Ink delivery system and method

Abstract

An ink delivery system is provided. The ink delivery system includes at least one ink cartridge dispenser including an ink cartridge holder for holding an ink cartridge storing printing ink, at least one ink level sensor, a rotatable ink fountain roller and an ink fountain blade, forming a dispensed ink area receiving printing ink from the ink cartridge. The ink delivery system also includes a support supporting the at least one ink cartridge dispenser movably across a longitudinal axis of the ink fountain roller. The ink cartridge dispenser is movable along the support and fixable to the support manually. A method for supplying printing ink is also provided.

Claims

1. A method for supplying printing ink to a printing unit of a printing press, comprising: arranging at least one ink cartridge dispenser carrying an ink cartridge on a linear support; moving the at least one ink cartridge dispenser on the linear support by hand across a longitudinal axis of an ink fountain roller; dispensing printing ink through an open end of the ink cartridge to a dispensed ink area; rotating the ink fountain roller; and transporting the printing ink to the printing unit in the printing press.

2. The method of claim 1, wherein the at least one ink cartridge dispenser is stationary during printing.

3. The method of claim 1, further comprising the step of moving an ink agitator blade in the dispensed ink area across the longitudinal axis of the ink fountain roller.

4. The method of claim 3, further comprising the step of moving the ink agitator blade independently from the position of the at least one ink cartridge dispenser.

5. The method of claim 3, wherein the ink agitation blade can be turned off as desired.

6. The method of claim 1, further comprising the step of sensing an ink level in the dispensed ink area with an ink level sensor.

7. The method of claim 6, wherein the step of dispensing printing ink is controlled by a signal derived from the ink level.

8. The method of claim 6, wherein the at least one ink level sensor is stationary during a print job.

9. The method of claim 6, wherein a plurality of ink cartridges are arranged.

10. The method of claim 1, further comprising the step of: manually actuating a clamp to secure or release the at least one ink cartridge from the linear support.

11. The method of claim 10, wherein the at least one ink cartridge slides along the linear support when the clamp is released.

12. The method of claim 10, the at least one ink cartridge is fixed to the linear support when the clamp is secured.

13. The method of claim 1, wherein very small amounts of ink are dispensed along the ink fountain at the same time.

14. The method of claim 1, wherein an operator moves the at least one ink cartridge by sliding the at least one ink cartridge along the linear support to a desired position.

15. The method of claim 1 further comprising the step of: positioning the at least one ink cartridge dispenser by hand on the linear support.

16. The method of claim 1, wherein the at least one ink cartridge includes five ink cartridges.

17. The method of claim 1, wherein the linear support includes at least one stop or marking for identifying a desired position of the at least one ink cartridge dispensers.

18. A method for supplying printing ink to a printing unit of a printing press, comprising: arranging a plurality of ink cartridge dispensers on a linear support, each ink cartridge dispenser carrying an ink cartridge; moving the plurality of ink cartridge dispensers on the linear support by hand across a longitudinal axis of an ink fountain roller; dispensing printing ink through an open end of the ink cartridges to a plurality of dispensed ink areas; rotating the ink fountain roller; and transporting the printing ink to the printing unit in the printing press.

19. The method of claim 18, wherein there are 5 ink cartridge dispensers.

20. The method of claim 18, wherein the plurality of ink cartridge dispensers are positioned by hand in desired areas to provide spot color during printing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A preferred embodiment of the present invention will be elucidated with reference to the drawings, in which:

(2) FIGS. 1 and 2 show a printing press equipped with an ink delivery system in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

(3) FIGS. 1 and 2 show a printing press 10 equipped with an ink delivery system 20 in accordance with an embodiment of the present invention. Printing press 10 includes at least one printing unit 50 having a plate cylinder 52 and a blanket cylinder 54. The printing unit prints on a substrate, preferably on a web 56 via an impression cylinder 58. A dampening train 60 may provide a fluid to plate cylinder 52 an ink train 62 provides ink from ink fountain roller 4 to plate cylinder 52. Printing press 10 can be an offset printing press or a variable cutoff printing press. Variable cutoff printing presses are able to print a plurality of print jobs having a variety of cutoff lengths. In order to accommodate a variety of cutoff lengths, circumferences of plate and blanket cylinders may be varied, for example, blanket and plate cylinders of different sizes may be employed, existing cylinders may be packed or padded to increase their circumference, or printing plates and blankets having a variety of thicknesses that may be interchanged. The ink delivery system 20 includes ink cartridge dispensers 30 coupled to a rail 2, an ink fountain assembly 40 and an ink agitator assembly 6.

