Information
-
Patent Grant
-
6348963
-
Patent Number
6,348,963
-
Date Filed
Thursday, January 25, 200123 years ago
-
Date Issued
Tuesday, February 19, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 355 75
- 355 76
- 271 259
- 271 276
- 271 277
- 101 486
-
International Classifications
-
Abstract
A leading edge chuck provided at a leading edge clamp unit and a trailing edge chuck provided at a trailing edge clamp unit are removable from a rotating drum. Therefore, a direction in which the rotating drum rotates in order for printing plates to be mounted thereon, a direction of rotation when the printing plates are exposed, and a direction of rotation in order for the printing plates to be removed from the rotating drum may all be made into a same, single direction. Accordingly, labor impacting working effectiveness, such as switching the rotational direction of the rotating drum, can be eliminated, and image exposure can be conducted rapidly.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus by which sheet material is subjected to a predetermined processing, and an image recording apparatus.
2. Description of the Related Art
Generally, a photosensitive printing plate (hereinafter referred to as a “printing plate”), in which a photosensitive layer is formed on a support formed in a sheet configuration such as a thin aluminium plate, is utilized in printing. The printing plate is used as a printing plate for printing when development processing and the like is effected after an image has been recorded by exposure.
In such an image exposure apparatus in which a printing plate is subjected to image exposure, a light beam corresponding to image data to be recorded on the printing plate is irradiated on the printing plate while the printing plate is mounted to a revolving drum and held thereto as the rotating drum is rotated at a high speed, whereby the printing plate is scanned and exposed.
Among image exposure apparatuses in which a printing plate is exposed to light using a rotating drum, there is an image exposure apparatus that uses a fixing device to fix non-image portions of both ends of the printing plate along the circumferential direction of the rotating drum by clamping the ends of the printing plate to the rotating drum when the printing plate has been mounted to the rotating drum. Such a fixing device generally nips the printing plate ends between clamp portions and the rotating drum by urging the clamp portions facing the printing plate toward the periphery of the rotating drum with an urging force.
However, because a leading edge portion of the printing plate is clamped by a clamp that is continuously fixed to the rotating drum, there has been the need to switch a trailing edge of the printing plate with the leading edge (i.e., reverse the rotating drum) at the time the printing plate is ejected. There has thus been a problem in that switching the rotation of the drum from a normal rotation to a reverse rotation not only requires time, but the interval until the next image is exposed becomes long and working efficiency is poor.
SUMMARY OF THE INVENTION
The present invention has been devised in consideration of the facts described above. An object of the present invention is to provide an apparatus and method in which sheet material is subjected to a predetermined processing, and an image recording apparatus, which can improve working efficiency.
This object is achieved in accordance with the principles of the present invention by an apparatus for subjecting sheet material to predetermined processing, the apparatus comprising:
(a) a rotatably mounted drum having a periphery for winding sheet material thereon;
(b) a leading edge clamp unit movable to a withdrawn position separated from the drum and to a clamping position proximate the drum, the leading edge clamp unit including a leading edge chuck for clamping the leading edge of the sheet material to the drum;
(c) a trailing edge clamp unit movable to a withdrawn position separated from the drum and to a clamping position proximate the drum, the trailing edge clamp unit including a trailing edge chuck for clamping the trailing edge of the sheet material to the drum;
(d) a processing element by which sheet material on the periphery of the drum is subjected to predetermined processing;
(e) a wrapping element, that moves in correspondence with a clamp operation of the leading edge chuck, to wrap the sheet material on the periphery of the drum in a sequence of a sheet material front portion, a middle portion and an end portion; and
(f) a separation element, that moves in correspondence with an unclamp operation of the leading edge chuck, to separate the sheet material from the periphery of the drum in a sequence of the sheet material front portion, middle portion and end portion.
The object is also achieved in accordance with the principles of the present invention by a method of subjecting sheet material to predetermined processing, using a rotatable drum having a periphery on which sheet material is wound, the method comprising the steps of:
(a) clamping the sheet material leading edge to the drum;
(b) winding the sheet material on the drum periphery in order of the sheet material front portion, middle portion and end portion;
(c) clamping the sheet material trailing edge to the drum;
(d) subjecting the sheet material on the drum periphery to predetermined processing;
(e) disengaging the clamp on the sheet material leading edge; and
(f) removing the sheet material from the drum periphery in order of the sheet material front portion, middle portion and end portion.
