US2294018A - Paper cutter - Google Patents

Description

Aug. 25, 1942. D HORST 2,294,018

PAPER CUTTER Filed Feb. 10, 1941 INVENTOR. J04 lus DAN/EL Boesr Patented Aug. 25, 1942 UNlTED STATES PATENT OFFICE PAPER CUTTER Julius Daniel Borst, San Francisco, Calif.

Application February 10, 1941, Serial No. 378,164

(Cl. 30-294) I 12 Claims.

This invention relates to paper cutters, and particularly to a single-bladed device for cutting sheet material along either straight or curved lines.

Briefly, the invention comprises a sled-like body, with runners which slide over the sheet to be cut and hold it down, while a foot, fixed centrally of the runners and projecting ahead of them beneath the sheet, guides the latter upwardly onto a sharp blade held at a preferred angle to produce a clean cut. The foot and the runners act together to hold the sheet under the proper tension during the cutting operation, and no pressure need be exerted on the device beyond that necessary to push it forward. A handle is provided to guide the unit, which is made of a transparent plastic, and has in addition slots cut thru the body for the added convenience of the operator in watching his work. The blade assembly is freely removable for sharpening or replacement, and is so situated within the body of the device that it is almost impossible for even a child to cut himself while using it. The device is so formed that the entire body member, including the receiver into which the blade assembly is fitted, may be manufactured in a single die molding operation, and a similar economy is obtained in forming the blade assembly itself.

The advantage of such a device will be obvious when compared with the use of scissors, razor blades, knives, and other common cutting instrumerits. It will out along either curved or straight lines with equal facility, and without irregularities between successive cuts, as frequently experienced when scissors are used. It affords a substantial saving in time, as cuts of any length may be made as fast as the hand can direct the cutter along the desired path. While I have referred to its use in cutting paper, it will be apparent that it may be used on any sheet material, such as cardboard, Bristol board, Cellophane, cloth, or with sheets formed from various plastics, with equal facility. The cost of manufacture is small, and the design is such as to utilize the best available blade steel, which may be obtained economically from sources such as safetyrazor blades, fragmented and re-sharpened, for example. At the same time the blade is so protected as to reduce danger of cutting the fingers to a negligible factor and so the invention is particularly suited for the use of children.

Other objects and advantages of my invention will be apparent as the structure is more fully understood from the following description and the accompanying drawing, wherein is set forth what is now considered to be a preferred embodiment. It is to be understood that this particular embodiment is exemplary of the spirit of my invention, and that variations therefrom in the details of construction or arrangement of the parts may accordingly be effected and yet re-. main within the spirit and scope of the invention as set forth in the appended claims.

The details of construction will be explained with particular reference to the drawing, in which:

Fig. 1 is a perspective view of my device;

Fig. 2 is a front View of the invention;

Fig. 3 is a side sectional View, showing its rela-- tion to a sheet of paper during the cutting operation;

Fig. 4 is a bottom view of the device; and

Fig. 5 is a perspective view of the blade: assembly.

In the drawing, the preferred embodiment of. my invention is illustrated in Fig. 1, which shows: the complete device in perspective, assembled; and ready for use. The cutter unit, generally referred to as I, comprises the body member 2 and the blade assembly 4.

Body member 2 is preferably formed as a unit of transparent molded material of the class known as plastics, and has been designed to require the least number of operations for the most economical manufacture. The molding process itself will be referred to at greater length hereafter.

The body member 2 has a pair of spaced parallel runners 5 which ride on the sheet material 6 to be cut and hold it down against the supporting surface. It is desirable that the cutting operation take place on a smooth fiat surface. The runners 5 cooperate with the blade assembly 4 to keep the sheet 6 flat against the supporting surface and to keep the sheet material between the runners under a slight tension during the cutting operation. Runners 5 are connected by a top plate 1, from the rear of which a trans verse brace 9 extends downwardly between the runners to provide additional rigidity. At their forward ends lo the runners 5 are curved inwardly and their lower surfaces ll inclined upwardly, while the top plate 1 curves downwardly to meet them in a nose l2 which acts as an additional cross brace.

