Interdental cleaner

Technical Field The invention relates to devices for cleaning the interdental space, in particular a toothbrush toothbrush-shaped toothbrush with a brush part.

Background of the Invention [0002] Various types of interdental brushes or toothpicks have long been used. Currently, plastic toothpicks are commonly used, and an early example of an interdental brush is disclosed in JP-1979-170098U. In one of the embodiments described herein, the toothpick is in the form of a hard synthetic resin stick that has been partially coated with a soft synthetic resin. A part with a soft toothpick material is used to remove plaque and the like from teeth.

A further example of the same general structure is shown in US-A-6, 158,444 (corresponding to WO 98/16169), where a rod-shaped nose made of plastic has been coated with a soft thermoplastic elastomer (TPE).

[0004] Further interdental brushes of a similar type are disclosed in EP-A-153.011 and US-3,775,848, and some of the more recent designs are shown in WO-A-2009/150964, WO-A2012 / 156025, WO-A-2013/176297, WO- A-2014/005659, WO-A-2014/023395, WO-A2014 / 023424, JP-A-2013188299, JP-A-2013192866 and US-A-2014/0008837.

[0005] Some of the interdental brushes or toothpicks described in these patent publications are available on the market, and many of them have many different disadvantages experienced by users. Some toothpicks are too weak, which means they break during use. Other interdental brushes have an inefficient brush part, which leads to incomplete tooth cleaning. In addition, some toothpicks are uncomfortable in gripping and can slip. In conclusion, a large proportion of interdental brushes according to the state of the art is difficult to use.

[0006] From the above description, it is understood that there is a field for improvements.

Summary of the invention The object of the invention is to provide a new type of interdental brush that is improved with respect to the condition of the piece and which eliminates or at least reduces the drawbacks described above.

[0008] This aim, like the further objects that will be described in the following description, was achieved by means of an interdental brush as defined in the appended claim 1 with preferred embodiments defined in the dependent claims.

[0009] In one aspect, an interdental brush is provided that has a handle and a cleaning portion formed by an elongated object made of a thermoplastic material. The cleaning portion has a coating which comprises a hot vulcanized rubber and which forms

- 2 peripheral, flexible brush parts. The object has a part that, when it is coated, forms a cleaning part. This cleaning part narrows towards the free blanket and has axial protuberances and grooves, forming some kind of projections that support the adhesion of the coating and which give the flange-like brush system its favorable bending properties, balanced by adequate stiffness. The cleaning part has been given a very slim shape, which increases the possibility of effectively cleaning the space between the teeth in the mouth.

[0010] An interdental brush of this type is advantageous because this combination of materials and hot vulcanization provides a favorable balance between stiffness and elasticity. The active part of the brush contributes to an efficient cleaning process.

[0011] In one embodiment, the gum comprises a thermosetting gum, preferably a silicone-based gum with particularly advantageous properties. Hot vulcanization forms networks in a thermosetting material, which enhances the structure of the interdental brush.

[0012] The rubber preferably has a Shore hardness in the range of 10-60 Shore A, preferably 1530 Shore A. The thermoplastic material forming the object can be a polyamide that absorbs moisture from the mouth, which makes the interdental brush more plastic and thus less susceptible to breaking. The object is preferably reinforced with glass fiber in a proportion of 5-30% of the weight, preferably 10-20% of the weight.

[0013] The rubber coating can also be applied at least partially to the handle to form a favorable relief structure thereon. This increases the grip comfort and reduces the slipperiness. It also allows you to use the interdental brush for promotional purposes. The brush portion may form peripheral brushing flanges whose outer dimensions gradually decrease towards the free end of the cleaning portion, and the peripheral portion of the brushing flanges preferably forms a substantially circular shape. Effective cleaning is therefore achieved here because tooth contact has been improved.

