US2768578A

US2768578A - Lock-up mechanism for dry offset printing plates

Info

Publication number: US2768578A
Application number: US384964A
Authority: US
Inventors: John W Park; Otto R Wolf
Original assignee: Tribune Co
Current assignee: Tribune Co
Priority date: 1953-10-08
Filing date: 1953-10-08
Publication date: 1956-10-30
Anticipated expiration: 1973-10-30

Description

30, 1956 J. w. PARK ETAL 2,768,578

LOCK-UP MECHANISM FOR DRY OFFSET PRINTING PLATES 5 Sheets-Sheet 1 Filed Oct. 8, 1953 Filed 001;. 8, 1953 FIE4 J. W. PARK ETAL LOCKUP MECHANISM FOR DRY OFFSET PRINTING PLATES 5 Sheets-Sheet 2 Oct. 30, 1956 J. w. PARK ETAL 2,768,578

LOCK-UP MECHANISMFOR DRY OFFSET PRINTING PLATES Filed Oct. a, 1953 5 Shee'ts-Sheet 5 I; 5.1 Q fi Ki em 7 A7 /7/ 1 Q7 7 Z Pd Mi l lfiw w ll M --mmmiwwk y i f X M M W w MM? R &

Oct. 30, 1956 J. w. PARK ETAL LOCK-UP MECHANISM FOR DRY OFFSET PRINTING PLATES Filed on. a, 1953 5 Shuts-Sheet 4 mmirm Oct. 30, 1956 J- w. PARK ET AL 2,768,578

LOCK-UP MECHANISM FOR DRY OFFSET PRINTING PLATES 5 Sheets-Sheet 5 Filed Oct. 8, 1953 mm 5; mm

N m N United States Patent M LOCK-UP MECHANISM FOR DRY OFFSET PRINTING PLATES John W. Park, Kenilworth, and Otto R. Wolf, Oak Park, 111., assignors to Tribune Company, Chicago, Ill., a corporation of Illinois Application October 8, 1958, Serial No. 384,964

16 Claims. (Cl. 1014 15l.1)

Our invention relates to web printing presses and more particularly to mechanism for applying, tightening and adjusting thin, flexible printing plates upon the plate cylinder of such a press for printing by the dry ofi'set method.

One of the objects of the invention is to provide in such a mechanism means whereby a plurality (usually two) of such plates, each extending part way around the cylinder, may be readily and quickly attached to or disengaged from lock-up devices whereby said plates may be tightened and adjusted upon the cylinder.

A more specific object is to provide in a mechanism of this character movable lock-up bars and means by which the edges of the plates may be definitely located and moved into or out of engagement with attaching elements on the lock-up bars.

Another object of the invention is the provision of means whereby three or more sets of dry offset printing plates may be applied to, and locked up on, a printing cylinder.

Other objects and advantages of the invention will be apparent from the following description of an illustrative embodiment thereof, taken in connection with the accompanying drawing, in which:

Fig. 1 is a top plan view of a printing cylinder and attached plates applied by the mechanism of our invention;

Fig. 2 is an enlarged detailed view, principally in elevation and broken away for convenience in illustration, of a part of the mechanism near the left-hand end of Fig. 1, being taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged partial sectional view taken substantially on the line 3-3 in Fig. 1;

Fig. 4 is a transverse sectional view taken substantially on the section line 4-4 in Fig. 1;

Fig. 5 is a partial sectional view taken substantially on the line 55 in Fig. 7 and at approximately the position indicated on Fig. 1;

Fig. 6 is a partial lengthwise sectional and elevational view taken substantially on the line 6-6 in Fig. 1 and Fig. 8;

Fig. 7 is a partial lengthwise sectional view taken substantially on the section line 7--7 in Fig. 5;

Fig. 8 is a partial transverse sectional view taken substantially on the section line 88 in Fig. 1;

Fig. 9 is a similar view showing certain of the parts in difierent position and illustrating the tool or pin whereby the auxiliary lock-up bars are moved to plate disengaging position;

Fig. 10 is a partial lengthwise sectional View taken substantially on the section line 1010 in Fig. 5; and

Fig. 11 is a partial lengthwise sectional view taken substantially on the section line 11-11 of Fig. 10.

