EP2036727B1 - Printing device, adjusting method and printing process - Google Patents

Description

The present invention relates to a screen printing device conical object.

He is known in particular by the document US 6,223,653 a printing device comprising a frame, means for rotating the object relative to the frame, a screen carrying a pattern to be printed and a screen support carried by the frame. Two toothed crowns are arranged on two opposite sides of the screen. These crowns are engaged in two racks extending opposite one another on the screen support. This rack-and-pinion drive is able to rotate the screen around its center and move it in a first direction relative to the frame. Other drive means are arranged on the frame to move the screen support relative to the frame in a second direction perpendicular to the first direction. During printing, the screen is moved to describe an arc whose center is the taper center of the object.

However, this printing device is complex and its implementation is complicated.

The document NL 1 002 118 C2 discloses a printing device according to the preamble of claim 1.

The object of the present invention is to provide a simpler printing device.

• un bâti ;
• un écran mobile par rapport au bâti, l'écran portant un maillage présentant un motif à imprimer sur la portion conique de l'objet, le motif ayant la forme d'un développé de cône présentant un centre de motif et une plage angulaire d'étendue du motif ;
• une racle portée par le bâti, la racle étant propre à presser le maillage de l'écran contre la portion conique de l'objet pour appliquer le motif sur la portion conique de l'objet, le dispositif comprenant :
• des moyens d'entraînement en rotation de l'écran d'un axe de rotation, lesdits moyens d'entraînement en rotation de l'écran comprenant un unique moteur,
• des premiers moyens de déplacement du moteur d'entraînement en rotation de l'écran, lesdits premiers moyens de déplacement s'étendant selon une première direction,
• des deuxièmes moyens de déplacement du moteur d'entraînement en rotation de l'écran, les deuxièmes moyens de déplacement s'étendant selon une deuxième direction perpendiculaire à la première direction, les premiers moyens de déplacement portant les deuxièmes moyens de déplacement.

For this purpose, the subject of the invention is a screen printing device for an object having at least one conical portion, the conical portion having a center of conicity and a taper angle, the device comprising:

• a building;
• a screen movable relative to the frame, the screen having a mesh having a pattern to be printed on the conical portion of the object, the pattern having the shape of a cone developed having a pattern center and an angular range of extent of the pattern;
• a squeegee carried by the frame, the squeegee being adapted to press the mesh of the screen against the conical portion of the object to apply the pattern on the conical portion of the object, the device comprising:
• means for rotating the screen of an axis of rotation, said means for rotating the screen comprising a single motor,
• first means for moving the drive motor in rotation of the screen, said first moving means extending in a first direction,
• second means for moving the drive motor in rotation of the screen, the second moving means extending in a second direction perpendicular to the first direction, the first moving means carrying the second moving means.

• les premiers moyens de déplacement comprennent une première coulisse solidaire du bâti et un premier chariot guidé dans la première coulisse, les deuxièmes moyens de déplacement comportant une deuxième coulisse portée par le premier chariot et un deuxième chariot guidé dans la deuxième coulisse, le deuxième chariot portant les moyens d'entraînement en rotation de l'écran ;
• les premiers et les deuxièmes moyens de déplacement comportent chacun un unique moteur d'entraînement en déplacement du premier chariot et respectivement du deuxième chariot ;
• le dispositif comprend une liaison mécanique réversible entre le moteur d'entraînement en déplacement du premier chariot et le premier chariot, et une liaison mécanique réversible entre le moteur d'entraînement en déplacement du deuxième chariot et le deuxième chariot ;
• le dispositif comprend une liaison mécanique réversible entre et le moteur d'entraînement en rotation et l'écran ;
• le moteur d'entraînement en rotation et les moteurs d'entraînement en déplacement sont réversibles :
• le dispositif comporte en outre des moyens d'entraînement en rotation de l'objet par rapport au bâti à une vitesse angulaire prédéfinie et ledit moteur d'entraînement en rotation de l'écran est propre à faire pivoter l'écran à une vitesse angulaire qui dépend uniquement l'angle de conicité de l'objet et de la vitesse angulaire de rotation de l'objet ;
• le premier chariot et le deuxième chariot sont déplacés sur une course dont la longueur dépend uniquement de la position du centre de conicité de la portion conique de l'objet et de la plage angulaire d'étendue du motif ; et
• les premiers et deuxièmes moyens de déplacement sont adaptés pour permettre le déplacement manuel du premier chariot et du deuxième chariot par rapport au bâti dans la première direction et respectivement dans la deuxième direction, les moyens d'entraînement en rotation de l'écran sont adaptés pour permettre le pivotement manuellement de l'écran autour de l'axe de rotation, et le dispositif comprend :
• des moyens de lecture de la position du premier chariot, de la position du deuxième chariot et de l'angle de rotation de l'écran dans un repère cartésien fixe par rapport au bâti,
• des moyens de calcul propres à calculer à partir des positions lues les coordonnées de la course de déplacement du premier chariot et du deuxième chariot ainsi que des angles de rotation de l'écran dans le repère cartésien, et
• des moyens de commande aptes à commander le déplacement du premier chariot, du deuxième chariot et la rotation de l'écran en fonction des coordonnées et des angles calculés.

