US2492838A - Mechanical pencil of the screw feed type - Google Patents

Description

D- 1949 J. 'r. BRUBAKER ,4

MECHANICAL PENCIL OF THE SCREW FEED TYPE Filed Sept. 21, 1944 V :5 Shets-Sheet 1 INVENTOR, JOHN TEE'UEHKEKI Dec. 27, 1949 3, BAKE 2,492,838

MECHANICAL PENCIL OF THE SCREW FEED TYPE Filed Sept. 21,,1944 3 Sheets-Sheet 2 INVENTOR I 1515 JOH/YTEfl/ZAKEIQ Dec. 27, 1949 J. T. BRUBAKER MECHANICAL PENCIL OF'THE SCREW FEED TYPE Filed Sept. 21, 1944 3 Sheets-Sheet 3 Patented Dec. 27, 1949 MECHANICAL PENCILOF THE SCREW FEED TYPE John T. Brubaker, Luray, Va.

Application September 21, 1944, Serial No. 555,139

18 Claims. (01. 120-18) This invention relates to a mechanical pencil of the screw-feed type.

A prime object is to provide an article of this character having novel means to grip the lead and feed it b rotation of a, tubular propeller through which the lead is fed by the gripping means which engages the lead at one or more slots in the tubular propeller.

A second object is to provide a novel expansible and contractile gripper structure operable to release the lead when necessary for re-filling.

Another object is to provide the pencil with a novel slide having gripper means swiveled thereon and engageable with the lead at one Or more slots in a rotatable propeller tube, and which gripper means is expansible and contractile in combination with camming means to move the same to lead-releasing position.

Still another object is to provide novel nonrotary means to support the lead without contact with the barrel, engageable and disengageable with the lead under control of an independently adjustable lead-feed tube.

A furtherobject is to provide a novel means to hold the lead in projected position against danger of accidental receding.

The more specific objects and advantages will become apparent from a consideration of the description following, taken in connection with the accompanying drawings illustrating operative embodiments by way of example.

In said drawings:

Fig. 1 is a view through one form of the improved pencil taken approximately centrally and longitudinally;

Fig. 2 is a perspective view showing the novel slidable nut and lead-gripper means swiveled thereon; v

Fig. 3 is a cross-section taken on the line 3'-3 of Fig. 1;

Fig. 4 is a central longitudinal sectional view taken through a modified form of the pencil;

Fig. 5 is a horizontal section taken on the line 55 of Fig. 4;

Fig. 6 is a perspective view of the jaw-separating spring employed in the form ofFig. 4;

Fig. '7 is a substantially central longitudinal sectional View through a further modified form of pencil;

Fig. 8 is a cross-sectional view taken. on the line 8--8 of Fig. '7;

Fig. 9 is a fragmentary elevation of the lower portion of the lead propeller used in Fig. 7;

Fig. 10 is a perspective view of that portion of the lead propeller shown in Fig. 9;

Fig. 11 is a perspective view of the lead supporting jaws;

Fig. 12 is a view of another modified form of pencil, being partly in elevation and partly in section taken approximately centrally and longitudinally;

Fig. 13 is a cross-section taken on the line I3-l3 of Fig. 12;

Fig. 14 is a cross-section taken on the line l4l4 of Fig. 12;

Fig. 15 is a fragmentary sectional view of a modified form of lead gripper or feed jaw;

Fig. 16 is a view partly in elevation and partly in approximate longitudinal section through a final modified form of pencil;

Fig. 17 is a longitudinal central sectional view taken at a right-angle to Fig. 16;

Fig. 18 is a cross-section taken on the line |B|8 of Fig. 17; and

Fig. 19 is a cross-section taken on the line l9-l 9 of Fig. 16.

Referring specifically to the drawings wherein the same reference characters designate the same or similar parts through the different views, and first to the form of Figs. 1 to 3, the improved pencil has a barrel or casing at I0, open at the top and at the lower end, preferably having a tapered portion II as shown open at the apex so that the lead or marker I2 may project therethrough.

Detachably screw-threaded in the top of the barrel at 13 is a tubular bearing in the form of a plug M. It will be noted that such plug above the screw-threads l3 engages the inner wall of the barrel along a plain surface l5 of any desired extent. This cap is provided with a resilient clip [6, whereby the pencil may be detachably engaged with a pocket of an article of clothing, or other support.

