JP7519592B2 - Paper transport device - Google Patents

Description

The present invention relates to a paper transport device. More specifically, it relates to a paper transport device suitable for a paper folding device of a bag making machine that produces envelopes.

Conventionally, in a bag making machine (e.g., Patent Document 1) that folds a medium such as paper to make an envelope, a pair of conveying rollers is provided that constitutes the front stage of a paper folding device and introduces the paper to a paper folding section in the rear stage. The pair of conveying rollers is positioned downstream in the conveying direction from the glue application section, based on the envelope making process of folding the paper after glue application. In addition, the width direction length of the upper roller of the pair of conveying rollers is shorter than the width direction length of the lower roller, so that the upper roller does not come into contact with the glue applied to the surface of the paper in the glue application section.

WO2019043760A1 publication

The configuration disclosed in Patent Document 1 is sufficient when the paper is transported in only one direction, glue is applied in the glue application section, the paper is introduced into the folding section by the transport roller pair, and only the bottom flap of the envelope is folded back and pressed to produce a finished envelope. However, some users would like to transport the finished product further in the opposite direction and fold back the top flap of the envelope at the nip of the transport roller pair. In this case, when focusing on the transport roller pair, the width direction length of the upper roller of the transport roller pair is insufficient, so the same configuration does not allow for uniform folding.

The object of the present invention is to provide a paper transport device that can meet the needs of users, is small, simple, and inexpensive to configure, and is suitable for use in a bag making machine that produces envelopes.

In order to achieve the above object, the present invention provides a paper transport device including a drive roller that is connected to a first drive source and rotates, and a cylindrical driven roller that is disposed opposite the drive roller,
The roller has a support shaft that passes through the hollow interior of the driven roller, and is provided with a first driven roller that abuts against the drive roller and rotates together with the drive roller, and a second driven roller that can be moved by rotating the support shaft between a contact position where it abuts against the drive roller and rotates together with the drive roller to press the fold of the paper , and a retracted position where it retracts from the glue application point of the paper with a predetermined gap from the drive roller.

The invention described in claim 2 is characterized in that, in the paper transport device described in claim 1, the second driven roller is supported rotatably on the support shaft and is supported by an end support body that is fixed to the support shaft and causes the second driven roller to rotate eccentrically.

The invention according to claim 3 is the paper transporting device according to claim 1 or 2, characterized in that the first driven roller is rotatably supported by the support shaft.

The invention described in claim 4 is characterized in that, in the paper transport device described in any one of claims 1 to 3, it is provided with a second drive source that moves the second driven roller to the abutment position and the retracted position.

The invention described in claim 5 is characterized in that it comprises a paper transport device described in any one of claims 1 to 4, a glue application unit that applies glue to predetermined locations on the paper , and a paper folding unit that folds the predetermined locations on the paper .

According to the invention described in claim 1, the second driven roller can be easily changed between a retracted position and an abutting position with respect to the drive roller by rotating the support shaft. By setting the second driven roller to the retracted position, a predetermined gap is formed between the second driven roller and the drive roller, and the top surface of the paper to be transported does not contact the second driven roller, and the paper can be transported only by the transport force between the first driven roller and the drive roller. Therefore, if there is a part on the top surface of the paper to be transported that should not be interfered with by the second driven roller, such as a glue-applied part, it can be easily avoided. Also, if there is no part on the top surface of the paper to be transported that should not be interfered with by the second driven roller, by setting the second driven roller to the abutting position, the paper can be transported while being nipped (pressed) over a wide area by both the nip part between the first driven roller and the drive roller and the nip part between the second driven roller and the drive roller.

According to the invention described in claim 2, the second driven roller can be easily changed between the retracted position and the abutting position with a simple and inexpensive configuration. As a result, the entire device can be made compact.

According to the invention described in claim 3, the first driven roller can abut against the drive roller and rotate coaxially with the support shaft of the second driven roller, without being affected by the movement of the second driven roller between the retracted position and the abutment position.

According to the invention described in claim 4, by connecting a second drive source to the support shaft and rotating the support shaft to a predetermined angle using the second drive source, the second driven roller can be automatically moved between the contact position and the retracted position, which is convenient for the operator.

