TWISTED BRUSH, METHOD FOR PRODUCING A TWISTED BRUSH, AND APPARATUS FOR PRODUCING A TWISTED BRUSH

Abstract

A twisted brush (1) having a bristle carrier (2) made of twisted together wire portions (3) which have oval and/or elliptical cross sections, at least in the distal portion (4) of the bristle carrier (2). Further, a twisted brush (1) whose bristle carrier (2) has an extraction protection (12) at a distance from its proximal end (11) is also provided. Using this extraction protection (12), the bristle carrier (2) can be fastened to the handle (7) of the twisted brush (1) in a manner protected against extraction. Moreover, a method for producing a twisted brush is also provided, wire portions (3), of which at least one is profiled, i.e. has at least two regions (4a, 6a, 13a) with different cross sections, are twisted together to form the bristle carrier (2). Further a brush production machine (20) having a wire-forming device (19), by which, in at least one region (4a, 6a, 13a) of a wire portion (3) to be profiled, a cross section of the wire portion (3) can be modified such that the wire portion (3) after profiling has at least two regions (4a, 6a, 13a) with differently formed cross sections.

Description

INCORPORATED BY REFERENCE

The following documents are incorporated herein by reference as if fully set forth: German Patent Application No. 10 2017 103 615.6, filed Feb. 22, 2017, and German Patent Application No. 10 2018 101 085.0, filed Jan. 18, 2018.

BACKGROUND

The invention relates to twisted brushes, in particular mascara brushes or interdental brushes, having a bristle carrier made of at least two wire portions twisted together, wherein a set of bristles is embodied at a distal portion of the bristle carrier.

Further, the invention also relates to a method for producing a twisted brush having a bristle carrier made of at least two wire portions twisted together, in particular a brush of the above-described type, and a brush production machine for producing twisted brushes, in particular brushes of the above-described type.

Twisted brushes have already been disclosed in the prior art in various embodiments. Inter alia, they find use as so-called interdental brushes in the field of dentistry and as so-called mascara brushes in the field of cosmetics.

SUMMARY

The invention considers the object of improving the handling of twisted brushes and of simplifying the production of such brushes.

In order to achieve the object, a brush having one or more features of the invention is provided. Accordingly, provision is made, in particular, for at least one wire portion of the at least two wire portions of the twisted brush to have at least two regions with different cross sections. Here, the different cross sections may have different forms or identical forms and different sizes. Thus, a region of one of the wire portions, which forms a proximal section of the bristle carrier, may be provided with, for example, a cross section that is particularly suitable for fastening a handle to the bristle carrier. In a region of the at least one wire portion which, for example, forms a distal portion of the bristle carrier, the wire portion may have a cross section which has particularly positive properties in view of fastening the set of bristles to the bristle carrier and/or which leads to a particularly small hole diameter that is passable by the brush. A particularly small passable hole diameter is desirable for, in particular, those twisted brushes that are used as interdental brushes and should also be introduced into small interdental spaces. To this end, oval and/or elliptical cross sections are particularly suitable.

Regions of the wire portion which have different cross sections may also be understood to mean infinitesimally small regions of a wire portion within the context of the claimed invention.

In particular, this can simplify the handling of such a twisted brush. This applies, in particular, when the latter is used as an interdental brush that is intended to be inserted into interdental spaces with its distal portion of its bristle carrier.

It may also be advantageous if the at least one of the at least two wire portions already has the at least two regions with different cross sections before the wire portions are twisted to form the bristle carrier. In this way, it is possible to avoid a subsequent deformation of the bristle carrier, said subsequent deformation possibly not being sufficiently precise.

A brush having one or more features of the invention for the purposes of improved handling of twisted brushes of the type set forth at the outset, in particular if they are used as interdental brushes which are intended to be inserted into interdental spaces with their distal portion of their bristle carrier. In particular, a brush is provided here, in which the wire portions that form the bristle carrier have oval and/or elliptical cross sections, at least in regions which form the distal portion of the bristle carrier.

It should be mentioned here that the features of the disclosed brushes could be combined with one another in a particularly advantageous manner. Thus, for example, it is possible to provide a twisted brush whose bristle carrier is optimized firstly in respect of fastening a handle to the bristle carrier and secondly in respect of a passable hole diameter that is as small as possible.

The use of wire portions with elliptical and/or oval cross sections, at least in the distal portion of the bristle carrier, leads to a reduction of an external dimension or of an external diameter of the bristle carrier in its distal portion in comparison with conventional bristle carriers which, for example, are produced from wire portions with a circular cross section. The minimization of the external dimensions of the bristle carrier in its distal portion leads to a minimal passable hole diameter for the brush that is smaller in comparison with conventional brushes. Thus, the brush according to the invention can also be inserted into narrow interdental spaces while having at least comparable stability and durability of the brush. This is desirable for convenient handling of such a twisted brush as an interdental brush.

By using wire portions with an oval or elliptical cross section, it is possible to apply individual filaments of bristle material, which are clamped between the two wire portions when said two wire portions are twisted, in an improved manner directly to the outer side of the twisted together wire portions. This improved attachment of the individual bristle filaments to the outer sides of the twisted together wire portions can succeed particularly well if the twisted together wire portions are arranged relative to one another with their elliptical cross sections and subsequently twisted together in such a way that one of two co-vertices of the elliptical cross section of one wire portion faces a co-vertex of the at least one further wire portion with an elliptical cross section.

The use of wire portions which have such oval and/or elliptical cross sections even in the proximal portion of the bristle carrier may simplify the fastening of a handle to a proximal portion of the bristle carrier. This is particularly the case if the handle is molded onto the proximal portion of the bristle carrier.

