US2774425A

US2774425A - Means for longitudinally slitting webs of paper or other flexible material

Info

Publication number: US2774425A
Application number: US399138A
Authority: US
Inventors: Hornstein Victor; Schelp Karl
Original assignee: Jagenberg Werke AG
Current assignee: Jagenberg AG; Jagenberg Werke AG
Priority date: 1953-12-18
Filing date: 1953-12-18
Publication date: 1956-12-18
Anticipated expiration: 1973-12-18

Description

Dec. 18, 1956 v. HORNSTEIN EIAL 2,774,425

MEANS FOR LONGITUDINALLY SLITTING WEBS OF Filed Dec. 18, 1953 PAPER OR OTHER FLEXIBLE MATERIAL 2 Sheets-Sheet 1 21220 1212160115 1 HzDZmz/ja Ki? 1L 5 Dec. 18, 1956 v. HORNSTEIN ETAL 5 MEANS FOR LONGITUDINAL-LY SLITTING WEB-S OF PAPER OR OTHER FLEXIBLE MATERIAL Filed Dec. 18, 1953 2 Sheets-Sheet 2 Fig. M

lav e ia s l/T iopmiem United States Patent MEANS FQR LGNGITUDINALLY SLITTING WEBS OF PAPER OR OTHER FLEXIBLE MATERIAL Victor Hornstein, Dusseldorf-Lohausen, and Karl Schelp, Dnsseldorf-Wersten, Germany, assignors of one-half to Jagenberg-Werke Akt.-Ges., Dusseldorf, Germany Application December 18, 1953, Serial No. 399,138

15 Claims. (Cl. 164-60) The present invention broadly relates to the art of slitting webs of flexible material.

Specifically this invention relates to means for longitudinally slitting webs of paper or other flexible material.

Still more specifically this invention relates to means for longitudinally slitting running webs of paper or other flexible material in which the Web to be slit is guided between a smooth counter-cylinder or counter-roll and one or more disk knives that cooperate with the countercylinder.

This form of slitting in practice termed notch-slitting is limited in its possibilities of use and is generally more or less restricted to use with materials susceptible to being slit in this fashion and with respect to which too high pretensions are not made as regards a smooth and carefully produced slit edge. However, notch-slitting has certain advantages compared to the more commonly used slitting means which consist of circular knives and counter-disk knives in that the counter-disk knives that normally cooperate with circular disk knives in the prior art are replaced by a single smooth roll or the countercylinder; additionally, notch-slitting permits the possibility of sirnple adjustment for different widths of slits or strips obtained from a web by a simple axial displacement of the disk knives that cooperate with the smooth counter-cylinder.

In order to provide for completely slitting a running web of material, circular knoves in a notch-slitting operation, that is the slitting means that cooperate with a smooth counter-cylinder, rest on the counter-cylinder with a determined pressure. For this reason such slitting means are not provided with very sharp slitting edges so as to prevent the spoilation or wear of the cutting edge and the formation of scores or grooves on the smooth counter-cylinder. To the contrary, the cutting edges of knives used in notch-slitting have a slightly rounded edge which will efiect the inconvenience of a rough incision. Furthermore, in instances where a diskknife having a very sharp cutting edge cooperates with a smooth counter-cylinder under positioning pressure determined by a threaded spindle or other suitable cutting means, the sharp cutting edge is exposed to rapid wear and tear due to the vibration of the smooth countercylinder during the course of the operation of the slitting machine, since the disk knives due to being rigidly fastened down do not yield or participate in the vibrations of the counter-cylinder independently thereof.

Therefore, the present invention has for an object to provide means for longitudinally slitting running webs of paper or other flexible material permitting the use of a disk knife or knives having sharp cutting edges and whi h knife or knives cooperate with a smooth countercylinder.

