US3828672A - Apparatus for fitting flexible printing plates and rigging to printing press cylinders - Google Patents

Abstract

This printing press includes improved mechanism for clamping the edges of a flexible printing plate adjacent the leading and trailing edges of the saddle of a printing press cylinder. An auxiliary roll mechanism permits the flexible printing plate or rigging sheet to be held smooth and under tension during its installation on the cylinder.

Description

United States Patent [191 Gazzola, deceased et al.

APPARATUS FOR FITTING FLEXIBLE PRINTING PLATES AND RIGGING TO PRINTING PRESS CYLINDERS Inventors: Ivaldo Gazzola, deceased, late of Lausanne, Switzerland; by Eles Gazzola; by Lanfranca Gazzola, both of Lausanne, Switzerland heirs; Salvatore F. DAmato, Floral Park; Chauncey P. F oote, Jr., Katonah,

both of NY.

Assignee: American Bank Note Company,

New York, NY.

Filed: Oct. 17, 1972 Appl. No.: 298,376

U.S. Cl 101/247, 38/49, 72/158,

72/213, 10l/4l5.1, 271/51 Int.Cl B41f 13/24,B65h 37/00 Field of Search 101/415.1, 247, 231;

[ Aug. 13, 1974 [56] References Cited UNITED STATES PATENTS 2,629,324 2/1953 Smith l0l/415.1 2,701,521 2/1955 Taylor l01/DIG. 12 2,887,317 5/1959 Schunemann.... 271/51 3,614,926 10/1971 Brechtel 101/415.l X 3,750,573 8/1973 Haeusler et a1 l0l/415.l

FOREIGN PATENTS OR APPLICATIONS 1,034,654 7/1958 Germany 101/217 Primary ExaminerC1yde l. Coughenour Attorney, Agent, or Firm--Cooper, Dunham, Clark, Griffin & Moran [57] ABSTRACT This printing press includes improved mechanism for clamping the edges of a flexible printing plate adjacent the leading and trailing edges of the saddle of a printing press cylinder. An auxiliary roll mechanism permits the flexible printing plate or rigging sheet to be held smooth and under tension during its installation on the cylinder.

7 Claims, 12 Drawing Figures PATENTED AUG 1 31914 sum 2 [IF 7 PATENTED AUCI 3 1974SHEET 5 OF 7 APPARATUS FOR FITTING FLEXIBLE PRINTING PLATES AND RIGGING TO PRINTING PRESS CYLINDERS CROSS-REFERENCES US. Pat. applicationSer. No. 173,555, filed Aug. 20, 1971, now U.S. Pat. No. 3,762,319, by the same inventors, entitled Plate Wiping Mechanism for Intaglio Press, discloses an apparatus which may be used on the same press with the present invention.

US. Pat. application Ser. No. 188,195, filed Oct. 12, 1971, now US. Pat. No. 3,759,177, by the same inventors, entitled Printing Press With Sheet Inspection Station, discloses another apparatus which maybe used on the same press with the presentinvention.

US. Pat. application Ser. No. 195,364, filed Nov. 3, 1971, now US. Pat. No. 3,749,330, by the same inventors, entitled Apparatus for Delivering Sheets Onto A Moving Strip of Material, discloses another apparatus which may be used onthe same press with the present invention.

US. Pat. application Ser. No. 298,443 filed Oct. 17, 1972, by the same inventors, entitled Printing Pressure Control Apparatus Forlntaglio Press, discloses another apparatus which may be used on the same press with the present invention.

US. Pat. application Ser. No. 298,444f1led Oct. 17, 1972 by the same inventors, entitled Paper Feed Mechanism for Cylinder Press, discloses another apparatus which may be used onthe same press with the present invention.

