Apparatus and method for changing plates in a rotary printing press

Abstract: A plate exchanging apparatus in a rotary printing press for removing an old plate (P1) unfixed from a plate cylinder (20) having a plate fixing unit (25) and setting a new plate (P2) on the plate cylinder by the plate fixing unit includes a full-automatic plate mounting controller (91B) and a semi-automatic plate mounting controller (91C). The full-automatic plate mounting controller executes a full-automatic plate exchanging mode to automatically remove the old plate from the plate cylinder and automatically set the new plate on the plate cylinder using a plate holder. The semi-automatic plate mounting controller executes a semi-automatic plate exchanging mode to remove the old plate from the plate cylinder by a combination of automatic and manual operations and set the new plate on the plate cylinder by a combination of automatic and manual operations.

Description: Background of the Invention The present invention relates to a plate exchanging apparatus and method in a rotary printing press, which automatically removes an old plate from a plate cylinder and setting a new plate on the plate cylinder. As a plate exchanging apparatus of this type, one is generally disclosed in Japanese Patent Laid-Open No. 11-77968. The plate exchanging apparatus disclosed in this reference has a cassette which is swingably supported by frames and has a new plate setting unit for setting a new plate and an old storage unit for storing an old plate, and an actuator for reciprocating the cassette between a plate mounting position and a retreat position. In this arrangement, when the cassette is moved from the retreat position to the plate mounting position by the actuator, the distal end of the cassette opposes the plate fixing unit of the plate cylinder. When the plate cylinder rotates almost one revolution from this state, an old plate whose leading and trailing edges are released from the plate fixing unit of the plate cylinder is stored in the old plate storage unit of the cassette. In the conventional plate exchanging apparatus described above, however, the old plate may contact the inner surface of the old plate storage unit during the storage of the old plate in the old plate storage unit, thereby damaging the surface of the old plate. Summary of the Invention It is an object of the present invention to provide a plate exchanging apparatus and method in a rotary printing press, which can prevent damage to the surface of an old plate during plate removal and bending of the old plate, thereby reliably reusing the old plate. In order to achieve the above object of the present invention, there is provided a plate exchanging apparatus according to claim 1 and a plate exchanging method according to claim 9. DE-A4 130 359 resembles claim 1, EP-A-0 933 206 resembles claim 6 and EP-A-0 268 857 resembles claims 8 and 14. Brief Description of the Drawings Fig. 1 is a view showing the schematic structure of a whole rotary printing press according to the first embodiment of the present invention; Fig. 2 is a view seen from the arrow II of Fig. 1; Fig. 3 is a view seen from the arrow III of Fig. 2; Fig. 4 is an enlarged side view of the driver of the plate holder shown in Fig. 3; Fig. 5 is a view seen from the arrow V of Fig. 4; Figs. 6A and 6B are sectional views taken along the line VI - VI of Fig. 2; Figs. 7A and 7B are sectional views taken along the line VII - VII of Fig. 2; Fig. 8A is a sectional view taken along the line VIIIA - VIIIA of Fig. 2, and Fig. 8B is a view seen from the arrow VIIIB of Fig. 8A; Fig. 9 is a block diagram of the main part of the rotary printing press according to the present invention to show its electric arrangement; Fig. 10 is a flow chart showing selection between full-automatic plate mounting and semi-automatic plate mounting in the rotary printing press according to the present invention; Fig. 11 is a flow chart showing the operation of full-automatic plate mounting in the rotary printing press according to the present invention; Fig. 12 is a flow chart following Fig. 11 to show the operation of full-automatic plate mounting; Fig. 13 is a flow chart showing the operation of semi-automatic plate mounting in the rotary printing press according to the present invention; Figs. 14A and 14B are sectional views taken along the line XIIII - XIIII of Fig. 2 to show states in full-automatic plate exchanging operation wherein a new plate is set on the plate holder and a plate catch is opened, respectively; Figs. 15A and 15B are sectional views taken along the line XIIII - XIIII of Fig. 2 to show states in full-automatic plate exchanging operation wherein a safety cover is opened and the plate holder is moved to the second position, respectively; Figs. 16A and 16B are sectional views taken along the line XIIII - XIIII of Fig. 2 to show states in full-automatic plate exchanging operation wherein an old plate is removed and a new plate is inserted in the plate fixing unit of a plate cylinder, respectively; Figs. 17A and 17B are sectional views taken along the line XIIII - XIIII of Fig. 2 to show states in full-automatic plate exchanging operation wherein the new plate is set on the plate cylinder and the safety cover is closed, respectively; Figs. 18A and 18B are sectional views taken along the line XIIII - XIIII of Fig. 2 to show states in semi-automatic plate exchanging operation wherein the safety cover is closed and opened, respectively; Figs. 19A and 19B are sectional views taken along the line XIIII - XIIII of Fig. 2 to show states in semi-automatic plate exchanging operation wherein the fixed old plate is unfixed from the plate fixing unit of the plate cylinder and the old plate is being removed, respectively; Figs. 20A and 20B are sectional views taken along the line XIIII - XIIII of Fig. 2 to show states in semi-automatic plate exchanging operation wherein the new plate is being inserted in the plate fixing unit