US3672252A

US3672252A - Apparatus for severing a sheet

Info

Publication number: US3672252A
Authority: US
Inventors: Willard G Symonds
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1970-11-18
Filing date: 1970-11-18
Publication date: 1972-06-27
Anticipated expiration: 1989-06-27
Also published as: CA941730A; FR2114408A5; GB1367794A

Abstract

Apparatus for severing a sheet of material such as photographic film or paper, comprising a plane table having a cutting edge; a knife movable into and out of shearing relationship with the cutting edge; a shaft supporting the knife and having a longitudinal axis spaced ahead of the cutting edge outboard thereof, the knife being pivotally movable about said axis; and levers for supporting the shaft for movement in an arc about a pivot. A spring urges the knife inwardly toward the cutting edge, and also acts to restore the knife to its initial position after each cutting operation. Advantageously the spacing of the shaft ahead of the cutting edge is such that a first plane through the shaft axis and a line along the cutting edge forms an acute angle of 10*-15* with a second plane through said line and normal to the plane table. The principles apply to cuts straight across a sheet, and to oblique cuts (in the latter case, said line extends across a terminal point of the knife edge).

Description

United States Patent Symonds [4 1 June 27, 1972 [54] APPARATUS FOR SEVERING A SHEET [72] Inventor: Willard G. Symonds, Rochester, NY.

[73] Assignee: Eastman Kodak Company, Rochester,

[22] Filed: Nov. 18, 1970 [21] Appl. No.: 90,501

[51] Int. Cl ..B26d 5/10 [58] Field ofSearch ..83/582,633,634, 636, 600, 83/610-612 [56] References Cited UNITED STATES PATENTS 1,952,961 3/1934 Yates ..83/611 2,623,589 12/1952 Price.... .....83/1l0 947,744 l/19l0 Stohr ..83/371 1,565,654 12/1925 Laukhuff.... ....83/582 X 3,376,775 4/1968 Eliason ..83/582 Primary Examiner-Donald G. Kelly Attorney-Walter O. Hodsdon and Henry M. Chapin [5 7] ABSTRACT Apparatus for severing a sheet of material such as photographic film or paper, comprising a plane table having a cutting edge; a knife movable into and out of shearing relationship with the cutting edge; a shaft supporting the knife and having a longitudinal axis spaced ahead of the cutting edge outboard thereof, the knife being pivotally movable about said axis; and levers for supporting the shaft for movement in an are about a pivot. A spring urges the knife inwardly toward the cutting edge, and also acts to restore the knife to its initial position after each cutting operation. Advantageously the spacing of the shaft ahead of the cutting edge is such that a first plane through the shaft axis and a line along the cutting edge forms an acute angle of l0-l5 with a second plane through said line and normal to the plane table. The principles apply to cuts straight across a sheet, and to oblique cuts (in the latter case, said line extends across a terminal point of the knife edge).

11 Claims, 4 Drawing Figures PATENTEDJURN in SHEET 2 OF 2 F IG. 4

APPARATUS FOR SEVERING A SHEET BACKGROUND OF THE INVENTION 1. Field of the Invention My invention relates to novel apparatus for severing a sheet of material, and more particularly to such apparatus that is simple and inexpensive in construction and which is particularly useful for shearing long photographic film and paper into shorter lengths.

2. Prior Art Shearing apparatus for this purpose has been known for years but is more complicated and expensive in construction than is desirable, andrequires frequent sharpening. Moreover, difficulty has been encountered with prior devices in shearing tough materials such as poly(ethylene terephthalate) photographic film bases of various thicknesses. When such apparatus is preset for shearing one thickness of such polyester sheet, it will not shear thicker sheets. It will shear thinner sheets, but the wear on the blades is then excessive, and frequent resharpening is necessary.

THE DRAWINGS FIG. 1 is a perspective view of one embodiment of my novel device for cutting straight across a sheet;

FIG. 2 is an elevational view of my novel device as viewed from the rear of FIG. 1;

FIG. 3 is a side elevational view of my device as seen from the right in FIG. 1, and from the left in FIG. 2; and

FIG. 4 is a schematic plan view showing my apparatus as designed to cut an arrow or fish tail shape in a sheet.

SUMMARY OF THE INVENTION In general my novel apparatus for severing a web or sheet of material comprises a plane table T for supporting the web, having one edge E acting as a cutting edge for receiving'the web in position to be severed. Edge E is stationary during a cutting operation, but in some instances it may be made adjustable for presetting the apparatus; A knife K, having a cutting edge which is inclined with respect to edge E, is movable into and out of shearing relationship with the cutting edge. Knife K is supported by a shaft S having a longitudinal axis which is spaced ahead of the cutting edge outboard thereof. The arrangement is such that when shaft S is parallel to the cutting edge E, a first plane through both the cutting edge and the longitudinal axis of shaft S forms an acute angle A of at least (advantageously 10-I5") with a second plane passing through the cutting edge and normal to table T. Moreover knife K is pivotably movable about the longitudinal axis of its shaft 8 during shearing movement. When the ap paratus is adjusted for proper cutting, shaft S usually is not absolutely parallel to edge E, but is essentially parallel, with a slight angularity thereto which may be 0.001 to 0.005 inch per inch of length. This angularity is well known as crossover" in this art, and the term essentially parallel as used herein is intended to encompass such a slight departure from absolute parallelism.