The aforementioned object is also achieved by a brush having additional features of the invention. This brush is distinguished, in particular, by virtue of the bristle carrier having an extraction protection at a distance from its proximal end. By provision of this extraction protection, the bristle carrier can be reliably secured to a handle, which can be arranged or is arranged at a proximal portion of the bristle carrier. This can prevent the bristle carrier from inadvertently detaching from the handle while the brush is in use. The use of an extraction protection arranged in such a way is particularly advantageous if the handle of the twisted brush is molded onto the proximal portion of the bristle carrier. The extraction protection has a distance from the proximal end of the bristle carrier. Therefore, the bristle carrier can have a comparatively slender design in its proximal portion. This allows the provision of a slender handle at the proximal portion of the bristle carrier. Comparatively little material for the handle needs to be used in the proximal portion of the bristle carrier in the case of the brush according to the invention. Then, the extraction protection can be displaced into a region which lies between the set of bristles and the proximal portion of the bristle carrier.

It may be expedient if at least one wire portion, preferably each wire portion, of the wire portions that are twisted together for producing the respective bristle carrier has at least two regions with differently shaped cross sections. Here, the extraction protection may be formed by a change in cross section of the bristle carrier along its direction of longitudinal extent that results from the different cross sections of the at least one wire portion in the case of twisted together wire portions.

It may be advantageous if multiple or all wire portions have identical profiling, i.e. identical regions with different cross sections.

Thus, it is possible, for example, to use wire portions which each have a round, circular, oval or else elliptical cross section in one region and are provided with a cross section deviating therefrom in an adjacent region. If two such wire portions with their respectively identical cross sections are placed next to one another and subsequently twisted in this manner, a bristle carrier arises which has at least one change in cross section along its direction of longitudinal extent. It should be mentioned here that the cross section of the bristle carrier may also be understood to mean the cross section of an imaginary envelope of the bristle carrier.

The bristle carrier may have an intermediate portion between its distal portion and its proximal portion. A proximal shoulder may be formed between the intermediate portion and the proximal portion as an extraction protection. The handle of the twisted brush may be connectable to the bristle carrier in interlocking fashion by way of this proximal shoulder and may be connected to said bristle carrier in the use position. This is particularly the case if injection-molding material is insert molded around the bristle carrier in the proximal portion thereof for the purposes of producing a handle.

In this context, it may be advantageous if, for the purposes of producing the extraction protection, the bristle carrier has in its intermediate portion an external dimension that is measurable in a spatial direction oriented transversely to the direction of longitudinal extent of the bristle carrier and that is smaller than an external dimension, measured in the same spatial direction, of the bristle carrier in its adjacent proximal portion. In the case of such dimensions of the bristle carrier in its proximal portion and its intermediate portion adjacent thereto, particularly reliable interlocking fastening of a handle to the proximal portion of the bristle carrier can be achieved by way of the extraction protection provided thus.

Further, the bristle carrier may have a distal shoulder between the intermediate portion and the distal portion. For the purposes of producing such a distal shoulder between the intermediate portion and the distal portion, an external dimension, measurable in a spatial direction oriented transversely to the direction of longitudinal extent of the bristle carrier, of the bristle carrier in its intermediate portion may be smaller than or else larger than an external dimension, measured in the same spatial direction, of the bristle carrier in its distal portion. By way of example, the distal shoulder can be used as a positioning aid for attaching an injection mold in order to inject a handle onto the proximal portion of the bristle carrier.

In their regions which form the proximal portion of the bristle carrier, the wire portions may have, at least in part, circular or elliptical or oval or half-round cross sections. The use of wire portions with regions that form the proximal portion of the bristle carrier and have half-round cross sections may be advantageous, in particular for molding a handle onto a mascara brush. In this way, the at least two wire portions can be placed against one another with their preferably non-arched flat sides and twisted in such a way that a free area or open area which corresponds to a difference area between the cross-sectional area of an imaginary envelope, which surrounds the two wire portions placed against one another in such a way, and the sum of the cross-sectional areas of the wire portions placed against one another, may be particularly small.

If the intermediate portion of the bristle carrier is also insert molded with injection-molding material for the purposes of producing a handle at the proximal end of the bristle carrier, it may be advantageous for regions of the wire portions that form the intermediate portion of the bristle carrier to have semicircular cross sections. In this way, it is also possible to produce the minimization of the above-defined free surface in the intermediate portion of the bristle carrier. It should be noted that, in the process, the two wire portions that are twisted together to form the intermediate portion face one another with their preferably non-arched flat sides of their respective semicircular cross section in order to obtain the desired minimization of the free area.

It may be particularly advantageous if the wire portions in the proximal portion of the bristle carrier have circular or elliptical or oval cross sections, while the wire portions in the intermediate portion of the bristle carrier have the above-described semicircular cross sections. This allows a production of a particularly sharp geometric transition in the form of a shoulder between the intermediate portion and the proximal portion of the bristle carrier, said geometric transition facilitating a reliable extraction protection for the bristle carrier from the subsequently applied or molded-on handle of the twisted brush.

In order to minimize the passable hole diameter of the brush, i.e. the dimension through which the brush according to the invention can just still be guided through with its distal portion, regions, in particular distal regions, of the wire portions which form the distal portion of the bristle carrier may have oval and/or elliptical cross sections. It should be noted that the wire portions twisted together in the distal portion of the bristle carrier may face one another with one of their co-vertices of their elliptical cross section in each case. In this way, an external diameter or an external dimension of the bristle carrier in its distal portion can be kept particularly small and the minimal passable hole diameter of the twisted brush can be minimized.

The already aforementioned handle of the twisted brush may be fastened to the bristle carrier, in particular insert molded about the latter, in such a way that it at least partly encloses the proximal portion and the extraction protection. It may be particularly advantageous if the handle is fastened to the bristle carrier, in particular insert molded about the latter, in such a way that it at least partly encloses the proximal shoulder and also at least one part of the intermediate portion of the bristle carrier.

