US2826142A - Adjustable cylinder for duplicating machines - Google Patents

Description

March 1, 195 H. F. BRUNS' 2,826,142

ADJUSTABLE CYLINDER FOR- DFJPLICATING MACHINES Filed Nov. 20, 1953 I 3 Sheets-Sheet 1 INVENTOR 1 /5/25 452T F Bea v:

ATTORNEY March .11, 1958 H. F. BRUNS 2,826,142

ADJUSTABLE CYLINDER FOR DUPLICATING MACHINES Filed Nov. 20, 1953 3 Sheets-Sheet 2 INVENTOR M525 1552 rifled/vs.

March 11,1958 H. F. BRUNS 2,826,142.

ADJUSTABLE CYLINDER FOR DUPLICATING MACHINES Filed Nov. 20. 1953 3 Sheets-Sheet 3 W62 LE JC NJ' ATTORNEY United States Patent F ADJUSTABLE CYLINDER FOR DUPLICATING MACHINES Herbert F. Bruns, Chicago, 111., assignor to Ditto, Incorporated, Chicago, 111., a corporation of West Virginia Application November 20, 1953, Serial No. 393,383

6 Claims. (Cl. 101-142) This invention relates to an offset duplicating machine and constitutes a continuation-in-part of co-pending applications, Serial No. 712,538, filed November 27, 1946 (now Patent Number 2,660,113, issued November 24, 1953) and Serial No. 154,009, filed April 5, 1950 (now Patent No. 2,753,795), and in particular relates to spaced members which constitute a cylinder having plate and impression surfaces, respectively, engageable with a blanket roll for offset lithographic printing.

It is an object of this invention to provide a cylinder for a duplicating machine, the plate and impression surfaces of such cylinder being relatively adjustable to each other.

It is another object of this invention to provide a cylinder constituted by spaced members which at any position of adjustment relative to each other, maintain a fixed driving relation between one of such members and the blanket roll.

The invention is concerned with an offset duplicating machine having a rotatable blanket roll engageable with plate and impression surfaces respectively provided on spaced members which are mounted for rotation about a common axis disposed parallel to the axis of the blanket roll, such plate and impression surfaces being concentric to the axis of rotation of the spaced members characterized in that such spaced members are interconnected by a mechanism which is readily operable to angularly adjust the members relative to each other and which positively and constantly maintains the members in controlled spaced relation.

Referring now to the accompanying drawings, wherein;

Figure 1 is a side view, in section, of a portion of a duplicating machine including a blanket roll and a cylinder having plate and impression surfaces;

Figure 2 is a vertical section through the machine, showing the cylinder and the drive shaft therefor in elevation;

Figure 3 is a section and elevation, taken substantially on line 33 of Figure 2;

Figure 4 is a section and elevation taken on line 4-4 of Figure 2;

Figure 5 is a sectional detail, on the line 5-5 of Figure 3, showing one of the ring cams, for controlling the ink form roll and the moisture form roll, fixedly secured to the impression sector of the cylinder; and t Figure 6 is a sectional detail, taken on line 66 of Figure 3, showing the connection of the cylinder driving gear to the plate sector of the cylinder.

Referring to Figures 1 through 6, cylinder 1 comprises a plate holding member and a paper holding or impression member. The plate member consists in a cylindrical sector 2 having an accurately machined peripheral sur faces 3 (Figures 3 and 4) and integral inwardly extending flanges 4 and 5, provided with arcuate, outwardly extending hubs 6 at their inner ends, and outwardly pro jecting, stepped bosses 7 on their outer faces. The impression member similarly comprises a cylindrical sector 8 having an accurately machined peripheral surface 9 and "ice end flanges 10 and 11, terminating at their inner ends in arcuate outwardly extending hubs 12. Stepped bosses 13 also project outwardly from these end flanges. The hubs 6 and 12 of the sectors 2 and 8 are seated upon the cylinder supporting shaft 14. Arcuate clamping members 15 and 16 embrace the hubs 6 and 12, respectively, at both ends of the cylinder, and are held in clamping relation by bolts 17 extending through a radial bore on each hub 12, through a diametric bore near each end of shaft 14 and through a circumferentially elongated slot 18 in each hub 6, so that the plate sector 2 may be angularly adjusted relative to the shaft 14 and the impression sector 8, while the angular relation between the shaft and the impression sector 8 remains fixed. The adjustment of the plate sector 2 may be effected by a manually adjustable member, such .as turnbuckle rod 19, having a peripherally notched adjusting wheel 20 secured to its central portion and having right and left hand threaded ends, disposed in correspondingly threaded sleeves 21 and 22 pivotally secured upon pins 23 and 24 carried by lugs on the respective sectors. A spring detent 25 appropriately secured to threaded sleeve 22 bears against the notched circumference of the hand wheel to hold the same in adjusted position. A pair of strong resilient members, such as tension springs 26, are connected to pins carried by the respective sectors and tend to draw the sectors together against the turnbuckle. By such construction, the adjusting wheel 20 is accessible through the gap between the adjacent ends of the sectors 2 and 8.

