US2722176A

US2722176A - Control for printing presses

Info

Publication number: US2722176A
Application number: US245657A
Authority: US
Inventors: Rupp Friedrich
Original assignee: MAN Maschinenfabrik Augsburg Nuernberg AG
Current assignee: MAN AG
Priority date: 1951-07-27
Filing date: 1951-09-08
Publication date: 1955-11-01
Anticipated expiration: 1972-11-01

Description

NOV. 1, 1955 RUPP 2,722,176

CONTROL FOR PRINTING PRESSES Filed Sept. 8, 1951 5 Sheets-Sheet 1 INVENTOR P21502104 EuPP NOV. 1, 1955 RUPP 2,722,176

CONTROL FOR PRINTING PRESSES Filed Sept. 8, 1951 Y 5 Sheets-Sheet 2 INVENTOR FRIEDRICH 20 BY WWW! ATTORNEYS wi l Nov. 1, 1955 F. RUPP 2,722,176

CONTROL FOR PRINTING PRESSES Filed Sept. 8, 1951 5 Sheets-Sheet 5 INVENTOI? FRIEDRICH RUPP WMM ATTOQNEYS United ee CONTROL FOR lRINTING PREssEs Friedrich Rupp, Augsburg, Germany, assignor to Maschinenfabrik Augsburg-Numberg A. G., Augsburg, Germany, a corporation of Germany Application September 8, 1951, Serial No. 245,657 Claims priority, application Germany July 27, 1951 8 Claims. (Cl. 101-358) This invention relates to certain improvements in printing machines, more particularly of the two-revolution type.

It is an object of the invention to provide means for double inking of the form, so as to improve the quality of the print for special cases.

The double inking as such is achieved by causing the printing form to sweep past the inking device twice as much as in case of single inking before making a print. Since normally on a two-revolution printing press a print is made after each inking operation, means have to be provided to ensure that in case of double inking the devices for preparation of the printing process are periodically put out of operation, i. e., that no paper sheet is fed after the first inking of the printing form and that the printing cylinder is not moved into its op erative position. Where an electric stop motion is provided by which the machine is stopped in case of nonarrival of a printing sheet, the function thereof has tobe stopped in the same rhythm inwhich the sheet feeting device is put out of operation. This stopping of the various printing steps in known machines is effected pneumatically by compressed air control. It hasbeen found, however, that the pneumatic control is complicated and expensive.

According to the present invention, on the contrary, the device for changing over from single to double inking is designed for purely mechanical operation. The control device according to the invention comprises a set of permanently rotating cam discs each operating a roller lever which can be engaged and disengaged and neutralizes one of the control functions required for the printing operations in case of single inking. The cam discs are arranged side by side on a common shaft and are jointly driven in the rhythm of the machine. Through roller levers operated by said cams the periodical neutralization of the functions required for the printing of a sheet is achieved. Such functions are the lowering of the impression cylinder towards the form, the feeding of the sheet by the sheet feeding device and the automatic stopping of the machine by the control device in case of non-arrival of a sheet. The cams are put out of operation by lifting the roller levers from the cams by turning the common lever shaft through drivers.

The control device according to the present invention is extremely simple both in construction and in operation since it is possible to change over from single to double inking and vice versa by a single manipulation.

Further objects, features and advantages of the present invention will be seen from the following detailed description thereof in connection with the accompanying drawing showing by way of example and purely schematically one embodiment of the invention and in which:

Fig. 1 is a side view of the device as viewed in the direction of arrow A in Fig. 2, with the side wallof the machine frame removed,

Fig. 2 is a section through 'the side chine frame and the cam discs,

Fig. 3 is a side view, partly in section, of the control of the means for lowering the impression cylinder,

Fig. 4 is a side view of the device for controlling the suction air for the sheet feeding device and Fig. 5 is a side view of the control of the stop motion, and Fig. 6 is a schematic showing of a printing press embodying this invention.

Similar reference numerals denote similar parts in the diiferent views.

Referring now to the drawing in greater detail, and first to Fig. 6, the invention is shownas applied to"a sheet-fed flat bed printing press of the two-revolution type. The rotating impression cylinder is intermittently lowered every second revolution by rotation of the eccentric bearing 101 through the linkage 102, in order to press against the printing form 103 as it passes beneath cylinder 100. During alternate revolutions, the cylinder 100 is raised so that the form 103 can pass freely beneath it during the return travel of the form.

The sheets to be printed are fed to the impression cylinder 100 from the stack 104 by means of suction air grippers 105, which pick the sheets singly from the stack and lay them on the table 106. Electrical contacts and feelers 107 are arranged on table 106 whereby the feelers will sink onto the table and close an electric circuit to stop the press if no sheet lies. on the table to interrupt the closing of the circuit by the feelers 107. Thus the press is automatically stopped if the grippers fail to present a sheet for printing and before the impression cylinder can be lowered against the form 103. After printing, the sheets are withdrawn from cylinder 100 by grippers 108 moving on chain delivery mechanism 109 to be deposited upon the stack 110.

