US2207785A

US2207785A - Rotary photogravure printing press

Info

Publication number: US2207785A
Application number: US195114A
Authority: US
Inventors: Curtis S Crafts
Original assignee: GOSS PRINTING PRESS CO Ltd
Current assignee: GOSS PRINTING PRESS Co; GOSS PRINTING PRESS CO Ltd
Priority date: 1938-03-10
Filing date: 1938-03-10
Publication date: 1940-07-16
Anticipated expiration: 1957-07-16

Description

July 1 6, 1940.

l c. l s. CRAFTS ROTARY PHOTOGRAVURE PRINTING PRESS Filed March 1o, 1938 Wig 11 Sheets-Sheet l July 16, 1940.

c; s. CRAFTS ROTARY PHoToGRAvuRE PRINTmG Pass Filed March 1o, 19.38 Y

l1 ShetS-Sheet 2 mit July 16, 1940. Qs. CRAFTS 2,207,785

ROTARY PHOTGRAVRE PRINTING PRESS Filed March 10,. 1938 11 Sheets-Sheet 5' July 16, 1940.

, C. S. CRAFTS ROTARY PHOTOGRAVURE PRINTING PRESS I Filed March 10, 1938 1l SheetS--Sheei'I -4 dttornegs 11 SheetsfSheet 5 July 1,6, 1940. c. s. GRAF-rs ROTARY PHOTOAGRAVURE PRINTING PRESS Filed March 1o; 193s mll NNJ 1- 4- QS \Qw\ m: S4 /7 v 1 l l l I l Il wzl..

C.' s. CRAFTS ROTARY HOTOGRAVURE PRINTING PRESS r11 shets-sheet s Filed March lO, 19258 (Ittornegs Juli 16, 1940.

C. 5. CRAFTS RDTARY PHOTGRAVURE PRINTING PRESS .I ulyl 16, 1940.

l1 Sheets-Sheetl' -Filed March 10, 1938 l Gttomeg rlll'll July 16,1940. c. s. CRAFTS ROTARY PHOTOGRVURE PRINTING'v PRESS 11 sheets-sheet 8 Filed ,March 10, 1958 July v16, 1940. c. s. CRAFTS 2,207,785

ROTARY PHoToGRAvURE PRINTING Pmzsns l Filed March 1o',k '1938v 11 sheets-sheet s (lttomegs July 16, 1940. 'c. s.. CRAFTS 2,207,785

- l ROTARY rHoToGRAvuRE PRINTING mass Filed March' 1o, 19.38 11 shets-she'et 1o 311 e tor E ClttornegS July 1s, 1940.` cls. CRAFTS; *2,207,785

ROTARY PHOTGRAVURE PRINTINGTRESS Filed Ma-rch 10. 1938 ll Sheets-Sheet 1l Patented 16,1940l 2,207,785 no'rAny PnoToGRAvUnE PRrN'rmG PRESS Curtis S. Crafts, Oak Park, Ill., assignor to The Goss Printing Press Company, Chicago, Ill., a

corporation of Illinois Application March 1 0, 1938, Serial No. `195,114!

1s claims.- (ci. 10i-153) The present invention relates to rotary intaglio printing presses and more particularly to novel and improved impression mechanisms of e such presses. l

Objects and advantages of lthe invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by prac'- tice with the invention, the same being realized v and attained by means ofthe instrumentalities l and combinations pointed out in the appended claims. i 'I'he invention consists inthe novel parts, constructions, arrangements, combinationsand im-` provements herein shown and described. l The accompanying drawings, r/eferred to herein and constituting va. part hereof, illustrate one embodiment of the invention, `and together with the description, serve to explain the principles of the invention. Of the drawings:

Figure 1 is a side elevation of. an embodiment of the present invention, with certain parts broken away;

Figures 2 and 2A are a vertical. sectional view, on an enlargedfscale -taken through the end frame of the structure shown in Figure 1;

Figure 3 is a vertical sectional view taken on the line 3 3A of Figure 1;

FigureI 4 is a fragmentary horizontal sectional viewtaken on the line 44 of Figure 3;

Figures 5 is a fragmentary end elevation of the impression mechanism with thesideframe vremoved. l

Figure '6 is a similareview with the partsin position to permit removal orreplacement of the impression roller; Figure '7 is a vertical section taken on theline 1-1 of Flgure';

Figure 8 is a fragmentary detailedv side eleva- 4Q tion of the limit switch operating means shown inFigure1; I Figure 9 isa fragmentary detailed horizontal section taken on the line 9-9 ofv Figure 1;

