JP2001121676A - Double-side printable sheet-fed printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a registering accuracy by accurately positioning a reversing gripper for gripping a sheet. SOLUTION: When a reversing gripper 7 for gripping a sheet in the case of double-sided printing finishes turning to a rear side of a rotating direction of a reversing cylinder 3, a positioning member 22 for supporting the pawl 9 from the central side of the cylinder 3 a pawl 9 of pawls 8, 9 contacted with the pawl 9 disposed at the central side of the cylinder 3 is provided as a solving means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-fed printing press capable of switching between single-sided printing and double-sided printing and capable of printing on both sides, and more particularly, from a printing unit on the upstream side to a printing unit on the downstream side. The present invention relates to a reversing gripper provided on a reversing cylinder constituting a paper delivery unit for delivering sheets.

[0002]

2. Description of the Related Art Conventionally, as this type of sheet-fed printing press, for example, one disclosed in Japanese Patent Publication No. 56-2017 has been known. An outline of the configuration will be described below with reference to FIGS.

As shown in FIG. 4, the sheet-fed printing press receives the sheet 1 from an impression cylinder (not shown) of an upstream printing unit to an impression cylinder 4 of a downstream printing unit. A paper delivery unit is provided between the two printing units. The paper transfer unit includes a transfer cylinder (not shown), a storage cylinder 2 and a reversing cylinder 3 in order from the upstream side, and the sheet 1 printed by the upstream impression cylinder is stored via the transfer cylinder. Delivered to 2.

Since the storage cylinder 2 has a diameter twice as large as the transfer cylinder and the reversing cylinder 3, that is, a double-diameter cylinder, the gripper 5 grips the front edge of the sheet 1 and the sheet 1. A total of two paper suction devices 6 are provided at positions opposed to each other by approximately 180 degrees.

[0005] The reversing cylinder 3 is provided with a reversing gripper 7 for gripping the leading edge or trailing edge of the sheet 1, and the function thereof differs between single-sided printing and double-sided printing.

That is, in the case of single-sided printing, the reversing gripper 7 is moved from the gripper 5 of the storage cylinder 2 to the front of the sheet 1 at a pair contact point A (reception position of the sheet 1) of the storage cylinder 2 and the reversing cylinder 3. The gripper 7 grips and receives the edge, and the reversing gripper 7 rotates together with the reversing cylinder 3 while maintaining the state, and contacts the contact point B with the impression cylinder 4.
(The delivery position of the sheet 1) to the impression cylinder 4.

On the other hand, in the case of double-sided printing, when the gripper 5 of the storage cylinder 2 passes the contact point A while holding the sheet 1, and then, when the paper suction device 6 reaches the contact point A, the sheet The trailing edge of the sheet 1 is gripped and received by the reversing gripper 7. Then, as the reversing gripper 7 rotates, the sheet 1 is turned upside down as the reversing cylinder 3 rotates, and then delivered to the impression cylinder 4. As described above, in order to make the function different between single-sided printing and double-sided printing, the reversing gripper 7 has a configuration different from that of the gripper 5 such as the storage cylinder 3.

The reversing gripper 7 can grip the sheet 1 by the cooperation of the two claws 8, 9, and can rotate the reversing cylinder 3.
Can be turned around a rotation axis along the axial direction of. In the case of double-sided printing, the reversing gripper 7 gripping the trailing edge of the sheet 1 rotates with the rotation of the reversing cylinder 3 toward the rear side in the rotation direction of the reversing cylinder 3 around the rotation axis. The sheet 1 is turned over and delivered to the impression cylinder 4. It should be noted that the reversing gripper 7 is spaced apart on the rotation axis.
Are lined up.

More specifically, one claw 8 is fixed to a claw shaft 10 that is a rotation axis, and the other claw 9 is fixed to a claw tube 11 that supports the claw shaft 10 via a bearing. Thus, the two claws 8, 9 are pivotable about a common rotation axis. The claw tube 11 through which the claw shaft 10 has penetrated
It is coaxial with the claw shaft 10 and is supported by a plurality of bearing bodies 12 fixed to the reversing cylinder 3 via bearings.

[0010] A spring is interposed between the claws 8 and 9 to generate a predetermined gripping force. By operating the following claw opening / closing control mechanism against the spring force, the claw 8 is operated. , 9 as well as the turning operations of the claws 8, 9.

As shown in FIGS. 7 and 8, gears 13 are fixed to one end of the claw shaft 10 and the other end of the claw tube 11, respectively. Each gear 13 has a tooth of a segment gear 14 as a driving member. The portions 15 are in mesh with each other, and the claw shaft 10 and the claw tube 11 are individually driven and controlled by the respective segment gears 14.

