Printing press

Information

  • Patent Grant
  • 6561093
  • Patent Number
    6,561,093
  • Date Filed
    Thursday, May 17, 2001
    23 years ago
  • Date Issued
    Tuesday, May 13, 2003
    21 years ago
Abstract
A printing press includes a printing unit, a plate making unit, and a control unit. The printing unit has a plate cylinder. The plate making unit is provided in the printing unit and performs plate making for a plate mounted on an outer surface of the plate cylinder. The plate making unit is supported to be movable between an operative position where it performs plate making while closing at least part of the printing unit, and a wait position where it opens at least part of the printing unit. The control unit selectively operates the printing press at a first speed at which normal printing is performed and a second speed lower than the first speed. The control unit serves to enable the printing press to operate at the first speed when the plate making unit is located at the operative position, and disable the printing press to operate at the first speed when the plate making unit is not located at the operative position.
Description




BACKGROUND OF THE INVENTION




The present invention relates to a printing press with a plate making unit which performs plate making for a plate mounted on a plate cylinder in a printing unit.




Generally, when performing plate making for a plate, it is required to increase the efficiency of plate making operation and to eliminate the space where a plate making unit is to be installed. Hence, in recent years, a plate making unit independent of the printing press is not provided, but a plate making unit added to the printing press itself performs plate making directly on the printing press. More specifically, a plate before plate making is mounted on a plate cylinder in a printing unit, and the plate making unit is moved to abut its head against the plate cylinder. Subsequently, the plate cylinder is rotated, and simultaneously the head is moved in the axial direction of the plate cylinder, thereby performing plate making for the plate. When the plate is to be supplied/removed or maintenance is to be performed, the plate making unit is separated from the printing unit.




In a printing press of this type, the front surface of the printing unit which opposes the plate cylinder has an opening so that a plate can be supplied to or removed from the plate cylinder and the maintenance for the inking unit and the like can be performed. An openable safety cover is provided to this opening to close it during printing. In the conventional printing press described above, a movable plate printing unit must be provided, together with an openable safety cover, between adjacent printing units. For this reason, the work space for the operator in front of the printing unit is narrowed, and the workability is decreased. Since both the safety cover and plate making unit are movable, and must be arranged in a limited space in front of the printing unit, the entire structure becomes complicated.




SUMMARY OF THE INVENTION




It is an object of the present invention to provide a printing press in which the workability of an operator during plate changing operation, maintenance, and the like is increased.




It is another object of the present invention to provide a printing press with a simplified structure.




In order to achieve the above objects, according to the present invention, there is provided a printing press comprising a printing unit with a plate cylinder, a plate making unit provided in the printing unit and adapted to perform plate making for a plate mounted on an outer surface of the plate cylinder, the plate making unit being supported to be movable between an operative position where the plate making unit performs plate making while closing at least part of the printing unit, and a wait position where the plate making unit opens at least part of the printing unit, and control means for selectively operating the printing press at a first speed at which normal printing is performed and a second speed lower than the first speed, the control means serving to enable the printing press to operate at the first speed when the plate making unit is located at the operative position, and disable the printing press to operate at the first speed when the plate making unit is not located at the operative position.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a side view schematically showing a printing press according to an embodiment of the present invention;





FIG. 2A

is a partially sectional side view of the main part of the printing press of

FIG. 1

, and





FIG. 2B

is a view seen in the direction of arrow I of

FIG. 2A

;





FIG. 3

is a plan view of the main part of the printing press shown in

FIG. 1

;





FIG. 4A

is a perspective view of a printing unit the opening of which is closed with the plate making unit shown in

FIG. 2A

, and

FIG. 4B

is a perspective view of the printing unit the opening of which is open;





FIG. 5

is a perspective view of the printing unit from which a cover and the plate making unit are removed;





FIG. 6

is a front view of the plate making unit shown in

FIG. 2A

;





FIG. 7A

is a partially cutaway side view of the plate making unit shown in

FIG. 2A

, and

FIG. 7B

is a view seen in the direction of arrow II of

FIG. 7A

;





FIG. 8

is a perspective view of the base unit shown in

FIG. 7A

;





FIG. 9

is a longitudinal sectional view of the base unit shown in

FIG. 8

;





FIG. 10A

is a side view of the plate making unit shown in

FIG. 2A

,

FIG. 10B

is a view seen in the direction of arrow III of

FIG. 10A

, and

FIG. 10C

is an enlarged view of a portion IV of

FIG. 10B

;





FIG. 11

is a perspective view, seen from the rear side, of the guide structure of an exposure unit;





FIG. 12

is a perspective view, seen from the front side, of the guide structure of the exposure unit;





FIGS. 13A and 13B

are a partially cutaway plan view and partially cutaway side view, respectively, of the position adjusting mechanism of the exposure unit;





FIG. 14

is an enlarged perspective view of the position adjusting mechanism of the exposure unit; and





FIGS. 15A and 15B

are front views showing the position adjusting mechanism of the exposure unit according to other examples.











DESCRIPTION OF THE PREFERRED EMBODIMENT




The present invention will be described in detail with reference to the accompanying drawings.





FIG. 1

schematically shows a printing press according to an embodiment of the present invention. Referring to

FIG. 1

, a printing press


1


is comprised of a feed unit


3


for feeding paper sheets one by one, four printing units


4


-


1


,


4


-


2


,


4


-


3


, and


4


-


4


sequentially arranged in the sheet convey direction to print the sheets fed from the feed unit


3


for the respective ink colors, a delivery unit


5


for delivering the sheets printed by the printing units


4


-


1


to


4


-


4


, and a control unit


6


for controlling the entire printing press


1


.




