US2451765A - Filler reinforcing means and guard for mechanical pencils - Google Patents

Description

Oct. 19, 1948. J. L. MORTON FILLER REINFORCING MEANS AND GUARD FOR MECHANICAL PENCILS Filed 001; 5 1946 INVENTOR cibhizlJibrion R- 30mm AGENT Patented Oct. 19, 1948 FILLER REINFORCING MEANS AND GUARD FOR MECHANICAL PENCILS John L. Morton, Endicott, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application October 5, 1946, Serial No. 701,501

4 Claims. 1 The present invention relates to mechanical re.- fillable lead or crayon holders of the type commonly known as mechanical pencils and in which the graphite or other writing stick, crayon, lead or filler is adapted to be projected from or withdrawn into the body of the holder by a screw-- feed action occasioned by relative turning movement between the body portion of the writing implement and the eraser-retaining or other cap or head.

Heretofore, writing implements of this type have possessed one serious limitation, to wit, that unless extremely light pressure is applied to the writing surface by the point of the crayon stick or filler, the latter is subject to breakage. This extremely annoying phenomenon is due to the fact that the filler, being formed of pressed graphite or similar compound, is inherently relatively fragile and britle and, if the same be projected from the end of the surrounding ferrule an appreciable distance, the bending torque at the point of entry of the filler during normal use of the implement is sufficiently great as to cause the projecting portion of the filler to break off from the remainder of the encased filler. Such rupture of the filler is occasioned by a combination of factors, principal among which are the relatively sharp slant or angle of incidence between the filler and the writing surface which is convenient to and preferred by most users of such implements, and the degree of writing pressure applied to the writing surface.

Another limitation that is attendant upon the use of mechanical pencils of the type set forth above is the necessity of withdrawing the filler into the body of the holder after each use thereof to prevent accidental breakage of the filler in the pocket of the user, as well as to prevent the clothing from becoming soiled due to repeated contact with the filler proper.

The present invention is designed to overcome the above noted limitations that are attendant upon the use of mechanical pencils of the type outlined above and, toward this end, contemplates the provision of a metal or other reinforcing sheath which surrounds the filler and which is slidably disposed within the bore of the ferrule and is yieldingly maintained in a projected position wherein it completely surrounds and conceals the projected portion of the filler and thus reinforces the latter and prevents the same from damage. The reinforcing sheath is adapted to be automatically and telescopically retracted into the body of the ferrule so as to expose only the immediate end of the projected portion of the filler upon application of writing pressure to the writ-; ing surface. Upon withdrawal of the writing pressure by lifting of the implement from the writing surface, the sheath is adapted to return to its normal protective position relative to the filler. In this manner the filler is protected against rupture upon application of writing pressure to. the writing surface, as well as being protected from accidental breakage, such as is frequently the case when the implement is carried in the pocket of the user. Additionally, the clothing of the user is protected from becoming soiled due to contact with the filler proper. V

The provision of a mechanical pencil of the character briefly outlined above being the prin-. cipal' object of the invention, another object thereof is to provide a protecting means for the filler which will in no manner interfere with the normal feeding movements of the implement and which will require no modification in the design or construction thereof.

Simplicity, convenience of arrangement of parts, ruggedness and durability and comparative low cost of manufacture are further desiderata I that have been borne in mind in the production and development of the present invention.

' In the accompanying single sheet of drawing forming a part of this specification:

Fig. 1 is a fragmentary side elevational view, partly in section, of a mechanical pencil constructed in accordance with the principles of the present invention.

Fig.2 is a sectional view taken substantially longitudinally and centrally through the lower regions of the pencil. In this view, the conventional spiral filler or crayon feeder, as well as certain other parts, have been removed to more clearly reveal the nature of the invention.

Fig. 3 is a sectional view, similar to Fig. l, showing a modified form of mechanical pencil.

Fig. 4 is a view, similar to Fig. 1, showing the pencil in actual use.

Referring now to Figs. 1, 2 and 4, the pencil involves in its general organization an outer shell or casing H3 which is shown in outline only by means of broken lines. Fitted within the lower tapered end of the shell i0 is a hollow tapered metal ferrule l2 having a central bore l4 through which the crayon stick or filler proper I5 projects and from which it is adapted to be projected at will by means of a conventional feeding mechanism.

The ferrule I2 is provided with a reduced portion l8 which is telescopically received within the bore of the shell I0 and maintained therein by 3 means of a tight frictional fit so that when the pencil is in actual use these parts are, in effect, as one and are possessed of no relative turning movement therebetween.

