Paper Feed Mechanism For Cylinder Press

Abstract

Apparatus for supplying sheets to be printed to the impression cylinder of an intaglio press, including a first sheet feeding cylinder for transferring sheets to the impression cylinder. The first sheet feeding cylinder is fixed on a shaft journaled on the ends of a pair of links, which are pivoted at their other ends for rotation about a fixed axis. A second sheet feeding cylinder and a gear are fixed on a shaft which rotates about that axis. The links are rotatably mounted on that shaft, which is driven in synchronism with the plate cylinder of the press. A gear fixed on that shaft meshes with another gear fixed on the shaft of the first sheet feeding cylinder. The links may be driven by a motor and appropriate gearing to swing the first sheet feeding cylinder between a printing position where it is in rolling contact with the impression cylinder and a retracted position where it is spaced from the impression cylinder far enough to allow access to the impression cylinder and the plate cylinder. Latches may be provided for holding the paper feed cylinder in either its printing position or its retracted position.

Description

CROSS-REFERENCES

United States patent application Ser. No. 173,555, filed Aug. 20, 1971, by the same inventors, entitled "Plate Wiping Mechanism for Intaglio Press", now U.s. Pat. No. 3,762,319, dated Oct. 2, 1973, discloses an apparatus which may be used on the same press with the present invention. U.S. Pat. application Ser. No. 188,195, filed Oct. 12, 1971, by the same inventors, entitled "Printing Press with Sheet Inspection Station", now U.S. Pat. No. 3,759,177, dated Sept. 18, 1973, discloses another apparatus which may be used on the same press with the present invention.

U.S. Pat. application Ser. No. 195,364, filed Nov. 3, 1971, by the same inventors, entitled "Apparatus for Delivering Sheets Onto a Moving Strip of Material", now U.S. Pat. No. 3,749,330, dated July 31, 1973, discloses another apparatus which may be used on the same press with the present invention.

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

BRIEF SUMMARY OF THE INVENTION

The present invention is illustrated as applied to an intaglio press having a plate cylinder rotatable about a horizontal axis and an impression cylinder rotatable about a parallel horizontal axis located above the plate cylinder. Sheets to be printed are fed to one side of the impression cylinder and are delivered from the opposite side after passing through the nip of the impression and plate cylinders, where they are in rolling contact. The sheets are transferred to the impression cylinder from a sheet feeding cylinder, running in rolling contact with the impression cylinder, and located alongside it. The sheet feeding cylinder, in that position, restricts access to the impression cylinder. It is frequently necessary for the pressman to get access to the impression cylinder for the purpose of changing or repairing the resilient outer coating of the cylinder, which is subject to heavy pressure and consequent wear, as well as occasional damage.

The present invention is concerned with an improved press whereby the pressman can get more convenient access to the impression cylinder. This access is provided by making the final cylinder in the sheet feeding train retractable, so that it can be swung to a position spaced away from the impression cylinder, thereby allowing the pressman ready access to the impression cylinders.

DRAWINGS

FIG. 1 is a fragmentary elevational view, somewhat diagrammatic, showing an intaglio press embodying the invention, with certain parts broken away.

FIG. 2 is a sectional view taken on the line 2--2 of FIG. 1, on an enlarged scale.

FIG. 3 is a sectional view taken on the line 3--3 of FIG. 2.

FIG. 4 is a diagrammatic illustration of the controls for the apparatus of FIGS. 1-3.

DETAILED DESCRIPTION

The press illustrated includes a front vertical frame member 1 and a rear vertical frame member 2. The frame members 1 and 2 rotatably support a plate carrying cylinder 3 and an impression cylinder 4. Sheets of paper to be printed may be supplied by conventional sheet feeding mechanisms to a train of sheet feeding cylinders 5, 6, 7, from which they are transferred to the impression cylinder 4, and pass through the nip between the impression cylinder and the plate carrying cylinder 3, where they are printed. The printed sheets are then removed by a conveyor 9, running over a sprocket 8.

An intaglio press, such as that illustrated, prints from a smooth plate in which the lines, dots or other indicia to be printed are recessed, as by engraving. Ink is first applied over a selected area or possibly the entire plate, and is then wiped away from the smooth surfaces, leaving ink only in the recesses. Thereafter, a sheet to be printed is forced against the plate under heavy pressure, thereby transferring the ink from the recesses to the sheet.

