EP2683271B1 - Method and device for producing brushes - Google Patents

Description

The invention relates to a method and an apparatus for producing brushes.

Various methods of making brushes are known. Conventionally, a brush body is provided with an array of holes ("hole pattern") corresponding to the desired arrangement of bristles. Bundles or tufts of bristles are then inserted into the holes of the brush body and anchored therein by means of impressed small metallic anchors or by means of loops.

In an alternative method of making brushes that has become established in just a few years and is referred to as Anchor Free Tufting (AFT), the bristle tufts are attached to a small brush head plate without the use of loops or anchors. and the carrier plate is then inserted into or attached to a brush body or handle. In a variant of the AFT method brush handles are made with a hole pattern that corresponds to the desired tuft pattern. Bristle tufts are then inserted into these holes and attached to the brush handles. The attachment ends of the tufts are then covered with a small plate.

The closest to the state of the art forming DE 39 20 769 C2 describes a method for producing brushes without anchor, in which the individual tufts are separated at the same time and sucked through hoses in a holding plate. Each hose transports a bristle tuft. Subsequently, the free tufts ends are heated so that the filaments fuse together. WO 2007/087694 A1 discloses a method of making a brush, wherein the individual bristle tufts are produced in a process step by sequentially pushing the removed bristles into an opening of a support. In the device according to the DE 40 27 288 C2 are tufted over several parallel sleeves in a movement process bristle tufts and a a holder pushed where they are cut. Subsequently, the parallel arranged tufts are pushed together in the bristle carrier, optionally with the interposition of a guide plate, which may also have oblique channels.

The present invention relates to a method and apparatus for making a brush based on the AFT method.

The invention provides a method and a device that are simple and above all very fast and low maintenance.

• Sequenzielles, nacheinander einzelnes Entnehmen von Borstenbüscheln aus einem Borstenvorrat, in welchem die Borsten parallel gepackt untergebracht sind,
• Transportieren des entnommenen Borstenbüschels mittels einer Transporteinrichtung zu einem, einen Teil der fertigen Bürste bildenden Basisteil, welches Öffnungen zur Aufnahme von einzelnen Borstenbüscheln hat,
• sequenzielles, nacheinander einzelnes Einstoßen des Borstenbüschels in die zugeordnete Öffnung von der Rückseite des Basisteils aus, wobei zwischen der Transporteinrichtung und der Rückseite des Basisteils eine Führungsplatte mit Umlenkkanälen vorgesehen ist, durch die Borstenbüschel in die Öffnung im Basisteil gestoßen werden, und
• ankerfreies Befestigen der Borstenbüschel am Basisteil.

The method according to the invention is used in particular for producing a toothbrush and provides the following steps:

• Sequential, successively individual removal of bristle tufts from a bristle supply, in which the bristles are housed packed in parallel,
• Transporting the removed bristle tufts by means of a transport device to a base part which forms part of the finished brush and which has openings for receiving individual bristle tufts,
• sequentially, one at a time, individually piercing the bristle tufts into the associated opening from the rear side of the base part, wherein between the transport means and the rear side of the base part a guide plate with deflection channels is provided, through which bristle tufts are pushed into the opening in the base part, and
• Ankerfreies attaching the bristle tufts on the base part.

In the method according to the invention, tufts of bristle stock, in particular a magazine, are removed in succession, that is to say sequentially, and transported to form a base part. This base part may be either a kind of plate, which is then connected to the brush body, or be a portion of the brush body itself. The front side of the base part is the side from which the bristles of the later brush protrude, whereas the back side is the usually closed, that is bristle-free, side. A guide plate is provided between the transport means and the back side of the base part which has deflection channels through which bristle tufts are pushed into the opening in the base part. This can be obliquely directed Make tufts in the base part or combine several tufts into a common, large tuft so that, for example, elongated bristle tufts are formed. Different tuft geometries can also be realized if, for example, the inlet of the deflection channel is circular, the outlet can have a polygonal or, more generally, non-circular geometry, so that the tufts are always taken from the magazine with the same tuft-singulation geometry, but different cross-sectional geometries be realized in the base part. The deflection channel thus leads, as predicated on the term "deflection", a displacement of individual bristles or of an entire tuft transversely to the linear direction of impact.

• Die Umlenkkanäle und die Öffnungen können schräg verlaufen und die Büschel schräg stehend im Basisteil verankert werden und/oder
• mehrere aufeinander zu auf eine gemeinsame Öffnung im Basisteil zu verlaufende Kanäle sind vorgesehen (wobei hier auch z.B. ein in Einstossrichtung verlaufender Kanal mit einem schräg verlaufenden Umlenkkanal einer gemeinsame Öffnung im Basisteil zugeordnet sein kann), so dass mehrere Büschel in verschiedene, nebeneinander angeordnete Kanäle und über diese in eine gemeinsame Öffnung im Basisteil eingestoßen werden zur Bildung eines gemeinsamen Büschels und/oder
• zumindest ein Umlenkkanal ist vorgesehen, der mehrere Büschel aufnimmt, um sie zu einem gemeinsamen Büschel zu vereinen, wobei dieser Umlenkkanal vorzugsweise mehrere nebeneinander liegende Einlässe hat, von denen aus sich die einzelnen Kanäle zu einem gemeinsamen Umlenkkanal vereinen, und/oder
• dass wenigstens ein Umlenkkanal einen Einlass hat, dessen Geometrie sich von der des Auslasses des Umlenkkanals unterscheidet.

Here are several variants possible, which can also be combined with each other:

• The deflection channels and the openings can run obliquely and the tufts are anchored obliquely in the base part and / or
• a plurality of toward one another to a common opening in the base part to extending channels are provided (which here, for example, a running in the direction of insertion channel with an oblique deflection a common opening in the base part can be assigned), so that several tufts in different, juxtaposed channels and be pushed through this into a common opening in the base part to form a common tuft and / or
• at least one deflection channel is provided, which receives a plurality of tufts to unify them into a common tuft, said deflection channel preferably has a plurality of adjacent inlets, from which unite the individual channels to a common deflection channel, and / or
• in that at least one deflection channel has an inlet whose geometry differs from that of the outlet of the deflection channel.

