US2997947A

US2997947A - Multiple rotary printing machine

Info

Publication number: US2997947A
Application number: US857637A
Authority: US
Inventors: Ritzerfeld Wilhelm; Ritzerfeld Gerhard
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-12-10
Filing date: 1959-12-07
Publication date: 1961-08-29
Anticipated expiration: 1978-08-29
Also published as: GB898123A; CH377384A; DE1149725B

Description

1961 w. RITZERFELD ET AL 2,997,947

MULTIPLE ROTARY PRINTING MACHINE 5 Sheets-Sheet 1 Filed Dec. 7, 1959 J vemolg. N Z1 W W N WS 9% in \II llllllllllllllllllllllll ll lllllllllllllllllllllllllll 510i Aug. 29, 1961 w. RITZERFELD ETAL 2,997,947

MULTIPLE ROTARY PRINTING MACHINE Filed Dec. '7. 1959 5 Sheets-Sheet 2 1961 w. RITZERFELD ET AL 2,997,947

MULTIPLE ROTARY PRINTING MACHINE Filed Dec. 7. 1959 5 Sheets-Sheet 3 Aug. 29, 1961 Filed Dec. 7. 1959 Fig. 4

W. RITZE RFELD ET AL MULTIPLE ROTARY PRINTING MACHINE 5 Sheets-Sheet 4 Jnvenfoa: mum/m r W (in; W s. m

1961 w. RITZERFELD ET AL 2,997,947

MULTIPLE ROTARY PRINTING MACHINE Filed Dec. '7, 1959 5 Sheets-Sheet 5 venfo 1;:

H wgzmz sa 46A 2,997,947 MULTIPLE ROTARY PRINTING MACHINE Wilhelm Ritzerfeld, Schorlemer Allee 14, Berlin-Dahlem,

Germany, and Gerhard Ritzerfeld, Franzensbader Str.

21, Berlin-Grunewald, Germany Filed Dec. 7, 1959, Ser. No. 857,637 Claims priority, application Germany Dec. 10, 1958 7 Claims. (Cl. 101-91) lected sections of the printing form, such as lines or columns. Such selective printing, however, is very desirable for printing order forms, bills, statements and similar forms.

It is one object of the present invention to improve lithographic printing machines of the type in which a negative printing form is inked and brought into contact with a copy sheet so that not only printing of the entire text, but also printing of selected lines and columns is possible.

Another object of the present invention is to provide a printing machine of this type in which two copy sheets are simultaneously printed to receive the complete text of the printing form, and selected sections of the printing form, respectively.

Another object of the present invention is to provide a printing machine capable of producing imprints of selected sections of a printing form adjacent each other on a copy sheet while at the same time another copy sheet is imprinted with a complete text of the printing form.

Another object of the present invention is to provide a lithographic printing machine with manually operated selector elements which can be operated to effect printing of selected portions of the printing form in adjacent positions on a copy sheet.

Another object of the present invention is to provide a lithographic printing machine in addition to the standard pressure roller, with another pressure roller cooperating with the printing roller along another printing line, so that two copy sheets can be simultaneously printed.

Another object of the present invention is to hold during a single revolution of the printing roller, one pressure roller in continuous contact with the printing form on the printing roller, and the other pressure roller only temporary rolling contact with the printing form.

With these objects in view, the present invention mainly resides in a rotary printing machine capable of simultaneous or selective printing of two copy sheets, one of which receives imprints of selected portions of the printing form, whereas the other copy sheet receives the entire text of the printing form.

One embodiment of the present invention comprises a printing roller, means for holding a negative printing form on the printing roller, a first pressure roller having a printing position cooperating with the printing roller along a first printing line, a second pressure roller, supporting means supporting the secbnd pressure roller for movement to and from a printing position defining a second printing line with the printing roller, and means for eifecting movement of the second pressure roller to and from said printing position repeatedly during each revolution of the printing roller.

When first copy sheets are supplied to the first printing 2,997,947. Patented Aug. 29., 1961 ice line, a complete imprint of the printing form is produced on the first copy sheets. When second copy sheets are supplied to the second printing line, and the second pressure roller is moved to and from its printing position, only selected sections of the printing form will be printed on the second copy sheets, and since the printing roller and the second pressure roller transport the second copy sheet only when in printing position, the imprints appear adjacent each other on the second copy sheets.