In principle, the use of at least two separate wire portions is conceivable for producing the bristle carrier. However, particularly when using the brush according to the invention as an interdental brush, it may be advantageous if the wire portions are two interconnected limbs of a wire piece that is bent along a bending line. Here, preferably, the bending line may be embodied at a distal end of the bristle carrier. In this way, it is possible to avoid sharp edges at the distal end of the bristle carrier, said sharp edges possibly posing an injury risk when using the brush as an interdental brush.

Further, it is possible that the above-described bending line is arranged in the middle of the wire piece. In this context, it should be noted that the individual regions with different cross sections, to the extent that these are provided, may then preferably be introduced into the wire piece in a manner that is mirror symmetrical with respect to the bending line.

Further, provision can be made for the at least two wire portions to be twisted together over a partial region of the respective length. The goal of this is that of fastening the set of bristles to the bristle carrier. However, it is also possible for the at least two wire portions, which form the bristle carrier of the brush, to be twisted together over their entire length. This may simplify the fastening of a handle to the bristle carrier.

At least two or multiple or all wire portions of the brush may have identical profiles or different profiles, as already described above. Thus, it is possible to provide, in a particularly simple manner, twisted brushes with differently designed bristle carriers by combining differently designed, or else identically designed, wire portions.

In one embodiment of the twisted brush, provision can further be made for at least one wire portion of the at least two wire portions to taper in the direction of its distal end. As a result, at least the distal end of the bristle carrier may obtain dimensions that are as small as possible, as a result of which it is possible to minimize the hole diameter that is passable by the twisted brush. This is particularly advantageous for developing a twisted brush which, as an interdental brush, is suitable for particularly narrow interdental spaces. Here, provision can be made, in particular, for the at least one tapering wire portion to have a conical, conical-frustum-shaped, pyramid-shaped or pyramidal-frustum-shaped embodiment.

Particularly in the case of such a brush, which has at least one tapering wire portion, which preferably tapers toward its distal end, the different cross sections of the at least two regions of the wire portion may have the same cross-sectional form, but have differently large cross-sectional areas. By way of example, this is the case in those brushes in which at least one of the wire portions of the bristle carrier has a conical, conical-frustum-shaped, pyramid-shaped or pyramidal-frustum-shaped embodiment.

Particularly in the case of the wire portion which has a form that tapers along the extent of its longitudinal axis, the regions with different cross sections may be infinitesimally small regions.

Further, provision can be made in the brush, in particular in such a brush which has at least one or more features of the invention first described above, for the wire portions to have cross sections that deviate from an oval or elliptical cross-sectional form or do not have any oval and/or elliptical cross sections, at least in regions which form the distal portion of the bristle carrier. Consequently, the wire portions may have e.g. circular or polygonal or rectangular cross sections in these regions.

The production of twisted brushes according to the invention, in particular, may be made easy by way of a method having one or more features of the inventive method. In particular, a method for producing a twisted brush having a bristle carrier made of twisted together wire portions is proposed, in which at least two wire portions are twisted together to form a bristle carrier, at least one of said wire portions being a profiled wire portion having at least two regions with differently formed cross sections. Here, provision can also be made for multiple or all of the wire portions to be twisted to have such a profile.

The at least one of the wire portions may be supplied in profiled fashioned and may be twisted, or else be profiled in such a way that the wire portion, after profiling, has at least two regions with differently formed cross sections.

However, preferably, multiple or even all wire portions are profiled in such a way that, after profiling, they each have at least two regions with differently formed cross sections. The profiles obtained by each of the wire portions may preferably be identical.

After profiling, it is possible, for example, to place bristle material between the profiled wire portions and twist the wire portions together to produce the bristle carrier.

It may be advantageous if regions of the identical or correspondingly profiled wire portions with the same cross section are twisted together in each case. In the process, a bristle carrier may arise which, according to the cross sections of the individual regions of the wire portions, has a proximal portion with a cross section having a first form, an intermediate portion with a cross section with a different form and/or a distal portion with, once again, another form. The wire portions, in the process, may have identical cross sections in each case in each of the portions of the bristle carrier.

In an advantageous embodiment of the method according to the invention, provision is made for the wire portions to be connected to one another to form a wire piece, for the wire piece to be bent along a bending line after profiling the wire portions in order to bring the wire portions into the relative position, required for twisting against one another, with respect to one another. Thus, finally, a wire portion is arranged in each case on both sides of the bending line. Once the wire portions that continue to be connected to one another along the bending line have reached this position, they can be twisted together to form the bristle carrier.

The profiling of the wire portions can be effectuated by a wire-forming device and/or a wire-aligning device.

Depending on the application, the wire portions, preferably on both sides of a bending line, in particular the aforementioned bending line, may be provided by a wire-forming device and/or a wire-aligning device with a circular cross section in respectively one region and/or with an oval cross section in respectively one region and/or with an elliptical cross section in respectively one region and/or with a semicircular cross section in respectively one region.

Prior to the profiling, the wire portions can be drawn off a storage roll. In the process, it may be advantageous to straighten the wire portions by a wire-aligning device, for example the already aforementioned wire-aligning device. In this context, straightening the wire portions may mean that a basic radius of the wire portions is removed, particularly when they are drawn off a wire roll and supplied to the wire-forming device.

As a further improvement in the field of producing twisted brushes, a brush production machine of the aforementioned type with one or more features of the invention directed to such a machine is also provided. This brush production machine is configured to produce twisted brushes, in particular those having one or more features of the invention as described herein, in particular, it is characterized in that the brush production machine has a wire-forming device, by which, in at least one region of a wire portion to be profiled, a cross section of the wire portion to be profiled is modifiable such that the wire portion after profiling has at least two regions with differently formed cross sections.

It may be advantageous if the brush production machine has a wire alignment device disposed upstream of the wire-forming device in the wire transportation direction. This may comprise a plurality of alignment rolls, in particular driven alignment rolls, through which the wire supplied to the wire reshaping device or a supplied wire portion runs in order to remove an initial radius, which may be present in a wire wound off a storage roll, and in order thus to straighten the wire.

