FR3037081A1 - METALLIZATION METHOD AND TOOL FOR PERFORMING COMPLEX DEGRADES - Google Patents

Abstract

The invention provides a method of metallizing the surface of a workpiece (1), the workpiece being held on a support arm (20), the method comprising the steps of: a) projecting on the workpiece a base coat , b) applying a treatment for decreasing the surface tension of the base coating, and c) projecting at least one redox solution comprising metal ions on the workpiece to metallize a surface of the workpiece, wherein, when in step a), the work support arm of the workpiece extends vertically, the method being characterized in that it further comprises a step of tilting the work support arm of the workpiece from the vertical position between the workpiece step a) and step c). The invention also provides a tool for tilting the workpiece according to this method.

Description

FIELD OF THE INVENTION The invention relates to a method of metallizing a surface of a part such as a bottle or a bottle, and a tool for supporting the part allowing the implementation of this method.

The invention is particularly applicable to the metallization of glass or plastic parts. DESCRIPTION OF THE PRIOR ART Document FR 2 934 609 already discloses a metallization process for a part such as a bottle, which may be made of glass, plastic, composite material, metal or the like. This process involves several steps of preparation and treatment of the part to improve the efficiency of the metallization. In particular, the method comprises firstly a step of projecting a base varnish on the surface of the part, then allowing the deposited metal to adhere to the surface of the part. A surface treatment is then used to oxidize the base varnish and change the surface tension of the varnish to improve its wettability. This surface treatment is for example a flame, that is to say the exposure for a reduced duration of the room to a flame. The treatment may then comprise an activation step, or sensitization of the surface to be covered, by spraying a solution based on stannous chloride SnCl 2, and then rinsing. Finally, the metallization itself is carried out by projecting on the surface of the piece one or more redox solutions containing metal ions, causing a precipitation of metal directly on the surface of the piece. For example, the metallization is advantageously carried out by simultaneous spraying of a solution containing Ag + silver ions, and a reducing solution. For the industrial implementation of this step, the piece to be metallized is fixed on a support. For example, in the case where the piece is a bottle or a bottle, it is mounted on a support by its mouth, the support being arranged vertically of the piece, below or above it.

In addition, the carrier generally causes the workpiece to rotate to provide uniform metallization over the entire circumference of the workpiece. Such a metallization process makes it possible to produce an opaque or translucent metal coating, depending on the quantity of metal precipitated on the surface, and therefore on the duration of the redox solution spray and / or the speed of rotation of the piece on its support. It is also possible to perform metallization gradients, from a translucent zone to a completely opaque zone, by varying the amount of metal deposited along the surface of the part.

However, in view of the industrial constraints of production of the parts, all the possibilities of gradients are not allowed. Indeed, the method of metallization by spraying redox solutions involves spraying these solutions in excess relative to the amount of metal to be deposited on the surface of the workpiece.

The spraying results in a runoff of water and silver on the surface of the workpiece, which flows along the workpiece to the ground due to gravity, and some of the money may be drop on the piece. Thus, the most opaque part of a metallization gradient is necessarily on the side of the part closest to the ground when the spraying is carried out. It is understood that for a bottle, if the bottle is held by its mouth, by a support disposed under the bottle, it is possible to make a metal gradient from the base, translucent or transparent, towards the mouth of the bottle completely opaque.

If, on the other hand, the bottle is held at its mouth by a support placed above the bottle, a metallic gradient is obtained from the mouth, which is translucent or transparent, towards the base, completely opaque. It is therefore not possible to produce a double gradient, comprising a completely metallized and opaque part in the middle of a part, and two less metallized parts at the ends of the part. DESCRIPTION OF THE INVENTION The purpose of the invention is to overcome the drawbacks of the prior art by proposing a metallization process that makes it possible to produce a double gradient 3037081 3 in one piece, comprising at the ends of a piece two relatively little metallized areas, and between the ends, at least a relatively more metallized area. The invention also aims to provide a tool for implementing this method.