The outlet of the deflection channel usually has the same geometry and size as the adjacent opening in the base part.

One embodiment provides for the guide plate to be placed on the rear side of the base part and removed from the base part before it is fastened to the base part.

Since the bristle tufts are sequentially individually, ie successively individually stuffed directly into the base part, no great adaptation of the tool to other base parts is required on the device side.

In addition, in the state of the art, work has mostly been carried out with a tool-side support whose openings correspond exactly to the openings in the base part. First, this carrier was filled with bristle tufts, and then this carrier was transported to the base part to be filled. The manufacture of the numerous carriers operating in a device is relatively expensive. In addition, the conversion of the device for other brushes consuming.

In the method according to the invention and in the device according to the invention, this conversion can be made much simpler.

In the method according to the invention, the position of the base part is aligned with the stationary tool for pushing for each hole to be filled and thus moved. One possibility for this is to move the base part for the sequential piercing at least in two directions, in order to align the opening to be filled with the bristle tufts to be inserted.

This method is, as immediately apparent, very easily adaptable to completely new tufts.

In particular, the method can be adapted very quickly to new patterns if the base part is moved using a freely programmable, at least 2-axis positioning device, in particular a freely programmable, preferably 2-axis industrial robot.

It is particularly advantageous if the bristle tufts are transported sequentially by a tuft picker to the final position, from which they are pushed axially into the opening to be filled. For the separation of the bristle tufts as well as for the transport is thus only one Required movement, which may be, for example, a circular arc movement or a linear movement of the tuft picker.

The tuft picker does not necessarily have to move back and forth between the pickup position and the dispensing position. It would also be conceivable to provide a ring or circular tuft picker which rotates permanently in one direction.

The bristles used are made of plastic.

The back stuffing of the bristle tufts has the advantage that the tufts protrude so far from the base part as far as possible, thanks to a usually front stop, as desired, regardless of the length tolerances of the individual bristles. In addition, bristles with pre-machined bristle tips, for example, rounded, pointed bristle tips or the like may optionally be used.

According to the preferred embodiment, during the insertion of the tufts into the base part in the transport device, only axial pressure is exerted on the bristle tufts. That is, the bristle tufts is not clamped radially. When clamping, namely, the tuft end could widen in the gap, which would make it difficult to insert into the openings. Such a radial clamping force will occur in particular in so-called tenter.

Since the base part usually has a small thickness and the length of the openings over which the tufts are held, also correspondingly low, provides an advantageous method step, that a guide member is positioned on the device side with through holes before inserting the tufts on the front of the base part , The bristle tufts are inserted through the openings in the through holes in the guide part. Preferably, but this is not necessarily the case, the tufts protrude on the front even out of the guide part.

The front-side guide member may be formed as a clamper for the tufts, for example, in that the through-holes have a cross-section sufficiently large in relation to the tufts inserted therein that the tuft or temples are press-fitted in the through-holes. The Clamping the tufts prevents the tufts from being pulled out when the back guide plate is removed rearwardly from the base.

The front ends of the tufts may contact a profiled pressure member during or after loading of the base member to provide a profiled brushing surface. The brush surface is the front side working surface of the brush formed by the bristle ends. This pressure part can either already be present during the plug and serve as a stop or pressed against the bristles after the plug, so that they rest against the pressure part and image the shape of the pressure part.

The bristle tufts protruding from the back of the openings of the base part are cut off after being pushed in according to the preferred embodiment. The tolerances of the individual bristle lengths are thereby fully compensated, because on the front can be done on the printing part a precise length adjustment, the back is then simply cut off.

This cutting can be done by cutting tools or a heated tool, especially a so-called hot knife. There is a contact between the hot tool and the individual tufts, the life of the cutting tool is very high.

The bristle tufts are attached on the back, for example by thermal fusion and / or gluing and / or embedding in a molded plastic compound. Of course, these attachment methods can also be combined with each other arbitrarily.

As already explained above, the bristles stuffed into the base part are preferably pre-rounded or preprocessed in advance.

During cutting, according to one embodiment, the tufts are held radially only from the base part and, if present, the guide part. At the two ends no lateral fixation is provided, the ends are only frontally on the device and are thus fixed axially.

The back of the bristle tufts and the base part is covered. This can be done, for example, that the brush body in the region of back tuft ends has a recess which is closed by a prefabricated or molded cover part. Another possibility of covering the bristle tufts on the back is to form a prefabricated cover part on its side facing the base part with molded-on projections, so-called sacrificial structures, which soften during the subsequent heating, in particular become liquid, in order then to strike against the base part or, more generally to be pressed against the brush body. If the base part and the brush body are two different parts, it goes without saying that the brush body can also be provided with such sacrificial structures in order, after its heating, to be connected to the possibly also heated base part. This lid member may be provided with protruding cleaning protrusions in any shape to be used as a tongue cleaner or the like.

Alternatively, the base part is overmolded. If the base part is not already on the brush body at the same time, but rather a part to be fastened to the remainder of the brush body, the base part can be overmolded during production of the brush body. The encapsulation of the base part is not limited to this variant.

A particularly advantageous embodiment of the invention provides that the bristle tufts are attached to the back anchorless, in particular by fusing and / or gluing and that the assembled base is then inserted from a Beborstungsstation in a cavity of a mold half of an injection mold and thereby with its edge on the edge of a from the associated cavity outgoing opening rests and the bristle tufts protrude into the opening. On the back side, a brush section is molded onto the base part, which covers the bristle tufts. By the invention, the effort that is required for the production of the carrier plates, significantly reduced, because the carrier plates no longer migrate from the bristle machine to the injection molding tool, whereby the timing of injection molding and bristle machine no longer necessarily be coupled together. In the prior art, the bristle ends of the bristle tufts were first fused together, which was usually done in the hole plate equipped with the bristle tufts and produced in a complex manner. Subsequently, this perforated plate was in a Injection mold transported to overmold the tufts. The bristled base part was always transported in the prior art, including the support plate in an injection molding tool or another station of an injection molding tool. The carrier plate served to support against the injection pressure during injection molding of the brush body (head and stem). However, the present invention provides that these provided with the hole pattern of the brush carrier plates when making the brush body no longer provide as support plates in the injection mold. In the method according to the invention and in the device according to the invention, however, an opening (preferably a single opening) in the region of the cavity to be ejected is provided in a mold half of the injection molding tool into which the plurality of bristle tufts protrude. The base part is located exclusively or almost exclusively only with its peripheral edge on the edge of the cavity extending from the opening and is preferably supported only at this edge.

