US2165231A

US2165231A - Printing machine

Info

Publication number: US2165231A
Application number: US147507A
Authority: US
Inventors: Franklin E Curtis
Original assignee: Multigraphics Inc
Current assignee: AB Dick Co
Priority date: 1937-06-10
Filing date: 1937-06-10
Publication date: 1939-07-11
Anticipated expiration: 1956-07-11
Also published as: GB499800A; FR839157A

Description

July l l, 1939.

E. E. CUR-ns PRINTING MACHINE 4 Sheets-Sheet 1 Filed June 10, 1937 July ll, 1939. F. E. CURTIS PRINTING MACHINE Filed June lO, 1957 4 Sheets-Sheet 2 Ohh.

' INVENTOR.

- BY @M/ @0L/w? July l1, 1939. F. E. cuRTls PRINTING MACHINE 4 Sheets-Sheet 3 Filed June l0, 1937 July 11, 1939. F.E.URT1S 2,165,231

lPRINTING MACHINE Filed June 10, 1937 4 Sheets-Sheet 4 @of INVENTOR. I Q7 w ATTORNEYS.

Patented July 11, 1939 mm1-mc. mennen Franklin E.

Willoughby, Ohio, assignor to Curtis, Addressograph-Multlgnph Corporation, Cleveland, Ohio, a corporation of Delaware Application .im 1o, 1931, serial No. 141,501 22 anims. (ci. loi-141) This invention relates to improvements in printing machines, and is especially concerned with improvements in and relating to rotary printing or duplicating machines of the planographic offset type.

The general object of the present invention is to provide an improved compact, planographic duplicating machine, especially adaptable for general office use, simple in operation, and which will require but a minimum amount of attention by the operator, to the end that comparatively unskilled operators may successfully operate the machine over continued periods of time.

The primary object of this invention is to provide very effective means for receiving a sheet feed from the top of a pile, effectively locate it as it is passing into the grip of the two members of the printing couple, and thereafter discharge it, all arranged so as not to injure or mar the forward edge of the sheet, and at the same time allow the sheet to be fed rapidly'into coaction with the couple. v

Other objects of this invention will become more apparent from the following description, reference being had to the accompanying drawings in which there is illustrated a preferred embodiment of the invention. The essential features of the invention will be summarized in the claims.`

Fig. 1 is a substantially centrally located longitudinally extending section through the printing machine and feeding mechanism; Fig. 2 is a sectional plan view of the mechanism illustrated in Fig. 1, the plane of the section being substantially as indicated by the offset lines 2--2 on Fig. 3; Fig. 3 is aside elevation of the machine looking in the same direction as Fig. 1, with the side cover plate removed and certain other parts broken away to illustrate more clearly the operating mechanism for the printing machine;

Figs. 4, 5 and 6 are sectional details on an enlarged scale of certain parts of the sheet feeding and guiding mechanism which are directly associated with the printing drum; Fig. 7 is a fragmentary vertical section, the plane of the section being indicated by the line 'l-'I on Fig. 1; and Fig. 8 is a fragmentary detail of the sheet stripping mechanism.

Referring now to the drawings, wherein there is illustrated a preferred form of the invention, there is shown a frame comprising a. pair of side plates II and I2, tied together by suitable crossframe members, some of which are generally indicated at I0. This frame is supported by suitable legs I4; Rotatably journalled in this frame are a pair of horizontally extending shafts l5 and I6, the former supporting a transfer roll I8 and the latter a printing plate or form roll I9. These shafts are preferably mounted in eccentric bushings in the well known manner to permit them to be adjusted and aligned one with each other.

The form roll comprises a hollow cylindrical drum I9 which carries the printing plate B. This drum has its wall diverted inwardly, as indicated at 20, to provide a gap in which the plate retaining devices are mounted. One of these retaining devices comprises a bar 2I which is fixedly secured -within the gap of the drum and is provided with a series of tongues or projections 22 adapted to enter elongated openings 23 formed in the end of a planographic or other similar flexible printing plate B.

At the other side of the gap is a plate-retaining member 25 in the form of a yoke, provided at each end with a bar-like formation 28, which lies along the ends of the drum. 'I'hese bars are each provided with a slotted opening 29, through which pivot pins 26 pass. 'Ihese pins are carried by suitable ears 36, formed on the drum I9. Springs 3| are interposed between the retaining device and the drum, as indicated in Fig. 1, and are positioned to rock the retaining device -inwardly toward the axis of the drum and to move it bodily toward the pivot pin 26. The inwardly diverted portion of the drum -wall is provided with a series of pockets 24. The material 24a of the drum between these pockets forms a flat vsupport for the inwardly bent end of the plate.

