Printing press

[0001] The entire disclosure of Japanese Patent Application No. 2000-189213 filed on Jun. 23, 2000, including specification, claims, drawings, and summary is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a printing press, which can drive an ink supply apparatus solely by an oscillation drive motor, for example.

[0004] 2. Description of the Related Art

[0005] An ink supply apparatus of a printing press for supplying ink to the surface of a plate attached to a plate cylinder comprises an ink fountain for storing ink, and a group of rollers for transferring ink from the ink fountain while uniformly distributing the ink in respective directions. The ink transferred to the end portion of the group of rollers is supplied to the plate cylinder via an ink form roller.

[0006] In general, such an ink supply apparatus (hereinafter referred to as an “inker”) for effecting ink supply operation employs a drive system such that the ink supply apparatus is mechanically connected to a driving side (main unit) which includes a plate cylinder and which rotates the plate cylinder, to thereby receive rotational torque from the driving side.

[0007] Further, for a short-time operation such as an operation for a printing preparation, maintenance, or cleaning of the inker, there has been developed a system for breaking the mechanical connection between the inker and the driving side by means of a clutch and for rotating the inker independently of the main unit by means of a separate drive source (motor) (Japanese Patent Application Laid-Open (kokai) No. 63-315244).

[0008] Meanwhile, when rainbow printing is to be performed for preventing forgery, an oscillation apparatus is built into the inker in order to adjust oscillation conditions of an oscillating roller.

[0009] A known oscillation apparatus is of a hydraulic-control-type in which ink stored in the ink fountain is supplied to the oscillating roller, and the oscillating roller is reciprocated along an axial direction thereof by means of a hydraulic cylinder, whereby the ink is supplied to the plate cylinder while being spread in the axial direction of the oscillating roller (see, for example, Japanese Patent Application Laid-Open (kokai) No. 63-264352 and Japanese Utility Model Application Laid-Open (kokai) No. 63-170138).

[0010] In the above-described hydraulic-control-type oscillation apparatus, a mechanism for controlling the hydraulic cylinder is complicated; and oscillation width and the number of times of oscillations are difficult to adjust finely.

[0011] In view of the foregoing, a two-motor-type oscillation apparatus may be employed, which uses a motor for the oscillation drive and a motor for the oscillation width adjustment instead of the above-described hydraulic cylinder. However, in such a case, it becomes necessary to install two motors having the same specifications for each inking unit for a single color.

[0012] However, in the case where a separate drive source is provided in order to improve maintainability or the like as described above, three drive sources are needed in total for each inking unit for a single color.

SUMMARY OF THE INVENTION

[0013] In view of the foregoing, an object of the present invention is to provide a printing press, which can drive an inker solely by use of a motor for oscillating an oscillating roller.

[0014] Another object of the present invention is to reduce the number of motors to be installed, thereby reducing cost and saving space.

[0015] In order to achieve these objects, the present invention provides a printing press, comprising a first rotary member; a first motor for rotating the first rotary member; a second rotary member rotated by the first motor and movably supported in an axial direction thereof; a second motor for moving the second rotary member in the axial direction and for rotating the second rotary member; connecting/disconnecting means for selectively permitting and stopping transmission of rotation from the first motor to the second rotary member; and a clutch for stopping transmission of rotation from the second motor to the second rotary member when the first motor is connected to the second rotary member by the connecting/disconnecting means such that the first motor can rotate the second rotary member and for connecting the second motor with the second rotary member such that the second motor can rotate the second rotary member when transmission of rotation from the first motor to the second rotary member is stopped by the connecting/disconnecting means.

[0016] The connecting/disconnecting means may be frame moving means for separating a first frame supporting the first rotary member and a second frame supporting the second rotary member from each other, to thereby stop transmission of rotation from the first motor to the second rotary member.

[0017] Alternatively, the connecting/disconnecting means may be a second clutch provided between the first rotary member side and the second rotary member side and adapted to stop transmission of rotation from the first motor to the second rotary member.

[0018] The first rotary member may be a cylinder or an oscillating roller of an offset printing press.

[0019] Preferably, the printing press further comprises a sensor for detecting a state in which the first frame and the second frame are in proximity to each other, wherein the clutch is prevented from entering a connected state when the sensor detects the state in which the first frame and the second frame are in proximity to each other.

