FOLDING APPARATUS FOR WEB ROTARY PRESS

Abstract: A folding apparatus for a web rotary press, which folds signatures obtained by cutting a web by a combination of a cutting cylinder (6) and a pin cylinder (7), has a folding cylinder (12), a gripper cylinder (16), a speed reduction cylinder (19), and a pair of upper and lower transfer cylinders (23, 25). The folding cylinder (12) has pins (13) and insertion blades (14) on an outer surface at equal angular intervals. The pins (13) are alternately arranged with said insertion blades (14). The gripper cylinder (16) has gripper plates (17) and a diameter substantially 1/1.5 times that of said folding cylinder (12). The speed reduction cylinder (19) is rotated at a peripheral velocity lower than that of said gripper cylinder (16) and has gripper units (20). The upper and lower transfer cylinders (23, 25) are rotated at the same peripheral cylinder (19) and have gripper units (24, 26) at surface positions at equal intervals.

Description: Background of the Invention The present invention relates to a folding apparatus for cutting a web printed by a web rotary press into sheets of predetermined size and folding the cut sheets. A conventional web rotary press has a folding apparatus for cutting a printed, dried and cooled web into sheets of predetermined size and folding the cut sheets into halves along their path of travel or perpendicularly thereto. The folding methods in the conventional folding apparatuses are: former folding for causing a former to fold a web into halves along its path of travel before the web is cut; single or double signature parallel folding for causing a folding cylinder to fold signatures into halves or quarter perpendicularly to their path of travel; and chopper cross folding for causing a chopper to hold parallel-folded signatures into halves along their path of travel. These folding methods can be used singly or in combination in accordance with the signature specifications. In a chopper folding apparatus among the conventional folding apparatuses for performing the above-mentioned folding methods, each signature conveyed by chains abuts against a paper stop. A plate-like chopper blade moves downward toward the center of the stopped signature and then into a gap between lower rollers, thereby folding the signature into halves. However, the conventional chopper folding apparatus cannot perform high-speed folding at a speed exceeding a given maximum speed. When a conventional chopper folding apparatus is used, an overall speed of the printing press including a printing apparatus and a delivery apparatus must be decreased corresponding to the maximum speed of the chopper folding apparatus. This has prevented development of high-speed printing presses. As described in Japanese Utility Model Publication No. 55-13341, two pairs of signature conveying means and delivery means are arranged. Printed and parallel-folded signatures are alternately fed to the two pairs of assemblies, and are folded with choppers at a relatively low speed. The cross-folded signatures are then discharged. According to this conventional apparatus, a pair of speed reduction cylinders are brought into rolling contact with a gripper cylinder having a diameter twice that of each speed reduction cylinder. The feed speed of each signature delivered from the gripper cylinder is reduced by each reduction cylinder and the signature is fed to upper or lower chopper folding path. Even after the grippers of the speed reduction cylinder are opened to release a leading end of the signature, the trailing end of the signature is held by the gripper and speed reduction cylinders which are rotated at different speeds. The signature is then unstably conveyed and is often misaligned. Folding precision in the chopper unit in the subsequent process is thus degraded. In the worst cast, the chopper unit is jammed with signatures, and printing operation must be interrupted. Summary of the Invention It is, therefore, a principal object of the present invention to provide a folding apparatus for a web rotary press wherein chopper folding can be performed with high precision without decreasing a parallel folding speed, thus providing high folding efficiency. It is another object of the present invention to provide a folding apparatus for a web rotary press wherein signatures are not misaligned and folding precision is improved. In order to achieve the above objects of the present invention, there is provided a folding apparatus for a web rotary press, which folds signatures obtained by cutting a web by a combination of a cutting cylinder and a pin cylinder, comprising: a folding cylinder adapted to be in rolling contact with the pin cylinder located in an upstream thereof and having pins and insertion blades at a plurality of positions on an outer surface at equal angular intervals, the pins being alternate