Preferably, a plurality of selector elements are provided which can be manually set to efiect movement of the second pressure roller to the printing position whenever a desired section of the printing form passes through the second printing line. In one embodiment of the present invention, the supporting means of the second pressure roller are actuated by electromagnetic means, and manually operable push buttons are connected to selector contacts which are successively engaged by a contact arm rotating in synchronism with the printing roller. Only selector contacts which are manually set by operation of the push buttons, are ettective to cause actuation of the electromagnetic means.

Another embodiment of the present invention employs mechanical means, such as selector earns for moving the second pressure roller to and from its printing position. The cams are exchangeable in accordance with desired selections, and are connected for rotation to the printing roller so that the movement of the second pressure roller to and from its printing position is placed in timed relation with the turning movement of the printing roller, and with the movement of the printing form through the second printing line.

In the preferred embodiment of the present invention, the first pressure roller on which a complete imprint is produced on a copy sheet, has substantially the same diameter as the printing roller, and includes holding means for holding the respective copy sheet on the peripheral surface thereof. In this manner, the copy sheet is not transported by the cooperating printing roller, and first pressure roller, but is fixedly attached to the first pressure roller during the printing operation.

The copy sheets for the second pressure roller are successively supplied to the bight between the second pressure roller, and the printing roller and printing form, and are gripped and transported by the cooperating rollers in the printing line. The desired exact position of the copy sheet is determined by a stop and by holding means which are operated when the actuating means for moving the second pressure roller to and from its printing position are manually started.

Since the second copy sheet is not secured to the second pressure roller, the diameter of the second pressure roller is substantially smaller than the diameter of the printing roller.

The electrical control of the second pressure roller requires contacts and switches which are supplied with low voltage. The electromagnetic means used in the arrangement of the present invention are preferably energized by high voltage.

In one embodiment of the present invention, the first and second pressure rollers are respectively arranged below and above the printing roller, and the first copy sheets are supplied from one side of the printing roller and delivered on the other side of the same, whereas the second copy sheets are supplied from the other side of the printing roller and delivered on the same side from which the first copy sheets are supplied.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be 3 best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a fragmentary schematic side view, partly in section, of a lithographic printing machine in accordance with one embodiment of the present invention;

FIG. 2 is a fragmentary side view illustrating a part of FIG. 2 on an enlarged scale and in greater detail;

FIG. 3 is a fragmentary schematic view of the embodiment of FIG. 1, mainly illustrating the electric circuits of the arrangement;

FIG. 4 is a developed schematic fragmentary plan view of the embodiment of FIG. 1; and

FIG. 5 is a fragmentary schematic side view of another embodiment of the present invention provided with cam means for actuating the pressure roller by which selective printing of desired sections of the printing form is effected.

Referring nowto the drawings, and more particularly to FIGS. 1, 2, 31and 4, a rotary printing roller '1 is mounted on a shaft 3, and is rotated by a motor, not shown. A printing form 2 is attached to the peripheral surface of the printing roller 1 by holding-or clamping means, shown in FIG. 3. The printing form carries a negative mirror script text which may contain a head portion, and a number of sections, such as lines,, which are located on corresponding peripheral surface sections of the printing roller 1.

The printing form 2 on the printing roller is inked by inking means including the

cylinders

8, 9, 10, 11, and the ink supplying means 12. The printing form is moistened by rollers 4, 5 and 6 which receive the liquid from the container 7. V

The first pressure roller 13 is covered with an elastic sheet 14, and mounted on a shaft 15. A

gear transmission

16, 17, 18 and '19 connects the pressure roller 13 with the printing roller 1 for rotation in timed relation. Pressure roller 13 has clamping or holding means 23 for gripping the leading edge of a copy sheet which is supplied from a stack of sheets 23. Feeding means'22 feed the uppermost copy sheet 21'into engagement with a stop 24 so that the position of the copy sheet is exactly determined. When the copy sheet 21 is in the correct position, stop 24 is automatically withdrawn, and the transporting rollers 25 and 26 move into a transporting position for transporting copy sheet 21 at a suitable speed toward the clamping means 20 of the pressure roller 13. These operations are performed in timed relation, since transmission means, not shown, connect one of the gears 16 to 19 to operating means for stop 24 and for transporting rollers 25 and 26. This arrangement, however, is not an object of the present invention.

