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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotary printing press, and more
particularly to an apparatus for automatically mounting a plurality of
printing plates, each delivered to the side of a respective printing unit,
on a plate cylinder at respective predetermined positions and for
automatically removing each printing plate from the plate cylinder after
use, the apparatus including an auxiliary apparatus adapted to rationalize
the processing of fresh printing plate immediately before mounting on the
cylinder and of the used printing plates immediately after removal from
the cylinder.
2. Description of the Prior Art
Various apparatus for automatically mounting and removing printing plates
on a plate cylinder at predetermined positions are disclosed in the
applicant's Japanese Patent Laid-Open Publications Nos. 58-140254,
58-188657 and 60-216350, while an apparatus for automatically distributing
the printing plates from a plate making chamber to the respective printing
units is disclosed in the applicant's Japanese Patent Laid-Open
Publication No. 60-52343.
Of the prior art publications mentioned above, Japanese Patent Laid-Open
Publications Nos. 58-188657 and 60-73850 are directed to the apparatus of
the type same as that disclosed in the present application. However, a
problem with these prior apparatus is that a mechanical hand for directly
retaining the printing plate during the mounting and removing thereof is
too complex in construction for maintenance, thus often incuring troubles
and hence impairing the efficiency.
Further, usually four rows of printing plates, two in each row, namely
eight printing plates in all are mounted on a peripheral surface of the
plate cylinder. To exchange the used printing plates for new ones,
removing one used printing plate and then mounting one new printing must
be repeated eight times. Specifically, for each exchange, the mechanical
hand removes one used printing plate from the peripheral surface of the
plate cylinder and then carries the removed printing plate to a plate
discharging position, whereupon the mechanical hand moves to a plate
introducing position to pick up one new printing plate and then brings the
new printing plate onto the peripheral surface of the plate cylinder. this
exchanging operation must be repeated eight times, which requires a long
time and hence impairs the efficiency.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an apparatus
for automatically mounting and removing printing plates which apparatus
can eliminate the prior art problems mentioned above.
Another object of the invention is to provide an apparatus for
automatically mounting and removing printing plates in which apparatus the
strokes of a mechanical hand, for bringing a new printing plate from a
plate introducing position to a plate cylinder and for bringing a used
printing plate from the plate cylinder to a plate discharging position,
are shortened so that removing of the used printing plate and mounting of
the new printing plate can take place speedily.
The first object of the invention is accomplished by an apparatus for
automatically mounting and releasing a printing plate in a rotary printing
press, said apparatus comprising: a mechanical hand including a retainer
mechanism for retaining the printing plate, an inserter mechanism for
forcing a gripping-side bent end of the printing plate into a gripping
groove of a plate cylinder, a pusher mechanism for pushing the printing
plate against a peripheral surface of the plate cylinder, a shaft
supporting said inserter mechanism and said pusher mechanism, a base
supporting said shaft such that the latter is movable when thrusted, a
positioning mechanism for pivotally moving said shaft relative to said
base to thereby position the printing plate on said plate cylinder at a
predetermined position; a main body having a support shaft and an arm for
supporting and moving said mechanical hand; an angular displacement
mechanism for angularly moving a printing-plate gripping and releasing
shaft of said plate cylinder; a control mechanism for controlling motions
of said mechanical hand, said main body and said angular displacement
mechanism in timed relation to one another for mounting and removal of the
printing plate.
The second object of the invention is accomplished by an auxiliary
apparatus for automatically mounting and removing a printing plate in a
rotary printing press, said apparatus comprising: a main body including a
shaft and an arm; a magazine associated with said main body and including
a plate take-out unit for positioning a plurality of successive fresh
printing plates in order, and a plate storage unit for temporarily storing
a plurality of used printing plates; a mechanical hand adapted for holding
a printing plate and supported by said shaft and arm of said main body,
said mechanical hand being actuated by said shaft and arm for
reciprocating between said magazine and a peripheral surface of a plate
cylinder.
According to a third aspect of the invention, there is provided an
auxiliary apparatus for automatically mounting and removing a printing
plate in a rotary printing press, said apparatus comprising: a main body
including a shaft and an arm; a magazine associated with said main body
and including a plate take-out unit for positioning a plurality of
successive fresh printing plates in order, and a plate storage unit for
temporarily storing a plurality of used printing plates; a plate
transportation terminal for receiving a desired number of fresh printing
plates from a carrier, adapted to transport the fresh printing plates to
respective printing units, and for temporarily storing the received fresh
printing plates in order; and a mechanical hand adapted for holding a
printing plate and supported by said shaft and arm of said main body, said
mechanical hand being actuated by said shaft and arm for reciprocating
between said terminal and said magazine, and between said magazine and a
peripheral surface of a plate cylinder.