of the plate cylinder and the new plate is set on the plate cylinder, respectively; and Fig. 21 is a sectional view taken along the line XIIII - XIIII of Fig. 2 to show a state in semi-automatic plate exchanging operation wherein the safety cover is closed. Description of the Preferred Embodiments The present invention will be described in detail with reference to the accompanying drawings. Fig. 1 schematically shows the structure of a rotary printing press according to the first embodiment of the present invention. Referring to Fig. 1, a double-sided sheet-fed rotary printing press 1 is schematically comprised of a sheet feed unit 2, four printing units 3A to 3D for face side printing lined up on the upper side, four printing units 4A to 4D for reverse side printing lined up on the lower side, and a delivery unit 5. The sheet feed unit 2 has a conventional widely known sucker unit (not shown) for feeding out sheets 11 stacked on a sheet pile plate 10 to a feeder board 12 one by one. Each sheet 11 fed out to the feeder board 12 is gripped by the grippers of a transfer cylinder 13 of the first-color printing unit 3A by a swing unit (not shown) provided at the distal end of the feeder board 12. Each of the four printing units 3A to 3D for face side printing has a plate cylinder 15 on which a plate is set, a blanket cylinder 16 in contact with the plate cylinder 15, and an impression cylinder 17 in contact with the blanket cylinder 16 and having a diameter twice that of the blanket cylinder 16. An inker 18 for storing an inking device is provided above the plate cylinder 15. The sheet 11 gripped by the grippers of the transfer cylinder 13 is then transferred to the grippers of the impression cylinder 17 and gripped by them. While the sheet 11 is being conveyed between the blanket cylinder 16 and impression cylinder 17, first-color printing is performed on its face side. Each of the four printing units 4A to 4D for reverse side printing has a plate cylinder 20 on which a plate is set, a blanket cylinder 21 in contact with the plate cylinder 20, and an impression cylinder 22 in contact with the blanket cylinder 21 and having a diameter twice that of the blanket cylinder 21. An inker 23 for storing an inking device consisting of a group of a large number of rollers (not shown) is provided below the plate cylinder 20. The sheet 11 is transferred from the grippers of the impression cylinder 17 of the face side printing unit 3A to the grippers of the impression cylinder 22 of the reverse side printing unit 4A and gripped by them. While the sheet 11 is being conveyed between the impression cylinder 22 and blanket cylinder 21, first-color printing is performed on its reverse side. After that, second- to fourth-color printing operations are sequentially performed on the face and reverse sides of the sheet 11 by the face side printing units 3B to 3D and reverse side printing units 4B to 4C. The sheet 11 gripped by the grippers of the impression cylinder 22 of the fourth-color reverse side printing unit 4D is transferred to a gripper unit provided to a gripper bar extending between the pair of right and left delivery chains of the delivery unit 5, and gripped by them. The sheet 11 gripped by the gripper unit is conveyed by the delivery chains and released from the gripper unit by a cam mechanism. Thus, the sheet 11 falls on a sheet pile plate 24 and is piled there. As shown in Fig. 3, a leading edge plate clamp 25 and trailing edge plate clamp 26 are provided in a notch formed in the outer surface of the plate cylinder 20. The two clamps 25 and 26 have bottom clamping rails 25a and 26a and gripper boards 25b and 26b, respectively. A pair of reference pins 27 lined up in the axial direction of the plate cylinder 20 vertically stand on the upper surface of the bottom clamping rail 25a of the leading edge plate clamp 25. The reference pins 27 engage with a pair of notches 7 formed in the leading edge of a new plate P2 to position the new plate P2 in the circumferential and widthwise directions. The arrangement of the cylinders and the plate clamp units described above are not different from those of a conventional widely known double-sided sheet-fed rotary printing press. A plate mounting unit in the sheet-fed rotary printing press, which is employed by each of the reverse side printing units 4A to 4D will be described with reference to Figs. 2 to 21. Plate inserting apparatuses employed by the respective printing units 4A to 4D have completely the same structure, and accordingly only the plate mounting unit employed by the printing unit 4A will be described. Referring to Fig. 2, the printing unit 4A has a pair of opposing frames 30, and a pair of chain guides 31 are fixed to the inner sides of the upper portions of the frames 30. A pair of chains 32 are supported by the chain guides 31 to be vertically slidable, and a plurality of elongated blocking plates 33 horizontally extend between the chains 32. As shown in Fig. 3, a safety cover 34 formed by the plurality of blocking plates 33 is driven by sprockets 35 to open/close the front surface of the plate cylinder 20. The teeth of each sprocket 35 oppose the inside of the corresponding blocking plate 33. More specifically, the teeth of the sprockets 35 mesh with the chains 32, and the sprockets 35 are rotated clockwise or counterclockwise in Fig. 3 by a safety cover drive motor 87 (Fig. 9) which drives in the forward/reverse directions. When the sprockets 35 rotate clockwise, the safety cover 34 moves upward to open the front surface of the plate cylinder 20. When the sprockets 35 rotate counterclockwise, the safety cover 34 moves downward to close the front surface of the plate cylinder 20. A pair of reference pins 36 stand vertically from a lowermost blocking plate 33A of the plurality of blocking plates 33. The reference pins temporarily position the plate before holding. A plate inserting apparatus 40 will be described with reference to Figs. 2 to 5. Referring