JPH04111440U - Dirt prevention cover - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to prevent the occurrence of double images on the printed surface or scratches on the printed surface. [Structure] A gauze cloth 2 is fixed to one side of a polyester film 1 with a double-sided tape 3 so as to have slack.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a stain prevention cover, especially for sheet-fed offset printing machines capable of double-sided printing. The present invention relates to a stain prevention cover that is wound around a paper discharge cylinder to prevent printing paper from being soiled.

0002

[Conventional technology]

Conventionally, sheet-fed sheets capable of double-sided printing are equipped with a front-side printing unit and a back-side printing unit. Offset printing machines are widely known. And, such a sheet-fed offset printing machine A printing machine has been proposed in which the paper delivery cylinder functions as an impression cylinder for printing on the back side. (Utility Model Publication No. 10939/1999).

0003 FIG. 3 is a schematic diagram of the cylinder arrangement of the printing press. In the figure, numeral 101 is a paper feed section, numeral 1 02 is the paper insertion section, 103 is the paper feed cylinder, and 104 is the surface printing It is a unit. This surface printing unit 104 is similar to known offset printing machines. , impression cylinder 105, blanket cylinder 106, plate cylinder 107, water section 108, and ink section 10. 9 and a paper discharge cylinder 110.

0004 Further, reference numeral 111 in the figure is a paper ejecting section, and this paper ejecting section 111 is the same as the paper ejecting cylinder 110. An axially supported sprocket (not shown) and the required spacing between this sprocket and It is formed by winding a paper ejection chain 113 around a sprocket 112 that is pivotally supported by There is. A required number of grippers 114 are attached to this paper ejection chain 113. The gripper 115 of the impression cylinder 105 opens and the gripper 114 grips the paper a. It is formed in a known manner so as to be conveyed to a paper discharge table 116. For this reason, the above exclusion The paper cylinder 110 serves to guide the paper a to the paper discharge section 111.

[0005] On the other hand, the paper delivery cylinder 110 also serves as an impression cylinder for printing on the back side. 10, the blanket cylinder 117, plate cylinder 118, water section 119, and ink section 120 are sequentially The arrangement constitutes a back printing unit 121. Furthermore, the gripper 114 supported by the paper ejection chain 113 is attached to the paper ejection cylinder 110. It is formed to move in and out of the notch 110a in synchronization with rotation, and the above pressure While receiving the paper from the cylinder 105 and conveying it to the paper discharge section 111, the back side of the paper a is transferred to the blanket cylinder 1. 17 to perform back side printing.

[0006] By the way, at this time, the paper delivery cylinder 110 receives the image printed by the front surface printing unit. The ink adheres to the paper delivery cylinder 110, resulting in double images on the printed surface. the Therefore, a method has been adopted in which the surface of the paper delivery cylinder 110 is made rough. However, the surface of the paper delivery cylinder 110 is made rough, and the reverse side is printed using thick paper instead of coated paper. If this is not done, problems such as scratches may occur on the printed surface. There is a point.

[0007] In order to prevent the occurrence of scratches, the paper delivery cylinder 110 is covered with a flexible gauze-like cloth. A method of attaching certain fabric materials loosely has been proposed (Patent Publication No. 3-750). No. 7).

[0008]

[Problem that the idea aims to solve]

However, when printing on the back side with the fabric material attached to the paper delivery cylinder, the front side printing There are problems such as printing problems such as gauze marks on the printed surface. . This invention was developed in view of the above-mentioned problems. The purpose is to provide a stain prevention cover that can prevent the occurrence of scratches. .

