US 3196788 A
Description (OCR text may contain errors)
July 27, 1965 D. H. KNOWLES 3,
BEARER RING DESIGN FOR FOUR COOPERATING CYLINDERS Filed March 19, 1962 2 Sheets-Sheet 1 y I I @V ,6 49 I 529 6 l 34 Ill 54 Z 26? I 35 IO A: i: s 9
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PLATE P/iC/(ED fie zrzwfl frzowleg 5 OBWMMVMVL y 27, 1965 D. H. KNOWLES 3,196,788 7 BEARER RING DESIGN FOR FOUR COOPERATING CYLINDERS Filed March 19, 1962 2 Sheets-Sheet 2' 4 ELAN/(7 m INVENTOR. Q zemi/jzmoze N I BY United States Patent 3,196,738 REARER RlNG DESTGN FQR FQUR CGfDPERATlNG (IYLlNDlERS Dennis H. Knowles, Hinsdale, ill, assignor to Miehle- (loss-Dexter, Incorporated, @hicago, llllh, a corporation of Delaware Filed Mar. 19, 1962, Ser. No. 1%,505
7 Clairns. (Cl. Elli-$17) The invention relates to the provision of bearer rings on the plate and blanket cylinders of a perfecting press of the blanket to blanket type and has reference more particularly to an arrangement where cooperating bearer rings are located in separate planes to avoid interference of the bearer rings on the blanket cylinders which determine the spacing between blanket eylinders with those that determine the distance between the plate-blanket cylinders.
Plate and blanket cylinders on offset presses designed to print simultaneously on both sides of a continuous web of paper instead of a single sheet may have a narrow gap in their surface. The width of the gap is made as small as practical, although it may be as much as one-half or threefourths of an inch. The cylinders rotate simultaneously for the purpose of transferring the inked image from the plate to the blanket, and it is desirable to operate the cylinders so that they apply considerable pressure against each other. Also, since the cylinders are driven by gears of equal size, one on each cylinder, they operate exactly at the same speed and they are timed so that the gaps come together or coincide on each revolution. Because of the pressure between the cylinders, there is a tendency for the surfaces to expand toward each other when the gaps coincide, the pressure or squeeze being momentarily relieved. Thus, when the gaps have passed and the pressure is restored, a slight bump takes place which produces vibration and causes streaks or unevenness in the inking, particularly at the leading edge. It has been observed that this vibration increases and streaking gets worse as press speeds increase. This condition may not be serious for some types of printing, but if high quality is desired the result may be objectionable.
One solution for the above described difliculty is to design the cylinders of the proper size so that solid rings called bearer rings, having the same diameter as the pitch diameter of the driving gears, can be installed on each end of each cylinder. When the cylinders rotate for a printing operation the rings will contact each other. Also, the plate and blanket cylinders can be packed to the desired size in order to produce the required diameters and the required impression or squeeze between the surfaces. When the cylinders are so constructed and arranged with bearer rings, the bump and the objectionable streaking will be substantially eliminated. An additional advantage of running on bearer rings is that cylinder speeds are more constant and do not fluctuate due to slight variations in diameters of plate and blanket caused by uneven packing.
A perfecting press of the type shown in the drawings has two printing couples each consisting of one plate and one blanket cylinder and the sheet or web is passed between the blanket cylinders whose surfaces run in contact for printing on both sides. One of the objects of the present invention is to eliminate the objectionable streaking as described by the provision of bearer rings on both ends of each of the cylinders to insure accurate spacing between all the cylinders and smooth contact at all times.
However, the diameter of the bearer rings which determine the spacing between the blanket cylinders may be different than the diameter of the rings which determine the spacing between the plate and blanket cylinders. If the Working diameter of the plate and blanket are differeat, the bearer rings on the blanket cylinders for spacing ice the plate-blanket cylinders are not suitable for proper spacing between the blanket cylinders and thus an additional pair of bearer rings are needed. Therefore, another object of the invention resides in the provision of carer rings on the plate and blanket cylinders of a Web offset press and wherein the pairs of bearer rings at each end of the cylinders are staggered so to lie in different planes in order to avoid interference between said pairs of bearer rings.
Another object of the invention is to provide a bearer ring arrangement for the plate and blanket cylinders of a perfecting web offset press and wherein each blanket cylinder will have a pair of bearer rings at one end in spaced relation, being separated by a spacer element and wherein each blanket cylinder will also have at its opposite end a pair of bearer rings in adjacent relation, having approximately side-by-side contact with each other.
With these and various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended thereto.
in the drawings which illustrate an embodiment of the device and wherein like reference characters are used to designate like parts;
FIGURE. 1 is a fragmentary schematic view showing the printing cylinder arrangement for a perfecting type of web lithographic offset press, with the inking rollers and dampening rollers also being schematically shown in operative relation therewith;
FIGURE 2 is a plan view from above substantially on line 2-2 of FIGURE 1 looking down on the combination of plate and blanket cylinders and showing the bearer ring arrangement of the invention; and
FIGURE 3 is a schematic view showing the various plate and blanket cylinders of FIGURE 2 in spaced separated relation with the diameters of the plate and blanket and also the typical bearer rings being indicated to better illustrate the invention.
