MXPA00008120A - Deck configuration for a printing press - Google Patents

Abstract

A deck for a printing press includes first and second rolls (48,49) which are mounted for linear movement on a pair of spaced parallel rails (54,55). A rotatable ball screw (78,88) moves the rolls along the rails. The axis of the screw substantially intersects the axes of the rolls.

Description

METHOD AND APPARATUS FOR SAMPLING AND INK INSPECTION FOR A PRINT PRESS BACKGROUND This invention relates to the measurement and adjustment of ink for a printing press. More particularly, the invention allows the color of the ink to be inspected and adjusted using components of the actual press before the operation of the press is initiated. Various physical properties of the printing ink, such as balance, density and tone, are factors that contribute to the success of the printed product. Obtaining the proper physical properties for a particular press operation is usually a time-consuming process. The printing industry needs the ability to quickly and scientifically obtain adequate color shade. The process of measuring and adjusting the ink is conventionally carried out within an ink mixing area in a location outside the press and without the actual press components. At the beginning of the work operation, additional measurements and adjustments must be made on the press. This is expensive in terms of the time the press remains inactive while the measurements are executed and ink adjustments are made. A prior art device is available for sampling ink and for printing the ink on a piece of paper. However, the ink is not sampled from the actual anilox pseudo-roller. That would be used on the press. Instead, a pseudo anilox roller is used. The anilox roller is a small roller with surface characteristics that are similar to those of an actual anilox roller. The pseudo anilox roller is clamped with a rubber roller to measure the ink and does not use the scraper blade dosing system of an actual anilox roller. The device is typically used to extend a sample of ink onto a piece of paper instead of the actual substrate that is printed on the press. Since the ink sample is obtained and printed without the use of actual press components, the ink sample will not necessarily be an accurate representation of the ink to be printed by the press. Consequently, additional measurements and adjustments must be made on the press during the installation of the actual printing operation.

BRIEF DESCRIPTION OF THE INVENTION The invention allows the press operator or the ink technician to achieve the correct ink balance, density, tone, etc. inside a press platform or from outside the press instead of the mixing area. The anilox roller assembly for the next press operation can be prepared outside it, for example, in a graduation area if the press includes a graduation area. The anilox roll assembly includes the current anilox roll and a scraper blade dosing system to be used on the press within a particular press operation. An effective mechanism or auxiliary pulse rotates the Sunday roller to keep the anilox roller moistened with ink. A manual ink sampling device includes a structure, a handle and a printing roller and a transfer roller that are rotatably mounted in the structure. A sample of the current substrate that will be printed on the press is cut from the substrate and lined with tape to the removable print roller. The transfer roller is pressed against the rotating anilox roller and caused to rotate by the anilox roller. The rotation of the transfer roller causes the printing roller to rotate and feed the substrate between two rotating rollers. The ink is transferred from the anilox roller to the transfer roller and then to the substrate. The ink that is printed on the substrate can be inspected for tone, density, etc. and any desired changes to the ink can be made outside the press before the anilox roller assembly is transferred to the press. The device can also be used with presses that are not equipped with a grading structure and carriages. In this type of press the inks can be checked in the press before production starts.

DESCRIPTION OF THE DRAWINGS The invention will be explained in conjunction with the illustrative embodiments shown in the accompanying drawing, in which Figure 1 is a side elevational view of a conventional flexographic printing press; Figure 2 is a side elevation view of a flexographic press and a graduation area for storing and comparing press components; Figure 3 is an elongated side elevation view of the graduation area; . Figure 4 is a top view of the color pallet truck of one of the color pallets of the press; Figure 5 is a view taken along line 5-5 of Figure 4; Figure 6 is a rear perspective view of a tape sampling device that is formed in accordance with the invention; Figure 7 is a partially exploded view of the device of Figure 6; Figure 8 is a perspective view of the device of Figure 6; Figure 9 is an exploded perspective view of the device of Figure 6; Figure 10 is a fragmentary rear perspective view showing the device of Figure 6 pressed against an anilox roll; Figure 11 is a front perspective view similar to Figure 10; Figure 12 is a side elevational view of the structure of Figure 10; Figure 13 is a perspective view of the printing roller after the ink is printed on the substrate; Figures 14-17 are side elevational views of other embodiments of the sampling devices according to the invention.

