Printing machine ink transfer mechanism

Abstract

A printing machine ink transfer mechanism with quick, free and easy access to replace each of the electropneumatic valves and also the ability to use pneumatic power in both directions of travel of each of the multi-fabric doctor roll jacks and also solving the problem of lack of access to the electropneumatic valves, coils and springs for repair and maintenance or replacement of each of them by using the design of two-way pneumatic jacks and converter manifolds and also configuring the electropneumatic valves available outside the multi-fabric doctor roll assembly and also Improved design of seals protecting internal components of the Doctor Roll multi-fabric U-shaped configuration.

Description

Description of the invention Title of the invention (as stated in the declaration) Ink transfer mechanism of printing machines Technical background of the relevant invention The technical field of the invention relates to the ink transfer mechanism of printing machines, especially aluminum can decorators, including a multi-fabric doctor roll, which has very fast, free and easy access to replace each of its electro-pneumatic valves outside the multi-fabric doctor roll assembly, while its seals are designed in an improved way with a U-shaped profile to achieve long life, and also uses pneumatic force in both directions of travel of the multi-fabric doctor roll assembly to move each of the rolls separately. Technical problem and stating the objectives of the invention One of the problems in the design of the ink transfer mechanism in previous inventions is the problem of delay or jamming of the spring of the actuators or pneumatic jacks. This problem is clearly evident due to the use of springs in one-way pneumatic jacks with spring return. The use of springs in this system has caused the speed of movement of the pneumatic jack in rollers or areas that require maximum ink transfer to be out of our control due to the fatigue of the spring due to the increase in the operating cycle and operating time. Also, the resistance force against the spring, which can be referred to the shape and design of the seals between the rollers or sheaths, which the cross-sectional profile of the seals in previous inventions provides a low coefficient of elasticity and greater resistance to displacement in terms of the cross-sectional profile, which, along with the wear and tear and fatigue of the springs, causes the doctor rollers to undergo their cycle with a delay to the point that sometimes the one-way pneumatic jack gets stuck and the spring force is no longer able to move the doctor roller. It will not be a roller. Since this system is for controlThe amount of ink transfer works intelligently. On the one hand, after the half-life of the springs, this weakness is partially compensated by increasing the speed of the operating cycle in each roller. On the other hand, this increase in the operating cycle itself accelerates the depreciation and fatigue of the spring, and in fact, in a very short period of time it helps to maintain the transferred thickness of the ink. However, this increase in the speed of the operating cycle itself is a reason for the acceleration of the speed of spring fatigue in a faster period of time, to the extent that the spring force for pressing the multi-fabric doctor roll rollers decreases so much that it reduces the efficiency of this system. As a result, the accuracy of ink transfer decreases over time in the rollers or areas that require maximum ink thickness transfer, and the print quality decreases with the decrease in ink thickness to the point where this fatigue of the springs leads to jamming of the pneumatic jacks or rollers. For this reason, another problem that current systems face in these situations is the lack of quick access to the spring for replacing them. In order to access the spring, the entire doctor roll assembly must be removed from the machine and then, in a time-consuming process,It must be completely disassembled, which in turn requires a lot of manpower and time, which in addition to the complicated process of replacing the spring also increases the production downtime. Of course, an important point to mention in this regard is the very high speed of the printing machine, or decorator, which prints an average of about 1000 to 1500 cans per minute, which indicates the importance of having as few downtimes as possible. In order to solve the above problem, the present invention has been designed using the innovative configuration of two-way pneumatic jacks and the special design of the compressed air return paths of the pneumatic jacks and the use of two fully efficient and practical converter manifolds to convert the compressed air paths of the pneumatic jacks on the main axis into electro-pneumatic valves to solve the above problem. It has also been designed as an innovative step to integrate the multi-fabric roller doctor set with electro-pneumatic valves into a coherent pack to facilitate and accelerate its installation or replacement. Another technical problem of the existing art is the placement of electro-pneumatic valves inside the axis of the multi-piece doctor roller, which is why, in the event of a need to fix a defect or repair or service or replace any of its internal components, such as electro-pneumatic valves or electromagnetic coils, in our current systems, we have limited access to them, and in order to access, service or replace any of them, it is necessary to open the entire doctor roller assembly and carry out a complicated and time-consuming process of dismantling it, which causes an excessive increase in the time, cost and manpower spent on replacing just one of the electro-pneumatic valves. For example, it often happens that due to a spring getting stuck or breaking in any of the one-way jacks or burning out of one of the electromagnetic coils, each of the pneumatic valves must be removed from the machine and the time-consuming process, along with manpower, must be spent just to replace each of the mentioned items, so that this assembly can be completely reassembled and repaired. With the aim of solving this problem, the new inventive system uses the innovative configuration of electro-pneumatic valves along with their placement outside the multi-fabric doctor roll assembly, as well as the innovative step of using standard electro-pneumatic valves and designing compressed air path converter manifolds to achieve regular connection of each valve to the pneumatic jacks. This solves this problem and increases efficiency by using easy and fast repairs and maintenance in this new system. After the failure of any of the electro-pneumatic valves, the desired electro-pneumatic valve can be replaced immediately in the fastest time and in a maximum of 3 minutes using a clamping arm with only two screws, unlike the previous system that requires a long stop of the printing machine due to the failure or jamming of one of the valves, while its cost and service time are much higher compared to the present invention. Another problem with previous inventions is the design of the seal profile that protects the internal components of the multi-fabric