The object is also achieved in accordance with the principles of the present invention by an apparatus for recording an image on a printing plate, the apparatus comprising:
(a) a rotatably mounted drum having a periphery for winding a printing plate thereon;
(b) a leading edge clamp unit movable to a withdrawn position spaced from the drum and to a clamping position proximate the drum, the leading edge clamp unit including a leading edge chuck for clamping the printing plate leading edge to the drum, and a moving mechanism, which when operated, moves the leading edge chuck between the withdrawn and clamping positions;
(c) a trailing edge clamp unit movable to a withdrawn position spaced from the drum and to a clamping position proximate the drum, the trailing edge clamp unit including a trailing edge chuck for clamping the printing plate trailing edge to the drum, and a moving mechanism, which when operated, moves the trailing edge chuck between the withdrawn and clamping positions;
(d) a recording head disposed for recording an image on a printing plate on the drum periphery;
(e) a wrapping element, that moves in correspondence with a clamp operation of the leading edge chuck, to wrap the printing plate on the drum periphery in a sequence of a printing plate front portion, a middle portion and an end portion; and
(f) a separation element, that moves in correspondence with a clamp disengaging movement of the leading edge chuck, to separate the printing plate from the drum periphery in the sequence of the printing plate front portion, middle portion and end portion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a schematic structural view illustrating an image exposure apparatus according to an embodiment of the present invention.
FIG. 2
is a perspective view of a leading edge (trailing edge) chuck on a rotating drum.
FIG. 3
is a cross-section view of the leading edge (trailing edge) chuck.
FIG. 4
is an expanded perspective view of portion of the leading edge (trailing edge) chuck for supporting the leading edge (trailing edge) chuck at the rotating drum.
FIG. 5A
is a plan view of portion of the leading edge (trailing edge) chuck for supporting the leading edge (trailing edge) chuck at the rotating drum.
FIG. 5B
is a cross-section view cut along line
5
B—
5
B of FIG.
5
A.
FIG. 6A
is a plan view of the portion of the leading edge (trailing edge) chuck for supporting the leading edge (trailing edge) chuck at the rotating drum.
FIG. 6B
is a cross-section view cut along line
6
B—
6
B of FIG.
6
A.
FIGS. 7A-7H
are views illustrating a series of steps from clamping to removing of the printing plate with respect to the drum periphery.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a preferred embodiment of the present invention will be described with reference to drawings. In
FIG. 1
, a schematic structural view of an image exposure apparatus
10
is illustrated. Using a photosensitive planographic plate (hereinafter referred to as a “printing plate
12
”), in which a photosensitive layer is formed on a thin (e.g., having a thickness of about 0.3 mm), rectangular plate support formed of, for example, aluminium, the image exposure apparatus
10
irradiates onto the printing plate
12
a light beam modified on the basis of image data, whereby the printing plate
12
is scanned and exposed. The printing plate
12
, for which image exposure has been completed by the image exposure apparatus
10
, is then subjected to development processing and the like by an unillustrated automatic developing apparatus.
A cassette loading section
18
, a plate-supplying conveyor section
20
, a recording section
22
and an ejection buffer section
24
are disposed inside a machine casing
14
to structure the image exposure apparatus
10
. The cassette loading section
18
is disposed at a lower right-hand side of
FIG. 1
inside the machine casing
14
. A plurality of cassettes
16
, that each accommodate a plurality of printing plates
12
, is loaded at a predetermined angle θ in a state in which the cassettes
16
are slanted in the cassette loading section
18
.
It is possible to process in the image exposure apparatus
10
numerous-sized printing plates
12
having different vertical and horizontal dimensions. Printing plates
12
of whatever size are accommodated in the cassettes
16
such that the photosensitive layers of the printing plates
12
face upward and an end thereof is positioned to correspond to a predetermined position. Further, a plurality of the cassettes
16
is loaded in the cassette loading section
18
such that an end of the printing plates
12
accommodated in each cassette
16
reaches a substantially constant height at predetermined intervals.
The plate-supplying conveyor section
20
is disposed above the cassette loading section
18
. The recording section
22
is disposed at a lower, central area within the image exposure apparatus
10
, adjacent to the cassette loading section
18
. A pair of side plates
26
(only one of which is illustrated in
FIG. 1
) is provided in the plate-supplying conveyor section
20
. A reversal unit
28
and a sheet unit
30
are mounted at the side plates
26
.
The reversal unit
28
is provided with a reverse roller
32
having an outside diameter of a predetermined dimension. A plurality of small rollers (in the present embodiment, four small rollers
34
A,
34
B,
34
C and
34
D are shown as an example) is provided at the periphery of the reverse roller
32
. The small rollers
34
A through
34
D are disposed so as to straddle the reverse roller
32
from the cassette loading section
18
to the recording section
22
, and an endless conveyor belt
36
is mounted on the small rollers
34
A to
34
D. Accordingly, the conveyor belt
36
is wound on the reverse roller
32
so that the conveyor belt
36
stretches to roughly half the circumference of the reverse roller
32
between the small roller
34
A and the small roller
34
D.
The sheet unit
30
is provided with a plurality of suction cups
38
that adsorb top ends of the printing plates
12
inside the cassettes
16
. The sheet unit
30
lowers the suction cups
38
down toward the top ends of the printing plates
12
inside the cassettes
16
loaded in the cassette loading section
18
, whereby the printing plates
12
are adsorbed by the suction cups
38
. The sheet unit
30
then raises the suction cups
38
that have adsorbed the printing plates
12
, whereby the printing plates
12
are extracted from the cassettes
16
and leading edges of the extracted printing plates
12
are inserted between the reverse roller
32
and the conveyor belt
36
. An outline of the position in which the suction cups
38
move is indicated in
FIG. 1
by a two-dot chain line.
