexible carrier element which consists, for example, of a thin hard material or at least partially of a soft material, with the result that dimensional and material elasticity is provided. This carrier element is preferably flat before it is installed in the head part, with the result that it can easily be covered with bristles. The hot die used for melting the bristle ends can provide a hard material with the desired top-surface shape, which may additionally be fixed by the bristle melt. Alternatively, in the case of a partially flexible carrier element, the topography is only produced during insertion into the head part or during use. It is possible for a shape which is flat in the rest state to be provided.
In the case of carrier elements with a soft component, the bristles are retained, at least in a subregion, by the elastic material and are thus mounted in a flexible manner. In order to achieve sufficient flexibility, it is preferable for the Shore A hardness of the elastic material to be selected to be below 70, for the carrier-plate thickness to be selected to be below 4 mm and for the layer thickness of the melted material to be selected to be below 1 mm. A topography which is flat or convex in the transverse and/or longitudinal direction of the head part is preferably selected, in order that a change in topography takes place during use.
Two-component carrier elements have the advantage that the hard component simplifies the ultrasonic welding, and may also serve as an anchoring means for the bristles, and the soft component ensures the desired elasticity and/or deformability.
Possible hard materials are the materials used for producing the head part, in particular polyethylene (PE), polypropylene (PP), PET, acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN). An in particular thermoplastic elastomer e.g., TPE, TPU, rubber, silicone, is preferably used as the soft material. In the case of a two-component configuration of the carrier element, said soft material is coordinated with the hard material, with the result that a non-releasable connection is produced.
A further possibility for a toothbrush according to the invention consists in using a rigid carrier element of which the top surface already has the desired topography. The rear surface may be configured to follow the profile of the top surface. Alternatively, the rear surface is planar, with the result that the carrier element has different thicknesses. The first variant has advantages in respect of the material consumption and the cooling times, although the AFT die has to be adapted to the shape of the rear side. In the case of the second variant, it is possible to use a conventional heating die with a planar front.
A further possibility for a toothbrush according to the invention consists in using a plurality of carrier elements, which in this case may also have a planar top surface. The desired topography is predetermined by the shape of the head part and/or the shape of the carrier elements, in particular by the position and alignment of the regions which are prepared for accommodating the carrier elements. According to the invention, the carrier elements are inserted at different heights and/or different orientations. It is thus advantageously possible for different bristle arrangements to be realized from a plurality of elements, in the manner of a construction kit, without new carrier plates having to be produced in each case. The carrier elements can be covered with bristles in parallel in the AFT machine, i.e., in one operation as a single-part bristle arrangement. In addition, zones with flexible components, e.g., flexible zones or cleaning elements, may be set up between the carrier elements.
The carrier element or the carrier elements is/are preferably connected to the head part by means of ultrasonic welding. In order to ensure satisfactory welding between these parts, the welding surface is preferably located in a single plane. The desired topography is thus preferably only formed within the region defined by the welding surface. For example, a peripheral welding border is formed in the border region of the rear surface, this border interacting with a corresponding mating surface on the head part. If this is not possible, for example because the carrier element has steps or other sudden changes in topography, it is possible to dispense with welding specifically in these regions. It is preferable, however, to utilize at least 25% of the theoretically possible welding surface on the periphery of the head.
The same material is advantageously used for the carrier element, or the hard component thereof, and the head part. The two parts are advantageously assembled in a largely flush manner, i.e., within the production tolerances, without edges or grooves. However, it is often not possible, in practice, to prevent a depression from forming on the boundary surface, allowing for deposits to form in said depressions. In order for these deposits not to be obvious to the user, the head part and carrier element are particularly preferably made of different colors.
In a development of the invention, the material of the carrier element comprises additives, such as flavorings, temperature indicators or antibacterial substances. Such additives are expensive and, rather than being used in the entire head part including the handle, by being provided on the carrier element are thus advantageously used only in the actual target region, i.e., during intended use, in the mouth.
