US2737109A

US2737109A - Inking means for rotary direct printing lithographic duplicators

Info

Publication number: US2737109A
Application number: US222405A
Authority: US
Inventors: James W Hertsch
Original assignee: Ditto Inc
Current assignee: Ditto Inc
Priority date: 1951-04-23
Filing date: 1951-04-23
Publication date: 1956-03-06
Anticipated expiration: 1973-03-06

Description

March 6, 1956 w. HERTSCH 2,737,109

INKING MEA FOR ROTARY DIREC RINTING LITHOGRAPHIC DUPLICATO Filed April 25, 1951 4 Sheets-Sheet 1 March 6, 1956 J. w. HERTSCH INKING MEANS FOR ROTARY DIRECT PRINTING LITHOGRAPHIC DUPLICATORS 4 Sheets-Sheet 2 Filed April 25, 1951 March 6, 1956 J. w. HERTSCH 2,737,109

INKING MEANS FOR ARY DIRECT PRINTING LITI-IOGRAP DUPLICATORS Filed April 23, 1951 4 Sheets-Sheet 3 FIE- E 152/3 72 for:

72177761; f/yerfs ck @yh g March 6, 1956 J. w. HERTSCH 2,737,109

INKING MEANS FOR ROTARY DIRECT PRINTING LITHOGRAPHIC DUPLICATORS Filed April 23, 1951 4 Sheets-Sheet 4 United States Patent INKING MEANS FOR ROTARY DIRECT PRINTING LITHOGRAPHIC DUPLICATORS James W. Hertsch, Evanston, Ill., assignor to Ditto Incorporated, Chicago, 11]., a corporation of West Virginia Application April 23, 1951, Serial No. 222,405

13 Claims. (Cl. 101-144) This invention relates to direct printing lithographic duplicators and, in particular, to one which is adapted for manual feeding.

An important characteristic of duplicators adapted for manual feeding is that the drum be rotated intermittently so as to provide a time interval during which the operator may position a copy sheet so that it will be fed into the printing couple in registration with the master sheet. Manual feed duplicators are particularly well adapted for ofiice work and so-called systems use in which the number of copies to be made in any given run is com paratively small.

It is an object of this invention to provide a lithographic duplicator in which the drum which carries the master sheet is intermittently rotated. One of the difliculties in adapting a lithographic duplicator for manual feeding is that of avoiding contact between the master sheet and the form rolls while the drum is stationary in home position without the use of costly throw-out mechanism. In this connection I have provided a segment type drum together with form rolls which are so positioned as to clear the segment when the drum is in home position.

A further object of this invention is to provide an improved manual feed lithographic duplicator which will operate without smudging, and in which slippage between the ink form roll and the master sheet is substantially eliminated.

Another object of this invention is to provide improved driving means for the ink form rollof a lithographic duplicator.

A still further object is to provide improved inking mechanism for a manual feeding lithograph duplicator which is operative to keep the ink distributed on the ink form roll when the drum is stationary in home position.

Further objects are to provide an improved direct printing lithographic duplicator having improved manual throw-out means of simplified construction, having simplified repellant applying means, and having a novel type of drum which permits copy sheets of varying sizes to be duplicated upon. 7

Other objects, features and advantages will become apparent as the description proceeds.

With reference now to the drawings in which like reference numerals designate like parts:

Fig. 1 is a diagrammatic representation of a preferred embodiment of my invention, showing the relationship of the parts when the drum is stationary in home position;

Fig. 2 is a view similar to Fig. 1, but showing the drum in a different position;

Fig. 3 is a diagrammatic representation illustrating the operation of the tripping mechanism.

Fig. 4 is a sectional elevation taken along line 44 of Fig. 7 showing the construction of the inking mechanism illustrated in Figs. 1 and 2.

Fig. 5 is a sectional elevation similar to Fig. 4 but taken along line 5-5 of Fig. 7;

Fig. 6 is a detailed view showing the manner in which the jump roll is mounted;

Fig. 7 is a plan view of the duplicator shown in Fig. 4;

Fig. 8 is a detailed section taken along line 8-8 of Fig. 7 showing the driving connection between the drum and the feed rolls;

Fig. 9 is a diagrammatic representation of a modified form of the invention; and

Fig. 10 is a diagrammatic representation of a-further modification.