As an alternative, if desired, the springs 26 may be eliminated and the adjustment and the maintenance of the adjusted spaced condition may be had by use of the turnbuckle rod 19 alone. It is preferred to employ the springs 26 to overcome any backlash which may be inherent in the loose fit between the threads on the rod 19 and the threads in the corresponding sleeves 21 and 22.

Secured to the left hand end flange 5 of the plate sector, by cap screws 27 extending through spacer sleeves 28 into the bosses 7, is a ring gear 29, as shown in Figures 2, 3 and 6. The ring gear 29 is provided with three cut-out portions 30, bringing the bosses 13 on the left hand end flange 11 of the impression sector 8. Hence, the ring gear29 is bolted to and carried by the plate member, exclusively. The ring gear 29 is in mesh with a gear 31, fast on a drive shaft 32 journalled in the side frames 33 and 34 and having on its outer end a variable speed drive pulley 35.

The bosses 13, integral with the left hand end flange 11 of the impression sector 8, serve as seats to support a left hand ring cam 38 (Figure 2). The cam is secured in position by cap screws 39, disposed in the cut-out portion 30 of the ring gear 29, as shown in Figures 3 and 5.

The bosses 13 integral with the end flange 10 at the right hand end of the impression sector 8 (Figure 2) serve as seats for a ring cam 40. The cam 40 is held in place upon the bosses 13 by cap screws 41.

Thus, the ring cams 38 and 40 are fixed with respect to, and are carried by the impression sector 8 exclusively. The ring cams 38 and 40 engage the cam following wheels on a moisture form roll 42 and on an ink form roll 43 and move them outwardly to clear the impression sector 8, and permit such rolls to move inwardly, into a position to make contact with the printing plate on the plate sector 2.

' The radial dimensions of the plate and impression sectors comprising the cylinder are quite critical and are accurately predetermined. They have been selected as a result of giving primary consideration to the plate and paper thicknesses which would most usually be employed. The .aim is to have the plate sector, with a printing plate in position thereon, of the same overall diameter as the impression sector, with a paper sheet thereon. In other words, the overall diameter of the cylinder as a whole, with the printing plate and paper thereon should be the same as nearly as possible. It has been found that printlng plates of .006 thickness are the most practical, from the standpoint of economy, flexibility, ease of typing, minimum embossing and durability. It has also been found that 16 lb. and 20 lb. paper stock represents between 90% and 95% of the material usually printed with a machine of this type. Printing plate thicknesses can be standardized without difficulty, but it is desirable to be able to run all weights of paper ranging from tissue to card stock, having thickness variations from .002" to .001". With such variations in paper thickness, it is obviously impossible to maintain the overall radii of the plate and impression sectors equal, without the use of shims, which are impractical in small duplicating machines. The paper most commonly used is approximately .004 inch thick. Accordingly, the radius of the impression segment is made .002 inch greater than that of the plate sector.