(4) An ink cartridge dispenser 30 in accordance with an embodiment of the present invention includes an ink dispensing head 1, an ink cartridge holder 31 and an ink level sensor 32. The ink dispensing head 1 is connected to the ink cartridge holder 31 and an ink cartridge 3 is inserted into the ink cartridge holder 31, so that an open end 38 of the ink cartridge 3 through which ink exits is directed to an area formed between an ink fountain roller 4 and an ink fountain blade 5. Sides 33 along longitudinal axis 34 of ink fountain roller 4 determine the width of the ink in the area. The ink fountain roller 4, driven by motor 39, rotates the printing ink in the dispensed ink area, taking with it a film of ink adhering to its surface and passing by the blade and transports printing ink to the printing unit of the printing press. The printing ink is either supplied directly or via a group of inking rollers to the plate cylinder.

(5) The ink dispensing head 1 includes means for releasing printing ink from an open end 38 of the ink cartridge 3. The printing ink is dispensed into the dispensed ink area through the open end 38 of ink cartridge 3. Usually, printing ink is released from an ink cartridge by moving a movable member in the ink cartridge in direction of the open end of the ink cartridge. Means to move the movable member in the ink cartridge 3 can be constituted of actuators like pneumatic or hydraulic cylinders, which are actuated in response to a manually sent signal or a signal sent by a press control system. The control of dispensing head 1 and/or the press control system is directly or indirectly connected to the ink level sensor 32, so that ink dispensing head 1 and thus the dispensing of printing ink can be controlled as a function of the ink level in the dispensed ink area. The sensing and processing of these signals can be carried out according to methods known in the art.

(6) Prefilled special or commercially available ink cartridges of any size, carrying any kind of ink, such as offset printing ink, can be used. It is understood by one skilled in the art that any fluid used for printing in printing presses is referred to as printing ink. In this embodiment, the ink level sensor 32 is mounted to a socket on the ink cartridge holder 31, so that the position of the ink level sensor 32 is fixed with respect to the ink cartridge holder 31, ink cartridge 3 and ink dispensing head 1. Thus, the ink level 32 is sensed in a fixed spot of the dispensed ink area when the ink cartridge dispenser 30 is stationary during a print job.

(7) The printing press 10 in this embodiment is a 33.5 inch wide printing unit and the ink delivery system 20 is equipped with two ink cartridge dispensers 30. In one of the two ink cartridge dispensers 30, an ink cartridge 3 is inserted in ink cartridge holder 31, the other one is shown without an ink cartridge inserted. A 75 inch wide printing unit could for example have six ink cartridge dispensers. The number of ink cartridge dispensers can be varied according to the width of the printing unit, the desired ink coverage or the printing speed. Furthermore, different ink cartridge dispensers can be used together in one ink delivery system according to the present invention.

(8) The ink cartridge dispensers 30 are movably coupled to a rail 2. The rail includes means for securely fixing ink cartridge dispensers 30 at their desired positions, so that ink cartridge dispensers 30 are stationary during printing. A releasable clamp 41 actuated manually for example could be used. The ink cartridge dispensers 30 can easily slide along the rail 2 when the means is released so the operator can position them as needed based on the print coverage. This will enable the operator to only feed a very small amount of ink in specific locations during a low coverage or spot color job. Rail 2 is mounted on a frame 35 of the printing press 10 and ink cartridge dispensers 30 can slide parallel to longitudinal axis 34 of ink fountain roller 4 along the dispensed ink area. As ink cartridge dispensers 30 are positioned by hand, low friction between the moving members of rail 2 is advantageous. Furthermore, ink cartridge dispensers 30 and/or rail 2 can be selected or designed to enable quickly removing and/or inserting of ink cartridge dispensers 30, thus reduce set-up time and ease maintenance. Positioning aids, such as stops for ink cartridge dispensers 30 or markings on rail 2 can also be arranged.

(9) To spread the ink out, an ink agitator assembly 6 is arranged at the ink fountain blade 5 and includes at least one agitator blade 7 that extends into the dispensed ink area. A base plate 36 is mounted to the bottom side of ink fountain blade 5. The at least one ink agitator blade 7 is mounted to an agitator blade carrier 37 that can be moved across the whole width of the dispensed ink area by any movement means known in the art. Agitating the ink across the whole width of the dispensed ink area is in particular advantageous for conventional print jobs, where a continuous ink film of uniform thickness is desired. It is also possible to move the at least one agitator blade 7 only in specific desired regions of the dispensed ink area. The at least one agitator blade 7 is interchangeable, so that the shape or material can be adjusted to different ink viscosities or desired agitation intensity.

(10) For print jobs that do not require agitation, for example low coverage jobs or spot jobs, agitation can be turned off or agitator assembly 6 can be removed. Regardless of the position or number of arranged ink cartridge dispensers 30, the ink agitator assembly 6 can agitate the ink across the whole width of the dispensed ink area. Thus, agitating of the ink is performed independent from ink dispensing.

(11) In the preceding specification, the invention has been described with reference to specific exemplary embodiments and examples thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative manner rather than a restrictive sense.