JP2003200382A - Sheet cutting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet cutting device, which is installed in a printing device or the like and can cut a paper sheet at a high speed and provide sheets of the same length by stopping a rotary blade at a standby position highly accurately even if the paper sheet runs at a high speed. <P>SOLUTION: In the sheet cutting device wherein a fixed blade 40 is arranged opposing to a rotary blade 39, and a brake wheel 49 having a near D-shape cross section and an arc-like curved face and a flat face on its outer peripheral face is arranged so as to rotate together with the rotary blade integrally, and a brake arm 50, which is supported on a side plate pivotally, is pressed against the outer peripheral surface of the brake wheel by the energizing force of a spring, and the sheet is cut by the rotary blade and the fixed blade while the rotary blade makes a turn from the standby position where the flat face of the brake wheel and the brake arm abut on each other and return to the standby position, an excessive rotation preventing means 2 is provided to lock the rotary blade at the standby position and release the lock when the rotation of the rotary blade is started. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a web (hereinafter referred to as "paper") drawn from a paper, a film or the like wound in a roll, and a sheet (hereinafter referred to as "sheet"). The present invention relates to a sheet cutting device for cutting into. More specifically, the present invention relates to a sheet cutting device that is mounted on a printer, a printing device, or the like and that is suitable for sequentially cutting into sheets while continuously traveling without stopping the feeding of paper.

[0002]

2. Description of the Related Art FIG. 8 shows an example of a printing device equipped with a sheet cutting device. The printing device 31 is provided with, for example, a first printing unit 35a and a second printing unit 36a of an inkjet system, is capable of double-sided printing, and has a paper P after printing.
Is cut into a sheet S having a predetermined length by the sheet cutting device 32 and discharged to the stacking tray 33. That is, in the printing device 31 shown in FIG. 8, the paper P pulled out from the unwinding roll is the guide roll 3
4 to be transported, and after being subjected to double-sided printing via the first printing section 35a and the second printing section 36a, the drag roll section 3
The sheet S having a predetermined length is cut by the rotary blade 39 and the fixed blade 40 of the sheet cutting device 32 provided between the sheet feeding device 7 and the delivery roll unit 38, and is discharged from the delivery roll unit 38 to the stacking tray 33. Has become.

A printing device 41 shown in FIG. 9 has a first printing unit 3
5b and the second printing unit 36b adopt the offset printing method, and the others are the same as those of the printing apparatus shown in FIG. 8, and therefore, the same configurations are denoted by the same reference numerals and description thereof is omitted. .

A sheet cutting device 32 mounted on such a printing device is shown in FIG. The sheet cutting device 32
The rotary blade 39 is rotatably supported between the left and right side plates 43, 43 standing upright from the base 42, and the fixed blade 40 is arranged parallel to the axial direction of the rotary blade 39.
The rotary blade 39 and the fixed blade 40 are configured to cut the paper P while the rotary blade 39 makes one rotation. FIG. 10 shows a state in which the sheet cutting device 32 is in the standby position.

One rotation shaft of the rotary blade 39 (not shown)
Is extended outside the right side plate 43, and the clutch 44
It is connected to the motor 45 via. Motor 4
5 is always rotated in a fixed direction at a predetermined rotation speed, and when the clutch 44 is engaged, the rotary blade 39 at the standby position is activated to cut the sheet P by the fixed blade 40 and the clutch 4
After 4 is cut, the rotary blade 39 is decelerated and stopped at the standby position by the configuration described later. The connection of the driving force of the motor 45 by the clutch 44 is performed by the solenoid 46. As a driving force transmission mechanism for the motor 45 to the rotary blade 39 by the solenoid 46 and the clutch 44 as described above, for example, Japanese Patent Laid-Open No.
A mechanism using a spring clutch as described in JP-A-323292 is adopted.

The other rotary shaft 48 of the rotary blade 39 is extended to the outside of the left side plate 43, and a part of the circumferential side surface of the rotary shaft 48 is cut so that the outer circumferential surface has a substantially D shape. A brake wheel 49 having an arcuate curved surface and a flat surface is provided. Brake arm 5 pivotally supported outside the side plate 43
0 is biased by the elastic force of the coil spring 51 so as to come into pressure contact with the outer peripheral surface of the brake wheel 49.

