JPH0380108B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet-fed rotary printing press with a reversing mechanism that can be used for single-sided printing and double-sided printing.

BACKGROUND ART With the diversification of printing, various types of sheet-fed rotary printing presses with reversing mechanisms that can be used for single-sided printing and double-sided printing have been proposed and put into practical use. In all of these types of printing machines, printing is carried out on one side of the paper held in the claw of the printing cylinder, and the paper is wrapped around the circumference of the cylinder. After holding the paper in its mouth and inverting it, it passes it to the next printing cylinder and prints on the back side, thereby performing double-sided printing.In the case of single-sided printing, the reversing operation of the paper by the reversing claw is stopped and the paper is left as it is. It is passed to the next printing cylinder and printed on the same side. As described above, the principle of the reversing mechanism for double-sided printing is the same for all types of printing presses proposed so far, but the structure of the reversing mechanism and the number, diameter, arrangement, etc. of the cylinders are different.

First, the one shown in Fig. 1 is called a three-piece type, and there are impression cylinders 1 and 1 installed in the front and rear printing units.
A transfer cylinder 2, a reversing cylinder 3, and a transfer cylinder 4 of double diameter are arranged between A and 1B, and the paper fed to the impression cylinder 1A by the swing 5 is
The pattern transferred from the plate cylinder 6A to the blanket cylinder 7A is printed, and the paper is wound around the transfer cylinder 4 via the transfer cylinder 2 by changing the grip of the nail. Then, after passing the point of contact between the reversing cylinder 3 and the transfer cylinder 4, the tail of the paper 8 wound around the transfer cylinder 4 is caught by the claw of the reversing cylinder 3, and the paper is wound around the reversing cylinder 3 in a trajectory as shown in the figure. Paper 8 by attaching
is reversed, and the reversed paper 8 is held in the claw of the impression cylinder 1B and passes between the blanket cylinder 7B, so that the pattern transferred from the plate cylinder 6B to the blanket cylinder 7B is transferred to the back side of the paper 8. , and double-sided printing is applied.

Next, the one shown in FIG. 2 is a one-piece type, and the impression cylinder 1 is in contact with the blanket cylinders 7C and 7D.
C and 1D are formed with double diameter, and both impression cylinders 1
A double-diameter reversing cylinder 3A is arranged between C and 1D. The paper 8 is reversed by the impression cylinder 1C and the reversal cylinder 3A.
It is carried out between.

Moreover, the one shown in FIG. 3 is of a two-cylinder type, and includes a blanket cylinder 7E, which is in contact with the plate cylinders 6C, 6D.
Impression cylinders 1E and 1F having the same diameter are in contact with 7F, and a reversing cylinder 3B having the same diameter as this is arranged between both impression cylinders 1E and 1F. Furthermore, reversal cylinder 3
A transfer drum 2A having the same diameter is in contact with the lower part of B. Then, the paper 8 is reversed by the reversing cylinder 3B and the transfer cylinder 2.
This is done between A and A.

In this way, conventional printing presses with a reversing mechanism are roughly divided into the three types mentioned above depending on the number, diameter, and arrangement of cylinders. The two-piece type shown has a large number of barrels, so the structure including the drive device and gripping claw device is complicated, increasing equipment costs, and the space occupied by the barrels is large, resulting in a large machine base. There is a drawback.
Furthermore, although the number of cylinders shown in Fig. 2 is small, the structure of the machine for reversing the paper requires that both the impression cylinders 1C and 1D and the reversing cylinder 3A be double cylinders, resulting in an increase in the size of the machine. There is a drawback. Furthermore, in the case shown in Fig. 2, the reversing claw that reverses the paper is equipped with a suction lever that attracts the tail end of the paper and transfers it to the reversing claw. The suction lever will suction the printed surface of the paper, so in order to avoid staining the printed surface due to suction, it is necessary to provide a margin without a pattern to a position that avoids the suction part, and it is necessary to provide a margin without a pattern after printing. The disadvantage was that there was a lot of discretion and losses increased significantly.

The present invention was developed in view of the above points, and the impression cylinder of each adjacent printing unit is made to have the same diameter as the plate cylinder, and a transfer cylinder with a double diameter is disposed between them, so that paper can be transferred on the upper side of each cylinder. A reversing claw device that reverses opening and closing using a cam mechanism and a suction device that reverses the rotation using a cam mechanism and suctions air using an intake device are installed on the outer periphery of the downstream impression cylinder. The number of cylinders can be reduced by installing a paper guide for adsorbing reversed paper above the transfer cylinder near the rotating discharge side of the transfer cylinder, and providing a paper guide on the outer periphery of the transfer cylinder to blow air to the reversed paper. By reducing the barrel diameter, we simplified the structure and downsized the machine base, eliminating the flapping of reversed paper and interference with the following paper, reducing printing problems, and making it possible to absorb non-printing surfaces. To provide a sheet-fed rotary printing press with a reversing mechanism that reduces loss due to cutting margins. Embodiments of the present invention will be described in detail below with reference to the drawings.