According to particular embodiments, the printing device comprises one or more of the following characteristics:

• the first moving means comprise a first slide secured to the frame and a first carriage guided in the first slide, the second moving means comprising a second slide carried by the first carriage and a second carriage guided in the second slide, the second carriage bearing the rotation drive means of the screen;
• the first and second moving means each comprise a single drive motor moving the first carriage and the second carriage respectively;
• the device comprises a reversible mechanical connection between the driving motor in displacement of the first carriage and the first carriage, and a reversible mechanical connection between the drive motor moving the second carriage and the second carriage;
• the device comprises a reversible mechanical connection between and the rotating drive motor and the screen;
• the rotary drive motor and the drive motors in motion are reversible:
• the device further comprises means for rotating the object relative to the frame at a predefined angular speed and said rotating motor of the screen is adapted to rotate the screen at an angular speed which depends only on the angle of conicity of the object and the rotational angular velocity of the object;
• the first carriage and the second carriage are moved on a stroke whose length depends solely on the position of the center of conicity of the conical portion of the object and the angular extent range of the pattern; and
• the first and second moving means are adapted to allow manual movement of the first carriage and the second carriage relative to the frame in the first direction and in the second direction, respectively, the rotation drive means of the screen are adapted to allow manual pivoting of the screen about the axis of rotation, and the device comprises:
• means for reading the position of the first carriage, the position of the second carriage and the angle of rotation of the screen in a fixed Cartesian frame relative to the frame,
• calculating means adapted to calculate from the read positions the coordinates of the displacement stroke of the first carriage and the second carriage as well as the rotation angles of the screen in the Cartesian frame, and
• control means adapted to control the movement of the first carriage, the second carriage and the rotation of the screen according to the coordinates and angles calculated.

Before printing, the printing device must be set to print exactly on the portion of the object intended for this purpose. However, this setting is difficult to implement because there are positional differences between the theoretical position of the pattern relative to the screen and games between the screen and the screen moving means. In addition, this setting must be changed whenever an object of a different shape or size needs to be printed.

Another object of the present invention is to provide an easier adjustment method for the printing device mentioned above.

1. a) une phase d'apprentissage comprenant les étapes suivantes:
   • déplacer le premier chariot et le deuxième chariot dans la première direction X et respectivement la deuxième direction Y, et faire pivoter l'écran de façon à superposer une partie du motif sur une partie de la portion conique ;
   • lire la coordonnée de position du premier chariot, la coordonnée de position du deuxième chariot et l'angle d'orientation de l'écran dans le repère cartésien,
   ladite phase d'apprentissage étant réalisée pour trois parties différentes du motif ;
2. b) une phase de calcul des coordonnées de la course de déplacement du premier chariot et du deuxième chariot à partir des coordonnées et des angles lus lors de la phase d'apprentissage.

For this purpose, the subject of the invention is a method of adjustment of the type comprising:

1. a) a learning phase comprising the following steps:
   • moving the first carriage and the second carriage in the first direction X and the second direction Y respectively, and rotating the screen in order to superimpose part of the pattern on a portion of the conical portion;
   • read the position coordinate of the first carriage, the position coordinate of the second carriage and the orientation angle of the screen in the Cartesian coordinate system,
   said learning phase being performed for three different parts of the pattern;
2. b) a phase of calculating the coordinates of the displacement stroke of the first carriage and the second carriage from the coordinates and angles read during the learning phase.

• pendant la phase d'apprentissage, un point initial, un point final et un point intermédiaire sont définis, le point initial étant situé à une extrémité initiale du motif, le point final étant situé à une extrémité finale du motif, le point intermédiaire étant situé entre les extrémités initiale et finale du motif, les trois points s'étendant selon un arc de cercle centré sur le centre du motif, et en ce que le premier et le deuxième chariots et l'écran sont déplacés de façon à disposer le centre du motif et un point défini dans un plan vertical contenant l'axe de révolution de l'objet ;
• la phase de calcul comporte les étapes suivantes :
  • calcul des coordonnées du centre de rotation de l'arbre de sortie du moteur d'entraînement en rotation de l'écran dans le repère cartésien et du rayon de rotation de l'arbre de sortie du moteur d'entraînement en rotation de l'écran autour de ce centre de rotation ;
  • calcul des coordonnées de la course de déplacement du premier chariot et du deuxième chariot dans le repère cartésien à partir des formules suivantes : $$\mathrm{X}\left(\mathrm{t}\right)=\mathrm{x}\mathrm{0}+\mathrm{R}\times \cos \left[\left(\mathrm{A}\left(\mathrm{t}\right)-\mathrm{A}\mathrm{1}\right)+\mathrm{A}\mathrm{0}\right]$$
    
    $$\mathrm{Y}\left(\mathrm{t}\right)=\mathrm{y}\mathrm{0}+\mathrm{R}\times \sin \left[\left(\mathrm{A}\left(\mathrm{t}\right)-\mathrm{A}\mathrm{1}\right)+\mathrm{A}\mathrm{0}\right]$$
    

