JPS6243969Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of the folding cylinder in the folding section of a letterpress or offset rotary printing press.

Generally, there are at least two folding cylinders with the same diameter in the folding section, and the first folding cylinder has a cutting blade, a needle, a rubber support for the saw blade of the second folding cylinder, etc., arranged in the axial direction of the surface of the cylinder. installed. The position of the tip of the insert blade approximately coincides with the surface of the cylinder, and the needle protrudes from or retracts from the surface of the cylinder. On the other hand, the second folding cylinder has a fixed gripping portion having a flat gripping surface in a groove portion formed in the axial direction of the surface of the cylinder, and a flat gripping surface, and the gripping surface is in contact with the gripping surface of the fixed gripping portion. A swinging grip part that is pivotably supported so as to be in contact with each other is attached,
In addition, a saw blade is attached to a groove formed in the axial direction on the other surface of the cylinder. The fixed gripper and the swingable gripper protrude several millimeters from the surface of the second folding cylinder. As the first folding drum and the second folding drum rotate, the inserting blade of the first folding drum is moved between the clamping surface of the fixed gripping part of the second folding drum and the clamping surface of the swinging gripping part. It is located in a position that allows access to and from the
Further, the needle is provided at a position where it can immediately pierce and stop the paper cut by the saw blade.

The paper printed in the printing section of the rotary printing press is sent to the folding cylinder via the nipping roller, which is vertically folded by a triangular plate, where it is cut by a saw blade and immediately stopped by pricking with a needle protruding from the cylinder. After being transported for a certain length by being wrapped around one folding cylinder,
The edges of the paper are released as the second folding drum is pushed between the open swinging gripping surface of the holding gripper and the fixed gripping surface by the insert blade of the first folding drum, and the needle is retracted. Ru. Thereafter, as the folding drum rotates, only the insert blade slips out from between the swinging grip part and the fixed grip part, and the swinging grip part closes and is formed on the clamping surface of the swinging grip part and the fixed grip part. The paper is gripped by the fine serrations and folded horizontally.

However, as shown in the first diagram, the first folding cylinder 1
When the second folding cylinder 3 rotates in the directions of arrows A and B and the insert blade 5 comes out from between the swinging gripper part 7 and the fixed gripper part 9, it is bent greatly, so it is very easy to break. . Further, when the blade 5 comes out, the paper 13 may be scraped out.

At this time, the fine serrations 4 and 6 are simply the paper 13.
The paper 13 is only held by increasing the contact friction with the paper 13.

The present invention takes into consideration the problems of the conventional folding cylinder as described above, and has a deep groove extending in the axial direction of the cylinder and having a V-shaped cross section, at least on the holding surface corresponding to the inserting blade of the swinging grip part. This shape prevents the insert blade from entering the deep groove and being bent greatly when it comes out from between the swinging grip part and the fixed grip part,
The object of the present invention is to provide a folding drum whose insert blade is difficult to break.

Embodiments of the present invention will be described below based on the drawings.

Figure 2 shows the first position where the insert blade has entered the deep groove.
FIG. 3 is a schematic cross-sectional view of the folding drum and the second folding drum.

The first folding cylinder 11 has a mechanism that protrudes from or retracts from the surface of the folding cylinder and stabs the paper 13 to stop it.
Alternatively, a needle 15 to be released and an insert blade 17 whose tip position is the same as the surface of the folding drum 11 are provided.

On the other hand, the second folding cylinder 19 is provided with a saw blade 21 for cutting the paper 13, and the groove portion 23 is provided with a swinging grip portion 25 and a fixed grip portion 27 for gripping the paper 13. The swinging grip part 25 swings around an axis 26 as shown by arrow K, and when the folding drum rotates and the swinging grip part 25 approaches the insert blade 17 of the first folding drum 11, it moves to the fixed grip part. 27
As the folding drum further rotates and the swinging gripping portion 25 moves away from the inserting blade 17 of the first folding drum 11, it gradually closes and approaches the fixed gripping portion 27.

Deep grooves 33, 35 are formed in the clamping surfaces 29, 31 of the swinging grip part 25 and the fixed grip part 27, extending in the axial direction of the folding cylinder and having a V-shaped cross section.

As shown in the second figure, the deep groove 33 of the swinging gripper 25 allows the insertion blade 17 to come out after pushing the paper 13 between the fixed gripper 27 and the swinging gripper 25, leaving the paper 13 behind. This is to prevent it from bending too much when introduced. Therefore, the depth, width, position, etc. of the deep groove 33 are determined in consideration of the length and thickness of the insert blade 17, the diameter of the folding drum, etc.

On the other hand, a deep groove 35 formed in the fixed grip part 27
When the insert blade 17 comes out from between the fixed gripper 27 and the swingable gripper 25, the paper 13 is
This is to increase the contact friction with the paper to prevent it from being scraped out, especially as in this example.
It is not necessary to have the same shape and size as the deep groove 33 of the swinging grip part 25, and it may be a fine jagged groove, for example.

As described above, the folding cylinder of the present invention has at least one deep groove extending in the axial direction of the cylinder and having a V-shaped cross section formed in the clamping surface corresponding to the inserting blade of the swinging grip part, and When the blade comes out of the gripping part, the insert blade is guided into the deep groove to reduce bending, so the insert blade is less likely to break and its lifespan is extended. Therefore, the number of times the insert blade must be replaced is reduced compared to the conventional method, and the work efficiency of the printing press is greatly improved.

In addition, when the thickness of the insert blade is 0.5 mm and the maximum insertion allowance between the swinging jaw portion 25 and the fixed jaw portion 27 of the second folding body is 4 mm, a deep groove having a V-shaped cross section with a width of 2 mm and a depth of 1 mm is formed 2 mm inward from the outer surface of the swinging jaw portion 25 and the fixed jaw portion 27 (the outer edge of the deep groove is therefore located 1 mm from the outer surface of the jaw portion).
When this was formed, the conventional (width 0.5 mm, depth
A 0.5mm/m groove is made 1mm/m from the surface of the second folding cylinder.
In the case of the above example, eight insert blades were broken in one month, but in the case of the above example, one was broken in five months.
Not a single sheet was bent.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a conventional first folding cylinder and a second folding cylinder, and FIG. 2 is a schematic cross-sectional view of the first folding cylinder and second folding cylinder of the present invention. 11...First folding cylinder, 13...Paper, 15...Needle, 1
7... Insert blade, 25... Rocking grip part, 27... Fixed grip part, 33, 35... Deep groove.

Claims (1)

[Scope of utility model registration request] A fixed gripping portion having a flat gripping surface and a swinging gripping portion having a flat gripping surface and pivotably supported so as to be able to swing freely such that the gripping surface abuts the gripping surface of the fixed gripping portion. In a folding cylinder of a folding section of a rotary printing press that is attached to a groove formed in a groove formed in the axial direction of the surface, at least a clamping surface corresponding to the inserting blade of the swinging grip part has a V-shaped groove extending in the axial direction of the cylinder. A folding drum characterized by forming one deep groove having a cross section.