to Fig. 5, the plate inserting apparatus 40 is comprised of a plate holder 41 for holding the new plate P2 by drawing by suction its leading edge, a pair of guide rails 42 serving as posture changing means to guide the plate holder 41, and actuators 43 for moving the plate holder 41. Each actuator 43 is constituted by a first actuator 43A for the plate holder and second actuator 43B for the plate holder. The rear portions of the two actuators 43A and 43B are connected and fixed to each other. The driving states, i.e., the operative state (ON) and the inoperative state (OFF), of the actuators 43A and 43B are combined to selectively position the plate holder 41 at three points A, B, and C described later. The plate holder 41 has an elongated rectangular parallelepiped shape, and has two rows of a large number of suction pads 45 on its front surface. Suction air from a suction pump 86 (Fig. 9) is supplied to the suction pads 45 as a negative pressure. As shown in Fig. 4, a pair of blind hole-type fitting insertion holes 46 are formed in the rear surface of the plate holder 41. Spherical sliding bearings 47 are fixed to the openings of the fitting insertion holes 46. As shown in Fig. 5, two pairs of rollers 48 are rotatably supported at the right and left ends of the plate holder 41. The pair of guide rails 42 respectively have a pair of guide grooves 50 with a U-shaped section. As shown in Fig. 5, the guide rails 42 are fixed to the inner sides of the right and left frames 30 such that the guide grooves 50 face each other. As shown in Fig. 4, each guide rail 42 is comprised of a lower straight portion 42a extending substantially vertically, a curved portion 42b with one end connected to the straight portion 42a, and an upper straight portion 42c connected to the other end of the curved portion 42b and inclined obliquely upward toward the plate cylinder 20. As shown in Fig. 16B, the inclination of the straight portion 42c is set such that it is substantially the same as that of the upper surface of the bottom clamping rail 25a of the leading edge plate clamp 25 which is positioned at a predetermined position when inserting the new plate. When the rollers 48 of the plate holder 41 are engaged in the guide grooves 50 of the guide rails 42, the plate holder 41 is movably supported to be guided by the guide grooves 50. Referring to Fig. 5, a pair of round rod-shaped driving levers 52 stand between the central portion and the ends of a driving shaft 51 rotatably supported between the frames 30. The distal ends of the driving levers 52 are slidably and inclinably coupled to the spherical sliding bearings 47 of the plate holder 41. That is, the plate holder 41 is swingably supported by the driving levers 52 to be movable in the longitudinal direction of the levers. The two ends of the driving shaft 51 project outwardly from the frames 30. One end of each of a pair of intermediate levers 53 is fixed to the corresponding projecting end of the driving shaft 51. The other end of each intermediate lever 53 is fixed with a rotor 54, and the rotor 54 is fixed to the rod of the corresponding first actuator 43A. The distal ends of the rods of the second actuators 43B are fixed to the frames 30. Referring to Fig. 4, when the rods of the two actuators 43A and 43B are at the retreat position, the plate holder 41 is positioned at the point A of the straight portion 42a of each guide rail 42. At the point A, the suction surfaces of the suction pads 45 are substantially vertical and substantially leveled with the front surface of the blocking plate 33A so that the new plate P2 can be set on the plate holder 41. The posture of the plate holder 41 in this state is defined as the first posture at which the new plate P2 is to be set on the plate holder 41, and the point A is defined as the first position. When the plate holder 41 is in the first posture, the new plate P2, the leading edge of which is drawn by suction with the suction pads 45, also becomes vertical. The plate holder 41 positioned at the first position is located immediately under the lowermost blocking plate 33A of the closed safety cover 34, as shown in Fig. 3. When the rod of each first actuator 43A is moved forward, the driving shaft 51 pivots clockwise in Fig. 4 through the corresponding rotor 54 and intermediate lever 53, and the plate holder 41 is positioned at the point B of the curved portion 42b of each guide rail 42. At the point B, the suction surfaces of the suction pads 45 of the plate holder 41 are inclined from the horizontal plane by an angle α, as shown in Fig. 16A, and the leading edge of the new plate P2 drawn by suction with the suction pads 45 is also inclined by the angle α. In this state, the leading edge of the new plate P2 to be drawn by suction with the suction pads 45 is retreated from an old plate removal port 62 to open the front side of the old plate removal port 62. An old plate P1 can accordingly be removed from the old plate removal port 62. The posture of the plate holder 41 at this time is defined as the second posture that enables removal of the old plate P1, and the point B is defined as the second position. When the rod of each second actuator 43B is also moved forward, the driving shaft 51 pivots further clockwise in Fig. 4, and the plate holder 41 is positioned at the point C of the straight portion 42c of each guide rail 42. When the plate holder 41 is positioned at the point C, the upper surface of the bottom clamping rail 25a of the leading edge plate clamp 25 of the plate cylinder 20 is located on the extension of the suction surfaces of the suction pads 45, as shown in Fig. 16B. The posture of the plate holder 41 at this time is defined as the third posture that enables insertion of the new plate P2 between the bottom clamping rail 25a and gripper board 25b, and the point C is defined as the third position. Referring to Fig. 4, the plate holder 41 is slidably supported by each driving lever 52. While the plate holder 