US3022727A - Web feed device for rotary printing press - Google Patents

Description

Feb. 27, 1962 i P. ZERNOV wEB FEED DEVICE FOR ROTARY PRINTING PR SS Filed Jul 11, 1960 3 Sheets-Sheet 1 m m m m PE 7-5.2 Zane/v0 & I

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Feb. 27, 1962 P. ZERNOV WEB FEED DEVICE FOR ROTARY PRINTING PRESS Filed July 11, 1960 5 SheetsP-Sheet 2 W h I-llllllllll m 1. V 1 \\N #1: ||L-||||I ELEV FLIHHE L I llllllllll ll Feb. 27, 1962 P. ZERNOV WEB FEED DEVICE FOR ROTARY PRINTING PRESS Filed July 11, 1960 s Sheets-She er. :s

INVENTOR. er-s2 Zea/vb States The present invention relates to a line of printing presses which employ a plurality of printing cylinders over which the web to be printed passes.

In in-line presses of the type to which this invention relates, for example, rotogravure presses, the only places to create or establish tension in the web which is moving through the machine is at the entry and discharge ends of the line of presses. That is to say, the amount of tension in the web must be established at the incoming and outgoing sides of the line. Developing this tension may be done conventionally in several way. For example, the supply roll may be braked and the rewinder at the discharge side may pull sufficiently to create the desired tension. Alternatively, power driven feed rolls may be used at the entry and discharge sides of the line. In any event, Where several presses are used in line, the web in the presses is of considerable length, being as much as thirty feet long between each pair of adjacent presses. This length of web creates difiiculties in properly distributing the tension throughout the length of the web, particularly in the middle portion of the web, that is, in the more centrally located presses. Stated otherwise, in conventional press lines, 'very little tension may be left in the more central portion of the web length.

in in-line presses, the entire line eventually can be adjusted to operate at a fairly balanced condition and when this equilibrium condition exists, the various printing cylinders are in good registry. This balanced condition, however, is easily upset due to many variables, such as, inter alia, web shrinkage due to the action of the driers, variable tension of the incoming web, variable elasticity of the web along its length, and changes in humidity and temperature. It is then necessary to reestablish the opcrating equilibrium of the presses, and the length of time required to do this is reflected in the amount of misregistry and the length of time during which this misregistry occurred.

Furthermore, due to even very slight dillerences in the circumferential size of the various printing cylinders arrayed in an in-line press, there exists a difference in the elocity of the web at the different printing couples, that is, at the different locations where the printing actually takes place in the line. This difference in printing cylinders circumferential sizes exists notwithstanding the painstaking efforts to produce cylinders of identical sizes. For example, the dimensions of the best pairs of matched cylinders may vary as much as three thousandths on their circumference. This variation in web velocity throughout its length is possible because of the variation in tension of the web coming into and leaving the point of printing.

In accordance with the present invention, a plurality of printing presses have been provided in which the velocity of the web as it moves through the line of presses is maintained constant throughout its length.

More particularly, the line of presses provided by the present invention has a series of power driven carrier rolls for supporting the web, which rolls are driven at an ideal or average velocity that is desired to be maintained in the line. The driven carrier rolls provided by the present invention furnish enough drive to the web to overcome the inherent inertia in the moving parts of the presses, and the web does not drive these carrier rolls. In other words, a delicately balanced condition is provided between the EfiZZEZ? Patented Feb, 2?, i362 driven carrier rolls and the web so that the rolls regulate the speed of the web. By furnishing some drive assist by means of the driven carrier rolls, and thereby relieving the Web of carrying and driving these inertia and friction loads of the machine, it is possible to be able to consistently print on low tensile strength material such as extensible webs of the cellophane, mylar or polyethlene type, and material as light as twenty pound paper.

By means of the present invention, power driven carrier rolls provide web tension and the tension is more evenly distributed throughout the line of presses.

An important aspect of the present invention is to provide a line of presses having power driven carrier rolls of the above type, in which a slip clutch is provided in the drive before the first carrier roll, by means of which clutch only enough torque is provided to overcome the drag or inertia effects of the machine.