In this regard, the invention relates to a method of metallizing the surface of a workpiece, the workpiece being held on a support arm, the method comprising the steps of: a) projecting onto the workpiece a coating of base, b) applying a treatment for decreasing the surface tension of the base coating, and c) projecting at least one redox solution comprising metal ions on the workpiece to metallize a surface of the workpiece, wherein in step a) the work support arm extends vertically, the method being characterized by further comprising a step of tilting the work support arm from the work position. vertically between step a) and step c). Advantageously, but optionally, the method according to the invention may further comprise at least one of the following features: after the inclination of the support arm (20), it can extend into a position between the vertical position and a horizontal position. step b) may comprise a flame treatment. The method may further comprise preliminary steps in step c), said steps comprising activation of the surface of the flask by stannous chloride sputtering and rinsing. the inclination of the support arm of the workpiece can be implemented between step a) and step b), between step b) and step c), or between the rinsing step and step c). The support arm of the part can be rotatable during the implementation of steps a) to c). The invention also relates to a tool for supporting a workpiece for implementing the method according to the preceding description, comprising: a first connector, adapted to be mounted integral in rotation with a support arm of the piece, and - a second connector, adapted to be mounted integral in rotation with a drive shaft, and the support tool being characterized in that the connectors are pivotally mounted relative to one another. another, so as to form between them a variable angle over an angular range, and in that it further comprises a member for transmitting a rotational movement from one connector to the other throughout said angular range.

Advantageously, but optionally, the support tool according to the invention may further comprise at least one of the following features: the angular range may be equal to 90 °. each connector may comprise, at one end, a conical pinion, and the motion transmission member may comprise a conical pinion adapted to mesh with the pinions of the two connectors. - The support tool may further comprise a housing formed of two shells, each connector being attached to a respective shell, and the shells being pivotally mounted to one another on said angular range. The tool may further comprise locking means of a connector at a plurality of angular positions in the angular range. The invention also relates to a vial support system comprising: - a support tool according to the foregoing description, - a one-piece support arm attached to the first connector of the support tool, and - a drive shaft, attached to the second connector of the support tool. The method according to the invention provides for tilting the workpiece from a substantially vertical position for the implementation of the redox solution projection step. In this way, the piece can be brought on a substantially horizontal axis, which has the effect of eliminating the flow of metal to other sections than the section that is to be metallized.

Thus, it is possible in particular to produce a gradient in which the ends of the part are weakly metallized and a portion between the ends is more strongly metallized. The proposed tool can be mounted directly on existing industrial installations. It makes it possible to impart to the part a rotational movement around its support arm regardless of the angle formed between the support arm and the drive shaft on which the tool is mounted, which makes it possible to conserve homogeneity of metallization on a circumferential section of the part, whatever the angle in which the support arm is located.

In addition, the tool makes it possible to block the piece and its support arm at several possible angles in an angular range, which makes it possible to bring parts of complex geometries into a horizontal position. DESCRIPTION OF THE FIGURES Other characteristics, objects and advantages of the invention will emerge from the description which follows, which is purely illustrative and nonlimiting, and which should be read with reference to the appended drawings, in which: FIGS. 1b schematically represent the implementation of the main steps of the method according to one embodiment of the invention; FIGS. 2a and 2b show a part mounted on a support tool during the implementation of the method; FIG. 2c represents a top view of a conveyor during the implementation of an oxidation-reduction solution spraying step; FIG. 3 schematically represents an overall view of a support tool according to a method of Embodiment of the invention, - Figures 4a and 4b show, in longitudinal section, a support system comprising a support tool, - Figures 5a and 5b are perspective views of elements of a tool d e support according to one embodiment of the invention.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT OF THE INVENTION Method for Metallizing a Part 5 Referring to FIGS. 1a and 1b, the main steps of a metallization process of a part 1 are represented. The part 1 to be metallized is advantageously a rigid part, made of a material such as a glass, a plastic, a composite material, or a metal, an alloy, etc.

The part 1 is preferably a bottle comprising a neck 10, such as for example a bottle intended for the storage of a cosmetic product or perfume, a bottle, etc. However, the piece 1 is not limited in its form to a bottle. It may for example be any other type of container, for example a glass, or any other three-dimensional object.

The metallization process comprises a succession of steps for treating the surface of the part to be metallized. To advantageously perform this succession of steps, the part 1 is positioned on a support arm 20, extending along a longitudinal axis. The support arm 20 is mounted on a conveyor and driven in translation 20 thereto, to bring the workpiece 1 to the various steps of the method. The support arm 20 is advantageously shaped to be able to be fixed to the workpiece 1 without degrading it. Thus, in the example in which the part 1 is a bottle provided with a neck 10, the support arm 20, visible in FIG. 3, may for example comprise a tube 21 adapted to be mounted inside or to the outside 25 of a neck 10 of a bottle, and two elastic rods 22 can be folded against each other for their insertion into the bottle through the neck. The elastic nature of the rods 22 tends to remove them once they are inside the bottle to bear against the inner walls of the bottle. This support makes it possible to hold the bottle in position relative to the support arm 20, and further to make the bottle integral in rotation with the arm 20 when it itself pivots. Alternatively the support arm may comprise at least one clamp (not shown) for fixing the workpiece by clamping the clamp on the workpiece.

