Infeed system of rotary press

Details Infeed system of rotary press Infeed system of rotary press

2000-04-18

2002-01-01

Mansen, Michael R. (Department: 3653)

Advancing material of indeterminate length

With material-responsive control means

To regulate longitudinal movement of material

C242S418100

Reexamination Certificate

active

06334564

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to an infeed system of a rotary press in which a paper web of a web roll supported by a web roll supporting means of a rotary press is supplied for a succeeding process such as a printing process in a printing section by means of infeed roll by which a paper web traveling amount can be controlled.
In a case where a plurality of paper webs printed by a rotary press are gathered or collated by a collator, it is required for the paper webs to have the same top and bottom dimensions with each other. Particularly, for a business-form rotary press carrying out printings on paper webs which are required to be gathered or collated by the collator after printings, it is very important for the paper webs to have constant top and bottom dimensions with each other even if materials, basis weights thickness or the like of paper webs to be collated are different from each other.
However, as is known, where the paper webs are fed by an infeed system of the rotary press, the traveling amounts thereof differ from each other in accordance with the materials, basis weights thickness or the like of the paper webs. Accordingly, in a case where such various different kinds of paper webs are printed, the traveling amounts differ from each other even if the paper webs are printed under the same printing conditions, hence providing inconvenience at the time when paper webs are gathered or collated.
In order to eliminate such defects, a first prior art providing a solution is disclosed for example, in Japanese Patent Publication No. HEI 4-51456. This prior art discloses a structure, as shown in
FIG. 2
, comprising a plate cylinder
1
, a blanket (rubber) cylinder
2
, an impression cylinder
3
, and a differential speed change gear
5
disposed in a power transmission means for the blanket cylinder
2
and the impression cylinder
3
which put a paper web between them, carry out printing on the paper web and make the same travel. The differential speed changer
5
comprises a Harmonic Drive (Trade Name) a speed of which is adjustable by an adjustment motor
4
. In this structure, the plate cylinder
1
, the blanket cylinder
2
and the impression cylinder
3
are coupled in series to each other and rotated at the same rotation number in directions reverse to each other.
According to this first prior art, the rotating speed of the impression cylinder
3
is adjusted by the differential speed change gear
5
with respect to the rotating speed of the blanket cylinder
2
thereby to change the traveling amount of the paper web. That is, in a case of thick paper web, the rotating speed of the impression cylinder
3
is decreased, and on the other hand, in a case of thin paper web, the impression cylinder
3
is adjusted reversely. In this manner, the traveling amount of the paper web can be changed.
A second prior art also provides a solution, in which the rotating speed of the infeed roll is adjusted in accordance with the change of the tensions in consideration that tensions of paper webs passing between rolls are changed in accordance with the change of the paper web thickness.
FIG. 3
is a schematic view showing the structure of the above second prior art. With reference to
FIG. 3
, a paper web
7
fed from a web roll
7
a
is fed in the paper web traveling direction and wound up in substantially S-shape around two infeed rolls
8
a
and
8
b
, which are rotated in directions reverse to each other at the same rotating speed, and the paper web
7
is then supplied on a side of the printing unit
9
, i.e. downstream side, in the paper web traveling direction.
The infeed rolls
8
a
,
8
b
and the printing unit
9
are driven by a drive line
10
from a press machine side through gear boxes
11
a
and
11
a
, respectively. In the gear box
11
a
driving the infeed rolls
8
a
and
8
b
, there is housed the differential speed change gear
5
having the speed ratio (gear ratio) which is adjustable by the adjusting motor
4
as like as in the first prior art mentioned above. Further, first and second tension detectors
12
a
and
12
b
for detecting the tension of the paper web
7
are arranged on both the upstream side and downstream side of the infeed rolls
8
a
and
8
b
, respectively.
In
FIG. 3
, reference numeral
13
denotes a controller for generating a speed change signal to the motor
4
. The controller
13
carries out a comparison operation of a detection value T
1
fed back from the second tension detector
12
b
disposed downstream side of the infeed rolls
8
a
and
8
b
with a set value T
2
preset by a setting device
14
, and the controller
13
then generates a signal, to the motor
4
, for adjusting the differential speed change gear
5
so as to rotate the infeed rolls
8
a
and
8
b
at the rotating speed at which the compared value becomes zero. Accordingly, the infeed rolls
8
a
and
8
b
are controlled so that the tension T
1
of the paper web
7
detected by the second tension detector
12
b
always becomes equal to the set value T
2
set by the setting device
14
thereby to keep constant the traveling amount of the paper web
7
. Further, reference numeral
15
denotes a brake means operating in response to the detection value detected by the first tension detector
12
a.
Further, it is to be noted that the term “traveling amount” used herein means a traveling distance (length) per unit rotation number of a prime mover (motor) of the rotary press, a traveling distance (length) per one rotation of the infeed roll or a traveling distance (length) per unit time.
In the first prior art mentioned above, when paper webs having different thicknesses are fed by the blanket cylinder
2
and the impression cylinder
3
as the infeed rolls with the tension applied to the paper web in the paper web traveling line and being maintained constant, the traveling amount of the paper webs differ in accordance with the thicknesses of the paper webs. Because of this reason, in the prior art, in order to make constant the traveling amounts of a plurality of paper webs having different thicknesses, it is necessary to obtain an aimed (target) traveling amount of the paper web by experimentally calculating a preset value to be inputted into the adjusting motor
4
for determining the speed ratio (gear ratio) of the differential speed change gear
5
with respect to each of the paper webs, measuring an absolute value of the paper web traveling amount by means of scale and so forth, in an operation stop condition of the printer,and then amending or correcting a feed amount by the infeed roll. Accordingly, it is very difficult to make travel the plurality of paper webs having different thicknesses at the same traveling amount. Furthermore, because the wind-up diameter of the web roll is changed as the paper web is fed, it is sometimes necessary to check the traveling amount at an intermediate time of the feeding as well as the feed-start time according to the condition of the web. In such case, some problems were caused on the printing process.
On the other hand, in the second prior art mentioned above, the detection value T
1
and the set value T
2
are compared by the controller
13
, and the signal for operating the adjustment motor
4
to adjust the motor rotating speed so as to make zero the compared value is generated to the motor
4
. According to this operation, the tension of the paper webs having different thicknesses at the traveling time can be made constant and the traveling speed of the paper webs can be hence maintained constant.
However, the detection value T
1
inputted into the controller
13
is a value of the tension, which is a predetermined tension applied to the paper web
7
, and therefore, this value T
1
is the value detected at time when the paper web is elastically and plastically deformed by the tension. Accordingly, even if the detection value T
1
is the same with respect to the different paper webs, the actual traveling amounts of the paper webs having different thicknesses and different elastic deformations due to

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