Variable cutoff folding device and printer comprising variable cutoff folding device

Abstract

 This variable cutoff folding device 100 comprises: a cutting mechanism 10 capable of changing a cutting length; a speed-increasing conveyor mechanism 20 capable of changing a conveying speed based on a change in the cutting length; a folding cylinder 40 having a pin device 41 and a thrust blade device 43, the thrust blade device 43 being configured to be displaced based on the change in the cutting length; and a jaw cylinder 50 configured to be rotationally displaced based on displacement of the thrust blade device 43.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to a variable cutoff folding device capable of handling a change in cutoff (cutting length) of a continuous paper printed by a digital printer, and a printer comprising the variable cutoff folding device.

Description of the Related Art

[0002] In a conventional rotary press, in order to change cutoff in a direction of continuity of a continuous paper, it is necessary to exchange the likes of a printing plate or a plate cylinder on which the printing plate is mounted, so that realistically cutoff could not be easily changed.

[0003] To counter this, a digital printer disclosed in Patent Document 1 identified below has become publicly known. The digital printer disclosed in Patent Document 1 differs from a rotary press in not requiring a printing plate. It is therefore possible to easily carry out a change in cutoff in a direction of continuity of the continuous paper.

[0004] However, the folding device disclosed in Patent Document 1 is a folding device that wraps cut sheets on a folding cylinder to produce a signature by a jaw cylinder, and there was a problem that since the circumference of the folding cylinder does not change, when cutoff of the continuous paper is changed, a cycle of the folding cylinder making a single rotation and a sheet spacing of continuously supplied cut individual sheets are not synchronous, whereby it becomes impossible to continuously wrap the individual sheets at an accurate wrapping position.

[0005] Accordingly, there appears a folding device, of the kind disclosed in Patent Document 2 identified below, that, accompanying a change in cutoff, adjusts timing when wrapping the cut sheets on the folding cylinder. (Hereinafter, this folding device is referred to as a "variable cutoff folding device".) The conventional variable cutoff folding device disclosed in Patent Document 2 comprises a printing device, a cutting device and a processing device, and, furthermore, comprises a first conveyor belt device and a second conveyor belt device between the cutting device and the processing device. The conventional variable cutoff folding device including these devices is configured to cut the web supplied from the printing device after changing the cutting length of said web and set a conveying speed of said web to a speed that accords with the cutting length of the sheets cut by the cutting device, and at the same time to set a sheet conveying speed in the first conveyor belt device to have an equal speed to that of the web conveying speed. Furthermore, the conventional variable cutoff folding device is configured to, when receiving said sheets from the first conveyor belt device by means of the second conveyor belt device, receive the sheets with the same speed as the sheet conveying speed in the first conveyor belt device, then change the sheet conveying speed during conveyance of the sheets and, when transferring the sheets to the processing device, transfer the sheets with the same speed as the sheet conveying speed in the processing device.

[0006] As a result of the variable cutoff folding device according to the conventional technology disclosed in Patent Document 2 comprising configurations of the above-mentioned kind, it becomes possible for a rotary press including such a folding device to implement processing such as folding of cut sheets (folding so as to crease in a direction perpendicular to a running direction), and so on, with high precision.

[Patent Document 1] JP 2011-157168 A

[Patent Document 2] JP 4191732 B2

SUMMARY OF THE INVENTION

[0007] However, there was a problem that in order to implement processing for folding cut sheets with high precision, the variable cutoff folding device disclosed in Patent Document 2 identified above must dispose a plurality of long conveyor belts between the cutting device and the processing device, whereby the device becomes large-sized. Specifically, it was a problem that in a printing factory where there is a desire for multimedia printing in small lots, when the variable cutoff folding device of Patent Document 2 is combined with a digital printer, installation space of the entire device ends up increasing, whereby a merit of digital printers, namely that facilities become compact, is lost.

[0008] Moreover, in order to transfer cutting of the continuous paper and the cut sheets to the processing device with high precision, the variable cutoff folding device disclosed in Patent Document 2 described above has two cutting mechanisms, namely a first and second cutting mechanism, provided, and after the continuous paper is first partially cut by the first cutting mechanism, a remaining portion not yet cut is cut by the second cutting mechanism, whereby the sheets are completed. It was a problem that due to cutting of the continuous paper being divided into two stages in this way, cut surfaces are not easily kept straight and quality is unstable compared to the case where all sheets are cut at one time.

[0009] The present invention was made in view of the above problems of the conventional technology, and an object of the present invention is to provide a variable cutoff folding device capable of providing a high quality signature while handling a change in cutoff, in a state that installation space of the entire device is maintained unchanged, and a printer comprising this variable cutoff folding device.

[0010] A variable cutoff folding device according to the present invention comprises: a cutting mechanism capable of cutting a continuous paper into individual sheets, and capable of changing a cutting length; a speed-increasing conveyor mechanism capable of conveying the individual sheets at an increased speed over a supply speed of the continuous paper, and capable of changing a conveying speed based on a change in the cutting length; a folding cylinder having installed on an outer circumferential surface thereof a pin device and a thrust blade device, the pin device being configured to stick a pin into a leading edge in a running direction of the individual sheets, and the thrust blade device being configured to thrust a thrust blade against the individual sheets stuck by the pin in said pin device and to be displaced based on the change in the cutting length; and a jaw cylinder having installed on an outer circumferential surface thereof a jaw device for gripping the thrust blade and being configured to be rotationally displaced based on displacement of the thrust blade device.