It may moreover be expedient if the brush production machine has a wire cutting apparatus. The latter may be disposed downstream of the wire-forming device in the wire transportation direction.

Expediently, the brush production machine may be configured to carry out the method according to the invention.

Conventional materials, in particular metals, metal alloys and polymers, may be used as a material for the wire portions, from which the bristle carrier is produced.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are described in more detail below on the basis of the drawing. In the figures, partly in a very schematic representation:

FIG. 1 shows a perspective illustration of a portion of a bristle carrier produced from two twisted together wire portions, wherein the wire portions each have a circular cross section,

FIG. 2 shows a perspective illustration of a portion of a further bristle carrier made of two twisted together wire portions, wherein the wire portions each have a semicircular cross section,

FIG. 3 shows a further perspective illustration of a portion of a bristle carrier of a twisted brush according to the invention, wherein the two twisted together wire portions of this bristle carrier each have an elliptical cross section,

FIGS. 4 to 6 show schematic end views of the bristle carriers illustrated in FIGS. 1 to 3 for the purposes of elucidating the free areas arising on account of the different cross-sectional geometries of the wire portions,

FIG. 7 shows a perspective illustration of a profiled wire piece according to the invention, having two external portions, in which the wire piece has a circular cross section, two respectively adjoining portions arranged further to the inside, in which the wire piece has a semicircular cross section in each case, and an intermediate region or an intermediate portion, in which the wire piece has an elliptical cross section,

FIG. 8 shows the wire piece illustrated in FIG. 7 and bent about a bending line, as a bristle carrier blank,

FIG. 9 shows the bristle carrier produced from the bristle carrier blank illustrated in FIG. 8 by twisting the two wire portions connected to one another at the bending line, wherein the bristle filaments of the twisted brush according to the invention illustrated in the subsequent figures, which bristle filaments are actually twisted between the wire portions, are not illustrated for a better overview,

FIG. 10 shows a partly cut side view of a bristle carrier inserted into an injection mold, having a set of bristles at its distal end,

FIG. 11 shows a side view of the brush which is completed after injecting injection-molding material into the injection mold illustrated in FIG. 10,

FIG. 12 shows an end view of the brush illustrated in FIG. 11,

FIG. 13 shows a perspective illustration of the brush illustrated in FIGS. 11 and 12,

FIG. 14 shows a very schematic perspective illustration of part of a brush production machine according to the invention,

FIG. 15 shows a perspective view of a bristle carrier blank for a bristle carrier of a twisted brush, comprising two wire portions connected to one another, wherein each of the two wire portions has a proximal portion with a round cross section and an intermediate and distal portion adjoining said proximal portion and having a rectangular cross section,

FIG. 16 shows a perspective view of a further bristle carrier blank for a bristle carrier of a twisted brush, comprising two wire portions connected to one another, wherein each of the two wire portions has a proximal portion with a round cross section and an intermediate and distal portion adjoining said proximal portion and having a pyramidal-frustum-shaped form that tapers toward the distal end of the wire portion,

FIG. 17 shows a perspective view of a further bristle carrier blank for a bristle carrier of a twisted brush, comprising two wire portions connected to one another, wherein each one of the two wire portions has a pyramidal-frustum-shaped form that tapers over the entire length of the wire portion,

FIG. 18 shows a perspective view of a further bristle carrier blank for a bristle carrier of a twisted brush, comprising two wire portions that are connected to one another, wherein each of the two wire portions has a conical-frustum-shaped form that tapers over the entire length of the wire portion, and

FIG. 19 shows an overview illustration of different cross-sectional geometries which can be used when designing the wire portions and their cross sections.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 10 to 13 show a twisted brush denoted by 1 overall, as is used, for example, as a mascara brush or an interdental brush. This brush 1 has a bristle carrier 2 made of two twisted together wire portions 3. A set of bristles 5 is embodied at a distal portion 4 of the bristle carrier 2 and a handle 7 is embodied at a proximal portion 6 of the bristle carrier 2.

In the case of the twisted brush 1 illustrated in FIGS. 10 to 13, the handle 7 is molded around the proximal portion 6 of the bristle carrier 2 using the injection molding method. Serving to this end is the injection mold 8 illustrated in FIG. 10, into which the bristle carrier 2 can be inserted with its proximal portion 6. By way of the injection opening 9 and the injection nozzle attached thereto, injection-molding material can be introduced into the interior of the injection mold 8 and the handle 7 can be produced by insert molding around the proximal portion 6 of the bristle carrier 2 and can be connected to the latter.

In one embodiment of the brush 1 according to the invention, provision is made here for using a bristle carrier 2, as illustrated in portions and very schematically in FIG. 3. Here, the wire portions 3 each have an elliptical cross section, at least in regions 4a which form the distal portion 4 of the bristle carrier 2. By using such wire portions 3 with an elliptical form in the cross section, it is possible to minimize a hole diameter that is passable with the brush 1, which hole diameter should be kept as small as possible, in particular for the use of the brush 1 according to the invention as an interdental brush. These regions 4a of the wire portions 3 may also be referred to as distal regions 4a.

FIGS. 1 and 2 show portions of bristle carriers 2, which are produced from wire portions 3 with a circular cross section (cf. FIG. 1) and from wire portions 3 with a semicircular cross section (cf. FIG. 2).

FIGS. 4 to 6 show the portions of bristle carriers 2 illustrated in FIGS. 1 to 3, respectively in a schematic end view. In these figures, the two wire portions 3 are in each case surrounded by a circle that represents an imaginary sleeve. On the basis of the free area or open area, which is denoted by reference sign 10 in each case and which emerges from the difference between the area delimited by the envelope and the overall cross-sectional area of the two wire portions 3, it becomes clear that the free area 10 is largest when use is made of wire portions 3 with a circular cross section. The smallest possible free area 10 is obtained when use is made of wire portions 3 with a semicircular cross section (cf. FIG. 5). Here, it is hardly possible to identify a free area 10 that is uncovered by the overall cross section of the two wire portions 3.

