US3049076A

US3049076A - Rotary lithographic multicolor printing machine

Info

Publication number: US3049076A
Application number: US853541A
Authority: US
Inventors: Ritzerfeld Wilhelm; Ritzerfeld Gerhard
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-11-18
Filing date: 1959-11-17
Publication date: 1962-08-14
Anticipated expiration: 1979-08-14

Description

Aug. 14, 1962 w. RITZERFELD ETAL 3,049,076

ROTARY LITHOGRAPHIC MULTICOLOR PRINTING MACHINE 7 Sheets-Sheet 1 Filed Nov. 17, 1959 Q Q Q mm 8 G a Q N C Jpvemoni Aug. 14, 1962 w. RITZERFELD ETAL 3,049,076

ROTARY LITHOGRAPHIC MULTICOLOR PRINTING MACHINE 7 Sheets-Sheet 2 Filed Nov. 17, 1959 x a a a R Nm mm Jnven/or;

Aug. 14, 1962 w. RITZERFELD ETAL 3,049,076

ROTARY LITHOGRAPHIC MULTICOLOR PRINTING MACHINE 7 Sheets-Sheet 3 Filed NOV. 17, 1959 we L? 6 Q Q G a 0 fi km 9% RN .3 Q Q a a N m Jnzenforz: mum/M Wsm 4, 1962 w. RITZERFELD ETAL 3,049,076

ROTARY LITHOGRAPHIC MULTICOLOR PRINTING MACHINE 7 Sheets-Sheet 4 Filed Nov. 17 1959 4, 1962 w. RITZERFELD ETAL 3,049,076

ROTARY LITHOGRAPHIC MULTICOLOR PRINTING MACHINE Filed Nov. 1'7, 1959 7 Sheets-Sheet 5 Jnvenfon: Maid/M Ljr We/S Aug. 14, 1962 w. RITZERFELD ETAL 3,049,076

ROTARY LITHOGRAPHIC MULTICOLOR PRINTING MACHINE 7 Sheets-Sheet 6 Filed Nov. 1'?

Jnvenfor:

Aug. 14, 1962 w. RITZERFELD ETAL 3,049,076

ROTARY LITHOGRAPHIC MULTICOLOR PRINTING MACHINE '7 Sheets-Sheet 7 Filed Nov. 17, 1959 llnited rates Patent 3,049,076 RUTARY MTHGGRAPHIC MULTICOLGR PRWTDJG MACl-HNE Wilhelm Ritzerield, Schorlemer Alice 14, Berlin-Dahlem,

Germany, and Gerhard liitzerfeld, Franzenshader Str.

21, Berlln-Grunewald, Germany lFiled Nov. 17, 1959, Ser. No. 853,541 Claims priority, application Germany Nov. 18, 195$ (Ilairns. (Cl. 101-137) The present invention relates to a printing machine, and more particularly to a lithographic printing machine having a rotary member for supporting a lithographic printing form for producing an imprint on a copy sheet.

Lithographic printing machines are known in which the copy sheets are transported by gripper chains, or run freely through the printing line formed by printing rolls.

The known machines of this type have the disadvantage that an exact registering of the copy sheets With the printing form can hardly be obtained, and that the copy sheets tend to stick to the printing form in such a manner that even strippers are incapable of obtaining a troublefree operation.

It is one object of the present invention to avoid the disadvantages of the printing machines of the prior art, and to provide a printing machine in which the copy sheet is held on a pressure roll in an exactly defined position.

A related object of the present invention is to provide a lithographic printing machine in which a copy sheet is fixedly attached to a pressure roll rotating in synchronism with a printing roll carrying the lithographic printing form.

Another object of the present invention is to provide holding means on the pressure roll which grip and hold the leading edge of the copy sheet.

Another object of the present invention is to interconnect the printing roll with the pressure roll for simultaneous rotation in such a manner that the printing form moves at the same speed as the copy sheet.

It is also an object of the present invention to produce the same speed of the printing form and of the copy sheet during passage through the printing line by rotating at least one of the rolls at a varying speed during each revolution, to compensate for a difference in diameter of the two cooperating rolls.

Another object of the present invention is to supply and remove copy sheets to and from the holding means, respectively during rotation of the pressure roller on which the holding means for the copy sheet are mounted.

A related object of the present invention is to move the means for supplying and for removing copy sheets at substantially the peripheral speed of the pressure roll and of the holding means for the copy sheet.

