US2509006A - Mechanical pencil with lead storage magazine - Google Patents

Description

May 23, 1950 R. J. LYNN MECHANICAL PENCIL WITH LEAD STORAGE MAGAZINE Filed Aug. -14, 1948 [/IIIIIII.

IIIIIII.

U Il

IN VEN TOR. Robert J. Lynn Patented May 23, 1950 UNITED STATES PATENT OFFICE .Robert AJ Lynn, Chicago, Ill.

:ApplicationAugust: 14, 1948,` Serial N o. 44,355

. .11 Claims. l

-My @invention .relates to .a Vmechanical pencil :in which is combined a chambered body .to which tis fitted a tipA which` mountsfa propelling mecha- .nism. .In the-presentpeneilthis tip is. removable rfromthe pencil body, together with the propelling fmechanism whichfconstitutes-a unit therewith. .When .tted :tothe body of the vpencil,.the tip has capacity fol-relative 4rotation whereby to operate -the propelling/mechanism.

The features of invention with which .I am .here v,concerned yrelate to the Yprovision .Within -`the v`chambered .pencil lbody of a guide tube .adapted .for .cooperation with the propelling ,mechanism ofthe tip, and lto .the means and .method `whereby this guide tube may be -an- .chored xedlyin place. This .tube ,is :extended axially Y:within Vthe pencil `-body which is. .also vin ,the form of -a tube. The anchoragebetweenthe .twof-tubesis. conflnedtoa short distance .ator A near .the vlower ends` thereof. ,Elsewhere .anannu1arf Yspace intervenesbetween the tubes,V ,avail- .ableas a 4magazineifor the storage` of reserve leads vwhichmay-be putin or taken out .through the top end ofthebody tube whenever .a closure `cap ,at that point is removed.

AA substantial saving .intime .andcost-maybe .i effected'by-.utilizing-'for Vthe bodyand .guide tubes ia-,suitablecomposition material which is .moldable under heat-.and,.pressure. 'which initially vareseparate o and independent becomen'n the process oftheirassembly, united mechanically and inapwaywhich is immovable, inseparable, and permanent, one withrespect vto --theothen The resultis a' pair oftubes,4 onewith- :in the other, spaced apart. for -.their lfull length `.except at their lower ends vwhere .one is united to the other,..and reach embodying such. special features of contour'- or cross section as may-be :desired/for most :eiective cooperation -with vthe alead vpropelling mechanism which is comprisedin :the-.operating tip.

V.This invention `is-also concerned with the provisionfat-fa pointspacedfrom the union ofthe tubes-atm` near theirlowerends f..a second means of connection therebetween1 and of r the method employed in v.making .such fconnection. .This-.second Ipoint. of connection utilizes :anexpansible ring fitted into an annular -spacebetween the-twovtubes -andzfadaptedfto be wedged .f radially inwardly orr outwardly. into an expanded state; in response-.to insertion. of one tube axially within the other tube. :Suchan expansiblel ring is then maintainedvfixedlyrand permanently in a l.predetermined.position where it may also serve as a .bottom closureavfor-aspare-lead magazine in the upper end'region of the pencil.

Certain :suggestive: embodiments tof' this. inven- .tion are: iliustratedin vthe accompanying draw- ;ingzin zthe aimannerjollowing.:

. Figure .11 is an :elevational-avion! :.of the :pencil These two tubes vand partlyin elevation, ofthe ltube as it appears before itis formed into thebody ofthepresent pencil;

yFig. v6 whichis adetailin longitudinalsection .shows the body tube intherst stage of the molding. treatment prior to assembly .of thev guidetube therewith;

Fig. 7 is asimilar View. showing the Abody and guide tubes intheirrelative positions at the commencementof the .second stage ofthe molding .treatment in the process of their assembly.

