US2594705A

US2594705A - Control for stack supply and stack delivery for printing presses

Info

Publication number: US2594705A
Application number: US20083A
Authority: US
Inventors: Roy F Aberle
Original assignee: SOUTHWORTH MACHINE CO
Current assignee: SOUTHWORTH MACHINE CO
Priority date: 1946-09-20
Filing date: 1948-04-09
Publication date: 1952-04-29
Anticipated expiration: 1969-04-29

Description

April 29, 1952 R. FQABERLE 2,594,705

CONTROL FOR STACK SUPPLY AND STACK DELIVERY FOR PRINTING PRESSES Original Filed Sept. 20, 1946- 8 Sheets-Sheet l y 559 f L04 ya if April 29, 1952 R. F. ABERLE v.2,594,705

' CONTROL FOR STACK SUPPLY AND STACK DELIVERY FOR PRINTING PRESSES original Filed sept, *2o. 194e 8 sheets-sheet z 5&7 @5j Y i f7 J9 A fw 17 \jf afg/L April 29, 1952 R. F. ABl-:RLE 2,594,705

CONTROL FOR STACK SUPPLY AND STACK DELIVERY EoR PRINTING PREssEs 8 Sheets-Sheet 3 Original Filed Sept. 20,

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' CONTROL FOR STACK SUPP Y AND STACK DELIVERY FOR PRINTING PRE Original Filed Sept. 20, 1946 APH] 29, 1952 R. F. ABI-:RLS

CONTROL FOR STACK SUPPLY AND STACK DELIVERY FOR PRINTING PRESSES Original Filed Sept. 20, 1946 April 29, 1 952 R. F. ABERLE 2,594,705

CONTROL FOR STACK SUPPLY AND STACK FOR PRINTING PRESSES sheets-sheet 6 DELIVERY Original Filed Sept. 20, 1946M April 29, 1952 R, F, ABERLE 2,594,705

CONTROL FOR STACK SUPPLY AND STACK a DELIVERY FOR PRINTING PRESSES Original Filed Sept 20i 1946 8 -Shetatg-Sheei, 7

9 A70 ZZ/@567756 i?, MM Y April 29, 1952 R. F. ABER-Lr; 2,594,705

' CONTROL FOR STACK SUPPLY' AND STACK DELIVERY FOR PRINTING PRESSES Original Filed Sept. 20. 1946 8 She'etS-lSheet 8 Patented Apr. 29, 1952 CONTROL FOR STACK SUPPLY AND STACK DELIVERY FOR PRINTING PRESSES Roy F. Aberle, Portland, Maine, assignor to Southworth Machine Company, Portland, Maine, a

corporation of Maine Original application September 20, 1946, Serial No. 698,252, now Patent No. 2,542,073, dated February 20, 1951. Divided and this application April 9, 1948, Serial N0. 20,083.

September 18, 1947 4 Claims.

This invention relates to printing presses and is most particularly applicable to sheet-fed lithographic offset presses. Among the objects of the invention are to improve the general organization of a press and its driving gearing; to provide improved supply stack and delivery stack supports and improved control over the raising and lowering of the stack supports in accordance with the action of the sheet-feeder mechanism.

In the drawings:

Fig. l is a diagram showing the main rolls of the press;

Fig. 2 is a diagram, locking in the same direction as Fig. 1, showing certain of the driving connections and showing the pile delivery;

Fig. 3 is a Vertical sectional View, looking in the same direction as in Figs. 1 and 2, showing sheetconveying mechanism and mechanism for printing upon v(more specifically, numbering) the previously-printed sheets that are carried by the sheet-conveying mechanism;

Fig. 4 is a vertical sectional view of the press taken from the opposite point of view from Figs. 1, 2 and 3 and looking outward toward one of the side frames, showing especially the mechanism for applying pressure to the offset cylinder, many of the mechanisms of the press being omitted;

Fig. 5 is a view similar to Fig. 4 on a larger scale, showing also an electric switch responsive to separation of the main and offset cylinders;

-Fig. 6 is a fragmentary vertical sectional view taken on the line 6-6 of Fig. 4 on a larger scale;

Fig. 7 is a fragmentary vertical sectional View on the line '1 -'l of Fig. 6;

Fig. 8 is a diagram in the nature of a side elevation of the paper stack and paper stack platform of the feeding apparatus for use with the press;

