US2764087A - Web support for printing press - Google Patents

Description

Sept. 25, 1956 A. R. STOBB 2,764,087

WEB SUPPORT FOR PRINTING PRESS Filed July 15, 1952 2 Sheets-Sheet 1 fie. 2

INVENTOR.

ATTORNEYS Sept. 25, 1956 A. R. STOBB 2,764,087

WEB SUPPORT FOR PRINTING PRESS Filed July 15, 1952 2 Sheets-Sheet 2 INVENTOR. flxvrmfiSroaa l Arro/zwsys 2,764,087 WEB SUPPORT FOR PRINTING PRESS Anton R. Stobh, Hampton, N. J., assignor to Harris- Seyhold Company, Cleveland, Ohio, a corporation of Delaware Application July 15, 1952, Serial No. 298,923 Claims. (Cl. 101--181) This invention relates to improvements in web supports for printing presses, that is to say means for sup- Web vibration tends to impair the quality of the printing. It has been avoided in some machines heretofore tension on the web.

Another object is the provision of transverse bars fasned to the plate on its concave side,

permit limited movement of the ends of the plate toward and away from each other.

Another object is to control register of printing by changing the distance between impression cylinders through adjustment of the degree of bowing of the bridging plate.

Other objects and features of novelty will appear as I proceed with the description of that embodiment of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawings, in which Fig. l is a schematic side view in elevation showing d States Patent 0 two spaced impression cylinders with associated printing units, and embodying web supporting means in accordance with the invention.

Fig. 2 is a vertical detail sectional view on a larger scale, showing the adjustable mounting for the middle transverse bar, the view being taken substantially on the line 2-2 of Figs. 1 and 4.

Fig. 3 is a detail sectional view on the same scale as Fig. 2 showing a mounting for one of the end transverse bars.

Fig. 4 is a cross-sectional detail view tially on the line 44 of Fig. 2, and

Fig. 5 is a cross-sectional detail view tially on the line 55 of Fig. 3.

Fig. 1 of the drawing illustrates fragmentally and schematically a four color rotary olfset printing press having taken substantaken substan- In the drawing there are indicated four different printing comprising blanket and form cylinders 12 and 13 disposed generally beneath and in printing relation with impression cylinder 10, the second comprising blanket and form cylinders 14 and 15 disposed beneath and in printing relation with impression cylinder are positively driven in proper timed relation by suitable means, not shown.

A paper Web W is fed in a loop over the underside of the two impression cylinders 10 and 11, around approximately one-half of the periphery of cylinder 11 and back over impression cylinders 11 and 10. The web of course passes between the impression cylinders 10 and 11 on the one hand and the blanket cylinders 12, 14, 16 and 18 of the four printing units on the other hand, by means of which it is imprinted in four colors. The various units may be built alike and preferably are so built in order to realize the advantages of standardization, the lower units being disposed at an angle approximating from the upper units.

For practical reasons which it is not necessary to detail herein the impression cylinders 10 and 11 should be In one case for of the impres- It is also necthat both runs in the case of 22 the present inand 23 of a width at least web. Each plate means may may be fiat or bowed, to a greater or lesser extent, as illustrated. Each plate means when single, as preferred, is supported by the side members 24 and 25 of the machine frame in the following manner.

A tubular bar 27 is secured transversely to each of the plates 22, 23, for example by a welding operation, approximately half way between its ends. These plates 22, 23 are of fairly heavy gauge sheet material, preferably metal of the order of inch in thickness,

so that they 3 may have proper stiffness and yet be capable of being flexed; engagement with the web while permitting movement of the, sameover the plate with as little friction as possible.

As'shown in Fig. 2 the ends of bar 27 project somewhat beyond' the edges of plate 23, and. in these projeeting ends holes are drilled to receive pins 28; These pins in turn are mounted in brackets 29 that are suitably secured to the side members 24.and of the frame, machine screws 30 being illustrated for this purpose. In the lower flanges of the brackets 29 jackscrews 31 are threadably mounted, these screws having heads 32' by means of which they may be turned in the brackets and lock nuts 33 by which they may be held in adjusted position. It will be obvious that operation of these jackscrews will slide the bar 27 on the pins 28 either inwardly or outwardly as may be desired. The mounting of the lower bar 27 is the same as that of the upper one except that the brackets 29 are inverted, the jackscrews 31 being used to press the bar downwardly rather than upwardly.

In case it is desired to maintain the plates 22, 23 straight from end to end the jackscrews 31 may be so adjusted as to effect this result. On the other hand the jackscrews may be adjusted to effect a bowing of the plates outwardly away from planes tangent to the impression cylinders, the degree of curvature being determined by the extent of the manipulation of the jackscrews 31.

The two edges of the web may be of slightly different length due to moisture absorbed in greater degree along one edge than the other or to other causes. The invention contemplates adjustment of the two screws 31 to different extents for the purpose of counteracting this length difference and providing good contact between the bowed plate and the web entirely across the width of the latter. This may be done by adjusting the bar 27 outwardly on its end adjacent the loose edge of the web, thereby tending to equalize the tension of the web throughout its width, or by adjusting outwardly the end of the bar 27 adjacent the short edge of the web thereby tending to stretch that edge so as to make that portion of the web in contact with the plate of equal length at its opposite edges.