Advantageously, reference can be made to document FR 2 934 609 to obtain more details concerning the implementation of steps 100, 200 and 300 of the method described below. Returning to FIGS. 2a and 2b, the first step 100 of the method comprises the projection on the part 1 of a base coating. This coating makes it possible to smooth the surface of the part to prepare it for the projection of a metallic precipitate. It is advantageously a water-soluble or organic varnish, preferably water-soluble selected, depending on the constituent material of the part to be coated, from the following compounds: alkyds, polyurethanes, epoxys, vinyls, acrylics and mixtures thereof. Preferably, it is an epoxy varnish, or a water-soluble vinyl or polyurethane varnish. During this step, the part 1 is fixed to the support arm 20, which is in a vertical position, that is to say that the axis of the arm 20 is vertical. When the part 1 is a bottle having a cylindrical neck 10, the axis of the support arm 20 is generally coincidental with the axis of the neck 10, so that the axis of the neck is also vertical. In some cases the part 1 has a generally cylindrical shape, coaxial with the axis of the neck. This is particularly the case for most bottles. In these cases, the workpiece extends substantially vertically above or below the conveyor. In addition, the support arm 20 is rotatable about its longitudinal axis to rotate the workpiece 1. In this way, the base coat projection is uniform over the entire surface of the workpiece. The part is thus conveyed by the conveyor to a module 3 in which nozzles 30 project the base coating onto the part. Once the coating is sprayed onto the workpiece 1, the workpiece 1 is advantageously fired or exposed to UV radiation to crosslink the base coat. The method then comprises a step 200 of decreasing the surface tension of the base coating, to facilitate the adhesion of the metal precipitate on the part. This step 200 is advantageously a flaming step, i.e. a step of subjecting the surface of the workpiece 1 to a flame. For example this step can be implemented by rotating the workpiece, and subjecting it to a flame at between 1200 and 1700 ° C, for example 1400 ° C, for a duration of a few seconds, advantageously between 4 and 50 seconds. According to one example, with a flame temperature of 1400 ° C, the part being rotated at a speed of 120 rpm, the flaming lasts 20 seconds. In this step, the support arm 20 holding the workpiece is advantageously always in a vertical position, and rotates the workpiece, so as to allow a homogeneous flame of the entire surface of the workpiece. Alternatively, depending on the result to be obtained, the support arm 20 of the workpiece can be inclined relative to the vertical position in accordance with the description which follows in step 330. The workpiece 1 is always driven by the conveyor, since the output of the module 3 to a flaming module 4 comprising nozzles 40 flaming. Alternatively, the step 200 of decreasing the surface tension of the base coating can also be implemented by treatments of the corona treatment, plasma treatment or chemical treatment type, as described in more detail in the document FR 2 934 609.

The method then comprises a metallization step 300 comprising the projection 330 of at least one oxido-reducing solution comprising metal ions on the surface of the part 1. Advantageously, this step 330 is implemented using pairs of nozzles 50 positioned in a projection module 5. In a pair of nozzles, a first nozzle projects onto the part a solution of metal ions, for example silver ions Ag +, for example a solution of silver nitrate. The silver concentration of the Ag + ion solution is preferably chosen to be between 0.1 g / l and 100 g / l, and preferably between 1 and 60 g / l. A second nozzle simultaneously projects a reducing solution onto the part, for example a 15 g / L aqueous glucose solution. Alternatively, the reducing agent of the solution may be chosen from the group of compounds comprising borohydrides, dimethlaminoborane, hydrazine, sodium hupophosphite, formaldehyde, lithium aluminum hydride, reducing sugars, and mixtures thereof. The reducing agent concentration of the solution is preferably between 0.1 g / L and 100 g / L and preferably between 1 and 60 g / L. Advantageously, reference is made to document FR 2 934 609 to obtain further details on the possible choices of redox solution (s) and the implementation of projection step 330.

