Brush-tufting process

Abstract

A process for tufting a brush comprising a bristle carrier (10) provides that a thickening part (44) is received in a cluster of bristles (50) folded in a U-shaped form. The cluster of bristles (50) is pushed with its end thickened in this way into a hole (48). The peripheral edge (60) is then deformed to form an undercut, and the cross section of the hole (48) is reduced by at least 70% of the cross section of the thickening part (44). The thickening part (44) has the effect that the cluster of bristles (50) can no longer be pulled out of the hole (48). A brush-tufting device for carrying out the process is also described.

Description

[0001] METHOD FOR FILLING A BRUSH

[0002] The invention relates to a method and a device for stuffing a brush having a bristle carrier with at least one prefabricated hole and a bundle of bristles for each hole, wherein the or each hole has a wall defining the hole with an inner side and a peripheral edge enclosing the hole on a front side of the bristle carrier.

[0003] Brushes are stuffed in different ways.

[0004] The most conventional and widely used method of securing the bristle bundles in the corresponding hole uses a so-called anchor. The bristle bundle is folded into a U-shape, and the anchor is positioned at the inner end of the U. The anchor, along with the folded bristle bundle, is inserted into the hole via a stuffing tongue. The anchor cuts into the hole wall and anchors it there. This prevents the bundle from being pulled out.

[0005] Another method of stuffing involves heating all the bristles in a bundle, which remains unfolded, at one end and joining them together to form a drop. This thickened end is then anchored in the hole, for example, by reshaping the peripheral edge.

[0006] Finally, there is a variant in which a bundle of bristles is pushed through a through-hole in a plate or bristle carrier and protrudes slightly beyond the latter at the back. The protruding section is then melted, so that the bristles merge into one another at this point. The soft plastic is flattened by a stamp on the back of the plate or bristle carrier, so that the numerous bundles of bristles, which are melted on the back, form a kind of plate made of molten bristle material. This resulting unit is then overmolded on the back, for example. The object of the invention is to create a further manufacturing process that can be carried out very cost-effectively. Furthermore, a correspondingly operating device is to be created.

[0007] The invention provides for this purpose a method for stuffing a brush having a bristle carrier with at least one pre-made hole and a bundle of bristles for each hole, wherein the or each hole has a wall defining the hole with an inner side and a peripheral edge enclosing the hole on a front side of the bristle carrier, characterized by the following steps:

[0008] A bristle bundle is folded into a U-shape, and a thickening portion is inserted into the inner end section of the U, around which all the bristles of the associated bristle bundle extend. The bristle bundle, together with its thickening portion, is pushed into the hole so deeply that the thickening portion lies completely within the hole and is spaced from the peripheral edge in the insertion direction, wherein the thickening portion bridges immediately adjacent, opposite hole wall sections, and each thickening portion has a cross-section, viewed in the direction of insertion of the bristle bundle into the associated hole. After pushing at least one bristle bundle into its associated hole, the peripheral edge is plastically deformed by applying pressure by at least 70% of the cross-section of the thickening portion, so that in the area between the front side and the thickening portion, the hole is at least partially reduced in cross-section, and an undercut is created.to mechanically block the thickening part and the bristle bundle against pulling out.

[0009] Instead of an anchor that cuts into the wall of the hole, the invention provides a thickened part which alone does not provide sufficient resistance to pulling the bristle bundle out of the hole. However, the thickened part ensures that the bristle bundle is thicker in the fold area than without the thickened part. This means that the bristle bundle together with the thickened part can no longer be pulled out of the opening area of ​​the hole, which has only been subsequently narrowed by plastic deformation. By plastically deforming the peripheral edge, the area below the front surface of the bristle carrier is also plastically deformed, so that the material of the bristle carrier bulges radially inward. The aforementioned cross-section of the thickened part is the largest cross-section in a plane perpendicular to the insertion direction.The opposing hole wall sections bridged by the thickened portion are the sections where opposite ends of the thickened portion are closest to the inside of the hole or touch the inside. This means that the thickened portion can contact the inside of the hole at one or both opposite ends, be spaced from it, or be slightly pressed into the hole wall. The thickened portion thus divides the hole into two chambers and prevents the displacement of a bristle half from one chamber to the other. Preferably, the cross-section of the peripheral edge is plastically reduced by at least 90% or even by at least the cross-section of the thickened portion.