[0020] Preferably, the printing press further comprises an oscillation mechanism for converting rotation transmitted from the second motor to reciprocating motion of the second rotary member; an oscillation-width adjustment mechanism for adjusting an oscillation width of the second rotary member; and oscillation-width adjustment means for operating the oscillation-width adjustment mechanism.

[0021] Preferably, the oscillation mechanism includes a swing member which swings upon operation of the second motor, a moving member movably supported on the swing member, and an engagement member rotatably supported on the moving member and being in engagement with the second rotary member, and wherein the oscillation-width adjustment mechanism is configured such that, upon operation of the oscillation-width adjustment means, the oscillation-width adjustment mechanism moves the moving member to thereby adjust a distance between a swing center of the swing member and a rotation center of the engagement member. Preferably, the moving member is slidably supported on the swing member.

[0022] Preferably, the oscillation mechanism includes a crank mechanism whose input side is connected to the second motor, a swingably-supported swing lever whose base end side is connected to the output side of the crank mechanism, a slide lever slidably supported by the swing lever such that the distal end side of the slide lever can move toward and away from a swing center of the swing lever, a first link plate whose one end side is rotatably supported by the distal end side of the slide lever, a swingably-supported swing plate, the other end side of the first link plate being rotatably connected to the base end side of the swing plate, and a cam follower provided at the distal end side of the swing plate and inserted into a groove wheel of the second rotary member; and the oscillation-width adjustment mechanism includes a worm gear connected to the oscillation-width adjustment means, a worm wheel in meshing engagement with the worm gear, a transmission shaft coaxially connected to the worm wheel, a second link plate whose one end side is connected to the transmission shaft, and the slide lever whose base end side is rotatably connected to the other end side of the second link plate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

[0024]
FIG. 1A is a view schematically showing the overall structure of an embodiment in which the present invention is applied to an inker of a double-sided, multicolor offset press;

[0025]
FIG. 1B is an enlarged view of a hydraulic cylinder;

[0026]
FIG. 2 is an enlarged view of the inker;

[0027]
FIG. 3 is a side sectional view schematically showing the structure of a main portion of the oscillating roller oscillation apparatus;

[0028]
FIG. 4 is a plan view as viewed from the direction of arrow IV in FIG. 3;

[0029]
FIG. 5 is a front view as viewed from the direction of arrow V in FIG. 4;

[0030]
FIG. 6 is a horizontally-sectioned development view of a main portion of FIG. 3;

[0031]
FIG. 7 is a block diagram of an oscillation-width controller;

[0032]
FIG. 8 is a block diagram of an oscillation-speed controller;

[0033]
FIG. 9 is a flowchart for oscillation-width control;

[0034]
FIG. 10 is a flowchart for oscillation speed control;

[0035]
FIG. 11 is a block diagram of another example of the oscillation-width controller; and

[0036]
FIG. 12 is a schematic view sowing the structure of a drive force transmission mechanism of the inker.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] A preferred embodiment in which the present invention is applied to a double-sided, multicolor offset press will be described with reference to FIGS. 1A to 10.

[0038] As shown in FIGS. 1A and 1B, a sheet-feed table 11 is disposed within a feeder unit 10.

[0039] A feeder board 12 is provided in the feeder unit 10. The feeder board 12 feeds paper sheets 1 from the sheet-feed table 11 to a printing unit 20 one sheet at a time.

[0040] A swing apparatus 13 for transferring the paper sheets 1 to a transfer cylinder 21a of the printing unit 20 is provided at the distal end of the feeder board 12.

[0041] The transfer cylinder 21a is in contact with an impression cylinder 22a via transfer cylinders 21b to 21d. A blanket made of rubber is attached to the outer circumferential surface of the impression cylinder 22a.

[0042] A rubber cylinder 22b is in contact with the impression cylinder 22a at a position downstream of the transfer cylinder 21d.

[0043] A plurality of (four in the present embodiment) plate cylinders 23a are in contact with the impression cylinder 22a at positions upstream of the transfer cylinder 21d in such a manner that the plate cylinders 23a are arranged along the circumferential direction at predetermined intervals.

[0044] A plurality of (four in the present embodiment) plate cylinders 23b are in contact with the rubber cylinder 22b at positions upstream of the impression cylinder 22a in such a manner that the plate cylinders 23b are arranged along the circumferential direction at predetermined intervals.

[0045] A transfer cylinder 24 is in contact with the impression cylinder 22a at a position downstream of the rubber cylinder 22b.

