EP2763567B1 - Method and device for producing brushes and brush - Google Patents

Description

The invention relates to a method and a device for producing brushes, in particular toothbrushes.

Various methods of making brushes are known. A bristle holder is usually provided with a hole pattern which corresponds to the desired arrangement of bristles. Tufts of bristles are then inserted into the holes in the bristle holder and fastened therein by means of small metal anchors or loops.

In an alternative method, known as AFT (anchor free tufting), the tufts of bristles are attached to the bristle carrier without the use of loops or anchors. The bristle carrier can be equipped as a brush body in which the handle, neck and the essential part of the brush head are already designed as one part. The brush head then already has the hole pattern. Another possibility of the AFT process is to provide small brush head plates with hole patterns, which are then filled first. The completed brush head plate is then either inserted into the brush body having a receptacle and fastened thereon, or the brush head plate is extrusion-coated and, during the extrusion coating, either attached to the brush body or the brush body is only produced during the extrusion coating.

The DE 39 20 769 A1 describes a method and an apparatus for producing a brush, in which tufts of bristles are transported via vacuum or an air blast via tubes in openings in a bristle carrier. Then the filaments of the bristle tufts are melted on the back.

The DE 40 29 610 A1 shows a brush manufacturing process in which the tufts of bristles are melted in guides in a tool at one end of the tufts and are then pushed into a blind hole in a bristle holder and glued while still soft.

The WO 02/03831 A1 provides a completely different structure and a different way of producing a brush than the previously mentioned methods. Here, individual bristles spaced apart from one another are injection molded onto the previously produced bristle carrier and are thus only produced. The bristle carrier can have inclined openings into which the liquid plastic for the bristles is injected.

The EP 0 567 672 A1 suggests removing tufts of bristles from a magazine by inserting tubes into the magazine parallel to the direction of the bristles, so that the tubes each pick up and pull out a tuft of bristles. The tufts are clamped between jaws similar to a jaw chuck and then pushed into openings in a bristle holder on the front side, in order to then be heated at the rear end.

Bristle tufts, which are first pushed into a guide plate and partially protrude from it, describes the WO 2007/087694 A1 . The ends of the tufts protruding from the guide are then extrusion-coated to produce the brush body.

The JP 2003 061751 A has the object of a manufacturing process for brushes, in which the openings in the bristle carrier run obliquely and the tufts of bristles are inserted into the openings via correspondingly inclined insertion tubes.

Finally describes the EP 1 312 281 A1 a method for producing brushes, in which there are inclined openings in the bristle carrier. A pointed sleeve with a tuft accommodated therein contacts the bristle carrier on the back when a plunger presses the bundle into the opening.

The present invention relates to a method and an apparatus for producing brushes which are based on the above-mentioned AFT method, that is to say work without an anchor.

Modern toothbrushes no longer have tufts of bristles that run exclusively in parallel and have the same cross-section, but tufts of different sizes and sometimes inclined.

The object of the invention is to provide a method and an apparatus for producing brushes, by means of which the brushes can be produced more easily and more cost-effectively. The brush produced according to the invention is distinguished by a comparatively lower production price.

• Vorsehen eines Borstenträgers, welcher Teil der fertigen Bürste ist und eine Vorder- und eine Rückseite hat,
• Vorsehen von Öffnungen im Borstenträger zur Aufnahme von Borstenbüscheln, wobei
• zumindest eine Öffnung einen vorderseitigen Querschnitt hat, dessen Flächenschwerpunkt vom Flächenschwerpunkt des rückseitigen Querschnitts der Öffnung versetzt ist und/oder
• zumindest eine Öffnung, insbesondere die Öffnung mit unterschiedlichen Flächenschwerpunkten, einen vorderseitigen Querschnitt hat, der im Vergleich zum rückseitigen Querschnitt eine unterschiedliche Geometrie aufweist,

The method for manufacturing brushes according to the invention is characterized by the following steps:

• Providing a bristle holder, which is part of the finished brush and has a front and a back,
• Providing openings in the bristle carrier for receiving tufts of bristles, wherein
• at least one opening has a cross-section on the front, the centroid of which is offset from the centroid of the rear cross-section of the opening and / or
• at least one opening, in particular the opening with different centroids, has a front cross-section that has a different geometry compared to the rear cross-section,

Removing tufts of bristles from a bristle stock in which the bristles are packed in parallel,

Transporting the removed tufts of bristles to the bristle carrier by means of a transport device,
Providing an alignment tool on the front of the bristle carrier, which has receiving openings, the entrances of which are aligned with the cross sections on the front,

Pushing the tufts of bristles into the respectively assigned opening from the rear of the bristle carrier perpendicular to the rear of the bristle carrier, a guide-free gap being present on the rear of the bristle carrier, through which the bristle tufts are pushed into the bristle carrier and into the receiving openings, and
Anchor-free attachment of the bristle tufts to the bristle holder on the back.