The fixed blade 40 is pivotally supported between the side plates 43, 43 (not shown), and is urged by a pressing spring 53 (see FIG. 11) provided between the fixed blade 40 and the stay 52, so that both ends of the fixed blade 40 are supported. In the section, the sheets are in contact with the pillow bodies 54 provided on both sides of the rotary blade 39, and the sheet is cut as the rotary blade 39 rotates.

In the printing device 31 provided with the sheet cutting device 32, the printed paper is cut as follows. That is, the paper P drawn from the unwinding roll is double-sided printed and introduced into the sheet cutting device 32 at a predetermined speed without stopping. Rotary blade 39
In the standby position of No. 4, the clutch 44 and the motor 45 are not connected, and as shown in FIG.
The blade edge 39a of the rotary blade 39 and the blade edge 40a of the fixed blade 40 are set at an angle of θ1 about the axis of the rotary blade 39. Then, in this state, FIG.
As shown in FIG. 5, the brake arm 50 is in contact with the flat surface of the brake wheel 49 by the elastic force of the coil spring 51 (see FIG. 10). When the pulse-shaped trigger signal is input once to the solenoid 46, the clutch 44 is engaged and the driving force from the motor 45 is applied to the rotary blade 3
9, the rotary blade 39 is activated and rotates in the direction of the arrow, and the peripheral speed of the rotary blade 39 reaches the same speed as the paper feed speed at the angle of the rotary blade 39 as shown in FIG. The paper P is cut. With the rotation of the rotary blade 39, the brake arm 50 comes into pressure contact with the arc-shaped curved surface of the brake wheel 49 as shown in FIG.
A braking force acting in a direction opposite to the rotating direction of the rotary blade 39 will be applied.

The energization of the solenoid 46 is terminated, the clutch 44 is disengaged, and the driving force from the motor 45 is applied to the rotary blade 39.
Even after it is no longer transmitted to the rotary blade 39, the rotary blade 39 continues to rotate by inertia while being decelerated by the braking force generated by the pressure contact between the brake arm 50 and the brake wheel 49 on the arc-shaped curved surface. FIG. 13A shows a state in which the rotary blade 39 continues to rotate, and FIG. 13B shows a state in which the corresponding brake arm 50 and brake wheel 49 are pressed against the arcuate curved surface.

Then, from the state in which the brake arm 50 and the brake wheel 49 are pressed against the arcuate curved surfaces as shown in FIG. 13 (b), the brake arm 50 is moved to a flat surface of the brake wheel 49 as shown in FIG. 14 (b). To the standby position where it abuts against. When this happens, the brake arm 5
With 0, a large braking action is momentarily activated. FIG. 14A shows a state in which the rotary blade 39 corresponding to FIG. 14B has reached the standby position.

The inertia of the rotary blade 39, the driving force transmitted to the rotary blade 39, the rotation speed of the motor 45, and the brake arm 50.
By appropriately selecting various conditions such as the braking force by the brake arm 50, the brake arm 50 reaches the standby position where it contacts the flat surface of the brake wheel 49 as shown in FIG. 14B, and the inertia of the rotary blade 39 causes At the standby position, the rotary blade 3 is completely rotated without overrunning beyond the standby position.
It is possible to stop 9. It is relatively easy for the rotary blade 39 to make one rotation from the standby position and stop at the standby position without overrunning when the driving force (torque from the motor) of the rotary blade 39 is not large. I can say.

When the next trigger signal is input to the solenoid 46 after the rotary blade 39 has stopped at the standby position, the cutting operation is performed in the same manner as described above. An example of the trigger signal to the solenoid 46 and the operation timing of the rotation of the rotary blade 39 is shown in (i) and (ii) of FIG. FIG. 15 (i)
Indicates ON / OFF of the trigger signal, and (ii) indicates the relationship between rotation and stop of the rotary blade, and the sheet is cut at the timing indicated by the triangle in the time chart of the rotary blade in (ii) of FIG. The length of the sheet to be cut, that is, the cutting length is
It is determined by the time of one cycle between the trigger signal and the next trigger signal and the paper feed speed. Solenoid 4
By repeatedly inputting the trigger signal to the sheet 6, the sheets P are successively cut into sheets S with a length corresponding to the interval of the trigger signals.