A further object of the present invention is to provide a lithographic printing machine in which a copy sheet may be provided with a reversed imprint on one side, and with a positive imprint on the other side.

it is yet an object of the present invention to provide a lithographic printing machine in which a plurality of printing rolls are provided for supporting a plurality of printing forms which successively produce superimposed imprints on a copy sheet firmly held on a rotating pressure roll which cooperates with the printing rolls along a plurality of printing lines.

With these objects in view, the present invention mainly consists in a printing machine such as a lithographic duplicating machine. One embodiment of the present invention comprises a rotary printing roll including means for holding a preferably lithographic printing form; a rotary pressure roll cooperating with the printing roll along a printing line; and holding means secured to the pressure roll for holding a copy sheet on the same in an exactly defined position. In this manner, the printing form produces an imprint on the copy sheet passing through the printing line, and the position of the imprint will be exactly determined With reference to the holding means, particularly if the same grip the leading edge of the copy sheet.

In one embodiment of the present invention, the pressure roll and the printing roll have substantially the same diameter, so that they may be connected for rotation at the same rotary speed. In another embodiment of the present invention the diameter of one of the rolls is smaller and in this event transmission means must be provided to connect the two rolls in such a. manner that the printing form and the copy sheet have the same peripheral speed during passage through the printing line, while the two rolls are rotated at different rotary speeds when parts of the rolls not supporting the printing form and the copy sheet, pass through the printing line. in one embodiment of the persent invention only a single printing roll for a single printing form is provided, but in accordance with other embodiments of the present invention two, or three printing rolls carrying printing forms are provided, all of which define printing lines with a single pressure roll carrying a single copy sheet in an exactly determined position. All rolls are connected by a suitable transmission means for rotation in timed relation.

Preferably, correspondingly synchronized copy sheet supply means supply single copy sheets to the holding means, which are operated by control cam means to grip supplied copy sheets during rotation of the pressure roll.

In a similar manner, depositing means for printed copy sheets are provided which move toward the pressure roll, and receive printed copy sheets from the same while the holding means are automatically released by the control cam means.

It is evident that the embodiment of the present invention in which a plurality of printing rolls carrying printing forms are provided can be advantageously used for producing a multi-colored imprint on the copy sheet, while such imprints are exactly superimposed on the copy sheet due to the fact that the copy sheet is rigidly connected to the pressure roll, and passes through the several printing lines in exactly the same position. On the other hand, a plurality of printing rolls with different printing forms can be used for printing two diiferent text portions on the same copy sheet, for example a letter head, and the reproduction of a typewritten text.

It will be noted that the provision of a single pressure roll carrying the copy sheet successively through different printing lines, is a considerable advantage over prior art constructions in which a pressure roll has to be provided for each printing roll and printing form.

The pritning roll has preferably a hard peripheral surface, while the peripheral surface of the pressure roll is preferably covered with an elastic, exchangeable sheet.

It is advantageous to provide in the machine of the present invention, a sensing means for sensing the position of supplied copy sheets, and to control the position of the pressure roll from the sensing means in such a manner that the pressure roll is retracted to an inoperative position if the supplied copy sheet is not properly positioned.

For certain purposes it is desired to produce a reversed imprint on one side of the copy sheet, and a positive imprint on the other side of the copy sheet. A modified embodiment of the present invention accomplishes this result by supplying copy sheets to the holding means on the pressure roll only during every other revolution of the pressure roll. During the revolutions of the pressure rolls where the same carries no copy sheet, an imprint is produced on the elastic sheet covering the pressure roll, and when during the next following revolution of the pressure roll, a copy sheet is attached to the pressure roll, the outside of the copy sheet receives a direct imaosaore .9 print from the printing form. while the inside of the copy sheet receives an imprint from the imprint previously produced on the elastic sheet. Such indirect imprint is, of course, again reversed.

A copy sheet imprinted in this manner has on one side a readable text, and on the other side the same text in mirror script, with the two imprints exactly superposed.

In this manner, reproduced printing forms with reversed imprints can be reproduced, which is of particular importance for printing forms of which only a small number exists. A printing form produced by a photographic process, or by a writing operation, can be reproduced as often as desired by the above explained operation of the machine of the present invention.