41 moves along the straight portion 42a and straight portion 42c of each guide rail 42, when each driving lever 52 pivots, the plate holder 41 moves in the radial direction of this pivot movement as well. Thus, the pivot movements of the driving shaft 51 and driving lever 52 are converted into the linear movement of the plate holder 41 along the straight portions 42c and 42a. In this manner, the plate holder 41 can be moved along the straight portions 42a and 42c of the guide rails 42 without using link mechanisms or cam mechanisms having a complicated structure, and the pivot movements of the driving shaft 51 and driving levers 52 are converted into the linear movement of the plate holder 41. The number of components is therefore reduced, and the structure is simplified. A stationary cover and a plate removal cover will be described with reference to Figs. 2, 3, 6A, 6B, 7A, and 7B. Referring to Fig. 3, a plate removal cover 55 is arranged immediately under the plate holder 41 positioned at the first point A. As shown in Fig. 2, the plate removal cover 55 is fixed to a stationary cover 57 at its lower end through a pair of hinges 56, and can fall to the inside of the printing press about the hinges 56 as the pivot center, as shown in Fig. 6B. In the normal state, the plate removal cover 55 is supported vertically. As shown in Fig. 3, the stationary cover 57 is comprised of a front plate 58, horizontal plate 59, and rear plate 60, and has a crank-shaped section. The two ends of the stationary cover 57 are attached to the inner sides of the frames 30. An ink fountain 23a of the inking device stored in the inker 23 is provided below the horizontal plate 59. To supply ink to the ink fountain 23a, an opening 58a is formed below the front plate 58 of the stationary cover 57. As shown in Fig. 6A, the lower ends of a pair of cover opening/closing actuators 61 are pivotally mounted on the rear surface of the front plate 58 of the stationary cover 57, and the distal ends of rods 61a of the cover opening/closing actuators 61 are pivotally mounted on the rear surface of the plate removal cover 55. When the rods 61a move forward, the plate removal cover 55 pivots counterclockwise about the hinges 56 as the pivot center to close the front surface of the printing unit 4A. When the rods 61a move backward, the plate removal cover 55 pivots clockwise about the hinges 56 as the pivot center, as shown in Fig. 6B. The front surface of the printing unit 4A is thus opened to form the old plate removal port 62. Referring to Figs. 2 and 6A, a guide member 63 is comprised of a guide 63a formed by bending a rod into a U shape, and a pair of legs 63b formed by bending the two ends of the guide 63a at the right angle to support it in the cantilevered manner. Of the guide member 63, the legs 63b stand vertically at one end of the upper portion of the stationary cover 57, and the guide 63a extends horizontally parallel to the stationary cover 57 at a predetermined distance from it toward the central portion of the stationary cover 57. Thus, the old plate P1 held by a plate catch member (to be described later) is removed from the open end of the guide 63a. Referring to Fig. 2, a pair of rectangular windows 64 are formed in the two ends of the front plate 58 of the stationary cover 57. Referring to Figs. 2, 7A, and 7B, a pair of elongated rectangular fitting insertion holes 65 are formed in the two ends of the horizontal plate 59 of the stationary cover 57. Referring to Figs. 7A and 7B, link members (link mechanisms) 66 respectively have upper ends pivotally mounted on levers 67 fixed to the rear surface of the plate removal cover 55, and lower ends pivotally mounted on flat plate-like plate approach regulating members 68. The plate approach regulating members 68 have proximal ends pivotally supported by the rear surface of the front plate 58 of the stationary cover 57. In the state of Fig. 7A wherein the plate removal cover 55 closes the old plate removal port 62, the plate approach regulating members 68 are horizontally supported so that their swing end sides are parallel to the fitting insertion holes 65. From this state, when the plate removal cover 55 pivots clockwise in Fig. 7B about the hinges 56 as the pivot center through a predetermined angle smaller than 90°, the plate approach regulating members 68 pivot clockwise through 90° through the link members 66 about their proximal ends as the pivot center, so that they pass through the fitting insertion holes 65 to close the upper portion of the opening 58a. Referring to Figs. 2, 8A, and 8B, plate pushout members 70 oppose the rear sides of the windows 64. The lower ends of the plate pushout members 70 are fixed to the pivot shafts of plate pushout actuators 71 fixed to the front plate 58 of the stationary cover 57. When the pivot shafts of the plate pushout actuators 71 pivot counterclockwise in Fig. 8A, the plate pushout members 70 also pivot counterclockwise to project to the outside of the front plate 58 through the windows 64. A plate catch structure will be described with reference to Figs. 2, 3 and 14. Referring to Figs. 2 and 3, a bracket 74 with a crank shape when seen from the side surface horizontally extends between the lower ends of the frames 30, and has an upper surface 74a and lower surface 74b. A flat plate-like plate catch 75 has an elongated rectangular shape when seen from the front surface, and has a lower end connected to the lower surface 74b of the bracket 74 through hinges 76. The plate catch 75 is supported to be pivotal about the hinges 76 as the pivot center to open/close the lower portion of the opening 58a. A pair of support members 77 are provided to the two ends of the front surface of the plate catch 75. Refection type photosensors 77a directed toward the inside of the plate catch 75 are attached to the rear portions or near the rear portions of the support members 77. A pair of plate catch driving actuators 78 are pivotally mounted on