[0046] A delivery cylinder 31 of a delivery unit 30 is in contact with the transfer cylinder 24. A sprocket 32 is coaxially fixed to the delivery cylinder 31.

[0047] Further, a sprocket 33 is provided in a delivery unit 30.

[0048] A delivery chain 34 is extended between and wound around the sprockets 32 and 33.

[0049] A plurality of delivery grippers (not shown) are provided on the delivery chain 34 at predetermined intervals.

[0050] Delivery tables 35a and 35b on which printed paper sheets 100 are placed, are provided in the delivery unit 30.

[0051] As shown in FIG. 2, an inker 25 for supplying ink is provided for each of the plate cylinders 23a.

[0052] The inker 25 includes ink fountains 25a for holding ink; fountain rollers 25b for feeding ink from the ink fountains 25a; ductor rollers 25c for drawing the ink fed by the fountain rollers 25b; distribution rollers 25d for distributing the drawn ink; oscillating rollers 25e for spreading the ink in the axial direction through reciprocating movement along the axial direction; form rollers 25f for supplying the ink to the corresponding plate cylinder 23a; and a drive roller 25g for rotating these rollers 25b to 25f in an interlocked manner.

[0053] Further, an inker 25 having a similar structure is provided for each of the above-described plate cylinders 23b.

[0054] Moreover, a hydraulic cylinder 26 serving as frame moving means (not shown) is provided in the inker 25. The hydraulic cylinder 26 is used to move the inker 25 from a position indicated by a solid line to a position indicated by a two-dot chain line as shown in FIG. 1A.

[0055] When the inker 25 is moved to the position indicated by the two-dot chain line in FIG. 1A, the inker 25 separates from the impression cylinder 22a and the plate cylinders 23a, so that the inker 25 is mechanically disengaged from the main unit, as will be described later.

[0056] A sensor 27 for detecting the inker frame 20a is supported above the hydraulic cylinder 26 as shown in FIG. 1B. The present embodiment is configured such that an electromagnetic clutch 120, as shown in FIG. 12, can be turned ON when the sensor 27 becomes impossible to detect the inker frame 20a, and the electromagnetic clutch 120 cannot be turned ON when the sensor 27 detects the inker frame 20a.

[0057] That is, the clutch 120 cannot be turned ON when the inker frame 20a and the main unit frame 20b are in proximity to each other.

[0058] As shown in FIGS. 3-6, a support base 41 is attached to an inker frame 20a of the printing unit 20 to be located in the vicinity of a shaft end portion of the oscillating roller 25e.

[0059] A pair of L-shaped swing levers 43 are provided on the support base 41. The bent center portion of each swing lever 43 located between the distal end and base end thereof is pivotally supported by a support pin 42 such that the swing lever 43 can swing in a direction toward and away from the oscillating roller 25e.

[0060] The swing levers 43 are connected together by a plate 43b and bolts 43a.

[0061] A slide groove 43c is formed on each swing lever 43 to be located between the distal end and the bent center portion thereof.

[0062] A block 43d is slidably attached to the slide groove 43c of each swing lever 43.

[0063] The block 43d is supported by the corresponding end portion of a pin 45.

[0064] The distal end portion of a slide lever 44 and a first end portion of a first link plate 46 are rotatably connected to the pin 45.

[0065] In other words, the distal end portion of the slide lever 44 and the first end portion of the first link plate 46 are supported by the swing levers 43 via the pin 45 and the blocks 43d such that they can move toward and away from the support pin 42.

[0066] The base end portion of a swing plate 48 is rotatably connected to a second end portion of the first link plate 46 via a pin 49. A portion of the swing plate 48 located between the distal end and base end thereof is pivotally supported on the support base 41 via a support pin 47.

[0067] A cam follower 50 is attached to the distal end portion of the swing plate 48.

[0068] The cam follower 50 is inserted into a groove wheel 25ea provided at the shaft end portion of the above-described oscillating roller 25e.

[0069] The shaft end portion of the oscillating roller 25e is slidably supported such that the oscillating roller 25e can reciprocate in the axial direction thereof.

[0070] Meanwhile, a casing 51 is attached to the support base 41. The casing 51 includes an oscillation-width adjustment motor 52 which can be rotated in regular and reverse directions and is equipped with a brake.

[0071] A gear 53 and a drive gear 54 are coaxially attached to the drive shaft of the motor 52.

[0072] The drive gear 54 is in meshing engagement with a transmission gear 55 rotatably supported on the casing 51.

