EP2671676B1 - System for finishing a part made of a plurality of materials - Google Patents

Description

Field of the invention

The invention relates to a system for finishing a part formed from several materials and, more particularly, such a part in which each material has a different hardness. Such a system is for example known from the document EP 0073536-A2 , representing the preamble of claim 1.

Background of the invention

It is known practice to satin elements in order to improve their visual rendering. However, it is difficult, when the part is made of several materials, to properly satin finish only a part of the part. Currently, it is necessary to have a rotating brush and manually satin the desired parts. This results in too high a cost and a finish which is too heterogeneous from one satin part to another of the part.

Summary of the invention

The aim of the present invention is to overcome all or part of the drawbacks mentioned above by providing a system for finishing a part formed from several materials which allows the selective satin-finishing of one or more of the materials with great homogeneity.

To this end, the invention relates to a system for satin-finishing a part comprising at least two materials of different hardnesses, the system comprising at least one receiving device serving as a container for abrasive means comprising a hardness between those of said at least two materials of different hardnesses, a support device comprising means for fixing the part, means for bringing the part closer to the abrasive means and means for relative movement of the part with respect to the receiving device, said relative displacement forming the directions of the satin lines characterized in that each receiving device comprises a tank containing said abrasive means in powder form and in that the tank is elastic in order to block said abrasive means in powder form between the tank and the part even under the constraint of the approximation means while guaranteeing optimum satin finish of said at least one material having the lowest hardness without modifying the appearance of said at least one material having the greatest hardness.

It is therefore understood that the directions of the satin lines are directly obtained by the relative displacement means of the finishing system and are linear or concentric. Consequently, the time necessary to satin-finish the zones is always the same regardless of the number of zones to be satin-finish on the same part and the lines are perfectly homogeneous with respect to each other.

• les particules comportent un diamètre compris entre 0,3 mm et 1 mm ;
• les moyens abrasifs sont formés à partir de silice et/ou de corindon et/ou de ponce et/ou de diamant et/ou de nitrures et/ou de carbures et/ou d'alumine ;
• chaque dispositif de réception comporte en outre des moyens de vibration de la cuve permettant de renouveler la couche supérieure des moyens abrasifs quand les moyens de rapprochement écartent la pièce des moyens abrasifs ;
• les moyens de rapprochement comportent un actionneur permettant de presser la pièce contre les moyens abrasifs ;
• l'actionneur des moyens de rapprochement exerce une force comprise entre 1 Kg_f et 5 Kg_f ;
• les moyens de déplacement relatif comportent un moteur permettant à la pièce d'imprimer un mouvement de va-et-vient contre les moyens abrasifs selon lesdites directions de raies de satinage afin de rendre le satinage plus homogène ;
• le système comprend au moins deux dispositifs de réception afin de renouveler lesdits moyens abrasifs d'un des dispositifs de réception quand l'autre dispositif est utilisé pour finir ladite pièce ;
• lesdits au moins deux dispositifs sont montés sur un plateau déplaçables à l'aide d'un chariot afin de sélectivement positionner un desdits au moins deux dispositifs en vis-à-vis du dispositif de support.

In accordance with other advantageous characteristics of the invention:

• the particles have a diameter of between 0.3 mm and 1 mm;
• the abrasive means are formed from silica and / or corundum and / or pumice and / or diamond and / or nitrides and / or carbides and / or alumina;
• each receiving device further comprises means for vibrating the tank making it possible to renew the upper layer of the abrasive means when the approximation means move the part away from the abrasive means;
• the approximation means comprise an actuator making it possible to press the part against the abrasive means;
• the actuator of the approximation means exerts a force of between 1 kg _f and 5 kg _f ;
• the relative displacement means comprise a motor allowing the part to impart a back and forth movement against the abrasive means according to said directions of satin lines in order to make the satin finish more homogeneous;
• the system comprises at least two receiving devices for renewing said abrasive means of one of the receiving devices when the other device is used to finish said part;
• said at least two devices are mounted on a plate movable with the aid of a carriage in order to selectively position one of said at least two devices opposite the support device.

