PARTICULARLY FOR GOLD, SILVER AND COSTUME JEWELRY

Technical field The present invention refers to a diamond cutting machine with manual control, particularly for gold, silver and costume jewelry.

There are present in the market from many years diamond cutting machines that allow to decorate the outer surface of objects of gold, silver and costume jewelry in order to stand out reflecting bright light, giving the surface a particularly decorative effect.

Background Art

At the present state of the art, there are automatic machines controlled by the user by means of a data processing program with numerical control which allow to fully realize the piece of jewelry to be diamond simply by setting some data.

These machines that provide, on a supporting frame, a horizontal spindle for moving a driving head that rotates around a first axis substantially parallel to the surface of the workpiece. The driving head can have one or more tool- holder heads. Each tool-holder head usually includes four or six cutters interchangeable between them. To the supporting structure is also connected a piece-holder divider to which the object to be diamond cut is fixed. The divider is adjustable both around a second axis substantially parallel with respect to the machining surface to allow the machine to work rings, earrings and bracelets, both around an axis oblique with respect to the first axis to allow a greater variety of surface decorations.

Programs that control the machine are necessarily highly sophisticated and therefore extremely expensive given that even the smallest mistake on an article of precious metals can result in very high cost to the company that makes jewelry. This type of devices, in addition to being very expensive as already said, present other problems.

First of all, pieces created with an automatic or semi-automatic diamond cutting machine, are produced in series which means that although the cut are very accurate, they are equal to each other, lacking the charm of small imperfections made by the artisan.

Another drawback of this type of machine consists in the fact that you it is not possible to carry out diamond cutting of objects that have a thickness less than 0.20 mm, otherwise the tool ruins the metal, thus forcing companies to offer products not always highly competitive given the current price of precious metals. Another problem of know diamond cutting machines is due to the fact that existing machines are not able to carry out different types of processing that involve different planes of the piece to be diamond cut. For this reason, the user is forced to stop the processing by a machine of certain characteristics in order to continue with a second type of diamond cutting machine then often return to the initial machine, with considerable inconvenience and loss of time.

Disclosure of the Invention

The aim of the present invention is to eliminate the drawbacks and the problems noted above in known types of diamond cutting machines, particularly for gold, silver and costume jewelry that allows to work the surfaces of a piece with thicknesses less than 0.20 mm in order to increase the economic competitiveness of the product.

Within the aforementioned aim, a purpose of the present invention is to provide a machine that gives the possibility of obtaining a precise diamond cut but with the attractiveness of the small imperfections of the workpiece obtained by artisan manufacturing.

Another purpose of the present invention is to allow a low initial capital investment in the purchase of this machine devoid of the expensive technology that allows the electronic automation. Another object of the invention is to provide a diamond cutting machine that is multi-tasking and allow to perform different types of machining operations without forcing the operator to change location.

Another object of the invention is to provide a diamond cutting machine with manual control, particularly for gold, silver and costume jewelry, with means easily available in commerce and using materials in common use, so that the device is economically competitive.

This aim, these and other objectives, that will become better apparent hereinafter, are achieved by a diamond cutting machine with manual control, particularly for gold, silver and costume jewelry, according to the invention, comprising a supporting frame for a spindle, connected to motor means, for moving a driving head around an axis of rotation substantially parallel with respect to the machining surface of the workpiece to be diamond cut, characterized by the fact of comprising a manual drive means of said driving head, for approaching said driving head to the workpiece to be diamond cut along a direction of approach substantially normal to the machining surface of said workpiece to be diamond cut, said lever being pivoted on a fulcrum integrally connected to said supporting frame between an initial position and a final position of said lever. Brief description of the drawings Further characteristics and advantages of the invention will become apparent from the description of a preferred embodiment, but not exclusive, of the diamond cutting machine with manual control, particularly for gold, silver and costume jewelry, illustrated by way of non-limitative example in the accompanying drawings in which:

Figure 1 is the diamond cutting machine with manual control in front view;

Figure 2 shows a detail of the mechanism of working of the translating means interposed between the lever and the driving head, with the lever in the initial position; Figure 3 shows a detail of the mechanism of working of the translating means interposed between the lever and the driving head, with the lever in the final position;

Figure 4 represents the lever;

Figure 5 illustrates a side section of the diamond cutting machine with translating means in the resting configuration;

Figure 6 illustrates a side section of the diamond cutting machine with translating means in operating configuration and with the driving head working on the piece to be diamond cut; Figure 7 illustrates a side view of the diamond cutting machine provided with rotating arm.

