US2356509A - Mechanical pencil and method of making same - Google Patents

Description

ug. 22, 1944. F, Q DE| 2,356,509

MECHANICAL PENCIL AND METHOD oF MAKING SAME l Filed Sept. 27, 1943 2 Sheets-Sheet l jOJmi F. C. DELl Aug. 22, 1944.

MECHANICAL PENCIL AND METHOD OF MAKING SAME Filed Sept. 27, 1943 2 Sheets-Sheet 2 @mz3 NL BY Patented Aug. 22, 1944 BIECHANICAL PENCIL AND METHOD F MAKING Frank C. Deli, Chicago, lll., assignor to Antopoint Company, Chicago, Ill., a corporation of Illinols SAME Application September 27, 1943, Serial No. 503,937

16 Claims. (Cl. 1Z0-18) the tube. Mounted within said tube is a plunger,

or lead propeller, having one or more lugs or lateral projections that entersaid thread to travel therealong and propel a lead through the tip, as the tip is Vrotatedlin a predetermined direction with relation to the barrel.

Since, for war reasons, brass or other suitable metal tubing is not available for commercial manufacture, the present invention eliminates Athe need for the same, and yet provides for the spiraltraclrway to receive the propeller lugs for propelling a lead, said trackway being fixed in the tip to rotate therewith as the tip is rotated relatively to the barrel. To this end I have provided a coil spring of the required size and pitch, and a. novel arrangement of the same in the tip, so that the brass or similar metal tubing referred to above is eliminated.

I have also provided a novel arrangement of thin metal tube, of a metal more readily obtainable, so formed as to provide a. more efl'icient rotatable and removable friction grip between the tip and the barrel, and to hold the coil spring operative in position therein, said thin metal tube and coil spring being fixed to the tip to rotate therewith.

In addition to eliminating the need of using tubing made of brass or other suitable similar metal so vitally needed in war work, I have, by the use of the coil spring referred to above, accomplished several very valuable advantages. By reason of the coil spring being fixed to the tip only at the forward end portion of the spring, the major portion of the coil spring, including its rear end, being unattached to its surrounding thin metal tube, this unattached major portion beingl of springy nature due to its shape, although rigid enough to normally propel a lead, will yield should the propelling mechanism become jammed, and thus avoid a breakage of parts that might otherwise occur. In other words, this coil spring construction affords a flexibility and safety of operation as well as a normal positiveness of action, not possible in the old form of construction.

Another considerable advantage of the coil spring of the present invention is that due to the major portion of the coil spring being unattached to any surrounding parts, a much greater space is provided around the wire of the individual coils, to receive and hold lead dust as the same is shaved off from the leads as they'pass through the inner bore of the coil spring during operation of the pencil. Also any such lead dustas might accumulate from time to time around the coils has a much better chance to be shaken loose and out ofthe tip when inserting a new lead, by reason of the rear end and major portion of the coil spring being unattached.

Also considerable labor cost is saved by the fact thatthe major part ofzthe length of the-*coil spring is not attached to any other part, it being secured within the surrounding tube and to the tiponly at its forward portion.

A further advantage of this coil spring construction is that, due to its open formation, the propeller lugs may more readily pass into the rear open. end of the coil of the coil spring, when the propeller is being inserted into the tip after a new lead has been added.

Additional advantages possessed byV the coil spring arrangement described herein are economy of manufacture, eiliciency of operation, yieldable but positive action and ease and effectiveness in assembling.

Other objects, advantages and capabilities will later more fully appear.

My invention further resides in the combination, construction and arrangement of parts illustrated in the accompanyingy drawings, and while I have shown therein a. preferred embodiment, I wish it understood that the same is susceptible of modication and change without kdeparting from the spirit of my invention.

In the drawings:

Figure 1 is an enlarged side elevation of a mechanical pencil embodying my invention, although other external shapes may be used if desired.

Fig. 2 is a still more greatly enlarged fragmentary vertical longitudinal section taken on a median plane through the tip, propelling mechanism and lower end portion of the barrel.

Fig. 3 is an enlarged longitudinal section on a median plane through the metal portion of the tip, the friction grip tube for rotatably holding the tip to the barrel, and the spiral trackway coil spring.