'I'he plate B is positioned on the lugs 22 and then wrapped around the drum I9, whereupon the operator grasps the retaining member 25, rocking it about its pivot 26, and inserts the tines or prongs 21 thereof into openings 23a formed on the other end of the plate. On release of the retaining member, the springs 3l thereby tension the printing plate or member about the drum i9. The bar 25 is as shown in Figs. 1 and 2, provided with an elongated handlelike formation 33, whereby it may be readily grasped by the operator to withdraw it against the action of the spring 3| to remove the plate B from the drum.

After the plate has been wrapped around the drum, the operator need only press the free end of it with his thumb slightly into the recess, and then with his other hand grasp the yoke bar and draw it outwardly against its springs and allow it to swing inwardly so that the prongs 21 pass through the openings and the bar finds its own seat when these prongs occupy the recesses 24.

The offset or transfer roll I8 is provided with an oiset blanket 35. This blanket is preferably` same manner as is the printing plate. However,

inasmuch as the offset blanket requires little attention, a more permanent form of attaching device, such as illustrated in Fig. 1, may be used.

As shown in Fig. 4, the drum I8 is provided with a peripheral gap 36, within which is secured a plurality of tongues 31 arranged to enter suitable spaced openings inJthe offset blanket. The blanket is then wrapped around the periphery of the drum and the openings 38 in the other end of the blanket are inserted on ears 39, carried by an L-.shaped plate or bar 40. Passing through this bar are set screws, one of which is shown at 4|. These set screws are threadingly secured to a wall 33 of the drum I8, thereby facilitating the tensioning of the transfer or offset blanket.

The plate or pattern drum I9 is power-driven. As shown in the drawings, I provide a motor M, which may be supported in any suitable manner by the machine frame, such as by cross-frame members, not shown, but which are secured to the legs I4. The driving pulley v4| of this motor is connected by a driving belt 42 with a pulley y43, which is secured to a shaft 44, journalled in the frame plate I2. Secured to the shaft 44 on the inner side of the frame plate is a spur gear 45, which meshes with one gear of a compound idler gear member 46, journalled on a suitable stud 41, carried by the frame plate I2. The other gear 48, of the compound gear member 4S, meshes with another gear 49, which is journalled on a stud 58, secured to the frame plate I2. The gear 49 in turn meshes with a gear 5|, secured to the drum I9, as, for instance, by screws 52 (Fig. 2), and thus constitutes the driving `gear for the plate drum.

Rotatably journalled below the transfer or offset cylinder I8 is a platen roll 15. This roll is preferably of bare steel and is rotatably journalled on a shaft 11, which is supported by arms 53 of a bail or yoke 55. 'I'hese arms are pivotally mounted on a cross-shaft 54 carried by the frame members Il and I2.

'I'he platen roll is resiliently urged upward, toward the offset cylinder, by a pair of springs 55. Each spring is coiled about a threaded pin 51 (Fig. 1),v which is slidably mounted for vertical movement in one of the transverse frame members I8. 'I'he upper end of each pin 51 is provided with a notched head 58, arranged to receive the bar 55 of the platen support. Threadingly secured to the lower end of the pin is an adjusting finger nut 59, which serves to limit the upward movement of the pin and therefore the platen. 'Ihe relative adjustment of these nuts maintains absolute parallelism between the platen and transfer cylinder. A spring 68 secured to the bar I8 coacts with notches, indicated at 8|, formed on the nut 59,V to hold the nut positively in an adjusted position.

The pressure of the spring 56 which controls the pressure between the platen and the transfer roll is adjusted by a.pair of lock n'uts 62, the spring being interposed between the lock nuts and the cross-frame member I8. Thus, the platen may be raised or lowered to accommodate various thicknesses of paper, and to adjust pressure between the platen and the offset drum.

Ink is supplied to the pattern by an inking mechanism, best shown in Fig. 1.` 'I'his inking mechanism comprises the usual fountain 55. The fountain is provided with a fountain roll 88, against which the usual fountain plate 51 is adjustably positioned by a plurality of adjusting screws.. one of which is shown in Fig. 1 at y88. Ink is transferred from the fountain roll to a 'shown in Fig. 1.

transfer roll 61 by a ductor roll 68. This ductor roll is rotatably mounted on a shaft 69, supported by a pair of arms 18 pivotally secured to respective frame members |I and I2, as at 1|. The ductor roll is rocked periodically about the pivots 1| into alternate engagement with the fountain roll and the transfer roll, by mechanism to be hereinafter more. fully described.

The transfer ink roll 61 is drivingly secured to a shaft 12, andsecured to this roll is a gear 13, which meshes with the driving pinion 49, heretofore described. The ink roll 61 transfers the ink from the ductor roll to a form roll 80, which is journalled on a shaft 8|. The ends of this shaft are mounted in slots 82 formed in re'- spective bracket members 83, one` of which is These bracket members are pivotally secured to respective frame members il and I2 by pivot pins 84, and are normally stressed about their pivots to draw thei form roll into contact with the pattern or printing plate by a pair of springs, one of which is shown at 85 in Fig. 1.