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 best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a schematic side view, partly in section, illustrating a rotary lithographic duplicator according to one embodiment of the present invention;

FIG. 2 is a fragmentary side view, partly in section, illustrating a modified embodiment of the present invention in which two printing rolls are provided;

FIG. 3 is a schematic side view, partly in section, illustrating a further embodiment of the present invention in which three printing rolls are provided;

FIG. 4 is a fragmentary schematic side view illustrating a transmission between a printing roll and a pressure roll having different diameters;

FIG. 5 is a fragmentary schematic and developed plan view of the machine illustrated in FIG. 1;

FIG. 6 is a fragmentary, schematic and developed plan view of the embodiment shown in FIG. 2; and

FIG. 7 is a schematic side view, partly in section, illustrating a modified embodiment of the present invention for producing imprints on both sides of a copy sheet.

Referring now to the drawings, and more particularly to FIGS. 1 and 5, a stack of copy sheets is located in a suitable magazine and loosened by small jets of air blown through a row of nozzles d. The uppermost sheet is lifted off the stack by suction means 2 and transported in the direction of the horizontal arrow to the left as viewed in FIG. 1 and into a position located on a positioning plate 7 and engaging with its leading edge a positioning member 6 in the position shown in chain lines in FIG. 1. Positioning member 6 is turnable about pivot means 24, see FIG. 5, and connected by a link 23 to another link 22 which is operated by the armature of an electromagnetic means 21. When electromagnetic means 271 is energized, positioning member 6 is raised and releases the leading edge of the uppermost copy sheet. While the copy sheet is held by the positioning member 6 on positioning plate 7, the leading edge of the copy sheet is sensed by a pair of photocells 8, which control the exhauster means, not shown, which provide suction in the suction member 2. The circuit of photocells 8 is also connected to the circuit of an electric motor it which is set by known means to perform a single revolution, whenever started. Consequently, motor 10 is started when the first copy sheet is properly positioned in a slightly bulging position while its front edge engages the positioning means 6 and 7.

The shaft of motor 10 carries a gear 11 meshing with a gear 12 which is fixed to a shaft 12a on which a pair of control earns 13 is mounted. A pressure roll is turnably mounted in the side walls 100 of the machine, and its shaft 71 is connected to a pair of arms 14 terminating in cam follower rollers cooperating with the pair of rotary cams 13 as best seen in FIG. 5. Due to the shape of cams 13, pressure roll 15 will drop away from the printing roll "16 as soon as motor 10 turns cams 13 in clockwise direction as viewed in FIG. 1. In this manner, printing roll 16 is separated from pressure roll 15 at the beginning of the operation in which no copy sheet is located in the printing line BC so that an undesired imprint on the uncovered surface of an elastic sheet 26 on pressure roll 15 is prevented.

During further rotation of cams 13, pressure roll 15 is again moved toward printing roll 16 and defines with the same a printing line.

A row of spring-loaded holding means is turnably mounted on the pressure roll 15. The holding means 30 tend to move to a clamping position for clamping a copy sheet on the peripheral surface of the pressure roll 15, but are prevented from moving to the gripping and clamping position by engagement with a stationary cam 29. When holding means 39 has passed stationary cam 2? during rotation of the pressure roll 15 in counterclockwise direction, holding means 30 move to the gripping and clamping position.

A printing form 19 is secured by clamping

means

17 and 18 to a cylindrical peripheral surface portion of printing roll 16.

Shift 35 of printing roll 16 carries a fixed gear 36 which is driven from a regulable main drive motor so that the printing roll 16 rotates at a selected speed. Gear 36 meshes with a gear 37 driving a gear 38 which is mounted on a movable support 40 and drives gear 39 which is fixed on shaft 7-1 of the pressure roll 15. Since gear 38 is movable with support 40, it remains in meshing engagement with gear 39 even if pressure roll 15 moves in accordance with the position of the rotary cam 13.

Gear 39 meshes with another gear 43 on shaft 44 which carries a disc 26. A resilient means 27 is secured at one end to disc 26 and at its other end to a U-shaped member 9 which is mounted on a pair of pivot pins 25 and 25a in the side walls 1% of the frame. Ducts 25b pass through pivot pin 25a and through the yoke of member 9, and terminate in small ports on the yoke intermediate recesses 9a.