In Figs. 1, 2 and 3 there is diagrammatically shown a duplicating machine comprising a drum 10, a pressure roll 11, a repellent form roll 12 and an ink form roll 13. The drum is provided with a raised surface portion in the form of a segment 14 which is adapted to underlie a master sheet, or that portion thereof which is to be duplicated. The

form rolls

12 and 13 are spaced from the axis of the drum 10 in such a manner that they will be engaged and driven by the segment 14, or by the master sheet which overlies the same, so that the repellent and ink may successively be applied to the master sheet. The pressure roll 11 is likewise spaced from the drum axis in a similar manner.

The drum 10 is intermittently driven by any suitable type of intermittent driving mechanism to the end that the drum will remain stationary to permit the positioning of a copy sheet.

In the present embodiment of this invention, the intermittent driving mechanism of the single cycle type; that is, a tripping mechanism is provided which, when actuated, drives the drum through only a single cycle and causes it to come to rest in a home position. Thus, the period during which the drum is stationary is of indefinite length, this period being terminated by actuation of the tripping mechanism after the operator has manually positioned the copy sheet preparatory to feeding the same.

As shown in the drawings, this mechanism consists of a continuously rotating disk 15 having a single tooth 16 which is adapted to engage a pawl 17 pivotally mounted on the drum 10 by means of a suitable pivot 18. Suitable spring means 31 are provided for biasing the pawl inwardly into the path of the tooth 16.

A trip lever 19, pivoted at 21 is provided with a stop face 20 which engages the pawl to cause disengagement of the pawl and the tooth 16. Simultaneously, the trip lever serves to stop the rotation of the drum in home position. The trip lever is provided with a trip bar 22 disposed in front of the drum so that the trip lever can be manually operated. A latch 32 on the trip lever prevents rebound of the drum.

A comparison of Figs. 1 and 3 indicates that when the drum is stationary, depression of the trip bar 22 will cause the trip lever 19 to swing clear of the pawl 17, thus permitting the later to drop into the path of the tooth 16 so that the drum will be rotated through a single cycle. This tripping mechanism is shown and described in greater detail in Hernlund Patent No. 2,117,165.

Disposed in front of the bite of the drum and the pressure roll is a pair of

feed rolls

23 and 24 which are driven from the drum by means of suitable intermittent driving mechanism, such as a mutilated gear, as shown in Morrison Patent No. 2,220,264, or such as an oscillating sector as shown in Marchev Patent No. 2,268,045. The leading edge of a copy sheet is positioned in the bite of the feed rolls by the operator when the feed rolls are stationary. When the trip bar 22 is depressed so as to initiate the cycle, the feed rolls commence to rotate and will grasp the leading edge of the copy sheet and feed it into the bite of the segment and the pressure roll, the timing being such that proper registration is secured.

The inking mechanism comprises a continuously driven fountain roll which is engaged by a fountain blade 25 adjustably mounted in a suitable support 27, shown in Fig. 5. One or more

intermediate rolls

28 and 29, are disposed between the fountain roll and the ink form roll 13 for the purpose of transferring ink from the fountain roll to the ink form roll. It will be observed that the surface of the intermediate roll 28 is spaced from the surface of the fountain roll 25, and connection between the two is effected by the provision of a third intermediate roll, referred to herein as jump roll 39. The jump roll 30 .is mounted for vertical movement in timed relationship with the rotation of the drum so that it will contact both the fountain roll 25 and the intermediate roll '28 at those times when the segment 14 is clear of the ink form roll 13. During this position of the parts, as shown in Fig. 1, ink is transferred from one roll to the other so that an ink coating of the proper thickness will be applied to the surface of the ink form roll. At the same time, all of the rolls, including the ink form roll 13, are being positively driven from the fountain roll 25, and the arrangement is such that the peripheral speed of the ink form roll is equal to the peripheral speed at which the segment is driven. After the cycle has been initiated and the leading edge of the segment is about to engage the ink form roll, the jump roll is elevated into the Fig. 2 position so that the intermediate rolls 28 and 2S and the ink form roll will be driven from the drum. Thus slipping and smudging are prevented, for the segment does not have to accelerate these rolls; they are rotating at the same peripheral speed at the time they are initially engaged and driven by the segment.