Examples of the invention are described hereinbelow and illustrated in the drawings, in which:
a-c show a toothbrush according to the invention with a rigid curved carrier element,
a and b show a toothbrush with an elastic curved carrier element;
a and b show toothbrushes with a carrier element with an undulating top surface;
a and b show a toothbrush with a carrier element with a step;
a and b show a toothbrush with two carrier elements and a shoulder located therebetween;
a and b show a toothbrush with a carrier element comprising three segments;
a and b show a toothbrush with a carrier element with an undulating top surface;
a and b show a toothbrush with three carrier elements;
a and b show a toothbrush with a carrier element with a soft component and a hard component;
a-c, 14 show toothbrushes with a curved carrier element and bristles which can be moved relative thereto;
a-d and 16a-c show toothbrushes with a carrier element with a hard component in the form of a lattice; and
All of the toothbrushes shown in the figures have a handle part (not illustrated), a head part 1 and at least one carrier element 2 which is, or can be, connected thereto and has been covered with clusters of bristles 3 by AFT. According to the invention, the front surface 5 of the finished head part, said surface, in the cases with just one carrier element 2 (see
The carrier element 2, for the purpose of accommodating the clusters of bristles 3, has a plurality of cutouts 6 running between its top side 4 and its rear surface 8. By virtue of the alignment of these holes 6, it is possible to adjust the setting angle of the clusters of bristles 3. In terms of production, however, it is preferred for the holes 6 to run in the direction of the normal of the top surface 4. For fastening on the carrier element 2, the rear ends 3a of the clusters of bristles 3 are melted by a heating die 12 (see
The carrier element 2, alongside the actual bristle-carrying surface 2a, has a preferably peripheral border part 9 projecting from the rear side 8 thereof. This border part serves, on the one hand, for centering purposes during insertion into correspondingly adapted cutouts 7 in the head part 1 and, on the other hand, for realizing welding surfaces 10, 10′ for ultrasonic welding. The border 9 also serves as a lateral boundary for the bristle melt 11.
In the case of the toothbrush shown in
As is shown in
Furthermore, it is also possible for the bottom end 9a of the border part 9, together with the base 7a of the cutout 7, to serve as welding surface 10′. For this purpose, the parts 2b and/or 9a may have a tapered border 31 (see
In the case of the example from
As an alternative, the carrier element 2 may also consist of a flexible material or thin hard material which is flexible enough in order, following the bristle covering operation, to be inserted into the head part in the flat state, under pre-stressing and arching action. For this purpose, the material thickness of the hard material is preferably not more than 3 mm. The deformable part of the carrier plate is subjected to pre-stressing by the deformation, with the result that the flexibility which is present in this region during use can also be determined to a considerable extent by the production of the brush.
a shows a longitudinal section of a toothbrush with a rigid carrier element 2, of which the top surface 4 is of undulating form and the rear surface 8 is flat. The thickness of the bristle-carrying surface 2a is preferably between not less than 3 mm and not more than 10 mm. Although all of the clusters of bristles 3 are in fact of the same basic length, their free lengths from the root 3c on the top surface 4 as far as their front end 3b differ on account of the height profile of the plate 2a, with the result that different elastic properties of the bristles are realized. The angle of the cutouts 6, and thus the setting angle of the bristles, likewise varies. By means of such a carrier element, it is thus easy to produce bristle plates with different free bristle lengths and profile shapes, by use of a conventional flat AFT heating die.
b shows a cross section of modification of the example from
The toothbrush shown in
a and b show a toothbrush with two carrier elements 2 which are arranged in two cutouts 7 to the sides of an elevated region 18 in the center of the head part 1. This produces a front surface 5 with two different levels. The carrier elements 2 are fastened, as has been described above, by ultrasonic welding along the welding surface 10 on the border of the carrier elements 2, said welding surface being located outside the bristle arrangement, as seen in plan view (
Flexible cleaning elements 19 are arranged on the elevated region 18. Further in particular also flexible cleaning elements 20 are located outside the elevated region 18. The head part 1 has been produced with these elements, and the possibly provided elastic zone, by two-component injection molding. The elevated region 18 may also be realized by a further carrier plate which, as in the example of
a and b show a similar toothbrush, although in this case the central elevated region 18 is realized by a single carrier element 2 with a stepped height profile. This is narrower in the central region 18, and the shape of the cutout 7 is adapted thereto. Welding takes place beneath the border 2b of the carrier element 2 and in the border regions of the elevated region 18, with the result that the welding surface 10 runs on two levels. No welding takes place at the step locations 17. As an alternative, welding takes place on the base 7a of the cutout 7, along the surface 10′.
a and b show a further toothbrush with a centrally elevated region 18. The carrier element 2 has a central hole, with the result that it can be fitted over the elevated region 18. The carrier element 2 is welded to the head part 1 along the hole and on its outer border, as a result of which additional stiffening is achieved. Clusters of bristles 3 and flexible elements 20 are located on the carrier element 2.
