Patent Description:
Conventionally, a paper folding device (for example, Patent Document <NUM>) that folds a medium such as a paper sheet is configured as follows: the paper sheet is conveyed, a leading end side of the paper sheet is inserted into a paper sheet insertion space (diverging path), by continuing conveyance on a trailing end side of the paper sheet even after the leading end of the paper sheet abuts a stopper provided in the paper sheet insertion space and is prevented from proceeding, the paper sheet is bent outside the paper sheet insertion space to form a curved portion, the curved portion is sandwiched between a pair of rollers and pulled in, and the paper sheet is folded over to fold the medium.

Conventionally, in a buckle-folding type paper folding device including a folding tray, when a front surface portion <NUM> illustrated in <FIG> is crimped to piece portions <NUM>, the piece portions <NUM> are bent along a press roller (not illustrated). Therefore, wrinkles may be formed at portions of folds of the piece portions <NUM>. Regarding this problem, according to the technique disclosed in Patent Document <NUM>, since the folded piece portions <NUM> are conveyed only along a conveyance surface constituting the same plane as a conveyance surface of a folding unit in a paper sheet discharge direction without bending the folded piece portions along the press roller, it is possible to eliminate curving of the folded piece portions <NUM> at the folding unit. Therefore, wrinkles can be prevented from being generated in the folded piece portion, and as a result, a western envelope having a good appearance can be obtained.

However, in the paper folding device provided with the stopper as in the technique disclosed in Patent Document <NUM> described above, it is necessary to adjust a stopper position in accordance with various folding specifications, and when the stopper position is adjusted, it is necessary for an operator to manually adjust the stopper position or to provide an automatic moving mechanism of the stopper in the device. In a case where the operator manually adjusts the stopper position, the operation is complicated and the usability is not good. In addition, in a case where the automatic movement mechanism of the stopper is provided in the device, the operability is good, but the cost is high.

Furthermore, in the technique disclosed in Patent Document <NUM>, in the case of conveying and folding a paper sheet to which a glue is applied, there is a possibility that the glue adheres to the inside of a folding mechanism such as a stopper, and adversely affects the quality of a product. <CIT> discloses a paper folding device configured to fold a planar paper sheet while conveying the paper sheet along a paper sheet conveyance surface, the paper folding device comprising a pair of first conveyance rollers disposed on an upstream side in a paper sheet conveyance direction, a pair of second conveyance rollers disposed on a downstream side in the paper sheet conveyance direction, a switching gate plate installed on the paper sheet conveyance surface between both pairs of the rollers, and a control unit configured to control an operation of an entire device, wherein the switching gate plate is switchable between a first guide position at which the switching gate plate is configured to interfere with the conveyed paper sheet and guides a leading end portion of the paper sheet upward so as to pass through an upper surface of an upper roller of the pair of second conveyance rollers and a second guide position at which the switching gate plate is configured to guide the leading end portion of the paper sheet toward a nip portion of the pair of second conveyance rollers along the paper sheet conveyance surface.

In view of the above-described problems in the conventional paper sheet folding device, an object of the present invention is to provide a paper folding device that prevents wrinkles from being generated in a folded piece portion, that can be configured simply and inexpensively without complicating a structure, and that has good operability, and that does not cause an adverse effect on the quality of a product due to adhesion of glue to the inside of a folding mechanism such as a stopper even when a paper sheet to which glue is applied is conveyed and folded.

In order to achieve the above object, the invention is a paper folding device comprising the features of independent claim <NUM>. The paper folding device is configured to fold a planar paper sheet while conveying the paper sheet along a paper sheet conveyance surface, the paper folding device including: a pair of first conveyance rollers disposed on an upstream side in a paper sheet conveyance direction; a pair of second conveyance rollers disposed on a downstream side in the paper sheet conveyance direction; a switching gate plate installed on the paper sheet conveyance surface between both pairs of the rollers; a folding plate disposed above the switching gate plate; and a control unit that configured to control an operation of an entire device, wherein the switching gate plate is switchable between a first guide position at which the switching gate plate is configured to interfere with the conveyed paper sheet and guide a leading end portion of the paper sheet upward so as to pass through an upper surface of an upper roller of the pair of second conveyance rollers and a second guide position at which the switching gate plate is configured to guide the leading end portion of the paper sheet toward a nip portion of the pair of second conveyance rollers along the paper sheet conveyance surface, the folding plate is configured to be movable in a vertical direction in a substantially horizontal state, and is switchable between a folding position close to the switching gate plate disposed at the second guide position and a retracting position retracted at a predetermined interval from the switching gate plate, and the control unit is configured to perform control to, after guiding the leading end portion of the paper sheet to be conveyed by the switching gate plate disposed at the first guide position so as to pass through the upper surface of the upper roller of the pair of second conveyance rollers by a predetermined amount, switch the switching gate plate to the second guide position, and then lower the folding plate disposed at the retracting position to the folding position in a substantially horizontal state so as to sandwich the paper sheet on the switching gate plate, thereby folding back the leading end portion of the paper sheet along a surface of the upper roller of the pair of second conveyance rollers.

