US3521559A

US3521559A - Two-color offset printing

Info

Publication number: US3521559A
Application number: US568838A
Authority: US
Inventors: Arthur W Sejeck; James C Garman
Original assignee: Multigraphics Inc
Current assignee: AB Dick Co
Priority date: 1966-07-29
Filing date: 1966-07-29
Publication date: 1970-07-21
Anticipated expiration: 1987-07-21
Also published as: DE1611184B2; GB1181730A; NL149747B; DE1611184A1; DE1611184C3; NL6710523A

Description

July 21, 1970- A. w. SEJECK ETAL TWO-COLOR OFFSET PRINTING 6 Sheets-Sheet-l Filed July 29, 1966 I NVENTORS.

A RTHUR W SEZJE'OK Janzs C. GARMAN Arrow/Ev,

ly 1970 A. w. SEJECK ETAL 3,521,559

TWO-COLOR OFFSET PRINTING Filed July 29, 1966 e Sheets-Sheet 2 Fig. 5 1 JAMES C-GARMAN I ATTORNEX} y 1970 A. w. SEJECK ETAL 3,521,559

' Two-0011012 OFFSET PRIN'iING Filed July 29-, 1966 INVENTO/ibj ARTHUR WSEyE K JA MES C. GARMA/v BY W M 6m ATTORNEY- July 21, 1970 A. w. SEJECK ETAk TWO-COLOR OFFSET PRINTING 6 Sheets-Sheet 4 Filed July 29, 1966 INVENTORS. A RTHUR \MSzueclr JAMES C. GARMAN V ATTORNEY.

y 1970 A. w. SEJECK ETAL 3,521,559

TWO-COLOR OFFSET PRINTING Filed July 29, 1966 6 Sheets-Sheet 5 INVENTORS.

ARTHUR WSEJECK JAMES CZGARMAN mma A T TORNE Y.

July 21, 1970 A. w. SEJECK ETAL 3,521,559

TWO-COLOR OFFSET PRINTING Filed July 29, 1966 6 Sheets-Sheet 6' 'INVENTORS. ARTHUR W SEuEcK JAMEs C. GARMAN Maxed ATTORNEY United States Patent 3,521,559 TWO-COLOR OFFSET PRINTING Arthur W. Sejeck, Kirtland, and James C. Garman,

Wickliffe, Ohio, assignors to Addressograph-Multigraph Corporation, Cleveland, Ohio, a corporation of Delaware Filed July 29, 1966, Ser. No. 568,838 Int. Cl. 1341f 7/08, 13/14 U.S. Cl. 101-137 9 Claims ABSTRACT OF THE DISCLOSURE A rotary offset lithographic duplicator is provided with an attachment in the form of an auxiliary head which can be mounted on the frame of the main machine, and which carries an auxiliary master cylinder positioned in operative relation to the blanket cylinder of the main machine and arranged to be driven from the blanket cylinder gear. The auxiliary head embodies an auxiliary frame which is rockably affixed to the main machine frame and an ink system frame which is shiftable on the auxiliary frame to allow the ink rollers to be placed in operative relation to the auxiliary master cylinder, or to be withdrawn therefrom to provide operator access permitting ready changes of masters and cleaning of the blanket between runs. The ink form rolls are arranged to shift well clear of the auxiliary master cylinder to permit such shifting action without interference, and axial adjustment of the auxiliary master cylinder position is provided for to permit, during a run, exact lateral register of the auxiliary impression with the main impression on the blanket.

Special mounting means are provided which make it possible to achieve ready alignment of the auxiliary cylinder axis parallel to the blanket cylinder axis plus proper printing pressure, and this means includes the rockable mounting of the auxiliary frame, as aforesaid, enabling shifting the attachment between the running position with gears meshed and a standby position with gears unmeshed, but without disturbing its fully adjusted condition.

This invention relates to printing or duplicating, and to the provision on small offset rotary printing presses or duplicators of means for applying a second color image on the blanket for transfer to a copy sheet simultaneously with the transfer of an image of a first color from the usual printing head.

In a preferred form of the invention, the means for printing the second color is conceived of as an attachment to existing duplicators, especially those of the familiar Multilith type manufactured by Addressograph-Multigraph Corporation, and is arranged so that it can 'be readily mounted on the machine and properly adjusted into exact coacting relationship with the other machine parts. Moreover, the means, whether or not formed as an attachment, is preferably arranged to be moved into and out of operative arrangement with the other parts of the equipment so that it can be readily used or not at the operators option.

One of the aspects of a rotary duplicator, especially of the lithographic type is the arrangement of various cylinders and rolls about the axis of and in surface contact with a master cylinder. Some are for applying ink and/ or moisture to the surface of a master and others are for receiving the image from the master and transferring that image to a copy sheet. This mutually contacting arrangement tends to restrict access to the master cylinder for the purpose of attaching or releasing masters, and to the blanket cylinder for cleaning the image from its surface when necessary. With the normal single master, single color arrangement, adequate space is available to make a workable arrangement, but when a second master cylinder and its accompanying ink and moisture rolls are added to the assembly, great difficulty is often experienced in attaching masters to or detaching them from either master cylinder, adjustingthe cylinders for peripheral register, and in cleaning the blanket.