The reversal unit
28
rotates the reverse roller
32
and the conveyor belt
36
in the direction that the printing plates
12
are extracted from the cassettes
16
(i.e., in the direction of arrow A in FIG.
1
). Accordingly, the printing plates
12
are nipped between the reverse roller
32
and the conveyor belt
36
and extracted from the cassettes
16
. The printing plates
12
are then mounted on the periphery of the reverse roller
32
, whereby they are curved, conveyed and reversed. The radius of the reverse roller
32
is of a dimension (e.g., 100 mm) such that kinks or bends are not generated in the printing plates
12
at the time the printing plates
12
have been curved.
As indicated by the solid line and the two-dot chain line in
FIG. 1
, the side plates
26
move horizontally in accordance with the position of the cassettes
16
from which the printing plates
12
are to be extracted. Accordingly, the suction cups
38
of the sheet unit
30
oppose the printing plates
12
within the cassette
16
that has been selected.
Further, a guide
40
is provided below the small roller
34
D at the side plate
26
. Printing plates
12
reversed by the reversal roller
32
are sent toward the guide
40
from between the reversal roller
32
and the conveyor belt
36
at the small roller
34
D side. A conveyor
42
is disposed above the recording section
22
, and printing plates
12
sent out from the reversal unit
28
are guided to the conveyor
42
by the guide
40
.
Further, the guide
40
oscillates in accompaniment with a movement of the side plates
26
such that the guide
40
ensures that the direction in which the printing plates
12
are guided is always toward the conveyor
42
. The small roller
34
D near the recording section
22
moves in accompaniment with the movement of the side plates
26
to alter the direction in which the printing plates are fed out from the reversal unit
28
. When the small roller
34
D moves, the small roller
34
C moves to provide a substantially constant tension to the conveyor belt
36
. Accordingly, printing plates
12
fed out from the reversal unit
28
are gently curved by the guide
40
.
At the conveyor
42
, a conveyor belt
48
is wound between a roller
44
adjacent to an area beneath the plate-supplying conveyor section
20
and a roller
46
adjacent to an area above the recording section
22
. The conveyor
42
is slanted such that the roller
46
is disposed lower than the roller
44
. A roller
50
that opposes the roller
46
is disposed at the conveyor
42
. Printing plates that have been sent to the conveyor
42
are conveyed on the conveyor belt
48
and nipped by the roller
46
and the roller
50
.
A rotating drum
54
and a recording head
56
are mounted on a rack
52
at the recording section
22
. A puncher
58
is disposed above the rotating drum
54
. Printing plates
12
are nipped by the roller
46
and the roller
50
, and the leading edges of the printing plates
12
are inserted into an opening
60
in the puncher
58
and retained. When the leading edges of the printing plates
12
are inserted into the opening
60
, the puncher
50
forms a position-determining notch at a predetermined position in the leading edges of the printing plates
12
.
When a notch is formed in the printing plate
12
, the conveyor
42
drives in reverse the conveyor belt
48
and the rollers
46
and
50
, and extracts the leading edge of the printing plate
12
from the opening
60
of the puncher
58
. Further, an unillustrated oscillating means is disposed at the conveyor
42
. Using the roller
44
as an axis, the roller
46
is lowered by the oscillating means toward the rotating drum
54
of the recording section
22
. Accordingly, the leading edge of the printing plate
12
on the conveyor belt
48
is disposed at a predetermined position at the periphery of the rotating drum
54
, by the printing plate
12
on the conveyor belt
48
being directed toward the rotating drum
54
and conveyed thereto.
The rotating drum
54
is rotated by the unillustrated oscillating means only in a counter-clockwise direction of
FIG. 1
(i.e., in the direction of arrow B in FIG.
1
).
A leading edge clamp unit
200
is disposed at a predetermined position along the periphery of the rotating drum
54
. The leading edge clamp unit
200
is provided with a leading edge chuck
62
and a moving mechanism
202
. The moving mechanism
202
moves the leading edge chuck
62
in the radial direction of the rotating drum
54
, and can take a predetermined position at the circumferential surface of the rotating drum
54
and a position removed from the rotating drum
54
. Structural details of the leading edge clamp unit
200
will presently be discussed.
Here, when a printing plate
12
is to be mounted on the rotating drum
54
, the position of the leading edge chuck
62
is decided in advance to be at a predetermined position at the circumferential surface of the rotating drum
54
(at this time, the leading edge chuck
62
is in a state of separation from the moving mechanism
202
). In a state in which the leading edge of the printing plate
12
is fed from a tangential direction by the conveyor
42
and nipped by the rotating drum
54
and a squeeze roller
66
that acts as a presser roller, the leading edge of the printing plate
12
(see arrow C in
FIG. 1
) temporarily stops the rotating drum
54
at a position corresponding with the leading edge chuck
62
(i.e., a printing plate mounting position), or rotates the rotating drum
54
at an ultra-low speed.
