US3892038A - Single sheet paper slitter - Google Patents

Abstract

A paper-cutting device comprises a blade-holding member having a gauging surface area that surrounds a blade protruding a distance limited to substantially the thickness of a sheet of paper to be cut. Penetration of the blade is thus limited to a single sheet of paper. Because of its very short extension from the gauging surface, the blade will not cut a soft yielding material such as the hand of the user. The blade-holding member may be part of or attached to an elongate article, such as a pen or pencil, which provides a manipulating handle and enables the device to be used with a straight-edge.

Description

United States Patent 1 Novak 1 SINGLE SHEET PAPER SLITTER [76} Inventor: Phillip J. Novak, 3123 Lehman Ave., Salt Lake City, Utah 84119 {22] Filed: June 25, 1973 [21] Appl. No.: 373,242

[52] [1.5. CI. 30/294; 30/1649, 30/317; 30/D1G. 3 [51] Int. Cl B26b 29/00 [58] Field of Search 30/294, 317, 286, 293, 30/DIG. 3, 164.9

[56] References Cited UNITED STATES PATENTS 1,134,500 4/1915 Anttila et a1 30/293 1,216,889 2/1917 Todd 30/DlG. 3

1,274,966 8/1918 Wentz 30/294 1,374,882 4/1921 Curtis l 30/DlG. 3

1,503,739 8/1924 Zurcher 30/286 1,627,515 5/1927 Laird 1 30/293 X 2,145,985 2/1939 Krajicek l, 30/320 X 2,215,216 9/1940 Gits et a1. 30/320 2,237,331 4/1941 Bodkin et a1. 30/320 X 2,555,142 5/1951 Levin 30/320 1451 July 1,1975

Primary Examiner-A1 Lawrence Smith Assistant Examiner-J. T. Zatarga Attorney, Agent, or Firm-Mallinckrodt & Mallinckrodt [57] ABSTRACT A paper-cutting device comprises a blade-holding member having a gauging surface area that surrounds a blade protruding a distance limited to substantially the thickness of a sheet of paper to be cut. Penetration of the blade is thus limited to a single sheet of paper. Because of its very short extension from the gauging surface, the blade will not cut a soft yielding material such as the hand of the user, The blade-holding member may be part of or attached to an elongate article, such as a pen or pencil, which provides a manipulating handle and enables the device to be used with a straight-edge.

5 Claims, 6 Drawing Figures SINGLE SHEET PAPER SLITTER BACKGROUND OF THE INVENTION 1. Field The invention is in the field of cutting devices, specifically those having a penetrating blade and a handle for grasping and manipulation.

2. State of the Art Several cutting devices utilizing a single blade of slit ting or slicing paper are known. One such device is disclosed in U.S. Pat. No. 3,249,091, and another is currently being marketed by the Eversharp Pen Company under the trademark Clipit. With all these devices, the blade is pushed through the paper and then cuts from underneath. The slitting or slicing action obtained is much the same as that of a knife used to slit envelopes open, slicing up from the bottom of a fold or a sheet to be slit.

SUMMARY OF THE INVENTION According to the invention, a blade is fixedly secured in and protrudes a limited distance from a holding member having a surface area that surrounds the blade and serves as a gauge that limits blade penetration. The surface area is smooth and flat or gently curved. The holding member may be part or or attached to manipulating means, such as a pencil, pen or other elongate article facilitating use with a ruler or other straight-edge.

In use, the gauging surface is pressed flatwise against a sheet of paper to be cut, which must be on a firm flat surface, such as a stack of similar sheets. The blade penetrates the sheet to be cut, with the depth of out being limited by the gauging surface.

Cutting of the paper is accomplished by drawing the device over the paper surface along the desired path while the blade penetrates the paper to the gauging surface and while the paper is supported by a firm support from underneath, for example, by the sheets under it in the stack of sheets. By limiting the extent of protrusion of the blade from the gauging surface, a single sheet of paper can be effectively cut. A protective cover for the blade when not in use is not necessary, since a soft and yielding material, such as human skin and flesh, will be deflected around the blade and will not be cut.

