The present invention concerns a brush and a method for manufacturing such a brush.
In particular, the invention concerns a rotating brush for brushing a pavement surface, which brush, as is known, is suspended under a vehicle, such that, as a result of the movement of the vehicle and the rotation of the brush, a large surface of the pavement can be treated in a short time by means of such a brush.
More in particular, it concerns rotating brushes designed to be implemented when carrying out heavy brushing operations, for example for brushing loose, brushing away respectively, weeds growing from out of the road surface, as well as for brushing away grass and weeds growing rank as of a roadside or the like over the edge of a road surface.
It is known to provide such brushes with bundles of fibres which are composed of metal, usually steel fibres. Every bundle of fibres hereby usually consists of a number of twisted fibre twines. In particular, use is made of lengths of twined steel cable for these bundles of fibres.
It is also known that, during the use of such brushes, the bundles of fibres tend to unravel, such that they can open up entirely at their free ends, which is disadvantageous in that the efficiency of the brush effect is considerably reduced. In order to remedy this, it is known to provide a casing around the bundle of fibres in the shape of a case made of plastic slid over every bundle of fibres, which counteracts the unravelling of the bundles of fibres a the free ends of the latter. The cases will wear away together with the fibres.
The use of such separate cases, as shown in
The present invention aims a brush which is more efficient, both from a point of view of its construction and from a point of view of the manufacturing, than the embodiments known until now, and whereby, in particular, also the above-mentioned disadvantages are excluded.
To this end, the invention concerns a brush according to claim 1
By a coating is meant a casing according to the invention which, as will become clear from the preferred embodiments described hereafter, fits tightly around the bundle of fibres, as opposed to the conventional cases which fit loosely over the bundles of fibres with a play of a few millimetres. Naturally, this casing is also made such that it offers sufficient resistance in order to prevent an undesired, considerable unravelling.
By making use of a casing consisting of a coating, it is as if it were already connected as such to the accompanying bundle of fibres over its entire length. Hence, it is excluded that such coating will come loose prematurely. Another major advantage consists in that separate cases do no longer have to be provided for, and that nor any fastenings have to be realised to this end, as a result of which the manual operations during the production can be considerably reduced, resulting in a lower cost price and a more economical product.
As the bundles of fibres consist of pieces that are detached, in particular cut off from a fibre twine that has been provided with a coating beforehand, such as a coated cable or the like,when manufacturing brushes, in order to form the coated bundles of fibres, fibre twines or cables which are already coated and which are possibly available on the market can be taken as a basis, which only remain to be detached at the required lengths. This does not exclude that also fibre twines, for example twisted cables, can be taken as a basis which are especially provided with a coating in order to realise the aforesaid brush and which are then, as mentioned above, cut to pieces of the required length.
Preferably, the coating is made of plastic, in particular plastic which has cured around the bundles of fibres or the fibre twine out of which these bundles of fibres have been made, such that a good adhesion between the coating and the fibre twine is automatically obtained.
Although preference is given to plastic, this does not exclude other possibilities. Thus, for example, the coating may consist of a shoe-like structure, woven or wrapped around the bundles of fibres, made of any suitable material whatsoever, for example made of thin metal wire.
Although the invention is in the first place meant for rotating brushes with bundles of fibres which consist as such of metal, in particular plaited, twined or twisted cable parts, it is not excluded to apply it in combination with bundles of fibres which are made as such of another material than metal.
The bundles of fibres are contained in holders which are in turn fixed to a part of a brush body. This fastening preferably takes place by providing the holders through openings in the aforesaid part of a brush body and by welding them in these openings. As opposed to the known embodiments whereby the holders are welded to the lower side of a part of a brush body, the aforesaid fastening offers several advantages, namely that it is rigid, that the holders, by sticking them in the holes, automatically take up the right position, such that the use of jigs for positioning the holders during the welding can be excluded, and that the holders can be welded quicker and more easily to the brush body, such that this results in an additional reduction of the production time.
The present invention also concerns a method for manufacturing a such brushes, characterised in that, for the formation of the bundles of fibres of this brush, a coated fibre twine can be taken as a basis, preferably a plasticised fibre twine, and more in particular a plasticised twined or twisted steel cable, of which pieces at the length of the fibre bundles concerned are detached, in particular cut off; and in that, subsequently the bundles of fibres are provided in bush shaped holders at one far end, with which they are in turn fixed to a part of a brush body.
This method is particularly efficient, for it excludes the conventional time-consuming operation of applying and fixing separate cases. Moreover, the bundles of fibres do not have to be provided with a coating one after the other.
The coated fibre twine, which is taken as a basis to form bundles of fibres, may consist of a product which is available on the market, or it can be especially made beforehand in view of the invention. To this end, a continuous fibre twine or cable is first provided with a coating and then divided in pieces of the required length. The coating can be applied in any way whatsoever, for example by extruding a plastic covering around the fibre twine or cable, by wrapping a plastic strip around the fibre twine and by fusing it around the fibre twine by means of heat, by applying one or several plastic shrinkage shoes around the fibre twine, etc.
