US2203093A - Mechanical pencil - Google Patents

Description

D. KAHN MECHANICAL PENCIL Filed Nov. 1, 1937 2 Sheets-Sheet 1 June 4, 1940.

June 4, 1940. D. KAHN MECHANICAL PENCIL Filed Nov. l, 1937 2 Sheets-Sheet 2 Patented June 4, 1940 PATENT OFFICE MECHANICAL PENCIL David Kahn,

Kahn, Inc.,

Woodcliif, N. 'J., assignor to David North Bergen Township, Hudson County, New Jersey, a corporation of New Jersey Application November 1, 1937, Serial No. 172,245

'7 Claims.

This invention relates to mechanical pencils of the type wherein a movable lead is employed, the lead being actuated by a spiral member for projection, retraction and expulsion.

More particularly, the present invention relates to a'pencil of the type disclosed in my prior application for patent on a Mechanical pencil, filed July 2, 1934, and bearing Serial No. 733,524. This application is a continuation in part of said prior application.

It is essential in devices of this character that, for quiet and efficient operation, the spiral actuating tube be freely revoluble with respect to the runner tube. In order that this may take place the actuating tube must be supported at its ends in such manner as to have a minimum of friction against the supporting surfaces.

To this end one important object of the invention is to provide, at the ends of the actuating tube, anti-friction Washers against which such ends bear.

A second important object of the invention is to provide an anti-friction washer for the beforementioned purpose so seated in the tip as to be securely held in position.

With the above and other objects in view, the invention consists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawingsand particularly pointed out in the appended claims.

In the accompanying drawings like characters of reference indicate like parts in the several views, and:

Fig. 1 is a side view of the improved pencil, partly in section.

Fig. 2 is an enlarged vertical section on the longitudinal median line of Fig. 1.

Fig. 3 is a still further enlarged longitudinal section at right angles to Fig. 2.

Fig. 4 is an elevation of the operating parts with the barrel and lead holder removed.

Fig. 5 is a section on the line 5-5 of Fig. 2.

Fig. 6 is a section on the line 6-6 of Fig. 3.

Fig. 7 is a section on the line 1-4 of Fig. 2.

Fig. 8 is a side elevation of the eraser and its retaining means.

Fig. 9 is a bottom plan view of the parts shown in Fig. 8.

Fig. 10 is a section on the line Ill-I0 of Fig. 2.

In the present embodiment of the invention there is disclosed a pencil having a barrel preferably consisting of a lower, preferably opaque part [0 and anupper preferably transparent part I I. On the lower part there is provided a tapered extension or lower end l2, internally threaded preferably with a lefthanded thread as at IS. The lower end of the pencilin this, and the other forms hereinafter mentioned, constitutes a tip having a lower portion 14, of substantiallyconical form and a collar or neck l5. In the form illustrated in Figure l and Figure 2 this collar or neck is externally threaded to engage the lefthanded threads of the tapered lower portion l2 of the barrel.

In this form of the invention the tip M is provided with a bore extending from top to bottom thereof and the upper part of this bore is such as to provide a cylindrical recess it below which the bore tapers to form a frusto-conicalportion.

ll. The frusto-conical portion of the bore extends downwardly and ends at a shoulder below which there is a cylindrical portion having a bore ill of small diameter, another shoulder, and a final portion having a still smaller bore I9, slight-,.

ly larger than the diameter of the lead 20. In this form of the invention there is also provided a runner tube, well shown in Figures 2 and 3. It will be observed that this runner tube is made from a thin sheet of metal, shaped or cut so that when it is rounded up into tubular form there is provided a body 2| of cylindrical form having a slot 22 extending through the upper portion and a lower portion provided with a slit 23, the tube being compacted at its lower end to engage in the. frusto-conical bore 11 and thus not only compress the tube but also to insure its frictional engagement with the tip l4.

Within the tube body 2|, there is provided, as shown in Figure 3, a lead carrier 21 of tubular form adapted to frictionally engage the lead 20, and having between its ends a lug 29, formed from a pair of projecting parts of the lead carrier. These parts project through the slot 22, and extend outwardly thereof. Surrounding, and close-, ly engaged with the tube 2|, is an actuating tube 30 having a spiral slot 3| formed therein and extending through the wall thereof. The lug 29 projects through the slot 22 and engages in the slot 3| of the spiral actuating tube.

Above the lug 29 the lead carrier is provided with a slot 32 extending longitudinally thereof for purposes presently to be described. Within the lead carrier 21 there is provided a lead ejector in the form of a rod 33 having at its upper end.

upper part II projects therethrough and into the slot 3 l From an inspection of Figures 2 and 3 it will be seen that just above the tapered portion of the bore H, the tip is provided, as previously stated, with a cylindrical bore H5, in which is seated a washer 35, against which the lower end of the spiral actuating tube 3!! abuts. In other words, the lower end of the spiral actuating tube is socketed in a recess in the top of the tip I4 and bears against an anti-friction washer 35 so provided as to eliminate the major part of the friction of the bearing of tube 30 against the tip I l. The anti-friction washer preferably is a fiber washer lubricated with petroleum jelly, the latter being distributed throughout the pores or interstices of the washer body. This is entirely different from mere surface lubrication.

