JPH0344982B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention connects two small-sized offset printing devices and reverses the sheet to be printed depending on the operating mode of the small-sized offset printing device. The present invention relates to a sheet conveying device that conveys sheets manually or normally.

[Conventional technology]

Today's compact offset printing presses, although consistently simple in construction, have reached a high level of automation, for example in the presetting of the number of copies to be printed and in the automatic loading of plates. ing. These printing presses are therefore particularly suitable for processing at low cost a wide variety of jobs with small numbers of copies, for example sporadic jobs. Additionally, these compact offset printing machines are easy to handle and maintain, so even semi-skilled personnel can use them.

The structure of a small offset printer's order job is such that, even if the number of copies is extremely small, it is possible to
This trend is changing more and more, as we now have to print in color. Double-sided printing often saves paper and shipping costs. An example is an academic paper. However, printing sheets twice on one single color compact offset printing press is time consuming and therefore costly.

By the way, in order to eliminate this drawback, if we were to create a small offset printing press capable of converting from two-color printing to double-sided printing, we would use a known reversing device used in ordinary offset printing presses. For example, the complexity required to do so simply cannot be matched by the simplicity of a small offset printing press. Furthermore, it is unreasonable to expect a semi-skilled person to switch the reversing device, which must be done with great expertise and discretion.

From German Application No. 2 559 034 a Dandem compact offset printing press is known, in which the reversal of the sheet between a first printing unit and a second printing machine is carried out by turning over a reversing shaft. It is done. In this reversal axis, the conveyed sheets first stop once and then are accelerated again, so that the conveying speed of the conveyor of this small-sized offset printing press is disadvantageously fundamentally limited. Ru. In this reversal axis, there is also the risk that the sheets printed on one side will become smeared with grease. By turning over, the sheet is turned inside out, so that the printing form which is directed in the imaging process to the printing form provided in the first printing device must be used in the second printing device.

In addition, the Federal Republic of Germany Patent Publication no.
No. 2918499 shows an envelope transport device consisting of two cooperating band drives, each band twisted 180 degrees in the central region. During the transport of the envelope, the two band drives perform a reversal of the envelope around an axis running in the transport direction; during this reversal of the bands, the printed sheet is exposed to the printed side. The disadvantage is that oil adhesion is unavoidable.

[Problem that the invention seeks to solve]

It is therefore an object of the present invention to provide a compact offset printing press which is compatible with the simple construction of this type of printing press on the one hand and the high degree of automation on the other hand, and which allows for the clean transport of sheets. The object of the present invention is to provide a sheet conveying device which allows the realization of a compact offset printing press that is reliable and, furthermore, easy to operate.

[Means for solving problems]

This object is achieved according to the invention by a device having the characteristics of the features of claim 1.

[Effect]

The device according to the invention can be applied in all cases where the sheet format is small and allows for the construction of a paper transport device that is simple, inexpensive and, moreover, easy to use. The sheets are transported without soiling them. Since the sheets are simply turned over during the reversing process without reversing from front to back, the same type of printing plates can be used in both printing devices.

An advantageous embodiment of the invention is that a reversing transport wheel supporting the gripper bridge is provided in the sheet transport device. Such a device can not only be used in repositionable two-color compact offset printing presses, but also can be installed to connect two separate compact offset printing presses. If virtually only DIN A4 plates are handled in a small offset printing press, the operator need only adjust the control device accordingly for reversing purposes. Such easy handling can be expected even by a semi-skilled person.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The printing units 10 and 11 of the two-color compact offset printing press shown in FIG.
2 are connected to each other. This sheet conveying device 1
2 essentially consists of a conveying chain 13 which extends over sprockets 14 and 15 and carries, for example, seven gripper bridges 16 which are arranged at equal distances from each other. Each gripper bridge 16 is rotatably supported on a support rod 17 which is attached to the conveying chain 13, as seen in FIG. Kuwaezume Bridge 1
6, the rotation axis of the support portion 18 extends in the paper feeding direction. In the gripper bridge 16 there are at least two scissor grippers 19, which are preferably constructed in a symmetrical manner, for example as forceps-shaped grippers. Instead of a conveying chain, toothed belts can also be used.

The sheet transport device 12 is surrounded by side walls 20 . The sprocket 14 of the conveyance chain 13 is
It is located in the printing device 10 and works in combination with the impression cylinder 21 thereof. On the other hand, the other sprocket 1
5 is located above the paper feed table 22, and a suction feed conveyor 23 runs through the paper feed table 22, and a pull-in roller 24 is provided at the upper end of the suction conveyor 23. A drying device 25 is arranged above the sheet transport device 12 in the first printing device 10 .

In the lower part 8 of the conveying chain 13, the gripper bridges 16 can be pivoted through 180 DEG about their supports 18 if a control device, not shown in the drawings, is in the appropriate state of adjustment.
As a control device, it is possible, for example, to provide a guide rail along which guide rollers connected to the individual gripper bridges fit into and run. Under appropriate adjustment of the control device of the sheet transport device 12, it is also ensured that the gripper bridge 16 does not pivot in the lower part 8 of the chain. In the upper part 9 of the conveyor chain 13, the gripper bridge 16 is not pivoted if forceps-shaped grippers are used. If the standard type of gripper in the delivery device is used, the gripper bridge 16 will pivot in the upper part 9 of the chain and return to its original position.