[0011] The variable cutoff folding device according to the present invention may be configured such that the speed-increasing conveyor mechanism includes: a belt conveyor including a suction hole; and a suction device for suctioning the individual sheets via the suction hole.

[0012] Moreover, the variable cutoff folding device according to the present invention may be configured further comprising: a downward-of-folding conveyor mechanism provided on a downstream side of the speed-increasing conveyor mechanism and an upstream side of the folding cylinder, the downward-of-folding conveyor mechanism being configured to synchronize with a circumferential speed of the folding cylinder and convey the individual sheets with the same speed as the circumferential speed of the folding cylinder.

[0013] In addition, the variable cutoff folding device according to the present invention may be configured such that a stopper is installed in the folding cylinder to form a pair with the pin device, the stopper being configured to be butted against by the individual sheets on a downstream side of a position where the pin of the pin device protrudes.

[0014] Furthermore, the variable cutoff folding device according to the present invention may be configured such that the cutting mechanism is a cutter cylinder having a cutter installed protruding from an outer circumference of the cutter cylinder, and when the cutting length is maximum, a circumferential speed of the cutter cylinder, the folding cylinder, and the jaw cylinder are the same speed as the supply speed of the continuous paper.

[0015] Note that the present invention may be configured as a printer comprising the above-described variable cutoff folding device.

[0016] The present invention makes it possible to provide a variable cutoff folding device capable of providing a high quality signature while handling a change in cutoff, in a state that installation space of the entire device is maintained unchanged, and a printer comprising this variable cutoff folding device.

Brief Description of the Drawings

[0017] 

Fig. 1 is a view showing an example of configuration of a variable cutoff folding device according to a present embodiment.

Fig. 2 is a view showing an example of configuration of a lower conveyor belt.

Fig. 3 is a view showing an example of configuration of a pin device and a stopper.

Fig. 4 is a view showing an example where a speed-increasing conveyor mechanism conveys individual sheets cut with a maximum cutoff.

Fig. 5 is a view showing an example where a folding cylinder collects a following individual sheet during maximum cutoff.

Fig. 6 is a view showing an example where the speed-increasing conveyor mechanism conveys individual sheets cut with a minimum cutoff.

Fig. 7 is a view showing an example where the folding cylinder collects a following individual sheet during minimum cutoff.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Preferred embodiments for carrying out the present invention are described below with reference to the drawings. The following embodiments and examples are not intended to limit the inventions set forth in the claims, and the combinations of features described in the embodiments and examples are not all necessarily indispensable for the means for solving the problem provided by the invention.

[0019] Fig. 1 is a view showing an example of configuration of a variable cutoff folding device according to a present embodiment.

[0020] As shown in Fig. 1, a variable cutoff folding device 100 according to the present embodiment cuts a post-printing continuous paper W (Web) by a cutting mechanism 10, conveys post-cutting individual sheets FP (Flat Paper) by a speed-increasing conveyor mechanism 20 and a downward-of-folding conveyor mechanism 30, collects the individual sheets FP by a folding cylinder 40, and grips and folds the individual sheets FP by a jaw cylinder 50, thereby producing a signature having an arbitrary number of individual sheets FP overlapped. In Fig. 1, arrow X indicates a conveying direction of the individual sheets FP, arrow Y indicates a rotating direction of the folding cylinder 40, and arrow Z indicates a rotating direction of the jaw cylinder 50.

[0021] The individual sheets FP may be configured in a variety of sizes according to a type of the continuous paper W supplied and according to a change in cutoff due to the cutting mechanism 10.

[0022] A length in a width direction of the individual sheets FP is always determined constant based on a length in a width direction of the continuous paper W supplied. Specifically, the length in the width direction is configured compatible with any of a Japanese broad sheet standard (546 mm) and a Japanese tabloid sheet standard (406.5 mm).

[0023] A length in a running direction of the individual sheets FP is changeable according to a change in cutoff. That is, the length in the running direction of the individual sheets FP differs from the length in the width direction of the individual sheets FP in being changeable according to an operational setting of the variable cutoff folding device 100. Specifically, the length in the running direction is configured compatible with any of a two section portion of a Japanese broad sheet standard (813 mm) and a two section portion of a Japanese tabloid sheet standard (546 mm) .

[0024] In the present embodiment, a cutoff of a two section portion of a Japanese broad sheet standard (813 mm) is assumed to be a "maximum cutoff". Moreover, a time when the variable cutoff folding device 100 is operating with a setting where the individual sheets FP undergo maximum cutoff is referred to as "during maximum cutoff". On the other hand, a cutoff of a two section portion of a Japanese tabloid sheet standard (546 mm) is assumed to be a "minimum cutoff". Moreover, a time when the variable cutoff folding device 100 is operating in a state where the individual sheets FP undergo minimum cutoff is referred to as "during minimum cutoff".

