Infeed system of rotary press

Abstract: In a rotary press, a traveling amount of a paper web (7) is controlled by an infeed system including infeed rolls (8c,8a), by which the paper web is fed to a subsequent stage for such as printing process. The infeed system of the rotary press includes traveling amount measuring device disposed on a traveling line of a paper web travelled by the infeed rolls for measuring a traveling amount (17) of the paper web under a tension free state and generating a signal representing the measured result, and a traveling amount controlling device (13) for controlling the traveling amount of the paper web fed by the infeed rolls in response to the signal from the traveling amount measuring means.

Description: BACKGROUND OF THE INVENTION The present invention relates to an infeed system of a rotary press in which a paper web of a web roll supported by a web roll supporting means of a rotary press is supplied for a succeeding process such as a printing process in a printing section by means of infeed roll by which a paper web travelling amount can be controlled. In a case where a plurality of paper webs printed by a rotary press are gathered or collated by a collator, it is required for the paper webs to have the same top and bottom dimensions with each other. Particularly, for a business-form rotary press carrying out printings on paper webs which are required to be gathered or collated by the collator after printings, it is very important for the paper webs to have constant top and bottom dimensions with each other even if materials, basis weights thickness or the like of paper webs to be collated are different from each other. However, as is known, where the paper webs are fed by an infeed system of the rotary press, the travelling amounts thereof differ from each other in accordance with the materials, basis weights thickness or the like of the paper webs. Accordingly, in a case where such various different kinds of paper webs are printed, the travelling amounts differ from each other even if the paper webs are printed under the same printing conditions, hence providing inconvenience at the time when paper webs are gathered or collated. In order to eliminate such defects, a first prior art providing a solution is disclosed for example, in Japanese Patent Publication No. HEI 4-51456. This prior art discloses a structure, as shown in Fig. 2, comprising a plate cylinder 1, a blanket (rubber) cylinder 2, an impression cylinder 3, and a differential speed change gear 5 disposed in a power transmission means for the blanket cylinder 2 and the impression cylinder 3 which put a paper web between them, carry out printing on the paper web and make the same travel. The differential speed changer 5 comprises a Harmonic Drive (Trade Name) a speed of which is adjustable by an adjustment motor 4. In this structure, the plate cylinder 1, the blanket cylinder 2 and the impression cylinder 3 are coupled in series to each other and rotated at the same rotation number in directions reverse to each other. According to this first prior art, the rotating speed of the impression cylinder 3 is adjusted by the differential speed change gear 5 with respect to the rotating speed of the blanket cylinder 2 thereby to change the travelling amount of the paper web. That is, in a case of thick paper web, the rotating speed of the impression cylinder 3 is decreased, and on the other hand, in a case of thin paper web, the impression cylinder 3 is adjusted reversely. In this manner, the travelling amount of the paper web can be changed. A second prior art also provides a solution, in which the rotating speed of the infeed roll is adjusted in accordance with the change of the tensions in consideration that tensions of paper webs passing between rolls are changed in accordance with the change of the paper web thickness. Fig. 3 is a schematic view showing the structure of the above second prior art. With reference to Fig. 3, a paper web 7 fed from a web roll 7a is fed in the paper web travelling direction and wound up in substantially S-shape around two infeed rolls 8a and 8b, which are rotated in directions reverse to each other at the same rotating speed, and the paper web 7 is then supplied on a side of the printing unit 9, i.e. downstream side, in the paper web travelling direction. The infeed rolls 8a, 8b and the printing unit 9 are driven by a drive line 10 from a press machine side through gear boxes 11a and 11b, respectively. In the gear box 11a driving the infeed rolls 8a and 8b, there is housed the differential speed change gear 5 having the speed ratio (gear ratio) which is adjustable by the adjusting motor 4 as like as in the first prior art mentioned above. Further, first and second tension detectors 12a and 12b for detecting the tension of the paper web 7 are arranged on both the upstream