Modes for carrying out the Invention

With reference to the above figures, the diamond cutting machine with manual control, particularly for gold, silver and jewelry costume, according to the invention, which is identified in its entirety with the reference numeral 1, comprises a supporting frame 2 for a spindle 3, connected to motor means 24, for moving a driving head 4 around an axis of rotation 10 substantially parallel to the surface of the workpiece to be diamond 9. Normally, the driving head 4 has at least one tool-holder head 5 which can be provided with one or more cutters.

A main feature of the invention is to comprise manual drive means of the driving head 4, for the approach of the head 4 to the workpiece 9 along a direction of approach 20. The direction 20 is substantially normal to the machining surface of the workpiece 9 and is normally perpendicular to a work table, defining a worktop parallel to the ground.

Advantageously, manually operated means have a lever 7 operatively connected to the driving head 4 and pivoting on a fulcrum 8 integrally connected to the frame 2 between an initial position 7' and a final position 7". In the embodiment here presented, it is provided a piece-holder divider 11, per se known, connected to the supporting frame 2 for fixing the workpiece to be diamond 9. The divider 11 is rotatable both around second axis 25 substantially parallel to the machining surface, and around axis 30 oblique with respect to the axis 10.

As from Figure 5, the workpiece to be diamond cut 9 is placed on a mask 17 in hard plastic connected to the piece-holder divider and by the lever 14, per se known, is placed in the most suitable position on the worktop. Because of levers 12 and 13, per se known, which act on the axis 25 and 30 and the lever 14, the workpiece 9 is oriented in the space, in order to present to the cutter the face to be machined.

Advantageously, translation means are provided interposed between the lever 7 and the driving head 4, to ensure the connection of these two elements (7 and 4). Preferably, such translating means comprise a rod 21 having its two ends pivoting respectively on the lever 7, in correspondence of a third axis of rotation 15, and on an arm 22 associated with a portion of the driving head 4, in correspondence of a second axis of rotation 16. The portion of the head 4 can be for example a protruding 29 (Figs. 5 and 6] which slidably engages on a guide 23 defined on the rotatable column 28 supporting the head 4 and that extending along the direction of approach 20.

It can be further provided a handle 6 associated to the supporting frame 2, for supporting the operator's hand that actuates the lever 7. Advantageously, the initial position 7' of the lever 7 corresponds to the resting configuration of the translating means.

As from Figure 3, the final position 7" of the lever 7 corresponds to the configuration of maximum lowering "Z" of the driving head 4.

Preferably, the lever 7 has a first abutment surface 18 in the initial position 7' and a second abutment surface 19 relative to the final position 7" on an end stop 27 integrally connected to the frame 2, in order to limit the use of lever 7 itself and facilitate its maneuverability (see fig. 4).

Advantageously, means may be provided for restoring the resting configuration. With reference to Figure 2, said restoring means may comprise a spring 26 (or other similar elastic means) for returning the arm 22 so as to bring the lever 7 in the initial position 7'. The spring 26 has a first end integrally connected to the frame 2 and the other end associated to the arm 22. In the embodiment here presented, the spring 26 is interposed between the end stop 27 and the arm 22.

In the variant embodiment illustrated in Figure 7, the diamond cutting machine has means of rotation of the column 28 around the direction of approach 20, operable by the user such as by a crank handle (not shown) placed at the base of the column 28 itself, and that a person skilled in the art can easily accomplish.

Advantageously, it can be expected that the column 28 also includes an arm 31, supporting a rotating tip 32 removably associated with a hub 33 of the arm 31 (like the tip of a drill), arranged to be rotated around the direction 20 by means of the aforesaid rotation means, so that the user, by operating the crank handle, can choose to use the arm 31 alternatively to the head 4. The tip 32 is arranged to be rotated eccentrically with respect to a chosen axis 35 affecting on a point on the outer surface of the workpiece to be diamond cut 9 defined by the user, in order to allow the engraving of circular lines (circles, ellipses, semi- circumferences, etc.) on the workpiece 9 and is also arranged to be moved along the direction of approach 20 by the manual driving means described above (and that, similarly to what was seen, including the lever 107 and the handle 106), between a between an initial position 32' and a final position which corresponds to a configuration of maximum lowering of said tip itself. Also the arm 31 can be powered by motor means 24 or by other driving means 124.

During normal operation, the driving head 4 rotates on itself around the axis 10 by putting in rotation the cutter on the tool-holder head 5 that acts on the workpiece to be diamond cut 9.