Brief description of the drawings

• la figure 1 est un exemple d'application d'une pièce formée de plusieurs matériaux ;
• la figure 2 est une représentation en coupe d'un dispositif de réception selon l'invention ;
• la figure 3 est une représentation en perspective d'un système de finissage selon l'invention ;
• la figure 4 est une représentation en perspective d'un dispositif de support selon l'invention.

Other features and advantages will emerge clearly from the description which is given below, by way of indication and in no way limiting, with reference to the appended drawings, in which:

• the figure 1 is an example of application of a part formed from several materials;
• the figure 2 is a sectional representation of a reception device according to the invention;
• the figure 3 is a perspective representation of a finishing system according to the invention;
• the figure 4 is a perspective representation of a support device according to the invention.

Detailed description of the preferred embodiments

The part formed from several materials according to the invention can in particular be integrated into or form all or part of the covering of a timepiece without distinction. Thus, it could form all or part of a case, a bracelet, a bezel, a dial, a crystal, a push-piece and / or a crown. It is also possible to integrate or compose parts formed from several materials belonging to a watch movement such as, for example, a bridge and / or a plate and / or an oscillating weight.

In the example shown in figure 1 , the explanation of the invention will be given from an annular body 3 comprising inlaid decorations 5, 7, 9, 11, 13 forming the graduations of a bezel 1. Thus, the bezel 1 comprises a body 3 in a first material which is inlaid by at least one decoration 5, 7, 9, 11, 13 in one or more other materials. The bezel 1 is intended to form a part which is very resistant to wear, the visual quality of which is improved, in particular in terms of contrast.

As shown in figure 1 , it can be seen that each decoration can, advantageously according to the invention, be of any shape, such as, for example, a geometric figure 7, 9, 11, an alphanumeric character 5 or even a phosphorescent indicator 13.

The body 3 is preferably made of a first hard material, that is to say of a hardness greater than 800 Hv, such as for example a ceramic. The first material can, by way of example, comprise an oxide, a carbide or a nitride based on aluminum, titanium, zirconium or silicon to form all or part of the body 3. Of course, other materials hard are possible.

According to the invention, the second material or the other materials used for the decorations 5, 7, 9, 11, 13 are of lower hardness than the first material. Thus, advantageously, the invention relates to a finishing system 21 of such a part 1, each material of which has a different hardness. The system 21 advantageously makes it possible to satinize the material or materials having the lowest hardness without modifying the appearance of the material having the highest hardness. Thus, in a nonlimiting manner, the other less hard materials can be a composite ceramic, a glass, an enamel, a metal or a metal alloy.

However, it will be understood that the hardest material could be that or those of the decorations 5, 7, 9, 11, 13 and not that of the body 3 as will be explained below.

According to the invention, the finishing system 21 comprises at least one receiving device 23, 23 'serving as a container for abrasive means 20 and a support device 25 comprising means 22 for fixing the part 1. In addition, the system 21 further comprises means 27 for bringing the part 1 closer to said abrasive means 20 and means 29 for relative displacement of the part 1 with respect to the receiving device 23 along the lines desired satin finish.

Advantageously according to the invention, the approximation means 27 and the relative displacement means 29 can be mounted either on the support device 25 or on the receiving device 23. In the example of figure 3 , the approximation means 27 and the relative displacement means 29 are mounted on the support device 25.

Each receiving device 23, 23 'comprises a tank 24, 24' containing said abrasive means 20 in powder form in which the approximation means 27 at least partially immerse the part 1.

According to the invention, the powder of abrasive means 20 is formed by particles whose hardness is greater than the material (s) to be satin-finished but less than the material (s) to be left intact. Preferably, part 1 will therefore be polished prior to its finishing using the system 21. It will be understood that only part of part 1 will have its surface condition modified, that is to say that at least one of the materials used will not be altered on the surface. By way of example, the particles, the diameter of which may be between 0.3 mm and 1 mm, may be formed from silica and / or corundum and / or pumice and / or diamond and / or nitrides and / or carbides and / or alumina.