One of the objects of the present invention is to overcome this drawback which is common to duplicators with two-color arrangements, and to make the gaining of access to the cylinders a convenient and speedy operation with no loss of proper adjustment in the process.

The foregoing object is accomplished by making a portion of one of the printing heads shiftable in a direction to cause the ink rolls associated with one of the master cylinders to move away from the cylinder surface, and thereby give access 'both to that cylinder and to the other master cylinder and the blanket.

Another object of the invention, when in the form of an attachment, is to provide a convenient means for mounting the attachment on an existing machine, and for quickly and readily adjusting the same for proper parallelism of the cylinder axes, cylinder pressure, and the like.

Another object of the invention is to provide an arrangement such that a master on each master cylinder can be easily individually inked up and made ready Without interference from the equipment associated with the other color.

A further object of the invention is to provide means whereby the master cylinder for the second color can be readily brought into timed relationship to the cylinder for the first color whenever the second color printing device is restored to operative condition after being in a nonuse condition.

Still another object of the invention is the provision of means whereby the operator can readily and quickly adjust the two images placed on the blanket by the two cylinders, so that the images will be in perfect register.

Another object of the invention is the provision of an improved and simplified slide means which is proof against lateral separation, especially suited to the shiftable mounting of one of the printing head portions with respect to the other, but also of general utility in the art of machine construction.

Other objects, features and advantages will appear hereinafter as the description proceeds.

In the drawing:

FIG. 1 is side elevation of a second color attachment for a lithographic duplicator according to the invention, related portions of the duplicator being shown in phantom;

FIGS. 2 and 3 are diagrammatic side elevations of the second color attachment to an enlarged scale looking in the opposite direction from FIG. 1, showing the drive train for operating the attachment and illustrating the parts of the mechanism in two different positions;

FIG. 4 is a detail elevation illustrating the operation of the ink form rolls and is taken looking in the opposite direction from FIG. 1;

FIG. 5 is a detail view similar to FIG. 4 but with the side plate removed and showing the parts in a different position;

FIG. 6 is a detail elevation substantially on line 66 of FIG. 4 with parts being shown in section;

FIG. 7 is a detail section showing the form roll mounting to a larger scale and taken substantially on line 77 of FIG. 6;

FIG. 8 is a detail section taken on line 88 of FIG. 7;

FIG. 9 is a detail section taken substantially on lines 99 of FIGS. 1 and 11;

FIG. 10 is a detail section showing the improved slide arrangement to a larger scale;

FIG. 11 is a detail elevation substantially on line 11- 11 of FIG. 9;

FIG. 12 is a detail elevation to a larger scale looking from the opposite direction of FIG. 1 and showing the moisture control mechanism for the second color attachment;

FIG. 13 is an end elevation of the mounting means for the second color attachment showing the same to an enlarged scale and taken substantially on line 1313 of FIG. 1;

FIG. 14 is a section substantially on line 1414 of FIG. 13;

FIG. 15 is a section substantially on line 1515 of FIG. 13.

Referring to the drawings, FIG. 1 illustrates a known type of lithographic duplicating machine indicated generally at 11 having a main frame 13 on which are rotatably mounted a blanket cylinder 15 and an impression cylinder 17. Cooperating with the blanket cylinder is a master cylinder 19 rotatable on a rocking frame 21 secured to the main frame 13 in a known manner and which, for the purposes of this description, may be considered a part of the main frame. The frame 21 also carries an ink train 23 and a moisture system 25 for supplying the master cylinder 19 with ink and moisture during printing. The

cylinders

15, 17 and 19 are geared together for common rotation and are driven by suitable power means of conventional form (not shown).

The parts described to this point are all well-known and are customary in conventional offset lithographic duplicators.

THE ATTACHMENT IN GENERAL In order to make it possible to do printing work in two colors, the known machine 11 is provided with the attachment of this invention. A pair of foundation castings 29 and 31 (FIGS. 1 and 13) are bolted or otherwise secured to main frame 13 and rockably mount between their upper ends, by means which will be discussed in detail hereafter, a second color attachment indicated generally at 33. The attachment includes an auxiliary frame designated 35 which provides rotary support for a second master cylinder 37. Also mounted on frame 35 is a train of rolls 39 terminating in a moisture form roll 41 for providing moisture to the master cylinder. Slidably mounted on the upper surface of the frame 35 is an ink unit having a frame 43 carrying an ink fountain 45 and a train of ink rolls 47 terminating in ink form rolls 49 and 51 for supplying ink to the surface of the master cylinder 37.

As best seen in FIG. 2, a drive train is provided for powering the master cylinder 37 and various ones of the rolls in the ink and moisture trains. This consists primarily of a gear 53 on the blanket cylinder which meshes with a gear 55 on the master cylinder 37. The latter drives the moisture system through suitable gearing as shown and powers the ink system through a toothed belt and sprocket drive 57 and an additional gear train 59 associated therewith including gears 61 and 63 which are associated 'with axially shifting vibrator rolls '65 and 67 respectively, each of which drives its respective form roll by friction contact therewith. A negator spring urged belt tightener 68 bears against the belt of the drive 57 to maintain it in engagement with its sprockets while the ink unit 43 is being shifted from its FIG. 2 position to its FIG. 3 position. It will be noted that the drive arrangement provides for operating the ink gear train 59 in either position of the ink unit 43. By this arrangement the usual oscillating ducting action of the ink unit is maintained in proper time with the cylinders in the interest of securing smooth uniform ink deposit regardless of whether the ink unit has been shifted or not.

