JPS61188148A - Printing press - Google Patents

Abstract

PURPOSE:To make it feasible to feed each sheet of paper to printing barrels accurately by a method wherein a separating feeder feeding deposited paper sheet by sheet as well as another paper feeder feeding the sheets of paper successively to printing barrels are provided on a printing press. CONSTITUTION:Sheets of paper P0 are deposited on a paper separating feeder 13 while an intermittently driven conveyor mounted below the deposited paper P0 frictionally draws out the papers P0 sheet bysheet on a paper feeding table 25 until each sheet is once stopped as soon as the rear end of each sheet is positioned on the left side end of feeding table 25. A toothed feeding belt 31 of paper feeder 12 to be driven continuously along the lower side of table 25 is provided with a pair of protrusions 32 on the periphery thereof. When the belt 31 is driven, the protrusions 32 are protruded upward from the surface of table 25. Finally when the belt 31 is further driven to make the protrusions 32 hit the rear end of paper P1 still stopped on the table 25, the protrusions 32 may push each sheet of paper P1 to printing barrels 22, 23.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing press, and particularly to a printing press characterized by its paper feeding device.

In a rotary printing press that prints on sheets, the accumulated sheets are separated one by one and intermittently fed out and sent to a printing cylinder for printing.

In the case of a sheet-fed printing press that prints thin paper using conventional technology, when the paper is separated into sheets one by one by a paper feeder and sent to the printing cylinder, the leading edge of the fed paper is placed on the printing cylinder side. ; A device (mouth device) for holding the edge is provided, and printing is performed while the paper is pulled by this holding device.

However, even when printing on sheets of paper, when the paper is thick to a certain extent, such as business cards, postcards, invitation envelopes, etc., the above-mentioned paper feeding method can cause scratches. The paper was unsuitable and could not be used because it did not bend or was wrinkled. Therefore, in the case of thick paper, special printing machines are used depending on the type of paper.

Therefore, there has been a desire for a paper feeding device that can be commonly used for various types of thick paper, but in reality, it has never been provided.

It is therefore an object of the present invention to provide a printing press which is equipped with such a versatile sheet feeding device and which also allows for accurate sheet feeding onto the printing cylinder of the printing press. At the same time, a paper feed detection device is provided in connection with the paper feed device to detect the presence or absence of paper feed, and/or whether it is correct or incorrect, and a signal from this detection device causes the printing machine to It is an object of the present invention to provide an apparatus having a configuration for bringing about either a printing state or a non-printing state.

In order to accomplish this purpose, the present invention has the following configuration.

The printing press is equipped with a device that first stacks the ready sheets of paper to be printed and then separates and feeds the stack of sheets one by one. Next, there is a paper feeding device that sequentially transports the separated and fed sheets of paper one by one toward the printing cylinder of the printing press. In the case of the invention, the paper feed device is constructed with a toothed belt or chain provided with projections. This is an endless rotary conveyor type and works in conjunction with a paper feed table.

When sheets of paper are fed one by one from the paper separating and feeding device onto the paper feeding table, the protrusion of the conveyor belt of the paper feeding device moves with respect to the paper feeding table, and the protrusion separates the trailing edge of the paper. At this time, the paper is fed into the printing cylinder by pushing it from behind. Therefore, there is no need for a device to hold the leading edge of the paper on the printing cylinder side.

“Furthermore, in the configuration of the present invention, the paper feeding device is provided with a device that detects whether the paper being fed is in a regular state (including the presence or absence of paper) or in an irregular state. This sensing device generates a signal regarding the paper feed status, participates in the printing operation of the printing cylinder of the printing press, and brings the printing press into a state where the paper is either printed or not printed. This paper feed detection device may be installed at an appropriate position on the paper feeding device described above.

Since the present invention has such a configuration, this paper feeding device can accurately and easily feed a wide variety of relatively thick sheets of paper.
This method has many advantages in terms of operation, such as eliminating the need to feed paper into the printing machine and eliminating wasted paper, and also greatly reduces costs since a dedicated machine is not required.

Although not described in detail in this specification, this paper feeding device can be used even when the thickness of the paper is relatively thin, and therefore there is considerable flexibility regarding the thickness of the paper.

Furthermore, it is convenient in that it is possible to respond to irregularities in paper supply without having to stop the rotational movement of the printing cylinder of the printing press itself.

Although the present invention can be applied to both offset printing and letterpress printing, the case where it is applied to an offset printing machine will be described below using examples.

1 and 2 are side views of an offset printing machine in which the paper feeding device of the present invention is incorporated. 10 represents the entire printing press, and 11 represents the framework of the printing press. Reference numeral 13 is a paper separation and supply device, and 12 is a paper feeding device, both of which constitute a paper feeding device 14. 21 is a plate cylinder, 22 is a blanket cylinder, and 23 is an impression cylinder, and these cylinders can be collectively called a printing cylinder.

In FIG. 1, paper Po is deposited on the paper separation and supply device 13. There is a conveyor that is driven intermittently at the bottom of the pile of paper, and the paper is fed out onto the paper feed table 25 one by one using a friction method, so that at least the trailing edge of the paper is at the left end of the table 25. The paper will be temporarily stopped there.

31 is a toothed belt for feeding the paper of the paper feeding device 12, which runs continuously below the table 25. The belt 31 has two protrusions 32 attached to its outer periphery.