The two segment gears 14 are shown in FIGS.
As shown in FIG. A control cam 18 (plate cam) is mounted on the barrel shaft 17 of the reversing barrel 3 coaxially with the barrel shaft 17.
Is provided with a traveling roller 19 that travels on a cam surface (peripheral surface) of the control cam 18. When the traveling roller 19 travels on the cam surface, the segment gear 14 pivots about the rotation pin 16, whereby the pawl shaft 10 and the pawl tube 11 rotate via the gear 13, and the pawl 8 , 9 are controlled.

As shown in FIG. 7, two control cams 18 are provided at both ends of the reversing cylinder 3 for each segment gear 14. Two control cams 18 corresponding to each segment gear 14 have a cam surface. Are different from each other, one for single-sided printing and the other for double-sided printing. As shown in FIG. 8, the traveling roller 19 can be moved and adjusted in the axial direction. When switching between single-sided printing and double-sided printing, the traveling roller 19 is moved from one control cam 18 to the other to switch. This is the same for the other segment gear 14.

In the single-sided printing, as shown in FIG. 5, the reversing gripper 7 is connected to the storage cylinder 2 at the point of contact A with the tips of the claws 8 and 9 facing rearward in the rotation direction of the reversing cylinder 3. The leading edge of the sheet 1 is gripped, and the sheet 1 is moved to the contact point B with the impression cylinder 4 with the rotation of the reversing cylinder 3 while maintaining the state.
After that, as shown by a radiation 81, a predetermined angle is turned around the rotation axis toward the front in the rotation direction of the reversing drum 3, and a predetermined angle is turned before the contact point A toward the rear in the rotation direction. In the state 5, the next sheet 1 is gripped.

In double-sided printing, as shown in FIG.
The trailing edge of the sheet 1 is grasped at the contact point A with the storage cylinder 2 with the tip ends of the claws 8 and 9 facing forward in the rotation direction of the reversing cylinder 3, and thereafter, as shown by the radiation 82, the reversing is performed. In accordance with the rotation of the drum 3, the rotation of the rotation of the reversing drum 3 is performed about 180 degrees around the rotation axis toward the rear side. After the paper 1 has been delivered to the impression cylinder 4, as shown by radiation 83, the paper 1 is turned approximately 180 degrees forward in the rotation direction of the reversing cylinder 3 so that the front end side again faces forward at the point of contact A with the storage cylinder 2. I do.

[0016]

By the way, in such a sheet-fed printing press, high accuracy in registration is required. Therefore, in a sheet-fed printing press having the reversing cylinder 3, the downstream press cylinder 4 Delivery accuracy is important. That is, as described above,
With the reversing gripper 7 gripping the trailing edge of the sheet 1, approximately 1
Since the configuration in which the sheet is rotated by 80 degrees is employed, the gripper located at the leading end of the inverted gripper 7 (the part that grips the sheet 1) when the inverted gripper 7 that has gripped the sheet 1 has finished rotating. In the radial direction of the reversing cylinder 3 (the thickness direction of the sheet 1)
Position accuracy is important.

Therefore, it is necessary to keep the gripping portion of the reversing gripper 7 at a constant position in the turning end state and to keep that state up to the delivery position. However, in the above-described conventional sheet-fed printing press, the reversing gripper is required. 7 is held by the control cam 18 and the segment gear 14, the backlash of the segment gear 14 and the accuracy of each member such as the cam surface and the traveling roller 19 are factors. There is a problem that the position tends to vary. In addition, since the phases of the claw shaft 10 and the claw tube 11 are held by the segment gears 14 and the like, factors such as the accuracy of the members are amplified and appear at the grip portion.

Further, when the gripping force is increased to securely grip the sheet 1, the claws 8 and 9 are bent by the gripping force to change the gripping position of the gripping portion. There is a possibility that the sheet 1 is shifted in the paper feed direction (the circumferential direction of the reversing cylinder 3).

SUMMARY OF THE INVENTION Therefore, the present invention has been made in view of the above-mentioned conventional problems, and has as its object to improve the register accuracy by positioning the reversing gripper gripping a sheet with high accuracy.

[0020]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a sheet-fed printing press capable of performing double-sided printing according to the present invention comprises a printing unit on an upstream side and a printing unit on a downstream side. The reversing cylinder 3 of the paper transfer unit that transfers the sheet to the reversing cylinder 3 is configured to grip the front edge or the rear edge of the sheet by the cooperation of the two claws 8 and 9.
A reversible gripper 7 is provided which is pivotable about a rotation axis along the axial direction of the sheet cylinder. In the case of double-sided printing, the reversible gripper 7 is fed from the storage cylinder 2 located upstream of the reversing cylinder 3 from the sheet paper. The sheet is received by grasping the trailing edge of the sheet and turning the sheet around the axis of rotation with the rotation of the reversing cylinder 3 toward the rear side in the rotation direction of the reversing cylinder 3 to turn over the sheet and deliver it to the downstream printing unit. In the sheet-fed printing press capable of performing double-sided printing, when the reversing gripper 7 gripping the sheet in the case of two-sided printing finishes turning the reversing cylinder 3 backward in the rotation direction, two claws 8 and 9 are used. And a claw positioning support portion 22 for abutting against the claw 9 located on the center side of the reversing cylinder 3 to support the claw 9 from the center side of the reversing cylinder 3.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sheet-fed printing press capable of performing double-sided printing according to the present invention will be described below with reference to FIGS. 1 to 3; The description is omitted, and portions having substantially the same function are denoted by the same reference numerals.