It is preferable that the rotary blade 39 makes one rotation, stops accurately at the standby position without overrun, and waits until the next trigger signal is input. When the paper feed speed is low, the rotation speed of the motor 45 is low, and the cutting cycle is long, a sufficient return time can be secured even if the rotary blade 39 overruns, so that the cut sheet lengths are aligned. It will be good. However, the number of sheets cut into sheets per unit time is small, which means that the cutting ability is low. This means that printing is performed at a low speed, and it cannot be said that it is sufficiently compatible with recent printing apparatuses having an improved printing speed.

When the paper feed speed is increased, the rotation speed of the motor 45 is increased accordingly, and the cutting speed is increased,
Overrun due to inertia of the rotary blade 39 cannot be avoided. FIG. 16B shows the brake wheel 49 in a state where the rotary blade 39 slightly overruns the standby position and overruns.
16 shows the positional relationship between the brake arm 50 and FIG.
16A shows a state of the rotary blade 39 corresponding to FIG. FIG. 17 is a partially enlarged perspective view of the sheet cutting device 32 in the state of FIG. When the rotary blade 39 overruns in this manner, the rotary blade 39 is pushed back in the opposite direction by the action of the coil spring 51 that repels the brake arm 50, and the overrun causes a return until returning to the standby position. Need time. However, before the rotary blade 39 returns to the standby position (for example, the rotary blade 3
The following trigger signal is input to the rotary blade 39
It also happens that the rotation starts. In such a case, as shown in FIG. 16 (a), the rotary blade 39 overruns, and the blade edge 39 a of the rotary blade 39 and the blade edge 40 a of the fixed blade 40.
The next rotation starts when and are at the angle θ2. The angle θ2 between the blade edge 39a of the rotary blade 39 and the blade edge 40a of the fixed blade 40 shown in FIG.
Θ1 at the standby position of the rotary blade 39 shown in (a)
And θ2 <θ1.

When the next rotation starts from the position of the rotary blade 39 before returning to the standby position as shown in FIG. 16 (a), it is the same as if the trigger signal was input earlier, and the cut sheet length is It is shorter than the set length. When such a rotary blade 39 overruns, the rotary blade 3 at the next startup
Angle θ2 between blade edge 39a of blade 9 and blade edge 40a of fixed blade 40
Is not always constant and varies, so that the rotary blade is activated from an unspecified position, resulting in uneven sheet lengths. As a result, the sheets that have been stacked look bad and the quality is poor. If there are such irregular sheets, it is necessary to cut them with a cutting machine, which is troublesome and costly.

In order to prevent overrun of the rotary blade, for example, it is possible to increase the elastic force of the coil spring to increase the braking force by the brake arm, but it is necessary to increase the starting torque from the standby position. However, using a large capacity motor is not a good solution.

[0017]

The present invention was created as a result of earnest research in view of the above-mentioned actual circumstances,
An object of the present invention is to provide a sheet cutting apparatus that can stop a rotary blade at a standby position with high accuracy even at a high sheet feeding speed, enable high-speed cutting of a sheet, and obtain a sheet with a uniform cut length.

[0018]