Fig. 4 is an enlarged side elevation of the frictitn grip tube looking at the side having the short sli Fig. is a view similar to Fig. 4 but looking at the opposite side.

Fig. 6 is an enlarged side elevation of the metal portion of the forward end of the tip.

Fig. 7 is an enlarged sideelevation of the coil spring of my improved tip construction. Fig. 8 is a longitudinal section of the friction grip tube taken on the line r`8-8 ofN Fig. 9 is a longitudinal section of the friction grip tube taken on the line 9--9 of Fig. 8.

Fig. 10 is a longitudinal section on a median plane through the forward tip portion'of Fig. 6.

Fig. 11 is an enlarged transverse section through the friction grip tubetaken on ktheline II--II of Fig. 8, showing the tube in slightlyvexaggerated expanded position before being inserted into the barrel.

Referring more in .detaill to the drawings, my improved pencil comprises a body portion or barrel I havingat its lower end a reduced portion 2 tapered downwardly and inwardly, and forming with the barrel the annular shoulder .3 against which abuts the end 4 of the non-metallic portion 5 of the tapered tip 6. Portion-5 is preferably formed of a plastic material. Thelower or forward end- 1 .of the tip is formed preferably of metal,` and at its nose portion has a pair of oppositely positioned' slits 8` to enable frictional gripping of the lead 9. The metal portion 1 of the tip at its upper or inner end is formedk with a cylindrical collar l0 of smaller 4diameter, than `the largest diameter of the portion 1, these two parts being connected together by a shoulder portion II. t As shown in Figs. 4, 5, 8 and 9, I have provided a tube I2 preferably of thin, black or other more readily available metal, and of an outside diameter to enable it to be inserted longitudinally into the cylindrical collar I0 until its lower end touches` the inside walls of the 'lower tip portion 1, or not as desired, as will be understood in Figs. 2 and 3. Tube I2 is formed on one side, and extending longitudinally throughout its length andthrough the thickness of the wall, with a slit I3, while on its opposite side and 180 degrees removed from slit I3 is a shorter slit I4 whichis closed at both ends. The metal on each side of slits I3 and I4 is resilient, and if desired may be bent slightly outwardly to enable a frictional gripping action when the parts are assembled and the tube I2 is pushed into the longitudinal bore I5 in the forward end of the barrel (seeA Fig. 2).

The bending slightly outwardly of the edg portions of the metal on each side of slit*l I3 will preferably be effected by inserting a key (not shown) of suitable shape into the appropriately shapedopening I3' (Fig. 5) and turning the same to bend said edgesl outwardly and if desired move the key a desired distance along thev slit I3. Or other suitable means may be y emv ployed for this bending action. This slight outward bending of the metal along the edges of the slit I3 enables the resilient thin metal to be forced inwardly a slight distance when the tube I2 is forced with a slight push into the longitudinal bore I5 when applying the tip to the baris longitudinally slidable therein. When the coil spring I6 and the tube I2 are assembled together and passed into collar I0 to the position shown in Figs. 2 and 3, the vmetal of collar I0 will be swaged or 'otherwise compressed inwardly to tightly grip the end of the tube therein, the adjacent portion of the coil spring `II therewithin being,` by the same swaging action, simultaneously gripped within tube I2, to be firmly held therein against either longitudinal or rotational move ment at that portion within collar I0. As seen in Figs. 2 and 3, the coils of coil springs I6, at

' that portion-within collar I0, will be slightly indented into the metal of tube I2 to more eifectively hold these parts together. All of that portion of' the coil spring lying within the tube I2 between the inner end of collar I0, and the inner or free end of this tube is, however, unattached to the tube, but is free to be sprung either longitudinally orjrotationally. by the lugs I1, I3 of the lead propeller I9 should theseparts become jammed, duringoperation of the pencil. Also this unattached feature of the coilspring provides ample space around the coils for deposit of lead dust which may be shaved off the leads during theirforward feeding movement, which dust, from time to-time, may be knocked out of the tube by tapping upon the end of the tip when there is no lead therein. Those coils which project forwardly ofthe forward end of tube I2act to guide and laterally support the lead when its rear end passes beyond tube I2.

