EP1681959B1

EP1681959B1 - Method for manufacturing a brush lamel and a corresponding brush lamel

Info

Publication number: EP1681959B1
Application number: EP04791434A
Authority: EP
Inventors: Mauno Kirkkala
Original assignee: Sajakorpi Oy
Current assignee: Sajakorpi Oy
Priority date: 2003-10-13
Filing date: 2004-10-07
Publication date: 2009-08-12
Anticipated expiration: 2024-10-07
Also published as: RU2006116486A; RU2344736C2; DK1681959T3; DE602004022577D1; WO2005034678A1; EP1681959A1; ATE439062T1; ES2329139T3; FI20031485A0; PL1681959T3

Abstract

The invention relates to a method for manufacturing a tuft-type brush lamel (10). The brush lamel (10) is intended to be used in a sweeping machine, and is formed of separate brush tufts (13) formed from brush filaments (16), which are attached to a hub piece (11). The brush lamel (10) is manufactured using a moulding process, in which the brush filaments (16) and the moulding mass (30) are brought between mould halves (17.1, 17.2), which, when the mould halves (17.1, 17.2) are pressed together, the hub piece (11), to which the bristle tufts (13) are attached, is formed from the moulding mass (30), and which bristles tufts (13) are preferably formed when the mould halves (17.1, 17.2) are pressed together. In addition, the invention also relates to a brush lamel manufactured according to the method.

Description

The present invention relates to method for manufacturing a tuft-type brush lamel, which brush lamel is intended to be used in a sweeping machine, and which brush lamel is formed of separate bristle tufts formed from brush filaments, which are attached to a hub piece. In addition, the invention also relates to the brush lamel manufactured using the method.
Brush lamels according to the title are used, for example, in street-sweeping machines. In these machines, the lamels are set next to each other on a brush core, thus forming a unified brush that rotates around its longitudinal axis.
At least two different types of brush lamels are known from the prior art. The brush portion of the brush lamel is formed of plastic filaments or steel wires. The hub ring of the lamel, to which the brush portion is attached, can be either metal or plastic. There is also one or more protrusions on the inner circumference of the hub ring. The protrusion is generally aligned towards the centre point of the ring and one of its functions is to prevent the free rotation of the brush lamel around the brush core. The number of protrusions can, of course, vary. There can be one, two, or even several of them, depending, for example, on the machine manufacturer's brush-core model.
The state of the art in brush lamels, is represented by various 'zig-zag' model brush lamels. In these, the hub ring is bent at a few points to give it lateral wave shapes. As a result, the outer circumference of the continuous bristle portion is brought into an endless contact with the ground being swept over the entire length of the brush core, thus resulting in unbroken bristle contact with the surface being swept. However, in these wave-shaped models several rotation-prevention protrusions must be used. One of their functions is to align the outermost points of the bent wave-shaped centre pieces with next to the corresponding points in the adjacent lamels.
One brush-lamel manufacturing method representing the state of the art is disclosed in Finnish patent number 87977 . In it, both the hub ring of the lamel and the rotation-prevention protrusions are manufactured from plastic materials, as is the bristle portion. The same manufacturing method can also be applied to the manufacture of brush lamels according to Finnish patent 102350 . It is a kind of adaptation of the already previously established metal-hub 'zig-zag' model. In a metal-hub brush lamel, the hub ring is bent laterally following a rounded line, whereas in the brush lamel according to patent FI-102350 the hub ring is bent laterally following an angular line.
However, a drawback with the aforementioned brush lamel equipped with a laterally bent plastic hub ring is the poor ring rigidity. This appears, for instance, in the bent hub ring of the brush lamel trying to straighten out, when it comes under severe sweeping stress. The internal diameter of the hub ring consequently increases, allowing the brush lamel to rotate on the brush core. The brush lamels set next to each others on the brush core loosen and the brush must be reassembled.
According to the prior art, the aforementioned brush lamels have the common feature that, when the brush rotates, the bristles of the outer circumference of the brush lamel form an unbroken contact, in the direction of the circumference of the lamel, with the ground being swept. However, it has been observed that a uniform and essentially continuous contact with the ground being swept does not give the best possible sweeping result. Instead, tuft-type brush lamels or brush strips that are straight or that are set spirally and installed parallel to the longitudinal axis of the brush core and over the entire length of the brush core, they detatch dirt better when they impact the ground being swept.
Very many manufacturers of sweeping machines use brush strips. Tuft-type brush strips are used, for instance, in airport runway cleaning. In these lamels, the bristle filament is folded in two and attached to elastic, either plastic or rubber, collars. The bristle tufts thus formed are pressed into a metal hub ring with the aid of steel wire threaded through the collar component. As a manufacturing and structural solution they are, however, quite expensive.
On the other hand, the sweeping effect of brush lamels has also been further improved by cutting off the bristle filaments, which are attached radially to the outer circumference of the hub ring, close to the outer circumference of the hub ring, thus breaking the continuous brushing contact with the ground being swept. As the state of the art, reference is made in the case of a tuft-type brush lamel to US patent 3,274,634 (L. R. Godfrey ). It applies the mechanical attachment of tuft-type bristles to the hub ring. However, it is quite slow and cost-intensive to manufacture tuft-type brush lamels separately from each other in this way, which limits their use in sweeping machines.
The present invention is intended to achieve an improvement to the aforementioned problems. The characteristic features of the brush-lamel manufacturing method according to the invention are stated in Claim 1. In addition, the invention also relates to a corresponding brush lamel, the characteristic features of which are stated in Claim 6.
The brush-lamel manufacturing method according to the invention and, at the same time, also the brush lamel including separate bristle tufts are characterized by the fact that its manufacture takes place surprisingly using a moulding process in which