Figure 10 is a fragmentary vertical section taken on the line lil-l0 of Flgure3:

Figure l1 is a view similar vto Fig. 2A of a modified embodiment of the invention;

Figure 12 isv a diagrammaticview of this modification;- and v Figure 13 is a similar view of an impression arrangement o f the prior art.- This application is in part a continuation of my prior copending application Ser No; 165,281, med sept.- 23, 1937. The inventionprovides a novel and improved impression mechanism for rotary photogravure printing' pressesof the type. having a driven printing cylinder and impression roller anda rotatably mounted heavy backup cylinder, one mounted above the other, so that the paper is 5 pressed against the intaglio printing cylinder by the back-up cylinder exerting its pressure through the impression roller.

'I'he invention has for its object'the .provision of improvements in the general arrangement and construction of parts in the impression mechanism for such a printing press. Afurther ob- -ject of the invention is the provision of a novel and improved impression mechanism which will operate with fractional width rolls as Well as with full width rolls. A further object is the provision of a rotary photogravure press in which the impression cylinder is positively limited in its downward movement towards the printing cylinder and is resiliently held downwardly against 90 these positive limits. Still another object is the provision of an improved rotary photogravure press in which the parts are moved accurately by electric motors and may be moved away from and returned to any desired position.

In an illustrative embodiment of the inventionl means are provided by the invention for raising and lowering the back-up cylinder at one or the other or both ends by automatic power means; such as a motor, and manual means as well, for 3 0 raising and lowering the impression roller with Itheba'ck-up cylinder, while permitting a limited 'relative movement between the impression roller and the back-up cylinder.

The back-up cylinder is preferably operated 35 by means of a threaded shaft by which it is posin certain positionsof the back-up cylinder despite the means for raising and lowering said cylinder.

back-up cylinder. Also when using. fractional Width 'impression rollers substantially uniform 56 impression roller on the web to be printed, de-

rao

pressure may be exerted by both ends of the spite the tendency of the impression roller to give non-uniform pressure due to the length of shaft extending from one end ofthe fractional width roller.

i With the printing press of the type dened, should the web break, thus necessitating complete re-threading of the new web, or should it be necessary for any other reason to move back the back-up cylinder and the impression roller from the printing cylinder, the previous adjustments made for correctprinting pressure for the particular'intaglio cylinder used would have to be again obtained when the roller and cylinders are 4once more placed in operative position.

In accordance with the present embodiment, means are also provided to accurately indicate and measure the position of the center of the back-up 'cylinder with respect to the impression roller and the printing cylinder, so that once the correct pressure has been obtained for any work being done on the printing press, this same 'setting may be referredtoV after the back-up cylinder has been raised out of position whereby the correct printing pressire may be established before placing the machine again in operation.

Also, either one or the other end of the impression roller may be held to limit its relative movement with reference to the back-up cylin Ader and impression roller may be provided, so

.Y that the actuating means, such as the motor driven and the impression roller and back-up means, will be automatically stopped when the roller and cylinder are in proper printing position or are in proper withdrawn position and it Amay further be provided to prevent downward movement of the back-up cylinder and impres sion roller by the motor, in case the pressure between the impression roller and the printing cylinder becomes excessive, such as mightresult from the use of too large an impression roller for the work under consideration, or an improper setting of parts of the press.

being forced linto too close contact with the sur-l face of the printing cylinder, which would result in injury thereof. l

In this embodiment ofthe invention the impression roller, back-up cylinder and printing cylinder have ltheir axes in substantially the same vertical plane. The printing cylinder is cylinder are rotated by contact with each other and the web. The impression roller is mounted in pivoted arms, which in turn are mounted on vertically movable blocks slidable in guideways inthe press frame, and these ,blocks carry stops which limit movement oi the arms andthereby limitl the downward movement of the impression roller and may also serve to hold either end of the impression roller at'` a fixed point. These vertically movable blocks carry -the back-up cylinder by means of self-alining bearings, and the' -heavy springs normally holding the 2,207,785 v f i back-up cylinder is preferably of relatively heavy construction. Extending upwardlyv from the blocks are threaded shafts threaded into a sleeve which is slidably splined to a worm gearl so that the lsleeve may move upwardly beyond the gear. Pressing against the upper portion of each sleeve is a relatively heavy spring which applies Y its fore to the back-up cylinder through the sleeve, the downward movement of the sleeve and cylinder being limited by the worm gear.