The upper or inner end of the propeller I9 is formed with a non-circular head to nt within a non-circular bore in 'the barrel (not shown) in the well known manner, for example as shown in my U. S. Patent 1,929,969, granted October 10, 1933, for MechanicalpenciL to enable leadfeeding operation of the parts. The inner end of the coilsY of the coil spring being open enable a 'more free insertion of the propeller lugs I1, I8

thereinto, and a correspondingly greater certainty of operation when-a new lead is inserted.

As will be understood from the above, rotation of the tip with relation to the barrel will cause a longitudinal movement of the propeller and a corresponding feeding movement of the lead. It will thus be seen that I have not only eliminated the need of brass tubing which is required in war work, but I have at the same time provided a more effective pencil in which the particular arrangement of the coil spring in the friction grip tube enables the rear and major portion 'of the coil spring to be unattached to the tube,v thus providing a greater flexibility of operation with positive action, prevention of breakage of parts should the lead propelling mechanism become jammed, open coils at the inner end of the coil spring to more effectively receive the lugs ofthe propeller when reassembling the parts after insertion of a new lead, and an easier and more certain way of temporarily storing and later rerel. I'I'he shorter slit I4 on the opposite side l of the tube aids in producing this resilient grip which grip is sufficient to hold the tip onto the barrel, enable its rotation with relation to the barrel, and enable the tip to be removed from the barrel for reloading when desired.

, Inserted longitudinally within tube I2 is a coi springIB, which before the parts are assembled moving the lead dust shaved off from time to time from the leads during their passage through the tip.

The tube I2 may be rolled from fiat, thin, sheetmetal to. bring the side edges side by side but slightly spaced apart to give a frictional gripin the boreof the barrel, and in any appropriate manner form the closed ended shorter slity I4 in the opposite side either before or after rolling the sheet into tubular form as desired. The coil spring I6 may be formed of any suitable metal in any of the well known manners. Th e coll spring and tube are then assembled in the collar II and swaged together as earlier described, the coil spring being so positioned in the tube that its rear end will extend substantially to the rear end of the tube in any unattached and yieldable manner for purpose hereinbefore pointed out.

Having described my invention, I claim:

l. In a mechanical pencil, a barrel, a tip rotatably mounted on the barrel. a metal nose on said tip, said nose having a rearwardly extending cole lar, a metal tube having its front end portion inserted into said collar, a coil spring within the tube, the collar tightly gripping the adjacent portion' of the tube, and the last mentioned portion of the tube tightly gripping the adjacent portion of the coil spring, and a propeller having a lateral projection engageable between the coils of the coil spring to move the propeller longitudinally when the tip is rotated relatively to the barrel, and means for holding the propeller against rotation with relation to the barrel when the tip is rotated thereon.

2. In a mechanical pencil, a barrel, a tip'rotatably mounted on the barrel, a metal nose on said tip, said nose having a rearwardly extending collar, a metal tube having its front end portion inserted into said collar, a coil spring within the tube, the collar tightly gripping the adjacent portion of the tube, and the last mentioned portion of the tube tightly gripping the adjacent portion of the coil spring, and a propeller having a lateral projection engageable between the coils of the coil spring to move the propeller longitudinally when the tip is rotated relatively to the fbarrel, the coil spring rearwardlyof the collar being unattached to the tube, and means for holding the propeller against rotation with relation tov the barrel when the tip is rotated thereon,

3. In a mechanical pencil, a barrel, a tip rotatably mounted n the barrel, a metal nose on said tip, said nose having a rearwardly extending collar, a metal tube having its front end portion inserted into said collar, a coil spring within the tube, the collar tightly gripping the adjacent portion of the tube, and the last mentioned portion of the tube tightly gripping the adjacent portion of the coil spring, and a propeller having a lateral projection engageable between the coils of the coil spring to move the propeller longitudinally when the tip is rotated relatively to the barrel, the coil spring rearwardly of the collar being unattached to the tube, the rearmost coil of the coil spring terminating in a free end to receive the projection of the propeller as it is threaded thereinto, and means for holding the propeller against rotation with relation to the barrel when the tip is rotated thereon.

