Printing – Stenciling – Rotary machines
Reexamination Certificate
2001-01-26
2002-10-22
Yan, Ren (Department: 2854)
Printing
Stenciling
Rotary machines
C101S116000
Reexamination Certificate
active
06467407
ABSTRACT:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a stencil printing machine for sandwiching a print sheet between a printing drum wound with a stencil sheet and a roller to thereby transfer the print sheet and printing the print sheet by supplying ink from an inner portion of the printing drum. Particularly, the present invention relates to a stencil printing machine preventing ink from being leaked from between the printing drum and the stencil sheet in the stencil printing machine.
An explanation will be given of an example of a structure of a conventional stencil printing machine and a problem thereof in reference to FIG.
11
through FIG.
13
. As shown by
FIG. 11
, the stencil printing machine is provided with a printing drum
100
in a shape of a hollow cylinder and an outer roller
101
provided outside of the printing drum
100
. The printing drum
100
and the outer roller
101
are arranged by interposing a predetermined interval therebetween and central axes thereof are in parallel with each other.
First, the printing drum
100
is provided with two pieces of side plates arranged to be opposed to each other by interposing a predetermined interval therebetween and one piece of a shaft
103
for coaxially connecting the two side plates
102
. The side plates
102
and the shaft
103
are rotatably provided in a frame of the printing machine. The side plates
102
and the shaft
103
are driven to rotate by being connected to driving means, not illustrated.
Outer peripheral faces of the side plates
102
are wound with a flexible peripheral wall
104
. One end of the peripheral wall
104
is fixed and placed on the respective side plates
102
. The other end thereof is connected by a spring. The peripheral wall
104
is formed with an ink-permeable perforated portion
105
substantially in a rectangular shape. The perforated portion
105
corresponds to a printing area. Further, a surrounding of the perforated portion
105
constitutes a nonperforated portion
109
for preventing ink from permeating therethrough. Although not illustrated, ink supplying means is provided at the inner portion of the printing drum
100
. The ink supplying means can supply ink to an inner peripheral face of the printing drum
100
. An inner roller
106
is provided at the inner portion of the printing drum
100
. The inner roller
106
is attached pivotably to the shaft
103
. The inner roller
106
is moved to lift and lower at predetermined timings in synchronism with rotation of the printing drum
100
and presses the peripheral wall
104
to an outer side in printing operation. The peripheral wall
104
pressed by the inner roller
106
is deformed to an outer side against urge force of the spring, mentioned above.
As shown by
FIG. 12
, a perforated stencil sheet
107
is wound around the outer peripheral face of the peripheral wall
104
of the printing drum
100
. The stencil sheet
107
covers all of the perforated portion
105
of the peripheral wall
104
. The stencil sheet
107
is of a size covering the nonperforated portion
109
at the surrounding of the perforated portion
105
. When the printing drum
100
is rotated, the inner roller
106
is lifted and lowered in synchronism therewith. A print sheet
108
is supplied between the printing drum
100
and the outer roller
101
at a predetermined timing. The print sheet
108
is transferred while being sandwiched between the peripheral wall
104
deformed outwardly by being pressed by the inner roller
106
and the outer roller
101
. During the time period, ink is transcribed onto the print sheet
108
by permeating from the perforated portion
105
through a perforated portion of the stencil sheet
107
to thereby carry out stencil printing.
However, the stencil sheet
107
is only wound around the outer peripheral face of the peripheral wall
104
and brought into contact therewith. Therefore, when the stencil sheet
107
is applied with pressure by being sandwiched between the inner roller
106
and the outer roller
101
, as shown by
FIG. 13
, ink which has permeated through the perforated portion
105
of the peripheral wall
104
spreads to outer sides. Thereby, there has been a case in which ink leaked out from a gap between the nonperforated portion
109
of the peripheral wall
104
and the stencil sheet
107
.
SUMMARY OF THE INVENTION
Hence, it is an object of the present invention to provide a stencil printing machine capable of preventing ink from leaking out from between a peripheral wall and a stencil sheet in order to resolve the above-described problem.
In order to achieve the above-described object, according to a first aspect of the present invention, there is provided a stencil printing machine comprising:
a printing drum
1
in a cylindrical shape having a peripheral wall
7
having an ink-nonpermeable nonperforated portion
123
around an ink-permeable perforated portion
121
, wound with a perforated stencil sheet
127
on an outer peripheral face of the peripheral wall
7
and rotating around a central axis line of the printing drum
1
per se;
ink supplying means provided at inside of the printing drum
1
for supplying ink onto an inner peripheral face of the peripheral wall
7
;
an inner roller
23
provided at the inside of the printing drum
1
in parallel with the printing drum
1
and brought into contact with the inner peripheral face of the peripheral wall
7
over the perforated portion
121
and the nonperforated portion
123
; and
an outer roller
63
provided at outside of the printing drum
1
in parallel with the printing drum
1
and brought into contact with the outer peripheral face of the peripheral wall
7
;
wherein a thickness t
2
of the nonperforated portion
123
is formed to be thicker than a thickness t
1
of the perforated portion
121
and the nonperforated portion
123
is projected to the inner peripheral face of the peripheral wall
7
; and
wherein the nonperforated portion
123
is sandwiched between the inner roller
23
and the outer roller
63
.
According to a second aspect of the present invention, there is provided the stencil printing machine in the stencil printing machine according to the first aspect:
wherein a portion of the nonperforated portion
123
formed to be thicker than the perforated portion
121
is constituted by a projected portion
125
provided on the nonperforated portion
123
on the side of the inner peripheral face of the peripheral wall
7
; and
wherein the projected portion
125
is formed along both side edge portions of the perforated portion
121
in a direction of rotating the printing drum
1
.
According to a third aspect of the present invention, there is provided the stencil printing machine in the stencil printing machine according to the first aspect:
wherein a portion of the nonperforated portion
123
formed to be thicker than the perforated portion
121
is constituted by a projected portion
125
provided on the nonperforated portion
123
on the side of the inner peripheral face of the peripheral wall
7
; and
wherein the projected portion
125
is formed along both side edge portions and a rear side edge portion of the perforated portion
121
in a direction of rotating the printing drum
1
.
According to a fourth aspect of the present invention, there is provided the stencil printing machine in the stencil printing machine according to the second aspect or the third aspect:
wherein the inner roller
23
is formed with recess portions
129
brought in mesh with the projected portions
125
and constituting recesses lower than a height of the projected portions
125
at portions of the inner roller
23
brought into contact with the projected portions
125
formed along the both side edge portions of the perforated portion
121
.
According to a fifth aspect of the present invention, there is provided the stencil printing machine in the stencil printing machine according to the first aspect:
wherein the nonperforated portion
123
is constituted by coating an ink-nonpermeable material to
Motoe Katsuro
Nogi Hideaki
Kanesaka & Takeuchi
Riso Kagaku Corporation
Yan Ren
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