US1655417A - Lead pencil - Google Patents

Description

w. F. HAACK LEAD PENCIL Filed Feb, 25, 1924 INVENTOR WM fflmaq BY 2 fiRNEY 2n my foresaid patent is in'the main satisworking chamber;

' 4 of the plunger and serving to prevent any new lead;

QPatented Jan. 10,1928.-

' 1,655,417 UNITED STATES PATENT OFFICE.

WILLIAM I. HAACK, OF OAK PARK, ILLINOIS.

LEAD PENCIL.

Application filed February 23, 1924. semi No. 694,550.

This invention relates to lead pencils of lower nd of th n w l d, Still an th r the magazine type, which contain a cenobject is to provide a lead gripping device tral chamber in which the working lead is on the lower end of the plunger, by which held and through which it is advanced by a partly used lead may be retracted, rea a plunger or pusher as the point of the lead leased, and returned to the magazine, and wears away. another lead of a different color or quality A magazine lead pencil of the type above substituted therefor. outlined is disclosed in Letters Patent N0. Other bjects and attendant advantages 1,469,786, granted to me October 9, 1923. of the invention will be apparent to per- In the aforesaid Letters Patent the working sons kill d i thi t f th f ll i lead is guarded at its upper or inner end description, taken in connection with the against lateral displacement from the lower accompanying drawi g i whi h I have end otthe plunger by means of a laterally illustrated a ractical and preferred emofiset depending finger or nib on the lower bodiment of t e invention, and wherein 15 end of the plunger which overlies one side Fig. 1 is an elevation, partly in axial Secof the upper end portion ot the lead and tion, of my improved magazine lead encil, travels in the longitudinal entrance channel showing the plunger in a position W erein to the working chamber through which the the lead-guiding and centering sleeve on lead is introduced. While this feature of its lower end has struck the bottom of the :5

" factory, yet I have found that occasionally, Fig. 2 is a similar view of the lower porand especially where the upper end of the tion of Fig. 1, showing a further advanced lead isnot perfectly square, the lower end position of the plunger wherein its lower of the plunger will sometimes get out of end has projected through and beyond the so 2- register with the lead, crowding down one lower end of the lead-guiding and centerside of the latter, and thus failing to prop ingsleeve; e p I erly perform its function of advancing the Fig. 3 is a view similar to Fig. 4, showing lead through the point or tip ,of the 811611. the plunger and lead-guiding and centerga if the plunger is retracted efoie ing sleeve partially retracted but in the same the, working lead is sufiiciently advanced in relative positions to a h th as i Fi 2;

' the point, the upper end of the lead may Fig. 4 isa view similar to Figs. 2 and 3, swing sidewise out of register with the lower SllOWlIlgtl'lG plunger fully retracted and its end of the plunger. lower end relocked to the lead-guiding and ,The main object of the present inventlon. centering sleeve, and also showing a new 3 which is in the nature of an improvement lead entering the working chamber; i upon the lead-advancing means of my afore- Fig. 5 is a view similar to Figs. 2, 3 and Said P is t0 provide a centering and 4, showin' the new leadfully seated in the positive holding device for the upper end workingc amber and the plunger and sleeveoftheworking lead carried on the lower end fully engaged with the upper end of the possibility of thelead at any time getting Fig. 6 is a detail elevation, broken out "out or register with the plunger Another betw it d f th l objector the invention is to provide a lead- .Fig. 7 is a fragmentar detail "pf the guiding and centering device of the charlower end portion ofthe p unger as viewed 10 45 -cte r above-mentioned that shall" be y'ieldfrom the left, of Fig. 6; v ably attached to the lower 'end of t e Fig: 8 is a side elevation ofthe lead-guid plunger, so that, when said" guiding and mg and centering sleeve; centering device strikes. the bottom of the F1g. l9 is an edg'qelevation of thedeallworking chamber, the lower end of the gnidm and"cent er1ng. sleeve as viewed so lunger may follow through the same and e on t e left of Fig. 8;' continue to feed the fragment of the'lead F g.10' is a top p an v1ew.of F1g 8 "through the tip of the pencil and thereby Fig. 11"is an enlarged cross-section on create in the lower end of the working the line 11-11 of Fig. 5; chamber a well or pocket which, when a Fig. 12 is an 'ged cross-section-on'the new lead is introduced intothe working hne 1212 of Fig. 5; and i chamber, serves to accurately center the Fig. 13 is a cross-section through the.

' shell and magazine on the line 13-13 of Fig. 1.