Since the operations are timed, clamping means 20 passes the copy sheet in the moment in which it is supplied, so that clamping means 20 grips the leading edge of the copy sheet when clamping means 20 is opened and closed by the stationary cam 27 during rotation of pressure roller 13. In this manner, the copy sheet is wrapped around the peripheral surface of the pressure roller 13 and moves with the same through the printing line A-B between the printing roller 1 and the pressure roller 13.

The shaft end portions 15 are mounted in movable supporting means which'move pressure roller 13 to a printing position in which the copy sheet on the peripheral surface of the pressure roller 13 is in contact with the printing'form. 2 along the printing line A-B. After a single revolution of the printing roller has been completed, pressure roller 13 is again retracted in the conventional manner.

Consequently, the above described arrangement corresponds to a lithographic machine for printing the entire text of the printing form as a positive imprint on a copy sheet mounted on pressure roller 13.

In accordance with the present invention, additional apparatus is provided for printing selected sections of the same printing form on another copy sheet. A second printing roller 29 is turnably mounted on shaft 30 which is supported in movable supporting means 31 shown to be a pair of levers 31 which are fixed to a shaft 32. Shaft 32 is turnable in the frame of the machine, and consequently pressure roller 29 is moved toward and away from printing roller 1 and aprinting form 2 thereon, whenever movable supporting means 31 are turned about the axis of shaft means 32. 7

As best seen in FIGS. 2 and 4, a gear 37 having teeth of special shape is secured to shaft 30 and rotates with pressure roller 29. A corresponding gear 38 is fixed on the shaft 3 of printing roller 1, and meshes with gear 37. The tooth shape of

gears

37 and 38 is such that the

rollers

29 and 2 are connected for synchronous rotation even if the pressure roller 29 is retracted from its printing position by actuation of the movable supporting means 31. A fixed stationary'stop 39 limits the movement of the movable supporting means so that gears 37 and 38 can never be separated.

Electromagnetic means 36 is connected by a

linkage

34, 35 to a pin means 33 at the free end of levers 31. Spring means 131 tend to retract pressure roller 29, but as long as electromagnetic means 36 is energized, pressure roller 29, will assume a printing position cooperating with the printing form 2 and with printing roller 1 along a second printing line. A table 52 is arranged in a sub stantially horizontal plane, and other copy sheets 51 are supplied to table 52 while pressure roller 29 is retracted, and in order to determine the exact position of copy sheets 51, a stop means 53 is provided at the end of table 52 and engages the leading edge of copy sheet 51.

Stop 53 is connected to an articulated

lever system

56, 57 which is operated by an electromagnetic means 55. A spring 60 tends to move stop 53 into a position retracted from table 52 and permitting passage of copy sheets. A holding means 58 is turnably mounted on

levers

56, 57 and is urged by a spring 59 to a position engaging a copy sheet 51 on table 52. In the position illustrated in FIG. 2, the electromagnetic means 55 is energized, and holding means 58 is retracted, while stop 53 is in its operative position. In this position, a copy sheet 52 is supplied between the printing roller 1 and the pressure roller 29. Table 52 has a cutout 68 in the region of the printing line between the

roller

2 and 29, and therefore pressure roller 29 can move to its printing position when actuated by electromagnetic means 36.

FIG. 3 illustrates an electric circuit and electrical control means for operating the

electromagnetic means

55 and 36. Aset of contacts K1 to K19, and elongated contact 65 are mounted on a stationary insulating plate 61. A shaft 43 passes through the center of the circular plate 61, and carries fixed thereon a coupling disc 42 which rotates with shaft 43. Shaft 43 is connected by gears 41, 40 and 16 to the shaft 3 of the printing roller so that coupling disc 42 rotates in timed relation with printing roller 1. Coupling disc 42 has a notch cooperating with a. pawl 45 which is turnable on a pin 46 secured to a contact arm member 44 which is freely turnable on shaft 43. A spring 47 urges coupling pawl 45 into a position engaging the circular periphery of coupling disc 42. Such movement, however, is normally blocked by a manually operated stop member 48 which is held by spring 50 in a position blocking turning movement of pawl 45 under action of spring 47. 7

When member 48 is manually actuated, it releases coupling pawl 45 which will engage the peripheral surface of disc 42 under the action of spring 47,and slide on the same until it snaps into the notch 142 in coupling disc 42. In this coupling position, pawl 45 is taken along by coupling disc 42, and since pawl 45 is mounted on the contact arm member 44, contact member turns with shaft 43 and coupling disc 42, and consequently in synchronisrn. with the printing roller 1. Moreover, the relative posi- .tion of the contact 63 on contact arm member 44 with respect to the printing form 2 is exactly determined by the notch 142.