For the purposes of molding a handle 7 onto the proximal portion 6 of the bristle carrier 2, it is advantageous to keep the free area 10, i.e. the area of the cross section of the sleeve that is not covered by the cross section of the wire portions 3, as small as possible. For the use of the brush 1 as an interdental brush, a good compromise between free area 10 that is as small as possible, a minimized passable hole diameter and durability of the bristle carrier 2 can be obtained when using wire portions 3 which have oval and/or elliptical cross sections, at least in the distal portion 4 of the bristle carrier 2.

The twisted brush 1 illustrated in FIGS. 10 to 13 has a bristle carrier 2 which has an extraction protection 12 at a distance from its proximal end 11. This extraction protection 12 is present in the form of a change in cross-sectional geometry along the direction of longitudinal extent of the bristle carrier 2. With the extraction protection 12, it is possible to prevent the bristle carrier 2 being extracted from the handle 7 arranged at the proximal portion 6 of the bristle carrier by way of injection molding.

The extraction protection 12 facilitates an interlocking connection between the bristle carrier 2 and the insert molded handle 7.

In the embodiment of the brush 1 as illustrated in FIGS. 10 to 13, the wire portions 3 each have three regions 4a, 6a and 13a with differently shaped cross sections in each case. The extraction protection 12 is formed by a change in cross section of the bristle carrier 2 along its direction of longitudinal extent caused on account of the different cross sections. As a result, the bristle carrier 2 has an intermediate portion 13 between its distal portion 4 and its proximal portion 6, said intermediate portion representing a cross-sectional tapering of the bristle carrier 2. A proximal shoulder 14 is embodied as an extraction protection 12 between the intermediate portion 13 and the proximal portion 6. By way of this proximal shoulder 14, the handle 7 has an interlocking connection with the bristle carrier 2 after being molded onto the proximal portion 6 of the bristle carrier 2. FIGS. 10 and 11, in particular, show that the bristle carrier 2 has an external dimension that is measurable in a spatial direction oriented transversely to the direction of longitudinal extent of the bristle carrier 2 and that is smaller than an external dimension, measured in the same spatial direction, of the bristle carrier 2 in its adjacent proximal portion 6.

Moreover, the bristle carrier 2 has a distal shoulder 15 between the intermediate portion 13 and the distal portion 4. For the purposes of producing the distal shoulder 15, an external dimension, measurable in a spatial direction oriented transversely to the direction of longitudinal extent of the bristle carrier 2, of the bristle carrier 2 in its intermediate portion 13 is smaller than an external direction, measured in the same spatial direction, of the bristle carrier 2 in its distal portion 4. The distal shoulder 15 may serve as a positioning stop for the injection mold 8 illustrated in FIG. 10. In the embodiment of the brush 1 illustrated in FIGS. 10 to 13, the wire portions 3 respectively have circular cross sections in their regions 6a which form the proximal portion 6 of the bristle carrier 2. These regions 6a may also be referred to as proximal regions 6a of the wire portions 3.

The wire portions 3 of the brush 1 illustrated in FIGS. 10 to 13 respectively have semicircular cross sections in their regions 13a, which form the intermediate portion 13 of the bristle carrier 2 and may therefore also be referred to as intermediate regions 13a. Here, the two twisted together wire portions 3 are oriented relative to one another in the intermediate portion 13 in such a way that they face one another with the non-arched flat sides of their respective semicircular cross section. Due to the use wire portions 3 with a semicircular cross section in this intermediate portion 13, the bristle carrier 2 of the brush 1 according to the invention obtains a taper in its intermediate portion 13 relative to the remaining portions 4 and 6 of the bristle carrier 2. The transition from the taper in the intermediate portion 13 to the expansion in the proximal portion 6 then forms the above-described extraction protection 12.

As already mentioned above, the wire portions 3 in the distal portion 4 of the bristle carrier 2 have elliptical cross sections. This qualifies the brush 1 for use as an interdental brush which has a particularly small passable hole diameter and which therefore may also be easily introduced into comparatively narrow interdental spaces.

Here, the two twisted together wire portions 3 in the distal portion 4 of the bristle carrier 2 are oriented in such a way that they face one another with in each case one of their two co-vertices of their elliptical cross section. Then, the bristle filaments forming the set of bristles 5, which are arranged between the two wire portions 3, are also clamped in the region of the co-vertices of the elliptical cross sections that face one another.

The handle 7 is fastened to the bristle carrier 2 in such a way that it encloses the proximal portion 6 and the extraction protection 12 in the form of the proximal shoulder 14, and part of the intermediate portion 13 of the bristle carrier 2.

As elucidated by FIGS. 7 to 9 and 10 to 13, the wire portions 3 are two interconnected limbs of a wire piece 17 that is bent along a bending line 16. The wire portions 3 are still connected to one another, even in the use position, at one distal end 18 of the bristle carrier 2. Then, the bending line 16 of the bristle carrier 2 is situated at the distal end 18 of the bristle carrier 2. In this way, sharp edges and/or transitions, which may constitute an injury risk when using the brush 1 as an interdental brush, are avoided in this region.

FIG. 8 elucidates that the bending line is arranged in the middle of the wire piece 17 and the profiling introduced into the wire portions 3 arranged on both sides of the bending line 16 is mirror symmetrical with respect to the bending line 16.

The brush 1 illustrated in FIGS. 10 to 13 can be produced using the method described below. For the purposes of producing the twisted brush 1, wire portions 3, which are present here in a connected fashion to form a wire piece 17, as may be identified in e.g. FIG. 14, are profiled by a wire-forming device 19 of a brush production machine 20 according to the invention in such a way that the wire piece 17 on both sides of an initially still imaginary bending line 16 has regions 4a, 6a, 13a with different cross-sectional geometries.