A coil spring C resiliently urges the knife K in two directions, in toward the cutting edge E and up toward a reset position to which the knife returns after each cut.

The principles of construction described generally above are applicable to a wide range of sizes and shapes of apparatus, depending on the particular needs. They have been applied to devices for chopping 16 mm wide photographic film, and to devices for chopping film as wide as 6 and 12 inches and more. Moreover, the principles are universally applicable to various materials and thicknesses, being useful on webs of photographic paper, cellulose acetate film base, and tough poly(ethylene terephthalate) film base.

The apparatus can be operated with table T horizontal as shown, or tilted, or even inverted.

THE SPECIFIC EMBODIMENT In the specific apparatus shown in FIGS. 1-3 for illustrating the principles of my invention, table T is securely bolted at its sides to two upstanding frame members 11 and 13 which are joined on their tops by a cross bar 15.

Knife K is supported on shaft S by a pair of

brackets

17 and 19 having bores fitting over shaft S, with the brackets being fixed by set screws to the shaft which itself is rotatably mounted at its ends in bores which extend through front end portions of two

parallel lever arms

21 and 23. Alternatively, for greater strength, the ends of shaft S can be fixed by set screws rigidly to the lever arms, and the brackets can be rotatable on the shaft.

Adjacent their rear ends the

arms

21 and 23 have bores through which a second shaft 25 passes and has its ends extending into, and rotatable in, bores in a pair of blocks 27 and 29 which are adjustably bolted to the inside surfaces of frame members 11 and 13 by

bolts

28 and 30 located off center of the blocks. Shaft25 acts as a pivot for the lever arms to permit knife K-to be moved up and down.

Arms

21 and 23 are staked or otherwise fixed to shaft 25 to rotate therewith.

For moving knife K up and down there is provided still another lever arm 31 which is located centrally on, and has bores receiving, shafts S and 25. Lever arm 31 projects forward of shaft S for manual actuation, or for engagement with a plunger or other actuating mechanism. Lever arm 31 is fixed by a set screw or other device to shaft 25, but is not fixed to shaft S which can rotate therein. Alternatively, actuating force can be applied to lever arms 21 and/or 23 at points between shafts S and 25.

An adjustable stop bolt 35 extends through cross bar 15 to engage lever arm 23 at its uppermost position so as to assure the end portion 37 of knife K remains in position adjacent to cutting edge E upon the completion of each cut. In addition, a set screw 38 projects down from arm 23 in position to engage the top edge 40 of knife K to prevent the bottom edge of the knife from overlapping the table T and preventing the next downward movement of the knife. Return of knife K to its initial position and proper positioning of knife portion 37 are assured by coil spring C which is mounted at one end over an adjustable bolt 39 projecting forwardly from cross bar 15, and at the opposite end extends through a bore in knife K. The angular relationships are shown clearly in FIG. 3, being such that the spring urges the knife K both upwardly away from table T, and in toward cutting edge E.

As pointed out above, the longitudinal axis of shaft 25 and the cutting edge E are essentially or substantially parallel although a slight crossover" angularity is desirable. The amount of angularity can be adjusted by loosening one or both of

bolts

28 and 30, whereupon the blocks 27 and/or 29 can be swung eccentrically around the bolts to the slight extent required.

Spring C is important for bringing end portion 37 of the knife from a position slightly above and in front of edge E down and rearwardly into contact with edge E at the start of the cutting operation, but once the out has started at one end of knife K it will proceed completely across the knife without further need for spring pressure. As a practical matter, however, the spring is continuously operative both for starting the cutting operation and for resetting the knife K after each cut.

It is evident that spring C can be located close to either end of knife K rather than near the center. Also, for heavy cutting of wide sheets a plurality of springs can be used, for example two located near the ends of the knife.

My principles apply also to the cutting of a sheet with a shape other than straight across the sheet, for example one or more oblique cuts, such as the arrow-shaped or fish tailshaped cut shown in FIG. 4 schematically. A shaft S carrying an appropriately shaped shearing knife K again has its axis spaced in front of an appropriately shaped cutting edge E on the end of a plane table T. Here the angular relationship of 10-l5 is defined between (a) a first plane which passes through both axis S and a line L which is essentially parallel thereto and extends across the foremost or leading corner or corners of edge E, and (b) a second plane which includes line L and is normal to table T.