doctor roll against environmental contamination such as any leakage of ink and solvents, etc. In the previous invention No. 11292244, due to the placement of these seals on the end edges of adjacent sheaths, the sheaths generate shear forces resulting from the transverse displacement of the sheaths to the seals, which will result in much faster wear of the seals, resulting in leakage of materials, solvents, and ink into the protected assembly of the doctor roll, causing wear and tear, and failure of the electropneumatic valves.Also, the shape of the seal used in the previous patent No. 9446581 and patent No. 6422144 indicates that these seals, due to the shape or profile of the cross-sectional area due to having 90-degree corners on both sides and a very small distance from the edges of the sheaths that move laterally, cause the seal to have a smaller elastic range than deformation due to lateral displacement of the sheaths and a greater resistance force to deformation regardless of its rubber material and salt, which ultimately leads to greater wear and shorter life of the seals and leakage of materials, solvents, and ink into the protected Doctor Roll assembly, causing premature wear and damage and failure of the electropneumatic valves in a faster time period. In order to solve this problem, a U-shaped elastomer seal has been designed. Through this, the seals, while sitting in the grooves intended for them on the sheaths for sealing, also create a distance from the end edges of the sheaths through the U-shape for which it is designed. In addition to eliminating the shear force of the sheath edges on the seals, this design also increases its elasticity coefficient, which consequently increases the life of the seals and, as a result, increases the life of the entire Doctor Roller assembly. A description of the state of the prior art and the history of developments related to the claimed invention. Patent No. 11292244, registered in the United States in 2018 with the title Printer Doctor Roller and Electromagnetic Valve Protective Member Embedded in Doctor Roll, includes a multi-fabric doctor roller configured through a mechanism of one-way spring-return pneumatic jacks in such a way that each of the doctor roller rollers is capable of controlling the reciprocating motion of each roller separately through pneumatic valves located inside the rollers. This invention differs from the present invention due to the design of the one-way spring-return jacks and the design of the pneumatic valves inside the axis of the doctor roller assembly and the lack of access to the pneumatic valves and springs of the one-way jacks for service or replacement, as well as the shape of the design of its seals. Patent No. 9,446,581, registered in the United States in 2014 as a printing machine ink supply device, includes a multi-fabric doctor roller configured through a mechanism of one-way spring-return pneumatic jacks in such a way that each of the doctor roller rollers is capable of controlling the reciprocating motion of each roller separately through pneumatic valves located inside the rollers. This invention differs from the present invention due to the design of the one-way spring-return jacks and the design of the pneumatic valves inside the axis of the doctor roller assembly and the lack of access to the pneumatic valves for service or replacement, as well as the design of its seals. Patent No. 6,422,144, registered in the United States in 2002 under the title of Ink Feeding Device with Vibrating Rollers, includes a multi-fabric doctor roller configured through a mechanism of one-way spring-return pneumatic jacks in such a way that each of the doctor roller rollers is capable of controlling the reciprocating motion of each roller separately through pneumatic valves located inside the rollers. This invention differs from the present invention due to the design of the one-way spring-return jacks and the design of the pneumatic valves inside the axis of the doctor roller assembly and the lack of access to the pneumatic valves for service or replacement, as well as the design of its seals. Providing a solution to an existing technical problem along with an accurate, sufficient, and integrated description of the invention An aluminum beverage can printing machine in its modern models has 8 inks, which are known as 8-color machines. Each ink is generally composed of a fountain (4), a fountain roll (2), a doctor roller (1.1) integral or multi-piece (1), several ink transfer rollers, and an end roller called a plate cylinder on which a printed design or plate or image is placed. Each ink is ultimately responsible for transferring one color of ink to a printed design. The ink is placed in the fountain chamber. Then, when the printing machine starts working, the fountain roll, which is soaked in the ink inside the fountain, rotates inside the fountain. Under the fountain, at the point where the fountain connects to the fountain roll, there is an adjustable blade along the length of the fountain roll, through which the thickness of the ink is adjusted on the surface of the fountain roll. The position of the multi-fabric doctor roll (1) is parallel between the fountain roll and the upper steel roll (3) or the first roll that receives ink from the doctor roller. In normal mode, it is constantly in contact with the steel roll and is rotated by the rotational force of the steel roll.The operation of the multi-fabric doctor roll mechanism is as follows: each of the rollers (1.6) has a rubber coating for transferring ink, and each of these rollers is completely separate, and has free rotational movement through the bearings (1.7) on which they are assembled, and also has separate transverse movement through the cylinders (1.11) or two-way pneumatic jacks, which are controlled through electro-pneumatic valves (1.2). The working process is as follows: by activating each of the pneumatic valves by the PLC system, each of the rollers (1.6) of the multi-fabric doctor roll associated with these valves is separated from the upper steel roll and comes into contact with the fountain roll. They continue to rotate through the rotational force of the fountain roll, in this way they are impregnated with the ink that was created on the surface of the fountain roll. By activating the pneumatic valves again, the same roller returns to its previous location, that is, contact with the upper steel roll, and through movement The steel roller rotates and transfers the ink received from the fountain roller to the upper steel roller.This process for the entire ink transfer width by each of the multi-fabric doctor roll rollers enables us to control each of the multi-fabric doctor roll rollers in timing by controlling the timing program of the electro-pneumatic valve signals by the PLC system and ultimately allows us to control the ink transfer rate, for example, at 7 points of the ink transfer width in a 7-fabric doctor roll in the inkers of printing machines. In fact, a PLC controller system receives information about the ink transfer rate and density, which is previously calculated for each printed label, through an input program, then processes them and sends them to