US2374668A

US2374668A - Printing press

Info

Publication number: US2374668A
Application number: US324627A
Authority: US
Inventors: Davidson William Ward
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-03-18
Filing date: 1940-03-18
Publication date: 1945-05-01
Anticipated expiration: 1962-05-01

Description

y 1, 1945- w. w. DAVIDSON 6 PRINTING PRESS Filed March 18, 1940 5' Sheets-Sheet 1 ATTORNEYS.

y 1, 1945. w. w. DAVIDSON 2,374,668

PRINTING PRESS Filed March 18, 1.940 5 Sheets-Sheet 2 INVENTOR. k I v 7 4249 7/2/36! fiavzdaon ATTORNEYS.

y 1945. w. w. DAVIDSON 2,374,668

PRINTING PRESS Filed March 18, 1940 5 Sheets-Sheet 3 N m W i 3V uv w; |l;\\\\\\\\ .m um 1 @h u g i R 1 \j a t Q w: N \Ej q L INVENTOR.

Wa/zdfiaujoifion 7 ATTORNEYS.

y 5 w. w. DAVIDSON 2,374,668

PRINTING PRESS Filed March 18, 1940 5 Sheets-Sheet 4 INVENTOR.

m WQ/MJQVAdSOIZ I BY M ATTORNEYS.

y 1945' w. w. DAVIDSON 2,374,668

PRINTING PRESS Filed March 18, 1940 5 Sheets-Sheet 5 IN VENIOR.

ATTORNEYS.

Patented May 1, 1945 UNITEDQSTATES PATENT OFFICE 34 Claims. (01. 101-142) The two most commonly used types of'printing are: direct letter press printing, inwhich ink is applied to raised type which then prints directly upon the sheet to be printed; and off-. set lithographic printing, in which the image from an inked lithographic plate is first transferred to a rubber blanket which in turn prints it upon the sheet to be printed. Each form of printing has its advantages and presents special problems.

The present invention relates to a press which is capable of doing both direct and onset printing satisfactorily. Thi press uses two printing rolls, one twice as large as the other. In offset printing the smaller roll is the blanket roll. It makes one revolution in engagement with the first half of the large roll which bears the plate so that the ink is thus transferred to the blanket. The blanket roll thenmakes its secand revolution in cooperation with the second half of the large roll which has a, platen surface for pressing the sheet in contact with the blanket, thus printing the sheet. In direct printing the smaller roll serves as the platen to press the sheet against the plate or type. carried b the large roll. However, this multi-purpose press has presented some complications with respect to registration, stripping the sheet from the press, and delivery of the 'sheet. According to the present invention these complications are grippers for registration, stripping and delivery, although this presents the difflcult problem ofobtaining uniformity of registration with the delivery grippers forming part of the chain delivery. If stop fingers are provided for each of the independent gripper units positioned at diiferent points along the length of the chain simultaneously greatly reduced and in fact the combination of this type of press with the other delivery, the successive gripping units must be made identical and must be provided with some means for insuring identical coaction with the printing rolls in order that they will feed successive sheets uniformly.

The delivery of sheets from a multi-purpose press has presented special problems because of the fact that the sheet is printed on its lower face by offset printing and on its upper face by direct printing. It is desirable to have the sheet delivered printed-face up so that the quality of the printing may be easily observed as the sheets are delivered. To make the printing visible it is necessary to deliver the sheet without turning it over in the case of direct printing and after turning it over in the case of oflset printing. This application is in part a continuation of applicants copending application, Serial No. 272,053 (now Patent No. 2,306,044) and is intended to cover the broad common subject matat once by using delivery chains having-twice features described herein may be said to solve some problems relating to printing in general.

With high quality printing accurate registration of the sheet is essential. It has been the practice to provide grippers and registration stop fingers carried by one of the printing rolls, the sheet being fed against the stop fingers and carried into or through the press by the grippers. It has also been the practice to provide delivery grippers carried by another roll or by chains to grip the sheet after it has been printed, pull it away or. strip it from the printing rolls, and deliver it to ap ee tW Sets Of ppers, one for registration am. one for stripping and delivery, have introduced various complications and have of course been costly to manufacture, especially where chain deliveries were used for the sake of better delivering the sheet to a pile. Such chain deliveries have conventionally included a plurality of grippin units at different points on the chain for engaging successive sheets.

One solution to this problem is touse the same the length of the periphery of this smaller roll and having only one gripping unit thereon. Because of this particular length of the chain, this single gripping unit cooperates with the smaller roll for each second revolution thereof, or, in other words, for each printing revolution thereof. Since there is a single gripping unit, the problem of making and maintaining multiple gripping units identical within close tolerances is avoided. Furthermore, it has been found that with a single gripping unit no special means is required to insure its identical coaction with the printing roll for successive sheets since the ordinary chain and sprocket accomplishes this result. It might be assumed that such a short chain, only twice the length of the periphery of the roll around which it extends. would be unable to draw the sheets entirely out of the bite. It has been found, however, that by extending the chain delivery generally in the direction of feed to the press, i. e. in the direc-- tion opposite to that from which the sheets are fed, the sheets will be dependently delivered and furthermore can be turned over in the case of offset printing or delivered. without turning'in the case of direct printing. Iii-the case of direct printing the .sheet is released as it approaches .the end of the chain delivery loop, at which point and-before releaseit may pass into the bite of delivery rollers which may be provided vention will be apparent from. the following description and from the drawings, in which:

Fig. l is a vertical longitudinal sectional view through the embodiment of the invention chosen for illustration.