A lead propeller or feed tube is generally designated l1, and located centrally and longitudinally of the barrel. This feed tube is preferably made in a single piece, and at the upper end has a journal [8 rotatably mounted in the bore of the plug M as a bearing. A knob or any equivalent IQ is threaded or otherwise attached at 20 to the journal l8, and it is adapted to be peripherially manually gripped in order to rotate the feed tube I! in either direction. The feed tube is held against accidental longitudinal displacement relatively to the bearing I l since it has a shoulder 20 engaging the under surface of the latter in opposition to the knob 19, such shoulder being formed at the larger end of a cone 2|.

The lead 12 is fed or supplied to the tube l1 23 has a neck or extension 26, on which a ring 7 2'! is swiveled, and with which. it is interengaged may be in any desired lengths and it is propelled or fed through the bore or central opening of the feed tube IT by successive rotations of the knob IS according to the extent which the lower end of the lead abrades or wears. Through such rotation of the knob [9 in one direction, tube I! will be turned so that its screw-threads 35 through interengagement with those at 35 will move the slide 23 as suggested in the dotted line position of Fig. 1, during which action, the

. lead will be gripped by the jaws 32 since the reat an annular groove 28 in the extension and an...

annular rib 29 on the ring. This ring constitutes part of a gripper generally designated 38, and which is completed by.one or moreresilient arms 3|. Each arm adjacent its" distal end has a lead gripping jaw 32, which optionally may be serrated or roughened as at 33 to increase its degree of engagement withthe lead I2.

Said feed tube I1 has a pair of diametrically opposite longitudinal slots 34 therethrough, although one slot and one arm and jaw 3I-32 will suffice in most instances, in which the jaws 32 are positioned to slide. The feed tube H has external screw-threads at 35 which are engaged by the screw-threads 3B in the bore of the nut or slide 23.

Extensions or fingers 31 rise from the jaws 32 and are engageable with the exterior surface of the cone 2|:and forcedat the upper extreme of movement of the feeding device 38 to release the lead preparatory to its being replenished.

Located within the tapered portion II of the barrel is a pair of holding jaws 38 adapted at their facing surfaces to contact directly the lead I2, as shown in Figs. 1 and 5. The upper or larger ends of jaws 38 are engaged by a disk or plate 39, rigid on or integral with and forming part of the feed tube I'I. These jaws 38 may be independent of the feed tube, but as shown they are preferably interconnected therewith as by means of pins 40, rising one from each jaw, occupying diametrically arranged slots M in the disk 39 and being held against detachment therefrom by heads 42 on the pins 40.

The construction described is such that all parts as a unit are slidably removable from and replaceable into the barrel I0 through the detachment of plug or tube I4 at the screw-threads I3, it being clear that the jaws 38 will be withdrawn with the feed tube H in view of the interconnection therewith at the pins 40, and notwithstanding the presence of the ribs 25, since the slots 4| may be registered therewith and slidably receive the same.

In the use of the pencil, it is to be observed that the jaws 38 project below the portion -II of the barrel so that thelea'd-will be supported by the jaws and cannot contact the barrel which is a cause of frequent fracture of lead in existing constructions. Also the degree of pressure which the jaws 38 have on the lead may be regulated by the longitudinal position of the feed tube II governed by the adjustment or position of the plug I4, which correspondin lv presses the disk 3.! against the upper ends of the jaws or recedes therefrom to enable the jaws'to separateby upward movement-along the'inclined surfaces of the tapered portion 1 I It will be'clear that the parts are so proportioned .as to accommodate lead of various diameters or thicknesses. it being realized that the differences in the diameters usually is in thousandths of an inch.

Further, with respect to operation, the lead I2 silient arms 3I are biased to contract or move toward each other. However, when the lead is worn, and needs replenishing, knob I9 is turned in the retrograde direction to move the feeding device 22 upwardly to the full line position of Fig. 1, during which movement the fingers contact the cam or cone 2| and separate the jaws 22 and thus release the used or short length'of lead. Such separation of the jaws need merely be a matter of a thousandth or a few thousandths of an inch. When the jaws are thus separated, a new length of lead I2 is supplied to the pencil and the knob I9 slightly turned in the opposite direction so that the jaws under their bias will grip the. lead which may thereafter be fed through the operation of the pencil as described.

