Improvement and enhancing of grinding wheels for the machine working of marble, granite and the like

Abstract: A shaped diamond wheel (1), at certain height, determined by both the type of grinding wheel which is being used and the working stage, is provided with a rotating feeling pin (2), consisting of a metal element a few millimetres high, suitable for the function it has to fulfil, which projects for few hundreths af a millimetre with regard to the shape of grinding wheel, the rotating feeling pin not interfering with the working of stone, with the exception of very small portion of stone (3) which come into contavt with the rotating feeling pin (2).

Description: It is a well known fact that there are various types and sizes of chamfering machine tools currently on the market; for example, there are expensive and complex machines the structures of which allow the installation of a frame, on which the wood or steel template is fixed, which faithfully reproduces the desired shape; said machines besides being costly and taking up a lot of floor space also entail a lot of hard work for the construction of the necessary templates. Smaller machines, also on the market, have been created, but these do not guarantee the execution of a perfect job. Their major shortcoming is the fact that, not being provided a template of the desired shape, this must be accomplished simply by the machine tool's travel, a fact that does not always allow the desired degree of precision. US-A-2 327 407 discloses a machine for smoothing or chamfering burred edges and particularly the edges of sheet metal. The machine comprises a pair of chamfering tools rotating on a common shaft associated with a stopping pin rotating on the same shaft. Said stopping pin is arranged for limiting the travel of the workpiece towards the chamfering tools, in order to limit the chamfering operation. The object of this invention is a specific grinding wheel, which may also be applied to machine tools currently on the market, which overcomes the above mentioned shortcoming and, in particular, gives the possibility of working with a portable or work-table chamfering tool, without having to provide a template each time it has to be used. According to the invention, a grinding system for forming a product having a finished contour, comprising a first and a second grinding wheel and a honing wheel, said wheels being rotatable and having identically contoured peripheral grinding surfaces for grinding the edge of a stone, whereby the first and the second grinding wheels are each provided with a rotating stopping flange having a radius which is a few hundredths of a millimeter smaller than an adjacent portion of the contoured surface and having a non-abrasive peripheral surface for contacting a stone to be machine worked, whereby the axial position of the stopping flange of the second grinding wheel is different from that of the first grinding wheel. For a better understating of the foregoing a more detailed description follows, making reference to the following figures: Fig. 1 shows a side view of a diamond wheel; Fig. 2 shows a cylindrical diamond wheel; Fig. 3 shows a diamond wheel for shaping; Fig. 4 shows a diamond wheel for honing; and Fig. 5 shows a diamond wheel for polishing. With reference to the above figures, the grinding wheels specified in this invention consist of a shaped diamond wheel (1) which at a certain height, determined by both the type of grinding wheel which is being used and the stage of machine working, is provided with a rotating stopping flange (2). Said rotating stopping flange (2) consists of a metal element, which is recessed for a few hundredths of a millimeter with, regard to the shape of the grinding wheel. The rotating stopping flange (2), therefore, does not influence the machine working of the stone until this is nearly finished; in fact, only when the outline of the stone coincides exactly with the outline of the grinding wheel, a small part of the stone (3) comes into contact with the rotating stopping flange (2). The contact between the rotating stopping flange and the stone prevents the upper and lower parts of the grinding wheel from carrying out their task, thus ending a phase of the machine working. Obviously, during this phase of the working, a small portion of un-machined stone shall remain under the rotating stopping flange, this will be completed by a specific grinding wheel, such as the one shown in fig. 4 and featuring a rotating stopping flange (2) located in a different position, with regard to the previous grinding wheel, thus allowing the partially unworked stone to be finished. As may be seen from the attached illustrations, besides what has been shown as an example, the grinding wheels may have different shapes, so as to be able to execute all the various possible working stages. For example, the grinding wheel shown in fig. 1 is particularly recommended for grinding and carrying out the so-called "owl's beak" shape. The grinding wheel shown in fig. 2 is useful for grinding the slab to be treated. Fig. 5 shows an extremely fine grained grinding wheel, as you may easily see, without the rotating stopping flange and which is especially useful for polishing and finishing the previously machined piece.

Claims: A grinding system for forming a product having a finished contour, comprising a first and a second grinding wheel and a honing wheel, said wheels being rotatable and having identically contoured peripheral grinding surfaces for grinding the edge of a stone, whereby the first and the second grinding wheels are each provided with a rotating stopping flange (2) having a radius which is a few hundredths of a millimeter smaller than an adjacent portion of the contoured surface and having a non-abrasive peripheral surface for contacting a stone (3) to be machine worked, whereby the axial position of the stopping flange (2) of the second grinding wheel is different from that of the first grinding wheel. A grinding system according to claim 1, characterized in that said grinding wheels are diamond coated wheels. A grinding system according to claim 1 or 2, characterized in that said rotating stopping flange is made of metal. A grinding system according to anyone of the preceding claims, characterized in that a further grinding wheel is provided having a continuous shape for polishing and finishing the previously machined piece.

Inventors: LUPI QUINTILIO, LUPI, QUINTILIO
Applicants: LUPI QUINTILIO, LUPI, QUINTILIO
Application year: 1991
Main classification: B24D5
IPC codes: B24B9, B24B55, B24D5, B24D7