The term “bristle carrier” encompasses both prefabricated brush bodies with a handle, neck and head section with openings therein, which may also be overmolded with a second or third component, and head plates with openings that are provided on the brush body.

The method according to the invention provides two features and embodiments which are to be realized alternatively or together in a brush and in at least one opening: one feature provides at least one opening in the bristle holder, via which bristle tufts are produced which run obliquely, that is to say obliquely to the front of the bristle holder can be. An alternative feature provides that there is no sloping opening (different areas of focus), but at least one opening with different geometries on the front and rear cross section. Different geometries means that there is a different geometric shape and not just a differently dimensioned cross section, as would be the case with a circular opening that only tapered. Examples of different geometries are e.g. a circular cross-section on the back, which merges into an elongated, angular or strip-shaped cross-section on the front. Of course, the two features can also be combined in one opening, i.e. a sloping opening has different geometries on the back and front cross-section. Furthermore, at least one inclined opening and at least one opening with a different cross section can also be present in the same bristle carrier.

In the previous bristle carriers, for example, oblique bores were made in the bristle carrier to anchor obliquely extending tufts of bristles, which is complex in terms of production technology. Such obliquely drilled openings are not provided in the invention in order to anchor oblique tufts in the bristle carrier.

It has surprisingly been found that, contrary to the previous methods, the tufts of bristles do not have to be guided if they are inserted into the bristle carrier into an opening which either runs obliquely and / or has different geometries on the rear and front. The plug perpendicular to the back can therefore be used independently whether the openings are straight, straight and additionally have a cone, run obliquely or have a different cross-section on the front and the back. This simplifies stuffing. Up to now, guide plates have always been provided for plugging oblique openings, which rest on the bristle carrier on the back or on the front, depending on whether the tufts were stuffed from the front or the back. The invention takes a completely different path, because it provides a guide-free gap on the back, from where tamping takes place. The individual bristles can bend slightly and move relative to one another via the guide-free gap, so that a kind of tension compensation takes place between the adjacent bristles if they are pushed perpendicularly to the rear into an opening which runs obliquely and / or which has a different cross section, so that the Bristles are bent unevenly or moved towards each other.

According to the preferred embodiment, the rear cross-section has a larger cross-sectional area than the front for easier pushing in of the bristle tufts, but above all so that the bristles are not clamped too far.

In addition, any tuft cross-sectional shapes can be achieved without the openings having to have a correspondingly complicated through hole. The rear cross section can namely have a simple circular cylindrical or funnel-shaped shape, and only the front opening, that is to say the front cross section, is formed, for example, on a short piece with the desired cross sectional shape of the tufts of bristles. As a result, conventional tamping tools can be used in which the tufts of bristles have a circular cross section when they are fed. The front opening of the opening can then have a different geometry, that is to say a geometry deviating from a circular shape, for example an oval, strip-shaped or angular shape.

The preferred embodiment provides that the opening is designed with different centroids and / or other cross-sectional geometries in such a way that the bristles of the bristle tuft are held in parallel only together with the alignment tool before the bristle tuft is attached. This means that the Tufts of bristles in the opening alone could not be held in their final orientation based on the condition prior to being attached to the bristle carrier. This is because, in contrast to the prior art, the opening does not define a straight, geometrically identical channel that is long enough to keep the tufts of bristles parallel and to clamp them. If the alignment tool with its receiving opening were not used in the method according to the invention, the bristles of the bristle tuft in the opening or openings with different centroids and / or other cross-sectional geometries would be chaotically aligned with one another. The alignment tool is therefore crucial before fastening together with the opening in order to position the tufts of bristles exactly.