The base part is held on the edge in the cavity.

According to the preferred embodiment, the base part lies with its edge closed circumferentially on the likewise closed circumferential edge of the opening, so that a sealing effect is achieved.

By the method according to the invention, in which the perforated plates no longer circulate between the boring machine and the injection-molding tool, the entire production and the entire apparatus can manage with significantly less perforated plates.

It is now also possible to store the bristled base parts in a cache or buffer memory. During maintenance work on the injection molding tool or the bristle machine, therefore, it does not come to a standstill of the other machine, which significantly increases the overall flexibility.

Preferably, a plurality of cavities are provided in the mold half of the device according to the invention in order to increase the discharge rate of the entire device.

The mold half with the at least one cavity can also, and this is preferably formed in several parts. A first and a second molded part, if appropriate also further molded parts with in particular a plurality of juxtaposed cavities or rows of cavities, can be used. The cavity associated with a brush is then divided into several sections, for example into a section in the first and into a section in the second shaped part. These cavities merge into one another and form the total cavity of the mold half. However, the first molded part is separable from the second molded part and may u.U. as a means of transport or ejection tool for the one or more seated in it base parts. Thus, the first molded part can be fitted independently of the second molded part first with the bristled base parts and only then be coupled to the second molded part, namely immediately prior to injection molding. However, since the first molded part is very easy to produce due to the lack of hole pattern, many first molded parts can be manufactured and used relatively inexpensively, which significantly improves the cycle time and flexibility of the entire device.

However, it is also possible to make each mold half in one piece. The brush body is then placed in the mold half and this removed after spraying

It should be emphasized that, according to the preferred embodiment, the so-called brush body could be injected in the injection molding tool, which can be designed in one or more parts. This brush body is usually the brush handle, the brush neck and a part of the brush head. The other part of the brush head is formed by the base part.

However, it is also an embodiment useful, especially at cheaper brushes, in which the base part itself already has almost the entire head and essentially the entire handle or stem of the brush. Of course, this base part also forms a brush section and is then bristled and then overmoulded, at least in the back of the head or in the style area.

Some of the openings in the base can remain tuft-free and can be closed by spraying. This makes it possible to realize different bristle tuft arrangements with the same base part. Alternatively or in addition To close the tuft-free openings elastomeric profile parts, which have any cross-sectional shapes, be injected or injected or secured in openings. These profile parts are not bristles, but different profile parts with smaller or larger cross-sectional area than the usual bristles. For example, the parts can also have a cross-sectional shape deviating from the circular shape. In particular, such profile parts are used to produce a gum massaging effect.

The aforementioned other way to close the tuft-free openings, is in the back molding of plastic. In this case, either only the tuft-free openings can be closed, or it can front side projecting profile parts are molded with at the same time. The front-side guide part can serve as an injection mold.

The bristle tufts are separated from the bristle supply to the side of the bristle longitudinal direction and, in particular, moved individually to the openings via the transport device. Thus, no transport tubes known in the prior art are used for the transport device, which dip into the supply in the longitudinal direction of the bristles and receive and clamp a tuft of bristles. On the one hand, high cycle times can be realized by the lateral removal, and on the other hand, the tufts are significantly less or not compressed at all, which improves their positioning when entering the openings.

The method according to the invention is also used in particular in connection with brushes in which, in addition to the bristle tufts, at least one flexible element, preferably of TPE, projects from the brush head and is injection-molded onto the brush head. These soft-elastic elements may be positioned at the edge of the brush head and protrude or lie in the bristle field, i. be surrounded by bristle tufts. These soft-elastic elements have e.g. the function of achieving a gum massage when brushing your teeth.

The soft-elastic element, for example, integrally merges into a flexible section on the connection from handle to head and / or even into the handle, so that a bending elasticity or a non-slip feel is achieved in these sections.

The invention also provides a device for producing a brush, in particular a so-called brush-making machine, which preferably uses the aforementioned method according to the invention. The apparatus comprises a magazine having a bristle supply in which bristles are accommodated in parallel, a bristle tuft picking device sequentially picking bristle tufts for a brush from the bristle stock one after the other, one transporting means for transporting the individual bristle tufts to a stuffing station wherein the stuffing station comprises a holder for base parts of the brush to be installed, a guide plate between the transport means and the rear side of the supplied base part with deflection channels, through which bristle tufts are pushed into the opening in the base part, and a plunger, over which the tufts of bristles are sequentially, successively individually be pushed from the back through the guide plate into the base part.

The variants of the embodiment of deflection channels described above can of course also be implemented in the device according to the invention, individually or in any desired combination.

In particular, the device comprises a closed-loop receiving device, for example a receiving table, a chain, an index table or, more generally, a type of circle with receptacles for the base parts on which they are moved, to individual stations, e.g. to cut through the bristle tufts and attachment of the tufts and optionally closing the back of the open brush body or molding of the brush body.

Preferably, the removal device is integrated into the transport device.

Another possibility is that the transport device moves the tufts along a linear or curved path to the stuffing station. Such so-called tufts are in the EP 0 972 465 B1 shown.

The device according to the invention preferably further comprises a tuft picker, which transports the tufts sequentially to the final position, from which they are pushed axially into the opening to be filled. A transfer after the separation of the bristle tufts on another device or a carrier that brings the tufts up to the position immediately before the impact, thus eliminating.

The device according to the invention also comprises a station in which the base part for the sequential piercing is moved at least in two directions in order to align the opening to be filled with the bristle tufts to be filled, this station in particular having a freely programmable, preferably 2-axis industrial robot Has shift of the base part.

The preferred embodiment provides for integrating a cutting device into the device with which the bristles protruding from the base part on the rear side are cut off. In particular, the cutting device is moved transversely to the bristles without any support. In the prior art, the bristles are cut off at the back by acting as a counter knife a device-side support plate through which the tufts protrude. This plate stabilizes the tufts and on the surface of the plate a knife is driven along, which cuts off the tufts. Although this type of cut is reliable, but leads to wear of the cutting device and is therefore maintenance and spare part intensive than the device according to the invention, in which no support plate is provided on the tool.