The inking mechanism 34 is shown in detaii in Figs 4-7 inclusive, in combination with other parts of the duplicator which is diagrammatically shown in Figs. 1-3.

The structural members of the duplicator include

side frames

35, 36,

plates

47 and 48 in which the various ink rolls are mounted, and a plate 44 which is disposed between plate 47 and side frame 35. Ail of the aforementioned plates and side frames are parallel to each other and are related by suitable spaces and transverse members not shown.

The inking mechanism is driven from a drive pinion 37 through

idlers

40, 41 and 42. Idler 42 engages a pinion 38 which is secured to the end of the shaft 39 of the fountain roll 25. The drive pinion 37 forms a part of or is connected to suitable continuously operating driving means not shown, such as an electric motor. Thus, the fountain roll may be continuously driven. The idler 4t) and a cam 43 which is secured thereto are rotatably mounted in the side frame and plate 4 2-. The

idlers

41 and 42 are mounted in a bracket 45 which is secured to the side frame, the bracket also serving to support the end of the fountain roll shaft 39 and to form a guard for the pinion 38.

The fountain roll 25 and the intermediate roll 28 are journaled in the

plates

47 and 48, as are the form rolls 12 and 13. The jump roll 30 and intermediate roll 2%! are mounted in the

plates

47 and 48 in a special manner.

As shown in Figs. 6 and 7, the opposite ends of the jump roll 39 are journaled in bearings 50.

The bearings are provided with notches 51 so that they may be received in slots 52 formed in the plates 4'7 and 43. Thus, the jump roll is mounted for vertical movement between the solid line position shown in Fig. 5 in which it contacts the

rolls

25 and 28 and the dotted line position in which it is out of contact with those rollers.

The jump roll is actuated by a rock shaft 53 journaled in

plates

47 and 48. An arm 5-ion the rock shaft carries a cam follower 55 which rides on the cam 43. A spring 56 extends between the arm 54 and a pin 57, mounted in plate 44, to urge the cam follower into engagement with the cam surface. The rock shaft is also provided with arms 58 and links 59 which provide a connection between the rock shaft and the bearings 50 of the jump roll. Springs 62 urge the bearings 50 and the jump roll downwardly.

In operation, rotation of the cam 43 will cause the jump roll to move up and down, thereby providing an intermittent driving connection for the rolls 2% 29 and 13, while at the same time serving to transfer ink thereto. The cam is provided with high portion 6d and a iow portion 61. The gearing is such that the cam rotates once for each revolution of the drum. The angular length of the high portion 60 corresponds to the angular length of the segment 1 whereas the angular length of the lower portion corresponds to the angular length of the remainder of the drum. The timing is such that during the time that the ink form roll 13 is engaged and driven by the segment 14, the jump roll will be in its elevated position. Thus, the rolls 2 5, 29 and 13 are at this time being driven by the segment. At other times during the revolution of the drum, the rolls 2%, 29 and 33 are being driven from the fountain roll 25, and the speed of the latter is such that the peripheral speed of the ink form roll 13 is substantially the same as the peripherai speed of the segment. Thus, the ink form roil is set into rotation prior to the time that it is engaged by the segment, and since it is rotating at the same peripheral speed, there will be no slippage or smudging of the characters on the segment.

When the drum is at rest in its home position, the ink roll 25 is being continuously driven, and the ink form roll 13 and other rolls will be intermittently driven. Thus, the ink is kept distributed on the various rolls preparatory to a subsequent printing operation. it will be observed that the disk 15 is provided with only a single tooth 16 sothat proper timing of the cam 43 and of the drum 10 may be maintained. As shown in Fig. 4, a gear 63 is secured to the drum shaft 64, the gear mashing with and being driven by drive pinion 37. The disk 15 is also secured to the drum shaft 64 so that the gear and the disk will rotate continuously, just as the fountain roll 25. The drum 10 is rotatably mounted on the drum shaft, and as pointed out heretofore, a driving connection is established between the drum and the drum shaft for a single revolution by the momentary depression of the trip bar 22.

