US3056323A - Progressive transverse web cutting apparatus - Google Patents

Description

f "i Q Q Oct. 2, 1962 E. M. KWITEK 3,056,323

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PROGRESSIVE TRANSVERSE WEB CUTTING APPARATUS 5 Sheets-Sheet 2 Filed April 14, 1958 r S QQ ATTORNEYS.

United States Patent 3,056,323 PROGRESSIVE TRANSVERSE WEB CUTTING APPARATUS Edwin 1V. Kwitek, Green Bay, Wis., assignor to Paper Converting Machine Co., Inc, Green Bay, Wis, a corporation of Wisconsin Filed Apr. 14, 1958, Ser. No. 728,302 4 Claims. (Cl. 83-342) This invention relates to web perforating apparatus, and is particularly useful in the perforating or scoring or weakening along transverse lines of paper webs of the tissue paper type, such as facial tissue, etc.

This application is a continuation-in-part of my copending application, Serial No. 659,511, filed May 16, 1957, now Patent 2,870,840 and reference is hereby made thereto.

In paper winding machines, and particularly in machines handling thin tissue paper such as facial tissue, toilet paper tissue, etc., a problem has long existed with respect to the transverse weakening or perforating of the paper because the thin paper web tears readily. Because of this, webs of limited width have to be employed and the speed of operation and production substantially curtailed. The weakening or scoring of the paper transversely of the web is to provide, after slitting and in the finished paper product, lines along which the paper can be readily divided. As stated, the weakness of the paper tissue makes such weakening or scoring operation extremely diflicult, and the machines today employed can handle commercially only webs of limited width. If apparatus could be provided which would allow rolls of paper of much greater width to be treated in the machine, production could be greatly increased and the cost of the paper-winding operation substantially reduced.

Another difficulty experienced in the production of wound, perforated webs is where a multi-ply web is employed. Frequently, two-ply tissue, for example, is desired. Conventional perforating operations of such multiply webs often result in plies that open up when the web is unwound prior to use. When this occurs, the unwound portion of the web can become useless, since a single ply is materially weaker than the composite web.

I have discovered mechanism which etfectively perforates or weakens the paper web transversely of the web while at the same time applying the weakening or perforating operation at shortened intervals transversely of the web so that a lessening of tension upon the paper is produced and paper webs of greatly increased width can be effectively handled in the machine at high speed. At the same time, the mechanism provides a welding or pinching of plies along the perforations to overcome the problem of a multi-ply web opening up.

These results are achieved by perforating the web in restricted areas progressively across the web rather than perforating the web all the way across in one machine step, with the result that a minimum of strain or stress upon the paper web is imposed during the perforating operation and an extremely wide web can be fed from the roll through the machine to give an even and clean-cut perforated line across the web.

An object of the present invention is to overcome the difficulties referred to above and to achieve the new results described. A further object is to provide a weakening or perforating apparatus which brings about the perforation at isolated points transversely of the web as the web is moving forward, so that a minimum of stress is applied to the web at any single instant. Another object is to provide a shearcut mechanism in which a paper web is perforated transversely of the web, the perforations being accomplished in sequence across the web as the web advances in the machine. Still another object is to pro- 3,056,323 Patented Oct. 2, 1952 vide a web-cutting apparatus in which blade means and anvil means sever a web passing therebetween, the blade means being so oriented that only a single point of contact is made between the blade means and the anvil means at a given time. Yet another object is to provide blade means and anvil means of the character described in the object immediately preceding as part of rotating rolls. A still further object is to provide mechanism of unique and sturdy character which remains effective in. the shearcut perforating of sheets after long use, while at the same time permitting rapid operation of the perforating mechanism. Other obejcts and advantages, both general and specific, will appear as the specification proceeds.

The invention is shown, in an illustrative embodiment, by the accompanying drawings, in which FIG. 1 is a broken, diagrammatic showing of paperwinding apparatus employed in connection with my invention; FIG. 2 is an enlarged fragmentary front elevational View of the machine, showing a portion of the frame and elements for driving the rolls that cooperate in cutting a traveling web; FIG. 3 is an enlarged fragmentary front view of the cutting rolls of the machine; FIG. 4 is a view similar to FIG. 3 but showing a modified arrangement of cutting knives; FIG. 5 is an enlarged fragmentary top view of a modified form of the invention; and FIG. 6 is a side View of the apparatus seen in FIG. 5.

in view of the fact that most of the parts of a Webwinding machine are old in the art, it is believed unnecessary to describe such parts in detail, and it should be sufiicient to refer to them in a general Way by reference to the diagrammatic showing in FIG. 1.