During this step, the support arm 20 of the workpiece 1 is inclined, automatically or manually, with respect to the vertical position in which it was during steps 100 and 200. Advantageously, the support arm 20 is inclined until its longitudinal axis is in a position between the vertical position and a horizontal position. For example, the support arm is inclined in a horizontal position. Preferably, as shown in FIG. 2a, the support arm 20 is inclined at an angle such that a surface S of the part to be metallized in a homogeneous manner extends substantially vertically. In this way, the gravity 10 resulting in a vertical run off of the surplus chemical reaction, they remain on the surface S of the workpiece to be metallized. A preferred embodiment is that in which the piece is a symmetrical bottle of revolution about an axis coincident with the axis of the neck 10 of the bottle.

In the embodiment of FIG. 2a, it is desired to metallize a horizontal strip of the surface of the bottle. The surface is a circumferential surface extending perpendicularly to the axis of revolution of the bottle. According to this example, the support arm 20 is advantageously inclined until it reaches a horizontal position, so that the bottle also extends horizontally and the strip S to be metallized extends vertically. Alternatively, as shown in FIG. 2b, when the surface S to be metallized is a strip extending in a direction forming a non-zero angle α with the axis of the neck 10, the support arm 20 is inclined by an equal angle at the angle α relative to the vertical, so as to bring the surface S in a substantially vertical direction 25 during the projection step. Preferably, a is less than or equal to 90 ° so that the bottle does not bother the conveyor. In addition, the piece 1 the piece is preferably always rotated around the arm 20 during the 330 projection step. The fact that the surface to be metallized extends along a vertical direction during the projection step 330 while pivoting around the arm 20 makes it possible to eliminate the effects of gravity tending to make the reaction surpluses run off. of oxidation-reduction along the piece towards one of its ends. Instead, the surpluses remain on the projection surface, evenly distributed over the entire circumference of the workpiece by rotation of the workpiece. Counteracting the effects of gravity allows various gradations to be made on the surface of the workpiece, by modulating the rotational speed of the workpiece around the support arm 20 and / or the duration of the projection of the oxidizing solution. reductive. For example, it is possible to leave the ends of the piece devoid of metal coating, and make a gradient from each end to a strip between the ends, this strip being opaque because fully coated with metal.

Alternatively or in addition, the modulation of the gradient on the surface of the part can also be obtained by modulating the speed of the conveyor and by varying the concentrations of the reagents of the redox solution (s). It is also possible to make several disjoint strips separated by an uncoated metal zone. If necessary, a gradient can be made between the zone and each banner. Advantageously, but optionally, the method further comprises preliminary steps 310, 320 to the projection of redox solutions, to prepare the surface to be metallized. During a preliminary preliminary step 310, the part 1 is brought, at the output of the flaming module 4, into a module 6 in which an activation solution is projected onto the part. This solution is advantageously a stannous chloride solution. The activation step 310 can be carried out according to the sensitization step described in the document FR 2 763 962. It is then immediately followed, in the same module, by a step 320 of rinsing residues of stannous chloride, by spraying a rinsing liquid, for example water. The part can then be dried by air circulation (not shown).

Advantageously, the inclination of the support arm 20 in perspective of step 330 is implemented at the end of this rinsing step 320. Alternatively, it can be implemented before or after the flaming step. The inclination can be implemented manually or automatically.

Returning to step 330 of redox solution projection to metallize the workpiece, the workpiece 1 is then brought into a finishing module 7 to obtain a finishing layer during a finishing step 400. Advantageously, the support arm 20 of the part is repositioned vertically for the implementation 5 of this step, the repositioning can be performed manually or automatically. The finishing step is carried out for example by projection on the piece of a finishing varnish. Advantageously, reference will be made to the finishing step described in FR 2 934 609 for further information on the possible implementations of the finishing step. Tool and Support System of a Part With reference to Figures 3 to 5b, will now be described a support tool 15 for carrying out the method described above. This tool 9 comprises a first connector 90, adapted to be mounted integral with a support arm 20 of the part, shown in dashed lines in FIG. 4b. The connector 90 is advantageously a shaft comprising means 20 for rotating the support arm. For example, these means may take the form of splines (not shown) arranged on the circumference of the connector 90, and adapted to cooperate with complementary splines of the support arm 20. Alternatively, one of the connector 90 and the support arm 20 can receive the other by snapping, tightening, or screwing, etc. The support tool 9 also comprises a second connector 91. This second connector is adapted to be mounted integral with a drive shaft 23. This drive shaft 23 is itself mounted on the conveyor 2 and is driven by rotation and translation by the conveyor 2.

