US2982206A - Impression cylinder pressure setting mechanism - Google Patents

Description

y 1961 H. E. PEYREBRUNE 2,982,206

IMPRESSION CYLINDER PRESSURE SETTING MECHANISM Filed Feb. 24,1958 2 Sheets-Sheet 1 INVENTOR. HENRI a. PEYREBRUNE ATTORNEYS United States Patent llVIPRESSION CYLINDER PRESSURE SETTING MECHANISM Henri E. Peyl'ebrune, River Forest, 11]., assignor to Miehle-Goss-Dexter, Incorporated, Chicago, Ill., a corporation of Delaware Filed Feb. 24, 1958, Ser. No. 716,903

' 3 Claims. (Cl. 101-283) cylinder when said cylinder is in its operative or impression position.

In flat bed and cylinder presses, which may be either printing presses or die cutting and creasing presses, the

printing or die cutting form to be reproduced is supported on the bed and suitable mechanism is provided to impart continuous reciprocating motion to the latter. During the operative stroke of the bed the impression cylinder is moved to its operative or impression position for coaction with the form to effect an impression on sheet material passed therebetween and on the return or inoperative stroke of the bed the cylinder continues to rotate in the same direction but it is raised to an inoperative position so as to provide clearance for the form.

In order to print an impression or die cut and crease a sheet, considerable pressure must be exerted between the impression cylinder and the form during the operative stroke of the bed. The amount of pressure required, however, is dependent to a great extent upon the specific requirements of each particular form to be processed. It

i is essential, therefore, that convenient and accurate means be provided for adjusting the impression pressure in ac- 2,982,206 Patented May 2, 1961 ice Elf the coacting members, can be properly compensated Because the known pressure control mechanisms do not incorporate means for preloading the respective parts against the force of the impression, press manufacturers have attempted to accomplish a similar result by bringing the bed and cylinder bearers into engagement before the form reaches the impression position. This is done by extending the bed bearers forwardly beyond the leading edge of the form so that they engage the cylinder bearers and thereby compress the pressure control members before the actual impression starts. The space available for this purpose, however, is extremely' limited and although it has proven adequate whereby to take up all I of the clearances, it is not sufficient to permit the members to be fully compressed before the impression begins. As a result, the slight relative movement of the cylinder due to the continuing compression of the control members after the impression has started, causes a variation in density of the impression throughout the lengthof each sheet.

It will be appreciated that the overall movement of the impression cylinder resulting from clearances and the compression of the various control elements, is relatively infinitesimal. However, incredibly, small changes involving one or two thousandths of an inch can mean i the difference between high quality work and just mediocre prints and, therefore, the provision of means whereby relative motion of the impression cylinder after the impression has started, can be eliminated or substantially reduced, is extremely important.

It is a primary object of this invention, therefore, to provide impression pressure adjusting mechanism which can be adjusted conveniently and with the utmost precision and which incorporates mechanism whereby at least some of the adjustable members can be preloaded Y against the force of impression.

cordance with the specific requirements of each job so 7 that it can be maintained at a minimum and thereby avoid imposing unnecessary and excessive strains on the mechamsm.

In addition, such adjusting mechanism should incorporate means for removing all clearances between the coacting members and for precompressing said members prior to the cylinder and form going on impression to preclude any relative movement between the members after the impression has started which will have an adverse efli'ect upon the quality of the work produced.

Heretofore, it has been standard practice to provide relatively heavy jack screws on each side of the press which are adjustable whereby to vary and thereafter maintain the pressure setting of the impression cylinder. Such means, however, cannot be calibrated with any degree of accuracy and thus numerous readjustments are required and considerable time is Wasted each time a pressure change 'is made before a precise corresponding setting is obtained at both ends of the cylinder.

It is also known to utilize adjustable eccentric means to control and adjust the pressure setting of the impression cylinder. Such devices provide a relatively high degree of accuracy as compared to the jack screws, however not any of the known devices incorporate means for preloading the coacting members against the force of impression. Therefore, numerous readjustments invariably are required before relative movement of the cylinder,

due tothe take up of the clearances and the compression Another object of this invention resides in the provision of a rotatable eccentric member for eifecting impression pressure adjustment and which presents a maximum surface area to resist the force of impression.