The feeding mechanism includes an elongated guide sleeve 20 which is but slightly shorter than the overall length of the pencil and the lower end of which is securely held by a friction fit or otherwise in the upper portion of the bore I4 of the ferrule I2. In the regions of the sleeve 20 above the ferrule the former is slotted as at 22 throughout a major portion of its length, one edge of the slot appearing in the drawing in elevation throughout the various views. A filler retainer and feeder is slidably disposed within the bore of the sleeve 20 and includes a second slotted sleeve 24 of small diameter into the lower end of which the upper end of the filler I is telescopically received and held by a light frictional fit. The medial regions of the inner sleeve 24 is formed with a lateral protuberance 26 which projects outwardly through the slot 22 of the sleeve 20. An ejecting pin 28 is slidably disposed within the inner sleeve retainer 24 and is provided with a laterally turned upper end 30 which projects through the slot 32 in the inner sleeve and the slot 22 of the outer sleeve 20.

The protuberance formed by virtue of the laterally turned end 3|] of the ejecting pin 28 and the protuberance 26 formed on the retainer sleeve 24 are adapted to be received in adjacent convolutions of a conventional spiral feeder 34 which appears in Figs. 1 and 4 but which has been omitted from Fig. 3 for the sake of clarity of disclosure. The feeder 34 is adapted to receive on its upper end a suitable eraser-retaining cap or head (not shown) by means of which it may be turned relative to the shell and ferrule assembly III, I2.

It will be seen that turning movement of the spiral feeder 34 in one direction or the other will cause the retainer sleeve 24 and ejecting pin 28 to slide upwardly or downwardly, as the case may be, within the body of the guide sleeve while these two parts maintain their relative positions with respect to each other. However, when the spiral feeder 34 is turned in such a direction and to an extent sufficient to cause the lower protuberance 26 to leave the convolute path in which it is guided, it will cease to have motion, while the upper protuberance will continue to descend in its spiral path, carrying with it the body portion of the ejecting pin 28 which will thus force the filler from its frictional fit within the retainer sleeve 24. It will, of course, be understood that during turning movement of the spiral feeder 34 in one direction or the other the filler I5 will be fed outwardly from or withdrawn into the body of the pencil.

The arrangement of parts described above is purely conventional in its design and no claim is made herein to any novelty associated with the same, the novelty of this invention residing rather in the construction and arrangement of parts now to be more fully described and claimed.

Loosely slidable within the bore I4 of the ferrule I2 is a reinforcing sleeve 50, the internal diameter of which is slightly greater than the external diameter of the filler I5 and the external diameter of which is slightly less than the internal diameter of the bore I4. The sleeve is thus freely slidable in a vertical direction longitudinally of the pencil relative to both the :filler and the ferrule and is capable of being projected from or retracted into the latter. In Fig.

2 it is shown in its fully projected position and in Fig. 4 it is shown as being retracted.

The upper end of the sleeve 50 is provided with a laterally turned lug 52 which projects outwardly through the slot 22 formed in the guide sleeve 20. This lug 52 determines the limiting or fully projected position of the sleeve 50. A coil spring 54 of relatively light construction surrounds the lower end of the guide sleeve 20 and bears at its lower end against the upper end of the reinforcing sleeve 50. At its upper end the spring 54 bears against the underneath side of a Washer 56 which in turn bears against the lower end of the spiral feeder 34.

From the above description it will be seen that normally the reinforcing sleeve 50 is maintained in its projected position as shown in Fig. 2 wherein the lower end and writing point of the filler I5 is completely concealed from view and sheathed from contact with the clothing of the user when the pencil is carried on his person. With the parts in this position, the filler is not subject to accidental damage, while at the same time the clothing of the user is protected from contamination.

When the pencil is applied to a writing surface in the usual manner, as illustrated in Fig. 4, gentle pressure of the lower end of the implement against the writing surface will cause the reinforcing sleeve 50 to be pushed back into the ferrule to an extent just sufficient to expose the writing point of the filler I5. In this manner, any torque which would ordinarily be applied to the filler in a direction normally tending to cause breaking of the latter will be borne by the reinforcing sleeve and the filler will be protected against breakage.

In Fig. 3 a modified form of the invention is illustrated. In this view similar reference characters have been applied to those parts which correspond to similar parts in the other views to thus avoid repetitious description.