Motor mea-ns and manual means are provided for rotatv ing the worm gears to raise and lower the back-up cylinder and these motor means may be selectively coupled to either orv both of the worm gears so that the ends of the back-up cylinder maybe raised either an equal or,l an unequal A member extends from one block and contacts with a fixed indicator of the micrometer. type so as to show the position 'of the back-up cylinder with reference to the printing cylinder,

and thereby give an accurate micrometric indication ofA their relative position and the printing pressure produced thereby, as well-as the degree of vcompression of the impression roller.

' Limit switches are provided for controllingthe motor action. Oneof these limit switches may far. Another limit switch vprevents movement of the backing cylinder andimpression roller to too low a position, and this 'niay include a microswitch which will accurately stop the motor at the right point in the .downward travel of the back-.up cylinder and impression roller. Another limit switchI is provided which is vadapted to open the motor circuit when the impression springs are prevent the backing cylinder being'raised too too highly compressed,-th us guarding. against the operator lowering the impression roller with a -la-rge roller in 'place at the'time when the machine is adjusted for using a smaller roller.

The limited relative movement between the impression` and back-up cylinder holds the roller out of contact with theprinting cylinder'as the back-up cylinder is raised, and also provides a spacev between the impressionroller and back-up vcylinder for paper in case a web break causes the web to wrjap around -the impression roller, at which time the impression roller and back-up cylinder may move upwardly and away from their normal position against thecompressionof the back-up cylindersea-ted.

According to the present invention, the printing pressureis exerted solely by the weight of the back-up cylinder and impression roller through the compression of the resiliently'covered impression roller, and the possible dovvrh ward'movement of the back-upcylinder will beA limited by the sleeves and wormgears. Thus, when printing from fractional width rolls, the downward movement of the back-up cylinder lwill be limited and only a certain maximum pres- Referring now in retail tothe illustrative emu.

`bociiment of the invention as shown in the accompanying drawings,there is vprovided theconventional rotatably driven intaglio-or rotary photogravure 'printing cylinder -\20, '.rotatably journalled in the side frames 2| and 22 and adapted tov be driven in the conventional manner. mediately above thel cylinder lis rotatably mounted a resilient impression roller 24, and immediately above the impressionttrolleris a rotatable pressure cylinder 26,' pressing'roller 24 towards the cylinder 20 t'o the webwhich is Ai'ecl between the cylinder. 20 "and the roller 24.

As is usual with'this general type of'con'struction, the axes of the rotary members 20,'24'and A26 are preferably parallel and in the same vertical plane.

Cylinder 26 is rotatably mounted by means of its reduced shaft ends, and Athe self-alining'antifriction bearings 26, in vertically movable rbearing blocks 2 1which are vertically slidable in a guideway formed inthe side 1frames 2| and 22. More ,indetail, the cylinder 26is reduced at its ends to Aand screw 34.

provide a cylindrical portion30 and a slightly smaller cyindricalportion 3|. yThefinner race of bearing 26 is iitted over the' portion 3|,-and is retained thereon by means of-the bearing cap 33 The outer race of bearing 26 is seated `in a cylindrical aperture in the bearing side by lmeans of the combined retaining and sealing plate 36 and the cap 31, these members being held to theblockf21`by suitable screws.

The side edges 33 of the bearing block 21 are parallel and flt closely within the vertical Aedges I40 forming the guideway, and the bearing block is restrained against any but vertical movement by means of the-plates 4| and' 42 bolted'to its edges. Means are provided for raising, lowering and supporting the pressure cylinder 26,` and as embodied,'these means comprise motor-driven screw means mounted in an .upper part ofthe side frames 2|. and 22, A vertically extending rod 60 has its lower end'securely fastened in a recess in the upper part of bearing block 21 by means of the blocks 6|, and the upper end of this rod is threaded and passes through the correspondingly vois threaded sleeve 62. Sleevef62 is provided with a shoulder 63 by which it, the rod 60, and cylinder 26 are supported on the upper face ofhub 64, this hub being rotatably mounted by means of ball bearings 66 which are supported in members 61 and 63 bolted to the upper-and lower faces, respectively, of supports 63. 'Supports 63 are positioned between the spaced-apart vertical members of the side frame, and rest uponj shoulders formed at the upperpart of thel Sleeve 62 is provided with a vertical helically coiled spring 10 is compressed andex-` c erts its force downwardly upon-the upperportion Aof the screw rod 60. Spring 10 is seated on the spring seat 1| and uponl theapertured seat 12, and is encasedl within the hollow cylinder 13 which slides` overthe seat 1|. Beat. 1| retains a bau bearing 1s whiii is also mounted on a stub .1.6 projecting downwardly from the cap 11 which'is bolted to the upper cross member 1l of the frame, closing the aperture 13 within which is the spring 10 and cylinder 13.v The apertured seat. 12 is supported on a shoulder 80 of the collar 8|, which is slit at 82 and may be tightened by screw 83 to lsecurely clamp. the lower end ofthe hollow cylinder 13. The collar 8| is internally ythreaded and is fitted. to the threaded exterior of theblell86. Bell 85 is enlarged towards itslower end fand receives the ball thrust bearingv 86 which is also supported on a cylinder 8 1 near the upper'v ends.` of the sleeve 62,'and thereby the force of the spring 10, reacting against the cross member 18, isapplied to the screw 60 through sleeve 62,-