Upon said drawings, illustrating a preferred embodiment of the invention, the reference numeral 15 indicates a printing cylinder mounted on a horizontal shaft 16 and having 4 sets of

flexible plates

17, 18, such as are used in dry offset printing, applied thereto. The cylinder has recesses or cut-

outs

19 and 21 near the opposite ends 2,768,578 Patented Oct. 30, 1955 thereof for receiving in accessible position certain of the mechanism of the invetnion, as will be hereinafter described. Said cylinder is also provided with a spur gear 22 arranged to intermesh with a corresponding gear on a companion impression cylinder and said cylinders are adapted to be driven in the customary nianner from a suit} able press drive (not shown). Bearets 23 are provided on the cylinder at the opposite ends thereof for engagement with mating bearers on the companion cylinder, and there is a hub 24 on the shaft 16 adjacent the outer face of the gear 22, in accordance with the usual construction of rotary printing presses. v

The cylinder 15 is cut away on the opposite sides thereof to provide longitudinally extending recesses or wells 25 (see Figs. 4, 8 and 9) in which most of the plate lock-up mechanism is located. This mechanism on each side of the cylinder is the same, and separate mechanism is provided for each of the plates, of which, as above stated, there are four sets of two each on the cylinder, as shown. The mechanism in each well for one set of plates consists of two similar assemblies which are the same except for reverse (i. e., right-handand left-hand) arrangement. Therefore a description of the elements of one assembly in each well will, for most purposes, suffice for an understanding of all of the different lock-up mechanisms.

Referring now to Figs. 8 and 9, the reference numeral 26 indicates a lock-up bar which is pivotally mounted on a sectional shaft 27 extending lengthwise of the cylinder (see Figs. 4, 5, 10, and 11, in addition to said Figs. 8 and 9). Said bar 26 has at the base thereof horizontal portions 28 (see Fig. 5 particularly), and compression springs 29 (of which 4 are shown for each of the mechanisms-see Figs. 6 and 10) extend between these portions of the bar and fixed support bars 31 which are provided with depending studs 32 on which said springs 29 are positioned. Said springs thus serve to hold the lockup bar 26 normally in the position shown in said Figs. 5, 8 and 9. In this position an outer beveled portion 33 of said bar 26 is in contact with a mating beveled portion 34 on a portion 35 of an inset section of the cylinder 15, said portion 35 overlying a part of the well 25. Said inset segment of the cylinder, of which said portion 35 forms a part, is secured to the cylinder block by means of countersunk screws 35. The beveled extremities of said portions 35 of the cylinders are spaced apart as shown in said Figs. 8 and 9, and also in Fig. 4, and when the bars 26 are in their normal vertical position, as shown in Figs. 8 and 9, the outer extremities thereof are spaced apart to the maximum extent permitted by said beveled portions 34 of said cylinder parts 35. The cylinder elements 35 have extension 40 thereon, in the area between adjacent sets of the

printing plates

17, 18 and the extensions on opposed elements 35 contact each other, as shown in Figs. 8 and 9 and in Fig. 4.

Said bars 26 carry pins 36 near the outer ends thereof adapted to enter holes 37 in inwardly turned portions 38 of the

flexible printing plates

17, 18, which, as shown in Figs. 8 and 9, are loose on the cylinder.

Auxiliary bars 41 are pivotally mounted on the shafts 27 and have vertical portions normally held in engagement with the bars 26 by means of compression springs 42 extending between horizontal portions 43 of said auxiliary bars and the fixed support bars 31, said springs surrounding studs 44 carried by the bars 31 similar to the studs 32 on which the springs 29 are positioned (see Figs. 6, 8, 9 and 10). The outer ends of the vertical portions of the bars 41 are reduced in thickness and are formed with holes 45 (see Fig. 5) to receive the ends of the pins 36. Vertical slots 46 are provided in the bars 41 just beneath the reduced outer portions of the latter and are adapted to receive the edges of the inwardly turned portions 38 of the

plates

17, 18.

Said bars 41 may be turned on their pivots to the position shown in Fig. 9 by means of tools 47 in the form of pins each having a handpiece 48 thereon, said tools being adapted to be inserted through angular holes 49 in the portions 35 of the cylinder. When one of the auxiliary bars 41 has been turned on its pivot to the position shown in Fig. 9 by means of two of the pins 47, the edge of the

plate

17 or 18 may be inserted in the slot 46 as shown in that figure. Upon withdrawal of the pins 47 the bar 41 will be turned on its pivot by the springs 42 from the position shown in Fig. 9 to the position shown in Fig. 8 and the pins 36 during this movement will pass through the apertures 45 in the outer end of the auxiliary bar 41 and through the apertures 37 in the inwardly turned part 38 of the

printing plate

17 or 18.