Important advantages result from having the ring gear 29 secured only to the plate sector 2 and the cams 40, 38 secured only to the impression sector 8, and from having the plate sector 2 mounted for adjustment relative to the supporting shaft 14. As explained below, the blanket roll 45 carries a gear 46 which is continuously in mesh with the ring gear 29. Hence, when the plate and impression sectors are adjusted relative to each other by the adjusting wheel 20, the plate sector 2 and the blanket roll 45 do not have relative movement, but the impression sector 8 and the blanket roll 45 do have relative angular movement. In other words, the plate sector and the impression sector are relatively adjustable one to the other while maintaining a fixed driving relation between the plate sector and the blanket roll. As a result, the plate sector 2 and blanket roll 45 may be adjusted rela tive to the impression sector 8 and the cylinder shaft 14, to raise or lower the position of the image transferred to the paper by the blanket roll, but this adjustment does not change the position on the blanket roll to which the lmage is transferred by the printing plate. Hence, the formation of double images, on the blanket roll, after adustment, is eliminated, and the cleaning of the blanket roll between adjustments is unnecessary.

As shown in Figure 1, the blanket roll has a discontinuous surface which, together with the fixed driving relationship between the blanket roll 45 and the plate sector 2, provides a further important advantage in the operation of the machine. Normally, a smear or blob of ink will accumulate at the leading edge of the printing plate on the plate sector 2. If a continuous blanket roll were to be used, this blob of ink would be transferred to the blanket roll. Hence, if the impression sector 8 were to be adjusted angularly relative to the plate sector 2, such smear of ink on the blanket roll would be transferred to the sheet being printed. The only manner in which such transfer of ink can be eliminated, when using a continuous surface blanket roll, is to clean the blanket roll after each adjustment of the sectors 2 and 8. However, by using a discontinuous surface blanket roll, such as 45, and by setting the blanket roll to initially contact the plate sector, during rotation, at a line spaced from the leading edge of the plate, the said smear of ink on the leading edge of the printing plate will be accommodated, without contacting the blanket roll, in the gap provided in the surface of the blanket roll. Since the angular position of the blanket roll relative to the plate sector is fixed, an adjustment of the impression sector relative to the plate sector will not cause a transfer of the blob of ink from the plate sector leading edge to the blanket roll. In this fashion positioning the image in different locations on the paper sheet or the use of diiferent size sheets can readily be effected and the necessity of I cleaning the blanket roll after each adjustment is eliminated.

The throw out cams 38 and 40 for the ink and moisture form rolls 42, 43 are mounted on the impression sector 8 for the reason that their function is to move the rolls out of contact before they can engage the impression sector and to drop them back in at the trailing end of the impression sector so that they are in position to engage the plate on the plate sector 2.

The leading and trailing end faces of the plate sector 2 carry clamps 47 for the corresponding ends of the printing plate, but since these clamps may be constructed in accordance with the disclosure of Patent No. 2,586,146 issued February 19, 1952, they will not be described herein.

From the foregoing description, it will be noted that the invention provides a cylinder having plate and impression surfaces which are easily adjustable relative to each other. Such ease of adjustment is permitted by the adjustment mechanism, which as shown herein comprises the turnbuckle rod 19 but which, without departing from the scope of the invention, could readily be substituted by a hydraulic cylinder or other equivalent mechanism. The adjustment mechanism of this invention positively maintains the sectors 2 and 8 in controlled spaced relation to each other and which, without necessitating removal of bolts or other fastening devices, permits the sectors to be readily adjusted angularly relative to each other, while at all times maintaining a fixed driving relation, by means of gears 29 and 46, between the plate sector 2 and the blanket roll 45.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and al though specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation. Changes in form and in the proportion of parts, as well as the substitution of equivalents are contemplated, as circumstances may suggest or render expedient, without departing from the spirit or scope of this invention as further defined in the following claims:

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, what I claim is:

1. A duplicating machine comprising a drive shaft having a gear thereon, a main cylinder including plate and impression segments having their adjacent ends spaced apart, one of said segments being mounted for angular adjustment relative to the other of said segments so as to permit upper and lower margin adjustments in the printed copy as desired, adjustable positioning means disposed between adjacent ends of said segments adapted to secure the adjustable segment in a selected position of angular adjustment relative to the other of said segments, an ink form roll mounted for movement toward and from the main cylinder for applying ink to a plate on the plate segment, cam means carried exclusively in fixed relation by the impression segment for moving the form roll out of contact therewith, a ring gear concentric with the axis of said cylinder carried exclusively by, and in fixed relation to the plate segment, said ring gear being disposed in mesh with the gear on said shaft for rotating the cylinder, and a blanket cylinder mounted for rotation adjacent the main cylinder and having a gear mounted thereon, adapted to mesh with said ring gear so that the angular adjustment between said plate segment and said blanket cylinder is constant irrespective of variations in the angular adjustment of said segments.