The press illustrated is a multicolor press. The ink applying mechanism includes a carriage 10 (FIG. 1) on which are mounted three ink reservoirs 11, 12 and 13 connected by ink conveying roller trains 15, 16 and 17 to rollers 20, 21 and 22, which transfer the ink to the plate on the cylinder 3. The rollers 20, 21 and 22 are contoured, so that each contacts a portion only of the surface of the cylinder 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 the colors overlap, if desired.

The plate carrying cylinder 3 turns clockwise, as viewed in FIG. 1. A wiping roll 25 is rotatably mounted so that its periphery runs in contact with the plate cylinder 3, and thereafter becomes immersed in a suitable cleaning liquid 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 the cylinders 3 and 4, the only ink remaining on the plate is in the recessed lines.

The plate cylinder 3 is driven by a motor 27 through a multiple V-belt drive 28 and a suitable gear train indicated by a dot-dash line 29 in FIG. 1, which gear train also is connected to the impression cylinder 4 and the sheet feeding roll 6, as indicated. The wiping roll 25 is driven by a motor 30, which may be controlled as described in our U.S. Pat. No. 3,762,319, mentioned above. The motors 27 and 30 are located at the back of the press, as viewed in FIG. 1, and thus do not interfere with access to the cylinders 3 and 4 by an operator standing just to the left of the frame member 1.

The last sheet feeding cylinder 7 is fixed on a shaft 31 which is rotatably journaled at its ends in the ends of a pair of links 32. The ends of the shaft 31 do not extend all the way through the link 32 but only extend into recesses 32a in the inner faces of those links. The other ends of the links 32 are rotatable on a shaft 33 on which the second paper feed cylinder 6 is fixed. A gear 34 is also fixed on the shaft 33 and meshes with a gear 35 fixed on the shaft 31. A pair of pinion gears 37 are rotatable on the shaft 33 and each is fixed to one of the links 32. The pinion gears 37 cooperate with racks 38 driven by hydraulic motors 40, (see FIG. 3).

At its left end, as viewed in FIG. 2, the shaft 33 has fixed thereon a gear 41, which is connected to gear train 29, so as to be driven synchronously with the plate cylinder 3 and the impression cylinder 4.

A pair of latches 42 are provided for holding the paper feed cylinder 7 in its printing position. As illustrated, each latch 42 comprises a piston 43 having a nose 43a receivable into a conical recess 32b on the end of one of the links 32. The axis of the conical recess 32b is aligned with the axis of the shaft 31. Each piston 43 is biased by a spring 49 toward the latching position where the nose 43a is received in the recess 32b.

A similar pair of latches 50 are provided for holding the paper feeding cylinder 7 in its retracted position, shown in dotted lines in FIG. 3.

The latches 42 and 50 may be withdrawn from their latching positions by hydraulic motors 44 and 51, or other suitable control mechanisms.

When the paper feed cylinder 7 is in its printing position, as shown in full lines in FIG. 3, it is so synchronized with the impression cylinder 4 that a set of sheet grippers 45 on the cylinder 7 are adjacent the cylinder 4 at the same time that sheet grippers 46 on that cylinder are passing the point of tangency of the two cylinders. The sheet grippers 45, 46 and their operating mechanism may be of conventional construction, and are not illustrated.

When it is desired to retract the cylinder 7 to the dotted line position shown in FIG. 3, the latches 42 and 50 are released by means of the hydraulic motors 44 and 51. The hydraulic motors 40 are then actuated to drive the racks 38 to the right as shown in FIG. 3, thereby rotating the links 32 about the shaft 33 and moving the cylinder 7 orbitally about the axis of shaft 33 from the full line position shown to the dotted line position, thereby rendering the entire left side of the impression cylinder 4 accessible to the press operator. During this retraction, the gears 34 and 35 remain in mesh, so that after the operator finishes his work on the impression cylinder 4, the paper feed cylinder 7 can be restored to its printing position simply by releasing the latches 50 holding the links 32 in the retracted position and actuating the hydraulic motors 40 to drive the links 32 in the counterclockwise direction and thereby to bring the paper feed cylinder 7 into contact with the impression cylinder 4. The latches 42 are then engaged to hold the paper feed cylinder 7 in its printing position.