BRIEF SUMMARY OF THE INVENTION The invention comprises three principal parts; namely: I

1. a clamp for holding the leading edge of a flexible printing plate or flexible rigging on the periphery of a printing cylinder;

2. a mechanism for maintaining the plate smoothly on the cylinder and under tension during the installation of the plate on the cylinder; and

3. a mechanism for clamping the trailing edge of the plate to the cylinder periphery. I

The mechanism for clamping the leading edge of the plate to the cylinder periphery may be of any suitable conventional construction.

The mechanism for holding the plate smooth and under tension during installation includes an auxiliary roller, a carriage supporting the roller and movable between:

1. a retracted position in which the roller is spaced from both the printing and pressure cylinders of the press; and

2. either of two active positions in which the roller engages one cylinder or the other.

The carriage is pivotally supported for movement between these three positions, and provision is made for locking the carriage in any one of the three positions. The carriage includes a pair of spaced parallel arms, with an extension on each arm slidable on the arm. The pivots for the auxiliary roller are on the extensions. Hydraulic motor means are provided on the arms for moving the extensions so that the roller may apply substantial pressure either to the pressure cylinder or the plate cylinder, so as to maintain substantial tension on a plate or sheet mounted thereon and clamped at the leading edge only. Means are provided to limit the movement the channeled jaw. These rails have flanges which are received in the channels. Roller bearings are captured between the flanges and the bottoms of the channels.

A row of spaced coil springs biases the lower jawtoward a position in which the plate is under tension. The lower jaw and the upper jaw assembled with it may be moved against the tension of the springs to a tension releasing position by means of a single cam joumaled on a pin fixed to the middle of the cylinder and rotatable by means of an external tool. The follower for the cam comprises a roller bearing rotatable on an 'arbor fixed on the lower jaw. The cam is provided with a concave notch which engages the follower when the plate tension is relieved, so that the cam and follower remain securely in their tension relieving positions, until the cam is rotated by the external tool.

, DRAWINGS FIG. 1 is a fragmentary elevationalview of an intaglio printing press embodying the invention, with certain parts broken away.

FIG. 2 is a fragmentary sectional view taken along the line 2-2 of FIGS. 1 and 3, on an enlargedscale.

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2, with certain parts omitted.

FIG. 4 is an enlarged fragmentary sectional view showing the mechanism for clamping the printing plates to the plate cylinder.

FIG. 5 is an exploded fragmentary view showing the mechanism for clamping the leading edge of the plate to the plate cylinder.

FIG. 6 is a sectional view taken along theline 6--6 of FIG. 4.

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 6.

FIG. 8 is a sectional view taken along the line 8-8 of FIG. 6, showing the parts in positions in which the printing plate is under tension.

FIG. 9 is a view similar to FIG. 8, showing the parts in positions in which the plate tension is relieved.

FIG. 10 is a view taken along the line 10-10 of FIG. 4.

FIG. 11 is a sectional view on an enlarged scale, corresponding to a left to right reversed view of the lower portion of FIG. 4, with a cover for the clamping mechanisms added.

FIG. 12 is a sectional view taken along the line 12-12 of FIG. 11. 7

DETAILED DESCRIPTION The press illustrated includes a frontvertical frame member 1 and a rear vertical frame member 2 (FIG. 2).

tween the impression cylinder and theplate carrying cylinder 3. The printed sheets are then removed by a conveyor 9, running over a sprocket 8.

The press illustrated is a multicolor press. The ink applying mechanism includes a carriage (FIG. 1) on which are mounted three ink reservoirs l1, l2 and 13 connected by ink conveying roller trains l5, l6 and 17 torollers 20, 21 and 22, which transfer the ink to the plate on thecylinder 3. Therollers 20, 21 and 22 are contoured, so that each contacts a portion only of the surface of thecylinder 3. Typically, only one color of ink will be applied to any given portion of the surface of the plate, although it may be arranged that colors overlap, if desired.