The operation of the switchable two-color compact offset printing press described above is as follows.

A suction head 26 picks up the uppermost sheet 7 from the feed pile 27 and passes it onto a pull-in roller 24. A pull-in roller 24 feeds the sheet 7 to an impression cylinder 21 of the printing device 10 . During the printing interval of this printing device 10, the sheet 7 undergoes its first printing, as indicated by a triangular mark 28 in the figure. From the impression cylinder 21, the sheet transport device 12 receives a sheet 7 printed on one side with a gripper bridge 16, along which the path of the lower chain part 8 guides it. As soon as the sheet 7 has completely left the sprocket 14 (position 1),
Grip bridge 16 transporting sheet 7
begins to rotate. In this case, the sheet 7 is turned over about its longitudinal axis. Between positions 1 and 2 of the reversing process (these positions are shown in FIG. 2 as well as in FIG. radiate the side that has been exposed. In position 3 of the reversing process, the sheet 7 and therefore also the gripper bridge 16 transporting it are vertical. The subsequent positions 4, 5, 6 of the reversing process not only account for a further reversing movement of the sheet 7, but also that in position 6 the sheet 7 is completely reversible and reaches the feed tray 22. 16
It is clearly shown that the paper is passed from the scissor gripper 19 to the suction feed conveyor 23. This suction feed conveyor 23 guides the leading edge of the sheet between draw-in rollers 24 which transport the sheet 7 further to the impression cylinder 2 of the second printing device 11.
Supply to 1. Here, the sheet 7 has a triangular mark 2 in the figure on the unprinted back side facing upward.
As shown at 9, printing is performed again.
A chain delivery device 30 receives the double-sided printed sheets 7 from the impression cylinder 21 of the second printing device 11 and directs them to a delivery pile 31 .

When single-sided, two-color printing is to be carried out, the sheet transport device 12, not shown in the figure, should be Set up a control device that is not configured. In this case, the sheet that has been printed for the first time is fed without reversal to the second printing device 11, and a second printing is made there on the side that has already been printed.

The drive of the sheet transport device 12 can be achieved, for example, with a spur gear 32 mounted on the shaft of the sprocket 14 and in mesh with a drive gear (not shown) mounted, for example, on the shaft of the impression cylinder 21. .

The second embodiment, which is different from the first embodiment, is for the case where there is a series of small orders that require two-color printing on one side or one-color printing on both sides.
It consists of two separate one-color compact offset printing presses which can be connected to each other by a reversing sheet transport device 35. That is, for such purposes, two
It is expedient to combine several compact offset printing machines by means of this reversing wheel sheet transport device 35. In this case, in the first small offset printing machine 36, there is a
Two paper guide plates 38 are inserted, and a second paper guide plate 38 is inserted.
For example, a small offset printing machine 37 with wheels 39
It is advantageous if the structure is such that it can be easily moved by having a.

The reversing conveyor wheel type sheet conveying device 35 is essentially a cart 40 having a structure in which a shaft 42 of a reversing conveyor wheel 43 is rotatably supported on a side wall 41.
It consists of At the center of this shaft 42, 4
There is a support (conveyance) arm vehicle 44 that is divided into two parts. A gripper bridge 45 is rotatably supported at the free end of each arm of the support arm wheel 44. The axis of rotation in its support part 46 extends perpendicular to the direction of rotation of the ring, ie with respect to the individual radially outwardly extending arms of the support arm wheel 44 . Each gripper bridge 45 has two forceps-shaped grippers 47. The reversing conveyance wheel 43 is driven via a spur gear 48 fixed to the shaft 42. This driving spur gear 48
The associated drive gear is not shown in the figure.

By means of a limiting device, which is not shown in detail, the gripper bridges 45 can be swiveled through 180° about their respective support axes during the rotation of the reversing conveyor wheels 43 within a constant circumferential region. Can be done.

Immediately adjacent to the reversing conveyor wheel 43 and on the carriage 40, a further sheet conveying device 50 is provided, which consists of a forceps-shaped gripper 52 on a circulating conveying chain 51. Conveyance chain 5
1 is a pair of 3 different sprockets 5
It was previously recommended to me on 3rd. This sheet conveying device 50 is also supplied with blowing air,
Attached to the upper end is a paper feed tray 54 with suction conveyor rollers 55 , through which the sheet conveyor chain 51 receives the sheets, which are gripped by forceps-shaped gripper bridges 52 . I will lead 7. A transparent cover 56 covers the top of the reversing wheel type sheet transport device 35 to the first compact offset printing machine 36.
3 to the paper feed section area of the second compact offset printing press 37. It should be noted that the width of the entire carriage 40 and the parts attached to it are determined so that these parts can be inserted between the side wall frames of adjacent compact offset printing machines 36 and 37. ing. Note that before this insertion, the suction head 26 of the paper feed section of the small offset printing machine 37 is swiveled upward, but it is removed.

The operation of the device described above is as follows.