FIG. 4

This figure illustrates the control mechanism for actuating: (1) the hydraulic motors 40 which move the feed cylinder 7 between its printing position shown in full lines in FIG. 3 and its retracted position, shown in dotted lines; and (2) the latches 42 and 50 which hold the cylinder 7 in its printing position and its retracted position, respectively.

In FIG. 4, a manually actuated three-position switch 52 is biased to its center position by means of springs 52e. In that center position, all contacts of the switch 52 are open. Switch 52 has four contacts 52a, 52b, 52c and 52d. When the switch 52 is actuated to the left from the position shown in the drawing, i.e., from the "off" position to the "print" position, the contacts 52a and 52c are closed. When the switch 52 is moved to the right from its center position, i.e., from the "off" position to the "retract" position, contacts 52b and 52d are closed.

Three automatic switches are shown, namely a limit switch 53, which is open when the feed cylinder 7 is in its printing position, a limit switch 54, which is open when the feed cylinder 7 is in its retracted position, and a switch 55, which is closed when a cover 56 (FIGS. 2 and 3) is removed. The switch 55 is a safety control member having a safe (open) condition and operated to an active (closed) condition when the cover is removed.

The cover 56 is mounted on removable hinge pins 57, of conventional construction, appearing at the upper end of the cover in the drawings. The lower end of the cover, when in place as shown, is attached to brackets 60, which extend inwardly from the frame members 1 and 2 of the press. The cover 56 is provided to prevent accidental contact between the top of the pressman's head and the under sides of the feed cylinders 6 and 7, when the press is operated. The cover is attachable only when the cylinder 7 is in its printing position, and is necessarily removed when the cylinder 7 is in any other position.

In order to change the feed cylinder 7 from its printing position to its retracted position, or vice versa, the cover 56 must be removed, so as to close the switch 55. Normally, the operation of moving the cylinder 7 starts with that cylinder in either its printing position or its retracted position, so that either the switch 53 or the switch 54 is opened.

Assume that the cover 56 is removed, and that it is desired to move the roll 7 from its retracted position to its printing position. The switch 52 is moved from its center position to its left-hand position, closing the contacts 52a and 52c. Contact 52a closes an obvious circuit for energizing a relay 61 having an instantaneous contact 61a and a time delay contact 61b. Closure of contact 61a completes a circuit for energizing a solenoid 62 which operates a valve 63 controlling the flow of hydraulic fluid to the latch operating motors 44 and 51. The valve 63 is biased to a position such as that shown schematically in the drawings, in which the motors 44 and 51 are in their latching positions. When the switch 52 is operated to close contacts 52a and 52c, solenoid 62 is energized and operates valve 63 to releae all the latches 42 and 50. Then, after a certain time delay determined by the characteristics of solenoid 61, contact 61b is closed, completing a circuit through the contact 52c for energizing a solenoid 64. The solenoid 64 and another solenoid 65 together control a valve mechanism 66 which in turn controls the hydraulic motors 40. Energization of solenoid 64 operates valve 66 from a neutral position to a position in which the hydraulic motors 40 are operated in a direction to drive the feed cylinder 7 to its full line or printing position, shown in FIG. 3. As soon as the cylinder 7 has reached the printing position, the limit switch 53 opens, and switch 52 may be returned to its neutral center position, whereupon all the latches return to their latching positions, and the cylinder 7 is latched in its printing position.

If the switch 52 is released while the motors 40 are driving the cylinder 7 between its retracted and printing positions, contacts 52a and 52c open. Contact 52c thereby opens the circuit for valve 64 so that the motors 40 stop, leaving the roll 7 in a mid-position. However, the limit switches 53 and 54 both remain closed so that contact 52a is shunted, and the latches continue to be held in their latch releasing position. Whenever it is desired to complete the operation of the roll 7 to its printing position, the pressman simply actuates the handle for controlling the switch 52 back to its left-hand position and holds it there until the roll 7 reaches its printing position.

