US1932371A - Mechanical pencil - Google Patents

Description

. c. R. KEERAN MECHANICAL PENCIL Filed Feb.A 14, 1931 Oct. 24, 1933.

Patented Oct.i24, 1933 UNTED STATES PATENT OFFICE 1,932,371 MECHANICAL PENCIL Ware Appiication February 14, 1931.' serial No'. 515,684

11 Claims.

This invention relates to mechanical pencils of the type in which thelead is both propelled and withdrawn positively by operation of the mechanism, and which includes a magazine for spare leads and a holder in which an eraser is removably carried. The invention consists in certain improvements in the mechanism and in the means for mounting it in the barrel of the pencil designed to facilitate assembly and disassembly, so that minor repairs can be readily made by the user or by the dealer without the necessity of shipping the device back to the factory. The invention therefore comprises certain features and elements of construction herein shown and described, as indicated by the appended claims.

In the` drawing:

Figure 1 is an axial section on a scale somewhat larger than the actual size of the article, and showing the pencil equipped with a mechanism embodying this invention.

Figure 2 is an axial section on a still larger scale, showing the lower end portion of the pencil and the lead-propelling mechanism therein.

Figure 3 is a sectional View similar to Figurer 2, showing the propelling mechanism in position after ejecting a lead.

Figure v4 is a transverse section taken as indicated at vline 4-4 on Figure 2.

Figure 5 is a side elevation Apartly in section of the guide tube for the lead-propelling plunger with the spare lead chamber and eraser socket which are associated therewith.

l Figure 6 is a detail view of the lead-propelling carrier and plunger. f

l While the mechanism herein illustrated and its manner of operation are familiar in a general way, the particular arrangement of theY parts and their assembly in the pencil barrel has been worked out to insure satisfactory operation, but particularly to simplify repairs or adjustments which may occasionally be required and to provide for taking upwear in the working parts'. As illustrated, the pencil barrel, 1 is formed with a bore at 2, in which the spirally slotted tube, 3, is accommodated. The lower end of this tube, 3, is tightly secured in a "sleeve, 4, which itself is forced into an enlarged bore, 5, of the barrel adjoining the bore, 2, This anchors the spiral tube, 3, in the barrel as a permanent fixture therein. Journaled Within the tube, 3, for rotation about its axis is the slotted tube, 6, which is permanently anchored in the lower end of a cylindrical chamber, '7, serving as a spare lead magazine, as indicated in Figure 1, and the upper end of said chamber, 7, is surmounted by an enlarged cylindrical (Cl. 1Z0-18) portion, 8, which functions as a socket to receive the metallic holder, 9, in which'the removable eraser, l0, is carried. The cylindrical parts, 7 and 8, may be made integral by a familiar drawing process, such as is employed in the manufacture of cartridge shells, and the slotted tube, 6, may be attached to the part, '7, in any suitable manner,

as by flaring and swedging over its extreme end in the form of a flange, 6a, opposing the slight shoulder, 6b, which abuts the outer or lower side 65 of the bottom wall of the cylinder, 7 Since the tube, 6, is hollow, a disk, 1l, will be inserted to form a closed bottom Wall for the magazine chamber, 7.

At the opposite or lower end the slotted tube, 6, is threaded to receive a retaining nut, 12. The iixed sleeve, 4, provides at its outer end a shoulder, 14, which serves as a stop for the nut, 12, and preferably a washer, 13, is interposed between the nut and said shoulder to facilitate rotation of the tube, 6. At'the upperr end of the barrel a metallic bushing, 15, is inserted yinto a counterbore, 16, with its iiange, 15a, engaging the upper end of the barrel, l. This bushing serves as a journal bearing for the tubular part, 7, while its flange, 15a, 80 provides a stop shoulder for engaging the transversev wall, 8a, oi the eraser socket, 8. Thus, by proper adjustment of the nut, 12, the rotative member, consisting of parts, 6, 7 and 8, maybe secured in the barrel, 1, with the stop shoulders accurately related to permit relative rotation oi the parts without appreciable end play. Preferably, the nut, 12, and the end of the tube, 6, are formed with a tapered thread somewhat similar to a pipe thread, so that the nut will hold tightly without any tendency to back olf, but may be threaded somewhat farther onto the sleeve, 6, for taking up wear if required.

The'lead, indicated at 17, is held in a familiar manner by the frictional grip of a hollow plunger, 18, whose end is slightly flared at 18a by reaming to facilitate insertion of the blunt end of the lead therein. At its opposite end the plunger, 18, is formed with a laterally projecting lug, 19, which extends through the slot, 20, of the tube, 6, and into the spiral slot, 21, of the tube, 3. Thus, when the tube, 6, is rotated, the lug, 19, is forced to traverse the spiral slot, 21, causing the plunger, 18, to slide longitudinally within the tube,

6, and move the lead through the tip, 22. The frictional grip of the hollow plunger, 18, upon the end of the lead, 1'7, permits the plunger to withdraw the lead within the barrel as well as to propel it outwardly through the tip, 22, depending on the direction of rotation of the tube, 6.

However, the propulsion of the lead outwardly is assisted by the presence of a solid plunger, 23, within the hollow plunger, 18, and provided with a lug, 24, which. also engages the spiral slot, 21, of the tube, 3. The lugs, 19 and 2li, are longitudinally spaced apart, and as shown, this spacing is such that they engage consecutive turns of the slot, 2l. When the lead is so nearly used up that only a short piece remains in the tip, 22, and plunger, 18, the plunger will have traveled its full range into the bore, 25, adjacent the shoulder, 26, of the tip, 22, and at this position the lug, 19, will be rested against the innei` shoulder, de, of the sleeve, e. Further rotation oi the sleeve, 6, is permitted by the terminal portion, 21a, of the slot, 21, which is formed at right angles to the axis instead o obliquely, like the helical portion, and while the lug, 19, is swinging through a partial turn through this terminal portieri, 21a, the lug, 24, continues to traverse the adjacent spiral portion, thus moving the plunger, 23, downwardly within the hollow plunger, 18, and ejecting the fragment or lead, 17a, therefrom, as indicated in Figure 3.