The pressure of the form roll against the pattern is limited by a pair of set screws, which aremounted in the respective bracket members 83. One of these set screws is illustrated at 85 in Fig. 1, as being threadingly mounted in an ear 81 formed inthe bracket and engaging a boss 88 of the adjacent frame member. A suitable lock nut 89 is provided to lock it in position.

The printing machine with which the present invention is concerned is especially adapted for use as a planographic or lithographie printing machine, and therefore is furnished with a moistening A'or repellent applicator mechanism to provide the planographic or lithographie plate with a suitable liquid for the usual purpose of rendering portions of suchplate non-receptive to the ink. This moistening or repellent applicator mechanism is best illustrated in Fig. 1 and as there shown comprises a pan 90, adapted te be lled with a suitable liquid.- This pan rests on bosslike vformations 9| of respective frame members II and I2. Rotatably mounted in the frame members |I and I2, is a fountain roll 92 with its lower region'extending into the pan 90. This roll is driven by a mechanism hereinafter to be more fully described.

The moistening or repellent liquid is transferred from the fountain roll to a form roll by a ductor roll 93. This ductor roll is rotatably mounted on a shaft 94, supported between a pair of arms 94a, which are pivotally secured to respective frame members II and I2, as at 94h. The ductor roll 93 is intermittently rocked from contact with a fountain roll 92 into contact with a formroll 95, by mechanism to be hereinafter described.

The form roll 95 of the moistening or repellent I mechanism is rotatably mounted on a shaft 96, carried between a pair of arms 91, which are pivoted to the respective frame members and l2 as indicated at 98, in Fig. 1. is resiliently maintained in contact with a. printing plate B, by suitable springs, such as the spring 99, illustrated in Fig. 1, as being interposed between the upper end of the form roll supporting arm 91 and a pin |08 secured to the frame I2. A suitable adjusting screw |8| is mounted in the form roll supporting arm 91, in a. manner similar to the screw 86, heretofore described in connection with the form roll 88, and serves to limit the pressure of the form roll against the pattern or printing plate.

Both the form roll 95 and the ductor roll 93 The form roll l are provided with absorptive fabric coverings |02 to enable them to convey the liquid from the fountain roll to the printing plate.

`The fountain rolls 56 and 92 of the inking and repellant applying mechanism are intermittently driven. As shown in Fig. 3, the shafts which support 'the two fountain rolls have secured thereto ratchets respectively designated |06' and |01. The ratchet |01 of the repellent fountain roll 92 is intermittently progressed by a pawl H0, pivotally mounted as at III, on a plate H2, which is I pivotally mounted on the shaft |05. The upper end of this plate is connected by a link H3, with a lever H4, which is secured to a rock shaft H5, suitably journalled in the frame member H. Secured to this rock shaft is a second arm H6, which is provided with a roller H1, arranged to engage a cam H9, carried by the offset roll drum I8.

The ink fountain roll 66, heretofore mentioned, is operated by the cam H9. As shown, a pawl |30 is mounted at one end of a lever I 3 I, the other end -of which is pivotally connected as at |32 with a lever |33, which is secured to the rock shaft H heretofore described, as beig rocked by the cam H9. The ductor roll 68 of the lnk fountain is reciprocated by the lever |3|.

The driving connection between each of the links H3 and |3| and its respective ductor roll is such that the ductor rolls remain in contact with their respective fountain and form rolls for a period of time. One of the arms 95 which supports the ductor roll 93 is provided with a pin |2| which passes through a slot |20 in the driving link H3. Secured to the pin |2| and mounted at either side of the link H3 are friction disks |50. These disks are secured to the pin and frictionally embrace the link H3, so that, as the link moves to the left (Fig. 3), the friction disks |50 and the pin |2| of the ductor roll move with the link as a unit. When, however, the link has moved the ductor roll into contact with the fountain roll 92, further movement of the rolls is, of course, restricted by such contact. The link then moves between the friction disks, thereby allowing the ductor roll to remain in contact with the fountain roll until such time as the link H3 starts its right-hand movement (Fig. 3). On the reverse movement, the ductor roll remains in contact with the form roll 95, for a similar period of time.

'I'he connection between the ductor roll 68 of 5 the inking mechanism and the link |3I, is also such that this ductor roll remains in contact with its fountain roll 66, and its distributing roll 61 for a considerable period of time. As shown in Fig. 3, one of the ductor roll supporting arms is provided with a pin |35, which projects through the frame member H, thence through an elongated opening |34 in the link |3|, and into an opening |36 in a strip |31. The strip |31 is frictionally carried by the link |3|, being pressed between a pair of fibre strips |38 by compression springs |39, surrounding a pair of studs |53 carried by the link. These studs pass through an elongated slot |54 in in the strip |31, allowing endwise motion of the strip with respect to the link. When the link |3| moves to the right' (Fig. 3), the arms 10 are swung in a clockwise direction and the ductor roll 68 is brought into contact with the fountain roll 66. vThis contact is maintained for an interval of time, due to continued movement of the link and slipping of the strip |31. When, however, the link moves to the left, the ductor roll is disengaged from the fountain roll and is moved into contact with the distributing roll 61. This contact is also maintained for an interval of time due to the frictional engagement of the strip |31 with the link and is broken only when the direction of movement of the link is again reversed.