According to a fourth aspect of the invention, there is provided by an
auxiliary apparatus for automatically mounting and removing a printing
plate in a rotary printing press, said apparatus comprising a main body
including a shaft and an arm; a magazine associated with main body and
including a plate take-out unit for positioning a plurality of successive
fresh printing plates in order, and a plate storage unit for temporarily
storing a plurality of used printing plates; a plate transportation
terminal for receiving a desired number of fresh printing plates from a
carrier, adapted to transport the fresh printing plates to respective
printing units, and for temporarily storing the received fresh printing
plates in order, said terminal being disposed at such a position that said
terminal agrees with said magazine in level and orientation in the
direction of transporting the printing plates; means for shifting said
main body longitudinally along said plate cylinder; and a mechanical hand
adapted for holding a printing plate and supported by said shaft and arm
of said main body, said mechanical hand being actuated by said shaft and
arm for reciprocating between said magazine and a peripheral surface of a
plate cylinder and also for connecting said magazine and said terminal
with another.
Many other advantages and features and additional objects will become
apparent manifest to those versed in the art upon making reference to the
detailed description and the accompanying drawings in which certain
embodiments incorporating the principles of the present invention are
shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, with parts broken away, of a principal
portion of an automatic printing-plate mounting and removing apparatus
embodying the present invention;
FIG. 2 is a vertical rear cross-sectional view taken along line 2--2 of
FIGS. 1 and 3;
FIG. 3 is a horizontal front cross-sectional view taken along line 3--3 of
FIGS. 1 and 2;
FIG. 4 is a vertical rightside cross-sectional view taken along line 4--4
of FIGS. 2 and 3;
FIG. 5 is a leftside elevational view taken along line 5--5 of FIGS. 2 and
3;
FIG. 6 is a vertical side cross-sectional view of an auxiliary part of the
apparatus, showing the manner in which a shaft for gripping and releasing
a trailing end of a printing plate is rotated;
FIG. 7 is a vertical side cross-sectional view similar to FIG. 6, but
showing a modified auxiliary part;
FIG. 8 illustrates the manner in which a printing plate is mounted on a
printing drum;
FIG. 9 illustrates the manner in which the printing plate is removed from
the printing drum;
FIG. 10 is a schematic view showing a control system for the embodiment
employing the mechanism of FIG. 6;
FIG. 11 is a perspective view showing a first embodiment of an auxiliary
apparatus for plate mounting and removal;
FIG. 12 is an enlarged perspective view of a principal portion of FIG. 11;
FIG. 13 is a perspective view showing a second embodiment of the auxiliary
mounting and removal apparatus;
FIG. 14 is an enlarged perspective view of a principal portion of FIG. 13;
FIG. 15 is a perspective view, as viewed from the rear side, of another
principal portion of FIG. 13;
FIG. 16 is a perspective view showing a modified form of the first
embodiment of FIG. 11;
FIG. 17 is a perspective view showing another embodiment of a right half
portion of each of FIGS. 11 and 13;
FIG. 18 is an enlarged plan view showing a floor of FIG. 11;
FIG. 19 is a vertical leftside cross-sectional view taken along line 19--19
of FIG. 18.
DETAILED DESCRIPTION
As shown in FIGS. 2 and 3, a mechanical hand 1 for mounting and removing a
printing plate is composed of various members on a base 10. The base 10 is
secured to a wrist 51 of a main body 5 via a compression spring 52. A pair
of shafts 16, 16 is journaled by a pair of brackets 24, 24 projecting
forwardly from the base 10. The shafts 16, 16 are axially movable on the
brackets 24, 24 when the shafts 16, 16 are thrusted. A block 18 is
slidably supported centrally on the pair of shafts 16, 16, which extend
through the block 18. A pair of blocks 17, 17 is fixedly mounted on the
pair of shafts 16, 16 and is disposed one at each side of the block 18.
Also, a pair of brackets 25, 25 is fixedly mounted on the pair of shafts
16, 16 at opposite end portions thereof, each bracket 25 being disposed
outwardly of a respective one of the brackets 24.