According to the invention recited in claim <NUM>, in the paper folding device recited in claim <NUM>, the control unit is configured to perform control such that after the leading end portion of the paper sheet is folded back by lowering the folding plate, a leading end fold-back portion of the paper sheet after the leading end portion of the paper sheet is folded back is further conveyed toward the nip portion of the pair of second conveyance rollers by the pair of first conveyance rollers, and the leading end fold-back portion of the paper sheet is sandwiched and conveyed by the nip portion of the pair of second conveyance rollers to press and fold the leading end fold-back portion of the paper sheet.

According to the invention recited in claim <NUM>, in the paper folding device recited in claim <NUM>, the switching gate plate is further switchable upward toward the pair of first conveyance rollers as a third guide position, the pair of first conveyance rollers and the pair of second conveyance rollers are configured to be able to perform forward rotation and reverse rotation, and the control unit is configured to perform control to retract the folding plate to the retracting position and switch the switching gate plate upward toward the pair of first conveyance rollers as the third guide position after the pair of second conveyance rollers press the leading end fold-back portion of the paper sheet, then switch the switching gate plate to the second guide position to guide the paper sheet along the paper sheet conveyance surface toward a nip portion of the pair of first conveyance rollers after guiding a rear end portion of the paper sheet upward so as to pass through an upper surface of an upper roller of the pair of first conveyance rollers by a predetermined amount by reversely rotating the pair of second conveyance rollers and conveying the paper sheet in a reverse direction from the downstream side to the upstream side, and then fold back the rear end portion of the paper sheet along a surface of the upper roller of the pair of first conveyance rollers by lowering the folding plate to the folding position in a substantially horizontal state so as to sandwich the paper sheet on the switching gate plate.

According to the invention recited in claim <NUM>, in the paper folding device recited in claim <NUM>, the control unit is configured to perform control such that after the folding plate is lowered to fold back the rear end portion of the paper sheet, a rear end fold-back portion of the paper sheet after the rear end portion of the paper sheet is folded back is further conveyed toward the nip portion of the pair of first conveyance rollers by the pair of second conveyance rollers, and the pair of first conveyance rollers are reversely rotated to sandwich and convey the rear end fold-back portion of the paper sheet at the nip portion of the pair of first conveyance rollers, thereby pressing the rear end fold-back portion of the paper sheet.

According to the invention recited in claim <NUM>, in the paper folding device recited in any one of claims <NUM> to <NUM>, a crease processing unit is further provided on the upstream side in the paper sheet conveyance direction of the pair of first conveyance rollers, and the crease processing unit is configured to form a crease in advance in a fold line when the planar paper sheet is folded.

According to the invention recited in claim <NUM>, in the paper folding device recited in any one of claims <NUM> to <NUM>, a distance by which the switching gate plate disposed at the second guide position and the folding plate disposed at the folding position approach each other is set such that at least a gap that allows the paper sheet to be conveyed is secured between the folding plate and the switching gate plate.

The invention recited in claim <NUM> is a bag making machine including the paper folding device recited in any one of claims <NUM> to <NUM>.

According to the invention recited in claim <NUM>, since it is not necessary to provide the paper sheet insertion space (diverging path) and the stopper as the paper folding mechanism, it is possible to simply and inexpensively configure the paper folding mechanism without complicating the structure. In addition, since the folding position is automatically adjusted in accordance with various folding specifications by the control unit, it is possible to provide a paper folding device with good operability. Furthermore, wrinkles are prevented from being generated in the folded piece portions, and even in the case of folding, glue does not adhere to the inside of the folding mechanism such as the stopper, and the quality of the product is not adversely affected.

According to the invention recited in claim <NUM>, after the leading end portion of the paper sheet is folded back by lowering the folding plate, the leading end fold-back portion of the paper sheet after being folded back is controlled to be pressed and folded by the nip portion of the pair of second conveyance rollers, so that it is possible to reliably impart a folding habit to the paper sheet.

According to the invention recited in claim <NUM>, since the two positions of the front end portion and the rear end portion in the paper sheet conveyance direction can be folded back on the same folding mechanism, the work efficiency is good. In addition, space saving and inexpensive configuration can be achieved.

According to the invention recited in claim <NUM>, after the front end portion and the rear end portion in the conveyance direction of the paper sheet are folded back by lowering of the folding plate, the nip portion of the pair of second conveyance rollers and the nip portion of the pair of first conveyance rollers are controlled to press and fold the paper sheet, so that it is possible to reliably impart a folding habit to the paper sheet.

According to the invention recited in claim <NUM>, a crease processing unit is further provided on the upstream side in the paper sheet conveyance direction of the pair of first conveyance rollers, and the crease processing unit is configured to form a crease in advance in a fold line when the planar paper sheet is folded to form a fold starting point, so that the paper sheet can be folded cleanly and accurately. In addition, it is possible to suppress print cracking that occurs at the time of folding the paper sheet.