[0010] The bundle is secured mechanically by deforming the peripheral edge, achieving bundle extraction forces of at least 15 N per bundle. The thickened section is therefore not welded to the wall. A major advantage of the method according to the invention is that the tamping force of the tamping tongue is significantly lower than with the previous tamping method using an anchor, in which the tamping tongues had to be replaced more frequently, which in turn led to device downtime. Furthermore, it is advantageous if the opening area of ​​the hole, i.e., the area below the peripheral edge, is narrowed, as this reduces the risk of contaminants entering the hole.A further significant advantage is that the requirements for the thickening part are significantly lower than for the anchor, which is usually made of metal and had to have correspondingly sharp edges in order to be able to cut into the wall.

[0011] The deformation after insertion of the bristle bundle at the peripheral edge can take place in the cold state, ie at room temperature, or alternatively by heating the peripheral edge after insertion of the bristle bundle.

[0012] Heating could be achieved by a heated tool, which causes the deformation. A particularly material-friendly option for forming the peripheral edge is the use of a sonotrode. This sonotrode rests against the peripheral edge and, through its movement, heats the bristle carrier in the peripheral edge area while simultaneously applying pressure.

[0013] A sonotrode can be used that runs completely around the bristle carrier in a ring or partially around the peripheral edge in the contact area. This allows the peripheral edge to be deformed in a closed ring, in segments, or in points.

[0014] The sonotrode can be slotted lengthwise and consist of several bowl-shaped sonotrode sections.

[0015] The sonotrode's advance movement can occur toward the tufting tool or together with it. It is possible for the bristle bundle to be already accommodated in the sonotrode during advance. Alternatively, the sonotrode is only advanced after the bristle bundle has been pushed into the hole, in order to at least partially surround the bristle bundle and deform the peripheral edge.

[0016] As an alternative to using a sonotrode, a punch can be used which deforms the bristle carrier in the area of ​​the peripheral edge with a single impact.

[0017] Preferably, the punch is at room temperature, meaning it is not heated when it is moved against the peripheral edge. This reduces the demands on the punch.

[0018] Preferably, the wall defining at least one hole should be at room temperature when inserting the bristle bundle, i.e., the bristle carrier or at least the wall defining the hole is not heated. This also reduces the energy required to manufacture the brush.

[0019] The thickened section is typically made of plastic, paper, or cardboard. This facilitates brush recycling, especially if the bristle carrier is also made of plastic. Paper or cardboard is less problematic when the plastic melts than the metal anchor used previously. Preferably, and this is particularly important for recycling, the thickened section is made of the same plastic as the brush body. If the bristle carrier is composed of different materials, i.e., different plastics, it is advantageous if the thickened section is made of the same plastic material as the wall surrounding the hole. This also contributes to an optimal recycling process.

[0020] The cross-section of the thickened portion, viewed in the direction of insertion of the bristle bundle into the associated hole, is preferably matched to the cross-section of the associated hole in such a way that the thickened portion leaves the wall of the associated hole unchanged during insertion, i.e., does not press into the wall at all. This reduces the force exerted by the stuffing tongue and its wear.

[0021] Alternatively or additionally, the thickening part can deform elastically, i.e. compress or bend.

[0022] To ensure that the thickened part does not cut into the wall of the hole, the thickened part has a maximum clear width seen in the axial direction of the hole, which, according to a variant of the invention, is smaller than the distance between the immediately adjacent, opposite hole wall sections. Furthermore, the maximum clear width must not be so small as to rule out the possibility of bristles being pulled out between the ends of the thickened part and the adjacent wall. Therefore, the maximum clear width should be less than the diameter of a bristle smaller than the distance between the immediately adjacent, opposite hole wall sections. In an example with a circular hole, this means that the minimum corresponds to the maximum clear width greater than the diameter of the hole minus the diameter of a bristle.

[0023] In the case of a non-circular hole, this refers accordingly to the sections of the hole wall that are opposite the furthest points of the thickened part (relative to the viewing direction in the axial direction).

[0024] Alternatively, the thickening part is pressed diagonally into the wall to elastically deform it and be slightly clamped in the hole, or the thickening part cuts slightly into the wall of the hole (more precisely, the thickening part lightly scratches the wall of the hole). Alternatively, or in addition, the thickening part can deform elastically, i.e., it can be compressed or bent.

[0025] The bundle pull-out forces required in the toothbrush industry are typically in the range of 20-25 N per bundle. These values ​​are at least achieved by the process according to the invention after forming the peripheral edge.