The bars 26 have offsets 51 near their outer ends so that the outer ends of the bars 41 may be seated beneath these offsets.

With the

bars

26 and 41 in contact with each other and with the pins 36 extending through the apertures 45 in the bar 41 and the apertures 37 in the printing plate, as shown in Fig. 8, said

bars

26 and 41 may be moved as a unit to tighten the plate upon the cylinder by means of cams or eccentrics 52 mounted on sectional shafts 53 extending lengthwise of the cylinder.

Said shafts 53 at the opposite ends of the cylinder 15 extend into the

cutouts

19 and 21 respectively, in the cylinder and have square ends 54 adapted to be engaged by a wrench to rotate the end sections of the shaft and cause said cams 52 to engage a bearing surface 55 on the lock-up bar 26 to move said bar away from the seated position shown in Figs. 5, 8 and 9 to the inwardly inclined position shown in Fig. 4.

The second set of plates from each end are locked up by cams or eccentrics 52 on inner sections of the shaft 53, which are in line with said first-mentioned sections, and carry gears 56 meshing with gears 57 on a sectional shaft 58, each section of which extends through the cylinder the length of two sets of the

plates

17, 18 and protrudes into the

cutout

19 or 21, the outer end portions thereof being squared as indicated at 59 to receive a wrench for rotation of said shaft sections. Such rotation of one of the sections of said shaft 58 actuates the one of the inner sections of the shaft 53, through the

gears

57 and 56, and causes the eccentrics 52 on said such section of the shaft 53 to act upon bearing surfaces 55 on the corresponding bar 26 for the one of the inner sets of

printing plates

17, 18.

Ratchet wheels 61 (see Fig. 2) are provided on the outer ends of the outer sections of tie shaft 53 and cooperate with pawls 62 which are pivoted on studs 63 on the ends of the cylinder 15 within the cut-out 19 or 21 to prevent reverse rotation of the said shaft 53. A spring 64 fastened by screws 65 to said end portion of the cylinder 15 biases the pawl 62 toward the ratchet 61. Corresponding

parts

66, 67, 68, 69 and 78 are employed to prevent reverse rotation of the shaft 58.

The ends of the outer sections of the shaft 27 extend beyond the gears 22 and are squared as indicated at 71 to receive a wrench for rotation of said shaft, for a purpose which will presently appear. Said outer sections of the shaft 27 extend only the length of one set of the

printing plates

17, 18, and in line therewith are inner sections each extending the length of one of the inner sets of the printing plates.

Each of said inner sections of the shaft 27 has mounted on the end thereof a bevel gear 72 (see Fig. 3) in mesh with a pinion 73 on the end of a stub shaft 74 bearinged in a sleeve or bushing 75 extending inwardly at an angle from the exterior of the cylinder between the first and second sets of printing plates. Said stub shaft 74 is formed with a hexagon socket 76 in the outer end thereof to receive a wrench for rotating said shaft and, through the pinion 73 and gear 72, the shaft 27. The bushing 75 has a flange 77 thereon positioned in a cut-out 78 in the cylinder element 35 to which said bushing is attached by screws 79, and the pinion is secured to a reduced portion of the stub shaft 74 by means of a pin 81. The outer end of the stub shaft 74 is flanged as indicated at 82 and the flange thereon overlies the flange 77 on the bushing 75.

The mechanism just described is located between the first and second sets of

printing plates

17, 18, counting from each end of the cylinder 15. Diagonal holes 49 through which the pins 47 are inserted to actuate the auxiliary bars 41 are located between the first and second sets of printing plates, as well as beyond the end plates and between the two inner plates, and said auxiliary bars 41 have extensions 83 (see Figs. 10 and 11) extending beyond the bars 26 so that said extensions may be engaged by said pins 47 to move the bars 41 relative to bars 26.

Each outer section of the shaft 27 has a threaded portion 84 thereon positioned within a tapped lug 85 on the lock-up bar 26 so that rotation of said shaft section will cause movement of said bar 26 lengthwise of the cylinder. Lugs 86 on the auxiliary bar 41 are butted to the ing 85 and to lugs 87 on the lock-up bar 26, so that said lengthwise movement of the bar 26 will cause corresponding movement of the auxiliary bar 41 therewith, and such lengthwise movement of said bars will effect lengthwise adjustment of the printing plates of an outer set for purposes of correction of registration of such plates when used for color printing.