the upper surface 74a of the bracket 74, and the distal ends of rods 78a of the actuators 78 are pivotally mounted on the rear surface of the plate catch 75. When the rods 78a of the actuators 78 are moved backward, the plate catch 75 pivots clockwise in Fig. 3 about the hinges 76 as the pivot center to close the lower portion of the opening 58a. When the rods 78a of the actuators 78 are moved forward, the plate catch 75 pivots counterclockwise in Fig. 3 about the hinges 76 as the pivot center to open the lower portion of the opening 58a. As shown in Fig. 14A, when the plate catch 75 is closed, as the leading edge of the new plate P2 is to be drawn by suction with the suction pads 45 of the plate holder 41, the support members 77 support the trailing edge of the new plate P2, as will be described later. From this state, when the plate catch 75 is opened as shown in Fig. 14B, the trailing edge of the new plate P2 separates from the support members 77, and abuts against the distal end of the plate catch 75 to be supported by it. At the same time, the trailing edge of the removed old plate P1 is supported by the rear surface of the plate catch 75, as will be described later. Fig. 9 shows the main part of the rotary printing press. Referring to Fig. 9, the rotary printing press has a full-automatic plate mounting button 80, a semi-automatic plate mounting button 81, a plate suction button 82 for operating the suction pump 86, and a plate catch button 83 for operating the actuators 78. A plate mounting start button 84 automatically removes the old plate and starts the operation of supplying the new plate in the full-automatic plate exchanging mode. An operation button 85 drives leading and trailing edge plate clamp opening/closing actuators 89 and 90 in order to supply the new plate P2 in the semi-automatic plate exchanging mode. A drive motor 88 rotates all the cylinders of the printing press. When exchanging the plate, the drive motor 88 rotates the plate cylinder 20 for a predetermined amount in the forward/reverse directions. A control unit 91 controls the operations of the actuators and the like described above upon operation of the buttons described above. The actuator 89 serves to open/close the leading edge plate clamp. When the actuator 89 is operated, the leading edge cam shaft (not shown) of the leading edge plate clamp 25 in Fig. 3 pivots in the forward/reverse directions by a predetermined amount through a lever (not shown). When the leading edge cam shaft pivots, the gripper board 25b swings to grip and release the leading edge of the plate with the bottom clamping rail 25a. When the trailing edge plate clamp actuator 90 is operated, the trailing edge cam shaft (not shown) of the trailing edge plate clamp 26 in Fig. 3 pivots in the forward/reverse directions by a predetermined amount through a lever. When the trailing edge cam shaft pivots, the gripper board 26b swings to grip and release the trailing edge of the plate with the bottom clamping rail 26a. The operation of changing the plate full-automatically will be described with reference to Figs. 10, 11. 12, and 14A to 17B. As shown in Fig. 14A, the first and second actuators 43A and 43B are set inoperative to position the plate holder 41 at the first position. The full-automatic plate mounting button 80 is turned on to select full-automatic plate exchanging mode (step S1 in Fig. 10). In Fig. 14A, the trailing edge of the new plate P2 is placed and supported on the support members 77 of the plate catch 75, and the leading edge of the substantially vertical new plate P2 is set on the suction pads 45 of the plate holder 41 from the outside of the guide 63a of the guide member 63 (step S3 in Fig. 11). Hence, the notches 7 of the new plate P2 engage with the reference pins 36 of the lowermost blocking plate 33A of the safety cover 34. At this time, since the new plate P2 is deflected between the support members 77 and reference pins 36, its notches 7 are pushed by the reference pins 36 so that the new plate P2 is reliably positioned before set by the plate holder 41. Then, the plate suction button 82 is turned on (step S4) to operate the suction pump 86 (step S5). The leading edge of the new plate P2 is drawn by suction with the suction pads 45 of the plate holder 41, so that the new plate P2 is held by the plate holder 41. At this time, the suction force of the suction pump 86 is adjusted to such a degree that the new plate P2 is drawn by suction to be slidable with respect to the suction pads 45. When the plate catch button 83 is turned on (step S6), the actuators 78 are operated to move the rods 78a forward (step S7). Hence, as shown in Fig. 14B, the plate catch 75 is opened, and the trailing edge of the new plate P2 is unfixed from the support members 77. The new plate P2 is accordingly supported on the distal end of the plate catch 75 in a slightly inclined state. The holding operation of the new plate P2 is thus completed. At this time, since the leading edge of the new plate P2 is held by the plate holder 41 and the trailing edge thereof is supported on the distal end of the plate catch 75, the rear surface of the upper portion of the new plate P2 covers the removal path of the old plate P1 (to be described later) which is to be removed from the old plate removal port 62. When the plate mounting start button 84 is turned on (step S8), the safety cover drive motor 87 is driven in the forward direction (step S9), and the sprockets 35 rotate clockwise, as shown in Fig. 15A. Hence, the safety cover 34 moves upward to open the front surface of the plate cylinder 20, and the reference pins 36 of the blocking plate 33A disengage from the notches 7 of the new plate P2. The actuators 61 are then operated (step S10) to pivot the plate removal cover 55 such that its upper end falls toward the plate cylinder 20, thereby opening the old plate removal port 62. Simultaneously, as the plate removal cover 55 falls, the plate approach regulating members 