US3018726A - Valve for effecting automatic double inking of the printing plate in a vertical press - Google Patents

Description

Jan. 30, 1962 J. A. ETHIER ,7

VALVE FOR EFFECTING AUTOMATIC DOUBLE INKING OF THE PRINTING PLATE IN A VERTICAL PRESS Filed Feb. 2, 1961 c lind y 35 valve A f d vo/ve 5 transfer Vfi C J-1 (y/maelvalve 2 sheaf on c I/nder valve 2 no sheet on cylinder valve open valve closed 5 IN l/ENTOR Joseph Ade/mar E TH/E'R 4 BYWWW PATENT AGENT to be printed have relatively large dimensions.

cases, in order to obtain a better printing quality, it is usual to effect a double'inking of the printing plate. 'A I sheet to be printed is fed to the press only at each two cycles of the machine, that is after two runs of the inking rollers over the printing plate.

United States PatentO T 3,018,726 VALVE FOR EFFECTING AUTOMATIC DOUBLE INKING OF THE PRINTING PLATE IN A VER- TICAL PRESS Joseph Adelmar Etbier, 6513 De Normanville St., Montreal, Quebec, Canada Filed Feb. 2, 1961, Ser. No. 86,700 Claims. (Cl. 101-280) The present invention relates to printing press and more particularly to an attachment which automatically produces the double inking of the printing plate in a vertical printing press.

In the printing art it is usual to print a sheet after a single back and forth inking run of the inking rollers on the printing plate. However in certain cases the quality of the'print is poor mostly when glossy and/or light colored inks are employed or again when the areas In these 5 Several types of printing presses are already equipped with a double inking mechanism but presses having a vertical plate and more particularly the press known 'under the name Miehle Vertical manufactured by -M1ehle Printing Press'and Manufacturing Company of Chicago,'Illinois, U.S.A.,, are not provided with such a system and in order to effect the double inking it is necessary to operate a knob by hand which controls a valve for cutting off the vacuum to the feeder or separator shoes which transport blank sheets from the feeder table to the transfer table. This operation must be repeated for each printing of a sheet and as it is not automatic it requires the constant attention of the operator.

The main object of the present invention resides therefore 1n the provision of a printing press with a vertical plate of the type of the Miehle Vertical printing press and provided with a mechanism for automatically effectmg double inking.

Another important object of the present invention resides in the provision of a mechanism of the character described which is very simple in construction and which perfectly synchronizes the necessary operations for effect mg double inking in conjunction with the operating cycle of the press.

Stillanother important object of the present invention resides in the provision of a valve for effecting double inking which is connected to the vacuum system of the machine and which functions in dependence with the ent invention will become more apparent during the following disclosure, and by referring to the drawings, in which:

FIGURE 1 is a schematic side elevation of a vertical ,plate printing press provided with the double inking attachment in accordance with the invention;

FIGURE 2 is a longitudinal section of the valve for effecting the double inking;

FIGURES 3 and 4 are schematic views showing dif- L ferent stages of operation for effecting the double inking;

and

3,013,726 Patented Jan. 30, 1962 FIGURE 5 is a schema indicating the relation between the impression cylinder movement and the opening and closing of the valves of the vacuum circuit.

In the drawings the same reference characters indicated the same elements throughout.

The Miehle Vertical printing press comprises a bed or frame for vertically mounting a printing plate 1, an impression cylinder 2, a transfer table 3 secured to the frame of the cylinder 2 and a feeder table 4. The plate 1 and impression cylinder 2 are guided in a vertical up and down movement in synchronism but in opposite directions by means of the racks 5 and 6 respectively secured to the bed of the plate 1 and to the frame of the cylinder 2, said racks meshing with a common pinion 7. Inking rollers 8 are also mounted for vertical up and down movement in order to ink the printing plate 1.

In order to transfer a sheet F to be printed one at a time and successively between the different elements of the press, a system is provided to produce vacuum. This system comprises a vacuum pump 9 provided with three valves A, B, C, actuated by cams for opening and closing these valves in synchronism with the operation of the machine.

The first valve A is connected in series with the tubing 10 which produces suction in the separator shoes 11, which serve to separate the top sheet F from the stack of sheets disposed on the feeder table 4 and transfer this sheet F onto the transfer table 3. The separator shoes 11 are mounted on a transfer bar itself secured to the outer end of pivotable arms (not shown in the drawings) and v of conventional construction.

The second valve B of the pump 9 is connected in series in the tubing 12 which communicate with holes 13 made in a transverse row in the transfer table 3 and which serve to suck and retain a sheet F on the transfer table 3.

The third valve C of the vacuum pump 9 is connected in series in the tubing 14 which communicates with a series of holes 15 made in a transverse row at the periphery of the impression cylinder 2. The holes 15 are also in communication with a tubing 16 connected to a diaphragm valve 17 disposed within the impression cylinder 2 and serving to actuate a clutching mechanism 18. When a sheet F to be printed is retained on the impression cylinder 2 by means of the suction produced through holes 15 there is an increase of vacuum in the diaphragm valve 17 which produces the clutching of the cylinder and rotation of the latter for printing the sheet by the printing plate 1 when the cylinder moves upwardly and the printing plate moves downwardly through the racks S and 6 and pinion 7.