In order to solve the above problems, according to the present invention, a rotary blade is rotatably supported between side plates, and a fixed blade is disposed so as to face the rotary blade. ,
A brake wheel in which the rotary blade is connected to a rotary drive source for rotating the rotary blade in one direction via a clutch, and has a substantially D-shaped cross section and an arcuate curved surface and a flat surface on an outer peripheral surface,
A brake arm provided so as to rotate integrally with the rotary blade and pivotally supported by the side plate is pressed against an outer peripheral surface of the brake wheel by a biasing force of a spring, and a flat surface of the brake wheel and the brake arm are provided. In the sheet cutting device that cuts a sheet with the fixed blade while the rotary blade makes one rotation from the standby position where the rotary blade abuts to the standby position, the rotary blade is locked at the standby position to start the rotary blade. In this case, the rotary blade is provided with an over-rotation preventing means for releasing the lock. According to this, in synchronization with the activation timing of the rotary blade, the over-rotation preventing means unlocks the rotary blade at the standby position, the clutch is engaged, the driving force from the drive source is transmitted, and the rotary blade is activated. Then, the rotation is continued, the paper is cut with the fixed blade, and while being decelerated by the braking force generated by the pressure contact of the brake arm with the brake wheel, it is rotated by one revolution to reach the standby position by the over-rotation prevention means. , It will be locked at the standby position. Therefore, activation of the rotary blade can always be started from the standby position, and the rotary blade can be reliably locked in the standby position without causing overrun due to inertia after one rotation of the rotary blade, which enables high-speed paper feed. Even when cutting paper at a high speed, it is possible to obtain high-quality sheets with a uniform cutting length,
A significantly large number of cut sheets can be obtained, and for example, sheets can be cut at high speed in response to high-speed printing. Therefore, there is also an advantage that it is not necessary to align the cut sheets with a cutting machine. Further, in the conventional sheet cutting apparatus, in order to stop at the standby position without overrun after one rotation from the start of the rotary blade, the inertia of the rotary blade, the driving force transmitted to the rotary blade, the drive source It is necessary to properly select various conditions such as the number of revolutions and the braking force by the brake arm, and there are fluctuations in the braking force due to mechanical loss such as wear of the cutting edge and changes in the sliding resistance of the sliding part. , Subtle and not easy,
In this sheet cutting apparatus, since the over-rotation preventing means prevents the rotary blade from overrunning and can be reliably stopped at the standby position, the inertia of the rotary blade, the driving force transmitted to the rotary blade, and the drive source. There are advantages that various conditions such as the number of revolutions of the motor and the braking force by the brake arm are loosely set, adjustment is not necessary, and that no skill is required for manufacturing.

Further, the over-rotation preventing means is pivotally supported by the solenoid attached to the side plate and the side plate so as to be rotatable, and a locking portion is provided at a tip end thereof so that the over-rotation preventing means can be swung by the solenoid. It is preferable that the swinging member includes a stopper blade that is formed with an engaging claw portion that engages with a locking portion of the swinging member and that rotates together with the rotary blade. According to this, by engaging the locking portion of the swinging member with the engaging claw portion of the stopper blade, the rotary blade is securely positioned at the standby position without causing overrun due to inertia after one rotation of the rotary blade. Can be locked, and the activation of the rotary blade can always start from the standby position. In addition, the solenoid, which is a component of the over-rotation preventing means,
Since a commercially available product can be adopted and the structure is simple, there is an advantage that the manufacturing cost is low.

A brake wheel that rotates integrally with the rotary blade may be arranged outside the side plate, and the stopper blade may be attached to the outer end surface of the brake wheel. According to this, the attachment of the over-rotation preventing means of the rotary blade can be performed by effectively utilizing the empty space in the vicinity of the brake wheel or the like on one side plate side, and moreover, it can be made compact. For example, there is an advantage that the printing apparatus can be easily installed without major modification.

The stopper blade has an arcuate cam surface except for the engaging claw portion, and the engaging portion of the swing member is
If the engagement roller engages with the engagement claw portion of the stopper blade, and if the engagement roller comes in contact with the stopper blade at an angle outside the standby position, the engagement roller is Since the rotary blade is rotated while contacting, the deceleration of the rotary blade can be mainly caused by the braking force of the brake arm, and the deceleration of the rotary blade can be easily adjusted.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. Of course, the present invention is not limited to the following embodiments. FIG. 1 is a partially exploded enlarged perspective view showing an embodiment of the sheet cutting apparatus of the present invention, showing a state in which a rotary blade over-rotation preventing means is mounted. Since this sheet cutting apparatus 1 is provided with the rotary blade over-rotation preventing means 2 in the conventional apparatus shown in FIG. 10, the illustration of the entire sheet cutting apparatus is omitted and the same configuration is adopted. Are denoted by the same reference numerals and detailed description thereof will be omitted.

The rotary blade over-rotation preventing means 2 is roughly rotatably supported by a solenoid 3 attached to a side plate 43 and the side plate 43 at an intermediate portion thereof, and is provided with a locking portion at its tip portion. ,
A swing arm 5 connected to the plunger 3a of the solenoid 3 at the base end, and an engaging claw portion 6a that engages with the locking portion.
And a stopper blade 6 formed with. Less than,
A more specific description will be given with reference to FIG.