68 pivot through the link members 66. The pivoting plate approach regulating members 68 close the upper portion of the opening 58a. The first actuators 43A are operated (step S11) to position the plate holder 41 at the point B as the second position, as shown in Fig. 15B. At the second position, the plate holder 41 is switched to the second posture that allows removal of the old plate P1, as described above. The drive motor 88 is driven in the reverse direction (step S12) to pivot the plate cylinder 20 in the reverse direction by a predetermined amount. When the plate cylinder 20 stops (step S13), the actuator 89 is operated (step S14) to open the leading edge plate clamp 25 of the plate cylinder 20, thereby releasing the gripped leading edge of the old plate P1. Subsequently, the plate cylinder 20 pivots in the reverse direction by a predetermined amount and stops (steps S15 and S16). After that, the actuator 90 is operated (step S17) to open the trailing edge plate clamp 26 of the plate cylinder 20, thereby releasing the gripped trailing edge of the old plate P1. Subsequently, when the plate cylinder 20 rotates in the reverse direction (step S18), the trailing edge of the old plate P1 is unfixed from the plate cylinder 20 and is guided by the plate removal cover 55, so that the old plate P1 is removed outside the printing press through the old plate removal port 62. As shown in Fig. 16A, when the old plate P1 is removed, its trailing edge is guided downward along the inner side of the guide 63a of the guide member 63. The leading edge of the old plate P1 disengages from the leading edge plate clamp 25, and the trailing edge of the old plate P1 is supported by the plate catch 75. At this time, since the trailing edge of the old plate P1 is detected by the photosensors 77a, it is confirmed that the old plate P1 is stored in the plate catch 75, and the control unit 91 stops rotation of the plate cylinder 20 upon reception of output signals from the photosensors 77a (step S19). In this manner, since completion of removal of the old plate P1 is detected by the photosensors 77a, the next new plate P2 can be supplied safely and reliably. At this time, the leading edge plate clamp 25 faces the end faces of the straight portions 42c of the guide rails 42. When the actuators 43B are operated (step S20), the plate holder 41 moves to the straight portion 42c of each guide rail 42, as shown in Fig. 16B. and is positioned at the third point C. The inclination of the straight portion 42c and the inclination of the upper end face of the bottom clamping rail 25a of the leading edge plate clamp 25 become substantially equal, and the upper end face of the bottom clamping rail 25a is located on the extension of the suction surfaces of the suction pads 45 of the plate holder 41 positioned by the straight portions 42c. Hence, the leading edge of the new plate P2 drawn by suction with the suction pads 45 is inserted between the bottom clamping rail 25a and gripper board 25b. At this time, the plate holder 41 is positioned at the third point C such that the notches 7 of the new plate P2 are pushed by the reference pins 27. When the notches 7 of the new plate P2 engage (come into contact) with the reference pins 27, the plate holder 41 pushes the new plate P2 toward the reference pins 27, while sliding on the new plate P2, against the suction force of the suction pads 45. Therefore, the notches 7 of the new plate P2 are further urged against the reference pins 27, and the new plate P2 is positioned to face the leading edge plate clamp 25. Subsequently, the actuator 89 is operated (step S21), and the leading edge of the new plate P2 is gripped between the gripper board 25b and bottom clamping rail 25a. Regarding insertion of the new plate P2 to the leading edge plate clamp 25, since the guide rails 42 have the curved portions 42b in addition to the straight portions 42c that serve for plate insertion, the guide rails 42 do not project between the adjacent printing units more than necessary. Thus, the plate holder 41 positioned at a position other than the third position where the new plate P2 is to be inserted does not project between the adjacent printing units. As a result, the work space between the adjacent printing units is not narrowed, and the workability of maintenance and inspection is improved. Since the guide rails 42 have the straight portions 42a serving to set the new plate, the suction surfaces of the suction pads 45 of the plate holder 41 positioned at the first position become vertical. Hence, in the operation of holding the new plate P2 with the suction pads 45, since the new plate P2 can also be set in the vertical state by its own weight and drawn by suction with the suction pads 45, it can be set on the plate holder 41 easily. Since the new plate P2 is held by the plate holder 41 only at its leading edge, the plate holder 41 itself can be downsized. When the suction pump 86 becomes inoperative (step S22), the new plate P2 drawn by suction with the suction pads 45 of the plate holder 41 is released. Therefore, the new plate P2 is held only by the leading edge plate clamp 25. Subsequently, the plate cylinder 20 pivots in the forward direction by a predetermined amount and stops (steps S23 and S24). After that, the actuator 90 is operated (step S25) to grip the trailing edge of the new plate P2 with the gripper board 26b and bottom clamping rail 26a, and the new plate P2 is set on the plate cylinder 20, as shown in Fig. 17A. Both the first and second actuators 43A and 43B become inoperative (step S26), and the plate holder 41 is moved from the third position to the first position along the guide rails 42 and positioned there, as shown in Fig. 17B. Then, the actuators 61 become inoperative (step S27), and the plate removal cover 55 closes the old plate removal port 62. When the actuators 71 are operated (step S28), the plate pushout members 70 project from the windows 64 of the stationary cover 57, and