According to the invention recited in claim <NUM>, after the leading end portion of the paper sheet is folded back by lowering of the folding plate, the leading end fold-back portion of the paper sheet after being folded back is conveyed while being guided by the gap between the adjacent switching gate plate and the folding plate, so that it is possible to reliably transfer the leading end fold-back portion to a pressing processing unit by the nip portion of the pair of conveyance rollers at the next stage without generating wrinkles or the like.

According to the invention recited in claim <NUM>, by using the paper folding device for folding the paper sheet in the present invention in a bag making machine for manufacturing an envelope, the entire device can be configured simply and inexpensively, and operability is good, which is preferable.

<FIG> illustrates a bag making machine <NUM> according to an embodiment that employs a paper folding device (second folding unit <NUM>) of the present invention. <FIG> is an overall configuration diagram of the bag making machine <NUM>. The bag making machine <NUM> includes a paper feeding unit <NUM>, a first crease processing unit <NUM>, a second crease processing unit <NUM>, a first folding unit <NUM>, a glue application unit <NUM>, a second folding unit <NUM>, and a paper ejection unit <NUM> in this order from an upstream side in a conveyance direction in a device body 10A.

A "western envelope" of a general form has a horizontally long rectangle, and a sealing port is formed on a long side. When the western envelope is manufactured by the bag making machine <NUM>, for example, as illustrated in <FIG>, glue is applied to folded piece portions <NUM> on both sides of a rear surface portion <NUM> of a paper sheet <NUM>, and a front surface portion <NUM> is folded back and crimped to the piece portions <NUM>.

Specifically, the bag making machine <NUM> manufactures a western envelope <NUM> by processing the planar paper sheet <NUM> illustrated in <FIG> as illustrated in <FIG> while conveying the paper sheet in an F direction.

The paper sheet <NUM> includes the front surface portion <NUM>, the rear surface portion <NUM>, the glue substitute piece portions <NUM> protruding to both sides of the rear surface portion <NUM>, and a rearmost surface portion <NUM>. As illustrated in <FIG>, the paper sheet <NUM> is folded at first fold lines <NUM> which are boundary lines between the rear surface portion <NUM> and the piece portions <NUM>, and further folded at a second fold line <NUM> which is a boundary line between the front surface portion <NUM> and the rear surface portion <NUM> as illustrated in <FIG>. A glue is applied to the surfaces of the piece portions <NUM> folded back at the first fold lines <NUM>. Both edge portions of the front surface portion <NUM> folded back at the second fold line <NUM> are joined to the piece portions <NUM>. Note that the first fold lines <NUM> extend along the conveyance direction. The second fold line <NUM> is along a direction orthogonal to the conveyance direction (that is, a width direction).

As a product, the western envelope <NUM> of <FIG> may be used, but by processing the western envelope <NUM> illustrated in <FIG> as illustrated in <FIG> while conveying the envelope <NUM> in an F' direction, the rearmost surface portion <NUM> may be further folded along a third fold line <NUM> which is a boundary line between the rear surface portion <NUM> and the rearmost surface portion <NUM>. According to the above configuration, when the contents are inserted into the envelope and then sealed using a tape or a glue, the front surface portion <NUM> on which the rearmost surface portion <NUM> is folded back can be sealed cleanly since there is a folding habit.

The paper feeding unit <NUM> includes an air suction belt-type air paper feeding unit <NUM>, an elevator-type paper feeding tray <NUM> that ascends and descends according to a paper sheet loading amount, and a pair of conveyance rollers <NUM> that further convey the paper sheet fed by the air paper feeding unit <NUM> to a downstream side in the conveyance direction. Further, the air paper feeding unit <NUM> includes a sensor <NUM> that detects that an uppermost paper sheet of the paper sheets stacked on the paper feeding tray <NUM> is attracted to a lower surface of the air paper feeding unit <NUM>, and a sensor <NUM> that detects an upper limit position of the uppermost paper sheet of the paper sheets stacked on the paper feeding tray <NUM>.

Note that the bag making machine <NUM> includes seven pairs of conveyance rollers <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> in addition to the pair of conveyance rollers <NUM>. The seven pairs of conveyance rollers constitute a conveyance surface <NUM> on which the paper sheet <NUM> is conveyed, and the conveyance surface <NUM> is flush from the air paper feeding unit <NUM> to the pair of conveyance rollers <NUM>. Furthermore, on the conveyance surface <NUM> on which the paper sheet is conveyed, a sensor <NUM>, a sensor <NUM>, a sensor <NUM>, a sensor <NUM>, a sensor <NUM>, and a sensor <NUM> that detect passage of the paper sheet at each position (detect double feed) are disposed. Each sensor uses, for example, an optical transmission sensor.

As illustrated in <FIG>, the first crease processing unit <NUM> includes an upper mold having a convex upper portion and a lower mold having a concave lower portion, and forms a lateral crease in a direction perpendicular to the paper sheet conveyance direction as the second fold line <NUM> and the third fold line <NUM> of the paper sheet <NUM>. As the crease processing unit <NUM>, a known mechanism can be employed.