Referring now to Figs. 4 to 6, wherein a modified form of lead holding jaws is shown, the lead is heldin writing position and against recession therefrom by a plurality of jaws functioning generally likethose at 38 and designated 41. Jaws 41 extend below the barrel as in the first form of the invention for the same purpose, and the surfaces thereof which contact and hold the lead 46 are serrated or otherwise roughened as at 48. The upper outer edges of the jaws 41 are preferably'cut .away at 49 to provide clearance for upward adjustment or variation of the position of jaws 4'I.

When the feed tube recedes, the jaws 41 will separate and move upwardly by reason of their contact with the tapered wall of the lower portion of the barrel and also by reason of the expansive or straightening action of an arcuate spring 54 which is located in a recess 55 of one of the jaws 41, and which spring in its terminals has notches 56' of sufiicient size to enable the lead 46 to be fed without contact with such spring 54. It is to be understood that in all positions of the jaws 41 the serrations 48 will hold the lead against recession or retraction; and it is to be understood that these serrations and/or spring 54 may .be used in the first form as well as all succeeding forms of the invention.

Another modified-form of the invention is disclosed in Figs. 7 to 11. In this form I use a barrel or casing I0 having a lower tapered end portion II.'. At the upper end, a tubular bearing I4 is screw-threaded as at I3 having a resilient attaching clip I6 thereon. A pair of diametrically opposite longitudinal ribs 25' are provided on th interior of the wall of. the barrel I0. 0perable centrally and disposed longitudinally within barrel IIIis a feedingtube structure generally designated 51, preferably in a single piece. This structur includes a tubular journal I8 and the structure 57 has a central longitudinal bore 58, through which the lead I 2' is supplied from above. An operating knob I9 is secured to the upper end of the journal I8 as at 20 in any suitable manner in opposition to a shoulder 20' formed at the upper end-of a conical cam 2|. All parts described with primed numerals coratlases resp'ond in constraction-and operation to the same- Tluineral's unprim'ed as used in the first form.

The feed tube structure throughout most of itslengthhas a helical slot 58, into which proeject one or more gripping-jaws 59, preferably roughened or serrated at their inner ends at 60 for directengagement with the 'lead l2. Jaws 59 arecarried by arms tl mounted in any suitable manner-on'a slide 6i which have peripheral slots 62 interengaged w-ith the ribs '25 so that the slide cannot turn. The slide also has a bore or central opening as so that it may freely Islide 'along-the'tube structured]. Jaws 59have spreading 'fingersii l to co-act withthe cam or cone 29' for the samereaction as is true between the fin- :"gers 37 and-"cam 3| in the first form.

"The knob l 9' may beturned in either-direction to turn the feeding device 51 accordingly and through such turning, the 'interengagement of "the jaws 'orlgrippers'59 with the helical groove 58 'will move the slide Bl longitudinally of the barrel, the .jaws159 functioning like the jaws 32 of the first form, and in'addition functioning as a propelling means in view'of the interengagement of the grippers 59 with the helical groove or slot 58. 2

Movement of the arms St to the upper limit in Fig. 1causesfingerst'l to their contact with the cone 2! to spread and release the lead. In the dotted line position of Fig. 7, the lead will be .gripped by the jaws BB-so as to be fed through rotation of the feed tube 51 and sliding of element 6!.

Tube 51 :and parts connected thereto may be removed and replacedas a unit like the generally corresponding parts in the other forms of the inventionThe tubezstructure 51in this form, however, has a plate or disk 64, at its lower end in contact with the upper surfaces of gripping jaws '-'85'for the lead 12', the disk having slots 66 in its periphery for registry with the ribs to enable removal thereover. The jaws 65 are loose within the tapered portion ll and function generally like those at 38 and 41, being loose and gripping the lead 12 at theirfacing surfaces. Disk 64 has a bifurcated downward extension .forming generally triangular tines 61 which are of less thickness than the lead 12' and which are disposed between the jaws 65. Th rotation of the feed tube-5l since the tines B'lare rigid therewith, will also rotate the jaws 65. The adjustment of feed tube 1'51 at the threads 13 determine the degree of gripping of jaws 65 against the lead, it being clear that opposite movement of the feed tube 51 *will permit expansion of the jaws 65 to accommodate thicker leads or leads of greater diameter.