The present invention provides a line of printing presses in which a series of power driven carrier rolls are spaced apart throughout the line, for example, preferably one roll for each printing cylinder. in this manner the tension of the web is maintained in separate sections of the web length. Stated otherwise, the tension of the web is maintained between each power driven carrier roll and its adjacent printing cylinders. Thus the several lengths of Web, through which the tension is separately maintainable, are relatively short as compared to the entire length of the web in the entire line of presses. As a result of the shorter length of web which must be controlled as to tension, it is possible to get a much faster response or correction for each individual printing cylinder. Regardlessot the signalling or correcting devices used, they can perform their correction more quickly because they only need to vary the web length between two adjacent web decks.

ermits a faster correcting response to reestablish balanced conditions in the line because the tension changes can be made more quickly in these shorter web lengths.

Furthermore, with the above arrangement, a much more stable press is provided because when a variation is introduced into the line, a balanced condition will be reestablished faster. This is possible because there has been provided several key references, one between each printing station, to effect constant velocity throughout the web length and permit each printing unit to find its balanced condition between each set of power driven carrier rolls. One printing unit will not materially effect the one adjacent to it.

These and other objects and advantages of the present invention will appear as this disclosure progresses, reference being had to the accompanying drawings, in which- FIGURE 1 is an elevational side view, taken from the operators side, of a portion of a printing press line, certain parts shown as being broken away, in section or removed, and the view being more orless aschematic showing;

FIGURE 2 is a detailed elevational view of a portion of the machine shown in FIGURE 1, certain parts being broken away; j

FIGURE 3 is a plan view of the machine shown in FIGURE 2, certain parts being in section or broken away;

FIGURE 4 is a fragmentary sectional view taken along line 44 in FIGURE 1, but on an enlarged scale;

FIGURE 5 is a detailed elevational view taken generally from line 5-5 in FIGURE 4;

FIGURE 6 is a view taken generally along the line 66 in FIGURE 7, and;

FIGURE 7 is a sectional view taken along line 7-7 in FIGURE 6.

Referring in greater detail to the drawings, and parincludes the horizontally disposed pair of beams or chan- The arrangement provided by this invention thus.

nels I and 2 which are arranged in parallelism. The pairs of vertical supports 3 hold the channels 1 and 2 above the floor F and over the several printing units A, B and C. The channels, vertical supports and presses are all secured together as a complete line.

Only three printing units have been shown, but as many as eight are often used together in a single in-line rotgravure operation, and the invention is not limited to use with any particular number of presses.

Each of the presses A, B and C are substantially identical for purposes of this disclosure and each have, respectively, a printing cylinder Ca, Cb, and Cc which are suitably journalled for rotation in the side walls of their respective presses in the well known manner. Each of the printing cylinders may be driven from a common drive shaft 5 and with which they each have an adjustable running register 6. The cylinders are thereby each adjustable relative to the drive shaft and to one another for registry purposes.

Each of the presses also has an impression roll 7 adjacent to its printing cylinder and the actual printing is done on the Web W as it passes between the printing cylinder and the impression roll. A nip printing couple is formed at these printing locations by the impression roll which firmly presses the web against the cylinder.

A conventional overhead drier 8 having various supporting rollers for the web may also form part of each press and the length of the web between adjacent printing cylinders may be about thirty feet in length. Thus in a line having eight presses, a web length of 250 to 300 feet within the complete line or" presses is not uncommon.

Other conventional idler rolls iii, 11 and 12 are provided for supporting the web as it moves through the line.

At the entry side of the first press A, the web passes from a supply roll and over various pre-feed rolls (not .shown) and then over the guide roll 13, and into the conventional infeed means if. This feed means includes a pair of idler rolls 14- and 15 between which is a center driven roll 16 having a gear 16:; secured to its shaft that is driven from the main drive of the machine through Worm 165 on shaft 5. This feed means acts to pull the web from the supply roll (not shown) and feed it at a precisely metered rate.

At the discharge end of the press line is located an outfeed means for the web in the form of nip rolls 17 and 18, between which is located the driven feed roll 19.

The infeed means and the outfeed means act to create tension in the web located in the press line. However, as previously indicated, this general tension may also be created in different ways and specific feed means may not be necessary. For example, the supply roll (not shown) at the entry side of the press line may have means for creating a braking action; the rewinder (not shown) at the discharge side of the press line may be controllably driven sufficiently to provide the desired tension. In any event it is necessary to provide means for creating, and maintaining tension at the entry and discharge sides of the press line.