DESCRIPTION OF THE SPECIFIC PROCEDURES The invention will be explained in conjunction with a flexographic printing press that uses an anilox roll to transfer the printing ink from an ink source or scraper blade to a printing plate roller that prints an image on a screen or substrate. However, it will be understood that the invention can be used with other types of presses and with inking rollers other than anilox rolls such as a coating roll. As used herein, the term "anilox roll" refers broadly to an engraved roll of a press that is used to transfer ink from one area or component of the press to another. Figure 1 illustrates a conventional flexographic press 10 including a pair of side frames 11 and a central print cylinder 12 that is rotatably mounted on side structures to rotate about an axis 13. A plurality of color platforms 14 are mounted around the central printing cylinder, and each color platform includes a plate roller 15 and an anilox roller 16. A web W is unwound from an uncoiler 17 and wraps the central printing cylinder for rotation therewith. As the web rotates with the central printing cylinder, each of the plate rollers prints an image on the web. The color dryers 18 are mounted between adjacent color platforms and the printed web is moved through the tunnel dryer 19 to a rewinder 20. Figure 2 illustrates a similar flexographic press 21 and a graduation area or preparation area 22 where the components of the color platforms for the next operation of the press are prepared while the press is printing the current operation. The press 21 similarly includes a central printing cylinder 23 and color platforms 24. Each of the color platforms supports a plate roller 25, a roller 26, and a color platform cart 27. The platform cart color includes the ink system for the press. The plate rollers and the anilox rollers are shown in their non-operative forced positions in Figures 1 and 2. When the press is in operation, the plate rollers are adjacent to the surface of the central printing cylinder, and the anilox rollers do contact with the printing plates on the plate rollers. The ink is therefore transferred to the plates and the images are transferred to the screen or substrate. The plate rollers, the anilox roller and the color platform carts are removably mounted on the press and the components on the left side of the press can move from the press to the graduation area 22 by means of a robot 30. The components on the right side of the press can be moved into a second area by the robot 32. The robots and the procedure for transferring the components between the press and the grading area is described in the co-pending Pending American Patent entitled "Quick Change System for a Press ", Series No. 09 / 222,210, filed on December 29, 1998. The graduation area includes a pair of support structures 33, and each support structure includes four support platforms 34-37. Referring to Figure 3, each of the support platforms can support a plate roller 25, an anilox roller 26, and a color platform car 27 from one of the color platforms of the press. Each plate roller includes a pair of trunnions 38 which are supported by the support structures 33. Similarly, the anilox rollers include trunnions 39 (see also Figure 4) and the color platform trolleys include inactive non-rotating trunnions 40 which they are also supported by the support structures 33. The plate cylinder journals 38 and the anilox roller journals 39 can be rotatably and removably mounted on the structure of the flexographic press in the conventional manner by bearing heads or die heads. The non-rotating stumps 40 of the color platform carts are not supported on the color platform of the press. The car is supported by the structure of the press, although it essentially "floats" so that any inconsistencies in car manufacturing do not result in misalignment within the press. Referring to Figures 4 and 5, each of the color platform carts 27 includes a structure 42 for supporting a roller 26 and an ink handling system 43 for an individual color platform. The ink handling system 43 includes a scraper sheet assembly 44, an ink container 45, a pump 46, a viscosity control system 47, a drip tray 48, and the hoses and piping required. Such components are well known, and a detailed description is not necessary. The expensive 27 is independent of the press and provides a fully integrated ink supply system. The entire carriage, including the anilox roller 26, is a conveyor between the indexing area 22 and the press 21. The graduation structure is equipped with a conventional mechanism system or auxiliary actuator that will provide the rotation of the anilox roller needed for the purposes of impregnated with ink. When the time comes for the impregnated ink, be active this system. Color sample cutouts can be taken and prepared personnel can make whatever ink and layout changes are required to achieve the desired printing parameters. The graduation structure 33 also includes the required motor for the ink pump. The carriage 27 contains the pump heads. Like the structure, the press includes an effective mechanism and a motor for the ink pump mounted permanently on it. The invention facilitates the achievement of the correct ink balance, density, tone, etc. while the anilox roller and the ink handling system are mounted either on the press or outside it in the graduation area. Referring to Figures 6-9, an ink sampling device 51 is used to transfer an ink sample from an anilox roll to a piece of the weft or substrate that is cut from the actual weft or the substrate to be printed on. the press. The device 51 includes a generally U-shaped structure 52 and a roller of plate or transfer roller 53 and a printing roller 54 which are rotatably mounted in the structure. A handle 55 is attached to the structure to allow the operator to press the plate roller against an anilox roller while the anilox roller is rotated by the effective mechanism. The structure 52 includes an end plate 56 and a pair of side plates 57 that are bolted to the end plate. A top plate 58 is bolted to each of the side plates. The plate roller 53 includes a cylindrical outer surface and a pair of trunnions 61. Each trunnion is rotatably mounted in a bearing 62 which is mounted in an opening 63 in one of the side plates 55. Each of the bearings 62 is prevented from axial movement by the head of a screw 64. The print roller 54 includes an outer cylindrical surface 55 and a pair of trunnions 66. Each trunnion is rotatably mounted in