As shown in Figure 1, the pencil may be provided with a pocket clip, 30, which is in general of the usual design, having a ball end, 3l, formed on its spring tang which extends along the barrel,

, l, near its Lipper end. The tang is oiset at 32 to pass through an aperture, preferably in the form of a slot, 1a, in the barrel, and within the barrel a terminal portion, 33, extends against the wall of the counterbore, 16. For locking the clip in this position the bushing, 15, is reduced at its inner end at 15b, forming an annular groove in which the eXtreme end of the terminal, 33, is engaged. This groove having a depth substantially equal to the thickness of the stock at 33, holds g the clip firmly, because its transverse portion, 32,

drawing the bushing, 15, so as to release the part, 33.

In fact, the removal of any part of the mechanism except the spirally slotted tube, 3, is readily accomplishedby unscrewing the nut, 12, which releases the rotative element comprising the tubular parts, 6, 'l and B. Since the slot, 20, extends through the threaded end of the tube, 6, this rotative element may be withdrawn upwardly 'through the barrel as soon as the nut, 12, and washer, 13, Vare taken ofi. If these parts are rst turned counter-clock-wise far enough to feed the plungers, 18 and 23, to the upper end of the spiral tube, 3, the latter will drop out of the barrel readily, or may even remain frictionally engaged with the tube, 6; otherwise, the removal of the tube, 6, will permit the plunger lugs, 19 and 2li, to be disengaged from the slot, 21, by reason of the extra clearance afforded in the tube, 3, and these small parts can be easily shaken out of the barrel. l

The tip, 22, is shown screwed onto the threaded end oi the sleeve or bushing, 4., at 22a, and thus forms a removable housing for the nut, l2, serving to prevent any disturbance rofthe adjustment of the nut when the parts are assembled. It is well understood that when the barrel, 1, is made of ceiluloid or like material it is sometimes subject to a gradual shrinkage, ltending to shorten its length; in this event the` threaded engagement of the tip, 22a, will .permit it always to be screwed tightly against the lower end of the barshr -i away from the ages.

vI claim:

1. 1n a pencil comprising a tubular barrel and a tip thereon, a lead-propelling mechanism, means located near the tip securing said mechanism within the barrel and -nea-ns securing the tip to the barrel independent oithe means securing the propelling mechan sm.

2. in a pencil comprising a tubular barrel and `a lead-operating mechanism functioning therein,

means for loclting said mechanism in said barrel, a tip detachably secured to the barrel independently of said mechanism locking means, said locking means being accessible upon detachment of the tip and operable at will for release removal of the lead-operating mechanism.

3. In a mechanical pencil comprising a tubular barrel and a lead-operating mechanismv functioning therein, a removable tip for the writing end ci the pencil and a nut housed in said tip securing said mechanism in said barrel.

4. In a mechanical pencil comprising a barrel and a lead-feeding mechanism functioning therein, and means for locking said mechanism in operative position in said barrel, said locking means having a bore to permit the lead to be fed therethrough.

5. in a mechanical pencil comprising a tubular barrel, a lead-operating mechanism functioning therein, a tubular lead magazine forming the upper part of said operating mechanism, said magazine being enlarged at its outer end to form a head for the pencil and serve as an eraser seat or socket, said magazine and head being formed of a single piece of tubing but or" diierent diameters respectively. y

roo

6. In a mechanical pencil comprising a tubular barrel and a lead-feeding mechanism therein,` a

bushing inserted inthe writing end of the barrel, having means for arresting the feeding movement of the mechanism, and means for attaching a tip member to said bushing.

7. 1n a mechanicalpencil comprisinga tubular 1 barrel and a lead-feeding mechanism therein, a bushing secured in the writing end of said barrel having an internal shoulder which serves as a stop for the lead-feeding movement of the mechf anism, the bushing itself providing abearing for centering the rotating part of the nieclflanisrnl in the barrel, and said bushing including an eXtension beyond thev barrel formed to receive a detachable tip for the pencil.

8. In a mechanical pencil comprising a tubular barrel, a lead-feeding mechanism including a longitudinally slotted tube, a lead vholder yand a leadY expeller functioning therein, a bushing fixed in the writing end of the barrel, said mechanism;` also including a shoulderedpart stopped against bushing disposed at the writing end and the lead tube extending through said bushing, together with a washer on the tube between the bushing and the nut, and means on the mechanism engaging the barrel to check the mechanism and said lead tube against movement toward the writing end of the pencil while permitting rotation of the mechanism about its axis in the barrel.

10. In a mechanical pencil comprising a barrel with a lead-operating mechanism therein which includes a lead tube extending beyond one end of the barrel, and a head protruding from the op-V the barrel at its upper end, a threaded -bushing tted tightly in the bore of the barrel at the lower end with its threaded portion protruding therefrom, a lead-operating mechanism extending throughout the barrel and provided with a head having a transverse shoulder abutting the flange of the bushing at the upper end, said mechanism including a part which protrudes from the bushing at the lower end of the barrel, said protruding part being threaded, and a stop nut adjustably screwed thereon, together with a hollow tip forming an extension of the barrel and threaded for securement on the threaded protruding portion of the bushing at the lower end of said barrel, whereby said tip is removable to afford access to the nut for dismantling the mechanism or adjusting it to take up wear or compensate for shrinkage of the barrel.

CHARLES R. KEERAN.

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