a brush preform is formed from the brush filaments joined-together using a moulding mass,
formed brush preform is brought between mould halves, and
when the mould halves are pressed together, the hub piece, to which the bristle tufts are attached, is formed from the moulding mass, and the brush preform is sheared into the said separate bristle tufts in the circumferential direction.

According to one embodiment of the invention, the formation of the separate brush tufts can take place surprisingly as late as the moulding process. In it, tuft-like bristle bunches, which are separate from each other, are sheared from a unified bristle preform strip, when the mould halves are pressed together during moulding. As a first advantage, this achieves the rapid production of brush lamels while as a second advantage it achieves the precise radial positioning of the bristles around the hub piece.
According to one embodiment, the bristle tufts are placed at a set angle, relative to the circumference of the hub piece, when the mould halves are pressed together. This achieves a continuous contact with the ground being swept.
According to one embodiment, the protrusions for positioning the adjacent brush lamels on the brush core and preventing the free rotation of the brush lamel can, surprisingly, be formed as a unified structure during moulding. This simplifies the construction and manufacture of the brush lamel.
In addition, a brush lamel with a structure according to the invention has good annular rigidity, while its tuft-like bristle bundles give a good sweeping result. The good annular rigidity is, for its part, achieved using an axially straight hub ring, which is surprisingly not bent into the lateral wave shape that characterizes, for example, zig-zag model brush lamel models that consequently achieve a comprehensive sweeping area.
Several different moulding processes can be applied in the invention. According to a first embodiment, extrusion moulding and compression moulding can be applied. In that case, the bristle tufts are sheared in connection with the compression moulding. According to a second embodiment, injection moulding, in which the shearing of the tufts takes place, can also be applied.
The invention, which is not restricted to the embodiments described in the following, is examined in greater detail with reference to the accompanying drawings, in which

Figure 1: shows a first example of a brush lamel according to the invention, and a cross- section of it,
Figure 2: shows cross-sections of examples of the positioning of the bristle tufts on the outer circumference of the hub ring, rela- tive to its circumferential direction, seen from the direction of the bristle fila- ments,
Figure 3: shows a second example of a brush lamel according to the invention, cut into a sector piece,
Figure 4: shows the brush lamel of Figure 3 in greater detail, seen from the roots of the brush tufts,
Figure 5a: shows a first example of a brush preform formed from brush filaments, when applying injection moulding,
Figures 5b and 5c: show a second example of a brush preform formed from brush filaments, when applying extrusion and compression moulding,
Figure 6: shows an example of the mould halves used in the manufacturing method according to the invention, and
Figure 7: shows a schematic cross-section of the lower mould half of Figure 6, when manufac- turing a brush lamel according to the invention.