[0009]

[Means to solve the problem]

This invention consists of a front-side printing unit, a back-side printing unit, and a sheet on which front-side printing has been completed. It is equipped with a paper eject cylinder that holds the paper and ejects it to the outside while printing on the back side. Contamination that adheres to the paper cylinder and prevents the printing surface of sheets of sheet-fed offset printing machines from being soiled. This stain prevention cover is made of a slippery and flexible sheet. A sheet-like base material and a fabric material covering at least one side of this sheet-like base material are integrally bonded. At the same time, the sheet-like base material can be attached and detached by bringing it into contact with the paper delivery cylinder. The fabric material is bonded with slack to the sheet-like base material. It is characterized by being

0010

[Effect]

If backside printing is not performed, the sheet-like base material is placed between the paper delivery cylinder and the fabric material. Wrap the stain prevention cover so that it is located between the two. This prevents scratches from occurring. It can be prevented. Also, when printing on the back side, use a cover to prevent stains. Easily removed from the paper delivery cylinder. This prevents duplication on the printed image. can do.

[0011]

【Example】

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of a stain prevention cover according to the present invention. The code 1 in the figure is a rectangular shape. It is a polyester film with a small coefficient of friction and a thickness of about 0.1 mm. One side of this polyester film 1 has the same length in the width direction and a length in the longitudinal direction. A slightly longer specially processed gauze cloth 2 is polymerized. Then, gauze cloth 2 is Double-sided tape 3 attached to the back side of the periphery of both longitudinal ends of the Lyester film, 3 shows a state in which both edges of the gauze cloth 2 are folded back onto the back side of the polyester film 1. By gluing the polyester film 1 with slack in the longitudinal direction, is fixed to. Note that an ink repellent may be applied to the surface of the gauze cloth 2. preferable. Here, the double-sided tape 3 is folded onto the back side of the polyester film 1. The reason for attaching it in this state is that when it is glued on the surface of polyester film 1, the glued part This is because scratches may occur on the printed surface. Also, replace gauze cloth 2 with polyester fibre. The material that is glued to Lum 1 with slack in the longitudinal direction is polyester with a low coefficient of friction. This is to allow the gauze cloth 2 to move freely on the tell film 1 to some extent. This is because if the gauze cloth 2 is pulled and attached so that it does not move at all, scratches will occur on the printed surface. Because it comes to life.

0012 At both ends of the reverse side in the longitudinal direction of the stain prevention cover configured in this way, Attach mounting tapes 4, 4 having the same length. Then print on the back side If not, wrap it around the paper delivery cylinder 5 with mounting tape 4, 4 as shown in Figure 2. Ru. Then, the gauze cloth 2 of the stain prevention cover and the printing paper temporarily become one body. Can be moved to prevent scratches on the printed surface can do. In addition, when printing on the back side, place a dirt prevention cover on the paper output cylinder. Remove from 5. This causes duplication in the image on the printed side. can be prevented.

[0013]

[Effect of the idea]

The present invention is a sheet-fed printer equipped with a front-side printing unit and a back-side printing unit as described above. By having a structure that can be attached to and detached from the paper output cylinder of a offset printing machine, the present invention eliminates contamination. The damage prevention cover can be easily installed and removed. Also, print on the back side. If you do not do this, you can prevent scratches from occurring and when printing on the back This has effects such as being able to prevent double images from occurring.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a stain prevention cover according to the present invention.

FIG. 2 is a front view showing a state in which the stain prevention cover of the present invention is wound around a paper discharge cylinder.

FIG. 3 is a schematic illustration of a commonly used printing press cylinder arrangement.

[Explanation of symbols]

1 Polyester film (sheet-like base material) 2 Gauze cloth (fabric material) 5 Paper discharge cylinder 104 Surface printing unit 121 Back side printing unit

Claims (1)

[Scope of utility model registration request] Claim 1: A front-side printing unit, a back-side printing unit, and a paper delivery cylinder that holds a sheet on which front-side printing has been completed and discharges the paper to the outside while printing on the back side, and includes a paper sheet that is attached to the paper delivery cylinder. This is a stain prevention cover that prevents stains on the printed surface of sheets of sheet-fed offset printing presses. A cloth material covering at least one side of the material is integrally bonded to the sheet-like base material, and the sheet-like base material is configured to be removably attached to the sheet-like base material so as to be in contact with the above-mentioned paper delivery cylinder, and the cloth material is attached to the sheet-like base material. A stain prevention cover characterized by being joined with slack.