[0073] One end portion of a drive shaft 56, which is rotatably supported on the support base 41 via a bracket 41a, is coaxially connected to the transmission gear 55.

[0074] A worm gear 57 is coaxially attached to the drive shaft 56.

[0075] A worm wheel 58, which is rotatably supported on the support base 41, is in meshing engagement with the worm gear 57.

[0076] A transmission shaft 59 is rotatably supported on the support base 41, and one end portion of the transmission shaft 59 is coaxially connected to the worm wheel 58.

[0077] One end portion of a second link plate 60 is fixedly connected to the transmission shaft 59.

[0078] The other end portion of the second link plate 60 is rotatably connected to the base end portion of the slide lever 44 via a pin 61.

[0079] That is, when the motor 52 is driven, the slide lever 44 is moved via the drive gear 54, the transmission gear 55, the drive shaft 56, the worm gear 57, the worm wheel 58, the transmission shaft 59, the second link plate 60, and the pin 61, so that the slide lever 44 slides along the slide groove 43c of the swing lever 43 together with the pin 45 and the block 43d. As a result, the pin 45, serving as the center of swinging motion of the first link plate 46, can be brought closer to and further away from the support pin 42 serving as the center of swing motion of the swing levers 43. Thus, the distance between the pins 42 and 45 can be adjusted.

[0080] A potentiometer 62 is provided within the casing 51.

[0081] A gear 63 is coaxially attached to the input shaft of the potentiometer 62 and is in meshing engagement with the gear 53.

[0082] Therefore, when the motor 52 is driven, the gear 53 rotates, and the rotational amount of the gear 53 is detected by the potentiometer 62 via the gear 63. Thus, the distance between the pins 42 and 45 can be detected.

[0083] On the inker frame 20a, the base end portion of a support shaft 64 is supported in a cantilever manner in the vicinity of the support base 41 such that the axis of the support shaft 64 becomes parallel to the axis of the oscillating roller 25e.

[0084] A transmission gear 65 is coaxially attached to the support shaft 64 at a position near the inker frame 20a.

[0085] A rotary drum 66 is coaxially attached to the distal end portion of the support shaft 64.

[0086] A universal joint 67 is attached to one end surface of the rotary drum 66 to be offset with respect to the center axis of the rotary drum 66.

[0087] The base end portion of a shaft 68 is connected to the universal joint 67.

[0088] The distal end portion of the shaft 68 is connected to the base ends of the swing levers 43 via a universal joint 69.

[0089] Further, as shown in FIG. 12, the transmission gear 65 is in meshing engagement with a drive gear 71 of an oscillation-mechanism drive motor 70 via a gear train 100.

[0090] Specifically, the oscillation-mechanism drive motor 70 is fixedly supported on the inker frame 20a, and the drive gear 71 of the motor 70 is in meshing engagement with an intermediate gear 101. An intermediate gear 102, which is coaxial and integral with the intermediate gear 101, is in meshing engagement with an intermediate gear 103. Further, an intermediate gear 104, which is coaxial and integral with the intermediate gear 103, is in meshing engagement with the transmission gear 65 via an intermediate gear 105.

[0091] Therefore, when the drive gear 71 is rotated through operation of the oscillation-mechanism drive motor 70, the rotary drum 66 is rotated via the intermediate gears 101 to 105, the transmission gear 65, and the support shaft 64. As the rotary drum 66 rotates, the universal joint 67 revolves, and consequently, the shaft 68 reciprocates along its axial direction. This reciprocating motion of the shaft 68 is transmitted to the base ends of the swing levers 43 via the universal joint 69, so that the distal ends of the swing levers 43 can be swung about the support pin 42.

[0092] Moreover, as shown in FIG. 12, a gear train 110 and an electromagnetic clutch (tooth clutch) 120 are disposed between the intermediate gear 103 and the distribution roller 25d.

[0093] Specifically, similar to the case of the oscillating rollers 25e, the distribution roller 25d is rotatably supported on the inker frame 20a. A transmission gear 111 is attached to one end of the distribution roller 25d, and is in meshing engagement with one coupling gear 113 of the electromagnetic clutch 120 via an intermediate gear 112.

[0094] In addition to the coupling gear 113, the electromagnetic clutch 120 has a coupling gear 114, which is coaxial with the coupling gear 113. The coupling gear 114 is in meshing engagement with the intermediate gear 103.