The carrier element 2 of the toothbrush shown in
a and b show a toothbrush with two different levels, realized by three separate carrier elements 2 with border parts 9 of different lengths L, L′. These are inserted into three cutouts 7 separated by webs 30 or into a common cutout (not illustrated) and welded on the base 7a thereof (welding surface 10′). As an alternative, welding may also take place on two levels on the surface 10, beneath the respective bristle-carrying surfaces 2a. The central carrier element 2 comprises both conventional bristles and a flexible cleaning element 19.
a and b show a toothbrush with a carrier element with a soft component and a hard component. The actual bristle-carrying part 2a of the carrier element 2 is formed from a soft material 21, which is elastically deformable. The bristles are thus suspended and/or anchored in an elastic manner. The cushion-like part 21 yields under loading, which is particularly advantageous for the teeth. For easier connection to the head part 1, the carrier element 2 has a peripheral frame part 22 made of preferably the same hard material as the head part. The arching is produced during the production of the carrier element 2. The underside of the frame part 22 rests on corresponding shoulders 7b in the recess 7 in the head part 1, the contact surface defining the welding surface 10. The cavity between the underside 8 of the carrier element 2 and the base 7a of the cutout 7 allows, during use, a certain deflection of the elastic part 21, and in some circumstances even a reversal from the convex state to the concave state.
a-c and 14 show a carrier element and the head part of the toothbrush in the case of which the rear ends 3a of the clusters of bristles 3, rather than being firmly fused to the bristle-carrying surface 2a, can be displaced in the holes 6. This is achieved by suitable material selection, e.g., polypropylene for the carrier element and polyamide for the bristle filaments. Furthermore, rather than being melted to form a uniform bristle coating, the rear ends 3a are melted, by a heating die 12 having protrusions 23, to form separate webs 24 made of bristle melt. For the resilient mounting of the clusters of bristles 3, an elastic membrane 25 is arranged in the head part. In the case of
a-d and 16a-c show toothbrushes with a two-component carrier element 2. The latter comprises a hard component in the form of a lattice, in this case formed from sleeves 26, with holes 6 for accommodating clusters of bristles, and webs 27 which connect said sleeves. Also provided is a frame part 22 which is made of the hard component and of which the edge 31, which in the application case is directed toward the base, is of tapered configuration and serves as welding surface 10. The region between the sleeves 26 is filled with an elastic soft material 28. In the example from
a and b show the side view, in the longitudinal and transverse directions, of a further toothbrush, in the case of which the carrier plate 2 is only welded to the head part 1 in four subregions 10. This four-point suspension renders the carrier plate particularly compliant. For this purpose, the head part has lateral cutouts 30 through which a cavity 32 beneath the carrier plate is accessible. The carrier plate is spaced apart from the head part there to a considerable extent, i.e., by more than 0.5 mm. Deposits between the brush head and carrier plate may thus be washed out to good effect. The carrier plate consists predominantly of elastomeric material or of a thin layer, e.g., less than 1 mm, of a hard component and can be deflected in a flexible manner in relation to the welding surfaces 10. The carrier plate is preferably provided with a lateral border of 2 mm or more (not shown here) in order that the unsightly bristle melt is not visible to the user. All of the variants described above may also be realized as exchangeable heads, without the carrier element being permanently welded to the toothbrush handle. It is also possible for the flexible carrier plate to perform a sensor function, e.g., for monitoring the contact pressure.
While the invention has been described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments or constructions. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the embodiments are shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more, less or a single element, are also within the spirit and scope of the invention.
Number | Date | Country | Kind |
---|---|---|---|
102 59 723.5 | Dec 2002 | DE | national |
This is a Continuation of application Ser. No. 12/805,064 filed Jul. 9, 2010 which in turn is a Continuation of application Ser. No. 12/379,992 filed Mar. 5, 2009 which in turn is a Continuation of application Ser. No. 11/645,664 filed Dec. 27, 2006, which in turn is a Continuation of application Ser. No. 11/291,911 filed Dec. 2, 2005, which in turn is a Division of application Ser. No. 10/388,744 filed Mar. 17, 2003. The entire disclosures of the prior applications are hereby incorporated by reference herein in their entireties.
Number | Date | Country | |
---|---|---|---|
Parent | 10388744 | Mar 2003 | US |
Child | 11291911 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 12805064 | Jul 2010 | US |
Child | 13067844 | US | |
Parent | 12379992 | Mar 2009 | US |
Child | 12805064 | US | |
Parent | 11645664 | Dec 2006 | US |
Child | 12379992 | US | |
Parent | 11291911 | Dec 2005 | US |
Child | 11645664 | US |