ball bearing 86, bell and collar 8|. By rotating -collar 8| with reference to the bell 85, the compression of spring 10 may be varied to vary the printing pressure, and means are provided for facilitating this relative'movement comprising the sockets 30 to receive a turning bar, and key 3| which vholds the bell 85 against rotation with respect to the cylindrical housing 33 bolted toV the upper surface of the support 63. Suitable lubricating means 85 are provided for the interengaging threaded portionsof the members 8| A and.86.'- block 21, and isretained therein on the inner 1 f The interior of the bell 65, the seat 12 and the spring 10 are preferably cylindricaLand slightly larger'than the threaded end of the rod 50, so that the rod may telescope into the spring.

The interior of the support 53 within which is mounted the gear hub 54, the sleeve 52 and their associated parts, is preferably closed by means sof of the web 31, so that these parts may be run in oil, and suitable oil retainingl rings 98 are provided to prevent leakageof oil down the rod 60. In order to further guard against the dripping of oil on the pressure cylinder 25, an accordionlpleated boot |00 surrounds the rod 50 and is attachedto the member 58 by plate |0|, and to the member 25 by plate |02.

As shown in Figure 3, the. spring construction and means for vertically moving the bearing block -21and`the cylinder end is duplicated at each end of the press, and by this means the pressure on the two ends may be independently varied if desired.- v

j -Means are provided for raising and lowering either or both ends of the cylinder 25, and for this purpose a shaft |0` extends from one side of `the press to the other, and is rotatably mounted` parallel to cylinder 26. This shaft may be turned manually by hand wheel ||2 or by power from motor ||4.`

Sleeve 62 is'driven from the shaft ||0 by means of the worm gear ||5 formed integrally with the hub 54, and this worm gear meshes with worm ||6 which is rotatably mounted by means of bearings ||1 in the web 31.' Worm ||6 is formed as a sleeve and surrounds hand wheel shaft |l3 which is rotatably journalled in the sleeve by means of the-bushings |20, thereby permitting relative moyement between the worm 6 and the shaft |3.- At its inner end, shaft ||3 is'keyejd I to4 a coupling sleeve |22 which surrounds the adjacent end of shaft ||0 and is pinnedthereto by taper pin |23, so that shafts `||0 and ||3 are driven together. A positive clutch resiliently moved to coupling position is provided between the sleeve |22 and the'worm ||6, and as embodied, this comprises a toothed clutch collar |26 mounted on the inner end of worm ||6 and held thereto by key |26 and set screw |21, while the 4 other clutch member comprises a sleeve |30 slidably splined on sleeve |22 and resiliently moved into clutch engaging position by means of the compression spring |3|. This clutch may be 5 disengaged by movement of the collar |33 to the right (Figure 4) so as to compress spring |3| and at the same time move the clutch sleeve |30 out of mesh with the clutch member |25.

At the other end of the press, these means are l0 duplicated for raising and lowering the screw rod -50, but the clutch at that end is disengaged by being moved to the left rather than the right'.

'Means are provided for selectively disengagingeither of the two clutching members, and as em- 16 bodied, a rod |35 extends from one side of the press to the other, being slidably mounted in suitable bearings formed in the cross bars |31, supported between the frame members. lOn thisl rod |35 are clamped brackets |40 which support the 20 collarsvl33, and a handle |42 pivoted at |43 and pivotally connected to the rod |35 by pivot pin |44 serves to move the rod towards one end or the other of the press. By moving the rod to the right (Figure 3), the left-hand clutch is disengaged and only the right-hand end of the cylinder will be raised or. lowered, while by moving theV rod to the left, only the left-hand end of the cylinder will be raised or lowered.` In its normal position and as shown, both ends of the cylinder 25 will be raised or lowered simultaneously and an equal amount.