When gear 43 rotates disc 26, the resilient member 27 will pass through a dead-center position located in a plane passing through the axis of shaft means 44 and then tend to contract again in a direction of turning movement of disc 26. Suction is applied by suitable means, not shown, to the duct 25b. The U-shaped memher 9 is movable from the position illustrated in FIG. 1 toward the positioning means 6 and into corresponding recesses of the same to apply suction to a copy sheet engaged and positioned by the positioning means 6 in the position illustrated in chain lines. When a copy sheet 1 is thus picked up by the member 9, it is moved toward the row of holding means 30, and consequently member 9 is a supply means for supplying copy sheets to the holding means 30. The rotary motion of member 26, and therefore the reciprocating motion of supply means 9 takes place in timed relation with the rotation of pressure roll 15 and gear 3'9, and consequently the holding means 3% will pass supply means 9 at the moment in which the same supplies a copy sheet 1 to the vicinity of the pressure roll and of the holding means 30. At the same moment, cam 2.? operates the holding means 30 to grip the supplied copy sheet, and to hold its leading edge firmly on the peripheral surface of the pressure roll 15 whereby the position of the held copy sheet is exactly determined in relation to the position of the printing form 1d due to the fact that printing roll 16 and pressure roll 15 are connected for synchronous rotation by the

gear train

36, 37, 33 and 3%.

Another gear 42 is driven through gear ll from gear 34, and is connected to the shaft means 33a to a U-shaped depositing member 33 which is formed with suction ducts 33b in the same manner as supply means 9. Since depositing means 33 is rotated in timed relation with the rotation of the copy sheet held by the holding means 30, it applies suction to the printed copy sheet at the moment in which holding means 3t! is operated by the cam 29 to release the copy sheet which is then transported to a receiving station 34 where it is released by the depositing means 33 when the suction in the same is termi nated.

A container 48 for a moistening liquid receives a roll 47 which transfers a liquid to roller 46 from which the liquid is transferred by roller 45 to the printing form to moisten the same.

A container 53 for a suitable ink is provided from which the ink is taken by a roller 52, and transferred through rollers 51, 5t) and 49 to the surface of the printing form 19.

The lithographic printing machine illustrated in FIGS. 1 and 5 operates in the following manner:

A copy sheet is lifted off the stack by the suction member 2, and transported toward the positioning means a which is in the position shown in broken lines. In this manner, the leading edge of the copy sheet is placed in a desired position parallel to the axis of the pressure roll, and a small bulge is formed about pins 5. Photocells 8 sense the leading edge of the copy sheet, and are operatively connected to the means producing a negative suction pressure in supply means 9 in such a manner that no suction is applied by the supply means 9 if the copy sheet is improperly positioned in the positioning means 6. At the same time, the photocells 8 provide an impulse for the start of the electric motor 19 which performs a single revolution.

Motor 1% drives cam 13 through gears 11 and 12, so that at the moment of the start of motor 10, cam follower lever 14 is released, and pressure roll 15 drops out of engagement with printing form 19 on printing roll 16. in this manner, an undesired printing on the elastic sheet 2% is prevented. The main drive motor, not shown, drives through gear 36 all rotary elements in synchronism with the printing roll 16. The printing form is moistened by roller 4-5, and inked by

rollers

49 and 50. Printing roll 16 and pressure roll 15 rotate in the directions of the arrows so that the inoperative parts of the periphery first pass through the printing line.

Eisc 26 turns, and supply means 9 is turned by resilient means 27 until supply means 9 abuts a fixed stop 31 in a position holding the copy sheet 1 in the region of the surface of the pressure roll 15. At the moment in which spring-loaded holding means 30 is released by the stationary cam 29, holding means 30 moves to a gripping position and grips the copy sheet held by supply means 9 to hold the copy sheet on the cylindrical surface of the pressure roll 15, and more particularly on the elastic sheet Zti.

As disc 26 continues its turning movement, resilient means 27 is stretched until it passes through the deadcenter position located in a plane passing through the axis of shaft 4 's. From there on, resilient means 27 contacts again, and further turning of disc 26 effects an angular movement of supply means 9 to a position engagin another fixed stop 32. In this position, the yoke of supply means 9 is located in corresponding recesses of the positioning means 5 which is in the position shown in chain lines, in which the suction ports of supply means 9 are located on a copy shet held in positioning means 6, 7, and move such copy sheet to the illustrated position in timed relation with the movement of the pressure roll 15 and the holding means 30. In the event that a sheet is improperly positioned in positioning means 6, 7, the photocells f8 prevent through suitable means, not shown, the application of suction to the copy sheet by supply means 9 so that no copy sheet can be supplied to the holding means 3b in an undesired position in which the imprint will not be properly located.