Fig. 2 is a horizontal sectional view taken ap-v proximately on the line 2-2 of Fig. '1' but showing the gripper at a different position.

Fig. 3 is a fragmentary vertical transverse view taken approximately on the line 3-3 of Fig. 2.

Fig. 4 is a corresponding view taken approximately on the line 4-4 of.Fig. 1.

Fig. 5 is a fragmentary longitudinal. vertical sectional view showing particularly a transverse cross section of the gripping unit on an enlarged scale.

Fig. 6 is a somewhat similar view on a slightly smaller scale showing the grippers closed.

Fig. 7 is a. fragmentary view taken approxi- I mately on the line 1-7 of Fig. 5 showing the plan of a gripper finger.

Fig. 8 is a view corresponding to Fig. l but showing the press converted for letter press printing, Fig. 1 showing it arranged for offset printing.

A preferred form of the invention has been chosen for illustration and description, in compliance with Section 4888 of the revised statutes, but persons skilled in the art will readily perceive other means for accomplishing the same results, and the claims are therefore to be'construed as broadly as possible, consistent with the prior art.

In the illustrated embodiment of the invention the press is carried by side frames H and includes two printing rolls, namely a large roll l2 and a small roll it. The sheets are fed to these printing rolls by a final feed unit It to which the sheets are supplied by a conveyor 86. As illustrated in Fig. 1, the press is adapted to perform offset lithographic printing. To this end the smaller roll l3 carries a blanket it which is first rotated in contact with a plate mounted on the peripheral urface of plate holder 20 and then with a platen 2|. Of course, the plate need not be a lithographic plate, but for offset printing it usually will be. Lithographic plates must be dampened and inked successively and; accordingly, dampening rolls 22 and inking rolls 23 are provided, the plate holder 20 carrying the plate into contact with the last roll of each set.

gather such ink, however, and in turn applies it to the blanket it of the smaller roll ll, which maybe called the blanket roll. A sheet of paper to be printed is then fed between the printing rolls l2 and i3 and, the ink image thus applied to the blanket is printed on the sheet. The sheet then passes from between the printing rolls, and the blanket roll next rotates on the plate to begin a new cycle of the process.

Direct printing usually is performed with raised type or the raised portions of a plate. In Fig. 8,

the plate or type is represented by the removable type 2t. This type runs in contact with the final inking roll 23 and then prints directly onto the sheet. In this instance the other half of the large roll I2 and the second revolution of the smaller roll l3 may be idle. The last of the dampening rolls 22 should be moved so as not to touch the type 26. Preferably, the dampening rolls together with portions of the side walls 21 comprise a removable dampening unit which, as seen in Fig.8, has been removed. Likewise, in converting the press for letter press printing (printing with raised surfaces) the blanket iii of Fig. 1 may be replaced by a special surface member 28 which may be formed of anymaterial heretofore .used for letter press printing. For conventional type the material should be one suitable for the process known as making ready.

It will be observed that in the offset printing of Fig. 1 the underside of the sheet is printed, and in orderfor the printing to be visible for inspection as the press continues to print it is necessary for the sheet to be turned over in delivery. In direct printing, as shown in Fig. 8,"

on the other hand, the sheet is printed on the upper surface and is therefore desirably delivered without being over-tumed so that it may easily be viewed for inspection. Thus, it is seen that it is desirable to have delivery means which will turn the sheet over or deliver it without tuming it at will.

In offset printing the sheet has a tendency to stick to the blanket I8, especially when a large area of the blanket is inked, and it is desirable to provide some means for, positively pulling the full length of the sheet entirely from the blanket. Furthermore, with direct printing there are often a few lines of type near the leading end of the sheet and then a few lines of type near the rear end of the sheet with no intervening type, as illustrated in Fig. 8. Through-the intervening position the large printing roll does ,not engage the plate, and usually these grippers are carried The water applied by the dampening rolls 22 I maintains a film on the non-image portion of the plate, and this film of water in turn prei vent this portion of the plate from gathering by the platen roll so that they serve the additional function of initially stripping the sheet from the inked printing surface of the other printing roll. These grippers pass the sheet to a second set of grippers which complete the task of stripping the sheet. If these second grippers are mounted on a pair'of spaced chains, they may also deliver the sheet to its ultimate point "of stacking. Otherwise, they usually pass the sheet on either to a chain delivery comprising a third set of grippers carried by a pair of spaced chains or to delivery rollers, either of which moves the sheet to its ultimate point of delivery.

For some printing extremely accurate registration is desirable. This is particularly true for multi-color work in which a sheet is printed first with one color and later with one or more other colors and the colors should be perfectly registered with respect to one another. In short, it is essential for a satisfactory, high quality press that successive sheets be positioned accurately in the same position on the type or blanket rolls so that the printing will appear at the same position on all sheets of a given run. This necessity would seem to be a positive bar to any attempt to save money by utilizing the grippers of the chain delivery for the registration grippers since the,

use of a plurality of grippers for successive sheets obviously makes uniformity of registration of successive sheets extremely difficult. Even if successive gripper units could be made identical and if means is devised for assuring the uniform coaction between these successive grippers and the printing roll around which they rotate, there is the difficulty of maintaining them identical in spite of wear.