When the machine is idle,` it is desirable to move both the ink repellent form roller and the ink form roller out of contact with the pattern or printing plate. Again, at .times it is desired to supply the repellent only, while at other times it is desirable to supply the printing plate with ink only. Therefore, there is provided a mechanism, about to be described. which may selectively move either or both of the form rolls out of contact with the pattern cylinder. as desired. f

As shown in Figs. 1 and 3, a shaft 40 is journalled in the frame members H and I2, and on its outer end is provided a knob |4|, to enable it to be readily grasped and turned by the operator. The knob is provided with a suitable pointer |42, which coacts with an index plate |43, secured to the frame of the machine, and which bears indicia indicating the position of the form rolls.

As shown best in Fig. 1, the shaft |40, intermediate its ends, is provided with a cam-like formation |44, which is arranged to selectively engage the bracket' members 83 carrying the form roll 80, and rock such roll about the bracket pivots against the action of the spring 85, thereby moving the ink form roll out of contact with the printing plate.

Secured to the shaft |40, as shown in Fig. 3, is a cam |46, which is engaged by a roller |41 mounted at one end of a lever |48, pivoted as at |49 to the frame Il. The upper end of this lever has pivoted thereto a link or bar |50, which is guided in its movement by a pin |5I, carried by the frame member H and projecting through a slot |52, formed in the lever. The left-hand end of this lever, as illustrated in Fig. 3, engages a lip |55, formed on one of the form roll supporting arms 91 of the repellent applicator f'orm roll, and consequent upon the rotation of the cam |46 moves such form roll againts the action of its spring 99 out of engagement with the printing plate.

The formation of the cam |46 and the cam shaft |44 is such that when the shaft is turned to the position illustrated in Fig. 3, both form rolls are in contact with the printing plate. As the cam is rotated from the on position, shown in Fig. 3, in a counter-clockwise direction to the position designated Rep. only, the cam surface |44 acts to move the ink form roll away from t'he printing plate, thereby permitting the application of repellent only. Further' movement of the shaft |40 in a counter-clockwise direction, to the ofi position, brings the cam |46 into action, moving the repellent applicator form roll also out of contact with the prinitng plate, thus positioning both form rolls free from the drum.

Further vmovement of the shaft |40 in a counterclockwise direction to the ink only position moves the cam shaft |44 out of active engagement with the brackets 83, thereby releasing the ink form roll for contact with the printing cylinder, whereas the cam |46 remains active, retainfis llever 2 I 5,'heretofore described.

the bite of the offset printing roll i8 and the platen roll 15. This sheet feeding mechanism is of the type wherein the uppermost sheet in the stack is separated by buckling from the remaining sheets and then fed into the biteof the printing rolls.

The sheet feeding mechanism is best illustrated in Figs. 1, 2, 3 and 7. Asl there shown, there is provided a paper supporting table 200, which is slidably mounted for vertica1 movement in theframe, the arrangement being such that Ithe table 200 may be raised at periodic intervals to maintain the uppermost sheet in the stack in a horizontal plane, passing substantially. through the bite of the platen and offset printing roll.

As illustrated inv Fig. 1, the paper table comprises a horizontalI plate-like member having side flanges 20|, each of which is provided with a pair of rollers 202. These rollers projectoutwardly from the sides of the table 200 and engage the walls of slotted openings 203 formed in the respective frame plates Hand |2, thus guiding the table for vertical movement.

The table 200 is periodically raised by a ratchet mechanism, which is operated by the offset roll lshaft I5, and when raised is maintained in` position by suitable detent mechanism. 4The table 200 is provided at either end with ar depending plate |99, which is provided with a vertical rack 204. lThese racks are engaged by pinions 205,

which are drivingly secured to a shaft 206, journalled in the frame plates l|| and |2. -Drivingly secured to the outer end of this shaft, as shown in Fig. 3, is a ratchet Wheel 201, which is periodically engaged by a pawl 208 carried by a lever 209. This lever is pivotally mounted as at 2|0 on a lever .2| I, which is pivoted to the frame intermediate its end as at 2|2. At its other end this lever 2|| is provided with a roller 2|3, which is yintermittently engaged by a cam II8, on the cylinder I8.