Before supplying means 9 moves from the sheet gripping position to the copy sheet supplying position, positioning means 6 must be raised by electromagnetic means 21 which is accomplished by a suitable rotary control cam closing a switch in the circuit of electromagnetic means 21.

Similarly, at the moment in which holding means 30 grips a sheet supplied by suction supply means 9, suction is disconnected from supply means 9 by a valve closed by a cam rotating in synchronism with the other rotary members. Directly after the holding means 30 pass through the printing line BC, th epressure roll 15 is shifted by cam 13 to its operative position, and the printing form 19 contacts the copy sheet held by holding means 34}, and produces an imprint thereon during further rotation of the pressure roll 15 and printing roll 19. When the printing operation has been completed, and the copy sheet has passed through the printing line, the cam 29 is again engaged by the holding means 30 which are opened and release the copy sheet. Depositing means 33, rotating in synchronism with the pressure roll 15, applies suction to the released copy sheet and carries the same in counterclockwise direction to a position located above the receiving table 34, and at this moment, a valve is closed by a cam so that no suction is applied by depositing means 33 to the transported copy sheet, which is conequently released, and drops onto the table 34.

The resilient means 27 has the effect to accelerate the motion of the supply means 9 with the transported copy sheet, so that copy sheet 1; is supplied to the holding means at the peripheral speed of the pressure roll 15 at which the holding means move. In this manner, a smooth transfer of the copy sheet from the supply means 9 to the moving pressure roll 15 is possible.

Referring now to the embodiment illustrated in FIG. 2 and FIG. 6, it will be seen that the embodiment of FIG. 2 mainly distinguishes from the embodiment of FIG. 1 by the provision of an additional printing roll 54 which carries a second printing form 57 held by clamping

means

55, 56. A gear 59 is fixedly secured to shaft 58 of the second printing roll 54, and is connected by a gear 6% to the gear as which is associated with the first printing roll 16. In this manner, a synchronous rotation of the two printing rolls, which have the same diameter, is assured. Moistening means 61, 62, 63, 64 and inking means 65, 66, 67, 68, 69 and 70 are provided for applying a film of moisture, and the ink to the second printing form 57.

The two printing rolls 16 and 54 define two printing lines BC, and D-E with the pressure roll 15 which has substantially the same diameter as the printing rolls 16 and 54.

As described with reference to FIG. 1, pressure roll 15 is movable, and in the embodiment of FIG. 2 in which two printlng rolls are provided, pressure roll 15 is guided by a guide means 150 for movement in a direction perpendicular to a plane passing through the axes of

shafts

35 and 58. Consequently, the peripheral surface of the pressure roll 15 will engage both printing rolls in the illustrated position, but when cam 13 is turned at the be ginning of the operation, pressure roll 15 will drop off both printing rolls and will be spaced from the same the same distance to prevent imprints on the elastic cover sheet 2%. Cam 13 is driven in the same manner as described with reference to FIG. 1. Motor 16 and gears 11, 12 are turned about the axis of shafts 71 as compared with the embodiment of FIG. 1.

In the modified embodiment of FIG. 2, a modified device is provided for supplying copy sheets to the holding means 30. A feeding means 2:: provided with rollers engaging the uppermost copy sheet 1 of the stack is reciprocated to move the copy sheet into a position between guide sheets 72, 73 and a pair of transporting

rollers

74, 75 against a stop 76 while rollers 74, '75 are still separated. In this position, copy sheet 1 is held in place by a member '77, and is sensed by photocells 3. If the tion will remain established although the shape of gear 107 is irregular. Directly after points b of the printing roll and of the pressure roll have passed through the printing line, the portion 107' becomes effective, and accelerates the rotation of pressure roll so that the points a of the peripheral surfaces of the pressure roll and printing roll again pass at the same time through the printing line.

FIG. 7 illustrates another modified embodiment of the present invention which in most respects corresponds to the embodiment described with reference to FIGS. 1 and 5. The arrangement of the pressure roll 15, the holding means 13 with cam 29, the printing roll 16 with inking and moistening means, and the suction supply means 9 cooperating with positioning means 6 is as described with reference to the embodiment of FIG. 1. Instead of suction feeding means 2 shown in FIG. 1, frictional feeding means 211 are provided Which will feed successive copy sheets 3 from a stack to the positioning means 6 when the same are in the position shown in chain lines in FIG. 7.