Fig. 9 is a diagram in the nature of a plan view of a fragment of the feeding apparatus of Fig. 8;

, Fig. 10 is a diagram of control circuits for many of the elements of the press;

Fig. 11 is a diagram showing the control of the feeder pump motor;

Fig. 12 is an elevation, partly broken away and partly diagrammatic, showing the form rolls for the main cylinder and mechanism for controlling the operation of these form rolls;

Outline of general organization of machine The illustrated machine contains many of the features of the machines of my prior Patents Nos. 2,140,256 and 2,257,490 and is especially adapted to be used in combination with the sheet-feeding mechanism shown in my copending application Serial No. 590,225, filed April 25, 1945, now Patent No. 2,497,849, dated February 21, 1950, a continua- In Canada CTI 2 tion-in-part of application Serial No. 490,556, filed June 12, 1943, now abandoned; and is a division of copending application Ser. No. 698,252, filed September 20, 1946, now Patent No. 2,542,- 073, Ydated February 20, 1951.

The main frame of the press ,includes opposite interconnected side plate sections 25 which are preferably flanged at their lateral margins, the flanges serving to cover and protect various gears, chains, bearings and control mechanisms that Aare located adjacent to the two side plates 25.

Sheets fed successively by feeding mechanism such as that of said applications enter the machine from the right as shown in Figs. 1, 2 and 3 are momentary stopped are laterally aligned and are then gripped-by gripper fingers on a gripper bar 33 carried by chains |80. The course of chains is indicated in Figs. 1, 2 and 3.

The sheet is carried by the traveling gripper bar 33 to and partly around a rubber covered offset cylinder 40, the offset cylinder having a recess adapted to receive the gripper bar.

As shown in Fig. 1 offset cylinder 40 cooperates with a main cylinder indicated generally at 42. Main cylinder 42 comprises opposite end portions 42a mounted on a shaft IISG, a lithographie plate holder segment 43 having hub portions 43a also mounted on the shaft |66, and an interchangeable impression segment 44 detachably secured to the opposite end portions 42a. Depending upon the character of the work being doneimpression segments having surfaces of various materials may be used as more fully described hereinafter.

.As explained in the above patents, a lithographic plate on segment 43 offsets an image onto the offset cylinder 40, the sheet is then carried in between the offset cylinder and the impression segment 44 of the main cylinder, which results in the image being printed from the offset cylinder 40 onto the lower surface of the sheet.

The timing and arrangement of the main and offset cylinders and the feeding mechanism, paper stop ngers, side jogger mechanism and gripper bar 33 is such that a sheet to be printed is presented to the nip between the offset and main cylinders at each revolution of the main cylinder, or in other words, at each second revolution of the offset cylinder.

The main cylinder 42 is provided with platedampening mechanism indicated generally at 50 and plate-inking mechanism indicated generally at 55 so as first to dampen the water-receptive blank portions of the lithographie plate and then to ink the ink-receptive image-carrying portions during the time that the impression surface 44 is cooperating with the offset cylinder 40. Further rotation of the main` cylinder then brings the dampened and inked lithographie plate on segment 43 into position to offset its inked image onto the rubber surface of the offset cylinder 40.

A supplemental roll 60, for instance carrying a rubber plate having raised letters, is arranged to offset onto the otherwise blank surface of the impression segment 44 of the main cylinder. The image thus transferred to the impression surface 44 is then printed onto the upper surface of the sheet simultaneously with the printing onto the lower surface of the sheet by offset cylinder 40.

Leaving the nip between the oifset cylinder 43 and the impression segment 44, the printed sheet is released by the grippers of bar 33 and simultaneously gripped by a circularly moving second set of grippers 18 (Fig. 3), which move around axis 1| (Fig. l), and at the end of an approximately 90 circular travel release the sheet and ytransfer it to third grippers Bi] (Fig. 3), which are carried by chains |42-in a generally triangular `path, as shown in Figs. il and 3.

On the first or downwardly inclined portion of this triangular path away from the offset -cylinder, the sheet-may be subjected to a further vprinting operation. Mechanism for such further printing preferably comprises, as shown in Fig. 3, Yone -or more rotating serial numbering units `85 and cooperating platen rolls 9| between which the sheet is carried (Fig. 3) so that the sheet is numbered on its lower surface upon which it had previously received an impression Yfrom the offset cylinder.