As a specific object, the invention provide sia mounting for the slitting means which permits the knife or knives to follow the vibrations of the smooth counter-cylinder so that the knife or knives are not damaged and premature wear and tear thereof is avoided. e

2,774,425 Pate ted D .8 .955

One means of accomplishing the aforegoing object provides a structural disposition in which the disk knife means resting upon or riding on the smooth countercylinder cooperates with a second disk knife means also applied against the counter-cylinder. The structure is such that the intermediate space between the disk knife means, which are opposed to one another, corresponds to the diameter of the counter-cylinder, and this space is maintained invariable by mounting both knife means on a lever means rockably mounted about a fixed center of rotation. Due to this arrangement, the smooth counter-cylinder is contacted from opposite points in a snap-gauge-like fashion with the effect that one of the knife means serves as a distance sustainer to the other. In the instance where the machine is running with no load, that is if the dead weight of the disk knives is balanced for example by counter-poise or counter-cylinder, the pressure between the disk knives and the counter.- cylinder will be practically equal to zero, whereas the so-called chip pressure caused by the slitting operation will not be greater than the pressure necessary for effectively intersecting the web or webs of material.

This supporting arrangement which maintains an invariable distance between the cooperating disk knife means supported on a lever that is freely movable around a stationary pivot, permits the knives to follow the vibrations emanating in the smooth counter-cylinder, thus eliminating damage to the knives and premature wear and tear due to any suddenly increasing bearing pressure between the knife means and the counter-cylinder.

The second disk-knife means cooperating with the first disk-knife means may, in a modification, be replaced by a smooth roll. This is in instances where the machine is slitting thin or preferably uniformly thick webs of material. The smooth roll lies upon the surface of the web that is guided around the counter-cylinder. Thus in this case, the disk-knife means and the guide roll cooperate in the same manner as the two disk-knife means previously mentioned. However, the guide roll function'- ing as a distance sustainer for the disk-knife means bears or rolls 01f on the paper or flexible web being slit rather than being disposed in direct contact with the countercylinder. In the first instance, the second disk-knife means runs in the same cutting path as the first diskknife means. Specifically where disk-knife means are mounted one above the other in relation to a horizontal counter-roll or cylinder they would be in the same vertical plane, although this is not to be considered a limitation.

If the web to he out has an irregular thickness, due to overlappings or the like and a guide roll was utilized which would have to adapt itself to the bearing pressure of a disk knife rigidly connected therewith, then the bearing pressure would be increased and the danger of premature wear and tear of the cutting tools or knives and a constant scoring or deterioration of the counter cylinder would be present. Thus in order to eliminate this disadvantage, the invention has for a further object and as a specifically modified form, to provide a mounting including a disk-knife means and a smooth guide roll that cooperates therewith but which is capable of yielding in accordance with variations of thickness arising in the web being slit.

In this form, the mounting for the disk-knife means and guide roll includes two independent levers, one carrying the disk knife and the other the guide roll. Both levers are mounted for movement around a common center but are limited as to the minimum distance that can exist between the ends thereof carrying the knife an r es st lwb an d u b s p w eps Wi this r me t t e he rin Pressu e 9. I th d sk a periphery of the

knives

3 and 4;

knife thatiis required to slit the ,web is sustained to be substantially constant as regards its effect on the smooth counter-cylinder. The two' lever means are urged toward one another by 'Spring means. Therefore the mounting has the elfect of a rigid connection between the disk knife and guide tell if. the web is of uniform thickness. Howe'ver, when there is a variation in the thickness of the web, the spring normally maintaining the guide roll and disk knife' at an invariable distance, will permit the yielding of the guide roll to accommodate the variation in thickness. 7 Further and more specific objects will be apparent from the accompanying drawings schematically illustrating two embodiments of the invention and in which: Figure 1 illustrates an arrangement in which a second disk-knife means functioning as a distance sustainer, co-

operates with the first disk-knife means.

Figure 1a is a front view of Figure 1.

Figure 2 illustrates an arrangement in which a guide roll cooperates with the first disk-knife means.

Figure 2a is a front view of the arrangement shown in Figure 1.

