JP2003001793A - Sheet feeding device in printing press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeding device, permitting the regulation of a feeding amount due to the change of thickness of a sheet during the operation of a printing press. SOLUTION: A lever 11, swung by the rotation of a cam 14 and swinging a roller frame 3 for supporting a push roller 2 in conjunction with the swinging of the same, is supported by an eccentric shaft unit 13 at one end of a regulating shaft 12 supported rotably. A worm wheel 24 is attached to the other end of the regulating shaft 12 and a worm 23 is meshed with the worm wheel 24 while the worm 23 is connected to a motor 22. The regulating shaft 12 is turned by the driving of the motor 22 and the lever 11 is swung by the turning of the shaft 12 to swing the roller frame 3 operated in conjunction with the swinging of the lever 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device in a printing machine in which a sheet whose front end in the transport direction is registered by a front pad is fed toward between an impression cylinder and a blanket cylinder.

[0002]

2. Description of the Related Art An ink image of a printing plate wound around the outer periphery of a plate cylinder is transferred to a blanket cylinder, and the ink image on the blanket cylinder is printed on a sheet fed between the blanket cylinder and the impression cylinder. In such an offset printing machine, the stacked sheets set in the paper feed section are conveyed forward one by one, and each sheet is brought into contact with the front pad to register the leading edge, and then the gripper provided on the impression cylinder. The sheet is fed between the blanket cylinder and the impression cylinder at the timing and the rotation position of the gripper of the device.

As a sheet feeding device in which the leading end is registered, the lever is rocked by the rotation of a cam that rotates integrally with the blanket cylinder, and the roller frame that supports the pressing roller is rocked in conjunction with the rocking of the lever. It has been conventionally known that it is moved.

In the feeding device utilizing the rotation of the cam as described above, the pressing roller is held in the lowered position by the cam projection formed on the cam, and the sheet is held in the pressed state against the pressing roller in the lowered position. ing.
Therefore, the sheet is fed forward while the pressing roller is held in the lowered position. The sheet feeding amount is determined by the circumferential length of the cam projection.

Here, the moving amount (lowering amount) of the pressing roller from the standby position with respect to the feed roller is determined by the height of the cam projection, and if the standby position is always constant,
When sheets having different thicknesses are loaded in the sheet feeding unit due to lot change, the force with which the pressing roller presses the sheet changes, and the feeding amount of the sheet changes.

Therefore, in the sheet feeding device, the standby position of the pressing roller can be adjusted according to the thickness of the sheet.

[0007]

By the way, in the conventionally known sheet feeding device, an adjusting knob is incorporated in the feeding device, and the standby position of the presser roller is adjusted by rotating the adjusting knob. Therefore, when adjusting the standby position, it is necessary to stop the printing machine each time, and there is a disadvantage that the operating rate of the printing machine is reduced.

An object of the present invention is to provide a sheet feeding device capable of adjusting the standby position of the pressing roller during the operation of the printing machine.

[0009]

In order to solve the above problems, according to the present invention, one end of an L-shaped lever is brought into contact with the outer periphery of a cam that rotates integrally with a blanket cylinder, and the rotation of the cam causes the rotation of the cam. The lever is swung, the roller frame is swung in conjunction with the swing of the lever, and the pressing roller supported by the roller frame is moved with respect to the feed roller provided below the feed roller. In a sheet feeding device in a printing machine in which a sheet is pressed by a pressing roller to be fed between a blanket cylinder and an impression cylinder, an eccentric shaft portion supporting the lever on an adjustment shaft rotatably supported by a frame of the printing machine. And a drive device for rotating the adjustment shaft is provided.

Here, as the drive device, a device in which a worm wheel is attached to the adjustment shaft and a worm meshing with the worm wheel is rotated by a motor can be adopted.

According to the above construction, when the driving device is driven to rotate the adjusting shaft, the lever swings and the roller frame also swings in conjunction with the swing, so that the standby position of the presser roller is changed. Can be adjusted.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 2, a pressing roller 2 is provided above the feed roller 1. The pressing roller 2 is rotatably supported by a roller frame 3.