As has been found, this support-free cutting is preferably easy to implement by a heatable tool in which the hot tool contacts the bristles and cuts.

The heatable tool is in particular formed with a current-carrying heating wire, which may be a round wire or a flat wire, wherein in experiments with the flat wire very good results have been achieved.

In a fixing station for the bristle tufts, the bristles are welded together in tufts or in total and / or glued and / or potted.

The device-side guide member, which is fed to the front of the base member is moved along with the base member from station to station and positioned the tufts.

In order to make the position of the front ends of the bristles unambiguous, in particular in the case of a profiled brush surface, the device has an deliverable profiled pressure part which contacts the bristle tufts during or after the stopper. A counter-pressure part can be driven from the back against the tufts.

• Figuren 1a bis 1h aufeinanderfolgende Schritte des erfindungsgemäßen Verfahrens, die in der erfindungsgemäßen Vorrichtung durchgeführt werden,
• Figur 2 eine schematische Draufsicht auf eine Station der erfindungsgemäßen Vorrichtung, in der Borstenbüschel einem Magazin entnommen werden,
• Figur 3 eine perspektivische Ansicht der Station nach Figur 2 mit einigen weggelassenen Teilen,
• Figur 4 eine vergrößerte Detailansicht von Figur 3,
• Figur 5 eine Schnittansicht durch die Station nach Figur 3,
• Figur 6 eine schematische Perspektivansicht einer weiteren Station der erfindungsgemäßen Vorrichtung, bei der Borsten geschnitten werden,
• Figur 7 eine Detailschnittansicht durch die Station von Figur 6,
• Figuren 8a bis 8c aufeinanderfolgende Schritte in der Station nach Figur 6 mit einem anderen Messer,
• Figur 9 eine schematische Draufsicht auf eine erfindungsgemäße Vorrichtung,
• Figur 10 eine perspektivische Ansicht eines Spritzgusswerkzeugs als Teil der erfindungsgemäßen Vorrichtung,
• Figur 11 eine Draufsicht auf ein Formteil des Spritzgusswerkzeugs nach Figur 10,
• Figur 12 eine Draufsicht auf beborstete Basisteile, welche in das Formteil nach Figur 11 eingelegt sind,
• Figur 13 eine Unteransicht des mit Basisteilen versehenen Formteils nach Figur 12, - Figur 14 eine alternative Ausführungsform zu Figur 11, bei der zusätzlich Abstützfortsätze in die Öffnung des Formteils hineinragen,
• Figur 15 eine perspektivische Draufsicht auf eine noch unbeborstete Zahnbürste gemäß einer weiteren Ausführungsform, die ein weichelastisches Element aufweist,
• Figur 16 eine perspektivische Rückansicht der Zahnbürste von Figur 15, in beborstetem Zustand,
• Figur 17 eine perspektivische Rückansicht einer im Vergleich zur Zahnbürste nach Figur 16 leicht modifizierten Variante, und
• Figur 18 eine modifizierte erfindungsgemäße Vorrichtung.

Further features and advantages of the invention will become apparent from the following description and from the following drawings, to which reference is made. In the drawings show:

• FIGS. 1a to 1h successive steps of the method according to the invention, which are carried out in the device according to the invention,
• FIG. 2 a schematic plan view of a station of the device according to the invention in which tufts are removed from a magazine,
• FIG. 3 a perspective view of the station after FIG. 2 with some omitted parts,
• FIG. 4 an enlarged detail view of FIG. 3 .
• FIG. 5 a sectional view through the station after FIG. 3 .
• FIG. 6 a schematic perspective view of another station of the device according to the invention, are cut in the bristles,
• FIG. 7 a detailed sectional view through the station of FIG. 6 .
• FIGS. 8a to 8c successive steps in the station FIG. 6 with another knife,
• FIG. 9 a schematic plan view of a device according to the invention,
• FIG. 10 a perspective view of an injection molding tool as part of the device according to the invention,
• FIG. 11 a plan view of a molding of the injection molding after FIG. 10 .
• FIG. 12 a plan view of bristled base parts, which in the molding after FIG. 11 are inserted,
• FIG. 13 a bottom view of the provided with base parts molding FIG. 12 , - FIG. 14 an alternative embodiment to FIG. 11 in which support extensions additionally protrude into the opening of the molded part,
• FIG. 15 3 is a perspective top view of a still unborn toothbrush according to a further embodiment, which has a soft-elastic element,
• FIG. 16 a rear perspective view of the toothbrush of FIG. 15 , in bristled condition,
• FIG. 17 a perspective rear view of a compared to the toothbrush after FIG. 16 slightly modified variant, and
• FIG. 18 a modified device according to the invention.

In FIG. 1 Several sequential steps for making brushes, here in the form of toothbrushes, are shown. The brush has a brush body 10 with a brush head, which in the following forms a base part 12. The base part 12 has numerous passage openings 14, which are filled with bristle tufts 16, which are fastened to the base part 12.

In FIG. 1 It can be seen that a transport device 18, which will be explained in more detail below, conveys individual bristle tufts 16, which are pushed by a device from the transport device 18 into the openings 14 from the rear side of the base part 12.

For this purpose, the transport device 18 has a receiving opening 22 which is filled with a bristle tuft 16 and moved to the base part 12. The device 20 comprises a linearly movable plunger 24, which is inserted axially into the receiving opening 22 in order to push the bristle tufts 16 into the opening 14 of the base part 12 aligned with the receiving opening 22. The base part is moved along two axes and aligned with the opening to be filled 14 on the bristle tufts 16 to be introduced.

On the back of the base part 12 is a guide plate 17, on which in turn the transport device 18 rests. The guide plate 17 is part of the corresponding Stopfstation and is automatically placed after supplying a toopfopfenden base member 12 on this.

The guide plate has numerous channels, which on the rear side (facing the transport device 18) each have an inlet and on the front side (to the base part 12) have an outlet. Many of the channels are aligned exactly in the insertion direction (direction of movement of the plunger 24). However, some channels are designed as deflection channels 19, which move the tufts inserted into them transversely to the direction of insertion.

