US2571830A - Telescoping pencil - Google Patents

Description

Oct. 16, 1951 P. w. BUELL TELESCOPING PENCIL Filed Jan. 2, 1948 IN VEN TOR. /C/L W50/ELL Patented Oct. 16, 1951 TELESCOPING PENCIL Paul W. Buell, Elmira, N. Y., assignor to Point-- Matic Pencil Co., Inc., Elmira, N. Y., a corporation of New York Application January 2, 1948, Serial No. 6

1 Claim. 1

This invention relates to a pencil in which the lead is fed by the relative sliding movement between two telescoping barrel portions.

A particular object of the invention is to provide a pencil structure that will have a number of features of construction that will combine to produce a pencil that will operate under all circumstancesin which lead may be stored for use, and one in which the lead holding means is so constructed that the lead will be firmly and securely held to provide a xed writing point down to the last small piece of lead being used in the writing operation.

A further object of the invention is to provide in a pencil structure of the character referred to a novel method of telescopically mounting the barrel portions of the pencil so that they have close sliding t without marring the under barrel surface, will resist accidental telescoping action and will remain in perfect alignment at all times.

Still further objects of the invention provide for the close machining of the lead tube so that the lead may be properly held and fed, a simplified construction that is sturdy, will not get out of order, will not require skill in filling with lead or adjusting the parts preparatory to writing and one that can be made at minimum cost.

With vthese and other objects in View, the invention comprises certain constructions hereinafter described and then particularly pointed out in the claim and a preferred embodiment of my invention is illustrated in the accompanying drawing, in which:

Figure l is a view in sectional elevation of a pencil constructed in accordance with my invention,

Figure 2 is a greatly enlarged fragmentary section in elevation of a part of the pencil where the barrels telescope showing a preferred form of structure,

Figure 3 is a section on the line 3-3 of Figure 2,

Figure 4 is a section on the line 4 4 of Figure 1 showing a modified form of barrel connecting means,

Figure 5 is a section taken on the line 5-5 of Figure l showing the relation of the barrel and lead tube,

Figure 6 is a vertical view of the pencil, parts being shown in section, illustrating the first movement of lead feed action, and

Figure '7 is a view similar to Figure 6 showing the completed movement of the .lead feeding action, and

(Cl. 1Z0-14.9)

Figure 8 is a greatly enlarged sectional vie of the lower end of the lead tube showing a and lower barrels are arranged for relative telescoping movement to progressively feed the lead at intervals as it is Worn by the Writing action.

The upper barrel I0 of tubular construction and-v open at both ends is arranged at its lower end to closely t over the upper end of the lowerbarrel II, and is arranged to receive by friction fit a removable plug cup I2 in the upper end thereof. The cup I 2 forms a closure at the upper:

end of the barrel in either position of use, that is to expose the eraser I3 therein or the closed end of said cup I2. The cup is positioned by the annular flange I4 which rests on the upper edge of the barrel. The barrel carries the usual clip I5 and in the interior adjacent the upper end of the barrel has force tted therein a spring cup formed by providing a plug I6 with a central bore I'I or recess in which a coil spring I8 is lodged.

The latter is held in the cup by a disk I9 whichv has a central opening for passage of the lead feed rod 20, the upper end of which is secured in any suitable manner to the end of the spring I8. The disk I9 may be frictionally retained in place in the cup or threaded therein as desired.

In Figure 7, an adjustable plug 2I is threaded' into the cup to close the spring recess and by adjusting this plug, the tension of the spring.

may be varied or adjusted to compensate in'lead feeding action.