The printing press operates in the following conventional manner. During the upward stroke of the impression cylinder 2 and of the transfer table 3 to finally reach transfer table 3 in the topmost position of the cylinder 2.

The valve A closes and the sheet is released by the shoes 11 onto the table 3 and is retained thereon by suction exerted by holes 13, valve B having been previously opened as shown in FIGURE 5.

The table 3 and impression cylinder 2 then move downwardly but the cylinder does not rotate because valve C is closed and during this time the plate 1 moves upwardly and is inked by the inking rollers 8, which again ink the plate during the downward movement of the latter. When the cylinder reaches its lowermost position, the valve B closes releasing the sheet F on the transfer table 3 and said sheet is transferred from the table 3 to the periphery of cylinder 2 by means of grippers 19 and is positioned on the cylinder in such a way that the marginal portion of the sheet will close or block the holes opening at the surface of the cylinder 2.

Valve C opens for a short time and the higher vacuum existing in tubing 14, holes 15 being blocked, actuate the diaphragm valve 17 which causes clutching of cylinder 2 whereby during subsequent upward movement of the cylinder the latter will rotate in the direction of arrow 20 (see FIGURE 3), during which time plate 1 moves downwardly to print the sheet on the cylinder 2.

If the holes 15 would have remained opened in the absence of a sheet on the cylinder, the lower degree of vacuum in tubing 14 and 16 would have been insufficient to cause clutching and rotary impression movement of the cylinder 2. When the cylinder 2 has reached its top most position, the sheet on the cylinder is released, rotation of the cylinder is stopped and the delivery grippers 21 transport the printed sheet on delivery table (not shown).

Therefore during the upward stroke of the cylinder 2, the separator having the separator shoes 11 transfers a blank sheet from the feeder table 4 to the transfer table 3 and the cylinder meanwhile prints another sheet mounted on said cylinder. When the cylinder and the transfer table 3 are in their topmost position, there is transfer of a printed sheet from the cylinder to the delivery table and each time the cylinder and its transfer table 3 are in their lowermost position there is a transfer of a blank sheet from said transfer table 3 to the cylinder 2. Thus a printing step occurs each time the cylinder moves upwardly and inking of the printing plate at each cycle of the cylinder. Therefore, there is a single inking and the press does not have any automatic means for effecting double inking.

In accordance with the present invention, the means for effecting double inking comprises a valve 25 more particularly illustrated in FIGURE 2. The body of this valve defines a cylindrical chamber 26 closed at one end by a perforated removable cover 27 maintained in position by a lock washer 27'. A piston 28 is reciprocable Within the chamber 26 and is provided with a piston rod 29 passing through the hole of cover 27 and having an externally threaded end for receiving a nut 30 and a wingnut 31. A coil spring 32 surrounds the piston rod 29 and abuts at one end against washer 27 and at the other end against the nut 30. Spring 32 normally resiliently retains the piston 28 in upper limit rest position in which it abuts against cover 27. Piston 28 is provided at its periphery with an annular groove 33 completely surrounding the piston and having a circular rectangular or square cross section. The groove 33 is disposed opposite ports 34 and 35 opening within the valve chamber 26 and disposed at right angles to each other so that groove 33 establishes communication between said two ports in the rest position of the piston 28. The port 34 is at the end of a bore in the valve body 25 which is connected to tubing 10 while port 35 opens at the exterior of the valve body to be connected to the transfer shoes 11.

Valve A of the press establishes communication between the vacuum pump 9 and the transfer shoes 11 in the rest position of the piston 28, in the same manner as if valve 25 was absent. The end of the cylinder 26 opposed to cover 27 is provided with an opening 36 in communication with a tube 37 which is connected to tubing 14 already connected to the holes 15 of the impression cylinder 2. The force exerted by spring 32 is adjusted by means of the nuts 30 and 31 in such a way that when there is no sheet F on the impression cylinder 2 and that i the holes 15 are therefore opened to the atmosphere, the vacuum existing in tubing 14 and tube 37 is insufficient for producing the displacement of the piston 28 in valve 25 against the action of spring 32. On the other hand,

when there is a sheet F on the impression cylinder and this sheet blocks holes 15, there is an increase in the vacuum in tubing 14 and tube 37 and the vacuum is sufiicient to produce displacement of piston 28 against action of spring 32 to thereby close the communication between the ports 34 and 35 and stop suction exerted by the transfer shoes 11 on the topmost sheet F on the stack of sheets on feeder table 4.

The insertion of valve 25 in the vacuum circuit of the press effects the double inking in the following manner:

FIGURES 3 and 4 of the drawings illustrate the cylinder 2 and the transfer table 3 a little above their lowermost position and corresponding to point 38 in the schema of the upward and downward movements of the cylinder illustrated in FIGURE 5. FIGURE 3 illustrates the cylinder on which there is no sheet F to be printed. The vacuum produced in tubes 14 and 37 is insufficient for closing valve 25 and therefore there is vacuum at the transfer shoes 11. Thus during the upward stroke of the cylinder, valve A opens and a sheet F is transferred onto the transfer table 3. This sheet is thereafter transferred onto the cylinder 2 and during the subsequent upward stroke of said cylinder, this sheet is printed. But as this sheet is on the cylinder, as indicated in FIGURE 4, the vacuum is higher in tubes 14 and 37 during opening of valve C because holes 15 of cylinder 2 are blocked by said sheet. Thus valve 25 closes and the transfer shoes 11 are inactive and there is no transfer of the sheet between feeder table 4 and transfer table 3. Therefore in the subsequent upward stroke of the cylinder, the latter remains bare and there is no printing taking place. Thus, the transfer shoes 11 are alternately active and inactive at each upward stroke of the cylinder and therefore a sheet is fed for printing at each two cycles of the press and double inking can be produced, that is two back and forth runs of the inking rollers on the printing plate 1.

If desired, there can be provided means for blocking the piston 28 in its upper limit position, for instance a pin can be inserted in a hole made in the piston rod 29 just above the top of the valve body 25 in order to prevent downward movement of the piston. This can be effected to prevent double inking whenever desired.

While a preferred embodiment in accordance with the present invention has been illustrated and described it is understood that various modification may be resorted to without departing from the spirit and scope of the appended claims.

What I claim is:

1. In a printing press including a vertical printing plate, an impression cylinder cooperating with said printing plate in a vertical up and down movement, a transfer table associated with said cylinder, a feeder table mounted on said press at substantially the level of said transfer table in the topmost position of the latter, means for transferring a blank sheet to be printed from said feeder table to said transfer table, means for transferring a blank sheet from said transfer table to said cylinder, a vacuum supply, a first valve and a first tubing connecting said first named means to said supply, said transfer table having holes at its surface, a second valve and a second tubing connecting said holes of said transfer table to said vacuum supply, said cylinder having a series of holes at its periphery, a third valve and a third tubing connecting said cylinder holes to said vacuum supply whereby a sheet on said cylinder blocks said cylinder holes and produces an increase of vacuum in said third tubing, .the combination with said press of a valve mounted in series with said first tubing and comprising an element movable between a first position and a second position blocking and opening said first tubing, respectively, by-pass tubing connecting said third tubing to said valve, said movable element taking its blocking position under an increase of vacuum in said third tubing and in said by-pass tubing, that is when a sheet blocks the holes of said cylinder, and said movable element taking its opening position of said first tubing upon a decrease of vacuum in said third tubing and by-pass tubing, that is when said cylinder holes are opened to atmosphere.

2. In a printing press including a vertical printing plate, an impression cylinder cooperating with said printing plate in a vertical up and down movement, a transfer table associated with said cylinder, a feeder table mounted on said press at substantially the level of said transfer table in the topmost position of the latter, means for transferring a blank sheet to be printed from said feeder table to said transfer table, means for transferring a blank sheet from said transfer table to said cylinder, a vacuum supply, a first valve and a first tubing connecting said first named means to said supply, said transfer table having holes at its surface, a second valve and a second tubing connecting said holes of said transfer table to said vacuum supply, said cylinder having a series of holes at its periphery, a third valve and a third tubing connecting said cylinder holes to said vacuum supply whereby a sheet on said cylinder blocks said cylinder holes and produces an increase of vacuum in said third tubing, the combination with said press of a valve mounted in series with said first tubing and comprising an element movable between a first position and a second position blocking and opening said first tubing, respectively, by-pass tubing connecting said third tubing to said valve, said movable element taking its blocking position under an increase of vacuum in said third tubing and in said by-pass tubing, that is when a sheet blocks the holes of said cylinder, and said movable element taking its opening position of said first tubing upon a decrease of vacuum in said third tubing and by-pass tubing, that is when said cylinder holes are opened to atmosphere, said valve comprising a body having a cylindrical chamber and said movable element consisting of a cylindrical piston movable within said valve comprising a body having a cylindrical chamber and said movable element consisting of a cylindrical piston movable within said chamber and provided with a peripheral annular groove, said first tubing opening within said chamber by means of ports in register with said groove in the opening position of said piston, a spring disposed between said piston and said valve body and resiliently maintaining said piston in its opening position, said by-pass tubing being connected to a port in said cylindrical chamber opposite an end of said piston whereby increase of vacuum produced in said by-pass tubing and in said cylindrical chamber causes displacement of said piston towards said by-pass port and causes said piston to take its blocking position.

3. The combination as claimed in claim 2, further including means for adjusting the force exerted by said spring.

4. The combination as claimed in claim 2, wherein said piston has a piston rod protruding from said valve body, said piston rod having a threaded outer end, a nut screwed on said end, said spring surrounding said piston rod and abutting against said nut and against said valve body.

5. The combination as claimed in claim 2, wherein said groove has a rectangular cross-section.

References Cited in the file of this patent UNITED STATES PATENTS 872,108 Brett Nov. 26, 1907 1,942,490 Quizley J an. 9, 1934 1,956,647 McCoy May 1, 1934 1,957,812 Stein May 8, 1934 1,974,544 Rowell Sept. 25, 1934

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