Each inner section of the shaft 27 has a threaded portion 88 thereon positioned within a tapped lug 85 on the second plate 26 and said lug 85 and lugs 87 (not shown) on said second plate are butted to lugs 86 on the second auxiliary bar 41 so that rotation of an inner section of the shaft 27, by means of the

gears

72 and 73 and stub shaft 74, will cause lengthwise movement of said second bars 26 and 41 to effect adjustment for registration of the plates carried by said second bars.

The shafts sections 27 are bearinged in lugs 89 on the cylinder block extending outwardly from the base of the well 25, and lugs 91 and 92 on the

bars

26 and 41, respectively, are provided on opposite sides of one of the lugs 89 (see Fig. 11) at sufficient distance therefrom to permit the aforesaid endwise movement of said

bars

26 and 41.

It will be noted from Fig. 4 that in the intermediate parts of the cylinder the shafts 27 on each side of the well 25 are journaled between an inset block 93 and the block 89 which is attached to said block 93 by screws 95; also that each shaft 53 is journaled between a block 96 and said block 93 to which such block 96 is attached by screws 97; and that each shaft 58 is journaled between said block 93 and the lower part 98 of one of the inset segments of which the overlying element 35 forms a part, the attachment of these members being effected by means of screws 99.

The inturned edge portions 38 of the plates are preformed with a substantially right angle bend as shown in the drawings.

To apply a plate of one of the end sets to the cylinder, the auxiliary bar 41 adjacent the lock-up or actuating bar 26 to which one edge portion of the plate is to be connected is first displaced by the pins 47 to the position shown in Fig. 9 of the drawings. The extremity of the plate is then inserted in the slot 46 in said auxiliary bar 41. Upon withdrawal of the pins 47, the springs 42 will return said auxiliary bar 41 to the normal position shown in Fig. 8. During this movement the edge portion of the plate will be guided so that the holes 37 therein, which are then in alignment with the holes 45 in the bar 41, will be brought into register with the pins 36 on said actuating bar 26, and said

holes

45 and 37 will receive said pins, thus connecting this edge of the plate to said actuating bar.

The same procedure will then be followed to connect the edge portion 38 at the other side of the plate to the corresponding actuating bar 26 on the other side of the cylinder. The other plate of the end set may be connected to its actuating bars 26 in the same manner.

If adjustment of a plate of an end set is required to properly register it with a corresponding plate on another cylinder (in color printing), lengthwise adjustment may be efiected by turning the end section of the appertaining shaft 27 in one direction or the other by a wrench applied to the square end 71 of said shaft at the end of the cylinder.

To tighten a plate of an end set on the cylinder, the shafts 53 may be turned by a wrench applied to the square ends 54 of these shafts, thus causing the eccentrics 52 on said shafts to move the actuating bars 26 on their pivots, which, as above noted, are the shafts 27. By moving these bars differentially, adjustment of the plate circumferentially of the cylinder for correction of registration may be effected.

' The other plate of such end set may be course be adjusted in the same way.

To apply and adjust the plates of an intermediate set the same procedure is followed except that the lengthwise adjustment of the applicable sections of the shafts 27 is accomplished by means of the radial shafts 74 and the rotation of the applicable sections of the cam shafts 53 to pivot the actuating bars 26 is accomplished by means of the shafts 58 and the

gears

56 and 57 carried by said sections of the shafts 53 and said shafts 58 respectively.

Various changes and modifications in the above-described illustrative embodiment of our invention may of course be made within the scope of the appended claims.

We claim:

1. In a web printing press, a plate cylinder having provision for attachment thereto of a set of thin, flexible printing plates for offset printing comprising two plates around the cylinder, and lock-up mechanism for each of said plates including: a plate-actuating bar positioned within the cylinder and having projections thereon, said plates having inturned edge portions provided with holes for receiving said projections whereby a plate may be connected to said actuating bar, a shaft inside the cylinder on which said plate-actuating bar is mounted, means for pivotally moving said bar to cause tightening of the plate circumferentially on the cylinder, an auxiliary bar hingedly mounted on said shaft adjacent said plate-actuating bar and being normally movable therewith as a unit but alsobeing arranged for independent pivotal movement on said shaft, said auxiliary bar being engageable with an inturned edge portion of the plate and being accessible from the exterior of the cylinder for movement relative to said "actuating bar to disengage said inturned edge of the plate from the projections on the latter bar.

