Tester with interchangeable inserts to be applied to the grinding wheels of machines for the grinding and shaping of marbles, granites, glasses and similar materials

Abstract: A device tester with interchangeable inserts to be applied to grinding wheels for machines for the grinding and shaping of marbles, granites, similar materils, woods, glass, etc., made up of a support and of an interchangeable tester insert. This assembly enables a perfect grinding (abrasion), without leaving burns, grooves or waves on the surfaces worked. The invention takes its place in the applications field of machines for working marbles, granites, and materials of every kind, and in the scientific field of mechanics.

Description: The invention presented concerns a tester system for working marbles and the like, comprising a first and a second grinding element, arranged one adjacent to the other and apt to rotate about a rotating axle to abrade a material to be worked, and an annular tester insert arranged between said grinding elements. For clarity, a brief definition is given of it as a "tester". In the specific language, it is a mechanical element that, when placed on the rotating axle of a grinding wheel in operation, has the characteristic of not going beyond the depth of grinding desired, once it has come into contact with the material to be worked. By "interchangeable" is meant that the "insert" element, depending on the type of working or of material to be worked, can be changed: for example, at one time the one having a tooth can be used in order that it block the machining rotation, or the perfectly round insert may be used where there is no need for blocking. This is useful since the parts of the grinding wheel are of a highly abrasive material, while the tester is of a non-abrasive material, but one that does not abrade, so that the tester serves to keep the distance of the grinding wheel from the working surface constant. The invention takes its place in the field of applications of machines for the working of marbles, and other materials of every type and in the scientific field of mechanics. Most recently, many kinds of testers have been protected by patent but the tester forming the subject of today's invention is surely such as to obviate the difficulties found in those to date built. We mention here some of the preceding techniques: PCT WO9401261A (L. DE NONI), EPO 478518 (Q. LUPI). The testers known currently on the market are fixed testers, which are blocked and rotate with the same rpms of the grinding wheel even when in contact with the stone to be shaped, with consequent wear of the tester and hammering of the worked stone. Rotating testers that, while rotating together with the wheel, when they come in contact with the stone are arrested, braking and rubbing against the material itself, while the grinding wheel goes on working. The disadvantage is that owing to the inertia of the outer part of the tester burns can form on the parts of the stone that first come into contact with the tester, with consequent deformation and wear of the tester itself. Mention may be made of the spacer plate tester. Said plate is not in contact with the grinding wheel, but is inserted free in a groove in this latter, through an approach system mounted on the machine, since said plate is calibrated to strike against the stone to be worked. The difficulty with this system is that, besides being more expensive than other types, in order to have a perfect shaping the grinding machine must be positioned perfectly perpendicular to the surface to be worked, otherwise waves and trenches can be produced in the surface itself, depending on how the machine is positioned relative to the stone to be worked. Before going ahead with the description of the invention being presented, it is worthwhile mentioning the previous inventions of the same inventor protected by patents: 1. Application for Italian patent no. RM96U000009 of January 15th 1996, and RM96A000020, and FCT of January 13th 1997 relative to RM96A000020. 2. Application for Italian patent no. RM97A0490 of January 8th 1997. In the present invention, the problems mentioned above with reference to the prior art are solved by the tester system defined in claim 1. The invention presented, which marks a further step ahead in the specific technique, is now to be described for explanatory, and not imitative, purposes, reference being made to the version currently preferred by the inventor and on the basis of the attached figures of which a list follows. Fig. 1 Schematic representation of the grinding wheel in which the support is inserted, with the interchangeable insert housed on the interior. Fig. 2 Schematic representation of the grinding wheel in which is housed the tester support and the interchangeable insert in an exploded view; in it are visible: 1 tester insert support outfitted with tongue; 1a support for the tester insert in the version without tongue; 2a interchangeable tester insert in the version in which, when inserted in support 1, a rotation is not possible, that is, it remains blocked; 2b interchangeable tester insert in the version in which, when insertd in support 1, rotation is possible when it comes in contact with the material to be machined; 2c interchangeable tester insert in the version in which, when inserted in the support without tongue, rotation is possible when it comes in contact with the material to be machined; 3a and 3b lock rings 4a upper element of the grinding wheel, seen from above; 4a1 upper element of the grinding wheel, seen from below; 4b lower element of the grinding wheel, 5 anti-rotation support pin for the support; 6 ball bearing 7 lock screw F tooth for anti-rotation blocking of the interchangeable insert N central core of the bearing. The support 1 (fig. 2) is a plate of suitable length that has a bearing of the ball or similar type attached at one end. The interchangeable insert 2a or 2b, which can have sundry configurations, is housed on the outside part of the element that contains the bearing 6 mounted on support 1. The tester insert 2a can be outfitted with a tooth F, which is the element that prevents rotation once applied on support 1 depending on whether it is wished to use a blocking system or not. The interchangeable tester insert 2a positioned on its support, by means of tooth F, which prevents its rotation, both when the grinding wheel turns and when it performs its function in contact with the stone to be machined. The interchangeable tester insert 2b, when inserted in support 1, does not rotate when the grinding wheel turns, but only when it comes into contact with the stone to be worked does it begin to rotate, accompanying the working with a motion of translation, thus not causing any wear and not damaging the material itself in any way. In the support without tongue 1a, which has a ball bearing or similar fixed on its interior, is inserted by housing in it the interchangeable tester insert 2c, which can have sundry configurations, it constituting another variation that can perform the function of tester. Just as for the other versions, with considerable economic savings both during use and in its production. The interchangeable insert 2c, housed on support 1a, as too insert 2b, lodged on support 1, since independent in the dragging of rotation both of support 1a, and 1 and of bearing 6, when it is in contact with the stone to be worked, becomes independent of the inertia that causes its rotation, and begins to translate, accompanying the working, thus preventing the burning due to braking that is caused by some of the current techniques. Elements 4a and 4b, respectively above and below the grinding wheel, press the bearing between themselves, and the whole remains fixed by means of rings 3a and 3b, which are so built as to contain said bearing 6, which in its turn is inserted in support 1 or 1a, which contains the interchangeable insert 2a or 2b or 2c, they having the function of tester. The ball bearing 6, housed in support 1 or 1a, has the task of making the support itself independent in the rotation of the grinding wheels. Bearing 6 is available on the market and the grinding wheels, such as those shown for example, 4a-4b, have been in use, in sundry configurations, for a long time. By means of support 1, the interchangeable insert 2a or 2b can be used for more than 3/4 of its -- perfectly circular --circumference, permitting its use too with grinding machines that are not perfectly perpendicular to the material to be worked: This fact is another of the advantages offered over earlier techniques. By shifting the point of support of support 1, by means of pin 5 on the machine, the interchangeable tester insert 2a or 2b works in any direction over the 360° of the plane. Said interchangeable insert 2a or 2b or 2c can be made of any material, whether metal, glass, ceramic, etc., and may take on different configurations depending on the use to be made of it. The invention displays significant advantages costwise and in the simplicity of its use and manufacture. Furthermore, owing to its structure it is easier to use in comparison with earlier techniques.