A cam (not illustrated) is provided at the leading edge chuck
62
. By the rotation of the cam, an insertion space for the printing plate
12
is created at the circumferential surface of the rotating drum
54
. Thereafter, in a state in which the leading edge of the printing plate
12
has been inserted between the leading edge chuck
62
and the rotating drum
54
, the cam is rotated, and the leading edge of the printing plate
12
is nipped and held between the leading edge chuck
62
and the circumferential surface of the rotating drum
54
. At this time, the printing plate
12
is positioned with respect to the rotating drum
54
, by a position-determining pin (not illustrated) that protrudes from a predetermined position at the circumferential surface of the rotating drum
54
being set into the notch of the printing plate
12
formed by the puncher
58
.
When the leading edge of the printing plate
12
is fixed at the rotating drum
54
, the rotating drum
54
once again rotates, or continues to rotate, in the same direction (i.e., the direction of arrow B in FIG.
1
), whereby the printing plates
12
that are fed out from the conveyor
42
are sequentially wound onto the circumferential surface of the rotating drum
54
(see arrow D in FIG.
1
).
At an upper stream vicinity of the leading edge clamp unit
200
, the squeeze roller
66
that functions as a first presser roller moves toward the rotating drum
54
, whereby the printing plate
12
wound upon the rotating drum
54
is pressed toward the rotating drum
54
. The printing plate
12
is thus closely adhered to the circumferential surface of the rotating drum
54
.
A trailing edge clamp unit
68
is disposed at an upper stream vicinity of the leading edge clamp unit
200
. The trailing edge clamp unit
68
is provided with a trailing edge chuck
74
and a moving mechanism
69
. The moving mechanism
69
moves the trailing edge chuck
74
in the radial direction of the rotating drum
54
, and can take a predetermined position at the circumferential surface of the rotating drum
54
and a position removed from the rotating drum
54
. The trailing edge clamp unit
68
has substantially the same structure as that of the leading edge clamp unit
200
. Structural details of the trailing edge clamp unit
68
will presently be discussed.
At the trailing edge clamp unit
68
, while the printing plate
12
is wound onto the rotating drum
54
, the trailing edge chuck
74
is held by the moving mechanism
69
at a position removed from the rotating drum
54
, whereby interference with the printing plates
12
is prevented.
Here, at the point in time when the winding of the printing plate
12
onto the rotating drum
54
is roughly concluded and the trailing edge of the printing plate
12
arrives between the trailing edge clamp unit
68
and the rotating drum
54
, the moving mechanism
69
is operated and the trailing edge chuck
74
is mounted at a predetermined position at the rotating drum
54
(separate from the moving mechanism
69
). Thereafter, the trailing edge chuck
74
presses the trailing edge of the printing plate
12
against the outer surface of the rotating drum
54
where the trailing edge of the printing plate
12
is held. At this time, the squeeze roller
66
functions as a second presser roller and prevents the trailing edge of the printing plate
12
from rising, whereby the trailing edge of the printing plate
12
is reliably clamped.
In the recording section
22
, after the leading edge and the trailing edge of the printing plate
12
have been held at the rotating drum
54
, the squeeze roller
66
is moved away from the rotating drum
54
. Thereafter, while the rotating drum
54
is rotated at a high speed in the same direction (i.e., the direction of arrow B in FIG.
1
), a light beam modulated on the basis of image data is irradiated from the recording head
56
in synchrony with the rotation of the rotating drum
54
. Accordingly, the printing plate
12
is scanned and exposed on the basis of the image data.
Namely, the recording head
56
irradiates a light beam to conduct a main scanning by rotating the drum
54
and to conduct a sub-scanning along a rotational axis of the drum
54
in connection with the main scanning, such that an image may be recorded on the printing plate
12
.
When scanning and exposure of the printing plate
12
is completed, the leading edge chuck
62
that is holding the leading edge of the printing plate
12
momentarily stops (or rotates at an ultra-low speed) the rotating drum
54
at a position corresponding to the leading edge clamp unit
200
. In addition, the clamping of the printing plate
12
is released, and the printing plate
12
is nipped at the rotating drum
54
by a squeeze roller
204
that functions as a third presser roller. At the leading edge clamp unit
200
, the moving mechanism
202
is operated, and the leading edge chuck
62
is removed from the rotating drum
54
. Accordingly, the leading edge of the printing plate
12
is released.
Thereafter, with the squeeze roller
66
as a starting point, the printing plate
12
is fed away in a direction tangential to the rotating drum
54
by the rotation of the rotating drum
54
in the same direction.
As illustrated in
FIG. 1
, the printing plate
12
is guided by a guide plate
208
provided with a plurality of rollers
206
, and conveyed at a circular arc movement locus in the direction of the ejection buffer section
24
.
The clamping of the trailing edge of the printing plate
12
by the trailing edge chuck
74
is released at a predetermined timing based on the length of the direction in which the printing plate
12
is conveyed and the speed at which the rotating drum
54
rotates. In addition, the trailing edge chuck
74
is separated and moved away from the rotating drum
54
by the moving mechanism
69
of the trailing edge clamp unit
68
. Accordingly, the printing plate
12
is smoothly fed out toward the ejection buffer section
24
.