with the insertion blades; a gripper cylinder adapted to be in rolling contact with the folding cylinder, the gripper cylinder having a diameter substantially 1/1.5 times that of the folding cylinder and gripper plates which selectively correspond to the insertion blades upon rotation of the folding cylinder and the gripper cylinder; a speed reduction cylinder adapted to be in rolling contact with the gripper cylinder, rotated at a peripheral velocity lower than that of the gripper cylinder, and having first gripper units which selectively correspond to the gripper plates upon rotation of the gripper cylinder and the speed reduction cylinder; and a pair of upper and lower transfer cylinders adapted to be in rolling contact with two surface portions of the speed reduction cylinder, rotated at the same peripheral velocity as that of the speed reduction cylinder, and having second and third gripper units, respectively, at surface positions at equal intervals, the second and third gripper units selectively corresponding to the first gripper units upon rotation of the speed reduction cylinder and the pair of upper and lower transfer cylinders. Brief Description of the Drawings Fig. 1 is a side view showing a folding unit in a folding apparatus for a web rotary press according to an embodiment of the present invention; Figs. 2A to 2D are schematic side views for explaining single signature parallel folding in the folding unit shown in Fig. 1; and Figs. 3A to 3I are schematic side views for explaining double signature parallel folding in the folding unit shown in Fig. 1. Description of the Preferred Embodiment The present invention will be described with reference to a preferred embodiment in conjunction with the accompanying drawings. Fig. 1 is a side view of a folding unit in a folding apparatus for a web rotary press according to an embodiment of the present invention. Leading rollers 1, nipping rollers 2 and 3 are vertically arranged below a former which is arranged in a web feed unit (not shown) and which folds the web into halves along its path of travel. In this embodiment, a web 4 folded by the former into halves along its path of travel is guided to a folding unit 5. In the folding unit 5, cutting and pin cylinders 6 and 7 each with a diameter twice that of the plate cylinders are located below the nipping rollers 3. The web 4 is guided between the cylinders 6 and 7. A pair of cutting blades 8 are mounted at predetermined positions on the outer surface of the cutting cylinder 6 rotated in a direction indicated by arrow A. The predetermined positions are symmetrical with each other about the axis of the cutting cylinder 6. The cutting blades 8 extend along the entire length of the cutting cylinder 6. Cutting blade pads 9 made of an elastic material such as rubber are arranged at surface positions of the pin cylinder 7 rotated in a direction indicated by arrow B. The cutting blade pads 9 are symmetrical with each other about the axis of the pin cylinder 7. A plurality of pins 10 are pivotally arranged behind the cutting blade pads 9 with respect to the rotational direction of the pin cylinder 7 and constitute two arrays. The pins 10 pierce the leading end of the next web 4 after the trailing end of the current web 4 is cut between the cutting blade 8 and the cutting blade pad 9. Reference numeral 11 denotes a plurality of paper hold tapes in slidable contact with a web winding surface of the pin cylinder 7. A folding cylinder 12 is in rolling contact with the pin cylinder 7. The folding cylinder 12 has a diameter 1.5 times that of the pin cylinder 7 and is rotated in a direction indicated by arrow C. Three arrays of pins 13 and three insertion blades 14 are arranged at six equal angular positions on the surface of the folding cylinder 12. Each blade 14 extends along the entire length of the cylinder 7. The pins 13 are located opposite to the pins 10 upon rotation of the cylinders 7 and 12. The signature released from the pins 10 is pierced by the pins 13 and is wound around the upper surface portion of the folding cylinder 12. Reference numeral 15 denotes a plurality of paper hold tapes in slidable contact with the folding cylinder 12. A gripper cylinder 16 in rolling contact with the folding cylinder 12 is arranged obliquely therebelow. The gripper cylinder 16 has a diameter substantially 1/1.5 times that of the folding cylinder 12 and rotated in a direction indicated by arrow D. A pair of gripper plates 17 are arranged on the surface at equal angular intervals. Each gripper plate 17 is arranged opposite to a corresponding one of the insertion blades 14 upon rotation of the cylinders 12 and 16. When the insertion blade 14 is opposite to the corresponding gripper plate 17, it folds the center of the signature and inserts it into the corresponding gripper plate 17, so that the signature is wound around the lower