Figure 1 shows a first example of the brush lamel according to the invention, and a cross-section of it. Several such individual brush lamels 10 can be installed next to each other on a brush core to be installed in a sweeping machine. They are thus used to principally cover the entire length of the brush core and create an impacting brushing effect acting over the entire area being swept. When the brush core is rotated by the power source of the sweeping machine, the brush lamels 10 will rotate along with the core, around its longitudinal axis. It should be noted that the invention relates not only to the brush lamel 10 that is the subject of the invention, and its manufacturing method, but also to the use of a brush lamel 10, manufactured according to the method, together with several corresponding brush lamels 10, to make a brush core to be installed in a sweeping machine and consequently also such a sweeping machine to be attached, for example, to a work machine, in which sweeping machine the brush core including such brush lamels 10 can be installed and, if necessary, replaced.
The tuft-like brush lamel 10 according to the invention, shown in Figure 1, is formed of an annular hub-ring component, more generally of a hub piece 11, which is preferably straight when seen from the direction of the bristle filaments 16, and of separate tuft-like bristle bundles 13, formed of bristle filaments 16, attached to it.
On the inner circumference of the hub-ring component 11, there is the number of protrusions 12 required by each brush-core type for preventing the rotation of the brush lamel 10. The location and number of the protrusions 12 on the inner circumference of the hub ring 11 is determined, for example, by the type of the brush core, and it can, of course, vary. The protrusions 12 are used to lock the brush lamel 10 to the brush core, so that they will rotate at the same pace. The protrusions 12 prevent the free rotation of the brush lamel 10, relative to the brush core. According to one embodiment, the protrusions 12 can be manufactured from the same plastic material as the hub ring 11, thus forming a unified structure with it.
In addition, there are protrusions 14 on either side of the hub ring 11, by means of which adjacent brush lamels 10 are correctly aligned on the brush core.
Separate brush tufts 13, formed of bristle filaments 16, are attached to the outer circumference of the hub-ring component 11. Because the brush lamel 10 according to the invention is manufactured surprisingly using a moulding process, for example, the injection moulding process, the base parts 15 of the brush tufts 13 formed of brush filaments 16 are, according to the invention, moulded together with the hub ring 11. The tufts 13 and the hub piece 11 are preferably formed during moulding, as depicted in greater detail later in the description. The number of brush tufts 13 on the circumference of the hub ring 11 can vary, for example, according to the nominal diameter of the wholly plastic brush lamel 10.
Figure 2 shows cross-sections of examples of the alignment of the bristle tufts 13 to the outer circumference of the hub ring 11, relative to the circumferential direction of an annular, straight hub ring 11, when seen from the longitudinal direction of the bristle filaments. Figure 2 shows that the bristle bunches 13 can be attached to the outer circumference of the hub ring 11 in very many different position. Seen from the direction of the bristle filaments 16, and starting from the left-hand side of the series of figures, they can be relative to the hub ring 11, in a straight line parallel to the circumference of the hub ring 11, at a desired angle parallel to each other (as in Figures 1, 3, and 4), at right-angles to the direction of the circumference of the hub ring 11, or even, if desired, at alternating different angles relative to the different sides of the hub ring 11. More generally, the bristle tufts 13 can be on the outer circumference of the hub piece 11, at a set angle relative to the direction of the circumference of the hub ring 11, as shown in the second and fourth embodiments from the left-hand side of Figure 2. Using the tufts 13 in an angled position will achieve a good, comprehensive sweeping result, which impacts the surface being swept. There are thus several alternative positions, as there are also alternative shapes of the bristle bunches 13.
If when viewed from the direction of the bristle filaments 16, the position of the bristle tuft 13 on the outer circumference of the hub ring 11 is such that it makes the brush lamel 10 wider axially than, for example, the width of the straight hub ring 11, it is then possible to arrange according to the invention, for example, protrusions 14, made during the manufacturing stage of the brush lamel 10 from the same plastic material, for example, on the straight edge sides of the hub ring 11. This situation may arise, for example, when the bristle tufts 13 are on the outer circumference of the straight hub piece 11 at an set angle or at right-angles relative to the direction of the outer circumference of the straight hub piece 11. The protrusions 14 are aligned next to the corresponding protrusions in the adjacent brush lamels 10, when the brush lamels 10 are installed next to each other on the brush core. When the brush lamels 10 are rotated, the protrusions 14 catch on each other, thus retaining their full-cover positioning relative to each other.