The central block 18 has a vertical slot 181 in which a pin 20 mounted
eccentrically on a disk 182 is slidably received, the center of the disk
182 being operatively connected to a motor 21 for rotation in either
direction. As the motor 21 rotates, the pin 20 pivots to more the block 18
leftwardly and rightwardly. Further, a pair of load cells 19, 19 (FIG. 2)
for the purposes of pressure detection is mounted between the leftside
block 17 and the central block 18 and between the latter and the rightside
block 17, respectively, each load cell 19 having a thickness substantially
equal to the distance between the central block 18 and the respective side
block 17.
Two pairs of sucking disks 11, 11 and 11, 11 for retaining a printing plate
P is mounted one pair on each of the outer brackets 25, 25 fixedly secured
to the shafts 16, 16. A pair of claws 12, 12 for gripping the printing
plate P. An air cylinder 121 for moving the claws 12, 12 leftwardly and
rightwardly toward and away from each other, and an air cylinder 22 (FIGS.
1 and 3) for moving the claws 12, 12 forwardly and rearwardly, are fixedly
mounted on each outer bracket 25 via a unnumbered bracket. Thus in the
illustrated embodiment all of these members are attached to the brackets
25, 25 via the unnumbered brackets. As desired, the sucking disks 11, 11
or the claws 12, 12 may be omitted.
A pair of pushing plates 13, 13 is mounted on a pair of levers 131, 131 at
their respective free ends for forcing a gripping-side bent end portion of
the printing plate P into a gripping groove of a plate cylinder A. the
base of each lever 131 is supported by a pin 23 which is connected to a
piston rod of an air cylinder 231; the pin 23 and the air cylinder 231 are
attached to each of the brackets 25, 25 fixedly secured to the shafts 16,
16. The pin 23 and the cylinder 231 may be attached to each of the blocks
17, 17 fixedly secured to the shafts 16, 16. Therefore, the pushing plate
13 is angularly movable about the pin 23 upon actuation of the air
cylinder 231. Thus in the illustrated embodiment all of these members are
attached to the brackets 25, 25 via the unnumbered brackets. A proximity
switch 14 is supported on each of the pushing plates 13 for confirming
whether the gripping-side bend end of the printing plate P has been forced
into the gripping groove of the plate cylinder A.
A pair of rollers 15, 15 is supported by each of the brackets 25 fixedly
secured to the shafts 16, 16 and is disposed on the outer side of each
bracket 25. The rollers 15, 15 serve to push the printing plate P against
the plate cylinder A. Alternatively, an endless belt may be used instead
of these rollers 15, 15.
The main body 5 includes a lower link 53 pivotally connected to the wrist
51 by a wrist axle W, an upper link 54 pivotally connected to the lower
link 53 by an elbow axle X, a post 55 connected to the lower link 54 by a
shoulder axle Y, the post 55, and a base 56 supporting the post 55. The
post 55 serves as a Z axis which is horizontally rotatable with respect to
the base 56. A rotatable wheel (not shown) may be mounted on the underside
of the base 56. The rear end of the lower link 53 is pivotally connected
to a first auxiliary link 541 parallel to the upper link 54, the auxiliary
link 541 being pivotally connected to a second auxiliary link 531 parallel
to the lower link 53.
In the embodiment of FIG. 6 or 7, a shaft 34 or 3a4 for gripping and
releasing a gripping-side end of the printing plate P is mounted on the
plate cylinder A or A', while a mechanism 3 or 3a for angularly displacing
the shaft 34 or 3a4 is mounted on a frame F of a rotary printing press.
Specifically, in the embodiment of FIG. 6, the gripping and releasing shaft
34 extends longitudinally of the plate cylinder A along the peripheral
surface thereof; the printing plate P is mounted on the plate cylinder A
when the gripping and releasing shaft 34 is at a phase indicated by solid
lines, and is removed from the plate cylinder A when the gripping and
releasing shaft 34 is at a phase indicated by dash-and-two-dot lines.
An arm 35 projects from the gripping and releasing shaft 34 and is normally
urged by a spring 38 to pivot counterclockwise, and this counterclockwise
pivotal movement of the arm 35 is restricted by a stop 36 which is
engageable with a free end of the arm 35. When the arm 35 is pushed
inwardly against the bias of the spring 38, the gripping and releasing
shaft 34 is angularly displaced or moved clockwise; in this angularly
displaced position, gripping and releasing of the gripping-side end of the
printing plate P take place.