side and downstream side of the infeed rolls 8a and 8b, respectively. In Fig. 3, reference numeral 13 denotes a controller for generating a speed change signal to the motor 4. The controller 13 carries out a comparison operation of a detection value T1 fed back from the second tension detector 12b disposed downstream side of the infeed rolls 8a and 8b with a set value T2 preset by a setting device 14, and the controller 13 then generates a signal, to the motor 4, for adjusting the differential speed change gear 5 so as to rotate the infeed rolls 8a and 8b at the rotating speed at which the compared value becomes zero. Accordingly, the infeed rolls 8a and 8b are controlled so that the tension T1 of the paper web 7 detected by the second tension detector 12b always becomes equal to the set value T2 set by the setting device 14 thereby to keep constant the travelling amount of the paper web 7. Further, reference numeral 15 denotes a brake means operating in response to the detection value detected by the first tension detector 12a. Further, it is to be noted that the term "travelling amount" used herein means a travelling distance (length) per unit rotation number of a prime mover (motor) of the rotary press, a travelling distance (length) per one rotation of the infeed roll or a travelling distance (length) per unit time. In the first prior art mentioned above, when paper webs having different thicknesses are fed by the blanket cylinder 2 and the impression cylinder 3 as the infeed rolls with the tension applied to the paper web in the paper web travelling line and being maintained constant, the travelling amount of the paper webs differ in accordance with the thicknesses of the paper webs. Because of this reason, in the prior art, in order to make constant the travelling amounts of a plurality of paper webs having different thicknesses, it is necessary to obtain an aimed (target) travelling amount of the paper web by experimentally calculating a preset value to be inputted into the adjusting motor 4 for determining the speed ratio (gear ratio) of the differential speed change gear 5 with respect to each of the paper webs, measuring an absolute value of the paper web travelling amount by means of scale and so forth, in an operation stop condition of the printer,and then amending or correcting a feed amount by the infeed roll. Accordingly, it is very difficult to make travel the plurality of paper webs having different thicknesses at the same travelling amount. Furthermore, because the wind-up diameter of the web roll is changed as the paper web is fed, it is sometimes necessary to check the travelling amount at an intermediate time of the feeding as well as the feed-start time according to the condition of the web. In such case, some problems were caused on the printing process. On the other hand, in the second prior art mentioned above, the detection value T1 and the set value T2 are compared by the controller 13, and the signal for operating the adjustment motor 4 to adjust the motor rotating speed so as to make zero the compared value is generated to the motor 4. According to this operation, the tension of the paper webs having different thicknesses at the travelling time can be made constant and the travelling speed of the paper webs can be hence maintained constant. However, the detection value T1 inputted into the controller 13 is a value of the tension, which is a predetermined tension applied to the paper web 7, and therefore, this value T1 is the value detected at time when the paper web is elastically and plastically deformed by the tension. Accordingly, even if the detection value T1 is the same with respect to the different paper webs, the actual travelling amounts of the paper webs having different thicknesses and different elastic deformations due to the thickness difference, become different from each other. Thus, the correction or amendment of this matter is very troublesome to be handled. In an actual operation, in order to obtain a precise travelling amount of the paper web, it is necessary to actually measure the absolute value of the paper web travelling amount by means of a scale or the like after once stopping the feeding of the paper web and then to correct and preset the set value T2 of the tension in conformity with the measurement result of the absolute value of the travelling amount. These workings are made in accordance with the experience of the workers, requiring the skill and, hence, being troublesome and inconvenient. That is, in such a prior art, it is difficult to carry out the presetting of the fundamental travelling amount. Furtheron US-A-4057185 discloses an infeed System suitable for a rotary press in which a traveling amount of a paper web is controlled by an infeed roll, by which the paper web is fed to a subsequent process. A travelling amount of the