In order to better explain the characteristics of the invention, the following preferred embodiments are described as an example only without being limitative in any way, with reference to the accompanying drawings, in which:
The known brush 1 represented in
The bundles of fibres 5 consist of lengths of twined steel cable which are clamped in holders 6 at their top ends, which are in turn welded to the lower side of the part of the brush body 2. These holders are bush-shaped and have a top end 8 which is cut slantwise in relation to their longitudinal axis 7, such that, when they have been welded under the part of the brush body 2, they will extend at an angle, as represented.
The bundles of fibres 5 are each provided with a casing formed of a plastic case 9 slid over each bundle of fibres 5 concerned. In order to be able to apply these cases 9 over the sometimes more or less irregularly shaped bundles of fibres 5, the inner diameter of these cases is a few millimetres larger than the average diameter of the bundles of fibres 5. The cases 9 are fixed as they are slid with their top ends over the accompanying holder 6, and as they are fastened by means of a straining ring 10, usually in the shape of a ring pressed around it.
This known embodiment of a brush 1 has several disadvantages, as explained in the introduction.
By means of
This brush 1 is built in an analogous manner as those of
The invention is special in that the casing of the bundles of fibres 5 is no longer formed of a separate case 9, but of a coating 11 formed directly around every bundle of fibres 5, in this case made of plastic, preferably a somewhat flexible plastic.
The bundles of fibres 5 preferably consist of metal, in particular lengths of twined cable, composed of twined cable parts 12, in this case seven in number, which are each composed of bundles of thin steel wire 13. It is clear that the bundles of fibres 5 can have different diameters, but in practice they will usually have a diameter of 1 to 4 cm.
The coating 11 may consist of plastic cured around the bundles of fibres 5 and which thus fits closely to the outer side of these bundles of fibres 5. In combination with these bundles of fibres 5 which consist of a twined cable part, as represented in
At their top ends, the bundles of fibres 5, together with the part of the coating 11 which is situated there, are contained in the holders 6, in particular they are clamped therein as these holders 6 are pressed together around the coated bundles of fibres 5. According to a variant which is not represented, this coating 11 can possibly be removed at the top end of every bundle of fibres 5 concerned, although this is not necessary in practice.
It is clear that, regardless of whether the coating 11 either or not extends in the holder 6 concerned, no separate fasteners, such as the above-mentioned straining ring 10, are required to keep the casing in place.
Moreover, in the embodiment from
The holders 6 are hereby fixed to the part of the brush body 2 as these holders 6 are provided through openings 15 in this part of the brush body 2 and are welded in these openings 15, for example by means of each time two seals 16-17. As the holders are placed in openings 15, they are solidly anchored in the part of the brush body 2. Moreover, on condition that the openings 15 are accurately made, they are always positioned correctly, without any jig being required to this end during the welding, which is the case in the embodiments from
As shown in
As indicated in the figures, the bundles of fibres 5 extend together with their coating 11, preferably only through a part of the holders 6, such that the coated bundles of fibres 5 only extend with their top ends up to a distance D under the seals, among others 16-17, with which the holders 6 are welded to the part of the brush body 2. Thus is avoided that, at least when the coating 11 is made of plastic, this plastic ends up in the immediate vicinity of the seals concerned, so that any melting and evaporating of plastic, and any possible development of harmful vapours during the welding is minimised or excluded.
As is schematically represented in step A, a continuously coated fibre twine 20 is taken as a basis to form coated bundles of fibres 5, in particular a plasticised fibre twine 20, such as a plasticised twined steel cable, and pieces 21 thereof are detached at the length of the bundles of fibres 5 to be realised, in particular cut off.
Next, these pieces 21, which form the bundles of fibres 5 as such, as indicated in step B, are provided with one end in a bush-shaped holder 6, after which these holders 6, as indicated in step C, are pressed together around the coated bundles of fibres 5, as a result of which the latter are fixed in the holders 6.
Afterwards, the bundles of fibres 5 fixed in the holders 6 are fixed to a part of a brush body 2 by means of the holders 6, for example welded underneath it, as in the embodiment from
It is clear that the bundles of fibres 5 according to the invention, whose casing consists of a coating 11, and not of a separate case, can also be used in other embodiments of brushes whereby the bundles of fibres 5 are for example connected to the part of the brush body 2 in another manner than by means of holders 6, or whereby the bundle of fibres 5, together with the accompanying holders 6, can be connected to the part of the brush body 2 in a detachable and replaceable manner.
From what precedes it is also clear that the coating 11 has the same purpose and working principle as the known cases 9. For, the coating 11 is also meant to keep the fibres of the bundles of fibres 5 together and to counteract their unravelling or an undesired deformation of the far ends of the bundles of fibres 5. While in use, the coating 11 will wear together with the bundles of fibres 5.
The present invention is by no means limited to the above-described embodiments given as an example and represented in the accompanying drawings; on the contrary, such a brush and the aforesaid method can be made in all sorts of variants while still remaining within the scope of the invention.
Thus, for example, the material of which the coating 11 is formed must not be exclusively situated on the outside of the bundles of fibres 11. For it is not excluded to wrap the bundles of fibres 5 of individually plasticised steel wire 13 or the like and to subsequently fuse the entire bundle of fibres together, in which manner is also created a single unit provided with a coating.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.