Figure 3 shows a second example of a brush lamel 10 according to the invention, cut into sector piece while Figure 4 shows even more detail of the bristle bunches 13, examined at their roots 15. These show clearly the tuft-like bristle bunches 13, which now lie parallel at the same set angle relative to the circumferential direction of the hub ring 11. The bristle bunches 13, which are separate from each other, are used to create an impacting contact with the surface being swept, which covers most of the longitudinal direction of the brush core. By using tuft-like bunches 13 that are separate from each other, the laterally-non-bended straight hub ring 13 acquires, however, excellent annular rigidity. It retains well the circular annular shape required of it and does not, for example, straighten out or twist, even under great sweeping stress, as can happen in brush lamels according to the prior art, which that create a full-cover contact. Consequently, the inner diameter of the hub ring 11 retains its shape stability and prevents the brush lamel 10 from rotating uncontrollably and freely on the brush core.
As can be seen from Figures 3 and 4, the protrusions 12 preventing the rotating of the brush lamel 10 on the brush core, which are on the inner circumference of the hub ring 11 and the protrusions 14 on both sides of the hub ring 11, which align the adjacent brush lamels 10 relative to each other on its place can be surprisingly arranged as a single protrusion construction 12, 14. This simplifies at least the manufacturing process of the brush lamel 10 and its construction.
As can be seen from Figure 3, the unified protrusion construction 12, 14 can be at the same point in the axial direction on both sides of the actual hub ring 11. It can be located in axially direction at the points of intersection of the sequential bases 15 of the bristle tufts 13, precisely at the level of the outer ends of the bases 15, in the axial direction of the hub ring 11 that now lies between the opposing outer ends. Further, in the radial direction, the protrusion construction 12, 14 can extend from immediately below the bases 15 to the level of the curve of the inner circumference of the hub ring 11 (Figure 4). Thus, in connection with the protrusion 12, 14, an edge, which can engage in counter-surfaces in the brush core, remains below the bases 15 of the tufts 13. In this case, the protrusion construction 12, 14 is shaped taking cognizance the unified structure of the hub ring 11 as a rectangular prism.
Yet another additional structural feature that can be mentioned is the fact that the location of the protrusion 12, 14 on the hub ring 11 can be set in such a way that, it is in the boundary area between two consecutive tufts 13, being, however, at least partly below both tufts 13. Thus, when examining the situation in the axial direction, one end of the protrusion 12, 14 can be at one end of the head of the tuft 13 at one side of the hub ring 11 while correspondingly the protrusion 12, 14 on the other side of the hub ring 13 can be at the other end of the base 15 of the next tuft 13, which is thus the opposite end relative to the end of the base 15 of the previous tuft 13. Arranging the protrusion 12, 14 in this manner also helps to increase the annular rigidity of the hub ring 11. The annular rigidity can also be increased by arranging, reinforcing elements in the base parts 15 of the bristle tufts 13, of which a reinforcement 25 arranged between consecutive bristle tufts 13, for example, is shown in Figure 4.
In the following, the method according to the invention for manufacturing a brush element 10 is described in greater detail. According to on embodiment, the manufacturing process can begin, for example, from the brush preform 23, formed of ribbon-like brush filaments 16, and disclosed in Finnish patent number 87977 . In this connection, there is no need to become more familiar with its manufacture in greater detail. Figure 5a shows an example of such a brush preform 23, which is now preferably arranged in a ring set up.
The one side of the brush preform 23, for example particularly at the end on the side of its hub 24, can have a unified band-like arrangement. At this side, which is joined together, the bristle filaments 16 are secured to each other using a molten plastic compound injected on top of them and a band 24 extruded on top of it, or even by melting them together, so that they remain a single unbroken elongated totality, when the preform 23 is taken, for example, to an injection moulding process.
