US1793237A - Mechanical pencil - Google Patents

Description

Feb. 17, 1931. J. MEILNER MECHANICAL PENCIL Fired Dec' 2 Sheets-Sheet 1 l ATTORNEY I Z INVENTOR @www Y Feb 17, 1931. J. MEILNER MECHANICAL PENL 2 Sheets-Sheet 2 Filed Dec. 4, 1926 MMQ ATTORNEYS .if-klim, kwik It PatenieaFeb.17,1931

' .uNiTEDsTATEs Y PANY, or Nnw'Yon-K, Y.

, JOSEPH, MEILNEB, or oRANG-Efnnw JERSEY, assierioisf'ro y'iiliaise.riiiiioi,L COM; A coeronarion oFDnLAWAREi y Mnoiiariioan rendir.' i

j .Appiieaien inea. Membern-192e. semaine. 152,534. l i 5 This invention relates to;mechanical-peneA cils, land has 'particular reference to improve- Vments inthe mechanism for holding and operating any of the various marking mate- Y rials used in vsuch pencils. The term lead 1 is used herein for convenience when referring to such marking material orto parts associated with it, but that term is intended to include any of the v arious materials. ofdifi0 ferent colors which areormayxbeused in substantially all of each piece of leadz'inV connection with novel provisions whereby after the last of the lead has been expelled,

a new lead `may be inserted through the writing end of the pencil `and engaged with f a lead carrying mechanism in such away asl to permit moving the lead in or 'out ofthe pencil asand whendesired. In the present embodiment, the lead carrying mechanism comprises two relatively movable parts, one

L59 of whichis a feeding element such as a'rod:

which is actuated in either direction as 'hereinafter described, anda clutch Or'tube for holding the lead. This clutchY or tube ,will

n hereinafter'be referred to as the carrier tubev or, in some instances, as the carrier. The care` f rierandthe feeding rod are so associated that? the carrier will be held stationary in the pen' cil during the latter part ofthe fullV expelling movement of the feed rod to 'eject thelast of the lead from the carrier. The carrier is then held stationary during the forepart of the retracting movement'v of the-feed rod,

thereby clearing the end 'of -the carrier `to- 5 permit the engagement ofthe lead with the carrier. *The construction for effecting these relative-movements of the carrier and the feeding elements is much simpler than any prior construction for laccomplishing' the same or similar results with whichlapplicant isfamiliar; fandcan be produced at arelaj tively low cost.

Anotherv object `ofthe .invention is lto proV vide a new andyhighly satisfactoryf'way'of making an operating'screwj-or helix' for mechanical pencils. 1

The inventionhas vantages which will be apparent fromY this .i

specification and the drawings which accompany and form a' partoffsaid specification. Y

- In said drawings? y i Fig. .1 is a longitudinal section througha Apencil containing one embodiment of the inf vention.

Fig.`2 shows 0n a largerj'scalefdetails'V of Some of the mechanism shown in Fig. 1': v

`Fig showsfrom a differentangle the same mechanism as is shown in Fig-2:- Y

Fig. 4 shows on a largery scale details of the lead Icarrier tube and feed rod. i'

Fig. 5 is the same as Fig. 4,- 'except that the -Y parts` are shown inthe relative positions they assume at the end of the expellingmovement. Fig. 6 shows a/section on the line 6 6 of Fig; 2. f 1 e 'n ig. 7 shows a sectionron line 7-'-7 in Fig. 4.l

yen

Fig.V 8 shows a section'on line 8 8 in Y Fig. A

Figs-9,10 and'rll in detail the fea-V tures of a modified construction;V

Fig. 12 showsdetails of the construction f of the lead carrier and feedingrelement used. vin the modified form shownin'Figs'. 9, 10V

and 11.

Fig. 13 is a section onthe linelS-l of' Fig. 14 is a section on the line 14-1-14 ofk The construction shown in Figs. .1 to 8, inclusive, which' 'is' the preferred construction, comprises va'bdy 11 Voff'any'material suitable for thepurpose. Secured to one end of the body 11 is a sleeve 12. yThe-other end of the body 1.1 of the penciliisv provided with Va shell 13 tapered vor shaped in 'any desired manner to the form shown.

