The invention relates to a toothbrush and for a process which is intended for producing the same.
Toothbrushes with a conventional bristle arrangement comprising clusters of bristle filaments, e.g. made of a polyamide (PA) or polyester (PBT), and an additional flexible structure are known, for example, from WO 00/64307 and WO 01/21036. The conventional bristles here serve for customary teeth-cleaning purposes, while the flexible structure can perform different functions, e.g. massaging the gums, damping the cleaning movement, removing plaque, polishing the tooth surface, suspending the bristles in an elastic manner and/or sealing non-welded locations. WO 00/64307 discloses a toothbrush with rod-like flexible cleaning elements which are of approximately the same length as the conventional clusters of bristles and are arranged on the periphery of the head part of the toothbrush. In the case of WO 01/21036, elastic cleaning elements are of sheet-like, e.g. undulating, configuration and are arranged within the conventional bristle arrangement. In the case of WO 00/64307, a plurality of the flexible cleaning elements are connected to one another via a material bridge made of the same material.
Following the operation of covering the head part of the toothbrush with conventional bristles, the cleaning elements are produced by virtue of the head part being encapsulated by injection molding. The disadvantage here is that the bristle filaments have to be prepared for use, e.g. by virtue of the clusters of bristles being rounded or a predetermined profiling being produced, before the flexible structure is produced. Renewed insertion into the injection mold is then necessary in order to produce the flexible structure. It is possible here for the clusters of bristles to be damaged or contaminated. The elastic-structure shapes which it is possible to produce are limited, inter alia, for demolding reasons.
The object of the invention is to provide a toothbrush, with conventional bristles and a flexible structure, which is straightforward to produce. The intention is also to specify a corresponding production process.
According to the invention, in the case of a toothbrush of the type mentioned in the introduction, at least one flexible structure, e.g. a cleaning element, is arranged on a carrier element which consists of a hard material. This carrier element is connected to the head part. Such a toothbrush has production-related advantages since the additional part, i.e. the carrier element provided with the flexible structure, can be produced separately and straightforwardly connected to the head part.
The connection between the carrier element and the head part may be produced mechanically by clamping or snap-fitting or riveting, chemically by adhesive bonding, by ultrasonic welding, or thermally by welding or other methods of supplying heat. It is preferred, in terms of production, for the carrier element to consist of the same material as the head part since, in this case, only one hard component need be provided for producing the brush and there is no need to ensure material compatibility. This is advantageous, in particular, for ultrasonic welding.
The arrangement of the flexible structure on a carrier element consisting of a hard material has the following advantages: the additional part may be produced, and prepared for use, separately from the rest of the toothbrush body, comprising the handle and head part. In a straightforward further step, the carrier element is connected to the head part, it being possible to use any of the abovementioned connecting methods and the hard carrier element preferably being formed in adaptation to the head part. The carrier element may be formed, for example, such that, during the later connecting step, it engages around the head part in a clamping manner. On account of the hard carrier element, the additional part is easy to handle and can be gripped considerably more easily than an additional part produced entirely from a flexible material.
The additional part is small in comparison with the rest of the toothbrush. The necessary molds are thus also small and cost-effective. The basic toothbrush body and the bristle covering may be produced using a standard mold even if they are later provided with different additional parts. In order to produce toothbrushes with different additional parts, all that is necessary is to exchange the additional part and/or the corresponding mold therefor, which can be done in a straightforward and cost-effective manner.
A further advantage of producing the additional part and basic body separately is that it is possible to realize any desired shapes of flexible cleaning elements, e.g. even those which cross over the conventional bristles, come into contact therewith or displace the same when the additional part is inserted. The separate production does not pose any problems for the demolding of the flexible structure. It is possible to produce geometries by injection molding which would be extremely difficult to demold if the cleaning element were fitted directly on the bristle-covered head part.
Up until now, the flexible structure, for production-related reasons, has been produced from the same material as any flexible components on the handle part. The invention provides a greater degree of freedom for the material of the structure, with the result that it is possible to use, for example, a different degree of hardness.
A non-releasable connection between the additional part and the head part prevents the additional part from detaching during use and eliminates the risk of swallowing.
The conventional bristles are fastened, for example, directly on the head part, on a bristle plate acting as a further carrier element, or also on the carrier element for the flexible cleaning elements, all variants having advantages. During the operation of fastening the bristles on the head part or on the bristle plate, the flexible structure and the conventional bristles may be prepared independently of one another for later use before the head part and additional part are assembled, with the result that they do not damage or contaminate one another.
The conventional bristles, in both cases, may be prepared for use before or after the flexible structure is fitted. If the two components are provided on the carrier element, it is preferable first of all for the flexible structure, including any cleaning elements, to be integrally formed and then for the carrier element to be covered with bristles, which may be guided, for example, through cutouts in the soft or hard component.
