EP0346646B1 - Method and apparatus for manufacturing brush ware - Google Patents

Description

The invention relates to a method for producing bristle goods according to the preamble of claim 1 and a device according to the preamble of claim 9 for performing the method.

A variety of bristle products, particularly those commonly used in personal care, e.g. Toothbrushes, fine hand brushes, cosmetic brushes or the like, and those which serve for the fine application of media, such as brushes or the like, have special requirements for the quality of the bristles and the bristle stocking. For example, the free ends of the bristles on the use side should not have any sharp edges, fissures or the like, since these lead to skin injuries - in the case of toothbrushes in particular to mucous membrane injuries - or to an uneven application. In addition, bristles with a sharp-edged and irregular end of use wear out, break out, etc. For this reason, the ends of the bristles on the use side should be rounded so that they ideally form a spherical surface. The need to round the bristle ends and the problems encountered are fully described, for example, in US-A-2,227,126.

With many bristle products, it is also desirable to contour the envelope surface of the bristle ends in order either to achieve locally targeted cleaning action, as is the case, for example, with toothbrushes, or to achieve a flat application when the device is moved back and forth, for which shaving brush is an example , Paintbrushes or the like. It is either important to give the free end of a bristle bundle a certain contour, or else to contour all the bristles of a bristle stock. With certain brushes it may be desirable to contour both the individual bristle bundle and the entire bristle stock. The problem of contouring is also described in detail, for example, in US Pat. No. 2,227,126.

The rounding of the ends of the bristles on the usage side is generally carried out to date by a type of grinding process on the finished brush (US Pat. No. 2,227,126), the grinding tool and / or the bristles being guided in such a way that all the bristles of a bundle or of an entire bristle stock is recorded and rounded evenly. In the known case, this is done by multi-stage grinding with shape grinding tools of different contours. Likewise, the individual bristle bundles of the entire bristle stock are contoured by means of complex shaping tools and a no less complex guidance of the brush. Instead of using shape grinding tools, a round or conical grinding tool is also known for rounding the bristle ends, which moves over the bristle stock in different directions of movement, possibly also with a wobble movement. A uniform rounding of the bristle ends can only be achieved in this way if the bristle ends are aligned exactly in one plane and also all bristles are aligned parallel to one another. The first requirement is attempted to be met by trimming the free-standing ends of the bristles attached to the bristle holder with rotating knives. However, there are also differences in length and there are also bevel cuts. A parallel position of all bristles cannot be achieved in many cases, because for technical reasons, e.g. V-shaped, bristles are desired. Both circumstances lead to the fact that the bristles do not have rotationally symmetrically shaped ends, but rather flat cuts, bevel cuts or the like.

For contouring and rounding bristles, e.g. on toothbrushes, it is also known (EP-A-0 078 569) to mechanically process the free bristle ends using cutting tools, the bristles not to be processed being bent out of the orbit of the cutting tool. This process is complex and only enables the production of simple, concave contours with bristles longer in the outer row than in the inner area.

A thermal method is also known for rounding the ends of the bristles on the usage side and for contouring individual bundles or the entire bristle stock (US Pat. No. 2,426,328). The individual bristles are melted and rounded at their ends by touching a heating surface. However, in the case of plastic bristles, thickening occurs, which are often undesirable. These thickenings are to be removed by the known method, but again no perfect, spherical bristle end can be obtained. In the same way, individual bristle bundles are to be contoured in that they are pushed onto appropriately contoured, heated tools. Here too, the creation of a defined contour is largely left to chance and, above all, the problem of the formation of thickenings etc. is not solved.

None of the known methods for rotationally symmetrical machining, in particular for rounding the bristle ends, leads to a satisfactory quality. This has been done on the electron microscopic examinations the most widely used toothbrushes on the market ("Zahnärztliche Mitteilungen" 1987, number 16 pages 1740 to 1745; "Quintessence International" 1988, number 2 pages 87 to 107).