In the arrangement illustrated, the web 1 to be slit is fedotf of a supply reel, not shown, and guided around a smooth counter-cylinder 2 and then rewound by a suitable rewinding means, not shown.

the web around the counter-cylinder, the same will be slit into one or more strips by means or one or more disk knives 3 that bear against the opposite portions of the counter-cylinder 2. The disk knife 3 is operatively' coupled with a second disk knife 4 50 that the two knives or sets of knives where plural knives are embodied, lie facing one another and contact the periphery of the counter-cylinder 2 with the diameter of the countercylinder being equivalent to the spacing between the The knife means 3 and 4 are supported in a rotatable manner by pintle or axle means 3' 4' at the free ends of lever 5. This is a two-arm lever and substantially U-shaped in plan with the knife means being mounted in the free ends of the legs of the U. The lever 5 is pivotally mounted about a fixed center of rotation or pivot v6. Since the lever is rigid, a constant distance between'the

disk knives

3 and 4 and the counter-cylinder 2 is assured by means of the invariable angle of motion limitedby the center of rotation 6 and the centers of the

disk knives

3 and 4. Thus as is shown, the axis of the center of rotationfi lies in the same plane as the axis of the counter-cylinder and the respective legs of the lever 5 are at equal distance from the plane bi+ secting' the center 6 and the counter-cylinder 2.

In the form shown in Figures 1 and la, the two

knives

3 and 4 lie in a common slitting plane, that is the disk knife 4 runs in the slit that has been produced by the disk knife 3. However, the invention is susceptible to utilization. in instances where the disk knives lie in different slitting planes and disk knife 4 has a slitting function independent-of the slitting effected by the disk knife 3. Such embodiment, as shown in Figure 3 would include a mounting in which one disk knife 3 is offset from the other knife 4 in the direction longitudinally of the counter-cylinder 2.

In order to fully compensate for the dead weight of During passage of is not of uniform thickness. In this arrangement, the disk knife 3" is freely rotatably mounted in the end of a lever 5' rockably mounted about the stationary pivot 6.

Also rockably mounted about this same stationary center or pivot is a further lever 5", which'at its free end journals a smooth guide roll 4' The distance between the circumference of the disk knife 3 and the circumference of the guide roll 4" corresponds substantially to the diameter of the counter-cylinder 2. The lever 5"carries a stop 8 in a position adjacent to center of rotation 6 and which stop extends toward the counter-cylinder. A set-screw means 9 is carried by the lever 5' for cooperation with the stop 8. The contact between the set-screw and stop or abutment 8 determines the minimum 'distance between the periphery of knife 3" and roll 4" and a traction spring 10'connects the two leve1's'5', 5" together. This arrangement permits effective operation of the Web 1 in a manner with 'only slight bearing pressure existing between the knife 3 and the counter-cylinder 2,

and in which any vibrations emanating'in the counter-- cylinder 2 will not cause a detrimental increase of the bearing pressure since the'slitting means'as a whole constituted by the disk knife 3" and the guide roll 4'. re: main constant when websof normal thickness or uniformity in thickness are being slit since the

levers

5, 5"

jointly took about pivot 6'. However, in instances where V the web is of non-uniform thickness or an unevenness in the web is involved, the guide roll 4" will yield without increasing the bearing pressure to such an extent that the cutting edge of the knife will be damaged. lThe invention also contemplates an arrangement in which a guide roll is substituted for the knife 4 in the 7 form of Figure l. v

What is claimed is:

-l. Means for slitting a web of paper or other flexible material longitudinally thereofcomprising a smooth counter-cylinder around which a web to be slit passes, diskknife means movably mounted with respect to the axis of the counter-cylinder and cooperating with one portion of the counter-cylinder for slitting the web, said disk-knife means having an axis parallel to the cylinder axis, ad

ditional means freely rotatable about an axis parallel to the aforementioned axes and cooperating with an opposite portion of the countencylinder and means operably coupling the said additional means to the diskknife means so as to constitute a distance sustainer for the disk-knife means.

2. Means as'defined in and by claim 1 in which the additional means constitutesa second disk-knife means.

3. Means as defined in and by claim 1 in which the additional means constitutes a guide roll.

' 4. 'Means as defined in'and by claim 1 in which the additional means constitutes a second disk-knife means and in which the first and second disk-knife means lie in a common slitting plane.