During rotation of the contact arm 44, contact 63 will successively engage the contacts K1 to K19, and will finally pass over the long arcuate contact 65. After a single revolution, the free end of stop member 48 will engage the end of coupling lever 45 and will turn the same into the illustrated position releasing coupling disc 42 so that the contact arm 44 stops in its initial position.

Each contact K1 to K19 is connected to a manually operated switch, so that nineteen switches are provided, of which only five switches T1 to T 5 are shown.

A slip ring 144 is connected to contact arm 44 for rotation, and a slide contact 244 is in sliding engagement with slip ring 144 which is connected to contact 63.

Switches T1, T2, etc. and also contact 65 are connected to an electrical control apparatus 62, and the circuit is closed by a line connecting control apparatus 62 with slide contact 244.

Power is supplied to a transformer and rectifier apparatus 64 which is connected to control apparatus 62 and to electromagnetic means 36. The control apparatus 62 distributes low voltage to the contact arrangement 44, 61, and high voltage to the electromagnetic means 36.

The manually operated member 48 cooperates with a switch 54 which is connected into the circuit of electromagnetic means 55 by which a holding means 58 and a stop 53 is operated, as described with reference to FIG. 2.

The apparatus illustrated in FIGS. 1 to 4, operates in the following manner: A copy sheet 51 is placed on table 52 in a position engaging stop 53, while pressure roller 29 is retracted from its printing position by a spring 231. The manually operated member 48 is depressed against the action of spring 50, and opens switch 54 so that the electromagnetic means 55 is tie-energized, permitting spring 60 to withdraw stop 53 to release the leading edge of copy sheet 51, and permitting spring 59 to pull the holding means 58 into a position frictionally engaging Copy sheet 51.

At the same time, the free end of manually operated member 48 releases pawl 45 which is turned by spring 47 and moves to a coupling position engaging notch 142 in coupling disc 42. In this manner, contact arm 44 is coupled to shaft 43 for rotation in an exactly determined relative position to the printing form 2 on printing roller 16, and contact arm 44 starts rotating in timed relation with printing roller 1. Consequently the sections of the printing form 2 successively pass through the printing line between pressure roller 29 and printing roller 1. Contacts K1 to K19 are associated with such sections of the printing form, which are either lines or columns. The contacts K1 to K19 and the switches T1 to T19 constitute selector elements which are respectively associated with sections of the printing form. Any desired section can be selected for printing by rendering the respective selector elements operative. For example, to print the first, third and fifth sections of the printing form, the corresponding associated push buttons T1, T3 and T5 are depressed, so that the corresponding contacts K1, K3 and K5 are connected into the circuit of electromagnetic means 36 through electric control apparatus 62. When contact arm 44 passes a connected contact, a current will flow through contact 63 on the contact arm 44, slip ring 144, slide contact 244, apparatus 62, and through electromagnetic means 36 so that the same will attract its armature, and will turn through

linkage

34, 35, the movtracted, and since copy sheet 51 is not transported by

rollers

29 and 1 in the retracted position of pressure roller 29, copy sheet 51 remains stationary and is held by holding means 58 while the undesired second section of printing form 2 passes through the printing line without producing an imprint on the copy sheet.

When contact 63 on contact arm 44 engages the operative connected selector contact K3, another impulse passes through electromagnetic means 36, and pressure roller 29 again moved to its printing position, produces animprint of the third section of the printing form of the copy sheet, while transporting the copy sheet. When contact K3 is passed by contact 63, spring 131 retracts the pressure roller 29, and no imprint is produced by the fourth section of the printing form. This operation is continued, and since clamping means 58 holds the copy sheet stationary while pressure roller 29 is retracted and undesired sections of the printing form pass through the printing line, the desired and selected sections of the printing form are printed on copy sheet 51 in adjacent positions.