[0095] When electricity is supplied to the electromagnetic clutch 120, the coupling gear 113 and the coupling gear 114 are united by means of electromagnetic attraction force. When no electricity is supplied to the electromagnetic clutch 120, the coupling gear 113 and the coupling gear 114 can rotate freely.

[0096] Therefore, when the oscillation-mechanism drive motor 70 is operated in a state in which electricity is supplied to the electromagnetic clutch 120, its rotation is transmitted to the distribution roller 25d via the gear trains 100 and 110.

[0097] The electromagnetic clutch 120 is controlled by a control apparatus such that the electromagnetic clutch 120 comes into an engaged state only when the inker 25 is driven solely, and comes into an disengaged state during ordinary printing.

[0098] Further, as shown in FIG. 12, the other ends of the distribution roller 25d and the plurality of oscillating rollers 25e are mutually coupled through a gear train 130 and are connected with the main unit via a clutch 140 (in FIG. 12, a portion of the gear train 130 is omitted for simplification).

[0099] The clutch 140 is in an engaged state at all times, except the case in which the number of colors to be printed is small.

[0100] Accordingly, as shown in FIG. 12, the drive force from a drive motor 28 of the main unit, serving as the first motor, is transmitted to the oscillating rollers 25e and the distribution roller 25d, via the clutch 140 and the gear train 130, so that these rollers 25e and 25d rotate.

[0101] When the inker 25 is moved to the position indicated by the two-dot chain line in FIG. 1A by means of the hydraulic cylinder 26, the inker frame 20a, which supports the distribution roller 25d and the oscillating rollers 25e separates from a main unit frame 20b, which supports the impression cylinder 22a and the plate cylinders 23a, as shown in FIG. 12. Consequently, the engagement between the gear train 130 of the inker 25 and the clutch 140 of the main unit is broken to establish a state in which the main unit and the inker 25 can be driven independently of each other.

[0102] The hydraulic cylinder 26 for moving the inker 25 is controlled by an unillustrated control apparatus in such a manner that the inker 25 is positioned at the position indicated by the two-dot chain line in FIG. 1A only when the inker 25 is driven solely and that, during ordinary printing, the inker 25 is positioned at the position indicated by the solid line in FIG. 1A where the form rollers 25f come into contract with the plate cylinders 23a.

[0103] The hydraulic cylinder 26 serves as connecting/disconnecting means for separating the main unit and the inker 25 from each other and for connecting the main unit and the inker 25 to each other. Therefore, instead of moving the inker frame 20a, the main unit frame 20b may be moved, insofar as such a function is achieved.

[0104] Further, as shown in FIG. 7, the oscillation-width adjustment motor 52 and the potentiometer 62 are connected to an oscillation-width controller 80. The oscillation-width controller 80 controls the amount of rotation of the motor 52 on the basis of a signal from the potentiometer 62.

[0105] An oscillation-width setting unit 81 for inputting command signals such as an oscillation width of the oscillating roller 25e is connected to the oscillation-width controller 80.

[0106] Meanwhile, as shown in FIG. 8, the oscillation-mechanism drive motor 70 and a rotary encoder 72 connected to the motor 70 are connected to an oscillation-speed controller 90. The oscillation-speed controller 90 controls the motor 70 while checking the rotational speed of the motor 70 on the basis of a signal from the rotary encoder 72.

[0107] A rotary encoder 73 for detecting the rotational speed of the transfer cylinder 21a; i.e., the rotational speed of the plate cylinders 23a and 23b, and an oscillation speed setting unit 91 for inputting command signals such as the oscillation speed of the oscillating roller 25e, corresponding to the rotational speed of the plate cylinders 23a and 23b, are connected to the oscillation-speed controller 90.

[0108] Accordingly, the oscillation-speed controller 90 controls the oscillation-mechanism drive motor 70 on the basis of a signal from the rotary encoder 73, while checking the signal from the rotary encoder 72, such that the oscillation speed of the oscillating roller 25e becomes equal to the value input and designated by the oscillation speed setting unit 91.

[0109] As shown in FIGS. 7 and 8, the oscillation-width controller 80 and the oscillation-speed controller 90 are connected to each other, and the oscillation-width controller 80 drives the oscillation-width adjustment motor 52 after checking the drive state of the oscillation-mechanism drive motor 70 via the oscillation-speed controller 90.

