JPH05300B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a tractor for a printing machine.

BACKGROUND ART Conventionally, a belt 34 driven by a drive shaft 31 is rotatably provided on a holder 33 that is slidably held by a drive shaft 31 and a guide shaft 32.
There is a tractor for a printing machine that feeds paper by engaging a plurality of protrusions 35 formed on the outer periphery of the paper with a feed hole of the paper.

Problems to be Solved by the Invention In this type of device, the holder 33 is moved according to the width of the paper being used, and a lock mechanism (not shown) provided on the holder 33 is used to lock the holder 33 onto the guide shaft.
2, but loose paper will reduce printing quality, so the paper should be fixed in the left and right holders 33.
It is pulled by a belt 34. For this reason, the holes in the paper are easily torn, making it difficult to align the holder 33.

Means for Solving the Problem A pair of left and right holders are provided that are slidably held on the drive shaft, and a plurality of protrusions are formed on the outer periphery to be engaged with feed holes formed on the sides of the paper. In a tractor for a printing machine, the tractor body is connected to the drive shaft and rotatably attached to each of the holders,
A leaf spring is attached to one or both of the holders to bias the rotating body at least toward the outer edge of the paper.

Effect: Therefore, the distance between the protrusions on the rotating bodies of the left and right holders is made slightly larger than the distance between the spout holes on both sides of the paper, and the paper is pulled outward from the left and right, and at this time, the width of the paper is The leaf spring is bent by the tension to displace one or both of the left and right rotating bodies inward. Therefore, a situation in which excessive force is applied from the protrusion to the feed hole is avoided.

Embodiment An embodiment of the present invention will be described based on FIGS. 1 to 3. A pair of left and right holders 4 are slidably held on a drive shaft 2 and a guide shaft 3 that are parallel to the platen 1. These holders 4 are formed by joining a pair of support plates 5 and 6. One support plate 5 has a guide part 8 that rotatably holds the inner surface of the belt 7, which is a rotating body, and a connecting hole 9.
The fitting hole 10 and the bearing part 11 are integrally formed, and a presser plate 12 for holding down the paper is attached so as to be able to rise and fall freely. The other support plate 6 includes a shaft 14 having a claw 13 at its tip that is passed through the connecting hole 9 and resiliently engaged with the opening edge of the connecting hole 9;
A cylinder 15 that is slidably fitted onto the guide shaft 3 and fitted into the fitting hole 10 and a bearing hole 16 are integrally formed. The belt 7 is made of a somewhat hard synthetic resin but is flexible, and has a plurality of protrusions 17 formed at equal intervals on its outer surface and a large number of teeth 18 on its inner surface. these teeth 1
Both ends of a gear 19 that meshes with the belt 8 and transmits the rotational force of the drive shaft 2 to the belt 7 are rotatably supported in the bearing holes 11 and 16. Furthermore, a lock lever 20 is provided at the tip of the cylinder 15 to tighten the guide shaft 3 by rotating in one direction. A pair of leaf springs 21 that resiliently clamp both side edges of the belt 7 are attached to the inner surfaces of the support plates 5 and 6. Since these leaf springs 21 are formed in an annular shape so as to surround the guide portion 8 and the gear 19, they will not fall off from the holder 4.

In this configuration, the rotation of the drive shaft 2 is transmitted from the gear 19 to the belt 7 to feed the paper, but when setting the paper, the presser plate 12 is raised and the paper feeding hole is engaged with the protrusion 17 of the belt 7. Then, the holder 4 is slid along the drive shaft 2 and the guide shaft 3 according to the width of the paper so that the left and right belts 7 pull the paper outward on both the left and right sides, and the lock lever 20 fixes the holder 4 at an arbitrary position. Fold down the board 12 and hold down the paper. In this state, if the tension of the paper is strong, the left and right belts 7 can bend the inner leaf springs 21 and move inward, so that no excessive force is applied from the protrusion 17 to the paper feed hole. Therefore, it is possible to avoid the situation where the feed hole is torn. When adjusting the spacing between the holders 4, use the leaf springs 21 inside the left and right holders 4.
Ideally, the distance between the left and right holders 4 should be determined so that the protrusion 17 of the belt 21 engages with the paper feed hole in a state where the belt 21 is slightly compressed.

Note that the plate spring 21 is attached to either the left or right holder 4.
It may be set in For example, if the left edge of the paper needs to be aligned constant regardless of changes in paper width, the leaf spring 21 is attached to the right holder 4, and if the right edge of the paper needs to be aligned, the leaf spring 21 is attached to the left holder 4. It is better to install spring 21. In addition, the left and right holders 4
Both of the plate springs 21 located outside the belt 7
is not necessarily necessary. Furthermore, the same purpose can be achieved by using a sprocket wheel as the rotating body.

Effects of the Invention Since the present invention is constructed as described above, the gap between the protrusions of the rotating bodies of the left and right holders is made somewhat wider than the gap between the feed holes on both sides of the paper, thereby preventing the paper from becoming loose in the width direction. In this case, the leaf spring can be bent by the tension in the width direction of the paper, and the left and right rotating bodies can be displaced inward.
Therefore, it is possible to avoid a situation in which an excessive force is applied from the protrusion to the feed hole, thereby preventing the paper from being torn.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the present invention; Figure 1 is an exploded perspective view, Figure 2 is a plan view, Figure 3 is a horizontal sectional view, and Figure 4 is a conventional example. FIG. 2... Drive shaft, 4... Holder, 7... Belt (rotating body), 17... Protrusion, 21... Leaf spring.

Claims (1)

[Claims] 1 A pair of left and right holders slidably held on a drive shaft are provided, and a rotating body having a plurality of protrusions formed on the outer periphery that engages with feed holes formed on the side of the paper is connected to the drive shaft. In the tractor of a printing machine, the tractor is rotatably attached to each of the holders, and one or both of the holders are attached with a leaf spring that biases the rotating body at least toward the outer edge of the paper. Features a tractor with a printing machine.