Aiurther modified form is shown in Figs. 12 to 14-. This form of the invention primarily differs from the first form in that a feeding device .22 generally similar to that employed at 22 is operable in a position inverted with respect thereto, and with arms and jaws biased to ex- .pand rather than to contract. The barrel Hi conforms to that employed at IU, and'the bearing or'head M conforms to that at is, being, if

desired, the same as the latter and in screw-.

threaded attachment and adjustment at lfi with said barrel 19 The attaching clip is designated 16- and the barrel has ribs.25 like those at 25. The lead .feed tube Il is generally like that employed at H, being rotatable at a journal l8 within the head M and rotatabl .in either direction through the manipulation of a knob I9 screw-threaded or otherwise secured thereto.

ISaid knob Lil and a.pin or shoulder 2| attach tubal! to bearing I4 Said feed tube structure l'l has a liiskzat 39 -andall parts carried by the tube are detachable and replaceable-as a'unit as inthe other forms, 'thedisk 39 having slots 68' for registration :with and sliding-over thel'ibs 25 Depending from the disk 39 is a split holder tube :69,' the same having one or more longitudinal slits asshown. 'The'lead feed tube i-l has a central longitudinal bore or opening, through which the lead 10 supplied from the top. The slit or slits at :H Sin tube 69, enable the tube to be contracted about different sizes of lead 10,'accordingto'the.adjustment of jaws i2, and between which a-holdertube "SS-eXtends-and which jaws are engaged at thei-r upper or larger ends by the disk 39 and are housed within a lower conical portion il 'of the 'barrel ll), the holder tube 69 extending below the barrel-so as to support the lead withoutzcontact with the latter. The position of the jaws "l2 isgovernedbytheadjustment of theplug M at'th'escrew-threads 13 Althoughl'ha've shown a different means 'for holding engagement with the lead at the lower end of the pencil, .inithis form, it is to be understood that I may :lnterchangeably use such lead holding means at the lower end as is shown many of the other forms of the invention. "This is true not only .in this modified form, but-in'all otherforms.

Reverting to the leadfeed device22', the-same has a nut-23 in screw-threaded engagementwith the exterior screw-threads of the feed tube slil tit-"35 such nut being slidable butnon-rotatable in view of the interengagement of slot'sizid 'with the ribs 25 Swiveled on an extension 26* of nut 23* in the same manner'as between the nut -23 and'ring 27 in the first :form is a ring 21 from which depend resilient armsS l 'biased to expand or separate at lead-gripping members orjaws 32, which extend through diametrically opposite slots 34 in the feed tube if! to mountislidably but non-rotatably the feed device 22'. When this device 22' is practically in its uppermost position, the jaws t2 expand into an annular groove 13 provided in the inner surface of the barrel Hi. It will be noted that the outer portions of the jaws as at 14 present rounded noses, so that the jaws extend into the groove to release short lengths of lead. The'device 2| ismoved in either direction according to the direction of turning of knob 19 and when the noses 14 move out of the groove 13 they are moved or compressed toward each other by th :wall defining groove 13 which thus functions as a cam. The jaws will thus .feed or move the lead longitudinally of the feeder device l1 according to the operation of the latter. In Fig. 12, the jaws are'shown in. full .linesin the lead-releasing or expanded position, while in dotted linessuch device--22' .is shown in the leadgripping and f eeding'condition.

Referring now to the final modified form of Figs. 16 to 19, itembodies the'same generalprinciples as the preceding forms, but the feeding .movement of the parts is greatly shortened. In

this form, the barrel is shown at I0 and at its lower end has aconical or tapered portion ll while at the upper end it is closed by a bearing member M screw-threaded as at 13* into the casing or barrel l0 A resilient attaching clip -liiextends from the-bearing I4".

Journaledin the bearing HI is a lead feed tube ll having a centrallongitudinal bore ll through which the lead .lz issupplied from above and fed.

Retained in the conical portion li are lead .grippingjaws or segments '38), adapted attheir 'flatsurfaces to engage saidlead 12 .Said jaws at their flat surfaces may be plain, but are preferably serrated or roughened as at 38 in order to hold the lead l2 against retraction or recession into the barrel, but capable of extension slidably through and beyond the jaws 38 as required as the lead wears. It will be noted that such jaws extend outwardly beyond the barrel so as to support the lead directly without contact thereof against the barrel. Such serrations or teeth at 38 preferably provide horizontal shoulders 38 and upwardly and outwardly inclined surfaces 38 connecting them.