As illustrated in <FIG>, the second crease processing unit <NUM> includes an upper blade having a circular blade shape of a crease blade and a convex portion formed on an outer peripheral portion, and a lower blade having a circular blade shape and a concave portion formed on an outer peripheral portion. The second crease processing unit <NUM> is installed at two positions in the width direction perpendicular to the conveyance direction, and forms longitudinal creases along the paper sheet conveyance direction on the first fold lines <NUM> (two positions) of the paper sheet <NUM>. As the second crease processing unit <NUM>, a known mechanism can be employed.

The first folding unit <NUM> includes a pair of folding devices 3a and 3b disposed opposite to each other on both sides in the width direction perpendicular to the paper sheet conveyance direction. Each of the folding devices 3a and 3b includes a flap plate <NUM> that rotates around a rotation shaft <NUM> along the conveyance direction, and as illustrated in <FIG>, by rotating the flap plate <NUM> as illustrated in <FIG>, the piece portion <NUM> of the paper sheet <NUM> placed on the flap plate <NUM> in a state of being positioned on an outer side in the width direction can be folded inward so as to be aligned with a surface of the rear surface portion <NUM>.

The glue application unit <NUM> includes a pair of application devices 5a and 5b disposed opposite to each other on both sides in the width direction. Note that the application device 5a and the application device 5b have bilaterally symmetrical configurations.

The application devices 5a and 5b include nozzle portions, a position setting mechanism, and a vertical drive mechanism (not illustrated). The nozzle portion can apply glue to the conveyed paper sheet at a predetermined timing.

The second folding unit <NUM> is a paper folding device that folds the planar paper sheet <NUM> while conveying the paper sheet along the conveyance surface <NUM>, and includes the pair of first conveyance rollers <NUM> disposed on the upstream side in the paper sheet conveyance direction, the pair of second conveyance rollers <NUM> disposed on the downstream side in the paper sheet conveyance direction, a switching gate plate <NUM> installed between both pairs of the rollers, and a folding plate <NUM> disposed above the switching gate plate <NUM>.

The switching gate plate <NUM> is switchable between a first guide position at which the switching gate plate interferes with the conveyed paper sheet <NUM> and guides a leading end portion of the paper sheet <NUM> upward so as to pass through an upper surface of an upper roller <NUM> of the pair of second conveyance rollers <NUM> and a second guide position at which the switching gate plate guides the leading end portion of the paper sheet100 in the substantially horizontal direction toward a nip portion <NUM> of the pair of second conveyance rollers <NUM>, and the folding plate <NUM> is configured to be movable in the vertical direction while being in the substantially horizontal state, and is switchable between a folding position at which the folding plate approaches the switching gate plate <NUM> disposed at the second guide position and a retracting position at which the folding plate retracts at a predetermined interval from the switching gate plate.

Drive mechanisms <NUM> and <NUM> of the switching gate plate <NUM> and the folding plate <NUM> will be described.

As illustrated in <FIG> and <FIG>, the switching gate plate <NUM> is selectively disposed at the first guide position and the second guide position described above. <FIG> illustrates a state in which the switching gate plate <NUM> is disposed at the second guide position, and <FIG> illustrates a state in which the switching gate plate <NUM> is disposed at the first guide position.

In <FIG> is a front view when viewed from the front in the paper sheet conveyance direction, and <FIG> is a cross-sectional view when viewed from a C direction in <FIG>. In <FIG> is a front view when viewed from the front in the paper sheet conveyance direction, and <FIG> is a cross-sectional view when viewed from a D direction in <FIG>.

As illustrated in <FIG> and <FIG>, the drive mechanism <NUM> of the switching gate plate <NUM> operates as follows. That is, when a motor <NUM> operates, a second pulley <NUM> rotates via a first pulley <NUM> and a transmission belt <NUM>. Since a support shaft <NUM> of the switching gate plate <NUM> is connected to the second pulley <NUM>, the switching gate plate <NUM> rotates when the second pulley <NUM> rotates. Note that a rotation angle of the switching gate plate <NUM> can be detected by detecting both edges of a light shielding plate <NUM> attached to the support shaft <NUM> of the switching gate plate <NUM> by a first detection unit <NUM>, whereby the switching gate plate <NUM> can be selectively disposed at the first guide position and the second guide position.

As illustrated in <FIG> and <FIG>, the folding plate <NUM> is selectively disposed at the folding position and the retracting position described above. <FIG> illustrates a state in which the folding plate <NUM> is disposed at the retracting position, and <FIG> illustrates a state in which the folding plate <NUM> is disposed at the folding position.

In <FIG> is a front view when viewed from the front in the paper sheet conveyance direction, and <FIG> is a cross-sectional view when viewed from an A direction in <FIG>. In <FIG> is a front view when viewed from the front in the paper sheet conveyance direction, and <FIG> is a cross-sectional view when viewed from a B direction in <FIG>.