The mere contouring of individual bristle bundles has proven to be necessary at a very early stage of brush technology for shaving brushes and paintbrushes. In a known process technology (US-A-392 420, 1 923 884), the bristle bundle is pushed with its fastening-side end in advance onto a shaped surface, the contour of which corresponds to the desired contour at the end on the usage side. The latter contour arises from the fact that the bristles within the bundle move axially relative to one another in accordance with the contour of the shaped surface. In a similar method, the bristle bundle is pushed with its end on the usage side into a negative shape corresponding to the desired contour (US Pat. No. 764,898, 2,664,316). The bristle bundle contoured at the end on the use side is then connected to the bristle carrier at the opposite end, which can be done by adhesive bonding (US Pat. No. 764,898) or by thermal melting of the bristle ends (US Pat. No. 2,664,316). In the latter case, a largely mechanized process sequence is possible in that the bristle bundle is inserted into a guide channel which is closed at its end by a negative shape corresponding to the desired contour. The bristle bundle, which is tightly guided in the guide channel, is pushed into the negative shape with a piston, the effective piston surface of which in turn has the positive shape of the later contouring. A similar procedure is also known for a toothbrush (US-A-2 488 873), in which, however, a bundle with the attachment-side ends ahead of a positive shape by means of a piston with a corresponding negative shape, which engages the use-side end of the bristles , is postponed. In a similar method (EP-A-0 142 885), all the bristles of a bristle stock that are located in the channels of a guide device are pushed through with a push plate acting on their use-side end, which has negative contours for each guide channel on its top contoured axial displacement. Here, however, the exactness of the contouring depends very significantly and uncontrollably on the frictional forces within the guide channel and between the bristles.

The invention is directed to the production of bristle goods in which both the bristles are rounded at their end on the use side and also all bristle ends lie on an envelope surface deviating from a flat plane, which means either the envelope surface of individual bristle bundles and / or the envelope surface of an entire bristle stock . For the combined rounding and contouring, either only complex shape grinding processes (US Pat. No. 2,227,126) or thermal processes (US Pat. No. 2,426,328) are known.

The invention has for its object to enable a perfect rounding of the bristle ends with consistent and reproducible quality and to contour individual bristle bundles or the entire bristle stock, in which the bristle ends are rounded.

Based on the method according to the preamble of claim 1 (US-A-2 227 126), the object according to the invention is achieved in terms of process technology in that the bristles are clamped with their ends on the use side lying in a plane at a distance from these ends and on their ends on the usage side are rounded off by mechanical or chemical processing, then released from the clamping, then axially displaced relative to one another and finally fastened to the bristle carrier with the opposite ends.

In a departure from most known methods, the ends of the bristles on the use side are processed in the invention before they are attached to the bristle carrier in order to achieve a rotationally symmetrical design of the bristle ends. This eliminates all quality-reducing influences that result from a previous attachment of the bristles to the bristle carrier due to manufacturing tolerances (bristle length) and bristle position.

In the method according to the invention, the bristles, which can be processed in the form of short cuts or from the endless strand, are provided in such a way that their ends on the use side are located on a flat envelope surface. In this state, the bristles are clamped at a distance from their end on the use side and then rounded at these ends. This can be done in a conventional manner by grinding, but also by chemical etching processes or the like. Due to the fact that all bristles lie in one plane, the ends on the usage side can be rounded perfectly and evenly.

The bristles machined at their ends on the usage side are then released from the clamping and axially displaced relative to one another in order to produce any contour at the ends on the usage side. The bristles are only attached to the bristle carrier after rounding and contouring.

Of particular importance in the method according to the invention is the fact that the bristle ends lie on a flat envelope surface before processing. This can be achieved that the bristles with these ends are butted on a flat surface, but preferably it is provided that the bristles are cut flat after the clamping at a distance from the clamping to form the ends on the use side and then processed at these ends. This ensures that absolutely identical processing conditions are present for each individual bristle.

The bristles can be contoured after they have been released from the clamping, for example by axially displacing them against a negative shape with the desired contour. The bristles can then be attached to the bristle carrier at their opposite ends using one of the known technologies. In this method, the quality of the rounded ends is completely preserved during contouring, so that a contoured bristle trim, possibly also only contoured individual bundles, or a combined contouring of bundles and bristle trim in any shape of the usable area is achieved.

Thus, according to a variant of the method according to the invention, it can in particular be provided that all the bristles forming the bristle stock of a bristle article are clamped at a distance from their ends on a plane, use-side ends, their use-side ends are mechanically or chemically processed, then released from the clamping and then countered the negative shape is contoured.

In this way, the entire bristle fillet can be rounded in one operation and then contoured and then by one of the known methods, for. B. welding, joining, gluing, injection or foaming, attach to the bristle carrier.