Thus, if a double inking of the form 103 is desired, the intermittent operation of the various control func tions must be interrupted to operate only every fourth revolution of the cylinder instead of every second revolution. To this end, and referring to Figs. 1 and 2, it will be seen that a shaft 2 is secured in the side wall 1 of the machine frame, a toothed driving wheel 3 with a long hub 4 being mounted for free rotation on the shaft. Mounted on the hub 4 and connected thereto by keys are three

cam discs

5, 6, and 7 which rotate continuously together with the toothed wheel 3 which may be driven by any rotary shaft of the printing machine. Rotatably mounted in the side wall 1 of the machine below the

cams

5, 6, 7 is a second shaft 8 on whichare rotatably mounted three

levers

9, 10 and 11. The shaft 8 can be rotated in its bearing 13 by means of a hand lever 12 and thereby takes with it, by means of drivers to be hereinafter described, the three levers 9, 10, and 11, so that their

rollers

14, 15, and 16 do not engage the three

cam discs

5, 6, and 7 any longer. If the roller levers 9, 10, and 11 are released by the drivers, they are urged against the

cams

5, 6, and 7, together with their

rollers

14, 15, and 16, by means of

springs

17 and 18 and a spring-urged push button 36. The hand lever 12 is engaged in the sleeves 22 and 23in its end positions by means of a pin 21 provided on the handle 20.

The operation of the various cams will now be explained with reference to Figs. 3-5. t

Fig. 3 shows the means for rendering inoperative the wall of the madevice by which the impression cylinder is normally The hand lever 12 armed. 4.

amount that its roller 14 engages the periphery of cam 5 and on rotation thereof rides on said cam. When the cam part of disc 5 which rotates in the direction of the arrow lifts the roller 14, the lever 9 is turned or swung in a clockwise direction and the slotted rod or bar 26 is moved to the left. The spring 27 turns the lever 28 in a clockwise direction until the pin 29 strikes against the end of the slot 30. In this position the device for lowering the impression cylinder (not shown) which is connected with the lever 28 is in its operative condition, so that the impression cylinder can be lowered towards the printing form. On the other hand, when the roller 14 rides on the cylindrical part of the cam disc 5, the spring 17 will swing lever 9 in an anticlockwise direction and the slotted bar 26 is drawn to the right and to gether with it the pin 29 on lever 28 which now disconnects the cylinder lowering device (not shown) so that the impression cylinder is not lowered towards the form. When the cam disc rotates at half the number of revolutions, the impression cylinder will not be lowered with every second revolution as in case of a two revolution press, but only with every fourth revolution.

It will be understood that where the impression cylinder is lowered for printing only with every fourth revolution, a printing sheet must also be fed with every fourth revolution only. Accordingly, the suction grippers of the feeding device have to be periodically put out of operation. This is achieved in a very simple manner by controlling a shut-off device in the suction air duct leading to the suction grippers of the feeding device. This control system is shown in Fig. 4. The lever 11 on shaft 8 is acted upon by a spring 31 for engagement of its roller 16 with cam 7, thereby moving bar 32 to the right. This bar 32 is connected, through a lever 33, with a shut-off device, for instance, a cock or slide valve, in the suction duct at 34 leading to the suction grippers of the feeding device. On the other hand, when roller 16 rides on the cam circle of disc 7, the lever 11 is swung in a clockwise direction and the bar 32 is shifted to the left to such an extent that the lever 33 turns the shut-off device in suction duct 34 into its open position. Accordingly, the suction grippers of the feeding device are connected only with every second operation and therefore will feed a sheet only with every second stroke.

Where the machine is provided with an automatic stop motion, stopping the machine when no printing sheet is fed, this stop motion also has to be neutralised when in case of double-inking the sheet feeding is intentionally put out of operation with every second stroke, so as to prevent the stop motion from automatically stopping the machine. The control device shown in Fig. 5 serves to perform this neutralizing function. In the position as shown the roller 15 rides on the cam part of the cam disc 6 and the roller 35 on lever engages the spring-urged push button 36 of switch 37 so that the conducting bridge 38 connects the two

terminal contacts

39 and 40 for the control circuit of the feelers of the stop motion (not shown). Now, when the stop motion is put in operation in case of non-arrival of a sheet, the control circuit is short-circuited and the machine is stopped. On the other hand, when the roller rides on the cylindrical part of the cam disc 6 against which it is pressed by the spring-urged push button 36,-the push button 36 is moved upwards to such an extent that the conducting bridge 38 is lifted off from the

contact

39 and 40 and the control circuit is interrupted. In this case the stop motion will not act to stop the machine even when owing to the neutralized feeding device no printing sheet is fed.