The intermediate roll 29 is rotatably mounted on a stationary shaft 65. As shown in Fig. 4, the ends of shaft 65 are provided with depending vertically disposed slides 66 which are received in ways 67, the ways being mounted on the

plates

47 and 48. Thus, the intermediate roll 29 is vertically shiftable to permit operation of the throw-out. mechanism hereinafter mentioned. The roll 29 may be an oscillating roll, if desired. In such event, the stationary shaft 65 is provided with the usual thread which causes the roll to move back and forth axially, thus improving the distribution of the ink as it is transferred to the form roll.

The ink form roll 13 is rotatably mounted on an angularly adjustable shaft 68 which is mounted at its opposite ends in the

plates

47 and 48 by means of eccentric bushings 69 to which the shaft is secured. Thus, by rotating the shaft, the distance between the axes of the ink form roll and the drum may be regulated. A knob 70 is secured to one end of the shaft to facilitate this regulation. Thus, by turning the knob, the ink form roll may be thrown out of engagement with the segment; this is frequently done at the conclusion of a run when it is desired to remove excess ink from the master sheet. Springs 71 bear against the bushings 69 to provide a frictional engagement which prevents unintended rotation of the bushings.

The repellent form roll 12 is provided with similar throw-out means which includes a shaft 72, eccentric bushings 73, a knob 74 and springs 75.

The feed rolls 23 and 24 are driven from the drum by means of a gear which is secured to one end thereof by means of spacers 81 and screws 82. The gear 80 meshes with an idler pinion 83 which is mounted on a suitable pillar 84 projecting from the side frame 36. The idler pinion meshes with a pinion 85 which is secured to the upper feed roll 23. Suitable means, not shown, are provided for urging the lower feed roll 24 against the upper feed roll so that it may be driven thereby.

In order to permit continuous rotation of the drum, which may be desired at certain times, particularly when an automatic feeder is employed, an intermittent driving connection between the drum and feed rolls is provided. As shown in Fig. 8, the gear 80 is a mutilated gear which is provided with a dwell portion 86.

Segments

87 and 88 are secured to the gear adjacent the dwell portion. Segment 87 engages a locking disk 89 which is secured to the idler 83 which prevents the upper feed roll from rotation during the dwell period. The locking disk is provided with the usual flat or complemental surface 90 which is engaged by the arcuate surface of segment 87 for this purpose.

The segment 88 is disposed for cooperation with a roller 91 which is carried by the locking disk 89. The end portions of the segment 88 extend into the path of the roll and serve to initiate rotation of the locking disk and idler pinion, thus avoiding shock to the gear teeth.

The drum is provided with the usual means for bolding a master sheet. As shown in Fig. 4, this holding means may comprise a gripper 92 for gripping the leading edge of the master sheet and a tail clamp 93 having pins 94 which engage suitable perforations formed in the trailing edge of the master sheet. The tail clamp is mounted by means of springs 95 in the usual manner so that the master sheet may be maintained under tension.

The segment 14 may form anintegral part of the drum surface, or it may be a separate element which is secured thereto either permanently or detachably. In this connection, a series of interchangeable segments of dilferent sizes may be provided. Thus, it is possible to duplicate onto copy sheets of varying sizes, or to print on strips, tickets, shipping labels and the like without offsetting. Offsetting onto the pressure roll 11 is likely to occur if the copy sheet is smaller than that portion of the master sheet which overlies the segment. Thus, by the use of interchangeable segments, flexibility of operation is enhanced. The segments may be made of metal or of a flexible composition, such as rubber, the only requirement being that the segment be sufiiciently short so that it will clear the form rolls when the drum is stationary in its home position.

Suitable means, not shown, are provide for maintaining the pressure roll 11 out of engagement with the drum surface, as shown in Fig. 1; the pressure roll preferably being mounted for resilient engagement with the segment 14.

In operation, after a master sheet has been secured to the drum by means of the holding means 92 and 93 so that it overlies a segment of proper length, the motor or other driving means can be turned on. If the drum at this time is not in its home position, this being the Fig. 1 position, it will be rotated into this position and will then stop. At this time the inking mechanism is being continuously driven to maintain the ink distributed on the various rolls, the

rolls

28, 29 and 13 being intermittently rotated.