Similarly, the connector 91 is advantageously a shaft comprising means for driving in rotation from or through the drive shaft 23. In FIG. 3, the connector 91 comprises splines 910 adapted to drive splines in rotation. complementary to the drive shaft 23 (not shown).

Alternatively, one of the connector 91 and the drive shaft 23 can receive the other by snapping, tightening, screwing, etc. The connectors 90, 91 of the tool therefore extend along respective longitudinal axes, which are advantageously coplanar. In addition, the connector pins 90, 91 form between them an angle that can vary over an angular range. This angular range is advantageously between 10 and 100 °, preferably of the order of 90 °, to allow, in use, the support arm 20 to move from a vertical position to a horizontal position while the rotary shaft 23 remains upright.

To do this, the support tool comprises a housing formed of two shells 92, 93, the shells being able to be assembled one on the other by allowing a relative pivoting movement between the two shells on said angular range. In addition, each connector 90, 91 is attached to a respective shell 92, 93. The shells delimit between them, when assembled, an internal housing 94. Each connector 90, 91 comprises an end 902, 912 penetrating inside the housing 94 through an orifice arranged in the wall of one or both shells. Thus, each connector is integral in rotation with the shell on which it is mounted. According to a particular exemplary embodiment shown in FIGS. 4a and 4b, the first shell 92 comprises a bottom wall 920 comprising a circular edge and a cylindrical wall or cylinder sector 921 extending around a portion of the edge of the cylinder. the bottom wall 920, perpendicular to the plane of the wall 920. Advantageously, the cylindrical wall 921 extends over an angular aperture corresponding to the complementary of the relative angular range of rotation of the connectors over 360 °. The second shell 93 also comprises a bottom wall 930, comprising a circular edge of a diameter slightly smaller than that of the wall 920. The second shell 93 also comprises a cylindrical wall 931 extending circumferentially around the edge of the wall 930. perpendicular to the plane of the wall 930. The difference in diameter between the bottom walls 920 and 930 corresponds to the thickness of the cylindrical wall 930. Thus, the first shell 92 can be mounted around the second 93 and pivot on it. ci with respect to an axis passing through the centers of the bottom walls 920, 930, perpendicular to the axes of the connectors 90 and 91.

When the two shells 92, 93 are mounted one on the other, the cylindrical walls 931 extending in opposite directions with respect to the respective bottom walls 920, 930, the shells cooperate to form the housing 94. In addition, the first shell 92 comprises an orifice 922 adapted to receive a section of the connector 90. The connector 90 is rotatably mounted in the orifice 922 but is held fixed in translation by stop means 80 shown schematically in FIG. 4b. . The first shell 93 also includes an orifice 932 adapted to receive a section of the connector 91. The connector 91 is rotatably mounted in the orifice 932 but is also held fixed in translation by stop means 81. The second shell also comprises a second orifice 933 extending over an angular sector corresponding to the relative rotation range of the connectors.

When the shells are assembled, the orifice 922 opens into the orifice 933 so as to allow the pivot of the connector 90 relative to the shell 93 on the angular range of displacement. Similarly, the orifice 932 of the first shell opens on the portion of the shell 92 without cylindrical wall, so as to allow the pivot of the connector 91 relative to the shell 92 on the angular range of displacement. Thus, when the two shells 92 and 93 are mounted together, they form an articulation between the support arm 20 and the rotary drive shaft 23 via the respective connectors 90, 91, allowing pivoting of the support arm 20 relative to to the rotary drive shaft 23.

Advantageously, the tool 9 also comprises stop means 95 rotating one connector relative to the other connector on a plurality of relative positions among those covered by the angular pivot range. The stop means may advantageously be a plurality of shims in an arc of a diameter equal to the diameter of the shell 92. These shims may be interposed between the connector 91 and the cylindrical wall 921 to prevent relative rotation of these two elements. Depending on the angular sector covered by the wedges, several angles can thus be blocked.