According to the invention described in claim 5, the paper transport device includes a paper transport device described in any one of claims 1 to 4, a glue application unit that applies glue to predetermined locations on the paper , and a paper folding unit that folds the predetermined locations on the paper .
Therefore, the adhesive application portion on the upper surface of the paper being transported can be easily prevented from being interfered with by the second driven roller.

1 is a schematic overall configuration diagram of a bag making machine according to a first embodiment of the present invention; 2 is a plan view showing a state of paper being processed by the bag making machine of FIG. 1. FIG. 3 is a plan view showing a state in which the paper of FIG. 2 has been folded. FIG. 2 is a perspective view showing a Western-style envelope in the middle of being produced. 13A and 13B are diagrams showing how the paper is processed at a second folding portion. FIG. 6 is a diagram showing the state of processing of paper following FIG. 5 . FIG. 7 is a diagram showing the state of processing of paper following FIG. 6 . FIG. 8 is a diagram showing the state of processing of paper following FIG. 7 . FIG. 9 is a diagram showing the state of processing of paper following FIG. 8 . FIG. 10 is a diagram showing the state of processing of paper following FIG. 9 . FIG. 11 is a diagram showing the state of processing of paper following FIG. 10 . FIG. 12 is a diagram showing the state of processing of paper following FIG. 11 . 11 is a cross-sectional view showing a state in which the second driven roller has moved to a retracted position. FIG. 11 is a cross-sectional view showing a state in which the second driven roller has moved to a contact position. FIG. FIG. 4 is a cross-sectional view showing the structure of a second driven roller. FIG. 4 is a cross-sectional view showing a structure of a first driven roller. 11A to 11C are diagrams illustrating states before and after folding back a flap at a first fold portion. 13A and 13B are diagrams showing a state in which an envelope after glue application passes through a second driven roller in a retracted state.

Figure 1 shows an embodiment of a bag making machine 10 that employs the paper folding device (second folding section 6) of the present invention. Figure 1 is an overall configuration diagram of the bag making machine 10. The bag making machine 10 includes, in order from the upstream side in the conveying direction, a paper feed section 1, a first crease processing section 2, a second crease processing section 4, a first folding section 3, a glue application section 5, a second folding section 6, and a paper discharge section 7 in the device body 10A.

A typical "Western-style envelope" has a horizontally long rectangular shape with a sealing opening formed on the long side. When making a Western-style envelope using a bag making machine 10, for example, as shown in FIG. 4, glue is applied to the folded-over pieces 103 on both sides of the rear surface 102 of the paper 100, and the front surface 101 is folded and pressed against the pieces 103.

Specifically, the bag making machine 10 processes the flat paper 100 shown in FIG. 2(a) in the manner shown in FIG. 2(b) and FIG. 2(c) while conveying the paper in the F direction to produce a Western-style envelope 90.

The paper 100 is composed of a front surface portion 101 (bottom flap), a rear surface portion 102, glue substitute pieces 103 that protrude on both sides of the rear surface portion 102, and a rearmost surface portion 104. As shown in FIG. 2(b), the paper 100 is folded at a first fold 111 that is the boundary between the rear surface portion 102 and the piece portion 103, and as shown in FIG. 2(c), the paper 100 is folded at a second fold 112 that is the boundary between the front surface portion 101 and the rear surface portion 102. Glue is applied to the surface of the piece portion 103 that is folded back at the first fold 111. Then, both edges of the front surface portion 101 that is folded back at the second fold 112 are joined to the piece portion 103. The first fold 111 is aligned with the conveying direction. The second fold 112 runs along a direction perpendicular to the conveying direction (i.e., the width direction).

The final product may be the Western-style envelope 90 of FIG. 2(c), but the Western-style envelope 90 shown in FIG. 2(c) may be processed as shown in FIG. 3(a) to FIG. 3(b) while being conveyed in the F' direction, so that the rearmost surface portion 104 (top flap) is further folded at the third fold 113, which is the boundary between the rear surface portion 102 and the rearmost surface portion 104. With this configuration, when the contents are inserted into the envelope and then the envelope is sealed with tape or glue, the rearmost surface portion 104 can be neatly sealed to the folded-over front surface portion 101 because of the crease.