Preferably, all inlets 21 have the same geometry and size, in particular a circular shape.

In FIG. 1a deflecting channels 19 are shown, which run obliquely toward one another, have two separate inlets 21 and two outlets 23, which almost merge into one another. The outlets 23 are associated with a common opening 14, and over the two mutually facing deflection channels 19 an oversized opening is equipped with two tufts, which then unite to form a common tuft. As an alternative to the embodiment shown, a channel oriented axially in the ejection direction can fill an oversized opening 14 in the base part 12 with an adjacent deflection channel 19 running obliquely toward it.

The geometry of the oversized opening 14 is arbitrary, elongated openings or square or circular openings 14 may be provided as required.

While at FIG. 1 If the openings 14 all extend in the ejection direction or parallel thereto, openings 14 provided obliquely to the ejection direction can also be provided in accordance with the enlarged section, the deflection channels 19 being aligned with these. These obliquely placed openings 14 allow the embedding of slanted tufts 16 in the base part 12.

Another variant is that inlet and outlet 21 and 23 have different geometries, e.g. For example, some outlets 23 have an oval or angular geometry, where the cross-sectional area may be the same as inlet 21. In the corresponding deflection channel 19, bristles of the tuft are thus displaced relative to one another transversely to the ejection direction in order to produce the new tuft cross-sectional shape which corresponds to that of the associated opening 14. The channels in the guide plate 17 are produced in particular by wire or spark erosion. The guide plate is then cured to 50 to 60 Rockwell C.

As in FIG. 1 a, on the front side of the base part 12 is a device-side guide part 26, preferably in contact with the front side of the base part 12, whose through-holes 28 are aligned with the openings 14 to be populated.

Spaced apart from the guide member 26 is a stop member 30. The bristle tufts 16 are so deep into the guide plate 17, the base member 12 and the guide member 26 from the back of the base member 12, that is, from the back of the brush 10, pushed in that they front of the Guide member 16 protrude again and abut against the stop member 30.

As soon as all openings 14 to be equipped with bristle tufts 16 are provided, the in FIG. 1b fully populated state reached. The guide plate 17 can before reaching the in FIG. 1b shown state or later be pulled back up.

The guide member 26 may be formed as a clamping means for the tufts 16, for example by an additional, transversely to the insertion direction displaceable clamping piece which pushes the tufts 16 laterally in their guides or by the through holes 28 in relation to the or in the tufts inserted into them have such a large cross-section that the tuft or tufts 16 are press fit into the through holes 28.

It should be emphasized that, depending on the embodiment of the brush 10, not all openings 14 have to be filled with bristle tufts 16. It is possible to make variations on tufts and other geometries of the bristles possible to optionally assemble different openings 14 with bristle tufts 16.

In the in Figure 1c shown next method step, the stop member 30 is removed. Instead, a pressure member 32 is moved from the front axially to the bristle tufts 16 upwards, so that it contacts all the bristle tufts 16. The top of the pressure member 32 is profiled to form a complementary brush surface (formed by the front ends of the bristle tufts 16).

By the pressure member 32, the bristle tufts 16 are pressed back up in part and are unevenly back against the base member 12 out.

Optionally, a counterpressure part 36 complementary to the pressure part can be provided on this rear side so that the bristle tufts 16 can be axially fixed between the pressure part 32 and counterpressure part 36 as far as possible without play.

In order to achieve a tolerance compensation due to the different lengths of the individual bristles, it would be conceivable to design one of the pressure parts 32, 36 either elastically or elastically mounted.

Due to the pressure part 32, the front ends of the bristle tufts 16 have an exact alignment with the base part 12.

In the next step, which will be explained more clearly in the following, the bristle tufts 16 projecting from the rear side relative to the base part 12 are cut off ( FIG. 1 d) , so that the resulting free ends are just above the base part 12.

In the next process step, which could be carried out in the subsequent station, bristle tufts 16 are attached at the back. This attachment is done for example by welding.

One way of welding is in Figure 1e shown in which a hot plate 38 is pressed against the bristle tufts 16. The back ends of the thermoplastic bristles fuse together, preferably to form a continuous layer 40 (see FIG FIG. 1f ). During this fastening operation and also during the preceding cutting operation, the pressure part 32 preferably remains on the bristle tufts 16. The pressure part 32 can now be removed (FIG. Figure 1g ), and then a rear lid part 40 is applied to the back of the base part 12, at least in the region of the ends of the bristle tufts 16 welded together. This cover part 40 may be a prefabricated part. Alternatively, the lid member 40 may also be made by injection molding to the base member 12 or to the brush body. Of course, the aforementioned use of sacrificial structures on the lid or on the brush body can also be used.

During the foregoing process steps, it is preferable (not limiting) for the guide member 26 to be supported on the base member 12 to provide support and sealing.

In the following, individual of the method steps just explained above will be illustrated and described in more detail.

So shows FIG. 2 Further details of a possible embodiment of the station of the device according to the invention, in which the bristle tufts 16 are separated and transported to the base part 12. The device has its own station with a magazine 42, in which a bristle supply 44 is housed.

The bristles are aligned in magazine 42 parallel and ungrouped housed. They are pressed by adapted pressure means in the direction of the transport device 18.

The transport device 18 includes in the present, also not limiting embodiment to be pivoted about a pivot axis 46 to be pivoted removal device 48 with a plate-shaped bundle pickup, in the illustrated embodiment, a so-called circular arc having a receiving opening 50 for a bristle tufts 16. The receiving opening 50 is open on the side facing the brush holder 44 side. If the bundle taker to the right, based on FIG. 2 is pivoted, the receiving opening 50 comes in contact with the bristle supply 44. Due to the bias of the bristle supply 44 in the direction To this receiving opening 50, so many bristles press into the receiving opening 50 that it is completely filled.

The separation of the bristle tufts 16 thus takes place laterally to the longitudinal extension of the bristles, which in the present case would be perpendicular to the plane of the drawing. When the receiving opening 50 is filled with bristles, it is pivoted clockwise and in the in FIG. 2 shown position moves. A guide plate 52, which conforms to the shape of the plate 48, ensures that no bristles can fall out of the receiving opening 50.