The-chain-carried -third grippers 80 then carry the sheet onto the lower horizontal run of their triangular-path, in which the grippers are caused to open and drop the sheet, with its offset printed and numbered surface uppermost, onto an automatically lowered stack |58 (Fig. 2) on a platform V||3| on vwhich the newly arrived sheet is aligned `both longitudinally and transversely by corner-jogging vmechanism indicated generally at |23.

`Pressure mechanism and control of pressure `'nicchia/ism in accordance with sheet ,feed

AAs shown in Figs. 4 and 5 the shaft |62 of -the voffset cylinder is mounted in sliding blocks 325 which are vertically movable in guideways 326. Apressure control or cam shaft 328 is eccentrically mounted at 323 at -its ends and acts as a cam, through adjustable tappets 328e, to support the sliding blocks 325. Rotation of the camshaft 328 in a counterclockwise direction as viewed in Figs. 4 and 5 permits the offset cylinder to move away from the main cylinder, and rotation of the cam shaft 328 in a clockwise direction lifts the oifset cylinder and forces it under pressure against the main cylinder.

A sliding collar 338 (Fig. 6) on shaft 323 carries a horizontal connecting pin 33| which is guided through a slot in Aan arm 332a which extends from a xed collar 332 on shaft 328. Connecting pin 33| is adapted to be projected to the 'right in Fig. 6 to a position in which it underlies a shoulder 334 on a vertically reciprocable pressure fork or plunger 335.

A cam follower roller 336 (Figs. 4 and 5) on the pressure fork 335 is adapted to be contacted by cam surface 338 of a cam 329 mounted -on the shaft |56' of the main cylinder, to apply pressure to the pressure fork or plunger -335 at each rotation of the main cylinder.

The connecting pin 33| is urged to the left in Fig. 6 by a spring 340 which acts on the slidable collar 330, tending to disengage the pin 33| from 4 the pressure fork shoulder 334, thus allowing the pressure fork or plunger '335 to move idly.

A solenoid 342 (Fig. 5) has its movable arma- -ture 343 connected by a flexible cable 334 to the slidable collar 338. Energization of the solenoid 342 by means of a push-button switch 342a (Fig. 10) thus pulls the pin 33| to the right in Fig. 6, carrying it into the path of the pressure fork shoulder 334.

During continued printing, the pressure of pressure fork shoulder 334 upon the pin 33| retains the pin under this shoulder against the ac- -tion 'of the spring 340, thus keeping the pressure fork connected to the pressure control eccentric shaft 328 4as long as the pressure fork is sufliciently low in position for the shoulder 334 to bear lagainst the pin 33|.

The shape of the cam 339 on the main cylinder shaft is such that the high part of the cam surface 333 bears against cam follower roller 335 only during the presentation of the plate segment 43 to the offset cylinder.

In normal printing, pressure between the offset cylinder and the impression segment '44 is secured by latching the pressure fork in a pressure-applying position by detector-controlled latch mechanism.

A latch 350, Fig. '1, is slidably mounted in a block 35| and includes a bevelled portion 352 adapted to slide into a wedge shaped recess 353 in the pressure fork 325. Latch 350 is normally urged to the right or unlatched position in Fig. 'I by a spring 355, but upon the detection of feed of a'sheet to the press, latch 350 is urged to the left and into the recess 353 by a bell crank 351 which is connected by a flexible connection 358 to the movable armature 359 of a solenoid 368 as shown in Fig. 4.

Solenoid 350 is energized by the interruption of r'a light beam -by a sheet as the sheet is carried toward the offset cylinder by the gripper fingers 32 and gripper bar 33.

lIn Fig. 4 a source of light such as an electric lamp is indicated at v31|! and a photo-electric cell normally exposed to the light beam is indicated at 31|, the beam of light from lamp 318 to cell 31| being adapted to be interrupted by a properly fed sheet carried by the gripper -bar 33 passing along the upperrun of 'chain |80.

Referring to the wiring diagram of Fig. 10, solenoid 360 is normally de-energized and is adapted to receive its operating current through a circuit which includes the terminals D and F of a relay 330 which is de'energized when the photo-electric Vcell 31| receives light from the light source 318. When the beam from the light source 310 to the cell 31| is interrupted, the relay 380 is energized, closing the circuit between ter.- `minals D and F and sending an impulse through the circuit which includes the solenoid 350.