THE DRAWING Several embodiments representing the best mode presently contemplated of carrying out the invention are illustrated in the accompanying drawing, in which:

FIG. I is a fragmentary elevational view of the invention as incorporated in the pen-point-extending-andretracting plunger of a ballpoint pen;

FIG. 2, a perspective view of the same looking from above;

FIG. 3, a view similar to that of FIG. 1 but showing the device being used to slit a single sheet of paper on a stack of such sheets;

FIG. 4, a fragmentary elevational view of a writing instrument, with the device of the invention incorporated as a part of the usual attaching clip secured to the closure cap of such instrument;

FIG. 5, a similar view of the invention as embodied in a cap for attachment to the end of an ordinary pencil or the like; and

FIG. 6, a similar view of the invention as embodied in the end of a rod-like manipulating handle, the blade here being arcuate rather than pointed.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS In the embodiment shown in FIGS. [-3, a papercutting device according to this invention is incorporated in a mechanical ballpoint pen at the exposed, manipulating end of a plunger 11 provided for extending and retracting the writing point at the opposite end of the pen. The end surface 12 of the plunger is preferably flat and smooth and surrounds an extremely short blade 13 as a gauging surface for such blade, limiting its penetration. Blade 13 projects outwardly from gauging surface 12 a distance substantially equal to the thickness of a sheet of paper to be cut, e.g. within a range of about 4 to 25 mils. For general use in the cutting of newsprint or writing paper, a projection of about 9 mils in optimum.

In the operation of axial-feed pens such as shown in FIGS. 1-3, the plunger is depressed to extend the pen point to its operable position, and is again depressed to retract the pen point. When pressure is applied to the manipulating end of the plunger, such plunger moves coaxially into the pen body.

For purposes of the present invention, plunger 11 must be capable of exerting sufficient pressure to force blade 13 through the paper being cut. The plunger of a normal ballpoint pen is capable of exerting such pressure only when depressed to its ultimate degree of movement, which causes extension or retraction of the pen point as the case may be.

In the embodiment shown in FIGS. l-3, there is provided means for developing sufficient pressure on plunger 11 for utilizing the cutting capacity of blade 13, without depressing plunger 11 sufficiently to extend or retract the pen point. For this purpose, plunger 11 has an offset 14 arranged to abut against the marginal lip 10a of opening 15 in the body of pen 10 when the plunger is pressed sidewardly toward such offset. To accomplish this automatically, end surface 12 of plunger 11 is placed at an angle to the longitudinal axis of the pen such that an appropriate side thrust is imparted to plunger 11 and offset 14 thereof engages lip 10a when surface 12 is pressed against the paper to be cut, see FIG. 3. With offset 14 engaging lip 10a, plunger 11 is prevented from movement into the body of the pen l0, and sufficient pressure can be applied to plunger 11 to force blade 13 through a sheet of paper 16 on a stack 17 without depressing the plunger sufficiently into pen 10 to extend or retract the ballpoint at the other end thereof. When the pen is used for writing, plunger 11 can easily be depressed axially, so that offset 14 does not engage lip 10a.

Flat surfaces 18, formed laterally of and parallel with blade 13 on plunger 1 1, enable the user to properly orient the implement for cutting along a desired line and enable it to be used effectively with a ruler or other straight-edge. A single such surface could be used.

Blade 13 may be secured in the end of plunger 11 in any suitable manner. For example, a receiving recess may be provided in guaging surface I2 and an adhesive such as an epoxy resin used to hold the received base portion of blade 13 tightly in place.

In the embodiment of FIG. 4 a blade 19, corresponding to 13 in FIGS. l-3, is secured in a base 20 that rises from the attaching clip 21 on the cap 22 of a fountain pen or mechanical pencil and provides a gauging surface 23.

In the embodiment of FIG. 5, the device is in the form of a cap 24 for an ordinary pencil or the like 25 having an end adapted to fit into the receiving recess 26 of the cap. Gauging surface 27 is preferably sloped as illustrated with respect to the longitudinal axis of the cap, to make convenience in use of the blade 28 that protrudes therefrom.

The cutting device of this invention can also be provided at one end of a rod 29 or other member serving as a manipulating handle, see FIG. 6. A blade 30, here shown as arcuate in configuration, protrudes from gauging surface 31 at the end of the rod similarly to the blades l3, l9, and 28 of the foregoing embodiments. Here surface 31 is slightly curved, as indicated. Flat surfaces 32 may be provided as in FIGS. l3.

In all embodiments of the invention, the blade can be generally triangular in shape, as shown in FIGS. 1-5, having its leading edge sharpened and terminating in a point, as at 13a, which is advantageously blunted some what as indicated in FIG. 2. The blade can be of various shapes so long as it will penetrate and cut a sheet of paper under pressure of use. Thus, the arcuate shape of blade 30 in FIG. 6 is quite satisfactory.

In all instances, it is preferred that the blade be from stainless steel, but it can be made from any material which will hold a sharp knife edge.