According to particular embodiments, the adjustment method comprises one or more of the following characteristics:

• during the learning phase, an initial point, an end point and an intermediate point are defined, the initial point being located at an initial end of the pattern, the end point being at a final end of the pattern, the intermediate point being between the initial and final ends of the pattern, the three points extending in an arc of a circle centered on the center of the pattern, and in that the first and second carriages and the screen are moved so as to arrange the center of the pattern. pattern and a point defined in a vertical plane containing the axis of revolution of the object;
• the calculation phase comprises the following steps:
  • calculating the coordinates of the center of rotation of the output shaft of the drive motor in rotation of the screen in the Cartesian coordinate system and the rotation radius of the output shaft of the drive motor in rotation of the screen around this center of rotation;
  • calculating the coordinates of the displacement stroke of the first carriage and the second carriage in the Cartesian coordinate system from the following formulas: $$\mathrm{X}\left(\mathrm{t}\right)=\mathrm{x}\mathrm{0}+\mathrm{R}\times \cos \left[\left(\mathrm{AT}\left(\mathrm{t}\right)-\mathrm{AT}\mathrm{1}\right)+\mathrm{AT}\mathrm{0}\right]$$
    
    $$\mathrm{Y}\left(\mathrm{t}\right)=\mathrm{there}\mathrm{0}+\mathrm{R}\times \sin \left[\left(\mathrm{AT}\left(\mathrm{t}\right)-\mathrm{AT}\mathrm{1}\right)+\mathrm{AT}\mathrm{0}\right]$$
    

• X (t), Y (t) sont les coordonnées de la course de déplacement du premier chariot et du deuxième chariot dans le repère cartésien, t variant au cours du temps,
• x0, y0 sont les coordonnées du centre de rotation de l'arbre de sortie du moteur d'entraînement en rotation de l'écran dans le repère cartésien,
• R est le rayon de rotation de l'arbre de sortie du moteur d'entraînement en rotation de l'écran autour du centre de rotation,
• A0 est l'angle défini entre l'axe du repère cartésien et une droite passant par le centre de rotation et les coordonnées,
• A(t) est l'angle de rotation de l'arbre de sortie du moteur d'entraînement au temps t, A variant au cours du temps sur un secteur angulaire égal au secteur angulaire de la plage angulaire d'étendue du motif,
• A1 est l'angle d'orientation de l'écran enregistré lorsqu'une partie située à une extrémité initiale du motif est superposée sur une partie de la portion conique destinée à recevoir celle-ci ; et
• x1, y1 sont les coordonnées enregistrées lorsque ladite partie située à une extrémité du motif est superposée sur ladite partie de la portion conique.

In which :

• X (t), Y (t) are the coordinates of the displacement stroke of the first carriage and the second carriage in the Cartesian coordinate system, t varying over time,
• x0, y0 are the coordinates of the center of rotation of the output shaft of the drive motor in rotation of the screen in the Cartesian frame,
• R is the radius of rotation of the output shaft of the drive motor in rotation of the screen around the center of rotation,
• A0 is the angle defined between the axis of the Cartesian coordinate system and a line passing through the center of rotation and the coordinates,
• A (t) is the angle of rotation of the output shaft of the driving motor at time t, A varying over time over an angular sector equal to the angular sector of the angular extent range of the pattern,
• A1 is the orientation angle of the recorded screen when a portion at an initial end of the pattern is superimposed on a portion of the conical portion for receiving the pattern; and
• x1, y1 are the coordinates recorded when said part located at one end of the pattern is superimposed on said portion of the conical portion.

The invention also relates to a printing method comprising the steps of the adjustment method described above.

The adjustment method and the printing method may be used by any printing device comprising a frame, a screen movable relative to the frame, a scraper carried by the frame and at least two means of driving the screen in two perpendicular directions.

• la figure 1 est une vue en perspective du dispositif d'impression selon l'invention ;
• la figure 2 est une vue de côté de l'écran et de l'objet à imprimer ;
• la figure 3 est une vue en coupe du dispositif d'impression selon la ligne III-III illustrée sur la figure 1 ;
• la figure 4 est une vue en coupe du dispositif d'impression selon la ligne IV-IV illustrée sur la figure 1 ;
• la figure 5 est une vue de dessus de l'écran du dispositif d'impression selon l'invention ;
• la figure 6 est une vue de dessus du dispositif d'impression selon l'invention ; et
• la figure 7 est un diagramme représentant les étapes du procédé d'impression selon l'invention.

The invention will be better understood on reading the description, given solely by way of example and with reference to the drawings, in which:

• the figure 1 is a perspective view of the printing device according to the invention;
• the figure 2 is a side view of the screen and the object to be printed;
• the figure 3 is a sectional view of the printing device according to the line III-III illustrated on the figure 1 ;
• the figure 4 is a sectional view of the printing device according to the line IV-IV illustrated in FIG. figure 1 ;
• the figure 5 is a top view of the screen of the printing device according to the invention;
• the figure 6 is a top view of the printing device according to the invention; and
• the figure 7 is a diagram showing the steps of the printing method according to the invention.