[0025] The cutting mechanism 10 is configured including a cutter cylinder 11, a cutter blade 11a, and a cutter blade receiver 11b. Moreover, the cutting mechanism 10 cuts the supplied continuous paper W into the individual sheets FP.

[0026] The cutter cylinder 11 is formed with a certain circumferential length and comprises one cutter blade 11a protruding from an outer circumferential surface of the cutter cylinder 11. Moreover, the cutter cylinder 11 cuts the continuous paper W, supplied at the same speed as a circumferential speed of the cutter cylinder 11 during maximum cutoff, one time every one rotation.

[0027] The circumferential length of the cutter cylinder 11 is configured to be the same length as the length in the running direction of the individual sheets FP during maximum cutoff. Moreover, if the cutter cylinder 11 rotates having a circumferential speed of the cutter cylinder 11 which is the same speed as the continuous paper W, the individual sheets FP can be configured maximum cutoff.

[0028] The cutter cylinder 11 includes a control means for changing the circumferential speed. Changing the circumferential speed of the cutter cylinder 11 results in a spacing at which the cutter blade 11a reaches a cutting position changing along with a change in the circumferential speed of the cutter cylinder 11. That is, the variable cutoff folding device 100 is configured such that changing the circumferential speed of the cutter cylinder 11 causes cutoff of the continuous paper W to change from "maximum cutoff" to "minimum cutoff".

[0029] The speed-increasing conveyor mechanism 20 is configured including a lower conveyor belt 21, a lower suction device 22, an upper conveyor belt 23, and an upper suction device 24. In addition, the speed-increasing conveyor mechanism 20 conveys the individual sheets FP cut by the cutting mechanism 10 toward the downward-of-folding conveyor mechanism 30. Moreover, the speed-increasing conveyor mechanism 20 conveys the individual sheets FP at a speed which is faster than the conveying speed of the continuous paper W supplied to the cutting mechanism 10.

[0030] The speed-increasing conveyor mechanism 20 is configured capable of changing a conveying speed. The conveying speed of the speed-increasing conveyor mechanism 20 is slowest during maximum cutoff and fastest during minimum cutoff. When the conveying speed of the speed-increasing conveyor mechanism 20 is slowest (during maximum cutoff), the speed-increasing conveyor mechanism 20 conveys at a conveying speed which is several percent faster than the conveying speed of the continuous paper W up to the cutting mechanism 10. On the other hand, when the conveying speed of the speed-increasing conveyor mechanism 20 is fastest (during minimum cutoff), the speed-increasing conveyor mechanism 20 conveys at a conveying speed which is 1.5 times that during maximum cutoff.

[0031] Fig. 2 is a view showing an example of configuration of the lower conveyor belt. As shown in Fig. 2, the lower conveyor belt 21 includes a belt portion 21a, a belt portion suction hole 21b, a top plate 21c, and a top plate suction hole 21d. Moreover, the lower conveyor belt 21 is a conveyor mechanism installed in a lower portion of a conveying path of the individual sheets FP. The lower conveyor belt 21, along with an upper conveyor belt 23, conveys the individual sheets FP by sandwiching the individual sheets FP between the lower conveyor belt 21 and upper conveyor belt 23.

[0032] The belt portion 21a is a belt suspended by a plurality of rollers. The belt portion 21a forms a certain path by being suspended by the plurality of rollers and circuits using a rotational driving force of the rollers as a power source. This certain path includes a path of passage of the individual sheets FP. The path of passage of the individual sheets FP in the lower conveyor belt 21 is from directly after the cutting mechanism 10 to a most upstream position of the downward-of-folding conveyor mechanism 30.

[0033] As shown in Fig. 2, the belt portion suction hole 21b is a circular-shaped round hole formed in the belt portion 21a. Moreover, the belt portion suction holes 21b are formed with a certain pitch in parallel to the running direction of the individual sheets FP, and are formed in a plurality of columns. In view of a length in the running direction of the individual sheets FP conveyed, in order to convey the individual sheets FP stably, a pitch in the long direction of the belt portion suction holes 21b is preferably about 25 mm.

[0034] The top plate 21c is installed on an inner side of the lower conveyor belt 21 and is installed directly below a conveying path along which the individual sheets FP pass in the lower conveyor belt 21. The top plate 21c is fixed to a frame or the like installed in the variable cutoff folding device 100. Moreover, the top plate 21c fixes the lower suction device 22.

[0035] The top plate suction hole 21d is a slit hole formed in the top plate 21c. Moreover, the top plate suction holes 21d are formed with a certain pitch in parallel to the running direction of the individual sheets FP, and are formed in a plurality of columns.

[0036] Columns formed in parallel to the running direction of the belt portion suction hole 21b and columns formed in parallel to the running direction of the top plate suction hole 21d are formed such that respective columns overlap. Therefore, when the belt portion 21a is being driven, the belt portion suction hole 21b necessarily passes above the top plate suction hole 21d, hence the variable cutoff folding device 100 makes it possible for suction power from the lower suction device 22 to be transmitted to the individual sheets FP via the belt portion suction hole 21b, thereby making it possible for the individual sheets FP to be conveyed while being restrained.