[Paper Feeding Unit 1]
The paper feed section 1 has an air suction belt type air paper feed unit 12, an elevator type paper feed tray 11 that rises and falls depending on the amount of paper stacked, and a transport roller 81 that transports the paper sent out by the air paper feed unit 12 further downstream in the transport direction. In addition, the air paper feed unit 12 is provided with a sensor 22 that detects when the topmost paper sheet stacked on the paper feed tray 11 is sucked to the bottom surface of the air paper feed unit 12, and a sensor 21 that detects the upper limit position of the topmost paper sheet stacked on the paper feed tray 11.

In addition to the transport roller 81, the bag making machine 10 is equipped with six transport roller pairs 82, 84, 85, 86, 87, and 88. The six transport roller pairs form a transport surface 200 along which the paper 100 is transported, and the transport surface 200 is flush with the paper from the air paper feed unit 12 to the transport roller pair 88. In addition, sensors 23, 24, 25, 26, 27, and 28 are arranged on the transport surface 200 along which the paper is transported, to detect the passage of the paper at each position (detect double feed). Each sensor is, for example, an optical transmission sensor.

[First crease processing portion 2]
1, the first crease processing unit 2 is composed of an upper mold having a convex upper portion and a lower mold having a concave lower portion, and is configured to form horizontal creases in a direction perpendicular to the paper conveyance direction as the second fold 112 and the third fold 113 of the paper 100. A known mechanism can be used as the crease processing unit 2. The first crease processing unit 2 may also be composed of an upper mold having a concave upper portion and a lower mold having a convex lower portion.
[Second crease processed portion 4]
1, the second crease processing unit 4 is composed of an upper blade with a round crease blade 83 having a convex portion formed on the outer periphery and a lower blade with a round crease blade having a concave portion formed on the outer periphery, and is installed at two locations in the width direction perpendicular to the conveying direction to form vertical creases along the paper conveying direction at the first folds 111 (two locations) of the paper 100. A known mechanism can be used as the first crease processing unit 4.

[First folding portion 3]
The first folding section 3 is composed of a pair of folding devices 3a, 3b arranged opposite each other on both sides in the width direction perpendicular to the paper conveying direction. Each folding device 3a, 3b has a flap plate 32 that rotates around a rotation shaft 31 along the conveying direction, and as shown in Fig. 17(a), a portion 103 of the paper 100 placed on the flap plate 32 located on the outer side in the width direction can be folded back inward to match the surface of the rear surface portion 102 by rotating the flap plate 32 as shown in Fig. 17(b).

[Glue application unit 5]
The glue applying section 5 is made up of a pair of applicators 5a, 5b arranged opposite each other in the width direction. The applicators 5a and 5b have a symmetrical configuration.

The application devices 5a and 5b each have a nozzle section, a position setting mechanism, and a vertical drive mechanism (not shown). The nozzle section is capable of applying glue to the transported paper at a predetermined timing.

[Second folding portion 6]
As shown in FIG. 1, the second folding section 6 is a paper folding device that folds a flat paper sheet 100 while transporting it along a transport surface 200, and includes a first pair of transport rollers 86 arranged upstream in the paper transport direction, a second pair of transport rollers 87 arranged downstream in the paper transport direction, a switch gate plate 63 installed between the two roller pairs, and a folding plate 62 arranged above the switch gate plate 63.

13, the first transport roller pair 86 as the paper transport device includes a drive roller 862 that rotates while being connected to a first drive source (not shown), and a cylindrical driven roller 861 that is disposed opposite the drive roller 862. Furthermore, the driven roller 861 includes a first driven roller 8612 that is always in contact with the drive roller 862 and rotates together with the drive roller 862, and second driven rollers 8611 and 8613 that are arranged coaxially with the support shaft 72 that penetrates the hollow interior of the driven roller 861 and that are configured to be selectively movable between a contact position where the drive roller 862 contacts the drive roller 862 and rotates together with the drive roller 862 and a retracted position where the drive roller 862 is retracted with a predetermined gap therebetween by rotating the support shaft 72 by a predetermined angle.

In this embodiment, the first driven roller 8612 and the second driven rollers 8611 and 8613 are arranged on either side of the first driven roller 8612, respectively, on the same axis of the support shaft 72, and the drive roller 862 has a length that allows them to be used together, and both the second driven roller 8611 and the second driven roller 8613 are configured to move in the same phase with respect to the drive roller 862 between the abutment position and the retracted position.