Theplate carrying cylinder 3 turns clockwise, as viewed in FIG. 1. A wiping roll 25 is rotatably mounted so that it runs with its periphery in contact with theplate cylinder 3, and also becomes immersed in a suitable solvent in a tank 26. The wiping roll 25 removes the ink from the surface of the plate on the printing cylinder, between the lines on the plate, so that as the plate approaches the nip of thecylinders 3 and 4, the

only ink remaining on the plate is in the recessed lines.

Theplate cylinder 3 is driven by amotor 27 through a multiple V-belt drive 28 and a suitable gear train (not shown). Conveyor 9 is driven from theplate cylinder 5 through a bevel pass shown at 29 in FIG. 1. The wiping roll is driven by amotor 30, which may be controlled as described in our copending application, Ser. No. 173,555, mentioned above.

The cylinder for applying and relieving printing pressure between theplate cyoinder 3 and theimpression cylinder 4 is shown in detail in our copending application, Ser. No. 298,433, mentioned above.

AUXILIARY ROLLER FIGS. 2-3

Anauxiliary roller 32 is rotatably supported on a pivotally mountedcarriage 33. Thecarriage 33 comprises a pair ofarms 34, 35, which are pivotally mounted ontrunnions 36, 37, fixed on the inner sides of the front andrear frame members 1 and 2.

The left ends of thearms 34, 35 as they appear in the drawings, carry a T-shaped head, best seen at 35a in FIG. 3. The T-shapedhead 35a has formed therein an arcuate slot 35b which receives the shank of ascrew 40, which is threadedly received in theframe member 2. By tightening thescrew 40, thearm 35 may be locked in any angular position.

In order to select the angular operating positions of thecarriage 33 accurately, each of thearms 34, 35 is provided near its outer end with ahousing 41, which encloses a locatingpin 42. Eachpin 42 has an enlarged head, tapered at its end, and is receivable in any one of threeholes 43, formed in theframe members 1 and 2. Aspring 44 is held in compression between a shoulder on thehead 42 of the locating pin and the inner end of thehousing 1, and biases the locating pin toward the position where its head is received in one of theholes 43. The outer end of the shank ofpin 42 extends through the top of thecasing 41 and is provided at its inner end with ahandle 45 by means of which thehead 42 may be withdrawn from one of the holds 43 for the purpose of shifting the operating position of thecarriage 33.

Thearms 34, 35 are provided with a pair of exten- .sions 46, slidable in suitable channels provided in thearms 34, 35. Theextensions 46 are operated by means ofhydraulic motors 47, which are pivotally fixed at their left-hand ends toposts 48 fastened to thearms 34, 35. Thehydraulic motors 47 operatepiston rods 50, which are pivotally fixed to theextensions 46.

A pair ofstops 51 are fixed on theframe members 1 and 2 in alignment with the ends of theextensions 46, when thecarriage 33 is in its retracted position, as shown in full lines in FIG. 3. Eachstop 51 is provided with anadjustable screw 52, by means of which the stop positions of theextensions 46 may be varied as required.

In the normal running condition of the press, thecarriage 33 is in its retracted position, shown in full lines in FIG. 3, so that theextensions 46 engage their stop screws 52, and the surface of theroller 32 does not engage the surface of either theplate cylinder 5 or thepressure cylinder 4.

When a plate is being installed on theplate cylinder 5, the leading edge of the plate is first fastened to theplate cylinder 5 by means of a clamp generally indicated at in FIG. 3. Thecarriage 33 is then released from its position illustrated in full lines and is turned clockwise from that position about thetrunnions 36 to a position in which thepins 42 engage theuppermost holes 43 and theroller 32 engages theprinting plate 61 adjacent the leading edge of the saddle St: on which the plate is to be mounted.Theplate cylinder 5 is then rotated counterclockwise, with theroller 32 holding theplate 61 smoothly and firmly against the saddle 5a. When the trailing edge of the plate moves near theroller 32, then that trailing edge may be clamped in aclamping mechanism 62, shown in detail in FIGS. 4 and 6-12.