In order to simplify the manufacture of the tuft carrier and to allow pure injection molding of the tuft carrier including the openings, all openings should be designed without undercuts in the direction perpendicular to the rear. This means that no slanted slides or the like are required in the injection molding tool. Rather, the bristle carrier can be removed from the mold simply by moving the injection mold halves apart.

The rear cross section forms the mouth of a rear opening section and the front cross section forms the mouth of a front opening section, the opening sections being sections of the respective hole. The opening sections should each run perpendicular to the back or front of the bristle carrier part. This means that the two opening sections can be manufactured without an oblique hole or without an undercut. In particular, but this is not to be understood as restrictive, the two opening sections merge directly into one another without an intermediate section having to connect the opening sections.

At least one opening with the front and rear cross sections should preferably be designed without an inclined channel, that is to say there is no opening section with an inclined central axis in the at least one opening, which would require a drill to be inclined to the front. or to cut the back into the bristle holder or to provide an inclined slide during injection molding.

In particular, the method according to the invention provides that the bristle tufts, that is to say all the bristle tufts, are stuffed perpendicularly to the rear and / or front into the at least one opening with the different front and rear cross sections. In this case, all openings, regardless of whether the front and the rear cross-section are designed differently or identically, are always plugged perpendicular to the back. The bristle ends protruding from the rear are attached in particular by melting, gluing or overmolding the bristle tufts or by combinations of these fastening methods, e.g. first melting, then additional extrusion coating.

If the rear cross-section of the opening, preferably even all of the openings, is larger than the front cross-section of the associated opening, the tufts can be inserted more easily and can be clamped in the region of the front cross-section, but this is not absolutely necessary.

One embodiment of the invention provides that all openings in the bristle carrier have the same cross-sectional area on the rear side, so that each opening in the region of the rear side can be produced in the same way. If the openings have the same front cross-sectional area, each opening receives the same or substantially the same number of bristles or filaments. However, it is also possible and advantageous to use tufts of bristles with different numbers of bristles or filaments, so that the brush has areas with thicker and thinner tufts, which is particularly advantageous for the cleaning effect with toothbrushes.

Bristle carriers with openings whose front cross sections are strip-shaped can be used, as a result of which the tufts of bristles are given a strip-shaped cross section.

In order to enable a good attachment of the tufts of bristles, the rear opening section can run in a funnel shape towards the front, but without reaching the front. The back opening section with the Funnel extends over more than 60% of the thickness of the bristle carrier in the area of the associated opening.

The device according to the invention for producing brushes, in particular with a method according to the invention, comprises
an alignment tool over which a bristle carrier, which is part of the finished brush and has openings for receiving tufts of bristles, is positioned with its front side adjacent to the alignment tool,
a transport device for feeding tufts of batches, a guide-free gap being present between the transport device and the rear of the bristle carrier to be equipped,
wherein the bristle carrier has at least one opening with a cross-section on the front, the center of area of which is offset from the center of gravity of the back cross-section of the opening and / or at least one opening, in particular the opening with different centers of gravity, with a cross-section on the front that has a different cross-section compared to the rear cross-section Has geometry,
a stuffing tool that pushes the tufts from the transport device across the gap perpendicular to the back of the bristle holder into the bristle holders and into receiving openings in the bristle holder, the aligning tool having at least one receiving opening that runs obliquely to the rear and / or an inlet with one of has a circular shape deviating geometry, and
a fastening tool for anchor-free fastening of the bristle tufts to the bristle holder.

The device according to the invention is optionally also distinguished by the features which have been explained above in connection with the method according to the invention and by features of the subsequent claims directed to the method. Conversely, the method according to the invention is also optionally carried out using the device, with features such as are presented below for the device and are defined in the subclaims for the device.

The preferred embodiment provides that the alignment tool has a support surface for the bristle carrier, so that the bristle carrier rests directly on the alignment tool. As a result, there is no gap between the opening in the bristle carrier and the corresponding, inclined receiving opening and the other receiving openings in the alignment tool. The hole pattern in the alignment tool in the area of its top corresponds to the front hole pattern of the bristle holder.

For clear and fixed positioning of the bristle holder, it is provided that the support surface is formed in a recess adapted to the bristle holder. The bristle holder is thus held laterally in the alignment tool.

The alignment tool optionally has various receiving openings, namely receiving openings with a circular cross section and receiving openings with a strip-shaped cross section.

There are also receiving openings with different cross-sectional areas, so that the bristle tufts have different cross-sectional areas.