The printing press


1


is operated selectively at the first speed at which sheets are supplied from the feed unit


3


to enable printing, and the second speed lower than the first speed. At the second speed, no sheets are supplied from the feed unit


3


, and a blanket applied on the blanket cylinder or the plate is changed. Also, in order to check whether the printing pressure between the blanket cylinder and impression cylinder is appropriate, maintenance in which, e.g., printing is performed to check the printing pressure is performed.




Work spaces


8


-


1


,


8


-


2


,


8


-


3


, and


8


-


4


, where plate change and maintenance of the inking unit and the like are performed, are provided between the four printing units


4


-


1


to


4


-


4


and between the printing unit


4


-


4


and delivery unit


5


. The inking unit (not shown) with a roller group, a dampening unit (not shown), and a plate cylinder


10


, blanket cylinder


11


, an impression cylinder (not shown) and the like rotatably supported between a pair of frames


9


A and


9


B (FIG.


5


), are provided in each of the printing units


4


-


1


to


4


-


4


. As shown in

FIGS. 4A

,


4


B, and


5


, each of the frames


9


A and


9


B has high-wall portions


9




a


and low-wall portions


9




b


alternately like comb teeth at its upper portion.




As all of the printing units


4


-


1


to


4


-


4


have the same structure, the printing unit


4


-


2


and a plate making unit


35


attached to it will be described hereinafter. Referring to

FIG. 2A

, a notch (not shown) is formed in the outer surface of the plate cylinder


10


to extend in an axial direction (a direction perpendicular to the sheet convey direction). A leading edge plate clamping unit


12


for clamping the leading edge of the plate and a trailing edge plate clamping unit


13


for clamping the trailing edge of the plate are provided in this notch. A pair of levers


15


are swingably supported by the frames


9


A and


9


B through a shaft


16


. Guide rollers


17


extending in the axial direction of the plate cylinder


10


are axially supported at the distal ends of the levers


15


.




The levers


15


are driven to swing by a driving unit (not shown). When the levers


15


swing, the guide rollers


17


reciprocally move in a direction to come close to and separate from the outer surface of the plate cylinder


10


. Hence, the guide rollers


17


are positioned at a wait position (solid line), a guide position (an alternate long and two short dashed line) where they guide an old plate


23


B in plate removal, and a plate mounting position (an alternate long and a short dashed line) where they come in contact with the outer surface of the plate cylinder


10


and mount a new plate


23


A on the outer surface of the plate cylinder


10


.




A U-shaped guide member


19


for mounting the new plate and cantilevered by a pair of legs


19




a


is attached to the front surface (in sheet convey direction) of an upper cover


21


that closes the upper portion of the printing unit


4


-


2


. The guide member


19


guides the new plate


23


A inserted in the leading edge plate clamping unit


12


of the plate cylinder


10


. An opening


22


is formed below the upper cover


21


of the printing unit


4


-


2


, that is, in the front surface of the plate cylinder


10


. Plate change and maintenance of rollers and the like are performed through the opening


22


.




As shown in

FIG. 2B

, a detection switch


24


is attached to the low-wall portion


9




b


of the frame


9


B. The detection switch


24


detects that the plate making unit


35


has moved from the operative position where it performs plate making to the wait position (inoperative position) where plate change operation is possible, as will be described later.




As shown in

FIGS. 4A and 4B

, a pair of plate making unit ON/OFF detection sensors


25


A and


25


B are attached to the lower end of the front surface of the upper cover


21


above the opening


22


to oppose the plate making unit


35


. As shown in

FIG. 5

, guide members


26


A and


26


B are fixed to the respective upper end faces of the low-wall portions


9




b


of the frames


9


A and


9


B. Guide grooves


26




a


extending in the sheet convey direction (direction of arrows A-B) are formed in the upper surfaces of the guide members


26


A and


26


B. A home position dog


27


is fixed to the inner surface, closer to the sheet convey direction, of the high-wall portion


9




a


of the frame


9


A. An almost cubic engaging block


31


serving as a regulating means is fixed under the home position dog


27


.




A vertically extending V-shaped engaging recess


32


is formed on the end face, in the sheet convey direction, of the engaging block


31


. The engaging recess


32


is formed of slant surfaces


32




a


and


32




b


slanting to one side and the other side, respectively, in the axial direction (direction of arrows C-D) of the plate cylinder


10


. As the engaging recess


32


is formed V-shaped, the distance between the slant surfaces


32




a


and


32




b


gradually decreases in the moving direction (direction of arrow A) of the plate making unit


35


toward the operative position.




Circular cylindrical engaging pins


29


A and


29


B project on the inner surfaces of the high-wall portions


9




a


of the frames


9


A and


9


B to oppose each other at a position between the home position dog


27


and engaging block


31


. Engaging projections


30


A and


30


B are fixed under the respective engaging pins


29


A and


29


B.




The plate making unit


35


will be described.




Referring to

FIG. 2A

, the plate making unit


35


has a base unit


36


, a stage


37


fixed on the base unit


36


, a table


38


movable on the stage


37


in the axial direction of the plate cylinder


10


, and an exposure unit


39


with a head


40


and integrated on the table


38


to perform plate making for the plate. The exposure unit


39


irradiates (exposes) the plate cylinder


10


with a laser beam from its head


40


, while moving in the axial direction of the plate cylinder


10


, to print an image on the entire plate mounted on the plate cylinder


10


.




The base unit


36


of the plate making unit


35


will be described with reference to

FIGS. 7A and 7B

,


8


,


9


, and


10


A,


10


B, and


10


C.




Referring to

FIG. 8

, the base unit


36


has a box-like base frame


43


extending in the axial direction (direction of arrows C-D) of the plate cylinder


10


. The base frame


43


is comprised of a rectangular upper plate


44


, a pair of side plates


45


A and


45


B, and a front plate


46


having windows


46


A and


46


B. The upper plate


44


and front plate


46


form an L-shaped section. Almost cubic engaging blocks


48


A and


48


B serving as regulating means are fixed to the upper corners at the two ends of the front plate


46


.