Referring to the drawing, 15 designates the cylindrical body or shell of the pencil, which is made of any suitable diaphanous .or translucent material which will render \Vithin approximately the upper half of the the interior parts visible through the'same.

shell 15 is mounted a stationary compartmental magazine 16, which may be conveniently formed by sheet-metal bent into the corrugated cylindrical form illustrated in Fig. 13, each of the longitudinal corrugations constituting a chamber to hold a reserve lead L. The magazine 16 fits the shell 15 sufliciently tightly to be held stationary relatively thereto, and at its lower end the magazine registers with the upper squared end of the shank or stem portion 17: of'a tapered tip or point member 17 The shank 17 is turned down relatively to the 'diameter of the upper end of the tip 17, thereby forming an annular shoulder 18 against which the lower end of the translucent shell 15 abuts so as to form a flush joint with the'external surface of the tip.

As best she a in Figs. 11 and 12, the

shank 17' and major portion of the tip17 are formed with a central circular working chamber 19 and a radial slot 20' leads into said working chamber through the circumference of the shank. The lower portion of the tip is formed with a central axial bore 21 of reduced diameter relatively to' the working chamber 19 and of such a sizeas to fit the leads with suflicient freedom to permit the leads to be pushed therethrough by the plunger, but with suflicient snugness and friction to hold the leads steady when the pencil is in use and against falling out. This construction provides an annular lower .end wall '19 for the working chamber 19.

' end of the shell 15. This plug 25 has a circular flange 26 that abuts against the upper end of the shell and italso carries a cup 27 constituting a holder for an eraser 28.

Snugly fitting the reduced upper end of the shell 15 is a sleeve 29 formed with an inter-- nal flange or lip 30 that overhangs the flange 26 and locks the plug 25 in place. Covering the cup 27 and eraser 28 is a cap 31 that. has

a' tongue and groove engagement 32 with the cup 27, so that, by turning the cap 31 the spiral tube 24 is rota-t ed to. advance or retract'the plunger rod. To use the eraser, the'cap 31 alone is removed. To reload the magazine, the cap 31 and sleeve 29 are-firstremoved, whereupon 'the' plug 25 can be lifted out, without the necessity of withdrawing the spiral tube 24. The lower end of'the spiral tube 24 forms an annular upper end wall 19 forlhe working chamber 19.

Describing now those features wherein my present improvement mainly resides, the plunger rod 22 is formed a slight distance above its lower end with an integral'thiu fiat web-like portion 33 that is extended laterally beyond one side of the rod to form a lug 34 ,(Figs: 6, 7 and 11). The web 33 and lug 3 1 may be formed by mashing the rod, which'also forms upper and lower cam inclines 35 and 36 at the junctions of the web with sections of the rod above and below the web. Encircling the lower end of the plunger rod is a spring metal sleeve shown in isolated detail in Figs. 8, 9 and 10, and comprising a pair of opposed approximately semi-circular sleeve sections 37, two opposed edges of which arespaced by a slot 38, while the. other opposed edges are integrally joined by a U-shaped spring connector or rib 39, which, as shown in Fig. 11, lies in the groove 20 and itself receives the lug 34 on the plunger rod, 'whereby the latter and the sleeve are locked against rotation as they are fed up and down. The opposed sections 37 embrace and somewhat loosely fit the lower end portion of the plunger rod, normally extending some dis.- tance below the latter; and to yieldably lock this sleeve member to the plunger rod, the

sections 37 thereof are formed with a pair of opposedindentations or internal locking lugs 40 that are normally engaged on opposite sides of the reduced portion or web 33 of the plunger rod. T.his lead-guiding and centering sleeve, when thus yieldably locked on the plunger rod, as shown in the sectional view' Fig. 11, projects for'about half its length below the lower end of the plunger rod; and this projecting portion of the sleeve, after a lead has been entered into the working chamber, telescopes over and lightly grips the upper end of the lead, as

clearly'shown in Fig. 5, and thus prevents the lead and plunger from getting out of register through lateral displacement. of the lead out of the path of the plunger,- and likewise makes impossible the jamming of the lower end of the plunger down past one "side of the lead which, as hereinabove stated, sometimes occurs when the upper end of the lead and the lower end of the plunger are not perfectly flat or square.

In the practical use of the pencil, themagazines having been loaded, the first lead is introduced to theworking chamber bv turning the tip 17 and its shank 17' rela i tively to the shell to bring the upper 'end of the slot 20 into register with one of the lead compartments of the magazine, whereupon the lead in the said compartment drops into the slot 20. The pencil is then tipped to horizontal or approximately horizontal position with the slot 220 uppermost. This causes the lead to drop from the slot into the working chamber 19. By then returning the pencil to vertical position, with its tip end down, the lower end of-the lead enters the bore 21 of the tip and is centered thereby. The cap 31 is then turned, thereby feeding the plunger rod downwardly until the lower portion of the lead-guiding and ,centering sleeve telescopes over and grips the upper end of the lead, as'seen in Fig. 5. Thereupon the feed movement is continued until the point of the lead projects below the point of the pencil, whereupon the latter is primed and ready for use. As the point wears away through use, the lead is advanced from time to time by turning the cap 31.. \Vhen the lead and plunger have advanced to the point illustrated in Fig. 1, wherein the guiding and centering sleeve has struck the lower end wall 19 of the working chamber, the plunger is still further advanced, and the portion of the plunger above the web 33 is thereby forced between the locking lugs 40, which expands the sleeve; but the latter still engages the rod through the friction of the lugs on the sides of the rod as the latter is retracted to open the working chamber for the admission of the next lead, as shown in Fig. 3. As soon as the up er end of the sleeve strikes the lower end of the spiral 24, which forms the upper wall 19 of the working. chamber, a slight further retraction of the' plunger causes the locking lugs 40 to slide,