According to the present invention these seemingly irreconcilable considerations are reconciled. At the same time that highly satisfactory registration is secured by the chain delivery grippers, the chain delivery itself is made more economical than heretofore,

One key to the solution is using a chain delivery with a single gripping unit, indicated generally by reference numeral 29. This in turn is made possible by carrying the chain delivery around a printing roll which makes more than one revolution for each printing (the roll I3) and making the chains 3| short enough to return the gripping unit to the feeding position for each printing. In the simple form illustrated, in which the roll I3 makes two revolutions for each printing, the chain is only twice the length of the periphery of roll I3. This is an exceptionally short length for the delivery chains, particularly since the chains go around one of the printing rolls, and except for this invention would appear to be an insufficient length for the purposes of stripping a long sheet from the blanket roll and carrying a long sheet through the press'when the sheet is not gripped by the printing rolls.

By using a single gripping unit 29 the problem of obtaining and maintaining identity between a plurality of gripping units is avoided. Furthermore, it has been discovered that by driving the chains 3| by sprockets 32 mounted on the printin roll l3 (or otherwise rotating directly therewith) the uniformity of coaction between the grippers and theroll on successive printings is entirely satisfactory. This has been found to be true with a conventional roller chain and corresponding sprocket, and' it is believed that it would be true of any chain and sprocket in which the chain seats between the teeth of the sprocket, either by a Vtype of engagement with the teeth or in the illustrated form by seating uniformly somewhere on the bottom curvature 33 between the teeth 34. Even wear has no objectionable effect because there is substantially no wear during one printing run, or evenmany runs, and when the plate is changed for a different run, registration adjustments must b made anyway.

If desired, special shaping of the leading faces of the teeth and the surface between them may be provided to be more obviously dependable as to uniformity of positioning of the roller in the sprocket, but this has been found to be unnecessary. However, it is preferred at present that the teeth 34 be a little thicker from face to face of the sprocket than is conventional for a given chain size so that, as seen in Fig. 3, they will fit snugly within the links of chain 3| so as to prevent side play thereof. The teeth are of course tapered at their points. prevented by making one sprocket adjustable toward and from the other. As a matter of fact, further time may show that it is not necessary to prevent side play since the chain will never have a chance to move much laterally between its reception of the sheet and the delivery of the sheet to the bite. The chains also extend around sprockets 35 which are driven by the chains.

It is somewhat desirable that the gripping unit be located entirely within the imaginary cylinder formed in part by the surface of the blanket l8, as this will make it unnecessary to notch the other printing roll I2 to receive the gripping unit. It is not diflicult to shape the gripping finger 36 to accomplish this result in so far as the gripping finger is concerned. However, it is desirable that the gripping finger be raised a fairly substantial distance as seen in Fig. 5 in order to facilitate feeding the sheet 31 beneath it. It is evident, however, that for accurate registration purposes the stop against which the sheet is registered must extend all the. way between the gripping seat 38 and the gripping finger 36. According to the present invention this is accomplished by providing a stop 39 carried by the gripping finger 36 instead of being carried by the seat 38 as is customary. Thus, it is evident that as the gripping finger 36 is lowered, the stop 39 is lowered likewise. .This stop is preferably made arcuate as shown so that it may fit fairly closely to the gripping seat 38.

The'gripping seat 38 comprises the gripp r bar which supports the entire gripping unit. As'seen best in Fig. 3, the gripper seat or bar 38 is secured directly to the chain 3!. The chain 3| is provided with a special link plate 4| having a lug 42 bent therefrom. This lug fits into a slot 43 in the gripper bar 38 and is secured therein by a screw 44. The same construction is duplicated at the other end of the gripper bar 38. The gripper bar carries a gripper rod 46, which may be journaled in two or more brackets 41 carried by the gripper bar 38. The rod may be maintained in its axial position by collars 48 secured to the rod 46 by setscrews.

A plurality of the gripper fingers 36 are mounted on and actuated by the ripper rod 46. It is that they can slide along the rod and providing actuating and positioning collars 49. Each collar 49 may desirably be positioned between two legs SI of once! the gripping fingers 38. When secured rigidly-to the rod 46 by a setscrew 52, it will prevent movement of the-gripping finger 38 in either direction along the rod 46. The side of the rod Side play may also be.

46 against which the screw 52 bears is preferably flattened, as seen in Fig. 5, so that the collar 49 is in effect keyed to'the rod 46. As seen best in Fig, 5, the collar 49 is notched at 53 an has a loose engagement with the finger 36. When the rod 46 is rotated in a counterclockwise direction as seen in Fig. 5, the collar 49 engages the bottom of the finger 36 and raises the finger 36. When the rod 46 is rotated in the opposite direction, the finger 36 is lowered against the seat 38 by spring 54. As the finger 36 seat en the seat 38 or rather on the sheet 3'! thereon, rod 46 and collar 49 continue to turn slightly so that the collar 49 ceases to engage the bottom of finger 3-6. This makes the gripper finger 36 independent of the collar 49 and henc independent of the other gripper fingers so that each gripper finger is pressed by its own spring 54. If desired, one or more of the springs may be provided with an additional spring 56 so as to grip the sheet 31 quite tightly. This has been found to be particularly desirable in the case of offset printing so as to dependably strip the sheet from the blanket.

