US2438628A - Pencil sharpener - Google Patents

Description

March 30, 1948. J. A. YERKES PENCIL SHARPENER Filed Aug. 12, 1944 3 heets-Sheet 1 March 30, 1948. J. A. YERKES 2,438,628

PENCIL SHARPENER Filed Aug. 12, 1944 3 Shets-Sheet 2 Patented Mar. 30, 1948 UNITED STATES PATENT FFICE PENCIL SHARPENEB John A. Yerkes, New York, N. Y.

Application August 12, 1944, Serial No. 549,214

10 Claims. 1

ihis invention relates tpBnCi1 Sharpeners,

and more particularly to pencil sharpeners of the type which include one .or more rotatable cutters.

Oneof the primary objects .of the invention is to provide for the production of a lar e Variety of shapes of pencil-points, to enable the operator to select a shape which is most suitable for the particular type of pencil andthe kind of work to be done.

Another important object of the-invention is to enable the operator to select, and produce the desired shape of penciloint without removing the housing or chip, container.

A further important object is to enable the selection of a particular point to be changed after insertion of the pencil into the machine, without injury to the existing point.

Other objects are simplicity of construction, ease of assembly and use of inexpensive parts.

Additional objects and advantages will be apparent from the following description, taken in connection with the drawings, in which:

Figure 1 is a central vertical sectional view of the preferred form of my pencil sharpener, with the usual housing or chipecontainer omitted;

Figure 1a is a fragmentary sectional view of the handle of the indicator arm-shown in Fig. 1, taken on line a-a of that figure;

Figure 2 is a diagrammatic perspective view of the end of a pencil sharpened to a relatively short point; v

Figure 3 is a similar view of the end of a pencil sharpened to a relatively longer point, in the usual manner;

Figure i is a fragmentary enlarged diagrammatic view, partly in central vertical section, of a modified form ofthe invention;

Figure 5 is a top plan View of the auxiliary cutter blade shown in Fig. 1

Figure 6 is an end elevational view of the auxiliary cutter blade shown in Fig. 5;

Figure 7 is a top plan view of a modified form of auxiliary cutter blade;

Figures 8, 9., 10 and 11 are. fragmentary diagrammatic perspective views of the ends of pencils with points such as may be produced by the modified form of the invention illustrated in Fig. l; and

Figure 12 is a fragmentary central vertical sectional view of a modified form of adjusting means for the cutter blade shown in Fig. 1, parts being omitted or bro-ken away and other partsbeing shown in elevation. I

Broadly considered-,the, above-mentioned objects of the invention are accomplished by one or more rotatable cutters in association with an auxiliary cutter which performs the combined functions of a pencil stop and point sharpener.

In the preferred form of the invention the cutter assemblage is carried by a head or cuttercarrier, which is rotatably mounted on a suitable base or support, which may take various forms or shapes for use in a horizontal or vertical position.

By way of illustration, the support maybe-a base casting -i with an integral cylindrical shafthousing 2 and a gear-housing 3 into which an internal gear i is pressed. A flanged cylindrical portion 5 may be provided for reception of the usual housing orchip container (not shown). These parts are fixed and do not rotate.

The rotating parts of the device include a frame 5, shaft 8 and cutters I5, It. Frame 6, having a central aperture l, for-insertion of the pencil to be sharpened, is preferably integral with hollow shaft 8, rotatably housed in shafthousing 2. Keyed to shaft 8 by set-screw 9 or other suitable means is a handle l0, which may be manually rotated. One or more cutter shafts, such as pins H, l2, are suitably secured to frame 6, for example by threaded shoulders I3, M, respectively, and have rotatably mounted upon them preferably cylindrical milling cutters l5 and it, on which are pressed spur gears i1 and it, respectively.

If handle ii! is revolved manually (or by power means, when desired and provided for), shaft 8 and its integral or rigidly attached frame 6 will revolve; milling cutters l5 and it will be rotated in an orbital path, carried with frame 6, and cutters Hi, It, through the meshing of spur gears ll, l8 and internal gear l, will also rotate axially on pins H and 42. This form-0f .construction and its operation are well known.

