Printing machine and a method of printing

• US 20080264276A1
• Filed: 11/02/2007
• Published: 10/30/2008
• Est. Priority Date: 11/03/2006
• Status: Active Grant

• Current Assignee: Machines Dubuit
• Original Assignee: Machines Dubuit
• Inventors: Dumenil, Francois
• Granted Patent: US 8,070,244 B2
• Time in Patent Office: Days
• US Class Current: 101/40
• CPC Class Codes: B41F 13/46 Printing units for inserting latest news
• CPC Class Codes: B41F 17/08 for printing on filamentary or elongated articles, or on articles with cylindrical surfaces
• CPC Class Codes: B41J 3/4073 Printing on three-dimensional objects not being in sheet or web form, e.g. spherical or cubic objects B41J3/283, B41J3/286 take precedence; building up a 3D object using individual droplets from jetting heads B29C64/112
• CPC Class Codes: B41J 3/40733 Printing on cylindrical or rotationally symmetrical objects, e. g. on bottles
• CPC Class Codes: B41J 3/543 with multiple inkjet print heads B41J2/17503, B41J2/2103 take precedence

Abstract

The invention relates to a printing machine comprising a support plate (42) and a printer unit (44) fastened to the support plate (42) to project ink onto articles for printing. The printer station includes at least one additional printer unit (46, 48, 50), and the printer units (44, 46, 48, 50) are arranged beside one another on a circle centered on the axis of rotation (B-B) of a mandrel (8), when the mandrel (8) is placed in its printing position. The invention also provides a method of printing.

Claims

1. A printing machine (2) for printing articles that are substantially in the form of bodies of revolution, the machine (2) comprising:

a structure (4);

mandrels (8) for carrying articles for printing, each mandrel (8) being suitable for being driven in rotation about an axis of rotation (B-B) corresponding substantially to an axis of symmetry of the article for printing;

drive means (22) for driving the article for printing so as to cause the mandrels (8) to be moved between transfer positions and at least one printing position;

a turntable (6) carrying the mandrels (8), the turntable (6) being driven in rotation by the drive means (22);

displacement means (28, 29, 30, 32, 33) for moving the mandrels (8) in a radial direction relative to the turntable (6) to move the mandrels (8) away from or towards the or each printer station (12), each mandrel (8) being moved between at transfer positions and at least one printing position; and

a printer station (12) comprising a support plate (42) and a printer unit (44) fastened to the support plate (42) to project ink onto the articles for printing;

the printing machine being characterized in that the printer station (12) includes at least one additional printer unit (46, 48, 50), and in that the printer units (44, 46, 48, 50) are arranged beside one another around a circle (C-C) centered on the axis of rotation (B-B) of a mandrel (8) when the mandrel (8) is placed in its printing position.

2. A printing machine (2) according to claim 1, characterized in that it includes a control unit (82) suitable for calculating theoretical instants for triggering the projection of ink from each printer unit (44, 46, 48, 50) onto an article as a function of data representative of a pattern for printing on said article, of the size of said article, and of the position and the speed of rotation of the mandrel (8) carrying said article.

3. A printing machine (2) according to claim 2, characterized in that the control unit (82) includes manual adjustment means for adjusting the theoretical instants at which ink is projected from each printer unit (44, 46, 48, 50).

4. A printing machine (2) according to claim 2, characterized in that it includes at least:

drive means (122) provided with a drive shaft (123) for driving each mandrel (8) in rotation;

transmission means (106, 108, 122) for transmitting the rotation of the drive shaft (123) to the or each mandrel (8);

a first encoder (124) suitable for determining the speed of the drive shaft (123);

at least one second encoder (126) suitable for determining the peripheral speed of rotation of the mandrel (8) when driven in rotation; and

a processor unit (125) suitable for comparing the speed of the drive shaft (123) with the peripheral speed of the mandrel (8) and for modifying the speed of the drive shaft (123) as a function of the peripheral speed of the mandrel (8) so that the peripheral speed of the mandrel (8) is constant.

5. A printing machine (2) according to claim 1, characterized in that it further includes drier means (78) suitable for setting the or each ink printed on the articles, and in that the drier means (78) are arranged facing a mandrel (8) while the mandrel (8) is placed in the printing position.

6. A printing machine (2) according to claim 5, characterized in that the drier means (78) comprise at least one optical fiber.

7. A printing machine (2) according to claim 5, characterized in that it includes displacement means (80) for displacing the drier means (78) in a direction that is radial relative to said circle (C-C).

8. A printing machine (2) according to claim 1, characterized in that it has a single printer station (12).

9. A printing machine (2) according to claim 1, characterized in that all of the printer units (44, 46, 48, 50) of the printer station face the same mandrel (8), and in that the printer units are suitable for printing on the article carried by said mandrel (8), the mandrel (8) being positioned in the same location while the printer units (44, 46, 48, 50) are printing on the article.

10. A method of printing on articles presenting substantially the shape of a body of revolution, with the help of a printing machine (2) according to claim 1, the method being characterized in that it comprises a step (92) of printing and simultaneously driving a mandrel (8) in rotation about its axis of rotation (B-B) by drive means (122), said mandrel (8) being positioned in the same location while it is pivoting in a printing position, and an article for printing carried by said mandrel (8) being printed on by said printer units (44, 46, 48, 50).

11. A printing method according to claim 10, characterized in that it further includes a step (99) of drying the inks while the mandrel (8) is located in the printing position.

12. A printing method according to claim 10, characterized in that it includes the following steps prior to the step (97) of printing and driving the mandrel (8) in rotation:

installing a standard on said mandrel (8);

triggering (88) the projection of ink by each printer unit (44, 46, 48, 50) onto said standard;

visually inspecting the standard; and

adjusting (90) the theoretical instants for triggering the projection of ink by each printer unit (44, 46, 48, 50), said adjustment being made on the basis of the visual inspection of the standard.

13. A printing method according to claim 10, characterized in that it further includes the following steps, prior to the step (97) of printing and driving the mandrel (8) in rotation:

using a first encoder (124) for measuring (93) the speed of a drive shaft (123) of the means (122) for driving each mandrel (8) in rotation;

using a second encoder (126) for measuring (93) the peripheral speed of rotation of the mandrel (8); and

adjusting (94) the speed of the drive means (122) for driving the drive shaft (123) as a function of the peripheral speed of the mandrel (8) so that the peripheral speed of the mandrel (8) is constant.