The gripper rod 46 is actuated in the opening direction by an arm 58 rigidly mounted thereon and carrying a cam-following roller 59, stationary cams being provided for actuation of the roller 59. It is ggnstantly urged in the gripping direction by springs 66. With this method of actuation the rod 46 extends through a notch 6| in sprocket 32. It is only necessary to omit one tooth for this notch and it has been found that this does not interfere with the uniformity of the registration. If peculiar conditions should so require, however, the rod 46 could be actuated from within the sprocket 32, as by an actuator permanently extending through and carried by the sprocket and therefore not requiring the peripheral notch 6|.

Adjacent the roll l3 a cam 62 is provided for opening the gripper fingers 36 at the proper time for receiving the sheet 31 and closing the gripper fingers while the sheet is pressed against the stops 39. For offset printing a release cam 63 is provided along the bottom run of the chain 3|, and for direct printing a removable cam 64 (Fig. 8) is provided near the end of the upper run of chain 3| or, in other words, adjacent the end loop of the chain remote from the roll l3. With offset printing the gripping unit 29 draws the leading edge of the sheet around the sprockets or rather around rollers 66 or the like coaxial with sprockets 35. In this manner the sheet is turned over and, when it is released by operation of cam 63, it

drops face down into receiving box 61 positioned as shown in Fig. 1.

In the case of direct printing a receiving box 68 is positioned as seen in Fig. 8 and, when the leading end of the sheet 31 is released as seen in of the sprockets 35. Preferably, the

rollers

66 and 69 are adjustable along their respective shafts so that they may be placed on the margin of the sheet oralong some other line where rollers 69 will not smear the fresh ink thereon. It has been found that rollers 66 do not smear the ink in the case of offset lithographic printing. However, if

desired, the rollers 66 may be replaced for offset printing by rollers having knife edges or toothed v rollers to prevent the smearing of the underside of the sheet, which in this instance will be printed. In either event the pressure rollers 69 will be removed or raised high enough so that they will not press the sheet against a sharp edged or pointed roller 66. 7

Any suitable means may be provided for insuring proper entry of the sheet into the collection boxes. For example, the direct printed sheets may pass over a guide plate (not shown) between rollers 66 and the box 68. As seen in Fig. 1 for offset printing, stop arms 13 may be carried by the box 6'! to engage the leading edge of the sheet and stop the sheet after it has been released. The gripperbar 38 is preferably notched as seen at 14 to receive the ends of the arms I3 so that there will be no chance of the sheets slipping past the arms 13. The arms 13 are preferably provided with a crook or slightly upwardly facing shoulder I6 so that the following of the leading edge of the sheet will be retarded and the sheet will in efiect be thrust slightly to the left as seen in Fig. 1 to strike the bottom of the collecting box 61. The arms 13 may be adjustably carried by a bracket ll which in turn may be adjustably mounted on the box 61 so that a wide variety of sheet lengths may be dropped against the back of the box 6i.

0f course,'the sheet should always be released shortly before it strikes the stop arm 13 and, accordingly, the cam 63 is likewise made adjustable. As seen best in Fig. 4, this cam is mounted on a sliding bracket 19 which slides in slideway 19 except when locked by screwing in screw 8i. In order that the pressure of cam 63 on camfollowing roller 59 may not flex the chain too greatly and hence cause the gripping unit 29 and with it the leading edge of the sheet to be positioned improperly with respect to stop arms 13, a chain guide or backing plate 83 may be provided. As seen best in Fig. 4, this backing plate may engage a roller 84 rotatable on gripper rod 46. The backing plate 83 may be carried by a bracket 86 carried by cross rods 81 extending between the side plates H. I

Instead of dropping the sheets into collection boxes-61 or 66, they may be dropped onto suitable pile mechanism in which the support surface is gradually lowered as the height of the stacked sheets increases to keep the top of the stack approximately at a constant position. The space below box 61 is left clear for such mechanism. Likewise, the sheets may be dropped onto a conveyor which carries the sheets to a stack and such conveyors may be adjustable to receive the sheet either in the position of offset printing release or the position of direct printing release.

Operation Although the operation will be apparent from the foregoing description and from the drawings, it may be supplemented briefly for the sake of clarity. The sheets will be fed one at a time to the gripper fingers 36 as seen in Fig. 5. The feeding mechanism may be of any form so long as it feeds the sheets in-properly timed relationship and with accurate lateral and angularpositioning. As diagrammatically illustrated, the separated sheets will be moved forwardly by the biased conveyor l6 and simultaneously urged against a side guide 9|. The side guide will accurately position the sheets both laterally and angularly. The sheets are fed against stop fingers 92 which will be stationary at this time. Thereafter, pressure roll 93 will be lowered to press the sheet against stationary feed roll 94, whereupon gear segment 96 will be actuated to smoothly and associated parts is controlled by cams rotating with the large roll It.