Centrally of the top plate I and rear trans verse brace 9, a handle I4 reinforced by a downturned rim I5 is formed, and extends obliquely upward from body 2. Top plate 1 is pierced by a. 'central lengthwise aperture l6 and side apertures.

trapezium shape. During the molding operation by which body member 2 is formed, the front part of the slot 20 is formed about a right trapeziumshaped portion of the top-forming die, not shown, which projects into receiver l9 thru topdie slot 21, while the rear part of slot ZO-is formedby'arectangular projecting portion of the bottomforming die, not shown, which projects into receiverl9 thru bottom die slot 22. Thesedie portions are oppositely directed while forming the receiver IS in touching parallel paths, normal to top plate 1 and spaced so that the completed slot 20, is open at the forward. end 2.4 of receiver l9 and is of the proper shape to accommodatethe,

blade assembly 4. This form for slot 20 is particularly desirable, since it permits the blade assembly 4 to be inserted or removed by onesimple push .or pull parallel to top plate I, while at the same time providing adequate support.

Once in place, the blade assembly. 4- is held against forces pushing upwardly by the engagementof the receiver end 25 against. top plate 1, both forward of, and behind, top die slot 2|. Forward of die slot 2!, the receiver end 25,.is recessed slightly at 23 tofit snugly with a thickened cross-rib portion 28. of top plate 1. Forces tending to move the blade assembly backward are resisted by engagement of the receiver end 25. with rear transverse brace 9. and-by the wedging'action between top plate 1 and the lower portion of receiver l9, while the latter action is additionally efiective in controlling twisting movements of the blade assembly trelative to body 2 caused by engagement of the former with material to be cut. This is important, since the cutting action is best when the blade assembly 4 is. held at a preferred angle to the material to be cut.

The blade assembly 4 is illustrated in. detail in Fig. 5. It includes the receiver end 25,.and. a connecting segment 26 which are clamped tightly around the blade 21, and a foot 29 formed at the. lower end of the connecting segment 26-. Foot 29 is roughly elliptical in shape, with a rounded point 38 at its free end, adjacent which the foot is substantially flat and-slopes gently upward toward a humped neck 3| directlyv joining the connecting segment 28-.

The humped neck 3| is of such height that.

it will not touch the surface on which the sheet is being cut, and when the foot 29 is slid thereunder, the sheet will be raised to engage the cutting edge 32 of theblade 27.. It is important that the paper shall impinge directly on the cutting edge 32 and not catch against the corner 34. of the blade 21, as in the latter case it might.

tear rather than. cut clean.

The blade assembly 4, apart from. the blade 21, is formed as a single piece, which is stamped into the desired shape by conventional machine ery forming no part of the. present invention. The receiver end 25 and the connecting segment 26 arebent unfrom flat stock and pressed together about the blade 21, forming a unitary structure therewith. The blade 21 should be held in the receiver end 25 and connecting segment 26 at an angle of substantially to the horizontal. It has been my experience that this angle produces a cleaner cut than others, and that if substantially lesser or greater angles are used the sheet will ride up on the blade without cutting or will be torn and the sheet crumpled. Using this preferred angle of inclination however, I have found that. either straight line or intricately curved patterns may be cut by guiding the cutter with its handle. It is not necessary to exert pressure on the body member 2, asthe sled-like runners 5 will cooperate with the foot 29 to hold the sheet under just the tension required, and will guide the sheet onto the cutting edge 32 at. the optimum angle. It is of course understood that the sheet should be held down before the cutter at the beginning of a cut, and behind the cutter after the cuthas been initiated, to keep. it.from sliding. The clearance of theneck portion, 3,1, above the supporting surface permits this cutter to be used on smooth tables and similar surfaces without scratching or marring them. This is of particular value in, contrast with the common use of safety. razor blades, which cut into, and ruin the surface.

The blade holder is, tumbled to remove sharp edges, particularly along, connecting segment 2'5. It is found that this prevents the edges of the freshly cut sheet from catching thereagainst as the cutter is pushed forward. The holder may then be plated with nickel, chromium, or any other metal resistant, to oxidation, to prevent rusting.