Motor ||4 is connected for driving shaft ||0 at a reduced speed. lMotor ||4 is shown as suspended from one of the cross ribs |50 and has mounted on its shaft end a pinion |5| meshing with gear |52 whichis rotatably mounted by and keyed to shaft ||0, a hanger |54 being suspended from cross-rib |55 for the support of the central portion of the shaft ||0 and the rod |35. 0 'I'he motor operation of the shaft v| |0 is simi-lar to the manual operation 'previously described. As is customary in rotary photogravure presses, the pressure cylinder 25 does not press the paper directly against the printing cylinder 20, but acts through the intermediate impression' roller 24 which may be supported in vertical alinement with the

cylinders

20 and 25. The roller 24 is preferably resilient and is generally formed as a rubber-covered roller, the rubber covering srving to press the paper between it and the cylinder 20 into the cellular intagliated portions on the 'surface of the cylinder 20. As embodied, the impression roller 24 is rotatably mounted in pivoted arms which are supported from the vertically.

movable bearing block 21, and thus the impression roller is free to move up and down to a lim; ited extent, as it is squeezed between the

cylinders

20 and 25. r

Roller 24 is preferably Water-cooled to improve 00 the quality of printing, as well as the life of the As embodied, the roller comprises a.re A

roller. silientcovering mounted on a tubular steel core |6|y which is shrunk ontoatlie inserted roller ends |62. The roller ends |62 have an outward .portion of reduced diameter'to receive the inner race of ball bearing |63 which ts against the shoulder |64, the bearing .being concentric with the roller by means of the tapered. and slotted sleeve |66 and the threaded .sleeve |61, these 70 sleeves being forced inwardly by means of the cap |68 which is held to the shaft end by means of screws |10 threaded into the roller end.

Cooling water'is introduced into the interior of the core |6| through the shaft endV |62 by 7.5 means of a. packed joint which comprises a tube supportedon the outside of the bearing block 21, and stud |94 is provided with locking nuts |96 |12 fitted within a bore inthe roller end |62 and rotatable with respect thereto. This joint is packed by means of the packing |13 which is compressed by means` of the sleeve |14 forced inwardly by the screws |15 which are threaded 5 into the shaft end |62. The outer end of the tube |12. is angled and connects with a flexible hose |18 through which cooling water is supplied.

The construction of the other end of the roller may be a duplicate of that shown in Figure 7, but 10 the iiow of wateris opposite at the two ends of lthe roller.

Means are provided for rotatably supporting the roller 24, and as embodied these means comprise a pair of arms |80, one at each end of the 15 roller 24, pivoted by means of the pivot pins |8| which are supported in a bracket |82 depending from the bearing block 21. .These arms extent!` from oneside of the bearing block to a point directly beneath the cylinder'gjand are there 20` shaped to receive and clamp the ball bearing |63.

Means are provided for facilitating the removal and replacement of the roller 24 in its supporting arms |80,.and as embodied, a bell crank 200'is pivotally mounted on and beneath each of thev arms |80, being pivoted thereon by pivot pins 60 20|. This bell crank extends outwardly. of the press and on its lower surface is provided with an inwardly projecting'rail 202 which coincides with and forms an extension of the shorter rail projecting from the bearing socket |84. Bell 65 crank 200 may be latched in its upper position by means of pin 204 which is resiliently engaged by clip 205 projecting downwardly from bracket |82, and in its upper position is freev 'of possible contact with the printing cylinderv 20. as the 70 printing cylinder is removed'or replaced. In its I lower position (Figure 6), the bell crank is supported by means of pivot pin 20 Aand its upwardly directed end 201 contacts with a shoulder 208 formed on the upper edge of arm |80. In this' 76 position, the mmm ma m rom' a track for Vso that the possibility oi the roller running ci! the grooved portion 210 o! th roller end cap |60,

the track and dropping vonto the printing cylinder is substantially eliminated.