In the event that the bristle product to be produced consists of a plurality of bristles combined into multifilament groups, e.g. B. bundles, strips or packages, it can be provided according to a preferred embodiment that the groups of bristles are individually or in groups with their ends on the usage side against the negative shape contoured after processing the usage ends and releasing from the clamping.

In this way, one or more bundles, strips or packets can have a greater length or height within a bristle trim. It is also possible to combine round bristle bundles with narrow bristle strips or with bristle packs within a stock and to contour them differently, so that a multitude of cleaning options are possible and an optimal adaptation to a specific cleaning task is possible.

The method according to the invention can be carried out both in the case of so-called short cuts, that is to say bristles, brushes or the like cut to the length of use, and also when processing from the endless strand. In the latter type of processing, the endless strand is fed to the processing station in cycles in accordance with the bristle length to be processed in each cycle. In this way of processing, the method according to the invention can be transferred in a particularly advantageous manner in that the bristles are clamped at the leading end of the endless strand, cut off at a distance from this end from the endless strand to form the ends on the use side, mechanically or chemically processed at these ends, after loosening contoured against the negative form against the feed device of the endless strand, clamped at a distance from the opposite ends and cut to form the ends on the fastening side.

A short cut is thus formed from the endless strand in the usual way, the leading end forming the fastening-side ends of the bristles or bundles, while the end resulting from the processing station by cutting forms the ends on the usage side. These are then rounded mechanically or chemically and contoured against the negative shape by moving against the feed direction of the endless strand. Because of the contouring, the attachment-side ends are on an envelope surface that deviates from a flat plane, so that the bristles at these ends are advantageously cut back into a common plane in order to then attach them to the bristle carrier in a conventional manner.

In this case, the procedure is preferably such that the bristles or bristle units are released from the clamping at the fastening-side ends after being cut, are moved with these ends beforehand into a position in which they are fastened to the bristle carrier, and are clamped again.

Through the aforementioned measure, a uniform overlap for all bristles is achieved at the fastening-side ends, the clamping also being effective during the fastening phase, so that this clamping fulfills a diverse task, namely, on the one hand, fixing the bristles when cutting the endless strand, during subsequent dressing or rounding the ends on the usage side, when cutting the bristles on the ends on the fastening side and finally during the fastening phase.

To achieve the object in terms of device technology, the invention is based on a device according to the preamble of claim 1 (U.S.-A-2,227,126). In this known device, the holder takes up the bristle carrier with the bristles and the ends of the bristles are guided over grinding tools.

Instead, a device designed according to the invention is characterized in that a clamping device is provided, by means of which the bristles can be clamped individually or in groups at a distance from their ends on one side on the processing side at the processing point and initially in operative position with the processing device and after releasing the Clamping device and axial displacement of the bristles against each other can be brought into an active position with the fastening device.

In a preferred embodiment it is provided that the clamping device is at a distance assigned a cutting device by means of which the bristles can be cut flat to form the ends on the use side.

Another known device which is suitable for contouring the bristles (US-A-2 488 873, 2 664 316) consists of a device which closely guides the bristles in a channel, a device which is displaceable in the channel, on the fastening-side end of the bristles acting piston, a negative shape associated with the guide device, corresponding to the contour of the bristles at their usage ends, into which the bristles are displaced by means of the piston, and a device for fastening the bristles to the bristle carrier after the piston has been withdrawn.

This device is adapted to the invention in that after machining and releasing the clamping device, the piston can be moved into the channel in order to move the bristles against the negative shape.

If the bristle stock consists of a plurality of bristle bundles, strips or packets, and if the latter are not contoured in themselves, but only the individual bristle groups, then each bristle group is assigned a piston with a flat thrust surface, the cross section of which - as well as the cross section of the Guide channel - corresponds to that of the bristle group. If, on the other hand, the bristle groups are to be contoured at the same time, the piston can have a correspondingly contoured thrust surface, e.g. similar to a reducing piston. It should also be pointed out that after rounding and contouring, the bristle groups can be attached to the bristle carrier not only in parallel position but also in any angular position. It is always guaranteed that the contour is maintained and that the bristle ends are evenly rounded within each contour.