As theweb leaves the feed roll it passes through conventional dancer roll unit D which controls and maintains a certain tension in the web. at this location.

It can be seen that in the above line of presses there are a considerable number of moving parts, many of which have not been described, which have considerable inertia and create friction losses, and'which are conventionally driven by the web. This imposes a heavy load on the web and variations in tension in the length of the Web within the line of presses.

In accordance with the present invention, power driven carrier rolls are provided for the web, which rolls are spaced apart within the line of presses. The first of such rolls R1 is located just after the dancer assembly and is rotatably mounted between the channels '1 and 2.

The other power driven carrier rolls R2, R3. and R4, and their respective rubber covered nip rolls 20, 21 and 22 are similar and a description of one set of each is deemed to be sufiicient. These rolls are also mounted between the channels 1 and 2 as will be more fully described. It will be seen that a power driven roll is located between each adjacent pair of printing cylinders and one before the first cylinder Ca and one after the last cylinder Cc.

As will be fully described, the first roll R1 is driven from the main power source in the form of an electric motor M, and all of the subsequent rolls are driven from a common line of power and right angle gear boxes. Thus all of the rolls R1 to R4 are driven together in unison.

Referring in greater detail to the first roll R1, an air operated slip clutch 25 is mounted on the operator end of the roll R1, as clearly shown in FIGURE 4. More particularly, a stub shaft 26 is fastened by pin 27 to the shaft 28 of the roll R1 and forms an extension thereof. Shaft 26 is journalled in the bearing block 29 secured by bolt means St) to channel 1.

The clutch 25 is of conventional design and it is believed sufficient to say that shaft 26 is secured to one of its clutch elements, and a sleeve 31 is secured to the other of its clutch elements. i Thus the shaft 26 and sleeve 31 are engageable and disengageable with one another. A clutch gear'32 is rigidly secured to sleeve 31 and is in constant mesh with gear: 31a supported on shaft 31b and fixed to the timing pulley Sic. An endless timing belt 33 is trained over this pulley.

Power is transmitted to the clutch from the power driven center roll 16 via a timing pulley and the belt 33 trained thereover. Idler pulleys (not shown) to regulate belt tension may be utilized in the conventional manner. In this manner the drive for the carrier rolls is taken directly from the feed unit.

The clutch 25 is set so that only a predetermined speed is imparted to the carrier rolls R1 to R4. By means of this clutch only enough torque is provided to the carrier rolls to overcome mechanical losses in the line due to inertia, friction and other causes. Depending on the feed characteristics desired from the driven carrier rolls, and whether or not feed means are used at the entry and discharge sides of the line, the carrier rolls may or may not be of the positive nip type. Several variations may be used. For example, a positive nip may be provided for each carrier roll, no nip may be necessary for any of the carrier rolls, or a nip may be provided for only some of the carrier rolls.

In the illustration of the invention shown here, a positive nip is provided for each carrier roll, as will appear.

A rubber covered nip roll 4% is provided for cooperation with roll R1 and is adjustably mounted between channels 1 and 2 for shifting between a nipping or closed position and a throw-out or open position.

As shown in FIGURES 2 and 3, the nip roll 40 is urged to the nipping position by a pair of air operated members 44, one at each end of roll 49, members are securely mounted to the main frame by bracket 45 and each have a shiftable actuating rod 46 extending therefrom. The nip roll 49 is swingably mounted on a pair of arms 47, one at each end of the roll (only one arm is shown), which arms are pivoted at their upper end on pins 48 to their respective channels. Actuating rods 46 are pivoted to their respective arm '47 and when extended act to swing the roll 4!) to the nipping position. Member 44 has a spring 44a by means of which the roll 40 is spring biased to the open position, the members 44 being air operated in only one direction.

A manually operated handle 59 is used to actuate an air valve 51 to thereby cause air to be admitted to or released from members 44 via conduit 52 and 53, a central valve 54 regulated by the knob 55 is used to meter the air from the supply line 56 to the control valve 51. The operator can readily adjust the nippingpressure on roll R1 and also completely open the nip roll 46.