An engaging recess


49


is formed in the front end face of each of the engaging blocks


48


A and


49


B to extend in a V shape in the horizontal direction. The engaging recess


49


is formed of an upper slant surface


49




a


facing obliquely upward and a lower slant surface


49




b


facing obliquely downward. As the engaging recess


49


is formed V-shaped, the distance (opening of the recess) between the upper and lower slant surfaces


49




a


and


49




b


decreases in the moving direction (direction of arrows A-B) of the plate making unit


35


toward the operative position.




As shown in

FIG. 7A

, engaging pins


29


A and


29


B engage with the engaging recesses


49


of the engaging blocks


48


A and


48


B, respectively. This regulates the movement of the plate making unit


35


in the vertical direction (direction of arrows E-F), so the plate making unit


35


is positioned with respect to the plate cylinder


10


in the vertical direction (direction of arrows E-F). Since the engaging blocks


48


A and


48


B engageable with the engaging pins


29


A and


29


B are formed in this manner at the two ends of the plate making unit


35


, the plate making unit


35


is positioned without being slanted in the longitudinal direction. Thus, the plate making unit


35


is positioned accurately, high-precision plate making is enabled, and the printing quality is improved.




Referring to

FIGS. 7A and 7B

, an engaging pin


50


has a threaded portion


50




b


at its base and a hemispherical distal end portion


50




a.


The threaded portion


50




b


threadably engages with that portion of the front plate


46


of the base frame


43


which is below the engaging block


48


A, so the distal end portion


50




a


projects. The distal end portion


50




a


of the engaging pin


50


engages with the engaging recess


32


of the engaging block


31


. This regulates the movement of the plate making unit


35


in the axial direction (direction of arrows C-D) of the plate cylinder


10


, so the plate making unit


35


is positioned with respect to the plate cylinder


10


.




When the engaging pin


50


is rotated, it moves forward toward or backward from the front plate


46


to adjust the position of its distal end portion


50




a.


In this manner, the verticality of the plate making unit


35


is adjusted. As the distal end portion


50




a


of the engaging pin


50


is hemispherical, despite the rotation of the engaging pin


50


, it is held while it correctly engages with the engaging recess


32


of the engaging block


31


. As a result, the direction of the plate making unit


35


perpendicular to the sheet convey direction, and the verticality of the plate making unit


35


are adjusted correctly by cooperation of the engaging pin


50


and engaging block


31


.




As shown in

FIG. 10A

, two pairs of castors


53


A and


53


B engageable with the guide grooves


26




a


of the guide members


26


A and


26


B are attached to the pair of side plates


45


A and


45


B of the base frame


43


. A substantially L-shaped lever


51


A and inverted L-shaped lever


51


B are rotatably supported by each of the side plates


45


A and


45


B through pins


52


at their central portions. The castors


53


A and


53


B are pivotally supported at the lower ends of the levers


51


A and


51


B, respectively. Slide shafts


54


are inserted in the through holes of spring bearing members


55


fixed to the side plates


45


A and


45


B. One end of each slide shaft


54


is pivotally attached to the upper end of the lever


51


A or


51


B.




A nut


57


threadably engages with a threaded portion at the other end of each slide shaft


54


. A compression coil spring


58


is elastically mounted between the nut


57


and spring bearing member


55


. The spring forces of the compression coil springs


58


bias the lever


51


A clockwise in

FIG. 10A

about the corresponding pin


52


as the center of pivot, and the lever


51


B counterclockwise in

FIG. 10A

about the corresponding pin


52


as the center of pivot. Thus, the plate making unit


35


is supported to be movable between the operative and wait positions against its own weight and to be adjustable in the vertical direction. As shown in

FIG. 10C

, a narrow, ring-like engaging wheel


53




a


is integrally formed on the outer surface of each of the castors


53


A and


53


B. The width of the guide groove


26




a


of each of the guide members


26


A and


26


B is formed larger than the width of the engaging wheel


53




a


by 2δ.




As shown in

FIG. 9

, a pair of actuators


60


A and


60


B are pivotally mounted on brackets


61


, fixed to the lower surface of the front plate


46


of the base frame


43


, to oppose each other. A fixed state detection sensor


63




a


and a fixed state release detection sensor


63




b


are attached to each of the actuators


60


A and


60


B to detect forward/backward movement of a corresponding rod


64


. One end of a lever


65


is pivotally mounted on the distal end of each rod


64


. The other end of the lever


65


projects from the window


46


A outside the base frame


43


, and is pivotally mounted on a bracket


66


fixed to the outside of the front plate


46


through a pin


67


.




Each lever


65


has a hook


65




a


on its other end. When the rods


64


move backward, the corresponding hooks


65




a


engage with the engaging projections


30


A and


30


B, respectively, and the base unit


36


is fixed to the frames


9


A and


9


B. Simultaneously, the fixed state detection sensors


63




a


detect that the base unit


36


is fixed. When the rods


64


move forward, the hooks


65




a


of the levers


65


and the engaging projections


30


A and


30


B are disengaged from each other. Simultaneously, the fixed state release detection sensors


63




b


detect that the fixed base unit


36


is released.




In this manner, the actuators


60


A and


60


B have both the function of fixing the plate making unit


35


to the frames


9


A and


9


B and the function of detecting that the plate making unit


35


is fixed or released. As members that take charge: of the two functions can be shared, not only the number of components is reduced, but also the structure is simplified.




The moving structure of the exposure unit


39


in the axial direction (direction of arrows C-D) of the plate cylinder


10


will be described with reference to

FIGS. 7A

,


11


,


12


, and


14


.