Alternatively, the hulls 92 and 93 may comprise latching means which hold the hulls in a constant relative position until pressure is exerted to disengage the latching means. By way of example, there is shown a detent means 95 composed of a pin 950 projecting from the cylindrical wall 931 and several orifices 951 arranged on a surface facing the housing 94 of the cylindrical wall 921. the orifice in which the pin is engaged, several relative angular positions of the shells (and connectors) can be blocked. Finally, the support tool also comprises a member 96 for transmitting a rotational movement from one to the other connector over the entire angular range of relative displacement of the connectors. The member 96 comprises for this purpose a conical pinion which is arranged inside the housing, the conical pinion having an axis orthogonal to the plane in which the connectors 90, 91 extend. This axis corresponds to the pivot axis Relative to the two hulls 92, 93 and connectors. In addition, the end of each connector located inside the housing 94 also comprises a respective conical pinion 903, 913, adapted to mesh with the pinion 96. In this way, a rotation movement of the connector 91 taken from the rotary drive shaft 23 is transmitted by the bevel gear 96 to the connector 90 which then transmits it to the support arm 20 of the workpiece. In doing so, regardless of the inclination of the connector 90 relative to the connector 91, a rotational movement is still transmitted. In addition, to prevent the connector 91 from rotating all the housing 25 consisting of two shells 92, 93, means 82 preventing this drive can be provided. For example, it may be a bearing interposed between the connector 91 and the shell 93. Alternatively, and as shown in Figures 4a, 4b, and 5a, the shell 93 may comprise a protrusion 82 extending around the connector 91 and 30 having a square section end. As can be seen in FIG. 2c, the conveyor 2 is advantageously lined with slides 83 in the metallization module 5, the width of which corresponds to one side of the section of the protuberance 82.

In this way, even if friction between the connector 91 and the hull 93 causes it to rotate, the support tool is held fixed in one direction only by the slides at the approach of the module 5. An operator can take care to check that this direction is correct, and reposition the appropriate case 5 the tool in the right direction, for example a direction parallel to the direction of travel of the conveyor as in Fig 2c. A system comprising a tool 9, a support arm 20 and a drive shaft 23 mounted on a conveyor 2 can thus allow the assembly of a part for the realization of complex metallizations, and in particular metallizations comprising several gradients on a same room.

Claims (12)

REVENDICATIONS1. A method of metallizing the surface of a workpiece (1), the workpiece being held on a support arm (20), the method comprising the steps of: a) projecting (100) onto the workpiece a base coating, b ) applying (200) a treatment for decreasing the surface tension of the base coating, and c) projecting (330) at least one redox solution comprising metal ions on the workpiece to metallize a surface of the workpiece, wherein, in step a), the work support arm of the workpiece extends vertically, the method being characterized by further comprising a step of tilting the work support arm from the workpiece. vertical position between step a) and step c). 2. Method of metallizing a bottle according to claim 1, wherein at the end of the inclination of the support arm (20), it extends in a position between the vertical position and a horizontal position. . 3. Method of metallization of a bottle according to one of claims 1 or 2, wherein step b) comprises a flame treatment. 4. Method of metallizing a bottle according to one of the preceding claims, further comprising preliminary steps in the step c) projection, said steps comprising an activation (310) of the surface of the bottle by stannous chloride sputtering and a rinse (320). 5. Method of metallizing a bottle according to claim 4, wherein the inclination of the support arm (20) of the part is implemented between step a) and step b), between the step b) and step c), or between the rinsing step and step c). 6. Method of metallizing a bottle according to one of the preceding claims, wherein the support arm (20) of the part (1) is rotatable during the implementation of steps a) to c). 3037081 17 7. tool (9) for supporting a workpiece (1) for implementing the method according to one of the preceding claims, comprising: - a first connector (90), adapted to be mounted integral in rotation with a support arm (20) of the part, and 5 - a second connector (91), adapted to be mounted integral in rotation with a drive shaft (23), and the support tool being characterized in that the The connectors are pivotally mounted relative to one another so as to form a variable angle with each other over an angular range, and furthermore comprise a member (96) for transmitting a movement of rotation of a connector to the other over all said angular range. 8. Support tool (9) according to claim 7, wherein the angular range is equal to 90 °. 9. Support tool (9) according to one of claims 7 or 8, wherein each connector (90, 91) comprises, at one end, a bevel gear (903, 913), and the motion transmitting member (96) comprises a bevel gear adapted to mesh with the pinions of the two connectors. 10. Support tool (9) according to one of claims 7 to 9, further comprising a housing formed of two shells (92, 93), each connector being attached to a respective shell, and the shells being pivotally mounted the to one another on said angular range. 11. Support tool (9) according to one of claims 7 to 10, further comprising locking means (95) of a connector at a plurality of angular positions in the angular range. 30 12. Bottle support system comprising: - a support tool (9) according to one of claims 7 to 11, - a support arm (20) of a workpiece (1), fixed to the first connector ( 90) of the support tool, and a drive shaft (23) attached to the second connector (91) of the support tool.