The printing device 2 according to the invention is represented on the figure 1 . It comprises a frame 4 carrying a device 6 for rotating an object to be printed 8, and a system 10 for moving a printing screen 12.

According to the invention, the object to be printed 8 has at least one conical portion 13 having a center of conicity C _C and a taper angle α represented on the figure 2 . The center of conicity C _C is located at the virtual summit of the cone portion. The angle of conicity α is the angle defined between a generatrix 14 of the cone and the axis of revolution CC of the cone.

The frame 4 of the printing device has a generally parallelepipedal shape open on one of its faces 16 hereinafter called the front face, and on its opposite face 18 hereinafter referred to as the rear face.

The internal lateral faces of the frame 4 are equipped with four vertical rails 20, 22, 24 on which the driving device 6 is able to move to change the distance between the object to be printed 8 that it carries and the screen 12 depending on the diameter of the object to be printed 8. The traces of the guide walls of the rails 22 and 24 are shown in dotted lines on the figure 1 .

The frame 4 is furthermore equipped with locking means in the vertical position of the device 6, not shown.

The driving device 6 consists of a box 26, a motor / geared motor assembly 27 carried by the box 26 and a system 28 for retaining and locking the motor / gearbox motor 27 .

The box 26 forms an open cradle on its front and rear faces. It is equipped with rollers engaged in the vertical rails 20, 22, 24 of the frame 4.

The motor / gear motor assembly 27 is adapted to rotate the object to be printed around its axis of revolution CC at a predefined angular speed. Wo. It is equipped with an encoder 23 shown schematically on the figure 1 , able to read the angular position of the object.

The motor / gear motor assembly 27 is pivotable relative to the housing 26 around an axis AA perpendicular to the axis of revolution CC of the object 8, to orient the generator 14 of the conical portion 9 parallel to the screen 12 in a position shown on the figure 2 .

The retention and locking system 28 makes it possible to modify and fix the orientation of the motor / geared motor assembly and thus the orientation of the object 8 carried by the latter as a function of the angle of taper α of the object.

The retaining and locking system 28 comprises two upper tie rods 30, 32 passing through two orifices of the casing 26 and engaged in the motor / geared motor assembly 27, and two lower tie rods 34, 36 that are therethrough and movable in a cam arc of circle centered on the axis AA.

Each tie rod 30, 32, 34, 36 is equipped with a locking / unlocking handle for fixing the orientation of the driving device 6 and thus keeping the printing face of the object 8 parallel to the screen 12.

As visible on the figure 3 , the object to be printed 8 is held between a base 40 delimiting a complementary shape footprint to the shape of the bottom of the object 8 and a retaining tip 42 of the neck of the object 8 disposed opposite the base 40.

The base 40 is fixed to the output shaft of the motor / geared motor assembly 27. The tip 42 is able to be moved towards and away from the front face 16 of the frame 4 in order to grip axially the object 8 between the base 40 and the tip 42. For this purpose, a pneumatic cylinder 44 for moving the tip is attached to the motor / geared motor assembly 27. The base 40 further has a clearance 45 to allow rotation of the screen 12.

The system 10 for moving the screen 12 comprises a first elongate section 46 fixed at one of its ends to the upper face of the frame 4, and a second elongated section 48 carried by the first profile.

The first section 46 has an inverted U-section. It is provided with two slides 49, 50 extending parallel to the longitudinal axis of the profile 46, that is to say, parallel to the axis XX in a Cartesian coordinate system (X, Y, Z) fixed with respect to the frame 4 illustrated on FIG. figure 1 .

A first carriage 52 is guided on the slides 49, 50. As visible on the figure 3 , the first carriage 52 comprises a support plate 54 whose upper face 55 is provided with two pairs of slides 56, 58 engaged in the slides 49, 50 and a bearing cooperating with a worm 60.

The worm 60 is integral with an output shaft of a single motor 63 adapted to move the first carriage 52 on the slides 49, 50.

The slides 49, 50, the slides 56, 58, the bearing and the worm 60 form a reversible mechanical connection between the motor 63 and the first carriage 52.

The motor 63 is fixed to a lateral face 46A of the first profile 46. It is reversible and indexed to an encoder 64 shown schematically on the figure 1 . The motor 63 comprises means for cutting off its power supply.

The encoder 64 is able to read the coordinates (O, X) of the position of the first carriage 52 in the Cartesian frame (X, Y, Z) when the carriage is driven by the motor or when the latter is moved manually by a motor. operator.

The second section 48 is attached to the lower face 65 of the support plate 54 of the first carriage. It extends parallel to the Y-Y axis in the Cartesian coordinate system (X, Y, Z).

The second profile 48 is identical to the first profile 46.

Thus, the second profile 48 is also provided with two slides 66, 67 extending along its longitudinal axis on which a second carriage 68 is guided by a worm 70. The worm 70 is rotated by a single motor 72 fixed to a lateral face 48A of the second profile 48.

The motor 72 is reversible, indexed to an encoder 73 shown schematically on the figure 1 . The motor 72 comprises means for cutting off its power supply.

