Printing – Stenciling – Rotary machines
Reexamination Certificate
2000-09-11
2002-11-12
Funk, Stephen R. (Department: 2854)
Printing
Stenciling
Rotary machines
C101S120000
Reexamination Certificate
active
06477946
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-264540, filed Sep. 17, 1999; the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stencil printing machine of an inner pressure type for acting a printing pressure onto the inner peripheral surface of a printing drum.
2. Description of the Related Art
There is a conventional stencil printing machine of the inner pressure type that has been disclosed in the Japanese laid-open publication No. 10-100528, for example.
FIG. 1
is a partially sectional view of the conventional stencil printing machine of the above example. In
FIG. 1
, the parts of the outer peripheral surfaces of both a printing drum
100
and a pressure roller
101
are rotatably arranged in close proximity to each other. The peripheral surface of the printing drum
100
is made up of a screen. A stencil sheet
103
can be fitted on and removed from the outer peripheral surface of a screen
102
.
An inner press roller
104
is arranged or placed in the printing drum
100
so that the inner press roller
104
is rotatable around a lever
106
that is supported around the center of a supporting shaft
105
. The inner press roller
104
is moved between the standby position and the pressure position A. The standby position is separated in arrangement from the inner peripheral surface of the screen
102
. At the pressure position A, the inner press roller
104
presses the inner peripheral surface of the screen
102
. An inner press mechanism
107
is arranged in the printing drum
100
.
The inner press mechanism
107
comprises an inner press roller shift means
108
and a pressure adjustment means
109
for the inner press roller
104
. The inner press roller shift means
108
provides a driving power to the lever
106
so that the inner press roller
104
can be shifted between the standby position and the pressure position A. The pressure adjustment means
109
for the inner press roller
104
can adjust the pressure power of the inner press roller
104
at the pressure position A.
The inner press roller shift means
108
has a shifting motor
110
whose rotation shaft is fixed to a first gear
111
. This first gear
111
is meshed with a second gear
112
correctly. In addition, an eccentric cam
113
is fixed to the second gear
112
. The cam surface of the eccentric cam
113
contacts with a cam follower
114
that is supported rotatably by a lever
106
. When the shifting motor
110
is rotating, this rotation is transmitted to the eccentric cam
113
through the first and second gears
111
and
112
. Then, the lever
106
rotates according to the rotation position of the eccentric cam
113
, so that the inner press roller
104
is shifted between the standby position and the pressure position A shown in FIG.
1
.
The pressure adjustment means
109
for the inner press roller
104
has the adjustment motor
115
whose rotation shaft is fixed to a third gear
116
. The third gear
116
and a fourth gear
117
are meshed. A nut member
118
is fixed to this fourth gear
117
. A screw rod
119
is inserted to the threaded hole of this nut member
118
, and one end of a screw rod
119
is connected to one end of a spring
121
through an arm member
120
.
Other end of this spring
121
is connected to the lever
106
and the inner press roller
104
may press the screen
102
by the pressure of the spring
121
. When the adjustment motor
115
rotates, this rotation is transmitted to the screw rod
119
in order to rotate the screw rod
119
through the third gear
116
, the fourth gear
117
, and the nut member
118
. The screw rod
119
is thereby shifted toward the shaft direction thereof and a stroke of the spring
121
is changed in order to adjust the pressure power of the inner press roller
104
.
Next, a description will be given to an outline of the operation of the conventional stencil printing machine.
After perforations for printing a desired image pattern are made on the stencil sheet
103
, the perforated stencil sheet
103
(hereinafter, also referred to as the stencil sheet) is set up on the peripheral surface of the screen
102
forming the wall of the printing drum
100
by clamping the leading edge of the stencil sheet
103
.
Next, the inner press roller
104
is shifted to the pressure position A from the standby position by the inner press roller shiftmeans
108
and then both the printing drum
100
and the pressure roller
101
rotate simultaneously. Then, the inner press roller
104
presses the screen
102
, and in this state, the inner press roller
104
also rotates following the rotation of the printing drum
100
. Ink is supplied on the outer peripheral surface of the inner press roller
104
. Then, the ink adhered on the outer peripheral surface of the inner press roller
104
is moved onto the screen in turn.
In this situation, as shown in
FIG.1
, the print paper
122
is fed between the printing drum
100
and the pressure roller
101
and also continuously fed by the rotation of both the printing drum
100
and the pressure roller
101
. The print paper
122
between the printing drum
100
and the pressure roller
101
is fed to outside while pressing the print paper
122
, the screen
102
, and the stencil sheet
103
between the inner press roller
104
and the pressure roller
101
.
The ink of the image pattern on the screen
102
is moved (or printed) from the perforations on the stencil sheet
103
onto the print paper
122
according to the stencil pattern on the stencil sheet
103
. Because the print concentration on the print paper
122
is proportional to the pressure of the inner press roller
104
, the pressure of the inner press roller
104
may be adjusted by the pressure adjustment means
109
for the inner press roller
104
in order to adjust the concentration of the print on the print paper
122
.
However, because the inner press mechanism
107
is arranged in the printing drum
100
in the conventional stencil printing machine having the configuration shown in
FIG. 1
, it is impossible to reduce the diameter of the printing drum
100
as small as possible. That is, for example, although the stencil printing machine of a small size using small-sized print papers can be obtained by reducing the diameter of the printing drum
100
, it is impossible to reduce the stencil printing machine having the configuration where the whole body of the inner press mechanism
107
is contained in the printing drum
100
.
SUMMARY OF THE INVENTION
In the light of the above mentioned situations, the present invention has been made. An object of the present invention is, with due consideration to the drawbacks of the conventional technique, to provide a stencil printing machine having a small sized configuration by reducing the diameter of a printing drum thereof.
In accordance with a preferred embodiment of the present invention, a stencil printing machine has a printing drum, a pressure drum, a stencil sheet, an inner press roller, and an inner press mechanism. The outer peripheral surfaces of both the printing drum and the pressure drum are close to each other and rotatable independently. The stencil sheet is attached-on and removable from an outer peripheral surface of the printing drum. The inner press roller is arranged in an inner peripheral surface side of the printing drum, and is shifted between a pressure position at which the inner press roller presses the inner peripheral surface of the printing drum, and a standby position at which the inner press roller is separated in position from the inner peripheral surface. The inner press mechanism adjusts a pressure power of the inner press roller at the pressure position and which comprises an ink supply unit and a power transfer means. The ink supply unit is arranged at inside of the printing drum for shifting the inner press roller between the pressure position and the s
Berkowitz Marvin C.
Funk Stephen R.
Nath Gary M.
Novick Harold L.
Riso Kagaku Corporation
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