My invention pertains to certain features of novelty and improvement, which, in their preferred form, are illustratedin Figs. 1, 5 and'G. A preferably cylindrical shaft i9 is positioned in the bore of hollow shaft 8 in such manner as to permit longitudinal adjustment of shaft l9, or rotation of shafts 8 and I9 as a unit when handle it. is revolved. A key 29, with its upper face flattened, is pressed intoa suitable indentation in handle it and fits into a milled slot in shaft l9, preventing independent rotation of shaft l9, but permitting its limited longitudinal movement.

Loosely fitted into a slot 22 in handle in is an indicator arm 23, which is mounted for pivotal adjustment on a pin 24 pressed into suitable holes in handle I0. On the lower end of arm 23 is formed a gear sector 25, adapted to engage gear teeth 26 on shaft I9. Arm 23, or its upper portion 23a, is preferably a stamping of resilient metal normally slightly bent, so that it tends to press laterally against an indicator panel 23, preferably integral with handle I0. Panel 23 is preferably indented with a number of circular concave indentations, ten being indicated in the drawing, each identified by a numeral. The upper portion of arm 23 is drilled for reception of a pin 21, which, as shown in Figure 1a, is provided with a handle 3| and a curved end, 32 adapted to fit into any one of the indentations 29, to releasably secure arm 23 and shaft I9 in selected adjusted position. By this means shaft I9 may be shifted longitudinally to any position within the limits shown and locked in such adjusted position. In Fig. 1 shaft I9 has been shifted to the left a maximum distance, corresponding to position 10 on the panel 28.

Shaft I9 is milled to form a fiat portion 33 on which is mounted a flat auxiliary cutter blade 34, secured to shaft I9 by machine screws 35 and 33, or. by other suitable means. In its preferred form of embodiment, my auxiliary cutter, functioning as a combined pencil-stop and point-cutter, is in the form of a blade 34 (shown in Figs. and 6) preferably made of thin tool steel, ground at one end to form a substantially V-shaped pair of cut- 'ting edges 3I,and is provided with a pair of apertures 38, 39 adapted to receive screws 35, 33. The apex of the V formed by cutting edges 3? is slight-' ly flattened; the flat portion 49 does no cutting, but acts as a stop to prevent excessive feed of the pencil lead aftercompletion of the sharpening operation and produces a point which 'is frustoconical at its tip, as shown in Fig. 2.

Blade 34 is ground on both sides, in the vicinity of cutting edges 31, to produce concavities 4i; the path of the grinding wheel is indicated by dotted lines and 43 on Fig. 6.

Auxiliary cutter blade 34 is positioned between milling cutters I5, I6 (Fig. 1), arranged in converging positionto form a V-shaped or tapered space between them. At their apex there is a slight clearance 44 between cutters I5 and I3, through which space blade 34 projects. It is because of this small clearance that it is necessary to grind the concavities on blade 34.

Preferably the angle between cutting edges 31 of blade 34' is greater than the angle between milling cutters I5 and I6. In the drawings the latter angle is shown as'substantially 20, which is common practice, whereas the angle between cutting edges 31 is preferably 45: the latter angle, of course, may be subject to considerable variation.

In operation, if arm 23 is swung to the extreme left position, that is, to indentation 29 of po- 4 such as that indicated in dotted lines on Fig. i. This is similar to the ordinary point (Fig. 3), but the lead portion is dressed to form a cone 45 (Fig. l) bf larger angle, as clearly shown in Figure 2.

If an intermediate point is desired, it may be obtained by shifting arm 23 to any selected intermediate position (positions 2 to "9; Fig. 1). Thus any desired length of point may be selected between the limits illustrated in Figs. 2 and 3. As the point selected becomes longer, cone 46 becomes shorter, disappearing when the limit (point 41; Fig. 3) is reached. Thus it is possible to obtain an infinite variety of points between the sition 1, shaft I9 will be moved to the extreme right position and blade 34 will be shifted to the right until flat portion 40 of blade 34 coincides with apex 44 of cutters I5, I6, as to position. In this relative positioning of the parts the machine operates in the manner of an ordinary pencil sharpener, flat portion 40 acting as a stop and the usual pencil-point 41 (Fig. 3) being produced,

If an extremely short point is desired, arm 23 is swung to the extreme right, to the position 10 illustrated in Fig. 1, causing blade 34 to project to the left a maximum distance and resulting in the production of a pencil-point'on pencil 45 limits notedabove, although I prefer to limit the number to ten, as shown. a

, By means of the above-described preferred form of my invention a wide range of pencils, from those with small hard leads to those with large soft colored leads, may be sharpened to produce the point most suitable for its particularwork, with resulting economy of pencils and greatersatisfaction to the user.