[0014] In one embodiment, the brushing flanges are arranged at substantially equal intervals from each other along the cleaning portion and are preferably arranged in alternating pairs along the cleaning portion. The first pairs have two brush collars extending radially from the axis of the cleaning part in the first opposite direction, while the adjacent second pair has two brush collars extending radially from the axis in two opposite directions. The angle between these directions is around 90 degrees. This design of the active interdental brush part is beneficial for the cleaning contact with the teeth. If the protuberances of the body of the cleaning part protrude in the radial directions that overlap the first and second direction of the positioning of the brushing flanges, the advantages are even more clearly visible.

The grip portion may have a substantially rectangular cross section, giving two opposing, substantially flat gripping surfaces and an outer edge extending along the peripheral portion of the grip. In this way a comfortable grip has been achieved.

[0016] Furthermore, the holder may comprise a transition portion that tapers toward the cleaning portion, which further improves the grip.

[0017] Preferably, the axial length of the cleaning portion is in the range 35-55% of the total axial length of the interdental brush, and it is also preferred that the axial length of the handle - including the narrowed transition portion - is in the range 45-65% of the total axial length of the interdental brush. Thanks to these proportions, you can achieve an effective and comfortable tooth cleaning process.

[0018] In one embodiment, the cross section of the cleaning portion at the free end of the interdental brush is about 40-50% of the cross section of the cleaning part adjacent to the transition section. This design provides a slender active part of the interdental brush that increases the chance of cleaning all interdental spaces in the mouth.

Brief Description of the Drawing [0019] Next, embodiments of the invention will be described; reference is made to the attached schematic drawing, which shows non-limiting examples of how the idea of ​​the invention can be used in practice.

Fig. 1 shows a perspective view of the interdental brush according to one embodiment of the invention.

Fig. 2 shows a front view of the interdental brush.

Fig. 3 shows a side view of the interdental brush.

Fig. 4 shows a section along the line IV-IV of Fig. 2 on a larger scale.

Fig. 5 shows an axial cross-sectional perspective view of the interdental brush of Figs. 1-4.

Fig. 6 shows a side view of the cross section of the interdental brush of Fig. 5.

Fig. 7 shows the detail of Fig. 6 on a larger scale.

Fig. 8 shows a front view of an interdental brush in a basic size. Figs. 9-11 are sectional views taken along line IX-IX, XX and XI-XI of Fig. 8.

Fig. 12 shows an end view of the XII-XII of the interdental brush of Fig. 8.

Fig. 13 shows the detail of Fig. 12 on a larger scale.

Fig. 14 is a front view of the interdental brush of a slightly larger size than that of Fig. 8.

Figs. 15-17 are sectional views taken along line XV-XV, XVI-XVI and XVII-XVII of Fig. 14.

Figure 18 shows an end view of XVIII-XVIII of the interdental brush of Figure 14.

Fig. 19 shows a detail of Fig. 18 on a larger scale.

Fig. 20 shows a side view of the cross section of the interdental brush of Fig. 8.

Fig. 21 shows a section along the line XXI-XXI of Fig. 20.

Fig. 22 shows the corresponding cross section of the interdental brush of Fig. 14.

Fig. 23 shows a perspective view of the cleaning portion of the interdental brush.

Fig. 24 shows a corresponding perspective view of a complete cleaning part.

Fig. 25 shows an end view of the interdental brush with the tip cut off for purposes of illustration.

Fig. 26 shows a cross section of the interdental brush according to the condition of the piece for purposes of comparison.

Fig. 27 is a perspective view of a set of substrates for the production of interdental brushes.

Fig. 28 is a front view of the assembly shown in Fig. 27.

Fig. 29 is a perspective view of a set of complete interdental brushes.

Fig. 30 shows a front view of the assembly shown in Fig. 29.

DETAILED DESCRIPTION OF THE EMBODIMENTS Figures 1-6 show an interdental brush or toothpick 1 according to one embodiment of the invention formed by an elongated support or body 2, also referred to as a carrier. Figures 27-28 show a set of bodies 2 for the formation of toothpicks 1. The bodies 2 are made of a thermoplastic material, e.g. an amide plastic, preferably polyamide 6, which provides advantageous stiffness of the interdental brush 1. The toothpick body 2 is preferably reinforced with glass fibers.