The stopper blade 6 is fixed to the outer end surface of the brake wheel 49 with a screw 8 through a long hole 7 formed in the stopper blade 6, and is rotated together with the rotary blade 39. By adjusting the screw fixing position with the brake wheel 49 using the elongated hole 7, the engaging claw portion 6a of the stopper blade 6 and the rotary blade 3 are adjusted.
9 and the brake wheel 49 angular position, and
The position of the roller 9 provided on the swing arm 5 for stopping the rotation of the rotary blade 39 by engaging with the engaging claw portion 6a can be finely adjusted. The stopper blade 6 is
Except for the engaging claw portion 6a, an arc-shaped cam surface 6b having a predetermined radius is formed.

The swing arm 5 includes a pair of arm plates 11 and 1.
1 is arranged with a predetermined interval via the spacers 12, 12. A roller 9 is rotatably supported by a support shaft 13 between the end portions of the arm plates 11 and 11.
Bearing members 14, 14 are attached to the respective arm plates 11, 11 so as to face each other at the intermediate portion. A pivot 16 erected on a mounting plate 15 is passed through the bearing members 14, 14, and the swing arm 5 is supported rotatably about the pivot 16.
A screw 17 (not shown) formed in each of the arm plates 11 and 11 is passed through a through hole of the spacer 12, and the arm plates 11 and 11 are fixed and integrated with a nut (not shown). Annular groove 16a provided at the tip of the pivot 16
An E-shaped retaining ring 18 is attached to the shaft, and a grip ring 19 is attached to an annular groove 13a provided at the tip of the support shaft 13. The mounting plate 15 is fixed to the side plate 43 with screws.

The solenoid 3 is attached to the L-shaped bracket 21 fixed to the side plate 43 with screws.
The engagement pin 22 provided at the tip of the plunger 3a
Notch 11a cut from the upper side of the inner arm plate 11
When the solenoid 3 is energized and de-energized, the swing arm 5 is rotated between the engagement position and the retracted position as the plunger 3a moves.
That is, the plunger 3a is biased forward (parallel to the side plate) in the figure by the elastic force of the coil spring 23, and is retracted backwards against the elastic force of the coil spring 23 by energizing the solenoid 3. It is like this. When the solenoid is energized, the swing arm 5 is rotated to the retracted position, the engagement between the roller 9 and the engaging claw portion 6a is released, and when the energization is stopped, the swing force of the coil spring 23 causes the swing arm 5 to move. Is returned to the engagement position so that the roller 9 and the engagement claw portion 6a are engaged with each other.

The brake arm 50 is swingable around the support shaft 24 provided on the side plate 43, and the coil spring 51 is a receiving portion of the L-shaped receiving metal fitting 25 fixed to the side plate 43 with a screw. It is interposed between 25a and the brake arm 50, which is similar to the conventional one.

In the printing device 31 equipped with the sheet cutting device 1 having the above-described structure, the printed paper is cut as follows. That is, the paper pulled out from the unwind roll is double-sided printed and continuously introduced into the sheet cutting device 1 at a predetermined speed without stopping. At the standby position of the rotary blade 39, the clutch 44 and the motor 45 are not connected, and as shown in FIG. 2A, the blade edge 39a of the rotary blade 39 and the blade edge 40a of the fixed blade 40.
Means that the angle θ1 is maintained around the axis of the rotary blade 39. Then, as shown in FIG. 2B, the brake arm 50 is in contact with the flat surface of the brake wheel 49 by the elastic force of the coil spring 51. Further, as shown by the solid line in FIG.
Is not energized to the roller 9 of the swing arm 5.
Is in a state of being engaged with the engaging claw portion 6a of the stopper blade 6.

To activate the rotary blade 39, the solenoid 3 is energized at a timing slightly earlier than the trigger signal being input to the solenoid 46, and the coil spring 2 is activated.
The plunger 3a is moved against the elastic force of 3 to rotate the swing arm 5 counterclockwise to the retracted position, and the engagement between the roller 9 and the engaging claw portion 6a of the stopper blade 6 is released. (See the chain double-dashed line in FIG. 2C).