The device according to the invention also preferably comprises a bundle pickup with a variable receiving opening, so that the different bristle tuft cross sections can be implemented fully automatically very quickly.

The fastening tool can be a heating device for melting the rear bristle ends projecting from the bristle holder. It is possible to melt the tufts of bristles by contact with a hot surface or by ultrasound or by hot air or combinations thereof.

There may also be a spraying station in which the bristle carrier is overmolded on the rear, so that the bristle ends are no longer visible.

According to one embodiment of the invention, elastic fingers protruding from the front can also be molded on when overmolding. These fingers either protrude to the side of the bristle holder or through openings in the bristle holder.

In the method and the device, the tufts are preferably sequentially removed from the magazine and sequentially stuffed.

• Figur 1 eine schematische Ansicht einer erfindungsgemäßen Vorrichtung zum Herstellen von Bürsten nach dem erfindungsgemäßen Verfahren,
• Figur 2 und Figur 2a den Bündelabnehmer und die Stopfvorrichtung, die bei der Vorrichtung nach Figur 1 verwendet werden in Perspektiv- und in vergrößerter Schnittansicht,
• Figur 3 eine perspektivische Draufsicht einer Bürste, die nach dem erfindungsgemäßen Verfahren und mit der erfindungsgemäßen Vorrichtung hergestellt wird, wobei nur der Kopf dargestellt ist,
• Figur 4 eine Ansicht der Vorderseite des bei der Erfindung verwendeten Borstenträgers im Bereich des Kopfes,
• Figur 5 eine Ansicht der Rückseite des bei der Erfindung verwendeten Borstenträgers im Bereich des Kopfes,
• Figur 6 eine perspektivische Ansicht der Rückseite des Borstenträgers nach Figur 5,
• Figur 7 eine Draufsicht auf die Rückseite des mit Borstenbüscheln ausgestatteten Borstenträgers nach Figur 6 vor dem Befestigen der Borstenbüschel,
• Figur 8 eine Schnittansicht durch den Borstenträger nach dem Bestopfen und durch das Ausrichtwerkzeug,
• Figur 9 eine perspektivische Ansicht des Borstenträgers in bestopftem Zustand vor dem Befestigen der Büschelenden,
• Figur 10 eine schematische Schnittansicht durch den bestopften Borstenträger nach dem Befestigen der Borstenbüschel, und
• Figur 11 eine Bürste, die nach dem erfindungsgemäßen Verfahren und mit der erfindungsgemäßen Vorrichtung hergestellt wird.

Further features and advantages of the invention result from the following description and from the following drawings, to which reference is made. The drawings show:

• Figure 1 2 shows a schematic view of a device according to the invention for producing brushes using the method according to the invention,
• Figure 2 and Figure 2a the bundle taker and the tamping device, which after the device Figure 1 are used in perspective and in enlarged sectional view,
• Figure 3 2 shows a perspective top view of a brush which is produced by the method according to the invention and with the device according to the invention, only the head being shown,
• Figure 4 2 shows a view of the front of the bristle holder used in the invention in the area of the head,
• Figure 5 2 shows a view of the back of the bristle holder used in the invention in the area of the head,
• Figure 6 a perspective view of the back of the bristle carrier after Figure 5 ,
• Figure 7 a plan view of the back of the bristle carrier equipped with bristle tufts after Figure 6 before attaching the tufts of bristles,
• Figure 8 2 shows a sectional view through the bristle carrier after the plugging and through the alignment tool,
• Figure 9 a perspective view of the bristle carrier in the stuffed state before attaching the tuft ends,
• Figure 10 is a schematic sectional view through the stuffed bristle carrier after attaching the bristle tufts, and
• Figure 11 a brush which is produced by the method according to the invention and with the device according to the invention.

In Figure 1 shows a device for the production of brushes, in particular toothbrushes, which comprises several stations. However, the device can also be less than that in Figure 1 have stations shown, so that the brushes can also be forwarded to another device in a partially manufactured state. The type of transport of the individual parts of the brush is not relevant to the device and the method for producing the brushes, so that the in Figure 1 shown transport device between the individual stations is not to be understood as limiting.

A tool table 8 transports the partially manufactured brushes from one station to the other.

In the embodiment shown, so-called brush bodies are used as so-called bristle carriers, in which the handle, neck and head are already injection-molded as a common, one-piece plastic part. The bristle carriers have the reference number 10.