In case the machine is intended to operate with single inking, the three control functions areput out of operation. This is achieved in a simple manner by lifting the three

rollers

14, 15, and 16 from their

cam discs

5, 6, and 7 by such an amount that they do not even engage the cam parts thereof. The lifting of the

rollers

14, 15, and 16 is achieved by turning or swinging the

levers

9, 10 and 11 in a clockwise direction by means of the shaft 8, through hand lever 12. The pin 21 is removed from the bore in sleeve 22 by means of the hand lever and the lever is swung to the left until the pin 21 engages in the sleeve 23. With this rotation of shaft 8 in a clockwise direction the driving pin 24 abuts the stop pin on lever 9 and takes the same with it until the roller 14 is completely lifted off from the cam disc 5. This lifting of the

rollers

15 and 16 off

cam discs

6 and 7 is achieved by means of a lever 43 keyed to shaft 8, the pin 44 of this lever 43 pressing against the adjusting screws 45 and 46 at the ends of the levers 10 and 11 and turning the latter also in a clockwise direction until the

rollers

15 and 16 are entirely out of engagement with their

cam discs

6 and 7. The adjusting screws 45 and 46 serve for accurate adjustment of the lifting of

rollers

15 and 16 off the

cam discs

6 and 7.

When the control device according to the present invention is disconnected, the slotted bar 26 (Fig. 3) is disposed in its extreme left hand position and the lever 28 has no neutralizing function in regard to the lowering device of the impression cylinder. This device is then merely operated by its normal control, i. e., the impression cylinder is advanced towards the printing form with every second rotation of the impression cylinder. In the device for neutralizing the suction gripper as per Fig. 4 in a neutralized condition the bar 32 is also disposed in an extreme left hand position, so that the shut-off device in the suction duct 34 is open and the suction grippers act to feed a printing sheet with every gripper movement, i. c. with every second revolution of the impression cylinder. In the control device for the sheet control as per Fig. 5 the connecting contacts 39 and in a neutralized condition are continuously connected by the conducting bridge 38 so that the control circuit is closed by the feelers and the machine can be stopped when no sheet is fed.

It will be understood that it is also possible to neutralize periodically the function of other devices, such as, for instance, the control of the spraying device of the sheet delivery.

While the invention has been described in detail with respect to a now preferred example and embodiment of the invention it will be understood by those skilled in the art after understanding the invention that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefore, to cover all such changes and modifications in the appended claims.

What is claimed is:

1. A double inking control device for a printing press adapted for single and double inking operation and having means for intermittently lowering an impression cylinder into printing position, sheet feeding means for intermittently feeding sheets to be printed, stop-motion means for intermittently stopping said press upon failure of said sheet feeding means, and automatic control means for activating each said means in timed relation with the speed of said printing press, the combination which comprises a set of cams, means for driving said cams in timed relation with the speed of said press, a cam follower lever for each said cam, means connecting said levers with said automatic control means for interrupting the effect of said automatic control means on said cylinder lowering, sheet feeding and stop-motion means, and selector means for positioning said levers in operative engagement with said cams and maintaining said levers out of operative engagement with said cams.

2. Apparatus according to claim 1 in which said cams are mounted on a common shaft.

3. Apparatus according to claim 1 in which said cam follower levers are freely pivoted upon a common shaft for movement into and out of operative engagement with said cams and which includes means on said shaft for moving said levers out of operative engagement with said cams upon rotation of said shaft.

4. Apparatus according to claim 1 which includes means for urging said cam follower levers against said cams when said levers are positioned in operative engagement with said cams by said selector means.

5. In a printing press having cylinder lowering means, sheet feeding means and stop-motion means automatically activated for single inking operation, a double inking selector device for intermittently rendering ineffectual operation of all said means during double inking operation which comprises in combination a set of cams adapted to activate said device, means for driving said cams in timed relation with the speed of said press, a cam follower lever for each said cam, pivot means for mounting said levers in engagement with said cams effecting operation of said levers upon rotation of said cams, and selector means for moving said levers into operative engagement with said cams for double inking operation and out of engagement with said cams for single inking operation of said press.

6. Apparatus according to claim 5 in which said sheet feeding means is suction operated and which, includes means for producing suction for said sheet feeding means, a suction duct therefor, valve means in said duct for shutting off suction therein and means connecting one of said cam follower levers to said valve means for closing said valve means in one position of said lever.

7. Apparatus according to claim 5 in which said stopmotion means is electrically operated and which includes switch means for opening the electric circuit to said stopmotion means and means connecting one of said cam follower levers to said switch means effecting opening of said switch means in one position of said lever.

8. Apparatus according to claim 5 which includes mechanical linkage means connecting one of said cam follower levers to said cylinder lowering means for mechanically disengaging said lowering means in one position of said lever.

References Cited in the file of this patent UNITED STATES PATENTS Re. 4,084 Tucker Aug. 2, 1870 1,106,402 Pearce Aug. 11, 1914 1,106,403 Pearce Aug. 11, 1914 2,459,922 Crafts Ian. 25, 1949