Figure 6 shows an example of the mould halves 17.1, 17.2 used in the manufacturing process according to the invention. The mould halves 17.1, 17.2 and the manufacturing process based on a moulding process is described first of all in the case of an injection-moulding application. The mould arrangement is now formed of two mould halves 17.1, 17.2 that can be pressed against each other. The moulds 17.1, 17.2 can be equipped with connections, drill holes, cavities, slots, and other arrangements specific to the injection-moulding process, for leading the molten plastic composition, more generally the moulding compound into contact with the mould halves 17.1, 17.2 and processing it in a manner characteristic of the injection-moulding process. In this connection, there is no need to describe their location and nature in greater detail, as all aspects of the basic facts relating to injection-moulding technology in general will be quite apparent to one versed in the art.
As far as the injection moulding is concerned, the manufacturing process of the brush lamel 10 can, according to one embodiment, begin with the brush preform 23 of Figure 5a being placed in the lower mould half 17.1. In the mould half 17.1, there is a central pole hub 18, with a diameter such that the brush preform 23 can be placed on the bottom of the mould half 17.1, next to the mould surfaces 11', 26. Once the brush preform 23 is in the mould half 17.1, the entire mould is closed by pressing, for example, the upper mould half 17.2 against the lower mould half 17.1. When the injection-moulding mould halves 17.1, 17.2 are pressed together, the bristle filaments 16 remain pressed between them, at a distance from the side of the actual hub ring 11 being formed in the injection moulding.
After the mould totality is closed, the actual injection moulding takes place, in which most of the hot plastic compound required to form the hub piece 11 is led between the mould halves 17.1, 17.2. As a result, the hub strip 24 of the brush preform 23 is grown and the actual solid plastic hub ring 11 is formed from it. In addition, the bristle filaments 16 are then attached to the hub ring 11 that is formed.
When applying the brush preform 23 to the invention, according to one embodiment, the separate tufts 13 are formed only just in connection with this injection-moulding, due to the surprising and special construction of the mould halves 17.1, 17.2. At the same time, the bristle tufts 13 are placed at a set angle relative to the circumference of the hub piece 11, when the mould halves 17.1, 17.2 are pressed together. This is caused by the slant of the mould surfaces 26 of the mould part set for the bristle tufts 13 relative to the mould part 11' reserved for the hub ring 11. Finally, the mould totality 17.1, 17.2 is opened and the finished solid plastic brush lamel 10 is removed from it. On the other hand, the bristles 16 can also be placed in a tuft-like arrangement already before the actual injection moulding event, which will be described later in greater detail.
The mould halves 17.1, 17.2 are formed of metal pieces with a massive material thickness, in which mould surfaces 11', 15', 21', 26 can be arranged, for example, by milling, in order to injection mould the brush lamel 10 according to the invention. When viewed from the end of the mould halves 17.1, 17.2, the mould surfaces 26 are slant, as shown in Figure 5 and they are also aligned in the upper and lower mould halves 17.1, 17.2 to fit each other in an appropriate manner. There is a corresponding annular edge 21' in the moulds 17.1, 17.2, for the front edge 21 of the base 15 of the tuft 13.
Figure 7 shows a schematic cross-section of the lower mould half 17.1, of Figure 6, when manufacturing the brush lamel 10 according to the invention. There is a place 11' for the formation of the hub ring part 11, in the direct contact with the circumference of the hub cylinder 18 of the mould halves 17.1, 17.2. When viewed from the end of the mould halves 17.1, 17.2, it is more or less straight and flat. Because the slanting surfaces 26 corresponding to the locations of the tufts 13 and the place 11' of the hub ring component 11 are set, in the case according to the embodiment in question, at the same angle relative to each other, this mould totality can be used to manufacture the second placed type of brush lamels 10 shown from the left-hand side of Figure 2 and which is also shown in Figures 3 and 4. In addition, there can also be millings in the mould halves 17.1, 17.2, for forming protrusions 12, 14 from the unified same moulding material, during the injection moulding of the hub piece 11. The protrusions 12, 14 are used to fit the brush lamels 10 next to each other on the brush core and also to prevent the brush lamels 10 from rotating freely on the brush core.