Mechanism is provided, whereby the'pawl 200, l

which progressesthe ratchet wheel 201 to raise the paper yfeed table 200, is maintained out of engagement with the ratchet wheel until a predetermined number of sheets, or more specifically a predetermined thickness of a group of sheets, has

been fed from the table 200. .As' shown in Figs. 3 and 7, rotatably journalled on the ratchet wheel shaft 206, adjacent the 'ratchet wheel 201, is a lever 2 I5, one end of which is arranged to engage a pin 2 I 6, secured to the lower endv of thelever 209, and when in engagement therewith retains the pawl 208 out of engagement with the ratchet wheel. l y

As the sheets are fed from the stack W, they are withdrawn from beneath aseries of fingers or hold-down members 220, hereinafter to be more fully described, but which members are resiliently ydrawn downwardly toward the table as sheets are withdrawn from beneath their overhanging lips 22|. vOne of these fingers 220a) Fig. 7, is provided at its lowermost end with a pin 222, which is embraced by the slotted end of a lever y223, pivotedras at 224, to a plate 225. This plate extends transversely across themachineand is secured at itsends to respective frame members I I and I2. The lever 223 extends outwardly through a' suitable opening 2 26, in the frame member I0, andis provided at its outer end with a pin 221, which is engaged by the forked ends 228 of the As the sheets are drawn from beneath the fingers 220, and the fingers lowered, the lever 2I5 is rockedI about its pivot in a counter-clockwise direction. When a sufficient number of sheets have y been withdrawn to rock this arm a distance permitting the pin 2 I 6 to become disengaged from the forward end of the lever 2|5,.the pawl 200 engages the ratchet and raises the` same, and thus raising the table. This raising movementy of the table also raises the fingers, thereby resetting the lever arm 2I5.

The paper feed table is maintained in its raised position by a detent pawl 230, which is pivoted as at 23| to the frame member II, and maintained in engagement withy the ratchet wheel 201 by a spring 232, which is interposed between the arm 209 and the pawl 230, thus maintaining both the detent pawl 230 and the driving pawl 208, normally in lengagement with thev ratchet Wheel 201. i j When it is, desired to lower the table, to replenish the supply of sheets, the operator pushes in wardly on a knob 235 (Fig. 2), which is slidably mounted on the `outermost end of the shaft 206. This knob extends through an opening in the cover plate 330, which protects the operator fromthe moving parts. The inner end of the knob hub engages a bevelled nose 236 formed on the pawl, thus disengaging the detent pawl from the ratchet, permitting the table to drop, under the control of the knob. After a block .of sheets has been placed on the table, the rotation of the knob in the clockwise direction, raises the table, to bring the top-most sheet into feeding position, with a consequent slight raising of the fingers 22|. .Y

As heretofore mentioned, the sheets are separated before they kare fed into the bite of the printing rolls. This separating movement of the sheets withdraws them `frombeneath the fingers 22 I, and is accomplished 'by a feed roller 240, which is rotated rst in one direction and then in the other, andis bodily reciprocated into and out of contact with the sheets.

As shown in the drawings, the feed roller 240 is provided with a rubber sheathe orcovering 280, and is drivingly secured tor a shaft 24|, journalled in the arms 2| heretofore described.

This roller is rotated by a rack 243, formed on the undersurface of a link 244, pivotally attached as at 245 tothe lever |I6, which, as heretofore described, is drivingly secured to the rock shaft |I5, and is operated by the cam I9. The rack 243 engages a gear 245, drivingly secured to the shaft 24|. Thus, as the cam swingsk the lever IIS the roll 240 is rotated rst in one direction `and then in the other, 4as indicated on the arrows on Fig. 1.

A suitable spring, such as that shown at 246, Fig. 1, maintains the feed roll 240 in contact .with 'the uppermost sheet of the stack W.- As indicated,

and thereby withdraws a sheetfrom beneath the fingers 22| and carries it rearwardly. Due to a stop bar 248, which engages vsuch sheet at the rear of the roll, the sheet is buckled, as indicated at WI,- thus separating such sheet' from the remaining sheets in the stack.' After the sheet has been separated, the cam and rack mechanism operates to vrotate the feed roll 240 in a. counterclockwise direction, at a comparatively high rate of speed, and the st op bar is simultaneously raised out of contact with the paper, as hereinafter more fully described. The raising of the stop bar and the counter-clockwise movement of the fe@ roller results in the sheet being rapidly progressed toward the printing rolls.v

The sheet is guided in its movement toward the rolls by a pair of guide plates 250 and 25|,

secured to the frame members and |2, and

arranged to cause the sheet to progress in a somewhat tortuous path toward the roll, so that its forward edge is diverted in an upward direction to engage stop lips 252, carried by the printing drum, as will hereinafter be more fully described. The stop lips also serve to align the forward edge of the sheet in parallelism with the axis of the printing drum. The tortuous path of the sheet iiexes the sheet and prevents injury to the forward edge by impact against the stop lugs in the transfer drum hereinafter described. This buckling also permits irregularities in the sheet alignment to be automatically rectified.