2. In a web printing press, a plate cylinder having provision for attachment thereto of a plurality of sets of thin, flexible printing plates for offset printing, each set comprising two plates around the cylinder, and lock-up mechanisms for each of said plates, each of said mechanisms including a plate-actuating bar positioned Within the cylinder and having projections thereon, said plates having inturned edge portions provided with holes for receiving said projections whereby a plate may be connected to said actuating bar, a shaft inside the cylinder on which said plate-actuating bar is mounted, means for pivotally moving said bar to cause tightening of the plate circumferentially on the cylinder, an auxiliary bar hingedly mounted on said shaft adjacent said plate-actuating bar and being normally movable therewith as a unit but also being arranged for independent pivotal movement on said shaft, said auxiliary bar being engageable with an inturned edge portion of the plate and being accessible from the exterior of the cylinder for movement relative to said actuating bar to disengage said inturned edge of the plate from the projections on the latter bar.

3. In a web printing press, a plate cylinder having provision for attachment thereto of a set of thin, flexible printing plates for offset printing comprising two plates around the cylinder, and lock-up mechanism for each of said plates including: a plate-actuating bar positioned Within the cylinder and having projections thereon, said plates having inturned edge portions provided with holes for receiving said projections whereby a plate may be connected to said actuating bar, a shaft inside the cylinder on which said plate-actuating bar is mounted, means for pivotally moving said bar to cause tightening of the plate circumferentially on the cylinder, an auxiliary bar hingedly mounted on said shaft adjacent said plate-actuating bar and being normally movable therewith as a unit but also being arranged for independent pivotal movement on said shaft, said auxiliary bar being engageable with an inturned edge portion of the plate in a manner to move the same either toward or away from said actuating bar upon corresponding movement of the auxiliary bar and being accessible from the exterior of the cylinder for movement relative to said actuating bar to engage said inturned edge of the plate upon the projections on the latter bar or to disengage the same therefrom.

4. In a web printing press, a plate cylinder having provision for attachment thereto of a set of thin, flexible printing plates for offset printing comprising a plurality of plates around the cylinder, and lock-up mechanism for each of said plates including: a plate-actuating bar positioned within the cylinder and having projections thereon, said plates having inturned edge portions provided with holes for receiving said projections whereby a plate may be connected to said actuating bar, a shaft inside the cylinder on which said plate-actuating bar is mounted, means for pivotally moving said bar to cause tightening of such plate circumferentially on the cylinder, and an auxiliary bar hingedly mounted on said shaft adjacent said plateactuating bar and being norm-ally movable therewith as a unit but also being arranged for independent pivotal movement on said shaft, said auxiliary bar having a slot therein for receiving an inturned edge portion of the plate and retaining the same during movement thereof either toward or away from said actuating bar upon corresponding movement of the auxiliary bar and being accessible from the exterior of the cylinder for movement relative to said actuating bar to engage said inturned edge of the plate upon the projections on the latter bar or to disengage the same therefrom.

5. In a web printing press, a plate cylinder having provision for attachment thereto of a set of thin, flexible printing plates for offset printing comprising two plates :around the cylinder, and lockup mechanism for each of said plates including: a plate-actuating bar positioned Within the cylinder and having projections thereon, said plates having inturned edge portions provided with holes for receiving said projections whereby a plate may be connected to said actuating bar, a shaft inside the cylinder on which said plate-actuating bar is mounted, means for pivotally moving said bar to cause tightening of the plate circumferentially on the cylinder, an auxiliary bar hingedly mounted on said shaft adjacent said plate actuating bar and being normally movable therewith as a unit but also being arranged for independent pivotal movement on said shaft, said auxiliary bar having a slot therein for receiving an inturned edge portion of the plate and retaining the same during movement thereof either toward or away from said actuating bar upon corresponding movement of the auxiliary bar and being accessible from the exterior of the cylinder for movement relative to said actuating bar to engage said inturned edge of the plate upon the projections on the latter bar or to disengage the same therefrom said auxiliary bar having holes in the outer end thereof beyond said slot corresponding to the holes in said inturned edge portion of the plate whereby the projections on said actuating bar may pass through said auxiliary bar and through the corresponding holes in said edge portion of the plate when the latter is in its attached position.

