Method for printing on cylindrical objects

Patent metadata

Field	Value
Publication number	US-11926144-B2
Application number	US-202218053428-A
Country	US
Kind code	B2
Filing date	Nov 8, 2022
Priority date	Sep 13, 2018
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

An apparatus is disclosed for printing images on generally cylindrical objects. The apparatus comprises an impression station that includes a movable imaging surface for bearing an ink image; and a transport mechanism for advancing the objects through the impression station, comprising a drive member rotatably connected to a plurality of rotatable mandrels, each for mounting a respective one of the objects, the transport mechanism being configured to cause each object to rotate during passage through the impression station such that, within a nip region of the impression station, the surface of the object makes rolling contact with the imaging surface, thereby causing the ink image to be impressed on the object. An impression platen is provided opposite the imaging surface within the nip region, the impression platen being configured to apply a force, directly or indirectly, to the objects to ensure rolling contact between the objects and the imaging surface.

First claim

I claim:

1. A method of printing on the outer surfaces of generally cylindrical objects, which method comprises:
(a) mounting at a loading station each object on a respective mandrel rotatable about an axis, the mandrels being rotatably connected to a drive member of a transport mechanism;
(b) advancing the objects while mounted on the mandrels through an impression station that includes a moving imaging surface bearing an ink image;
(c) rotating each object about the axis of its respective mandrel during passage through the impression station while urging the object against the imaging surface, such that the surface of the object makes rolling contact with the imaging surface within a nip region, thereby causing the ink image to be impressed on the surface of the object, wherein the object is urged into rolling contact with the imaging surface during passage through the impression station by an impression platen provided in the nip region of the impression station on the opposite side of the objects from the imaging surface, the impression platen being configured to apply a force, directly or by way of the mandrels, to the objects to ensure rolling contact between the surface of the objects and the imaging surface, and being stationary at least in the direction of movement of the imaging surface within the nip region; and
(d) removing at an unloading station each object from its respective mandrel after passage through the impression station.

2. The method as claimed in claim 1 , wherein the force applied by the impression platen to urge the object into rolling contact with the imaging surface is directly applied on each object, by making rolling contact with a region of the surface of each object diametrically opposite a line of contact between the object and the imaging surface.

3. The method as claimed in claim 1 , wherein the force applied by the impression platen to urge the object into rolling contact with the imaging surface is applied on the drive member of the transport mechanism, so as to urge the mandrels supporting the objects towards the imaging surface.

4. The method as claimed in claim 1 , wherein the imaging surface is that of an endless intermediate transfer member (ITM) of an offset printing system that further comprises an imaging station for depositing at least one ink on the ITM, and a drying station to dry the ink and leave behind a tacky ink image to be transferred at the impression station onto an object, wherein an opposite surface of the ITM rests on a support surface contoured to match the surface of the impression platen.

5. The method as claimed in claim 4 , wherein the ITM is advanced through the nip region of the impression station at a speed substantially equal to twice that of the mandrels.

6. The method as claimed in claim 4 , wherein the working circumference of the ITM is selected such that said circumference is a whole number multiple of the pitch of the mandrels.

7. The method as claimed in claim 4 , wherein the ITM includes at least one no-print region and no object is mounted on a mandrel entering the nip region synchronously with each at least one no-print region.

8. The method as claimed in claim 7 , wherein one or more of the at least one no-print regions include a seam.

9. The method as claimed in claim 7 , wherein in absence of an object being mounted on the mandrel entering the nip region, no force is temporarily applied to ensure rolling contact with the imaging surface.

10. The method as claimed in claim 4 , wherein a) the impression platen is concave and the ITM passes in the nip region over a rotating drive or guide roller having a convex support surface; or b) the impression platen is flat and the ITM is guided over a stationary flat support surface; or c) the impression platen is convex and the ITM is guided over a concave support surface.

11. The method as claimed in claim 10 , wherein the support surface in contact with the ITM is made of, or coated with, a low-friction material.

12. The method as claimed in claim 10 , wherein the impression platen and the support surface are flat and wherein an endless belt encircles the support surface and is disposed between the ITM and the support surface.

13. The method as claimed in claim 4 , wherein the ITM is wider than the axial length of at least two objects so that at least two objects interact along a width of a common ITM, the objects being aligned or staggered one with another in the direction of the width, and wherein the at least two objects are transported by at least one drive member.

14. The method as claimed in claim 13 , wherein the two or more objects transported by the at least one drive member are aligned and synchronously urged into rolling contact with the common ITM.

15. The method as claimed in claim 1 , wherein the drive member of the transport mechanism to which the rotatable mandrels are connected is a flexible endless drive member.

16. The method as claimed in claim 15 , wherein the flexible endless drive member is constructed as a toothed belt or as a chain formed of links that are pivotably connected to one another.

17. The method as claimed in claim 15 , wherein mandrels are disposed on opposite sides of the drive member.

18. The method as claimed in claim 17 , wherein the drive member of the transport mechanism is constructed as a chain formed of links that are pivotably connected to one another and wherein the axle of each mandrel is aligned with a pivot pin connecting two links of the chain, the mandrels being symmetrically disposed on opposite sides of the chain.

19. The method as claimed in claim 1 , wherein A—the mandrels are releasably secured to the drive member and retained on the drive member by a mechanical detent and/or magnetic attraction; and/or B—each mandrel includes at least one internal passage for permitting air flow axially along the mandrel, so as to enable objects to be retained on the mandrels by suction, and to be blown off the mandrels pneumatically.

20. The method as claimed in claim 1 , wherein the objects, and/or the mandrels, are heated prior to entering the impression station, to cause impression of the ink image onto the surface of the object to occur at an elevated temperature.

Assignees

• Landa Labs 2012 Ltd

Inventors

• Landa Benzion

Classifications

• B41F17/006

  for printing on curved surfaces not otherwise provided for · CPC title

• B41J11/00214

  using UV radiation · CPC title

• B41F17/002

  Supports of workpieces in machines for printing on hollow articles · CPC title

• B41F13/0008

  Driving devices (B41F13/004 and B41F13/008 take precedence) · CPC title

• B41F17/08

  for printing on filamentary or elongated articles, or on articles with cylindrical surfaces · CPC title