When it is desired to duplicate, a copy sheet is fed into the bite of feed rolls 23 and 24, the trip bar 22 is depressed, and the drum will then be rotated through a single revolution. If the repellent and ink have not yet been applied to the master sheet, it may be desirable to rotate the drum several times before a copy sheet is fed therethrough for the reason that the repellent and ink are applied to the master sheet subsequent to the printing operation.

Due to the fact that when the drum is stationary in its home position, the segment clears the ink form roll 13, the latter is free to rotate, thereby permitting the continuous operation of the inking mechanism.

Since there is no particular load on the repellent form roll 12, it is not necessary to set this roll into rotation prior to its engagement with the segment. However, if such rotation is desired, a sector 97 may be secured to one or both ends of the drum 10 which will engage the periphery of the repellent form roll and cause the same to rotate at substantially the same speed as the peripheral speed of the segment. In this connection, the ink form roll 13 may be made slightly shorter than the repellent form roll, as shown in Fig. 7, so that it will not be engaged by the segment 97.

Suitable means, not shown, may be provided for applying moisture to the repellent roll. However, for comparatively short runs, such as are encountered in oflice use, it has been found that satisfactory results can be obtained by manually applying repellent to the repellent form roll prior to each run.

A modified form of my invention is shown in Fig. 9 in which the cam 43 is secured to the drum 10 and rotates therewith. Thus, the position of the jump roll 30 is controlled entirely by the angular position of the drum. When the drum is stationary in home position, the ink'form roll 13 and the other inking rolls are being continuously driven, rather than intermittently driven as in the modification shown in Figs. 4-7. In this modification, the intermittent drive may be provided by an electric motor, clutch and brake unit designated generally by the reference numeral 100. The ink fountain roll 25 may be continuously driven by an independent motor 101 at such a speed that the peripheral speed of the ink form roll 13 is substantially the same as the peripheral speed of the segment 14. In other respects, the inking mechanism is substantially the same as that shown in Figs. 4-7, as is the driving connection between the drum and the feed rolls.

In this type of intermittent drive, depression of the trip bar serves to release the brake and engage the clutch; a suitable cam on the drum automatically serves to disengage the clutch and energize the brake when the drum has completed one revolution. Thus the drum comes to rest in its home position. The construction and operation of such intermittent driving means is disclosed in copending application of Carl A. Levin, Serial Number 108,471, filed August 4, 1949, now Patent No. 2,645,174.

As an alternative to the independent motor 101, the fountain roll 25 may be continuously driven, through suitable gearing, from a pinion secured to the armature shaft of the unit 100, at the end opposite the clutch and brake portion thereof. To effectuate the principal objects of this invention, any continuous driving means for the fountain roll may be provided, and any intermittent driving means for the drum may be provided, just as long as the latter causes the drum to come to rest in a home position in which the segment clears the form rolls; irrespective of whether the dwell period is of indeterminate duration, as shown herein, or is of a predetermined duration which is suflicient to permit manual positioning at the bite of the feed rolls 23 and 24.

Another modification is shown in Fig. 10 in which the inking mechanism is continuously driven by a separate motor 102, and comprises just three rolls, the fountain roll 103, the ink form roll 104 and an intermittent roll 105. In this modification, the three rolls are mounted on fixed centers by means of a pair of plates 106. The rolls 103 and are in contact with each other, but there is a slight clearance between the intermediate roll 105 and the ink form roll 104. This clearance is sufliciently small so that a thin coating of ink on the intermittent roll 105 will be suflicient to establish driving contact between these

rolls

105 and 104. However, when the ink form roll 104 is being driven by the seg- 7 ment the driving. contact provided by the ink coa ing will permit a certain amount of slippage so that the peripheral speed of the ink form roll at this time is controlled by the peripheral speed of the segment 14.

The entire inking mechanism is pivotally mounted by means of a shaft 107 which passes through the plates liifi. An adjustabie stop 10%, suitably mounted on the side frame of the machine provides regulation for the contact between the ink form roll and the segment, and at the same time maintains the ink form roll away from the surface of the drum iii A suitable eccentric 195 which engages the plates 1%, serves as a throw-out means.