6. In a web printing press, a plate cylinder having ,provision for attachment thereto of a set of thin, flexible printing plates for offset printing comprising two plates around the cylinder, and lockup mechanism for each of said plates including: a plate-actuating bar positioned within the cylinder and having projections thereon, said plates each having inturned edge portions provided with holes for receiving said projections whereby a plate may be connected to said actuating bar, a shaft inside the cylinder on which said plate-actuating bar is mounted, means for pivotally moving said bar to cause tightening of the plate circumferentially on the cylinder, an auxiliary bar hingedly mounted on said shaft adjacent said plate actuating bar and being normally movable therewith as a unit but also being arranged for independent pivotal movement on said shaft, said auxiliary bar having a slot therein for receiving an inturned edge portion of the plate and retaining the same during movement thereof either toward or away from said actuating bar upon corresponding movement of the auxiliary bar and being accessible from the exterior of the cylinder for movement relative to said actuating bar to engage said inturned edge of the plate upon the projections on the latter bar or to disengage the same therefrom said auxiliary bar having holes in the outer end thereof beyond said slot corresponding to the holes in said inturned edge portion of the plate whereby the projections on said actuating bar may pass through said auxiliary bar and through the corresponding holes in said edge portion of the plate when the latter is in its attached position, said slot being provided in the outer edge portion of said auxilary bar and opening outwardly toward the periphery of the cylinder.

7. In a web printing press, a plate cylinder having provision for attachment thereto of a set of thin, flexible printing plates for offset printing comprising two plates around the cylinder, and lock-up mechanism for each of said plates including: a plate-actuating bar positioned within the cylinder and having projections thereon, said plates each having inturned edge portions provided with holes for receiving said projections whereby a plate may be connected to said actuating bar, a shaft inside the cylinder on which said plate-actuating bar is mounted, means for pivotally moving said bar to cause tightening of the plate circumferentially on the cylinder, an auxiliary bar hingedly mounted on said shaft adjacent said plate actuating bar and being normally movable therewith as a unit but also being arranged for independent pivotal movement on said shaft, said auxiliary bar having a slot therein for receiving an inturned edge portion of the plate and retaining the same during movement thereof either toward or away from said actuating bar upon corresponding movement of the auxiliary bar and being accessible from the exterior of the cylinder for movement relative to said actuating bar to engage said inturned edge of the plate upon the projections on the latter bar or to disengage the same therefrom said auxiliary bar having holes in the outer end thereof beyond said slot corresponding to the holes in said inturned edge portion of the plate whereby the projections on said actuating bar may pass through said auxiliary bar and through the corresponding holes in said edge portion of the plate when the latter is in its attached position, said slot being provided in the outer edge portion of said auxiliary bar and opening outwardly toward the periphery of the cylinder, and the outer extremity of the auxiliary bar in which said holes therein are located being reduced in thickness and disposed on one side only of the slot whereby-entry of the plate edge into the slot is facilitated.

8. In a web printing press, a plate cylinder having provision for attachment thereto of a set of-thin, flexible printing plates for offset printing comprising two plates around the cylinder; lock-up mechanism for each of said plates including: a plate-actuating bar positioned within the cylinder and having projections thereon, said plates having inturned edge portions provided with holes for receiving said projections whereby a plate may be connected to said actuating bar, a shaft inside the cylinder on which said plate-actuating bar is mounted, means including manually operable cam mechanism arranged to act upon said plate-actuating bar for pivotally moving said bar to cause tightening of the plate circumferentially on the cylinder, an auxiliary bar hingedly mounted on said shaft adjacent said plate actuating bar and being normally movable therewith as a unit but also being arranged for independent pivotal movement on said shaft, said auxiliary bar being engageable with an inturned edge portion of the plate and being accessible from the exterior of the cylinder for movement relative to said actuating bar to disengage said inturned edge of the plate from the projections on the latter bar, thereby facilitating removal of the plate from the cylinder; and means operable by the pressmen for moving said bars lengthwise of the cylinder to adjust the plate on the cylinder for purposes of registration correction.