'I'he stack fingers 220, heretofore mentioned, are best shown in Figs. 1 and '1. These fingers comprise vertically extending bars, provided with horizontally extending lips 22|, arranged to overlie and engage the forward end of the uppermost sheet in the stack. These fingers are slidably mounted in guideways formed in the plates 225, heretofore described. The guideways may comprise overhanging lips 255, struck out of the plane of the plate, as indicated in Fig. 7. Suitable tension springs 258 are interposed between ears 259 formed on the fingers and ears 260, formed on the plate member 225, and serve to maintain the fingers in contact with the stacked sheets.

'Ihe paper stop-bar 248, which is used whenever average or light-weight sheets are used, is a yoke-like member, having a bar portion encased in rubber or some similar gripping material 26|. The stop-bar is pivotally secured to a shaft 262 carried by the frame plates and I2. The stop-bar is rocked up and down by a cam 263, secured to the offset drum shaft I6 and which coacts with a roller 268 carried by one end of a bell crank 264, pivoted as at 265, to the frame member The outer end of the bell crank is connected to the stop-bar 248 by a link 265,

When comparatively heavy sheets are used, they require considerable distance for the formation of the separating buckle. The stop-bar is then moved up and held out of contact with the sheets, and the sheets are buckled against a rear paper guide. This guide comprises a platelike member 266 and extends vertically upward at the rear end of the stack of sheets. To retain the stop-bar 248 out of contact with the sheets, a manually operable plunger or cam 261 is provided. This plunger is slidably mounted in one of the end frame members and is arranged to be moved into position beneath the horizontally extending arm of the bell crank 264 of the stop operating mechanism. A spring 290 normally serves to retain the stop bar 248 in contact with the uppermost sheet of the stack.

A stop for the uppermost reach of the table when the stack of sheets are replenished is provided, and may comprise a rod 269, which may be secured to and depend from the shaft 262 supporting the stop member 248.

As heretofore. mentioned, the feed roll 280 is periodically moved up and down. It is raised out of contact with the sheet immediately after its counter-clockwise rotation, at which time the sheet has been gripped between the printing rolls to be further withdrawn from the stack, solely by the operation and contact of the sheet with such rolls. The movement of the feed roll is accomplished by the mechanism which was heretofore described in connection with the table raising mechanism and includes the roller 2|3, the cam 4I I8 and the arms 2| Inasmuch as the feed roll is journalled in these'arms, the swinging movement imparted thereto serves to raise and lower thefeed roll.

When, for any reason, it is desired to stop the paper feed such, as for instance, to enable sheets to be fed by hand, the roller 240 is raised out of contact with the sheets and the

ratchet mechanism

201 and 208 is rendered inactive. 'Ihe ratchet mechanism is also rendered inactive automatically whenever the table is raised a determined amount; that is, whenever the supply of sheets on the table has become or is about to become exhausted. At such time the uppermost feed table supporting roller 202 engages a lever 210, which is pivoted at 21| to the frame member |I, rocking the lever about its pivot and withdrawing the lever from locking engagement with a cam 212. 'I'his cam is rotatably journalled on the shaft |5, and consequent upon its release a spring 213 rocks the cam counter-clockwise about the shaft I5, causing the cam to engage a roller 214 secured to one of the levers 2|I which support the feed roll 240 and operate the ratchet mechanism. This swings the lever 2|| in a clockwise direction, raising the feed roll out of contact with the sheet and retaining the ratchet pawl 208 in its uppermost position. .A

suitable lever 215 is provided, whereby the operator may swing the cam 212 into locking reengagement with the arm 210, thus reestablishing the drive for the paper feed mechanism.

As heretofore mentioned, as the sheet W is fed from the stack to the guiding plates 250 and 25|, the forward edge is diverted slightly upwardly, so that it engages a series of fingers 252 carried by the printing drum. These ngers and their associated mechanism are best shown in Figs. 4, 5, 6 and 8. As there shown, the fingers 252 are struck up from a series of spaced plates 300, which are secured to a shaft 30|, journalled in the offset roll I8. These plates are swung about their pivot by a cam 302, secured to the frame of the machine, and which cooperates with a roller 303, carried by an arm 304, which is secured to the shaft 30|. The arrangement is such that when the parts are in the position shown in Fig. 4, the plates 300 are moved out of contact with a bar 306, which is pivotally secured as at 301 to the drum.

As the forward edge of the sheets are aligned by the ngers 252, the rotation of the drum relative to the stationary cam 302 causes the plates 300 to swing into the position shown in Fig. 5. However, th'e pressure between the

members

300 and 306 is limited by the force of the spring 308, which draws the members together. This spring is of such tension that the pressure between the members is insufficient to actually draw the sheet through the rolls, but is suflicient to frictionally retain the foremost end of the sheet in the recess formed in the drum so that it will not be interfered with by the platen. The frictional clamp provided by the

coacting members

300 and 306 is therefore a leader for the paper, rather than a gripper, in the ordinary sense.