This energization of relay 388, and consequently of the'solenoid 350, takes place during the offsetting portion of the cycle, that is, while theimage from the lithographie plate on segment 43 is being transferred to the offset cylinder, and hence while the pressure fork 325 is held in its depressed position of Fig. '1 by the high surface 338 of the cam 333. The notch 353 is accordingly in position to receive the latch 350.

The block 35| which carries the latch 350 is vertically slidably mounted in a stationary guide bracket 383 (Fig. 6) 'and a screw 384 which is rotatable in 'the bracket 383 is threaded into the block 35|. A rod consisting of jointed portions `385, 386 and 381 (Figs. 6 and 4)., 4fastened to the 384 to be turned to adjust the level of the block 35| and hence the level at which the latch 350 will hold the pressure fork during proper presentation of a sheet between the offset cylinder and impression segment. Normally the latchcarrying block 35| will be adjusted at such level that the latch 350 will have at least a slight clearance from the bottom surface of notch 353 as the latch enters the notch during the offsetting portion of the cycle.

When a properly fed sheet passes and interrupts the light beam at a time near the end of the oisetting portion of the cycle, the solenoid 360 inserts the latch in the notch 353 and holds it there until the latch is caught and held by the bottom surface of the notch when the cam sur- 'face 338 ceases to apply downward pressure to the pressure fork. When the trailing end ofthe sheet subsequently passes the light. beam, the

Vsolenoid 360 becomes deenergized.

active, and at the end of the offsettingportion of the cycle the pressure fork is not latched but is free to rise considerably higher than if it were latched. vThe resulting considerable rise of the pressure fork permits a considerable counterclockwise movement of the shaft 328 which allows the offset cylinder to drop out of position to press against the plate segment of thefmain cylinder, preventing the offsetting of a further image onto the oiset cylinder.

'Moreoven when thepressure fork fails to be latched by the latch 350, the shoulder 324 of the pressure fork will move higher than will the connecting pin 33|, breakingil the normal -frictional contact between these parts, whereupon the spring 340, Fig. 6, will pull .the pin 33| out from under the shoulder'334. Succeedingstrokes of the'pressure fork will thereupon be :idle and the oiset cylinder will remain out of contactwith the main cylinder until the solenoid .342 is reenergized by manual operation of the switch 342g.

It will be observed that inthe normal operation of the press, while sheets are being vnormally fed, the pressure fork or plunger 335 moves only through so much of its stroke .as effects the relatively slight separation and approach of thev axes of the oiset cylinder and themaincylinder appropriate to thefsuccessive presentation ofthe plate segment and impression segment to the offset cylinder.

Location of the light-beam Interruption of the light beamB from the-lamp 310 to the photoelectric cell 31| by the gripper bar 33 as the latter travels along the lowerrun of the chains |80 can be avoided by disposing the light beam so that it is not crossed by the gripper bar in this lower run of the chains. This may best be accompanied by locating thelamp 310 and cell V31| as indicated 'diagrammatically in Fig. 3, with both the lamp andv cell outside of the courses of the chains Isc, but' with @neef Vthese elements, for instance the lamp, somewhat above the other of these elementsv in such manner that the beam B, crosses the line of travel' 'otthe lmain cylinder. Apressure of the' offset cylinder is released when failure of feedis detected, the various operations vof the machine which are controlled by the switches 390e, 396i and 390C are also controlled 'by the detection lof failure of feed. It should be 6 5 .gripper bar only at the upper run of the chains The control of various parts of the press, and more especially the latch solenoid 360, by the interruption of the light beam B by the sheet being fed, involves certain further relations of the light beam to the press which may be summarized as follows:

The light beam is in a position such that the sheet being fed interrupts the beam while the lithographie plate segment 43 of the main cylinder is active, during the time the latch 350 is neither held in latching position by the pressure fork 325 nor held out of latching position by the pressure fork 325. the presentation of the plate segment to the offset cylinder the notch 353 in the pressure fork is located so as to permit free movement of the latch 35|] into or out of latching position.

The'point of interruption of the light beam by the paper is suiliciently near to the line of printing contact between the main and oifset cylinders to permit relatively short sheets to reach the line of printing contact and be gripped between the main and offset cylinders before the light beam is re-established after passage of the Sheet and the latch solenoid 363 accordingly de-energized.