In an example, a means for pushing the free end of the arm 35 inwardly, may
include a pair of straight levers 32, 32 centrally pivoted by a pair of
pins 31, 31, respectively, one end of each lever 32 being connected to a
drive unit, such as a piston rod of an air cylinder 33, 33' so that the
other end of each lever 32, 32' can push the free end of the arm 35 when
the gripping and releasing shaft 34 is at the gripping phase and also when
the gripping phase and also when the gripping and releasing shaft 34 is at
the releasing phase.
In a double width rotary printing machine, usually the gripping and
releasing shaft 34 has a double structure in which two arms 35, 35 are
spaced away from each other longitudinally of the plate cylinder A. To
cope with this double arm 35, a shift means 37 is used for shifting the
pair of levers 32, 32'.
In the embodiment of FIG. 7, like the embodiment of FIG. 6, the gripping
and releasing shaft 3a4 extends longitudinally of the plate cylinder A
along the peripheral surface thereof; the printing plate P is mounted on
the plate cylinder A when the gripping and relasing shaft 3a4 is at a
phase indicated by solid lines, and is removed from the plate cylinder A
when the gripping and releasing shaft 3a4 is at a phase indicated by
dash-and-two-dot lines. But in the embodiment of FIG. 7, gripping and
releasing of the gripping-side end portion of the printing plate takes
place when the arm 3a5 projecting from the gripping and releasing shaft
3a4 is at a position (broken-line position) that is angularly displaced
counterclockwise. During printing and a pause of operation, the arm 3a5 is
at an original position (solid-line position) that is angularly displaced
clockwise.
In an example, the means for angularly moving the arm 3a5 may include a
bell crank lever 3a2 pivotally connected at its midportion to a bracket
3a7 by a pin 3a1. One end of the lever 3a2 is connected to a piston rod of
an air cylinder 3a3, while a bifurcated bar 3a5 is pivotally connected at
its base to the other end of the lever 3a2 for catching the free end of
the arm 3a5. Accordingly, the bell crank lever 3a2 is pivotally movable,
about the pin 3a1, between the solid-line position and the broken-line
position. In response to this pivotal movement of the lever 3a2, the arm
3a5 is movable between the solid-line position and the broken-line
position via the bifurcated bar 3a6. Reference numeral 3a61 designates a
guide surface which serves to assist in connecting the arm 3a5 and the
bifurcated bar 3a6 to each other reliably. Since the shaft 3a4 has dead
points at a printing-plate holding position (solid-line position) and at a
printing-plate holding position (broken-line position), the shaft 3a4 is
not angularly movable until an exterior force is exerted on the shaft 3a4
so as to over the dead points.
While the printing machine is in operation, usually the bifurcated bar 3a6
is preferably stood-by at a position remote from the plate cylinder A'. To
move the bifurcated bar 3a6 to this stand-by position, the bracket 3a7 is
moved by a chain counterclockwise, namely, in the direction of drawing the
bifurcated bar 3a6 away from the arm 3a5, and then the piston rod of the
air cylinder 3a3 is extended to bring the bifurcated bar 3a6 away from the
plate cylinder A' to thereby return to the stand-by position.
For angularly moving the gripping and releasing shaft 3a4, firstly the
chain 3a10 is moved counterclockwise to bring the bracket 3a7, with its
associated members, until the bracket 3a7 arrives at a position past a
front end of the arm 3a5. Then the piston rod of the air cylinder 3a3 is
extended to bring, via the bell crank lever 3a2, the bifurcated bar 3a6
into contact with the guide surface 3a61 of the plate cylinder A,
whereupon when the chain 3a10 is moved clockwise, the bifurcated bar 3a6
is guided on the guide surface 3a61 of the plate cylinder A to catch the
free end of the arm 3a5 that is in the plate holding position.
In this position, when the piston rod of the air cylinder 3a3 is extended,
the arm 3a5 is angularly moved to the broken-line position so that
mounting and removing of a printing plate can take place. Reversely, if
the piston rod of the air cylinder 3a3 is shrunk, the arm 3a5 is angularly
moved to the solid-line position so that printing and a pause of operation
can take place.