Means are also provided for removing from f the press any water` which may leak through the packed joints at-the ends oi the roller, and for this purpose. the end cap' |68 Aprojects into a chamber 2|2 formed asa part of the member |04, and this chamber 2 2 slopes towards an aperture to which is connected the flexible hose' Motor control means are provided for controlling the operation of the motor so as to auto-` matically stop the movement ofthe cylinder rais-1 -by .abutmentv 201 on edge of block 21 when the cylinder 25 andY its supporting blockl 21 have been suiliciently raised. 2 .y

A similarlimit switch 220 provided with a laterally projecting ar1n22| is mounted below the switch 205 and is adapted to be engaged by the vertically movable'abutment 222 on the block 21 to limit the downward movement of the cylinder and thereby prevent the block 21 and cylinder 25 from being'l'owered too low and into a position where the cylinder might be damaged. Abutment 222 is vertically adjustable with reference to the block 21 to accommodate diHerent sizes of cylinders. j

In addition to the two foregoing limit switches which limit the movement of the'bearing block 21 an d cylinder 25with reference to the machine trame, there is provided a further limit switch which limits the movementof thecylinder with reference to the cylinder 20 and roller 24 and thereby prevents the building up of an excessive impression pressure, as well as permits the automatic return of thecylinder 25and roller 24 to proper printing position, after they have been moved upwardly. In other words, the downward movement of the cylinder -25 and itssupported roller 24 is limited when the spring 12 has been compressedva predetermined amount corresponding to the predetermined proper printing pressure between the impression roller 24 rotary photogravure cylinder 20.

As embodied (Figs. l, 2 and 8) thereis proand the vided a finger 230 to contact with the under faceof collar 6|l and it is pivotally mounted on a bracket 23| projecting laterally from the housing 93, and this finger is connected with an arm 234 which. isconnectedwith a bell crank 232 pivotally mounted on the fixed web 91 in bracket 235 by -means of link 2136 and is resiliently pressed upwardly by means of the tension spring 236.

The lower leg of bell crank 232 is formed as a pointer 231 which travels over a scale 2349 to give the operator an indication of the spring compression which creates the printing pressure, and an arm 240 is mounted coaxiallywith the bell crank 232,and is'connected thereto bythe arcuate slot 24| 'and screw 242 so as to permit relative `movement between the arm 240 and bell crank 232. Arm 240 is provided with a laterally projecting lug 244 which is adapted to contact with and move the plunger4 246 of the micro-limit switch 241V asoma I d l 4 mounted on .onev side ci the scale 239, this switchalso serving to interrupt the powergcircuit supplying motor H4. i v s Thus, the motor' I I4 causes` the-cylinder 25 and roller 24 to be lowered. In case the roller2'4 is not in place, or the cylinder .20 vhas vbeen removed,

limit switch

2,20 will stop the downward movement in the position shown in Figurel, but if both tl'e cylinder 20 and roller"24 areinplace, the roller 24 is squeezed between the cylinders'20 and 25 by the weight of the' cylinder25 causing a corresponding movement of the finger 230 and pointer 23-1. If the pressure is in excess of the predetermined printing pressure, lug 244 moves the switch plunger 246 to circuit opening position 'causing the power to be discontinued to motor ||4 and lthereby preventing damage to the mechanism.

Means are also provided for visually indicating to the operator the exact'and correct position of the pressure cylinder 25, and forthis .purpose a dial micrometer 249 (Figs. i and 9) of conventional construction is mounted'on the side frame 2 2| by means of bracket 250. A slidable bracket 25|, vertically positionable on the block 21 along guideway 253 held in desired position' by means of the screw 254, is provided with alaterally projecting arm 256 and an outwardly projecting shaft 250. .Arm 251 is rotatably journalled on shaft 256 and is urged in a counterclockwise direction byA means of the helical spring 259, its movement z 249. When the correct'printing position has once been determined, the screw 260 may be turned to produce a zero reading of the micrometer, and

thereafter the. operator` can determine by inspec-f' tion of the micrometer any deviation from this normal and correct. position for lthe cylinder 25 and block 21. Y y

The operation of the illustrative embodiment previously described will be apparent from the. detailed description thereof, but may be summarized, as follows:

With the entire mechanism off the impression,

spring 10 is compressed to a point where its total load is slightly greater than the maximum impression pressure which will be used. When this occurs, the back-up cylinder and its supporting mechanism 'are moved downward and the down'- ward load is carried by sleeve- 52 resting on the upper shoulder of the worm gear at 53.