As shown in FIGS. 2 and 4, the roller frame 3 is swingably supported around a support shaft 5 rotatably supported by the side frame 4 of the printing machine,
By the swing of the roller frame 3, the pressing roller 2 is moved up and down with respect to the feed roller 1. The presser roller 2 presses a sheet (not shown) that is fed underneath it when it descends, and presses it against the outer periphery of the feed roller 1, and the feed roller 1 that is rotated in one direction causes the sheet to pass between an impression cylinder (not shown) and a blanket cylinder. It is designed to be sent.

The sheet is fed while the pressing roller 2 is descending, and the feed amount is determined by the descending time of the pressing roller 2 and the rotation speed of the feeding roller 1.

An adjusting lever 6 is attached to a support shaft 5 which supports the roller frame 3. A bending piece 6a facing the back surface of the roller frame 3 is provided at an upper part of one side of the adjusting lever 6.
Is formed, and the screw shaft 8 is inserted into the insertion hole 7 formed in the bent piece 6a.

One end of the screw shaft 8 is fixed to the roller frame 3 so as not to rotate and is supported immovably in the axial direction, and the other end of the screw shaft 8 which penetrates the insertion hole 7 and faces the outside. The adjusting knob 9 is screw-engaged with. Also, the screw shaft 8
The spring 10 even supports the spring 10, and the spring 10 presses the roller frame 3 and the adjusting lever 6 in opposite directions so that the bent piece 6 a of the adjusting lever 6 moves away from the rear surface of the roller frame 3.

Therefore, when the adjusting lever 6 swings, the roller frame 3 also swings in the same direction as the adjusting lever 6. When the adjusting knob 9 is rotated with the adjusting lever 6 fixed, the adjusting knob 9 rotates in a state of contacting the bent piece 6a, the screw shaft 8 moves in the axial direction, and the roller frame 3 moves the adjusting lever. It is designed to swing with respect to 6.

Above the adjusting lever 6 is an L-shaped lever 11
Is provided. The middle of the lever 11 is rotatably supported around an eccentric shaft portion 13 provided at one end of the adjusting shaft 12.

As shown in FIG. 3, the adjusting shaft 12 is rotatably supported by the side frame 4. As shown in FIG. 2, one end of the lever 11 is provided with a cam 14 which rotates integrally with the blanket cylinder. A cam follower 15 that can contact the outer periphery is rotatably supported. For the spring 16 connected to the lever 11, the cam follower 15 is the cam 1
The lever 11 is urged in the direction of coming into contact with the outer circumference of 4.

One end of a link 17 is connected to the other end of the lever 11, and the other end of the link 17 is connected to the other end of the adjusting lever 6.

Therefore, the cam 1 having the cam projection 14a
When 4 rotates, the lever 11 swings and the lever 11
The adjusting lever 6 swings in conjunction with the swinging of the roller, the roller frame 3 also swings in the same direction as the adjusting lever 6, and the pressing roller 2 moves up and down with respect to the feed roller 1.

As shown in FIGS. 1 and 3, the adjustment shaft 12
Is rotated by the rotary drive device 20. In the rotary drive device 20, a worm 23 is attached to a rotary shaft 22a of a motor 22 supported by a blanket 21, and a worm wheel 24 meshing with the worm 23 is fixed to the other end of the adjustment shaft 12.

In FIG. 2, reference numeral 25 denotes a front pad for registering the leading edge of the sheet. The front pad 25 is attached to a shaft 26 provided on the upstream side of the feed roller 1, and the shaft 2
The rotation of 6 causes the leading end to swing vertically, and when swinging upward, the leading end projects onto the sheet conveying line to receive the leading edge of the sheet, and when feeding the sheet, swings downward to move the sheet. The tip of the conveyor line is set to sink downward.

The feeding device shown in the embodiment has the above-mentioned structure, and when the cam follower 15 is in contact with the base circle 14b of the cam 14, the pressing roller 2 is held at the standby position where it is separated from the feeding roller 1, and the cam 14 When the cam follower 15 starts to come into contact with the cam protrusion 14a by rotating, the pressing roller 2 descends.