The drum may be intermittently driven by an electric motor and brake clutch unit mil, as described in connection with Fig. 9.

I claim:

1. A direct printing lithographic machine comprising a rotatable segment adapted to carry a printing plate, a freely mounted pressure roll cooperating therewith so as to be engaged and driven by said segment during operation of the latter, an ink form roll and a repellent form roll cooperating with said segment, means for intermittently rotating said segment and for causing it to stop in a home position, said form rolls being located so as to be out of contact with said segment when said segment is stationary in its home position and so as, to be engaged and driven by surface contact with a printing plate overlying said segment during operation of the latter for applying ink and repellent to said printing plate, means for setting said ink form roll into rotation at a peripheral speed substantially equal to the peripheral speed of said segment and prior to the time that said ink form roll is engaged by said segment, Said lastnientioned means being inoperative during such time that said ink form roll is engaged and being driven by said segment.

2. A lithographic machine as claimed in claim i havin copy sheet positioning means disposed in front of the bite of said se ment and pressure roll and actuated by the rotation of said segment to control the timing at which copy sheet is fed into said bite.

3. A lithographic machine as claimed in claim 2 in which said positioning means comprises a pair of contacting feed rolls, and an intermittent driving connection between said feed rolls and said segment.

4. A direct printing lithographic machine comprising a rotatable segment adapted to carry a printing plate, an ink form roll positioned to be engaged and driven by surface contact with said printing plate for applying ink to said printing plate, means for intermittently driving said segment and for causing it to come to rest in a home position in which said segment and said printing plate are out of contact with said ink form roll, a fountain roll spaced from said ink form roll for delivering ink to said ink form. roll, means for continuously driving said fountain roll, and means for establishing a driving and ink transferring connection between said fountain roll and said ink form roll at certain times.

5. A lithographic machine as claimed in claim 4 in which said means for establishing a driving connection includes intermediate roll means for transferring a coating of ink from said fountain roll to said ink form roll, said intermediate roll means including a roll spaced from said form roll by a distance substantially equal to thethickness of the ink coatings on said spaced rolls so that a frictional drive between the two is established during. such times that said form roll is not engaged and driven by said segment, said fountain roll driving means, driving said fountain roll at a peripheral speed substantially equal to the peripheral speed of said segment and in a direction such that the adjacent peripheries of said spaced intermittent roll and said form roll move in the same direction.

6. A lithographic machine as claimed in claim 4' in which said means for establishing a driving connection 8 includes interme ia r ll means f r n fer ing i k. from said fountain roll to said ink form roll, said intermediate roll means including a jump roll, and means to. shift the position of said jump roll so that said driving connection is broken at the time that said form roll is being engaged and driven by said segment.

7. A direct printing lithographic machine comprising intermittently rotating drum and feed rolls, a segment secured to said drum for carrying a master sheet, a continuously rotating ink fountain roll, means for continuously driving said fountain roll at a peripheral speed substantially equal to the peripheral speed of said segment, an ink form roll positioned so as to be engaged and driven by said segment, intermediate roll means for transferring ink from said fountain roll to said form roll and for driving said form roll prior to the time it is engaged by said segment, whereby said form roll will be rotating at a peripheral speed substantially equal to the. peripheral speed of said segment at the time it is engaged thereby, and means for rendering said intermediate roll means inoperative during the period that said ink form roll is being driven by said segment.

8. A direct printing lithographic machine comprising a rotatable segment adapted to carry a printing plate, a pair of feeding and positioning rolls disposed in front of said segment and driven therefrom, an ink form roll positioned to be engaged and driven by surface contact with said printing plate, means for intermittently driving said segment and for causing it to come to rest in a home position in which said segment, and said printing plate are out of contact with said ink form roll so as to permit positioning of a copy sheet in the bite of said feed rolls, a fountain roll spaced from said ink form roll and for delivering ink to said ink form roll, means for continuously driving said fountain roll at substantially segment peripheral speed, and means for establishing a driving and ink transferring connection between said fountain roll and said ink form roll so that said ink form roll may be rotated at a peripheral speed substantially equal to that of said segment just prior to the time that it is engaged by said segment, said ink form roll being driven; by said segment at other times.

