Printing – Rolling contact machines – Rotary
Reexamination Certificate
1999-11-10
2001-11-27
Hilten, John S. (Department: 2854)
Printing
Rolling contact machines
Rotary
C101S219000, C101S485000
Reexamination Certificate
active
06321650
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a paper web feed unit used in a rotary press and equipped with a paper web traveling tension controller, and more particularly to a paper web feed unit which is used in a rotary press and in which a paper web having a width double that of paper used in a press unit is longitudinally cut, by use of cutting means, into two cut paper webs having substantially the same width; only one of the cut paper webs is passed through an angle bar section; and the traveling tension of each cut paper web is controlled by use of a paper web traveling tension controller.
2. Description of the Related Art
Japanese Patent Publication (kokoku) No. 51-007083 discloses a conventional rotary press in which a paper web is longitudinally cut, by use of cutting means, into two cut paper webs having substantially the same width; the first cut paper web is fed to a first press unit via an angle bar section; and the second cut paper web is fed directly to a second press unit without passing through the angle bar section.
In the rotary press, while the first cut paper web passes through the angle bar section, the traveling path thereof is transferred such that the first cut paper web is fed to the first press unit in a state in which the center line thereof is aligned with the center line of the second cut paper web that is fed to the second press unit.
Further, a traveling tension controller as disclosed in “Newspaper Printing Handbook,” pp. 111-112, published by Japanese Newspapers Association, Apr. 10, 1997 (§3 “Newspaper Offset Rotary Press,” (2) Infeed Tension) has generally been used to control the traveling tension of a paper web fed to a press unit.
The traveling tension controller is used to stabilize the traveling tension of a paper web fed to a press unit and is designed to control the traveling tension of the paper web at a location before the press unit by use of an infeed roller and a dancer roller.
FIG. 4
shows such a traveling tension controller combined with the above-described rotary press.
In
FIG. 4
, a paper web WO′ having a width double that of paper used in an unillustrated press unit of a rotary press is taken out of a paper roll W′ and is longitudinally cut, by use of cutting means C′, into two cut paper webs having substantially the same width. Subsequently, a first cut paper web W
1
′ of a single width is passed through an angle bar section D′, so that the center line of the first cut paper web W
1
′ coincides with the center line of a second cut paper web W
2
′ of a single width.
For the cut paper webs W
1
′ and W
2
′, paper web traveling tension controllers T
1
and T
2
are provided in order to enable the cut paper webs W
1
′ and W
2
′ to be fed to respective press units while their traveling tensions are controlled independently.
The paper web traveling tension controller T
1
(T
2
) includes a dancer roller
42
a
(
42
b
) connected to a fluid cylinder
41
a
(
41
b
). The dancer roller
42
a
(
42
b
) applies a pushing pressure to the cut paper web W
1
′ (W
2
′) due to projection of the piston rod of the fluid cylinder
41
a
(
41
b
), and moves in accordance with variation in the traveling tension of the cut paper web W
1
′ (W
2
′).
Further, an infeed roller
43
a
(
43
b
) driven by a drive source
45
a
(
45
b
) is provided upstream of the dancer roller
42
a
(
42
b
); and a sensor
44
a
(
44
b
) for detecting the position of the dancer roller
42
a
(
42
b
) is attached to the fulcrum of a support arm of the dancer roller
42
a
(
42
b
). The drive source
45
a
(
45
b
) receives a detection signal from the sensor
44
a
(
44
b
) and changes the circumferential speed of the infeed roller
43
a
(
43
b
) in order to control the amount of the paper web fed to the dancer roller
42
a
(
42
b
) such that the dancer roller
42
a
(
42
b
) is always located at a neutral position (ordinary position) in the slack/tension direction of the cut paper web W
1
′ (W
2
′).
Thus, a stable traveling tension is applied to the cut paper web W
1
′ (W
2
′) fed to the press unit.
The above-described conventional techniques involve various drawbacks, as described below.
In the rotary press disclosed in Japanese Patent Publication No. 51-007083, no paper web traveling tension controller is provided in a paper threading path extending from the cutting means of the paper web feed unit where a paper web taken out of the paper roll is cut to the press unit. Therefore, when the traveling tension of the cut paper web changes (for example, decreases) due to resistance of rollers for supporting and guiding the cut paper web and a paper dragging operation performed downstream of the press unit, the traveling cut paper web slacks and meanders, resulting in paper breakage or other problems. On the contrary, when the traveling tension of the cut paper web increases, wrinkles are generated in the traveling cut paper web, also resulting in paper breakage or other problems.
In order to overcome the above-mentioned drawbacks, as shown in
FIG. 4
, the above-described paper web traveling tension controller is combined with the rotary press disclosed in Japanese Patent Publication No. 51-007083. However, the rotary press shown in
FIG. 4
has a drawback in that a difference in traveling state is produced between the cut paper web W
1
′—which travels from the cutting means C′ to the infeed roller
43
a
along a paper threading path containing an angle bar section D′ which generates extremely high friction resistance—and the cut paper web W
2
′—which travels from the cutting means C′ to the infeed roller
43
b
along a paper threading path containing no angle bar section.
That is, when the rotary press is started and the supply of cut paper webs W
1
′ and W
2
′ to the respective press units is started at the same paper speed by means of paper drag rollers (not shown) provided downstream of the press units, the dancer rollers
42
a
and
42
b
of the paper web traveling tension controllers T
1
and T
2
start to move in the tensing direction of the cut paper webs W
1
′ and W
2
′ (rightward in
FIG. 4
) as the traveling tensions of the cut paper webs W
1
′ and W
2
′ increase. However, due to the action of the infeed rollers
43
a
and
43
b
, the dancer rollers
42
a
and
42
b
are controlled to return to the respective neutral positions (ordinary positions).
In the above-described case, since the cut paper web W
1
′ is subjected to the high friction resistance of the angle bar section D′, the cut paper web W
1
′ elastically deforms and stretches in a region between the angle bar section D′ and the infeed roller
43
a
, and thus travels slightly slower than the cut paper web W
2
′ in a region between the cutting means C′ and the angle bar section D′. As a result, in the region between the cutting means C′ and the angle bar section D′, a difference in traveling tension is produced between the cut paper web W
1
′ and the cut paper web W
2
′, with the result that the cut paper web W
1
′ slacks.
However, when the rotary press is operated continuously, the difference between the traveling tension of the cut paper web W
1
′ in the region between the cutting means C′ and the angle bar section D′ and the traveling tension of the cut paper web W
1
′ in the region between the angle bar section D′ and the infeed roller
43
a
converges to a constant value determined from the friction resistance between the angle bar section D′ and the cut paper web W
1
′, and in this state, the cut paper web W
1
′ starts to travel at substantially the same speed as the cut paper web W
2
′. Therefore, no significant problems occur.
However, when low speed operation and stoppage of the rotary press are performed repeatedly many times within a short period
Ogawa Yukio
Sakakura Takanobu
Serita Kazuo
Tsunashima Makoto
Armstrong Westerman Hattori McLeland & Naughton LLP
Crenshaw Marvin P.
Hilten John S.
Tokyo Kikai Seisakusho Ltd.
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