A cam follower 15 is provided on the outer circumference of the cam protrusion 14a.
The pressing roller 2 is held in the lowered position while the two are in contact with each other. The pressing roller 2 presses the sheet fed between the pressing roller 2 and the feeding roller 1 to the feeding roller 1 in the lowered position
The sheet is conveyed forward by the feed roller 1.

Here, the vertical movement amount of the pressing roller 2 due to the rotation of the cam 14 is always constant, and when the standby position of the pressing roller 2 is constant, the pressing roller 2 is fed by the pressing roller 2 when the sheet thickness changes. The force of pressing the sheet to 1 changes, and the feeding amount of the sheet changes.

When the feeding amount of the sheet changes, the sheet cannot be accurately clamped by the holding claws of the holding device provided on the impression cylinder, and the printing shift occurs at the time of printing.

Therefore, it is necessary to adjust the standby position of the pressing roller 2 according to the thickness of the sheet. When adjusting the standby position of the pressing roller 2, the motor 22 is driven. When the worm 23 is rotated by driving the motor 22, the rotation is transmitted from the worm wheel 24 to the adjusting shaft 12.

When the adjusting shaft 12 is rotated in the direction of the arrow in FIG. 2, the cam follower 15 moves upward while maintaining the state of being in contact with the outer periphery of the cam 14, and at the same time, the lever 11 moves between the adjusting shaft 12 and the adjusting shaft 12. Swing in the same direction. The link 17 is pushed down in conjunction with the swing, the adjustment lever 6 rotates leftward about the support shaft 5, and the rotation causes the spring 10 to contract. Therefore, the standby position of the pressing roller 2 where the cam follower 15 contacts the base circle 14b of the cam 14 is set to a position lower than the standby position before adjustment.

On the other hand, when the adjusting shaft 12 is rotated in the direction opposite to the arrow in FIG. 2, the lever 11 rotates leftward in the figure around the contact position between the cam 14 and the cam follower 15, and the rotation is interlocked with the rotation. And the adjusting lever 6 swings rightward around the support shaft 5. The roller frame 3 also swings in the same direction as the adjusting lever 6 in association with the swinging of the adjusting lever 6, and the pressing roller 2 is displaced upward.

Therefore, the standby position of the pressing roller 2 where the cam follower 15 contacts the base circle 14b of the cam 14 is set to a position higher than the standby position before adjustment.

[0032]

As described above, according to the present invention, the standby position of the pressing roller can be adjusted by rotating the adjusting shaft, and at the same time the printer can be operated.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a sheet feeding device in a printing machine according to the present invention.

FIG. 2 is a vertical sectional front view of the sheet feeding device shown in FIG.

FIG. 3 is a partially cutaway plan view showing a support portion of the adjustment shaft shown in FIG.

FIG. 4 is a partially cutaway plan view showing a support portion of the roller frame shown in FIG.

5 is a perspective view showing a lever, a link, an adjusting lever and a roller frame shown in FIG.

[Explanation of symbols]

1 Feed roller 2 Presser roller 3 roller frame 11 lever 12 adjustment axis 13 Eccentric shaft 14 cams 20 rotary drive 22 motor 23 Warm 24 worm wheel

Claims (2)

[Claims] 1. An L-shaped lever is brought into contact with the outer periphery of a cam that rotates integrally with a blanket cylinder, the lever is swung by the rotation of the cam, and the roller frame is interlocked with the swing of the lever. While swinging, the pressing roller supported by the roller frame is moved with respect to the feed roller provided below the pressing roller so that the sheet is pressed against the pressing roller by the feeding roller and fed between the blanket cylinder and the impression cylinder. In the sheet feeding device of the printing machine described above, an eccentric shaft portion that supports the lever is provided on an adjustment shaft that is rotatably supported by a frame of the printing machine, and a drive device that rotates the adjustment shaft is provided. Sheet feeding device in a printing machine. 2. The sheet feeding device in a printing machine according to claim 1, wherein the driving device is provided with a worm wheel attached to the adjusting shaft, and the worm meshing with the worm wheel is rotated by a motor.