[0037] A plurality of the lower suction devices 22 are installed below the path of passage of the individual sheets FP in the lower conveyor belt 21. Since the lower suction device 22 is fixed to the top plate forming the lower conveyor belt 21 and is not fixed directly to the belt portion 21a, the lower suction device 22 itself does not move. Moreover, suction power of the lower suction device 22 is transmitted to the individual sheets FP via the belt portion suction hole 21b. Such a configuration enables the individual sheets FP cut and rendered in sheet form to be conveyed reliably in a restrained state.

[0038] The upper conveyor belt 23 is a belt installed in an upper portion of the conveying path of the individual sheets FP. The upper conveyor belt 23, along with the lower conveyor belt 21, conveys the individual sheets FP by sandwiching the individual sheets FP between the upper conveyor belt 23 and lower conveyor belt 21. Moreover, the upper conveyor belt 23 circuits a certain path formed by a plurality of rollers, using a rotational driving force of the rollers as a power source. This certain path includes from directly after the cutting mechanism 10 to a position where a return roller 23a does not contact the folding cylinder 40. That is, the upper conveyor belt 23 is configured having a conveying path of the individual sheets up to a position more on a downstream side than that of the lower conveyor belt 21.

[0039] The upper suction device 24 is a suction device installed at a most downstream position of the lower conveyor belt 21 in the speed-increasing conveyor mechanism 20. Due to a relationship of installation between the rollers driving the lower conveyor belt 21 and rollers driving the downward-of-folding conveyor mechanism 30, space for installing the lower suction device 22 cannot be secured between the lower conveyor belt 21 in the speed-increasing conveyor mechanism 20 and the downward-of-folding conveyor mechanism 30. Therefore, since the individual sheets FP are not conveyed in a restrained state between the lower conveyor belt 21 in the speed-increasing conveyor mechanism 20 and the downward-of-folding conveyor mechanism 30, conveying trouble may occur. Accordingly, adopting a configuration where the upper suction device 24 is installed in an upper position of the conveying path to suction the individual sheets FP results in bridging between the speed-increasing conveyor mechanism 20 and the downward-of-folding conveyor mechanism 30 being performed without conveying trouble.

[0040] The downward-of-folding conveyor mechanism 30 is a belt conveyor installed downstream of the speed-increasing conveyor mechanism 20 and upstream of the folding cylinder 40. Moreover, the downward-of-folding conveyor mechanism 30 is configured including a downward-of-folding conveyor belt 31, a downward-of-folding suction device 32, and a pin receiving roller 33. The downward-of-folding conveyor belt 31 circuits a certain path formed by a plurality of rollers including the pin receiving roller 33, using a rotational driving force of the rollers as a power source. This certain path includes from a most downstream position of the speed-increasing conveyor mechanism 20 to a position where a pin device 41 installed in the folding cylinder 40 operates.

[0041] A driving speed of the downward-of-folding conveyor mechanism 30 is configured to be identical to a circumferential speed of the folding cylinder 40. As a result of such a configuration, when the folding cylinder 40 catches the individual sheets FP conveyed from the downward-of-folding conveyor mechanism 30, the individual sheets FP are enabled to be wrapped round the folding cylinder 40 in a state where a moving speed of the individual sheets FP and the circumferential speed of the folding cylinder 40 are set to the same speed, thereby enabling the individual sheets FP to be wrapped round the folding cylinder 40 without causing twisting, blockage, or the like. Therefore, the folding cylinder is enabled to reliably collect the individual sheets, thereby making it possible to prevent a lowering of operating efficiency.

[0042] The downward-of-folding suction device 32 is a suction device for suctioning the individual sheets FP from a lower portion of the conveying path of the individual sheets FP. The downward-of-folding suction device 32 takes over restraint of the individual sheets FP from the upper suction device 24. Such a configuration enables the individual sheets FP to be conveyed in a restrained state without being set in a free state, thereby enabling stable conveying of the individual sheets FP. Therefore, conveying trouble can be prevented.

[0043] The pin receiving roller 33 is configured including a groove portion (not illustrated). In addition, the pin receiving roller 33 is supported rotatably and in parallel to an axis of the folding cylinder 40. Moreover, since the pin receiving roller 33 is set such that a spacing between the pin receiving roller 33 and the folding cylinder 40 is narrow, when a pin of the pin device 41 has stabbed and penetrated the received individual sheets FP, a leading edge side of the penetrating pin is caused to enter the groove portion and the pin of the pin device is enabled to reliably stab a flimsy sheet. Therefore, the folding cylinder is enabled to reliably collect the individual sheets, thereby making it possible to prevent a lowering of operating efficiency.

[0044] The folding cylinder 40 is configured including the pin device 41, a stopper 42, and a thrust blade device 43. Moreover, the folding cylinder 40 is installed downstream of the downward-of-folding conveyor mechanism 30 and upstream of the jaw cylinder 50.