Producing the additional part, i.e. the carrier element with one or more flexible cleaning elements, preferably takes place by two-component or multi-component injection molding. In this case, a non-releasable connection is preferably produced between the components.
The flexible structure is preferably also arranged, e.g. molded, laterally on the carrier element, in which case, in the assembled state, it terminates laterally with the outer contour of the head part or projects beyond the same. It serves, for example, for sealing non-welded locations, for massaging the gums, e.g. by way of molded-on elastic elements which project slightly, or as impact protection during cleaning.
The flexible cleaning element preferably consists of an, in particular, thermoplastic elastomer, e.g. of natural or synthetic rubber. The material used for the basic toothbrush body is preferably used for the carrier element, in particular polypropylene, styrene-acrylonitrile, polyester, acrylonitrile-butadiene-styrene (ABS) or a polyurethane such as Isoplast®. The Shore A hardness of the soft component is preferably less than 90 and particularly preferably below 50.
The carrier element is particularly preferably covered with bristles by AFT (Anchor Free Tufting) technology. In this case, first of all, the hard-material carrier plate is produced with the flexible structure, in particular by two-component injection molding. Then, the bristle filaments are guided through cutouts in the carrier plate and/or in the flexible structure and, for fastening on the carrier plate and/or the flexible structure, are welded or adhesively bonded by way of their rear ends, which in the application case are directed toward the brush head. This has the advantage that it is possible to realize largely any desired bristle arrangements, in particular even sheet-like bristle structures. The carrier element is connected to the head part, in particular, by means of ultrasonic welding, e.g. as is described in DE200 06 311 U.
Since elastomeric material, in particular a thermoplastic elastomer, on account of the pronounced damping of the ultrasonic vibrations, can only be welded ultrasonically to a limited extent, the welding surface between the carrier element and head part is preferably kept at least partially free of the flexible component. For this purpose, the injection point of the soft component is preferably selected to be on the bristle-carrying side of the carrier element, in order that no material bridges from the soft component reduce the size of the welding surface. However, for the case where flexible elements are intended to be arranged in the region of the welding surface, they are preferably positioned to the side of the longitudinal axis of the toothbrush. This likewise produces non-welded locations laterally on the carrier element, while it is possible to weld the longitudinally front and rear regions between the carrier element and head part. This ensures that the carrier element is held well since the front and rear regions, in particular, and, to a lesser extent, the side regions, are subjected to loading by the cleaning movement and the corresponding leverages. Merely punctiform welding with non-welded locations may also be used specifically, in order that the brush head and carrier element can be moved in relation to one another and a certain level of flexibility of the brush head as a whole is thus achieved.
It is also possible for the flexible structure, in the manner of a sealing lip, to serve for the additional sealing of non-welded locations. As a result, the space between the carrier element and the head part is advantageously sealed against the ingress of water. It is thus not possible for any germs to accumulate in this region, and the brush is more hygienic. In order to achieve a reasonable sealing function, the Shore A hardness of the software component is preferably less than 50.
Examples for the invention are described hereinbelow and illustrated in the drawings, in which, purely schematically:
a-d show views of a toothbrush according to the invention in various assembly stages, the additional part being fastened on the head part by riveting;
a-e show views of a further toothbrush of which the additional part is fastened by riveting;
a-e show views of a toothbrush of which the additional part is fastened by welding;
a-e show views of a toothbrush of which the additional part is fastened by means of a snap-fitting connection;
a-e show views of a further toothbrush of which the additional part is fastened by a snap-fitting connection;
a-f show views of a toothbrush in the case of which the additional part is fastened in a clamping manner;
a-e show the production of a toothbrush by AFT;
a-e show views of a further toothbrush of which the additional part is fastened by a snap-fitting connection;
a-f show views of a further toothbrush, of which the additional part is fastened on the head part with play;
a-j show the production of a further toothbrush by AFT; and
a-c show views of a toothbrush with a lateral surround made of flexible material.
All of the toothbrushes illustrated have a basic body with a head part 1 and a handle part 2, which is only partially illustrated. An additional part 4 with a plurality of flexible cleaning elements 6 of different shapes, which are connected to a carrier element of likewise different shapes, is connected to the head part 1 when the toothbrush is in the finished state. The head part 1, furthermore, is provided directly (
a and c show a toothbrush of which the head part 1 has already been provided with clusters of bristles 3. The additional part 4 illustrated in
The carrier element 5 is adapted in shape to a cutout 9, visible in
For reasons of esthetics or hygiene, the bottom region of the hole 8 or of the head part 1 as a whole may be covered by a protective layer 22 made of soft plastic (cf.