As explained above, the approximation means 27 exerts a force sufficient to immerse a part of the part 1 in the powder of abrasive means 20. According to the invention, the tank 24, 24 'is elastic in order to adapt to the level of powder in the tank 24, 24 'relative to the force imposed by the means 27 of approximation. The tank 24, 24 'thus exerts a counter-force B intended to press the powder 20 between the tank 24, 24' and the part 1. In fact, during the development of the powder. system 21, it has been shown that a rigid tank allowed the powder to move and cover the part 1, making the finishing imperfect. It is therefore understood that, thanks to the elastic tank 24, 24 ′, the powder 20, advantageously, does not cover the whole of the part 1 even under the stress of the means 27 for bringing together while guaranteeing optimum finishing.

In addition, at each finishing, the particles of abrasive means 20 having rubbed on the part 1 become blunt. This is why, advantageously according to the invention, each receiving device 23, 23 'further comprises means 26, 26' for vibrating the tank 24, 24 'making it possible to renew the upper layer of the powder when the means 27 of approach separate the part 1 from the abrasive means 20. In fact, the upper layers of particles present in the tank 24, 24 'having participated in the finishing have seen their diameter decrease. Consequently, during the vibrations C, these smaller particles are mechanically displaced towards the bottom of the tank 24, 24 '. Thus, it is understood that the powder at the surface is renewed by particles of larger diameters, that is to say not blunt.

In the example shown in figure 4 , the fixing means 22 of the support device 25 comprise a fastener 30 formed of three movable fingers approaching to hold a part 1. This fastener 30 is mechanically connected to the approximation means 27. Preferably, the approximation means 27 comprise an actuator 28 making it possible to press the part 1 against the abrasive means 20 in the direction D in order to provide a force A against the abrasive means 20 necessary for the finishing. Preferably, the actuator 28 exerts a force of between 1 and 5 kg.

Finally, in the example shown in figure 2 , the relative displacement means 29 comprise a motor 31, which may belong to the actuator 28 of the approximation means 27, allowing the part to impart a back and forth movement E against the abrasive means 20 along said desired satin lines.

For an annular part 1 shown as an example in figures 1 and 4 , the satin lines will be concentric. The back-and-forth movement E will then be an alternation of trigonometric and retrograde rotations. In fact, during the development of the system 21, it was shown that a simple rotation made the finishing less homogeneous. Such a back and forth movement E can be exerted over an amplitude of between 5 and 20 mm depending on the size of the part 1. During development, it has been shown, in the case of a rotary movement E of back and forth. -and-comes, that an amplitude between 20 and 40 degrees gives a great homogeneity of satin.

In the case where the satin lines are linear, the motor of the relative displacement means will induce a back-and-forth movement E in translation.

A finishing process according to the invention therefore follows the following steps. First, a part 1 comprising at least two materials of different hardnesses is manufactured and then at least one of the faces is polished. Secondly, the part 1 is mounted on the fastener 30 of the fixing means 22, the polished surface being intended to come into contact with the abrasive means 20. Thirdly, the approximation means 27 are activated according to the movement D until part 1 touches the abrasive means 20.

Fourthly, the approximation means 27 exert a force between the part 1 and the abrasive means 20 necessary for the satin finish. Advantageously according to the invention, the abrasive means 20 in powder form are blocked by this force and the elastic counter-force B of the tank 24. From the third or fourth stroke, the relative displacement means 29 are also activated according to the invention. the back-and-forth movement E. The fourth beat may take a few seconds to obtain a satisfactory satin finish.

Fifthly, the approximation means 27 and the relative displacement means 29 are deactivated in order to move the part 1 away from the abrasive means 20. At the same time, the vibration means 26 are activated in order to renew the upper layer of the abrasive means. abrasive means 20 in powder form. The fifth beat may take a few seconds to obtain a satisfactory renewal.

After the fifth beat, a new cycle is started with a new part or with the same part, i.e. starting from the first beat or from the third beat.

In the example shown at figure 3 , it is noted that the finishing system 21 comprises two reception devices 23, 23 '. This embodiment is preferred in order to gain in productivity. Indeed, as visible at the figure 3 , while a part 1 is worked using a first receiving device 23, the second receiving device 23 'can be renewed by abrasive means. Thus, the new cycle explained above is initiated with the aid of the carriage 33 which will move the plate 32 so that the second device 23 'is positioned opposite the support device 25.