The ejection buffer section
24
is disposed to the inner side of an outlet
76
formed in the machine casing
14
, and is provided with an ejection roller
78
. A plurality of small rollers (as an example, small rollers
80
A,
80
B,
80
C,
80
D and
80
E) is disposed around the periphery of the ejection roller
78
. An endless conveyor belt
82
is wound between the small rollers
80
A through
80
E. The conveyor belt
82
is thus wound between the small rollers
80
A through
80
E around the ejection roller
78
in a range of between about ½ to about ¾ the circumference of the ejection roller
78
.
The small roller
80
A projects out toward the squeeze roller
66
of the recording section
22
, and is disposed opposite the roller
84
. The printing plate
12
fed out from the recording section
22
is guided between the small roller
80
A and the roller
84
and nipped therebetween by the same.
At the ejection buffer section
24
, while the printing plate
12
that is nipped by the small roller
80
A and the roller
84
is pulled out from the recording section
22
by the rotation of the ejection roller
78
in the same direction as that in which the printing plate
12
is extracted (i.e., the direction of arrow D in FIG.
1
), the printing plate
12
is guided to between the ejection roller
78
and the conveyor belt
82
, is nipped by the same and then wound around the ejection roller
78
. At this time, at the ejection buffer section
24
, the small roller
80
A and the roller
54
nip the leading edge (at the recording section
22
, the side of the leading edge chuck
62
) of the printing plate
12
, whereby the printing plate
12
wound around the ejection roller
78
is primarily held.
As indicated by the two-dot chain line in
FIG. 1
, at the ejection buffer section
24
, the small roller
80
A and the roller
84
move to a position facing the outlet
76
. The small roller
80
B above the small roller
80
A moves in accordance with the movement of the small roller
80
A to provide a constant tension to the conveyor belt
82
.
At the ejection buffer section
24
, when the leading edge of the printing plate
12
faces the outlet
76
, the ejection roller
78
is rotated in the direction that the printing plate
12
is ejected (i.e., the opposite direction of arrow D) at a rotational speed that corresponds to the speed at which the printing plate
12
is conveyed at processing apparatuses, such as an automatic developing apparatus and the like (not illustrated), provided adjacent to the outlet
76
. Accordingly, the printing plate
12
is fed out from the outlet
76
.
Hereinafter, structural details of the leading edge clamp unit
200
will be described. Further, since the structure of the trailing edge clamp unit
68
is the same as that of the leading edge clamp unit
200
(with the exception of a 180° difference in orientation), details thereof will be omitted.
As illustrated in
FIG. 2
, the leading edge chuck
62
is provided with a clamp
100
formed in a tie plate configuration of a predetermined length. The clamp
100
is disposed along the axial direction of the rotating drum
54
. A plurality of clamps
100
is provided at the rotating drum
54
in a row at predetermined intervals.
A clamp portion
102
is disposed at one width-direction end of each of the clamps
100
. The clamp portions
102
project toward the circumferential surface of the rotating drum
54
. The clamps
100
are disposed such that the clamp portions
102
face the upper stream side of the mounting exposure direction of the rotating drum
54
. Thus, the leading edge of the printing plate
12
is nipped between the clamp portions
102
and the circumferential surface of the rotating drum
54
, and the printing plate
12
is fixed to the rotating drum
54
.
A substantially rectangular recess
104
is formed in the clamps
100
at a plurality of areas on surfaces opposite the clamp portions
102
. As illustrated in
FIG. 3
, a leg
106
is mounted at each recess
104
.
A rectangular, block-configured base
108
is provided at the leg
106
. A leg portion
110
is vertically provided at the base
108
. A spindle
112
, which has a radius smaller than that of the leg portion
110
, projects vertically from the leg portion
110
.
A feed-through hole
114
which penetrates the recess
104
is provided at the clamp
100
, and the spindle
112
of the leg
106
is passed through the feed-through hole
114
. The clamp
100
is nipped by the leg portion
110
and a screw
116
that is screwed into the top of the spindle
112
, whereby the leg
106
is connected to the clamp
100
. The base
108
of the leg
106
is inserted into and fixed at the rotating drum
54
at a position further in from the outermost circumferential surface thereof (i.e., inserted into and fixed at slot portions
210
described below (see
FIGS. 5A
to
6
B)), whereby the leading edge chuck
62
is mounted to the rotating drum
54
.
A rest plate
118
formed of an elastic body is nipped between the leg portion
110
of the leg
106
and the clamp
100
. A keep plate
120
formed of a flexible member in a substantially rectangular configuration is nipped between the screw
116
and the clamp
100
. Further, the inside diameter of the feed-through hole
114
is slightly larger than the outside diameter of the spindle
112
.
Accordingly, the clamp portion
102
can be moved downward by applying an upward force to the end of the clamp
100
opposite the end provided with the clamp portion
102
. An urging leg
124
is thus provided adjacent to each leg
106
.
The urging leg
124
is provided with a substantially circular, plate-shaped wear plate
126
that may oppose the circumferential surface of the rotating drum
54
. A shaft
128
vertically disposed at the wear plate
126
is passed through a feed-through hole
130
formed in a pressed portion
122
of the clamp
100
.
A flange portion
132
is formed in the center of the shaft
128
along an axial direction thereof. An enlarged diameter portion
134
is formed at the feed-through hole
130
at the side opposite the rotating drum
54
. The flange portion
132
fits into the enlarged diameter portion
134
and prevents the shaft
128
from slipping through to the side of the clamp
100
at which the rotating drum
54
is provided.
A coiled spring
136
is disposed around the urging leg
124
between the wear plate
126
and the clamp
100
. The urging leg
124
is urged toward the rotating drum
54
by an urging force of the coiled spring
136
. A guide ring
138
is formed at each of the wear plate
126
and the clamp
100
, and prevents displacement of the coiled spring
136
.
When the base
108
of the leg
106
of the leading edge chuck
62
is inserted into a slot portion
210
(see
FIGS. 5A through 6B
; when seen in horizontal cross section, the slot portion
210
has a substantially inverted-T configuration) formed in the circumferential direction of the circumferential surface of the rotating drum
54
, so that the base
108
is fixed with respect to the rotating drum
54
, the wear plate
126
also makes direct contact with a bottom surface of the same slot portion
210
.
As illustrated in
FIGS. 5A through 6B
, the base portion
108
is formed in a substantial parallelogram in which the corner portions thereof have been roundedly chamfered. A relationship between a dimension H and a slot portion
210
width dimension W is expressed as H<W. Further, a relationship between a dimension C between a pair of opposing vertices and the same width dimension W is expressed as C>W. For this reason, it becomes possible to insert the base portion
108
into the slot portion
210
and remove the base portion
108
from the slot portion
210
by matching the dimension H direction with the width direction of the slot portion
210
. In addition, a state in which the base portion
108
is inserted into the slot portion
210
can be held and fixed by matching the dimension C direction with the width direction.
The clamp
100
is urged by the urging force of the coiled spring
136
in the direction in which the pressed portion
122
is separated from the circumferential surface of the rotating drum
54
, whereby the clamp portion
102
is urged toward the circumferential surface of the rotating drum
54
. The leading edge chuck
62
nips the printing plate
12
between the clamp portion
102
and the circumferential surface of the rotating drum
54
by the urging force.
As illustrated in
FIG. 4
, a rotating shaft
214
may be inserted into the top of the screw
116
. The rotating shaft
214
is rotatably moved in at least a 90° range by a driving force of an unillustrated driving means. The rotating shaft
214
can selectively match the H dimension direction or the C dimension direction of the base
108
with the width direction of the slot portion
210
. Further, the rotating shaft
214
is structured to be movable in an axial direction, and is also structured to selectively move the held leading edge chuck
62
to a predetermined position at the circumferential surface of the rotating drum
54
or a position separated from the rotating drum
54
.
Here, the rotating shaft
214
and the screw
116
are fit together via an unillustrated elastic means. Ordinarily, the elastic means moves in a state in which it is fit together with the rotating shaft
214
, but in a state in which the leg portion
108
is fit together with the slot portion
210
and fixed thereto, when the rotating shaft
214
is moved in a direction away from the rotating drum
54
, the state in which it is fit together with the screw
116
is released, and only the rotating shaft
214
is able to rise.
The working of the present embodiment will hereinafter be described.
At the image exposure apparatus
10
, image data to be exposed is input, the size and number of the printing plates
12
to be subjected to image exposure are set, and when the order to initiate image exposure is given, image exposure processing of the printing plates
12
is initiated. An operation panel is provided at the image exposure apparatus
10
. The image exposure apparatus
10
may be a kind in which instructions are given by operation of a switch at the operation panel, and it may be a kind in which initiation of processing by the image exposure apparatus
10
is ordered by a signal from an image processing apparatus that outputs image data to the image exposure apparatus
10
.
At the image exposure apparatus
10
, when processing is initiated, the reversal unit
28
and the sheet unit
30
are moved to a position corresponding to the cassettes
16
in which the printing plates
12
of a selected size are accommodated. The printing plates
12
within the appropriate cassette
16
are adsorbed and extracted by the suction cups
38
, then fed toward between the reversal roller
32
of the reversal unit
28
and the conveyor belt
36
. Accordingly, the printing plates
12
are nipped and conveyed by the reversal roller
32
and the conveyor belt
36
, and sent toward the conveyor
42
.
The conveyor
42
inserts leading edges of the printing plates
12
into the opening
60
of the puncher
58
, and the puncher
58
forms a position-determining notch at a predetermined position in the printing plates
12
. When the notches are formed in the printing plates
12
, the conveyor
42
extracts the printing plates
12
from the opening
60
of the puncher
58
and feeds the printing plates
12
to the circumferential surface of the rotating drum
54
(see FIG.
7
A).