4. In a mechanical pencil, a. barrel, a tip rotatably mounted on the barrel, a metal nose on said tip, said nose having a rearwardly extending collar, a metal tube having its frontend portion inserted into said collar, a coil spring within the tube, the collar tightly gripping the adjacent portion of the tube, and the last mentioned portion of the tube tightly gripping the adjacent portion of the coil spring, and a propeller having a lateral projection engageable between the coils of the coil spring to move the propeller longitudinally when the tip is rotated relatively to the barrel, the coil spring rearwardly of the collar being unattached to the tube, the unattached rear portion of the coil spring being free for resilient distortion should the lead propelling parts become jammed while the propeller projection is in enextending rotatably into the bore ofthe barrel,

the coil spring extending rearwardly from the collar within the tube and unattached to the tube, and means for holding the propeller against rotation with relation to the barrel when the tip is rotated thereon, said tube having a longitudinal slit extending from the collar to and through the free end of the tube.

6. A mechanical pencil comprising a barrel having a bore, a tip rotatably mounted on-saidbarrel, said tip having a nose portion provided with a rearwardly extending collar, a tube extending longitudinally into the collar, a coil spring within the tube, the collar and those portions of the tube and coil spring within the collar being xed to rotate together with the tip, the tube extending rearwardly from the collar and extendlng rotatably into the bore of the barrel, the coil spring extending rearwardly from the collar within the tube and unattached to the tube, the collar being forced inwardly to grip the tube, and the tube being forced inwardly to grip the coil spring, and ,means for holding the propeller against rotation with relation to the barrel when the tip is rotated thereon.

7. A mechanical pencil comprising a barrel having a bore, a tip rotatably mounted on said barrel, said tip having a nose portion provided with a rearwardly extending collar, a tube extending longitudinally into the collar, a coil spring Within the tube, the collar and those portions of the tube and coil spring within the collar being iixed to rotate together with the tip, the tube extending rearwardly from the collar and extending rotatably into the bore of the barrel, the coil spring extending rearwardly from the collar within the tube and unattached to the tube, that portion of the tube normally within the barrel having a longitudinal slit, the portion of the tube on the side of the slit pressing outwardly against the wall of the bore of the barrel to removably and rotatably hold the tube in the barrel, and means for holding the propeller against rotation with relation to the barrel when the tip is rotated thereon.

8.In a mechanical pencil a barrel having a bore, a tip rotatably and removably mounted on the barrel, the tip having a hollow cylindrical portion, a tube in said cylindrical portion and extending rearwardly a substantial distance therefrom, a coil spring Within the tube, the cylindrical portion being fixed to the tube, andthe tube being xed to the coil spring adjacent the outer end portion of the latter, the remainder of the coil spring being unattached to the tube, a propeller longitudinally movable in the coil spring,

. a projection on the propeller normally engaggagement therewith, and means for holding the ing the trackway between the coils of the coil spring, that portion of the coil spring unattached to the tube being yieldable longitudinally to prevent breakage of parts should the lead propelling mechanism become jammed.

9. In a mechanical pencil a barrel having a bore, a tip rotatably and removably mounted on the barrel, the tip having a hollow cylindrical portion, a tube'in said cylindrical portion and spring, a projection on the propeller normally engaging the trackway between thecoils of the coil spring, thatv portion of the coil spring unattached to the tube being yieldable longitudinally to prevent breakage of parts should the lead `propelling mechanism become jammed, the rearwardlyextending portion of thetube entering the bore of the barrel and having a rotatable and longitudinal removable friction grip therein.

l0. In a mechanical pencil a barrel having a bore, a tip rotatably and removably mounted on the barrel, the tip having a hollow cylindrical portion, a tube in said cylindrical portion and extending rearwardly a substantial distance therefrom, a coil spring within the tube, the

'cylindrical portion being rmly secured to the tube, and the tube being firmly secured to the coil spring adjacent the outer end portion of the latter, the remainder of the coil spring being unattached to the tube, a propeller longitudinally movable in the coil spring, a projection on the propeller normally engaging the trackway between the coils of the coil spring, that portion of the coil spring unattached to the tube being yieldable longitudinally to `prevent breakage of parts should the lead propelling mechanism become'jammed, said tube having an open ended longitudinal slit in one side and a closed ended longitudinal slit in its opposite side, said rear- ,..wardly extending portion of the tube entering the bore of the barrel, the portions of the tube along the sides of 'the slits affording a friction grip of the tube within the bore of the barrel.