INK UNIT RETRACTION One of the problems in adding a second master cylinder to a duplicator to provide for printing a second color results from the fact that only about 120 of the blanket periphery and perhaps 45 of the main master cylinder 19 are normally exposed for access for the purpose of attaching or detaching masters and for cleaning the blanket surface between runs. As can be seen in FIG. 1, the addition of a second color attachment such as 33 very seriously reduces the access available in relation to the cylinders on the main machine, while the master cylinder on the attachment is almost completely masked by its ink and moisture trains.

.In order to provide for rapid attachment of masters to both master cylinders, and for cleaning of the blanket, the present invention provides a system whereby the ink unit 43 can be shifted back and forth on the auxiliary frame 35 between a forward operating position shown in FIGS. 1 and 2 and a rearward or access position shown in FIG. 3. When the parts are in the FIG. 3 position, it will 'be apparent that the upper portion of the master cylinder 37 will be well exposed for attachment and detachment of masters, and the access to the blanket cylinder 15 and master cylinder 19 of the main machine (see FIG. 1) will be greatly improved. The present invention embodies an improved slide mounting for the ink unit 43 on the auxiliary frame 35 illustrated in detail in FIG. 10. A base track member 69 having an upstanding lip 71 is screwed to the upper edge of each side plate of the frame 35. A moving track member 73 is screwed to each side plate of the ink unit 43 and has a horizontal lip 75 forming with an extension 70 of the member a channel 76 within which a margin of the base track member 69 is received. The extension 70 rides on the base track member 69 and abuts the lip 71 thereon. Also, the track member 73 is provided with a wall 72 normal to the extension 70 to permit securing the track member to the side plate in a direction transversely of the track. The base track has transverse elongate openings 77 associated with the mounting screws 78 to provide for lateral positioning of the base track member. It will be understood, of course, that the arrangements of the slides on the two sides of the machine are of opposite hand so that the possibility of lateral shifting in both directions is prevented. Preferably the track members are made of wear-resistant low friction synthetic resin and may be formed by molding or extruding. As can be seen in FIG. 10, an extremely effective slip joint can be provided which can be adjusted to a nice fit for smooth action with an interlocking arrangement which prevents separation of the parts in a direction normal to that of the sliding action. Placing of the screws 78 and lateral adjustment of the track 69 can be effected by shifting the ink unit 43 to expose the desired screw position. A very inexpensive arrangement is thus provided giving all the benefits of the much more costly machined dovetail slide connection. The sliding motion of the ink unit back and forth is preferably limited by front stops 79, one on each side of the auxiliary frame, and rear stops 81 also provided, one on each side of the auxiliary frame. Preferably the front stops each include an overhang cooperable with an adjustable hook 82 on each side of the ink unit frame 43 to strengthen the connection between the frames against loads tending to separate them during running.

To provide exact, rigid positioning for the ink unit when in its forward position, combined locking and positioning means are provided in the form of teeth 83 adjustably affixed to the auxiliary frame 35. There is a set of teeth on each side of the frame but for convenience, only one set is shown in the drawing (FIG. 4). Cooperable with the teeth 83 are matching teeth 85 on slides 87 associated with the ink unit 43 for vertical movement. A leaf spring 89 urges each slide upwardly, while the slides can be lowered in opposition to springs 89 by the cam lobes 91 acting on followers 93 attached to the slides. The cams are operated by a cross shaft 95 provided with a handle 97 (FIGS. 1, 9 and 11). The placement of teeth 83 is preferably such that the ink unit draws very slightly back from front stop 79 when the teeth engage.

INK FORM ROLL POSITIONING DURING SHIFTING OF INK INPUT The use of two ink form rolls is beneficial from the standpoint of providing adequate ink supply to the master cylinder and maintaining uniform ink distribution. It can be seen from FIG. 1, however, that if two or more form rolls are used, the forwardmost one will interfere with the master cylinder if the ink unit 43 were to he slid back. This invention provides a way of overcoming this problem by mounting the form rolls 49 and 51 to that they can be readily lifted to a position where all rolls will clear the master cylinder during shifting. The manner of accomplishing this is best seen in FIGS. 4 and 5 wherein the shaft of form roll 49 is shown as supported in one end of each of a pair of links 99 which are each supported for pivotal movement about the axis of the contacting vibrator roll 67. Similarly form roll 51 is supported in links 9911 related to the axis of the vibrator roll 65 in like manner. Each link carries a follower 101 adapted to coact with a cam 103 on shaft 95, the pairs of links at opposite ends of the shaft each coacting with a single such cam. The links are urged towards the cam by a tension spring 105 acting between them. Preferably each link carries a stop screw 107 for adjustable contact with a fixed stop 109 on the ink unit frame 43 to provide for the proper degree of pressure contact between the ink form rolls and the master cylinder 37 during printing.

From the above description it will be seen that manual operation of handle 97 will simultaneously release teeth 87 from teeth 83 and lift the form rolls from the surface of master cylinder 37, raising the forwardmost roll 67 to a height sufficient to clear the master cylinder (FIG. 5) whereby the ink unit 43 may be manually shifted rearwardly without interference.