As illustrated in <FIG> and <FIG>, the drive mechanism <NUM> of the folding plate <NUM> operates as follows. That is, when a motor <NUM> operates, a drive gear (not illustrated) attached to a drive shaft of the motor <NUM> rotates, and an interlocking gear <NUM> engaged with the drive gear rotates. A base portion of a second link member <NUM> is fixed to a rotation shaft of the interlocking gear <NUM> so as to be rotatable, and one end portion of a first link member <NUM> is attached to a free end thereof. A pinion <NUM> is attached to the other end portion of the first link member <NUM>, and the pinion <NUM> meshes with a rack <NUM> in an immovable state. Therefore, the first link member <NUM> converts the rotational motion of the second link member <NUM> into the linear motion (reciprocating motion) of the pinion <NUM> on the rack <NUM>. The folding plate <NUM> is attached to a rotation shaft of the pinion <NUM>, and the folding plate <NUM> moves up and down (reciprocates) along an elongated hole <NUM> integrally with the linear motion (reciprocation) of the pinion <NUM>. Note that a vertical position of the folding plate <NUM> can be detected by detecting both edges of a light shielding plate (not illustrated) attached to the rotation shaft of the interlocking gear <NUM> by a second detection unit <NUM>, whereby the folding plate <NUM> can be selectively disposed at the folding position and the retracting position.

A pressurization unit <NUM> includes an upper mold 8a that can move up and down and an immovable lower mold 8b, and further applies pressure by sandwiching a folded part of the paper sheet <NUM> folded at the second folding unit <NUM> between the upper mold and the lower mold to strengthen the folded part.

The paper ejection unit <NUM> includes a pair of conveyance rollers <NUM> and a paper ejection tray <NUM>. The pair of conveyance rollers <NUM> are provided to operate as discharge rollers. Specifically, as illustrated in <FIG>, the pair of conveyance rollers <NUM> are disposed in the vicinity of the pair of second conveyance rollers <NUM> of the second folding unit <NUM> and on the downstream side in the conveyance direction. The paper ejection tray <NUM> is inclined obliquely upward from a position below the conveyance surface <NUM> and toward the downstream side in the conveyance direction.

Next, an operation of the bag making machine <NUM> having the above configuration will be described.

First, the paper sheet <NUM> illustrated in <FIG> is placed on the paper feeding tray <NUM>. At this time, the front surface portion <NUM> is located on the downstream side in the conveyance direction. Then, a switch (not illustrated) is turned on to start the operation.

Next, another embodiment of the first folding unit will be described. In another embodiment illustrated in <FIG>, the basic configuration of the folding of the piece portion <NUM> by the flap plate <NUM> of each of the folding devices 3a and 3b of the first folding unit <NUM> is the same as that in <FIG> described above, but is different in that an upper guide plate <NUM> is provided above the lower guide plate <NUM> with a predetermined gap, and that a pair of rollers (a driving roller <NUM> and a driven roller <NUM>) that further convey the paper sheet <NUM> conveyed on the lower guide plate <NUM> to the downstream side are provided. Note that, in the lower guide plate <NUM>, notches are formed in the nip portion of the pair of rollers.

In <FIG>, the flap plate <NUM> of each of the folding devices 3a and 3b of the first folding unit <NUM> is located on the outer side in the width direction, and the piece portions <NUM> on both sides of the paper sheet <NUM> are placed on the flap plates <NUM>.

Next, in <FIG>, the flap plate <NUM> rotates toward the inner lower guide plate <NUM>, whereby the piece portion <NUM> is folded inward at the creased first fold line <NUM> and aligned on the rear surface portion <NUM> via the upper guide plate <NUM> as illustrated in <FIG>.

Thereafter, in <FIG>, the flap plate <NUM> rotates in a direction away from the outer lower guide plate <NUM>. Then, the paper sheet <NUM> on which the piece portions <NUM> are folded is conveyed downstream in the conveyance direction by the pair of rollers (the driving roller <NUM> and the driven roller <NUM>). By rotating the flap plate <NUM> in a direction away from the lower guide plate <NUM> by at least a predetermined angle before the conveyance of the paper sheet <NUM> is started, it is possible to prevent the flap plate <NUM> and the upper guide plate <NUM> from becoming a load at the time of conveying the paper sheet <NUM> and to stably convey the paper sheet <NUM> without generating wrinkles.

In <FIG> described above, the upper guide plate <NUM> and the driven roller <NUM> are provided, so that it is possible to prevent the paper sheet from being bent and wrinkled when the paper sheet is folded.