surface portion of the gripper cylinder 16. Reference numeral 18 denotes a plurality of paper hold tapes in slidable contact with the signature winding surface of the gripper cylinder 16. A speed reduction cylinder 19 is in rolling contact with the gripper cylinder 16 and is located obliquely above the cylinder 16. The speed reduction cylinder 19 is rotated in a direction indicated by arrow E and has an outer diameter such that a peripheral velocity thereof is lower than that of the gripper cylinder 16. A ratio of a number of revolutions of the gripper cylinder 16 to that of the speed reduction cylinder 19 is about 3 : 1, but a ratio of an outer diameter of the gripper cylinder 16 to that of the speed reduction cylinder 19 is about 1 : 2. Six gripper units 20 each constituted by grippers and gripper pads are arranged on the speed reduction cylinder 19 at six equal angular positions, respectively. The gripper unit 20 can be located opposite to a corresponding one of the gripper plates 17 upon rotation of the cylinders 16 and 19. Each gripper unit 20 receives the signature from the gripper plate 17 so as to wind the signature on the upper surface portion of the cylinder 19. Reference numerals 21 and 22 denote upper and lower paper hold tapes in slidable contact with the upper and lower surfaces of the speed reduction cylinder 19. An upper transfer cylinder 23 is arranged obliquely above the speed reduction cylinder 19 and is in rolling contact therewith. The upper transfer cylinder 23 has a diameter 1/1.5 times that of the speed reduction cylinder 19 and is rotated in a direction indicated by arrow F. Two gripper units 24 having the same arrangement as that of the gripper units 20 are arranged on the surface of the upper transfer cylinder 23 at equal angular intervals. Each gripper unit 24 can be opposite to a corresponding one of the gripper units 20 upon rotation of the cylinders 19 and 23. A lower transfer cylinder 25 is arranged obliquely below the speed reduction cylinder 19 and is in rolling contact therewith. The lower transfer cylinder 25 has a diameter 1/1.5 times that of the speed reduction cylinder 19 and is rotated in a direction indicated by arrow G. Two gripper units 26 having the same arrangement as that of the gripper units 20 are arranged on the surface of the lower transfer cylinder 25 at equal angular intervals. Each gripper unit 26 can be opposite to a corresponding one of the gripper units 20 upon rotation of the cylinders 19 and 25. Reference numeral 27 denotes a plurality of paper hold tapes in sliding contact with the surface of the upper transfer cylinder 23. Reference numeral 28 denotes a plurality of upper paper hold tapes in sliding contact with the lower surface of the upper transfer cylinder 23 and offset from the tapes 27 in the axial direction of the cylinder 23. Reference numeral 29 denotes a plurality of paper hold tapes in sliding contact with the surface of the lower transfer cylinder 25. Reference numeral 30 denotes a plurality of lower paper hold tapes in sliding contact with the lower surface of the lower transfer cylinder 25 and offset from the tapes 29 in the axial direction of the cylinder 25. With the above arrangement, every other gripper unit 20 is selectively located opposite to one gripper unit 24 of the upper transfer cylinder 23 to transfer the signature to the upper transfer cylinder 23. Each remaining gripper unit 30 is selectively located opposite to one gripper unit 26 of the lower transfer cylinder 25 to transfer the signature to the lower transfer cylinder 25. The signature gripped by the upper gripper unit 24 is fed onto the upper tapes 28. The signature gripped by the lower gripper unit 26 is fed onto the lower tapes 30. Chopper units (not shown) are arranged on the upper and lower tapes 28 and 30, respectively. The operation of the folding unit having the arrangement described above will be described with reference to Fig. 1 and Figs. 2A to 2D. The printed web 4 folded by a former (not shown) into halves along its path of travel is guided by the leading rollers 1 and the like to the gap between the cutting cylinder 6 and the pin cylinder 7. The first array of pins 10 holds the leading end of the web 4 to wind the web 4 around the lower half of the surface of the pin cylinder 7 upon 1/2 revolution of the pin cylinder 7. In this case, the prospective trailing end of the web 4 is cut by the cutting blade 8. The leading end of the next web 4 is held by the second array of pins 10. The cylinders 6 and 7 in Fig. 2A show this state. More particularly, Fig. 2A shows a signature 4K wound around the pin cylinder 7 and nine signatures 4A to 4J preceding the signature 4K by 1/2 revolution each. In other words, upon each 1/2 revolution of the pin cylinder 7, the signature 4K is moved to the position of the signature 4J, and the signature 4J, to the signature 4H, and so on. In