In the modified form of Fig. 3, the reinforcing sleeve I50 is considerably shorter than the sleeve 50 in the other form of the invention and is provided with an annular lug I52 at its upper end which normally rests at the bottom of an enlargement III formed in the bore II 4 of the ferrule II 2. The spring I54 is wholly disposed within the enlarged portion II! of the bore and its upper end bears against a washer I56 which in turn bears against the lower end of the spiral feeder I34. In this form of the invention the spiral feeder I34 extends to a point close to the upper end of the ferrule II 2,

The invention is not to be limited to the exact arrangement of parts shown inthe accompanying drawing or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit of the invention. For example, while the protective and reinforcing sleeve 50 has been shown as being incorporated with a mechanical pencil which operates upon the spiral feeder principle, obviously the same may be employed in connection with other types of mechanical pencils employing feeding means other than those controlled by a spiral element such as that shown at 34 herein. Additionally, while the element I5 herein'has been termed a crayon or lead the definition herein intended is applicable to writing elements formed of pressed graphite, graphite compounds and other variously colored compositions commonly grouped in the art and included under the term fillers. Only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

What is claimed is:

1. In a mechanical pencil of the character de' scribed, a ferrule having a central bore extending therethrough, a crayon stick disposed in said bore, means for feeding said stick to project the same from or to withdraw the same into said ferrule, a reinforcing sleeve slidably disposed in said bore and surrounding said stick and movable from an advanced position wherein a relatively short length thereof projects beyond the end of said ferrule to a retracted position wherein it is substantially fully withdrawn into the latter, and means yieldingly maintaining said sleeve in its advanced position, said sleeve being adapted when the crayon stick is projected a slight distance beyond the end of said ferrule to substantially conceal the stick and to become at least partially retracted against the action of said yielding means to expose the writing point of the stick when writing pressure is applied to a writing surface by the writing end of the pencil.

2. In a mechanical pencil of the character described, a ferrule having a central bore extend-- ing therethrough, a crayon stick disposed in said bore, means for feeding said stick to project the same from or to withdraw the same into said ferrule, a reinforcing sleeve slidably disposed in said bore and surrounding said stick and movable from an advanced position wherein a relatively short length thereof projects beyond the end of the ferrule to a retracted position wherein it is substantially fully withdrawn into the latter, and a coil spring bearing against said sleeve and normally urging the latter to its advanced position, said sleeve being adapted when the crayon stick is projected a slight distance beyond the end of the ferrule to substantially conceal the stick and to become at least partially retracted against the action of said spring toexpose the writing point of the stick when writing pressure is applied to a writing surface by the writing end of the pencil.

3. In a mechanical pencil of the character described, a ferrule having a central bore extending therethrough, a guide sleeve having an end thereof secured in said bore, said sleeve and ferrule being disposed in concentric relationship, a crayon stick extending completely through said bore and projecting into said guide sleeve, means associated with said guide sleeve for feeding said stick to project the same from or withdraw the same into said ferrule, a reinforcing sleeve slidably disposed in said bore and surrounding said stick, said reinforcing sleeve being normally freely movable relative to the ferrule and stick from an advanced position wherein a relatively short length thereof projects beyond the end of the ferrule to a retracted position wherein it is substantially fully withdrawn into the latter, and a spring surrounding said guide sleeve and bearing against said other sleeve and normally maintaining the latter in its advanced position, said latter sleeve being adapted when the crayon stick is projected a slight distance beyond the end of the ferrule to substantially conceal the stick and to become at least partially retracted against the action of said spring to expose the writing point of the stick when writing pressure is applied to a writing surface by the writing end of the pencil.

4. In a mechanical pencil of the character described, a ferrule having a central bore extending therethrough, a crayon stick disposed in said bore, means for feeding said stick to project the same from or to withdraw the same into said ferrule, a reinforcing sleeve slidably disposed in said bore and surrounding said stick and movable from a position wherein a relatively short length thereof projects beyond the end of the ferrule to a retracted position wherein said projecting length is substantially fully withdrawn into the ferrule, said reinforcing sleeve being disposed substantially wholly within said bore, a flange formed on said reinforcing sleeve, a spring surrounding said reinforcing sleeve and having one end thereof bearing against said flange to normally urge the sleeve to its advanced position, said sleeve being adapted when the crayon stick is projected a slight distance beyond the end of the ferrule to substantially conceal the stick-and to become at least partially retracted against the action of said spring to expose the writing point of the stick when writing pressure is applied to a writing surface by the writing end of the pencil.

JOHN L.. MORTON.

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

UNITED STATES PATENTS Number Name Date 2,005,485 Wells June 18, 1935 2,063,637 Stossel Dec. 8, 1936

Images