The grip fingers 33 are opened to receive sheet 31 by cam 32 which operates through cam follower 59, arm 58, rod 46 and collar 49, the notch 53 of which engages the bottom of grip finger .36.

As-roller 59 runs off of cam 32, the grip fingers 36 will be allowed to close under the influence of springs 54 and 56 (Fig. 7) and grip the sheet by pressing it against the gripper bar 38.

The sheet thus gripped will be carried into the bite between rolls l2 and I3, where it will be printed. ,In the case of lithographic printing the sheet will be continuously gripped by the two printing rolls l2 and I3 and hence each sheet will be controlled by them until the printing of the sheet is complete. In the case of letter press printing there may be intervals during the printing of a single sheet when the sheet'is not gripped by the printing rolls, and in these intervals the sheet will nevertheless be moved forwardly by the gripping unit 29 carried by the chain 3|. After the leading edge of a direct printed sheet has passed into the bite between

rollers

66 and 69, which may be regarded as'both feeding and delivery rollers, the cam 64 will release the leading edge of the sheet and the sheet will then be advanced by the driven roller 66 and the pressure roller 69 and will eventually be discharged by them into the collecting box 68. For sheets short enough to leave the printing rolls before being released by gripper 29, rollers 69 are not necessary, but are desirable.

In the case of offset printing the pressure roller 69 may be omitted or raised, cam 84 will be removed, and the gripping unit 29 will continue to grip the sheet until it has carried it around the rollers 66, which in this instance may be special v non-smearing rollers, as previously stated. The distance from roll [3 along the upper run of chain 3| and around the roller 66 to the bottom thereof is sufficient so that the longest sheets for which the. press is designed will be completely stripped from the blanket roll |3. Thereafter, the gripping unit 29 will be operated by cam 63 to release the sheet which will strike stop arm 13 and be guided by it into the collection box 61. Correct positioning of the sheet as it strikes the stop arm 13 will be assured by backing plate 83 which prevents undue flexing of the chain under the influence of the pressure of cam 63 on roller 59.

For offset lithographic printing the plate is mounted on the plate holder 20, a conventional rubber blanket is mounted on the roll I 3, and the segment 2| serves as a platen. The roll I2 may be called a plate-platen roll; and the roll I 3, a transfer roll. The plate or plate holder rotates in contact with the final dampening roll 22 and with the final inking roll 23, then applies the inked image to the blanket l8, and this blanket during the next revolution of the smaller roll |3 prints the image on the underface of the sheet of paper, pressing it against platen 2|. Both of the final rolls 22 and 23, normally resiliently urged toward roll l2, are shifted by cams, diagrammatically represented at 91, carried by the plateplaten roll, preferably by the platen segment 2|,

so as not to engage this platen segment. 7

For direct printing the plate holder 20 is removed and the platen segment 2| is replaced by-a type or plate holder which may be similar to the plate holder 20 or may beof a kind that is capable of receiving removable type, for example as shown at 20'; The plate holder, whether it be of the kind shown at 20 (only of lesser radius) or the kind using removable type as shown at 20, is applied to the drum in the position ordinarily occupied by the platen 2| so that the sheets will be fed to it instead of to the platen 2|. The dampening unit including rolls 22 and frame portion 21 is removed. The plate or type 23 in the position of the platen 2| is inked and the ink is printed thereby directly to the upper face of the sheet,

the roll I 3 now serving as a platen. The coveringv of roll |3 will be changed to correspond to the type of printing surface applied to the roll l2. Thus, if the roll I2 is provided with a rubber plate, the rubber blanket l8 may sometimes be left on the roll l3. For metal type or plates, especially electrotypes, it may be preferred to substitute a blanket oftougher and harder rubber or other slightly resilient matter. In other instances a conventional surface, such as tympan sheet, may be desired, which incidentally is suitable for the process of making ready. Any desired surface may be used on roll l3.

From the foregoing it is seen that a combination of printing press and registering, stripping and delivery means is provided which is extremely simple and economical to manufacture, registers sheets accurately, carries them between the printing rolls when they are not gripped thereby, strips them from the printing rolls, and deposits them on a pile with the printed side up regardless of whether the underface or upper face is printed. All of this is accomplished largely by virtue of using a single gripping unit which in .tum is made possible by making the length of the chains carrying it correspond to a multiple of the periphery of one of the printing rolls, this printing roll making two revolutions for each 1 printing. By chain and sprocket" are meant any members which operate in like manner and include interengaging positioning formations.

I claim:

1. A printing press including a plate-platen roll adapted to bear a plate and a platen for offset printing and a plate or type for direct printing, a second roll adapted to have a transfer surface thereon a d making two revolutions for one revolution of he plate-platen roll whereby it rotates the transfer surface first in contact with the plate and then in cooperation with the platen,-said second roll. also serving as a platen for direct printing, and chain delivery means for feeding sheets to the bite and for delivering sheets from the bite including chains extending around said second roll and extending away therefrom, a single gripper unit carried by the chains and cooperating with the rolls. for each printing, and means for causing said gripper unit to release the sheet approximately as it reaches the remote loop of the chains or optionally after it has passed around said loop whereby the sheet may be released with the printed face up regardless of which face is printed.