this case, when the pin cylinder 7 is rotated by 1/2 revolution, the gripper cylinder 16 and the upper and lower transfer cylinders 23 and 25 are also rotated by 1/2 revolution, the folding cylinder, 1/3 revolution; and the speed reduction cylinder 19, 1/6 revolution. Peripheral velocities of the pin cylinder 7, the folding cylinder 12 and the gripper cylinder 16 are identical. The peripheral velocities of the speed reduction cylinder 19 and the upper and lower transfer cylinders 23 and 25 are identical and smaller by about 35% than that of the pin cylinder 7. With this arrangement, the signatures 4J and 4H preceding the signature 4K by 1/3 revolution each of the folding cylinder 12 are wound around the folding cylinder 12 while they are being held by the pins 13. The further preceding signature 4G is transferred from the pins 13 to the gripper plate 17 and is about to be wound around the gripper cylinder 16. The signature 4F is gripped by the gripper plate 17 and is wound around the gripper cylinder 16. The further preceding signatures 4D and 4E are gripped by the gripper units 20 of the speed reduction cylinder 19 and are wound therearound. The signature 4C is gripped by the gripper unit 20 and is located opposite to a non-gripper portion of the upper transfer cylinder 23. The gripped end of the signature 4C passes through the contact point of the cylinders 19 and 23 and the signature 4C is then wound around the speed reduction cylinder 19. The signature 4B preceding by 1/6 revolution of the speed reduction cylinder 19 from the signature 4C is transferred from the gripper unit 20 in the speed reduction cylinder 19 to the gripper unit 24 of the upper transfer cylinder 23 and wound therearound. The signature 4B is then released from the gripper unit 24 and is fed by the upper tapes 28. The signature 4A preceding by 1/6 revolution of the speed reduction cylinder 19 from the signature 4B opposes a non-gripper portion of the upper transfer cylinder 23, and then the gripped end thereof reaches the contact point between the lower transfer cylinder 25 and the speed reduction cylinder 19 while the signature 4A is being wound around the speed reduction cylinder 19. Fig. 2B shows a state wherein the respective cylinders are rotated through angles corresponding to 1/4 revolution of the pin cylinder 7 from the state in Fig. 2A. A new signature 4L is wound around the pin cylinder 7 while it is being held by the pins 10. The signature 4K is held by the pins 13, and the center of the signature 4K reaches the contact point between the cylinders 7 and 12. The center of the signature 4H is gripped by the gripper plate 17, and the signature 4H is about to be folded into halves. The signature 4G has already been folded into halves and is wound around the gripper cylinder 16. The signatures 4D and 4E are wound around the speed reduction cylinder 19. The signature 4D is about to be gripped by the gripper unit 24 in the upper transfer cylinder 23. The signature 4C is wound around the gear reduction cylinder 19 after it has passed the contact point between the upper transfer cylinder 23 and the speed reduction cylinder 19. The signature 4A is transferred to the gripper unit 26 in the lower transfer cylinder 25 and is wound around the lower transfer cylinder 25. It should be noted that the signature 4B conveyed by the upper tapes 28 in Fig. 2A is subjected to cross folding in a chopper unit (not shown). Fig. 2C shows a state wherein the respective cylinders are rotated through angles corresponding to 3/4 revolution of the pin cylinder 7 from the state of Fig. 2B. In this state, the signatures 4E to 4M are moved by one revolution of the pin cylinder 7 from the state of Fig. 2A, i.e., by two pitches of the gripper unit 20 of the speed reduction cylinder 19. The signature 4F is now located at the position of the signature 4D in Fig. 1A. The signature 4D is gripped by the gripper unit 24 in the upper transfer cylinder 23 and is wound therearound. The signature 4D is then released from the gripper unit 24 and is conveyed onto the upper tapes 28. The signature 4C is gripped by the gripper unit 26 in the lower transfer cylinder 25. The signature 4A is conveyed by the gripper unit 26 and is about to be released therefrom. Fig. 2D shows a state wherein the respective cylinders are rotated through angles corresponding to 1/4 revolution of the pin cylinder 7 from the state of Fig. 2C. In this state, the signatures 4F to 4N are moved by one revolution of the pin cylinder 7 from the state of Fig. 2B, i.e., by two pitches of the gripper unit 20. The signature 3F is now located at the position of the signature 4D in Fig. 1B. The signature 4E is wound around the speed reduction cylinder 19. The signature 4C is wound around the lower transfer cylinder 25 while it is being held by the gripper unit 26 thereof. The signature 4A is released from the gripper