When the belt moves, the protrusion 32 protrudes above the surface of the table 25 (note that the table 25 is provided with a slit that allows the protrusion 32 to pass through). By the way, as mentioned above, the paper is stopped on the table 25, but the belt 31 moves and its protrusion 32 touches the rear end of the paper (
or the trailing edge), the protrusion 32 pushes the paper P1 from behind and advances it to the printing cylinder 22,23. Although the number of protrusions on the belt is two on the periphery of the belt in this embodiment, it should be noted that this is an example and is not definitive. The paper PI is printed while passing between the printing cylinders 22 and 23, and is stored in the paper discharge device 15 as a paper P2. Reference numeral 16 denotes paper feed detection devices, and in the drawing, two of them are placed above and below near the right end of the table 25. This detection device detects abnormal situations such as the presence or absence of paper on the table 25, overlapping of two or more sheets of paper, and bending of paper, and in the event of an abnormality, it issues a signal to stop the printing operation of the printing machine. It is something to do.

As the detection device, an electric one such as a photoelectric switch or a contact type switch, or a mechanical linkage mechanism, locking or releasing mechanism can be used. It is sufficient that the detection device detects an abnormality in the paper supply as described above, issues some kind of signal, stops the printing operation, and brings the printing machine into a non-printing state. It is not particularly limited.

FIG. 2 shows this non-printing state. At this point, all paper printing has been completed, and there is no paper on the table 25 of the paper separation and supply device 13 and the paper feed device 12. Therefore, the detection device 16 senses the absence of this paper, and the plate cylinder 2
1. The rubber cylinder 22 and impression cylinder 23 are separated from contact. This operation is known to those skilled in the art as carving. Various mechanisms for implementing this are conventional and known.

Therefore, although the mechanism related to this shell removal forms part of the present invention, we do not believe that it is necessary to describe it in detail. Alternatively, depending on the case, the supply of printing ink may be further stopped.

As can be seen from the above, if paper feeding is normal, the printing cylinders 21, 22, and 23 operate in contact with each other, and printing is performed when the paper is inserted between the blanket cylinder 22 and the impression cylinder 23. On the other hand, if there is an abnormality in the paper feed, the printing cylinders 21, 22, 23 are released from contact and no printing is performed on the paper. , 'Furthermore, the paper feeding device 12
The installation position and number of the above fraudulent paper detection devices 16 will be described. The installation position may be a position on the table 25 close to the paper separation/feeding device 13 or a position on the printing cylinder 22.2.
3, or any intermediate position between them. In short, the purpose of this paper feed detection device is to immediately put the printing press into a non-printing state when there is an abnormality in paper feeding, and to bring the printing press into a printing state when paper feeding is normal. All you have to do is make a matching arrangement and use the number.

It is desirable that the paper feeding device include a mechanism for regulating the curvature of paper feeding or the printing position in the vertical direction during printing. That is, in order to correct the curvature of the paper feed (the inclination with respect to the traveling direction of the paper), a device or a side guide for guiding the paper is usually provided on the paper feed table 25.

Therefore, in the present invention, appropriate side guides are provided as shown as 36 in the drawings to keep the paper moving correctly and at the same time guide the paper according to the various sizes of the paper. ing. So the paper is the protrusion 32 of the belt 31.
The sheet is placed into a printing machine while being accurately positioned by the side guides 36 mentioned above.

Further, an adjusting device may be provided for the feeding device to adjust the vertical and vertical printing positions that occur when there is a shift in the front-back direction of the paper.

Further, as for the paper separation/feeding device, in addition to the friction type paper feeding described in the embodiment, a vacuum suction type may be used to feed the paper sheets one by one onto the paper feeding table.

Also, the paper feeding device 12 may be of the link chain type, but it is of course advantageous to use it.

In this case, it is easy to provide the protrusion 32 using a link plate.

Since the present invention is constructed as described above, in the case of sheet-fed printing, especially when the paper is somewhat thick,
Various variations in paper size, shape and thickness can be accommodated conveniently. Paper feeding to the printing press is precisely positioned and conveniently performed. In addition, since there is no need for the front edge holding section of the paper, the printing machine of the present invention can print even on the front edge portion of the paper that cannot be printed if it is present, and it is now possible to print on the entire surface of the paper. There is. Moreover, with the invention the printing press is simplified and more efficient both from a structural and operational point of view. Therefore, it has many advantages such as being economically inexpensive.

[Brief explanation of drawings]

Fig. 1 is a side view schematically showing the structure of the printing press of the present invention, and shows the printing cylinder in a printing state, and Fig. 2 is a view similar to Fig. 1. However, the printing cylinder is in a state where it is not printing. [Explanation of symbols of main parts] 10 Printing machine. 13 Paper separation and supply device 12 Paper feed device 14 (12, 13) Paper feed device 31 Toothed belt with protrusions 32 Protrusion 16 Paper feed detection device

Claims (1)

[Scope of Claims] 1. In a printing press equipped with a paper feeding device including a device for separating and feeding paper and a paper feeding device for feeding the paper separated and fed by the device to the printing press, the paper feeding device comprises: It is composed of a toothed belt or chain with protrusions for paper feeding, and is also provided with a paper feed detection device for detecting the status of paper being fed to the paper feeding device, and a A printing press characterized in that the printing press is brought into a state of printing paper or a state of not printing paper by means of a signal. 2. The printing machine according to claim 1, wherein the paper feed table of the paper feeding device is provided with a guide device for regulating the position of the paper.