A similar procedure is used in applying a flexible rigging sheet to thepressure cylinder 4. Theclamps 63 and 64 used respectively at the leading and trailing edges of the rigging sheet on thepressure cylinder 4 need not be exactly like theclamps 60 and 62 of the plate cylinder, since the location of the rigging sheet on thepressure cylinder 4 does not involve the degree of precision required for the location of theplate 61 on theplate cylinder 5.

LEADING EDGE CLAMP FIGS. 4-5

Theclamping mechanism 60 for the leading edge of theprinting plate 61 is best seen in these two figures. Thisclamping mechanism 60 includes aninner jaw 65 recessed in and fastened to theplate cylinder 5 by screws 69 (FIG. 10), and anouter jaw 66, which may be fastened to theinner jaw 65 by means of a series of spaced machine screws 67.Outer jaw 66 is provided on its inner face, at its margin remote from theplate 61, with a projecting flat surface 68, whose thickness is less than the thickness of theplate 61, so that thejaws 65 and 66 will tend to contact on the inner teeth of the jaws when in their clamped positions. The face of thejaw 66 which engages theplate 61 is provided with a plurality of rows of sharppointed teeth 66a near the edge of theplate 61, and with a plurality of rows of teeth 66b having flattened or truncated points, engaging theplate 61 farther from the edge than the sharp points 660. This construction insures that the marginal edge ofplate 61 will be held tightly by thesharp points 66a, and allows theplate 61 to shift laterally where it is located under the flat points 66b.

Theouter jaw 66 is also provided with a plurality of spacedopenings 66c (FIGS. 4, 8 and 9), which loosely receive the heads of locatingpins 70, which are firmly fixed in thelower jaws 65, and which are received in openings in theplate 61 to fix its location precisely and accurately with respectto thecylinder 5.

TRAILING EDGE CLAMPING MECHANISM FIGS. 4 and 6-10 The trailingedge clamping mechanism 62 includes aninner jaw 71 and anouter jaw 72. Thejaws 71 and 72 are located in arecess 73 formed in the outer surface of the cylinder between the plate supporting saddles. Theinner jaw 71 does not touch the bottom of that recess, but is supported outwardly from it, as clearly appears in the drawings, especially FIGS. 4 and 7-9. Theinner jaw 71 is provided at each end with achannel 71a (FIG. 7), extending parallel to the inner and outer surfaces of the jaw. A pair of rails 74 are fixed to the bottom of therecess 73 by means of bolts 75. The upper ends of the rails 74 have flanges projecting toward theinner jaw 71, and received in thechannels 71a.Roller bearings 76, best seen in FIG. 7, are captured between the flanges of the rails 74 and the bottoms of thechannels 71a. The flanges of the rails 74 are provided withrecesses 74a (FIG. 6), to receive thebearings 76 and hold them in position. The vertical dimensions of theinner jaw 71 and itschannel 71a, as compared to the vertical dimensions of the rails 74 and its flange, as viewed in FIG. 7, are such that theinner jaw 71 is supported solely by the rails 74, and its under surface is spaced above the bottom of therecess 73.

Theinner jaw 71 is provided with a plurality of spaced apertures 71b (FIGS. 4 and 7), in which are receivedsprings 77, which are held in compression between one wall of therecess 73 and aspring retainer 78 threadedly received in the aperture 71b, and adjustable in position by means of ahexagonal head 78a. This assembly is best seen at the top of FIG. 4.

Thesprings 77 bias theinner jaw 71 and theentire clamping mechanism 62 in a direction to maintain theflexible printing plate 61 under tension.

Theinner jaw 71 is provided with a secondrow of spaced apertures 710, in which are threadedly received a plurality ofscrews 80 havinghexagonal heads 80a at their outer ends. The inner ends of thescrews 80 abut against a surface at the side of therecess 73.