The interior of the body llgof the pencil isv tubular fora part ofits length to accomf modate a t'uhe14 whichffserves as a part'of the driving mechanism, and may also be used as a container for eXtra leads. tached to one end of the tube 14 is an element 15 journaled in the sleeve 12. Y 4A cup-shaped member 16 containing an ,y eraser 17 is frictionally supported in the elevment 15 and engaging' With the exterior of the member isa cap 1S which maybe removed When it isf'desired to have access to the eraser 17 for making erasures or to' permit removal of the member 16 and eraserto give accessto the lead storage chamber in the tube 14. It isapparent from the description just giventhat the tube 14, member 15 and eraser holder 16 may berotated as a unit -bvturning the cap 18 rela-tive to the body 11 of the pencil.

Secured' to one e'nd-of the tube'14` is a split tube21. The tubes 21 and 14 are held against endwise movement in one direction in the pencil b y a Washer 22 ,surrounding the tube l21 'and actingfbetweenthe Vend ofthe tube 14 and a shoulder onV the interior of the pencil. `Endwise movement of the saine parts kin the :other direction is prevented by a Washer 23 and a member having `the appearance of an eyelet which is snugly tted on Vthe tube 21 so as :to hold the Washer 22 in engagement with the end of the body 11 ofthe pencil. UThe Washers 22 and 23 not only prevent the endwise` movementsmentioned.,butthey alsoserve as bearings .lixingtheaXis of .rotation ofthe tubes 14 and V21. i

Slidably mounted in the split tube 21 isV a vlead carrier tube 27 which is vpreferably formed of .thin resilient lmaterial and :has an internal `diameter cor-responding closely to the :diameter of the Ilead 2S. lThe vcarrier tube 27 is preferably cut away to provide an opening through Which projects an operating portion 32 of a lead feed rod 33. The

1 and 2. Not-ches 39 in the portion '.32 l'of the feeding element engage With a helix-41 on the interior of thepenc'il. By rotating the head 18- relative to fthe bodyof .the pencil, the kengagement of :the.1notches 39. With the helix will drive the 'lead feedrrod133 iifn either direction, Yas desired. ATWhen that di-4 rection isthe one which feeds fthe .lead outward of the ipencil, the `head 32 `of the .rod Will cooperate With'the end :40 of a wing 42 formed-on the lead carrier tube27 :at'one sideV of :the slot .in the `tube and ycause the `feed rod 33 and-'carrierrtube 27 to move asa rveaesvff tinued movement of the feed rod 33 will' until the end 401 of the Wing 42 engages-the i cause the head 32 to act against the .tend 40 Y of the Wing, which end is suitably V*formed v.to vact as a cam andl thereby move the Wing 42 aside and bring the end 40 Aof Vthe `ivino" -behind a shoulder 46 formed on the split tube'21 by cutting aWayf the f'split tube as shown at 47. The movementA of the feed Yrod 33 Which'e'ects theoperation of the Wing 42 Vdescribed ivill-alsocause the rod 33 to move relative to thecarrier tube 27 until the end ofthe rod 33-projecfts from the end lof the carrier tube `27 asshoWn in F ig. 5, thereby ejectinglthe last fof the "lead-from the carrier tube 127 to Areceive `the inserted lead. Y

Continued reverse movement Will Withdraw the head 32`from engagement lWiththe Wing 42 and permit the Wing .to .be disengaged from the shoulder 46 on the split tube, after Which the :carrier tube and' feed-rod move as unit during the rest 'ofthe reverse` or reti-acting movement, ,so Aas to draw the lead into the.v pencil. l y y rThe Ihelix l41 is Fmadenof Wire of suitable cross-section,resting'in aV helical groove on the interior :of the pencil. In manufacturing the pencils .a suitable tool is vfirst lrun through the barrel to out the .helical groove and ythe Wire Ylheliai is .then vrun into the g-roove. As a result, a `durable and otherwise fhighly satisfaotery construction is made possible. fact, the construction is as satisfactory for all practical vpurposes ,as Y prior constructions which :cost .a great deal more. to make.v

rlhe Vmodified construction shown iny Figs.f

9 tto 12,'inclusive, is .the same 'as `the preferred InAk construction in most respects, the principal differences .being in `the mechanism for effecting relative.movements of the lead Afeed rodand the ,-leadca-rfrier tube.