To set up a four-page Wide roll on impression, the'r'oller is positioned into its socket an'd is adjusted on both ends by means of adjusting nuts |96 until there is approximately M; inch space between the rubber roller and the back-up cylinder. The entire mechanism is then lowered until the rubber roller contacts the printingcylinder by which it is supported, and the 1A; inch clearance between the rubber ro1land the back-up drum has just -been taken up. The pointer'on the dial 249 is then set to zero by means of adjusting screw 260 and 264'. The backing rollis then loweredthrough its. mechanism until the correct reading isl obtained on the 'dial indicator.- This being the proper impression for printing with the four page wide roll, the lower limit switch 220 is then set to stop the mechanism in its downward motion at this point. Should the web break and wrap around the rubber roller, the impresi. sion roll can move upwards as soon as the combined pressure'of the rubber and the paper bev come equal to and greater than the load on spring 10, since the sleeve 52 is free to slide vertically in wormgear H5` and since $4; inch space ,wasl originally allowed in the setting between the rubber roll and the back-up roll. During the printing process, however, spring load is taken on lip 53 and, consequently, the full weight of the back-up roller is never exerted on the rubber roll and printing cylinder.

To set a one page wide rubber roll when the rubber is on the outside page: The backing roll and rubber roll are moved oif impression. Then the rubber roll is set in its sockets and both ends are brought up by means of adjusting screws or nuts |96 until the rubber roll is tangent to the backing roll on both ends. Then the side on which the rubber roller lies is lowered about 1/8 inch. The entire device is then lowered until the rubber contacts the printing cylinder 'and the backup drum just contacts the top of the rubber roller, in which position the dial indicator is set to zero. The mechanism is then lowered until the proper reading is obtained on the dial indicator, and the lower limit switch then set. In this\way, the unbalanced weight of the roller stock is supported on the extreme end by the ad;v

justing nuts |96 while that bearing on Ith'e stock nearest the rubber itself is free to swing a distance of 1/8 inch away from theback-up roller.

Figures 11 and I2-i1lustrate a modiled embodiment of the present invention and,` as shown, the parts are generally similar to those of Figures l to 10. However, and as shown structurally in Figure l1 and diagrammatically lh Figure 12, the back-up cylinder 25, the impression roller 24 and the intaglio printing cylinder` 20 are not in the same vertical plane, but the axis of the impression roller 24 lies ahead of the plane connecting the axes of cylinders 20 and-25, that is, the pointof impression, which is the point at which the paper is pressed against the intaglio cylinder 20,

'is beyond the plane passing through the axes of

cylinders

20 and 25. y y

In the past, it' has been customary to have the back-up cylinder, impression roller and -printing cylinder vertically alined, with all of their axes in a common plane, as shown in Figure 2A, or in some cases the impression roller has been placed as shown in'Figure 13, with its axis lying in ade vance of the plane connecting the

axes'of cylinders

20 and 25. Infeither of these caseshow ever, the impression relier 24 tends to move back and forth in an amount determined by the play in the impression roller bearings, thereby resulting in poor quality printing. When the roller is placed as shownin Figure 13, the roller is constantly being driven from the cylinder 20,'and is urged into thel narrowing space between the cyl`- inders 20 and 25, but due to its resilient covering, the roller moves back and forth and its com-v vtending to move to one side or the other, but alwaysvbeing restrained towards a central position by its support and bearings. However, by placing the roller axis as shown in Figures 11 and 12,

thedriving torque and roller compression act in a single v direction and tend to press V the roller against the bearings for 'the roller, thereby holding the roller in a constant position, and producing a constant impression pressure.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within 'the scope of the accompanying claims 1. Ina rotary photogravure 'printing press an impression roller, a pressure cylinder, means for rotatably supporting said cylinder, pivotally mounted means radially movable with respect to said cylinder for rotatably supporting said roller whereby the roller may move toward and from said cylinder and angularly thereof, and an outwardly extending trackway to receive and support the roller while it is moved to and from its ,other support. 'f

- 2. In a rotary photogravure printing press-an impression roller, a rotatable pressure cylinder, means for positively limiting downward movement of the cylinder, means for resiliently resisting upward movement of the cylinder, and motor operated means for selectively raising or lowering either or both ends of the cylinder.

3.A a rotary photogravure printing press two press rame members having guideways, a bearing support vertically movable` in each guideway, springs forcing the supports downwardly, a pres- `sure cylinder rotatably mounted in said bearing support, an angularly movable impression roller mounted beneath said cylinder and normally held parallel therewith, means for angularly moving the impression roller relative to the cylinder and .means for variably positioning said cylinder.