The point of interruption of the light beam by the paper is however sufficiently spaced from the line of printing contact so that the interrupting effect of an empty gripper bar does not persist up to the time that the impression segment becomes active, but on the contrary the beam is re-established and the latch solenoid 316|!i is cle-energized in time to let the latch 350 move out of the notch 353 before the impression segment is presented to the offset cylinder.

These conditions are best provided for in the press herein shown by locating the light beam B so that it is approximately 4 from the line of printing contact between the main and oiTset cylinders at thev point where the beam is interrupted by the paper.

Limit switches responsive to application of pressure to oset cylinder Numerous operations of the machine are controlled by a limit switch indicated at 390 in Fig. 6 which preferably constitutes a single throw. gang switch comprising switches 390e, 39W and 390, which control various circuits as shown by the wiring diagrams of Figs. l0 and ll. The limit switch 39B, including its three component switches, is responsive to the applicationof pressure to the offset cylinder, normally tending to open, but being closed whenever the onset cylinder is held up in position to press against the Since, as indicated above, the

explained here that the employment of three limit switches 393e, 39Hb and 39|-c rather than a fsmallerlnumber of such switches, is described herein in'the interest of simplicity. All three. `ofthese limit switches act simultaneously in response to Ythe releasev and application of .pressurel at the oiset cylinder. The skilled electrician .willfpe able to cause a lesser number of limit `switches to exercise the samecontrolling functions .by utilizing more complicated, or apparently more complicated, control circuits.

As indicated above, during ageing-vea 1A `vertically movable rod-394 "is pivotally connected to an arm 3328' constituting a projection from collar 332, and rod `384 and has fastened thereto near` its bottom end a bracket 395 ladapted to depress a cam follower roller 395 on an foperating arm 391 of the limit switch 398. The adjustment of the switch and rod 394 is r`such that in the pressure applying positions of the-oliset cylinder the limit switch 398 is closed. A spring 398 may be provided to lassist the upward return of rod 394 and bracket 395 upon release of the `latch 358.

Prevention of latching of pressure fork while pressure fork is disconnected from ofsetcylindef- As indicated above, the several switches which 'comprise the gang limit switch 398Vcontrol several of the operations of the press. Switch 39D, when open as indicated in Fig. 10 as in the event of disconnection of the pressure fork and offset cylinder, breaks the circuit through the latch solenoid 350. This renders the latch 358 incapa- `ble of moving to latching position until the oiset cylinder has first been connected to the pressure fork by means of the pin'33| by manualoperation of the push-button switch 342e, and the oiset cylinder brought again into pressure relation to the main cylinder.

Thus it is assured that the pressure fork, while disconnected from the oiset cylinder, will be capable of rising during each revolution of cam 339 sufficiently high so that it is possible to pro'- ject the pin 33| into the path of this shoulder 334 for reconnection of the pressure fork and oiset cylinder.

v Pile delivery As the sheets are discharged fromthe gripper bars |46 of the delivery conveyor the-sheets drop -printed side up upon a stack |188 supported on a-table indicated diagrammatically at |81; Fig. 2, and slidable vertically on slides-518. l

A suitable mechanism for lowering the table |88 as the paper accumulates thereon may comprise chains 519-shown in Fig. 2 adapted to be raised or lowered by corresponding sprockets 58D. Each sprocket 588 is fast on a shaft 58|/ which also carries a worm gear 582 'meshing'with a worm 583 on a shaft 584. A ratchet wheel 586 on `shaft 584 is adapted to be engaged by a ratchet pawl 598 pivotally mounted on a bell crank 592, and bell crank 592 is continuously oscillated by an eccentric 593 on shaft 415, a cam follower 59d,

yoke 595 and a connecting link 59B.

The ratchet pawl 595 includes a tailportion 591 carrying a cam follower roller 598. Acurved cam p1ate`588 is mounted on the vertically ino'va'ble armaturel of a solenoid 682 abovethepath of ,y

cam follower roller 598. When the solenoid`682 is not energized the curved cam plate 588 depresses the cam follower roller 598 and tail 591 of the pawl V598, so as to retain the pawl out of engagement with the ratchet wheel 586, thus allowing the pawl to swing idly. On the otherihand when solenoid 582 is energized as described hereinafter cam plate 888 is lifted sufficiently to allow the -pawl 598 to drop into engagement with'the teeth of the ratchet wheel 585 as yshown in Fig. 2.V