In FIG. 1, 1d designates a paper web which leads from any suitable source. The invention herein may be employed on a rewinder or upon any form of mechanism. The Web 1t) passes over rolls 11, 12 and 13, as shown in PEG. 1, and thence between an anvil roll 14 and a perforating roll 15 which is equipped with structures embody my invention. Mounted in recesses 16 in the perforating roll 15 are knife'holders 17 equipped with knives generally designated 18. The knives 18 are in an angled arrangement so that the cutting edges of these knives or blades 18 cooperate with the hardened surface of anvil roll 14 in forming perforations successively across the web. That is, since each knife 18 is at an angle to the axis of perforating roll 15 (also at the same angle to anvil roll 1- the cutting edge of each knife 13 has a single point contact with anvil roll 14 at any given time. By disposing the blades 26 of each knife 18 in a spiral row as shown, contact is first made between a blade 26a on one end of the roll 15 and last made with a blade 26a on the opposite end, as seen in FIG. 3. After perforation, the web 16 passes over the intermediate roll 19, the slitting roll 20 cooperating with the slitter 21, and thence over the bedroll 22 to the turret 23 onto which the paper is wound upon cores in a well-known manner. The rotatable mandrel turret 23, bedroll construction, and other mechanism herein are described in greater detail in the G. M. Kwitek Patent No. 2,512,900.

In the specific illustration given, the slitter 21 is driven through the gear 24 meshing with the drive gear 25. Since such mechanism is well known, a further detailed description herein is believed unnecessary.

In the practice of my invention, 1 provide the perforating roll 15 with a transverse series of blades 26, as illustrated in FIGS. 2 and 3, and th blades, thus supported in a line longitudinally of the roll, are successively brought into engagement with anvil roll 14. With thi structure, the thin tissue is carried over the roll 14 and is sequential contact with blades 26 to bring about progressive perforating of the paper as the paper is advanced over the roll. In other words, viewing the operation from FIG. 3, there is first a perforating of the paper film at the right-hand side of the roll 14, and then, as the web is: advanced, the remaining portion of the web is successively perforated, the perforating action occurring incrementally as the paper is carried forwardly until the final perforation occurs between the blade and the segmental knife at the left-hand side of FIG. 3. The resulting perforation is at a slight angle to a transverse line across the sheet. The deviation from exact normal is, however, only about /8" in a 4 /2" long blade, which is not noticeable.

Where, however, it becomes important to minimize the eifect of the slight angled perforating operation, th structure of FIG. 4 can be employed, in which a perforator roll 115 is shown equipped with a plurality of knife blades 126 which cooperate with anvil roll 114 to transversely perforate a web traveling therebetween. In FIG. 4, the knives 126 are arranged in a V pattern so that perforations on opposite sides of the center line of a traveling web occur at identical positions. Where, for example, a web 90" wide is being slitted by slitter 21 into twenty rolls of tissue each 4 /2 wide, the apparatus shown in FIG. 3 would result in a /a offset of the perforation in each roll which, over the twenty rolls, would amount to 2 /2". The apparatus of FIG. 4, however, would have the edges of the 90 wide sheet perforated at directly opposite points, while the central portion of the sheet as at 126a would lead the side cuts by 1%. Another variation in the construction of the device of this invention is shown in FIG. 4, that relating to the means for providing the bonds or unperforated areas between perforations in a given roll. In FIG. 4, the cutting edges of knives 126 are uninterrupted, while the surface of the hardened perforator 1'011 114 is provided with a plurality of equally-spaced grooves 114a. In FIG. 3, the surface of hardened anvil roll 14 is unbroken, While the blades 26 are notched as at 261).