The engagement of the sheets between the two printing members actually serves to complete the Withdrawal of the sheets from the stack. As the drum rotates into its printing position, the sheet is printed and ejected, as indicated in Fig. 6. There, it will beI seen, that as the drumv progresses, the stationary cam 302 cooperates with the roller 303 to rock the fingers 300 counterclockwise, and, as the outermost end of the lever 304 engages a pin 309 of the bar 306, suchV bar is rocked clockwise.

These rocking movethe outer edge of eachof them, as well as the forward edge of the sheet, out of the recess formed in the drum.

' Further rotation of the drum bringsthe prongs 3l0 of the bar 306 and the lingers of the plates 300 between the tines 32| of a stripper plate 320.-

This plate is such that the movement of the drum causes the tines to engage the uppersurface of the sheet rand prevent it from following the drum upwardly. Thereupon, the printed sheet is fed into a receptacle 325 removably mounted between the frame members Ilfand I2, as illustrated in Fig. 1. i

It will be seen that those moving parts which lie outside of the frame plates Il and l2 are enclosed by cover plates 330. While the upper part of the machine may be enclosed, even while the machine is in actual operation, by a removable cover 33| Whichextends from one side plate tol the other. Thus, a high degree of safety is insured to unskilled operators.

Reference is hereby made to divisional applications led November 13th, 1937, for claims on certain subject matter illustrated herein, namely:

\ Serial No. 174,394, for Paper feeding mechanism;

Serial No. 174,395, for Means for attaching printing plates to drums; Serial No. 174,396, for Material applicator for planographic printing machines.

I claim:

1. A combination with a printing couple of a ypaper feed comprising a raisable table adapted to support a pile of sheets, said table extending beneath one member of the couple, stationary guides between the table and couple to direct Said sheet first downwardly then upwardlyv diagonallyand means for feeding thel top sheet of the pile between said guides.

2. In a printing machine, the combination of a rotary platen,` a rotary drum coacting with'thek platen and having a recess, a locator mounted in the recess comprising'an arm with an inwardly projecting lug, a spring pulling the arm inwardly with less force than will grip and pull the sheet, means for supporting a pile of sheets, a movable feeding member adapted to engage the endmost sheet of a pile and force the same into the mouth of the locator to cause the forward end of the sheet to abut said lug, said feeding member continuing its engagement with the sheet until the sheet is gripped by the platen and cylinder.

3. The combination of a printing couple one member of which is provided with a paper locator, means for shoving a sheet of paper into the mouth of the locator and continuing shoving against it until the sheet is gripped by the co- .through the space between the fingers in the rotation of the drum.

5. The combination of a. printing couple, a locating device on one member of the couple adapted to engage the forward end of the sheet r vice, and means fordiverting the course of the sheet between the'shoving means and the locating device to prevent injury to the extreme front edge of the sheet.

6. The combination of a printing couple, a paper locating device on ,one memberthereof, means for supporting a pile of sheets, means for engaging the endmost sheetof the pile and feeding it toward the couple and into coactionwith thelocating device, guiding means acting on the sheet between the pile and couple to divert it while leaving it free to bend and thus reduce the impact on the locating device, and means for continuing the feeding action on the sheet until the sheet is gripped by the coaction ofthe two members of the couple.

7. The combination of a printing couple, one member of whichis provided with sheet locating device having a stop shoulder and acted on by a spring which is not strong enough to positively grip the sheet and pull it, and a paper feeding device to feed a sheet into the mouth of the locating device and continue to push the sheet therein until after such mouth has passed the line of coaction of the two members of the couple.

8. In a printing machine, the combination of two rotary members of arprinting couple, a locator mounted in a recess in one of thevmembers comprising a member with an inwardly projecting shoulder, a spring tending to move the member inwardly with less force than can the grip and pull sheet, means for vshoving the sheet into the mouth of the locator while the locator is in front of the line of coaction of the two members of the couple, and continuing such shoving until the sheet is gripped by the two members of the couple,and means 'for opening such mouth after it has passed such line of coaction to free the forward end of the sheet after the sheet has been gripped by the couple.

9. The combination of a rotary printing cylinder, a paper locating device thereon comprising two movable members one having a bar against which the sheet may rest, the other having a stop finger to engage the end of the sheet, the latter member projecting beyond the finger to engage the opposite face of the sheet from. the bar, whereby the movement of the sheet, independent of the printing cylinder, is limited and the forward portion thereof frictionally engaged, means for thereafter moving one member of the locating device to open the mouth of the clamp to release the sheet and moving the other member of the device to change the direction of the sheet.

10. The combination of a` drum, a rubber blanket held thereon by having its ends inturned into a gap in the drum, a bar carried by the drum overlying one inturned end portion of the blanket, a movable member acted on by a spring and lmoving the bar-to engagefthe sheet and change .the direction thereof.

11.In a printing machine, the combination of a rotary drum having a gap, a movable bar mounted in said gap, .a plate adapted to coact with the bar, a spring tending to move the plate.

inwardly, a finger' carried by the plate and adapted to enter a recess in the bar, whereby the extreme end of" the sheet will be engaged by the finger while the forward portion of the sheet is frictionally engaged by the bar and plate.