The different protrusion of individual bristles or bristle groups within a bristle stock, which is generated by the displacement by means of the pistons, can be achieved either by different piston strokes or by all pistons being seated on a common carrier and correspondingly different in length.

If the bristles or bristle groups are processed from the endless strand and fed intermittently by means of a conveying device, the device according to the invention is designed such that, in alignment with the conveying device, the clamping device is arranged with a number of channels corresponding to the number of endless strands that after the leading ends have been introduced of the endless strands in the channels, the clamping device can be closed, and that a cutting device for cutting the bristles from the endless strand and for forming the bristle ends on the user side is arranged in the conveying direction in front of the clamping device, the device for rounding the ends on the user side being movable in front of them and the clamping device. It is particularly advantageous for optimum rounding that the simultaneous cutting of the individually clamped bristle strands in a flat plane achieves an exact flushness of the bristle ends in a flat envelope surface.

With this design of the device, bristles can be cut from the endless strand in cycles in a single work station and trimmed at their ends on the use side. Instead, the individual work steps, such as cutting and dressing and the subsequent work steps can also be carried out on a closed movement path with individual processing stations in order to obtain shorter cycle times.

According to a further advantageous embodiment, it is provided that the guide device in the feed direction of the bristles is arranged behind the clamping device and behind this a carrier with the pistons, and that a pushing device acting on the processed bristle ends is arranged in front of the clamping device, by means of which the bristles enter the channels of the guide device can be pushed in until the ends on the use side are flush with the end face of the clamping device near them.

With this design, it is ensured that the ends on the use side, after dressing, reach a common plane corresponding to the plane of the thrust device and, when the pistons are subsequently retracted, the bristles or bristle groups cover the exact paths for their contouring. This is possible, for example, if the negative shape is in front of the end face the clamping device can be moved and then the pistons on the carrier can be moved into the channels of the guide device.

Finally, it can be provided that a cutting device is arranged on the end face of the clamping device facing away from the negative form, which, after the guide device has moved away, cuts off the ends of the bristles projecting beyond this end face to form the ends on the fastening side. With the cutting device, the ends protruding due to the contouring are trimmed in such a way that the fastening-side ends that arise lie in a flat plane.

If the entire processing takes place at one station, the cutting device for cutting the bristles to length from the endless strand can simultaneously form the cutting device for cutting off the ends projecting beyond the end face of the clamping device.

In order to obtain a uniform overhang of all bristles or bristle groups necessary for the attachment at the attachment-side ends, it is preferably provided that the cut-off bristles can be displaced by means of the negative form with the clamping device open until they are in a plane plane lying attachment-side ends project beyond the face of the clamping device facing away from the negative shape with a length necessary for its attachment to the bristle holder.

The negative form thus also serves as a push element for moving the bristles into a fastening position. The contour previously given to the bristles remains exactly the same.

Finally, the clamping device can serve for axially securing the bristles during the fastening of the bristles to the bristle carrier, so that it fulfills a diverse function. If the individual work steps take place at different work stations, the clamping device is moved with the bristles and moves from work station to work station. In this way of working, a number of clamping devices corresponding to the number of work stations must then be present.

• Figur la - 1 i eine schematische Ansicht der für die Durchführung wesentlichen Bauteile einer Vorrichtung in den verschiedenen Stufen eines Verfahrens zur Herstellung einer Bürste;
• Figur 2a - 2e verschiedene Verfahrensstufen bei der Herstellung konturierter Borstengruppen, z. B. Borstenbündel;
• Figur 3 ein Ausführungsbeispiel in Form einer Zahnbürste im Schnitt und
• Figur 4 ein Ausführungsbeispiel einer Rundbürste im Schnitt.

The invention is described below using an exemplary embodiment shown in the drawing. The drawing shows:

• Figure la-1 i is a schematic view of the essential components for the implementation of a device in the various stages of a method for producing a brush;
• 2a-2e different process stages in the production of contoured bristle groups, for. B. bundles of bristles;
• Figure 3 shows an embodiment in the form of a toothbrush in section and
• Figure 4 shows an embodiment of a round brush in section.