While in the other embodiments of the present invention, the feeding means are once operated for each revolution of the pressure roll to supply a copy sheet to the pressure roll during each revolution, the arrangement of FIG. 7 includes operating control means for the feeding means by which the feeding means 2a are operated only during every second revolution of pressure roll 15.

The printing roll 16 is driven by a main motor, not shown which can be continuously regulated, and drives through gear 36 all other rotary elements, and also the supply means 9 and the depositing means 33 in timed relation with the rotation of the printing roll 16.

A member 181 is articulated at 186 to the feeding means 2a, and is rigidly connected to a horizontal bar 181) which is slidably guided for rectilinear movement in guide means 133 and 184. A cam follower 182 is mounted at the end of bar 180 and is urged by a spring 185 into engagement with an eccentric cam 179 which is connected for rotation to a gear means 189 and is slidable on a shaft 190. Gear means 189 has teeth only along half of its periphery, while the remaining part of the periphery is smooth. The gear teeth of gear means 189 mesh with the gear 187 which turns with printing roll 16. The smooth peripheral portion of gear means 189 cooperates with the holding cam 183 which is secured to gear 187.

Since the radius of gear means 189 is twice as great as the radius of gear 187, the eccentric cam 179 will be turned to reciprocate bar 131) with feeding means 2a, so that the copy sheet will be supplied to the positioning means, and later on transferred to the pressure roll 15. During the following revolution of the printing roll 19, the feeding means 2a will not be operated, and no copy sheet will be fed.

The photocells 8 are connected for this operation, and are only effective when feeding means 2a supplies a copy sheet to the positioning means 6, 7. The embodiment illustrated in FIG. 7 operates in the following manner. Assuming that during a first revolution of the pressure roll 15 and of the printing roll 16, no copy sheet was supplied to the holding means 30, the elastic sheet on pressure roll 15 will contact the printing form 19 while passing through the printing line, and the mirror-script printing from 19 will produce a reversed, and consequently positive imprint on the elastic sheet 20. During the next revolution of the printing roll 19 and of the pressure roll 15, the gear portion 189 becomes effective, and a copy sheet is fed by the feeding means 2a first to the positioning means, and then from there by the supply means 9 to the holding means so that during the second revolution of the pressure roll, a copy sheet will be located on the previously imprinted elastic sheet 20 and pass through the printing line BC. Printing form 16 produces a positive imprint on the outer side of the copy sheet on pressure roll 15, while at the same time the inner surface of the copy sheet receives a negative reversed imprint of the 10 positive imprint previously made on the elastic sheet 29. In this manner, the copy sheet is imprinted on both sides, and this operation is particularly suited for producing new printing forms, since the imprint on the inside of the copy sheet is again in mirror-script corresponding to the originally used printing form 19.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of printing machines differing from the types described above.

While the invention has been illustrated and described as embodied in a lithographic printing machine in which the copy sheet is fixedly attached to a pressure roll, 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 applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

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

1. In a lithographic printing machine, in combination, at least one rotary printing roll means having an at least partly cylindrical peripheral surface and including means for holding a printing form on said surface; a rotary pressure roll means having an at least partly cylindrical surface cooperating with said peripheral surface of said printing roll means along a printing line; transmission means connecting said printing roll means and said pressure roll means for rotation in timed relation for effecting movement of said peripheral surfaces through the printing line at the same speed while the printing form passes the printing line; an imprint receiving sheet attached to said peripheral surface of said pressure roll means to pass through the printing line; holding means secured to said pressure roll means for gripping a copy sheet supplied to said pressure roll means and for holding the copy sheet on said peripheral surface of said pressure roll means; supply means for supplying single copy sheets to said pressure roll means and being passed by said holding means during rotation of said pressure roll means, said supply means including a supply member mounted for reciprocating angular movement about an axis and having a free end, suction means at said free end of said supply member, a rotary member connected to said transmission means for rotation about another axis in timed relation with said pressure roll means, and a resilient member connecting said supply member and said rotary member at points spaced from the axes of the same so that said resilient member passes through the plane defined by the axes of said rotary and supply members during rotation of said rotary member whereby movement of said supply member to the end positions thereof is accelerated; stationary control cam means for operating said holding means to perform a gripping motion when passing said free end of said supply member when the same is in one end position for gripping a supplied copy sheet; and operation control means including an eccentric cam means driven by said transmission means in synchronism with said roll means, feeding means for feeding single copy sheets from a stack to said supply member in the other end position, linkage means operatively connected to said feeding means and including a cam follower cooperating with said eccentric cam means for effecting feeding of a single copy sheet by said feeding means only during every second revolution of said pressure roll means so that copy sheets are gripped and held by said holding means only during every second revolution whereby during revolutions of said pressure roll means during which no copy sheet is supplied and held on the peripheral surface of the same, said imprint receiving sheet receives a reversed imprint of said printing form, Whereas during every second revolution of said pressure roll means, the copy sheet held by said holding means receives on the outer side thereof a reversed imprint of said printing form, and receives on the inner side thereof facing said sheet a right imprint of the printing form from the reversed imprint produced on said sheet during the preceding revolution of said pressure roll means.