2. A printing press includinga plate-platen roll adapted to bear a plate and a platen for offset printing and a plate or type for direct printing,

a second roll adapted to have a transfer surface thereon and making two revolutions for one revolution of the plate-platen roll whereby it rotates the transfer surface first in contact with the plate and then in cooperation with the platen, said second roll also serving as a platen for direct printing, means for feeding sheets toward the bite, and chain delivery means for delivering sheets from the bite including chains extendingaround said second roll and extending away therefrom generally in the direction of feed, a gripper unit carried by the chains, and means for causing said. gripper unit to release the sheet before it passes around the remote loop of the chains or optionally after it has passed around said loop whereby the sheet may be released with the printed face up regardless of which face is printed.

8. A printing press including a plate-platen roll adapted to bear a plate and a platen for offset printing and a'plate or type for direct printing, asecond roll adapted to have a transfer surface thereon and making two revolutions for one revolution of the plate-platen roll whereby it rotates the transfer surface first in contact with the plate and then in cooperation with the platen, said second roll also serving as a platen for direct printing, means for feedingsheets toward the bite, and chain delivery means for delivering sheets from the bite including chains extending around said second roll and extending away therefrom generally in the feeding direction, a shaft spaced from the second roll, sprockets on the shaft driven by and supporting the chain, a roller keyed to the shaft, a gripper unit carried by the chains, and means for causing said gripper unit to release the sheet before it passes around the roller or optionally after it has passed around said roller whereby the sheet may be released with the printed face up regardless of which face is printed.

4. A printing press including a plate-platen roll adapted to bear a plate and a platen for offset printing and a plateor type for direct for direct printing, means for feeding sheets toward the bite, and chain delivery means for-delivering sheets from the bite including chains extending around said second roll and extending away therefrom generally in feeding direction, a

shaft spaced from the second roll, sprockets on the shaft driven by and supporting the chain, a roller keyed to the shaft, gripper unit carried by the chains, means for causing said gripper unit to release the sheet before it passes around the roller or optionally after it has passed around said roller whereby the sheet may be released with the printed face up regardless of which face is printed, and a pressure roller adapted to press the sheet against the driven roller to continue the movement of the sheet after its'release by the gripperunit.

5. A printing press including printing rolls, the first of which makes more than one revolution for each printing and the second of which has a portion cooperating therewith for printing, and chain registration-delivery means including a chain extending around said first roll, having a, length corresponding to more than the periphery of said first roll and carrying a single gripping unit cooperating with said rolls for successive printings by cooperation of said first roll and said portion,

6. A printing press including printing rolls, the

first of which makes more than one revolution for each printing and the second of which has a portion cooperating therewith for printing, and chain registration-delivery means including a chain extending around said first roll, having a length corresponding to more than the periphery of said first roll and carrying a single gripping and registration-stop unit cooperating with said rolls for successive printings by cooperation of said first roll and said portion, said chain extending around and being drivenby a sprocket angularly rigid with the first roll and having a seating engagement with the links of the chain.

7. A printing press including printing rolls, one of which makes more than one revolution for each printing, and chain registration-delivery means including a chain extending around said one roll and having a length corresponding to more than the periphery of said roll and carrying a single gripping and registration-stop unit cooperating with said roll for successive printings, said chain extending around and being. driven by a sprocket angularly rigid with the roll.

8. Ina printing press including a printing roll,

the sheet against the roller means, and collection means positioned to receive the sheet where it is ejected by the roller and roller means without being turned over or where it is released by the gripper unit after being carried around the roller means. v

9. In a, printing press including printing rolls, means for feeding a sheet toward the bite of the printing rolls, and chain delivery means including chains passing around one of the printing rolls and away therefrom in the feeding direction, a gripping unit adapted to seize and grip the sheet as-the unit passes adjacent said roll, and means for releasing the gripping unit after it has carried the sheet around a loop in the chain to turn the sheet over.

10. In a printing press including printing rolls, means for feeding a sheet toward the bite of the printing rolls, and chain-delivery means including chains passing around one of the printing rolls and away therefrom in the feeding direction, a gripping unit adapted to seize and grip the sheet as the unit passes adjacent said roll, means for releasing the gripping unit after it has carried the sheet around a loop in the chain to turn the sheet over, and sheet-stopping means effective to overcome the momentum of the sheet as it is released whereby the sheet may be allowed to drop on a pile.

11. A printing press including printing rolls and chain registration means including a chain formed in a closed loop, one portion of which from the roll by the chain, and means for releasing the g ipping unit at a position spaced from said roll after it has drawn the sheet therefrom. 13. A printing press including printing rolls, chain registration means including a chain formed in a closed loop, one portion of which moves with the periphery of one roll as it isengaged by the other, a single gripping and registration-stop unit carried by the chain, cooperating with said roll for successive printings, and after each such cooperation being drawn away from the roll by the chain, and means for releasing the gripping unit at a position spaced from said roll after it, has drawn the sheet therefrom, and means for feeding a sheet to the stop and gripping means for each printing. 14. The combination of a press'having printing rolls adapted to print optionally the upper or the lower face of a sheet, and delivery means including gripper means and means including endless fiexible means for controlling the gripper means to draw the sheet away from a roll of the press and deliver it optionally either face up, said delivery means in one instance carrying the sheet around one end of the loop to turn it over.