After the two compact offset printing presses 36 and 37 are connected to each other by the reversing wheel sheet transport device 35, the unit formed by these three parts forms a two-color compact offset printing press. Even though
It can also be used as a double-sided printing machine. Here, it is assumed that the combination unit of the printing press described above is set for double-sided printing. In this case, suction head 2
6 picks up the uppermost sheet 7 from the feed pile 27 and passes it to a pull-in roller 24 which transfers the sheet 7 to the pressure of a first compact offset printing machine 36. It is supplied to the barrel 21.
After the first printing is done, the chain type paper ejection device 30
receives the sheet printed on one side from the impression cylinder 21 and supplies it to the reversing conveyor wheel 43. On this occasion,
The non-printed side of the sheet runs along a paper guide plate 38.

The gripper bridge of the chain-type sheet discharge device 30 inverts the sheet and transfers it to the gripper bridge 4 of the conveyor wheel 43.
Hand over to 5. As soon as the sheet 7 has completely left the chain delivery device 30, i.e. a little after position 1, the pivoting of the gripper bridge 45 about its support begins. At this time, the sheet 7 is turned over about its longitudinal axis. Sheet 7
now travels through the positions 2, 3, 4, 5, 6 shown. In position 6, the sheet is completely turned over, is received by the forceps-shaped gripper bridge 52 of the paper transport device 50, and is fed via the feed tray 54 to the suction transport rollers 55. At this time, since the printed side of the sheet slides along the paper feed tray 54, an air cushion is created under the sheet 7 being conveyed on the upper surface of the paper feed tray 54 by the blown air. If this is done, ink staining on the already printed side is advantageously prevented. The suction conveyance roller 55 is
It forces the received sheets between the drawing rollers 24. The draw-in roller 24 serves to ensure that the sheet 7 reaches the gripper of the impression cylinder 21 of the second compact offset printing machine 37 in an orderly manner. Here, a second printing is performed on the sheet 7 as shown by the triangular mark in the figure, but since the sheet is reversed by the reversing conveyance wheel 43, the second printing is performed on the back side. becomes. The sheets printed on both sides are received by a chain-type delivery device 30 and sent to a delivery pile 31.

If single-sided two-color printing is to be performed instead of double-sided printing, the control device of the reversing conveyor wheel type sheet transport device can be readjusted by a simple lever operation. In this way, during the conveyance of the sheet 7 by the reversing conveyance wheel 43, no reversal of the sheet 7 about its longitudinal axis occurs. That is, the sheet 7 is printed in two colors on one side and sent to the output pile 31.

The three-part compact offset printing unit described above is a component in which a reversing conveyor wheel 43 is fixedly integrated to connect both printing devices in one switchable two-color compact offset printing press. It is clear that it can also be constructed in an integral form. In this case, the second
The paper feeding section of the printing apparatus is configured so that the conveyance device 50 is not required.

[Effects of the Invention] As explained above, the present invention allows sheets to be processed by adjusting the sheet transport device after leaving one printing device and before reaching the next printing device. By reversing the axis of rotation around the axis of rotation extending in the direction of paper transport, it is possible to match the simple construction of small offset printing presses, on the one hand, and the high degree of automation on the other hand, ensuring a clean transport of the sheets. Furthermore, it is possible to realize a small-sized offset printing machine that is guaranteed and easy to operate.

[Brief explanation of drawings]

FIG. 1 is a diagram of a two-color compact offset printing press that can switch from single-sided two-color printing to double-sided printing according to the present invention, and FIG. 2 is a cross-sectional view of the sheet conveying device of the two-color compact offset printing press shown in FIG. FIG.
A diagram of a combination of two compact offset printing machines,
FIG. 4 is a sectional view of the reversing conveyor wheel type sheet conveying device of FIG. 3. 7... sheet of paper, 10, 11... printing device, 12
...Sheet paper conveyance device, 16,45... Grip grip, 19... Scissors grip, 35...
Reversing transport wheel type paper transport device, 36, 37...Small offset printing machine, 43...Reversing transport wheel, 47...
Forceps-shaped grip.

Claims (1)

[Scope of Claims] 1. A sheet paper machine that connects two small-sized offset printing devices and transports sheets to be printed either inverted or normally, depending on the operating mode of these small-sized offset printing devices. In the conveying device, several gripper bridges 16 are arranged at equal intervals on a sheet conveying device 12, which is arranged between two printing devices 10, 11, each of which holds a sheet. It has at least two scissor jaws 19 for gripping the leading edges, each gripper bridge 16 being rotatable about a rotation axis in the sheet transport device 12 extending in the direction of sheet transport. It is possible to switch from normal sheet conveyance to sheet reversal, and during sheet reversal, each gripper bridge 16 is moved along the path between the two printing devices 10, 11. A sheet conveying device characterized in that a control device for rotating the sheet by 180° about the rotation axis is provided. 2. The apparatus according to claim 1, wherein a reversing conveyor wheel 43 for supporting the gripper bridge 45 is provided inside. 3. Device according to claim 1 or 2, in which the scissor jaws are symmetrically designed, for example as forceps-shaped jaws 47.