2. In a lithographic printing machine, in combination, at least one rotary printing roll means having a peripheral surface including a cylindrical surface portion and a non-cylindrical surface portion, and including means for holding a lithographic printing form on said cylindrical surface portion; a rotary pressure roll means having a peripheral surface including a cylindrical surface portion and a non cylindrical surface portion, the radii of said cylindrical surface portion being different, said pressure roll means cooperating with said printing roll means along a printing line defined by said cylindrical surface portions; holding means secured to said pressure roll means for holding a copy sheet on said peripheral surface of the same so that the printing form produces an imprint on the copy sheet passing through the printing line; and transmission means connecting said printing roll means and said pressure roll means for rotation in timed relation and rotationally phased so that said cylindrical surface portions cooperate with each other when passing through said printing line, and so that said non-cylindrical surface portions pass simultaneously through said printing line, said transmission means including means for rotating one of said roll means at a different rotary speed when said cylindrical surface portions pass through said printing line than when said non-cylindrical surface portions pass through said printing line to compensate for the different diameters of said cylindrical surface portions so that said printing and pressure roll means complete one revolution in the same time With said cylindrical surface portions moving at the same peripheral speed, and said non-cylindrical surface portions moving at different peripheral speeds.

3. A lithographic printing machine as set forth in claim 2, wherein said transmission means is a gear train including a gear having a toothed portion with a greater radius, and another toothed portion with a smaller radius.

4. A machine as set forth in claim 2, wherein said cylindrical surface portion of said rotary pressure roll means has a greater radius than said cylindrical surface portion of said printing roll means; wherein said transmission means includes a train of meshing gears, one of said meshing gears being secured to said rotary pressure roll means for rotation therewith and having a toothed portion of greater diameter extending through an arc corresponding to the arc of said cylindrical surface portion of said pressure roll means, and a toothed portion of smaller radius extending through an arc corresponding to the arc of said non-cylindrical surface portion of said pressure roll means.

5. In a printing machine, in combination, at least one rotary printing roll means having means for holding a printing form thereon; a rotary pressure roll means cooperating with said printing roll means along a printing line, means connecting said printing roll means with said pressure roll means for rotation in timed relation; holding means secured to said pressure roll means for gripping and holding a copy sheet; supply means for supplying single copy sheets to said pressure roll means and being passed by said holding means during rotation of said pressure roll means, said supply means including a supply member mounted for reciprocating angular movement about an axis and having a free end, suction means at said free end of said supply member, a rotary member connected to said transmission means for rotating about another axis in timed relation with said pressure roller means, and a resilient member connecting said supply member and said rotary member at points spaced from the axes of the same so that said resilient member passes through the plane defined by the axes of said rotary member and said supply member during rotation of said rotary member whereby movement of said supply member to the end positions thereof is accelerated; stationary control cam means for operating said holding means to perform a gripping motion when passing said free end of said supply member when the same is in one end position thereof; and feeding means for feeding single copy sheets to said free end of said supply member when the same is in the other end position thereof.

References Cited in the tile of this patent UNITED STATES PATENTS 956,751 Barr May 3, 1910 1,086,722 Langston Feb. 10, 1914 1,123,455 Wood Jan. 5, 1915 1,779,310 Fischer Oct. 21, 1930 1,976,582 Schultz Oct. 9, 1934 2,072,235 Wormser Mar. 2, 1937 2,317,993 Harrold May 4, 1943 2,909,117 Crissy Oct. 20, 1959 2,911,907 Davidson Nov. 10, 1959