The bristle carriers are placed from a magazine 11 onto so-called holders 12, which are permanently attached to the tool table 8 and rotate with it, for example.

In a first station there is a bundle pickup 14 which can be operated with a stuffing tool 16 (see Figure 2 ) is coupled. In this station, the bristle carriers 10 are filled with tufts of bristles either sequentially or in a tamping process.

In a later station, the ends of the tufts are trimmed on the back, for example with a knife 17 (for example a milling cutter), or with a hot wire designed as a knife. The knife 17 is only symbolic Figure 1 shown.

In a subsequent station, the tuft ends protruding on the rear side opposite the bristle carrier 10 are melted, so that the bristles or filaments are fused together. For this purpose, a heating device 18 is provided, which is also only shown symbolically.

There is then a station in which the stuffed bristle carriers 10 provided with the tufts are overmolded in one or more steps on the back, at least in the area of the head. The injection mold bears the reference number 20.

Finally, the finished brushes are removed from the tool table 8.

In Figure 2 the bundle pickup 14 is shown, which comprises a magazine 22 with unsingle bristles 24 arranged in parallel therein. A removal device 26 serves as a separator and comprises an arcuate section with an outer recess 28. The removal device 26 is pivoted back and forth in the direction of the arrow.

When the depression 28 is in the region of the magazine 22, bristles are pressed into the depression 28 perpendicular to the rear of the bristle carrier, so that a bristle tuft or bundle is formed. When swinging back into the Figure 2 The position shown is the tufts of bristles 30 above the head of the bristle carrier 10, which has numerous openings that complement one another to form a hole pattern.

The bundle collector 14 with its removal device 26 can also serve as a transport device for the bundles or tufts that transport them to the tamping tool 16.

The depression 28 is aligned with the opening in the bristle carrier 10 to be filled next, and then the tuft of bristles 30, which lies in the depression 28, is pressed into the opening by the stuffing tool 16.

The bristle carrier 10 is aligned before the next tamping process in such a way that the next opening to be tamped lies below the incoming recess 28. For this purpose, a so-called X-Y slide or, generally, a device 32 is provided.

On the back of the bristle carrier 10, a guide-free gap S is present when the plug is plugged, that is to say the bristle tufts 30 are not guided in this area, but rather are guided through this gap without a guide.

It should be emphasized that in Figure 2a the removal device 26 is made somewhat thicker than in FIG Figure 2 . The thickness of the removal device 26 is variable. In addition, it is also possible for the transport device to move the individual tufts into a type of guide which is somewhat higher in order to optimally guide the individual tufts of bristles perpendicularly to the rear when they are stuffed. However, the gap S is always present.

In Figure 3 the finished brush head can be seen. It can be seen here that there are bristle tufts 34 which have a circular tuft cross section, the bristle tufts 34 with a circular cross section having different cross-sectional areas, that is to say thicker and thinner tufts are present. In addition, rectangular bristle tufts 36 are present, which have a strip-shaped, more or less rectangular tuft cross section. Finally, there are bristle tufts 38 of any cross-section, here for example circular, angular and strip-shaped, which run obliquely to the front 40 of the bristle carrier in the region of the head, that is to say in the region of the bristle tufts 30-38. The remaining tufts of bristles 34, 36 are perpendicular to the front and back 40, as is the case with conventional toothbrushes.

In the area of the head, the bristle carrier 10 is plate-shaped, so that the front 40 and the rear 42 run essentially parallel to one another. In addition, it may also be the case that the front and back 40 and 42 run slightly conically towards one another towards the tip 44 of the brush, which, however, is negligible with regard to the vertical alignment of the bristle tufts.

In the Figures 4 and 5 the front 40 and the back 42 of the bristle carrier 10 in the area of the head and the so-called hole pattern can be seen. It is particularly in Figure 5 and in Figure 6 It can be seen that preferably each opening 46-50 widens from the front 40 to the rear 42, so that the rear cross section, that is to say the mouth of the opening 46-50 at the rear 42, has a larger cross section than the front cross section, that is to say the mouth of the Opening 46-50 at the front 40.

In particular, the openings have their smallest cross section at the mouth to the front, that is to say the front cross section.

The largest cross-sectional area is the rear cross-section of each opening 46-50.