In the lower mould half 17.1, a more or less vertical wall follows the lowest position of the mould surface 26, and forms a threshold for the peak position 20.1' of the next mould surface 26. There is a sharp shear area 20.1' in this peak position. In addition, there can also be a slot 25' at this upper position, for which a counter-surface is arranged in the upper mould half 17.2. This groove-counter-surface 25' creates the reinforcing element 25 shown in Figure 4. The upper mould half 17.2 has a corresponding type of construction, which fits onto the surface 26, 25', 20.1' and shapes of the lower mould half 17.1. In the upper mould half 17.2, there is also a corresponding shear area 20.2', which is positioned together with the shear area 20.1' of the lower mould half 17.1 to create a shearing effect acting on the brush preform 23, when the mould halves 17.1, 17.2 are pressed axially against each other.
Thanks to these shear areas 20.1', 20.2', when the mould halves 17.1, 17.2 are pressed together, the brush preform 23, which is formed, for example, of brush filaments. 16 melted together at one end and set between the mould halves 17.1, 17.2, is sheared into parts of the set lengths. The shearing is directed at the band 24 of the brush preform 23. This brush preform 23, sheared between the injection-moulding moulds 17.1, 17.2 in a surprisingly manner, together with the hot plastic compound brought between the mould halves 17.1, 17.2, forms, in the pressing stage, on the outer circumference of the hub piece 11, bristle tufts 13 that are clearly separate from each other and are shaped like the said mould halves 17.1, 17.2. The actual hub ring 11 with its protrusions 12, 14 is formed simultaneously from the molted plastic mass. The band 24 of joined brush filaments pressed inside the plastic compound remains inside the base parts 15 of the brush tufts 13. When the mould halves 17.1, 17.2 are pressed together, it is sheared into parts that are clearly separate from each other and are the length of the base part 15 of the tuft 13.
Figure 4 shows particularly clearly the melted-together bristle tufts 13 formed in the hub ring 11 through the injection moulding method. The figure shows that the front edge 21" of the mass front formed by the hot plastic compound, for example, of polypropylene, extends radially to a distance from the ends of the brush filaments 16 that are joined together. The edge 21" of the front does not, however, extend so far as to ooze out from the radial direction of the mould halves 17.1, 17.2. Figure 4 also clearly shows the difference of angle between the hub ring 11 and the brush tufts 13 and the points 20 where the brush preform 23 is sheared. The difference in angle is caused by the shape of the mould halves 17.1, 17.2, as, for example, the difference in angle between the mould surface 11' corresponding to the hub ring 11 and the mould surface 26 corresponding to the bristle tufts 13.
The above description concerns the manufacture of a brush lamel 10 when applying an annular brush preform 23. A ribbon-like, continuous brush preform, which is not in a particular closed annular arrangement, but has an elongated shape, can also be considered. In that case, the continuous brush-preform ribbon in led into the mould totality, in which it bends once around the mould cylinder 18. This is followed by the shearing and moulding process referred to above. Once the finished brush lamel has been removed from the mould totality, a new length of brush preform is led into the mould totality.
According to yet a second moulding-process embodiment, instead of the injection-moulding embodiment described above, it is also possible to apply an extrusion-compression moulding process. In it, it is also possible to apply, for example, the mould totality 17.1, 17.2 shown in Figures 6 and 7, except for the mould functions required by injection moulding. The brush lamel 10, which it thus obtained, can now also correspond to that in Figures 3 and 4.
Figures 5b and 5c show an example of the formation of a brush preform 23, applying this second embodiment. In Figure 5b, an elongated brush preform 23 is prepared, in which the brush filaments 16 are joined to each other at one end in a comb-like arrangement. The joining together of the brush filaments 16 can take place, for example, by heating them, in such a way that their ends melt and consequently join to each other. The melted base part 24 can be, for example, about 10-mm wide and 3-mm thick.
Next, most of the moulding compound 30 forming the hub ring 11 is brought to the joined-together and cooled end of the brush preform 23. In this stage, the hot plastic mass 30 is fed, for example by extrusion, to form a layer on top of the base 24. The amount of plastic 30 is regulated to a volume that roughly corresponds to the volume of the hub ring 11 of the brush disc 10. An example of the dimensions of the layer of molted plastic mass 30 formed is one in such which its material thickness (d) is 4 - 10 mm, for example, 6 - 7 mm. The layer 30 can extend longitudinally on both sides of the filaments 16 for a distance of, for example, 15 - 40 mm, for example 25 mm. The dimensions given are not, of course, in any way limits, instead they are naturally affect by the dimensions required in the brush lamel 10 being manufactured at the time. However, a sufficient amount of molted plastic composition 30 must be produced for it to fill all of the cavities between the mould halves 17.1, 17.2, which were already described in the previous embodiment, when they are pressed together, and which are applied in this case too in the following manufacturing stage.