Referring to

FIG. 7A

, the stage


37


extends in the axial direction of the plate cylinder


10


and is fixed on the upper plate


44


of the base frame


43


. As shown in

FIG. 11

, a pair of opposing side plates


70


A and


70


B are provided upright at the two ends of the stage


37


. A motor


71


which is selectively driven in the forward/reverse direction is fixed to the side plate


70


A. Rotation of the motor shaft of the motor


71


is transmitted to a ball screw


72


which is rotatable between the side plates


70


A and


70


B and the movement of which in the axial direction is regulated.




A pair of parallel rails


73


are mounted on the upper surface of the stage


37


so as to extend in the axial direction (direction of arrows C-D) of the plate cylinder


10


at a predetermined distance from each other. As shown in

FIG. 12

, four sliders


75


are fixed to the lower surface of the table


38


such that they fit on the corresponding rails


73


and guide the table


38


along the rails


73


in the direction of arrows C-D. As shown in

FIG. 14

, screw holes


38




a


to threadably engage with the ball screw


72


are formed in the side end faces of the table


38


to extend through them in the axial direction of the plate cylinder


10


. When the motor


71


is driven in the forward/reverse direction, the table


38


moves in the direction of arrows C-D through the ball screw


72


.




The exposure unit


39


is placed on the table


38


to be movable in the sheet convey direction, i.e., in a direction (direction of arrows A-B) to come close to and separate from the plate cylinder


10


. The exposure unit


39


is fixed to the table


38


with a pair of clamp plates


84


A and


84


B (

FIG. 14

; to be described later), and moves together with the table


38


. As shown in

FIG. 3

, an exposure unit home position sensor


76


for detecting the home position dog


27


fixed to the frame


9


A is attached to the table


38


. When the motor


71


drives the plate making unit


35


to move in the direction of arrow D, the exposure unit home position sensor


76


detects the home position dog


27


. Upon detection of the home position dog


27


, movement of the plate making unit


35


is topped, and an exposure start position where the plate mounted on the plate cylinder


10


is to be exposed by the head


40


is determined.




In this manner, when the exposure start position for the plate is determined by the exposure unit home position sensor


76


, exposure always starts at the same position, so a position error in plate making can be prevented. In addition, since the home position dog


27


is fixed to the frame


9


A and the exposure unit home position sensor


76


is fixed to the table


38


, the position of the head


40


in the axial direction of the plate cylinder


10


can be detected with reference to the frame


9


A. Hence, the position of the head


40


can be correctly detected without being influenced by the position precision of the plate making unit


35


at the operative position and the position precision of the head


40


with respect to. the plate making unit


35


. As a result, high-precision plate making is enabled, and the printing quality is improved.




As shown in

FIG. 6

, a pair of detection target members


78


A and


78


B are attached to the upper portion of the front surface of a cover


77


that closes the plate making unit


35


entirely. As shown in

FIGS. 4A and 4B

, when the plate making unit


35


comes close to the printing unit


4


-


2


and closes its opening


22


, the detection target members


78


A and


78


B are detected by the plate making unit ON/OFF detection sensors


25


A and


25


B. In other words, the plate making unit ON/OFF detection sensors


25


A and


25


B and the detection target members


78


A and


78


B detect that the plate making unit


35


is located at the operative position. For example, the detection target members


78


A and


78


B are formed of light-emitting elements, and the plate making unit ON/OFF detection sensors


25


A and


25


B are formed of light-receiving elements. When it is detected that the plate making unit


35


is located at the operative position, the control unit


6


sets the printing press


1


in the print mode. When it is not detected that the plate making unit


35


is located at the operative position, the control unit


6


sets the printing press


1


in the non-print mode.




As shown in

FIGS. 2A and 2B

, a cam


79


for actuating the detection switch


24


is attached to the lower end of the cover


77


on the frame


9


B side. The cam


79


has a notch


79




a


at its rear end. With this arrangement, the plate making unit


35


moves from the operative position, indicated by a solid line and where it performs plate making, in a direction (direction of arrow B) to separate from the plate cylinder


10


, and is positioned at the inoperative position indicated by an alternate long and two short dashed line and where it awaits in plate change. At this time, the notch


79




a


of the cam


79


opposes the detection switch


24


. When the detection switch


24


detects the notch


79




a,


the control unit


6


allows the printing,press


1


to perform plate change.




The structure for finely adjusting the exposure unit


39


in the direction (direction of arrows A-B) to come close to and 'separate from the plate cylinder


10


will be described with reference to

FIGS. 13A

,


13


B, and


14


.




As shown in

FIG. 14

, a groove


81


with a rectangular section and extending in the direction of arrows A-B is formed at the center of the lower end face of the exposure unit


39


. A cylindrical pipe


82


with a screw hole


82




a


is fixed in the groove


81


. A groove


83


with a V-shaped section and extending in the direction of arrows A Bis formed at the center of the upper surface of the table


38


to correspond to the groove


81


. The exposure unit


39


is detachably placed on the table


38


such that the pipe


82


is accommodated in the groove


83


. The pair of clamp plates


84


A and


84


B are arranged on the two sides, opposing each other in the axial direction of the plate cylinder


10


, of the exposure unit


39


.




In this arrangement, the exposure unit


39


is placed on the table


38


so as to be movable through the pipe


82


in th e direction (direction of arrows A-B) to come close to and separate from the plate cylinder


10


. When the driving means (not shown) is actuated to clamp the exposure unit


39


and table


38


with the clamp plates


84


A and


84


B, the exposure unit


39


is fixed on the table


38


. The pair of screw holes


38




b


to threadably engage with thumbscrews


93


are formed in one end face of the table


38


.