The openings 46-50 run from the rear side 42, as in FIGS Figures 5 and 6 can be seen, slightly conical towards the front 40. A kind of funnel can result.

The openings 46 are standard openings with circular front and rear cross sections, in which the tufts of bristles are also anchored perpendicular to the front 40. It can be seen, inter alia, that the openings 46 with a circular cross-section have different cross-sectional areas on the front, but the same cross-sectional areas on the rear, which simplifies production. Here, for example, the same countersinks or countersinks can be used for all of these openings 46. The different cross-section on the front side is then produced by using drills with different cross-sections.

There are also openings 48 in the bristle carrier 10, in which the rear cross section is larger than the front cross section, but the geometry of the rear cross section is different from the front cross section. For example, this is not to be understood as restrictive, the rear cross section is formed by a circle, which is generated by using a countersink or countersink. This countersink or countersink can be the same as the openings 46 so that the cross-sectional area of the rear cross-section (mouth of the opening 48 at the rear 42) is the same as that of the openings 46. However, the front cross-section of the openings 48 has a strip shape or an oval Shape, i.e. a different cross-sectional geometry than on the rear cross-section.

As an alternative to drilling or milling, the openings are made entirely by injection molding, e.g. by stamp, also possibly movable stamp, which are provided on the injection mold halves. If the punches are movable, they are preferably not movable obliquely to the demolding direction, but only in the demolding direction.

Finally, there are openings 50 in which the rear cross section is again larger than the front cross section. The openings 50 are also characterized in that the so-called center of gravity of the rear cross-section (center 52 of the corresponding circle) is laterally offset from the center of gravity 54 of the front cross-section when one looks perpendicularly at the back or front of the bristle carrier. The openings 50 are, in particular, this is also not to be understood as restrictive, those openings in which the bristle tufts 38 are inserted which run obliquely to the front side 40.

The openings 56 have, for example, a circular rear cross section and a polygonal front cross section.

Optionally, but this is not absolutely the case, all openings have the same rear cross-section, which simplifies production.

As an alternative to the embodiment according to the Figures 4 to 7 The bristle carriers 10 can also have openings which all have the same front cross-sectional area, so that the same number of bristles are always provided for each bristle tuft.

In Figure 7 the bristle tufts inserted into the openings, more precisely the tuft ends of the bristle tufts 34-38 protruding from the rear side 42, can be seen.

Figure 9 shows the bristle carrier 10, which is completely filled with tufts of bristles. The ends of the tufts protruding from the rear 42 can be seen. In addition, it can be seen that the bristle carrier 10 has an edge 57 which is pulled up laterally on the rear side 42, so that the rear side 42 is somewhat recessed relative to this edge 57.

Figure 8 shows an alignment tool 58, which simultaneously forms the holder 12. The alignment tool 58 has a recess 60 which is adapted to the bristle holder 10, this recess 60 being present only in the region of the head and part of the neck of the bristle holder. The bristle carrier 10 is thus received in the alignment tool 58 and held in a fixed position.

The alignment tool 58 has on its upper side (here: bottom of the depression 60) a contact surface which is directly opposite the front side 40 and it preferably, which is not to be understood as limiting. Receiving openings in the alignment tool 58 form a hole pattern on the upper side, which corresponds exactly to the hole pattern of the bristle carrier 10 on its front side 40, the individual openings being exactly aligned with one another.

The receiving openings determine the orientation of the bristle tufts of the later brush. The corresponding receiving openings for the bristle tufts 34, 36 run perpendicular to the contact surface of the alignment tool in the region of the depression 60 and thus perpendicular to the front side 40.

Without the alignment tool 58, the bristles of the tuft would not remain aligned parallel before the tufts of bristles are attached. For the openings with different center of gravity and / or other cross-sectional geometries on the front and back, it is therefore provided that the openings, together with the alignment tool, hold the still unsecured bristles of a tuft of bristles in parallel.

The receiving openings 62, which in Figure 8 can be seen, however, run obliquely to the front 40 and take up the obliquely extending bristle tufts 38.

In the embodiment shown, which is not to be understood as restrictive, the bristle tufts protrude through the alignment tool 58.

The tufted bristle carriers are, as related to Figure 1 already described, move to a station with the alignment tool 58, where the bristle tufts are trimmed on the back. This state is in Figure 9 shown.