When in this position the pawlland ratchetwheel cooperate to turn the worm 584 and parts driven thereby, to lower the stack table |0|. De-energization of the solenoid '682 immediately stops n the lowering' of the stack'table.

shows fa A-st'ack 2 ,-of sheets to 'be prin-ted, vcarried #byaltable 't3 lsupported-bybracket 85 whichiis slideably mountedv on` guide IVbars-89.

vlSheets are lifted singly and in succession from vtop yof #stack |2 by 'reciprocating Vsuction V'picker nozzles 55 vwhiclrmove downwardly and upwardly through ygaps `betwe'en-successive` sets ofthe V'cords |821, picking up :the trailing -end --porti'on Aof the top sheet. lifting =this 'trailing end 'portion above the pathof travel of the/next set oflcords |18, and holding it fthere untilsuch set of cords 18a complete -the `vseparatirm of the `fsheet *from `the stack. -The lsuction in the nozzles -56 is then broken Fand Athe Atraveling cords |18a #advance 'the sheet into 'the press.

`)Lifting 'of the 'sheets is facilitated by'inter- -mittent blasts of air directed against theupper right-face 'of the'stackofr Fig. 8 byfair-blast nozzles |48, such blastsof-air fannin'g outthetop several sheets lof :the stack and accomplishing the first pai-trof the `elevation ofthe trailing edgepora tion o'f the ltop sheet.

ySuctionis `supplied :to -the Vnozzles 56 'through nexibleltubes 83y (FigsfV andfll) ',:a'suction lheader conduit 1 5c, conduits t1 51- and -15afand4 a mechanically controlled valve -14 Iwhich breaks `thessuc- `tion at 'the propertimes, aV conduit 1 3, `and Iazflexible "coupling 13f-which leads to the suctionf'side of a 'motorfdriven l`air pump indicated" diagrammatic'ally at |8805- Air is-supplied underpressure `to-thefnozzles '|551fro`m Athe pressure Yside fof the pumpl (Fig. 1l) `under the control of a rne- -chanically actuated .piston 'valve Hi `Table |3 lis Vadapted to -jbe Velevated by -a chain `851L driven -by sprocket 851 on a shaft -85 vfwhich fis *rotated by a worm :gear 98, v'A worm '91, Aadapted -to'drive the wormfge'arf, is carried `on Va :shaft v'98 which Aalso c'arries a ratchet `wheel 208. An "eccentrically weighted .plate/28| is freely--rotatable'on shaft 948 and car- -ri'esa pivotallyy mounted. pawl 2 82l adapted to Vfall by f: gravity into fengagement 'with the teeth o --ratchet 'wheel288. The center offgravityfof the :plate 28| is toward the right of the'shaft 88 as seen in Fig. 8, which causesl theplate 28| 'to tend to rotate about the shaft 98'ina clockwise direction, tending to keep a pin 283, carried by plate 20|, in engagement with *the vupper end of va -slot 2M in --a `pitrnan 285. The lower end of thispitman is 'pivotally connected to` an eccentric pin 2 |15a 'on a continuously driven-shaft 18. Y

Apapr stack `-heightlfee'ler roller, 5 is carried by theupper'endof 'a nieinber' and bears'upon `the -topmostfsheet ofthe stack. VMembert' is Vpivotally 'connectedto thein'ner arm of a double 'cra`1`fik88EL 'df 'which thebuter arm is pivotally connect-edito the `lower end of a connecting rod 88". Rod'b carries aslotte'd head 289 which slidabl'y engages apin`2l8 at'the right 'en'dof'a lever l2 I l which 'S'pVOtally mllnted 'n 'a 'Stud 2|2 projecting "from a'sideirameplate of the feeder. Theend'of the'leverll oppositetotlie pin 2|0 is adapted to detain a shoulder 20|a (Fig. 9) which is integral with the hub of the plate 20| and which projects radially therefrom, see Fig..

29, thus preventing thev plate from rotating clockwise, as viewed in Figure 8. As the height of the top of the stack I2 decreases, the control feeler roller l5 and member 08 descend, the crank |38n rotates, the connecting rod 08b descends and the detent lever 2|| .disengages the shoulder4 20|a and allows the plate to rotate clockwise, as viewed in Figure 8, bringing the pawl 202 into position to engage a new tooth or teeth on the ratchet-wheel 200. Operation of the pitman 205 then results in actuating the pawl 202 to turn the ratchet-wheel 200, shaft 08, and shaft 95 and move the chain 85a to lift the table |3 and thereby raise the top of the stack to the appropriate level for feeding from the top of the stack. A handwheel 08a may be provided on shaft 98 for adjusting the paper stack table and also for lowering it to receive a further supply of sheets.

