US2323003A

US2323003A - Apparatus for cutting paper sheets

Info

Publication number: US2323003A
Application number: US381015A
Authority: US
Inventors: Baur Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-10-06
Filing date: 1941-02-28
Publication date: 1943-06-29
Anticipated expiration: 1960-06-29

Description

June 29, 1943. R 2,323,003

APPARATUS FOR CUTTING PAPER SHEETS Filed Feb. 28, 1941 2 sheets-sheet;

INVENTOR Fall! 3410' 6. fyw

ATTORNEY Patented June 29, 1943 APPARATUS FOR CUTTING PAPER SHEETS Paul Baur, Heidenhelm-on-the-Bren z, Germany; vested in the Alien Property Custodian Application February 28, 1941, Serial No. 381,015 In Germany October 6, 1939 3 Claims. (01. 164-45) The invention relates to apparatus for cutting paper sheets into strips, by means of circular knives, usually known as a paper slitter.

Heretofore, the paper sheet would automatically rotate two rotatable knives, by the knife peripheries following the sheet of paper. In other cases, electric motors were applied to one set of the shafts of the disc knives. Both of these forms had many disadvantages, and the object of the present invention is to overcome the same.

The invention consists in providing means for rotating the paper cutting knife with a velocity directly dependent upon the circumferential velocity of the paper sheet roll as it is being wound.

The invention may be carried out in various embodiments, one of which is to provide the shaft of the knives with a roller, and dispose transmission means between that roller and the paperroll, with means for adjustment of said transmission means.

In each of the embodiments, a method of slitting paper is utilized which consists in subjecting a rotary knife to a velocity in direct ratio to the velocity of the paper sheet being wound on its roller after having been slit.

The invention will be further described hereinafter, an embodiment shown in the drawings, and the invention will be finally pointed out in the claims.

In the accompanying drawings,

Fig. J. shows a sectional view, partly diagrammatic;

. Fig. 2 shows a front view, and

Fig. 3 shows a detail view of the adjusting means.

Similar characters of reference indicate corresponding parts throughout the various views.

Referring to the drawings, the paper sheet I travels in the direction of the arrow la, along the sled l U and over the pressure roller 3, and is then wound upon the roll shaft 2b, which rotates in the direction of the arrow 2a, and increases in circumference as the sheet is wound thereon. The roller 3 rotates in the direction of the arrow 3a, and is capable of idling depending on the amount of paper wound upon the shaft 2b, in the manner well known. The paper sheet passes between the

circular knives

4 and 5, and is cut into strips thereby, depending in width upon the space between the knives, in the manner well known. The knife 4 is suitably supported by the shaft la and by bearings therefor not shown, and also known. The knife 5 is supported on the shaft 1. The shaft 1 is suitably supported by yokes l, which are supported by a carrier 8a,

having dovetail connections with a fixed support 9, secured to the sled Ill.

The improved device consists of the following. To the shaft I of the knife 5 is secured a roller 6, which rotates at all times at the same speed as that of the knife 5. Between the roller 6 and the pressure roller 3, is placed a roller ll,movable in the direction of the arrow I la. It is supported by a shaft lib, to each end of which a link He is connected, these links llc having a crossbar lld and at right angles to this crossbar lid is the adjustment device I2. This has a spring 20 interposed between a shoulder 20a on a rod 2|, which is secured to the crossbar lid. The tension of the spring 20 can be varied by a screw like piston l5, having a round disc I50. movable in a casing l3. The roller l I may be provided with a rubber covering H, to increase the friction hold between it and the rollers B and 3. Thus the roller H is suitably adjusted by the device l2, since it is disposed in the bite formed by the roller 6 and roller 3. The knife 5 is thereby driven by the pressure roller 3 which in turn is driven by the roll 2. The screw 15 varies the friction between rollers 6 and 3; hence, roll 2 controls roller 3 and controls the knife 5 by reason of the intermediate roller II. The roll 2 of wound paper strips gradually increases in circumference and during that time is supported by

rollers

30 and 3|, in the manner well known.

It is known, to rotate single circular knives for the cutting of paper. Heretofore, the circular knife or a pair of them was driven by means of electromotors with a cutter knife at one or both ends of the motor shaft. The objections are: the numerous motors are very expensive in regard to installation and upkeep, particularly on account of the number required on large paper making machines. Furthermore, difliculties have resulted from endeavoring to adjust the velocities of the knife and paper. Heretofore, it was also customary to allow the knives to rotate with uniform high velocities as the paper sheet had a high velocity to accomplish the slitting automatically. For low velocity of the paper as it exists at the commencement of operations, this high velocity of the knives is not necessary, with the consequence that in comparison with the work done in cutting, a comparatively high wear and tear on the knives took place.

Also difiiculties ensued in obtaining the high knife velocities necessary for the high speed of the paper, which may be over 1200m a minute.

But the invention just described overcomes these Objections by the method and means described, because the velocity of the knife is dependent directly upon the paper winding velocity. and because the knives are driven indirectly by the paper roll and in a ratio thereto. By this, the velocity of the knife is always in a certain ratio to the paper velocity, so that, on the one hand, by low paper velocities, a high knife velocity is avoided with the loss of wearing of the knife, and on the other hand, with very high paper velocities, a very high velocity is given to 10 the knife, so as to cut the paper efliciently.

I have described an embodiment of my invention, but changes may be made therein without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. In a paper slitter, having a paper supply roll for supplying a paper sheet, a circular knife for slitting the paper sheet, and a take-up roll for the slitted sheet, the combination of an idler roll under said paper sheet rotatable by the peripheral speed of the take-up roll, means transferring the peripheral speed of the idler roll to the knife for giving the circular edge of the knife the same peripheral speed as the velocity of the paper sheet being cut, and means for adjusting the last named means.

2. In a paper slitter, having a paper supply roll for supplying a paper sheet, a circular knife for slitting the paper sheet, and a take-up roll for the slitted-sheet, the combination of an idler roll under said paper sheet rotatable by the peripheral speed of the take-up roll, means transferring the peripheral speed of the idler roll to the knife for giving the circular edge of the knife the same peripheral speed as the velocity of the paper sheet being out, said means including a roll for the circular knife and rotatable therewith. and a transfer roll peripherally contacting with the peripheral surface of the idler roll and with that of the knife roll, and means for adjusting the transfer roll pressure upon the idler roll and upon the knife roll. I I

3. A paper cutting apparatus set forth in claim 1 wherein the adjustable means is a pair of members, one threaded within the other, the innermember having a spring coa'cting between this member and the idler roller mounting.

PAUL BAUR.