'and means for moving the plate away from the bar to free the sheet and for moving the bar outwardly to change the direction of the freed end.

12. The combination of a rotaryprinting couple, a paper locating device on one member of the couple comprising a pair of coacting members each movable, spring means for moving one member toward the other to frictionally clamp the forward edge of a sheet of paper between them, means for thereafter moving one of the members away from the other to release the sheet, and means for moving the other member to divert the course of such released sheet.

13. The combination of a printing member, a paper locating device -mounted thereon comprising an inwardly movable member carrying a stop shoulder, whereby .the forward end of the sheet may be engaged and located and the forward portion frictionally clamped, and a stripping device having a recess at its forward edge through which the clamping members may move and pass to idle position on one side of the stripping -member while the sheet travels on the other side of it.

14. In a printing machine, the combination of two rotary members of a printing couple, a locator mounted in a recess in one of the members, a spring tending to move one member of the locator inwardly with less force than will the grip and pull sheet, means for shoving the sheet into the mouth of the locator while the locator is in front of the line of coaction of the two members of the couple, and continuing such shoving until the sheet is gripped by the two .members of the couple, means for opening such mouth after it has passed such line of coaction to free the forward end of the sheet after the sheet has been gripped by the couple and a paper ejecting device coacting with the locator to direct the printing sheet toward a receptacle.

15. The combination, in a printing couple inachine, of a drum, which is provided with a paper locator which is adapted to engage the forward edge of a sheet fed into the mouth of the locator, a paper ejecting device coacting with the locator to direct the printing sheet toward a receptacle, the sheet locator having a spring actuated bar carrying a projecting portion and a paper stop, and an ejecting device comprising a plate having spaced fingers, the projecting portion of the locator passing through the spaces between the fingers of the ejectingdevice in the rotation of the drum.

16. In a printing machine, the combination of a rotary drum having a gap, a roller platen beneath the drum, a paper locating and discharging device located in the gap, means for supporting a pile of sheets, means for feeding the top sheet of the pile toward the pass between the drum and platen, top and bottom plates providing a chute between which the sheet passes in a diverted course into the mouth of the locating device while such mouth is in front of the line of coaction of the drum and platen, and means acting after the mouth is at the rear of such line of coaction to open the mouth and free the forward end of the sheet, and a paper stripper along the underside of which the freed sheet may pass.

17. The combination of a rotary printing cylinder, a paper locating device thereon comprising two movable members one being a bar against which the sheet may rest and the other having a stop finger to engage the end of the sheet, the latter member projecting beyond the finger to engage the opposite face of the sheet from the bar, whereby the movement of the sheet independent of the member, is limited and the forward portion thereof frictionally engaged, means for moving one member of the locating device to open the mouth of the clamp to release the sheet and moving the other member of the device to change the direction of the sheet, and a stripping device having recesses in its forward edge through which the members of the locating device may pass to idle position while the sheet passes on the other side of the stripping device.

18. The combination of a drum, a bar carried by the drum, a movable member acted on by a spring and adapted to coact with the bar to frictionally engage the forward portion of a sheet between them, and means for moving said member away from the bar to free the sheet, and means for moving the bar to engage the sheet and change the direction thereof, and a paper stripper serving to engage the sheet and direct it, said strippers being provided with recesses through which portions of the feed bar member may pass after freeing and diverting the sheet.

19. A printing machine comprising a rotary printing couple and an automatic paper feed,

characterized in that one of the cylinders of the couple is provided with a locator into the mouth of which the sheet may pass, and the feeding mechanism is automaticallyv connected in such timed relation with said cylinder that the feeding mechanism engages the sheet and pushes it into the locator in advance of the coaction of the couple and continues the pushing action as the cylinders rotate until the sheet is gripped by the coaction of the cylinders.

20. The combination of a roller platen, a rotary drum above it carrying a paper locating device. a table extending beneath the drum adapted to carry a pile of sheets, a movable member adapted to engage the top sheet of the pile and automatic mechanism for operating said member in such timed relation with the drum and for such length of time that it will feed the sheet into the mouth of the locating device and-continue its engagement with the sheet `until the sheet is gripped between the platen and drum.

21. The combination with a printing couple, one member of which carries a sheet locating device, and automatic means coupled in timed relation with the member of the couple carrying the locating device for shoving a sheet into coaction with the locating device and continuing the shoving action until the paper is gripped between the members of the couple.

22. The combination of a printing couple, a sheet locating device mounted on one member of the couple and comprising two cooperative clamping members and a comparatively weak spring causing them to approach each other, whereby the fed sheet may be frictionally clamped but with insufficient force to pull it into the grasp of the couple,` and automatic means connected in timed relation with the couple for shoving the endmost sheet of a pile into coaction wtih the locating device and continuing