paper web is measured and the travelling amount of the paper web is controlled in response to the measured signal. SUMMARY OF THE INVENTION An object of the present invention is to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide an infeed system of a rotary press capable of accurately measuring an absolute value of travelling amount of a paper web regardless of material, basis weight (thickness) or the like of the paper web, always maintaining the travelling amount thereof to an aimed (target) travelling amount and making constant the travelling amount of the paper web in conformity with gathering or collating operation of a collator. This object is achieved by the characterizing features of claim 1. Further advantageous embodiments of the present invention may be taken from the dependent claims. According to the infeed system of the rotary press of the present invention mentioned above, the amount of travelling the paper web from the web (roll) to the subsequent stage or process such as printing process is measured under the no-tension (tension free) state on the paper web travelling line by the travelling amount detector, and accordingly, the travelling amount measured under this state can be measured as an absolute value with no relation to the material of the paper web and the basis weight thickness thereof. The thus measured value is compared with the target travelling amount thereby to control the travelling amount of the paper web of the infeed rolls by the control means. The travelling amount of the paper web by means of infeed rolls can be mechanically controlled in accordance with the travelling amount of the paper web under the tension free state, and accordingly, in a case where paper webs different in their materials, basis weights or thicknesses and the like are fed, the travelling amount of the paper webs can be always maintained substantially to the target travelling amount and the collation by the collator can be made properly constant. Furthermore, it is not necessary to carry out the measurement or correction of the travelling amount by stopping the operation of a machine at every time when a different paper web is used, thus eliminating loss of working time, being convenient and advantageous. The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Fig. 1 is a schematic diagram showing a structure and arrangement of an infeed system of a rotary press according to one embodiment of the present invention; Fig. 2 is a schematic sectional view of one conventional structure of an infeed system of a rotary press; and Fig. 3 is a schematic diagram showing another conventional structure of an infeed system of a rotary press. DESCRIPTION OF THE PREFERRED EMBODIMENT One preferred embodiment of the present invention will be described hereunder with reference to Fig. 1, in which the same reference numerals used in Figs. 2 and 3 are added to corresponding elements or arrangements, respectively. With reference to Fig. 1, in addition to the first and second infeed rolls 8a and 8b in the conventional arrangement, a third infeed roll 8c is arranged. This third infeed roll 8c is positioned on the upstream side of the paper web feed direction of the infeed rolls 8a and 8b at a position separated by a predetermined distance from the first infeed roll 8a in the travelling direction of the paper web 7 so as to be rotatable in the same direction of the first infeed roll 8a. The third infeed roll 8c is operatively connected to the first gear box 11a, which is the driving source common to that of the first and second infeed rolls 8a and 8b, through a transmission mechanism having the same speed ratio (gear ratio) as that of the infeed rolls 8a and 8b. A rotation speed of an output side of the first gear box 11a is made optionally adjustable by means of the differential speed change gear 5 having the rotational speed which is adjustable by the motor 4 as in the second prior art mentioned hereinbefore. Furthermore, in the transmission mechanism connecting the third infeed roll 8c and the first gear box 11a, another gear box 11a' which houses another differential speed change gear 5a having a rotational speed adjustable by another adjusting motor 4a connected to the controller 13 are incorporated so that the rotating speed of the third infeed roll 8c can be solely adjusted independently of the first and second infeed rolls 8a and 8b. A paper web detector 16, such as ultrasonic sensor, for detecting the travelling paper web 7 is disposed at a position sufficiently below the portion between the first and third infeed rolls 8a and 8c which are rotatable in the same direction, the paper web detector 16 being directed upward, as viewed. And a paper web travelling amount detector 17 for detecting the travelling amount of the paper web 7 is arranged upstream side of the first infeed roll 8a. The