unit 26 and is conveyed onto the lower tapes 30 toward a chopper unit (not shown). By the operation sequence as described above, the web 4 is held by the pins 10 in the pin cylinder 7, and the prospective trailing end is cut. The obtained signature is gripped by the pins 13 of the folding cylinder 12 and is wound therearound. The center of the wound signature is gripped by the gripper plate 17 in the gripper cylinder 16 and is folded into halves upon rotation of the gripper cylinder 16. The folded signature is gripped by the gripper unit 20 in the speed reduction cylinder 19 and is gradually wound therearound. The wound signature is conveyed by the speed reduction cylinder 19 rotated at a peripheral velocity slower than the gripper cylinder 16. The conveyed signatures are then alternately gripped by the gripper units 24 and 26 of the upper and lower transfer cylinders 23 and 25, respectively. The upper transfer cylinder 23 conveys the signature at the same peripheral velocity as that of the speed reduction cylinder 19 and delivers the signature onto the upper tapes 28. The signature is thus conveyed in the corresponding chopper unit. Similarly, the lower transfer cylinder 25 conveys the signature at the same peripheral velocity as that of the speed reduction cylinder 19 and delivers the signature onto the lower tapes 30. The signature is thus conveyed in the corresponding chopper unit. Speed reduction of the signature and feed path selection of the signatures into the upper and lower delivery paths are separated. When the signatures are delivered onto the tapes 28 and 30, the trailing ends of the signatures are released. As a result, the signatures can be stably conveyed and are free from misalignment. Double signature parallel folding in the folding apparatus will be described with reference to Figs. 3A to 3I. In this case, the upper transfer cylinder 23 is not used, so that the gripper units 24 are kept inoperative. Every other gripper unit 20 of the speed reduction cylinder 19 is kept inoperative. One of the gripper plates 17 in the gripper cylinder 16 is also kept inoperative. After these preparatory procedures are completed, the web 4 is fed between the cutting cylinder 6 and the pin cylinder 7. In the same manner as in parallel folding in Figs. 2A to 2D, the web 4 is cut by the cutting blade 8 and is held by the pins 10. The web is wound around the pin cylinder 7. The leading end if the web 4 is held by the pins 10 and the respective cylinders are rotated through angles corresponding to two revolutions of the pin cylinder 7. Since one of the gripper plates 17 is held inoperative, the three signatures 4A, 4B and 4C sequentially gripped by the pins 13 are wound around the folding cylinder 12. One signature 4D is wound around the pin cylinder 7. In this state, when the respective cylinders are rotated through angles corresponding to 1/4 revolution of the pin cylinder 7, the pins 13 holding the signature 4A pierce and hold the signature 4D. The signature 4D overlays the signature 4A and is wound around the folding cylinder 12. In this case, the center of the signature 4B is located opposite to the gripper plate 17. When the respective cylinders are rotated through angles corresponding to 1/4 revolution of the pin cylinder 7 from this state, the center of the signature 4B is gripped by the gripper plate 17, as shown in Fig. 3C, so that the signature 4B is folded into halves. When the respective cylinders are further rotated through angles corresponding to 1/4 revolution of the gripper plate 17, the signature 4B is wound around the gripper cylinder 16, as show in Fig. 3D. At the same time, the signature 4C passes over the inoperative gripper plate 17, and the signature 4E is held by the pins 13. When the respective cylinders are further rotated through angles corresponding to 1/4 revolution of the pin cylinder 7, the gripped end of the folded signature 4B is located opposite to the speed reduction cylinder 19, and the gripped end of the overlaying signatures 4A and 4D is located opposite to the gripper cylinder 16, as shown in Fig. 3E. When the respective cylinders are rotated through angles corresponding to 1/4 revolution of the pin cylinder 7, the folded signature 4B is transferred to the gripper unit 20 of the speed reduction cylinder 19 and is wound around the gear reduction cylinder 19, as shown in Fig. 3F. At the same time, the center of the overlaying signatures 4A and 4D is located opposite to the gripper plate 17, so that the signature 4F overlays the signature 4C. When the respective cylinders are rotated through angles corresponding to 1/4 revolution of the pin cylinder 7 from this state, the signature 4B is moved by 1/2 pitch of the gripper unit 20, as shown in Fig. 3G. At the same time, the center of the overlaying signatures 4A and 4D is gripped by the gripper plate 17, so that the signatures 4A and 4D