4 to 10 show an embodiment of a sheet-fed rotary printing press with a reversing mechanism according to the present invention, FIG. 4 is a schematic configuration diagram thereof, and FIG. 6 is a side view of the reversing claw device, FIG. 7 is a plan view of the impression cylinder with a reversing function, FIG. 8 is a side view of the paper guide, and FIG. 9 is a plan view of the reversing claw device.
Figure 0 is an explanatory diagram of the operation. In the figure, a first printing unit 11 and a second printing unit 12
are plate cylinders 1 each with a printing plate attached to its circumferential surface.
3, an inking device and a water supply device (not shown) that supply ink and water to the plate surface, and the plate cylinder 13
A blanket cylinder 14 having the same diameter and onto which the image on the printing plate is transferred is disposed below the blanket cylinder 14 with its circumferential surfaces facing each other. Further, below each blanket cylinder 14, an impression cylinder 15 and an impression cylinder 16, which have the same diameter and apply printing pressure to the paper between themselves and the blanket cylinder 14, are arranged so that their circumferential surfaces are in opposition to each blanket cylinder 14. A transfer cylinder 17 with a double diameter is provided between both impression cylinders 15 and 16 with their circumferential surfaces facing each other. Reference numeral 18 denotes a paper feed cylinder that is equipped with a gripping claw device and is in contact with the impression cylinder 15, grips the ends of the sheets of paper 20 that are fed one by one onto the differential plate 19, and supplies them to the first impression cylinder 15; Reference numeral 21 denotes a paper take-up cylinder that is in contact with the second impression cylinder 16 and assists in passing the paper 20 from the impression cylinder 16 to the paper delivery chain 22 in order to convey the paper 20 after double-sided printing to the paper delivery device.

The first impression cylinder 15 among the cylinders arranged as described above includes a plurality of gripping pawl devices 23 which are arranged in parallel in the axial direction and are composed of a pawl rest that opens and closes using a cam mechanism.
(hereinafter abbreviated as claw 23) is provided in the outer periphery notch, and the end of the paper 20 held by the claw of paper feed cylinder 18 is gripped by this claw 23 and wrapped around the circumferential surface as the cylinder rotates. It is configured as follows. Further, the transfer drum 17 is provided with a pair of notches 24 formed in a triangular shape whose starting end is a point that bisects the outer periphery, and at the end of each notch 24 in the direction of rotation of the drum, there is a claw. A plurality of gripping claw devices 25 (hereinafter abbreviated as claws 25), which are configured with a claw rest and are arranged in parallel in the axial direction, are arranged. This pawl 25 is configured to pick up the tip of a sheet of paper 20 from the pawl 23 of the impression cylinder 15 every half rotation of the transfer cylinder 17 and wrap it around the circumferential surface as the cylinder rotates.

Next, the second impression cylinder 16 has a function as a reversing cylinder for reversing the paper 20 in addition to a function as an impression cylinder for applying printing pressure. That is, in the outer peripheral notch 26 of the impression cylinder 16, a reversing shaft 27 and a pipe-shaped suction lever shaft 28 are supported by pillows 29 at both ends of the cylinder and bearings (not shown) in the notch 26. A claw shaft 31 is provided at the free end of a claw shaft arm 30 fixed to both ends of the reversing shaft 27.
is rotatably supported. Further, on the same reversing shaft 27, a plurality of claw base arms 32 are connected to the claw shaft arm 3.
0, and a claw stand 33 extending over substantially the entire length of the barrel 17 is supported between the tip ends thereof. Reference numeral 34 denotes a reversing pawl as a plurality of reversing pawl devices that grip the paper 20 between the pawl stand 33 and the pawl 25 on the transfer cylinder 17 and the pawl 25 on the transfer cylinder 17 on the pawl shaft 31, with a phase shift in the direction of the cylinder axis. Parallel is fixed. A cam lever 35 is fixed to the protruding end of the reversing shaft 27, and a cam follower 36, which is pivoted to the free end of the cam lever 35 so as to be able to move back and forth in the axial direction, is connected to the cam of the reversing cam 37 fixed to the machine frame side. It is pressed against the surface by the elastic force of the spring member. By rotating the impression cylinder 16 with the cam follower 36 facing the reversing cam 37, the reversing shaft 2 is rotated during one rotation.
7 is reciprocated once in the forward and reverse directions at a predetermined timing, and the claw base 33 and the reversing claw 34 are reciprocated between the solid line position and the chain line position in FIG. 6 via both arms 30 and 32. It is composed of Reference numeral 38 is a reversing gripping cam fixed in the notch 26 of the impression cylinder 16, and when the cam lever 39 fixed to the pawl shaft 31 reaches the chain line position by rotation of the reversing shaft 27, its play is The cam followers 40 at the ends are positioned so as to face each other, and when the cam lever 39 is reversed to the chain line position and stopped, the reversing claw 34
The cam surface is formed so that the reversing pawl 34 closes due to the elastic force of the spring member at the beginning of the return toward the solid line position. Reference numeral 41 denotes a grip release cam fixed to the frame side, and when the claw shaft 31 is in the solid line position, the cam lever 41 fixed to the claw shaft 31
The cam follower 43 at the free end is positioned so as to face each other, and the reversing claw 34 is in the solid line position and is reversed in cooperation with a spring member when the single-sided printing paper facing the claw 25 of the transfer cylinder 17 is held in its mouth. A gripping cam surface is set to open and close the claw 34. Further, the release cam surface is set so as to similarly open and close the reversing pawl 34 when releasing the paper for single-sided printing or double-sided printing where the reversing pawl 34 faces the pawl of the paper discharge chain 22.

On the pipe-shaped suction lever shaft 28, the same number of suction levers 44 as paper tail suction devices as the reversing pawls 34 are arranged in parallel with a different phase in the axial direction from the reversing pawls 34. Cam follower 46 at the free end of the cam lever 45 fixed to the protruding end
is pressed against the cam surface of the suction cam 47 fixed to the frame side by the elastic force of the spring member, and the impression cylinder 16 rotates, thereby reciprocating at a predetermined timing as shown by the trajectory shown by the chain line in FIG. It is configured to rotate. The suction lever 44 is connected to an air pump (not shown) on the machine side via a rotary valve provided inside the suction lever shaft 28 and at the end of the shaft.
The paper 20 is connected to the reversing claw 34 and is configured to attract the paper 20 when the reversing claw 34 grips the paper 20 and pass it between the reversing claw 34 and the claw base 33 by the rotation.

Further, in the vicinity of the rotating discharge side of the transfer cylinder 17 and the impression cylinder 16, a paper guide 48 formed in a hollow rectangular shape with an arcuate cross section and having approximately the same length as the cylinder length is connected to the machine base by a hose 49. It is connected to the side air pump and is installed above the transfer drum 17 along the circumferential surface thereof, and on the side surface of the transfer drum 17, as shown in FIG. Many suction holes 50
is drilled. And this paper guide 48 is
External air is sucked at a predetermined timing, and the paper 20 that has been wrapped around the transfer drum 17 and released from its claws 25 is sucked and adsorbed to the surface, and the suction holes 5
It is configured to spread the paper 20 according to the arrangement of zeros. On the other hand, on the outer periphery of the transfer drum 17, a plurality of paper guides 51 formed in an arc shape with rubber tubes are arranged in parallel in the axial direction on the side preceding each pawl 25 with respect to the rotational direction of the transfer drum 17. rotary valve and hose 5 on the end of the body shaft
It is connected to the air pump on the machine side via 2 and 53. A large number of air blow holes are provided on the outer circumferential side of the paper guide 51, and air is ejected at a predetermined timing to assist the adsorption of the paper 20 to the suction side paper guide 48, and to assist the subsequent paper 20. It is configured to facilitate entry between the paper guide 48 and the circumferential surface of the transfer cylinder 17.

A single-sided printing operation by the sheet-fed rotary printing press with a reversing mechanism configured as described above will be explained. In the case of single-sided printing, the cam follower 36 of the reversing cam 37 is moved in the axial direction to separate from the cam surface, so that the reversing claw 34 and the claw base 33 open and close at this position without being reversed from the solid line position in FIG. Make it. In addition, the suction lever 44
The suction lever 44 and the air pump connected to the paper guides 48 and 51 are stopped so that they do not rotate from the position shown in FIG. When printing is started after preparing in this manner, the sheets of paper 20 fed one by one onto the differential plate 19 pass through the paper feed cylinder 18 and reach the claws 23 of the impression cylinder 15.
The paper is put in the mouth and wound around the impression cylinder 15, and as it passes between the blanket cylinder 14 and the blanket cylinder 14, printing is applied to the surface on the blanket cylinder 14 side. When each cylinder further rotates, the pawl 23 of the impression cylinder 15 and the pawl 25 of the transfer cylinder 17 face each other to change the grip on the paper 2.
0 is wound around the circumferential surface of the transfer drum 17. When each cylinder further rotates and the pawl 25 of the transfer cylinder 17 and the reversing pawl 34 of the impression cylinder 16 face each other, the cam follower 43 passes over the peak of the grip release cam 41, thereby opening and closing the reversing pawl 34. By simultaneously opening and closing the claws 25, the leading edge of the paper 20 is gripped by the reversing claws 34. Then, when the paper 20 held in the reversing claw 34 passes between the blanket cylinder 14 and the impression cylinder 16, printing is applied to the same side as the previously printed side, and single-sided printing is performed. When each cylinder rotates and the reversing pawl 34 and the pawl of the paper ejection chain 22 face each other, the cam follower 43 comes into contact with the paper release cam surface of the gripping and releasing cam 41, thereby opening and closing the reversing pawl 34, and at the same time, the paper ejection chain 22 opens and closes. The claws 22 open and close, and the paper 20 is held in the claws of the paper discharge chain 22 and transported and discharged.

Next, the double-sided printing operation will be explained based on the above-mentioned figures and the operation explanatory diagram of FIG. When switching from single-sided printing to double-sided printing, the reversing claw 34 that gripped the leading edge of the paper 20 during single-sided printing now grips the tail end of the paper, making it necessary to change the relative position of the transfer cylinder 17 with the claw 25. Therefore, for this purpose, each cylinder on the downstream side including the impression cylinder 16 and the transfer cylinder 17 must be installed according to the size of the paper 20.
The phase with each cylinder on the upstream side including
The paper release timing for opening and closing the claw 25 is delayed by approximately the same amount as the paper size. Also, reversing cam 3
The cam follower 36 for 7 is moved so as to come into contact with the cam surface, and the suction lever 44 is also made rotatable, and the suction lever 44, paper guides 48, 51
Start the air pump. When you start printing after preparing in this way, the claw 23
The paper 20, which is held in its mouth and printed on the surface on the blanket cylinder 14 side, is transferred from the claw 23 to the claw 25 of the transfer cylinder 17, and is wound around the transfer cylinder 17 as the cylinder rotates. As each cylinder rotates further, the pawl 25
While holding the tip of the paper in its mouth, the paper passes through the contact points of both cylinders 16 and 17 and is wound until the tail end reaches the contact point of both cylinders. FIG. 10a shows this state. At this time, the starting end of the paper guide 51 crosses the contact point between the cylinders 16 and 17, and air is ejected, and the paper tail is released from the grip between the cylinders 16 and 17. At the same time, the suction lever 44 suctions the air, so that the end of the paper is suctioned by the suction lever 44. When each cylinder further rotates slightly and reaches the position shown in FIG. At the same time, the suction lever 44 which has attracted the paper 20 is rotated by the action of the suction cam 47 and the end of the suctioned paper is exposed between the reversing claw 34 and the claw stand 33. At this time, the reversing claw 34 begins to return in the opposite direction due to the action of the reversing cam 37, and the cam follower 40 reverses the gripping cam 3.
8, the reversing claw 34 closes and the air in the suction lever 44 is cut off, causing the reversing claw 3 to close.
It begins to rotate in the direction of escaping from 4, and the paper tail is reversed claw 3
4 and pulled in the direction of rotation of the impression cylinder 16. Slightly earlier than this, the pawl 25 of the transfer cylinder 17 opens and closes to release the paper edge, and the paper guide 48
sucks air, so the flapping paper 20 is stretched out by the suction by the paper guide 48 and the tension of the reversing claw 34, as shown in FIG. It is pulled while being attracted. At this time, since the suction holes 50 of the paper guide 48 are arranged in a V-shape, the paper 20 is stretched in the width direction as well as in the vertical direction. FIG. 10c shows the paper 20 being stretched and pulled by the reversing claw 34. By doing this, the paper 20 is turned over so that the surface printed earlier comes into contact with the circumferential surface of the impression cylinder 16, and then each cylinder rotates further and the paper 20 passes between the cylinders 14 and 16. Sometimes, printing is performed on the back side of the paper 20 to perform double-sided printing. At the start of printing on the back side, that is, at a position where each cylinder has rotated further than in FIG. However, at this time, the latter half of the preceding paper 20 is attracted to the paper guide 48, so there is no interference between the paper 20 and the paper 20A, and the printing surface is not stained. And the reversing claw 34 and the claw stand 33
This is because the reversing cam 37 returns to the solid line position in Fig. 6 between the time the paper 20 is caught and the contact point with the pawl of the paper ejection chain 22 is reached, so the rest is the same as in the case of single-sided printing. The paper 20 is opened and closed by the action of the gripping and releasing cam 41 to cause the paper 20 to be gripped by the claws of the paper discharge chain, and the paper 20 is conveyed and discharged.