An adjuster


85


is comprised of a rectangular parallelepiped stationary member


86


, an almost cubic movable member


87


movable in the direction of arrows A-B, and a differential screw


90


which can move the movable member


87


with respect to the stationary member


86


. A pair of guide members


94


A and


94


B oppose each other at a gap slightly larger than the width of the movable member


87


, and form a U shape together with an attaching plate


95


. The guide members


94


A and


94


B are is fixed to the rear end face of the stationary member


86


with screws. The differential screw


90


has a threaded portion


88


and a threaded portion


89


integrally formed at the distal end of the threaded portion


88


and with a pitch smaller than that of the threaded portion


88


. A handle


91


is integrally attached to the proximal end of the threaded portion


88


.




The threaded portion


88


of the differential screw


90


extends through a screw hole in the movable member


87


to threadably engage with it, and the threaded portion


89


threadably engages with a screw hole in the stationary member


86


. The movable member


87


is guided in the direction of arrows A-B such that it is sandwiched between the guide members


94


A and


94


B. A pair of spacers


92


are attached to the front end of the stationary member


86


. The thumbscrews


93


threadably engage with the screw holes of the stationary member


86


to extend through them. A screw


96


threadably engages with the screw hole of the movable member


87


to extend through it.




In this arrangement, when the respective thumbscrews


93


are threadably engaged with the screw holes


38




b


of the table


38


, the stationary member


86


is fixed to the table


38


. When the screw


96


is threadably engaged with the screw hole


82




a


of the pipe


82


, the movable member


87


and pipe


82


are integrated with each other. The clamp plates


84


A and


84


B are released, the exposure unit


39


is set movable in the direction of arrows A-B with respect to the table


38


, and the handle


91


is rotated clockwise.




The pitch of the threaded portion


88


threadably engaging with the movable member


87


is larger than that of the threaded portion


89


threadably engaging with the stationary member


86


, and the stationary member


86


is fixed to the table


38


. Thus, the moving amount of the movable member


87


in the direction B with respect to the threaded portion


88


is larger than that of the threaded portion


88


in the direction A, so the movable member


87


slightly moves in the direction of arrow B. At this time, the pipe


82


integrated with the movable member


87


also slides in the groove


81


to slightly move in the direction of arrow B. Thus, the exposure unit


39


to which the pipe


82


is fixed also slightly moves in the direction of arrow B, so that it is finely adjusted with respect to the table


38


in the direction (direction of arrows A-B) to come close to and separate from the plate cylinder


10


.




If the pitch of the threaded portion


88


threadably engaging with the movable member


87


is smaller than that of the threaded portion


89


threadably engaging with the stationary member


86


, as the handle


91


is rotated clockwise, the movable member


87


moves in the direction A. Thus, the exposure unit


39


is finely adjusted in the direction A.




The plate making operation of the printing press with the above arrangement will be described.




First, as shown in

FIG. 4B

, the opening


22


of the printing unit


4


-


2


is opened to allow plate change or maintenance of the inking unit and the like. At this time, the plate making unit


35


is separate from the printing press


1


in the direction of arrow B, and is located at the opposite side in the work space


8


-


2


, i.e., at the wait position (inoperative position) indicated by the alternate long and two short dashed line in FIG.


7


A. At the wait position, as the plate making unit ON/OFF detection sensors


25


A and


25


B do not detect the detection target members


78


A and


78


B, the control unit


6


controls the printing press


1


in a state wherein its operation at the first speed is disabled, i.e., a state wherein normal printing cannot be performed.




When the castors


53


A and


53


B roll in the guide grooves


26




a


of the guide members


26


A and


26


B, the plate making unit


35


moves from the wait position in the direction of arrow A, and is positioned at the operative position indicated by the solid line in FIG.


7


A. At this time, the head


40


comes close to the outer surface of the plate cylinder


10


, and plate making operation is enabled. At the operative position, the engaging recesses


49


of the engaging blocks


48


A and


48


B of the plate making unit


35


respectively engage with the engaging pins


29


A and


29


B of the frames


9


A and


9


B, as shown in

FIG. 7A

, to position the plate making unit


35


in the vertical (up-and-down) direction.




Simultaneously, the distal end portion


50




a


of the engaging pin


50


of the plate making unit


35


engages with the engaging recess


32


of the engaging block


31


of the frame


9


A. Since the engaging recess


32


extends in the vertical direction as described above, the engaging pin


50


of the plate making unit


35


is allowed to move along the engaging recess


32


in the vertical direction. Hence, the engaging blocks


48


A and


48


B and engaging pins


29


A and


29


B correctly position the plate making unit


35


in the vertical direction.




When positioning the plate making unit


35


in the vertical direction, even if it moves (is positionally shifted) in the vertical direction, the compression coil springs


58


absorb this movement (positional shift). Hence, the plate making unit


35


can be positioned by only moving it to the operative position. This improves the plate making precision and printing precision, and greatly reduces the load of the operator and preparation time, thereby increasing the productivity.




When the distal end portion


50




a


of the engaging pin


50


of the plate making unit


35


engages with the engaging recess


32


of the engaging block


31


of the frame


9


A, the plate making unit


35


is positioned in the axial direction of the plate cylinder


10


. At this time, as shown in

FIG. 7A

, the engaging recesses


49


of the engaging blocks


48


A and


48


B of the plate making unit


35


engage with the engaging pins


29


A and


29


B of the frames


9


A and


9


B. Since the engaging recesses


49


extend in the axial direction of the plate cylinder


10


as described above, the plate making unit


35


is allowed to move such that its engaging recesses


49


slide on the engaging pins


29


A and


29


B of the frames


9


A and


9


B.




As shown in FIG. IOC, a play corresponding to the distance 2δ is set between the engaging wheel


53




a


of the castor


53


B and the guide groove


26




a.