A further object is to provide simple and efficient means for effecting adjustment of the eccentric pressure control member and which means serve the dual function of preloading said member against the force of impression.

Other objects and advantages will become apparent from the following description and accompanying drawings wherein:

Figure 1 is a side elevation of the cylinder assembly of a flat bed and cylinder press;

Figure 2 is an enlarged sectional view taken substantially along line IIII of Figure 1;

Figure 3, is a sectional view along line lIIIII of Figure 2; and

Figure 4-, is a partial view of the mechanism for retaining the pivot pins in their operative positions.

In Figure 1, the invention is illustrated as embodied in a conventional flat bed and cylinder press wherein an impression cylinder 10 is adapted to coact with areciprocating bed 1'1 to effect impressions on sheets of formed in the side faces of the bearing block so as to maintain it against any lateral movement while permitting it to move vertically upon actuation of the cylinder control mechanism.

Mounted below the bearing block 16 are a pair of compression springs 19. These springs are seated in the frame member 14 and are adapted to exert constant pressure against the bottom face of the bearing block tending to maintain the latter and thus the impression cylinder in its raised or inoperative position. When the cylinder is moved downwardly to its operative position as shown in Figure 1, the springs 19 are compressed and serve to return the cylinder to its raised position upon return of the cylinder actuating mechanism to its inactive position. Guide rods 20 maintain the springs against lateral displacement and are seated in the frame member 14. The upper ends of said rods project into openings provided therefor in the bearing block and it will be noted that the recesses in the bearing block are deep enough to permit vertical movement of the said block through its maximum stroke without interference with said guides.

Movement of the cylinder to its operative or impression position against the pressure of the springs 19 is effected by means of an oscillatable eccentric cylinder actuating member 21 which is located above the bearing block 16 between a cylinder control block 22 and a spacer block 23. As shown in Figures 1 and 2, the actuating member 21 is formed with bearing surfaces 24 and 25 adjacent its lateral edges. These surfaces are concentric with respect to the axis A of said member and are seated in the control block 22, the bottom surface of which is formed with a concave semi-cylindrical seat having the same radius as the bearing surfaces 24 and 25. Intermediate the bearing surfaces 24 and 25, and on the lower half of the actuating member 21 is a curved surface 26 which is formed eccentric with respect to the bearing surfaces 24 and 25 about the axis B. This surface in turn is seated in a correspondingly curved seat formed in the upper edge of the block 23 which is mounted on the top surface of the bearing block 16 and is adapted to slide laterally thereon, as viewed in Fig. 1, when the cylinder actuating member 21 is oscillated.

Thus the cylinder actuating member 21 is, in effect, a toggle which, upon being moved to the rotative position as shown in Figure 1, wherein the respective axes A and B are coincident With a vertical plane through the axis of the journal 15, moves the bearing block 16 downwardly against the pressure of the springs 19 to its impression position. When the member 21 is rotated clockwise, as viewed in Figure l, the axis B is moved out of said plane, thus relieving the pressure on the bearing block 16 and permitting the springs 19 to raise the cylinder to its inoperative position.

Oscillating motion is imparted to the member 21 for the purpose of raising and lowering the impression cylinder, through an arm 27 which is formed integral with said member and which has pivotally connected to its free end a connecting link 28. The opposite end of the latter member is connected to suitable actuating mechanism, not shown, but which is arranged to oscillate the member 21 in timed relation to the reciprocating movement of the bed 11.

Thus, it will be apparent that each time the bed 11 moves on its printing stroke, which is to the right as viewed in Figure 1, the member 21 will be rotated counter-clockwise to the position illustrated in order to move the impression cylinder to its impression position where in the cylinder bearers 29 are brought into contact with the bed bearers 31 under a predetermined pressure. As the bed commences its return stroke, the member 21 is rotated clockwise whereby to break the toggle and permit the cylinder to raise to its inoperative position to provide clearance for the form.

