US2071352A - Pencil sharpener - Google Patents

Description

Feb.- 23, 1937. E- Q MEYER 2,071,352 l PENCIL SHARPENER Filed Feb. 25, 1955 l I I f @M www Patented Feb. 23, 1937 UNlTED STATES garant orties 14 Claims.

My invention relates to the type of pencil sharpener in which a Xed blade is mounted in a holder and the end of a pencil is inserted in a cone-shaped socket, the pencil then being rotated toi cut a point on the wood of the pencil and a point on the lead.

In such type of pencil Sharpener, an object and feature of my invention is the construction of a base support or holder on which a double edged safety razor blade of the standard dimensions may be utilized for cutting and sharpening the pencil, such blade being held in contact with the base by a clamping plate.

In connection with using a removable blade, a further object and feature of my invention is utilizing a spring mounted at one side of the supporting base and engaging an edge of the blade, thereby retaining the other edge in correct position for cutting and sharpening the pencil. This sharpening edge is preferably thrust against abutment shoulders and hence is held in the correct position in regard to the recess in which the pencil is inserted and a slot connecting with this recess.

A further detailed feature of my invention is providing an enlargement in the slot by which the edge of the blade engages the pencil to facilitate discharge of the cuttings of lead from the pencil, this enlargement also positioning the lead so that it does not contact with any surface or edge except the cutting edge of the blade and thereby prevent the danger of breaking the lead which is a common fault of many of these types of pencil Sharpeners.

A further detailed feature of my invention is in the mounting of the spring to engage the edge of the blade in that a shoulder on the base has an opening or slot therein from' which extends a longitudinal groove, a leaf spring being inserted in this groove and the spring having a bend so that it may extend through the slot to engage the edge of the blade.

Another feature of my invention is that the blade may be shifted so that one of the end perforations engages a screw threaded stud which supports the clamping plate in clamped relation to the blade and this provides a section of the blade extending beyond the holder so that the blade may be used as a knife blade or for cutting paper or the like. With this arrangement when the blade is shifted towards one end, that is towards the end having the enlargement of the slot to accommodate the lead of the pencil, the device may be used as a lead Sharpener and as a knife.

(ci. 12o-9s) Another feature of my invention when the blade is centered, is that as the lead causes the quickest dulling of the blade, that the blade may be turned edge for edge and reversed and thus obtain four sharpening positions.

My invention is illustrated in connection with Fig. 5 is a view similar to Fig. l with the blade projecting from the holder to form a knife.

Inthe drawing 1 employ a base or body structure ll. This has a bearing surface I2 at the top and a marginal rim I3 on one side. has a side opening lf3 on the inside and a longitudinal slot l5 extending from this opening. The opening and the slot have a bottom surface I6 which is below the bearing surface I2 of the face. A pressure spring II is of a leaf spring type and has an end i8 with a kink caught in the groove I5. The free portion Iii of the spring extends into the opening, the spring being tensioned whereby the free end has a tendency to move towards the axial center of the supporting base o-r l holder. The purpose and function of this spring is detailed hereinunder. The spring is of lesser height than the distance from the bottom I6 of the opening and slot to the top of the rim I3.

At the opposite side of the base there is a secy ond rim 25, this having spaced apart abutment shoulders 2t and 21 at right angles to the supporting surface I2 and parallel to the rim I3. Thus betweenthe abutment shoulders 26 and 21 there is a longitudinal slot 28, this slot having a widened section 29. The bottom of the base at one side has an enlargement dil in which there is a conical socket 3l extending inwardly from the large end or base 32. The axis of the cone slopes upwardly towards the surface I2 on which the blade rests at a suitable angle to give the desired cone shape to the point of the pencil and the lead. The abutment shoulders 26 and 21 are preferably at right angles to the surface I2 but the plane including the edge of the blade and the axis of the cone or pencil is somewhat greater than a right angle, to give a better cutting action on the usual blades in which the cutting edge is midway between the upper and lower sides of This rim A N the blade; this being formed by a V-shaped taper of the edge of the blade.