Accordingly, when positioning the plate making unit


35


in the axial direction of the plate cylinder


10


, even if it moves (is positionally shifted) in the axial direction of the plate cylinder


10


, the engaging blocks


48


A and


48


B are allowed to move in the same direction, and the movement itself is absorbed by the play 2δ.




Thus, the plate making unit


35


can be positioned by only moving it to the operative position. This improves the plate making precision and printing precision, and greatly reduces the load of the operator and preparation time, thereby increasing the productivity. If the verticality of the plate making unit


35


need be adjusted, the engaging pin


50


is rotated to move the distal end portion


50




a


forward/backward.




When the plate making unit


35


is positioned at a position where it can perform plate making, the plate making unit ON/OFF detection sensors


25


A and


25


B oppose the detection target members


78


A and


78


B, as shown in FIG.


7


A. In this state, the plate making unit ON/OFF detection sensors


25


A and


25


B detect that the plate making unit


35


is positioned at the operative position. When it is detected that the plate making unit


35


is at the operative position, the control unit


6


drives the actuators


60


A and


60


B, supported by the base frame


43


, to move the rods


64


backward, as shown in FIG.


9


. When the rods


64


move backward, the hooks


65




a


of the levers


65


engage with the engaging projections


30


A and


30


B of the frames


9


A and


9


B. Hence, at the operative position, the plate making unit


35


is fixed to the frames


9


A and


9


B.




At this time, the fixed state detection sensors


63




a


of the actuators


60


A and


60


B detect that the plate making unit


35


is fixed, and output detection signals to the control unit


6


. Based on the detection signals from the fixed state detection sensors


63




a


and detection signals from the plate making unit ON/OFF detection sensors


25


A and


25


B, the control unit


6


determines that the plate making unit


35


is in the plate making possible state and the printing possible state, i.e., that the plate making unit


35


can be operated at the first speed. In this manner, since the plate making unit ON/OFF detection sensors


25


A and


25


B and fixed state detection sensors


63




a


arranged above and under the plate making unit


35


detect the plate making possible state and printing possible state, the plate making unit


35


at the operative position is reliably positioned in the vertical direction.




When the distance between the head


40


and the outer surface of the plate cylinder


10


need be adjusted, the exposure unit


39


is finely adjusted by moving it with respect to the table


38


in the direction of arrows A-B by using the adjuster


85


shown in

FIGS. 13A

,


13


B, and


14


. Subsequently, the driving means (not shown) is driven to clamp the table


38


and exposure unit


39


with the clamp plates


84


A and


84


B, thereby fixing the exposure unit


39


to the table


38


. When the exposure unit


39


is fixed to the table


38


in this manner with the clamp plates


84


A and


84


B, the distance between the head


40


and plate cylinder


10


which is adjusted once is maintained during plate making operation, so defective plate making is prevented.




Subsequently, the thumbscrews


93


and the screw holes


38




b


of the table


38


are disengaged from each other, and the screw


96


and the screw hole


82




a


of the pipe


82


are disengaged from each other, so the adjuster


85


is removed from the table


38


and exposure unit


39


. Since the adjuster


85


is removable in this manner, the plate making units


35


of the plurality of printing units


4


-


1


to


4


-


4


can be adjusted with one adjuster


85


. Thus, the cost is reduced, and the number of adjusters


85


that need management is reduced.




When an exposure start button (not shown) is operated, as the control unit


6


already recognizes that plate making is possible., it outputs a plate making operation start signal to the motor


71


(FIG.


3


). The motor


71


drives the ball screw


72


to rotate in the forward direction. The exposure unit


39


is thus guided along the rails


73


to move from the position indicated by the alternate long and two short dashed line in the direction of arrow D. When the exposure unit home position sensor


76


detects the home position dog


27


, rotation of the motor


71


is temporarily stopped, and the exposure unit


39


is positioned at the home position.




When the exposure unit


39


is positioned at the home position, the motor


71


rotates in the reverse direction to move the exposure unit


39


in the direction of arrow C. Thus, the head


40


performs plate making for the plate mounted on the plate cylinder


10


. When the exposure unit


39


is positioned at the position indicated by the alternate long and two short dashed line, the motor


71


is driven in the forward direction again, and the exposure unit


39


moves in the direction of arrow D. When the exposure unit home position sensor


76


detects the home position dog


27


, the exposure unit


39


is positioned at the home position again.




In this manner, since the home position dog


27


is fixed to the frame


9


A and the exposure unit home position sensor


76


is fixed to the table


38


, the position of the head


40


in the axial direction of the plate cylinder


10


can be detected with reference to the frame


9


A. Accordingly, the position of the head


40


can be detected correctly without being influenced by the position precision of the plate making unit


35


at the operative position and the position precision of the head


40


with respect to :the plate making unit


35


. As a result, high-precision plate making is enabled, and the printing quality is improved.




Since the plate making unit


35


is provided to each of all the printing units


4


-


1


to


4


-


4


, in each of the printing units


4


-


1


to


4


-


4


, the position of the head


40


is detected with reference to the frame


9


A. Therefore, the register accuracy is improved, and the complicated, skilled operation by the operator of adjusting the positions of the plate cylinders


10


for the purpose of registration is reduced, greatly reducing the load of the operator. Also, the preparation time can be greatly shortened, and the productivity is increased.




After plate making, a print start button (not shown) is operated with the plate making unit


35


being located at the operative position. As the control unit


6


already recognizes that printing is possible, it starts printing operation. At this time, the plate making unit


35


closes the opening


22


of the printing unit


4


-


2


, as shown in FIG.


2


A. In other words, the plate making unit


35


functions as a safety cover, so an exclusive safety cover need not be provided.