Incidentally, Figure 14 is a cross-sectional view showing the state in which the second driven rollers 8611, 8613 are arranged in a contact position in which they abut against the drive roller 862 and rotate together, and Figure 13 is a cross-sectional view showing the state in which the second driven rollers 8611, 8613 are arranged in a retracted position in which they are retracted from the drive roller 862 with a predetermined gap therebetween.

Figure 15 is a cross-sectional view showing the structure of the second driven roller 8613. Specifically, the second driven roller 8613 is a hollow roller 76 made of a metal material such as aluminum, and its surface layer is composed of a rubber or other elastic material layer. Both ends of the second driven roller 8613 are supported by the end supports 73 via the bearing members 74 so that they can rotate freely, and the support shaft 72, which is positioned eccentrically from the center of rotation of the second driven roller 8613, is passed through the end supports 73 and fixed integrally using screws 78 and 79. Note that the length of the screw 78 is shorter than that of the screw 79 in consideration of assembly, and is set to a length that fits inside the hollow roller 76 after assembly.

Both ends of the support shaft 72 are rotatably supported by the support frame 75 via bearings 91. The bearings 91 are supported in elongated holes (not shown) formed in the support frame 75, and are pressed against the drive roller by springs 92. Note that the second driven roller 8611 has the same configuration as the second driven roller 8613, so a description of it will be omitted here.

The movement of the second driven rollers 8611, 8613 to the abutment position and the retracted position may be configured so that the operator manually rotates an adjustment dial attached to the support shaft 72, but more preferably, a second drive source 70 such as a gear motor is connected to the support shaft 72, and the second drive source 70 rotates the support shaft 72 to a predetermined angle, thereby providing a control means for selectively and automatically moving the second driven rollers 8611, 8613 to the abutment position and the retracted position. This is convenient for the operator.

Figure 16 is a cross-sectional view showing the structure of the first driven roller 8612. Specifically, the first driven roller 8612 is a hollow roller made of a metal material such as aluminum, and its surface layer is made of a rubber or other elastic material layer. The first driven roller 8612 has a bearing member 77 that is disposed between the outer circumferential surface of the support shaft 72 and the inner circumferential surface of the first driven roller 8612 and supports the first driven roller 8612 rotatably relative to the support shaft 72. The first driven roller 8612 is not directly fixed to the support shaft 72, but is prevented from moving in the axial direction by the second driven rollers 8611 and 8613 that are disposed on both sides of the same axis and are fixed to the support shaft 72 using screws 78 and 79, respectively.

With the above configuration, by rotating the support shaft 72 to a predetermined angle, the second driven rollers 8611, 8613 can be easily changed between a retracted position and an abutting position with respect to the drive roller 862. By setting the second driven rollers 8611, 8613 to the retracted position, a predetermined gap is formed between the second driven rollers 8611, 8613 and the drive roller 862, and the top surface of the paper to be transported does not come into contact with the second driven rollers 8611, 8613, and the paper can be transported only by the transport force between the first driven roller 8612 and the drive roller 862. Therefore, if there are any parts on the top surface of the paper to be transported that should not be interfered with by the second driven rollers 8611, 8613, such as glue application parts, they can be easily avoided. In addition, by setting the second driven rollers 8611 and 8613 in the abutment position, the paper folded over the glue application area can be uniformly pressed over a wide area in both the nip between the first driven roller 8612 and the drive roller 862, and the nip between the second driven rollers 8611 and 8613 and the drive roller 862.

As described above, in the present invention, the configuration in which the second driven rollers 8611, 8613 retract to avoid the glue application area of the paper, and the configuration in which the second driven rollers 8611, 8613 come into contact and press against each other at the nip area can be realized in a single paper transport device (paper folding device). Therefore, it can be constructed simply and inexpensively, and as a result, the entire device can be made compact.

[Pressure unit 8]
The pressure applying section 8 is composed of an upper die 8a that can move up and down and a fixed lower die 8b, and by clamping the folded portion of the paper 100 that has been folded in the second folding section 6 between the upper and lower dies, further pressure is applied to make the folded portion stronger.