The encoder 73 is able to read the position coordinates (Y, O) of the second carriage 68 in the Cartesian coordinate system (X, Y, Z) when the second carriage 68 is driven by the motor 72 or when the latter is manually moved. by an operator.

The second carriage 68 is similar to the first carriage 52. It consists of a support plate 74 having an upper face 75 integral with two pairs of slides 76, 78 engaged in the slides 66, 67 and a step 80 cooperating with the worm 70.

It further comprises a support 82 fixed on the underside of the support plate 74. A portion of the support 82A extends projecting and transversely to the support plate 74.

The slides 66, 67, the slides 76, 78, the bearing 80 and the worm 70 form a reversible mechanical connection between the motor 72 and the second carriage 68.

A motor / gear motor assembly 84 is fixed on the upper face of the support portion 82A so that its output shaft 87 extends along an axis BB, parallel to the axis ZZ of the Cartesian coordinate system (X, Y, Z ). The output shaft 87 passes through an opening in the support portion 82A. Its end is fixed to a gripper 85 for gripping the screen 12.

The motor / geared motor assembly 84 comprises a single motor 86 set on a gear unit, the assembly being reversible, indexed to an encoder 87 shown schematically on the figure 1 . The motor 86 comprises means for cutting off its power supply.

The encoder 87 is able to read the angle of rotation of the screen 12 in the Cartesian frame (X, Y, Z) when the screen is driven by the motor 86 or when the latter is manually moved by an operator.

The screen 12, shown on the figure 5 , comprises a frame 89 for maintaining a mesh 90 fixed on the lower face of the frame 89.

The mesh 90 has a pattern 92 to print in the form of a cone developed. This developed cone is formed of two circular arcs of different radius centered on a point called center of the pattern C _M. The two arcs are separated by a distance corresponding to the height of the pattern. They extend over a width defined by an angular range θ extent of the pattern (on the view it is noted a delta).

The printing device 2 further comprises a doctor blade 94 shown schematically only on the figure 1 . The doctor blade 94 is driven in displacement vertically relative to the frame 4 to press the mesh 90 against the conical portion 13 of the object to be printed 8 and thus apply the pattern 92 to the latter, the mesh 90 being sandwiched between the conical portion 13 of the object 8 and the squeegee 94.

The printing device 2 further comprises a control unit 96 able to control the motor / gear motor units 27, 84 and the motors 63, 72 as a function of the angular position information of the object, the position of the first carriage 52 , position of the second carriage 68 and angular position of the screen 12 transmitted by the encoders 23, 64, 73, 87.

The control unit 96 includes a memory and a processor. The processor is adapted to execute the instructions of a computer program stored in the memory.

The program is operable to execute instructions for executing a printing device setting method and a printing method described above.

To print the pattern 92 on the generator 14 of the conical portion of the object, the screen 12 must be positioned relative to this object so that the center of the pattern C _M is located at the intersection point of the object. a plane containing the mesh 90 and the axis of revolution CC of the object, in a position illustrated on the figure 2 .

Then, the output shaft 87 of the drive motor 86 of the screen must pivot around this point of intersection hereinafter called center of rotation of the screen O (x0, y0), the center of rotation O (x0, y0) being concurrent in the center of the pattern C _M.

The method of setting the printing device is intended to define the coordinates X (t), Y (t) successive first carriage 52 and the second carriage 68 and the successive rotation angles A (t) of the screen 12 around the center of rotation O (x0, y0).

The adjustment method of the printing device starts with a learning phase comprising a step of adjusting the vertical position of the drive device 6 relative to the frame 4 and a step of adjusting the orientation of the device. motor / motor reduction gearbox 27 with respect to the casing 26.

For this purpose, the box 26 is moved on the vertical rails 20, 22, 24 until the conical portion 13 of the object is separated from 0 to a few millimeters from the screen 12.

The motor / gear motor assembly 27 is tilted about the axis AA to arrange the generator 14 of the object 8 horizontally and parallel to the mesh of the screen 12, as shown in FIG. figure 2 . The orientation of this assembly 27 is fixed by means of the retaining and cam locking system 28.

During a step 98, the user superposes a part of the pattern located at one end of the latter with respect to the object 8.

For this purpose, the power supplies of the motors 63, 72, 86 are cut off and an operator moves the first carriage 52 along the slides 48, 50, the second carriage 68 along the slides 66, 67, and the screen 12. around the BB axis to place the part of the pattern to print on the object.

When the first 52 and second 68 carriages, as well as the screen 12 are positioned, the user activates during a step 102 the control unit 96 so that it reads and records in the Cartesian frame (X, Y, Z) the position coordinates (x1, O) of the first carriage 52 and the coordinates (O, y1) of the second carriage 68, as well as the angle of orientation A1 of the screen 12.

Steps 98 and 102 are repeated for a portion located at the other end of the pattern, the control unit 96 then recording the position coordinates (x2, y2) of the first 52 and second 68 carriages as well as the angle A2 orientation of the screen 12.

Steps 98 and 102 are also repeated for a third part of the pattern 92 located between the two ends of the pattern, the control unit 96 then recording the position coordinates (x3, y3) of the first 52 and second 68 carriages as well as the angle A3 of orientation of the screen 12.