As a result, since an openable safety cover is not necessary, the structure is simplified. Since the space in front of the printing unit


4


-


2


is not narrowed more than necessary, the plate change operation and maintenance workability increase. Since the control unit


6


controls the printing press


1


in the plate making possible state and printing possible state on the basis of both the detection signal from the fixed state detection sensor


63




a


and the detection signals from the plate making unit ON/OFF detection sensors


25


A and


25


B, the plate making operation and printing operation are performed reliably.




When plate change or maintenance of the rollers or the like is to be performed, in

FIG. 2A

, the plate making unit


35


is moved from the operative position indicated by the solid line in the direction of arrow B and is positioned at the position indicated by an alternate long and two short dashed line. At this time, the detection switch


24


detects the notch


79




a


of the cam


79


, so it is detected that the plate making unit


35


is positioned at the inoperative position. On the basis of the detection signal from the detection switch


24


, the control unit


6


controls the printing press


1


to enable plate change and maintenance.




When a plate change button (not shown) is operated to change the plate, the driving means (not shown) positions the levers


15


at the guide position indicated by the alternate long and two short dashed line, as shown in FIG.


2


A. The trailing edge plate clamping unit


13


of the plate cylinder


10


releases the plate. The plate cylinder


10


rotates through substantially one revolution clockwise in

FIG. 2A

, and the plate is released by the leading edge plate clamping unit


12


. Thus, the old plate


23


B is removed from the plate cylinder


10


through the opening


22


of the printing unit


4


-


2


while it is guided by the guide rollers


17


.




When the leading edge of the new plate


23


A supported by the legs


19




a


of the new plate mounting guide member


19


is inserted in the leading edge plate clamping unit


12


, the leading edge plate clamping unit


12


closes to clamp the new plate


23


A. The levers


15


pivot slightly clockwise in

FIG. 2A and

, with the guide rollers


17


being positioned at the plate mounting position indicated by the alternate long and short dashed line, the plate cylinder


10


rotates substantially through one revolution counterclockwise. Thus, the trailing edge of the new plate


23


A is inserted in the trailing edge plate clamping unit


13


. The trailing edge plate clamping unit


13


closes to clamp the trailing edge of the new plate


23


A, so the new plate


23


A is mounted on the outer surface of the plate cylinder


10


.




In this manner, when the detection switch


24


detects that the plate making unit


35


is positioned at the inoperative position separate from the plate cylinder


10


, plate change operation is enabled. The old plate


23


B to be removed and the new plate


23


A to be supplied will not damage the head


40


or the like, and will not scratch the surface of the new plate


23


A.




When maintenance of the rollers or the like is to be performed, a tool or the like is inserted through the opening


22


which is opened when the plate making unit


35


is positioned at the inoperative position, and maintenance is performed. In this manner, when it is detected that the plate making unit


35


is at the inoperative position, the control unit


6


performs control operation to enable plate change operation and maintenance. Thus, plate change operation and maintenance can be performed reliably.





FIGS. 15A and 15B

show modifications of the adjuster. An adjuster


185


shown in

FIG. 15A

uses, in place of the differential screw


90


shown in

FIG. 14

, a shaft


97


having a shaft portion


97




a


and a threaded portion


97




b


formed at the distal end of the shaft portion


97




a.


The shaft portion


97




a


of the shaft


97


loosely extends through a hole in a movable member


87


that fixes and holds the screw


96


, and the threaded portion


97




b


of the shaft


97


threadably engages with a hole in a stationary member


86


to be fixed by it. A pair of fixing rings


98


fixed to the shaft portion


97




a


to correspond to the two surfaces of the movable member


87


regulate the movable member


87


from moving in the axial direction of the shaft portion


97




a.






In the adjuster


185


with the above arrangement, when the handle


91


is rotated, the shaft


97


moves in a direction to come close to or separate from the exposure unit


39


. Accordingly, the movable member


87


supported by the shaft portion


97




a,


and the screw


96


also move in the direction to come close to or separate from the exposure unit


39


, thereby finely adjusting the exposure unit


39


with respect to the new plate


23


A mounted on the plate cylinder


10


.




An adjuster


285


shown in

FIG. 15B

uses, in place of the differential screw


90


shown in

FIG. 14

, a shaft


99


having a threaded portion


99




a


and a shaft portion


99




b


formed at the distal end of the threaded portion


99




a.


The threaded portion


99




a


of the shaft


99


threadably engages with the movable member


87


that fixes and holds the screw


96


, and the shaft portion


99




b


of the shaft


99


loosely extends through a hole in a stationary member


86


. A pair of fixing rings


98


fixed to the shaft portion


99




b


to correspond to the two surfaces of the stationary member


86


regulate the shaft


99


from moving in its axial direction.




In the adjuster


285


with the above arrangement, when the handle


91


is rotated, the shaft


99


rotates without moving in the axial direction. As the threaded portion


99




a


rotates, the movable member


87


and screw


96


are fed in the direction to come close to or separate from the exposure unit


39


, thereby finely adjusting the exposure unit


39


with respect to the new plate


23


A mounted on the plate cylinder


10


.




In the above embodiment, the opening


22


of each of the printing units


4


-


1


to


4


-


4


is entirely closed with the plate making unit


35


. However, the opening


22


need not always be entirely closed. It suffices as far as at least the necessary minimum part of the opening


22


is closed.




Although the engaging recesses


49


of the engaging blocks


48


A and


4


.


8


B and the engaging recess


32


of the engaging block


31


are formed with a V shape, they may alternatively be formed with a U shape. It suffices as far as the distance between the slant surfaces


49




a


and


49




b


gradually decreases toward the inner part of the recess.




