EP0281050A2

EP0281050A2 - Abrasive grinding wheel, particularly for working stone materials such as marble, granite and the like

Info

Publication number: EP0281050A2
Application number: EP88102982A
Authority: EP
Inventors: Pierluigi Ravelli
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-03-06
Filing date: 1988-02-29
Publication date: 1988-09-07
Also published as: IT1202644B; IT8719608A0; EP0281050A3

Abstract

"The present invention relates to an abrasive grinding wheel for working stone materials such as marble, granite and the like comprising a supporting body (2) associable with a rotating operating assembly. The peculiarity of the invention resides in the fact that it comprises an elastically resilient mass (10) peripherally defining a region with a shape substantially complementary to the shape of the part (12) being machined. Portions (13,20) in abrasive material, constituted by a mixture of rubber and carborundum or possibly of sections (20) of emery cloths, are provided on said region.

Description

The present invention relates to an abrasive grinding wheel for working stone materials such as marble, granite and the like.
As is known, to perform the surface shaping and finishing of stone materials such as marble, granite and the like, abrasive grinding wheels are currently used which have a relatively hard mixture having abrasive material with different dimensions, that is to say with different grain, so as to pass in succession from the initial shaping operation which confers the intended shape, to the successive workings which gradually lead to a smoothing of the surface, until the final polishing is achieved.
With the currently available grinding wheels it occurs that it is absolutely necessary that the entire series of abrasive grinding wheels which is used to perform the shaping, up to the final finishing and polishing operations, have exactly the same internal configuration.
This fact entails considerable difficulties in the step of manufacturing the grinding wheel, since considerable constructive precision is required.
An incorrect shape of one of the grinding wheels of the series of grinding wheels which are used in succession would unavoidably lead to surface flaws.
Assuming, by way of merely informative example, a configuration constituted by a rounded edge on a slab, it occurs that, if not all the grinding wheels used have the same identical shape, said grinding wheels only work in some points of the profile with damage both of the grinding wheel, which becomes more worn in some points, and of the profile itself, which would end by having an irregular surface.
Another problem found with known grinding wheels , in this type of machinings, resides in the fact that it is necessary that the various grinding wheels which are used in succession be perfectly positioned and centered with respect to the part being machined, since an incorrect positioning of the grinding wheel with respect to the part would lead to defective machinings, even in the case in which the shape of the grinding wheel is produced perfectly.
The aim of the invention is indeed to eliminate the above described disadvantages by providing an abrasive grinding wheel for the surface shaping and finishing of stone materials, which allows to always adapt itself correctly to the configuration and shaping of the region being machined, without requiring an exasperated precision in configuration, in the production of the entire series of grinding wheels with different granulometries, which are used to execute all the operational steps.
Within the above described aim, a particular object of the invention is to provide an abrasive grinding wheel which allows to automatically position itself with respect to the part being machined, so as to always have precise and correct machinings.
Still another object of the present invention is to provide an abrasive grinding wheel which, by virtue of its peculiar constructive characteristics, is capable of giving the greatest assurances of reliability and safety in use.
Not least object of the present invention is to provide an abrasive grinding wheel for the surface shaping and finishing of stone materials of the type of marble, granite and the like, which is easily obtainable starting from elements and materials commonly available on the market, and which is furthermore competitive from a merely economical point of view.
The above described aim, as well as the objects mentioned and others which will become apparent hereinafter, are achieved by an abrasive grinding wheel for the surface shaping and finishing of stone materials of the type of marble, granite and the like, according to the invention, comprising a supporting body associable with a rotating operative assembly, characterized in that it comprises an elastically yielding mass peripherally defining a region with a configuration substantially complementary to the shape of the part being machined, at least portions in abrasive material being provided in said region.
Further characteristics and advantages will become apparent from the description of two different possible embodiments of an abrasive grinding wheel for the surface shaping and finishing of stone materials of the type of marble, granite and the like, illustrated only by way of non-limitative example in the accompanying drawings, wherein

figure 1 is a schematic and partially sectional view of an abrasive grinding wheel with abrasive surface portions produced with a mixture of rubber and carborundum and shaped for the machining of a semicircumferential edge:
figure 2 is a partial view of the grinding wheel of figure 1;
figure 3 is a side sectioned view of an abrasive grinding wheel, shaped for the production of edges in the shape of a quarter circumference, with abrasive portions constituted by emery cloths;
figure 4 is a side view of the grinding wheel of figure 3.