In this embodiment of FIG. 7, the bifurcated bar 3a6 is used in both
mounting of the printing plate (solid-line phase) and removing of the
printing plate (dash-and-two-dot-line phase). Therefore, the bracket 3a7
supporting the bifurcated bar 3a6 must be moved between the above two
phases. One example of the means for moving the bifurcated bar 3a6 is as
follow. The bell crank lever 3a2 and the air cylinder 3a3 are supported by
the bracket 3a7 fixedly connected to a point of the endless chain 3a10. On
the other hand, the chain 3a10 is guided along an arcuate rail 3a9
concentric with the peripheral surface of the plate cylinder A, and is
driven by the output-side sprocket of the drive 3a8 which is rotatable in
either direction.
Accordingly, after the chain 3a10 is moved in such a direction that the
bifurcated bar 3a6 is removed from the arm 3a5, the piston rod of the air
cylinder 3a3 is extended to bring the bifurcated bar 3a6 outwardly of the
peripheral surface of the plate cylinder A'. In this position, when the
chain 3a10 is lowered along the rail 3a9, the bifurcated bar 3a6 is moved
onto the plate removal phase (dash-and-two-dot lines).
In the double width rotary printing machine, usually the gripping and
releasing shaft 3a4 has a double structure in which two arms 3a5 are
spaced away from each other longitudinally of the plate cylinder A. To
cope with this double arm 3a5, 3a5, two bell crank levers 3a2, 3a2, two
air cylinders 3a3, 3a3 and two bifurcated bars 3a6, 3a6 are necessary.
The procedure of mounting the printing plate will now be described in
connection with FIG. 8A-G.
1. For bringing the mechanical hand 1, waiting at a predetermined position,
close to the printing plate P waiting at a predetermined position, the
wrist axle W, the elbow axle X, the shoulder axle Y and the waist axis Z,
all of the main body 5, are rotated individually to a suitable extent so
as to bring the mechanical hand 1 to a position substantially the same
level with the gripping-side bent end P1 of the printing plate P and so as
to stop the mechanical hand 1 at such a position that the base 10 is
parallel to the printing plate 1. (FIG. 8A)
2. When four sucking disks 11, 11, 11, 11 are attached to the outer surface
of the printing plate P by the action of sucking, and also when the
rightside and leftside claws 12, 12 are actuated, the printing plate P is
held by the mechanical hand 1 as the rightside and leftside edges of the
plate P are gripped. Confirmation of this sucking and holding is made by
detecting a reduction of pressure by a pressure detection switch (not
shown) at a vacuum source. (FIG. 8B)
3. With the printing plate thus held, the hand 1 is again moved, by
rotating each axle of the main body, until the gripping-side bent end P1
of the printing plate P is brought close to the gripping groove a1 of the
plate cylinder A. (FIG. 8C)
4. On the other hand, in order to stop the plate cylinder A in a phase
registered with the plate mounting position, any positional error is
detected by the number of bits of a rotary encoder 002 (FIG. 10), and if
necessary, the plate cylinder A is further moved to the plate mounting
position. (FIG. 8C)
5. Then, the pusher plates 13, 13 of the mechanical hand 1 are driven by
the air cylinders 231, 231 to force the gripping-side bent end P1 of the
printing plate P into the gripping groove a1 of the plate cylinder A.
Confirmation of this insertion is made by detecting the peripheral surface
of the plate cylinder A by proximity switches 14, 14. (FIG. 8D)
6. As the block 18 is moved to the right or left by the motor 21 of the
mechanical hand 1, the blocks 17, 17 are pushed via the pressure detection
load cells 19, 19, and the brackets 25, 25 are displaced via the shafts
16, 16. This displacement is transmitted to the sucking disks 11, 11 and
the claws 12, 12 mounted on the brackets 25, 25 via the unnumbered bracket
and is then transmitted to the printing plate P supported by the sucking
disks 11, 11 and the claws 12, 12. Then the printing plate P comes into
abutment with a plate positioning stop (not shown) of the plate cylinder
A. The counter force created at that time is detected by the pressure
detection load cells 19, 19 disposed between the blocks 17, 18; the motor
21 is terminated according to the detected value. (FIG. 8D)
7. With displacing the mechanical hand 1 from the position of FIG. 8D to
the position of FIG. 8E by moving properly each axle W, X, Y of the main
body 5, the gripping-side bent end P1 of the printing plate P is hooked on
the edge of the gripping groove a1 of the plate cylinder A, and the
printing plate P is pushed against the peripheral surface of the plate
cylinder A by the rollers 15. Confirmation of this pushing is made by a
limit switch 57 (FIG. 4). In the meantime the printing plate P is released
from the sucking disks 11, 11 and the claws 12, 12; this releasing is made
by a pressure detection switch (not shown) at the vacuum source. (FIG. 8E)
8. As the printing drum A is rotated clockwise, the gripping-side bent end
P1 of the printing plate P is moved along with advancing of the edge of
the gripping groove a1 of the plate cylinder A, and the printing plate P
is pushed against the peripheral surface of the plate cylinder A by the
rollers 15. Therefore, the printing plate P is curved in conformity with
the curvature of the peripheral surface of the plate cylinder A. And as a
trailing bent end P2 of the printing plate P approaches the gripping and
releasing shaft 34 of the plate cylinder A, the rotation of the plate
cylinder A is terminated. Detection of this stopped position is made by a
rotary encoder 002 (FIG. 10). (FIG. 8F)
9. The gripping and releasing shaft 34 or 3a4 of FIG. 6 or 7 is angularly
moved to open.