paper web travelling amount detector 17 comprises, for example, a pair of rolls which are rotatable without slipping and an encoder detecting the rotational speed of these rolls. Further, the first and second gear boxes 11a and 11b are connected with a drive line 10 on which a drive line rotation speed detector 18 is arranged, and an infeed roll rotation speed detector 19 is also arranged on one of the first and second infeed rolls 8a and 8b so as to detect the rotating speed thereof. These detectors 17, 18 and 19 are operatively connected to the controller 13 so that the detected values r1, r2 and r3 of these detectors are inputted to the controller 13. The controller 13 is provided with a setting device 20, and information of the material, basis weight (thickness) and the like of the paper web 7 are inputted into the setting device 20 and, according to these information, there is determined an initial feed amount of the paper web 7 with respect to the target travelling amount thereof, which is then inputted into the controller 13 as the initially set feed amount α. In the structure mentioned above, the paper web 7 taken out from the web roll 7a is fed to the printing unit 9 side through the third, first and second infeed rolls 8c, 8a and 8b, which are arranged in this order from upstream side to the downstream side of the paper web travelling direction. The paper web 7 of the web roll 7a is taken out by the third infeed roll 8c disposed most upstream side. In this paper web feeding process, the above three infeed rolls 8c, 8a and 8b are rotated at the same speed by means of the drive line 10 and the gear box 11a. The rotation speed of the rolls at this time is controlled by the differential speed change gear 5 which is adjusted by the adjusting motor 4 thereby to finely adjust the travelling amount of the paper web 7. As mentioned above, in this paper web feeding process, since the third roll 8c and the first roll 8a are rotated at the same speed, no tension is applied to the paper web 7 (tension free state) between these rolls 8c and 8a, so that a loop portion 7b of the paper web 7 suspended downward is formed between these rolls 8c and 8a as shown in Fig. 1. Then, the paper web 7 in this loop portion 7b is passed through the travelling amount detector 17. The paper web 7 passing through the travelling amount detector 17 is pulled by the first infeed roll 8a disposed downstream side of the third infeed roll 8c, and then, the roller of the travelling amount detector 17 is rotated thereby to detect the travelling amount of the paper web portion to which no tension is applied (no-tension or tension free portion). The thus detected signal r1 is inputted into the controller 13. With reference to Fig. 1, a height H, as viewed, of the loop portion 7b of the paper web 7 between the rolls 8c and 8a is detected by the paper web detector 16, and the detected value (signal) r4 is inputted into the controller 13. The height H of the loop portion 7b is changed in response to the rotation speed of the third infeed roll 8c arranged upstream side the loop portion 7b. Further, since it is desired for the height H of the loop portion 7b to be always constant, this height H is adjustable to be always constant by finely adjusting the rotation speed of the third infeed roll 8c by the differential speed change gear 5a which is controlled by the controller 13 via the adjusting motor 4a of in response to the signal corresponding to the detected value r4 by the paper web detector 16. The initially set feed amount α to the target travelling amount of the paper web 7 set in accordance with the paper web material, basis weight (thickness) and the like of the paper web 7 is preset in the controller 13 by means of the setting device 20. Then, the controller 13 operates to compare the initially set feed amount α with the travelling amount of the loop portion of the paper web 7 calculated from the detection signal r3 from the infeed roll rotation speed detector 19, to calculate a differential feed amount between the travelling amount of the paper web and the initially set feed amount α, that is, a feed amount for converting the travelling amount, and then to generate a correction signal for correcting the travelling amount of the paper web 7 so as the differential feed amount becomes zero to the adjusting motor 4 of the gear box 11a. This correction signal is generated until the travelling amount of the loop portion 7b of the paper web 7 accords with the initially set feed amount α. After the completion of the initial setting, the transmission of the correction signal of the first gear box 11a from the controller 13 to the adjusting motor 4 is stopped. As mentioned above, by presetting the initially set feed amount α, the travelling amount of the paper web nearly the target travelling amount can be obtained at the initial