11. In a mechanical pencil a barrel having a bore, a tip rotatably and removably mounted on the barrel, the tip having a hollow cylindrical portion, a tube in said cylindrical portion and extending rearwardly a substantial distance therefrom, a coil spring within the tube, the cylindrical portion being rmly secured to the tube, and the tube being firmly secured to the coil spring adjacent the outer end portion of the latter, the remainder of the coil spring being unattached to the tube, a propeller longitudinally movable in the coil spring, a. projection on the propeller normally engaging the trackway between the coils of the coil spring, that portion of the coil spring'unattached to the tube being yieldable longitudinally to prevent breakage of parts should the lead propelling mechanism become jammed, the rearmost coil of the coil spring being open and terminating in a free end to guide the propeller projection into the spiral space between the coils of the coil spring upon the inser' tion of a new lead.

12. In a mechanical pencil a barrel having a bore, a tip rotatably and removably mounted on the tube, a propeller longitudinally movable in the4 coil spring, a projection on the propeller normally engaging the trackway between the coils of the coil spring, that portion of the coil spring unattached to the tube being yieldable longitudinally to prevent breakage of parts should the lead propeller mechanism become jammed, the tube and coil spring also extending a, distance forwardly of the hollow cylindrical portion.

13. In a mechanicalpencil, a barrel having a bore, a tip rotatably and removably mounted on the barrel, an open ended tube ilxed to the tip, a coil spring within the tube and fixed near one end" thereto and otherwise unattached to the tube, saidvcoil spring constituting a lead guide means, the tube rotatably and removably extending into the bore of thebarrel, and a propeller nose portion at its upper end having a rearwardly the barrel, the tip having a hollow cylindrical and the tube being rigidly xed to the coil spring -adjacent the outer end portion of the latter, the remainder of the coil spring being unattached to extending tubular collar and in'its forward portion a hollow interior, a thin metallic tube extending through the collar and contacting said hollow interior, said tube also extending rearwardly into the bore of the barrel, a coll spring in the tube and extending approximately the length thereof, said collar having a radially pressed gripping engagement with the tube, and that portion of the tube within the collar having a radially pressed gripping engagement with the adjacent portion of the coil spring, the coil spring otherwise being unattached to the tube so that its rear portion will be freely yieldable longitudinally and have spaces between the coils to hold lead dust; a propeller having a lateral projection engageable with the coils of the coil spring, said tube having an open ended longitudinal slit in one side and a closed ended longitudinal slit in the opposite side, said slits affording a frictional grip between the tube and the bore in the barrel, said yieldable rear portion of the coil spring affording a cushioning action to prevent breakage of parts should the lead propelling mechanism become jammed, and means for holding the propeller against rotation with relation to the barrel when the tip is rotated thereon.

15. The method of producing tips for mechanical pencils, which consists in forming a metallic nose portion to have a cylindrical collar, forming from thin' metal a tube having a longitudinal slit extending from end to end through one side wall, forming a shorter, closed ended slit through the opposite side wall, placing an open ended coil spring within said tube, positioning the assembled coil spring and tube within the collar with a considerable portion of the tube and coil spring extending rearwardly from the collar, and swaging the collar against the tube and the tube against the adjacent portion of the coil spring and causing the coils of the coil spring to bite into the tube for that portion within the ing from thin metal a tube having a longitudinal slit extending from end to end throughone side wall, forming a shorter, closed ended slit through the opposite side wall, placing an open ended coil spring within said tube, positioning the assembled coil spring and tube within the collar 5 with a considerable portion of the tube and coil spring extending rearwardly from the collar, and swaging the collar against the tube and the tube over the swaged collar and portion of the tube.

FRANK C. DELI.

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