The operation of the roll 7 from its printing position to its retracted position is similar to that described above. In this case, the handle of switch 52 is moved to its right-hand position, as shown in FIG. 4, thereby closing contacts 52b and 52d. The operation of relay 61, solenoid 62 and valve 63 is the same as before, since all latches are released simultaneously, in either direction of operation. Instead of energizing solenoid 64 to operate valve 66, however, solenoid 65 is energized and operates valve 66 to drive the motors 40 in the opposite sense, so that the roll 7 is moved to its retracted position. As soon as the handle of switch 52 is released, that switch returns to its center position and latches 50 hold the roll in its retracted position.

Claims

We claim:

1. A printing press comprising:

a. a frame including spaced parallel side frame members;

b. a plate cylinder rotatably supported at its ends by said frame members;

c. an impression cylinder rotatably supported at its ends by said frame members;

d. means driving said cylinders in rolling engagement;

e. paper feed mechanism including a paper feed cylinder;

f. means supporting the paper feed cylinder for movement between a printing position where it is in rolling contact with the impression cylinder and a retracted position spaced from the impression cylinder, said supporting means including:

1. a pair of parallel links, each supported at one end for rotation about a pivot point operatively connected to the press, said points defining a fixed axis parallel to the impression cylinder axis;

2. bearing means at the other ends of said links rotatably supporting a shaft on which the paper feed cylinder is fixed; and

3. motor means for driving the links about said fixed axis and thereby swinging the paper feed cylinder orbitally about said axis between a printing position where it is in rolling contact with the impression cylinder and a retracted position spaced from the impression cylinder, said paper feed cylinder in its retracted position being spaced far enough from the impression cylinder to permit access thereto;

4. a first gear rotatable about said fixed axis and driven in synchronism with the plate and impression cylinders; and

5. a second gear fixed to the paper feed cylinder and meshing with the first gear;

6. said first and second gears remaining in mesh throughout the swinging movement of the paper feed cylinder on said links, so that the feed cylinder is always in synchronism with the plate and impression cylinders.

2. A printing press as in claim 1, in which said motor means includes a gear fixed to one of said links for rotation therewith, and a motor operatively connected to said gear for driving it to swing the paper feed cylinder between its printing position and its retracted position.

3. A printing press as in claim 2, in which:

a. said gear is a pinion;

b. said motor means includes a rack cooperating with the pinion; and

c. said motor drives the rack.

4. A printing press as in claim 1, including:

1. a second shaft journaled in said frame members for rotation about said fixed axis, said first gear being fixed to said second shaft;

2. said one ends of said links being rotatable on said second shaft;

3. a second paper feed cylinder fixed to said second shaft for rotation therewith and cooperating with the first-mentioned paper feed cylinder.

5. A printing press as in claim 1, including latch means for holding the paper feed cylinder in its printing position.

6. A printing press as in claim 1, including latch means for holding the paper feed cylinder in its retracted position.

7. A printing press as in claim 1, including gears fixed to both of said links for rotation therewith, and motor means operatively connected to said gears for driving them in unison to swing the paper feed cylinder between its printing position and its retracted position.

8. A printing press as in claim 1, comprising:

a. first latch means for holding the paper feed cylinder in its printing position;

b. second latch means for holding the paper feed cylinder in its retracted position;

c. means biasing said first and second latch means to their latching positions; and

d. latch releasing motor means for releasing the latch means against the force of the biasing means.

9. A printing press as in claim 8, including:

a. a manual control member having an OFF position and two ON positions;

b. means responsive to movement of the manual control member to either of its ON positions to operate the latch releasing motor means and after a predetermined time delay, to operate the link driving motor means.

10. A printing press as in claim 9, including:

a. first limit control means actuated when the paper feed cylinder is in its printing position;

b. second limit control means actuated when the paper feed cylinder is in its retracted position; and

c. means including said first and second limit control means for maintaining said latch means released as long as the printing feed cylinder is between its printing and retracted positions.

11. A printing press as in claim 8, including:

a. a cover for the paper feed cylinder in its printing position;

b. a safety control member operated to a safe condition by said cover when the cover is in place, and operated to an active position when the cover is removed; and

c. means including said safety control member in its active position only for energizing the latch releasing motor means and thereby preventing release of the latch means while the cover is in place.