If the coordinates (x1, y1), (x2, y2) and (x3, y3) coincide, the output shaft 87 of the motor 86 is located at the center of rotation O (x0, y0).

If the coordinates (x1, y1), (x2, y2) and (x3, y3) are aligned, the pattern to be printed 92 is intended to be printed on a cylindrical object.

To perform steps 98 and 102, the user can for example identify on the mesh 90 of the screen an initial point PA located at an initial end of the pattern 92, a PC end point located at a final end of the pattern 92 and a intermediate point PB between the initial point PA and the end point PC, the points PA, PB and PC being inscribed along an arc centered on the center of the pattern C _M. Then, the screen 12 is moved to place the initial point PA and the center of the pattern C _M in a vertical plane containing the axis of revolution CC of the object, the coordinates (x1, y1, A1) are then recorded. The trolleys 52, 68 and the screen 12 are moved in the same way to record the coordinates (x2, y2, A2) obtained when the intermediate point PB and the center of the pattern C _M are placed in a vertical plane containing the axis of revolution CC, and the coordinates (x3, y3, A3) obtained when the initial point PA and the center of the pattern C _M are positioned in a vertical plane containing the axis of revolution CC.

The method of setting the printing device is continued by a calculation phase comprising a step 104 during which the control unit 96 calculates the coordinates (x0, y0) of the center of rotation O of the output shaft 87 of the motor 86 in the Cartesian coordinate system (X, Y, Z) and the radius R of rotation of the output shaft 87 around this center (x0, y0).

The coordinates (x0, y0) of the center of rotation O are obtained from the coordinates (x1, y1), (x2, y2) and (x3, y3). Indeed, a single circle passes through these three coordinates.

The radius R of rotation of the output shaft 87 of the motor 86 is obtained from the following formula: $$\mathrm{R}=\sqrt{(x0-x1{)}^2+(\mathrm{there}0-\mathrm{there}1{)}^2}$$

• x0 et y0 sont les coordonnées du centre de rotation de l'arbre de sortie 87 dans le repère cartésien (X, Y, Z),
• x1, y1 sont les coordonnées de position du premier chariot et du deuxième chariot enregistrées lorsque la partie initiale du motif 92 est superposée à la position conique.

In which :

• x0 and y0 are the coordinates of the center of rotation of the output shaft 87 in the Cartesian coordinate system (X, Y, Z),
• x1, y1 are the position coordinates of the first carriage and the second carriage recorded when the initial portion of the pattern 92 is superimposed on the conical position.

$$\mathrm{Y}\left(\mathrm{t}\right)=\mathrm{y}\mathrm{0}+\mathrm{R}\times \sin \left[\left(\mathrm{A}\left(\mathrm{t}\right)-\mathrm{A}\mathrm{1}\right)+\mathrm{A}\mathrm{0}\right]$$

During a step 106, the control unit 96 successively calculates the position of the first carriage and the position of the second carriage in the Cartesian coordinate system (X, Y, Z) from the following formulas: $$\mathrm{X}\left(\mathrm{t}\right)=\mathrm{x}\mathrm{0}+\mathrm{R}\times \cos \left[\left(\mathrm{AT}\left(\mathrm{t}\right)-\mathrm{AT}\mathrm{1}\right)+\mathrm{AT}\mathrm{0}\right]$$

$$\mathrm{Y}\left(\mathrm{t}\right)=\mathrm{there}\mathrm{0}+\mathrm{R}\times \sin \left[\left(\mathrm{AT}\left(\mathrm{t}\right)-\mathrm{AT}\mathrm{1}\right)+\mathrm{AT}\mathrm{0}\right]$$

• X (t), Y (t) sont les coordonnées du premier chariot 52 et du deuxième chariot 68 dans le repère cartésien (X, Y, Z) au temps t, t variant au cours du temps, l'ensemble des coordonnées X (t), Y (t) calculées à partir de différent temps t définissant la course de déplacement du premier chariot 52 et du deuxième chariot 68,
• x0 et y0 sont les coordonnées du centre de rotation de l'arbre de sortie 87 du moteur 86 dans le repère cartésien (X, Y, Z),
• R est le rayon de rotation de l'arbre de sortie 87 du moteur 86 autour du centre de rotation O(x0, y0),
• A0 est l'angle d'orientation de l'écran 12 défini entre l'axe X du repère cartésien (X, Y, Z) et la droite passant par les coordonnées (x1, y1) et les coordonnées O(x0, y0),
• A(t) est l'angle de rotation de l'écran 12 au temps t, A variant au cours du temps sur un secteur angulaire égal au secteur angulaire de la plage angulaire (θ) d'étendue du motif, A(t=0) est égal à l'angle A1 moins un éventuel angle de surcourse avant impression, A(t=(t fin)) est égal à l'angle A3 plus éventuellement un angle de surcourse après impression,
• A1 est l'angle d'orientation de l'écran 12 enregistré lorsque la partie située à l'extrémité initiale du motif est superposée sur une partie de la portion conique 13 destinée à recevoir cette partie du motif, et
• A3 est l'angle d'orientation de l'écran 12 enregistré lorsque la partie située à l'extrémité finale du motif est superposée sur une partie de la portion conique 13 destinée à recevoir cette partie du motif.