Claims: A tester system for working marbles and the like, comprising a first (4a) and a second (4b) grinding element, arranged one adjacent to the other and apt to rotate about a common rotating axle to abrade a material to be worked, and an annular tester insert (2a; 2b; 2c) arranged between said grinding elements, characterised in that it further comprises: an annular support member (1; 1a) for lodging said tester insert so that said tester insert is interchangeable; a ball bearing (6), arranged at said rotating axle through said support member, to uncouple this latter member from the rotation of said grinding elements so as to make said tester insert idle with respect to said grinding elements, wherein said first (4a) and second (4b) grinding elements have respective lock rings (3a, 3b) for mounting said ball bearing (6). The tester system according to claim 1, wherein said support member (1) has a tongue projecting outwardly, apt to abut an anti-rotation pin (5). The tester system according to claim 2, wherein said tester insert (2a) has an anti-rotation tooth (F) apt to abut said tongue of said support member (1). The tester system according to any of the preceding claims, wherein said tester insert (2a; 2b; 2c) is rested onto said support member (1; 1a). The tester system according to any of the preceding claims, wherein said tester insert (2a; 2b; 2c) is made in a material selected in a group comprising metal, glass and ceramic.

Inventors: DI MATTIA MAURO, DI MATTIA, MAURO
Applicants: DI MATTIA MAURO, DI MATTIA, MAURO
Application year: 1998
Main classification: B24D5
IPC codes: B24B9, B24B5, B24D5