signals to activate each of the electro-pneumatic valves. The electrical signals activate the electro-pneumatic valves, and these valves, using compressed air, cause each of the pneumatic jacks and finally the multi-fabric doctor roll rollers to move, and in this way, the ink transfer rate and density can be controlled completely separately, electrically and automatically at several points of the ink transfer width.Also, a sensor is provided for each of the multi-fabric doctor roll rollers to ensure the correct operation of the jacks and pneumatic valves. A number of non-contact sensors are also used to verify and control the density of the transferred ink on the other rollers of the printing machine by sending signals to the PLC to provide feedback on the ink transfer process. The PLC system uses these signals to automatically correct the movement rate of the multi-fabric doctor roll rollers using electro-pneumatic valves, and this operation is used as a closed loop to increase the accuracy of the transferred ink. In the present invention, the multi-fabric roll doctor includes a main shaft (1.10) on which a sensor (1.19) for controlling the position of the rollers (1.6) is installed, which here includes seven sensors, each sensor being specific to controlling the position of a roller, and inside the main shaft, seven pneumatic cylinder chambers (1.11) are configured with a forward path and a return path of compressed air for each pneumatic cylinder. Each cylinder has a piston (1.12) with a shaft to provide the movement of the rollers. Each piston uses two separate seals (1.15 and 1.16) for each of the forward and return paths. Each cylinder is closed by a cylinder cap (1.13), and each cap has a dynamic seal (1.17) that seals the piston shaft, and an O-ring (1.14) is configured at the flange seat of each cap on the main shaft for static sealing of the cap. Each piston shaft is connected to a sleeve (1.8) via a connecting pin (1.18), which is the connecting interface for transmitting the reciprocating motion of the pneumatic jack to the sleeve, and a bearing (1.7) is placed on each sleeve. A roller (1.6) With a rubber cover that achieves its free rotational movement through the bearings installed on it. Between each sheath and its neighbor, a seal (1.9) is designed in the shape of a U-shaped cross-section, which allows us to achieve a high coefficient of elasticity and also prevents the edges of the sheaths from contacting the seal when moving the sheaths, which prevents premature wear of the seals and damage to internal components due to leakage of contaminants, ink and solvents to internal components and roller jamming. Electropneumatic valves (1.2) on the outside of the doctor roll assembly are designed to control the reciprocating motion of the pneumatic jacks of each roller. By connecting them to the under-valve compressed air exchanger manifold (1.3) and also the main axis compressed air exchanger manifold (1.4), through the very complex design of the exchanger manifolds, all the compressed air return paths of the pneumatic jacks can be connected to the electropneumatic valves in a regular manner as a coherent and integrated pack. Explanation of shapes, maps and diagrams Figure 1 - Shows the location of a printing machine ink transfer mechanism on the inkers of beverage can printing machines. Figure 2 - Exploded view of an ink transfer mechanism, showing its three-dimensional components and parts. Figure 3 - A sectional view showing the components of a printing machine ink transfer mechanism. Figure 4 shows a sectional view of the cross-section of a roller. A clear and precise statement of the advantages of the claimed invention over prior inventions. 1- Easy and fast service and maintenance, with less cost and manpower for troubleshooting and replacing electropneumatic valves by using the configuration of electropneumatic valves outside the multi-fabric Doctor Roller assembly, as well as using standard electropneumatic valves with the ability to respond to electrical signals in 10 milliseconds, with the ability to replace any defective electropneumatic valve in just 3 minutes with the tightening of two small screws, unlike the system of previous inventions, which required the entire assembly to undergo a time-consuming and, of course, costly, complete disassembly process in order to damage any of the components of the electropneumatic valves or burn their coils. 2- Eliminating problems related to spring fatigue and jamming and lack of access to replace them. 3- Reducing service and maintenance downtime through easy troubleshooting and quick access to electropneumatic valves for replacement. 4- Increasing printing accuracy by increasing control accuracy by using double-sided pneumatic jacks and eliminating springs in single-sided jacks. 5- Eliminating the problem of electro-pneumatic valve coils burning due to being trapped in a closed space without heat transfer and increasing its efficiency. 6- This system's more resistant and longer-lasting sealing is achieved by seals with a U-shaped cross-section, which, due to its cross-sectional shape, has high elasticity, which greatly increases the life of the seal and increases the protection of internal components compared to the sealing system of previous inventions. 7- The ability to produce, use, and commercialize it for the first time in our country in the beverage can printing industry, given the very high price and the sanctions that the only Japanese manufacturer in the world, I.Mer Co., has imposed to prevent access to our country's printing industry. 8- Significantly increasing the life and service interval of the new system from 6 months to more than 18 months through changes made to the jacks, electro-pneumatic valves, and seals. Description of at least one implementation method for implementing the invention The introduced technological mechanism can be used to replace all old doctor rolls in printing machines or can decorators with just a few screws holding it in place. Explicit mention of the industrial application of the invention The technology introduced in the present invention can replace the old doctor rollers in printing machines, especially all Concord and Rutherford can decorators in all beverage can manufacturing companies in different countries around the world, as well as in companies producing linear or rotary printing machines, especially beverage can printing machines around the world, and these companies can benefit from it. Brief description of the invention A printing machine ink transfer mechanism with quick, free and easy access for replacing each of the electropneumatic valves and also the ability to use pneumatic power in both directions of travel of each of the multi-fabric doctor roll jacks and also solving the problem of lack of access to the electropneumatic valves and coils and springs for maintenance or replacement of each of them by using the design of two-way pneumatic jacks and converter manifolds and also the configuration of the electropneumatic valves accessible outside the multi-fabric doctor roll assembly and also the improved design of the seals protecting the internal components of the U-shaped multi-fabric doctor roll.

