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:
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.
The toothbrush shown in
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
The carrier element 2 of the toothbrush shown in
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 |
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102 59 723.5 | Dec 2002 | DE | national |
This is a Continuation of application Ser. No. 13/765,151 filed Feb. 12, 2013 which in turn is a Continuation of application Ser. No. 13/067,844 filed Jun. 29, 2011 which in turn 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 | |
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Parent | 10388744 | Mar 2003 | US |
Child | 11291911 | US |
Number | Date | Country | |
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Parent | 13765151 | Feb 2013 | US |
Child | 14083896 | US | |
Parent | 13067844 | Jun 2011 | US |
Child | 13765151 | US | |
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 |