At the recording section
22
, when the leading edges of the printing plates
12
are held at the rotating drum
54
by the leading edge chuck
62
(
FIG. 7B
) while the leading edges of the printing plates
12
are squeezed by the squeeze roller
66
, the printing plates
12
are wound on the rotating drum
54
while being squeezed by the squeeze roller
66
(FIG.
7
C), and the trailing edges of the printing plates
12
are held at the rotating drum
54
by the trailing edge chuck
74
(FIG.
7
D).
Thereafter, at the recording section
22
, while the rotating drum
54
is rotated at a high speed in the same direction, a light beam based on image data from the recording head portion
54
is irradiated onto the printing plates
12
, whereby the printing plates
12
are scanned and exposed. When scanning and exposure of the printing plates
12
is completed, clamping of the printing plates
12
by the leading edge chuck
62
is released. The printing plates
12
are removed from the rotating drum
54
(
FIG. 7E
) and fed to the ejection buffer section
24
(FIG.
7
F). Clamping of the printing plates
12
by the trailing edge chuck
74
is released at a predetermined timing (FIG.
7
G), and the printing plates
12
are removed from the rotating drum
54
(FIG.
7
H).
At the ejection buffer section
24
, the printing plates
12
are nipped and conveyed by the small roller
80
A and the roller
84
, and wound on the ejection roller
78
. Thereafter, the small roller
80
A and the roller
84
are moved opposite the outlet
76
, and the printing plates
12
are fed out from the outlet
76
at a predetermined conveyance speed.
According to the present embodiment, the leading edge chuck
62
of the leading edge clamp unit
200
and the trailing edge chuck
74
of the trailing edge clamp unit
68
are removable from the rotating drum
54
. Therefore, the direction in which the rotating drum
54
rotates in order for the printing plates
12
to be mounted thereon, the direction of rotation at the time the printing plates
12
are exposed, and the direction of rotation in order for the printing plates
12
to be removed from the rotating drum
54
may all be made into the same, single direction. Accordingly, labor that impacts working effectiveness, such as switching the rotational direction of the rotating drum
54
, can be eliminated, and image exposure can be conducted rapidly.
Further, by the provision of a squeeze roller
66
, rising of the leading edges and trailing edges of the printing plates
12
from the rotating drum
54
can be prevented, and a smooth clamping operation becomes possible. Particularly in the present embodiment, because the leading edge clamp unit
200
and the trailing edge clamp unit
68
share a common function, the present invention is both rational and economical.
Claims
- 1. An apparatus for subjecting sheet material to predetermined processing, the apparatus comprising:(a) a rotatably mounted drum having a periphery for winding sheet material thereon; (b) a leading edge clamp unit movable to a withdrawn position separated from the drum and to a clamping position proximate the drum, the leading edge clamp unit including a leading edge chuck for clamping the leading edge of the sheet material to the drum; (c) a trailing edge clamp unit movable to a withdrawn position separated from the drum and to a clamping position proximate the drum, the trailing edge clamp unit including a trailing edge chuck for clamping the trailing edge of the sheet material to the drum; (d) a processing element by which sheet material on the periphery of the drum is subjected to predetermined processing; (e) a wrapping element, that moves in correspondence with a clamp operation of the leading edge chuck, to wrap the sheet material on the periphery of the drum in a sequence of a sheet material front portion, a middle portion and an end portion; and (f) a separation element, that moves in correspondence with an unclamp operation of the leading edge chuck, to separate the sheet material from the periphery of the drum in a sequence of the sheet material front portion, middle portion and end portion.
- 2. The apparatus according to claim 1, wherein the processing element includes a recording head for recording an image on the sheet material.
- 3. The apparatus according to claim 1, further including a rotating element connected to the drum, the rotating element being operable for rotating the drum in only one direction during wrapping of the sheet material, during predetermined processing, and during separation of the sheet material.
- 4. The apparatus according to claim 3, wherein the separation element pulls the sheet material in a direction non-contrary to the rotation of the drum when separating the sheet material from the drum.
- 5. The apparatus according to claim 1, wherein the separation element includes a rotation element and a guide.
- 6. The apparatus according to claim 1, wherein the leading edge clamp unit includes a moving mechanism, which when operated, moves the leading edge chuck between the withdrawn and clamping positions.
- 7. The apparatus according to claim 1, further including:a leading edge chuck separation and connection element that, in association with the clamp operation of the leading edge chuck, separates the leading edge chuck from the moving mechanism and, in association with the unclamp operation of the leading edge chuck, connects the leading edge chuck to the moving mechanism, and a leading edge chuck mounting element that removably mounts the leading edge chuck on the drum.
- 8. The apparatus according to claim 7, wherein the leading edge chuck separation and connection element includes a moving mechanism rotating shaft and a leading edge chuck screw.
- 9. The apparatus according to claim 7, wherein the leading edge chuck mounting element includes a leading edge chuck base and slots formed along the periphery of the drum corresponding to the leading edge chuck base.
- 10. The apparatus according to claim 1, wherein the trailing edge clamp unit includes a moving mechanism, which when operated, moves the trailing edge chuck between the withdrawn and clamping positions.