A limit switch 6 0, not provided in the said copending application, is located on the feeder s0 that its operating arm 6| 0a is adapted to be cammed to the right in Fig. 8 by rotation of the plate 20| in a clockwise direction, and the limit switch v6H) is so arranged that such movement of its arm closes the switch, closing a circuit through the solenoid 602 of the pile delivery control mechanism.

Thus each time the table I3 of the feeder is elevated by the mechanism of Figs. 29 and 30, the table |0| (Fig. 2) at the delivery end of the press is correspondingly lowered.

It is often convenient, especially in starting the press, to run the press idly without feeding paper through it and in this operation the feeder paper stack table I3 may either be empty or the top of the stack l2 may be suiciently low so that it does not engage the feeler I5, and consequently during such running the table |3 may be caused to rise. In such idle running of the press, the limitl switch 3|0b will be open because of the absence of pressure at the offset cylinder, and because this limit switch 39|)a is interposed in the circuit of pile delivery control solenoid 602 (Fig. l0) the latter will not be energized. Accordingly, when the press is run idly, the pile delivery table |0| will not automatically lower even though the feeder paper stack table I3 rises.

A manually operated switch 6|| is also interposed in the circuit of the pile delivery control solenoid 602 and by opening this switch, automatic lowering of the pile delivery table'can be suspended both during idle running and during printing.

Control of sheet feed.

made for permitting feed of the sheets notwithstanding the separation of the combined and offset cylinders.

The limit switch 300C which opens, as previously explained, when pressure is not applied to the offset roll, is interposed (Fig. l1) in the holding circuit of the motor switch |010. A manually operable switch |010 is also interposed in this holding. circuit, in parallel with the limit switch 300C.

With the manual switch |010 closed, the holding circuit will be automatically established through the switch |010 upon closing the push button starting switch |012, notwithstanding the limit switch 390c may be open as a result of separation of` the main and offset cylinders. With the press and the conveyor of the feeder runningI and the feeder pump motor also working, sheets may be fed through the press in order to make certain that all parts of the press are properly adjusted to accommodate the sheets.

Closing the switch 342e, Fig. l0, will energize the solenoid 302 to effect connection between the pressure fork 325 and the offset cylinder, and thus bring the offset cylinder into pressure relation to the combined cylinder, whereupon printing will begin and the several limit switches including limit switch 300- will close. Thereupon the operator can open manual switch |010, Fig. ll, and further operation of the feeder pump motor will depend upon limit switch 300 remaining closed. At any time thereafter at which a sheet fails to be properly fed, and the offset and combined cylinders separate, limit switch 300c will open and automatically stop the feeder pump motor |06| and feeder air pump |060. This feed .of further sheets is thus instantly stopped, al-

though the pickers 50 and conveyors of the feeder continue to be driven in timed relation to the main cylinderv and-the yvarious conveyors of the press `by the driving connections described in said application Serial No. 590,225.

Review of control circuit wiring diagram Many of the elements of the control circuit and their functions have been described above. Referring to Fig. l0, a suitable alternating current line is shown as adapted to supply current to the electric lamp 310, the photoelectric cell 31|, the photoelectric relay 380 and a photoelectric amplification network indicated diagrammatically at |090, under the control of the manually operated switch |09! The photoelectric amplification network |000 -is of such character as to transmit amplied cur- Y vAs previously described, and.' as will, be apparent from the diagram of Fig. '10, the latch solenoid 360, the numbering unit solenoid 540, the supplemental offsetting cylinder solenoid |080, and the counter |032 are connected in parallel so that each is adaptedI to receive an impulse when the photoelectric relay 380 operates to close the circuit between contacts D and F in the event that limit switch 39|]B is closed.

Manually controlled switches 540e, |080, and |0923, connected in series with the solenoids 540, |080 and counter |002 respectively, are adapted to be opened so as to prevent operation of any of these elements as desired. Thus, the press may be run without its numbering unit functioning, or without its supplemental offsetting cylinder functioning, or without its counter functioning, or without any or all of these functioning, as desired.