[0045] A circumferential speed of the folding cylinder 40 is configured to synchronize with a circumferential speed of the cutter cylinder 11 and have the same speed as the circumferential speed of the cutter cylinder 11. Moreover, a length of a half circumference of the folding cylinder 40 is configured to be longer than "a length of the individual sheets FP during maximum cutoff + a length in a rotating direction of the stopper 42". Therefore, the folding cylinder 40 according to the present embodiment is configured to wrap round one of the individual sheets FP every half rotation of the folding cylinder 40.

[0046] Fig. 3 is a view showing an example of configuration of the pin device and the stopper. As shown in Fig. 3, two of the pin devices 41 are installed with equal spacing in a close vicinity of an outer circumferential side of the folding cylinder 40 and are configured to enable a pin to protrude from an outer circumferential surface of the folding cylinder 40 at a pin stabbing position by, for example, a cam or the like. The pin stabbing position is configured to be a position where the individual sheets FP conveyed from the downward-of-folding conveyor mechanism 30 come closest to the folding cylinder 40.

[0047] As shown in Fig. 3, the stopper 42 is provided forming a pair with each of the pin devices 41 and is installed on a downstream side (in terms of rotating direction, a forward direction side) of when the pin of the pin device 41 protrudes from the outer circumference of the folding cylinder 40. Such a configuration makes it possible for a head edge position of the conveyed individual sheets FP to be fixed and for the pin to be stabbed accurately in a leading edge in the running direction of the individual sheets FP, thereby enabling a high precision signature to be produced.

[0048] Two thrust blade devices 43 are installed with equal spacing at an outer circumference of the folding cylinder 40 and are configured to cause a thrust blade to protrude thereby causing a sheet group collected by the pin device 41 to be gripped by the jaw cylinder 50. The thrust blade device 43 is configured to cause the thrust blade to protrude at a position of smallest distance between the folding cylinder 40 and the jaw cylinder 50.

[0049] The thrust blade device 43 changes a phase according to a change in cutoff. Assuming a position during maximum cutoff to be a reference position of the thrust blade device 43, the thrust blade device 43 is configured capable of being rotationally displaced by a maximum of 35° from the reference position, centered on a rotation axis of the folding cylinder 40. A direction of rotational displacement is an identical direction to the rotating direction Y of the folding cylinder 40 when cutoff is shortened, and is a reverse direction to the rotating direction Y of the folding cylinder 40 when cutoff is lengthened. Note that a configuration for changing the phase manually may be adopted as a changing means, or a configuration for changing the phase automatically by installing a control device may be adopted as a changing means.

[0050] The jaw cylinder 50 is configured including a jaw device 51. The jaw cylinder 50 is installed on a downstream side of the folding cylinder 40 and is configured having a rotation axis parallel to the rotation axis of the folding cylinder 40. Moreover, a rotating direction of the jaw cylinder 50 is configured to be the reverse of that of the folding cylinder 40.

[0051] A circumferential speed of the jaw cylinder 50 is configured to synchronize with and have the same speed as that of the folding cylinder 40. Moreover, a circumferential length of the jaw cylinder 50 is configured to have the same circumferential length as the circumferential length of the folding cylinder 40.

[0052] The jaw cylinder 50 is configured capable of rotationally displacing a phase according to the phase change of the thrust blade device 43. A direction of rotational displacement is an identical direction to the rotating direction Z of the jaw cylinder 50 when cutoff is shortened, and is a reverse direction to the rotating direction Z of the jaw cylinder 50 when cutoff is lengthened.

[0053] The jaw device 51 is configured including a jaw cam (not illustrated), a cam follower of the jaw cam (not illustrated), and a jaw blade (not illustrated). In the present embodiment, the jaw device 51 is installed with equal spacing in two places at an outer circumference of the jaw cylinder 50. Moreover, an installation position of the jaw device 51 is configured such that when the folding cylinder 40 and the jaw cylinder 50 rotate and the thrust blade device 43 installed in the folding cylinder 40 operates, the thrust blade can be received. That is, a relationship of installation position between the thrust blade device 43 and the jaw device 51 is configured such that when the folding cylinder 40 and the jaw cylinder 50 are rotating, the thrust blade device 43 and the jaw device 51 oppose each other at a position where the folding cylinder 40 and the jaw cylinder 50 come closest to each other.

[0054] That concludes description of the example of configuration of the variable cutoff folding device 100 according to the present embodiment. As mentioned above, the variable cutoff folding device 100 according to the present embodiment cuts a printing-completed continuous paper W by a cutting mechanism 10, conveys individual sheets FP rendered in sheet form to a downward-of-folding conveyor mechanism 30 by a speed-increasing conveyor mechanism 20, further conveys the individual sheets FP to a folding cylinder 40 by the downward-of-folding conveyor mechanism 30, collects an arbitrary number of the individual sheets FP by the folding cylinder 40, and, when the arbitrary number of the individual sheets FP have been collected, grips the collected arbitrary number of the individual sheets FP by a jaw cylinder 50, thereby producing a signature. Moreover, the variable cutoff folding device 100 of the present embodiment is configured to operate with a cutting spacing of the cutting mechanism 10, a conveying speed of the downward-of-folding conveyor mechanism 30, and a circumferential speed of the folding cylinder 40 and the jaw cylinder 50 synchronized and having the same speed.

[0055] Next, operation of the variable cutoff folding device 100 according to the present embodiment is described. Note that specifically the description below proceeds divided into the cases of during maximum cutoff and during minimum cutoff.

[0056] First of all, operation performed by the variable cutoff folding device 100 in a state set during maximum cutoff is described. That is, the speed-increasing conveyor mechanism 20 conveys the individual sheets FP cut by the cutting mechanism 10 slightly more quickly.

[0057] First, an operator using the variable cutoff folding device 100 sets cutoff of the individual sheets FP to 813 mm. As mentioned above, in the present embodiment, the circumferential length of the cutting mechanism 10 is configured to be a length equal to maximum cutoff, hence setting the supply speed of the supplied continuous paper W and the circumferential speed of the cutter cylinder 11 to be equal results in cutoff of the individual sheets FP being constant at 813 mm.

[0058] Fig. 4 is a view showing an example where the speed-increasing conveyor mechanism 20 conveys individual sheets cut with maximum cutoff. In Fig. 4, the dashed line α indicates "a length of a half circumference of the folding cylinder 40", the dashed line β1 indicates "a length of the individual sheets FP cut with maximum cutoff", and the dashed line γ indicates "a spacing caused by action of the speed-increasing conveyor mechanism 20". Note that since a position of the individual sheet FP3 is a position of the individual sheet FP3 at exactly the time when cut by the cutting cylinder 11, the individual sheet FP3 is not subject to action of the speed-increasing conveyor mechanism 20.

[0059] As shown in Fig. 4, the speed-increasing conveyor mechanism 20 conveys the individual sheets FP1, FP2, FP3, ..., FPN of cutoff 813 mm to the downward-of-folding conveyor mechanism 30. At this time, the individual sheets FP are conveyed at a post-cutting conveying speed which is faster than a pre-cutting conveying speed (in other words, accelerated after cutting), hence the speed-increasing conveyor mechanism 20 creates a spacing between adjacent individual sheets FP, and this spacing corresponds to a difference in the pre-cutting conveying speed and post-cutting conveying speed. However, during maximum cutoff, the difference in speed is small, hence the spacing created by the speed-increasing conveyor mechanism 20 is negligible.

[0060] When the speed-increasing conveyor mechanism 20 conveys the leading individual sheet FP1 to the downward-of-folding conveyor mechanism 30, the downward-of-folding conveyor mechanism 30 butts the individual sheet FP1 against the stopper 42 of the folding cylinder 40 at the same speed as the circumferential speed of the folding cylinder 40 (refer to Fig. 5).

[0061] Simultaneous to the individual sheet FP1 being butted against the stopper 42, the pin device 41 of the folding cylinder 40 operates, and the folding cylinder 40 collects the individual sheet FP1. When the folding cylinder 40 makes a half rotation (rotates to a next butting position of the stopper 42) in a state where the individual sheet FP1 is collected, the speed-increasing conveyor mechanism 20 butts the individual sheet FP2 conveyed via the downward-of-folding conveyor mechanism 30 against the stopper 42, similarly to the individual sheet FP1.

[0062] Fig. 5 is a view showing an example where the folding cylinder 40 collects a following individual sheet during maximum cutoff. As shown in Fig. 5, a combined length of "maximum cutoff" indicated by the dashed line β1 and "a spacing caused by action of the speed-increasing conveyor mechanism 20" indicated by the dashed line γ is equal to "a length of a half circumference of the folding cylinder 40" indicated by the dashed line α. Therefore, if positioning is once performed, the individual sheets FP of maximum cutoff collected by the folding cylinder 40 are necessarily collected in a state where a leading edge in the running direction is butted against the stopper 42, thereby enabling a cyclical collect operation in the folding cylinder 40 to be accurately performed. In other words, it becomes possible to produce a high quality signature.

[0063] Then, the jaw cylinder 50 grips a sheet group having an arbitrary number of sheets collected therein and conveys a thus formed signature to an accumulating mechanism or the like, not illustrated, which is installed on a downstream side.

[0064] That concludes description of operation of the variable cutoff folding device 100 during maximum cutoff. Next, operation of the variable cutoff folding device 100 during minimum cutoff is described. A problem when changing cutoff it that the circumferential length of the folding cylinder 40 cannot be changed. That is, cutoff of the individual sheets FP becoming shorter means a length in the running direction becoming shorter, which in turn means an arrival spacing of the individual sheets FP also inevitably becoming shorter. Therefore, a head edge position of the individual sheets FP conveyed to the folding cylinder 40 arrives faster than the folding cylinder makes a half rotation, whereby it becomes impossible to stab a leading edge side in the running direction of the individual sheets FP at an appropriate pin stabbing position. Accordingly, in the variable cutoff folding device 100 according to the present embodiment, it is decided to overcome this problem by utilizing a difference in conveying speed due to the speed-increasing conveyor mechanism 20.