INK FORM ROLL NIGHT LATCH ARRANGEMENT While the

links

99 and 99a are pivoted n the vibrator shafts, preferably on the exterior of bushings 111 (FIG. 6) which support the shafts, it can be seen in FIGS. 4 and that the openings 113 which receive the bushings are slightly elongate so that the upper ends of the links can be placed in either of two positions. The position shown in FIGS. 4 and 5 is the one providing minimum distance between vibrator and form roll centers and is the pressurized position for running. When the machine is to be idled for some time, pressure between the vibrator and form rolls must be relaxed to prevent flattening the rolls, and this night latch positioning is accomplished by shifting the

links

99 and 99a so that the other ends of their elongate openings 113 will embrace the bushings 111 to space the roll centers farther apart. Preferably this shift is accomplished by means of pairs of

control links

115, 115 which are driven by eccentric shafts 117 as seen in FIG. 4, which shafts can be manually rotated by suitable handles 118, seen in FIG. 1.

INK FORM ROLL POSITION FOR BLANKET CLEANUP At certain stages in the operation of the machine, especially during adjustment for register, it is desirable to feed sheets for cleaning the image from the blanket and removing residual ink from the master image with the ink form rolls out of contact with the master. This can be accomplished by turning handle 97 anticlockwise, but only about half of the usual distance so that cam 91 will not move far enough to release the ink unit locking teeth 83, 85. When this is done, the ink form rolls are raised enough to clear the master surface, but the contact is maintained between cylinders 37 and which is desirable to effect removal of ink from the master at the same time. A slight detenting recess 120 (FIG. 5) in the cam surface signals this position by feel to the operator so that he does not overshoot the intermediate position.

FORM ROLL REMOVAL AND REPLACEMENT At this point it may be noted that the ink form rolls 49 and 51 are mounted so as to be easily removed for cleaning and/or replacement. FIGS. 6, 7 and 8 show that each form roll actually has a shaft which is short enough to be received between the side plates. In each of the

links

99 or 99a is clamped an eccentric bushing 131 in which is rotatably carried a short shaft segment 133 with a half-socket head 135. A roller bearing 137 is mounted on each end of the roll shaft 130, as by a screw 138, and each bearing is received in one of the half sockets 135. To hold the bearing tightly in the halfsocket, a cap 139 is attached to each half-socket by screws 141. As can be seen from FIG. 7, the cap 139 is designed to be retained with the roll 49 since the ring 142 with which it is provided is smaller than the bearing 137.

Whenever it is desired to clean or change form rolls, it is only necessary to remove screws 141, slide both caps 139 towards the

roll

49 or 51 and lift the assembly free of the half sockets. A form roll is installed by merely reversing the process.

Rotation of the clampable eccentric bushings 131 provides an adjustment for bringing the form roller into parallelism and uniform pressure, contact with the vibrator roll surface.

OPEMTIONAL CONTROLS FIGS. 9, 10, 11 and 12 show how the various steps in printing operation are controlled by a single lever 143 which is movable to several angular positions in series to effect such control. The lever is secured to the end of a main shaft 145 which is rockable in the auxiliary frame 35 and also axially shiftable therein. The shaft rotatably supports the second master cylinder 37 by means of bearings 147 secured to the cylinder. The shaft also carries operating mechanisms for raising and lowering the moisture form roll 41, for raising and lowering the ink form rolls 49, 51, for moving the second master cylinder into and out of printing contact with the blanket cylinder, and for performing these operations in proper sequence.

As seen in FIGS. 9 and 11 the shaft 145 is drivingly connected to an ink cam 149. Its opposite end (FIG. 12) is drivingly connected to a moisture cam 151 which includes in addition to its moisture control profile a series of detent notches marked I, II, III and IV for convenience and cooperable with a spring pressed detent roller 153. The ink cam coacts with a follower 155 which actuates a linkage consisting of a link 157 pivoted on the ink unit 43, and a link 159 pivoted to the first link at 160, and at its other end to a crank arm 161 drivingly connected to the cross shaft 95 previously described. This linkage is so constructed that the high point of cam 149 turns the shaft 95 an amount sufficient to raise the ink form rollers just free of the surface of master cylinder 37.

At this time it may also be noted that actuation of the handle 97 to its complete throw position to place the ink form rolls in the FIG. 5 position, also lifts the follower 155 entirely clear of cam 149 to a level above the top of auxiliary frame 35, so as to be in a clear position for shiftin the ink unit 43 back and forth as heretofore described.

Looking at the other side of the machine as seen in FIG. 12, the moisture cam coacts with a follower 163 which drives a bell crank 165 acting on the link 167 pivoted as at 168 on the auxiliary frame and held against the bell crank by spring 169. The upper end of the link 167 carries the shaft of moisture form roll 41. A pin 171 and fork 173 are associated with a rock shaft 175 which by a similar interconnection drives another link 167 (not shown) on the operators side of the machine for providing duplicate movement of the other end of the shaft of the moisture form roll 41.