lIn-.the `mod-itied qconstnuction, the feed irod 50 has a projection y.5.-1 gengaging between the turns-of the 'helix ,52 and .extend-ing through a slot '53,fin 'the lead carrier tube v54 .and a slotr in `rthe'fsplit tube. It is preferred to have the sides vofthe slot 5 3 in'frictional engagement fWi-th fthe sides -o-f-the projection 51, the purpose of the frictional `engagement being to .afford a .means for yieldingly mai-ntaining .the-lead feed rod and the lead carrier tube indifferent-relative posit-pons. Y mliedseonstructionfthe split 'tube 56 is made of resilient material and is preferclutch'ofthe portion ofther split tube ad'- jacent the writing end of the pencil.V When the pencil is operated to fully expel alead,

Vthe carrier tube will be driven to the position shown in Fig. 11; During its movement to that position, it will expand the clutch'on the split tube, the driving connection for so expanding the clutch being aoided by engagementof theprojection 51 with one end of the slot 53 in the lead carrier tube. The final expelling movement of the parts will cause the feed rod to project through the opening in the writing end of the pencil as indicated in Fig. 11.

A Then the movement of the parts is reversed the clutch just described will hold the lead carrier tube 54 stationary while the connection between the lead feeding'rod and the helix 4l afforded by the projection 51 will causel the rod to be retracted in the carrier tube far enough to permit insertion; of thev lead inthe said tube. Further lretracting movement will cause the projection 5l on Y the rod to engage the closed end of the slot in the carrier tube and rod and the Vcarrier tube will thereafter move as a unit during the rest of the retracting movement and the first part of the expelling movement;

It should, perhaps, be made clear that the clutch on the end of the split tube is so constructed that when it is allowed to close up after the withdrawal therefrom of the lead carrier tube, the interior of the clutch is not brought closely enough into contact with the lead to cause the clutch to pull the lead out` of the carrier tube 54: during the retracting movement of the parts.

While embodiments of the invention have been described in considerable detail herein, Y

it is notthe desire to be limited to such details except in so far as they are included in l element mounted in and having a limited movement relative tothe lead carrier tube, means for driving saidl feeding `element in either direction, and devices including a resilient portion of the carrier tube iiexed byV the final expelling movement of the feeding element for holding the lead carrier tube against movement during the first part of the retracting movement of the feeding element, but ineffective to hold the lead carrier tube against further retractive movement.V

9.. In a mechanical pencil, a pencil body having a ktubular interior provided with a shallow spiral groove, ,a wire helixresting in said groove and having a part of the diameter of the wire projecting into said tubular interior, a lead feedingelement carrying a projection engaging `with saidk ,projecting portion of the helix, and means for effecting a relative rotary movement of the feeding elementand helix to drive the feeding element. Y

3. The method ofmaking'the operating helix for a mechanical pencil whichcomprises cutting a shallow spiral groove on the interior of the barrel ofthe pencil and threading a Wire helix into said groove by a relative f rotation of said barrel and helix. n

4. In a mechanical pencil," a lead carrier tube, a feed rod in and having a limitedsliding movement relative to the carrier tube, means including a head on the feed rod for driving the feed rod in either direction, a

stationary clutch member, an expandible' clutch member carried by theV carrier tube and expanded by the head on the feed rod to engage the stationary clutch member during the iinal lead feeding movement of the rod, said expanded member being held in expanded conditionv during the first part of the retracting movement of the feed rod. Y

5. In a mechanical pencil, a leadcarrier tube, a feed rod mounted. in and havingla ec Y.

limited movement'relative tothe lead carrier tube, means including a helix, a head on the feed rod and a split tube for driving thel feed, rod in either direction, said split tubesignature..

v Y JOSEPH MEILNER.

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