Specifically, in FIG. 6, with the piston rod of the air cylinder 33 shrunk,
as the straight lever 32 is pivotally moved about the pin 31 to push the
free end of the arm 35 against the bias of the spring 38 by the free end
of the lever 32, the shaft 34 is angularly displaced clockwise to open.
Confirmation of this angular displacement is made by a limit switch (not
shown) located at the end of the stroke of the air cylinder 33.
In FIG. 7, when the bell crank lever 3a2 is angularly displaced to the
broken-line position as the bifurcated bar 3a6 catches the arm 3a5 and the
piston rod of the air cylinder 3a3 is extended, the arm 3a5 also is
angularly displaced to the broken-line position by the bifurcated bar 3a6.
As a result, the shaft 3a4 is angularly displaced counterclockwise to
open.
10. The mechanical hand 1 is moved toward the shaft 34 by rotating each
axle of the main body 5, thereby inserting the trailing bent end P2 of the
printing plate P into the portion of the shaft 34. (FIG. 8G)
11. The shaft 34 or 3a4 is closed to retain the printing plate P.
Specifically, in FIG. 6, with the piston rod of the air cylinder 33 shrunk,
as the straight lever 32 is pivotally moved about the pin 31 to release
the free end of the lever 32 off the free end of the arm 35, the arm 35
returns to the position of the stop 36 under the bias of the spring 38,
thus causing the shaft 34 to be angularly displaced counterclockwise to
complete closing operation.
In FIG. 7, when the arm 3a5 is angularly displaced to the solid-line
position by shrinking the piston rod of the air cylinder 3a3, the shaft
3a4 is angularly displaced clockwise to close. Then, the arm 3a5 is
released off the bifurcated bar 3a6 to return the stand-by position.
12. The mechanical hand 1 is returned to the initial stand-by position by
rotating each axle of the main body 5.
The procedures of removing the printing plate P will now be described in
connection with FIG. 9A-F.
1. The mechanical hand 1 (FIG. 9A) waiting at the initial position is moved
close to the printing drum A by moving each axle of the main body 5. (FIG.
9B)
2. On the other hand, confirmation as to whether the plate cylinder A is
stopped in the plate releasing phase, is made by the number of bits of the
rotary encoder 002 (FIG. 10). If the plate cylinder A is not stopped at
the plate releasing phase, the plate cylinder A is further rotated to the
plate releasing position. (FIG. 9B)
3. The shaft 34 or 3a4 is rotated to open, in the same manner as described
above at paragraph 9 of the procedures of plate mounting.
But the predetermined stop position of the plate cylinder A when removing
the printing plate P is the phase indicated by dash-and-two-dot-lines in
FIGS. 6 and 7.
Therefore, in FIG. 6, using the pin 31', the lever 32' and the air cylinder
33', when the piston rod of the air cylinder 33' is extended, the shaft 34
is opened so that the trailing bent end P2 of the printing plate P is
removed from the plate cylinder A to float off the peripheral surface of
the plate cylinder A. (FIG. 9C)
In FIG. 7, as the shaft 3a4 is moved to the plate releasing position in the
same manner as described above at paragraph 9 of the procedures of plate
removing, the trailing bent end P2 of the printing plate P is removed from
the plate cylinder A' to float off the peripheral surface of the plate
cylinder A'.