The two modifications of apparatus described in detail above have been found particularly advantageous for cutting tough polyester sheets of various thicknesses, and without requiring frequent resharpening. Cutters available previously had to be especially designed and set for one specific thickness, and would not operate successfully on thicker material. Previous cutters would operate successfully on thinner sheets, but then excessive wear on the knife edges occurred and they had to be resharpened too frequently.

My improvements can be ascribed mainly to the automatic self loading of the knife blade against the knife edge of the cutting table, resulting from the described positioning of shafts S and S, and the described angular relationship, taken together with the spring for assuring the initial correct positioning of the knife and its return to position upon completion of a cutting operation.

Furthermore, my apparatus is simple and inexpensive to construct, and is universally adaptable to the cutting of various sheet materials such as paper, cellulose acetate film, and polyester film.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

I claim:

1. In apparatus for severing a sheet of material, comprising in combination,

a horizontal table lying in a reference plane for supporting said sheet, one edge of said table forming a stationary cutting edge lying in a plane normal to said table for receiving said sheet in position to be severed, a knife movable from an initial position into and out of shearing relationship with said cutting edge, a first shaft supporting said knife and having a longitudinal axis laterally spaced from said normal plane, and lever means for supporting said first shaft for movement in an arc about a pivot, the improvement wherein:

said knife is pivotally movable about said longitudinal axis of said first shaft and biased by resilient means into engagement with said cutting edge.

2. In apparatus in accordance with claim 1, wherein said resilient means comprises a spring for urging said knife into contact with said cutting edge during cutting movement thereof.

3. In apparatus in accordance with claim 2, said last named means comprising a resilient spring mechanism acting both to urge said knife into contact with said cutting edge and to resiliently urge said knife and said shaft in a direction out of shearing relationship with said cutting edge to restore said knife to the initial position thereof after completion of a severing operation.

4. In apparatus in accordance with claim 1, said knife being fixed to said shaft, and said shafl being joumalled for rotation in said lever means.

5. In apparatus in accordance with claim 1,

support means projecting from said table normal thereto,

said lever means comprising a second shaft spaced rearwardly from said first shaft and mounted in said support means to act as said pivot.

6. In apparatus in accordance with claim 5, wherein said resilient means comprises a resilient spring mechanism urging said knife into contact with said cutting edge during cutting movement thereof, said spring mechanism extending between said support means and said knife and also acting to urge said knife in a direction out of shearing contact with said cutting edge to restore said knife to the initial position thereof after a severing operation.

7. In apparatus in accordance with claim 6, adjustable stop means for limiting the upward movement of said knife and for limiting the pivoting movement of said knife on said first shaft in the direction of said cutting edge upon restoration of said knife to said initial position.

8. In apparatus in accordance with claim 1 said shaft being so positioned that a first plane extending through the longitudinal axis of said shaft and also through said cutting edge, forms an acute angle of at least 10 with said normal plane. 9. An apparatus in accordance with claim 8, said acute angle being between 10 and 15.

10. In apparatus in accordance with claim 1, said cutting edge being straight and essentially parallel to said axis.

11. In apparatus in accordance with claim 1, said cutting edge being non-parallel to said axis.

'ggg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 672 \252 Dated June 27L 1972 lnventor(s) Willard G. Svmonds It is certified-that error appears in the above-identified patent that said Letters Patent are hereby corrected as shown below:

and

Column 3, line 32, delete "horizontal".

Signed and sealed this ZL tb day of October 1972.

(SEAL) Attest:

EDWARD M.FLETC IHER,JR. ROBERT GOTI'SCHALK 'Attestung OfflCGl" Commissioner of Patents

Claims

1. In apparatus for severing a sheet of material, comprising in combination, a horizontal table lying in a reference plane for supporting said sheet, one edge of said table forming a stationary cutting edge lying in a plane normal to said table for receiving said sheet in position to be severed, a knife movable from an initial position into and out of shearing relationship with said cutting edge, a first shaft supporting said knife and having a longitudinal axis laterally spaced from said normal plane, and lever means for supporting said first shaft for movement in an arc about a pivot, the improvement wherein: said knife is pivotally movable about said longitudinal axis of said first shaft and biased by resilient means into engagement with said cutting edge.

4. In apparatus in accordance with claim 1, said knife being fixed to said shaft, and said shaft being journalled for rotation in said lever means.

5. In apparatus in accordance with claim 1, support means projecting from said table normal thereto, said lever means comprising a second shaft spaced rearwardly from said first shaft and mounted in said support means to act as said pivot.

8. In apparatus in accordance with claim 1, said shaft being so positioned that a first plane extending through the longitudinal axis of said shaft and also through said cutting edge, forms an acute angle of at least 10* with said normal plane.

9. An apparatus in accordance with claim 8, said acute angle being between 10* and 15*.