My pencil sharpener is designed to use a standard type of razor blade 35, such blade has opposite parallel cutting edges 36, practically all of which blades are provided with a central perforation 3l and some of these with end perforations 38. It is usual to join such perforations by a slot 39 through the blade connecting the several perforations, however, blades with a single central perforation will operate with my pencil Sharpener. Also, usually the blades have end tabs 40, forming a convenient finger grip. Moreover, such blades are usually flat and may rest on the fiat surface I2. The measurement from cutting edge to cutting edge of the blade is slightly less than the measurement between the shoulders 2l and 28 and the vertical edge of the rim I3 across the base so that the blade may be easily slipped into place between the rims and the end I9 of the spring I'I contacted with the edge of the blade opposite the socket for inserting the pencil.

In order to hold the blade rmly in position, I employ a central screw threaded stud 45 extending upwardly from the base above the flat supporting surface I2. A clamping plate 46 is provided. This is slightly arched so that the center 4l is slightly above the hat surface I2. This clamping plate has marginal opposite edges 48 which have a sliding fit in the vertical inside walls of the rims on opposite sides of the base. These sides are also provided with cutout longitudinal recesses 49 adjacent the slots 23 on one side and the opening I4 in the slot I5 on the opposite side. 'Ihese cutout sections are made equal so that the clamping plate may be reversed. This clamping plate has a central perforation 5B of sufficient size to pass freely over the threaded stud 45. A knurled nut 5I is threaded on this stud and bears on the upper surface of the clamping plate, thus causing the marginal edges of the plate to press downwardly on the upper side of the blade adjacent its cutting edge and thereby hold the blade flat on the surface I2 in a position for sharpening a pencil.

The function of the spring Il is to press the blade so that one cutting edge is in contact with the abutment shoulders 26 and 21. Moreover, such spring accommodates blades which are slightly different in measurement between their cutting edges. Hence the cutting edge of the blade is in contact with the abutment shoulders 26 and 21 before it is clamped in place by the clamping plate.

It is believed the manner of sharpening a pencil is obvious, the end of a pencil being inserted in the conical socket 3I. The pencil is thrust inwardly until it engages the cutting edge of the blade through the slot portions 28 and 29. The pencil is then rotated on its axis and a conical point is cut on the end of the pencil, the cutting blade cutting away both the wood of the pencil and the centrally located lead, thus sharpening both the wood portion and the lead of the pencil. The wood shavings discharge mainly through the slot 28 and the lead cuttings are discharged mainly through the enlarged section 29 of the slot. This enlargement is sufficient to accommodate the cuttings from the lead in one or more sharpenings of a pencil so that this lead may be cleared by inverting the pencil Sharpener and shaking the lead cuttings from the slot. Also any pencil cuttings which do not pass upwardly over the blade may be readily shaken from the socket 3| and the slot 28.

In View of the fact that the lead in being sharpened dulls the razor blade more rapidly than the cutting of the pencil, by using a double edged razor blade I may use four sections of the blade for sharpening the lead, that is two positions on each cutting edge of the blade, by reversing the blade end for end and then turning it over and then again reversing it end for end.

When it is desired to use the device as a knife, the blade may be inserted so that one of the end perforations 38 lines with the stud 45. The clamping plate is then secured in position by the nut 5I which arrangement allows a portion of the blade to extend beyond the end of the base I I as shown in Fig. 5. Thus the projecting part of the blade may be used as a knife blade.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

l. A pencil Sharpener having a supporting base with two abutment shoulders on one side, a socket for a pencil and a slot communicating with the socket between said shoulders, a blade having a cutting edge, means to press the blade to contact a portion of the cutting edge with the abutment shoulders, and means to clamp the blade to the base.

2. A pencil Sharpener as claimed in claim l, the means to press the blade comprising a spring mounted in the base and engaging the blade to move the whole blade to engage the cutting edge 4. A pencil Sharpener as claimed in claim 3, the `i means to press the blade sidewise comprising a spring secured to the base and engaging the edge of the blade opposite the cutting edge.