In which :

• X (t), Y (t) are the coordinates of the first carriage 52 and the second carriage 68 in the Cartesian coordinate system (X, Y, Z) at time t, t varying over time, the set of X coordinates ( t), Y (t) calculated from different time t defining the displacement path of the first carriage 52 and the second carriage 68,
• x0 and y0 are the coordinates of the center of rotation of the output shaft 87 of the motor 86 in the Cartesian coordinate system (X, Y, Z),
• R is the radius of rotation of the output shaft 87 of the motor 86 around the center of rotation O (x0, y0),
• A0 is the orientation angle of the screen 12 defined between the X axis of the Cartesian coordinate system (X, Y, Z) and the line passing through the coordinates (x1, y1) and the coordinates O (x0, y0). ,
• A (t) is the angle of rotation of the screen 12 at time t, A varying over time over an angular sector equal to the angular sector of the angular range (θ) of the extent of the pattern, A (t = 0) is equal to the angle A1 minus a possible overtravel angle before printing, A (t = (t end)) is equal to the angle A3 plus possibly an overtravel angle after printing,
• A1 is the orientation angle of the screen 12 recorded when the portion at the initial end of the pattern is superimposed on a portion of the conical portion 13 intended to receive this part of the pattern, and
• A3 is the orientation angle of the screen 12 recorded when the portion at the end of the pattern is superimposed on a portion of the conical portion 13 for receiving this part of the pattern.

The first carriage 52 and the second carriage 68 are moved on a path whose length depends solely on the position of the center of conicity C _C of the conical portion 13 of the object and the angular range θ of the pattern.

During a step 108, the control unit 96 calculates the angular range of rotation of the screen around the output shaft 87. This is equal to the angular range θ extent of the pattern. Then, the unit calculates the rotation angles A (t) of the screen over time.

The angular velocity W _E of rotation of the screen 12 is a function of the angular velocity W _O of rotation of the object 8 of the cone angle α of the object 8. In particular, the speed W _E of rotation of the screen 12 is obtained from the following formula: $${\mathrm{W}}_{\mathrm{E}}={\mathrm{W}}_{\mathrm{O}}\times \tan \left(\mathrm{\alpha }\right)$$

• W_O est la vitesse angulaire de rotation de l'objet autour de l'axe C-C, et
• W_E est la vitesse angulaire de rotation de l'écran autour de l'axe B-B.

In which :

• W _O is the rotational angular velocity of the object around the axis CC, and
• W _E is the angular rotation speed of the screen around the axis BB.

The printing method according to the invention comprises the steps of the adjustment method followed by a printing step 110 of the objects for which the printing device has been set.

During printing, the control unit 96 controls the motors 63, 72 and 86 so that the screen is moved according to the successive coordinates X (t), Y (t) calculated during the step 106 and successive rotation angles A (t) calculated during step 108. Meanwhile, the control unit 96 controls the gear motor assembly 27 so that the object pivots at an angular speed W _O.

Alternatively, it is possible to use a pattern already printed on the object to record the coordinates (x1, y1, A1), (x2, y2, A2) and (x3, y3, A3). In this case, the user superimposes the screen pattern on three different portions of the pattern already printed on the object.

Advantageously, the printing device according to the invention allows a deflection angle of the screen 12 of 360 ° When the pattern extends over the entire periphery of the object, the axis of rotation of the rotation shaft 87 is positioned close to the center of the pattern C _M.

Claims (13)

1. Device (2) for printing by means of serigraphy an object (8) which has at least a conical portion (13), the conical portion having a centre of conicity (Cc) and an angle of conicity (α), the device comprising:

   - a frame (4);

   - a screen (12) which can be moved relative to the frame, the screen carrying a mesh (90) which has a pattern (92) to be printed on the conical portion of the object, the pattern having the shape of a conical evolute which has a pattern centre (Cm) and an angular extent range (θ) of the pattern;

   - a doctor blade (94) which is carried by the frame, the doctor blade being capable of pressing the mesh of the screen against the conical portion of the object in order to apply the pattern to the conical portion of the object:

   - means (84,86) for rotatably driving the screen about a rotation axis,

   characterized in that it comprises :

   - first means (46,49,50,52,63) and in that the means for rotatably driving the screen comprising a single motor (86),for moving the motor for rotatably driving the screen, the first movement means extending in a first direction (x),