For explaining the invention reference is made to FIG- URE 1 which illustrates schematically a web lithographic offset press of the perfecting type, the same being indicated by numeral 10. Said press prints on both sides of a web 11 as the same passes between the blanket cylinders 12 and 13. Blanket cylinder :12 is in surface contact with a plate cylinder 14 and blanket cylinder 13 is likewise in surface contact with a plate cylinder 15. The plate cylinders are each supplied with ink by conventional inking mechanism and a damping liquid is supplied to the plate cylinders in the customary manner for lithographic offset presses.
Referring to the inking mechanism for the plate cylinders, it will be observed that an ink fountain 16 is provided for each cylinder and which supplies ink to an ink fountain roller 17. An ink pickup roller 18 and an ink transfer roller 2% transfer the ink to a first drum 21. Said drum is in contact with the two ink transfer rollers 22 which, in turn, contact a second drum 24. From the second drum 2d the ink is transferred by the pair of ink transfer rollers 25 to the plates, respectively. The dampening mechanism includes a container for containing a supply of liquid. A fountain roller 31 transfers the liquid to a surface contacting pickup roller 32 which supplies the liquid to a drum 33. A pair of plate dampening rollers 34- transfers the liquid from the drum to the plate cylinders, respectively.
In FIGURE 2 the bearer rings are shown in associated relation with the printing cylinders and with each other. The plate cylinder 15 having the end shafts 35 and 36 is journalled respectively at 37 and 38 in the side frames ill and 41 of the press. The gear 42 is fixed to the end shaft 36 and at respective ends of the cylinder 15 the a bearer rings 43 and 44 are located. The blanket cylinder 13 has end shafts 45 and 46 and which are journalled by the respective members 4'7 and 48 suitably mounted in the side frames of the press. At the left end of the blanket cylinder 13 the two bearer rings 50 and 51 are mounted, and it will be seen that said rings are s aced, by the spacer member 52, a distance slightly in excess of the width of a bearer ring. The inside ring 51 is in peripheral contact with the bearer ring 43 and these two contacting rings have the same diameter as will be understood from FIGURE 3. At the opposite end of the blanket cylinder 13 bearer rings 53 and 54 are mounted in close side by side relation. The inside ring 53 has contact with bearer ring 44 and at the end of shaft 46 a gear 59 is fixed which meshes with gear 42. The diameter of the bearers, namely 4-3, 51 and 4-4, 53 is the same as the pitch diameter of gears 42 and 4-9.
The coacting cylinders 12 and 14- are journalled in a manner similar to the coacting cylinders 13 and 15, and bearer rings are provided therefor in a manner substantially as described. As regards plate cylinder 14 it will be seen that the end shafts 55 and 56 are journalled at 57 and 58 in the side frame of the press. The bearer rings 60 and 61 are mounted at respective ends of cylinder 14 and the diameters of these rings are the same as those provided for cylinder 15. The blanket cylinder 12 is journalled by the end shaft 62 and 63 by means of members 64 and 65 which are suitably mounted in the press side frame. The left end of this blanket cylinder is provided with two bearer rings 66 and 6'7 in close side-by-side relation. However, at the right hand end of this cylinder the two bearer rings 63 and 70 are mounted in spaced relation with the spacer member 71 being located between. The gears 72 and 73 are fixed to shafts 56 and 63, respectively, and said gears have meshing relation with each other. Gear 73 also meshes with gear 49 so that all of the cylinders are driven in unison atthe same rotational speed, since all of the gears have the same pitch diameter.
The material covering the blanket cylinders 12 and 13 is relatively soft compared to the plates mounted on the plate cylinders. Thus in order to achieve image transfer from plate to blanket without distortion, the diameters of the plate and blanket should be determined to establish a condition of true rolling according to the theory and practice disclosed in the patent to Sites 2,036,835, granted April 7, 1936. For a specific example of true rolling, reference is made to FIGURE 3. Said figure shows the plate and blanket cylinders for a web fed olfset perfecting press which will print on a page 22% inches in length. The plates are shown as over-packed, and the blanket under-packed in relation to the diameters of the bearers. It will be clear from FIGURE 3 that the bearer rings on the blanket cylinders for the plate blanket combinations cannot be employed for controlling the spacing between the two blanket cylinders. This is due to the fact that the blanket diameter 7.248 inches is less than the bearer diameter, namely 7.250 inches, and accordingly there would be no contact between the blankets and consequently no printing. When the existing bearer rings on the plate-blanket cylinders are not suitable for proper spacing of the blanket cylinders, an additional pair of rings must be added to each blanket cylinder and this increases the number of rings on each side of the press from four to six. Thus, it is necessary to stagger the several pairs of bearer rings to avoid interference and as a result the bearer rings are disposed in three different planes at respective ends of the cylinders. More specifically, considering the right hand end of FIGURE 2, it will be seen that the plate-blanket bearers 44 and 53 are disposed in a different plane from that of the plateblanket bearers 61 and 68, and that the additional pair of bearer rings, namely 54 and 70 needed to establish the spacing between the two blanket cylinders are disposed in a third plane. In addition to staggering the bearer rings, another characterizing feature of the combination resides in the fact that a spacer member is required on each blanket cylinder but at opposite ends. In other words, the bearers on one end of each blanket cylinder are separated by a spacer element, whereas the bearers at the opposite end of each blanket cylinder are mounted in close side-by-side relation.