For convenience the cam positions have been marked with Roman numerals corresponding to those used for the detent positions so that the simultaneous action of the parts can be better understood. Thus, when handle 143 is so placed that detent notch I is engaged by roller 153, the follower 163 will be on the high point of cam 151 and the moisture form roll 41 will be moved out of contact with master cylinder 37. Likewise, follower 155 will be on the high land of cam 149 so that the ink form rolls will be raised. This is the starting or off position.

Moving to detent position II, it is now apparent, lowers the moisture form roll but maintains the ink form rolls raised, and is known as the moisture position.

Detent position III (the position shown in FIGS. 11 and 12 of the drawings) provides for both moisture and ink form rolls to be lowered so as to ink the master image and is referred to as the ink position.

Moving to detent position IV makes no change in the ink and moisture form rolls, but effects another type of change. As best seen in FIGS. 9 and 11, the shaft 145 has integrally attached eccentric sections 177 each of which nest nest in an opening in one end of a turnbuckle link 179, one on each side of the machine, the arrangement on the operators side being the only one shown since both are the same. Each turnbuckle has a threaded end passing through a bore in a perch 181 rockably secured to the main machine frame 13. Each turnbuckle is anchored to its perch by the

clamp nuts

183 and 185, which serve to provide initial set-up adjustment of the machine as will presently appear. When the handle 143 is moved to detent position IV, the eccentric portions 177 of shaft 145 are rotated to effective position and serve to draw the second master cylinder 37 into contact with the blanket cylinder 15 to place an ink image on the blanket ready for printing. This is known as the cylinder contact position.

As can be seen from the above description, when a fresh master has been placed on the cylinder 37, moving the handle 143 through the sequence of detent steps I, II, III and IV gets the second color image onto the blanket in condition ready for printing, and moving the handle sequentially in the opposite direction brings the second color operation to a stop in an orderly fashion by first separating the master cylinder from the blanket cylinder, and then lifting the ink form rolls and moisture rolls in that order.

An additional position for handle 143 is indicated in FIG. 11 by the presence of notch 187 in the ink cam. When the shaft 145 is shifted clockwise sufficiently to place the follower in notch 187, the ink form rolls are allowed to be lowered into contact with the master cylinder 37, but without moisture form roll contact. This is called a clean up position and permits running down the ink in the ink train, after the ink fountain has been emptied or functionally disconnected, by placing an absorbent clean up sheet on the master cylinder. Lack of moisture form roll contact prevents unnecessary application of ink to the moisture system during this process.

ADJUSTING THE REGISTER In order to bring the two color images on the blanket cylinder into proper lateral register, the present invention provides means for moving the second master cylinder into desired laterally adjusted position while the duplicator is running so that the results can be observed and a very precise adjustment achieved. Referring to FIG. 9, it will be recalled that the entire shaft 145 is axially shiftable on the auxiliary frame 35. A series of elements are trapped on the shaft between two thrust nuts 189 and 191. In order from left to right these elements are a thrust bearing 193, a collar 195 and the master cylinder 37 on its

bearings

147, 147. The collar 195 is provided with a flat 197 which cooperates with a key 199 atfixed to the inside of auxiliary frame 35 and permits sliding motion of the collar but prevents any rotary or rocking motion. As can be seen in FIG. 9, one end of the collar 195 is exteriorly threaded and makes threaded connection with a rotary bushing 201. The bushing has a toothed flange or gear 203 meshing with a pinion 205 rotatable by means of a manual control knob 207. By rotating the knob 207 in one direction the threads on collar 195 cause the same to be shifted to the left, and with it the shaft and cylinder 37. Opposite rotation of knob 207 causes shifting of the cylinder 37 and shaft 145 to the right.

It is customary to have the main master cylinder clamped to its drive gear in an adjustable manner so that small peripheral adjustments of the cylinder can be made and the impression thereby can be adjusted lengthwise of the copy sheet. The present invention contemplates a similar adjustable connection for the second master cylinder 37 and its gear 55 so that it is possible to make a peripheral adjustment in the master position after clamping to the second master cylinder, thus providing for precise longitudinal register between the first master image and the second master image on the blanket surface.

ATTACHMENT MOUNTING MEANS AND SET-UP ADJUSTMENTS Referring to FIGS. 13 to 15, the

foundation castings

29 and 31 have a shaft 209 fixed between them. One end of the shaft carries a sleeve 211 rockable on the shaft and having a peripheral surface 213 eccentric to the shaft axis. A bracket 215 rockably receives one end of the shaft. A bracket 217 has a socket clampably receiving the sleeve 211 and thereby rockably receiving the other end of the shaft via the sleeve bore. Means are provided for clamping the sleeve in an adjusted position within its socket, shown as flanged clamp screw 218. The brackets are secured to the lower surface of the auxiliary frame 35 at opposite sides thereof by means of screws 219, FIGS. 1, 14 and 15. The screws occupy elongate slots in the auxiliary frame structure to allow for front to back adjustment.

By means of the described mounting features, it is possible to line up the attachment quickly and accurately upon the machine by the following procedure.

(A) Arm 143 is turned to cylinder contact position IV.

(B) Sleeve 211 is turned to the neutral (FIG. 15) position.

(C) Screws 219 and turnbuckle nuts '183 and are loosened.

(D) The auxiliary frame 35 is slid forward on its

brackets

215 and 217 until the bearer rings on both ends of the second master cylinder and the blanket cylinder are in firm contact.