Next, when a pulse-shaped trigger signal is input once to the solenoid 46, the clutch 44 is engaged, the driving force from the motor 45 is transmitted to the rotary blade 39, and the rotary blade 39 is activated to move in the direction of the arrow. When rotated, the peripheral speed of the rotary blade 39 reaches the same speed as the paper feed speed at the angle of the rotary blade 39 as shown in FIG. 3A, and the paper P is cut.
With the rotation of the rotary blade 39, the brake arm 50 comes into pressure contact with the arc-shaped curved surface of the brake wheel 49 as shown in FIG. 3B, and the braking force directed in the direction opposite to the rotational direction of the rotary blade 39 is applied. The work is similar to the conventional one. Even at this stage, the swing arm 5 moves as shown in FIG.
It is in the retracted position as shown in. Even after the solenoid 46 is de-energized, the clutch 44 is disengaged, and the driving force from the motor 45 is not transmitted to the rotary blade 39, the rotary blade 39 is inertially shaped into an arc shape of the brake arm 50 and the brake wheel 49. Continuing to rotate while being decelerated by the braking force generated by the pressure contact with the curved surface is similar to the conventional one. 4 shows a state in which the rotary blade 39 is further rotated from the angle shown in FIG. 3, (a) shows the rotating state of the rotary blade 39, and (b) shows the rotary blade 39 shown in (a). The positional relationship between the brake wheel 49 and the brake arm 50 corresponding to the position is shown, (c) shows the state of the swing arm 5 corresponding to the position of the rotary blade 39 shown in (a), and is in the retracted position. FIG. 5 is a partially enlarged perspective view of the sheet cutting apparatus 1 showing a state corresponding to FIG.

When the energization of the solenoid 3 is stopped at the timing when the rotary blade 39 further rotates, the swinging arm 5 returns to the engaging position by the elastic force of the coil spring 23, and the roller 9 stops. It comes into contact with the cam surface 6b of the blade 6 and becomes ready to engage with the engaging claw portion 6a of the stopper blade 6. Since the cam surface 6b of the stopper blade 6 has an arc shape, the roller 9 rolls on the cam surface as shown in FIG. 6 (c). FIG. 6A shows a state in which the rotary blade 39 continues to rotate, and FIG. 6B shows a state in which the corresponding brake arm 50 and brake wheel 49 are pressed against the arcuate curved surface.

Then, the rotary blade 39 further rotates, and as shown in FIG.
From the state where the brake arm 50 and the brake wheel 49 are pressed against the arcuate curved surface as shown in (b), as shown in FIG.
2C, the engaging claw portion 6a of the stopper blade 6 comes into engagement with the roller 9 of the swing arm 5 as shown in FIG. Even if tries to rotate due to inertia, further over rotation (that is, overrun) is prevented, and in the standby position,
The rotary blade 39 will stop (see FIG. 2A).

After the rotary blade 39 is stopped at the standby position, the rotary blade 39 is activated from the standby position by energizing the solenoid 3 and inputting a trigger signal to the solenoid 46 at the same timing as described above. The cutting operation is performed in the same manner as described above, and the sheet P is cut into the sheet S.

Each component of the sheet cutting device 1 including the solenoid 46 and the solenoid 3 is designed to be controlled by an appropriate control device (not shown). In Figure 7,
FIG. 7 (I) shows the relationship between ON / OFF of the trigger signal to the solenoid 46 of the sheet cutting apparatus 1, ON / OFF of the operation signal to the solenoid 3, and rotation and stop of the rotary blade 39.
Is ON / OFF of the trigger signal input to the solenoid 46, (II) of FIG. 7 is ON / OFF of the operation signal of the solenoid 3, and (III) of FIG. 7 is the rotation and stop of the rotary blade 39 with time. Shows. The paper is cut at the timing indicated by the triangle in the time chart of the rotary blade in (III) of FIG. One cycle of the front and rear trigger signals represents the cutting cycle of the paper, and the cutting length of the paper is determined by the paper feeding speed and the cutting cycle.

As is clear from the above, according to this sheet cutting device, the roller of the swing arm is engaged with the engaging claw portion of the stopper blade, so that the overrun due to the inertia of the rotary blade after one rotation is performed. Therefore, the rotary blade can be reliably locked in the standby position without causing any trouble, and the activation of the rotary blade can always be started from the standby position. Therefore, even if the sheet is cut at a high sheet feeding speed, a high-quality sheet having a uniform cutting length can be obtained, and a significantly large number of sheets can be obtained per unit time. Therefore, the sheet can be cut at high speed in correspondence with high-speed printing. In fact, FIG.
In the conventional sheet cutting apparatus shown in FIG. 1, the sheet feeding speed has been stopped at 15 m / min so far, but in the sheet cutting apparatus according to the embodiment of the present invention shown in FIG. 1, the sheet feeding speed is 54.2 m / min. However, it was confirmed that a high cutting accuracy of ± 1 mm or less was obtained, and high-speed cutting of about 3.6 times or more of the conventional cutting was possible. In addition, there is a great advantage that it is not necessary to align the cut sheets with a cutting machine.