When theprinting plate 61 is first installed on the press, thescrews 80 are backed off so that their ends are spaced from the side of therecess 73. The only force then tending to hold theprinting plate 61 under tension is the force due to thesprings 77. After the plate has been installed on the press, thescrews 80 may be tightened, thereby placing theplate 61 under additional tension. Note that there is no structure limiting the movement of thelower jaw 71 in a downward direction as viewed in FIG. 6. In other words, the forces due to thespring 77 and the compression in thescrews 80 are opposed only by the tension in theplate 61, so that theplate 61 is held firmly and smoothly in place on the press.

In order to relieve the tension in theplate 61, thescrews 80 must first be backed off so that their inner ends are not engaging the sides of therecess 73. Acam 82 is provided for moving thelower jaw 71 against the compression of thesprings 77. Thecam 82 is mounted on apivot pin 83, and is rotatable on that pin by means of an externally applied key or other tool, as shown at 84 in FIGS. 8 and 9. In the plate tensioning position shown in FIG. 6, thecam 82 is spaced from arecess 71d formed in thelower jaw 71. A cam follower is located in therecess 71d, and comprises aroller bearing 85 rotatable on astud 86. When thecam 82 is rotated through from the position shown in FIG. 6, the surface of the cam engages theroller bearing follower 85, and forces thelower jaw 71 upwardly, as viewed in FIG. 6 and also in FIG. 9. This compresses thesprings 77, and relieves the tension in theprinting plate 61, as is shown in FIG. 9.

Theouter jaw 72 is similar in structure and function to theouter jaw 66 of theclamp 60, described above. Theouter jaw 72 is held in place in clamping position on thelower jaw 71 by means of a plurality ofscrews 87,.best seen in FIGS. 6-7.

Theouter jaw 72 is longer than theinner jaw 71, so that its ends overhang that inner jaw and the rails 74, as seen in FIG. 7. A pair ofsprings 88 are held in compression between the ends of theupper jaw 72 and the rails 74. When thescrews 87 are loosened to remove a plate from the clamp, thesprings 88 are effective to separate thejaw 72 from thejaw 71, thereby readily releasing theplate 61 from the grip of the clamp.

When thecam 82 is rotated 90 from the position shown in FIG. 6, aconcave recess 82a becomes alined with theroller bearing 85 and holds thecam 82 andfollower 85 securely in position, so that the tension in theprinting plate 61 continues to be relieved.

COVER PLATE FIGS. 11-12 These figures illustrate a cover plate 91, which is placed over theclamp assemblies 60 and 62, to close the space between those clamp assemblies and thereby to prevent the accumulation of dirt or foreign material in therecess 73. As seen in FIG. 11, the plate 91 has a pair ofwings 91a and 91b, each having agasket 92, 93 of compressible material bonded to its extremity. Thegasket 92 is adapted to engage the leading edge of theprinting plate 61, thegasket 93 is adapted to engage the outer surface of theouter jaw 71 of theclamp mechanism 72.

The cover plate 91 has integrally formed therewith twoupstanding lugs 910, in which are received a pair of lockingrods 92. Eachrod 92 has a taperedtip 92a adapted to engage a corresponding recess in anend plate 93 of thecylinder 5. Aspring 94 encircles eachrod 92 between one of thelugs 91a and a shoulder 92b formed on therod 92. Thespring 94 biases the lockingrod 92 toward the locking position shown in FIG. 12, in which thetip 92a engages the recess inend plate 93. The inner ends of the lockingrods 92 are encircled by acommon sleeve 95. Eachrod 92 has pinned to its inner end asleeve 96 to which is welded ahandle 97 having a projectingend 97a accessible through an opening in the plate 91. By moving thehandles 97a to the dotted line positions shown in FIG. 12, the locking pins 92 are withdrawn from the recesses in theend plates 93, so that the cover assembly 91 may be removed.