From the description thus far it is evident that each I time the actuating member 21 is oscillated, the impression cylinder is moved through a fixed distance, vertically and the extent of such movement is substantially equivalent to the distance between the respective axes A and B. Therefore, in order to vary the degree of pressure exerted between the respective impression cylinder and bed bearers when in the impression position, the vertical position of the control block 22 must be adjusted accordingly in order to raise and/or lower the axis of rotation of the cylinder actuating member 21.

As shown in Figure 1, the control block is adjustably mounted in an opening 32 provided therefor in the cap member 33 and the side walls 34 of said opening constitute guides which are adapted to fit into corresponding grooves formed in the side walls of the control block so as to prevent any lateral movement thereof but which permit the block to be adjusted vertically.

The vertical position of the control block 22 is readily adjustable and it is maintained in its adjusted position by means of a pressure control member 36 which is rotatably mounted in the cap member 33 with its axis coincident with a vertical plane through the axis of the journal 15. The pressure control member is provided with concentric bearing surfaces 37 along its lateral edges which engage the frame member 33, see Figure 2, and which are separated by an intermediate curved surface 38, the axis of which is eccentric with respect to the axis of the bearing surfaces. The eccentric surface has coaction with an adjustment block 39 arranged intermediate the pressure control member 36 and the control block 22, whereby to adjust the vertical position of said control block upon rotation of the member 36. The adjustment block 39 is seated on the control block 22 and its upper edge is formed so as to correspond in curvature with the eccentric surface 38. Thus when the member 36 is rotated the eccentric surface 38 thereof effects a corresponding vertical displacement of the control block 22 which in turn lowers or raises the axis of rotation of the actuating member 21 to thereby increase or decrease the pressure relation between the bed and cylinder in the impression position.

The pressure control member 36 is adapted to be rotated in the cap member 33 whereby to vary the angular position of its eccentric surface 38 by means of two tension rods 41 and 42 one of which is pivotally connected to said member on each side of the axis thereof. The member 36 is grooved to accommodate the tension rods which project upwardly through aligned openings 44 and 45 formed in the cap member 33 and the free ends thereof project beyond said member and are threaded to receive the adjustable nuts 46 and 47. Bushings 48 and 49 are seated in the upper ends of the openings in the cap member to provide seats against which the respective nuts coact to effect adjustment of the member 36.

Thus it will be seen that by loosening one of the nuts 46 or 47 and tightening the other, the pressure control member 36 can be rotated in either direction about its axis in the cap member whereby to vary the angular position of the eccentric surface 38. This in turn effects a corresponding vertical displacement of the adjustment block 39 and therewith the control block 22 which in turn raises or lowers the axis of rotation of the member 21 to thereby increase or decrease the pressure relation between the cylinder and the bed in their operative position.

To provide for convenient assembly and disassembly of the mechanism, the tension rods are connected to the pressure controlmember 36 by means of clevis pins 43 which are inserted in the horizontal openings provided therefor in the control member 36 so as to project through the eyes in the depending ends of the tension rods. Each pin is formed with a reduced diameter neck 51 adjacent one end thereof and when they are placed in position they are located so that the said neck portion is adjacent the end face of the control member 36. The pins are locked in position by means of a plate 52 the edge of which is-adapted to fit into the neck portion 51 of the pins 43 and which plate is then secured to the control member by means such as the bolts 53. Thus the pins are normally retained against axial displacement but can readily be removed by loosening the bolts 53 and removing the plate 52.

The extent of the adjustment imparted to the pressure control member 36 at each end of the impression cylinder can be readily determined by means of an indicator 54 which is secured to the outer face of the control member 36 and is adapted to register on a scale 55 fixed to the cap member 33. The scale 55 preferably is calibrated with relation to the eccentric surface 38 and is adapted to register the extent of the adjustment in increments of .001 of an inch.

Thus it is a relatively simple matter to effect corresponding, infinitely variable precision pressure adjustments at each end of the impression cylinder and since the adjusting members are readily accessible such adjustments can be accomplished in a minimum of time.

The tension rods 41 and 42 are also utilized to lock the pressure control member in its adjusted position and to preload or precompress said member against the force of impression. As stated above, when an adjustment is to be made, one of the adjusting nuts 46 or 47 is loosened whereupon the other is tightened against its respective bushing 48 or 49 to effect partial rotation of the control member 36. After the adjustment is completed, the nut which originally was loosened is drawn up tight and sufficient tension is applied whereby any clearance existing between the top surface of the pressure control member 36 and the cap member 33 is removed and said members are actually precompressed against the force of impression.