(<NUM>) The paper sheet <NUM> on which the piece portions <NUM> are folded is conveyed downstream in the conveyance direction by the pair of conveyance rollers <NUM> and passes through the glue application unit <NUM>. In the glue application unit <NUM>, the nozzle portions 5a and 5b installed at two positions in the width direction move downward and abut on the surfaces of the piece portions <NUM> when the folded piece portions <NUM> on both sides of the paper sheet <NUM> start to pass, and the nozzle portions 5a and 5b move upward and the nozzle portions 5a and 5b are separated from the surfaces of the piece portions <NUM> when the passage of the piece portions <NUM> is completed. As a result, the glue is applied to the surfaces of the folded piece portions <NUM>. Note that the folded piece portions <NUM> pass through the nozzle portions 5a and 5b in a state of being pressed or after being pressed by the pair of conveyance rollers <NUM> located upstream of the nozzle portions 5a and 5b in the conveyance direction. Therefore, the glue application work by the nozzle portions 5a and 5b can be stably performed.

The second folding unit <NUM> is a paper folding device that folds the planar paper sheet <NUM> while conveying the paper sheet along the conveyance surface <NUM>, and includes the pair of first conveyance rollers <NUM> disposed on the upstream side in the paper sheet conveyance direction, the pair of second conveyance rollers <NUM> disposed on the downstream side in the paper sheet conveyance direction, the switching gate plate <NUM> installed on the paper sheet conveyance surface <NUM> between both the pairs of the rollers, the folding plate <NUM> disposed to face the switching gate plate <NUM>, and a control unit (not illustrated) that controls an operation of the entire device.

The switching gate plate <NUM> is switchable between the first guide position at which the switching gate plate interferes with the conveyed paper sheet <NUM> to bend the paper sheet conveyance direction outward from the paper sheet conveyance surface <NUM> and guides the leading end portion of the paper sheet <NUM> toward a surface of one roller of the pair of second conveyance rollers <NUM> and the second guide position at which the switching gate plate guides the leading end portion of the paper sheet along the paper sheet conveyance surface <NUM> toward the nip portion <NUM> of the pair of second conveyance rollers <NUM>.

The folding plate <NUM> is configured to be movable toward the switching gate plate <NUM> in a substantially horizontal state, and can be switched between the folding position close to the switching gate plate <NUM> disposed at the second guide position and the retracting position retracted at a predetermined interval from the switching gate plate <NUM>.

The control unit performs control to, after guiding the leading end portion of the paper sheet <NUM> to be conveyed by the switching gate plate <NUM> disposed at the first guide position so as to pass through a surface of one roller of the pair of second conveyance rollers <NUM> by a predetermined amount, switch the switching gate plate <NUM> to the second guide position, and then lower the folding plate <NUM> disposed at the retracting position to the folding position in a substantially horizontal state so as to sandwich the paper sheet <NUM> on the switching gate plate <NUM>, thereby folding back the leading end portion of the paper sheet <NUM> along the surface of one roller of the pair of second conveyance rollers <NUM>.

Specifically, as an embodiment, processing is sequentially performed as shown in the following (<NUM>-<NUM>)to (<NUM>-<NUM>).

(<NUM>-<NUM>) The paper sheet <NUM> on which the glue has been applied to the piece portions <NUM> is conveyed (in the F direction) to the second folding unit <NUM> by the pair of conveyance rollers <NUM>. At this time, the switching gate plate <NUM> is set upward toward the pair of second conveyance rollers <NUM> as the first guide position. Therefore, as illustrated in <FIG>, the paper sheet <NUM> is guided upward by the switching gate plate <NUM> such that the leading end portion of the paper sheet <NUM> passes through the upper surface of the upper roller <NUM> of the pair of second conveyance rollers <NUM>, and the conveyance is temporarily stopped when a position of the second fold line <NUM> of the paper sheet <NUM> reaches the folding position (position immediately below an end portion <NUM> of the folding plate <NUM>). Note that during this period, the folding plate <NUM> stays at the retracting position.

Note that, since an upper roller <NUM> of the pair of first conveyance rollers <NUM> is set to have a width dimension that does not contact the surface of the piece portion <NUM>, the glue applied to the piece portion <NUM> of the paper sheet <NUM> in the glue application unit <NUM> does not adhere to the pair of first conveyance rollers <NUM>.

(<NUM>-<NUM>) Next, as illustrated in <FIG>, the switching gate plate <NUM> is moved to the second guide position (substantially horizontal position) while the folding plate <NUM> stays at the retracting position.

(<NUM>-<NUM>) Next, as illustrated in <FIG>, the folding plate <NUM> disposed at the retracting position is lowered to the folding position in a substantially horizontal state so as to sandwich the paper sheet <NUM> on the switching gate plate <NUM>, whereby the front surface portion <NUM> of the paper sheet <NUM> is folded back from the second fold line <NUM> along the surface of the upper roller <NUM> of the pair of second conveyance rollers <NUM>. At this time, a distance by which the switching gate plate <NUM> and the folding plate <NUM> after lowering approach each other is configured such that at least a gap that allows the paper sheet to be conveyed is secured between the folding plate <NUM> and the switching gate plate <NUM>. For example, the gap of about <NUM> is secured.