(E) By adjusting the sleeve 211, the bottom of the auxiliary frame 35 can be made to contact both of

brackets

215 and 217 equally and firmly with the bearers remaining in proper contact, whereupon clamp screw 218 and screws 219 are tightened.

(F) The handle 143 is then moved to a separated cylinder position, e.g. position III, and the

clamp nuts

183 and 185 on both turnbuckles are adjusted to give the prescribed bearer spacing for such cylinder separated position which will result in the appropriate pressure during printing, e.g. about .012 inch.

INACTIVATION AND REACTIVATION There are times when it may be desirable to disconnect the second color attachment so that its parts will not have to operate idly while the main machine is printing a single color. The construction heretofore described makes it possible to do this easily without losing the accurate adjustment previously arrived at. This can be accomplished by merely backing off the lower nut 185 associated with each turnbuckle 179 and causing the attachment 33 to rock bodily away from the blanket cylinder about the axis of shaft 209 by a very small amount. This movement unmeshes gears 53 and '55 so that the entire second color attachment will be inactive. In order to hold the parts in this position and prevent inadvertent meshing of the gears, the bracket 215 is provided with a depending ear 221, and a blocking screw 223 is threaded in a boss 225 on the foundation casting 29. By threading the screw 223 forwardly it can be placed in a position to block the motion of car 221 and thereby prevent the attachment from rocking back so as to mesh the gears.

When reinstatement of operation of the attachment is desired, the blocking screw 223 is backed off and the attachment is swung forwardly about the axis of shaft 209 until nuts 183 bottom on their respective perches 181, the

gears

53 and 55 being placed to mesh in proper timed relation during the process. All that is then required is to tighten clamp nuts 185 and the attachment is again ready for operation. The attachment, however, is rather large and heavy, and the center of gravity, especially if the ink unit is retracted, is normally back of the shaft 209, so that a single operator may well have difficulty in holding the attachment at a position such that the gears remain in mesh while also tightening the nuts 185 properly. This inconvenience is overcome by providing a holding means comprising an eccentric disk 227 rockable on the casting 29 to a position in which it blocks swinging motion of the ear 221, where it is held by a tension spring 229. This position is shown in FIG. 14. For convenience, the disk may have a spiral outline so that its rotary position can be used as an adjustment to determine an exact angular position of the attachment, and an adjustable stop screw 231 may be set to give the proper angular limit of disk travel for this setting. A handle 233 (FIG. 1) on the exterior of the machine is used to swing the disk which, when it is swung far enough to move the spring 229 over center, remains inactive. While the disk is active, the operator may release the attachment and tighten the nuts 185, whereupon the disk 227 is moved to inactive position and the attachment is ready to run.

It is important during reactivation of the attachment to have the gears mesh in such a way that the cylinders will be in proper timed relation, and this invention provides a simplified means for accomplishing this. Heretofore captive spring retracted wrenches have been provided on the duplicating machine housing to engage the screws which clamp each cylinder to its driving gear. This simplifies making peripheral image position adjustments after the master is clamped on the master cylinder. Such an arrangement is also embodied in the present attachment, the gear clamping screws 235 which are associated with each of the main and second master cylinders being diagrammatically illustrated at 235 in FIG. 1. According to the present invention the retractable wrenches (not shown) are mounted on their respective frames at such locations that when they can be engaged with the heads of the respective gear clamping screws, the cylinders must be in proper time. The wrenches thus constitute physical contact locating means for the cylinders which insure a proper timing relationship of the cylinders whenever the attachment is being readied for reactivation.

OPERATION Specific aspects of the operation of the invention especially as to setting up and adjusting of the machine, and switching of the attachment from running condition to stand-by condition have already been described. The present description will concern itself with the overall operation of the machine under normal circumstances.

Assuming that the machine has been prepared by placing moisture and ink in the respective fountains, the operator moves the handle 97 anticlockwise to unlock the ink unit 43, :and shifts it rearwardly. He then attaches one master to the main master cylinder 19 and another to the second master cylinder 37 locating them carefully, of

course, in relation to the customary register marks. The main machine may then be started and operated in the usual way to apply ink and moisture to the main master. Also the ink unit 43 is shifted back to active position and locked by turning the handle 97 in a clockwise direction. Lever 143 is then stepped slowly through the II and III positions to apply moisture and ink to the second master. When both masters are inked properly, an image is placed on the blanket by contacting the main master cylinder with it, and the lever 143 is moved to IV position to place the second image on the blanket. Copy sheets are then fed to the blanket and the impressions inspected. If the images are out of register peripherally, a notation is made of the amount of movement required. If the images are out of register laterally, the knob 207 is merely adjusted just enough to bring them into exact register. Peripheral misregister, if any, is preferably corrected by releasing the ink unit via lever 97, shifting the ink unit out of the way, adjusting the clamped relation between the master cylinder 37 and its gear 55 by the amount noted, and then shifting the ink unit back to active position and locking it by means of lever 97.