As explained above, the push button switch 342 is depressed to energize solenoid 342 to pull the pin 33| to the right in Fig. 6, carrying it into the path of the pressure fork shoulder 334, thus effecting an initial connection between the pressure fork and the oiset cylinder, a connection which is maintained by pressure of the pressure fork shoulder 334 upon the pin 33| until failure of a sheet to be fed causes the latch 350 to fail to be engaged and held in the recess 353 of the pressure fork.

The operator can release the push button switch 342a as soon as a properly fed sheet has caused the latch 350 to hold the pressure fork.

Failure of feed of a sheet causes release of pressure upon the offset cylinder and causes limit switches 390e, 330| and 390C to open.

The open condition of limit switch 3%a ,(Fig. prevents energization of solenoid 300 and prevents latching of the pressure fork in its lower or pressure-applying position unless the offset cylinder has been moved into pressure relation to the main cylinder by means of the connecting pin 33|, and also prevents energization and operation of the counter |092.

The open condition of limit switch 300b prevents energization of solenoid 540 and prevents operation of the numbering mechanism, prevents energization of solenoid |030 and prevents offsetting from the supplemental oisetting cylinder.

lThe open condition of limit switch 330b (Fig. 10) also prevents energization of solenoid 602 and prevents automatic lowering of the pile delivery table. The open condition of limit switch 390b also prevents energization of solenoid 980 and so prevents operative contact of the form rolls with the plate segment of the main cylinder excepting in the event that the knob 990 (Fig. l2) is turned and held by hand to permit such operative engagement.

The open condition of limit switch 390 (Fig. l1) breaks the holding circuit of the feeder pump motor switch (unless the manual switch |019 is closed), and so stops the feed of sheets. Feed of sheets may, however, be carried on in the open condition of limit switch 390C by having the switch |079 closed.

I claim:

l. In a sheet-fed printing press, relatively movable main and offset cylinders, means for holding the cylinders engaged under pressure while a sheet is present therebetween, said means being responsive to the absence of a sheet to separate the cylinders, stack supports for supplying sheets to said cylinders and for receiving printed sheets discharged therefrom, said stack supports being vertically movable, means operable to eect raising the supply stack support and lowering the delivery 'stack support, a stack feeler normally vrendering the means .for raising the supply stack support ineffective, said feeler being operable by removal of sheets from the top of the stack to render the stack elevating means effective to raise the stack support, means rendering the means for lowering the delivery stack support ineffective while said supply stack support is at rest, an electric circuit including a switch and solenoid, the switch being located in a position to be closed by response of the stack feeler to initiate elevation of the supply stack support to energize the circuit, said solenoid being located in a position to render the lowering means for the discharge stack support efective, and a second switch in the circuit connected to the means for holding the cylinders engaged and operable by separation of the cylinders to open the circuit and hence to render the stack lowering mechanism ineffective without interfering with continued operation of the supply stack support elevating means.

2. In a sheet-fed printing press, relatively movable main and offset cylinders, means for holding the cylinders engaged under pressure while a sheet is present therebetween, said means being responsive to the absence of a sheet to separate the cylinders, stack supports for supplying sheets to said cylinders and for receiving printed sheets discharged therefrom, said stack supports being vertically movable, ratchet means operable to effeet raising the supply stack support and lowering the delivery stack support, each ratchet means comprising a ratchet wheel and pawl, a stack feeler normally holding the pawl of 'the supply stack operating mechanism ineffective, said feeler being operable by removal of sheets from the top of the stack to render the pawl eectively operable, a cam holding the pawl of the delivery stack operating mechanism ineffective, an electric circuit including a switch and solenoid, the switch being located in a position to be closed by operable engagement of the pawl and ratchet of the supply stack operating mechanism to energize the circuit, said solenoid being located in a position such that upon actuation it will render the pawl of the delivery stack support operating mechanism operably eective, and a second switch in the circuit connected to the means for holding the cylinders engaged and operable by separation of the cylinders to open the circuit .and hence render the pawl of the stack lowering mechanism ineffective.

3. In a sheet-fed printing press in accordance with claim 2, wherein there is eccentric operated means for constantly oscillating the pawls idly while the latter are held ineffective.

4. In a sheet-fed printing press in accordance with claim 2, wherein there is means for manually closing the second switch to restore operation of the stack support lowering means.

ROY F. ABERLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS