JPH0312515Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a paper spreading device for spreading paper before applying printing pressure in a sheet-fed rotary printing press.

[Prior art]

2. Description of the Related Art As a type of sheet-fed rotary printing press, a B-B double-sided printing machine is known, which prints by transferring images on the circumferential surface of a blanket cylinder onto both sides of a sheet of paper passing between upper and lower blanket cylinders. FIG. 1 shows a part of the cylinder arrangement of a conventional printing press of this type, in which a transfer cylinder 1 equipped with a gripping pawl device (hereinafter referred to as pawl) is mounted on a shaft of a printing unit. This transfer cylinder 1 is provided with a difference plate 2 by a paper feeding device.
The transfer cylinder 1 holds the paper 3 that is sent upward one by one in its mouth.
A swinging device 4 for changing the grip to the claw of the gripper is in contact with the swing device 4. On the downstream side of the transfer cylinder 1, an upper blanket cylinder 5 and a lower blanket cylinder 6 are arranged one above the other with their circumferential surfaces facing each other, and on the blankets of these circumferential surfaces,
An image from a plate surface on a plate cylinder (not shown) is transferred. The claws for holding the paper 3 are provided only on the upper rubber cylinder 5, and the paper 3 transferred from the swing device 4 to the claws of the transfer cylinder 1 is held at the upper part where the claws of both cylinders 1 and 5 face each other. After being gripped by the claw of the blanket cylinder 5, the end of the grip passes between the upper and lower blanket cylinders 5 and 6, whereupon the printing pressure increases, the image begins to be transferred, and double-sided printing begins. .

In this case, since images have been transferred to both sides of the blanket cylinders 5 and 6, if the paper 3 touches the blanket cylinders 5 and 6 before the printing pressure is applied, an extra image will be left on the touched area. The transfer may cause a printing problem called overlapping or stain the paper 3. Therefore, a gap is provided between the transfer cylinder 1 and the upper blanket cylinder 5, and the circumferential speed of the transfer cylinder 1 is made slightly faster than the circumferential speed of the blanket cylinders 5 and 6, so that the paper 3 fed out from the transfer cylinder 1 is pressed against the printing pressure. The paper 3 is prevented from touching the blanket cylinders 5 and 6 by slackening it before it gets stiff.
However, with this alone, the paper 3 still sag at the points indicated by symbols A, B, and C in the figure.
There is a very high possibility that the rubber cylinders 5 and 6 will come into contact with each other. Among these, the areas indicated by symbols B and C are immediately before the printing pressure area, so the image is transferred to the same location as when printing, so there is little risk of the image overlapping, but if you touch the area indicated by symbol A, it will sag. The images are shifted by that amount and overlap.

Therefore, as shown in FIG. 2, it has been proposed to provide an air tube 7 on the outer periphery of the transfer cylinder 1 to suck the paper 3, and to provide a paper guide 8 near the periphery to attach the paper 3. In recent years, with the increase in speed of machines, the paper 3 has become more prone to ripples at this point, and especially in the case of thin paper, the paper 3 often ripples.
It is difficult to completely prevent the paper 3 from coming into contact with the paper 3 at point A, which causes printing problems. It has also been proposed to blow air from above the circumferential surface of the transfer drum 1 to bring the paper 3 into close contact with the circumferential surface of the transfer drum 1; The air nozzle had to be installed away from the body surface, which resulted in poor air efficiency, and air turbulence occurred when a large amount of air was blown from a distance, making it impossible to expect a satisfactory adhesion effect. .

[Summary of the idea]

The present invention was devised in view of the above points, and the bristles are placed close to the conveying paper and extend in the axial direction of the cylinder near the circumferential surface of the transfer cylinder that transfers paper to the claws of the blanket cylinder. By providing multiple rows of brushes and an air outlet that blows air onto the conveyed paper through slits formed between the rows of brushes, slack in the conveyed paper is expanded and printing problems caused by contact with the blanket cylinder are prevented. The present invention provides a paper spreading device for a sheet-fed rotary printing press that is designed to prevent the occurrence of. Embodiments of the present invention will be described in detail below with reference to the drawings.

〔Example〕

3 to 5 show an embodiment of the paper spreading device according to the present invention, FIG. 3 is a schematic side view of a B-B type single-color double-sided printing sheet-fed rotary printing press in which this is implemented, and FIG. Similarly, FIG. 5 is a schematic side view of the vicinity of the transfer drum, and FIG. 5 is a front view from D in FIG. In the figure, a printing machine 11 includes a paper feeder 12 and a printing unit 1.
3 and a paper ejecting device 14, the paper feeding device 1
2 includes a paper stacking table 16 that loads paper 15 and automatically rises as the paper 15 decreases due to paper feeding, and a suction device (not shown) that sucks up the paper 15 one by one and sends it onto the differential plate 17. It is provided.

The printing unit 13 is equipped with an upper printing device 18 and a lower printing device 19 having substantially the same configuration, and each printing device 18, 19 has a blanket wrapped around its circumferential surface and extends in the direction shown by arrows E and F in the figure. A rotating upper blanket cylinder 20 and a lower rubber cylinder 21 are provided with their circumferential surfaces facing each other. Each rubber cylinder 2
0 and 21, plate cylinders 22 and 23, which have printing plates attached to their circumferential surfaces and rotate in the directions shown by arrows G and H in the figure, are in contact with each other, and each plate cylinder 20 and 21 stores ink. Inking device 24, 2 consisting of an ink fountain and a group of rollers that transfer the ink and supply it to the plate surface.
5, and water supply devices 26 and 27 each comprising a water cannon for storing dampening water and a group of rollers for transferring and supplying the dampening water to the plate surface. The image formed on the printing plate with the ink and dampening water is transferred to the blankets of the blanket cylinders 20 and 21. The reference numeral 28 is a transfer cylinder disposed between the upper blanket cylinder 20 and the difference plate 17.
Diagonally upward on the side is the paper 1 sent out onto the difference plate 17.
A swing device 29 is provided that holds the transfer cylinder 28 in its mouth, rotates it, and transfers it to the claw of the transfer drum 28. Transfer trunk 2
8 is disposed with its circumferential surface slightly spaced from the circumferential surface of the upper blanket cylinder 20, and its rotating direction is opposite to that of the upper blanket cylinder 20, as shown by arrow J in the figure. , the circumferential speed is set slightly larger than the circumferential speed of the upper blanket cylinder 20. Further, the transfer cylinder 28 is provided with a claw in the outer peripheral notch for holding the paper 15 in its mouth and transferring it to the claw of the upper blanket cylinder 20. It is provided so as to slightly protrude from the circumferential surface. Note that although the circumferential speeds of the two barrels 20 and 28 are different, the number of revolutions is the same, so there is no problem in changing the gripping of the claws. Reference numeral 30 is a transfer cylinder that is placed in contact with the downstream side of the upper blanket cylinder 20, and rotates in the direction shown by arrow K in the figure, and the claws of the upper blanket cylinder 20 change the paper 15 held in its mouth. A conveying claw is provided inside the outer circumferential notch.

The paper discharge device 14 includes a paper discharge cylinder 3 that is in contact with a transfer cylinder 30.
Sprocket 32 coaxial with 1 and paper ejection frame 3
3. A pair of left and right paper ejection chains 35 are suspended between the front end sprocket 34 and run in the direction shown by the arrow L in the figure. Each of the plurality of claw rods has a plurality of claws and a claw base arranged in parallel in the axial direction, which grip and convey the paper 15 as the paper discharge chain 35 runs. A paper stacking table 36 is provided below the conveyance end of the paper discharge chain 35, and is automatically lowered to load the paper 15 that is released from the claw and falls.

The printing unit 11 of the printing press configured as described above is provided with a paper spreading device 37 that spreads out slack in the paper 15 held in the claws of the transfer cylinder 28 and conveyed toward the upper blanket cylinder 20. There is. That is, on the upstream side of the paper conveyance with respect to the gripping location of both cylinders 28 and 20, which is indicated by the symbol P in FIG. A stay 40, which has approximately the same length as the transfer drum 28, is supported at both ends and is installed between a pair of left and right brackets 39 that are fixed to the top surface with bolts and project forward. 41 is bracket 3
A pair of left and right pipe holders are fixed to the stay 40 adjacent to the left and right pipe holders.Both ends of an air pipe 42, one end of which is closed, are inserted into and fixed to the left and right pipe holders, and an elbow 43 is inserted into the air pipe 42. The other end of the hose 44 connected thereto is connected to an air pump 45 shown in FIG. Also code 4
6 is a brush stand formed of a flat plate and extending in the axial direction of the barrel, and is fixed with bolts to surround the air pipe 42 with a plurality of metal fittings 47 welded to this. The stand 46 has two rows of brushes 4 parallel to each other in the conveying direction of the paper 15.
8 are planted with their bristles close to the paper 15 and extending in the axial direction of the trunk. This results in two rows of brushes 48.
In between, there is a slit 49 extending the entire length of the transfer drum 28.
A plurality of nozzle holes 50 as air blowing ports are formed at the base of the slit 49 and are bored through the air pipe 42 and the brush stand 46 in parallel in the axial direction. . That is, the two rows of brushes 48 serve as nozzles, and the air from the air pump 45 is configured to be ejected from the nozzle holes 50 and then blown onto the paper 15 through the slits 49.

The operation of the printing press and paper spreading device configured as above will be explained. The paper feeding device 12 feeds the differential plate 1.
The sheets of paper 15 sent out one by one onto the transfer cylinder 7 are held in the swing device 29, and are further held in the claws of the transfer drum 28, and as the transfer drum 28 rotates, they are wound around the upper semicircular circumferential surface of the transfer drum 28. This paper 15 has both cylinders 2
Since the claws 8 and 20 face each other, it is gripped by the claw of the upper blanket cylinder 20, and as the upper blanket cylinder 20 rotates, the gripped end reaches the printing pressure portion of the upper and lower blanket cylinders 20 and 21. As each cylinder further rotates, the paper 15
Double-sided printing is performed while applying printing pressure with the upper and lower blanket cylinders 20 and 21, and the printed paper 15 is transferred to the claws of a paper discharge chain 35 via a transfer cylinder 30. Then, the sheets are conveyed as the paper discharge chain 35 runs, and at the end of the conveyance, they are released from the claws and dropped onto the paper stacking table 36 to be stacked.

In such a printing operation, the upper blanket cylinder 20
Because the circumferential speeds of both cylinders 20 and 28 are different, the paper 15 that is conveyed while being held in the grip of the transfer cylinder 28 is drawn out at a speed attached to the transfer cylinder 28 rather than the pulling speed at the gripping end. The paper becomes faster and tries to loosen or loosen between the end of the mouth and the tail of the paper. However, a paper spreading device 37 is provided above the transfer drum 28, and two rows of brushes 48 bring their bristles close to the paper 15, and the nozzle hole 50 of the air pipe 42
The air from the air pump 45 is ejected from the air pump 45 and is blown onto the paper 15 through the slits 49 formed by two rows of brushes 48. Thus, it is brought into close contact with the circumferential surface of the transfer drum 28. In this case, as described above, the claws of the transfer barrel 28 protrude from the barrel circumferential surface due to the distance between the circumferential surfaces of the two barrels 28 and 20, but since the brush 48 is flexible, the claws do not come into contact with it. There is no problem because it turns and runs away. Therefore, the bristles of the brush 48 can be brought close to the body circumferential surface, that is, the paper 15, until a sufficient effect is achieved. Furthermore, since a slit 49 is formed by two rows of brushes 48, the nozzle hole 5
Air ejected from zero is not released into the atmosphere.

In this embodiment, an example is shown in which the air blowing hole opened at the base of the slit 49 is used as the nozzle hole 50, but it is also possible to use a long slit-shaped air blowing hole instead of a nozzle hole.

[Effect of idea]

As is clear from the above explanation, according to the present invention, in a sheet-fed rotary printing press, the bristles are placed near the circumferential surface of the transfer cylinder that transfers paper to the claws of the blanket cylinder, and the bristles are placed close to the conveyed paper. By providing multiple rows of brushes extending in the axial direction and an air blowing port that blows air onto the conveyed paper through slits formed between the rows of brushes, the conveyed paper can be easily moved between the gripped edge and the trailing edge of the paper. Even if the brushes try to sag or break apart, the brushes will prevent the breakage, and the air that is strongly blown out through the slits between the brushes will keep the brushes tightly attached to the trunk surface without being released into the atmosphere. Since the paper does not touch the blanket cylinder before printing pressure is applied, it is possible to prevent overprinting and paper stains, improving the quality of printed materials and reducing the amount of paper waste. . Furthermore, since the brush is flexible, there is no problem even if the claws protruding from the body circumferential surface touch it, and the bristles of the brush can be brought close enough to the conveyed paper, so the paper spreading function is extremely good. Since the bristles of the brush are not in contact with the paper surface, there is no risk of curling up the tip of the paper.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of the vicinity of the transfer cylinder and blanket cylinder to explain the necessity of the paper spreading device; Fig. 2 is a schematic side view of a conventional paper spreading device shown in correspondence with Fig. 1; 5 to 5 show an embodiment of the sheet-fed rotary printing press according to the present invention, and FIG. 3 is a schematic side view of a B-B type single-color double-sided printing sheet-fed rotary printing press in which this is implemented. Figure 4 is also a schematic side view of the vicinity of the transfer drum;
FIG. 5 is a front view of FIG. 4 viewed from D in an expanded state. 11...Printing machine, 15...Paper, 20...Upper blanket cylinder, 28...Transfer cylinder, 37...Paper spreading device, 48
... Brush, 49 ... Slit, 50 ... Nozzle hole.

Claims (1)

[Scope of utility model registration request] The bristles extend in the direction of the cylinder axis with the bristles close to the conveyed paper near the body circumferential surface on the conveyed paper attachment side of the transfer cylinder that transfers the paper conveyed by the claws on the body circumferential part to the jaws of the blanket cylinder. A sheet-fed rotary printing machine, comprising: a plurality of rows of brushes; and an air outlet that opens at the base of a slit formed between the rows of brushes and blows air in the direction of the conveyed paper through the slit. Exhibition device.