[Paper ejection section 7]
The paper discharge section 7 has a pair of conveying rollers 88 and a paper discharge tray 71. The pair of conveying rollers 88 is provided to operate as a discharge roller. Specifically, as shown in Fig. 1, the pair of conveying rollers 88 is disposed near and downstream in the conveying direction of the second pair of conveying rollers 87 of the second folding section 6. The paper discharge tray 71 is inclined obliquely upward from a position below the conveying surface 200 and toward the downstream in the conveying direction.

Next, the operation of the bag making machine 10 described above will be explained.

First, the paper 100 shown in FIG. 2 is placed on the paper feed tray 11. At this time, the front surface portion 101 is located downstream in the conveying direction. Then, a switch (not shown) is turned on to start operation.

(1) The topmost sheet of paper 100 on the paper feed tray 11 is sent toward the pair of transport rollers 81 while being attracted to the air suction belt in the air paper feed unit 12. After the sheet of paper 100 is handed over to the pair of transport rollers 81, the pair of transport rollers 81 transports the sheet of paper further downstream in the transport direction. The sheet then passes through the first crease processing unit 2. At this time, the first crease processing unit 2 is activated to form creases in the second fold 112 and the third fold 113 of the sheet of paper 100. This makes it easier for the front surface 101 to be folded back toward the rear surface 102. Also, it makes it easier for the rearmost surface 104 to be folded back toward the folded front surface 101.

(2) The paper 100 transported by the transport rollers 82 from the first crease processing unit 2 passes through the second crease processing unit 4. At this time, the first folds 111 (two locations, one on the left and one on the right in the width direction) of the paper 100 are located directly below the crease blades 83 (round blades) of the second crease processing unit 4, which are installed in two locations in the width direction perpendicular to the transport direction. The second crease processing unit 4 then operates to form a crease in the first fold 111. This makes it easier for the pieces 103 (two locations, one on the left and one on the right in the width direction) to fold inward.

(3) The paper 100 on which the crease is formed by the second crease processing unit 4 stops at the first folding unit 3. At this time, the flap plates 32 of the two folding devices 3a and 3b of the first folding unit 3 are located on the outer side of the width direction of the paper 100, and the pieces 103 on both sides of the paper 100 are placed on the flap plates 32 (FIG. 17(a)). In FIG. 17, the paper 100 is transported from the front to the back side of the drawing. Next, the flap plate 32 rotates toward the inner lower guide plate 33, so that the piece 103 is folded back inward at the first crease 111 that has already been creased and aligned with the surface of the rear surface portion 102 (FIG. 17(b)). After that, the flap plate 32 rotates in a direction away from the outer lower guide plate 33. Then, the paper 100 with the piece 103 folded back is transported downstream in the transport direction by the transport roller pair 85. The flap plate 32 that has rotated outward is maintained in that state until the next sheet of paper 100 arrives. Note that, with the flap plate 32 rotated inward, the sheet of paper 100 with the folded portion 103 is transported downstream in the transport direction, and before the next sheet of paper 100 arrives, the flap plate 32 may be operated to rotate outward.

(4) The paper 100 with the folded piece 103 is transported downstream in the transport direction by the transport roller pair 85 and passes through the glue application unit 5. In the glue application unit 5, when the folded pieces 103 on both sides of the paper 100 start to pass, the nozzles 5a and 5b installed at two locations in the width direction perpendicular to the transport direction move downward and come into contact with the surface of the piece 103, and when the passage of the piece 103 ends, the nozzles 5a and 5b move upward and separate from the surface of the piece 103. As a result, glue is applied to the surface of the folded piece 103. The folded piece 103 passes through the nozzles 5a and 5b while being pressed by the transport roller pair 85 located upstream of the nozzles 5a and 5b in the transport direction, or after being pressed. Therefore, the glue application work by the nozzles 5a and 5b can be performed stably.

(Processing of paper at second folding section 6)
The second folding unit 6 is a paper folding device that folds a flat paper sheet 100 while transporting it along a transport surface 200, and includes a first transport roller pair 86 arranged upstream in the paper transport direction, a second transport roller pair 87 arranged downstream in the paper transport direction, a switching gate plate 63 installed on the paper transport surface 200 between the two roller pairs, a folding plate 62 arranged opposite the switching gate plate 63, and a control means (not shown) that controls the operation of the entire device.

