Printing – Stenciling – Rotary machines
Reexamination Certificate
2000-09-14
2003-02-18
Hirshfeld, Andrew H. (Department: 2854)
Printing
Stenciling
Rotary machines
C101S118000
Reexamination Certificate
active
06520078
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stencil printing machine perforating stencil sheet mounted to a printing drum and capable of carrying out printing operation by using thereof, particularly to a stencil printing machine supplying perforated stencil sheet to a plurality of printing drums.
2. Description of the Related Art
FIG. 4
is a side view showing a conventional stencil printing machine. Stencil sheet S to be perforated is wound in a roll-like shape and is rotatably supported. The stencil sheet S reeled out from the stencil sheet S in the roll-like shape is constituted by a shape of a continuous strip. The reeled-out stencil sheet S is pinched between a thermal head
50
and a platen roller
51
.
The stencil sheet S is heated and perforated by the thermal head
50
(stencil making operation). In carrying out the heating and stencil making operation, the stencil sheet S is transferred by rotation of the platen roller
51
while being brought into contact with the thermal head
50
. Thereafter, the stencil sheet S is contained in a storage box
52
until finishing the heating and stencil making operation of one block by the thermal head
50
. The stencil sheet S is contained in the storage boxes
52
by feeding the stencil sheet only by the platen roller
51
while upper and lower load rollers
53
and
54
disposed above the storage box
52
are stationary and pinching the stencil sheet S. Further, a common transfer path
55
is arranged at the front side of the storage box
52
. The common transfer path
55
is provided with cutter means
56
for cutting one block of the perforated stencil sheet S.
After finishing the heating and stencil making operation, the thermal head
50
is moved in an upper direction to thereby release the stencil sheet S from being pinched by the thermal head
50
along with the platen roller
51
. The stencil sheet S finished with the heating and stencil making operation is
In the meantime, according to the stencil printing machine shown by
FIG. 4
, the perforated stencil sheet S is transferred to two of the printing drums
57
. Therefore, the stencil printing machine is provided with respective transfer paths
58
for feeding the stencil sheet S from the common transfer path
55
to the respective printing drums
57
and a switch mechanism
60
for selectively switching the paths to communicate the paths from the common transfer paths
55
to either of the transfer paths
58
. Each of the transfer paths
58
guides the stencil sheet S between upper and lower guide plates
58
a
and
58
b
and transfers the stencil sheet S by a plurality of transfer roller pairs
59
. The switch mechanism
60
is arranged between the common transfer path
55
and the respective transfer paths
58
and is provided with a shunt transfer path
62
movable by a solenoid
61
. The shunt transfer path
62
moved by the solenoid
61
opens the path to communicate from the common transfer path
55
to one of the transfer paths
58
or opens the path to communicate from the common transfer path
55
to the other of the transfer paths
58
.
The stencil sheet S transferred to one of the transfer paths
58
or the other of the transfer paths
58
, is pinched by a clamp plate
63
disposed at the printing drum
57
at its front end, fixed to the printing drum
57
, thereafter transferred by rotation of the printing drum
57
and is made to wrap on a peripheral face of the printing drum
57
. Further, the stencil sheet S is cut into one block by the cutter means
56
during the transfer operation or in arrival at the printing drum
57
.
Further, the stencil printing machine shown by
FIG. 4
is adopted in a printing machine. A portion of a constitution of the printing machine is not illustrated. A portion of a peripheral wall
64
of the printing drum
57
is ink-permeable. There is provided ink supply means, not illustrated, for supplying ink to an inner face of the peripheral wall
64
at inside of the printing drum
57
. There is provided pressing means, not illustrated, for pressing print sheet to the printing drum
57
below the printing drum
57
. The printing machine rotates the printing drum
57
, feeds print sheet between the printing drum
57
and the pressing means at predetermined timings and presses print sheet at image portions of the stencil sheet S mounted to the printing drum
57
. Printing ink supplied from inside of the printing drum
57
passes through the peripheral wall
64
of the printing drum
57
and is transcribed from perforated portions of the stencil sheet S onto print sheet to thereby form picture.
However, according to the above-described conventional stencil printing machine, when the perforated stencil sheet S is transferred to the printing drum
57
, there is needed the long transfer path
58
for transferring the perforated stencil sheet S to the printing drum
57
particularly remote from a position where the stencil printing machine per se is installed. Further, when the transfer path
58
is long, a large number of the transfer roller pairs
59
is needed. Further, there is needed the switch mechanism
60
for switching the paths from the common transfer path
55
to the respective transfer paths
58
. As described above, there poses a problem that in the conventional stencil printing machine, a number of constituent parts for transferring the perforated stencil sheet S is large.
Further, when a large number of the transfer roller pairs
59
is used, there is a concern in which balance of pinch pressure at the respective transfer roller pairs
59
is delicately deteriorated and the stencil sheet S is transferred in an oblique direction. Thereby, there poses a problem that there causes mounting position failure in which a position of mounting the stencil sheet S to the printing drum
57
is not disposed at a predetermined position or wrinkle is caused in the stencil sheet S mounted to the printing drum
57
.
Further, by prolonging the transfer path
58
, there poses a problem that the stencil sheet S is clogged between the upper and the lower guide plates
58
a
and
58
b
or a front end of the stencil sheet is folded. The above-described problem is liable to occur particularly in the stencil sheet S used in the printing machine since the stencil sheet S comprises a sheet produced by pasting a heat-sensitive film together with a porous supporter such as Japanese paper and accordingly, the stencil sheet S is easy to fold.
Hence, in order to resolve the above-described problems, it is an object of the present invention to provide a stencil printing machine capable of feeding stencil sheet to a plurality of printing drums without causing mounting failure or transfer failure.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a stencil printing machine comprising a plurality of printing drums arranged to be spaced apart from each other at intervals and wound with perforated stencil sheet at respective peripheral walls thereof, a stencil making unit for perforating the stencil sheet, and a moving mechanism for supporting the stencil making unit to be movable relative to the respective printing drums.
According to a second aspect of the present invention, there is provided the stencil printing machine according to the first aspect wherein the moving mechanism comprises a guide portion for supporting the stencil making unit movably relative to the respective printing drums, a drive portion for moving the stencil making unit via the guide portion, and position detecting means for detecting that the stencil making unit is disposed at a desired position.
According to a third aspect of the present invention, there is provided a stencil printing machine comprising a plurality of printing drums arranged horizontally to be contiguous to each other at intervals such that respective axis lines thereof are made parallel to each other and respective peripheral walls being wound with perforated stencil sheets, a stencil making unit for perforating and delive
Hirshfeld Andrew H.
Kanesaka & Takeuchi
Riso Kagaku Corporation
Williams Kevin D.
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