[0021] The toothpick 1 has a handle or handle 3, a cleaning part 4 and an intermediate transition part 5 tapering towards the cleaning part 4. The cleaning part 4 is provided with a coating C consisting of a self-adhesive hot vulcanized rubber, preferably a thermosetting rubber, such like a liquid, self-adhesive silicone rubber. Coating C forms peripheral elastic brush-shaped brushing flaps 6 whose outer dimensions or radial surface gradually decrease towards the free end or the tip 7 of the cleaning part 4. The flanges 6 of the cleaning brush are arranged at the same distances from one another (equidistant) along the cleaning 4.

[0022] The transitional section 5 improves the grip of the toothpick 1, because the user can place the fingers on this section 5 when performing repetitive cleaning movements. In addition, the transition section 5 improves the stiffness and hence the strength of the toothpick 1. The transition between the handle / holder and the elongated brushing portion is often a weak point of the interdental brush according to the condition of the piece.

The radial surface of the brushing flanges 6 is best shown in cross-sections in Figs. 20-21, the flange 6a closest to the handle 3 having the largest projection in the radial direction, while the flange 6b closest to the top 7 of the cleaning part 4 has the smallest in the radial direction of the tab. .

[0024] As best shown in Fig. 24, the equidistant brushing flanges 6 are arranged in alternating pairs along the cleaning part 4. The first pairs have two opposite flanges 6F extending radially from the central axis CA of the cleaning part 4 in the first counter-clockwise FOD, and the second pairs have two opposite flanges 6S,

5 extending radially from the center axis CA in the second opposite direction SOD. The angle between these FOD and SOD directions is preferably around 90 degrees, forming a four-wing form of the cleaning part 4; see Figures 13 and 19. The four-wing shape can also be described as the shape of a four-leaf clover seen from the tip of a toothpick 7

1. A cross system of equidistant brushing flanges 6 provides a very effective cleaning of the space between two teeth when the active cleaning part 4 of the toothpick 1 is moved in this space with repetitive motion.

The coating material C is also applied to the handle 3, as can be seen in Fig. 4. The elastic material C based on silicone forms a relief structure on the two opposite substantially flat surfaces 3a and 3b of the holder. The relieving structure is of the so-called negative type, i.e. the coating material C is left on certain surfaces such that the surface of the underlying substrate 2 is exposed. In this way, grooves 8-13 are formed in the C-material on the holder 3, which form a relief structure.

[0026] As the substrate 2 preferably has a light color, eg white, and the coating material C is preferably dark in color (see Figs. 8 and 14), the relieving structure has a very distinctive appearance, which is advantageous for promotional purposes, such as like showing trade marks, logos, etc. (like TePe®).

Furthermore, the relieving structure is advantageous in that it provides a secure grip of the toothpick 1 at the handle 3. As shown in Fig. 4, the handle 4 has a substantially rectangular cross-section forming two opposed faces 3a, 3b, provided with a relief structure. . These two surfaces 3a, 3b are preferably slightly curved towards the center of the toothpick 1 so as to form two opposite concave surfaces. This concave shape, which in Fig. 2 is seen as an oval shape, further improves the toothpick holder 1.

[0028] Figures 8-13 and Figs. 14-19, respectively, show two slightly different sizes of the interdental brush 1, 1 'according to the general design described above. The cleaning part 4 of the toothpicks 1 of Fig. 8 has a slightly smaller diameter or section than the cleaning part 4 'of the toothpick 1' of Fig. 14. The toothpicks 1 can be provided in various sizes and colors, depending on the user's requirements.