a bearing 67 positioned in a slot 68 in one of the top plates 58. A piston spring 69 extends in an upper opening 70 in each of the upper plates 58 and engages one of the bearings 67 outside the center of the bearing to retain the bearing in the slot. Each of the bearings 67 is prevented from axial movement by the head of a screw 71. • The piston springs 69 are conventional commercially available devices. Each piston spring includes a piston that is mounted in an alternating fashion within an externally threaded tube and a compression spring within the tube that elastically biases the piston toward the open end of the tube. The printing roller can be removed from the slot 68 and the structure by exerting sufficient force on the roller to force the pistons of the piston springs up and to move the bearings 67 past the pistons. The plate roller 53 is covered with an elastic material 72, for example, Buna-N rubber, vinyl, photopolymer, etc. which preferably have the same composition and durometer as a printing plate of a flexographic press and simulate the capacity of transport and separation of ink from the plates. Referring to Figure 7, a strip 73 of the weft material or substrate to be printed on the press is cut out of the weft and wrapped around the outer surface of the printing roll. The strip 73 is advantageously wrapped around most of the printing roller, and the ends 73 of the strip are secured to the printing roller by tapes 74 (Figure 13). In the illustrated embodiment, the strip 73 extends approximately 300 ° around the print roller. The strip 73 contacts the outer surface of the plate roller 53 at the point of attachment between the plate roller 53 and the printing roller 54. The free space at the point of attachment is such that the strip is frictionally engaged by means of the plate roller so that rotation of the plate roller rotates the strip and the printing roller. Figures 10-12 illustrate plate roll 53 which is pressed against an anilox roll 75 which is rotating by the effective mechanism. The anilox roll is moistened with ink 76 (Figure 12) which is contained in a conventional scraper blade assembly 77. As the plate roll contacts the rotating anilox roll, the plate roll is forced to rotate. The rotation of the plate roller 53 will cause the rotation of the strip 53 of the weft material and the printing roller 54. The rotating plate roller will collect the ink from the anilox roller and transfer the ink to the strip 73 in a very similar to the way the plot will be printed in the press. Figure 13 illustrates the strip printed on the ink 78. Just before the entire strip 73 is printed, the device is removed from the anilox roll and the ink that has been printed on the strip is inspected. For example, a color densitometer can be used to evaluate color shading and color density. The balance, tone and other characteristics of the printed ink can also be inspected using other well-known devices. Any adjustments to the ink can be made as long as the anilox roller and the ink system are in the graduation area if the press includes a graduation area or on the press before the work is started. Since the sample of ink that was printed on the strip 73 is transferred from the actual ink handling system and the anilox roll that is used on the press, the sample compares closely with the ink to be printed during the press operation real. The printing roller 54 is designed for easy and quick removal from the structure 52 so that a number of printing rollers can be wrapped with strips of the weft material. Another sample of ink can be printed by simply removing the first printing roller from the structure, sliding the ink from the plate roller 53 and inserting a new printing roller into the structure. An oscillating fastener 79 is mounted on the handle 55 and can be used to hold the sampling device in the scraper blade assembly as illustrated in Figures 10-12. Figure 14 illustrates a three-roll sampling device 82 that includes the upper roller 83, the intermediate roller 84 and the inner roller 85 that are rotatably mounted in the structure 86. A handle 87 is attached to the structure. Before the device is supported against an anilox roller 88, a sample strip of the weft material is woven between the upper and intermediate rollers 83 and 84, around the front portion of the intermediate roller 84, and between the intermediate and lower rollers 84 and 85. Most of the weft material is on the upper roller. The upper roller 83 and the intermediate roller 84 are connected by a band 90 so that the rotation of the upper roller causes the rotation of the intermediate roller. The user presses the upper roller 83 against the rotating anilox roller to bring the intermediate roller 84 up to this speed. The lower spring loaded roller 85 is brought against the anilox roller for alignment and control. When the rollers are at speed and aligned, the operator reduces the handle 87 from the position illustrated in shading at 87a to the position illustrated in solid pattern to bring the weft on the outside of the intermediate roller to contact with the anilox roller. When the strip of the weft material is almost finished, the operator releases the handle pressure to stop the feeding of the weft. The color information can be taken from the sample frame. The protectors 91 and 92 are included in this design 5 to protect the sample web from contact of the upper and lower rollers, which have ink therein. The upper and lower rollers will need to be cleaned after each use. Figure 15 illustrates another device 95 that is similar to the device of Figure 14 except that a pin 96 is provided as a mounting point for the weft sample that is rolled into a small generator roller. With this design, a flat spring can be added to the raster path to control the I-voltage of the raster. Figure 16 illustrates another embodiment of a device 98 in which the ink is transferred from the anilox roll 99 to an intermediate roll 100, which resembles a plate cylinder in its function. The web is inserted into the clamping point between the intermediate roller 100 and the left roller 101. This provides an advantage in that the ink path resembles the path of a flexographic press in operation. Alternatively, a pin can be added to this variation so that a roll of weft material could be suspended therefrom and the weft finished between the rolls. A flat spring interruption can be added to the system to control the tension of the frame. A upper roller 102 also makes contact with the anilox roller.