Ihe lower barrel II at its upper end is closed by a tube plug 22 in which is mounted a lead guide tube 23 which extends through the barrel, passing through a guide disk 24 Xed near the lower end of the barrel, and also passing through the lower tapered end 25 of said barrel. The lead tube 23 is Xed in the disk 24. The plug 22 can be removed from the kupper end of the tube 23 and the barrel II so that the space therebeneath may be used for lead storage as indicated as at 26. The upper end of barrel II near the extremity thereof is uted outwardly as at 2'I to provide elongated ridges which may be of any number as three or eight as shown to guide the upper barrel in its sliding movement over the lower barrel. A preferred form of structure is tha-t illustrated in Figures 2 and 3 wherein the upper endlk of the barrel I I is annularly fluted or grooved to provide a plurality of vertically spaced grooves 28 constituting seats for tension upper barrel from engaging and wearing the smoothly finished outer surface of the lower barrel, or marring the same.

The lower end of the lead guide tube 23 is slotted as at 30 and while actually shown or' reduced diameter for the purpose of illustration, the machining of said tube will be such that its inside diameter will be .050 reduced to .047 near the point and to .O46 at the tip to hold the lead tight enough to prevent it from falling outor turning. The slotted tip allows forv variation in the size of the lead and the point of'the barrel is just large enough to allow for this exipansion.

In using the pencil, a writing lead is inserted through plugY 22 into the' lead tube 23 and the upper barrel Hl' and a lead feed rod 20, are assembled with the lower barrel Il, with the feed rod extending into tubev 23\ to a point just above the lead in tube 23; Holding the pencil invertical position, the user presses the point of the pencil against the writing material. i8 is compressed as shown in: Figure 6 by the movement of the feed rod and the resistance of the lead which. is flush' with the lower edge of the barrel Il. Compression of the spring is accompanied by a relative telescoping movement between the upper and lower barrels. Upon release of; the pencil and the tension of the spring,

the latter projects the` lead to the position shownV in Figure 7 and the pencil is ready for Writing. The barrels maintainY their position of adjustment as above noted, the rod holds the lead in position and prevents it from sliding back and the spring provides theY right amount of tension to make the breaking of the lead an impossibility during writing even when excessive pressure is applied. The tension on thev spring is adjustable as above noted and the gripping force of' the lower end of the tube is just right to hold the lead so that it can be used down to about one thirty second of an inch in length so that loss of lead is minimized.

It is evident that while the slotting of the tube The spring as at 30 may be done only in the tip end thereof, said slots, as at 32 in Figure 8, may be made as long as desired and may extend into an enlarged part of the tube as shown.

Each time that the lead wears down it is simply necessary to apply telescoping pressure as above set forth with one hand to the upper barrel and then release the tension and the lead will have been advanced to provide a new writing supply that extends the correct amount beyond the end ofthe barrel.

My invention is not to be restricted to the precise details of construction shown since various changes and' modifications therein may be made without departing from the scope of the invention or sacricing the advantages to be derived from its use;

What I claim is:

A mechanical pencil comprising interfitting upper and lower detachable cylindrical barrels, one of said barrels'being'iluted to provide annularly spaced vertical ridges for frictional engage. ment with the other barrel to provide telescopic movement therebetween; a guide disk in the lower barrel, a lead tube supported in said disk concentrically of the lower barrel and slotted at its lower endV for frictionally holding lead, said lead tube extending substantially the length of said lower barrel to denne with the barre1 a storage space for leads above thel guide disk, a

plug in the upper end of the lower barrel tting/ about said lead tube and removable to provide access to said storage spacer a recessed plugrfxed in said upper barrel, a spring in the recess of the plug, a feed rod depending from said spring and extending into the leadV tube above a lead disposed therein, and a diskf closing the recess in said recessed plug and imprisoning said'y spring and said spring being compressible upon relative telescopic movement of said barrels and expandable to project lead beyond the end of thev lead' tube through said feed rod.

PAUL W. BUELL.

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

UNITED STATES PATENTS Number Name Date 1,340,331 Fischer 1 May 18, 1920 1,406,056' Michael Feb. 7, 1922 1,554,393 Wensink Sept. 22, 1925 1,849,914 Dclvin A Mar. 15, 1932

Images