Tube W is held in the bearing [4 against longitudinal movement by means of a pin or shoulder 2 l engaging the inner end of the latter, and by means of a knob 20 engaging the outer end of the latter, such knob being screw-threaded to tube H as in the preceding forms or attached in any other desired manner. At the inner end, tube ll has a disk or head 39 engaged with the upper ends of the jaws 38 so as to give the requisite pressure against the latter to clamp the lead l2, according to its size, it being clear that through turning of the bearing M that the feed tube ll will be longitudinally adjusted according to the position desired for said jaws 38 dependent on the size of the lead I2". Disk 39 is provided with radial peripheral slots 4 l to enable the feed tube and all parts carried thereby to be removed and replaced as a unit, such slots 4| enabling passage over relatively short diagrammatically opposite ribs 25 carried on the inner wall of barrel lll Said feed tube ll to a limited extent has screw-threads 35 provided thereon, and on which a nut 23 is screw-threaded at its bore. This nut has slots 24 corresponding to those at 4 l interengaged with the ribs 25 so that the nut cannot turn although it will slide through rotation of feed tube IT A ring 21 is swiveled on an extension or neck 26 in the same manner that the ring 21 is swiveled on the nut 23. This ring 21 has one or more resilient jaws or grippers 3| depending therefrom and extending through the slots 34' provided diametrically in the feed tube ll Such jaws optionally serrated at 33 and are biased or function to grip the lead l2 in order that the lead may be positively fed through the rotation of the knob 20 which will turn the feed tube li and cause sliding of the nut 23, ring 21 and the jaws or grippers. It will also be noted that the lower end walls at the slots 34 are inclined at 3'! so that adjacent the lower extremity of movement of the jaws, they will be automatically separated through the turning of the knob 20 and feed tube to release the lead, although the lead cannot recede due to its engagement by the teeth 38. With the jaws either separated or at their uppermost limit of movement, a new lead may be pushed down the feed tube until it is frictionally gripped by the teeth 38 above the short length of lead remaining between jaws 38 and thereafter jaws 33 may be fed downwardly to correspondingly feed the new lead against said short length of lead through the turning of the knob 29.

It will be noted that in this final form of the invention, successive relatively short feed movements for the lead are provided. Such a construction considerably reduces manufacturing costs.

In all forms of the invention, in lieu of the various jaws or grippers described, such as those at 3|, I may use the modified form disclosed in Fig. 15. In this modified form, each arm isiiesiliefit such as that at 3| which corresponds to that at 31. For instance, this arm may be biased to contract or expand according to the form of the invention in which it is used, and it has a surface at 33 to engage the side of a lead such as l2, which surface may optionally be plain or serrated. This arm 3 I has a lug or flange 15 which will overlap the upper end of the lead in order to provide a shoulder to push against it in addition to the frictional gripping of the side of the lead by the wall 33.

Attention is called to the fact that in all forms of the invention, the various parts are adapted for interchanging or each form is adapted to be modified or re-built embodying the parts and principles of the others. In addition, the parts may be made of any suitable materials, particularly metal, plastics or the like or be composite.

I claim as my invention:

1. A pencil having a barrel, a rotatable lead feed tube disposed within and longitudinally of the barrel, said tube having its bore opening at the top for supply of lead from the exterior of the pencil, a slide within the barrel, coacting means on the slide and the tube to move the slide along the tube through rotation of the latter, means to hold the slide from rotation relatively to the barrel, said tube having a slot, and the lastmentioned means being positioned through the slot for feeding engagement with lead in the barrel.

2. A pencil having a barrel, a rotatable lead feed tube disposed within and longitudinally of the barrel, said tube having its bore opening at the top for supply of lead from the exterior of the pencil, a slide within the barrel, coacting means on the slide and the tube to move the slide along the tube through rotation of the latter, means to hold the slide from rotation relatively to the barrel, said tube having a slot, the lastmentioned means being positioned through the slot for feeding engagement with lead in the barrel, and means against which the last-mentioned means is operable to impart a lead-releasing movement to the latter.

3. A pencil having a barrel, a rotatable lead feed tube disposed within and longitudinally of the barrel, a slide within the barrel, coacting means on the slide and the tube to move the slide along the tube through rotation of the latter, means to hold the slide from rotation relatively to the barrel, said tube having its bore opening at the top for supply of lead from the exterior of the pencil, said tube having a slot, the last-mentioned means being positioned through the slot for feeding engagement with lead in the barrel, a cam surface on one of the parts, and the last-mentioned means being movable against the cam means to impart a lead-releasing movement thereto.

4. A pencil having a barrel, a, rotatable lead feed tube disposed within and longitudinally of the barrel, a slide within the barrel, coacting means on the slide and the tube to move the slide along the tube through rotation of the latter, means to hold the slide from rotation relatively to the barrel, said tube having a slot, the lastmentioned means being positioned through the slot for feeding engagement with lead inthe barrel, a bearing in the barrel journaling and carrying said tube, jaw means to grip the lead at L menses 5. .A pencil having a barrel, :a rotatable lead feed tube disposed within and longitudinally of the barrel, a .slide within said barrel having a lead gripping jaw thereon, means to :hold the slide from rotation relatively to the barrel, said feed tubehaving 'a helical slot;said jaw extending into the slot and being positioned to function dually to :grip and'feedlead passing therethrough and to follow the helical slot.

6. A pencil having a barrel, .arotatable lead feed tube disposed within and longitudinally of the barrel, .a slide within said barrel having a lead gripping jaw thereon, means to hold the slide from rotation relatively to'the barrel, said 'feed tube having ahelical slot, said jaw extending into the slot and being positioned to function dually to grip and feed lead passing therethrough and to follow the helical -s1ot,'a cam pn'said feed tube, and said jaw being movable against said cam for lead releasing movement.

7. Apencil having a barrel member, a rotatable lead feed tube member disposed within and longitudinally thereof, a slide within the barrel member, coacting means between the slide and the tube member to move the slide along the tube member through the rotation of the latter, means to hold the slide from rotation relatively to the barrel, said tube member being slotted, means on the slide to grip and release lead for feeding movements, a cam on said feed tube, and said second-mentioned means being biased to move to lead-releasing position when engaging said cam.

8. A pencil having a barrel member, a' lead 'feed tube disposed within and longitudinally "thereof, a slide within the barrel means to hold the slide against rotation with respect thereto, a jaw on said slide, said tube having a helical slot therethrough, and said jaw extending through said slot functioning dually to grip and feed lead and to follow said slot to "impart feeding movement to the lead.

9. A pencil having a barrel member, a rotatable lead feed tube member disposed within and long'itudinally thereof, a slide within the barrel member means to hold the slide against rotation relatively the barrel member, a swivel attached to said slide. inter-engaging screw-threads on the tube member and slide said tube member having a slot. and a jaw member on the swivel extending into the slot and engageable with lead therein to feed the same.

10. A pencil having a barrel member, a rotatable lead feed tube member disposed within and longitudinally thereof, a slide within the barrel member means to hold the slide against rotation relatively the barrel member, a swivel attached to said slide, inter-engaging screw-threads on the tube member and slide said tube member having a slot, a jaw member on the swivel extending into the slot and engageable with lead therein to feed the same, jaw means at the writing end of the barrel having camming engagement with the latter for movement into contact with lead, and means to adjust the position of the tube mem} ber relatively to the jaw means to control the position of the latter and its degree of gripping engagement with lead.

11. A pencil having a barrel member, a rotatable lead feed tube member disposed within and longitudinally thereof, a slide within the barrel member means to hold the slide against rotation relatively thereto, a swivel attached to said slide, inter-engaging screw-threads on the tube member and slide, said tube member having a slot, 2.

did

jaw memberro'n the swivel extending into the slot and engageable with lead "therein to feed the same, jaw means atthe writing and of the barrel having camming engagement with the latter for movement into contact with lead, means to adjust the position vof the tube member relatively to the jaw means to control the position =of the latteland its degree "of gripping engagement with lead,and means interconnecting the tube member and jaw means FfOl' movement of the latter nnitarily with the tube member and for spreading movement.