The preceding description covers the provision of bearer rings for one combination of plate and blanket size relationship, but it should be understood that the principle applies to any relationship in which the diameters of the plate and blanket are unequal.
The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings, as various other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.
What is claimed is:
ll. In a web-fed offset printing press of the perfecting type, in combination, coacting plate and blanket cylinders, said blanket cylinders :also having coacting relation to print on both sides of a web passing between the cylinders, each plate and blanket cylinder having a bearer ring at respective ends in peripheral contact, whereby to form platcblanket cylinder bearer ring combinations and which are disposed in different planes, an additional bearer ring on each end of each blanket cylinder, said last mentioned bearer rings at respective ends of the blanket cylinders having peripheral contact, and said blanket bearer ring combinations being disposed in a plane different from that of the bearer rings for the plate-blanket combinations.
2. In a web-fed offset printing press of the perfecting type, in combination, coacting plate and blanket cylinders having relatively hard and soft operating surfaces respectively, said blanket cylinders also having coacting relation to print on both sides of a web passing between the cylinders, each plate and blanket cylinder having a bearer ring of the same diameter at respective ends and which are in peripheral contact, whereby to form plate-' blanket cylinder bearer ring combinations, said plateblanket cylinder bearer ring combinations being disposed in different planes but parallel to each other, an additional bearer ring on each end of each blanket cylinder and which are equal in diameter, said last mentioned bearer rings at respective ends of the blanket cylinders having peripheral contact, and said blanket bearer ring combinations being disposed in a plane different from that of the bearer rings for the plate-blanket combinations.
3. A web-fed offset printing press of the perfecting type as defined by claim 2, additionally including a gear drive operatively connecting :all the cylinders for rotation in unison and at the same speed.
4. A web-fed offset printing press of the perfecting type as defined by claim 2, additionally including a gear drive operatively connecting all the cylinders for rotation in unison and at the same speed, wherein the plate cylinders are overpacked so that their surface speed will be greater than the peripheral speed of the bearer rings for the plate-blanket combinations, and wherein the blanket cylinders are underpacked so that their surface speed will be less than the peripheral speed of the bearer rings for the plate-blanket cylinder combinations.
5. In a web-fed offset printing press of the perfecting type, the combination comprising a pair of coacting blanket cylinders and a plate cylinder in surface contact with each blanket cylinder, said cylinders being geared together to rotate in unison and at the same speed, the plate and blanket cylinders having engaging bearers of equal diameter at respective ends, additional bearers on the blanket cylinders having engaging relation and which are also equal in diameter but smaller than the first mentioned bearers, the bearers for the plate-blanket cylinder combinations and the bearers for the blanket cylinder awavse combinations being staggered so as to lie in different planes in order to avoid interference of the bearers with each other.
'6. A Web-fed oifset printing press of the perfecting type as defined by claim 4, wherein the plate cylinders are overpacked so that their surface speeds will be greater than the peripheral speed of the bearer rings for the plateblanket combinations, and wherein the blanket cylinders are underpacked so that their surface speed will be less than the peripheral speed of the bearer rings for the plate-blanket cylinder combinations.
'7. In a Web-fed oifset printing press of the perfecting type, the combination comprising a pair of coacting blanket cylinders and a plate cylinder in surface contact with each blanket cylinder, said blanket cylinders coacting to print on both sides of a Web passing between the cylinders, said cylinders being geared together to rotate in unison and at the same speed, the plate and blanket cylinders having engaging bearer rings of equal diameter at respective ends, additional bearer rings on the blanket cylinders having engaging relation and which are also equal in diameter but difii'erent in size from the first mentioned bearer rings, the bearer rings for the plate blanket cylinder combinations and the bearer rings for the blanket cylinder combinations being staggered so as to lie in different planes in order to avoid interference of the bearer rings with each other, and :a spacing element at one end of each of the blanket cylinders for spacing the two bearer rings at said end, said spacing element having an aligned relation with one of the bearer rings of a plate-blanket combination, and said spacing element spacing the said two bearer rings a distance just slightly greater than the width of the bearer ring in alignment therewith.
References Zited by the Examiner UNITED STATES PATENTS 640,447 1/00 Corbin 101-217 935,907 10/09 Harris 101217 1,027,384 5/12 Green l01143 1,120,771 1 2/ 14 Wagner et a1 10l143 1,178,907 4/16 Firm 10-1-l42 2,036,835 4/36 Sites 101-142 2,439,454 4/48 Crafts l01216 2,853,003 9/58 K aldschm'idt et a1 101-216 FOREIGN PATENTS 265,409 3/26 Great Britain.
0 ROBERT E. PULFREY, Primary Examiner.
ROBERT A. LEIGHEY, Examiner.