A modified form of the invention is illustrated in Fig. 4, by means of which a series of pencil points maybe produced which vary from the simple substantially conical point illustrated in Fig. 8, through the pointed cylindrical points of Figs. 9 and 10, to the blunt cylindrical. point shown in Fig. 11. i

It has been the practice to produce special blunt cylindrical points, such as are used by draftsmen and illustrated in Fig. 11, by equipping a sharpener with milling cutters of the formshown in outline in Fig. 4. Cutters 48 and 49 are dressed down to form frusto-conical portionsifl, 5|, respectively, their inner edge-s being disposed parallel to each other and separated byaspace 52, preferably as wide as the diameter of the pencillead. By this expedient the wooden end portion 53 of the pencil 54 is dressed frusto-conical in shape (shown in dotted outline in Fig. 4), whereas the lead is trimmed of all Wood and left cylindrical, as shown in Fig. 11.

In-the modification illustrated in Fig. 4, adifferent form of auxiliary blade is used. This'auxiliary blade 55 (Fig. 7 has a pair of cutting edges 53 converging to form a V with the apex slightly blunted to form aflat stop 51.- The angle formed between edges 56 (Fig. 7), while preferably larger than the angle-between the cylindrical walls of milling cutters 48 and '49 (Fig. 4), is preferably smallerthan the angle between vcutting'edges of blade 34 (Fig. 5). It should be n0ted-that,in the case of blade 55, it is unnecessary to grind concave faces such as concavities M of blade 34, since there is ample space for projecting blade 55 between cutters 48 and 49 (Fig. 4) without such grinding. Holes 53 and 59 in blade 55 servepurposes similar to ho1es'38 and 39 of blade 34.

Washers 60 and 6I,isecured to the ends of milling cutters 48, 49, respectively, by any suitable means, serve as auxiliarystops, which will be referred to hereinafter. I *do not limit myself to this particular form of auxiliary stop, however, since many other forms well known in the art may be used, H

In the operation of the modified form of the invention illustrated in Fig. 4, ifblade 551s projected between cutters 48 and 49 a, distance such as to bring the ends'of the cutting edges .56 of blade 55 to the line designated by point A',. a pencil point such as point 62 (Fig.3), will be'produced. Preferably no wood is cut by blade 55 and the base of the cone of lead, at-A, is located eX- '5 actly where the wood starts. "Point- 62-is preferably the shortest pointand -sh'ould'be compared with point 46 (Fig. 2)

If blade 55 iswithdrawn to point- 2B (Fig. 4) a pointed cyl-indrical-point-is produced (such' as point 63 of Fig. 9). This should be compared with point41 (Fig, 3') and maybe re'gardedas a eneral utility point. The base 'of' the cone of point 63 is at B.

If blade 55 is-withd'rawntathe line of point C, an extraordinarily long pointed cylindrical point 6 1 (Fig. 10) is produced. As'in Figs. 8 and 9, the dimensions ofthecone are substantially unchanged, butitsbase is at'point C,'leaving a longer cylinder of lead exposed.

In producing the pencil points illustrated in Figs. 8, 9 and 10, stop 51 of blade SE -(Fig. 7) functions in a manner similar to stop '40 of blade 34 (Fig. 5).

To produce a completely blunt cylindrical point, such as point 65 (Fig. 11), blade'55 is withdrawn to point D (Fig. 4), or farther, so that the converging cutting edges '56' are ineffective; the lead cone consequently disappears from the pencil point (see point D; Fig. 11). Since stop 57 of blade 55 'is withdrawn to'a position where it is no longer effective as a stop, auxiliary stops E and GI function to stop' the pencil lead and the sharpener functions in substantially the same manner as the simple blunt-point sharpeners of ordinary design hereinbefore described.