In FIG. 1 and FIG. 2, reference numeral 20 denotes a mounting base, which is mounted in the axial groove 3a of the reversing cylinder 3 with a screw 21. The axial groove 3a is formed over the entire length of the reversing cylinder 3 in the axial direction. Further, a total of four bearing bodies 12 are mounted on the mounting base 20 at predetermined intervals along the axial direction of the reversing cylinder 3. A claw tube 11 is pivotally supported by the support body 12, and one end of the claw tube 11 has a gear 13 meshed with a tooth portion of a segment gear (not shown).
Is installed. A claw shaft 10 is inserted into the claw tube 11, and the claw shaft 10 is rotatably supported by the claw tube 11. The other end of the claw shaft 10 (the side opposite to the gear 13 of the claw tube 11).
A gear 13 meshing with the teeth of a segment gear (not shown) is also mounted. That is, like the above-mentioned conventional,
The claw shaft 10 and the claw tube 11 are individually driven and controlled by respective segment gears constituting a claw opening / closing control mechanism.

The claws 8, which constitute the reversing gripper 7,
9, one claw 9 is attached to a claw shaft 10 and the other claw 8 is attached to a claw tube 11. Contrary to the conventional art, as shown in FIG. 2, when the reversing cylinder 3 is turned to the rear in the rotation direction, the inner claw 9 is on the claw shaft 10 and the outer claw 8 is on the claw tube 11 side. Fixed. The nails 8 and 9 have the same nail width.

On the other hand, the reversing cylinder 3 rotates in the direction of the arrow P in the figure, and the mounting base 20 is provided with a claw positioning support portion at a position rearward in the rotation direction of the reversing cylinder 3 with respect to the claw shaft 10. The positioning member 22 is attached. Then, as shown in FIG. 2, in a state where the reversing gripper 7 is turned rearward in the rotation direction of the reversing cylinder 3, the positioning member 22 is rotated.
The upper surface 22a (abutting portion) of the inner claw 9 abuts on the back surface 9a (the surface opposite to the surface on which the sheet 1 is gripped) of the claw 9 on the inner side (the side located on the center side of the reversing drum 3) is there. In a state where the reversing gripper 7 is in contact with the upper surface 22a of the positioning member 22, the sheet 1 gripped by the reversing gripper 7 is not used.
It is almost flush with the peripheral surface of. Further, the positioning member 22 is located inside the grip portion, and the inner claw 9 is pressed and urged against the upper surface 22a of the positioning member 22 by the segment gear, and the positioning member 22 is pressed against the back surface 9a of the inner claw 9. We support the back of the grip.

The positioning member 22 is, as shown in FIG.
It is provided substantially over the entire length of the axial groove 3a substantially in parallel with the claw shaft 10 which is the rotation axis, and the height of the flat upper surface 22a is constant along the rotation axis. Therefore, all the reversing grippers 7 arranged in a row are
In contact with the upper surface 22a of the second 2
The heights (gripping positions) of the gripping portions of all the reversing grippers 7 are constant.

Next, the operation of the reversing gripper 7 will be described. First, in double-sided printing, as shown in FIG. 3A, at a contact point A between the reversing cylinder 3 and the storage cylinder 2, the reversing gripper 7 moves the sheet 1 from the paper suction device 6 of the storage cylinder 2 to the rear edge. Grab and receive. Therefore, when gripping, the gripping portion at the tip of the reversing gripper 7 is already in a state in which the reversing gripper 7 faces forward in the rotation direction of the reversing cylinder 3.

Then, while holding the sheet 1, it rotates backward in the rotation direction of the reversing cylinder 3 with the rotation of the reversing cylinder 3, and reaches the contact point B with the impression cylinder 4. The turning ends. When the operation is completed, the gripper is positioned by the inner claw 9 contacting the upper surface 22a of the positioning member 22 and being supported from the inside by the upper surface 22a. Further, since the segment gear urges the inner pawl 9 toward the positioning member 22 and exerts a gripping force, the outer pawl 8 is also urged toward the inner pawl 9. Reaches the delivery position while maintaining the stable state,
The sheet 1 is stably delivered to the impression cylinder 4 at the delivery position without fluctuation.