4. By rotating each axle of the main body 5, the mechanical hand 1 is moved
so as to contact the printing plate P, and the sucking disks 11 and the
claws 12 retain the printing plate P. Confirmation of this retaining is
made by each detection switch described at paragraph 2 of the procedures
of plate mounting. (FIG. 9D)
5. Further, by rotating each axle of the main body 5, the mechanical hand 1
is moved to release or unhook the gripping-side bent end P1 of the
printing plate P off the edge of the gripping groove a1 of the plate
cylinder A. (FIG. 9E)
6. Moreover, by rotating each axle of the main body 5, the mechanical hand
1 retaining the printing plate P is moved to the plate discharging
position. (FIG. 9F)
7. The shaft 34 or 3a4 is angularly displaced to close.
8. Retaining or holding of the printing plate P by the sucking disks 11 and
the claws 12 is released, and then the printing plate P is disposed as
desired. Confirmation of this releasing is made by each detection switch.
9. By moving each axle of the main body 5, the hand 1 is returned to its
initial stand-by position.
The above operation of various parts is controlled and performed by a
Central Processing Unit.
In the case where the main body 5 is movable by itself, a control system
for course of travel of the main body and for the predetermined stop
position must be added.
As shown in FIG. 13, the mechanical hand 1 has a plurality of (four, for
example) sucking disks 11; upon receipt of a negative pressure, the
sucking disks 11 can be attached to the surface of the printing plate P to
thereby retain the printing plate P, and upon release of this negative
pressure, the sucking disks 11 can be detached from the surface of the
printing plate P to thereby release the printing plate P.
The remaining mechanisms mounted on the base 10 of the mechanical hand 1
are remote from the subject matter of the present invention, and therefore
their description, and therefore their description here is omitted for
clarity.
The mechanical hand 1 is supported by the main body 5, which is mounted on
the floor (FIGS. 11, 13), for example, or hanging from a beam 404 of the
ceiling (FIG. 16).
The main body 5 is generally composed of the lower link 53, the upper link
54, the post 55, and the base 56. The mechanical hand 1 is pivotally
connected to the lower link 53 by the wrist axle W (FIGS. 11 and 16), and
the lower link 53 is in pivotally connected to the upper link 54 by the
elbow axle X. Further, the upper link 54 is connected to the post 55 by
the shoulder axle Y (FIG. 16), and the post 55 is rotatably mounted on the
base 56 (FIG. 11).
The magazine 6 is associated with the main body 5 at such a position that
the mechanical hand 1 can reach the magazine 6 and that motion of the
mechanical hand 1 is not obstructed by the magazine 6. Usually, as shown
in FIG. 11 and 13, it is most suitably that the magazine 6 is located in
front of the main body 5 in confronting relation to the plate cylinder A
and with a predetermined space from the main body. In the case of the
hanging mechanical hand 1 of FIG. 16, it is most suitable that the
magazine 6 is located in front of the main body 5 with a predetermined
space therefrom.
The magazine 6 includes a fresh-plate take-out unit 61, and a used-plate
temporary storage unit 62. These two units 61, 62 may be a stationary type
(FIG. 11) in which they are fixed to the main body 5, or a detachable
cassette type (FIG. 13).
As shown in FIG. 12, the fresh-plate take-out unit 61 of the stationary
type magazine 6 includes a hanger 611, a positioning plate 612 mounted on
the front end of the hanger 611, plate advancing claws 613 projecting from
the rear end of the hanger 611, and an air cylinder 614 for driving the
claws 613. The hanger 611 has an at least horizontally extending upper
edge or bar, such as panel or cross bar, from which a plurality of
successive fresh printing plates P are hung in slightly forwardly inclined
posture, each fresh printing plate P having a gripping-side bent end P1
hooped on the hanger 611. The length of the hanger 611, in the illustrated
embodiment, substantially corresponds to the total width of the leading
printing plate P1 and the second printing plate P2. However, the present
invention is not limited to this embodiment and includes a hanger having a
length sufficient to support more than two printing plates in order, in
which case the advancing claws 613 is engaged with the rear edge of the
trailing printing plate. In this case, since the amount of movement of the
claws 613 is increased, the air cylinder 614 may be replaced with a clawed
chain conveyor (not shown) driven by a torque motor, for example.