9. in a web printing press, a plate cylinder having provision for attachment thereto of at least three sets of thin, flexible printing plates for offset printing, each set comprising two plates around the cylinder; plate lock-up mechanism fora plate in an end position on the cylinder, said mechanism including a plate-actuating bar positioned within the cylinder and having plate-engaging elements thereon, said plate having an inturned edge portion provided with means for interengagement with said plateengaging elements whereby the plate may be connected to said actuating bar, means for moving said bar to cause tightening of said plate cincumferentially on the cylinder, means for adjusting said plate-actuating bar lengthwise of the cylinder to correct the position of said plate for registration purposes, said last-mentioned means including a supporting shaft for the plate-actuating bar extending lengthwise of the cylinder and cooperating means on said shaft and said plate-actuating bar for causing movement of the latter lengthwise of said shaft upon rotation of the shaft; and a second corresponding but independent lock-up mechanism for a plate in a position on the cylinder intermediate the end plates, the means for adjusting the plate-actuating bar thereof for correction of registration including also a radial shaft at an intermediate position in the cylinder, gearing operatively connecting said radial shaft and the supporting shaft of said second mechanism, and means whereby said radial shaft may be manually turned to rotate said supporting shaft.

10. In a web printing press, a plate cylinder having provision for attachment thereto of at least three sets of thin, flexible printing plates for offset printing, each set comprising two plates around the cylinder; plate lock-up mechanisms for each of the plates in an end position on the cylinder, said mechanisms each including a plateactuating bar positioned within the cylinder and having plate-engaging elements thereon, said plates having inturned edge portions provided with means for interengagement with said plate-engaging elements whereby an inturned edge portion of the plates may be connected to said actuating bar, means for moving said bar to cause tightening of said plate circumferentially on the cylinder, means for adjusting said plate-actuating bar lengthwise of the cylinder to correct the position of said plate for registration purposes, said last-mentioned means including a supporting shaft for the plate-actuating bar extending lengthwise of the cylinder and cooperating means on said shaft and said plate-actuating bar for causing movement of the latter lengthwise of said shaft upon rotation of the shaft; and a second set of corresponding but independent lock-up mechanisms, one for each of the plates in a position on the cylinder intermediate the end plates, the means for adjusting the plate-actuating bar for correction of registration in each of said mechanisms of 9 the second set including a radial shaft at an intermediate position in the cylinder, gearing operatively connecting said radial shaft and the supporting shaft of such mechanism, and means whereby said radial shaft may be manually turned to rotate said supporting shaft.

11. In a web printing press, a plate cylinder having provision for attachment thereto of at least three sets of thin, flexible printing plates for offset printing, each set comprising two plates around the cylinder; plate lockup mechanisms for each side of each of the plates in an end position on the cylinder, said mechanisms each including a plate-actuating bar positioned within the cylinder and having plate-engaging elements thereon, said plates having inturned edge portions provided with means for interengagement with said plate-engaging elements whereby an inturned edge portion of one of the plates may be connected to said actuating bar, means for moving said bar to cause tightening of said plate circumferentially on the cylinder, and means for adjusting said plate-actuating bar lengthwise of the cylinder to correct the position of said plate for registration purposes, said last-mentioned means including a supporting shaft for the plate-actuating bar extending lengthwise of the cylinder and cooperating means on said shaft and said plate-actuating bar for causing movement of the latter lengthwise of said shaft upon rotation of the shaft; and a second set of corresponding but independent lock-up mechanisms, one for each side of each of the plates in a position on the cylinder intermediate the end plates, the means for adjusting the plate-actuating bar for correction of registration in each of said mechanisms of the second set including a radial shaft at an intermediate position in the cylinder, gearing operatively connecting said radial shaft and the supporting shaft of such mechanism, and means whereby said radial shaft may be manually turned to rotate said supporting shaft.

12. In a web printing press, a plate cylinder having provision for attachment thereto of at least three sets of thin, flexible printing plates for offset printing, each set comprising two plates around the cylinder; lock-up mechanisms for each of the plates in an end position on the cylinder, said mechanisms each including a plateactuating bar positioned within the cylinder and having plate-engaging elements thereon, said plates having inturned edge portions provided with means for interengagement with said plate-engaging elements whereby an inturned edge portion of one of the plates may be connected to said actuating bar, means comprising a shaft and eccentrics thereon for moving said bar to cause tightening of said plate circumferentially on the cylinder, and means for adjusting said plate-actuating bar lengthwise of the cylinder to correct the position of said plate for registration purposes, said last-mentioned means including a supporting shaft for the plate-actuating bar extending lengthwise of the cylinder and cooperating means on said shaft and said plate-actuating bar for causing movement of the latter lengthwise of said shaft upon rotation of the shaft; and a second set of corresponding but independent lock-up mechanisms, one for each of the plates in a position on the cylinder intermediate the end plates, the means for adjusting the plate-actuating bar for correction of registration in each of the mechanisms of the second set including a radial shaft at an intermediate position in the cylinder, gearing operatively connecting said radial shaft and the supporting shaft of such mechanism, and means whereby said radial shaft may be manually turned to rotate said supporting shaft.