12. Aipencil having :a barrel member, a-rotatablelead feed tube member disposed within and longitudinally thereof, a slide within the barrel member means to hold the slide against rotation relatively the "barrel member, a swivel attached tosa'id slide, inter-engaging screw-threa'ds- 'on the tube member and slide said tube member having a slot, a jaw member .on the swivel extending into the slotand engageablewith lead therein to "feed the same, said jaw member being resilient, a cam on the-tube memberfand -means on the jaw member engageablewith the cam adjacent one extremity of movement of the swivel to move the jaw member to lead releasing position.

18. A pencil-having a barrel, a rotatable lead feed tube disposed within and longitudinally thereof, a bearing screw-threaded in the upper end of the barrel "foradjustment, said'tube being journalled in said bearing, and extending exteriorly thereof so that it may be gripped for manual operation, said barrel having an internal longitudinallyextending spline, a nut in screw-threaded "engagement with 'the tube having a slot 'interengagedwiththe spline, a ringhaving a flange attaching and swiveling it on the nut, a pair of opposed lead gripping jaws extending from the ring, said tube having oppositely aligned slots, said jaws extending into :said slots for gripping engagement with lead therein.

14. A pencil having a barrel, a rotatable lead feed tube disposed within and longitudinally thereof, a bearing screw-threaded in the upper end of the barrel for adjustment, said tube being journalled in said bearing, and extending exteriorly thereof so that it may be gripped for manual operation, said barrel having an internal longitudinally extending spline, a nut in screwthreaded engagement with the tube having a slot interengaged with the spline, a ring having a flange attaching and swiveling it on the nut, a pair of opposed lead gripping jaws extending from the ring, said tube having oppositely aligned slots, said jaws extending into said slots for gripping engagement with lead therein, a disk at the lower end of said tube, lead gripping jaws at the writing end of the barrel engaging the latter along upwardly inclined surfaces, said disk having inwardly extending slots, the last-mentioned jaws having studs retained by the disk and slidably movable in said slots, one of said slots also functioning to clear said spline to enable removal of all parts with the tube as a unit.

to hold said slide against rotation relatively to the barrel, jaws extending from the slide having portions entering said slot functioning dually to follow the same to cause the nut to slide and to grip the lead between them, said jaws being resilient and adapted to contact said cam adjacent one extremity of movement to separate the jaws to release the lead.

16. A pencil having a barrel, a bearing adjustably screw-threaded in the upper end thereof, a

lead feed tube rotatably mounted in said bearing and disposed within and longitudinally of the barrel, an operating element on the tube engaging the outer end of the bearing, said tube having a cam provided with a shoulder engaging the inner end of the bearing, said tube having a helical slot therethrough, a slide surrounding the tube. means to hold said slide against rotation relatively to the barrel, jaws extending from the slide having portions entering said slot functioning dually to follow the same to cause the nut to slide and to grip the lead between them, said jaws being resilient and adapted to contact said cam adjacent one extremity of movement to separate the jaws to release the lead, a disk at the lower end of the tube, jaws to grip the lead at the lower end of the tube disposed within the latter and engaging the same along inclined surfaces, said jaws being engageable at their upper ends by said disk, and said tube having a bifurcated downward extension disposed between the 12 of the barrel having a concavity, and said jaw being resilient and normally tending to move into said concavity in lead-releasing position.

18. A pencil having a barrel, a lead feed tube rotatable therein and disposed longitudinally thereof, a nut threaded on said tube, means holding said nut against rotation relatively to the barrel, a swivel attached to said nut having a jaw, said tube having a longitudinally extending slot through which a portion of the jaw projects for feeding contact with lead therein, the inner wall of the barrel having a concavity, and said jaw being resilient and normally tending to move into said cavity in lead-releasing position, said tube having an extension at the writing end of the pencil through which the lead extends, said extension being split, and means engagin the extension and barrel under control of the tube to regulate the contraction of the extension with respect to the lead therein.

JOHN T. BRUBAKER.

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

UNITED STATES PATENTS Number Name Date 271,926 Schrag Feb. 6, 1883 845,422 Schmitz Jan. 4, 1910 1,552,638 Nelson Sept. 8, 1925 1,575,195 Fleming Mar. 2, 1926 1,621,990 Lippert et a1 Mar. 22, 1927 1,908,491 Steiger May 9, 1933 1,967,484 Stenerson July 24, 1934 FOREIGN PATENTS Number Country Date 3,061 Great Britain July 13, 1881

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