After contact 63 on contact arm 44 have passed over all selector contacts K1 to K19, contact 63 engages the longer contact 65 eifecting movement of the pressure roller 29 into rolling engagement With printing roller 1 along the printing line. However, since the printing form 2 has already passed through the printing line at this moment, no imprint is produced on the copy sheet 51, but the same is transported and finally ejected to drop into a receiving container 66 located on the right side of printing roller 1 as Viewed in FIG. 1.

After printing roller 1 has completed a single revolution, the end portion of pawl 45 is engaged by the free end of member 48 which has returned to its initial position under the action of spring 50. Engagement between pawl 45 and member 48 effects retraction of pawl 45 from the notch 142 and the coupling between the contact arm 44 and shaft 43- is disconnected so that contact arm 44 stops since it is no longer driven from shaft 3. Arm 67 of contact arm 44 restores switch 54 to its initial position so that stop 53 returns to its illustrated position, and clamping means 58 is again retracted since electromagnetic means 55 is energized through switch 54. During each revolution of printing roller 1, pressure roller 13 also performs a revolution, and the entire text of the printing form may be simultaneously printed on a copy sheet 21. At the moment in which clamping means 20 passes the copy sheet transported by supporting rollers 25 and 26, cam 27 closes clamping means 20, the copy sheet 21 is gripped, and pulled through the printing line A-B. Before the copy sheet passes through the printing line, and after the holding means 20 have passed through the printing line AB, pressure roller 13 is moved by conventional apparatus into a position engaging the printing form 2 on printing roller 1. After the printing form 2 has produced a complete imprint on the copy sheet held on the peripheral surface of pressure roller 13, stationary cam 27 against becomes operative by engaging-clamping means 20, so that clamping means 20 release the copy sheet which is deposited in the receiving means 28 located on the left side of the printing roller and of pressure roller 13, as viewed in FIG. 1. As is best seen from Fig. 1, copy sheets 51 and 21 are supplied from opposite sides of the printing roller, and are deposited on opposite sides of the printing roller in receiving means 28 and 66. This arrangement is particularly convenient, and is obtained by placing pressure roller 13 below the printing roller 1, and pressure roller 29 above printing roller 1.

In order to obtain the accurate imprint of the printing form on the copy sheet mounted on the peripheral surface of pressure roller 13, pressure roller 13 has substantially the same diameter as the printing roller 1. In contrast, pressure roller 29 has a substantially smaller diameter than printing roller 1, which facilitates its frequent movement, and has no detrimental eifect since the copy sheet 1 is transported by rollers 29 and 1 'at a by low voltage, and the electromagnetic means are controlled by a' higher voltage, which is obtained from rectifiers and transformers in

electric apparatus

62 and 64.

In the embodiment described with reference to FIGS. 1 to 4, the selector elements are contacts, and the actuating means for the supporting means 31 of pressure roller 29 is an electromagnetic means 36. In the embodiment of FIG. 5, mechanical means are provided for actuating the pressure roller 29. The means for supplying copy sheets to printing roller 3 and pressure roller 13, and the means for supplying other copy sheets to the printing roller 1 and the pressure roller 29 are not illustrated in FIG. 5 and correspond to the apparatus disclosed with reference to FIGS. 1 to 4. The shaft 3 ofprintingroller 1 is synchronized with pressure roller 29' as described with reference to FIG. 2, and printing roller 1 is connected by

gears

16, 17, 18 and 19 for rotation in timed relation with pressure roller 13. Pressure roller 29 is mounted on movable supporting means 76 which include a pair of anns and a shaft 32 mounted in the frame *of the machine. Cam follower rollers .74 and 75 are turnably mounted on the free ends of lever 76 and cooperate, respectively with. two rotary cams 68 and 69. Cam 68 has a longer cam lug corresponding "to ahead section of the printing form, and cam lug 69 is shorter corresponding to a line section of the printing form.