Both the preferred embodiment illustrated in Fig. 1 and the modified form shown in Fig. 4 utilize the i'mportant'feature of the projection of the auxiliary cutting blade 34 or'55 into the tapered space between the converging milling cutters I5, I 6 and 48, 49, respectively. The auxiliary cutters (blades 34, 55) revolve at" the same rate as the orbital revolution of the milling cutters (l 5, H or 48, 49) the auxiliary cutter tends to steady the pencil lead, sothat there is considerably less likelihood of breakage than if the lead were projected from between the milling cutters without the aid of the auxiliary cutter as a guide and stop,

Even after the pencil is inserted into the cutter assemblage a pencilpoint other than that registered in the machine may be selected without injury to the existing point, by shifting the auxiliary cutter 34 or 55 longitudinally, i. e., on the longitudinal axis-of thepencil being sharpened. The modified form of adjusting means for the auxiliary cutter blade, shown in Fig. 12, is adapted to be used in connection with the milling cutters 48, 49, and may be substituted for the blade adjusting means of Fig; 1. This modified adjustment may'be'preferable in certain forms of pencil sharpeners.

In the Fig; 12 form'ofadjusting means blade 34 is secured, by'screws35, 36, to a shaft [9a (similar to shaft [9 in Fig. 1) slidably mounted in the bore of hollow 'shaft' aa, which is secured to frame 6a by a threadedconnection 66, provided with a set screw 61. A key 20a pressed into a suitable indentation in the wall of hollow shaft -which-is loosely fitted between the end face 76 of hollow shaft 811 and a'shoulder 69 on handle Illa,

is rotatable independently ofhandle Illa or hollow shaft 8a. A pin'.'|'3, pressedinto an aperture in bushing 12, engages in a spiral groove" 68 in shaft l9a.

Step by step adjustment of knob 14, for corresponding adjustment of shaft lea and cutter blade 34 through the pin and groove connection 13-69, is facilitated by'the provision ofgrooves 77, preferably ten in number, spaced around a portion of the peripheral surface-of an enlarged The operation of this modi-fiedform of bladeadjusting means, relative to the other parts of the pencil sharpener-device disclosed and claimed herein, is substantially the'sameas that of the blade-adjusting means 'shownin Fig. 1 and described as the preferred form of embodiment.

Iclaim:

1. A pencil sharpener comprising a support, a head rotatably mounted on said support, substantially cylindrical milling cutters carried by said head with their cutting faces in converging relationship to forma tapered space between said cutters, and a cutting blade carried by said head substantially axially thereof and projecting between the converging ends of said cutters into the space between said cutters, said cutting blade having a substantially V-shaped cutting edge and the faces of said cutting blade being hollowground to permit the projection of said cuttin blade between the faces of said converging milling cutters.

2. A pencil sharpener comprising a support, a head rotatably mounted on said support, substantially cylindrical milling cutters carried by said head. with their cutting. faces in' converging relationship to form a tapered space between said cutters, a cuttingblade' carriedby said head substantially axially thereof and projecting between said cutters into the space between said cutters,v said blade having. a'substantially V- shaped cutting edge the faces" of which form an angle greater than the angle between the cutting faces of said cutters, whereby the point produced by said blade is of larger angle than the point produced by said cutters, and means mounting said cutting blade for'movement between a position substantially at the ends of said milling cutters and various other positions between said milling cutters.

3. A pencil sharpener comprising aisuppcrt, a frame rotatably mounted on said support, milling cutters rotatably mounted' on said frame in angular relationship forming aspace between said cutters, said cutters being substantially'cylindrical with their adjacent end portions frusto-conical, said frusto-conical end portions forming a substantially rectangular shaped space between adjacent longitudinally extending portions of said cutters, an auxiliary cutter on said frame substantially axially thereof and projecting between the ends of said cutters into the space be- 7 7 tween said cutters, and means mounting said auxiliary cutter for movement betweena position substantiallyat the ends of said millin cutters and various other positions between said milling cutters. r e r Y e g 4. A pencil sharpener comprising asupport, a frame rotatably mounted on said support, said frame including a hollow shaft, milling cutters rotatably carried by said frame in angular relationship, forming between them a space, an auxiliary cutter carrier slidably mounted in said hollow shaft, an auxiliary cutter carried by" said carrier and projecting between said milling cutters into said space, and manually-operable means engaging said carrier for adjusting said carrier and said auxiliary cutter to project said auxiliary cutter a selected distance axially into said space.

5. A pencil sharpenercomprising a support, a'

frame rotatably mounted on said support, said frame including a hollow shaft open at its ends, milling cutters rotatably carried by said frame in angular relationship, forming betweenthem a space, an auxiliary cutter carrier slidably mounted in said hollow shaft, an auxiliary cutter carried by said carrier and projecting between the ends of said milling cutters axially into said space, said hollow shaft and said cutter'carrier being slidably positioned in and removable from said support, a rotatable handle, and means detachably securing said handle to said frame to permit removal of said handle'and said cutter carrier from' said frame through an end of said hollow shaft. V I a 6. A pencil sharpener comprising a base, ahead rotatably mounted on said base, shafts carried by said head and projecting therefrom in substantially V -shaped arrangement, a substantially cylindrical milling cutter supported on each of said shafts, the cutting faces of said cutters being disposed in angular relationship to form a substantially V-shaped space between said cutters, an auxiliary cutter blade adjustably carried by said head substantially axially thereof and slidably mounted thereon to project the end of said blade between the ends of said cutters axially into the space between said cutters, means for rotating said head, means operable from the exterior of the device for adjusting said auxiliary cutter blade axially into said substantially V- shaped space for producing a point of selected length on a pencil inserted between said cutters, and means mounting said auxiliary cutter blade for movement between a position substantially at the ends of said milling cutters and another position between said miling cutters.

7. A pencil, sharpener comprising a support, milling cutters rotatably mounted on said support in axially-converging relationship forming a generally-tapered space between saidcutters for reception of a pencil tobe sharpened, an auxiliary flat blade point cutter rotatably mounted on said support on an axis of rotation coincident with the axis of said space, means for rotating said milling cutters about the axis of said space and for rotating said auxiliary cutteron said axis, and means mounting said auxiliary cutter for movement between a position sub- 8 stanti-ally at the ends of said milling cutters and various other positions between said milling cutters.

, 8 A pencil sharpener comprising a support, a framerotatably mounted on said support, said irame including a hollow member,;milli ng cutters rotatably carried by said frame in angular relationship forming between them aspace, an auxiliary cutter slidably mountedin said member and projecting between said milling cutters into said space, and manually operable means engaging, said auxiliary cutter for adjusting said auxiliary cutter to project said auxiliary cutter a selected distance axially into said space.

9. A pencil sharpener comprising a support, a frame rotatably mounted on said support, said frame includinga hollow member open at its endsymilling cutters rotatably carried by said frame in angular relationship forming between them a space, an auxiliary cutter carrier slidably mounted in said member, an auxiliary cutter carried by said carrier and projecting between the ends of said milling cutters axially into said space, said hollow member and said cutter member being slidably positioned in and removable 7 from said support, a rotatable handle-and means V tween said milling cutters.

detachably securing said handle to said frame to permit removal of said handle and said cutter carrier from said frame through an end of said hollow member. e

10.A pencil sharpener comprising a support, a head rotatably mounted on said support, milling cutters'carried by said head with their .cutting faces in converging relationship to form a tapered space between said cutters, a cutting blade carried by said head substantially axially thereof and projectable into the space between said cutters; said blade having a cutting edge with a contour arranged to assist in supporting the pencil point as the millingcutters andblade conjointly shape a pencil point having portions 7 of difierent angular relationship, and means mounting saidrcutting blade for movement between a position substantially at the ends of said milling cutters andvarious other positions be- JOHN A. YEBKES,

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED sTATEs PATENTS If I Date Number 319,546 Germany "1920

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