US2015877A - Revolving paper knife - Google Patents

Description

Oct. 1, 1935. v THOMPSQN 2,015,877

REVOLVING PAPER KNIFE Filed Dec. 5, 1954 INVENIOR. W670i? ((7 77/001PSO/V Fi -m 1 3 K BYJFM ATTORNEY.

Patented Oct. 1, 1935 REVOLVING PAPER KNIFE Victor T. Thompson, Montevista, 0010., assignor to Harold E. Thempson, Camas, Wash.

Application December 3, 1934, Serial No. 755,786

6 Claims. (01. 164-40) UNITED STATES A'E'ENT OFFICE My invention relates to a device for cutting a roll of paper into shorter lengths after it is tightly rolled and leaving a smooth surface at the point of severance.

It is particularly applicable to trimming rolls of paper, the ends of which have become damaged in shipment, but its greatest use probably will be in the manufacture of short rolls of paper such as sanitary paper, adding machine rolls and the like.

It has heretofore been necessary to cut the paper into the required width before rolling since, owing to the high co-efficient of friction of paper generally, a sharp edged knife cannot be used without burning both the knife and the paper, and a saw obviously leaves a very rough edge, which is undesirable.

The invention consists essentially of a pair of sharp edged cutting discs held on a shaft in spaced relationship, the spacing member being a saw slightly smaller than the discs. The function of the saw is to remove the shreds of paper after they are severed, to prevent friction on the adjacent sides of the cutter" discs, which are slightly concaved on their outer surfaces to prevent friction on the other sides.

The following drawing illustrates a preferred way of embodying the invention in a useful tool, in which,-

Fig. I is a side elevation of my new revolving paper knife in operative position, partly broken away to show its construction and shown engaged with a roll of paper which is being separated into two parts; I

Fig. II is an orthographic projection of Fig. I;

Fig. III is a detail of the cutting edge of my new revolving paper knife with some of the parts somewhat exaggerated for the purpose of a clearer showing of their construction as hereinafter pointed out;

Fig. IV is the same structure shown in Fig. III but more nearly as it will appear as actually constructed.

The revolving paper knife consists essentially of two sharp edged discs I and 2, provided with beveled edges la and 2a, the discs being slightly concave on the outside as shownat lb and 212. For the purpose of clearer illustration of this in the drawing the concavity is shown much exaggerated. Actually it will be on the order of thousandths of an inch instead of on the order of 32nds of an inch as might be suggested by the drawing of Fig. III. The purpose of this concavity, or it might be called relief, is to prevent the surface of the cutter back of the edge proper from contacting the roll of paper at the point of severance and during severance.

Mounted between the discs is a saw 4, having a diameter slightly less than the diameter of the discs I and 2. This saw will have fine teeth and 5 preferably there is a little set in the teeth and the thickness of the elements is as little as possible with the required stability.

The three elements consisting of the disc I, the disc 2 and the saw 5 are assembled between 001- lars 5 and 6 after the known manner and rigidly mounted upon a shaft 1 which will be provided with suitable bearings and connected to power means for revolving the saw at a high speed. I have found that a peripheral speed of the order of 6000 feet per minute is suitable, and it should be brought to full speed before being applied to the paper roll indicated by numeral It). The sharp edged discs l and 2, should be made of a high grade of steel suitable for the purpose and tempered according to the known art for such use.

In operation the revolving paper knife will remain relatively fixed and the paper rolls to be divided into short lengths will be moved to the paper knife or knives by suitable conveyor means, which has not been shown as it is no part of this invention; and/or the revolving paper knife may be mounted upon a hanger, allowing it to swing to the work much as a swinging cut-off saw is used in the lumber industry.

When my new revolving paper knife is brought to its proper speed and its edge brought in contact with a paper roll, the action is this. The edges of the revolving sharp edged cutters penetrate several sheets of paper ahead of the saw which removes a narrow kerf between the two sharp edged cutters. This action is extremely rapid, accomplished without any burning effect on the edges of the severed rolls which are not discolored and which have severance surfaces so smooth as to appear solid. Very little waste of paper stock is occasioned by the kerf or material removed from the roll, hence the operation is not only extremely rapid but is also economical.

I do not wish to restrict myself to any style of mounting or any purpose for which this revolving paper cutting knife may be used, but only to the extent indicated by the subjoined claims.

1. A paper roll cutter comprising a pair of sharp edged discs, 2. saw that is of less diameter than the discs and a mounting to hold the discs rigidly, one on each side of the saw.

2. The structure according to claim 1, charac terized by each disc being concave on the side opposite the saw.

3. In a revolving paper knife, a pair of beveledged cutting discs assembled in opposed relationship and mounted for revolution with their beveled edges inward and a saw member of less diameter than the discs that is rigidly held be-- tween said discs.

4. The combination according to claim 3 characterized by the teeth of the saw being provided with set and extending laterally into the space providedby beveling the discs.

5. As a new article of manufacture, a revoluble paper roll cutter comprising structures presenting two peripheral knife edges spaced apart and saw teeth between the knife edges arranged on a circle that is smaller than the circumference of the knife edges.

6. A revoluble circular paper roll cutter comprising in combination a shaft, a pair of sharp edged discs on the shaft, a circular spacing member between said discs, teeth on said spacing member arranged with their points on a circumference that is concentric with but smaller than the circumference of the discs and means for clamping the discs and saw in position for unitary operation with the shaft.

VICTOR T. THOMPSON.

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