The cams are mounted on a shaft 77 which is driven from printing roller 1 through a

gear train

16, 70,71, 72 and 73. As described with reference to FIG. 3, a coupling disc 42 rotates with shaft 77, and acoupling pawl 45 is operated by. a manually actuated member 48 to couple cams 69, 68. at the proper moment to shaft 77. In this manner, cams 68 and 69 rotate in synchronism with the printing roller 1. Only one cam 69 is shown, but it will be understood that a plurality of such cams '69 can be provided. Cam .69 is axially shiftable into an inoperative position, and is.'also turnable about shaft 77 so that by placing of the cam lug of cam 69 in adesired circumferential position, the moment of actuation of movable supporting means 76 and of pressure roller 29 can be determined. it several cams 69 are provided, several selected sections of the printing form 2 will be printed on the copy sheet supplied to the printing line between the printing forml. and the pressure roller 29, as described with reference to the embodiment of FIGS.

For example, if the headsection of the. printing form and the first, the third, and the fifth line section of the text are to be printed, corresponding cams are placed on shaft 77 inan operative position engaging cam follower roller '74, and the cam lugs are spaced in circumferential direction corresponding to the spacing of the selected section of the printing forrn. Wh'enthe machine is star-ted, cam

:cam lug of the first cam 69 engagesthe cam follower roller 74 and moves pressure roller 29 to printing position, After thisoperation, spring 131 again retracts pressure roller 29, so that the undesired second portion of the printing form passes throughthe printing line, while cop-y sheet 51 is held stationary by clamping means 58 as described with reference to FIGS. 1 and 2. 7

During printing of selected sections under the control of pressure -roller 29, another copy sheet can be heldby clamping means 26 on the pressure roller 13,-and receive a complete imprint or the'text of printing form '2.

I t will be understood that each 'of the elements described above, or two or more together, may also fin'd'a useful application inother types of rotary printing machines difiering from the types described above.

While the invention has been illustrated and described as embodied in a multiple rotary printing machine provided With two pressure rollers for simultaneous printing of selected sections, and of the entire text, 'of a printing form, it is not intended to be limited to'the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by app-lying current knowledge readily adapt it for various applications without omit-ting features that, from "the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adapations should and are intended to be comprehended Within the meaniiig and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. Rotary printing machine comprising, in combination, a printing roller, and means for holding a negative printing form on the peripheral surface of said printing roller; a first pressure roller having a printing position cooperating with said printing roller along a first printing line so that a copy sheet passing through said first printing line receives a complete positive imprint of said printing form during one revolution of said printing roller;

means for supplying copy sheets to said first pressure roller; means for depositing imprinted copy sheets after the same have passed through said first printing line; receiving means located on one side of said first pressure roller and of said printing roller for receiving deposited copy sheets; a second pressure roller, said pressure rollers being respectively, located above and below said printing roller; supporting means supporting said second pressure roller for movement to and from a printing position defining a second printing line with said printing roller; means located on said one side of said printing roller for supplying other copy sheets to said second printing line so that another copy sheet supplied to said'second printing line is gripped and transported between said second pressure roller and the printing form and receives a positive imprint only when said second pressure roller is in said printing position; other receiving means located on the other side of said printing roller for receiving the other copy sheets after the same have passed through the printing line; and means for effecting movement of said second pressure roller to and from said printingpposition and including a member rotating in timed relation with said printing roller and a plurality of selector elements respectively associated with diiferent sections of the peripheral surface of said printing roller and thereby with corresponding sections of a printing form supported on said peripheral surface, each selector element being operable between an operative positionand inoperative position, and causing in said operative position movement of said second pressure roller to and from said printing position for printing on the second copy sheet only selected sections of the printing form associated with operative selector elements.

2. A printing machine as set forth in claim 1 wherein said second pressure roller is located above said printing rollerpand wherein said first pressure roller is located below said printing roller. a

3. A printing machine as set forth in claim 2 and including a table extending between said printing roller and said second pressure roller for supporting the other copy sheets, said table having a cutout in the region of said printing line permitting passage of a portion of said secondpressure roller when the same moves to and from said printing position.

4. A printing machine as set forth in claim 3 and including a stop for engaging the leading edge of a copy sheet on said table to determine the position of supplied copy sheets; electromagnetic means operatively connected to said stop for moving the same between an operative position and an inoperative position; a switch connected into the circuit of said electromagnetic means; and manually operated means for actuating said switch at the start of each revolution of said printing roller.

5. A printing machine as set forth in claim 4 and including clamping means movable to a clamping position for holding a copy sheet on said table, and being operatively connected to said electromagnetic means to release the copy sheet when said stop is in said operative position.