15. A gripper unit for registering sheets for printing presses, including a gripper seat, a grip finger pivoted with respect to the seat to open therefrom to receive a sheet and to clamp the sheet thereagainst, and ,a registration-stop member carried by the grip finger and movable with it with respect to the seat to accurately position the sheet as to its entry within the gripper unit, the face of said stop member being approximately arcuate about the pivotal axis of the grip finger.

16. A printing press including a plate-platen roll adapted to bear a plate and a platen for offset printing and a plate or type for direct printing, a second roll adapted to have a transfer surface thereon and making two revolutions for one revolution of the plate-platen roll whereby it rotates the transfer surface first in contact with the plate and then in cooperation with the platen, said second roll also serving as a platen for direct printing, means for feeding sheets toward the bite, and chain delivery means for delivering sheets from the bite including chains extending around said second roll and extending away therefrom generally in the direction of feed, a gripper unit carried by the chains, and means for causing said gripper unit to release the sheet approximately as it reaches the remote loop of the chains or optionally after it has passed around said loop whereby the sheet may be released with the printed face up regardless of which face is printed.

17. A printing press including printing rolls, the first of which makes two revolutions for each printing and the second of which has a printing.

portion adapted to cooperate therewith for printing, and chain registration-delivery means including a chain extending around said first roll and having a length corresponding to twice the periphery of said first roll and carrying a single gripping and registration-stop-unit cooperating with said rolls for successive printings by cooperation between said first roll and said portion.

18. A printing press including upper and lower printing rolls of'which the lower roll is an inkbearing roll adapted to print the ink on a sheet, and chain delivery means including chains extending around and away from the lower roll, gripping means carried by the chains and adapted to strip a sheet from the lower roll and deliver it printed-side-up at a point spaced therefrom;

and stop fingers positioned uniformly with respect to the lower roll each time the gripping means,

passes therearound and moving with it for cooperating with the gripping means as the gripping means passes around said lower roll and accurately registering asheet with respect to the lower roll.

19. A printing press including printing rolls of which one is an ink-bearing roll adapted to print the ink on a sheet, and chain delivery means including chains extending around and away from the said roll, gripping means carried by the chains and adapted to strip a sheet from the said roll and deliver it at a point spaced therefrom, and stop fingers positioned uniformly with respect to the said roll and moving with it each time the gripping means passes therearound for cooperating with the gripping means as the gripping means passes around said lower roll and accurately registering a sheet with respect to the said roll.

means forming an angle into which the sheet is' fed and which, in closing of the finger, moves relatively in a direction opposite to the direction of feeding.

21. A printing press including printing rolls, a gripping unit passing around one of said rolls in predetermined relationship thereto and including a grip base, a movable grip finger and registration-stop means carried thereby, and feeding means for feeding a sheet into the gripping unit at such speed and direction that the sheet will be buckled by the stop means outside of the grip finger as the grip finger is closed; said stop means extending continuously from the grip finger when it is open to the grip base whereby a sheet fed betweenthe grip finger and the grip base cannot possibly slip past the stop means.

22. A two-purpose press having printing rolls adapted to print optionally the upper or lower face-of a sheet with different methods of printing, and delivery means for delivering the sheet eitherface-up so that, regardless of which face is printed, the printed face may be visible on the delivery pile for inspection.

- means for releasing the sheet gripper after it has traversed said loop and turned' over the sheet, to deliver the sheet with its other face up; the

last-named means for releasing the gripper being adjustable to release the gripper at the earliest possible moment afte'r traversing the loop which will produce satisfactory and dependable delivery of the sheet; the sheet in the position to which it drops upon said release being substantially visible from beyond the loop.

24. Sheet delivery apparatus adapted to turn a sheet over before delivering it, comprising a sheet gripper adapted to engage the sheet to be delivered and to thereafter move through a loop to reverse its direction of movement and means for releasing the sheet gripper after it has traversed said loop and turned over the sheet; said means being adjustable to release the gripper at the earliest possible moment after traversing the loop, which will produce satisfactory and dependable delivery of the sheet; the sheet in the position to which it drops upon said release being substantially visible from beyond the loop.

25. Chain feed and delivery apparatus for feeding sheets to the bite of a printing press formed by two members of which one is a cylinder rotating twice for each impression of a given printing member associated therewith comprising: chains extending generally around said cylinder and away therefrom and of such length as to make one cycle for each two revolutions of the cylinder, a single gripper unit carried by the chains and 00- operating with the cylinder for each printing, means for causing the gripper unit to open to receive the sheet before the gripper unit reaches the bite and for causing it to close on the sheet and carry the sheet to the bite in accurate registration with the printing member and means for causing the gripper unit to release the sheet after it has pulled at least the leading end of the sheet away from the cylinder.