The perforating roll 15 is rotatably mounted for coaction with the anvil roll 14 and is provided with four spaced knives 18. Each knife 18 is formed of a plurality of hardened steel blades 26 and is preferably resilient and is so supported as to enable the blade to flex during action. I prefer to employ a high carbon chrome steel (6265 Rockwell C scale) having the grain of the steel running transversely of its width and having the edges of the blade notched on both sides. By way of example, when such a blade has a thickness of .032", it is found that effective flexing occurs while at the same time excellent perforation is brought about. Such a blade provides four cutting edges and may b reversed in position upon the roll 15 so as to be effective in perforating the paper over a long period of time.

As indicated best in FIG. 1, the roll 15 is cut away to provide it notch or recess 16 providing a bearing surface 16a for the blades 26 of knife 18, and below the bearing surface 16a there is a further recess 27, relieving the forward edge of the blade 26 for flexing. The blade 26 is clamped upon the surface 16a by the knife holder 17, and I prefer to employ a fabric strip, or the like, between the holder 17 and the blade. The roll 15 is provided with a plurality of tapped recesses for receiving the screws 28, and the screws passing through the openings of the holder 17 are effective in securing each of the blades 26 in positions extending across the length of the roll 15. While the position of the blade may be varied, I have found that very effective operation has been obtained where the blade protrudes .060" beyond the periphery of the roll and in a plane at an angle of about 45 with the diameter of roll 15 passing through the cutting edge, but it will be understood that the positioning of th blade may be varied substantially depending upon the type or character of paper being perforated, etc.

While, in the illustration given, I have shown four longitudinal series of blades extending across the roll 14, it will be understood that the number of blades can be increased or diminished, depending upon the arrangement of the knives, the material being perforated, etc.

Both rolls 14 and 15 are rotated at the same linear speed by virtue of a direct drive existing in gears 29 and 30 mounted on the shafts of rolls 14 and 15, respectively, and supported within suitable bearings provided in frame 31, all of which can be readily appreciated from a consideration of FIG. 2.

Operation In the operation of the apparatus, the paper web 10 is advanced, as indicated by the arrows in FIG. 1, over the rolls 11, 12 and 13, and thence over the perforating roll 14. As the web is carried forwardly in the direction of the arrow on roll 14, the blade 26 at one end of the roll 15 engages the hardened surface of the roll 14, and then successively the blades 26 running longitudinally of roll 14 engage the surface of roll 14 so as to perforate the web transversely, the perforations, however, being produced sequentially from one edge of the web to the other. The perforated web 10 then leaves the roll 14, is slitted upon roll 18, and the slitted strips are wound each upon its separate core upon the mandrel turret 21.

When sharper cutting edges are desired, the notched blades 26 may be reversed in position or turned over to present new severing edges.

In the foregoing operation, it is found that high speeds can be obtained because the contact between the metal cutting parts is only for an instant and between separate members, while also because of the sequential perforating action of each longitudinal row of blades, the fragile tissue web is subjected to a minimum of tension, and tearing does not occur. Webs of a width far greater than those heretofore transversely scored or weakened may be effectively perforated by the present machine.

As indicated above, the cooperation of the blades 26 with the hardened surface of roll 14 produces a welding or a bonding action on web 10 when the same is constructed of a laminate or multi-ply of thin paper so as to avoid opening up of the plies after they have been transversely perforated.

While I have shown a specific structure in which perforation of the web is accomplished, it will be understood that the invention herein may be employed with other means for transverse weakening, scoring, etc., of web material. The mechanism described gives a clean-cut perforating action, and because of the sequential action described, there is no danger of overheating of metal parts and the apparatus can be used over long periods of high production without requiring change.

The same desirable advantages can be obtained in the modified form of the invention shown in FIGS. 5 and 6, which also provide the additional advantage of yielding a straight-across line of perforation. In other words, the line of perforation is exactly transverse to the length of the web, which eliminates the slight offset developed by the form of the invention shown in FIGS. 13, inclusive.

In FIG. 5, the numeral 216} designates generally a traveling web that is to be provided with a transverse perforation. Web 210 is seen to be suported on a pair of rolls 232, which may either be idler rolls or driven rolls, as the arrangement of a particular machine may require. Rolls 232 are suitably journaled in a frame (not shown), which may be similar to that shown in FIG. 2. Since the machine frames, bearings, and means for driving rolls are well known in the art, it is believed unnecessary to provide a detailed showing of these elements.