stage, and hence, an amount of the wastepaper web generating at the operation starting time can be substantially reduced. In the next step, the target travelling amount calculated from the signal r2 of the driving line rotation speed detector 18 and the absolute value of the travelling amount measured by the travelling amount detector 17 are compared by the controller 13 thereby to calculate a differential feed amount between the travelling amount and the target travelling amount. Then, the correction signal for correcting the travelling amount is of the paper web 7 so as to the differential feed amount becomes zero is outputted to the adjusting motor 4 of the first gear box 11a. That is, in the case where the travelling amount of the paper web 7 by means of the infeed rolls 8a, 8b and 8c is greater than the target travelling amount, a signal for decreasing (reducing) the paper web travelling amount is outputted to the adjusting motor 4, and on the other hand, in the case where the travelling amount of the paper web 7 by means of the infeed rolls 8a, 8b and 8c is smaller than the target travelling amount, a signal for increasing the paper web travelling amount is outputted to the adjusting motor 4, thus maintaining the paper web traveling amount always constant to the target travelling amount. The tension of the paper web 7 fed from the web 7a is detected by the tension detector 12a disposed at the predetermined position, and in response to the detected value, the operation of the brake 15 is adjusted. It is to be noted that the present invention is not limited to the described embodiment and many other changes and modifications may be made without departing from the scopes of the appended claims. For example, the travelling amount detector 17, mentioned above, comprising a pair of rolls and an encoder may be substituted with a non-contact type detector. Moreover, in order to create no tension to the paper web 7, at least two infeed rolls may be required, and in this meaning, the most downstream side infeed roll 8b may be eliminated. Although the present invention has been hereinbefore described very specifically and as adapted for a rotary printing press, it is not desired that the invention is limited by the exact details of this disclosure. A variety of modifications and alterations of the illustrated embodiments may be made in order to conform to design preferences or to the requirements of each specific application, without departing from the scope of the claims which follow.

Claims: An infeed system of a rotary press in which a travelling amount of a paper web (7) is controlled by an infeed roll (8c, 8a), by which the paper web is fed to a subsequent process, characterized in that an absolute value of travelling amount of the paper web is measured by a travelling amount measuring device (17) disposed on a traveling line of the paper web travelled by the infeed roll under a tension free state and adapted to generate a signal representing the measured result, and the travelling amount of the paper web is controlled by a controlling device (13) in response to the signal from the traveling amount measuring device. An infeed system of a rotary press for controlling a traveling amount of a paper web (7) according to claim 1 wherein said paper web (7) is fed from a web roll (7a) further characterized by comprising: at least first and second two infeed rolls (8c, 8a) disposed downstream side of the web roll to be rotatable in the same direction for feeding the paper web in a traveling direction thereof in the tension free state between the first and second rolls; a driving device (10, 11a, 4, 5) for driving the infeed rolls and adjusting the infeed roll rotation a traveling amount detection device (17) for detecting an absolute value of travelling amount of the paper web and generating a signal for the detected value; a rotation speed detection device (19) for detecting a rotation speed of the infeed rolls and generating a signal for the detection value; and a control device (13) operatively connected to said driving device, said travelling amount detection device and said rotation speed detection device for controlling the travelling amount of the paper web in response to the signals of the detection value of the traveling amount and the detection value of the rotation speed. An infeed system of a rotary press according to claim 2, characterized in that a third roll (8b) disposed downstream side of the second roll to be rotatable in a direction reverse to that of the second roll.

Inventors: ISHIKAWA AKIRA, ITO TAKASHI, KISHINE TOSHIAKI, ISHIKAWA, AKIRA, ITO, TAKASHI, KISHINE, TOSHIAKI, Kishine, Toshiaki, Soleil Takanodai A-203
Applicants: MIYAKOSHI PRINTING MACH, MIYAKOSHI PRINTING MACHINERY CO., LTD.
Application year: 2000
Main classification: B65H20
IPC codes: B41F33, B65H23, B65H20, B41F13