The switching gate plate 63 can be switched between a first guide position where it interferes with the transported paper 100, bending the paper transport direction away from the paper transport surface 200 and guiding the leading edge of the paper 100 toward one of the roller surfaces of the second transport roller pair 87, and a second guide position where it guides the paper 100 along the paper transport surface 200 toward the nip portion 873 of the second transport roller pair 87,

The folding plate 62 is configured to be movable toward the switching gate plate 63 while remaining in a substantially horizontal state, and can be switched between a folding position close to the switching gate plate 63 arranged in the second guide position, and a retreated position at a predetermined distance from the switching gate plate 63,

The control means uses the switching gate plate 63 arranged in the first guiding position to guide the leading edge of the paper 100 being transported so that it passes a predetermined distance toward one of the roller surfaces of the second transport roller pair 87, then switches the switching gate plate 63 to the second guiding position, and then controls the folding plate 62 arranged in the retracted position to be lowered in a substantially horizontal state to the folding position so as to sandwich the paper 100 on the switching gate plate 63, thereby folding the leading edge of the paper 100 back along one of the roller surfaces of the second transport roller pair 87.

Specifically, as an example, the processing is performed sequentially as shown in (5-1) to (5-8) below.

(5-1) The sheet 100, with glue applied to the one side 103, is transported by the transport roller pair 85 to the second folding section 6 (in the direction F). At this time, the switching gate plate 63 is set to face upward toward the second transport roller pair 87 as the first guide position. Therefore, as shown in FIG. 5, the sheet 100 is guided upward by the switching gate plate 63 so that the leading edge of the sheet 100 passes over the upper surface of the upper roller 871 of the second transport roller pair 87, and transport is temporarily stopped when the position of the second fold 112 of the sheet 100 reaches the folding position (the position directly below the end 621 of the folding plate 62). During this time, the folding plate 62 maintains its waiting position.

When the sheet 100 with glue applied to the piece 103 is transported to the second folding section 6 by the transport roller pair 85, the support shaft 72 is rotated by a predetermined angle, and the second driven rollers 8611, 8613 are moved to a retracted position so that the second driven rollers 8611, 8613 do not interfere with the glue application portion on the sheet with glue applied. At this time, as shown in Fig. 18, the position of the piece 103 with glue applied corresponds to the positions of the second driven rollers 8611, 8613 that have moved to the retracted position.
Furthermore, the first driven roller 8612 can be constantly in contact with and co-rotate with the drive roller 862 on the same axis of the support shaft 72 without being affected by the movements of the second driven rollers 8611 and 8613. Therefore, the glue-applied portion on the upper surface of the paper being transported can be easily prevented from being interfered with by the second driven roller, and the area of the paper 100 on which glue is not applied can be nipped and transported toward the switching gate plate 63.

(5-2) Next, as shown in FIG. 6, the folding plate 62 is kept in the waiting position while the switching gate plate 63 is moved to the second guide position (approximately horizontal position).

(5-3) Next, as shown in FIG. 7, the folding plate 62, which is disposed in the retracted position, is lowered to the folding position in a substantially horizontal state so as to sandwich the paper 100 on the switching gate plate 63, thereby folding back the front surface 101 of the paper 100 from the second fold 112 along the surface of the upper roller 871 of the second conveying roller pair 87. At this time, the distance that the folding plate 62 approaches the switching gate plate 63 after it has been lowered is configured so that at least a gap large enough for the paper to be conveyed is secured between the folding plate 62 and the switching gate plate 63. For example, a gap of about 1 mm is secured.

As a result of the above, the paper folding mechanism does not need to have a paper insertion space (diverter path) or a stopper, so it can be constructed simply and inexpensively without complicating the structure. In addition, the control means automatically adjusts the folding position to suit various folding specifications, providing a paper folding device with good operability. Furthermore, it prevents wrinkles from forming on the folded portion, and even when folding, glue does not adhere to the inside of the folding mechanism such as the stopper, which would adversely affect the quality of the finished product.