As an alternative to the curved path, which has the transport device 18 in the embodiments, a linear method can also be used.

From the transport device 18, the bristle tufts 16 are pushed directly into the base part 12 directly via the guide plate 17 without the interposition of a carrier plate or the like. It should be noted that the individual bristle tufts are removed sequentially from the magazine 42 and transported with the tuft picker to their final position before impact. A transfer to subcarrier is avoided here.

However, since the base 12 has numerous openings 14 which must be successively filled with bristle tufts 16, the base 12 is moved in two directions, X, Y. In order to be filled openings 14 are aligned with the receiving opening 50 and the next bristle tufts 16 to be injected.

The corresponding station preferably has a so-called X-Y carriage, on which the base parts 12 can be fastened and moved in one plane. A so-called X-Y carriage is a simple embodiment of a freely programmable, at least 2-axis positioning device, in particular a freely programmable 2-axis industrial robot.

FIG. 3 shows the magazine 42 with the tuft stock 44 in perspective view. To clarify the entire station several parts have been omitted, including the guide plate 17th

FIG. 3 further shows a bristle tufts 16, which is being pushed by the device 20 into an opening of the base part 12. A holder 54 positions and locks the guide member 26 to an alignment unit, such as an XY carriage, through which alignment of the base member 12 with the receiving aperture 50 occurs.

FIG. 4 shows that the bristle tufts 16 project from the guide member 26 on the front side after being pushed into the openings 14 of the base part 12. However, the bristle tufts 16 are also in front of the base part 12, either directly after the impact or after the start of the pressure part 32.

In particular, the inlets 21 have the same cross section as the receiving opening 50.

Contrary to the FIG. 1a For example, a guide-free gap 60 may be present between the back of the guide plate 17 and the transport device 18 (see FIG FIG. 4 ). Here it can possibly offer to perform the inlets 21 slightly larger than the receiving opening 50, since the tuft 16 could spread slightly at its free end.

Furthermore, it can generally be advantageous if the inlets 21 widen somewhat funnel-shaped towards the rear.

For easy insertion of the bristle tufts 16, the openings 14 are preferably provided on the back with a flared chamfer 62.

Also can be seen in FIG. 5 in that the base part 12 has a depression 64 in the region of the openings 14 on the rear side. In this recess 64, the lid member 14 is introduced or molded.

The transport device 18 is designed so that during the insertion of the bristles into the openings 14 in the transport device 18 exclusively axial pressure (that is, pressure in the bristle longitudinal direction) is exerted on the bristle tufts 16 to be introduced. That is, the wall around the receiving opening 50 is rigid, no radial clamping force is exerted on the bristles. The only clamping force is due to the preload in the Bristle supply 44 achieved, which is forwarded when singling the bristles in the receiving opening 50, so to speak.

FIG. 5 also shows another variant of deflection channels. Here, a plurality of deflection channels 19 and a centrally located thereto, aligned in the ejection direction channel are combined within the guide plate 17, to unite to a common deflection channel 19 'with a common outlet 23. The outlet 23 has an elongate shape to form a common, plate-shaped tuft 16. The outlet 23 preferably has a cross-sectional area which corresponds to X times the receiving opening 50, where X corresponds to the number of tufts 12 fed to the common opening 14.

The cutting of the bristle tufts 16 preferably takes place in a separate station of the device according to the invention, preferably by means of a heated tool.

FIG. 6 shows an embodiment of such a heated tool 70, which comprises a current-carrying, hot wire. This wire is moved substantially parallel to the back of the base part 12, as close as possible to the base part 12 along and separates the protruding bristle ends. Bristles can also partly melt together.

FIG. 7 shows the effects of heat on not yet cut bristle tufts 16, which merge together. In addition, however, the already separated ends of remaining in the base part 12 bristle tufts 16 merge, which is advantageous for positioning and attachment.

While in the FIGS. 6 and 7 a substantially circular cross-section wire as a tool 70 is shown in the FIGS. 8a to 8c to see an alternative embodiment with a so-called flat wire. This also current-carrying, heated wire is placed like a knife obliquely to the bristles to be separated.

In the FIGS. 5 to 8 It can also be seen that the bristle tufts 16 are not laterally supported in the region of their interface. Also, the tool 70 is not supported in the region of the base part 12, so that no wear occurs during cutting. The cutting takes place, so to speak, without support.

The bristle tufts 16 are either laterally only through the base part 12 (see FIGS. 8a to 8c ) or held by the base part 12 and the guide member 26. If, during cutting, the guide plate 17 should still be present, this contributes to the support. If cutting instead of cutting with a heated tool, the guide plate 17 could also be designed as a counter knife. In the axial direction, the bristle tufts 16 are positioned between the pressure part 32 and the counter-pressure part 36. This positioning should, but not in a limiting sense, be ensured even during cutting.

In order to prevent the severed ends of the bristle tufts 16 from falling onto the base part 12, the cutting is preferably carried out over the head, that is to say with the back side downwards (see, for example, FIG FIG. 8 ). Thus, the severed ends 72 simply fall down.

The fastening of the bristle tufts 16 on the base part 12 takes place, as stated, either by welding and / or by gluing and / or by casting, for example during the production of the cover part 40. The cover part 40 can in particular rear projecting cleaning projections 80 have to form a tongue cleaner. Alternatively, the supplied cover part 40 can be subsequently pressed or glued, even using the aforementioned sacrificial structures.

Not all openings 14 must be closed by a bristle tufts 16. It may, as already mentioned, even one or the other opening 14 remain unfilled. When later gluing or potting or injection molding, the corresponding opening 14 is then closed.

In addition, it is also possible that some openings with an elastomeric profile member 82 are fitted, as exemplified in FIG. 6 is shown. The corresponding opening 14 in the base part 12 corresponds to this one-piece profile part, whose cross section is significantly larger than that of a bristle tufts 16. The profile part 82 can serve as a massage extension for gums or the like. The profile part 82 may either be prefabricated and then mounted in the opening or molded immediately in / at the opening.

In FIG. 9 a device for producing the brush according to the method described above is shown. This device is designed as a tool, for example with a rotating table 100. Preferably, outside of the tool table 100, each bristle tuft 16 is moved individually to the base part 12 (in this case the brush body 10) via the removal device 48 and the transport device 18, wherein previously the brush body 10 is placed on the guide member 26. A magazine with empty guide parts 26 may be present and is not shown here for clarity.