With reference to the above described figures, the abrasive grinding wheel for the surface shaping and finishing of stone materials of the type of marble, granite and the like, generally indicated by the reference numeral 1, comprises a supporting body 2 which, in the specific example, is constituted by a nucleus with toroidal configuration provided with a central hole 3 for the coupling to the mandrel of a rotating operative assembly; naturally the supporting body may have any configuration deemed appropriate, also according to the configuration which the abrasive grinding wheel is to assume.
The peculiarity of the invention resides in the fact that an elastically yielding mass 10, constituted by vulcanized rubber having a hardness adjustable according to the machining requirements, is coupled on the active periphery of the supporting body 2.
Said elastically yielding mass is peripherally provided with a region with a configuration which is substantially complementary to the shape 11 of the part being machined, indicated at 12.
Abrasive material, which can be produced in various manners, is provided on said region.
As illustrated in figures 1 and 2, the abrasive material is constituted by a continuous layer 13 made of a mixture of rubber and carborundum, which offers a continuous abrasive region which is also elastically yielding.
According to the configuration of said region, the elastically yielding mass can be also directly made of the mixture of rubber and carborundum, while for more complicated configurations, such as for example the one illustrated in figures 1 and 2, it is economically more advantageous to make an elastically yielding mass in rubber and only the work profile made of the mixture of rubber and carborundum.
In the embodiment illustrated in figures 3 and 4, besides a different configuration, determined by a different shaping, the portions of abrasive material are constituted by portions 20 of emery cloth which are rigidly applied on the periphery of the elastically yielding mass, for example by glueing or by other similar methods.
The provision of the elastically yielding mass is considerably important in the production of the grinding wheel, since it allows to have an automatic adaptation of the shaping of the machining abrasive portion to the configuration of the region being machined, without requiring the provision of a series of grinding wheels , with different granulometries of abrasive mixture, which have perfectly identical configurations.
In fact the elastic yielding of the grinding wheel allows that even if the grinding wheels , which are used in succession, do not have a perfectly identical configuration, the abrasive region always adapts elastically to the part being machined, thus allowing to always machine the entire surface.
Furthermore, the elastic yielding of the region where the abrasive is provided allows the grinding wheel, in a way, to automatically position itself with respect to the configuration of the region being machined, always obtaining extremely precise results.
The type of grinding wheel described above can have any configuration deemed appropriate, so as to perform the machining of rounded edges, of edges with bevelings at the ends, hollowed out and the like, and can furthermore be configured to execute the machining of recessed regions in solid parts, as well as to execute machinings on edges having both a concave and convex development, as well as, naturally, a rectilinear one.
From what has been described it can thus be seen that the invention achieves the intended aims and in particular the fact is stressed that the provision of an abrasive grinding wheel which has at least an elastically yielding part which supports the abrasive portions allows it to adapt itself within wide margins to the shapes of the regions being machined, without thereby requiring an exasperated precision of the configuration of the abrading region of said grinding wheel.
Furthermore, as previously mentioned, the elastic yielding of the abrasive region allows to achieve an automatic positioning of the grinding wheel with respect to the region being machined, with consequently always optimum machining.
The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept.
Furthermore, all the details may be replaced with other technically equivalent elements.
In practice, the materials employed, so long as compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims

1. Abrasive grinding wheel, particularly for working stone materials such as marble, granite and the like, comprising a supporting body (2) associable with a rotating operating assembly, characterized in that it comprises an elastically yielding mass (10) peripherally defining a region (12) with a configuration substantially complementary to the shape of the part (12) being machined, at least portions (20,13) in abrasive material being provided in said region (12).

2. Abrasive grinding wheel, according to claim 1, characterized in that said at least portions in abrasive material are constituted by at least one layer (13) of a mixture of rubber and carborundum.

3. Abrasive grinding wheel, according to one or more of the preceding claims, characterized in that said elastically yielding mass (10) is constituted by said mixture of rubber and carborundum.

4. Abrasive grinding wheel, according to one or more of the preceding claims, characterized in that said elastically yielding mass (10) is constituted by a body in vulcanized rubber.

5. Abrasive grinding wheel, according to one or more of the preceding claims, characterized in that said at least portions in abrasive material are constituted by portions (20) of emery cloth.

6. Abrasive grinding wheel, according to one or more of the preceding claims, characterized in that said at least portions (13,20) in abrasive material are adapted to assume the configuration of the shape of the part being machined, with uniformity in machining in the entire shape of the part (12) being machined.