[0110] In the present embodiment, a clank mechanism is constituted by the support shaft 64, the transmission gear 65, the rotary drum 66, the universal joint 67, the shaft 68, the universal joint 69, etc.; an oscillation mechanism is constituted by the clank mechanism, the support base 41, the support pin 42, the swing levers 43, the slide lever 44, the pin 45, the first link plate 46, the support pin 47, the swing plate 48, the pin 49, the cam follower 50, etc.; an oscillation-width adjustment mechanism is constituted by the support base 41, the drive gear 54, the transmission gear 55, the drive shaft 56, the worm gear 57, the worm wheel 58, the transmission shaft 59, the second link plate 60, the pin 61, the slide lever 44, etc.; oscillation-width control means is constituted by the gears 53 and 63, the potentiometer 62, the oscillation-width controller 80, the oscillation-width setting unit 81, etc.; and oscillation speed control means is constituted by the rotary encoders 72 and 73, the oscillation-speed controller 90, the oscillation speed setting unit 91, etc.

[0111] In the double-sided, multicolor offset press equipped with the above-described oscillation apparatus for the oscillating roller 25e, when the paper sheet 1 is transferred from the sheet-feed table 11 of the feeder unit 10 to the transfer cylinder 21a via the feeder board 12 and the swing apparatus 13, the paper sheet 1 is transferred to the impression cylinder 22a (having unillustrated grippers) of the printing unit 20 via the transfer cylinders 21b to 21d and passes through the space between the impression cylinder 22a and the rubber cylinder 22b.

[0112] At this time, ink from the inker 25 is supplied to each of the plates attached to the plate cylinders 23a and 23b. As a result, ink held on the plate of each plate cylinder 23a at portions corresponding to an image thereof is supplied to the blanket at the outer circumferential surface of the impression cylinder 22a, and ink held on the plate of each plate cylinder 23b at portions corresponding to an image thereof is supplied to the blanket at the outer circumferential surface of the rubber cylinder 22b. Therefore, as the paper sheet 1 passes through the space between the cylinders 22a and 22b, the image of the impression cylinder 22a is transferred onto one face of the paper sheet 1 and the image of the rubber cylinder 22b is transferred onto the other face of the paper sheet 1.

[0113] The paper sheet 1 having undergone double-sided, multicolor printing is transferred to the delivery cylinder 31 via the transfer cylinder 24. Subsequently, after having been gripped by the grippers of the delivery chain 33, the paper sheet 1 is conveyed to the delivery tables 35a and 35b and is then delivered.

[0114] When ink is supplied from the inker 25 to the plate cylinders 23a and 23b in the above-described manner, the oscillation width and oscillation speed of the oscillating roller 25e are adjusted as follows.

[0115] <Oscillation-width Adjustment>

[0116] When an oscillation width of the oscillating roller 25e is input to the oscillation-width setting unit 81, as shown in FIG. 9, the oscillation-width controller 80 first checks whether the oscillation-mechanism drive motor 70 is being operated, on the basis of the signal from the oscillation-speed controller 90 (step Sa1).

[0117] When the oscillation-mechanism drive motor 70 is stopped, the oscillation-width controller 80 waits, without proceeding to the next step, until the oscillation-mechanism drive motor 70 starts its operation. When the oscillation-mechanism drive motor 70 is operating, the oscillation-width controller 80 proceeds to the next step.

[0118] This is because if the oscillating roller 25e is operated while the various rollers 25a to 25g of the inker 25 are stopped, the roller surface may be damaged due to friction therebetween.

[0119] Next, the oscillation-width controller 80 reads the oscillation width input from the oscillation-width setting unit 81 (step Sa2), and obtains a value of the potentiometer 62 corresponding to the input oscillation width, on the basis of a conversion table which defines the relationship between oscillation width of the oscillating roller 25e (the distance between the pins 42 and 45) and value of the potentiometer 62 (step Sa3). Subsequently, the oscillation-width controller 80 reads the current value of the potentiometer 62 (step Sa4) and checks whether the read value of the potentiometer 62 is equal to the value obtained in the above-described step Sa3 (step Sa5). When these values are equal to each other, the oscillation-width controller 80 returns to the above-described step Sa2 (the current status is maintained). When these values are not equal to each other, the oscillation-width controller 80 proceeds to the next step.