[0029] In addition to the relief structure of the grip 3, 3 ', the toothpicks 1 of Figs. 8 and 14 are provided with additional relief surfaces 14, 14' on opposite sides of the transition section 5, 5 '. These relief surfaces 14, 14 'further improve the comfortable grip of the toothpicks 1, 1' because the user can insert the end of his finger into a small cavity formed by the relief surface 14, 14 '. As described above, the relief surface 14, 14 'is formed by omitting the coating material C such that the surface of the underlying support or substrate 2 is exposed.

[0030] In Fig. 23 is shown a part 2a of the elongated body 2 that forms the cleaning part 4, before being coated. The body of the cleaning part 2 a narrows towards the tip 7 and has axial projections 15 and grooves 16 forming projections. These axial projections 15, 16 form

- a cross-shaped, four-winged or four-leafed clover-shaped cross-section, which - after covering - fits the four-leaf shape of the brushing flanges 6, as shown in Fig. 25, with the coated tip being cut off for purposes of illustration. The axial planes comprising the opposite directions FOD and SOD shown in Fig. 24 coincide with the projections 15 projecting radially from the body 2a, while the radial grooves 16 coincide with the inclined recesses 17 formed by the brush flanges 6.

This cross-shaped shape of the cleaning part 4 is advantageous because it increases the bending of the active part of the toothpick brush 1 in the direction of the pockets 17 along the cleaning part 4. It is preferred that the cleaning part 4 can be bent 180 degrees with respect to the handle 3. As seen in FIG. Fig. 25, the angle between the two intersecting planes comprising FOD and SOD forms an angle of 90 degrees, while the recesses are between (45 degrees) of these planes. The cross shape is additionally shown in Figs. 12-13 and 18-19, respectively.

[0032] A cross-section of an earlier type of interdistrict IC is shown in Fig. 26 for comparison with the cross design of Fig. 25. The known IC brush has only a few projecting brush parts BM with large spaces between them. This means that only the ends of the brush parts take an active part in the cleaning process. In contrast to this existing technique, the brush brackets 6 of the interdental brush 1 shown in Fig. 25 are a peripheral portion that forms a substantially circular shape. This means that the contact surface between the peripheral edges of the brushing flanges 6 is much larger with the toothpicks 1, 1 'described here. Therefore, the cleaning process performed by these toothpicks 1, 1 'is improved compared to the state of the art.

[0033] It has been found that certain proportions of the interdental brush are preferred. In Fig. 3, the axial lengths of the cleaning part 4 and the holder 3 (including the transition section 5) are shown as L1 and L2. In order to obtain an efficient active part, i.e. a cleaning part 4, its axial length L1 should be in the range of 35-55% of the total length L1 + L2 of the toothpick 1. This ratio is preferably in the range of 40-50%, most preferably about 45%. The toothpicks 1 manufactured in accordance with this ratio allow the user to perform elongated, repetitive cleaning movements, thereby utilizing a fully improved cleaning part.

[0034] Furthermore, a convenient grip of the toothpick 1 is achieved if the axial length (L2) of the handle 4 - including the axial length L3 of the transition portion 5 - is in the range 45-65% of the total length of the axial toothpick 1. This proportion is preferably in the range 50-60 %, most preferably about 55%.

[0035] The design of the active interdental brush portion 1,1 'is slim, as seen in Figs. 21-22. The transverse dimension or diameter D2, D2 'of the cleaning part 4 at the tip 7, 7' is approximately 45% of the transverse dimension or diameter D1, D1 'of the cleaning part 4 adjacent to the transition section 5, 5'. The smooth narrowing of the body 2a allows

- 7 user reaching for teeth and pushing the toothpick 1, 1 'into all interdental spaces during tooth cleaning. This slenderness can, of course, vary to some extent, and the proportion between the aforementioned diameters can be in the range of 40-50% with a very successful effect.

[0036] Returning to the materials used, the toothpick body 2 is made of a thermoplastic material, preferably of the polyamide 6 type. By using glass fiber reinforcement, advantageous properties - such as adequate stiffness - are achieved if the glass fiber ratio is in the range of 5-30% weight, preferably 10-20% of the weight, most preferably 15% of the weight of the thermoplastic material. Other types of fiber reinforcement are possible, such as carbon fiber or aramid fiber.