The gauging surface of the various forms of the device must have a substantially smooth surface which is also substantially flat to provide for proper sliding of the device over the paper which is being cut. Such surface should also have rounded shoulders about its periphery to facilitate sliding over paper surfaces.

A novel feature of the device of the invention, as mentioned previously, is that it is completely safe and will not cut the skin of the operator. By virtue of the very small protrusion of the blade and the surrounding of the blade with a gauging surface, such blade will not penetrate a person's skin, or similar yielding surface.

This novel feature makes it safe to incorporate the cutting device into the end of the feed plunger of an axialfeed ballpoint pen, as shown in FIGS. 1-3.

With proper use, the paper cutting device of this invention cuts only one sheet of paper at a time, no matter how many sheets of paper are beneath the one being cut. Because of this novel feature, the device can be conveniently used to open letters. The device is drawn directly over the envelope, and, because the cutter only cuts one thickness of paper, the sheets enclosed in the envelope are not damaged.

The size of the gauging surface is significant in the combination, as well as the distance the blade protrudes from such surface. Thus, the area of the gauging surface should be within the range of from about one two-hundred fiftieth of a square inch to about onesixteenth of a square inch and, as previously stated, the distance of protrusion of the blade from the guaging surface should be within the range of about 4 mils to about 25 mils.

When the invention is incorporated in an axial-feed ballpoint pen as shown in FIGS. 13, the blade 13 should not protrude from surface 12 more than mils.

Whereas this invention is here described and illustrated with respect to certain forms thereof, it is to be understood that many variations within the scope of the following claims are possible.

What is claimed is:

l. A writing instrument device for cutting a single sheet of paper at a time without danger of cutting the user, comprising a ballpoint pen having an elongate pen body, and a manually-depressible plunger extending axially of said pen body, with an exposed end of said plunger projecting through an opening in an end of said pen body and surrounded by a lip defining said opening, for extending and retracting a ballpoint at the other end of the pen body, said exposed end of the plunger serving as a blade-holding member and having a gauging surface adapted to be pressed flatwise against and drawn across a sheet of paper to be cut; and a blade fixedly secured in and having a cutting edge sloping down to and terminating at said surface and protruding therefrom a distance substantially equal to the thickness of a sheet of paper to be cut, said surface having an area flanking said blade and sufficient in extent to serve as a gauge that limits penetration of said blade to a single sheet of paper and prevents penetration of said blade into the skin of a user when said plunger is fingeroperated to extend or retract the ballpoint.

2. A device in accordance with claim I, wherein the plunger is provided with a lateral offset adapted to engage the lip of the opening when the plunger is pressed laterally during a cutting operation.

3. A device in accordance with claim 1, wherein the blade-holding member is provided with at least one flat area laterally of and angularly disposed with respect to the gauging surface such that it provides a guide in properly orienting the device and in using it with a straight-edge.

4. A device in accordance with claim 1, wherein the blade protrudes from the gauging surface a distance within the range of about 4 to about 25 mils.

5. A device in accordance with claim 4, wherein the gauging surface has an area within the range of about one two-hundred fiftieth to about one-sixteenthh of a square inch.

Claims (5)

1. A writing instrument device for cutting a single sheet of paper at a time without danger of cutting the user, comprising a ballpoint pen having an elongate pen body, and a manuallydepressible plunger extending axially of said pen body, with an exposed end of said plunger projecting through an opening in an end of said pen body and surrounded by a lip defining said opening, for extending and retracting a ballpoint at the other end of the pen body, said exposEd end of the plunger serving as a blade-holding member and having a gauging surface adapted to be pressed flatwise against and drawn across a sheet of paper to be cut; and a blade fixedly secured in and having a cutting edge sloping down to and terminating at said surface and protruding therefrom a distance substantially equal to the thickness of a sheet of paper to be cut, said surface having an area flanking said blade and sufficient in extent to serve as a gauge that limits penetration of said blade to a single sheet of paper and prevents penetration of said blade into the skin of a user when said plunger is finger-operated to extend or retract the ballpoint.

2. A device in accordance with claim 1, wherein the plunger is provided with a lateral offset adapted to engage the lip of the opening when the plunger is pressed laterally during a cutting operation.

3. A device in accordance with claim 1, wherein the blade-holding member is provided with at least one flat area laterally of and angularly disposed with respect to the gauging surface such that it provides a guide in properly orienting the device and in using it with a straight-edge.

4. A device in accordance with claim 1, wherein the blade protrudes from the gauging surface a distance within the range of about 4 to about 25 mils.

5. A device in accordance with claim 4, wherein the gauging surface has an area within the range of about one two-hundred fiftieth to about one-sixteenthh of a square inch.

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