Next, a piece, corresponding to the length of the circumference of the hub part 18 of the mould 17.1, 17.2, is cut from the brush-filament ribbon 23 covered at one end with molten plastic mass 30 and shown in Figure 5c, and is then wound around the hub part 18 of the lower mould 17.1. The piece is easy to handle, as it is welded together at one end. The cooled base part 24 of the filaments 16 remaining inside the molted plastic mass 30 holds the piece of the brush preform 23 together, until it is pressed between the mould halves 17.1, 17.2. When the upper mould 17.2 is closed after this, as already described in the previous embodiment, the molten plastic mass 30 is pressed between the filaments 16 and the mould halves 17.1, 17.2, at the same time forming the hub-ring part 11 of the brush disc 10. Simultaneously, the bristle tufts 13 are sheared from the unified ribbon 23 into separate parts and the base parts 15 of the bristle tufts 13 are formed. At the same time, the necessary protruding parts 12, 14 are formed on the inner circumference and sides of the hub ring 11. This pressing, in which the shearing of the bristle tufts 13 thus surprisingly also occurs, is referred to as compression moulding. In it, the mould halves 17.1, 17.2 need not necessarily even be essentially heated, instead the hub ring 11 is formed from the still hot and malleable plastic mass 30, because the comb-like brush preform 23 is lead from the extrusion straight to the mould halves 17.1, 17.2 to be pressed. By bringing most of the moulding mass 30 already to the brush preform 23, the construction of the mould halves 17.1, 17.2 is simplified, as is the moulding process itself.
Further, when applying injection-moulding, an embodiment, in which no actual brush- preform ribbon 23, 24 joined together at one end is used at all, can also be considered. In that case, separate, or perhaps very small bunches of brush filaments 16 can be loaded directly onto the mould surfaces 26 of the mould halves 17.1, 17.2. Thus, when the mould halves 17.1, 17.2 are pressed together, there is no shearing of an elongated unified ribbon, instead the brush filaments 16 form brush tufts 13 according to the invention already in their loading stage, due to the advantageous shaping of the mould halves 17.1, 17.2.
On the other hand, the embodiment applying a brush preform 23, in which the formation of the bristle bunches 13 takes place by shearing, appears, however, to be the more advantageous of these embodiments, because the loading of the bristles 13 in the mould half 17.1 may be difficult to implement in a way that is sufficiently rapid in terms of production efficiency. In addition, using a ribbon-like bristle preform 23, the bristles 16 and the bristle tufts 13 formed from them can be orientated more precisely into a radial arrangement than without the bristle preform 23. In addition, it can be difficult to arrange the individual bristle filaments 16 so that they remain in place of the sloping mould surface 26. In this case, it may help to arrange the mould surfaces 26 as slightly corrugated surfaces in the radial direction.
According to yet another embodiment, the shearing of the bristle tufts 13 can be improved by arranged at least one of the mould halves 17.1, 17.2 to rotate circumferentially, when they are pressed together. One example of the rotation can be 5 - 30 mm, for example, 10 - 20 mm. The rotating mould half 17.2 can be, for example, the upper half.
The shape and number of the bristle tufts 13 on the outer circumference of the hub ring 11 can, of course, vary considerably, according to the requirements set by the brush core of the sweeping machine. Similarly, the type and shape of the protrusions 12, 14 on the sides and inner circumference of the hub ring 11 can vary as required. As already stated above, it is also possible to combine protrusions 12 inside the hub ring 11 that prevent rotation on the brush core with protrusions 14 on the sides of the hub ring 11 to form a totality made from the same moulding compound.
It must be understood that the above description and the related figures are only intended to illustrate the present invention. The invention is thus in no way restricted to only the embodiments disclosed or stated in the Claims, but many different variations and adaptations of the invention, which are possible within the scope on the inventive idea defined in the accompanying Claims, will be obvious to one versed in the art.