[0120] When the above-described two values are not equal to each other, the oscillation-width controller 80 operates the oscillation-width adjustment motor 52 (step Sa6), reads the present value of the potentiometer 62 (step Sa7), and checks whether the read value of the potentiometer 62 is equal to the value obtained in the above-described step Sa3 (step Sa8) When these values are not equal to each other, the oscillation-width controller 80 repeats the above-described steps Sa6 to Sa8 until these values become equal to each other. When the values becomes equal to each other, the oscillation-width controller 80 proceeds to the next step.

[0121] When the above-described two values become equal to each other, the oscillation-width controller 80 stops the operation of the oscillation-width adjustment motor 52 (step Sa9), and checks whether the oscillation-mechanism drive motor 70 is being operated (step Sa10). When the oscillation-mechanism drive motor 70 is operating, the oscillation-width controller 80 returns to the above-described step Sa2. When the oscillation-mechanism drive motor 70 is stopped, the oscillation-width controller 80 ends the control.

[0122] Through this operation, the distance between the pins 42 and 45 is set via the drive gear 54, the transmission gear 55, the drive shaft 56, the worm gear 57, the worm wheel 58, the transmission shaft 59, the second link plate 60, the pin 61, and the slide lever 44.

[0123] <Oscillation-speed Adjustment>

[0124] When an oscillation speed of the oscillating roller 25e (the number of revolutions of the plate cylinders 23a and 23b during each round of reciprocating travel of the oscillating roller 25e) is input through the oscillation speed setting unit 91, as shown in FIG. 10, the oscillation-speed controller 90 first checks whether the transfer cylinder 21a is being rotated; i.e., whether the printing press is being operated, on the basis of the signal from the rotary encoder 73 (step Sb1).

[0125] When the printing press is not being operated, the oscillation-speed controller 90 waits, without proceeding to the next step, until the printing press is started. When the printing press is operating, the oscillation-speed controller 90 proceeds to the next step. This is because if the oscillating roller 25e is operated while the various rollers 25a to 25g of the inker 25 are stopped, the roller surface may be damaged due to friction therebetween.

[0126] Next, the oscillation-speed controller 90 reads the oscillation speed input from the oscillation speed setting unit 91 (step Sb2), reads the rotational speed of the transfer cylinder 21a; i.e., the rotational speed of the plate cylinders 23a and 23b from the rotary encoder 73 (step Sb3), and obtains a voltage value of the oscillation-mechanism drive motor 70 corresponding to the rotational speed of the plate cylinders 23a and 23b, on the basis of a conversion table which defines the relationship between rotational speed of the plate cylinders 23a and 23b and voltage value of the oscillation-mechanism drive motor 70 (step Sb4). Subsequently, the thus-obtained voltage value is divided by the input oscillation speed to thereby obtain the voltage value of the oscillation-mechanism drive motor 70 corresponding to the oscillation speed (step Sb5) Subsequently, the oscillation-speed controller 90 drives and controls the motor 70 in accordance with the voltage value (step Sb6).

[0127] Subsequently, the oscillation-speed controller 90 checks whether the printing press is being operated (step Sb7). When the printing press is operating, the oscillation-speed controller 90 returns to the above-described step Sb2. When the printing press is stopped, the oscillation-speed controller 90 ends the control. Through this operation, the pin 45 is moved via the drive gear 71, the transmission gear 65, the support shaft 64, the rotary drum 66, the universal joint 67, the shaft 68, the universal joint 69, and the swing levers 43 such that the pin 45 reciprocatively revolves about the support pin 42 with a period which always corresponds to the rotational period of the plate cylinders 23a and 23b. Consequently, the swing plate 48 is moved via the first link plate 46 and the support pin 47 such that the swing plate 48 swings about the pin 49 with a period which always corresponds to the rotational period of the plate cylinders 23a and 23b. Thus, via the cam follower 50 inserted into the groove wheel 25ea, the oscillating roller 25e reciprocates a plurality of number of times which always corresponds to the rotational period of the plate cylinders 23a and 23b.

[0128] Therefore, the above-described oscillation apparatus has the following advantages. (1) Since the oscillation width of the oscillating roller 25e is adjusted through control of the rotational amount of the oscillation-width adjustment motor 52, and the oscillation speed of the oscillating roller 25e is adjusted through control of the rotational speed of the oscillation-mechanism drive motor 70, the control mechanism for the oscillating roller 25e can be simplified. (2) Since the state of oscillation of the oscillating roller 25e is controlled by the above-described motors 52 and 70, the oscillating roller 25e can be operated with high responsiveness, and the oscillation of the oscillating roller 25e can be adjusted finely and easily.