The engaging pins


29


A and


29


B are provided to the frames


9


A and


9


B, and the engaging blocks


48


A and


48


B are provided to the plate making unit


35


. Alternatively, the engaging pins


29


A and


29


B may be provided to the plate making unit


35


, and the engaging blocks


48


A and


48


B may be provided to the frames


9


A and


9


B. Similarly, the engaging pin


50


may be provided to the frame


9


A, and a second engaging block


31


may be provided to the plate making unit


35


.




As has been described above, according to the present invention, since the plate making unit can serve as a safety cover as well, an openable safety cover becomes unnecessary, thus simplifying the structure. Since the space in front of the printing unit is not narrowed more than necessary, the plate change operation and maintenance workability increase.




Upon detecting that the plate making unit is positioned at the inoperative position, the printing press is controlled in the plate making possible state and printing possible state. Thus, plate making operation and printing operation are performed reliably.




Upon detecting that the plate making unit is positioned at the inoperative position, control operation is performed so a plate can be supplied to or removed from the plate cylinder, or maintenance for the ink unit and the like can be performed. Therefore, plate change operation and maintenance operation can be performed reliably.



Claims
  • 1. A printing press comprising:a printing unit with a plate cylinder; a plate making unit provided in said printing unit and adapted to perform plate making for a plate mounted on an outer surface of said plate cylinder, said plate making unit being supported to be movable between an operative position where said plate making unit performs plate making while closing at least part of said printing unit, and a wait position where said plate making unit opens at least part of said printing unit; and control means for selectively operating said printing press at a first speed at which normal printing is performed and a second speed lower than the first speed, said control means serving to enable said printing press to operate at the first speed when said plate making unit is located at the operative position, and disable said printing press to operate at the first speed when said plate making unit is not located at the operative position.
  • 2. A printing press according to claim 1, whereinsaid printing press further comprises detection means for detecting that said plate making unit is located at the operative position, and said control means enables operation of said printing press at the first speed on the basis of at least a detection signal from said detection means.
  • 3. A printing press according to claim 2, whereinsaid printing press further comprises a fixing mechanism for fixing said plate making unit at the operative position when said plate making unit is located at the operative position, and a fixed state detection sensor for detecting that said fixing mechanism fixes said plate making unit, and said control means enables operation of said printing press at the first speed on the basis of the detection signal from said detection means and a detection signal from said fixed state detection sensor.
  • 4. A printing press according to claim 3, wherein said control means drives said fixing mechanism in response to the detection signal from said detection means.
  • 5. A printing press according to claim 2, wherein said detection means comprises two photosensors that line up above said plate making unit in an axial direction of said plate cylinder.
  • 6. A printing press according to claim 1, whereinsaid printing press further comprises detection means for detecting that said plate making unit is located at the wait position, and said control means disables operation of said printing press at the first speed on the basis of a detection signal from said detection means.
  • 7. A printing press according to claim 6, wherein said detection means comprisesa cam member fixed to a lower portion of said plate making unit, and a mechanical switch attached to said printing unit and actuated by said cam member when said plate making unit is located at the wait position.
  • 8. A printing press according to claim 6, wherein said control means enables operation of said printing press at the second speed on the basis of a detection signal from said detection means.
  • 9. A printing press according to claim 1, further comprising a support mechanism for supporting said plate making unit to be movable between the operative position and the wait position.
  • 10. A printing press according to claim 1, whereinsaid printing unit has an opening corresponding to said plate cylinder, and said plate making unit closes the opening at the operative position and opens the opening at the wait position.
  • 11. A printing press comprising:a printing unit with a plate cylinder; a plate making unit provided in said printing unit and adapted to perform plate making for a plate mounted on an outer surface of said plate cylinder, said plate making unit being supported to be movable between an operative position where said plate making unit performs plate making while closing at least part of said printing unit, and a wait position where said plate making unit opens at least part of said printing unit; detection means for detecting that said plate making unit is located at the operative position, said detection means comprising two photosensors that line up above said plate making unit in an axial direction of said plate cylinder; and control means for selectively operating said printing press at a first speed on the basis of at least a detection signal from the detection means at which normal printing is performed and a second speed lower than the first speed, said control means serving to enable said printing press to operate at the first speed when said plate making unit is located at the operative position, and disable said printing press from operating at the first speed when said plate making unit is not located at the operative position.
  • 12. A printing press comprising:a printing unit with a plate cylinder; a plate making unit provided in said printing unit and adapted to perform plate making for a plate mounted on an outer surface of said plate cylinder, said plate making unit being supported to be movable between an operative position where said plate making unit performs plate making while closing at least part of said printing unit, and a wait position where said plate making unit opens at least part of said printing unit; detection means for detecting that said plate making unit is located at the wait position; and control means for selectively operating said printing press at a first speed at which normal printing is performed and a second speed lower than the first speed, said control means serving to enable said printing press to operate at the first speed when said plate making unit is located at the operative position, and disable said printing press to operate at the first speed when said plate making unit is not located at the operative position, wherein said control means disables operation of said printing press at the first speed on the basis of a detection signal from said detection means.
  • 13. A printing press according to claim 12, wherein said detection means comprises:a cam member fixed to a lower portion of said plate making unit, and a mechanical switch attached to said printing unit and actuated by said cam member when said plate making unit is located at the wait position.
  • 14. A printing press according to claim 12, wherein said control means enables operation of said printing press at the second speed on the basis of a detection signal from said detection means.
Priority Claims (1)
Number Date Country Kind
2000-145481 May 2000 JP
US Referenced Citations (3)
Number Name Date Kind
4718340 Love, III Jan 1988 A
5713287 Gelbart Feb 1998 A
6336404 Sakamoto Jan 2002 B1
Foreign Referenced Citations (3)
Number Date Country
19612927 Nov 1996 DE
2048785 Feb 1996 GB
11-314353 Nov 1999 JP