are folded together into halves and the folded overlaying signatures 4A and 4D are wound around the gripper cylinder 16. The single signature 4E and the overlaying signatures 4C and 4F are wound around the folding cylinder 12. A new signature 4G is wound around the pin cylinder 7. In this state, when the respective cylinders are rotated through angles corresponding to 1/4 revolution of the pin cylinder 7 from this state, the signature 4B is moved by 1/2 pitch of the gripper unit 20, as shown in Fig. 3H. At the same time, the overlaying signatures 4A and 4D are angularly moved through 45° and are wound around the gripper cylinder 16. The single signature 4E and the overlaying signatures 4C and 4F are angularly moved through 30°. The signature 4G is held by the pins 13 and is wound around the folding cylinder 12. A new signature 4H is held by the pins 10 and is then wound around the pin cylinder 7. Thereafter, the respective cylinders are rotated through angles corresponding to three revolutions of the pin cylinder 7, and the operations in Figs. 3E to 3H are repeated. As shown in Fig. 3I, the states of the cutting cylinder 6 to the gripper cylinder 16 are the same as those in Fig. 3H. The speed reduction cylinder 19 is rotated by one revolution, so that the overlaying signatures 4C and 4F and the overlaying signatures 4E and 4H are held on the surface of the speed reduction cylinder 19 to be separated by a distance corresponding to the pitch of the gripper unit 20. The overlaying folded signatures 4A and 4D are gripped by a gripper unit 26 of the lower transfer cylinder 25. The leading, folded signature 4B is released from the gripper unit 26 and is delivered onto the lower tapes 30. Thereafter, the respective cylinders are continuously rotated to deliver each overlaying folded signatures onto the lower tapes 30 for every revolution of the pin cylinder 7. Only the first signature 4B is delivered as a single signature, and the second and subsequent signatures are delivered as double signatures each. As described above, in single signature parallel folding shown in Figs. 2A to 2D, when the web 4 folded by the former is supplied to the folding unit, the web 4 is cut for every 1/2 revolution of the pin cylinder 7. The signature is subjected to parallel folding between the folding cylinder 12 and the gripper cylinder 16. The feed speed of the signature is decreased when it is transferred from the gripper cylinder 16 to the speed reduction cylinder 19. The signatures are alternately delivered on the upper and lower tapes 28 and 30 through the upper and lower transfer cylinders 23 and 25. As a result, former folding and parallel folding achieves an 8-page signature. The 8-page signature is then conveyed into the chopper unit and is subjected to chopper folding, thereby obtaining a 16-page signature. In double signature parallel folding in Figs. 3A to 3I, when the web 4 folded by the former is supplied to the folding unit, it is cut for every 1/2 revolution of the pin cylinder 7. The signatures are overlayed and parallel-folded for every revolution of the pin cylinder 7. The speed of the signatures is reduced while it is transferred from the gripper cylinder 16 to the speed reduction cylinder 19. The overlaying signatures are delivered onto the lower tapes 30 through the lower transfer cylinder 25. As a result, former folding and double signature parallel folding provides a 16-page signature. The signature is conveyed into the chopper unit and is subjected to chopper folding into halves, thereby obtaining a 32-page signature. When single signature parallel folding is switched to double signature parallel folding, the cylinder arrangement need not be modified, but simply some gripper units and gripper plates are held inoperative. In single signature parallel folding and the subsequent chopper folding in Figs. 2A to 2D, the peripheral velocity of the speed reduction cylinder 19 and the transfer cylinders 23 and 25 is lower than that of the cutting cylinder 6 to the gripper cylinder 16, so that the feed speed of the signature fed to the chopper unit can be decreased. Even if the speed of the signatures fed from the cutting cylinder 6 to the gripper cylinder 16 is increased in accordance with the printing speed, the signatures can be fed at a speed lower than the printing speed. As a result, high chopper folding precision can be maintained, and the number of folded signatures obtained is the total number of signatures from the upper and lower chopper units, thereby guaranteeing productivity corresponding to the printing speed. The folding apparatus for the web rotary press according to the present invention has: a folding cylinder with pins and insertion blades and in rolling contact with a pin cylinder; a gripper cylinder adapted to be in rolling contact with the folding cylinder and having a diameter 1/1.5 times that of the folding