5. Means as defined in and by claim 1 in which the additional means constitutes a second disk-knife means and in which the first and second disk-knife means lie in different'slitting planes. 7

6." In a web slitting mechanism a smooth counter-cylinde'r-around which a flexible web to be slit passes, a slitting means cooperable therewith to slit the web longi- 7 tudinally comprising a rotatable disk-knife, means and a further rotatable means, said disk-knife means and

furthe disk knives

3 and 4 and of the lever 5, a counterweight of the lever arms and the means and the cylinder and between the further rotatable about an axis parallel to the axis of the cylinder but on 'In Figures 2 and 2a, there is disclosed an arrangement that is' especially suitable for use when the web to be'slit' ther rotatable means being disposed on opposite sides of and cooperating with the counter-cylinder at areas thereof lying on opposite sides of a plane bisecting the cylinder so that the web passes between'the disk-knife means and the cylinder in its passage around the cylinder, lever means carrying the disk-knife means and the further freely rotatable means at a minimum distance apart and fixed pivot means supporting the lever means the side thereof adjacent'the side of the cylinderembraced by the webfin its passage. 1

7. Web slitting mechanism as defined in and by claim 6 in which the lever means is rigid and common to both the disk-knife means and the further freely rotatable means and the fixed pivot means has a center of rotation displaced laterally of the axis of the counter-cylinder but lying in the plane passing through the axis of the cylinder that is normal to the plane passing through the axes of the knife means and the further rotatable means in a direction axially thereof and the angle of motion of the lever means formed by the center of rotation of the lever means and the respective centers of the knife means and the further freely rotatable means being invariable.

8. Web slitting mechanism of the type defined in and by claim 6 in which the lever means includes two independently movable arms extending toward the axis of the counter-cylinder and lying on opposite sides of a plane passing through said axis, one arm carrying the disk-knife means and the other arm carrying the freely rotatable means and means operative to normally maintain the arms at a minimum distance apart for slitting webs of uniform thickness but operable to permit an increase of this distance upon an increase in the thickness of the web.

9. Web slitting mechanism of the type defined in and by claim 8 in which the means normally maintaining the arms at a minimum distance apart include mutually engageable stop means carried by each arm.

10. Web slitting mechanism of the type defined in and by claim 9 and resilient means normally urging the arms toward one another.

11. Web slitting mechanism of the type defined in and by claim 10 in which the further freely rotatable means is a guide roll.

12. Web slitting mechanism of the type defined in and by claim 11 in which the disk-knife means and the guide roll are aligned in a plane normal to the axis of the counter-cylinder.

13. In a web slitting mechanism a smooth countercylinder around which a web to be slit passes, a fixed pivot means displaced forwardly of the counter-cylinder with regard to the direction of movement of the web toward the counter-cylinder, lever means pivotally mounted on said pivot and including spaced interconnected arms extending toward the counter-cylinder and lying respectively on opposite sides of the axis thereof,

disk-knife means carried by one of the arms and freely rotatable means carried by the other arm, said disk-knife means cooperating with the counter-cylinder to slit the web longitudinally and said freely rotatable means cooperating with the counter-cylinder through the interconnected lever arms to control bearing pressure exerted on the counter-cylinder by the disk knife.

14. Web slitting mechanism of the type defined in and by claim 13 in which the two arms are independently pivotally mounted on the pivot, resilient means interconnecting and urging the arms toward one another and an abutment means carried by each arm and mutually engageable with one another to limit the movement of the arms toward one another while permitting movement of one arm relative to the other in the direction opposite to the minimum distance.

15. In a mechanism for slitting a web of flexible material longitudinally thereof a cylinder about which the web to be slit passes, a fixed pivot spaced from the cylinder and lying on the side thereof adjacent that side embraced by the web in its passage around the cylinder, lever arm means supported by the fixed pivot for rotation thereon and including portions extending toward the cylinder but lying on opposite sides of its axis, a disk-knife means carried by one of said portions for rotation about an axis parallel to the cylinder axis and cooperable with the cylinder for slitting the web, additional rotatable means carried by the other of said portions and cooperable with the cylinder at an area diametrically opposite the area engaged by the disk-knife means and means operably connected to the lever arm means for compensating for the dead weight of the lever arm means, the disk-knife means and the additional rotatable means.

References Cited in the file of this patent UNITED STATES PATENTS 1,765,208 Cunningham June 17, 1930 1,841,251 Miller Jan. 12, 1932 2,205,564 Johnstone June 25, 1940 2,553,052 Kwitek May 15, 1951 FOREIGN PATENTS 1,070,070 France Feb. 17, 1954 145,814 Sweden Apr. 1, 1954