An important feature of my invention as set forth above is the ease with which it may be manufactured. It will be obvious to those skilled in that art that a substantial contribution has been made in arranging the receiver so that it can be formed by the same operation which produces. the body member. The difficulties will be appreciated. when it is seen that the main extent of the receiver slot. is at right angles to the direction in which the dies must act to produce the main body, and that the slot must be closed both at the top and at the bottom to support'the blade assembly. By oppositely directing the die elements which extend thru slots 2| and 22 in touching parallel paths, it is possible to produce the desired result.

No other method of forming the receiver slot is known to me hich would enable the receiver slot to be. made at the same time as is the body member. My. use of staggered die members reduces to a single operation the formation of a type of member which by previously available methods would have required more than one step.

In summary, my invention comprises a cur.- ting device which may be safely used by children and adults; to cut sheet material along straight lines or complex curves. The device can be directed by the operator with great accuracy, and.

ceiver closed on both the sides from which the molding dies approach the space into which the plastic is forced.

I claim:

1. A cutting device, comprising a body, two runners extending into contact with a sheet to be cut, a foot arranged to slide beneath said sheet, and a blade secured in said body by frictional engagement and extending upwardly from said foot, at substantially 45 from the horizontal.

2. A device for cutting sheet material comprising a foot arranged to slide beneath said sheet, a blade extending upwardly at a preferred angle from said foot, a body member secured by frictional engagement to said blade, and runners extending downwardly from said body on either side of said blade.

3. A cutting device for sheet material, comprising spaced runners arranged to slide over said sheet, a foot arranged to slide beneath said material, and a blade extending upwardly at a preferred angle from said foot between said runners and secured to said runners by frictional engagement.

4. A device for cutting sheet material, comprising a body member, runners extending slidably over said sheet, a foot extending beneath said sheets, a blade extending upwardly at substantially 45 from said foot midway between said runners, and a handle extending angularly upwards from said body means for removably securing said blade to said body, comprising a receptacle formed in said body and an engaging portion formed on said foot and adapted to be held frictionally in said receptacle.

5. A body member for a paper cutting device, comprising spaced runners, a blade assembly receiver disposed between said runners and parallel thereto, and slots permitting access to said receiver by oppositely directed forming dies.

6. In a paper cutter, a body member having parallel runners and a blade assembly receiver disposed midway of and parallel to said runners, and forming slots afiording staggered, opposed forming die entryways to said receiver.

7. A paper cutter body member arranged for single-operation molding from plastic materials, comprising spaced parallel runners, a connecting member, a blade assembly receiver formed parallel to and midway of said runners, and slots affording staggered entry ports from opposite sides of said receiver.

8. In a molded body for a sheet material cutting device, a blade assembly receiving portion having the cross-sectional form of a right trapezium, and staggered, opposed slots permitting simultaneous entry into said receiving portion of opposed die members.

9. The method of forming a paper cutting device having a body and blade receiver therein restricted on both top and bottom sides of said receiver which comprises'forming the top portion of said body and a portion of said receiver by one die member having a projecting element for defining said receiver portion and simultaneously forming the bottom of said body and the remainder of said receiver portion by a second die member having an element projecting oppositely to said first projecting die element in the same plane therewith but staggered therefrom by the width of said second member.

10. A device for cutting sheet material, comprising a body member including spaced runners arranged for sliding over said sheet material, a socket formed midway between said runners, a blade member arranged to fit snugly in said socket, a cutting edge formed on said member at an angle of substantially 45 with said sheet material, and a handle formed on said body member.

11. In a device for cutting sheet material, the combination of a body member, spaced runners formed integrally therewith, a socket midway between said runners, and a cutting member arranged to be held fixedly in said socket by frictional engagement therewith.

12. In a device for cutting sheet material, the combination of a body member, spaced runners arranged to hold said sheet material during cutting, a receiver formed in said body between said runners, a foot arranged to fit slidably within said receiver and to be held therein by friction with the walls thereof, and apertures opening oppositely into the upper and lower portions of said receiver in staggered array.

JULIUS DANIEL BQRST.

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