26. Sheet delivery apparatus for delivering a sheet optionally either side up including two pairs of axially aligned sprockets disposed with each sprocket in alignment with a sprocket of the other pair, roller means between the sprockets of one pair and rotatably mounted coaxially therewith, chains extending around the sprockets, a gripper unit carried by the chains and engaging a sheet in the vicinity of the other pair of sprockets, means for causing the gripper unit to release the sheet optionally either before or after drawing the 4 sheet around the roller means, a pressure roller adapted to press the sheet against the roller means, and collection means positioned to receive the sheet Where it is ejected by the roller and roller means without being turned over or where it is released by the gripper unit after being carried around the roller means.

2'7. The combination of a printing press ineluding a printing roll and a member forming a printing bite therewith, chains extending partly while the leading edge of the sheet is moving with the gripping means, and means for again opening the gripping means after the gripping means has carried the sheet away from the printing roll to release the sheet at the desired delivery point; the construction and relation of the parts being such that the sheet is held in predetermined registration with the gripping means as the gripping means is closed, and the gripping means is rigidly disposed with respect to the printing roll with the sheet in predetermined registration with the printing roll as the sheet enters the bite.

28. The combination of a printing press includlng a printing roll and a member forming a printing bite therewith, chains extending partly around the axis of the printing roll, rotating with the printing roll and extending away there-' from, gripping means carried by the chains and at times rigidly disposed with respect to the printing roll, feeding means for feeding a sheet to the gripping means and moving it .as fast as the gripping means moves to cause its leading edge to move with the gripping means, means for opening the gripping means to receive a sheet as it is fed to the gripping means and for closing the gripping means after the sheet is fed thereto and while the leading edge of the sheet is moving with the gripping means, and means for again opening the gripping means after the grippingv means has carried the sheet away from the printing roll to release the sheet at the desired delivery point; the construction and relation of the parts ybeing suchthat the sheet is held in predetermined registration with the gripping means as the gripping means is closed, and the gripping means is rigidly disposed with respect to the printing roll with the sheet in predetermined registration with the printing roll as the sheet enters the bite, and stop means positioned uniformly with respect to the printing roll each time the gripping means receives a sheet, for cooperating with and movingwith the gripping means and accurately registering a sheet with respect to the printing roll.

29. In a printing press, sheet feeding mechanism, a printing couple comprising an upper drum, and a lower drum, the latter being 0nehalf the diameter of the upper drum and having its longitudinal axis offset, in the direction from which the sheets are fed, from the vertical plane which includes the longitudinal axis of the upper drum, means-for mounting either a lithographic plate or a type plate upon the upper cylinder, means whereby the lower cylinder may act either as an ofiset surface or a platen depending upon the type of plate used on the upper cylinder, and means for delivering printed sheets either forwardly from the printing couple in the event that direct printing is being done, or rearwardly toward the sheet feed in the event that offset printing is being done, whereby the sheets are in both cases stacked with their printed faces up.

30. Chain registration-delivery means for a ,press having a printing roll which makes two ciated with the roll from the time it closes upon I the sheet untilit delivers the sheet to the point at which printing thereof occurs.

31. A printing press including printing rolls, the first of which makes more than one revolution for each printing and the second of which has a portion cooperating therewith for printing, and chain registration-delivery means including sprockets rigidly mounted with respect to said first roll and rotating therewith, a pair of chains extending around said sprockets and each having a length corresponding to said number of revolutions of said sprockets and a gripping unit carried by said chains and cooperating with said roll for successive printings by cooperation of said first roll and said portion, means for feeding a sheet for each printing and positioning it to be gripped by the gripping unit in a predetermined position for producing a predetermined registration when the grippingunit carries the sheet to the printing position, and means for opening the gripping unit and closing it upon the sheet so positioned; said gripping unit from the time that it closes upon the sheet until after it has carried the sheet to the position of printing being carried by portions of the chains which are wrapped in engagement with the sprockets whereby the positioning of the gripping unit with respect to the roll will be rigid during said time.

32. A printing press including printing rolls, the first of which makes more than one revolution for each printing and the second of which has a portion cooperating therewith for printing, and chain registration-delivery mean includin sprockets rigidly mounted with respect to said first roll and rotating therewith, a pair of chains extending around said sprockets and each having a length corresponding to said number of revolutions of said sprockets and a gripping unit carried by said chains and cooperating with said rolls for successive printings by cooperation of said first roll and said portion, means for feeding a sheet for each printing and positioning it to be gripped by the gripping unit in a. predetermined position for producing a predetermined registration when the gripping unit carries the sheet to the printing position, and mean for opening the gripping unit and closing it upon the sheet so positioned.

33. A gripper unit for registering sheets for printing presses, including a gripper seat, a grip finger pivoted with respect to the seat to open therefrom to receive a sheet and to clamp the sheet thereagainst, and a registration-stop member'to accurately position the sheet as to its entry within the gripper unit, the face of said stop member being approximately arcuate about the pivotal axis of the grip finger.

34. In a two purpose press, the combination of a printing couple comprising a first cylinder adapted to carry a printing plate on one portion of its periphery and a platen surface on another portion thereof, and a second cylinder cooperating therewith and serving at times as a transfer surface for offset printing on one side of a sheet and at times as a platen surface for print-- ing on the other side of a sheet, and delivery means for delivering a sheet which has been printed in the couple either face up so that regardless of which face is printed, the printed face may be visible on the delivery pile for inspection.

WILLIAM WARD DAVIDSON.