[0026] Even if the thickened section elastically presses or cuts slightly into the wall, sufficient pull-out forces cannot be achieved by this alone, but only pull-out forces of up to a maximum of 10 N, as tests have shown. However, these minimal holding forces are sufficient to prevent the thickened section from being pushed back axially slightly after it has been mechanically pressed into its lowest position and before deformation at the peripheral edge begins. After being elastically compressed, the bundle of multiple bristles tends to expand and take up more space axially and would therefore push the thickened section back slightly. This is prevented by the thickened section, ensuring that the position is optimal during the forming of the peripheral edge.For this reason, the thickened section is clamped in the hole exclusively by elastic deformation of the wall, and / or the thickened section is elastically deformed and clamped in such a way that, after being pushed into the hole to its maximum extent, the thickened section remains fixed in position against a restoring force exerted by the bristle bundle in the axial direction before the peripheral edge is reshaped, i.e., it is not pushed back. For a brush with multiple bristle bundles, the average pull-out force of the bristle bundles is a maximum of 10 N, i.e., all bristle bundles are pulled out, determining the pull-out force, and the average value is determined.

[0027] The length of the thickened part is preferably a maximum of 0.2 mm larger than the clear width of the undeformed hole at the later contact points of the thickened part in order to achieve the desired light press fit.

[0028] Narrowing the hole in the area of ​​the peripheral edge can advantageously even lead to the bristle bundles being radially compressed in this area, i.e., between the thickened portion and the peripheral edge, during plastic deformation. This creates a more tightly packed bristle bundle.

[0029] To further simplify and accelerate production, a strip can be fed into the stuffing device, from which individual thickened sections are cut off and then processed directly in the stuffing device. For example, this could be a wound plastic strip from which individual, short sections are cut off and then placed in the inner end section of the U.

[0030] It is possible for this separation to occur before the ribbon reaches the inner end section. Alternatively, the free end of the ribbon is first fed to the stuffing tool, already at the bristle bundle to be stuffed. When this free end of the ribbon is then in the area of ​​the end section, this end is severed, forming the thickened section. This facilitates handling of the thickened section.

[0031] The thickened part may have a length measured in the axial direction of the hole that corresponds to a maximum of half the maximum depth of the associated hole. In particular, this length should correspond to at least 20% of the maximum depth to prevent the thickened part from tilting.

[0032] The thickening part can also have a cuboid shape or a wedge shape for the same purpose.

[0033] The method according to the invention can be used to plug not only circular holes, but also holes with a different shape in the axial direction, e.g., a square shape, an elongated shape, or an oval shape. Typically, the thickened portion extends through the area of ​​the hole with the largest clear width in the axial direction.

[0034] The invention further provides a brush stuffing device for carrying out the method according to the invention, comprising a feeder for thickened parts and a stuffing tongue, as well as a tool for forming the peripheral edge. Optionally, the brush stuffing device can also include a tool for separating the thickened parts from a fed strip. This eliminates the need to handle the small, delicate thickened parts individually to be added to the bristle bundles. Further features and advantages of the invention will become apparent from the following description and the accompanying drawings, to which reference is made. In the drawings:

[0035] Figure 1 is a perspective view of a variant of the brush stuffing device according to the invention,

[0036] Figure 2 is a schematic sectional view through a bristle carrier with inserted bristle bundle, before the plastic deformation of the peripheral edge,

[0037] Figure 3 is a schematic sectional view through the bristle carrier during the forming of the peripheral edge,

[0038] Figure 4 is a sectional view through a bristle carrier with two different sized thickening parts, and

[0039] Figure 5 is an axial view of an already filled hole in the bristle carrier before the peripheral edge is formed.

[0040] Figure 1 shows a brush stuffing device which inserts bristle bundles into holes in a bristle carrier 10.

[0041] The bristle carrier 10 can be the complete brush body or just a part of the brush body, e.g. a plate or the like.

[0042] The brush stuffing device comprises a tool tip 12, a bristle magazine 14, a bundle remover 16 pivotable about an axis X, and a stuffing tongue 18.

[0043] A feeder 20 feeds a belt 22 in the direction of arrow A laterally and at right angles to the stuffing direction of the tool tip 12.

[0044] The tape 22 is unwound from a roll, for example, and fed to the tool tip via an electric drive 24.

[0045] The movement of the tool tip 12 can, for example, be linear in the direction of arrow B, along a circular path or another curved path.

[0046] By way of example only and not as a limitation, in the illustrated embodiment the tool tip 12 is seated on a shaft 26 and can be pivoted back and forth about an axis D, from a stuffing position (front dead center) shown in Figure 1 to an opposite so-called bundle receiving position, which represents the rear dead center of the tool tip 12.

[0047] In the illustrated, non-limiting embodiment, the tool tip 12 sits on a connecting arm 28 to the shaft 26.

[0048] The stuffing tongue 18 is hinged at its rear end to a connecting arm 30, which is also pivotable about the axis D. Cam rollers 32 allow the control of the connecting arms 28, 30.

[0049] The movement of the stuffing tongue 18 is not identical to the movement of the tool tip 12, but rather the stuffing tongue 18 precedes the movement of the tool tip 12 when moving between the stuffing position and the bundle receiving position.

[0050] The tool tip 12 has a front part 34 that can contact the bristle carrier or be moved very close to its surface. The front part 34 is attached at its rear end to a so-called intermediate section 36 and can also merge into it as a single piece.

[0051] The front part 34 and the intermediate section 36 have a guide track 38 for the stuffing tongue in their interior.

[0052] From the top side 40 there is a feed channel 42 for the belt 22, which extends to the guide track 38 but ends there.

[0053] A processing unit 46 is used to cut short pieces from the strip, forming so-called thickened sections 44. These can be seen in the following figures.

[0054] Individual bristle bundles are inserted between the front part 34 and the intermediate section 36 through an insertion opening 53 into the guide track 38 and then stand in front of the band or the already cut-off thickened part 44, behind which, in turn, lies the front end of the stuffing tongue 18. The stuffing tongue 18 then presses the thickened part 44 against the bristle bundle, folding the bristle bundle into a U-shape as it pushes the bristle bundle into the guide track 38. Figure 2 shows a schematic view of a hole 48 in the bristle carrier 10.

[0055] The hole 48 and the remaining holes are blind holes that extend from a front side of the bristle carrier 10. Figure 2 shows that the bristle bundle 50 is folded in a U-shape and that the U has an end section 52 where it rotates 180°, with the thickened portion 44 located in the inner end section, ie, on the inside of the U, in the region of the end section 52.

[0056] The hole 48 is delimited by a circumferential wall 54 in the bristle carrier 10.

[0057] Figure 5 shows a sectional view through the hole 48, which in the present case is designed as a circular hole by way of example, but this is not absolutely necessary.

[0058] Bristles 58 are provided, each having a diameter f. The hole has an inner diameter D corresponding to its clear width.

[0059] The clear width W of the thickening part 44 is at most as large as the clear width D of the hole, but in particular smaller.

[0060] The clear width W of the thickened part 44 is preferably selected such that it is either not or slightly braced in the hole or cuts slightly into the wall 54. The minimum clear width W of the thickened part 44 in the longitudinal direction of the thickened part (seen in the axial direction) must, in the case of no bracing of the thickened part 44 in the hole, be greater than the diameter D minus the diameter f. This prevents a gap from forming between the wall 54 and the thickened part 44 through which a bristle 58 can be pulled out. Optionally, the thickened part 44 will elastically press / cut into the wall and / or elastically deform slightly.

[0061] The thickening part 44, for example, has an excess of a maximum of 0.2 mm compared to the clear width, which is sufficient to hold the bristle bundle 50 exactly in the lowest position into which it has been inserted.

[0062] Bundle extraction forces of a maximum of 10 N per bundle are achieved by the thickening part 44 before the peripheral wall is formed. Preferably, the thickening part 44 should provide a bundle extraction force of at least 4 N. For a brush with multiple bristle bundles, the average extraction force of the bristle bundles is a maximum of 10 N and a minimum of 4 N, i.e., all bristle bundles are extracted, determining the extraction force, and the average value is determined.

[0063] For circular holes 48, the clear width of the hole 48 is the diameter. For example, in an oval hole, the clear width is defined by the distance between the opposing hole wall sections 61, which are directly opposite the thickened portion 44 in the area of ​​its maximum clear width. In other words, the smallest gap between the thickened portion 44 and the wall 54 is provided there. The thickened portion 44 bridges the opposing hole wall sections 61.

[0064] The aforementioned dimensions mean that the thickened part 44 leaves the wall 54 unchanged when the bristle bundle 50 is pushed in, or the thickened part 44 is pressed minimally into the wall 54 but does not cut into it. In other words: the thickened part 44 has an elongated cross-section when viewed in the direction in which the bristle bundle 50 is inserted into the hole 48 (the insertion direction corresponds to the axial direction of the hole 48 in the illustrated embodiment). The clear width W of the thickened part 44 is a maximum of 0.2 mm larger than the clear width D of this hole 48, specifically in that area of ​​the hole 48 in which the thickened part 44 is also received. In Figure 5, this area is a vertically running volume strip that is laterally delimited by the outer surfaces (left and right) of the thickened part 44 and extends to the wall 54.

[0065] After the bristle bundle 50 has been pushed or pressed into the hole 48, the so-called peripheral edge 60, which represents the edge of the hole 48 on the front side 62 in the region of the mouth of the hole 48, is subjected to pressure.

[0066] At this point, i.e., during the stuffing process, the bristle carrier 10 is at room temperature, so that the wall 54 and the peripheral edge 60 are not above room temperature and have not been heated. The thickening part 44 provides the bristle bundle 50 with a thickening 64 at its end located in the hole 48, compared to the section of the bristle bundle 50 located outside the hole 48.

[0067] This thickening 64 is used to fix the bristle bundle 50 in the hole 48 by plastically deforming the bristle carrier 10 in the region of the peripheral edge 60.

[0068] For this purpose, a forming tool 66 is provided, which can be a separate tool or can also be formed by the tool tip 12.

[0069] The forming tool 66 can, for example, deform the peripheral edge 60 and the material beneath it by a single impact such that this material of the bristle carrier 10 plastically expands inward to narrow the hole 48 in the region of its opening, specifically by at least 70% of the cross-section of the thickened portion 44, preferably by at least 90% of the cross-section of the thickened portion 44, more preferably by at least the cross-section of the thickened portion 44. The constriction is designated by reference numeral 68 in Figure 3. The constriction 68 creates an undercut in which the thickened portion 64 can be located, but from which the bristle bundle 50 can no longer be withdrawn due to the thickened portion 44. A mechanical blocking occurs.

[0070] During this forming process, the bristle bundle 50 can optionally be radially compressed in the area between the thickened part 44 and the peripheral edge 60.

[0071] Preferably, the plastic deformation is carried out using the forming tool 66 with or without heating the peripheral edge 60. If the peripheral edge 60 is to be heated, the forming tool 66 can be heated at least in the region of its end face 70. Alternatively, and preferably, no such heating is provided; instead, the impact pulse is sufficient to plastically deform the bristle carrier in the region of the peripheral edge 60.

[0072] An alternative to such a singular impact impulse is a

[0073] Forming tool 66 in the form of a sonotrode 72, in which the end face 70 presses lightly against the peripheral edge 60 and vibrates in several axes or directions, whereby the plastic under the end face 70 heats up.

[0074] The bristle carrier 10 is, as mentioned, preferably made of a plastic.

[0075] The thickening part 44 is not made of metal, but of another material, in particular also of plastic, more precisely preferably even of the same plastic as the wall 54 and / or the bristles.

[0076] Alternatively, the thickening part 44 may be made of paper or cardboard, although this list is not exhaustive.

[0077] Figure 4 shows two thickening parts 44 whose cross-section, seen at right angles to the axial direction of the hole 48, is rectangular, so that the shape of the thickening part 44 is a cuboid.

[0078] Alternatively, the thickening part 44 can also have a wedge shape, with a thin or narrow end pointing toward the bottom of the hole 48. The thickening parts 44 have a length L in the axial direction that corresponds to a maximum of 50% of the maximum depth T of the hole 48.

[0079] In Figure 4, the upper hole 48 in the region of the peripheral edge 60 is already plastically deformed and narrowed, but the lower hole 48 is not yet.

[0080] In general, the wall 54 of the non-plastically deformed hole, or more precisely, the part of the wall that forms the peripheral wall, should initially be cylindrical. This facilitates the insertion of the unit consisting of the bristle bundle 50 and the thickening part 44.

[0081] The brush stuffing device shown in Figure 1 also comprises the forming tools 66 shown in Figure 3 with a ram or a sonotrode 72 and, in addition, in the processing unit 46, a tool 80 for separating the thickened parts 44 from the strip 22.

[0082] In the embodiment shown, this tool 80 is a cutting blade moved by a drive, which is moved back and forth.

Claims

Patent claims 1. A method for stuffing a brush having a bristle carrier (10) with at least one pre-made hole (48) and a bundle of bristles for each hole (48), wherein the or each hole (48) has a wall defining the hole (48) with an inner side and a peripheral edge surrounding the hole (48) on a front side of the bristle carrier (10), characterized by the following steps: A bristle bundle (50) is folded in a U-shape and a thickening part (44) is introduced into the inner end section of the U, around which all the bristles of the associated bristle bundle (50) extend. The bristle bundle (50) is pushed together with its thickening part (44) into the hole (48) so deeply that the thickening part (44) lies completely in the hole (48) and is spaced from the peripheral edge in the insertion direction, wherein the thickening part (44) bridges immediately adjacent, opposite hole wall sections (61) and each thickening part (44) has a cross-section in the direction of insertion of the bristle bundle (50) into the associated hole (48). After the at least one bristle bundle (50) has been pushed into its associated hole (48), the peripheral edge (60) is plastically compressed by applying pressure by at least 70% of the cross-section of the thickening part. (44) deformed,so that in the area between the front side and the thickening part (44), the hole (48) is reduced in cross-section at least in sections and an undercut is created in order to mechanically block the thickening part (44) and the bristle bundle (50) against being pulled out.

2. Method according to claim 1, characterized in that the plastic deformation also takes place while heating the peripheral edge (60).

3. Method according to claim 2, characterized in that a sonotrode (72) is used for forming, which sonotrode rests on the peripheral edge (60) and heats the bristle carrier (10) in this area and applies pressure to it.

4. Method according to one of the preceding claims, characterized in that a stamp is used for forming, which deforms the peripheral edge (60) with a singular impact.

5. Method according to claim 4, characterized in that the punch is at room temperature when it is moved against the peripheral edge (60).

6. Method according to one of the preceding claims, characterized in that the wall (54) delimiting the at least one hole (48) is at room temperature when the bristle bundle (50) is inserted.

7. Method according to one of the preceding claims, characterized in that the thickening part (44) consists of plastic, paper or cardboard.

8. Method according to one of the preceding claims, characterized in that the thickening part (44) consists of the same plastic material as the bristle carrier (10) or the bristles.

9. Method according to one of the preceding claims, characterized in that the cross section of the thickening part (44), seen in the direction of an insertion direction of the bristle bundle (50) into the associated hole (48), is matched to the cross section of the associated hole (48) in such a way that a) the thickening part (44) leaves the wall (54) of the associated hole (48) unchanged when pushed in or b) the thickening part (44) is clamped in the hole exclusively under elastic deformation of the wall (54) or by cutting into the wall (54) and / or under elastic deformation of the thickening part, that the thickening part (44) after the maximum insertion into the hole against a restoring force applied by the bristle bundle (50) remains in a fixed position in the axial direction before the peripheral edge is deformed.

10. Method according to claim 9 according to variant a), wherein, viewed in the axial direction of the hole (48), the associated thickening part (44) has a maximum clear width (W) which is smaller or greater by a maximum of 0.2 mm than the distance between the immediately adjacent, opposite hole wall sections, wherein the maximum clear width (W) is smaller than the distance between the immediately adjacent, opposite hole wall sections (61) by less than the diameter (f) of a bristle (58).

11. Method according to one of the preceding claims, characterized in that the bristle bundle (50) together with the thickened part (44) is clamped in the hole after being pushed in and before the peripheral edge (60) is formed in such a way that the bristle bundle (50) is held in the hole with a maximum pull-out force of 10 N, wherein in a brush with several bristle bundles (50) the average pull-out force of the bristle bundles is a maximum of 10 N.

12. Method according to one of the preceding claims, characterized in that the bristle bundles (50) are radially compressed in the region between the thickened part (44) and the peripheral edge (60) during plastic deformation.

13. Method according to one of the preceding claims, characterized in that a strip (22) is fed to the stuffing device, from which individual thickened parts (44) are separated and processed in the stuffing device.

14. Method according to one of the preceding claims, characterized in that the thickening part (44) has a length (L), measured in the axial direction of the hole (48), which corresponds at most to half the maximum depth (T) of the associated hole (48).

15. Method according to one of the preceding claims, characterized in that the thickening part (44) has a cuboid shape or wedge shape.

16. Method according to one of the preceding claims, characterized in that the holes (48) have a shape deviating from a circle when viewed in the axial direction.

17. Brush stuffing device for carrying out the method according to one of the preceding claims, with a feed for thickened parts (44) and a stuffing tongue (18) as well as a tool (66) for forming the peripheral edge (60) and, preferably, a tool (80) for separating the thickened parts (44) from a fed strip (22).

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