[0065] First, the cutter cylinder 11 raises a circumferential speed according to a change to minimum cutoff. Specifically, due to a length ratio between maximum cutoff (813 mm) and minimum cutoff (546 mm), the cutter cylinder changes to 1.5 times the circumferential speed. That is, performing cutting at 1.5 times the speed results in cutoff being set to minimum cutoff. Moreover, the circumferential speed of the folding cylinder 40 and the jaw cylinder 50 are raised simultaneously to match the rise in speed of the cutter cylinder 11.

[0066] Now, Fig. 6 is a view showing an example where the speed-increasing conveyor mechanism 20 conveys individual sheets cut with minimum cutoff. In Fig. 6, the dashed line α indicates "a length of a half circumference of the folding cylinder 40", the dashed line β2 indicates "a length of the individual sheets FP cut with minimum cutoff", and the dashed line γ indicates "a spacing caused by action of the speed-increasing conveyor mechanism 20".

[0067] As shown in Fig. 6, the speed-increasing conveyor mechanism 20 conveys the individual sheets FP1, FP2, FP3, FP4, ..., FPN of cutoff 546 mm to the downward-of-folding conveyor mechanism 30. As mentioned above, the speed-increasing conveyor mechanism 20 during minimum cutoff changes to 1. 5 times the conveying speed during maximum cutoff. That is, as shown in Fig. 6, the individual sheets FP1, FP2, FP3, and FP4 become shorter and the spacing between the individual sheets FP becomes larger, compared to during maximum cutoff.

[0068] When the speed-increasing conveyor mechanism 20 conveys the leading individual sheet FP1 to the downward-of-folding conveyor mechanism 30, the downward-of-folding conveyor mechanism 30 butts the individual sheet FP1 against the stopper 42 of the folding cylinder 40 at the same speed as the circumferential speed of the folding cylinder 40 (refer to Fig. 7).

[0069] Simultaneous to the individual sheet FP1 being butted against the stopper 42, the pin device 41 of the folding cylinder 40 operates, and the folding cylinder 40 collects the individual sheet FP1. When the folding cylinder 40 makes a half rotation (rotates to a next butting position of the stopper 42) in a state where the individual sheet FP1 is collected, the speed-increasing conveyor mechanism 20 butts the individual sheet FP2 conveyed via the downward-of-folding conveyor mechanism 30 against the stopper 42, similarly to the individual sheet FP1.

[0070] Fig. 7 is a view showing an example where the folding cylinder 40 collects a following individual sheet during minimum cutoff. As shown in Fig. 7, a combined length of "minimum cutoff" indicated by the dashed line β2 and "a spacing caused by action of the speed-increasing conveyor mechanism 20" indicated by the dashed line γ is equal to "a length of a half circumference of the folding cylinder 40" indicated by the dashed line α. Therefore, since the variable cutoff folding device 100 according to the present embodiment adopts a configuration that increases the speed of the post-cutting individual sheets FP by the speed-increasing conveyor mechanism 20 to create a spacing corresponding to the difference in speed, a distance between the leading edge in the running direction of the leading individual sheet FP and the leading edge in the running direction of the following individual sheet FP is equal to the length of a half circumference of the folding cylinder 40, thereby making it possible to fix an appropriate head edge position of the individual sheets FP even if a change in cutoff is performed.

[0071] Furthermore, due to the length of the individual sheets FP collected by the folding cylinder 40 becoming shorter, a central position of the individual sheets FP gripped in the jaw device 51 changes. Therefore, the thrust blade device 43 changes a phase according to a change being made from during maximum cutoff to during minimum cutoff.

[0072] Now, if the phase of only the thrust blade device 43 is changed, then a misalignment of synchronization between the thrust blade device 43 and the jaw device 51 occurs. In other words, it happens that when the thrust blade of the thrust blade device 43 operates, the jaw device 51 is not positioned at a place opposing the thrust blade device 43. It therefore becomes impossible for gripping of the sheet group by the jaw device 51 to be performed. Accordingly, the jaw cylinder 50 configured including the jaw device 51 changes a phase to synchronize with the change in phase of the thrust blade device 43. It therefore becomes possible for the folding cylinder 40 to collect an arbitrary number of the individual sheets FP, for the thrust blade device 43 that has undergone a phase change to operate, and for the thrust blade that has been operated to be gripped by the jaw device 51. In this way, the variable cutoff folding device 100 produces a signature and conveys the produced signature toward an accumulating mechanism or the like, not illustrated, which is installed on a downstream side.

[0073] That concludes description of operation of the variable cutoff folding device 100 during minimum cutoff.

[0074] As mentioned above, the variable cutoff folding device 100 according to the present embodiment is configured to cut a continuous paper W into individual sheets FP having an arbitrary cutting length by means of a cutting mechanism 10 configured capable of changing the cutting length, convey the individual sheets FP while increasing the speed of the individual sheets FP according to the change in cutting length by means of a speed-increasing conveyor mechanism 20 capable of changing a conveying speed, stab a pin into a leading edge in the running direction of the individual sheets FP by means of a pin device 41 installed in a folding cylinder 40, thrust a thrust blade against the individual sheets FP stabbed by the pin device 41 by means of a thrust blade device 43 installed in the folding cylinder 40 and configured capable of displacement according to the change in cutting length, and grip the thrust blade by means of a jaw device 51 installed in a jaw cylinder 50 configured capable of being rotationally displaced according to displacement of the thrust blade device 43, thereby producing a signature. The variable cutoff folding device 100 according to the present embodiment is thus configured capable of producing a high quality signature while handling a change in cutoff.