According to the above, since it is not necessary to provide the paper sheet insertion space (diverging path) and the stopper as the paper folding mechanism, it is possible to simply and inexpensively configure the paper folding mechanism without complicating the structure. In addition, since the folding position is automatically adjusted in accordance with various folding specifications by the control unit, it is possible to provide a paper folding device with good operability. Furthermore, wrinkles are prevented from being generated in the folded piece portions, and even in the case of folding, glue does not adhere to the inside of the folding mechanism such as the stopper, and the quality of the product is not adversely affected.

(<NUM>-<NUM>) Next, as illustrated in <FIG>, after the front surface portion <NUM> of the paper sheet <NUM> is folded back by lowering of the folding plate <NUM>, a leading end fold-back portion <NUM> of the paper sheet after the leading end portion of the paper sheet is folded back is further conveyed toward the nip portion <NUM> of the pair of second conveyance rollers <NUM> by the pair of first conveyance rollers <NUM>, and the leading end fold-back portion <NUM> of the paper sheet is sandwiched by the nip portion <NUM> of the pair of second conveyance rollers <NUM> and conveyed in the F direction to press and fold the paper sheet leading end fold-back portion <NUM>. Then, the entire front surface portion <NUM> is folded back and aligned with the surface of the rear surface portion <NUM>, and at that time, both edge portions of the front surface portion <NUM> are joined to the piece portions <NUM>. Thus, the western envelope <NUM> is obtained. Note that conveyance in the F direction is performed until the rearmost surface portion <NUM> of the paper sheet <NUM> passes through the nip portion <NUM> of the pair of first conveyance rollers <NUM> by a predetermined amount. At this time, the paper sheet <NUM> is conveyed through the gap between the folding plate <NUM> and the switching gate plate <NUM> (while being guided by both the plates). According to this, the paper sheet can be reliably delivered to a pressing processing unit by the nip portion <NUM> of the pair of second conveyance rollers <NUM> at the next stage without generating wrinkles or the like.

According to the above, after the leading end portion of the paper sheet is folded back by lowering the folding plate, the control is performed such that the paper sheet leading end fold-back portion after the folding is pressed and folded by the nip portion <NUM> of the pair of second conveyance rollers <NUM>, and thus, it is possible to reliably add a folding habit to the paper sheet.

As a product, the western envelope <NUM> may be used, but the rearmost surface portion <NUM> may be further folded along the third fold line <NUM> which is a boundary line between the rear surface portion <NUM> and the rearmost surface portion <NUM> by folding the western envelope <NUM> while being reversely conveyed in the F' direction. According to this configuration, when an operator seals the envelope with a tape or a glue after inserting the contents into the envelope, since the envelope has a folding habit, the rearmost surface portion <NUM> can be sealed cleanly on the folded front surface portion <NUM>. A processing method of folding the rearmost surface portion <NUM> will be described below.

(<NUM>-<NUM>) The switching gate plate <NUM> is further switchable upward toward the pair of first conveyance rollers <NUM> as a third guide position, and the pair of first conveyance rollers <NUM> and the pair of second conveyance rollers <NUM> are configured to be able to perform forward rotation and reverse rotation.

As described above, after the pair of second conveyance rollers <NUM> press the leading end fold-back portion <NUM> of the paper sheet <NUM> at the nip portion <NUM> of the pair of second conveyance rollers <NUM>, as illustrated in <FIG>, the folding plate <NUM> is retracted to the retracting position, and the switching gate plate <NUM> is switched upward toward the pair of first conveyance rollers <NUM> as the third guide position. Thereafter, the pair of second conveyance rollers <NUM> are reversely rotated, and the paper sheet <NUM> is conveyed in a reverse direction from the downstream side to the upstream side in the F' direction. As a result, the rearmost surface portion <NUM> of the paper sheet is guided upward so as to pass through the upper surface of the upper roller <NUM> of the pair of first conveyance rollers <NUM> by a predetermined amount, and the conveyance is temporarily stopped when the position of the third fold line <NUM> of the paper sheet <NUM> reaches the folding position (the position immediately below the end portion <NUM> of the folding plate <NUM>). Note that during this period, the folding plate <NUM> stays at the retracting position.

(<NUM>-<NUM>) Next, as illustrated in <FIG>, the folding plate <NUM> disposed at the retracting position is lowered to the folding position in the substantially horizontal state so as to sandwich the paper sheet <NUM> on the switching gate plate <NUM>, whereby the rearmost surface portion <NUM> of the paper sheet <NUM> is folded back from the third fold line <NUM> along the surface of the upper roller <NUM> of the pair of first conveyance rollers <NUM>. At this time, a distance by which the switching gate plate <NUM> and the folding plate <NUM> after lowering approach each other is configured such that at least a gap that allows the paper sheet to be conveyed is secured between the folding plate <NUM> and the switching gate plate <NUM>. For example, the gap of about <NUM> is secured.

<FIG> is a diagram schematically illustrating a folded state of the paper sheet <NUM> in <FIG>. The front surface portion <NUM> of the paper sheet <NUM> is folded onto the rear surface portion <NUM> from the second fold line <NUM>, and the rearmost surface portion <NUM> is folded back from the third fold line <NUM>.

According to the above, since it is possible to fold back two positions of the front end portion (front surface portion <NUM>) and the rear end portion (rearmost surface portion <NUM>) in the conveyance direction of the paper sheet on the same folding mechanism, the work efficiency is good. In addition, space saving and inexpensive configuration can be achieved.

(<NUM>-<NUM>) Next, as illustrated in <FIG>, after the rearmost surface portion <NUM> of the paper sheet <NUM> is folded back by lowering of the folding plate <NUM>, a paper sheet rear end fold-back portion <NUM> after a rear end portion of the paper sheet is folded back is further conveyed toward the nip portion <NUM> of the pair of first conveyance rollers <NUM> by the pair of second conveyance rollers <NUM>, and the paper sheet rear end fold-back portion <NUM> is sandwiched by the nip portion <NUM> of the pair of first conveyance rollers <NUM> and conveyed by a predetermined amount in the F' direction to press and fold the paper sheet rear end fold-back portion <NUM>. Then, the entire rearmost surface portion <NUM> is folded back and aligned with the surface of the rear surface portion <NUM>, and thereafter, the western envelope <NUM> as a finished product is conveyed in the F direction toward the pressurization unit <NUM> installed in a downstream portion of the second folding unit <NUM>.

<FIG> is a diagram schematically illustrating a folded state of the paper sheet <NUM> in <FIG>. The front surface portion <NUM> of the paper sheet <NUM> is folded onto the rear surface portion <NUM> from the second fold line <NUM>, and the rearmost surface portion <NUM> is further folded onto the front surface portion <NUM> folded onto the rear surface portion <NUM> by being folded back from the third fold line <NUM>.

According to the above, after the front end portion and the rear end portion in the conveyance direction of the paper sheet <NUM> are folded back by lowering of the folding plate <NUM>, the control is performed so as to press and fold the paper sheet at the nip portions of the pair of second conveyance rollers <NUM> and the pair of first conveyance rollers <NUM>, and thus, it is possible to reliably add a folding habit (fold lines) to the paper sheet.

In addition, the crease processing unit <NUM> is provided on the upstream side of the pair of first conveyance rollers <NUM> in the paper sheet conveyance direction, and the crease processing unit <NUM> forms creases in advance in fold lines (second fold line <NUM>, third fold line <NUM>) when the planar paper sheet <NUM> is folded to form a folding start point, so that the paper sheet can be folded cleanly and accurately. In addition, it is possible to suppress print cracking that occurs at the time of folding the paper sheet.

(<NUM>) Next, in the western envelope <NUM> conveyed from the second folding unit <NUM> to the pressurization unit <NUM>, the folded portions <NUM> and <NUM> are sequentially sandwiched and pressurized between the upper mold 8a and the lower mold 8b of the pressurization unit <NUM>. Therefore, the folded portions <NUM> and <NUM> become strong. The pressurized western envelope <NUM> is conveyed toward the paper ejection unit <NUM> by the pair of conveyance rollers <NUM>, and is ejected onto the paper ejection tray <NUM>.

Claim 1:
A paper folding device (<NUM>) that is configured to fold a planar paper sheet (<NUM>) while conveying the paper sheet along a paper sheet conveyance surface (<NUM>), the paper folding device comprising:
a pair of first conveyance rollers (<NUM>) disposed on an upstream side in a paper sheet conveyance direction;
a pair of second conveyance rollers (<NUM>) disposed on a downstream side in the paper sheet conveyance direction;
a switching gate plate (<NUM>) installed on the paper sheet conveyance surface between both pairs of the rollers;
a folding plate (<NUM>) disposed above the switching gate plate; and
a control unit that is configured to control an operation of an entire device,
wherein the switching gate plate is switchable between a first guide position at which the switching gate plate is configured to interfere with the conveyed paper sheet and guide a leading end portion of the paper sheet upward so as to pass through an upper surface of an upper roller (<NUM>) of the pair of second conveyance rollers and a second guide position at which the switching gate plate is configured to guide the leading end portion of the paper sheet toward a nip portion (<NUM>) of the pair of second conveyance rollers along the paper sheet conveyance surface,
the folding plate is configured to be movable in a vertical direction in a substantially horizontal state, and is switchable between a folding position close to the switching gate plate disposed at the second guide position and a retracting position retracted at a predetermined interval from the switching gate plate, and
the control unit is configured to perform control to, after guiding the leading end portion of the paper sheet to be conveyed by the switching gate plate disposed at the first guide position so as to pass through the upper surface of the upper roller of the pair of second conveyance rollers by a predetermined amount, switch the switching gate plate to the second guide position, and then lower the folding plate disposed at the retracting position to the folding position in a substantially horizontal state so as to sandwich the paper sheet on the switching gate plate, thereby folding back the leading end portion of the paper sheet along a surface of the upper roller of the pair of second conveyance rollers.