   - second means (48, 66, 67, 68, 72) for moving the motor for rotatably driving the screen, the second movement means extending in a second direction (y) perpendicular relative to the first direction, the first movement means carrying the second movement means,

   and in that the means for rotatably driving the screen comprising a single motor (86)and in that the means for rotatably driving the screen comprising a single motor (86).
2. The printing device (2) according to claim 1, characterized in that the first movement means (46,49,50,52,63) comprise a first slotted member (49,50) which is fixedly joined to the frame and a first carriage (52) which is guided in the first slotted member, the second movement means comprising a second slotted member (66,67) which is carried by the first carriage and a second carriage (68) which is guided in the second slotted member, the second carriage carrying the means for rotatably driving the screen.
3. The printing device according to claim 2, characterized in that the first movement means and the second movement means each comprise a single motor for movably driving the first carriage and second carriage, respectively.
4. The printing device according to claim 3, characterized in that it comprises a reversible mechanical connection between the motor for movably driving the first carriage and the first carriage, and a reversible mechanical connection between the motor for movably driving the second carriage and the second carriage.
5. The printing device according to any of claims 1 to 4, characterized in that it comprises a reversible mechanical connection between the motor for driving in terms of rotation and the screen.
6. The printing device according to any of claims 2 to 5, characterized in that the motor for driving in terms of rotation and the motors for driving in terms of movement are reversible.
7. The printing device according to any of the preceding claims, characterized in that it further comprises means for rotatably driving the object relative to the frame at a predefined angular speed and the motor for rotatably driving the screen is capable of causing the screen to pivot at an angular speed which is dependent only on the angle of conicity of the object and the angular rotation speed of the object.
8. The printing device according to any of claims 2 to 7, characterized in that the first carriage and the second carriage are moved over a path whose length depends only on the position of the centre of conicity of the conical portion of the object and the angular extent range of the pattern.
9. The printing device according to any of claims 2 to 8, characterized in that the first displacement means and second displacement means are capable of allowing the first carriage and the second carriage to be moved manually relative to the frame in the first direction and second direction, respectively, the means for rotatably driving the screen are capable of allowing the screen to pivot manually about the rotation axis, and it comprises:

   - means for reading the position of the first carriage, the position of the second carriage and the rotation angle of the screen at a Cartesian reference point which is fixed relative to the frame,

   - calculation means which are capable of calculating, from the positions read, the coordinates of the movement path of the first carriage and the second carriage and the rotation angles of the screen at the Cartesian reference point, and

   - control means which are capable of controlling the movement of the first carriage, the second carriage and the rotation of the screen in accordance with the coordinates and the angles calculated.
10. Method for adjusting a printing device according to claim 9, characterized in that it comprises:

    a) a learning phase which involves the following steps:

    - moving the first carriage and the second carriage in the first direction and the second direction, respectively, and causing the screen to pivot in order to superimpose a portion of the pattern over part of the conical portion;

    - reading the position coordinate of the first carriage, the position coordinate of the second carriage and the orientation angle of the screen at the Cartesian reference point,

    the learning phase being carried out for three different parts of the pattern;

    b) a phase for calculating the coordinates of the movement path of the first carriage and the second carriage from the coordinates and the angles read during the learning phase.
11. The adjustment method according to claim 10, characterized in that, during the learning phase, an initial point, a final point and an intermediate point are defined, the initial point being located at an initial end of the pattern, the final point being located at a final end of the pattern, the intermediate point being located between the initial end and final end of the pattern, the three points extending along an arc of a circle centred on the centre of the pattern, and the first carriage and second carriage and the screen are moved so as to arrange the centre of the pattern and a defined point in a vertical plane which contains the axis of revolution of the object.
12. The adjustment method according to any of claims 10 and 11, characterized in that the calculation phase involves the following steps:

    - calculating the coordinates of the centre of rotation of the output shaft of the motor for rotatably driving the screen at the Cartesian reference point and the radius of rotation of the output shaft of the motor for rotatably driving the screen about this centre of rotation;

    - calculating the coordinates of the movement path of the first carriage and the second carriage at the Cartesian reference point based on the following formulae: $$\mathrm{X}=\mathrm{x}\mathrm{0}+\mathrm{R\; x\; cos}\left[-\mathrm{A}\mathrm{1})+\mathrm{A}\mathrm{0}\right]$$

    

    $$\mathrm{Y}=\mathrm{y}\mathrm{0}+\mathrm{R\; x\; sin}\left[-\mathrm{A}\mathrm{1})+\mathrm{A}\mathrm{0}\right]$$

    

    
    where:

    - X(t), Y(t) are the coordinates of the movement path of the first carriage and the second carriage at the Cartesian reference point, t being varied over time,

    - x0, y0 are the coordinates of the centre of rotation of the output shaft of the motor for rotatably driving the screen at the Cartesian reference point,

    - R is the radius of rotation of the output shaft of the motor for rotatably driving the screen about the centre of rotation O,

    - A0 is the angle defined between the axis X of the Cartesian reference point and a straight line which extends through the centre of rotation O and the coordinates,

    - A(t) is the angle of rotation of the output shaft of the drive motor at time t, with A being varied over time over an angular sector which is equal to the angular sector of the angular extent range of the pattern,

    - A1 is the angle of orientation of the screen recorded when a portion located at an initial end of the pattern is superimposed over a part of the conical portion which is intended to receive it; and

    - x1, y1 are the coordinates which are recorded when the portion located at one end of the pattern is superimposed over the part of the conical portion.
13. Printing method for a printing device according to any of claims 1 to 9, involving the steps of the adjustment method according to any of claims 10 to 12 and a step for printing the object.

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