The protruding ends of the tufts are then heated so that the bristles fuse together, as in Figure 10 is shown. The ends of the tufts melt into a lump of plastic that completely or largely fills the opening in the bristle holder. The molten tuft ends can either be spaced apart from one another or a thin film of molten plastic can also result on the rear side 42.

The bristle ends are fused in a state in which the tufts of bristles are still received in the receiving openings of the alignment tool 58.

The bristle tufts are stuffed perpendicular to the front and / or back 40 or 42, as in Figure 2 you can see. There are preferably also no guide channels or guide plates between the stuffing tool 16 and the rear side 42, which would lead the obliquely extending bristle tufts 38 obliquely into the respective opening. The bristle tufts 38 are inclined by means of the front alignment tool 58 with the corresponding inclined receiving openings 62. Although the bristles of these oblique tufts 38 strive to align themselves differently and a certain tension is present in the tuft due to the deflection from the vertical plug movement in the oblique orientation in the receiving opening 62 "relaxes" the tuft when melting, so that even after the finished brush has been pulled out of the alignment tool 58, the bristles of the oblique bristle tuft 38 remain aligned, as was previously the case in the alignment tool 58.

The same also applies to the openings in which the rear cross section has a different geometry than the front cross section, for example in the openings 56 and 48.

Figure 10 also shows that the openings with the offset centroids have different sections. From the rear cross-section 64, an opening section a extends into the bristle holder 10 over a depth which preferably corresponds to more than 60% of the thickness of the bristle holder 10 in this area. This opening section a is oriented perpendicular to the front and / or back 40 or 42, which is symbolized by the central axis 68.

The opening section b starting from the front cross section 66 merges into the opening section a without an intermediate section or an inclined channel being present between the opening sections a and b.

The opening section b is also perpendicular to the front and / or back 40 or 42. This is symbolized by the central axis 70.

The openings 48 are also formed without an inclined intermediate channel between the opening sections, which originate from the rear and front cross sections 64 and 66.

In Figure 10 it can also be seen that a common opening section b 'for a plurality of adjacent openings can be present on the front side 40. Under certain circumstances, it would be possible here for the cone of the rear opening section a to merge directly into the front opening section b ', so that the narrowest cross-sectional area of the respective opening is, so to speak, an annular line formed by an edge. At the right opening in the embodiment according to Figure 10 the narrowest cross section is defined by the cylindrical opening section b, i.e. not by a pure edge.

Theoretically, it would of course be possible that the front opening section b does not extend cylindrically, but rather widens towards the front 40.

If bristle tufts with different numbers of bristles are to be used, it is advantageous if a bundle pickup 14 with a variable receiving opening is used. This can be achieved, for example, by a movable screen 72 (see Figure 2 ) is present, which can change the cross section of the recess 28.

As an alternative to fusing the tufts of bristles, they can also be glued or molded.

As before based on Figure 1 explained, the bristle carrier 10 is injected at least on the back in the area of the head, and if possible also encapsulated in the area of its stem. The fused bristle ends are covered in the area of the head. In particular, an elastomer is used for this spraying process.

When spraying with elastomer, elastic fingers 74 can also be molded on (see Figure 11 ). These elastic fingers 74 are present, for example, on the edge of the head and run forward like bristles in order to enable a massage effect. Elastic fingers 74 can also be injection molded in the middle or, more generally, between openings for tufts of bristles. In Figure 11 is a cross-shaped elastic finger as an example 76 indicated, which extends forward through a cross-shaped opening in the bristle carrier 10 and fulfills an additional cleaning function.

It should be emphasized that all of the aforementioned variants and individual features can also be used on bristle carriers which are designed as head plates. These plates have a hole pattern corresponding to the options shown above and are connected after plugging and fastening the bristle tufts with a brush body, which is either already sprayed in advance and has a receiving opening in the area of the head for inserting the head plates. As an alternative to this, the platelet-shaped bristle carrier can also be inserted into an injection molding tool, and the brush body is molded on.