- 11. The apparatus according to claim 10, further including:a trailing edge chuck separation and connection element that, in association with the clamp operation of the trailing edge chuck, separates the trailing edge chuck from the moving mechanism and, in association with the unclamp operation of the trailing edge chuck, connects the trailing edge chuck to the moving mechanism, and a trailing edge chuck mounting element that removably mounts the trailing edge chuck unit on the drum.
- 12. The apparatus according to claim 11, wherein the trailing edge chuck separation and connection element includes a rotatable shaft and a trailing edge chuck screw.
- 13. The apparatus according to claim 11, wherein the trailing edge chuck mounting element includes a trailing edge chuck base and slots formed along the periphery of the drum corresponding to the leading edge chuck base.
- 14. The apparatus according to claim 1, wherein the leading edge clamp unit is positioned in the clamping position by inserting and fixing the leading edge chuck in a slot portion formed in the drum.
- 15. The apparatus according to claim 1, wherein the trailing edge clamp unit is positioned in the withdrawn position by withdrawing and separating the trailing edge chuck from a slot portion formed in the drum.
- 16. A method of subjecting sheet material to predetermined processing, using a rotatable drum having a periphery on which sheet material is wound, the method comprising the steps of:(a) moving a leading edge clamp unit to a position proximate to the drum from a withdrawn position spaced from the drum; (b) clamping the sheet material leading edge to the drum; (c) winding the sheet material on the drum periphery in order of the sheet material front portion, middle portion and end portion; (d) moving a trailing edge clamp unit to a position proximate to the drum from a withdrawn position spaced from the drum; (e) clamping the sheet material trailing edge to the drum; (f) subjecting the sheet material on the drum periphery to predetermined processing; (g) disengaging the clamp on the sheet material leading edge; and (h) removing the sheet material from the drum periphery in order of the sheet material front portion, middle portion and end portion.
- 17. The method according to claim 16, wherein an image is recorded on the sheet material when subjecting the sheet material on the drum periphery to predetermined processing.
- 18. The method according to claim 16, further comprising releasing a clamp on the sheet material trailing edge after disengaging the clamp on the sheet material leading edge.
- 19. The method according to claim 16, wherein the sheet material is pulled in a direction non-contrary to the rotation of the drum when the sheet material is separated from the drum.
- 20. The method according to claim 16, wherein the drum revolves in only one direction through steps (a) through (f).
- 21. An apparatus for recording an image on a printing plate, the apparatus comprising:(a) a rotatably mounted drum having a periphery for winding a printing plate thereon; (b) a leading edge clamp unit movable to a withdrawn position spaced from the drum and to a clamping position proximate the drum, the leading edge clamp unit including a leading edge chuck for clamping the printing plate leading edge to the drum, and a moving mechanism, which when operated, moves the leading edge chuck between the withdrawn and clamping positions; (c) a trailing edge clamp unit movable to a withdrawn position spaced from the drum and to a clamping position proximate the drum, the trailing edge clamp unit including a trailing edge chuck for clamping the printing plate trailing edge to the drum, and a moving mechanism, which when operated, moves the trailing edge chuck between the withdrawn and clamping positions; (d) a recording head disposed for recording an image on a printing plate on the drum periphery; (e) a wrapping element, that moves in correspondence with a clamp operation of the leading edge chuck, to wrap the printing plate on the drum periphery in a sequence of a printing plate front portion, a middle portion and an end portion; and (f) a separation element, that moves in correspondence with a clamp disengaging movement of the leading edge chuck, to separate the printing plate from the drum periphery in the sequence of the printing plate front portion, middle portion and end portion.
- 22. The apparatus according to claim 21, wherein the apparatus includes:a leading edge chuck separation and connection element that, in association with the clamp operation of the leading edge chuck, separates the leading edge chuck from the moving mechanism and, in association with the clamp disengaging movement of the leading edge chuck, connects the leading edge chuck to the moving mechanism; a leading edge chuck mounting element that removably mounts the leading edge chuck on the drum; a trailing edge chuck separation and connection element that, in connection with the clamp operation of the trailing edge chuck, separates the trailing edge chuck from the moving mechanism and, in connection with the clamp disengaging movement of the trailing edge chuck, connects the trailing edge chuck to the moving mechanism; and a trailing edge chuck mounting element that removably mounts the trailing edge chuck on the drum.
- 23. The apparatus according to claim 21, wherein the recording head irradiates a light beam to conduct a main scanning by rotating the drum and to conduct a sub-scanning along a rotational axis of the drum in connection with the main scanning, such that an image may be recorded on the printing plate.
- 24. The apparatus according to claim 21, wherein the leading edge clamp unit is positioned in the clamping position by inserting and fixing the leading edge chuck in a slot position formed in the drum.
- 25. The apparatus according to claim 21, wherein the trailing edge clamp unit is position in the withdrawn position by withdrawing and separating the trailing edge chuck from a slot portion formed in the drum.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-016064 |
Jan 2000 |
JP |
|
US Referenced Citations (4)