This represents a decided advantage over the known pressure control devices because it makes possible a substantial reduction in the overall clearances which must be taken up and the number of members which must be compressed during the short interval after the bed bearers 56 engage the cylinder bearers 29 and before the leading edge of the form 12 reaches the point of impression. Thus the movement of the cylinder upon engaging the bed bearers will be suflicient to take up any remaining clearances between the other control members such as 21, 22 and 39 during the short interval provided for this purpose and, since the control member 36 is already precompressed, any relative movement of the cylinder resulting from compression of the other members after the impression commences will be so minute as to have little or no effect upon the printed impression.

Having thus disclosed a preferred embodiment of my invention, I claim:

1. In a printing press or like machine having a frame, an impression cylinder rotatably mounted in said frame for bodily movement between operative and inoperative impression positions with relation to a reciprocating bed, and mechanism including a toggle member-for moving the cylinder between said positions, the combination comprising an adjustable control block having co-action with said toggle member to produce a predetermined pressure between the bed and cylinder when the latter is in its operative impression position, a cylindrical element mounted for partial rotation in said frame about an axis located above said control block, said cylindrical element having an eccentric surface formed integral therewith for adjusting the position of :said control block upon rotation of said element whereby to vary the pressure between the bed and cylinder when said cylinder is in its operative impression position, link means pivotally connected to said cylindrical element and extending through openings in the frame, and manually operable means engaging said link means and having co-action with the frame, said manually operable means being adapted to be operated for first rotating said element to eifect adjustment of said control block and thereafter being operable to preload said element against the force exerted when the cylinder is in its impression position.

2. In a printing press or like machine having a frame, an impression cylinder rotatably mounted in said frame for bodily movement between operative and inoperative impression positions with relation to a reciprocating bed, and mechanism including a toggle member for moving the cylinder between said positions, the combination comprising an adjustable control block having coaction with said toggle member to produce a predetermined pressure be tween the bed and cylinder when the latter is in its operative impression position, a cylindrical element mounted for partial rotation in said frame about an axis located above said control block, said cylindrical element having an eccentric surface formed integral therewith for adjusting the position of said control block upon rotation of said element whereby to vary the pressure between the bed and cylinder when said cylinder is in its operative impression position, a pair of tension rods pivotally connected to said cylindrical element at diametrically opposite locations, said rods extending upwardly in parallel relation and extending through openings in the frame, and adjustable means threadedly engaging the projecting ends of the rods respectively and having co-action with the frame, whereby rotation of said respective adjustable means to tighten one and loosen the other will impart rotary motion to said element and whereby rotation to tighten both said adjustable means will preload said element against the force exerted when the cylinder is in its impression position.

3. In a printing press or like machine having a frame, an impression cylinder rotatably mounted in said frame for bodily movement between operative and inoperative impression positions with relation to a reciprocating bed, and mechanism including a toggle member for moving the cylinder between said positions, the combination comprising an adjustable control block having coaction with said toggle member to produce a predetermined pressure between the bed and cylinder when the latter is in its operative impression position, a rotatable element seated in the frame, means formed integral with said element for adjusting the position of the control block upon rotation of said element whereby to vary the pressure between the bed and cylinder when said cylinder is in its operative impression position, and manually operable means including members p-ivotally connected to said element and having coaction with the frame for first rotating said element to efiect adjustment of said control block and for thereafter compressing said element against the frame and in the direction of the force exerted on said element when the cylinder is in its impression position, to thereby reduce the relative movement of said cylinder resulting from compression and expansion of the said element and said frame as the cylinder goes on and off impression.

References Cited in the file of this patent UNITED STATES PATENTS 1,019,253 Hodgman Mar. 5, 1912. 1,380,469 Droitcour June 7, 1921 1,562,775 Leilich Nov. 24, 1925 2,079,001 Crafts May 4, 1937 2,743,672 Harless et al. May 1, 1956

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