Since the leading printing plate P1 is thus normally positioned in a
predetermined orientation and at a predetermined level (height) with
respect to the main body 5, it is possible to cope with the remote
take-out operation of the mechanical hand 1 precisely. Upon completion of
taking out of the leading printing plate P1 by the mechanical hand 1, the
above-described advancing mechanism is actuated to advance the succeeding
fresh printing plates in order and then to position the plates one at a
time for mounting.
Subsequently, in FIG. 12, the used-plate temporary storage unit 62 includes
an at least upwardly opening box, or a predetermined space defined by a
frame, disposed behind the fresh-plate take-out unit 61. The bottom side
621 of the box may be in the form of a plate, a net or a draining board,
which is connected at its one edge to a shaft 622 having an arm connected
to a piston rod of an air cylinder 623. As the piston rod of the air
cylinder 623 is extended, the bottom side 621 of the box is opened.
Reversely, as the piston rod of the air cylinder 623 is shrunk, the bottom
side 621 of the box is closed.
Accordingly, a plurality of used printing plates P removed from the plate
cylinder A during the plate exchanging, are introduced, by the mechanical
hand 1, into the storage unit 62 and are temporarilly stored therein. Upon
completion of the plate exchange, as the bottom side 621 of the box is
opened, the plurality of used printing plates P are discharged to the
exterior at once for disposal.
As shown in FIG. 13, the detachable cassette type magazine 6A is attached
to the front side of the main body 5 and includes a fresh-plate take-out
cassette 6A1, a inclined hanger 6A11 (in the illustrated embodiment, only
this hanger is stationary) for positioning the leading fresh printing
plate to be taken out, and a used-plate storage cassette 6A2.
The fresh-plate take-out cassette 6A1 is detachably supported by means of
an electromagnetic catch (not shown) for example, on a shelf mounted on
the front side of the main body 5. On the other hand, the hanger 6A11 is
in the form of a panel which is forwardly inclined and is spaced from the
fresh-plate take-out cassette 6A1 by a space sufficient for at least the
stroke of the mechanical hand 1 for plate take-out. The fresh printing
plates P are hung from the hanger 6A11, with the gripping-side bent end P1
of each plate P hooked on the upper edge of the hanger 6A11. As shown in
FIG. 14, the fresh-plate take-out cassette 6A1 is in the form of a box
having at its top an inlet opening and at its front an outlet. In the box,
a plurality of (eight at maximum for example) fresh printing plates P are
arranged in superposed relationship in order from the front side to the
rear side of the box, each fresh printing plate P being in upright posture
with its gripping-side bent end P1 facing upwardly and forwardly.
The fresh printing plates P arranged in the take-out order in the cassette
6A1 can be advanced one after another by means of a pair of spiral brushes
6A10 which is mounted on the cassette 6A1 so as to contact the opposite
upper portions of the printing plates P and which is driven by a
non-illustrated drive means for rotation. By the action of the brushes
6A10, the leading printing plate P is sent out of the cassette 6A1 to
learn against the surface of the forwardly inclined hanger 6A11.
Practically, however, the fresh printing plate P thus in contact with the
hanger surface is not always placed in a predetermined position in which
the plate P can be taken out with ease, that is, it is inevitable that
some positional error occurs.
To this end, as shown in FIG. 15, a fresh-plate positioning means is
provided. A pair of core-shaped brushes 6A110, 6A110 is mounted on a pair
of horizontal shafts supported on opposite sides of a chute 6A12, a
portion of the peripheral surface of each cone-shape brush 6A110 being
exposed. As each horizontal shaft is rotated by a non-illustrated drive
means, the fresh printing plate P is laterally shifted so as to enter
between a pair of side guide bars 6A111, 6A111. On the other hand, a shelf
6A112 is mounted on a surface of the chute 6A12 at its lower portion. As
the shelf 6A112 is raised by an air cylinder 6A113, the gripping-side bent
end P1 of the printing plate P is hooked on the upper edge of the hanger
6A11. Thus the stand-by position of fresh printing plates for take-out is
determined both horizontally and vertically.
Further, a tubular chute 6A12 of rectangular cross section is mounted at
the rear side of the hanger 6A11 for introducing the used printing plates
P. The used printing plate P removed from the peripheral surface of the
plate cylinder A is transported to the mouth of the chute 6A12 by the
mechanical hand 1, whereupon as the mechanical hand 1 releases the used | | |