Claims

Claims What is claimed: Claim 1) An ink transfer mechanism for printing machines (1), which consists of the following components: - A multi-fabric doctor roller (1.1), which has several multi-fabric doctor roller rollers (1.6) along its axis, each of which can independently receive ink from the fountain roll (2) and transfer it to the steel roll (3) in several areas of the ink transfer width through the compressed air force of the piston (1.12) of the pneumatic jacks, - Electropneumatic valves (1.2), which are used to control or move each of the pistons (1.12) of the pneumatic jacks by receiving electrical signals from the PLC system, - A main axis compressed air converter manifold (1.4) together with a sub-valve compressed air converter manifold (1.3) which are used to convert the arrangement of the compressed air paths of the main axis (1.10) to the arrangement of the compressed air paths of the electropneumatic valves (1.2), Claim 2) According to claim number one, a multi-fabric roll doctor (1.1) consisting of the following components: - a main axis (1.10), including two or more pneumatic cylinders (1.11), in particular with reciprocating compressed air paths, which are used to facilitate the reciprocating force of the piston (1.12) of the pneumatic jacks. - Piston (1.12), pneumatic jacks that facilitate the force of movement in both directions of reciprocation through compressed air, - Sleeve (1.8), which can have a reciprocating movement by connecting to each piston (1.12) of the pneumatic jacks through a connecting pin (1.18), - Sleeve seal (1.9), in a U-shape for sealing each sleeve (1.8) with its neighbor, which can protect the internal components against the leakage of contaminants and ink and solvents, - Multi-fabric doctor roll rollers (1.6), with a rubber coating, each of which is configured along the axis of the multi-fabric doctor roll (1.1) on a bearing (1.7) that facilitates their free rotational movement, - Connecting pin (1.18), which by establishing a connection between each piston (1.12) of the pneumatic jacks with a sleeve (1.8) provides the force of movement of the piston (1.12) Pneumatic jacks are transferred to the sleeves (1.8). - Cylinder cover (1.13), which is used for installing and disassembling each piston (1.12) inside a cylinder (1.11). Claim 3) According to claim number two, the sheath seal (1.9), through the U-shaped cross-section thereof, can create a gap with the end edges of the sheaths (1.8), which can provide a high elasticity coefficient that is used to eliminate the shear force of the edges of the sheaths (1.8) to the sheath seals (1.9).

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