MÜBBMÉßi-1 In Figure 17, a large diameter roller 104 has a weft sample wound to its surface. As the roller is brought into contact with the anilox roller 105 near the leading edge of the sample, the ink is transferred to the web. As the end of the sample approaches, the roller is removed from the anilox roller. If the roller is 20.32 cm in diameter, there will be essentially 63.5 cm of the weft to accelerate the roller, obtain a valid sample and remove the roller from the anilox roller. This design has the advantage of simplicity and low cost. Since only the weave makes contact with the anilox roller, only minimal cleaning will be required. This design lacks alignment characteristics and a direct method to accelerate the device roller. While a detailed description of the specific embodiments of the invention for the purpose of illustration was set forth in the above specification, it will be understood that many details given herein may be varied considerably by those skilled in the art without departing from it. of the spirit and scope of the invention.

Claims (13)

1. A method of sampling printing ink for a printing press comprising the steps of: mounting an anilox roller for rotation, providing printing ink to the anilox roller, rotating the anilox roller and keeping the anilox roller moistened with ink, pressing a roller rotating against the anilox roller to transfer the ink from the anilox roller to the rotating roller, pressing a substrate against the rotating roller so that the substrate is printed with ink, and inspecting the printed substrate.

The method according to claim 1, characterized in that the assembly step assembles the anilox roll out of line from the press and includes the step of mounting the anilox roll on a press for printing after the printing step.

3. The method according to claim 1, characterized in that the substrate is removed from a plot to be printed on the press.

The method according to claim 1, characterized in that the printing step includes the step of placing the substrate around a second rotating roller that is adjacent to the first mentioned rotating roller.

5. The method according to claim 4, characterized in that the substrate is fastened with tape to the second roller.

6. The method according to claim 1, characterized in that the anilox roll is the anilox roll that will be used in the press.

The method according to claim 6, characterized in that the step of providing ink includes the use of a scraper blade assembly to be used in the press.

8. An apparatus for sampling printing ink from a press for printing comprising: a structure, first and second rollers rotatably mounted on the structure, the rollers having cylindrical external surfaces and providing a point of attachment between them, a strip of printable material that extends through the fastening point and makes contact with the outer surfaces of the rollers, and a handle on the structure for transporting the apparatus and for pressing one of the rollers against an anilox roller of a printing press.

The apparatus according to claim 8, characterized in that the external surface of a roller simulates the external surface of a plate roller of a press for printing.

10. The apparatus according to claim 8, characterized in that the external surface of said roller is elastic. The apparatus according to claim 8, characterized in that the external surface of said roller is made of rubber. The apparatus according to claim 8, characterized in that the strip of the printable material extends around the cylindrical outer surface of the other roller. The apparatus according to claim 12, characterized in that the strip is fastened with tapes to the other roller. The apparatus according to claim 8, characterized in that the structure is provided with a pair of slots and the other of the rollers is removably mounted in the slots. The apparatus according to claim 14, characterized in that the other roller includes a pair of trunnions that are rotatably mounted on the bearings, the bearings that are mounted in the slots, and the means for releasably retaining the bearings in the slots.