In Figure 1 and Figure 1, the processing of the bristles from the endless strand is shown schematically. Here, three endless strands 1 are shown, which are fed from coils by means of a conveyor. This conveyor device includes two clamping devices 2 arranged one behind the other, which have guide channels 3 for the endless strands 1 and a slide 4 each, which narrows the cross-section of the channels 3 in a diaphragm-like manner and in this way fixes the endless strands 1. The first tensioning device 2 (shown on the right in the drawing) can optionally be moved back and forth in the conveying direction and advance the endless strands 1 cyclically by tensioning and then moving in the conveying direction with the second tensioning device 2 open at the same time. However, the pulling-off can also be carried out by means of a clamping device 5 arranged behind the second tensioning device 2, which likewise has a slide 6 which acts like an aperture and by means of which the channels 7 provided in the clamping device 5 can be narrowed. The last-mentioned embodiment is shown in FIGS. 1 and 1.

After insertion of the endless strands 1 into the channels 7 of the clamping device 5, the slide 6 is moved into the closed position, so that the endless strands 1 are clamped at their leading end. Then, as can be seen from the comparison of FIGS. 1 a and 1 b, the clamping device 5 is shifted to the left by approximately the necessary bristle length. A cutting device 8 then moves in front of the front end face 9 of the front tensioning device 2 and separates the individual bundles 10 from the endless strands 1. The ends 11 of the bundles 10 which later serve for fastening terminate approximately with the front end of the clamping device 5, while the ends 12 on the use side are free.

In the subsequent process stage according to FIG. 1, a conical grinding tool 13 is inserted in front of the ends 12 on the use side, which grinds over the ends on the use side in a translatory and a rotational movement. If necessary, a movement that is perpendicular to the plane of the drawing or a wobbling movement can also be superimposed.

After trimming the ends 12 of the bristle bundles 10 on the usage side, a guide device 14 is inserted in front of the clamping device 5 (FIG. 1 d), which is one of the channels 7 in FIG Clamping device has a corresponding number of aligned guide channels 15. Between the clamping device 5 and the guide device 14, a cutting plate 16 may also be inserted, the task of which will be explained later. By lifting the slide 6, the bristle bundles 10 are released in the clamping device 5. A pushing device 16 in the form of a plate then acts on the ends 12 of the bristle bundles 10 on the usage side, which pushes the bristle bundles 10 into the guide channels 15 of the guiding device 14 until they end flush with the ends 12 on the usage side with the rear end face 17 of the clamping device 5.

After the pushing device 16 has moved, a negative mold 18 is moved in front of the rear end face 17 of the clamping device 5 (FIG. 1e), which has a blind hole 19 for each bundle of bristles 10, the blind holes 19 with the channels 7 in the clamping device 5 and Channels 15 in the guide device 14 are aligned. The blind holes 19 have different depths. The bottom of the blind holes forms the later contour of the bristle bundle on the finished bristle product.

On the opposite side of the clamping device 5 and the guide device 14, a carrier 20 is arranged with a number of pistons 21 corresponding to the number of guide channels 15, which differ in length in the same way as the blind holes 19 in depth.

The carrier 20 with the pistons 21 is moved towards the guide device 14, so that the pistons 21 penetrate into the guide channels 15 and move the bristles 10 therein until they abut the bottom of the blind holes 19, so that the ends 12 on the use side Bristle bundles 10 lie in the desired contour, as shown in FIG. 1f.

Subsequently, the carrier 20 with the piston 21 and the guide device 14 are moved away (to the left in FIG. 1), so that the bristle bundles 10 with their opposite ends project beyond the clamping device 5 or the cutting plate 16 arranged in front thereof and by means of one in front of the cutting plate 16 guided cutting knife 22 are cut flush so that they lie in a common plane (Figure 1 h).

In order to determine the final length of the bristles or to be able to implement different bristle lengths, a spacer plate 23 can additionally be provided, which can be inserted between the clamping device 5 and the negative mold 18. For this purpose, the bristle bundles 10 are moved in the direction of their use-side end 12 when the clamping device 5 is open, in that when the clamping device 5 and the guide device 14 are fixed, the carrier 20 with the pistons 21 and the negative mold 18 are moved synchronously (to the right in FIG. 1). . This creates a gap between the clamping device 5 and the negative mold 18, into which the spacer plate 23 is inserted. This has recesses, for. B. slots or the like. On, which are penetrated by the bristle bundles 10. After the bristle bundles 10 are clamped again by means of the slide 6 in the clamping device 5, the cutting knife 22 is cut to length.