Further, in the conventional sheet cutting apparatus,
In order to stop the rotating blade at the standby position without overrun after starting after rotating once, the inertia of the rotating blade, the driving force transmitted to the rotating blade, the rotation speed of the motor, the braking force by the brake arm, etc. It is necessary to properly select the various conditions described above, and there are fluctuations in the braking force, etc. due to mechanical loss such as wear of the cutting edge and changes in the sliding resistance of the sliding parts. However, in this sheet cutting device, the over-rotation preventing means prevents the rotary blade from overrunning and can be reliably stopped at the standby position. Therefore, the inertia of the rotary blade and the driving force transmitted to the rotary blade are prevented. Also, there are advantages that various conditions such as the number of rotations of the motor and the braking force by the brake arm are loosely set, no adjustment is required, and that no skill is required for manufacturing.

In this sheet cutting device,
By attaching the stopper blade to the outer end surface of the brake wheel, you can install the over-rotation prevention means,
It is possible to effectively utilize the empty space near the brake wheel on one side plate side, and since it can be made compact, for example, it can be easily installed without major modification of the printing device. There is an advantage that can be. Further, as a solenoid or the like which is a component of the over-rotation preventing means, a commercially available one can be adopted, and since the structure is simple, there is an advantage that the manufacturing cost is low.

In the above-described sheet cutting apparatus as one embodiment of the present invention, various structures can be changed within the scope of the present invention. For example, in the above embodiment, the stopper blade is fixed to the brake wheel, but the invention is not limited to this, and the stopper blade may be attached to the rotary shaft of the rotary blade.

Further, in the above-mentioned embodiment, the excessive rotation preventing means for the rotary blade is provided on the brake wheel side, but it may be provided on the drive source side.

Further, in the above-mentioned embodiment, the solenoid for rotating the swing arm is fixed to the side plate. However, a solenoid supporting member separate from the side plate is attached to the base,
A solenoid may be fixed to the support member.

Further, in the above-mentioned embodiment, as the solenoid for rotating the swinging arm, the one in which the plunger is retracted by the energization and the plunger is projected by the stop of the energization is adopted, but the invention is not limited to this. A type in which the plunger retracts when the power is stopped and the plunger projects when the power is supplied may be used.

Further, in the above-mentioned embodiment, the swing arm is pivotally supported by the intermediate portion thereof to be swingable, but the present invention is not limited to this, and the swing arm is pivotally supported by the base end portion thereof, and the intermediate portion is supported. May be connected to a solenoid so that it can swing.

Further, in the above-mentioned embodiment, the swinging arm for preventing the excessive rotation of the rotary blade by engaging with the engaging claw portion of the stopper blade is adopted, but the plunger of the solenoid is directly connected to the stopper blade. The engaging claw portion may be engaged.

In the above embodiment, the elastic force of the coil spring is used to apply the urging force to the brake arm, but the present invention is not limited to this, and the tensile force of the coil spring may be used. Further, a torsion spring may be used instead of the coil spring.

[0045]

Since the sheet cutting apparatus of the present invention is configured as described above in detail, it is possible to stop the rotary blade at the standby position with high precision and cut the sheet at high speed even at a high sheet feeding speed. Then, it is possible to obtain a sheet with a uniform cut length. More specifically, according to the sheet cutting apparatus of the present invention, activation of the rotary blade can always be started from the standby position, and the rotary blade can be moved to the standby position without causing overrun due to inertia of the rotary blade after one rotation. The rotary blade can be reliably locked, and even when cutting paper at high paper feed speeds, high-quality sheets with a uniform cutting length can be obtained, and a significantly large number of sheets can be cut per unit time. You can get a sheet of
The sheet can be cut at high speed in response to high-speed printing. In addition, there is a great advantage that it is not necessary to align the cut sheets with a cutting machine. Other effects of the present invention will be apparent from the description of the specification and the drawings.

