US2471334A - Paper cutter - Google Patents

Description

1949. H. H. LEVIN 2,471,334

PAPER CUTTER Filed Oct. 20, 1947 2 Sheets-Sheet l O V w N \1 Fz'gl Fig.2

N H {Snvenbor Eagmabtorneg May 24, 1949; LEVlN 2,471,334

PAPER CUTTER Filed. Oct. 20, 1947 2 Sheets-Sheet 2 H M 'QSnvQntov M: figmflttor nets Patented May 24, 1949 UNITED STATES PATENT OFFICE Claims.

This invention proposes a safety cutter of the type employing a conventional safety razor blade adapted to be replaced when dull. Such devices, if made so that the blade remains exposed in its cutting tip or tips, are liable to cut the fingers of the user and, therefore, it has been proposed to pivot the blade and provide a spring for keeping the blade normally retracted. This swinging blade, however, is not entirely satisfactory and the present device undertakes to mount the blade in rigid relation with the handle and accomplish the safety requirement by arranging a guard which itself may swing sufficiently to expose either of the cutting tips of the blade. Furthermore, in devices of this sort it is desirable that the extent of exposure of the blade may be under definite control so that in one case it may be only slightly exposed so as to be useful for cutting clippings from the pages of magazines and papers, whereas, in the other case it is desirable that the blade may be more extensively exposed so that it may be used for cutting through relatively thick corrugated paper or the like where deep cuts are necessary. In the present device, these alternatives are accomplished by the setting of an adjustable stop conveniently located as will be explained.

In the drawings,

Figure 1 is a plan of the assembled device.

Fig. 2 is a side elevation partly in section of the assembled device.

Fig. 3 is a plan showing the swingable guard detached to adapt the device for blade replacement.

Fig. 4 is a plan partly in section of a portion of a modification affording an adjustment of the extent of exposure of the cutting tips of the blades.

Fig. 5 is a sectional side elevation of a portion 'of the same.

This safety cutter comprises two major relatively movable parts, to wit, a handle A detachably but rigidly holding a blade preferably of the safety razor type and a swingable guard B which normally is latched immovably to the handle so as to prevent inadvertent contact with the cutting edges of the blade. This guard, however, is

so pivoted to the handle that, when unlatched,

it may be swung against spring pressure to expose either the one or the other of the two cutting tips of the blade. This guard, being limited in 'its swing, serves also as a limit gauge for controlling the depth of cut in either of its four available positions; two on the one or the other side giving deep cuts, and two likewise for shallow cuts.

On one side, the cutting tip is freely exposed so as to be suitable for scribing either straight or curved lines on any portion of a surface, whereas, the other side of the guard is provided with a guide rail which serves to hold the cutting tip at a predetermined distance from the edge of a paper carton, for example, and thus enables the lid to be cut off accurately and easily.

In detail, the handle A comprises a central long fiat bar I which may be faced with wood 2, at one end to accommodate the hand and towards the other end the bar is provided with means for immovably mounting a replaceable safety razor blade 4. This means consists of a stud 3 fixed to the bar I and extending only the thickness of a blade therefrom to form a boss adapted to enter a conventional central recess in such blade. A hole 5 located in bar I to the rear of said stud, receives the enlarged shank 6 of a screw 1 which, in turn, passes through a conventional aperture 8 in the blade and this enlarged shank together with the stud aforesaid holds the blade permanently in alignment with the handle. This screw 1 also serves pivotally to hold the guard B in place and enables it to be temporarily removed for blade replacement purpose.

The guard, for convenience of manufacture, is composed of three plates, two of which 9 and Ill (in the form shown by Figs. 1 to 3) are in surface contact and the third ll slightly spaced from the middle plate a distance barely greater than the thickness of the blade so that, when the guard swings about its pivot, one or the other of the cutting tips of the blade are exposed. This swinging of the guard is accomplished by the pressure of the guard (when unlatched) against the surface to be cut into and normally is prevented by a latch or trigger l2 shaped somewhat after the fashion of a dumb-bell, the shank l3 of which passes through a narrow slot M in the central plate of the handle and also, adjacent each of its two exterior heads, through longer and wider slots l5 in two small side plates l6 and ll that are spaced from the central plate and held in position by a rivet l8 and washers l8 and I8". This means also furnishes a seat for one end of a small spring l9; the other end of the spring operating against the trigger I! so as normally to retain it in shallow notches 20 in each of the two outer plates of the guard. Sloping to the right and left from the open end of the notches 20 are two edges 20* and 20 which ride against the trigger l2 and cam it rearwardly against the pressure of the spring 19 until its further retreat is positively arrested. In the form shown by Figs. 1 to 3, the rear end of slot may act as a fixed stop; in which case, it will be perceived, that the inclination and dimensions of the edges All and 20 can determine the extent of exposure. If they are truly symmetrical with respect to the notch 20, then the exposure will be the same whether to the right or to the left, but if they are unsymmetrical, the exposure may be different in extent on the right or left, as may be predetermined. The guard B is shaped as shown by the drawings and, on one side, carries a guide rail 2| secured by one of the two rivets 22 and 23 which hold together the three plates of the guard itself.

The modification of Figs. 4 and 5' is basically the same as the former. But it is to be noted that in this case the stud 3 of the former is replaced by a boss 3 formed as an integral part of the middle plate 9 by a die stamping operation. This enables the boss 3 to be formed with two radial wings 3 and 3 which interfit with complementary apertures conventional with razor blades. Also this modification provides the depth-of-cut adjustment aforesaid.