Claims (13)

1. A method of manufacturing brushes, characterized by the following steps:

   providing a bristle carrier (10) which is part of the finished brush and has front and rear faces (40, 42),

   providing openings (46 - 50, 56) in the bristle carrier (10) for receiving tufts of bristles (34 - 38),

   at least one opening (50, 48) having a front-side cross section (66), the center of area (54) of which is offset from the center of area (52) of the rear-side cross section of the opening (50), and/or

   at least one opening (48), in particular the opening having different centers of area (52, 54), having a front-side cross section which has a different geometry in comparison to the rear-side cross section,

   removing tufts of bristles (34 - 38) from a bristle supply in which the bristles are accommodated so as to be packed in parallel,

   transporting the removed tuft of bristles (34 - 38) to the bristle carrier (10) by means of a transport device,

   providing an alignment tool (58) at the front side of the bristle carrier (10), the alignment tool (58) having receiving openings (62) the inlets of which are in alignment with the front-side cross sections,

   thrusting the tuft of bristles (34 - 38) into the respectively associated opening (46 - 50, 56) from the rear side of the bristle carrier (10) perpendicularly to the rear side (42) of the bristle carrier (10), the rear side of the bristle carrier (10) having a guide-free gap (S) provided thereon through which the tufts of bristles (34 - 38) are pushed into the bristle carrier (10) and into the receiving openings (62), and

   anchor-free fastening of the tufts of bristles (34 - 38) to the bristle carrier (10) on the rear side.
2. The method according to claim 1, characterized in that the opening having different centers of area and/or other cross-sectional geometries is configured such that the bristles of the tuft of bristles are held parallel only together with the alignment tool prior to the fastening of the tuft of bristles.
3. The method according to either of the preceding claims, characterized in that the rear-side cross section (64) is the mouth of a rear-side opening portion (a) and the front-side cross section (66) is the mouth of a front-side opening portion (b), and wherein all of the openings are formed so as to be free of undercuts when viewed in the direction perpendicular to the rear side.
4. The method according to any of the preceding claims, characterized in that bristle carriers (10) are used in which all of the openings (46 - 50, 56) have the same rear-side cross-sectional area or have different cross-sectional areas.
5. The method according to any of the preceding claims, characterized in that the receiving openings (62) each have an inlet having a cross section that corresponds in size and geometry to the respective front-side cross section of the associated opening.
6. The method according to any of the preceding claims, characterized in that at least one receiving opening extends obliquely to the front side.
7. The method according to any of the preceding claims, characterized in that bristle carriers (10) are used which have openings (48, 50) the front-side cross sections of which deviate from a circular shape, in particular are oblong, angular or strip-shaped.
8. The method according to any of the preceding claims, characterized in that bristle carriers (10) are used which have rear-side opening portions (a) that extend in a funnel shape towards the front side (40).
9. The method according to claim 8, characterized in that the opening portions (a) that extend in a funnel shape extend over more than 60% of the thickness of the bristle carrier (10) in the region of the associated opening (46 - 50, 56).
10. A device for manufacturing brushes, in particular by means of a method according to any of the preceding claims, comprising
    an alignment tool (58) above which a bristle carrier (10), which is part of the finished brush and has openings (46 - 50, 56) for receiving tufts of bristles (34 - 38), is positioned with its front side adjacent to the alignment tool (58),
    wherein the bristle carrier (10) has at least one opening (50, 48) having a front-side cross section (66), the center of area (54) of which is offset from the center of area (52) of the rear-side cross section of the opening (50), and/or has at least one opening (48), in particular the opening having different centers of area (52, 54), having a front-side cross section which has a different geometry in comparison to the rear-side cross section,
    further comprising a transport device for feeding tufts of bristles (34 - 38), a guide-free gap existing between the transport device and the rear side of the bristle carrier (10) to be loaded,
    a tufting tool which pushes the tufts from the transport device over the gap (S), aligned perpendicularly to the rear side of the bristle carrier (10), into the bristle carriers and into receiving openings in the bristle carrier (10), the alignment tool (58) having at least one receiving opening (62) which extends obliquely to the rear side and/or has an inlet having a geometry deviating from a circular shape, and
    a fastening tool for anchor-free fastening of the tufts of bristles to the bristle carrier.
11. The device according to claim 10, characterized in that the alignment tool (58) has a support surface for bristle carriers (10).
12. The device according to either of claims 10 and 11, characterized in that the alignment tool (58) has receiving openings with inlets having circular and/or non-circular, in particular oblong, polygonal or strip-shaped cross sections and/or receiving openings having different cross-sectional areas or identical cross-sectional areas.
13. The device according to any of claims 10 to 12, characterized in that the fastening tool is a heating device for fusing the bristle ends projecting from the rear side of the bristle carrier (10).

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