It will be observed that under this construction a quite considerable space exists between the actuating tube 30 and the lower part H and the of the barrel. This space is utilized, in the present invention, as a storage space for spare, leads and to that end there is provided a spacing member such as is best shown in Fig. 5. As there shown the member is formed of a pair of complementary halves 35 each of which consists of a pair of fiat or plane portions 31 arranged at right angles. At the angle between the two portions 3! is a connecting rib 37a of substantially semi-cylindrical form and projecting outwardly from the angle at the remaining edges are flanges 31b which extend outwardly at 135 from the portions 3?. When assembled the flanges 31b of one-half engage against the flanges 31b of the otherhalf so as to form a square tube having ribs at its corners which engage against the inner surface of the barrel. This tube extends from a point adjacent the lower end of the barrel portion it to a point about half-way of the length of the upper portion H and just below the lower or socket end of the eraser holder for a purpose presently described. Thus whenthe magazines formed between the members 36 and the barrel are loaded the leads project well above the upper end of the square tube. Furthermore, for purposes which will be presently explained, the flat portions 3? lie against or very close to the spiral tube 30. This lead holder, when inserted in the barrel performs two functions. It holds the spiral tube and the parts therein concentrically of the barrel and provides storage space for the spare leads L.

In constructions of this character, there must be provided means for supporting the lower ends of the spare or magazine-carried leads and for this purpose the barrel [G has wedged therein, at the point 4|, a washer .2, which supports the lower ends of the leads L. In the form of the invention here shown the washer 42 is a simple annular washer forced down slightly into the tapered portion of the barrel and the lead holder members 36 rest on this washer at their lower ends.

In order to hold the tube 30 from movement upwardly on the tube 2 I, the latter extends somewhat above the upper end of the tube 30 and a washer 46 is mounted on the tube 2! to rest against the upper end of the tube 38. Beneath the washer 46 is preferably provided an antifriction washer 2611. which is a fiber washer impregnated with a lubricant. Furthermore, as can be seen in Figure 7, the portions of the tube 2| adjacent its slot 22 are bent outwardly as at 41 to overlie the washer 46. In order to rotate the spiral tube 30, there is provided at the upper end of the tube a driver tube 49 which fits tightly around the upper end of the tube 30 and not only engages the tube frictionally but also is provided with a hole 50,,int which projects a lug 5| extending from the spiral tube. By this means a positive drive is given to the spiral tube. The driver tube 49 may also be frictionally fitted on the spiral tube 30 and in the manner drive the spiral. The frictional fitting, while. not a rigid connection, permits quick detachment of the driver tube from the spiral tube. The upper end of the driver tube 49 is formed as an expanded part 52 adapted to receive the eraser 53' and its holding cup 54. The expanded portion 52 is provided with slits 55 extending downwardly from its upper edge to form a circumferential series of spring fingers 56 having inturned lips 56a at their upper edges. The eraser holding cup 54 (Figs. 8 and 9) consistsof a thin metal stamping having a polygonal bottom 5411 provided with a central opening 54b. Spring arms 56c extend upwardly from alternate asides of the polygonal bottom and are each provided on its inner face with a spur 54d. I This cup is'of such dimensions that, upon the eraser '53 being placed therein as shown in Fig. 8 and the cup and eraser being inserted in the expanded portion'of the driver tube, the arms will be forcedin to cause the spurs 5 3d to engage in the eraser 53 and, when fully inserted, the'upper ends of these arms 540 will catch beneath the lips 56 without releasing the engagement of the spurs in the eraser. Thus the cup and eraser are securely held in the expanded portion of thedriver tube.

When an eraser is worn out the cup and remnant, of the eraser may be removed and separated; A

new eraser may then be placed in the cup and the cup replaced as before.

It will now be noted that, as the drivertube extends well down the spiral tube, the lower end 'of the driver tube lies closely above the upper ends of the members 36 so that these memberscannot accidentally fall out of the barrelf. Moreover the stored leads L lie closely around this lower end of the driver tube and the'shoulder 49a cidentally falling from the magazine in case the moving a lead from the magazine.

. .--4 forms a stop for preventing leads from ac-" Slidably fitted over the upper part of the driven-50 tube is a cap 51, which frictionally engages the part 52 and is thereby-held in position. This cap is preferably of the same external diameter as the barrel H and, as can be seen from Figure 1,

engages on top of a transparent section of the.

barrel 4 l or, it may engage on an opaque portion" on the barrel and the latter be provided middleway of its length with a transparent section. The usual clip 58 is applied to the pencil.

In order to connect the barrel sections a 58 is fitted in the upper end of thejsection ill, the sleeve being provided with lugs 58," which engage in the material of the barrel,- A flange 59 extends around the sleeve and above the flange the sleeve and lower end of the barrel section II, are provided with complementary screw threads" 66 by which'the section II maybe screwed on the sleeve and thus be removably attached to the section Iii. Obviously, when it is desired-to remove a lead from the magazine the cap SI eeve 3 60 will be removed and the section I l' unscrewed and removed thereby exposing the leads L for withdrawal.

In assembling the pencil, the followin illnocedur'e is followed:

Before the runner tubing containing the assembled lead carrier and ejector is inserted into the tip [4, the lubricating washer 35 is placed on the inside shoulder of the tip.

The next step is assembling of the lead carrier 21 and the ejector 33. Thereafter, the assembled lead cutter and ejector are introduced into the slot 22 of the runner tube 2| and the latter is formed into the tapered hole of the tip Thereafter, the spiral 30 is placed on the runner tube 2|. The lubricating washer 46a is now placed on top of the spiral 30. Then the metal washer 46 is placed on topof the lubricating washer. The ends of the runner tube are then spread open to provide ears to engage the washer 46, as shown in Fig. 8. The mechanism thus assembled is inserted into the barrel III, the tip I! being screwed into the barrel.

The lead holder washer 42 is then placed over the spiral and forced down until it becomes wedged into the lower part of the barrel as at the point 4|, Figure 2. Thereafter, the segmental portions 36 of the lead holder are inserted into the barrel so that the ribs fit tightly in the inner wall of the barrel, and thus also to act to centrally locate the spiral.

The lead holder segments 36 are forced downwardly until they touch the'washer42, the latter being the enclosure for the lead holder." The driver tube 49 is then frictionally. forced over the spiral. If desired, the slot 50 and projecting boss 5| on the spiral may be omitted and the driver tube simply held on the spiral by friction. The eraser cup and eraser is then inserted into the driver shell cap thus completing the assembly.

What is claimed is:

1. In a mechanical pencil, a barrel, a tip on the lower end of said barrel, an anti-friction fiber washer at the upper end of said tip, a runner tube having its lower end fixed in said tip and extending through said washer, actuating means rotatably fitted on said runner tube and having its lower end resting on said washer, and means to rotate the actuating means. I

2. In a mechanical pencil, a barrel, a tip on the lowerend of said barrel, a runner tube having its lower end fixed in said tip and extending through said washer, actuating means rotatably fitted on said runner tube and having its lower end resting on said washer, a second anti-friction fiber washer at the upper end of said actuating means, and

means to rotate the actuating means.

3. In a mechanical pencil, a barrel, a tip on the lower end of said barrel, an anti-friction grease impregnated fiber washer at the upper end of said tip, a runner tube having its lower end fixed in said tip and extending through said washer, actuating means rotatably fitted on said runner tube and having its lower end resting on said washer, a second anti-friction grease impregnated fiber washer fitted on said runner tube at the upper end of said actuating means, means on the runner tube to retain said second grease impregnated fiber washer on the runner tube and means to rotate the actuating means.

4. In a mechanical pencil, a barrel, a tip fixed on the lower end of said barrel having a recess in the upper portion thereof, ananti-friction grease impregnated fiber washer in said recess, a runner tube having its lower end fixed in said "tip and extending through said washer, an actuating spiral rotatably fitted on said runner tube and having its lower end within said recess and resting on said washer, a second anti-friction grease impregnated fiber washer fitted on said runner tube at the upper end of said actuating spiral, a metal washer fitted on saidrunner tube above the second fiber washer, means on said runner tube to retain said metal washer and the second fiber washer, and means operatively coupled with said actuating spiral to rotate the same.

5. In a mechanical pencil, a barrel, a tip on the lower end of said barrel, a runner tube having its lower end fixed in said tip, actuating means rotatably fitted onsaid runner tube, an

anti-friction fiber washer about said runner tube and resting on the upper end of said actuating means, and means to rotate the actuating means.

6. In a mechanical pencil, a barrel, a tip on the lower end of said barrel, a runner tube having its lower end fixed in said tip, an actuating means rotatably fitted on said runner tube and having'at least one of its ends bearing on a washer of a non-metallic material having anti-friction properties, and means to rotate the actuating means.

'7. In a mechanical pencil, a barrel, a tip on the lower end of said barrel having a recess in the upper portion thereof, a washer of a nonmetallic material having anti-friction properties in said recess, a runner tube having its lower end fixed in said tip and extending through said washer, actuating means rotatably fitted on said runner tube, and having its lower end within said recess and resting on said washer, a second washer of non-metallic material having anti-friction properties fitted on said runner tube at the upper end of said actuating means, a metal washer fitted on said runner tube above said second anti-friction washer, and means on said runner tube to retain said metal washer and said anti-friction washer in assembled relation.

- DAVID KAI-IN.

Images