the leading edge of the removed old plate P1 is pushed by the plate pushout members 70 to the outside of the stationary cover 57. The motor 87 is then driven in the reverse direction (step S29) so that the safety cover 34 moves downward to close the front surface of the plate cylinder 20. The operator manually removes the old plate P1 (step S30), and turns off the plate catch button 83 (step S31). Thus, the actuators 78 become inoperative (step S32), and the plate catch 75 pivots to close the lower portion of the opening 58a. Simultaneously, the actuators 71 become inoperative, and the plate pushout members 70 are stored in the stationary cover 57. The operation of exchanging the plate in the semi-automatic manner will be described with reference to Figs. 10, 13, and 18A to 21. If the full-automatic plate mounting button 80 is not turned on but the semi-automatic plate mounting button 81 is turned on (step S2 in Fig. 10), semi-automatic plate exchanging mode is selected. When the plate mounting start button 84 is turned on (step S40), the motor 87 is driven in the forward direction (step S41). Hence, from the closed state shown in Fig. 18A, the safety cover 34 moves upward, as shown in Fig. 18B, to open the front surface of the plate cylinder 20. The plate cylinder 20 pivots in the reverse direction by a predetermined amount and stops (steps S42 and S43). After that, the actuator 89 is operated to open the leading edge plate clamp 25 of the plate cylinder 20, so that the gripped leading edge of the old plate P1 is released. When the plate cylinder 20 pivots in the reverse direction by a predetermined amount and stops (steps S45 and S46), the trailing edge plate clamp opening/closing actuator 90 is operated (step S47) to open the trailing edge plate clamp 26 of the plate cylinder 20, so that the gripped trailing edge of the old plate P1 is released. When the plate cylinder 20 subsequently rotates in the reverse direction (step S48), the trailing edge of the old plate P1 is unfixed from the plate cylinder 20, as shown in Fig. 19A. Hence, the operator manually holds the trailing edge of the old plate P1, as shown in Fig. 19B. When the plate cylinder 20 subsequently rotates in the reverse direction through substantially one revolution and stops (step S49), the leading edge of the old plate P1 is also unfixed from the plate cylinder 20. Thus, the operator manually removes the old plate P1 (step S50). The operator then manually holds the new plate P2 (step S51), inserts it between the bottom clamping rail 25a and gripper board 25b of the leading edge plate clamp 25 of the plate cylinder 20, as shown in Fig. 20A, and turns on the operation button 85 (step S52). When the actuator 89 is operated (step S53), the trailing edge of the new plate P2 is gripped by the gripper board 25b and bottom clamping rail 25a. When the operator turns on the operation button 85 again (step S54), the plate cylinder 20 pivots in the forward direction by a predetermined amount, and stops, as shown in Fig. 20B (steps S55 and S56). The trailing edge plate clamp actuator 90 is then operated (step S57) to pivot a trailing edge cam shaft 26c. The trailing edge of the new plate P2 is thus gripped by the gripper board 26b and bottom clamping rail 26a, and the new plate P2 is set on the plate cylinder 20. The motor 87 is then driven in the reverse direction (step S58), so that the safety cover 34 moves downward to close the front surface of the plate cylinder 20, as shown in Fig. 21. The functional block of the control unit 91 shown in Fig. 9 will now be described. The control unit 91 in Fig. 9 is comprised of a plate exchanging mode determination unit 91A for determining one of the full- and semi-automatic plate exchanging modes as a selected mode in accordance with the operation of a corresponding one of the buttons 80 and 81, a full-automatic plate mounting controller 91B for executing the full-automatic plate exchanging mode selected by the plate exchanging mode determination unit 91A, and a semi-automatic plate mounting controller 91C for executing the semi-automatic plate exchanging mode selected by the plate exchanging mode determination unit 91A. The plate exchanging mode determination unit 91A executes steps S1 and S2 in Fig. 10. The full-automatic plate mounting controller 91B executes steps S5, S7 and S9 to S19 in Fig. 11 and steps S20 to S29 and S32 in Fig. 12. The semi-automatic plate mounting controller 91C executes steps S41 to S49, S53, and S55 to S58 in Fig. 13. In this embodiment, the present invention is applied to a sheet-fed rotary printing press for printing on sheet paper. The present invention can also be applied to a web rotary printing press for printing on a web. In steps S6 and S8 in the full-automatic plate mounting process in Fig. 11, the plate catch button 83 and the plate mounting start button 84 are manually operated. However, in steps S3 to S5, the buttons 83 and 84 need not be manually operated by arranging a detecting means for detecting that the new plate P2 is held in the plate holder 41. The flow automatically advances to the next step. As this detecting means, a photoelectric sensor for detecting that the new plate P2 is held in the plate holder 41 or a pressure sensor for detecting a decrease in pressure of the suction pump 86 when the suction pads 45 draw the new plate P2 by suction can be used. Similarly, when this detecting means may be arranged, the plate mounting start button 84 need not be manually operated in step S40 in the semi-automatic plate mounting process in Fig. 13, and the safety cover drive motor 87 can be automatically driven. As has been described above, according to the present invention, the old plate is removed while being gripped by the operator in the semi-automatic plate mounting function process. The old plate will not contact other members during plate removal. The old plate will not be damaged or bent during plate removal, thereby allowing reuse of the old plate.