[0075] In other words, the variable cutoff folding device 100 according to the present embodiment makes is possible to create a sheet spacing corresponding to cutoff by a change in the conveying speed based on the speed-increasing conveyor mechanism 20 and thereby set the individual sheets and sheet spacing to a length corresponding to the circumferential length of the folding cylinder 40, and thus makes it possible to provide a high quality signature while handling a change in cutoff, in a state that installation space of the entire device is maintained unchanged.

[0076] Moreover, the variable cutoff folding device 100 according to the present embodiment makes it possible to achieve a timing for wrapping the sheets around the folding cylinder 40 matched to the circumferential length of the folding cylinder 40 without, for example, performing timing adjustment by detecting a positional relationship of the individual sheets FP by an electronic device such as a sensor, and so on, and thus makes it possible to suppress cost of the entire device.

[0077] That concludes description of preferred embodiments of the present invention, but the technical scope of the present invention is not limited to the scope described in the above-mentioned embodiments. Various changes or improvements may be added to each of the above-described embodiments.

[0078] For example, the suction devices 22, 24, and 32 in the present embodiment adopt a configuration where a sheet is suctioned using a vacuum, but the scope of the present invention is not limited to such a configuration. For example, a configuration where a sucker is provided on a belt and the sheet is conveyed by directly suctioning by the sucker may also be employed.

[0079] In addition, the cutting mechanism 10 in the above-mentioned embodiments adopts a configuration employing a rotating-type cutter cylinder. However, a piston-type cutter which is capable of speed change and can cut at a constant speed may also be employed.

[0080] Moreover, the above-mentioned embodiments specifically described configurations for handling operation "during maximum cutoff" and operation "during minimum cutoff". However, cutoff is not limited to these two. That is, it is of course also possible to arbitrarily change cutoff in a range between "maximum cutoff" and "minimum cutoff" and produce a signature corresponding to the changed cutoff.

[0081] Furthermore, the variable cutoff folding device according to the present embodiment is preferably provided with the stopper 42, since the stopper 42 is capable of being reliably positioned at a head edge position of the conveyed individual sheets FP without being affected by the likes of kind or conveying speed of the individual sheets FP rendered in sheet form. However, the present invention is not limited to including the stopper 42, and, depending on conditions of the conveyed individual sheets FP (for example, rigidity, surface state, and conveying speed of paper, and so on), the variable cutoff folding device according to the present embodiment need not be provided with the stopper 42.

[0082] It is clear from descriptions of scope in the patent claims that modified examples of the kind described above are included in the scope of the present invention.

[0083] This invention may be utilized in a folding device capable of handling a change in cutoff (cutting length) of a continuous paper.

Claims

1. A variable cutoff folding device, comprising:

a cutting mechanism capable of cutting a continuous paper into individual sheets, and capable of changing a cutting length;

a speed-increasing conveyor mechanism capable of conveying the individual sheets at an increased speed over a supply speed of the continuous paper, and capable of changing a conveying speed based on a change in the cutting length;

a folding cylinder having installed on an outer circumferential surface thereof a pin device and a thrust blade device, the pin device being configured to stick a pin into a leading edge in a running direction of the individual sheets, and the thrust blade device being configured to thrust a thrust blade against the individual sheets stuck by the pin in said pin device and to be displaced based on the change in the cutting length; and

a jaw cylinder having installed on an outer circumferential surface thereof a jaw device for gripping the thrust blade and being configured to be rotationally displaced based on displacement of the thrust blade device.

2. The variable cutoff folding device according to claim 1, wherein
the speed-increasing conveyor mechanism includes:

a belt conveyor including a suction hole; and

a suction device for suctioning the individual sheets via the suction hole.

3. The variable cutoff folding device according to claims 1 or 2, further comprising:

a downward-of-folding conveyor mechanism provided on a downstream side of the speed-increasing conveyor mechanism and an upstream side of the folding cylinder, the downward-of-folding conveyor mechanism being configured to synchronize with a circumferential speed of the folding cylinder and convey the individual sheets with the same speed as the circumferential speed of the folding cylinder.

4. The variable cutoff folding device according to any one of claims 1 to 3, wherein
a stopper is installed in the folding cylinder to form a pair with the pin device, the stopper being configured to be butted against by the individual sheets on a downstream side of a position where the pin of the pin device protrudes.

5. The variable cutoff folding device according to any one of claims 1 to 4, wherein
the cutting mechanism is a cutter cylinder having a cutter installed protruding from an outer circumference of the cutter cylinder, and
when the cutting length is maximum, a circumferential speed of the cutter cylinder, the folding cylinder, and the jaw cylinder are the same speed as the supply speed of the continuous paper.

6. A printer comprising the variable cutoff folding device recited in any one of claims 1 to 5.

Drawing