After the pawls 8 and 9 are opened at the transfer position to transfer the sheet 1 to the impression cylinder 4,
Turns 180 degrees forward in the rotation direction of the reversing drum 3 while keeping the claws 8, 9 open, and at the receiving position, the claws 8, 9
9 closes and grips the trailing edge of the sheet 1 and again pivots approximately 180 degrees rearward in the rotational direction. In this way, even if the turning operation in the rotation direction rear side while repeatedly holding the sheet 1 is repeatedly performed, the gripping position is always maintained constant because the reversing gripper 7 is positioned by the positioning member 22. Can be
High register accuracy can be secured. In addition, since the positioning is performed by directly abutting the claw 9, the positioning accuracy is higher than that of positioning other members such as the gear 13 and the like. Since positioning is performed on the back side of the grip portion, positioning can be performed with even higher precision. Furthermore, even if the claws 8 and 9 bend or the like, the gripping portion is supported from the inside by the positioning member 22, so that the gripping position of the sheet 1 is stabilized.

On the other hand, even in single-sided printing, the positioning member 2
2 works effectively. That is, as shown in FIG. 3 (b), the reversing gripper 7 moves the gripper 5 of the storage cylinder 2 at the receiving position.
When the sheet 1 is received, the inner claw 9 abuts on the positioning member 22 and the reversing gripper 7 is positioned. The positioning member 22 extends from the receiving position to the delivery position.
In the state of being positioned.

Then, after the pawls 8 and 9 are opened at the transfer position and the sheet 1 is transferred, the reversing gripper 7 moves the pawls 8 and 9 to each other.
9 while maintaining the open state, once turns (approximately 120 degrees) in the rotation direction of the reversing drum 3, turns in the reverse direction in the rotation direction before the receiving position, and reaches the receiving position. The sheet 1 is grasped and is positioned again by the positioning member 22. In this manner, even in one-sided printing, the gripping portion is positioned by the positioning member 22 from the receiving position to the transfer position, that is, while the sheet 1 is being gripped, and the gripping position of the sheet 1 is stabilized. High register accuracy can be obtained.

In the above-described embodiment, all the reversing grippers 7 are positioned by one positioning member 22, but it is also possible to provide the positioning members 22 individually for each reversing gripper 7. Also, the configuration of the claw positioning support, such as the shape of the positioning member 22 and the location of the positioning, can be variously changed within the range intended by the present invention.

[0032]

As described above, by directly positioning the pawl with the pawl positioning support, the inverted gripper gripping the sheet can be positioned with high accuracy, and the register accuracy of a sheet-fed printing machine capable of duplex printing. Can be made more accurate than before.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of a sheet-fed printing press capable of performing duplex printing according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line QQ of FIG. 1;

FIG. 3 is a schematic explanatory view of a main part of the printing press as viewed from the front;
(A) shows the operation of the reverse gripper in the case of double-sided printing.
(B) shows the operation of the reversing gripper in the case of single-sided printing.

FIG. 4 is a schematic front view showing a main part of a conventional sheet-fed printing press.

FIG. 5 is a schematic front view showing a main part of the printing machine in one-sided printing.

FIG. 6 is a schematic front view showing a main part of the printing machine in double-sided printing.

FIG. 7 is a schematic plan view showing a main part of the printing press.

FIG. 8 is an enlarged view of a main part of FIG. 7;

[Explanation of symbols]

2 ... storage cylinder, 3 ... reversing cylinder, 7 ... reversing gripper, 8, 9 ...
Claw, 22 ... positioning member (claw positioning support)

Claims (1)

[Claims] 1. A reversing cylinder (3) of a paper transfer unit for transferring a sheet from an upstream printing unit to a downstream printing unit is provided with two front or rear edges of the sheet. A reversing gripper (7) is provided which is configured to be gripped by the cooperation of the pawls (8, 9) and is rotatable about a rotation axis along the axial direction of the reversing cylinder (3). In the case of double-sided printing, the rear edge of the sheet is gripped and received from the storage cylinder (2) located upstream of the reversing cylinder (3), and the rotation axis is centered with the rotation of the reversing cylinder (3). In the case of a two-sided printing sheet-fed printing press configured to turn over the sheet while turning to the rear side in the rotation direction of the reversing cylinder (3) and deliver it to the downstream printing unit, The reversing gripper (7) holding the sheet is behind the reversing cylinder (3) in the rotational direction. When the turning to the side is finished, the claw (9) of the two claws (8, 9) is brought into contact with the claw (9) located on the center side of the reversing body (3) and the claw (9) is moved. ) Support portion for pawl positioning (2)
2. A sheet-fed printing press capable of double-sided printing, the method comprising: