US1647078A - Pencil sharpener - Google Patents

Description

Patented Oct. 25, 1927.

i UN-irEn slilfras PATENT oFFicjE.

GEORGE W. BROWN, 0E CAPE ELIZABETH, MAINE, AssrGNoE, BY DIRECT ANnMEsNE ASSIGNMENTS, OFONE-HALE TO S'SAN` J. DODGE, 0F DAMARISCOTTA, MAINE, AND

ONE-HALE "ro EMMA BROWN, oEcAPE ELIZABETH, MAINE.

PENCIL' sHAErENERL My invention relatesto pencil sharpeners` and more particularly to that type employing a keen cutting-edge blfade to produce the proper point on the pencil. l

One of the principal `difculties heretofore niet with in the use of Sharpeners with blade cutters has been the tendencyv of breaking the lead point during the cutting operation.

Ifliave, for one of my objects, sought to overcome this troublevby providing a. sup'- port, 'not alone for the wood portion of the.. pencil, but for the whole length of the lead point vupon vwhich the cutting operation is i being performed.

In my Sharpener alarge proportion ofthe tapered portiony of the pencil has` circumferential Support or backing to resist thecutting thrust of the blade,'the latternot eri-- tending beyond the end lof the lead which is left in aI somewhat blunt'point.

.Another deiiciency characteristic of the conventional typeof blade'sharpenersis the lack of means to extract the short piece of lead after it has been broken off in the sha-rp? ener and become strongly wedged between the knife andthe wall of the sliarpener.

Vhile the breakagey of the lead is of infrequent occurrence in the manipulation of my sliarpener, still', the possibilityof experiencing this trouble is always present,"and forfthat reason Ihave provided means to meet this contingency. I' einploya small propelling plungerv which is always in positionV adjacent the end of the cutting chamber and by a slight 'movementv inwardly ofthisplunger .a piece of the' lead broken off from the main portion of the lead in the pencil mayy be dislodged from 'the small end of the taper edi chamber-in the Sharpener in which it had' becomefirmly wedged. Y A still further obj ect pertains to the align-vr ing-fof the pencilfprevious to the ycutting operation, Vwhereby whenk this Work is'completed itj may result in the procurement of a tap ered pencil end with the lead.symmetrically pointed and the wood .evenly cut on all sides of the lead .at a uniform distancef'rom they pointv thereof. Vithout' this' 'preliminary guidance, starting the cut concentrically,the above object is diiiicultl of attainment. y

Vith these and other objects view thel invention consists nin the novel features Ahereinafter described in the specification, and in Application led March '11',v 1926. Serial No. 91,500. j

the accompanying drawings in which the preferred embodiment lustratech- Y Fig. l is a perspective View of my sharp` ener as applied to a block type thereof; i

Fig. 2 isaplan view of the saine; i Fig. 3 is 1an enlarged section of the sharpener, taken on line 8 3, Fig. 2;" l

of my invention is il-v Fig. 4 is a transverse section of the same taken on line 4 4, Fig'. 2; v

Fig. 5 isr any enlarged section taken online 5-5-,1i+`i,e,-f.s,` 1 is a plan view of the'sharpener as' applied to 'a pencil holder; Y Y

Fig.7 is an enlarged view of the latter, inv

section, which is taken lon line 7-7, Fig.' 6;

Fig'. 8 is a view of the blank from whichis` -made the plunger and carrier for the projec-j tor shown lin Fig. 7; f

Fig. 9l shows' the completely formedl el'e-` i ment shown in Fig. 8;

Fig. l() is an enlarged' section taken onv line itl-10, Fig. 7; u

f Fig. V1l lis a fragmentary sectionalk view,

r'transversely of the Sharpener, greatly en-v larged, taken on lin-e 5-5, Fig. 3, andj show; ing. the Vsuperior support `or backing for the" lead. point when cutting isj taking place;

Fig. 12 `is a fragmentaryv sectional'vie'w',` greatly enlarged, ltaken* on a vertical planev coincident with'the aXis of the pencilandiv plunger'and shows the position of the'se'two `Glenientsand the cutting' blade,v rela-tively,v

Fig.f 13 showsA an alternative method of mounting the plunger. Y

,InI a-ll-view's, like characters'ofreference refer to similar parts. Y

In Figs. l and ilareshown two different applications of my Sharpener, employing,

however, equivalent elements in each case.

` In F ig. l I have illustrated my Sharpener in block form, the block l' being constructed of either of various materials, Vas wood, metal' or 'any one of the numerous plastic' substances, such as-iiber, vulcanized rubber' or fixture cement. 'v

Infeither case its' construction, follows closely the design illustratedin sectionalY de'-y tail in Fig. 3. From one end' of the blockl a .straight'hole 2,extends inwardly for a spaced distance or sufficiently far to provideI i anoutside bearing for the straight' portion 2 of the pencil and to locate and hold the latter at the correct angular relation with the cutting blade. The pencil thus confined may not wabble and cause a greater cut to bel chamber 4 starts on a taper predetermined for the pencil point 4. y

It will be observed that the interior wall of the cutting chamber 4 describes a straight ,sided frustro-coiiical, figure with the small end 5 identically the same in size as the diameter of the finished point of the lead. The tapered portion of the pencil, both wood and lead, consequently has a constant support and backing whenever either is or both are in contact with the cutting blade, and this support continues until the very end of the lead is formed to the final shape.