As already mentioned, in the feed station, each individual bristle tuft 16 is stuffed into the associated opening 14 by moving the laterally held guide part 26 in the X and Y directions.

The finished assembled base 12 is then moved to the tool table 100 and attached to this. The rotating tool table 100 transports one or more of the base parts 12 to a station in which Figure 1c Pressure and counterpressure 32, 36 align the tufts.

Thereafter, the tufts are cut off at the back by means of the tool 70. This cutting can take place in a subsequent station or in the station in which the pressure and counterpressure parts 32, 36 are applied for the first time.

Subsequently, the bristle tufts 16 are attached on the back, for example under the action of heat.

Finally, the lid part 40 is sprayed on. The finished brushes are removed and stacked, for example. The transport of the guide members 26 into the first station is not explicitly shown.

It should be emphasized in this context that instead of the base part 12 already formed on the brush body 10, it is also possible to use a plate-shaped base part which passes through all the stations before it is fastened to the brush body 10, for example by extrusion coating.

In the FIGS. 10 to 13 an injection molding tool is shown, which can be used as another station in a multi-station device for producing brushes.

The injection mold is in FIG. 10 illustrated stylized and includes a multi-part lower mold half 140 and an upper mold half 142, each having cavities, which merge into one another in the closed state of the tool and form a cavity to be ejected. The lower mold half 140 comprises at least two parts, namely a first mold part 144, which in the Figures 11 and 13 is shown in more detail, and a second mold part 146. The mold parts 140, 142 include a plurality of juxtaposed cavities 156th

The first molded part 144 has in the region of each cavity 146 an opening 148 which extends from the cavity 146 and which serves to receive the bristle tufts 16 of a base part 14. The edge 150, which is recessed and part of the cavity 146, surrounds the respective opening 148. This edge 150 serves as a support and support surface for the bristled base part 12. In addition to the edge 150, the cavity 146 also has a neck portion 152 as a transition between brush head and brush handle.

This neck portion 152 is how FIG. 10 shows, in the stem of the brush defining or receiving portion 156 of the cavity in the second mold part 146 via.

According to the preferred embodiment, only one opening 148 is provided for receiving all bristle tufts 16 of a base part 12. This makes the production of the first molding 144 particularly cost effective.

The opening 148 is designed either as a complete passage opening or as a blind hole. In any case, it must be ensured that the opening 148 is deep enough so that the front ends of the bristle tufts 16 do not protrude from the opening and abut an adjacent part such as the bottom of the recess 160 in the second mold part 146 or at the bottom of a blind hole-like opening 148 , The bristle tufts 16 thus project freely downwards.

The back not yet overmolded base parts 12 form according to the preferred embodiment of the head and stem of the brush. It is possible that in the head a bristled part is present, which is then encapsulated to form the stem. However, according to the preferred embodiment, the head and stem are integral, and the head has the openings 14 for receiving the bristle tufts 16.

For example, the bristled base part 12 with the method steps according to the FIGS. 1a to 1g and is released from the guide member 26 in a subsequent process step. The guide member 26 thus does not migrate together with the bristled base member 12 to the injection molding station.

Either the bristled base member 12 is then transported by machine or by hand to the first mold part 144 and inserted there into the openings 148, or there is provided an intermediate storage between Beborstungsstation and injection molding in which bristled base members 12 are stored.

After insertion into the injection-molded tool, the base part 12 lies in the cavities 146, 156. Subsequently, the upper mold half 142 is moved downwards in order to close the injection-molding tool.

In FIG. 12 the inserted base part 12 can be seen, wherein the base part 12 is cut off only in the neck area for the sake of simplicity.

In FIG. 12 are also the back together welded bristle tufts 16 shown. The base part 12 has the back of a trough-like depression, which is filled with closed injection molding tool by liquid plastic.

The injected plastic closes the brush head on the back. In addition, portions of, for example, the stem may be overmolded or molded with a second component in this or in another method step. Namely, as already explained, the base part 12 could consist only of the brush head or a part of the brush head, and the remaining partial areas would then be injection-molded in the injection molding tool

During spraying, the base part 12 is supported only at the edge of the opening 148. The bristle tufts 16 are not supported. This considerably simplifies the injection molding tool. According to the preferred embodiment - The base member 12 with its edge closed circumferentially on the likewise closed circumferential edge 150 of the opening 148, so that a sealing effect is achieved.

After opening the injection molding tool, the first mold part 144 is removed with the brush body the injection mold and either transported to another injection molding station or fed as a finished brushes a camp.

Since no perforated plates provided with bristled base parts 12 convey base members 12 from the bristle station to the injection molding station, these two stations or machines can operate decoupled from each other. Downtimes of one machine do not stop the other.

Alternatively, it would be according to FIG. 14 also possible to provide outgoing from a bottom of the opening 148 or from the second mold part 140 in the region of the recess 160 outwardly projecting into the opening in the direction of the base part 12 supporting extensions 170. The support extensions 170 are linear or, as shown, selective support points and preferably run conically towards the base part 12 in order to be able to slide between bristles. Also in this embodiment, however, there is no outgoing at the top 150, bridge-like support that extends between the bristle tufts 16 and the support is used.

As with all other embodiments, the opening 148 is sized so that all or at least several bristle tufts 16 protrude into the common or common opening.

In the embodiments of the toothbrush according to the invention according to the FIGS. 15 to 17 In addition to the bristle tufts 16, one or more soft-elastic elements 180 are also provided for cleaning the teeth and for massage of the gums on the brush head. However, these soft elastic protruding from the brush head elements 180 are not stuffed, but injected onto the base member 12, preferably before the plug. The one or more elements 180 extend forward next to the bristle tufts 16 and protrude from the base part 12.

These soft-elastic elements 180 may be positioned at the edge of the brush head and protrude or lie in the bristle field (see FIG. 15 ), ie be surrounded by bristle tufts 16.

