Patent Application
20060292971
The present invention relates to a grinding module for a rotating grinding brush, said grinding module comprising an elongate body part, at least one abrasive cloth that extends from the body part, and a plurality of bristles that project from the body part essentially in the same direction as the abrasive cloth; wherein said abrasive cloth comprises a holder for securing the abrasive cloth, said abrasive cloth being divided into a number of sub-segments that are delimited by slits; wherein the body part and the holder are provided with complementary mechanical interconnecting means, whereby the abrasive cloth is releasably mounted on the body part.
Today, rotating grinding brushes are configured from a hub with longitudinally extending grooves in which grinding modules with an abrasive cloth and bristles, be it assembled or separate, are mounted by being displaced axially into the grooves. That kind of abrasive cloth is known from eg WO 2004/103643.
In that structure the abrasive cloth lends itself for use in the grinding of essentially plane workpieces of eg wood, metal or plastics material and which are eg provided with profiles, various types of cut-outs or edge profiles. Depending on the grinding job in question, different types of abrasive cloths having different grinding characteristics can be used on the same hub, and thereby a very particular grinding effect is accomplished. This is preferably accomplished by adaptation of the kind of grinding material, abrasive grains or grain sizes of the abrasive grains to the concrete grinding job. Moreover, it is known to configure the abrasive cloths with one particular distance between the slits in order to provide a particular characteristic grinding feature which is unique to the concrete grinding job. Such distance between the slits is defined as a sub-segment. Thus, an abrasive cloth having short distance between the individual slits will be particularly suitable for grinding of areas on a workpiece having an uneven (ie profiled) surface, and likewise an abrasive cloth having a long distance between the individual slits will be advantageous for use in the grinding of the rather plane areas of the workpiece, not in the least for “edge-breaking”, ie the edges are rounded to remove any square transitions.
In order to facilitate the task of the operator, a process is employed that alternates between mounting of grinding brushes on the hub and grinding paper of a very particular characteristic, which most often has the practical consequence that the sub-segments on the abrasive cloth are made with a distance between the slits that is specific to precisely that abrasive cloth. Thus, the hub many alternatingly around its entire circumference be provided with different abrasive cloths, each of which is configured with one specific distance between the individual slits. Moreover the individual abrasive cloth may have a very particular grinding characteristic which is determined by eg the type and the extent of wear of the abrasive cloth.
In particular by alternatingly providing the cloth with abrasive cloths with different distances between the slits, a desired grinding characteristic for the grinding job in question is accomplished. Moreover, it is not possible to change every other abrasive cloth to maintain a constant speed of rotation on the grinding drum. However, there is a problem in connection with the mounting of the individual abrasive cloth; viz that the fitter has to take care to mount the various abrasive cloths correctly in the correct sequence on the hub, if the desired grinding characteristics are to be achieved. This requires careful attention on the part of the fitter, and likewise subsequent verification of the correct positioning of the individual abrasive cloths may be required.
It is therefore an object of the invention to provide an abrasive cloth configured for cooperating with a grinding module for a rotating grinding brush, whereby the problems of the prior art are obviated.
This is accomplished by the invention according to the characterising part of claim 1. Hereby an abrasive cloth is accomplished which is configured for cooperating with a grinding module for a rotating grinding brush, where, during the mounting procedure, the operator avoids having to ascertain that abrasive cloths of a relevant type of sub-segments are mounted in a correct sequence on the hub and having to exchange every other grinding segment. By the invention, the operator needs to focus only on having to provide a specific type of abrasive cloth, following which the mounting may take place without problems and without having to take into consideration a desired sequence around the hub.
Moreover the invention enables that it is avoided, in particular situations, to have to exchange every other grinding module and moreover that it is ensured that an abrasive cloth featuring the correct sub-segments is arranged in its right place in the sequence of segments. Hereby new and used grinding modules alternate on the hub at all times, and hereby it is possible to grind with the same speed of rotation on the rotating grinding brush.
The invention will now be explained with reference to the drawing, wherein
a-1c show various embodiments of an abrasive cloth according to the invention; and
a and 2b show a grinding module for use in combination with the abrasive cloth according to the invention; and
Thus,
Slitting of the abrasive cloth 1 with a specific distance between the individual slits 2 provides sub-segments 4, 5, 6 with a width that is determined by the distance between two slits 2 and as indicated by respective reference numerals 4a, 5a, 6a. Preferably the slits 2 are provided alternatingly in groups of one or more sub-segments 4, 5, 6 wherein the sub-segments 4, 5, 5 of each group are provided with the same distance between the slits 2. Those groups of sub-segments 4, 5, 6 are made in a general modular system, wherein each group of one or more sub-segments 4, 5, 6 has essentially the same expanse. Each group is divided by slitting into a desired number of sub-segments of between two and 16, and preferably between four and eight sub-segments, or the group may be undivided, ie there is exclusively one sub-segment in a group.
Preferably, the abrasive cloth 1 will be slit into sub-segments 4, 5, 6 with a distance of 3, 6, 12 or 24 mm between the individual slits 2 in a group.
Thus,
Apart from being provided with bores for attachment of bristles 8, the body part 7 of the grinding module 10 is also provided with a coupling part 12 that projects from the body part in a direction opposite that of the bristles 8. The coupling part 12 is configured such that it fits into the groove on the known, not shown hub. Thus, the grinding module 10 can be mounted on the known hub by displacement of the coupling part 12 axially into the groove of the hub as described above with respect to the prior art. If a hub is used that features differently configured grooves, the coupling part 12 will, of course, also be configured differently.
When the abrasive cloth 1 is mounted in the holder 14, the edge 3 thereof is arranged between the two flaps 16, 17 which are subsequently pressed towards each other and clamp the abrasive cloth 1 between the flaps 16, 17.
According to a further aspect the invention relates to an abrasive cloth configured for cooperating with a grinding module for a rotating grinding brush, said grinding module comprising an elongate body part, at least one abrasive cloth that extends from the body part, and a plurality of bristles that extend from the body part essentially in the same direction as the abrasive cloth; wherein said abrasive cloth comprises a holder with at least one elongate flap for attachment of the abrasive cloth, said abrasive cloth being divided into a number of sub-segments, said sub-segments being delimited by slits, and wherein the body part and the abrasive cloth are provided with complementary mechanical interconnecting means thereby releasably mounting the abrasive cloth on the body part.
Above, the invention was described with reference to a preferred embodiment of the grinding module and the grinding brush. However, several structural details may be varied without departing from the scope of this invention. For instance, the holder with the abrasive cloth may be secured to the brush profile by means of an adhesive, or the abrasive cloth and/or the holder with abrasive cloth may be cast integrally with the brush profile. Moreover, the abrasive cloth can be configured with a distance between the individual sub-segments. According to an alternative embodiment the grinding module may be cast directly in the hub.
With regard to choice of material for the individual parts, the options are numerous. The grinding module as such will typically be manufactured from extruded aluminium or plastics, whereby it may, in principle, be manufactured in an endless length that can be cut-off as desired. The holder for the abrasive cloth will preferably be manufactured from an inexpensive metal, its longevity being, as it is, limited.
