JPH0318157Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a mechanism for cutting the edges of printing paper, and more particularly to a cutting mechanism that prevents the edges from lifting up after cutting.

2. Description of the Related Art Some printing apparatuses, such as line printers, are equipped with a mechanism for cutting so-called selvedge portions on both sides or one side of printing paper, which are provided with paper feed holes, as paper processing means after printing. However, as a lever cutting mechanism, the shear type shown in FIGS. 1 and 2 is known. That is, the shear type cutting mechanism has a configuration in which the upper blade 1 and the lower blade 2 are each rotationally driven to cut the lug portion 3a from the traveling paper 3. However, in this cutting mechanism, the edge portion 3a after being cut advances as the paper travels and is lifted up as shown by the dotted line 3b due to the bending tendency of the perforation crease formed in the width direction of the paper. Then, there is a problem that the paper 3 gets caught in the drive shaft 4 of the upper and lower blades in the cutting mechanism and the paper feed tractor (not shown), resulting in damage to the paper 3. Conventionally, in order to deal with this problem, considering that the edge portion of the paper is selectively cut, a guide plate 5 is provided that is close to the upper blade 1 and guides the cut edge portion 3a downward toward the paper ejection side. A method has been adopted in which the ears are arranged so as to be movable up and down to prevent the ears from lifting up after cutting. However, with this method, the guide plate 5 must be manually moved up or down depending on whether or not the ear portion is to be cut, which is not only troublesome, but also lacks reliability as operations are often forgotten. It was hot.

This invention was developed based on the above-mentioned conventional situation, and a new printing paper edge cutting mechanism that enables highly reliable edge cutting without requiring any operations, regardless of whether the edge of the paper is cut or not. It is intended for the purpose of providing.

Briefly, the paper edge cutting mechanism of this invention has a perforation crease on the drive shaft of a rotary blade that moves in the paper running direction while floating due to its bending tendency after being cut by the blade. It is characterized by the addition of a metal edge pressing roller having a diameter slightly smaller than the diameter of the rotary blade and a smooth outer circumferential surface that can abut against the rotary blade and guide it downward.

Hereinafter, preferred embodiments of this invention will be described in more detail with reference to the drawings.

FIG. 3 is a front view showing an embodiment of this invention, and FIG. 4 is a sectional view taken along the line - in FIG.
Components equivalent to those in FIGS. 1 and 2 are given the same reference numerals. In Figures 3 and 4, paper 3
is fed in the direction of the arrow by a paper feeding tractor (not shown), and the ear portion 3a is cut by a pair of upper blade 1 and lower blade 2. If there is no guide means on the paper ejection side, the cut edge portion 3a will get caught up in the drive shaft 4 of the upper blade 1, etc., as described above, and the paper will be damaged. Therefore, in the present invention, as shown in the figure, a roller 6 is fixed to the drive shaft 4 adjacent to the upper blade 1 to abut on the perforation crease of the edge of the sheet in a floating position and guide it downward. This ear pressing roller 6 has a shape whose diameter is slightly smaller than the diameter of the upper blade so as not to interfere with the paper cutting of the upper blade 1, and has a smooth outer peripheral surface to facilitate paper running. For example, it is preferable to use a metal roller with good wear resistance. Note that reference numeral 7 is a fixed guide plate that guides the edge portion 3a of the cut sheet 3 downward.

In the cutting mechanism configured as described above, the edge portion 3a of the paper cut by the upper blade 1 and the lower blade 2 becomes floating due to the bending tendency of the sewing machine crease portion as shown in FIG. After coming into contact with the ear part pressing roller 6 and being guided downward, that is, being prevented from floating up, it moves downward along the next guide plate 7. Therefore, the paper edge portion 3a will not be caught in the drive shaft 4 of the upper blade 1, the paper feed tractor, etc. Moreover, since the selvage pressing roller 6 is a rotating body and does not come into contact with anything other than the perforation crease and the vicinity of both sides thereof, there is no fear that the paper feed hole will get caught.

Note that this invention is applicable not only to the above-mentioned shear type cutting mechanism, but also to a push type cutting mechanism in which a rotary blade is pressed against a roller to cut the paper. In this case, the ear portion pressing roller is fixed to the drive shaft of the rotary blade.

As is clear from the above explanation, according to the paper edge cutting mechanism of this invention, there is no paper damage caused by the edge of cut paper with perforation machine creases getting caught in the drive shaft of the rotary blade, etc. Further, unlike the conventional method, there is no need to manually operate the guide means for the ear portion up and down depending on whether or not the ear portion is to be cut, resulting in very good workability. Therefore, it is extremely useful to incorporate it into a line printer or the like, or to apply it to a paper post-processing device separate from a printing device.

[Brief explanation of drawings]

FIG. 1 is a front view showing a conventional printing paper edge cutting mechanism, FIG. 2 is a sectional view taken along the - line in FIG. 1, and FIG. 3 is a paper edge cutting mechanism according to an embodiment of the invention. The front view of Figure 4 is the − of Figure 3.
It is a sectional view along a line. 1...Upper blade, 2...Lower blade, 3...Paper, 3a...
...Paper edge portion, 4...Drive shaft, 5 and 7...
Guide plate, 6... Paper edge pressing roller.

Claims (1)

[Claims for Utility Model Registration] In a structure in which a rotary blade is brought into contact with and cuts an edge portion on the side surface of a paper with perforated creases used in a printing device, where a paper feed hole is provided, the drive shaft of the rotary blade 1 is provided. 4, the diameter of the rotary blade is larger than the diameter of the rotary blade that can come into contact with the perforation crease of the edge portion 3a of the paper 3, which moves in the paper running direction in a floating state due to its bending tendency after being cut by the blade, and can be guided downward. A printing paper edge cutting mechanism characterized in that a metal edge pressing roller 6 having a slightly small diameter and a smooth outer peripheral surface is attached.