2. A duplicating machine comprising a main drive shaft having a gear thereon, a main cylinder including plate and impression segments having their adjacent ends spaced apart, and an ink form roll mounted for movement toward and away from the main cylinder, the main cylinder comprising a shaft journalled for rotation on an axis fixed with respect to the drive shaft, means securing the impression segment to the shaft in fixed angular relation, means securing the plate segment to the shaft for angular adjustment, adjustable positioning means disposed between adjacent ends of said segments adapted to secure said plate segment in a position of angular adjustment relative to said impression segment so as to permit upper and lower margin adjustments in the printed copy, as desired, cam means fixed with respect to and carried exclusively by the impression segment for moving the form roll out of contact therewith, a ring gear concentric with the axis of said cylinder fixed with respect to and carried exclusively by the plate segment, meshing with the gear on the drive shaft and serving to rotate the cylinder, a blanket cylinder mounted for rotation adjacent the main cylinder and a gear mounted on said blanket cylinder concentric with the axis thereof adapted to mesh with said ring gear so that the angular adjustment between said plate segment and said blanket cylinder is constant irrespective of variations in the angular adjustment of said segments.

3. A duplicating machine comprising a main drive shaft having a gear thereon, a main cylinder including plate and impression segments having their adjacent ends spaced apart, an ink form roll mounted for movement toward and away from the main cylinder, a blanket cylinder mounted for rotation adjacent the main cylinder, a gear mounted on said blanket cylinder concentric with the axis thereof, the main cylinder comprising a shaft journalled for rotation on an axis fixed with respect to the drive shaft, means securing the impression segment to the shaft in fixed angular relation, means securing the plate segment to the shaft for angular adjustment, adjustable positioning means disposed between adjacent ends of said segments adapted to secure said plate segment in a selected position of angular adjustment relative to said impression segment so as to permit upper and lower mar gin adjustments in the printed copy, as desired, cam means fixed with respect to and carried exclusively by the impression segment for moving the form roll out of contact therewith, and a ring gear fixed with respect to and carried exclusively by the plate segment, meshing with the gear on the drive shaft and serving to rotate the cylinder, said ring gear being in mesh with the gear on the blanket cylinder, so that the angular adjustment between said plate segments and said blanket cylinder is constant irrespective of variations in the angular adjustment of said plate segment relative to said impression segment.

4. Apparatus in accordance with claim 1 in which said adjustable positioning means comprises resilient means interposed between the segments ur ing them in opposite directions relative to each other and in which a turnbuck e is utilized to select the position of angular adjustment of said adjustable segment.

5. x'trl o fset duplicating machine having a rotatable blanket roll engageable with plate and impression surfaces respectively provided on two spaced cylindrical sec tors mounted upon a common shaft, said impression sector being secured to said shaft in fixed angular relation thereto, said plate sector being secured to said shaft for an ular adjustment, said shaft mounted for rotation about an axis disposed parallel to the axis of the blanket roll, said plate and impression surfaces being concentric to the axis of rotation of the spaced sectors, said plate sector carrying a gear which is in driving engagement with a gear carried by the blanket roll for maintaining a fixed driving relation between said plate sector and said blanket roll, characterized in that said spaced sectors are interconnected by a mechanism for angularly adjusting said sectors relative to each other and which positively and constantly maintains said sectors in controlled space relation including resilient elements which urge said spaced sectors in one direction relative to each other, and an adjustable element which opposes the direction of thrust of said resilient elements.

6. Machine according to claim 5 characterized in that said adjustable mechanism comprises a turnbuckle which interconnects the spaced sectors and which has a manually operable adjusting wheel accessible through the space between said sectors.

References Cited in the file of this patent UNITED STATES PATENTS

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