A further example of a toothbrush of which the additional part 4 is connected to the head part 1 by riveting is illustrated in
a-e show a further example of a toothbrush, which ends up similar to a toothbrush according to
The additional part 4 of the toothbrush illustrated in
a-e show a further example of a snap-fitting connection between the additional part 4 and the head part 1 of a toothbrush according to the invention. Within the bristle arrangement made of conventional clusters of bristles 3, the head part 1 has a prepared region 13 for accommodating the additional part 4. This region 13 comprises a depression with a groove 12 running on the border of the latter in each case, perpendicularly to the alignment of the handle 2, said groove 12 providing the head part 1 with a certain level of elasticity or resilient action, as do also the grooves 12′ running on the lateral border of the head part. The prepared region 13 is slightly smaller than the basic surface area of the carrier element 5, with the result that the latter can be fitted into the region 13 in a clamping manner. As can be seen from the plan view in
a-f show a further example of a toothbrush according to the invention, in this case a plug-on toothbrush for an electric teeth-cleaning unit. The conventional clusters of bristles 3 are fastened on a separate bristle plate 18 which, in the assembled state, is connected to the matching head part 1 of the toothbrush or a disc 23 which is fastened in a rotatable or pivotable manner thereon. The flexible cleaning elements 6, which are rod-like in this case, are fastened on a carrier element 5 which is slightly curved in plan view and has a sheet-like extension 16, which is oriented essentially perpendicularly to the alignment of the cleaning elements 6. The additional part 4 can be introduced, by way of said extension 16, into a correspondingly shaped groove 14 in the disc 23. Arranged in the center of the head part 1 and of the groove 14 is a round cutout 15, in which a corresponding mating element 17 on the extension 16 of the additional part 4 engages. The additional part 4 and head part 1 are thus connected to one another in a well-fitting and clamping manner. At its bottom end, the bristle plate 18 has a groove 19 by means of which the bristle plate 18 can be fastened on the disc 23 or the lateral extensions 23 thereof. In the embodiment illustrated, the additional part 4 is moved along by the disc 23. As an alternative, it is possible for the additional part 4 to be fastened directly on the head part 1 and not to rotate as well.
a-e show an example of the production of a toothbrush by means of AFT technology.
The edge 30 of the carrier element 5, this edge in the application case being directed towards the base of the cutout 13, is tapered, just as in the example from
The AFT technology manages without anchors or clips for fastening the bristle filaments, which instead are welded directly on the carrier plate. This means that the width of a cluster of bristles is not determined by the anchor, with the result that it is also possible to realize finer structures, in particular also sheet-like bristle arrangements.
It is technically also possible, in the case of AFT, to prepare the bristle filaments for use before they are fitted on the carrier plate. The variant which is realized at present, however, is that where the bristles are only machined once they have been fitted on the carrier plate.
a-e show a variant of the toothbrush from
a-f show a further example of a toothbrush according to the invention. The head part 1 has a prepared region 13 for the carrier element 5 of the additional part 4, said region being larger than the carrier element 5 itself. The region 13 is, for example, a hole which passes all the way through the head part 1, see sectional drawings from
a-j show a further example of a toothbrush produced by means of AFT.
The carrier element 5 provided with conventional bristles 3 and the flexible structure 6, 6′, 6″ is inserted into a cutout 13 in the brush head 1. The brush head 1 is illustrated in various views without the carrier element 5 in
The carrier element 5 is connected to the brush head 1 by means of ultrasonic welding. The welding surface 26 is indicated by dashed lines. In order to realize the welding, the carrier element has, on its bottom border, a welding border 26′ which, during assembly, rests on the base of the cutout 13, the contact surface defining the welding surface 26. The welding border 26′ melts under the influence of ultrasound, with the result that the two parts 5 and 1 are connected to one another.
Since elastomeric material can only be welded ultrasonically to a limited extent, the welding surface 26, as far as possible, is kept free of this material, for example as in the case of the toothbrush from
In the example from
The non-welded locations 27 are sealed by the flexible regions 6″ here in the manner of a sealing lip, with the result that only a very small amount of water, if any at all, can penetrate into the cavity 28. For a good sealing function, material with a Shore A hardness of 50 or less is preferably selected. Non-welded locations between the head part and carrier element may also be used specifically, in order to achieve a certain level of flexibility between the two hard components.
As can be gathered from
The method of welding and sealing the components which has been described above with reference to
Number | Date | Country | Kind |
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10164336.5 | Dec 2001 | DE | national |
This is a Continuation of application Ser. No. 12/068,730 filed Feb. 11, 2008, which is a Continuation of application Ser. No. 11/362,069 filed Feb. 27, 2006, which is a Division of application Ser. No. 10/362,590 filed Mar. 17, 2003, which in turn is a National Stage of PCT/CH02/00717 filed Dec. 20, 2002, which claims the benefit of German Patent Application No. 10164336.5 filed Dec. 28, 2001. The entire disclosure of the prior applications is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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Parent | 10362590 | Mar 2003 | US |
Child | 11362069 | US |
Number | Date | Country | |
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Parent | 12068730 | Feb 2008 | US |
Child | 12382220 | US | |
Parent | 11362069 | Feb 2006 | US |
Child | 12068730 | US |