.Referring to Figs.y 3 and 5 it will be seen that the lead, even to the extreme end of the point, Vis supported and held against the cutting thrust of the blade by considerably more than a semi-circular portion of the wall of the cutting. chamber, or in other words, more than half of the peripheral surface ofthe lead has a perfect seat on the interior of the fi'ustro-conical shaped cutting chamber against which it may bear while the blade is operating on it, and under this condition there is little likelihood that breakage of the lead will occur.

4The diameter of the small end of the cutting chamber, as seen at 5,' depends o n the predetermined size desired for the point of the lead. As I stated kin my preamble somewhat blunt point is best suited for all practicalpurposes, so I construct the blade of such length that it will cut nowfurther than. the small end of the tapered portion of the cutting chamber. This produces a point very much stronger than a needle point and somewhat smaller than the thin leads quite generally lused in the present day lpropelling pencils. n

Extending outwardly from the small end of the frustro-conical cutting chamber 4 is ahole 8, made substantially the same size as the small end 5', which is also the size of the finished lead point,y and operating in this .hole is a plunger 9 which, should the occasion require, serves to f orce back `into the tapered chamber the piece of lead which may have broken off during the cutting operation.

It will be seen, by reference to Figs. 11 and 12, that the plunger 9 may also serve, when reciprocated kbaclrwardly and foi'- wardly, to smooth out any burrs or turned over poitionsvof the edge of the blade 3, incident to the cutting of the lead which oftentimes is somewhat gritty in its nature.

'Ihis plunger may b e secured in operative position in the hole 8 in any approved manner but I have elected to make it, in the case kof the block sharpener, integral with a yielding extension 10, which latter Ik fixedly v a part of a split collar 12 which isrslidably positioned within the borel Iof the holder sleeve 13. .The function ofthe plunger remains the same as tliatof the block sharpener plunger, but its actuation may be accomplished by means ofthe projectingrlip l 12 extending outwardly from the split ring A12. A slight pressure on the lip moves the plunger into or out of the cutting chamber,- its inward movement having the effect of dislodging anyl broken pieces of lead should this situation develop. v

Indents 14 extending into, the interior of .the sleeve 13 restrict the movement of the split ring 12 outwardly so as to prevent the complete withdrawal of the plunger 9 from out of the hole 8. These indents Vmay propeily be made in the sleeve subsequently to the insertion of the Vsplit ring thereinto. n

,So as to utilize the sleeve 13 to hold pencils varying Islightly* in diameter I cut a scarf llongitudinally thereof, making it 1 somewhat resilient, and I also make this scarf serve as keying means for the lip 12. .In Figs. 8 and 9 I illustrate the blank and vthe finished formedsplit collar 1,2, respect-1 tively. I prefer this construction on account of the low cost of manufacture. c

It is quite desirable at times to have the sharpener within easy reach of the user. In the case of the pencil holder type of sharpener, shown in Figs, 6 and 7 this desiderat-um is satisfied by mounting it on a pencil which Y willA be `carried in the users pocket. In the block form, shown in Figs. 1 and-3, the lloop 16,. to which av cord or ribbon mayl be attached, provides a handy and convenient method of securing` the Sharpener so that it will be instantly accessible. Or it.- may vbe attached to a watch chain to anchor one end in .the owners vest pocket.

In Fig. 13 I illustrate asomewhat dierent method of mounting the plunger 9 from'that shown in Fig. 1 Y n block 1, beneath the blade 3, is a depression 1 Awithin which the extension 10 from the plunger 9 may reciprocate. The bent-over end 10 operating in the depressionspace l restricts Vthe movement "of the member 10 outwardly by its abutting on the side wall of ,the depression, and this vrestrictionnprevents On the surfacerof the` lili the plunger 9 from completely withdrawing from out of the hole 8.

The operation of the Sharpener may be clearly understood by the reading ofthe foregoing description especially when taken in connection with the severalillustrations. The cutting operation should lbe stopped when the extreme end of the leadA reaches the outer end of the blade. Further cutting will produce no finer point and wastage of the pencil results if the operation iscontinued. The whole length of the cut is visible to the operator and it is thus easily ascertained when to desist cutting.

The preeminent features of my Sharpener are, briefly stated, the ability to support the pencil and give it backing along the whole length of the vtaper being cut, even to the extreme endA of the lead, as yat av, Fig. 3, thereby largely eliminating the trouble of breakage of points; the provision for removing from the small end of the tapering cutting chamber any piece of lead which may have been broken volf' and become lodged therein; and the ability to properly align the pencil in the Sharpener relative to the correct angular relationship with the blade before the start of the cutting operation.

And it may be pertinent to state at this time that while the most annoying trouble with pencil pointers is their tendency to lbreak the point of the lead when nearly formed, it is not always caused by faulty design or construction. Much inferior and defective material is marlreted,-such as pencils which are made up of small pieces of lead, cross-grained stock and bent leads a guide' provided with an open-ended, y

straight-side tapering chamber having an elongated length-wise slot through its wall,

`said chamber communicating, at itsvsmaller end, with an opening disposed at an angle to the axis of said chamber and in a plane parv allel to one of the sides thereof, a cuttingblade operable through said elongated slot and effective over the full length, only, o f the side ofvv said tapering chamber, and a plunger reciprocable in saidv opening and operable in close and parallel relation to, and inwardly of, said cutting-blade.

2. In a Sharpener of the class described, a guide having a smooth, straight-sided tapering chamber open at both ends and having an elongated, length-wise slot 'through the wall thereof, and a cutting blade, operable through said elongated slot and coextensive with the tapered chamber, terminating at the ap'eX ofv the tapered chamber whereby it isV effective over the entire-length onlyk of said tapering chamber.

GEORGE W. BROWN.

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