9. in a direct printing lithographic machine having a segment on which a master sheet may be mounted, a pressure, roll, an ink form roll, and a repellent form roll, the combination of a pair of contacting feed rolls disposed in front of the bite of said segment and a pressure roll, continuously rotating driving means, single cycle clutch means disposed between said driving means and said segment adapted to cause said segment to stop in an angular position which provides proper registration with a copy sheet positioned against the bite of said feed rolls when said feed rolls are stationary, said feed rolls being. driven from said segment, said form rolls being located so as to be out of contact with said segment when said segment is stationary in said angular position and so as to bedriven by surface contact with said segment during rotation of the same, and means for driving said ink form; roll at certain times when said ink form roll is not being driven by contact with said segment to rotate said ink form roll at a surface speed substantially equal to the surface speed of said segment, said last named means being inoperative when said ink form roll is engaged and riven by said segment.

10. in a direct printing lithographic machine having a segment on which a master sheet may be mounted, a pressure roll, an ink form roll, and a repellent form roll, the combination of a pair of contacing feed rolls disposed in front of the bite of said segment and a pressure roll, continuously rotating driving means, single cycle clutch means disposed between said driving means and said segment adapted to cause said segment to stop in an angular position which provides proper registration with a copy sheet positioned against the bite of said feed rolls when said feed rolls are stationary, said feed rolls being driven from said segment, said form rolls being positioned so as to be out of contact with said segment when said segment is stationary in said angular position and so as to be driven by surface contact with said segment during rotation of the same, and means for establishing a driving connection between said ink form roll and said continuously rotating driving means at certain times when said ink form roll is not being driven by contact with said segment to rotate said ink form roll at a surface speed substantially equal to the surface speed of said segment, said last named means being inoperative when said ink form roll is engaged and driven by said segment.

11. In a direct printing lithographic machine having a segment on which a master sheet may be mounted, a pressure roll, an ink form roll, and a repellent form roll, the combination of a pair of contacting feed rolls disposed in the front of the bite of said segment and a pressure roll, continuously rotating drive means, single cycle clutch means disposed between said drive means and said segment adapted to cause said segment to stop in an angular position which provides proper registration with a copy sheet positioned against the bite of said feed rolls when said feed rolls are stationary, said feed rolls being driven from said segment, said form rolls being positioned so as to be out of contact with said segment when said segment is stationary in said angular position and so as to be driven by surface contact with said segment during rotation of the same, a continuously rotating, fountain roll, means for continuously driving said fountain roll at a surface speed substantially equal to the surface speed of said segment, and means for establishing a driving connection between said ink form roll and said continuously rotating fountain roll at such times as said ink form roll is not being driven by contact with said segment whereby said ink form roll may be continuously driven at a surface speed substantially equal to the surface speed of said segment, said last named means being inoperative when said ink form roll is engaged and driven by said segment.

12. A direct printing lithographic machine comprising intermittently rotating segment and feed rolls, means for carrying a master sheet on said segment, a continuously rotating ink fountain roll driven by segment peripheral speed, an ink form roll positioned so as to be engaged and driven by said segment, and intermediate roll means mounted for engagement and disengagement with said fountain roll and said form roll for transferring ink from said fountain roll to said form roll and being driven by said fountain roll for driving said form roll only at times when it is not engaged by said segment and at the surface speed substantially equal to the surface speed of said segment.

13. A direct printing lithographic machine comprising intermittently rotating drum and feed rolls, a segment secured to said drum for carrying a master sheet, a continuously rotating ink fountain roll, means for continuously driving said fountain roll at a peripheral speed substantially equal to the peripheral speed of said segment, an ink form roll positioned so as to be engaged and driven by said segment, intermediate roll means for transferring ink from said fountain roll to said form roll and for driving said form roll prior to the time it is engaged by said segment, whereby said form roll will be rotating at a peripheral speed substantially equal to the peripheral speed of said segment at the time it is engaged thereby, said intermediate roll means including a displaceably mounted jump roll adapted to make and break contact with two adjacent rolls to transmit rotation from one to another, and cam means for actuating said jump roll in timed relationship with the rotation of said drum.

References Cited in the tile of this patent UNITED STATES PATENTS