If it is then necessary to remove the improperly placed images from the blanket, the operator lifts the ink form rolls on the main cylinder by the usual night latch control handles, and sets the handle 97 in the intermediate position heretofore described to raise the ink form rolls from the second master. The machine is then run with the paper feed on to pass several cleaning sheets to the blanket until no image is obtained, and is thereafter stopped. The ink form rolls on the main cylinder are then lowered. The handle 97 is again operated to unlock the ink unit and the same is shifted back to permit access to the cylinder 37, which is unclamped from its gear 55 and shifted peripherally the amount noted as being the peripheral misregister. The cylinder and gear are reclamped, and the ink unit 43 is shifted back to active position and locked by handle 97. The machine is then started up and operated as before to produce two color copy with the two impressions in proper register. When printing is complete, the lever 143 is stepped through positions III, II to position I, and the main machine is shut down and turned off in the usual way.

When it is desired to shut the machine down to a night latch condition for some possibly extended period, the operator will operate the usual night latch equipment on the main machine in the ordinary way, and will move the handles 118 of the ink unit to night latch position to relieve the pressure between the ink form rolls 49, 51 and the vibrator rolls 67, 65.

What is claimed is:

1. A duplicator comprising:

a main frame;

a blanket cylinder rotatable on the main frame;

a first master cylinder mounted on the main frame for coaction with the blanket cylinder;

an auxiliary frame mounted on the main frame adjacent the blanket cylinder;

a second master cylinder on the auixiliary frame arranged for coaction with the blanket cylinder;

an ink unit slidably mounted on the auxiliary frame for horizontal movement between an active position in which the ink unit lies above the second master cylinder and the ink rolls are adjacent the upper portion of the second master cylinder, and an inactive position in which the ink rolls are horizontally displaced from the second master cylinder to provide access thereto for attaching or detaching a master;

an ink form roller carried by the ink unit at a point such that when the ink unit is in its active position and the ink form roller is in contact with the second master cylinder, the ink form roller interferes with shifting motion of the ink unit towards its inactive position; and

means to raise the ink form roller relative to the rest of the ink unit to a level high enough to cause its path, during shifting of the ink unit to its inactive position, to clear the top of the second master cylinder, and to lower the ink form roller into contact with the second master cylinder when the ink unit is in its active position.

2. In a duplicator comprising a frame, a master cylinder rotatable on the frame and ink rolls for supplying ink to the master cylinder and in which the master cylinder is normally shrouded from access from above by the ink rolls and from beneath by other parts of the machine, the improvement comprising:

an ink unit slidably mounted on the frame for horizontal movement between an active position in which the ink unit lies above the master cylinder and the ink rolls are adjacent the upper portion of the master cylinder, and an inactive position in which the ink rolls are horizontally displaced from the master cylinder to provide access thereto for attaching or detaching a master;

an ink form roller carried by the ink unit at a point such that when the ink unit is in its active position and the ink form roller is in contact with the master cylinder, the ink form roller interferes with shifting motion of the ink unit towards its inactive position; and

means to raise the ink form roller relative to the rest of the ink unit to a level high enough to cause its path, during shifting of the ink unit to its inactive position, to clear the top of the master cylinder, and to lower the ink form roller into contact with the master cylinder when the ink unit is in its active position.

3. A duplicator as set forth in claim 2 which includes manually actuable means to lock said ink unit in active position or unlock the same for shifting to inactive position; and

mechanical means interconnecting said manually actuable means with the form roller raising and lowering means to raise the form roller in response to movement of the manually actuable means to unlock the ink unit, and to lower the form roller in response to movement of the manually actuable means to lock the ink unit.

4. A duplicator comprising:

a main frame;

a blanket cylinder rotatable on the main frame;

a first master cylinder mounted on the main frame for coaction with the blanket cylinder; an auxiliary frame; a second master cylinder on the auxiliary frame arranged for coaction with the blanket cylinder; and

means for mounting the auxiliary frame on the main frame adjacent the blanket cylinder and to provide adjustment of the axis of the second master cylinder into parallelism with the blanket cylinder axis comprising:

a foundation shaft carried by the main frame for mounting the auixiliary frame for rocking movement on the main frame to provide for placing the second master cylinder into or out of contact with the blanket cylinder, and

a mounting bracket at each side of the auxiliary frame clampably connected to the auxiliary frame, and associated therewith in a horizontally slidably arrangement when unclamped, one of brackets being directly rockable on one end of the foundation shaft, and the other being mounted on the other end of the foundation shaft by means of an eccentric sleeve which both provides for raising and lowering the other bracket with respect to the foundation shaft and provides for the aforesaid rocking motion of the auxiliary frame on the foundation shaft.

5. A duplicator comprising:

a main frame;

a blanket cylinder rotatable on the main frame;

an auxiliary frame mounted on the main frame adjacent the blanket cylinder;

a second master cylinder on the auxiliary frame arranged for coaction with the blanket cylinder;

means for rocking the auxiliary frame on the main frame to place the second master cylinder into or out of contact with the blanket cylinder including,

(a) adjustable links connecting the main frame frame and the auxiliary frame to provide for adjusting the ambit of the rocking motion of the auxiliary frame,

(b) a cylinder shaft, rockable in the auxiliary frame, on which the second master cylinder is mounted, v

(c) manual means for rocking the cylinder shaft,

and

(d) an accentric portion on the cylinder shaft operatively engaging one end of the link means; and

manual means for adjusting the axial position of the second master cylinder while the machine is running including means for mounting the cylinder shaft so as to be axially shiftable;

means securing the second master cylinder to the cylinder shaft for free rotation thereon but constraining it for axial movement therewith; and

manually operable means for adjusting the axial position of the cylinder shaft.