[Brief description of drawings]

FIG. 1 is a partially exploded enlarged perspective view showing an embodiment of a sheet cutting device of the present invention.

FIG. 2 is an explanatory diagram showing states of a rotary blade, a brake wheel, and a stopper blade at a standby position of the sheet cutting apparatus of FIG.

FIG. 3 is an explanatory diagram showing states of a rotary blade, a brake wheel, and a stopper blade at the time of cutting by the sheet cutting device shown in FIG.

FIG. 4 is an explanatory diagram showing states of a rotary blade, a brake wheel, and a stopper blade during rotation of the sheet cutting apparatus shown in FIG.

5 is a partially enlarged perspective view of the sheet cutting device in a state corresponding to FIG.

6 is an explanatory view showing a state of a rotary blade, a brake wheel, and a stopper blade during a further advanced rotation of the sheet cutting apparatus shown in FIG.

FIG. 7 is a time chart showing the operation timing of the sheet cutting apparatus shown in FIG.

FIG. 8 is a schematic diagram illustrating an example of a printing apparatus including a sheet cutting device.

FIG. 9 is a schematic diagram illustrating another example of a printing apparatus including a sheet cutting device.

FIG. 10 is a perspective view showing a conventional sheet cutting device.

11 is an explanatory diagram showing a state of a rotary blade and a brake wheel at a standby position of the sheet cutting device shown in FIG.

12 is an explanatory view showing a state of a rotary blade and a brake wheel at the time of cutting by the sheet cutting device shown in FIG.

13 is an explanatory diagram showing a state of a rotary blade and a brake wheel during rotation of the sheet cutting device shown in FIG.

14 is an explanatory diagram showing a state of a rotary blade and a brake wheel at a standby position after the cutting operation of the sheet cutting device shown in FIG.

15 is a time chart showing the operation timing of the sheet cutting apparatus shown in FIG.

16 is a view showing a cutting operation of the sheet cutting apparatus shown in FIG.
It is explanatory drawing which shows the state of a rotary blade and a brake wheel at the time of overrun exceeding a standby position.

17 is a partially enlarged perspective view of the sheet cutting device in a state corresponding to FIG.

[Explanation of symbols]

1 sheet cutting device 2 Over-rotation prevention means 3 solenoid 5 Swing arm 6 Stopper blade 6a Engaging claw 9 Laura 16 Axis 23 Coil spring 39 rotary blade 40 fixed blade 43 Side plate 49 brake wheel 50 brake arm

Claims (4)

[Claims] 1. A rotary blade is rotatably supported between side plates, and a fixed blade is disposed facing the rotary blade, and the rotary blade is unidirectionally moved through a clutch. A brake wheel, which is connected to a rotary drive source for rotating the rotary blade and has a substantially D-shaped cross section and an arcuate curved surface and a flat surface on the outer peripheral surface, is provided so as to rotate integrally with the rotary blade and is pivotally supported by the side plate. The brake arm is pressed against the outer peripheral surface of the brake wheel by the urging force of the spring, and the rotary blade makes one rotation to reach the standby position from the standby position where the flat surface of the brake wheel and the brake arm are in contact. In the meantime, in the sheet cutting device that cuts the paper with the fixed blade, the rotary blade is equipped with a rotary blade over-rotation preventing unit that locks the rotary blade at a standby position and releases the lock when the rotary blade is activated. That sheet cutting device. 2. The over-rotation preventing means is rotatably supported by a solenoid attached to the side plate and rotatably attached to the side plate.
A locking portion is provided at the tip end portion, a swinging member that is swingable by the solenoid, and an engaging claw portion that engages with the locking portion of the swinging member are formed, and rotate together with the rotary blade. The sheet cutting device according to claim 1, comprising a stopper blade. 3. A brake wheel that rotates integrally with the rotary blade is arranged outside the side plate, and the stopper blade is attached to an outer end surface of the brake wheel. The sheet cutting device described. 4. The engagement in which the stopper blade has an arcuate cam surface excluding the engaging claw portion, and the locking portion of the swinging member engages with the engaging claw portion of the stopper blade. The sheet cutting device according to claim 2 or 3, which is a roller.