Claims

A method for manufacturing a tuft-type brush lamel (10), which brush lamel (10) is intended to be used in a sweeping machine, and which brush lamel (10) is formed of separate brush tufts (13) formed from brush filaments (16), which are attached to a hub piece (11), characterized in that the brush lamel (10) is manufactured using a moulding process, in which
- a brush preform (23) is formed from the brush filaments (16) joined-together using a moulding mass (30),

- formed brush preform (23) is brought between mould halves (17.1, 17.2), and

- when the mould halves (17.1, 17.2) are pressed together, the hub piece (11), to which the bristle tufts (13) are attached, is formed from the moulding mass (30), and the brush preform (23) is sheared into the said separate bristle tufts (13) in the circumferential direction.
A method according to Claim 1, characterized in that most of the moulding mass (30) forming the hub piece (11) is arranged in the brush preform (23), before the brush preform (23) is brought between the mould halves (17.1, 17.2).
A method according to Claim 1, characterized in that the brush preform (23) is pressed between the mould halves (17.1, 17.2), after which most of the moulding mass is brought to the mould halves (17.1, 17.2) in order to form the hub piece (11) and to attach the brush filaments (16) as bristle tufts (13) to the outer circumference of the hub piece (11).
A method according to any of Claims 1 - 3, characterized in that, when the mould halves (17.1, 17.2) are pressed together, the bristle tufts (13) are brought to a set angle relative to the circumference of the hub piece (11).
A method according to any of Claims 1 - 4, characterized in that, in connection with the moulding process, protrusions (12, 14) are formed in the hub piece (11), in order to fit the brush lamels (10) next to each other on the brush core of the sweeping machine and to prevent the brush lamel (10) from rotating on the brush core.
A tuft-like brush lamel (10) for a brush core to be fitted to a sweeping machine, in which the brush lamel (10) is arranged to be formed from separate bristle tufts (13) formed from brush filaments (16), which are attached to the outer circumference of a hub piece (11) and which brush lamel is manufactured using the method according to any of Claims 1 - 5, characterized in that the brush filaments (16) are joined-together by using the moulding mass (30) and the bristle tufts (13) of the brush lamel (10) are on the outer circumference of the hub piece (11) at a set slant angle relative to the direction of the circumference of the hub piece (11).
A brush lamel (10) according to Claim 6, characterized in that the bristle tufts (13) alternate on the outer circumference of the hub piece (11) in different directions at a set angle relative to the direction of the circumference of the hub piece (11).
A brush lamel (10) according to Claim 6 or 7, characterized in that, in the moulding process, protrusions (12, 14) are formed on the hub piece (11), which fit into corresponding protrusions (12, 14) arranged on the adjacent brush lamels (10) and prevent the brush lamel (10) from rotating on the brush core and which protrusions (12, 14) preferably form a unified structure.
A brush lamel (10) according to any of Claims 6 - 8, characterized in that the hub piece (11) is straight in the axial direction.
The use of a brush lamel (10) manufactured according to the method of any of Claims 1 - 5, or of a brush lamel (10) according to any of Claims 6 - 9 together with several similar brush lamels (10) in order to make a brush core to be fitted to a sweeping machine.
The use in a sweeping machine of a brush lamel (10) manufactured according to the method of any of Claims 1 - 5, or of a brush lamel (10) according to any of Claims 6- 9 together with several similar brush lamels (10).