Claims: A plate exchanging apparatus in a rotary printing press for removing an old plate (P1) unfixed from a plate cylinder (20) having a plate fixing unit (25) and setting a new plate (P2) on said plate cylinder by said plate fixing unit, comprising: first control means (91B) for executing a full-automatic plate exchanging mode to automatically remove said old plate from said plate cylinder and automatically set said new plate on said plate cylinder using plate holding means (41); and second control means (91C) for executing a semi-automatic plate exchanging mode to remove said old plate from said plate cylinder by a combination of automatic and manual operations and set said new plate on said plate cylinder by a combination of automatic and manual operations, characterized by a plate catch (75) and a plate catch driving actuator (78) for moving said plate catch, wherein the first control means controls said plate catch driving actuator in the full automatic plate exchanging mode to move said plate catch to an old plate supporting position, and the second control means controls said plate catch driving actuator in the semi-automatic plate exchanging mode to prohibit the movement of said plate catch to the old plate supporting position. An apparatus according to claim 1, wherein said first control means executes as the full-automatic plate exchanging mode an automatic plate removal mode of automatically removing said old plate and an automatic plate supply mode of automatically setting said new plate upon completion of the automatic plate removal mode, and said second control means executes as the semi-automatic plate exchanging mode a semi-automatic plate removal mode of removing said old plate by the combination of automatic and manual operations and the semi-automatic plate supply mode of setting said new plate by the combination of automatic and manual operations upon completion of the semi-automatic plate removal mode. An apparatus according to claim 2, wherein said first control means continuously controls as the automatic plate removal mode at least release operation of said plate fixing unit, rotation of said plate cylinder, and holding operation of said old plate, and as the automatic plate supply mode at least holding operation of said new plate by said plate holding means, operation of inserting said new plate into said plate fixing unit by said plate holding means, fixing operation of said plate fixing unit, and rotation of said plate cylinder. An apparatus according to claim 3, wherein said first control means continuously controls operations including operation of forming an plate removal path as the automatic plate removal mode, and operations including operation of forming a plate supply path as the automatic plate supply mode. An apparatus according to claim 2, wherein said second control means continuously controls as semi-automatic plate removal mode at least release operation of said plate fixing means and rotation of said plate cylinder, and controls as the semi-automatic plate supply mode at least fixing operation of said plate fixing means and rotation of said plate cylinder in accordance with an input command. An apparatus according to claim 5, wherein in the full-automatic plate removal mode, said old plate unfixed from said plate cylinder is held by a plate catch member in the plate removal path, and in the semi-automatic plate removal mode, said old plate unfixed from said plate cylinder is held by an operator. An apparatus according to claim 1, wherein said apparatus further comprises selection means (80, 81, 91A) for selecting one of the full- and semi-automatic plate exchanging modes, and said first and second control means are selectively driven in accordance with an output from said selection means. Plate exchanging apparatus according to claim 1, wherein said second control means executing the semi-automatic plate exchanging mode removes the old plate from said plate cylinder by rotating said plate cylinder in a plate removal direction in the state that the old plate wound around a circumferential surface of said plate cylinder is held by an operator, at least at one end of the old plate being released from a plate fixing unit, and subsequently executing said semiautomatic plate exchanging mode to mount the new plate on said plate cylinder by a combination of automatic and manual operations. A plate exchanging method in a rotary printing press, which removes an old plate (P1) unfixed from a plate cylinder (20) having a plate fixing unit (25) and sets a new plate (P2) on said plate cylinder by said plate fixing unit, comprising the steps of: selecting a plate exchanging mode from said old plate to said new plate; executing a full-automatic plate exchanging mode of automatically removing said old plate from said plate cylinder and automatically setting said new plate on said plate cylinder using plate holding means (41) as a result of mode selection; and executing a semi-automatic plate exchanging mode of removing said old plate from said plate cylinder by a combination of automatic and manual operations and setting said new plate on said plate cylinder by a combination of automatic and manual operations as a result of mode selection, characterized by the following steps: the first control means controls a plate catch (75) driving actuator in the full automatic plate exchanging mode to move said plate catch to an old plate supporting position, and the second control means controls a plate catch driving actuator (78) for moving said plate holder in the semi-automatic plate exchanging mode to prohibit the movement of said plate catch to the old plate supporting position. A method according to claim 9, wherein the step of executing the full-automatic plate exchanging mode comprises the step of executing an automatic plate removal mode of automatically removing said old plate and an automatic plate supply mode of automatically setting said new plate upon completion of the automatic plate removal mode, and the step of executing the semi-automatic plate exchanging mode comprises the step of executing a semi-automatic plate removal mode of removing said old plate by the combination of automatic and manual operations and a semi-automatic plate supply mode of setting said new plate by the combination of automatic and manual operations upon completion of the semi-automatic plate removal mode. A method according to claim 10, wherein the step of executing the full-automatic plate exchanging mode comprises the steps of continuously controlling as the automatic plate removal mode at least release operation of said plate fixing unit, rotation of said plate cylinder, and holding operation of said old plate, and as the automatic plate supply mode at least holding operation of said new plate by said plate holding means, operation of inserting said new plate into said plate fixing unit by said plate holding means, fixing operation of said plate fixing unit, and rotation of said plate cylinder. A method according to claim 11, wherein the step of executing the full-automatic plate exchanging mode comprises the steps of continuously controlling operations including operation of forming an plate removal path as the automatic plate removal mode, and operations including operation of forming a plate supply path as the automatic plate supply mode. A method according to claim 10, wherein the step of executing the semi-automatic plate exchanging mode comprises the steps of continuously controlling as semi-automatic plate removal mode at least release operation of said plate fixing means and rotation of said plate cylinder, and controlling as the semi-automatic plate supply mode at least fixing operation of said plate fixing means and rotation of said plate cylinder in accordance with an input command. Method according to claim 9, wherein said second control means executing the semi-automatic plate exchanging mode removes the old plate from said plate cylinder by rotating said plate cylinder in a plate removal direction in the state that the old plate wound around a circumferential surface of said plate cylinder is held by an operator, at least at one end of the old plate being released from a plate fixing unit, and subsequently executing said semiautomatic plate exchanging mode to mount the new plate on said plate cylinder by a combination of automatic and manual operations.

Inventors: ASAI TAKESHI, ASAI, TAKESHI, ASAI, TAKESHI, C/O TORIDE PLANT
Applicants: KOMORI PRINTING MACH, KOMORI CORPORATION
Application year: 2000
Main classification: B41F27
IPC codes: B41F27, B41F13