Ordinarily the degree of bowing of the plates 22, 23 will not be varied to any great extent for different jobs of printing, but under some conditions adjustment to vary the bowing of one plate or the other maybe conveniently employed to modify the length of web along one run for the purpose of perfecting register in printing. The adjustment may be made while the press is in operation, which obviously is highly advantageous.

The ends of the plates 22, 23, are not fixed in the frame but are so mounted as to be capable of slight movement towardor away from each other while held against any substantial movement transversely of the plane tangent to the, impression cylinders. For this purpose inthe illustrated case a tubular bar 35 is welded or otherwise attached to each end of the plate. It projects beyond the edges of the plate as indicated in Fig. 3, and its ends are slidably mounted in grooves 36 formed in brackets 37 that are secured to the side members 24 and 25 of theframe by screws 38 or the like.

Slight clearance is provided between the bars 35 andthe sides of the grooves 36 sufiicient to permit thebars tomove readily in response to inward or outward movement of the bar 27. At the same time the bars 35 turn slightly in their grooves in response to the bowing movement. The grooves 36 extend at an angle to the vertical, which in the illustrated case is about The inclination'of'these grooves may vary however, as conditions may require. When the jackscrews 31. are adjusted'to' deerease'the' degree of bowing the ends of the plate tend torise-because of the turning of the bars 35in their grooves; but atthesame time outward movementof Their outer sides have smooth surfaces for the bars 35 in the inclined grooves carries the ends of the'plate downward so that in effect the distance bctween the ends and the adjacent impression cylinders remains approximately the same. In the same way when the bar 27 is moved outwardly to increase the bowing effect, the bars 35 tend to turn in the grooves and draw the ends of the plate inward but at the same time the bars 35 slide diagonally upward in the grooves and the two effects approximately cancel each other, so that the plate ends remain approximately the same distance as before from the adjacent impression cylinders. The radius of curvature of a plate may vary from infinity, which yields a flat surface, down to a finite number of such length as to produce maximum bowing, but under all conditions the radius of curvature of the plate is greater than the radius of one of the impression cylinders.

The web W traveling rapidly over the plates 22, 23 under tension hugs those plates and remains in contact with them. Hence there is no vibration of the web and damage 'to the printing from this cause is entirely eliminated.

Having thus described my invention, I claim:

1. In a web feed printing press, a pair of parallel cylinders spaced apart, a means for supporting the web intermediate the cylinders, comprising, flexible smooth plate means bridging a major portion of the distance between cylinders adjacent to but bowed outwardly from a plane tangent to both cylinders, said web traveling in direct contact with said smooth plate means whereby the ied by said plate means, and means for adjusting the degree of bowing length of the web path between cylinders may be varied for image registering purposes.

2. In a web feed printing press, a frame, two parallel cylinders spaced apart, a web running over said cylinders, a bar carried by said frame parallel to said cylinders and disposed between them, a flexible smooth plate mounted on said bar between cylinders adjacent the plane tangent to said cylinders, means for moving said bar inwardly and outwardly with respect to said plane, and means for confining the ends of said plate against movement perpendicular to said tangent plane while permittingmovement of said ends toward or away from each other.

3. A web feed printing press as defined in claim 2, wherein the ends of said bar are adjustable inwardly and outwardly relative to each other to compensate for slight differences in the lengths of the respective edges of the web.

4. Aweb feed press as defined in claim 2, comprising two bars attached to said plate near the ends thereof and parallel to the intermediate bar, and inclined guides carried by the frame in which said end bars float for confining the plate ends against movement perpendicular to said tangent plane while permitting movement thereof toward or away from each other.

5. In a web feed printing press, a pair of parallel impression cylinders spaced apart, two printing units associated with each of said impression cylinders, said units being disposed on opposite sides of the plane through the axes of the cylinders, means for feeding a web in a loop over one impression cylinder, outwardly around the other impression cylinder and back over the first. cylinder, and supporting means for both runs of said loop along substantially the entire distance between cylinders comprising flexible smooth plates longitudinally. bowed to guide said runs into bowed paths contiguous to the planes tangent to said cylinders on opposite sides thereof and comprising means for regulating separately the degree of bowing in the respective plates.

{References on following page) web running over said cylinders, and.

web between cylinders is stead-' of said flexible plate means, whereby the.

References Cited in the file of this patent 2,247,156 UNITED STATES PATENTS 2,551,821 752,896 Firm Feb. 23, 1904 1,482,352 Dausrnann Jan. 29, 1924 104,478 1,482,356 Dausmann Jan. 29, 1924 278, 21 1,569,064 Archbald Jan. 12, 1926 526,419 2,084,827 Schwartz et a1. June 22, 1937 0,9 2,107,743 Shoup Feb. 8, 1938 Gurwick June 24, 1941 Bengston May 8, 1951 FOREIGN PATENTS Australia July 21, 1938 Germany Jan. 19, 1913 Great Britain Sept. 18, 1940 France Dec. 12, 1927

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