down the cams 35 and re-engage with the opposite sides of the web 33, thereby reestablishing the yieldably locked engagement of the sleeve with the plunger. -The next lead may then be introduced in the manner already described, and so on until the magazine is empty. i

A noteworthy advantage which my improved magazine pencil possesses resides in its adaptability for the selective use at any time of leads of different colors or degrees of hardness. \Vhenever it is desired to change from one lead to another, this may quickly be done byret'racting the plunger and lead until the upper end of the yieldable sleeve strikes the lower end of the spiral tube 24, whereupon a slight further backward movement of the plunger will cause the lower cams 36 t0 expand the sleeve sufiiciently to let the lead dr'op away from the sleeve. The released leadfmay be returned first to the slot 20 by holding the pencil horizontal and then to an empty magazine compartment by tipping the pencil up side down. By then turning the slot 20 into i register with the compartment of the lead desired to be used, the new lead is introduced to the working chamber in the manner already described; and, on advancing the plunger, the locking lugs 4.0 first slide down the cams 36 into re-engagement with the web 33 under the transverse spring of the sleeve, whereupon the latter telescopes over and grips the new lead. It will thus be seen that when any lead has once been introduced to working position in the pencil, it does not have to be used up or discarded before another lead can be employed, but may be returned to its compartment for subsequent reuse, 'and'any other lead in the magazine substituted therefor. v

I claim: v

1. In a lead pencil, the combination of a shell, a-tip member fitted into one end of said shell and formed with a working cham her having annular end walls, a plunger rod,

a transversely elastic sleeve embracing the advance end of said plunger rod and having a portion thereof normally PIOJOUtlIlg beyond said plunger rod to telescope over and grip the rear end of a lead in said working chamber, and means yieldably connecting said sleeve to said plunger rod for simultaneous endwise movement of said sleeve and rod, said means permitting said rodto move endwise relatively to said sleeve and expand the latter when the ends of said sleeve contact with the end walls of said working chamber.

-2.In a lead pencil, the combination of a shell, a tip member fitted into one end of said shell and formed with a working chamber coaxial with said shell and having a lower annular end wall, a plunger rod, av longitudinally' split elastic sleeve embracing the advance end of said plunger rod and having a portion thereof normally projecting beyond said plunger rod to telescope over and grip the rear end of alead in said working chamber, and cooperating devices on said sleeve and plunger rod yieldably connecting said sleeve and-rod to each other under the spring action of said elastic sleeve, said cooperating devices permitting said rod to move through said sleeve and simultaneously expand the latter when the lower end of said sleeve contacts with the said lower end wall of said working chamber.

3. In a lead pencil, the combination of a shell, a tip member fitted into one end of said shell and formed with a working chamber coaxial with said shell and having annular end walls, a plunger rod formed with-a narrowed web portion rearwardly of its advance end, and a transversely elastic sleeve embracin and projecting beyond the advance on of said rod and formed with a pair of internal p'rotuberanees engaged with said narrowed web portion of the rod, whereby said rod is yieldably connected to said sleeve undert-he spring action of the latter with capacity of endwise movement relatively to said sleeve when the travel of said sleeve is arrested by either end wall of said working chamber.

4. In a" lead pencil, the combination of a shell, a tip'member fitted into one end of said shell and formed with a working chamber having annular end walls and a radial slot, at plunger rod, a transversely elastic sleeve embracing the advance end of said plunger rod and having a portion'thereof 'and expand the latter when the ends of said sleeve contact with the end walls of said working chamber.

5. In a lead pencil, the combination of a shell, a tip member fitted into one end of said shell formed with a Working chamber coaxial with said shell, a plunger rod for forcing the lead endwise through said working chamber, a spiral on the outer end of said plunger rod, a rotatable spiral tube in said shell engaged with the spiral of said rod to advance and retract the latter, said spiral tube formed with a transversely polygonal outer end, a plug removably fit-tin the outer end of said shell and formed with a circular flange andwitha socket fittin the polygonal end of said spiral tube, a s eeve embracing said shell and formed with an inturned flange overlying said circular flange for locking said plug in place, and a removable cap keyed to said plug for turning the latter and said spiral tube.

' WILLIAM F. HAACK.

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