cylinder and gripper plates opposite to the insertion blades; a speed reduction cylinder adapted to be in rolling contact with the gripper cylinder, rotated at a peripheral velocity lower than that of the gripper cylinder and having gripper units; and a pair of upper and lower transfer cylinders each with two gripper units opposite to the surface of the speed reduction cylinder. The signatures parallel-folded by the folding and gripper cylinders transferred to the speed reduction cylinder. The signatures are alternately transferred from the speed reduction cylinder to the upper and lower transfer cylinders. When the chopper units are arranged in the delivery path of the signatures fed from the upper and lower transfer cylinders, the parallel folding speed and the chopper capacity which correspond to a high printing speed can be maintained, and at the same time, the speed of signatures fed into the chopper units can be decreased, thereby improving productivity corresponding to high-speed printing and folding precision of the chopper units. In addition, when the conveyance speed of the signatures is decreased, they are firmly gripped by the corresponding gripper units. The trailing edge of each signature is released when the signature is delivered from the transfer cylinder. Therefore, signature misalignment can be minimized and folding precision is improved. Furthermore, when pattern assignment is considered, different patterns can be assigned to the upper and lower cylinders, thereby greatly facilitating the subsequent operation. Single signature parallel folding can be easily switched to double signature parallel folding, and operability can be improved. Signature cutting and signature overlaying are performed at different positions, thereby obtaining high cutting precision.

Claims: 1. A folding apparatus for a web rotary press, which folds signatures obtained by cutting a web (4) by a combination of a cutting cylinder (6) and a pin cylinder (7), comprising: a folding cylinder (12) adapted to be in rolling contact with said pin cylinder (7) located in an upstream thereof; a gripper cylinder (16) adapted to be in rolling contact with said folding cylinder (12); a speed reduction cylinder (19) adapted to be in rolling contact with said gripper cylinder (16); and transfer cylinder means (23, 25) adapted to be in rolling contact with said speed reduction cylinder (19), characterized in that said folding cylinder (12) has pins (13) and insertion blades (14) at a plurality of positions on an outer surface at equal angular intervals, said pins (13) are alternately arranged with said insertion blades (14), said gripper cylinder (16) has a diameter substantially 1/1.5 times that of said folding cylinder (12) and gripper plates (17) which selectively correspond to said insertion blades (14) upon rotation of said folding cylinder (12) and said gripper cylinder (16), said speed reduction cylinder (19) is rotated at a peripheral velocity lower than that of said gripper cylinder (16), and has first gripper units (20) which selectively correspond to said gripper plates (17) upon rotation of said gripper cylinder (16) and said speed reduction cylinder (19), and said transfer cylinder means (23, 25) comprises a pair of upper and lower transfer cylinders (23, 25) adapted to be in rolling contact with two surface portions of said speed reduction cylinder (19) rotated at the same peripheral velocity as that of said speed reduction cylinder (19), and respectively having second and third gripper units (24, 26) at surface positions at equal intervals, said second and third gripper units selectively corresponding to said first gripper units (20) upon rotation of said speed reduction cylinder (19) and said pair of upper and lower transfer cylinders (23, 25). 2. An apparatus according to claim 1, wherein the signatures (4A - 4L) comprise single signatures which are alternately delivered to said pair of upper and lower transfer cylinders (23, 25). 3. An apparatus according to claim 1, wherein the signatures (4A - 4L) comprise double signatures, said double signatures being delivered to only said lower transfer cylinder (25) when said upper transfer cylinder (23) is kept inoperative, some of said first gripper units (20) which are not adjacent to each other in said speed reduction cylinder (19) are kept inoperative, and said gripper plates (14) in said gripper cylinder (16) are selectively kept inoperative. 4. An apparatus according to claim 1, wherein a ratio of a number of revolutions of said gripper cylinder (16) to that of said speed reduction cylinder (19) is about 3 : 1, and an outer diameter ratio of said gripper cylinder (16) to said speed reduction cylinder (19) is about 1 : 2.

Inventors: NIITSUMA, TSUTOMU
Applicants: KOMORI PRINTING MACHINERY CO., LTD.
Application year: 1986
Main classification: B41F13
IPC codes: B65H45, B41F13