4. In a rotary photogravure printing press a pair of press frames having guideways, one 'frame at either side of the press, a slidable bearing block in each guideway, screw means for raising and lowering the slidable blocks, a motor for operating the. screw means, a pressure cylinder rotatably mounted in said blocks, an -impression roller, brackets in which said roller is rotatably journalled, means for pivotally supporting said brackets on said bearing blocks, spring means for applying a resilient force to said cylinder and roll r, means 'for indicating the relative position of t e pressure cylinder with reference to the printing cylinder, a limit switch, a pressure indicator,` and means Ycontrolled by the pressure indicator for operating they limit switch on tob great pressure between the pressure and printing cylinders.

5. In a rotary'photogravure printing .press ay pair of press frameshavingguideways, one frame at either side of the press, a slidable bearing block in each guideway, screw means for raising and lowering the slidable blocks, a motor for operating the screw means,` a pressure cylinder rotatably mounted in said blocks, an impression roller, brackets in which said roller is rotatably journailed, means for pivotally supporting said brackets on said bearing blocks, spring means for applying a resilient force to said cylinder and rollerl a limit switch, a pressure indicator, and means controlled bythe pressure indicator for operating the limit -switch on to'o great pressure between the pressure and printing cylinders.

6. Ina rotary photogravure printing press.

'the combination of a printing cylinder and a 75 'ygnessiirey cylinder, vertically movable bearing blocks in which the pressurecylinder. is rotatably supported, vmeans for positivelyiimiting down ward movement of the cylinder, means for in- 6 dependently resiliently pressing the ends of the pressure cylinder towards the printing cylinder,

and means for independently varying the limitinder by its ends, a motor, clutches connecting' the motor with the screw means, and a manual B means common to the clutches for selectively disengaging either clutch.

9. In a rotary photogravure printing press,ithe

-combination of a pressure cylinder, means for rotatably supporting the'cylinder-by its ends,

25 screw means attached-to the supports, athread.-

ed sleeveon each' screw, a gear held against axial movement and slidably keyed to the sleeve,

means -for limiting movement in one direction f lbetween the sleeve and gear, and 'a compression 30 spring resilientlypressing on each of Isaid sleeves. 10. In a rotaryphotogravure printing press,

the combination of .a pressure cylinder, means for rotatably, supporting the cylinder' by itsends, screw 'means'attached to the supports, a threaded u sleeve on each screw, a gear held against axial movement and slidably keyed to the sleeve, `means for limiting movement in one direction between the sleeve and gear. a compression spring the back-upcylinder and springs for holding the` back-up cylinder against its stops.. 50 12. A-rotary photogravureprinting press including in combination arotatably mountedv photogravure printing cylinder, a rotatably mounted, vertically movable back-up cylinder, arotatable impression roller compressed between the 55 cylinders, variably positionable stops limiting the downward movement of the back-up cylinder and' springs for holding the back-up cylinder against its stops, said springs serving to allow upward movement of the roller and back-up'cylinder in case a web wraps around the roller.

13. A rotary photogravure printing press including in combination a rotatably mounted photogravure printing cylinder, a rotatably mount- .ed. vertically movable back-up cylinder, a rotatable impression roller compressed between the l0 cylinders, variably positionable stops limiting. the downward movement of the back-up cylinder and springs for holding the back-up cylinder against its stops, said springs being movable with the limiting ymeans whereby movement of the limiting l5 means does not vary the vcompression of the springs. i l l 14. A rotary photogravure printing press including in combination a rotatably mounted photogravure printing cylinder, a rotatably mounted, vertically movable back-up cylinder, a fractional width rotatable impression roller com- -pressed between the cylinders, means forA supporting the rollex` adjacent to the back-up cylinder with one end of the rollerin contact with the back-up cylinder, and means for limiting. movement of the back-up cylinder towards the printing cylinder.

15. A rotary photogravure printing press including in combination a rotatably mounted pho- 80 togravure printing cylinder, a rotatably mounted, vertically movable back-up cylinder, a fractional width rotatable 'impression roller compressed between the cylinders, means for. supporting the roller adjacentto the back-up cylinder lwith one end of the roller in contact with the back-up cylinder, means for limiting move ment of the back-up cylinder towards the printing cylinder, and spring means opposing movement of the back-up cylinder with reference to 40 yits'lirniting means.

16. A rotary photogravure printing. press including in combination -a rotatably mounted photogravure printing cylinder, a rotatably mounted, vertically, movable back-up cylinder, a fractional width rotatable impression rollercompressed between the cylinders, means for 'sup- 4porting the roller'adjacent to the back-up cylinder-with one end of the roller in contact with thev back-up cylinder, means for variably limiting movement of the back-up cylinder towards the printing cylinder, said roller supporting means permitting the roller to be compressed towards the back-up cylinder.