FIG. 11 is a plan view of a paper guide showing another embodiment of the present invention. In this embodiment, the paper guide 48, which was rectangular in the previous embodiment, is divided into a plurality of parts, each of which is designated by the reference numeral 48A. As shown, they are formed into rod shapes and arranged in a V-shape. In this way, by connecting each paper guide 48A to an air pump with a hose and sucking external air through the suction holes provided on the surface, it is possible to suction the paper 20 while expanding it, as in the previous embodiment.

As is clear from the above description, according to the present invention, in a sheet-fed rotary printing press with a reversing mechanism, the impression cylinder of the adjacent printing unit is formed to have the same diameter as the plate cylinder, and a transfer cylinder of double diameter is disposed between them. The structure is simplified because the number of cylinders is reduced and the cylinder diameter is reduced by setting up a structure in which the paper is reversed on the upper side of each cylinder, and the paper is reversed between this transfer cylinder and the downstream impression cylinder. This makes it possible to reduce the size of the machine, resulting in significant cost savings, as well as reducing the number of times the paper needs to be re-picked, thereby improving printing accuracy. In addition, by using a paper guide installed above the transfer cylinder to attract and blow up the reversed paper, the reversed paper is stretched and reversed without flapping, and there is no interference between the reversed paper and the following paper. This prevents the printed paper from being damaged or smudged, significantly improving the quality of the printed material, and by inverting the paper on the downstream impression cylinder, it is possible to adsorb the non-printing surface, which limits the image area due to adsorption. Therefore, the cutting margin can be reduced and the amount of paper loss can be significantly reduced, and the suction area can be widened, reducing the amount of suction. Furthermore, unlike conventional devices, the paper reversal section and the reversal adjustment section for changing the paper size are located above the body, making it easier to see visually, improving operability, and reducing the height of the machine.

[Brief explanation of drawings]

1 to 3 are schematic configuration diagrams of a conventional sheet-fed rotary printing press with a reversing mechanism, and FIGS. 4 to 11 show an embodiment of a sheet-fed rotary printing press with a reversing mechanism according to the present invention, Figure 4 is a schematic diagram of its configuration, Figure 5
The figure is a side view of the outer periphery of the impression cylinder with a reversing function, Fig. 6 is a side view of the reversing claw device, Fig. 7 is a plan view of the impression cylinder with the reversing function, and Fig. 8 is a side view of the paper guide. FIG. 9 is a plan view, FIG. 10 is an explanatory view of the operation, and FIG. 11 is a plan view of a paper guide showing another embodiment of the present invention. 11, 12...printing unit, 13...plate cylinder,
15, 16...Impression cylinder, 17...Transfer cylinder, 25...
Gripping claw device, 33...claw stand, 34...reversing claw, 3
7...Reverse cam, 38...Reverse gripping cam, 41...
...Grip release cam, 44...Adsorption lever, 47...
Suction cam, 48, 51... paper guide, 50... suction hole.

Claims (1)

[Claims] 1. A first impression cylinder and a second impression cylinder having the same diameter as the plate cylinders respectively disposed in each adjacent printing unit;
A transfer cylinder which is formed to have a double diameter of these impression cylinders and is provided with a gripping claw device at a position that bisects the circumferential surface into two equal parts in the circumferential direction, and is arranged between the impression cylinders with their circumferential surfaces facing each other. , a plurality of reversing claw devices which are arranged in parallel on the outer circumference of the second impression cylinder so as to be freely openable and reversible and which are equipped with cam mechanisms for opening, closing and reversing; and a plurality of reversing claw devices that are connected to an intake device and are reversed in correspondence with each of the reversing claw devices. A reversing mechanism for reversing the paper above each of the cylinders, which is composed of paper tail suction devices freely arranged in parallel and equipped with a reversing cam mechanism, and a rotational discharge of the transfer cylinder and the second impression cylinder. a hollow paper guide provided on the transfer drum side surface with an intake hole installed above the transfer drum along the peripheral surface of the transfer drum and connected to an intake device; An inversion characterized by comprising: a hollow paper guide having air blowing holes arranged in parallel between the two gripping claw devices and connected to an air supply device formed on the surface of the paper guide side. Sheet-fed rotary printing press with mechanism.