FIG. 7 and FIG. 8 show a wire piece 17 profiled in such a way, said wire piece respectively having two wire portions 3, each with three regions 4a, 6a, 13a with different cross-sectional geometries, on both sides of its bending line 16 (cf. FIG. 8). Initially, a region 4a, in which the two wire portions 3 have an elliptical cross section, adjoins on both sides of the bending line 16. The region 4a with the elliptical cross section is followed in each case by a shorter region 13a, which has a semicircular cross section. Then, this region 13a with a semicircular cross section is respectively adjoined by a region 6a, which has a circular cross section, in each of the two wire portions 3.

The two proximal regions 6a of the wire piece 17 with a circular cross section, facing one another in FIG. 8, form the proximal portion 6 of the bristle carrier 2 after twisting the wire portions 3 arranged on both sides of the bending line 16. The two intermediate regions 13a of the wire piece 17 with in each case a semicircular cross section form the intermediate portion 13 of the bristle carrier 2 after twisting. Finally, the two distal regions 4a of the wire piece 17 with in each case an elliptical cross section form the distal portion 4 of the bristle carrier 2 after twisting the two wire portions 3.

After the wire piece 17 has been profiled, it is bent along the bending line 16 (cf. FIG. 8) and two limbs of the wire piece 17 separated from one another by the bending line 16 are placed next to one another as wire portions 3 of the bristle carrier 2 to be produced. Subsequently, bristle material can be inserted between the two wire portions 3 defined in this way and the wire portions 3 can be twisted together to form the bristle carrier 2 of the brush 1 in such a way that regions 4a, 6a, 13a of the wire portions 3, in each case with the same cross section, are connected to one another on both sides of the bending line 16 for the purposes of producing a distal portion 4, an intermediate portion 13 and a proximal portion 6 of the bristle carrier 2. These three aforementioned portions of the bristle carrier 2 then have cross-sectional geometries that differ from one another.

The wire piece 17 can be provided with a circular cross section in at least one region 6a in each case, with an oval or elliptical cross section in at least one further region 4a in each case and with a semicircular cross section in at least one further region 13a, i.e. it can be profiled, on both sides of the bending line 16 by the wire-forming device 19 of the brush production machine 20 and optionally also with a wire-aligning device 22 of the brush production machine 20, as is illustrated at least in part in FIG. 14.

If the wire piece 17 is rolled off a wire storage roll 23, as may likewise be identified in FIG. 14 as a constituent part of the brush production machine 20, it is expedient to straighten the wire piece 17 by the wire-aligning device 22. This is because the wire piece obtains a basic radius by being rolled onto the storage roll 23; it is necessary to remove said radius before profiling. Moreover, the brush production machine 20 comprises three wire clamps 24, by which the wire piece 17 can be held and drawn off the storage roll.

The wire-forming device 19 comprises two press halves 25 that are movable toward one another and onto the wire piece 17 arranged therebetween, by which the desired cross-sectional profiles can be produced on the wire piece 17. After the profiling, the wire portions 3 of the wire piece 17 to be profiled have, overall, at least two different cross sections. The wire piece 17 with its two wire portions 3 can be moved after profiling by a removal gripper 21 and be transferred to downstream stations of the brush production machine 20.

The wire-aligning device 22 is disposed upstream of the wire-forming device 19 on the brush production machine 20. The wire-aligning device 22 comprises a plurality of alignment rollers 26, of which individual ones, or else all, can be driven if required. Straightening of the wire piece 17 drawn off the storage roll 23 can be effectuated with the aid of these wire alignment rollers 26 prior to the profiling of said wire piece with the wire-forming device 19. However, where necessary, the wire alignment rollers 26 may also be used to change the original cross section, which, as a rule, is circular, of the wire piece 17 drawn off the storage roll 23 into an elliptical or oval cross section. If such a change in the cross-sectional geometry of the wire piece 17 that is drawn off the storage roll 23 is desired, it is advantageous to drive the wire alignment rollers 26 of the wire-aligning device 22. After the wire piece 17 has passed the wire-forming device 19 and obtained the desired profile, it reaches a wire cutting apparatus 27 of the brush production machine 20. Using this, the wire piece 17 can be cut to length. Here, the brush production machine 20 is configured to carry out the above-described method.

The twisted brush 1 illustrated in FIGS. 10 to 13 has a bristle carrier 2 which consists of two twisted together wire portions 3. Each of the two wire portions 3 comprises regions 4a, 6a and 13a with different cross sections.

Wire portions 3 that are connected to one another by way of a bending line 16 are also illustrated in FIGS. 15 to 18. The wire portions 3 illustrated in FIGS. 15 to 18 are not yet twisted together and not yet provided with a set of bristles 5, and may therefore also be referred to as bristle carrier blanks, from which it is possible to produce bristle carriers 2 for twisted brushes 1. All of the bristle carrier blanks illustrated in FIGS. 15 to 18 are suitable for producing a twisted brush 1.

The two bristle carrier blanks of bristle carriers 2 which are illustrated in FIGS. 15 and 16 each consist of two wire portions 3, wherein each of the two wire portions 3 in each case has a proximal region 6a, in which the respective wire portion 3 has a round cross section and, in this case, even a circular cross section.

Each of the proximal regions 6a is adjoined by an intermediate region 13a of the respective wire portion 3, which finally transitions into a distal region 4a of the respective wire portion 3. The wire portions 3 of the bristle carrier blank according to FIG. 15 have a rectangular cross section in the intermediate region 13a and in the distal region 4a. This leads to the bristle carrier 2, produced from the bristle carrier blank, having a comparatively small external dimension in its distal portion, and so a twisted brush 1 equipped with this bristle carrier 2 is suitable for comparatively small hole diameters, i.e., for example, comparatively small interdental spaces.

The bristle carrier blank illustrated in FIG. 16 comprises two wire portions 3, the intermediate region 13a and the distal region 4a of which have a pyramidal-frustum-shaped embodiment and thus have a taper in the direction of the distal end of the bristle carrier 2 or of the wire portions 3. This likewise promotes a comparatively small external dimension of the bristle carrier 2 in the distal portion 4 thereof, and so this bristle carrier 2, which may be manufactured from the bristle carrier blank illustrated in FIG. 16, is also particularly suitable for the production of an interdental brush.

In the wire portions 3, which are illustrated in FIGS. 15 to 18, the two wire portions 3, which are assigned to a bristle carrier 2, also have profiles that are identical to one another. This means that the two wire portions 3 which are interconnected via the bending line 16 each have the same sequence and design of the regions 4a, 13a and 6a.

The wire portions 3 of the blanks of bristle carriers 2 shown in FIGS. 17 and 18 each taper in the direction of their distal end. As already explained above, the two wire portions 3 of the exemplary embodiment illustrated in FIG. 17 have a conical-frustum-shaped form, i.e. a form that conically tapers toward the distal end. In the exemplary embodiment of a blank of a bristle carrier 2 with two wire portions 3, illustrated in FIG. 18, it is possible to identify that each of the wire portions 3 has a pyramidal-frustum-shaped form that tapers toward its respective distal end. Consequently, these wire portions 3 have regions with different, that is to say decreasing, cross sections.

In the exemplary embodiments of wire portions 3 according to FIGS. 17 and 18, which are suitable for the production of bristle carriers 2 of twisted brushes 1, the different cross sections of the respective three regions 4a, 6a and 13a of each wire portion 3 have the same cross-sectional form. However, the cross-sectional areas of the cross sections of each wire portion 3 become smaller, the closer they lie at the respective distal end of the wire portions 3.

In the exemplary embodiments of wire portions 3 which are illustrated in FIGS. 15 to 18, the wire portions 3 have cross sections that deviate from an oval and/or elliptical cross-sectional form, at least in the regions 4a which form the distal portion 4 of the bristle carrier 2. Consequently, no oval and/or elliptical cross sections are therefore present here.

FIG. 19 now shows a non-exhaustive collection of possible cross-sectional forms which can be used in the different regions 4a, 6a and 13a of the wire portions 3 within the scope of the production and design of wire portions 3. It should be expressly mentioned here that, in their different regions 4a, 6a and 13a, the wire portions 3 may also be provided with other cross-sectional forms or cross sections than those shown in FIG. 19.

As an improvement in the technical field of twisted brushes 1, such a brush 1 with a bristle carrier 2 made of twisted together wire portions 3 is provided, said wire portions having oval and/or elliptical cross sections, at least in the distal portion 4 of the bristle carrier 2. Further, a twisted brush 1 whose bristle carrier 2 has an extraction protection 12 at a distance from its proximal end 11 is also provided. With the aid of this extraction protection 12, the bristle carrier 2 can be fastened to the handle 7 of the twisted brush 1 in a manner protected against extraction. Moreover, a method for producing a twisted brush 1 is also provided, in which wire portions 3 are twisted together to form a bristle carrier 2, at least one wire portion 3 of said wire portions having at least two regions 4a, 6a, 13a with differently formed cross sections. A further subject of the invention is also a brush production machine 20 having a wire-forming device 19, by which, in at least one region 4a, 6a, 13a of a wire portion 3 to be profiled, a cross section of the wire portion 3 to be profiled can be modified such that the wire portion 3 after profiling has at least two regions 4a, 6a, 13a with differently formed cross sections.

LIST OF REFERENCE SIGNS

1 Brush

2 Bristle carrier

3 Wire portions

4 Distal portion of 2

4a Distal region of 3

5 Set of bristles at 2

6 Proximal portion of 2

6a Proximal region of 3

7 Handle

8 Injection mold

9 Injection opening

10 Free area

11 Proximal end of 2

12 Extraction protection

13 Intermediate portion of 2

13a Intermediate region of 3

14 Proximal shoulder

15 Distal shoulder

16 Bending line

17 Wire piece

18 Distal end of 2

19 Wire-forming device

20 Brush production machine

21 Removal gripper

22 Wire-aligning device

23 Storage roll

24 Wire clamps

25 Press halves

26 Wire alignment rollers

27 Wire cutting apparatus

Claims

1. A twisted brush (1), comprising a bristle carrier (2) made of at least two twisted together wire portions (3), a set of bristles (5) provided at a distal portion (4) of the bristle carrier (2), at least one of the wire portions (3) of the at least two wire portions (3) has at least two regions (4a, 6a, 13a) with different cross sections.

2. A twisted brush (1), comprising a bristle carrier (2) made of at least two twisted together wire portions (3), a set of bristles (5) provided at a distal portion (4) of the bristle carrier (2), and the at least two wire portions (3) have at least one of oval or elliptical cross sections, at least in regions (4a) which form the distal portion (4) of the bristle carrier (2).

3. A twisted brush (1), comprising a bristle carrier (2) made of at least two twisted together wire portions (3), a set of bristles (5) provided at a distal portion (4) of the bristle carrier (2), the bristle carrier (2) has an extraction protection (12) at a distance from a proximal end (11) thereof, the bristle carrier (2) being securable to a handle (7), which is arrangeable or arranged at a proximal portion (6) of the bristle carrier (2), by said extraction protection.

4. The brush (1) as claimed in claim 3, wherein at least one of the wire portions (3) has at least two regions (4a, 6a, 13a) with differently shaped cross sections, the extraction protection (12) is formed by a change in cross section of the bristle carrier (2) along a direction of longitudinal extent thereof that results from the different cross sections of the at least one wire portion (3).

5. The brush (1) as claimed in claim 3, wherein the bristle carrier (2) has an intermediate portion (13) between the distal portion (4) and the proximal portion (6), a proximal shoulder (14) is formed between the intermediate portion (13) and the proximal portion (6) as the extraction protection (12), and the handle (7) is connectable to the bristle carrier (2) in interlocking fashion by said shoulder and being connected to said bristle carrier in a use position.

6. The brush (1) as claimed in claim 5, wherein, for producing the extraction protection (12), the bristle carrier (2) has in the intermediate portion (13) an external dimension that is measurable in a spatial direction oriented transversely to the direction of longitudinal extent of the bristle carrier (2) and that is smaller than an external dimension, measured in a same spatial direction, of the bristle carrier (2) in the adjacent proximal portion (6).

7. The brush (1) as claimed in claim 6, wherein the bristle carrier (2) has a distal shoulder (15) between the intermediate portion (13) and the distal portion (4), and for producing the distal shoulder (15) between the intermediate portion (13) and the distal portion (4), an external dimension, measurable in a spatial direction oriented transversely to the direction of longitudinal extent of the bristle carrier (2), of the bristle carrier (2) in the intermediate portion (13) is smaller than or larger than an external dimension, measured in the same spatial direction, of the bristle carrier (2) in the distal portion (4).

8. The brush (1) as claimed in claim 5, wherein regions (6a) of the wire portions (3) which form the proximal portion (6) of the bristle carrier (2) have at least one of circular, elliptical, oval, or half-round cross sections.

9. The brush (1) as claimed in claim 5, wherein regions (13a) of the wire portions (3) which form the intermediate portion (13) of the bristle carrier (2) have semicircular cross sections, and there are two of the wire portions (3) that are twisted together to form the intermediate portion (13) that face one another with flat sides of said respective semicircular cross section.

10. The brush (1) as claimed in claim 5, wherein regions (4a) of the wire portions (3) which form the distal portion (4) of the bristle carrier (2) have at least one of oval or elliptical cross sections, and there are two of the wire portions (3) that are twisted together in the distal portion (4) of the bristle carrier (2) that face one another with in each case a co-vertices of their at least one of said oval or elliptical cross sections.

11. The brush (1) as claimed in claim 3, further comprising a handle (7) fastened to the bristle carrier (2) such that said handle at least partly encloses the proximal portion (6) and the extraction protection (12) of the bristle carrier (2).

12. The brush (1) as claimed claim 1, wherein the wire portions (3) are two interconnected limbs of a wire piece (17) that is bent along a bending line (16), and the bending line (16) is at least one of a distal end (18) of the bristle carrier (2) or arranged in the middle of the wire piece (17).

13. The brush (1) as claimed in claim 1, wherein the at least two wire portions (3) are twisted together over a partial region of respective lengths thereof or the at least two wire portions (3) are twisted together over entire lengths thereof.

14. The brush (1) as claimed in claim 1, wherein at least two of the wire portions (3) have identical profiles.

15. The brush (1) as claimed in claim 1, wherein at least one of the wire portions (3) of the at least two wire portions (3) tapers in a direction of a distal end thereof, such that the at least one wire portion (3) is conical, conical-frustum-shaped, pyramid-shaped, or pyramidal-frustum-shaped.

16. The brush (1) as claimed in claim 1, wherein the different cross sections of the at least two regions (4a, 6a, 13a) have a same cross-sectional form, but have differently sized cross-sectional areas.

17. The brush (1) as claimed in claim 1, wherein the wire portions (3) have cross sections that deviate format least one of an oval or elliptical cross-sectional form, at least in regions (4a) which form the distal portion (4) of the bristle carrier (2).

18. A method for producing a twisted brush (1), comprising providing at least two wire portions (3) with at least one of said wire portions being a profiled wire portion (3) having at least two regions (4a, 6a, 13a) with differently formed cross sections, and twisting said at least two wire portions (3) together to form a bristle carrier (2).

19. The method as claimed in claim 18, wherein at least two of the wire portions (3) are profiled before twisting for producing the bristle carrier (2), such that said at least two of the wire portions respectively have the at least two regions (4a, 6a, 13a) with differently formed cross sections, and the at least two regions (4a, 6a, 13a) of the profiled wire portions (3) that respectively have the same cross section are twisted together.

20. The method as claimed in claim 18, wherein the wire portions (3) are connected to one another to form a wire piece (17), the method further comprising bending the wire piece (17) along a bending line (16) after profiling the wire portions (3) in order to bring the wire portions (3) into a relative position, required for twisting, with respect to one another.

21. The method as claimed in claim 20, wherein the wire portions (3) are provided from at least one of a wire-forming device (19) or a wire-aligning device (22), with at least one of a circular cross section in respectively one said region (4a, 6a, 13a), an oval cross section in respectively one said region (4a, 6a, 13a), with an elliptical cross section in respectively one said region (4a, 6a, 13a), or with a semicircular cross section in respectively one said region (4a, 6a, 13a).

22. A brush production machine (20) for producing twisted brushes (1), the brush production machine (20) comprising a wire-forming device (19) adapted to modify, in at least one region (4a, 6a, 13a) of a wire portion (3) to be profiled, a cross section of the wire portion (3) to be profiled such that the wire portion (3) after profiling has at least two regions (4a, 6a, 13a) with differently formed cross sections.

23. The brush production machine (20) as claimed in claim 22, further comprising at least one of a wire alignment device (22) disposed upstream of the wire-forming device (19) in a wire transportation direction or a wire cutting apparatus (27).

24. The brush production machine (20) as claimed in claim 23, wherein the brush production machine (20) is configured to provide at least two of said wire portions (3) with at least one of said wire portions being a profiled wire portion (3) having the at least two regions (4a, 6a, 13a) with differently formed cross sections, and to twist said at least two wire portions (3) together to form a bristle carrier (2).