The adjustable means for setting the device for either a deep or a shallow cut is shown by Figs. 4 and 5 and comprises an adjustable stop 0 located in the shallow space between plate I and plate (I and pivoted thereto and having a knurled arcuate portion 30 exposed to one side and thus accessible to the thumb so that it may be swung in either one or two of its positions. It has a finger 3| which, in the one position can swing into the path of the latch I2 and so limit its retreat that the latch cannot ride its full distance along either edges 20 or 20'. A shoulder 32, by bearing against the side of the trigger limits the swing of stop C and accurately positions it. In this position, the latch, by reason of the flare in the edges 20* and 20 prevents the guard from swingingonly suflicient to expose very little of the cutting tip of the blade; whereas, when the stop is swung into its other position, the finger 31 is not in the path of the latch so that the latch can be entirely withdrawn from the slot 26 and the guard is then enabled to swing further until arrested by the edge 33 of the stop C.

From the foregoing, it will be perceived that the features of construction of this device are so devised and combined as to enable it to be readily produced so as to meet the needs of various classes of users. Thus, the guard may be omitted for those not often engaged in opening paper cartons. Likewise, for those only concerned with making relatively deep cuts, a considerable exposure as well to the right as left can be produced by providing the extremity of the mid-plate with similar cut-away or sloping corner edges I and l which serve, when contacted by the central plate of the guard to limit its swing. Or, as has been previously explained, the same end may be attained by making the elongated slot Hi of such length as to limit the retreat of the trigger l2 and thus determine the extent to which it may ride along the inclined edges 26 and 28 Thus, by making the corner edges l and l (or likewise the edges 2% and 28) either similar or else non-similar, equal or non-equal exposures to the right or left may be realized. So also, the formation of the pivoted stop in conjunction with either one or both of the edges 29* or 20* will afford desirable adjustments of exposure, and by forming the pivoted stop so that it does not limit the retreat of the trigger, four different exposures are obtainable in a single device; two by the corner edges l and l and two by the edges 20*- and 20*, as aforesaid.

I claim:

1. A utility tool comprising a handle; an elongated flat bar extending rigidly therefrom; a double-edged thin detachable cutting blade mounted immovably on said bar adjacent its extremity; a guard pivoted to said bar and having a notch in its rear end, a latch axially slidable in an elongated slot in said bar; and a spring urging said latch forwardly to normally retain it in said notch and thereby maintain said guard in alignment with said bar to cover both cutting edges of said blade; said latch being adapted to be finger-pressed to the rear out of said notch to permit said guard to swing either to the right or left to expose the tip of either edge of said blade.

2. A device conforming to claim 1 in which the guard has two end edges flaring from said notch upon which the latch may ride when pressed out of said notch to determine the extent of exposure of the cutting tips of the blade.

3. A utility tool comprising a handle; an elongated flat bar extending rigidly therefrom; a double edged thin detachable cutting blade mounted immovably on said bar adjacent its extremity; a guard pivoted to said bar and having a notch in its rear end, said guard having two end edges flaring from said notch upon which a latch may ride when pressed out of said notch to determine the extent of exposure of the cutting tips of the blade; a latch axially slidable in an elongated slot in said bar; a stop adjustable to limit the extent of rearward withdrawal of said latch; and a spring urging said latch forwardly to normally retain it in said notch and thereby maintain said guard in alignment with said bar to cover both cutting edges of said blade; said latch being adapted to be finger pressed to the rear out of said notch to permit said guard to swing either to the right or left to expose the tip of either edge of said blade.

4. The device of claim 3 in which said stop is pivoted to said bar and provides two seats; the one for permitting a relatively small rearward movement of said latch to afford a slight exposure of a cutting tip, and the other for permitting a greater movement of said latch to afford a greater exposure to said cutting tip.

5. A utility tool comprising a handle; an elongated flat bar extending rigidly therefrom; a double edged thin detachable cutting blade mounted immovably on said bar adjacent its extremity; a guard pivoted to said bar and having a notch in its rear end, said guard having a guide, on one side to enable material to be cut parallel with its margin and having two end edges flaring from said notch upon which a latch may ride when pressed out of said notch to determine the extent of exposure of the cutting tips of the blade; a latch axially slidable in an elongated slot in said bar; a stop adjustable to limit the extent of rearward withdrawal of said latch, said stop being pivoted to said bar and provided with two seats, the one for permitting a relatively small rearward movement of said latch to afford a slight exposure of a cutting tip, and the other for permitting a greater movement of said latch to afford a greater exposure to said cutting tip; and a spring urging said latch forwardly to normally retain it in said notch and thereby maintain said guard in alignment with said bar to cover both cutting edges of said blade; said latch being 6 adapted to be finger pressed to the rear out of UNITED STATES PATENTS said. notch to permit said guard to swing either to the right or left to expose the tip of either ber Name Date edge of i blade 1,222,356 Curry D 1917 HENRY LEVIN 1,489,631 Du Fresne Apr. 8, 1924 5 1,574,641 Christopherson Feb. 23, 1926 REFERENCE CITED 2,109,686 Breidenbach Mar. 1, 1938 2,376,887 Walters May 29, 1945 The following references are of record in the file of this patent:

Images