We claim:

1. A printing press, comprising:

a. a plate cylinder;

b. an impression cylinder rotatable about an axis parallel to the axis of the plate cylinder;

c. means including a frame supporting said cylinders for rotation about said parallel axes and for movement of one of said cylinders in a directionv perpendicular to its axis to shift said one cylinder between a printing position in which the cylinders are'in rolling contact and a non-printing position in which the cylinders are separated;

d. means on each cylinder for clamping the leading edge of a sheet;

e. means on each cylinder for clamping the trailing edge ofa sheet; l

f. a roller for applying pressure to such a sheet and its associated cylinder during installation of the sheet on the cylinder; and

g. means including a carriage supporting the roller for movement between a retracted position spaced from both the cylinders and either of two active positions in which it engages one cylinder or the other.

2. A printing press as inclaim 1, including means for 3. A printing press as inclaim 1, including means for locking the carriage in any of said three angular positions.

4. A printing press as inclaim 1, in which said carriage includes:

a. two parallel spaced arms pivotally mounted for rotation about a common axis;

b. an extension on each arm, slidable on its associated arm;

c. pivots for the roller on said extensions.

5. A printing press as inclaim 4, including motor means for driving the extensions along the arms.

6. A printing press as inclaim 5, including stop means mounted on the frame of the press for limiting movement of the roller toward the cylinders when the carriage is in its position corresponding to the retracted position of the roller.

7. A printing press as inclaim 1, in which:

a. said plate cylinder has a saddle for receiving a printing plate and a recess at the trailing end of the saddle for receiving a clamp;

b. said trailing edge clamping means includes a pair of jaws extending substantially the full axial length of the plate and engageable with the trailing edge of the plate, at least one of said jaws having channels at its ends extending parallel to the plate;

c. a pair of rails attached to the cylinder and having flanges received in said channels, said flanges and channels cooperating to support the slidable clamp;

d. spring means biasing the slidable clamp in a direction to stress the plate in tension over the saddle; and

e. cam means operable to stress the spring means in a sense to relieve the tension in the plate.

Claims (7)

1. A printing press, comprising: a. a plate cylinder; b. an impression cylinder rotatable about an axis parallel to the axis of the plate cylinder; c. means including a frame supporting said cylinders for rotation about said parallel axes and for movement of one of said cylinders in a direction perpendicular to its axis to shift said one cylinder between a printing position in which the cylinders are in rolling contact and a non-printing position in which the cylinders are separated; d. means on each cylinder for clamping the leading edge of a sheet; e. means on each cylinder for clamping the trailing edge of a sheet; f. a roller for applying pressure to such a sheet and its associated cylinder during installation of the sheet on the cylinder; and g. means including a carriage supporting the roller for movement between a retracted position spaced from both the cylinders and either of two active positions in which it engages one cylinder or the other.

2. A printing press as in claim 1, including means for pivotally supporting the carriage for movement between three angular positions corresponding to the retracted position and the two active positions of the roller.

3. A printing press as in claim 1, including means for locking the carriage in any of said three angular positions.

4. A printing press as in claim 1, in which said carriage includes: a. two parallel spaced arms pivotally mounted for rotation about a common axis; b. an extension on each arm, slidable on its associated arm; c. pivots for the roller on said extensions.

5. A printing press as in claim 4, including motor means for driving the extensions along the arms.

6. A printing press as in claim 5, including stop means mounted on the frame of the press for limiting movement of the roller toward the cylinders when the carriage is in its position corresponding to the retracted position of the roller.

7. A printing press as in claim 1, in which: a. said plate cylinder has a saddle for receiving a printing plate and a recess at the trailing end of the saddle for receiving a clamp; b. said trailing edge clamping means includes a pair of jaws extending substantially the full axial length of the plate and engageable with the trailing edge of the plate, at least one of said jaws having channels at its ends extending parallel to the plate; c. a pair of rails attached to the cylinder and having flanges received in said channels, said flanges and channels cooperating to support the slidable clamp; d. spring means biasing the slidable clamp in a direction to stress the plate in tension over the saddle; and e. cam means operable to stress the spring means in a sense to relieve the tension in the plate.

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