The workpiece 9, supported by the mask 17, has already been placed by the operator in the proper position by moving the levers 12, 13 and 14 (Fig. 5).

Referring to Figures 4 and 6, when the operator diamond cuts the workpiece 9, actuates the lever 7 by rotating it toward the handle 6 which for convenience grasps with the palm of the hand and bringing it from the initial position 7' to an operating position, whose maximum height z corresponds to the position 7" with the second surface 19 in contact with the lower face of the end stop 27 (fig. 4).

In so doing, the operator rotates the lever 7 around the fulcrum 8 to move from the initial position 7' towards the final position 7" (but it is not necessary that this position 7" is reached for diamond cutting the workpiece 9). In this way, the rotation of the lever 7 allows the rod 21 to translate toward the worktop along the direction 20 carrying with it the driving head 4 that flows through the guide 23. In this configuration, the cutter of the tool-holder head 5 affects an imprint on the workpiece 9 and the operator can prepare the surface of the workpiece for the subsequent imprint, releasing the lever 7 and subsequently actuating one or more of the levers 12, 13 and 14. When the operator releases the lever 7, through the action of the spring 26 the rod 21 goes up to the end stop 27, returning to the initial position 7' with the first abutment surface 18 in contact with the lower face of the end stop 27 itself.

The operation thus described is repeated as long as the diamond cutting of the workpiece is completed.

If the operator decides to change the machining on the workpiece 9 and decides to make circular shapes, by rotating the crank handle, the column 28 will be put in rotation and in front of him, the arm 31 will take the place of the head 4. Similarly, it is possible to return to the initial configuration. Operating the lever 107, which is a completely identical to lever 7, i.e. by rotating it toward the handle 106 and bringing it from the initial position 107' (which corresponds to the position 32' of the tip) to a working position in contact with the workpiece 9, the rotating tip 32 is lowered due to the same translating means already described for the driving head 4 and comes into contact with the workpiece 9. On the latter, thanks to strategically placed divider door - piece 11 will begin to describe the circular shapes predetermined smaller if the tip 32 is positioned close to the chosen axis 35, whose size is getting bigger as it moves away from axis 35.

As illustrated for the driving head 4, also for the arm 31 the same restoring means are provided, in such a way that when the operator releases the lever 107 the tip 32 returns to the initial position.

It is understood that a diamond cutting machine that, associated with the rotatable column 28, has other devices in addition to the driving head 4 and to the arm 31, is to be considered fully equivalent. From the above description it is thus evident that the invention achieves the proposed aim and objectives and in particular it is stressed the fact that there is provided a diamond cutting machine with manual control, particularly for gold, silver and jewelry costume, which allows the diamond cutting of parts which even have a thickness of less than 0.10 mm. The manual lowering of the driving head by means of the lever allows the technician to develop a great sensitivity that a numerical control program could never hone. This means that in the case in which the objects to be machined are made of precious metal, reducing the weight of the jewel, the competitiveness of the producer on the market increases considerably. It is therefore only thanks to the refined sensitivity transmitted by the machine to the operator's fingers (and vice versa) by means of the lever that can be possible to diamond cut the piece with the desired depth. The more or less strong vibrations, that the diamond cutting machine transmits to the operator and discharge on his fingertips, indicate to him if he can go even more in depth or, otherwise, the cutter has reached the limit and a further lowering damage of the jewel.

In practice, due to the use of the manual lever, it is as if a tip for diamond cutting is embedded onto the fingertips and therefore the operator maneuvers the diamond cutting machine with precise manual control, especially for gold, silver and costume jewelry.

Another advantage of the diamond cutting machine, according to the invention consists in the fact that the use of the manual lever makes possible the achievement of a semi-craft result of the product, in which the extreme precision of the machine is combined with the small imperfections (wanted and not) of the surface of the finished workpiece.

Another advantage of the invention is that the elimination of technologically advanced (and expensive) part of the machine saves a large portion of the initial capital to invest. Another advantage of the diamond cutting machine, according to the invention, consists in the fact that, thanks to the simple rotation of the column 28, the operator can choose the most suitable tool to achieve the desired design project, for example using first the driving head equipped with cutters and then the eccentric tip, then return to work with cutters.

Not least, the use of means easily available in the market and the use of common materials, make the device even more competitive from the economic point of view.

The invention thus conceived is susceptible to numerous modifications and variations, all within the scope of the inventive concept.

Moreover, all the details may be replaced with other technically equivalent elements.

In practice, the materials employed, as well as the dimensions, may be any according to requirements, provided they are consistent with the realization purpose.