Fig. 8V which is a similarview .shows the body -and guide .tubesintheir relative positionsat-the .conclusion .of .thesecond .stage Vof this molding treatment;

Fig.. 9 isianv elevational View of. a slightly different lead -guide ytubesassembled within amodie'c'l tubular pencil bodywhoselower end portionis here shown in longitudinalsection; f

Fig. .10 is La fragmentary View in elevation,..and partly rinsectionoia modified pencil wherein the `body .and lead V.guide .tube are .secured ,to-

Agether bymeans .somewhatdiierent from .that

which is elsewhere shown; and

Fig. l1l is a transverse section, taken on, line lI-I I of Fig. 10. v

The pencil of my invention comprises atubular body B having wallsl ofgenerally cylindrical contour for the major part `of its length, ,and produced Ydesirably from a suitablewcomposition material which is .susceptible of being moldedto shape under-the influence. ofheat Yand pressure.

:Nearits lower .end the body walls..are tapered inwardly at I lioria short distance. At this point is thejuxtaposed socketed 4large end of a tapered Atip T through whichis an vaxial .chamber accommodatinga coupling tube I5 whose lowerendfis V'lxedly anchoredI .tothetip in`v anyA approved way.

This coupling tube whichextends upwardly .and outwardly beyond thetop end of the tip maybe longitudinally slitted .at I1 ,at distances of .perhaps .7120"...apartto provide therebetweenarcuate sections which are outwardly bowed endwise, whereby these .circumferentially ubulged .sections become. radially :resilient for .a purpose which wil shortly appear.

frjprinlary` feature fof' this :invention .is'the `proivsion `ofzra guide 1 tube .,:20 xedly carried Within the chambered body B in spaced relation to its surrounding walls and in operative relation to a lead propelling mechanism which is carried by the tip T. This guide tube, as shown, may be produced from a composition material. Exteriorly its form is cylindrical throughout its upper end region with a smaller diameter which then tapers outwardly to provide a shoulder 22 in its medial region, and then continues through its lower end region where it changes to another diameter which is slightly enlarged except for a circumferential groove 23 near its lower end. The exterior surface of the tube contiguous to both sides of this groove is desirably knurled at 24, and therebelow the tube is shown as very 'slightlyincreased in diameter to provide a head 25 which is cylindrical and smooth. Interiorly the axial chamber of the tube is cylindrical, as at 26, throughout its lower end region (see Fig. 2) but opposite its tapered walls 22 this chamber changes form to provide opposed slots 2 which continue to its top end which is desirably closed by a wall 28.

A guide tube of this general description may be flxedly anchored within the body B in a very :i

effective and simple way. As suggested in Fig. the tubular body which is made from composition material is initially cylindrical with its walls Ill of uniform thickness. To adapt the body tube for reception of the guide tube therewithin, I employ a die having at one end a socket whose walls are tapered inwardly at 3i. An outwardly facing annular shoulder 32 provides a terminus for the tapering walls beyond which i5 an axial bore wherein is accommodated the shank of a sizing mandrel 33 that is projected outwardly into the die socket. By forcing the tubular body endwise into the die socket, while heated, up to the shoulder 32, the tube will be coned inwardly adjacent its end to provide tapered walls of short length (see Fig; 7) which progressively increase in thickness very slightly toward the 'tube end. In this operation the sizing mandrel acts to assure a predetermined internal diameter of the tube at its extreme end.

After this initial tapering of the body end has been effected, the tube is then fitted into a second die 35 (Fig. 8) having at one end a socket whose walls are tapered inwardly at 35 as far as an outwardly facing annular shoulder 31 beyond which the socket continues in the form of a cylindrical chamber 38 having a diameter and length the same as that of the head 25 at the lower end of the guide tube 20. An axial bore continues on through the die for accommodation of a guide mandrel 33 which is extended outwardly into the die socket. The guide tube, already in the form and shape illustrated in Figs. 1 and 2, is then assembled with the body tube, and the two tubes so intertted are advanced into the socket of the mold 35 which is heated. The guide tube readily reaches its final position wherein its head 25 occupies the cylindrical chamber 38, but the short tapered end walls il of the body tube engage the tapered walls 36 of the die a substantial distance before reaching the annular shoulder 31 (see Fig. 8). From and after this point the further endwise advance of the body tube is dependent upon heat and pressure which is applied in they requisite degree to flow the already thickened walls of the body tube lengthwise over the knurled portion 2d and into the circumferential groove 23 of the guide tube 20 (see Fig. 9). In this final operation the tapered walls ll of the body are caused to interengage positively with the knurls of the guide tube so as to lock one against axial movement relative tothe other. The body walls, at their point of juncture with the guide tube, remain slightly thicker than elsewhere whereby to provide a union of ample strength. In this final condition of assembly the body and guide tubes are inseparably, immovably, and permanently interlocked, as clearly shown in Figs. l and 9.

The annular space between the body and guide tubes provides a magazine which may be utilized for extra leads Z which are placed therein and removed therefrom through the open top end of the body tube which is normally closed by a closure 45 which inay take the form of an eraser unit the details of which are unimportant here. A bottom for the magazine may conveniently be provided by a ring 46 which may be frictionally fitted upon the shoulder constituted by the tapering walls 22 of the guide tube to remain in a fixed position thereupon. This ring may optionally have an outside diameter sufciently large to engage the surrounding body walls.

When the tip unit is operatively tted to the lower end of the pencil body, its coupling tube l5 is entered into the guide tube 20 for a distance insufcient to reach its tapering walls 22; in this assembled condition the bowed sections between the slits i1 resiliently engage the surrounding walls of the guide tube whereby to establish a frictional, yet separable, connection therewith, and one which permits the tip to be rotated relative to the pencil body. The coupling tube mounts a lead propelling mechanism including a plunger 5! having at its top a, head 5i which is flattened to enter into a pair of opposed slots 21 in the upper end region of the guide tube 20. In response to rotation of the tip upon the body the plunger is caused to travel endwise whereby to propel an active lead Z outwardly through the small end of the tip where it is frictionally supported in writing position. When assembled with the pencil body, the axial socket at the upper end of the tip receives the guide tube head 25 in close fitting relation, whereby to steady and maintain the one part axially with respect to the other independently of the lateral support which is afforded by the coupling tube.

Referring now to Fig. 9, the showing here is substantially identical with that in Fig. 1 except in four particulars, viz., the ring 56 is split at 51 so as to be expansible; the knurled portion 24 of the lead guide tube 20 is not interrupted by any circumferential groove such as the one designated as 23 in Figs. 1 and 2; the lead guide tube is of uniform external diameter from a point beyond the head 25 at its lower end; and the tapered lower end li of the pencil body B, which is interiorly cylindrical at 58 for a distance substantially the same as the length of the knurled portion 24 of the lead guide tube, is tapered outwardly at 59 for a substantial distance upwardly from this point.

In the assembly of the pencil of Fig. 9 the expansibie ring 5B is fitted loosely around the lead guide tube 20 along which it descends until engagement takes place with the tapered interior surface 58 near the lower end of the tubular pencil body. At this stage the lead guide tube which already has been entered through the lower end of the pencil body is advanced freely therein until its knurled portion 24 encounters the lower end of the body; at this point opposed endwise pressures are directed against the lead guide tube and the pencil body, whereby to force the one axially withfrespect'totheother. '-In this operation Lthe knurledpcrt-ionM is5V forcedfto -finalifposition within 4"the pencil 1body by `*forming therein 2small grooves in parallelism withfeach other --and.with thelaxis ofthe'body. "The-:forced 'lit thus provided is permanent.

jAt the-same`time1an`d during this same operation, the -lexpansible ring may beforced'endwise along fthe `interiori-y'-'t'apered -walls 59 L'of lthe fbo'dy to* be wedged thereby i inwardly into fpressureengagernent` with the lead `guide tube. 4In its final posi-tiona's shown iniFigQ, the 'ring willT provide an* 'interlocking connection' between fthef lbodfyland leadf guidetubefata ypoint remotefrom thefiri-terlocking lconnection which -is providedy iby the forced `t of the `-iknurle'd portion 124 of Vthe lead guide tube withinfthe-"cylindricalfwall 53 of 'th'e tubul'arf'body. `Accordingly 'the two tubesf-arecoaxially securedtogethen'but in spaced relation, except atthebottomy end of 'the fpencil, so as 'to lie-adequately and,permanentlysupported in'ixed positions relative to each other.

nReferring-now to *Figs yl0 and 11, I have there illustrated 'a :hollow 'pencil body B 'having its walls xtapered inwardly =at "Vl 5for "a f-short `Ydistance at the lower end. At this point is the'juxtaposed socketed" large 'end of a tapered tip "I" wherein'is tted' a guide tube'f78 having a knurled lowerend portionr T9" below Vwhichiis a-slightly en- 'larged head ISli. Within this 'tube vis accommoldated alead"propllingmechanism that mayjif desiredjbethe same'as the .one already described in nconnectionwiththe construction of Figs. 1 4.

vExteriorly the guide l'tube"'li3 iscylindrical in form throughoutits upper endregion, with a smaller diameter in its medial region which tapers outwardly to provide a shoulder `32. "The axial chamber linteriorly of the guide tube 'changes form in theregion of 'thetapered'shoulder tojprovide -opposed "slotsl'B for engaging with the fiattenedhead of the'lead propeller (not shown) in the manner already expiained. A ring lrwhi'ch is tted'around theguide' tube is 'Slidablel lengthwisethereupon to a position of restagainst the tapered shoulder `82. Thisring issplit atf'so as to be expansible.

`In the assembly of the'pencl offFigs. loifand 11, the expansible vringli'maybe-restedupon the upper endof an uprighttubul'ar" fixturer over which is -Vplaced the Atubular `bodyB 'withthe 'guideftube Ai8 looselyViitteditherewithin. By -a relative axial movement'i' 'thesel parts, the small- 'erupper end region ofthe 'guide tube`-'T8"isad vanceid freelywithin'the expans'ible rin'g'up'to 'the point of engagement` therewithOfitstapered 'portion "32; concurrently the "guide v`tube T8 is advanced upwardly within 4"tl're ltubiilar body iB' zso 'as to force'its "knurle'd "portion *T9 endwisc withinV the cylindricaichamber 8 l: at'rv the 'tapered lower end of the pencil body. In this operation two'thingshappen:l (l) the tapered wall portion 82 of the guide tube i3 acts as a circular wedge to expand the ring 85 outwardly/'into tight en- -aagemei-it with the surrounding Y.body vwalls, fand vism with eachother-and withfthe axis of'the ibody.

Such an interfitof. theaparts reslts Yfrom fan Vendwisefforcing.of -theleadguide tube''l relative to the fexpansibletringf-M and the'tubular tbody B"of^the..pencil. It '.prduces aLnorm-ally inseparable interlock v.at .two fspa'ced points b'etween the-leadwguide.tubeandzthe body, :andernay lli be vv`relied lupon fto resist eiectively frany possible relative rotary for fendw-ise movements :between theseparts. f v

It #isfdesirablefor .fthe I.purposes of @thisllinvention, `that thelbodyftube beniade of somefcomposition material--a plastic, it is .usually termed. The 1 material-Lof vwhichithe. guide tubeisfmadexis optionalit-mayJbeplastic or urnetal. .Also the special exterior formation rwhich .characterizes the v@guidetube ra-tfits lower end may-bemodiiied within certain-limitsso long as fitsexterlorembodies vone or more deiinit'ely lraised for V4sunken features with-which L-therfsurrounding Lbodyiltube. when finwardlyv disposed, may positively engage on-allsides. #Wl-ien assembly is iinallycompleted in the manner heretofore described, i'there rwill be "a lpositive `interlock 'between fthe body and guide ltubcs `at "one or more places such :as fto prevent any Amotion 'orv separation betweenfthese parts. l"Ihewancl'iorage thus iaffordedisfvery effective indeed, -vitassures a'maintenance ofithe guide ltube in a Yposition centrally of thebody tube, :and =there Vis -no deformation exteriorly :f the body 'tube/required for theinward displacement f-'its'walls for engagement with thefguide tube atfthe point where the anchorage is located. "This is a continuationiin partfcaseinrespect of my lapplication'iiled February 17, f19i'7,1under SeriallNoff'ZZQglll, now abandoned.

'If claim: l. ina pencil, "the combination with-.-at-separable propelling unit 'of anfassociatedplastictubular bodyhaving straight walls ,of :uniform thickness 'mit tapered inwardly" and thickened atfits lower end, anda guide 1 tube' within the 'tubular body Vspaced from the :walls thereof to afford therebetween an annular magazine openmnlyfat the pencil Itop, theguide tuberbeing' extended Ibelow the lower" end of the body .for `supportingrotatabie vengagement with the .propelling unit "whenthe' latterv is fitted: operativelyv to the*tapered pencil end, 4and ccoa'eting means Yintegral Vwith the bodyA andguide tube providing aninterlocking connection therebetiif'een, confinedfto theitaper-ed Kand liened wall fregio'ngof themed-y, adapted to sustain theguideltubexedlyeandginsepara'biy Within' thebody tube,centrallyV thereof.

2. A.Ina pencil'thecombination with aseparable propelling unit of an associatedplastic'tubular-v body'y having straight vwalls of 'uniformi` thickness but .tapered inwardly and Athickenedfat its lower end, andaguide tube -within the tubular body spaced from "the -rwalls thereof `to "afford therebetween rant annular magazine open .onlyl at .thea pencil top,:and. coacting meansv integral with .tpm

body land guider tube 'providing an interlockconnection therebetween, coniinedrto .theta- '.peredand thickened wall region of the body, Aadapted to sustain the. gri-ide tube-xedly andin- .separably---within vthe .body tube.. centrally-thereof.

-=3. -In a pencil., the f combination 4Vwith a.,.sep

.arable propelling .unit `of l.an .associated .plastic vrtubular Vbody having -astraight :walis ltaperedin- :wardlyat .its :lower end, and:` a guide tube .within v:the tubular bodyspaced from i the walls thereof to afford therebetweenan annularmagazineopen adapted to vsustain the .guide .tube .-ixedly .and

.insep arably within the-body tube, centmlly therefof.

.4. .-.-In ya pencil the v:combination .of `.a .tapered tip, fa.. .plasticchambered..penci1. .body substantially straight from end to end except at its lower end where the body is tapered inwardly to a diameter substantially the same as the larger end of the tip, and at an inclination substantially the same as the taper thereof, a guide tube extended centrally within the body chamber and into the tip for rotative engagement thereby, an anchorage for the guide tube confined to the region of the tapered lower end oi the body comprising means on the guide tube extending at varying distances from its axis interengaged by plastic material extended inwardly from the body walls, and means iixed to the tip extending into the guide tube for frictional engagement therewith for establishing a separable rotatable connection therewith.

5. In a pencil, the combination with a separable propelling unit of an associated plastic tubular body having straight walls of uniform thickness but tapered inwardly and thickened at its lower endfand a guide tube of plastic material within the tubular body spaced from the'walls thereof to aord therebetween an annular magazine opening only at the pencil top, the guide tube :being extended below the lower end of the body to enter into the propelling unit when iitted operatively to the tapered pencil end, and coacting means integral with the body and guide tube providing an interlocking connection therebetween, conned to the tapered and thickened wall region of the body, adapted to sustain the guide tube iixedly and inseparably within the body tube, centrally thereof.

6. In a pencil, the combination with a separable propelling unit, of an associated plastic tubular body having its walls at the lower end tapered inwardly and thickened, and a guide tube within the tubular body spaced from the walls thereof to afford therebetween an annular magazine open only at the pencil top, the guide tube being provided at one point intermediately of its ends with an upwardly facing shoulder, a ring fitted over the upper end portion of the guide tube and adapted to rest upon the shoulder to occupy substantially fully the annular space between the guide tube and the tubular body of the pencil whereby to provide a bottom for the magazine, and means providing an interlocking connection between the body and guide tubes, confined to the tapered and thickened wall region of the former adapted to sustain the guide tube iixedly and inseparably within the body tube, centrally thereof.

7. In a pencil, the combination with a separable propelling unit, of an associated plastic tubular body having its walls tapered inwardly and thickened at its lower end, a guide tube within the tubular body spaced from the walls thereof to afford therebetween an annular magazine open only at the pencil top, and coaoting means integral with the body and guide tube providing an interlocking connection therebetween, confined to the tapered and thickened wall region of the body, adapted to sustain the guide tube fixedly and inseparably within the body tube, centrally thereof.

8. In a pencil, the combination with a separable propelling unit, of an associated tubular body and a guide tube within the tubular body spaced from the walls thereof, the guide tube being vprovided exteriorly with a shoulder tapering inwardly towards its upper end, and an expansible ring fitted upon the guide tube shoulder to be outwardly wedged thereby when advanced downwardly thereupon, the ring, when expanded,

being arranged to engage with pressure the inside surface of the pencil tubular body whereby to provide an interlocking connection between the pencil body and guide tube.

9. In a. pencil, the combination with a separable propelling unit, oi an associated tubular body having a smaller inside diameter at one end, a lead guide tube within the tubular body spaced from the walls thereof, said guide tube having a diameter at one end substantially equal to the reduced inside diameter at the proximate end of the tubular body and being formed with knurls longitudinally disposed to enter into complementary grooves in the tubular body whereby to provide a frlctional and positive interlocking connection between the body and guide tube at that point, the guide tube at a point intermediately of its ends being formed exteriorly with an endwise tapering shoulder, and an expansible ring tted upon the shoulder and arranged to be outwardly wedged thereby into .pressure engagement with the tubular body walls to provide a second interlocking connection between the body and guide tube at a point spaced from the rst interlocking connection therebetween.

10. In a pencil, the combination with a lead propelling tip unit, of an associated tubular body, a lead guide tube within the body tube coaxial therewith and throughout its upper end portion spaced from the walls thereof, means adjacent the lower end of the .pencil body integral with one tube and extending toward the other tube and engageable therewith in coacting relation and in response to axial movement of one tube relative to the other whereby to establish an interlocking connection therebetween, one of the two tubes at a point removed from the interlocking connection being formed with a tapered shoulder whereby to vary the distance between the two tubes, and a split ring disposed between the two tubes and ltted around the tapered shoulder of the one tube adapted in response to relative axial movement therewith to be wedged radially toward the other tube Afor pressure en gagement therewith whereby to establish a frictional lock between the two tubes at a point remote from the lower end of the pencil body.

11. In a pencil, the combination with a lead propelling tip unit, of an associated tubular body, a lead guide tube within the body tube coaxial therewith and throughout its upper end portion spaced from the walls thereof, and means adjacent the lower end of the pencil body integral with one tube and extending toward the other tube and engageable therewith in coacting relation and in response to axial movement oi one tube relative to the other whereby to establish an interlocking connection therebetween.

ROBERT J. LYNN.

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

UNITED STATES PATENTS Number Name Date 1,723,787 Keeran Aug. 6, 1929 1,753,005 Grady Apr. 1, 1930 1,801,671 Keeran Apr. 21, 1931 1,827,884 Ellison Oct. 20, 1931 1,919,455 Wilson July 25, 1933 2,059,367 Hinds Nov. 3, 1936 2,087,519 Lynn July 20, 1937

Images