It is therefore understood that it is possible to envisage finishing the parts 1 by applying to each part 1 consecutively the abrasive means of a different type of at least two receiving devices 23, 23 'and / or at least two systems 21.

It is advantageously understood according to the system 21 of the invention that the time necessary to satin-finish the zones is always the same regardless of the number of zones to be satin-finish on the same part. In addition, the lines are perfectly homogeneous with respect to each other whether they are curved or linear.

Of course, the present invention is not limited to the example illustrated but is susceptible of various variants and modifications which will appear to those skilled in the art. In particular, it is also possible to finish parts 1 of very varied shapes, that is to say not limited to an annular shape presented to figures 1 and 2 , both for an element of a timepiece and outside of watchmaking as for tableware, for jewelry or for jewelry.

In addition, each system 21 can include more or less reception devices 23, 23 'and / or more or less support devices 25 without these embodiments going beyond the scope of the invention. By way of example, the same finishing system 21 could comprise two support devices 25 making it possible to finish two pieces simultaneously and six receiving devices 23, 23 'with three different types of abrasive means 20 used mounted on a single movable plate 32. by a trolley 33.

Finally, depending on the materials used for the part, the abrasive means must be adapted. They cannot be limited to the materials mentioned in the present description.

Claims (10)

1. A system (21) for satin finishing a part (1) including at least two materials of different hardnesses, the system (21) including:

   - at least one receiving device (23, 23') containing abrasive means (20) including a hardness greater than at least one material to be satin finished but less than at least one other material to be left intact among said at least two materials of different hardnesses,

   - a support device (25) including means (22) for fixing the part (1),

   - means (27) for approximating the part (1) to the abrasive means (20) and

   - means (29) for relatively displacing the part (1) with respect to the receiving device (23), said relative displacement forming the directions of the satin finishing lines, and

   - each receiving device (23, 23') includes a tank (24, 24') containing said abrasive means (20) in powder form, characterised in that the tank (24, 24') is elastic in order to press said abrasive means in powder form (20) between the tank (24, 24') and the part (1) even when the abrasive means are under the constraint of approximation means (27) ensuring optimum satin finish of said at least one material to be satin finished without modifying the aspect of said at least one other material to be left intact, and

   - the relative displacement means (29) are configured to form directions of satin finishing lines which are linear or concentric.
2. The system (21) according to the preceding claim, characterised in that the particles have a diameter comprised between 0.3 mm and 1 mm.
3. The system (21) according to one of the preceding claims, characterised in that the abrasive means (20) are formed from silica and/or corundum and/or pumice and/or diamond and/or nitrides and/or carbides and/or alumina.
4. The system (21) according to one of the preceding claims, characterised in that each receiving device (23, 23') further includes means (26, 26') for vibrating the tank (24, 24') allowing to renew the upper layer of the abrasive means (20) when the approximation means (27) move the part (1) away from the abrasive means (20).
5. The system (21) according to one of the preceding claims, characterised in that the approximation means (27) include an actuator (28) allowing to press the part (1) against the abrasive means (20).
6. The system (21) according to the preceding claim, characterised in that the actuator (28) of the approximation means (27) is configured to exert a force comprised between 1 Kgf and 5 Kgf.
7. The system (21) according to one of the preceding claims, characterised in that the relative displacement means (29) include a motor (31) configured to allow the part (1) to impart a back and forth movement (E) against the abrasive means (20) in said directions of satin finishing lines in order to make the satin finish more homogeneous.
8. The system (21) according to one of the preceding claims, characterised in that it comprises at least two receiving devices (23, 23') in order to renew said abrasive means of one of the receiving devices when the other device is used to finish said part.
9. The system (21) according to the preceding claim, characterised in that said at least two devices (23, 23') are mounted on a plate (32) displaceable by means of a carriage (33) in order to selectively position one of said at least two devices facing the support device (25).
10. The system (21) according to one of the preceding claims, characterised in that the part (1) is an element of the external parts of a timepiece.

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