5. A pencil Sharpener having a base with a bearing surface on the top and a rim on each side of the bearing surface, the said rims being parallel, one of the rims having two abutment shoulders spaced apart by a longitudinal slot, the base having a socket for a pencil communicating with the slot, a blade supported on the bearing surface,

a spring mounted in the rim opposite to that having the said shoulders, the said spring engaging an edge of the blade to move the entire blade to bring the cutting edge on the opposite side of the blade into contact with the two abutment shoulders, and means to clamp the blade to the base.

6. A pencil Sharpener as claimed in claim 5, the rim having the spring mounted therein being provided with a side opening, a portion of the spring being located in said opening to contact one edge of the blade.

7. A pencil Sharpener having a base with a flat upper bearing surface, two marginal rims, one on each side of the base extending upwardly from the bearing surface, said rims being parallel, one of the rims having two abutment shoulders spaced apart by a longitudinal slot, the base having a socket for a pencil communicating with said slot, a blade having a cutting edge and a second edge parallel thereto, a Spring mounted in the other rim and engaging the said second edge of the blade to move the entire blade to bring portions of the cutting edges of the blade into close contact with the two abutment shoulders, and a clamp to hold the blade against the flat bearing surface of the base.

8. A pencil sharpener as claimed in claim 7, the rim supporting the spring having a side opening and a longitudinal slot, the spring being a leaf spring with one portion secured in the slot and a free operating portion located in the opening to engage the second edge of the blade.

9. A pencil Sharpener having a base structure with a ilat upper surface and two marginal rims, said rims having surfaces at right angles to the bearing surface of the base and parallel one to the other, one of the rims having a longitudinal slot and the said surfaces of said rim forming two abutment shoulders, the base having a conical socket communicating with the slot, the opposite rim having an opening and a longitudinal slot communicating therewith, a leaf spring secured in the slot and having a free end operating in the said opening, a double edged blade having parallel cutting edges, a clamp to secure the blade to the base, the free end of the leaf spring engaging one of the cutting edges and forcing the other cutting edge to bring portions thereof into contact with the said abutment shoulders.

10. A pencil Sharpener having a base with a flat upper bearing surface, a rst rim extending upwardly above the bearing surface and having two aligned abutment shoulders spaced apart by a longitudinal slot, a socket for a pencil communieating with the slot, a blade having a cutting edge on one side resting on the base, a spring means secured to the base and engaging the other side of the blade to move the entire blade to bring portions of the first edge of the blade into engagement with the said two abutment shoulders, a clamping plate secured to the base to clamp the blade, said clamping plate having a longitudinal recess on one side to register with the slot in the first rim.

11. A pencil Sharpenerk as claimed in claim 10, the spring means employing a second rim extending at right angles to the bearing surface of the base and having a marginal opening, a slot eX- tending from the opening, the spring being a leaf spring having one end secured in the slot and the free end operating in the opening to engage the edge of the blade opposite the cutting edge.

12. In a device as described, the combination of a base having a at bearing surface and parallel rims, a double-edged flat blade having a perforation adjacent each end, a stud on the base over which either perforation may fit and a clamping means connected to the stud to clamp the blade to the base whereby an lend portion of the blade may extend beyond the base, one of the rims having a spring mounted therein to engage one of the edges of the blade and move the entire blade to bring portions of the other edge of the blade into close contact with the other rim.

13. In a device as described, the combination of a base having a at bearing surface, a pair of parallel rims on opposite sides of the bearing surface, a stud secured to the base, a double-edged blade having a perforation adjacent each end, either perforation being fitted over the stud, a clamping plate having parallel side edges to fit between the rims, a nut on the stud to bear against the clamping plate and thereby hold the blade with one end portion extending beyond the end of the base, one of the rims having an opening with a slot extending therefrom, a leaf spring having one end secured in the slot and a free end operating in the opening to engage one edge of the blade and to move the entire blade to bring portions of the opposite edge of the blade into close Contact with the opposite rim.

14. A pencil Sharpener as claimed in claim 9, the means to clamp the blade comprising an arched clamping plate having parallel side edges engaging the blade adjacent its cutting edges, a stud on the base, the blade and the plate having a perforation to fit over the stud and a nut threaded on the stud engaging the clamping plate whereby the blade may be clamped with its edge only adjacent the slot engaging both the abutments or only one abutment and project beyond the base.

EDWIN C. MEYER.

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