[0129] Accordingly, the above-described oscillation apparatus enables the oscillation state of the oscillating roller 25e to be adjusted with high responsiveness by use of a simple mechanism.

[0130] When an induction motor is used for the oscillation-width adjustment motor 52, as shown in FIG. 7, the oscillation-width controller 80 is not required to have a driver for the motor 52. However, when an oscillation-width adjustment motor 52′ composed of an ordinary servomotor is employed as shown in FIG. 11, an oscillation-width controller 80′ having a driver for the motor 52′ is used.

[0131] <Sole Drive of Inker>

[0132] In the printing press having the above-described configuration, at the time of cleaning work or maintenance, the inker 25 can be driven solely by use of the oscillation-mechanism drive motor 70.

[0133] That is, as indicated by the two-dot chain line in FIG. 1A, the inker 25 is separated from the main unit, and electricity is supplied to the electromagnetic clutch 120 in order to establish a mechanical connection between the oscillation-mechanism drive motor 70 and the distribution rollers 25d and the oscillating rollers 25e via the gear train 110.

[0134] Subsequently, when the oscillation-mechanism drive motor 70 is operated, rotation of the oscillation-mechanism drive motor 70 is transmitted to the oscillating rollers 25e via the gear train 100, the shaft 68, and the swing plate 48, so that the oscillating rollers 25e reciprocate. Simultaneously, rotation of the oscillation-mechanism drive motor 70 is transmitted to one distribution roller 25d via the gear trains 100 and 110 and is further transmitted to the remaining distribution rollers 25d and the oscillating rollers 25e via the gear train 130, so that the plurality of distribution rollers 25d and the oscillating rollers 25e are rotated.

[0135] As described above, a cleaning work or maintenance work for the inker 25 can be performed in a state in which the plurality of distribution rollers 25d and the oscillating rollers 25e are rotated. Further, since the inker 25 is separated from the main unit, in the main unit as well, a cleaning work such as exchange of plates of the plate cylinders 23a can be performed simultaneously with the or maintenance work for the inker 25.

[0136] Moreover, since the inker 25 is separated from the main unit, a worker can enter a space between the rubber cylinder 22b and the inker 25. Therefore, maintenance such as exchange of a blanket of the rubber cylinder 22b can be performed.

[0137] That is, the present embodiment enables different types of maintenance to be performed at the printing unit and the inker.

[0138] The above-described electromagnetic clutch 120 and the hydraulic cylinder 26 of the inker 25 may be controlled by the control apparatus in such a manner that they are simultaneously turned on and off through an automatic operation. Alternatively, the control may be performed such that the electromagnetic clutch 120 is brought into an engaged state automatically when the inker 25 is separated from the main unit by the hydraulic cylinder 26.

[0139] Alternatively, the control may be performed such that the electromagnetic clutch 120 is brought into a disengaged state automatically during ordinary printing; i.e., in a state in which the inker 25 is connected to the main unit by the hydraulic cylinder 26.

[0140] Moreover, instead of the hydraulic cylinder 26 for moving the inker 25, the clutch 140 may be used in order to establish and break the connection between the main unit and the inker in a manner interlocked with the electromagnetic clutch 120.

[0141] As described above, in the printing press of the present embodiment, the inker 25 having the oscillation-mechanism drive motor 70 is provided with the electromagnetic clutch 120 for establishing and breaking the connection between the oscillation-mechanism drive motor 70 and the distribution rollers 25d and the oscillating rollers 25e; and the clutch 140 for establishing and breaking the connection between the inker 25 and the main unit. Therefore, during an ordinary printing, the oscillating rollers 25e can be reciprocated axially by means of the oscillation-mechanism drive motor 70, and during cleaning or maintenance, the oscillating rollers 25e and the distribution rollers 25d can be rotated simultaneously with the reciprocation of the oscillating rollers 25e.

[0142] Therefore, disposition of a motor for solely driving the inker becomes unnecessary, so that the number of motors disposed for each inking unit for a single color can be reduced, and thus cost and size can be reduced.

[0143] As having been described specifically on the basis of the preferred embodiments, in the present invention, by use of the connecting/disconnecting means and the clutch, the first and second motors and the first and second rotation bodies can be connected and separated freely in periods other than the period of an ordinary printing. Therefore, the number of motors can be reduced to thereby reduce cost.

[0144] Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

Printing press

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CPC

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