Suitably mounted for rotation on the machine frame (not shown) are a perforating roll 215 and an anvil roll 214, best seen in FIG. 6. Perforating roll 215 is equipped with a plurality of knives or blades 218, much the same as is perforating roll 15 shown in FIG. 1. The anvil roll 214 is similar to perforating roll 14 also seen in FIG. 1. In the illustration given in FIGS. 5 and 6, the axes of rolls 214 and 215 are disposed at a slight angle with respect to a transverse line across web 210. The angle at which the axes are disposed to a transverse line is equal to the angle at which knives 2 18 are disopsed with respect to the axis of perforating roll 215. Thus, the angle of the blades is compensated for by the angle of the rolls so as to provide a line of perforations across sheet 210 that is transverse, the line of perforations being designated by the numeral 233 in FIG. 5. As can be readily seen in FIG. 5, the left-hand end of perforating roll 215 which carries the first to engage blade 226 is spaced forwardly (i.e., toward the entering end of the machine) of the right-hand end of perforating roll 215. The anvil roll is similarly disposed, as can be seen from FIG. 6, which is a side view of the apparatus of FIG. 5 as viewed from the left. Both rolls, therefore, have their axes inclined to the direction of travel of web 210' at an angle A which is the complement of the angle B representing the angle at which the blades 218 are disposed with respect to the axis of the perforator roll 215. Inasmuch as the angle of the blades with respect to the axis of the perforating roll is quite small, it is only necessary to incline the axes themselves slightly, i.e., at a small acute angle to a line perpendicular to the direction of movement of web 210.

While, in the foregoing specification, I have set forth a specific structure in considerable detail for the purpose of illustrating an embodiment of the invention, it will be understood that such details of structure may be varied widely by those skilled in the art without departing from the spirit of my invention.

I claim':

1. In web cutting apparatus, a frame, a cutting roll mounted for rotation in said frame and having a recess in the surface thereof, said roll in said recess carrying a row of cutting edge-equipped segmental resilient blades longitudinally thereof, each of said blades being arranged at an acute angle to a radial line extending from the axis of said roll to the blade cutting edge, each blade being rigidly supported in said recess and having inclined, outwardly-extending, free portions providing said cutting edge, said roll being provided with a further recess about each outwardly-extending :free blade portion and on the trailing side thereof for relieving the same for flexing, an anvil roll equipped with a hardened surface also mounted for rotation in said frame, said rolls being in parallel, sideby-side relation, each of said blades being arranged with its cutting edge disposed at an acute angle to the axis of said cutting roll, whereby the cutting edge of each segmental blade and the surface of said anvil roll are adapted to enter into progressive point contact, means for rotating both of said rolls at the same linear speed, and means for feeding a Web over said anvil roll.

2. In web cutting apparatus, a frame, a cutting roll mounted for rotation in said frame and having a recess in the surface thereof, said roll in said recess carrying a roW of cutting edge-equipped segmental resilient blades longitudinally thereof, each of said blades being arranged at an acute angle to a radial line extending from the axis of said roll to the blade cutting edge, each blade being rigidly supported in said recess and having inclined, outwardlyextending, free portions providing said cutting edge, said roll being provided with a further recess about each cutwardly-extending free blade portion and on the trailing side thereof for relieving the same for flexing, an anvil roll equipped with a hardened surface also mounted for rotation in said frame, said rolls being in parallel, side-by-side relation, each of said blades being arranged with its cutting edge disposed at an acute angle to the axis of said cutting roll, whereby the cutting edge of each segmental blade and the surface of said anvil roll are adapted to enter into progressive point contact, means for rotating both of said rolls at the same linear speed, and means for feeding a Web over said anvil roll, one of said anvil roll and said row of segmental blades being equipped with recesses along the line of contact therebetween to bring about a transverse perforation of a web passing therebetween.

3. The structure of claim 2 in which the first mentioned acute angle is about 4. The structure of claim 2 in which the second mentioned acute angle is about 1.

References Cited in the file of this patent UNITED STATES PATENTS 797,886 Deely Aug. 22, 1905 1,751,562 Stinger Mar. 25, 1930 1,768,070 Johnstone June 24, 1930 1,931,362 Streine Oct. 17, 1933 2,237,759 Kwitek Apr. 8, 1941 2,829,693 Jarvis Apr. 8, 1958 2,870,840 Kwitek Jan. 27, 1959

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