The brush body 10 is produced as a multi-component injection-molded part, in which a component, alone or in sections, forms the flexible element or elements 180. In the embodiment of the FIGS. 15 and 16 extends the material of the element 180 into the handle, where it forms a soft, more secure handle back. In the connection area 182 of the handle and head, the soft material forms a larger portion and provides a kind of elastic joint.

The variant according to FIG. 17 does not have a one-piece transition of the soft-elastic element 180 with the handle or the connection region 182. The sections formed here from the TFE material therefore have to be sprayed via separate injection points.

In the embodiments of the FIGS. 15 to 17 The back of the head is not yet shown closed. Here after the plug still the head must be closed on its back, for example by injecting a further component or welding or gluing a lid.

The soft-elastic elements are in particular of thermoplastic elastomer (TPE).

The variant with the soft-elastic elements need not be limited to the manufacturing process and a device with the guide plate, such as FIG. 18 shows. It is also possible to manufacture these toothbrushes without the guide plate 17. In this case, the method is carried out without the guide plate 17 with Umlenkkanälen 19, in particular between the transport means 18 for supplying bristle tufts 16 and the openings in the base part 12, ie between the movable portion of the transport device 18 and the back of the base member 12, a guide-free gap 184 is present, over which the bristle tufts 16 are inserted without guidance in the base part 12.

The corresponding device according to the invention consequently does not provide a guide plate, but the other features mentioned previously and in the claims (individually or in combination).

Claims (15)

1. A method for making a brush (10) by means of an apparatus, characterized by the following steps:

   sequential removal of single bristle tufts (16) one after the other from a bristle stock (44) in which the bristles are accommodated packed in parallel,

   transporting the removed bristle tuft (16) by means of a transport device (18) to a base member forming a part of the finished brush, which has openings (14) for receiving individual bristle tufts (16),

   sequential thrusting of single bristle tufts (16) one after the other into the associated opening (14) from the rear side of the base member (12), wherein between the transport device (18) and the rear side of the base member (12) a guide plate (17) with deflection channels (19) is provided, through which bristle tufts (16) are thrust into the opening (14) in the base member (12) by means of a tappet (24), and

   anchor-free attachment of the bristle tufts (16) to the base member (12).
2. The method according to claim 1, characterized in that for sequential thrusting the base member (12) is moved in at least two directions, in order to align the opening (14) to be filled with the bristle tuft (16) to be thrust in.
3. The method according to claim 2, characterized in that the base member (12) is moved by using a freely programmable, at least dual-axis positioning device, in particular a freely programmable, preferably dual-axis industrial robot.
4. The method according to any of the preceding claims, characterized in that by means of a tuft pick-up the bristle tufts (16) are sequentially transported into the final position, from which they are axially thrust into the opening (14) to be filled.
5. The method according to any of the preceding claims, characterized in that during thrusting in the transport device (18) exclusively axial pressure is exerted on the bristle tuft (16).
6. The method according to any of the preceding claims, characterized in that on the front side of the base member (12) an apparatus-side guide member (26) with through holes (28) is positioned before thrusting in the bristle tufts (16), wherein via the openings (14) the bristle tufts (16) are put into the through holes (28) to such an extent that they preferably protrude out of the front side of the guide member (26).
7. The method according to any of the preceding claims, characterized in that for fixing the bristle tufts (16) the same are thermally fused and/or bonded on the rear side and/or the ends are embedded into an integrally molded plastic compound.
8. The method according to any of the preceding claims, characterized in that the bristle tufts (16) are fixed on the rear side without anchor, in particular by fusing and/or bonding such that the loaded base member (12) from a bristling station is inserted into a cavity of a mold half of an injection molding tool and with its edge rests on the edge (150) of an opening (148) proceeding from the associated cavity (146) and the bristle tufts (16) protrude into the opening (148), and that on the rear side a brush portion, which covers the bristle tufts (16), is injection-molded to the base member (12).
9. The method according to claim 8, characterized in that during injection molding the base member (12) remains unsupported in the region of the opening (148) or that punctiform or line-shaped support tabs (170) between bristles press against the base member (12) in the opening (148), in order to support said base member during injection molding and/or that during injection molding the base member (12) rests against the injection mold only with its edge and/or the frontside ends of the bristle tufts (16) are axially unsupported in the injection mold.
10. The method according to any of claims 7 to 9, characterized in that the base member (12) is transported from the bristling station to the injection molding tool without any support plates.
11. The method according to any of the preceding claims, characterized in that the guide plate (17) is put onto the rear side of the base member (12) and/or removed from the base member (12) before fixing the tufts (16) at the same.
12. An apparatus for making a brush, in particular by a method according to any of the preceding claims, comprising:

    a magazine (42) with a bristle stock (44) in which bristles are accommodated packed in parallel, and

    a removal device (48) for bristle tufts (16) for removing bristle tufts (16) from the bristle stock (44) laterally to their longitudinal extension,

    a transport device (18) for transporting the individual bristle tufts (16) to a stuffing station,

    characterized in that the removal device (48) is formed such that single bristle tufts (16) for a brush are sequentially removed from the bristle stock (44) one after the other,

    that a guide plate (17) between the transport device (18) and the rear side of the supplied base member (12) is provided with deflection channels (19) through which the bristle tufts (16) are thrust into the opening (14) in the base member (12), and

    a tappet (24) is provided, by which single bristle tufts (16) are sequentially thrust into the base member (12) one after the other from the rear side through the guide plate (17).
13. The apparatus according to claim 12, characterized in that the transport device (18) moves the tufts (16) along a linear or curve-shaped path to the stuffing station.
14. The apparatus according to any of claims 12 to 13, characterized in that an apparatus-side guide member (26) is provided which can be supplied to the front side of the base member (12) and passes through stations together with the base member (12).
15. The apparatus according to any of claims 12 to 14, characterized in that the deflection channels and the openings (14) extend obliquely and the tufts (16) are obliquely anchored in the base member (12) and/or several channels converging towards a common opening (14) in the base member (12) are provided and/or that at least one deflection channel (19) is provided, which receives several tufts (16), in order to combine them to a common tuft, wherein this deflection channel (19) preferably has several inlets (21) located one beside the other, from which the individual channels combine to form a common deflection channel (19') and/or that at least one deflection channel (19) has an inlet (21) whose geometry differs from that of the outlet (23) of the deflection channel (19).

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