13. In a web printing press, a plate cylinder having provision for attachment thereto of at least three sets of thin, flexible printing plates for offset printing, each set comprising two plates around the cylinder; plate lock-up mechanisms for each of the plates in an end position on the cylinder, said mechanisms each including a plate-actuating bar positioned within the cylinder and having plateengaging elements thereon, said plates having inturned edge portions provided with means for interengagement with said plate-engaging elements whereby an inturned edge portion of one of the plates may be connected to said actuating bar, means for moving said bar to cause tightening of said plate circumferentially on the cylinder, an auxiliary bar mounted adjacent said plate-actuating bar and being movable relative thereto, said auxiliary bar being engageable with said inturned edge portion of the plate in manner to move the same toward or away from the actuating bar upon corresponding movement of the auxiliary bar, means whereby said auxiliary bar may be so moved relative to said actuating bar to connect said inturned edge portion of the plate therewith or to disengage the same therefrom, and means for adjusting said bars lengthwise of the cylinder to correct the position of said plate for registration purposes, said last-mentioned means including a supporting shaft for the plate-actuating bar extending lengthwise of the cylinder and cooperating means on said shaft and said plate-actuating bar for causing movement of the latter lengthwise of said shaft upon rotation of the shaft; and a second set of corresponding but independent lock-up mechanisms, one for each of the plates in a position on the cylinder intermediate the end plates, the means for adjusting the plate-actuating and auxiliary bars for correction of registration in each of the mechanisms of the second set including a radial shaft at an intermediate position in the cylinder, gearing operatively connecting said radial shaft and the supporting shaft of such mechanism, and means whereby said radial shaft may be manually turned to rotate said supporting shaft.

14. In a web printing press, a plate cylinder having provision for attachment thereto of at least three sets of thin, flexible printing plates for dry offset printing, each set comprising two plates around the cylinder, separate plate lock-up mechanisms for each of said plates, and separate adjusting mechanisms for each of said plates whereby the plates may be individually adjusted lengthwise of the cylinder to variable final positions for margin adjustment, at least one of said adjusting mechanisms being disposed between a set of said plates at an end of the cylinder and a set intermediate the end sets of said plates.

15. In a web printing press, a plate cylinder having provision for attachment thereto of at least three sets of thin, flexible printing plates for dry offset printing, each set comprising two plates around the cylinder, separate plate lock-up mechanisms for each side of each of said plates, and separate adjusting mechanisms for each side of each of said plates whereby the plates may be individually adjusted lengthwise of the cylinder to variable final positions for margin adjustment, at least one of said adjusting mechanisms being disposed between a set of said plates at an end of the cylinder and a set intermediate the end sets of said plates.

16. In a web printing press, a plate cylinder having provision for attachment thereto of a set of thin, flexible printing plates for offset printing comprising two plates around the cylinder, and lock-up mechanism for each of said plates including: a plate-actuating bar positioned within the cylinder and having projections thereon, said plates having inturned edge portions provided with holes for receiving said projections whereby a plate may be connected to said actuating bar, a shaft inside the cylinder on which said pl-ate actuating bar is mounted, means for pivotally moving said bar to cause tightening of the plate circumferentially on the cylinder, an auxiliary bar hingedly mounted on said shaft adjacent said plateactuating bar and being normally movable therewith as \a unit but also being arranged for independent pivotal movement on said shaft, said auxiliary bar being engageable with an inturned edge portion of the plate and the cylinder having a gap therein into which said inturned edge of the plate extends and an additional opening through which access may be had by a tool to said 11 auxiliary bar to move the same relative to said actuating 2,101,17 3 bar and thereby disengage said inturned edge of the 2,164,480 plate from the projections on the latter bar. 2,195,491 2,320,239 References Cited in the file of this patent 5 2,329,830 UNITED STATES PATENTS Keck June 7, 1,876,378 Wilkinson et a1. Sept. 6, 1932 12 Gegenheimer Dec. 7, 1937 Tornberg July 4, 1939 Marchev Apr. 2, 1940 Huck May 25, 1943 Crafts Sept. 21, 1943 Harrold et al. Oct. 9, 1945 Rowell et al Dec. 25, 1951 Chase et al May 26, 1953