6. Rotary printing machine comprising, in combination, a printing roller, and means for holding a negative printing form on the peripheral surface of said printing roller; a first pressure roller having a printing position cooperating with said printing roller along a first printing line so that a copy sheet passing through said first printing line receives a complete positive imprint of said printing form during one revolution of said printing roller; a second pressure roller; supporting means supporting said second pressure roller for movement to and from a printing position defining a second printing line with said printing roller so that another copy sheet supplied to said second printing line is gripped and transported between said second pressure roller and the printing form and receives a positive imprint only when said second pressure roller is in said printing position; a table for supporting other copy sheets; a movable clamping means movable to a clamping position for holding a copy sheet on said table; a stop movable to and from a blocking position for engaging the leading edge of a copy sheet on said table, said stop and said clamping means being located on opposite sides of said second pressure roller; an electromagnetic element for simultaneously effecting movement of said clamping means to said clamping position and movement of said stop out of said blocking position; actuating means connected to said supporting means for moving said second pressure roller to and from said printing position; control means operatively connected to said actuating means and including a rotary member; manually operated coupling means for coupling said rotary member to said printing roller for rotation in timed relation when a selected portion of said printing roller passes through said second printing line; a switch connected into the circuit of said electromagnetic element, said switch being operatively connected to said coupling means to actuate said electromagnetic element when said coupling means is moved to coupling position; and a plurality of selector elements manually settable between an operative position and an inoperative position, said selector elements being respectively associated with diiierent sections of the peripheral surface of said printing roller and thereby with corresponding sections of a printing form supported on said peripheral surface of said printing roller, said selector elements successfully cooperating with said rotary member during rotation of the same and causing movement of said second pressure roller to and from said printing position whenever a selector element in operative position is engaged by said rotary member whereby on the second copy sheet only selected sections of the printprinted.

7. Rotary printing machine comprising, in combination, a printing roller, and means for holding a negative printing form on the peripheral surface of said printing roller; a first pressure roller having substantially the same diameter as said printing roller and having a printing position cooperating with said printing roller along a first printing line so that a copy sheet passing through said first printing line receives a complete positive imprint of said printing form during one revolution of said printing roller; holding means on said first pressure roller adapted to hold the leading edge of a copy sheet for attaching the copy sheet to the periphery of said first pressure roller; 2. second pressure roller having a diameter substantially smaller than the diameter of said printing roller; supporting means supporting said second pressure roller for movement to and from a print-ing position defining a second printing line with said printing roller; means for supplying other copy sheets to said second printing line so that another copy sheet supplied to said second printing line is gripped and transported between said second pressure roller and the printing form and receives a positive imprint only when said second pressure roller is in said printing position; a table for supporting other copy sheets; a movable clamping means movable to a clamping position for holding a copy sheet on said table; a stop movable to and from a blocking position for engaging the leading edge of a copy sheet on said table, said stop and said clamping means being located on opposite sides of said second pressure roller; an electromagnetic element for simultaneously efi'ecting movement of said clamping means to said clamping position and movement of said stop out of said blocking position actuating means including electromagnetic shiiting means connected to said supporting means for moving said second pressure roller to and from said printing position; control means operatively connected to said actuating means and including a rotary contact arm member; manually operated coupling means for coupling said rotary contact arm member to said printing roller for rotation in timed relation when a selected portion of said printing roller pass through said second printing line; a switch connected into the circuit of said electromagnetic element, said switch being operatively connected to said coupling means to actuate said electromagnetic element when said coupling means is moved to coupling position; and a plurality of selector elements, each element including a selector contact and a push button for connecting said contact into the circuit of said electromagnetic means, said selector elements being respectively associated with different sections of the peripheral surface of said printing roller and thereby with corresponding sections of a printing form supported on said peripheral surface of said printing roller, said selector contacts successively cooperating with said rotary contact ann member during rotation of the same and causing movement of said second pressure roller to and from said printing position whenever a selector contact connected into said circuit is engaged by said rotary contact arm member whereby on the second copy sheet only selected sections or the printing form associated with operative selector elements are printed.

References Cited in the file of this patent UNITED STATES PATENTS 2,753,791 Thurmann July 10, 1956 2,787,212 Delplanque Apr. 2, 1957 2,843,039 Ritzerfeld July 15, 1958