(5-4) Next, as shown in FIG. 8, the folding plate 62 is lowered to fold the front surface 101 (bottom flap) of the paper 100, and then the first conveying roller pair 86 conveys the folded tip 105 of the paper after the leading edge of the paper is folded toward the nip 873 of the second conveying roller pair 87, and the folded tip 105 of the paper is pressed and folded by being sandwiched between the nip 873 of the second conveying roller pair 87 and conveyed in the F direction. Then, the entire front surface 101 is folded back to match the surface of the rear surface 102, and at that time, both edges of the front surface 101 are joined to the piece 103. This results in a Western-style envelope 90. The paper 100 is conveyed in the F direction until the rearmost surface 104 of the paper 100 passes through the nip 863 of the first conveying roller pair 86 by a predetermined amount. At this time, the paper 100 is transported through the gap between the folding plate 62 and the switching gate plate 63 (while being guided by both plates). This allows the paper 100 to be reliably delivered to the pressing section by the nip portion 873 of the second transport roller pair 87 in the next stage without wrinkles or the like occurring.

As described above, the leading edge of the paper is folded back by lowering the folding plate, and then the folded leading edge of the paper is pressed and folded by the nip portion 873 of the second conveying roller pair 87, so that the paper can be reliably folded.

The final product may be this Western-style envelope 90, but it may also be configured so that the rearmost surface portion 104 (top flap) is further folded at a third fold 113, which is the boundary between the rear surface portion 102 and the rearmost surface portion 104, by folding the Western-style envelope 90 while conveying it in the F' direction. With this configuration, when an operator seals the envelope with tape or glue after inserting the contents, the fold is created, so that the rearmost surface portion 104 can be neatly sealed to the folded-over front surface portion 101. The method of folding the rear surface portion 104 is described below.

(5-5) The switching gate plate 63 can be further switched to a third guide position, facing upward toward the first conveying roller pair 86, and the first conveying roller pair 86 and the second conveying roller pair 87 are configured to be able to rotate forward and backward.

As described above, after the second conveying roller pair 87 presses the leading edge folded portion 105 of the paper 100 with the nip portion 873 of the second conveying roller pair 87, as shown in FIG. 9, the folding plate 62 is retracted to the retreat position, and the switching gate plate 63 is switched to the third guide position and upward toward the first conveying roller pair 86. Then, the second conveying roller pair 87 is rotated in the reverse direction to convey the paper 100 in the F' direction from downstream to upstream, so that the rearmost surface portion 104 of the paper is guided upward so as to pass a predetermined amount over the upper surface of the upper roller 861 of the first conveying roller pair 86. When the position of the third fold 113 of the paper 100 reaches the folding position (the position directly below the end 622 of the folding plate 62), the conveyance is temporarily stopped. During this time, the folding plate 62 maintains the retreat position.

(5-6) Next, as shown in FIG. 10, the folding plate 62 is kept in the waiting position while the switching gate plate 63 is moved to the second guide position (approximately horizontal position).

(5-7) Next, as shown in FIG. 11(a), the folding plate 62 arranged in the retracted position is lowered to the folding position in a substantially horizontal state so as to sandwich the paper 100 on the switching gate plate 63, thereby folding back the rearmost surface 104 of the paper 100 from the third fold 113 along the surface of the upper roller 861 of the second conveying roller pair 86. At this time, the distance between the switching gate plate 63 and the lowered folding plate 62 is configured so that at least a gap large enough for the paper to be conveyed is secured between the folding plate and the switching gate plate. For example, a gap of about 2 mm is secured.

Figure 11(b) is a schematic diagram showing the folded state of the paper 100 in Figure 11(a). The front surface 101 of the paper 100 is folded over the rear surface 102 from the second fold 112, and the rearmost surface 104 is folded back from the third fold 113.

As a result of the above, two locations in the paper transport direction, the front end (front surface portion 101) and the rear end (rearmost surface portion 104), can be folded back using the same folding mechanism, resulting in good work efficiency. In addition, the system can be constructed in a space-saving and inexpensive manner.

(5-8) Next, as shown in FIG. 12(a), the folding plate 62 is lowered to fold the rearmost surface 104 of the paper 100, and then the second conveying roller pair 87 conveys the folded rear end portion 106 of the paper after folding the rear end of the paper toward the nip portion 863 of the first conveying roller pair 86. The nip portion 863 of the first conveying roller pair 86 pinches the folded front end portion 106 of the paper and conveys it a predetermined amount in the F' direction, thereby pressing and folding the folded front end portion 106 of the paper.