[0037] A preferred coating material C of the active part - i.e. the cleaning part 4 - is a self-adhesive, liquid, heat-vulcanized silicone rubber which has shown good results in practical tests. This thermosetting silicone based rubber has favorable chemical properties. In the vulcanization process, chemical networks are created as covalent bonds that can not be destroyed by thermodynamic means.

[0038] In contrast to the rubber described above, most of the interdental toothbrushes according to the condition of the piece have an active part or a coating consisting of a thermoplastic elastomer (TPE) with a physical network that forms weak bonds. When the thermoplastic elastomer is heated, the bonds are broken, which means that the polymer chains can be moved so that the material can be reprocessed. When thermoplastic elastomer is cooled, physical bonds are formed anew.

[0039] The chemical cross-linking of the silicone used in the embodiments described here confers on the active interdental brush 1, 1 '- i.e. a liquid silicone rubber (LSR) coating - better resistance to damage according to the condition of the brushes.

[0040] In order to obtain the advantageous flexibility of the interdental brush 1, 1 'and a convenient cleaning process, different hardnesses were tested using it. The material based on a silicone thermosetting rubber has demonstrated the most favorable properties if its hardness is 10-60 Shore A, more preferably 15-30 Shore A, most preferably about 20 Shore A. Practical tests of this silicone material also showed a favorable wear resistance.

[0041] In short, the manufacturing process of the above-described interdental brush can be performed as follows. Polyamide pellets are fed to a heated injection unit and melted therein. The molten material is then injected into a cold mold in which it hardens and is shaped according to the depressions of the forming tool. The liquid silicone is fed as two elements: the first element A and the second element B. One of these elements contains a catalyst, while the other element contains a cross-linking agent. Silicon is not produced until two elements are mixed together. At room temperature, the production of silicone takes weeks, while at higher temperatures the silicone is produced in a few seconds (depending on the thickness of the item).

[0042] The proportions of the elements A and B are 1: 1 and they are mixed and fed to the heated mold. In the form, a chemical reaction is initiated, called hot vulcanisation, during which a self-adhesive silicone rubber is produced.

[0043] Thus, the plastic bodies or carriers are forged in the cold part of the mold. Then, the bodies / carriers are transferred to heated recesses in which they are covered with silicone rubber, creating the expected coating of complete toothpicks.

[0044] Silicone is a thermosetting material that has been found to be useful in the type of manufacturing process and which has the properties expected of an interdental brush when it comes to sticking to the substrate, effective cleaning, adequate flexibility, and convenient grip and use. Preferred materials for the substrate that is coated by the coating are polyamides, in particular polyamide 6.

[0045] Before applying the coating C, a number of bodies 2 are set into sets, as shown in Figs. 27-28. From these figures it can be seen that the handle has an outer protuberance 18 that extends along its peripheral portion. Convexity 18 is a kind of recess 19, with the coating C being applied in the manufacturing process. Cavity 19 contributes to a comfortable grip of the complete toothpick covered with a shield. The substrates 2 are connected to each other by thin, break-off bridges or connections 20, consisting of a body material.

[0046] The connections 20 are maintained in the manufacturing process and keep the finished toothpicks 1 together in the kits shown in Figs. 29 - 30. Using the toothpick 1, the user simply breaks the connection between two adjacent toothpicks 1 and separates the toothpick 1 that he intends to use.

Finally, it should be mentioned that this idea of ​​the invention is in no way restricted to the embodiments and examples described above and many modifications are possible within the scope and scope of the invention as defined in the appended claims. For example, you can use specific versions of materials, and a specific toothpick project may differ. In addition, the shape of the flange section of the cleaning part can vary depending on the specific requirements. In addition to the shape of the cross, various shapes can be used, such as the shape of the star with many protruding sets of brushing collars. An alternative shape is the three-flange shape, which also provides a beneficial cleaning contact with the teeth.