The; structure, drive and operation of the other carrier rolls R2, R3, and R4 and their nip rolls will now be described, reference being made only to the second roll R2 but it being understood that the other rolls are similar.

Referring in particular to FIGURE 3, the shaft 60 of R2 is journalled in the pillow blocks 61 and 62 securely mounted on channels 1 and 2, respectively. A bevel gear 63 is secured to the outer end of shaft 60.

The drive between the carrier rolls is as follows. A right angle gear box 64 is located at the back end (as viewed in FIGURE 1) of the roll R1, that is, on the side opposite to the operators side. A drive tube 65 extends from this box 64 to another right angle gear box 66 located at the rear end of roll R2. Another drive tube 67 extends from box 66 to a third right angle gear box 68 located at the end of roll R3. Suitable couplings 70 connect the drive tubes to the gear boxes.

Within each of the gear boxes is a bevel gear 71 which is in constant mesh with the bevel gear carried on the end of each of the adjacent carrier roll shafts. The gear 71 is fixed to a shaft 73 rotatably mounted in the box, which shaft is fixed to the drive tubes extending from each end thereof, by key means 74. The various drive tubes and the shafts 73 may be considered as a single drive shaft.

The carrier rolls are thus all positively in synchronization with one another, deriving their power from the feed roll means 16.

The rubber covered nip roll 20 is mounted by its dead shaft 20a supported on the channels 1 and 2. A handle means 20b is secured to the end of shaft 201: for oscillating the latter between nipping and open positions. Eccentric sleeves 20:: are fixed to the ends of shaft 20a and these sleeves are rotatably mounted in the anti-friction bearing members 20d secured to channels 1 and 2. By oscillating the handle means 20b, the entire shaft 20b and its roller 20 are shifted bodily toward and away from the roll R2, and by simply throwing the handle in one direction the roller 20 is thrown off of the nip position. The handle and eccentric arrangement is of the over-center type and the spring 20e loads the roller in the over-center position and firmly against the roll R2. The effective length of the moment arm through which the spring acts to load the roll is the amount of eccentricity of the eccentrics.

Rsum

By means of the power driven carrier rolls the actual length of the web in the line of presses is, figuratively speaking, broken down into several separate lengths, which lengths are easily controlled and adjusted as to tension. Not only is a more uniform tension provided throughout the length of the web but the tension at the 6 entry and discharge sides of each printing cylinder is more nearly equalized.

The driving effect of the carrier rolls is sufiicient to relieve the web of a considerable load otherwise imposed upon it.

The velocity of the web is maintained constant through its length and can be accurately controlled.

A much faster correcting response is possible and a more stable operating press is provided.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

What is claimed and desired to be secured by'Letters Patent is:

1. A printing press line having a plurality of printing cylinders and an impression roll for each cylinder which forms a nip printing couple therewith and through which a Web is adapted to pass, said lineralso having means adjacent its entry and discharge sides for creating tension in the web in said line, a series of power driven carrier rolls spaced apart in said line for at least partially driving said web, means drivingly connecting said carrier rolls together so as to drive them in synchronization with one another, and a slip clutch for driving one power driven carrier roll in the line whereby the maximum velocity of said carrier rolls is limited to cause said rolls to deliver only a predetermined amount of torque to said web.

2. In a printing press line having a plurality of printing cylinders through which a web is fed, an impression roll for each of said cylinders and forming a nip printing couple therewith, infeed means for the web at the entry side of said line, outfeed means for said web at the discharge sde of said line, said infeed and outfeed means establishing tension in the web therebetween, a series of power driven carrier rolls for said web and located in spaced apart relation in said line, and drive transmitting means for drivingly connecting said carrier rolls to said web infeed means whereby said carrier rolls are driven by said infeed means.

3. A device as set out in claim 2 including a slip clutch in said drive transmitting means to limit the driving effect of said carrier rolls on said web to a predetermined value.

References Cited in the file of this patent UNITED STATES PATENTS 1,581,151 Yetter Apr. 20, 1926 1,661,209 Wolf Mar. 6, 1928 2,809,582 Crawford Oct. 15, 1957

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