The spacer plate 23 between the clamping device 5 and the negative mold 19 is then extended (FIG. 1 h) and the negative mold 19 is moved in the direction of the clamping device 5 until it abuts against it, so that the bristle bundles 10 with their fastening-side ends 24 are over protrude the insert 16 with the same length (Figure 1 i). In this position, the ends 24 are connected to the bristle carrier in a manner which is no longer shown and is otherwise known.

In FIGS. 2a to 2e, a single bristle bundle 25 is shown on the basis of three individual bristles 26 lying in the plane of the drawing. The pre-cut bristles 26 (FIG. 2a), which are combined into a bundle 25, are first clamped and trimmed at their ends 27 by rounding (FIG. 2b). The individual bristles 26 are then contoured by moving them against a negative shape in a guide channel by means of a contoured piston, so that, for example, the middle bristle 26 or a larger number of bristles in the central region of the bundle 25 end 28 towering over other bristles (Figure 2c). The dashed line in FIG. 2c indicates the cut for producing the ends 29 on the fastening side and with 30, 31 the waste of different lengths that occurs when cutting to length.

After contouring, the position of the bristles 26 within the bundle 25 can be fixed in that the bristles 26 are melted to a thickening 32 at their fastening-side end (FIG. 2d). This thickening 29 can then be used in a subsequent work step for fastening within the bristle carrier 33, for example by injecting, foaming or inserting (FIG. 2e).

FIG. 3 shows the method according to the invention using a finished bristle article in the form of a toothbrush 34, the back 36 of which is integral with the handle 35 and made of plastic. It has bristle bundles 37 and 38 of different lengths, the ends 39 and 40 of which on the use side lie in a contoured envelope surface and which in turn are contoured. The bristle bundles 37 and 38 can - similar to that described in Figures 2d and 2e - by means of thickenings 41 and 42 in Back 36 of the toothbrush 34 must be anchored.

FIG. 4 shows a round brush 43, as is also used, for example, for dental care and is placed on a drive shaft (not shown) by means of an axial bearing 44. The round brush 43 has an outer bristle ring made up of bundles 45 which are convexly contoured at their ends 46 on the use side. Furthermore, the round brush 43 has an inner bristle ring made up of bundles 47 which are concavely contoured at their ends 48 on the use side.

All of the features illustrated in the description, the claims and the drawings can be essential to the invention both individually and in any combination with one another or in another sequence.

Claims (20)

1. Process for the production of bristle products from plastic with bristles whose utilization-side ends are rounded and which lie in a contour deviating from the bristle-side surface of a bristle carrier and are fastened with their opposite ends on said bristle carrier, characterized in that the bristles lying with the utilization-side ends in a plane are clamped at a distance from these ends, then rounded mechanically or chemically on their utilization-side ends, next loosened from the clamping and axially displaced and contoured and finally fastened with the opposite ends on the bristle carrier.

2. Process according to Claim 1, characterized in that the bristles after having been clamped are cut flat at a distance from the clamping for formation of the utilization-side end, and then worked on these ends.

3. Process according to Claim 1 or 2, characterized in that the bristle after rounding are loosened from the clamping and contoured by axially displacing against a negative form and finally fastened with the opposite ends on the bristle carrier.

4. Process according to one of Claims 1 to 3, characterized in that all of the bristles forming the bristle field of a bristle product are clamped at a distance from their utilization-side ends, lying in a plane, then their utilization-side ends are mechanically or chemically worked and then loosened from the clamping and afterward contoured against the negative form.

5. Process according to one of Claims 1 to 3 for the production of bristle products with a large number of bristles gathered into multifilament groups, e.g., bundles, strips or packets, characterized in that the groups of bristles, after working the utilization-side ends and loosening from the clamping, are contoured individually in groups with their utilization-side ends against the negative form.

6. Process according to one of Claims 1 to 5, characterized in that the bristles, with their utilization-side ends in advance, are pressed against the negative form by axial displacement.

7. Process according to one of Claims 1 to 6, wherein the bristles or bristle groups are processed from an endless strand supplied in cycles, characterized in that the bristles are clamped on the front-running end of the endless strand, cut off at a distance from this end of the endless strand, with formation of the utilization-side ends, worked mechanically or chemically on these ends, contoured against the negative form and counter to the supply device of the endless strand after loosening from the clamping, clamped at a distance from the opposite ends and cut at these ends, with formation of the fastening-side ends.

8. Process according to one of Claims 1 to 7, characterized in that the bristles or bristle units are loosened from the clamping after the cutting on the fastening-side ends, and, with these ends in advance, are moved into a position in which they are fastened on the bristle carrier and again clamped.

9. Apparatus for the production of bristle products from plastic with a bristle carrier and bristles fastened thereon whose utilization-side ends are rounded and are lying in a contour deviating from the fastening surface of the bristle carrier, with a holder positioning the bristles at a working station, a device capable of being brought to act on the utilization-side ends of the bristles for rounding these ends, and a device for fastening the opposite ends of the bristles to the bristle carrier, characterized in that a clamping device (5) is provided, by means of which the bristles (10), individually or in groups, can be clamped at the working station at a distance from their utilization-side ends (12) lying in a plane, and can be brought at first into a working position at the working device (13) and then to the fastening device, after axially displacing the bristles.

10. Apparatus according to Claim 9, characterized in that the clamping device (5) is arranged at a distance from a cutting device, by means of which the bristles can be cut in a plane for formation of the utilization-side ends.

11. Apparatus according to Claim 9 or 10 consisting of a device for guiding the bristles tightly in a canal, a piston capable of being displaced in the canal and acting on the fastening-side ends of the bristles, a negative form allocated to the guiding device and corresponding to the contour of the bristles on their utilization-side ends, in which the bristles are displaced by means of the piston, characterized in that after loosening the clamping device (5), the piston (21) can be driven into the canal (15), in order to displace the bristles (10) against the negative form (18).

12. Apparatus according to Claim 11, characterized in that the guiding device (14) has several guiding canals (15), each for a group (10) of bristles, e.g. bundles, strips or packets, a piston (21) is provided for each guiding canal (15), and the pistons have different lengths, corresponding to the different displacement paths of the bristle units (10) until they settle on the negative form (18).

13. Apparatus according to one of Claims 9 to 12 with a feed device supplying in cycles the bristles or bristle groups in the form of endless strands, characterized in that the clamping device (5), with a number of canals (7) corresponding to the number of endless strands (1) is located in alignment with the feed device, in that the clamping device (5) can be closed after feeding in the front-running ends (11) of the endless strands (1) into the canals, and in that, in the feed direction, before the clamping device (5) there is located a cutting device (8) for cutting to length the bristles (10) from the endless strand (1) and for formation of the utilization-side bristle ends (12).

14. Apparatus according to one of Claims 9 to 13, characterized in that the device (13) for working the utilization-side ends (12) can be displaced before these and the clamping device (5).

15. Apparatus according to one of Claims 9 to 14, characterized in that the guiding device (14) is located in the supply direction of the bristles (10) behind the clamping device (5) and behind this (5) is located a carrier (20) with the pistons (21), and in that, before the clamping device (5) is located a pushing device (16) acting on the worked bristle ends (12), and by means of which the bristles (20) can be displaced into the canals (15) of the guiding device (14) far enough until the utilization-side ends (12) are lying flush with the face (17) of the clamping device (5) near them.

16. Apparatus according to one of Claims 9 to 15, characterized in that the negative form (18) can be displaced before the face (17) of the clamping device (5) and then the pistons (21) on the carrier (20) can be displaced into the canals (15) of the guiding device (14).

17. Apparatus according to one of Claims 9 to 16, characterized in that, on the side of the clamping device (5) turned away from the negative form (18), there is located a cutting device (22), which, after moving away the guiding device (14), cuts the ends of the bristles (10) extending beyond this side, with formation of the fastening-side ends (24).

18. Apparatus according to one of Claims 9 to 17, characterized in that the cutting device (8) for cutting to length the bristles (10) of the endless strand (1) also forms the cutting device (22) for cutting off the ends extending beyond the front side of the clamping device (5).

19. Apparatus according to one of Claims 9 to 18, characterized in that the cut bristles (10), with the clamping device being opened, can be displaced in this device (5) by means of the negative form (18) far enough until their fastening-side ends (24), lying in a plane, extend beyond the front side of the clamping device (5) turned away from the negative form (18) with a length necessary for their fastening to the bristle carrier.

20. Apparatus according to one of Claims 9 to 19, characterized in that the clamping device (5) serves for axial securing of the bristles during the fastening of the bristles (10) on the bristle carrier.

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