At this time, the support shaft 72 is rotated to a predetermined angle, and the second driven rollers 8611, 8613 are moved to a contact position where they come into contact with the drive roller 862 and rotate together. (The first driven roller 8612 always comes into contact with the drive roller 862 and rotates together.) Therefore, the folded rearmost surface portion 104 (top flap) can be uniformly pressed over a wide range (at least the width of the envelope) in both the nip portion between the first driven roller 8612 and the drive roller 862, and the nip portion between the second driven rollers 8611, 8613 and the drive roller 862.

Then, the entire rearmost surface portion 104 is folded back to match the surface of the rear surface portion 102, and the resulting Western-style envelope 90 is then transported in the F direction toward the pressure section 8 installed downstream of the second folding section 6.

Figure 12(b) is a schematic diagram showing the folded state of the paper 100 in Figure 12(a). The front surface 101 of the paper 100 is folded from the second fold 112 onto the rear surface 102, and the rearmost surface 104 is folded back from the third fold 113 and further folded onto the front surface 101 that is folded onto the rear surface 102.

As described above, the folding plate 62 is lowered to fold the front and rear ends of the paper 100 in the transport direction, and then the paper is pressed and folded at the nip between the second transport roller pair 87 and the first transport roller pair 86, so that a crease (crease) can be reliably created in the paper.

In addition, a crease processing section 2 is provided on the upstream side of the first conveying roller pair 86 in the paper conveying direction, and the crease processing section 2 is designed to form creases in advance at the creases (second crease 112, third crease 113) when folding the flat paper 100 to create folding starting points, allowing for neat folding with high precision. It is also possible to suppress printing cracks that occur when folding the paper.

(6) Next, the Western-style envelope 90 is transported from the second folding section 6 to the pressure section 8, and the folded sections 105 and 106 are successively sandwiched and pressed between the upper die 8a and the lower die 8b of the pressure section 8. Therefore, the folded sections 105 and 106 become strong. After being pressed, the Western-style envelope 90 is transported by the pair of transport rollers 88 toward the paper discharge section 7 and discharged onto the paper discharge tray 71.

In one embodiment of the present invention, a paper transport device suitable for a paper folding device of a bag making machine that produces envelopes has been described, but as a simple paper transport device, it can be applied to various machines, and is not limited to the above embodiment, but can be implemented with various modifications.

F: conveying direction F'; conveying direction R: rotation direction 3; first folding section 6; second folding section 10; bag making machine 10A; device body 62; folding plate 63; switching gate plate 64; driving mechanism 65; driving mechanism 72; support shaft 76; hollow roller 80; hollow roller 100; paper 101; front surface section 102; rear surface section 103; glue substitute piece section 104; rearmost surface section 105; fold-back section 106; fold-back section 111; first fold 112; second fold 113; third fold 861; driven roller 862; driving roller 8611; second driven roller 8612; first driven roller 8613; second driven roller

Claims (5)

A paper transport device including a drive roller that is connected to a first drive source and rotates, and a cylindrical driven roller that is disposed opposite the drive roller,
A support shaft is provided which passes through the hollow interior of the driven roller,
The paper conveying device is characterized in that the driven roller is provided with a first driven roller that abuts against the drive roller and rotates together with the support shaft, and a second driven roller that can be moved by rotating the support shaft between a contact position where it abuts against the drive roller and rotates together with the drive roller to press the fold of the paper, and a retracted position where it is retracted from the glue application point of the paper with a predetermined gap from the drive roller. 2. The paper transport device according to claim 1, wherein the second driven roller is rotatably supported by the support shaft and is supported by an end support member fixed to the support shaft and causing the second driven roller to rotate eccentrically. The paper transport device according to claim 1 or 2, characterized in that the first driven roller is rotatably supported on the support shaft. A paper transport device according to any one of claims 1 to 3, characterized in that it is provided with a second drive source that moves the second driven roller between the contact position and the retracted position. 5. A paper folding device comprising: a paper transport device according to claim 1; a glue application unit that applies glue to predetermined locations on the paper; and a paper folding unit that folds the predetermined locations on the paper.

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