6. A duplicator comprising:

a main frame;

a blanket cylinder rotatable on the main frame;

an auxiliary frame mounted on the main frame adjacent the blanket cylinder;

ink and moisture trains embodying respectively ink and mosture form rolls cooperating with the second master cylinder;

,(a) adjustable links connecting the main frame and the auxiliary frame to provide for adjusting the ambit of the rocking motion of the auxiliary frame,

('b) a cylinder shaft, rockable in the auxiliary frame, on which the second master cylinder is mounted,

(0) manual means for rocking the cylinder shaft,

and

(d) an eccentric portion on the cylinder shaft operatively engaging one end of the link means;

means securing the second master cylinder to the cylinder shaft for free rotation thereon but constraining it for axial movement therewith;

manually operable means for adjusting the axial position of the cylinder shaft;

cam means mounted on the cylinder shaft; and

means responsive to the position of the cam means due to rocking of the shaft for moving the ink and the moisture form rolls in correlation away from the second master cylinder, and for moving the ink and the moisture form rolls in correlation back into contact with the second master cylinder.

to the master cylinder and in which the master cylinder is normally shrouded from access from above by the ink rolls and from beneath by other parts of the machine;

1 3 7. A duplicator comprising: a main frame; a blanket cylinder rotatable on the main frame;

an ink unit slidably mounted on the frame for horizontal movement between an active position in which an auxiliary frame mounted on the mian frame adjacent 5 the ink unit lies above the master cylinder and the the blanket cylinder; ink rolls are adjacent the upper portion of the a second master cylinder on the auxiliary frame armaster cylinder, and an inactive position in which ranged for coaction with the blanket cylinder; the ink rolls are horizontally displaced from the an axially shiftable shaft on the auxiliary frame for romaster cylinder to provide access thereto for attatably supporting the second master cylinder, said taching or detaching a master; second master cylinder being mounted for rotation the frame and the ink unit thereby constituting a pair on the shiftable shaft but constrained for axial moveof mutually Sliding Part8 c pr ing tr m a s inment therewith; eluding cooperating track members forming a longia threaded member at one end of the shiftable shaft so tlldinal Sliding connection between the Parts and P mounted as to compel Sliding movement of th h ft venting their transverse separation while permitting therewith but held against rotation on the auxiliary assembly of the members in a direction transversely frame; of the track, the improvement comprising:

an element in threaded engagement ith the th d d two first track members of uniform cross section member and having a gear Wheel integral therewith; 2o adiustably secured to one of the sliding p a pinion in mesh with the gear wheel and selectively Said track members being of P C011- rotatable in either direction to effect axial movement figuration as to Provide hofiZOntal bases of the shiftable shaft; and and oppositely disposed upstanding lips,

means accessible exteriorly of the auxiliary frame for tWO complementary track members f niform rotating the pinion to thereby selectively shift the cross Section on the other of the Sliding P shaft axially while the machine is running to provide Said Complementary track members having eX- lateral register between an image on a master on tension means to ride p the horizontal the second master cylinder and an image placed on base of the first track mbers and abut the the blanket cylinder by the first master cylinder. P thereof,

8. Aduplicator comprising: mounting means normal to the extension means a in fr for securing the complementary track members a blanket cylinder rotatable on the main frame; to the other 0f the Sliding P and a first master cylinder mounted on the main frame for channel means embracing the margin of the b se o tion with th bl k li d of the mating first track member remote from an auxiliary frame mounted on the main frame adjacent Its P- the bllflket cylindler; References Cited a secon master cy inder on the auxiliar frame arranged for coaction with the blanket cylinder; UNITED STATES PATENTS ink and moisture systems cooperating with the second 1,968,849 8/1934 Morse 101 4 master cylinder; 2,000,463 5/1935 Browne SOS-3.6

an axially shiftable shaft on the auxiliary frame for 2,730,044 1/1956 Harrison 101 1s1 rotatably supporting the second master cylinder, said 51,843 6/1956 Faeber 101-352 X s nd master cylinder being mounted for rotation 2,845,860 8/1958 Mestre 101 177 on the shiftable shaft but constrained for axial move- 3,014,421 12/1961 Townsend 0 7 X ment therewith; 2,977,874 4/1961 Ritzerfeld et al. 101-247 X means accessible exteriorly of the auxiliary frame for 3,160,448 12/1964 Abernathy et selectively shifting the shaft axially while the machine 3,323,452 6/1967 Pasqllinelh 52 X is running to provide lateral register between an image 3,331,318 7/ 967 Augustyn et al. 101-216 on a master on the second master cylinder and an 3,404,626 10/ 1968 White et a 101-177 image placed on the blanket by the first master cylinder; FOREIGN PATENTS means for mounting the axially shiftable shaft for rock- 747,003 3/ 1956 Great Britain.

ing motion about its axis on the auxiliary frame; and means for controlling the conditions of the ink and moisture systems in correlation, including cams drivingly associated with the rockable shaft. 9. In a duplicator comprising a frame, a master cylinder rotatable on the frame and ink rolls for supplying ink ROBERT E. PULFREY, Primary Examiner 55 J. R. FISHER, Assistant Examiner US. Cl. X.R.