US2033687A - Pencil and method of producing same - Google Patents

Description

Mwdh 13.@9 QE F, Q DELl 1 PENCIL AND METHOD oF PRODUCING SAME Fild' April l2, 1933 4 I N1 m ,N

Patented Mar. 10, 1936 mural) STATES PATENT OFFICE Frank C. Deli, Chicago, Ill., assigner to Autopoint Company, Chicago, Ill., a corporation of Illinois Application April 12, 1933, Serial No. 665,730

6 Claims.

My invention relates to pencils and particularly to a novel method of construction resulting in economy in cost of production and greater strength and rigidity in operation.

It has been found to be desirable in automatic pencil construction to provide a tapered portion consisting largely oi non-metallic material in order to avoid slipperiness and to enable holding the pencil without fatigue. However, a part of the tip must be made of metal in order to provide the requisite strength. I have made a combination of metal and non-metallic parts and so designed the construction that it may be made by a series of steps in which the final structure has many advantages.

The pencil and the method of producing the parts will be more readily understood by reference to the accompanying drawing, in which:

Fig. l is a somewhat enlarged longitudinal n'sectional view through a pencil constructed in accordance with my invention;

Fig. 2 is a sectional view through the metal tube or cartridge before it has been shaped.

Fig. 3 is a similar view showing the tip after 'the first swedging operation.

Fig. 4 is a view of two telescoped tubes that are assembled as shown in Fig. 5, that figure showing the next operation, in which the cylindrical part is swedged onto the tubes.

' Fig. 6 shows the next operation in whichthe closed, tapered end has been cut off, the said end slitted, a transverse or diagonal notch cut in the cylindrical portion and tube, and a friction wing cut in the tube;-

Fig. 7 is a sectional view through the construction of Fig. 6;

Figs. 8 and 9 are views similar to Fig. 1 showing two modified forms oi the pencil construction and,

Fig. l is a sectional view on the line Ill-I0 of Fig. 6.

In the drawing I show in Fig. 1 a pencil body i@ having a reduced lower end Il, one part l2 of which is cylindrical and another part I3 is tapered. The body has an axial opening I4 therein of round cross-section.

The tip portion to which this invention relates consists of two parts, a tapered non-metallic portion l5 having a recess I6 therein shaped to t the -reduced portion H, and a metallic portion l 'l the exposed part of which is also tapered. The tapered metallic portion terminates in a shoulder I3 at the junction with the round cylindrical portion ls. Contained within the tip is -=a plain tube 20 and a threaded tube 2| telescoped therein. A transverse inclined notch 22` is cut through the cylindrical portion and the tube 20 and the non-metallic tip portion Il is molded in place, the material flowing into the notch 22 to provide an anchor. A plunger 23 5 having projections engaging the threaded tube serves to propel a lead indicated at 24 through the opening in the lower extremity of the tapered metal portion H. It will be noted that the metal at the point 25 of the tip is of thicker 10 cross-section than the remainder of the tip. The manner of obtaining this result will be described hereafter. The operation of the pencil is simple and need not be described in detail except to say that the plunger has a non-circular portion that slides within a non-circular recess formed in the part 26 of the pencil body, the lead being ejected by rotating the tip relative to the body.

In the construction of Fig. 8 the pencil body l is the same and the construction of the tip is substantially the same as that already described except that the threaded tube 2l is directly anchored into the metal tip portion Without the tube 2i! shown in Fig. 1. The operations of manufacture are the same with the exception noted.

In the construction of Fig. 9 the pencil body likewise remains the same and the tip construction is identical except that the tube 28 is threaded only at the upper end, said upper end 30 29 being swedged slightly to reduce the diameter and interiorly threaded at the reduced portion. This-entails a smaller or finer thread in the part 'Z9 and on the plunger 3) instead of the large rolled threads shown in the preceding illustrations. Otherwise the tip construction is the same.

Certain structural characteristics of a pencil body and tip give rise to the necessity for the production of the tip in the manner hereinafter 40 described. For example, it would seem, without knowledge of the actual facts, that the tapered metalic portion of the tip and the tube 2t, might readily be formed of one piece and thus .avoid the operations that are required to asthe sleeve 20 is, for practical purposes, out of the question. However, the tapered metalic portion I1, must be composed of relatively heavy metal, first, in order to provide adequate strength at the slitted end, and second, to enable the swedging of a relatively deep and sharp shoulder I8 at the point where the non-metalic molded material joins the metal portion I1. This could not be secured in a thin metal construction. For this reason, a part, such as shown at 2|,

is provided, the walls of which are of increasingA thickness from the open to the closed end. By the swedging operation described, the epen end is reduced in diameter, thereby thickening the walls and providing the adequate material at the point described.

The method of production of the tip portion is illustrated in Figs. 2 to 7 inclusive. The metal tip part is formed from a tube 3| having a closed end, the thickness of the metal of the tube increasing from the open to the closed end as best shown in Fig. 2 the showing being exaggerated. Of course, a tube open at both ends may be used, the wall thickness being progressively greater toward the end that is to be the small end of the taper. However, I prefer to use the closed tube as shown. In the next operation the round tube is located within the part shown in Fig. 3 and thereafter the cylindrical part 32 is swedged to reduce its diameter and the tube 20 is very slightly compressed as shown in Fig. 5 forming a mechanical bond between the parts. In the next operation as shown in Fig. 6 the pointed closed end is cut off to leave a lead opening, slits 33 are provided in the said end, a transverse notch 22\ is provided in the cylindrical part, and the wing 34 is cut in the tube 20. After the slitting operation a `further swedging operation is performed on the slit end to close the slits and insure a round lead opening. The threaded tube 2| is then placed within the tube 20 and an additional swedging operation performed to hold the tubes in proper position until the next operation is completed, that is the molding of the tip in place. The non-metallic tip part I5 is then molded in the position shown, providing a'uniform taper practically from end to end of the tip, the molding material being pressed into the notch 22 to insure a bond between the metallic and non-metallic parts and to anchor the spiral tube in place. It will be understood that while we have spoken of swedging'operations in changing the shapes, the same result may be secured by other machine operations.

The function of the wing 34 is to insure a substantially uniform friction between the tip and the body. Thus it is not necessary'to'rely on varying frictional contact between the reduced lower end of the body and the tapered recess in the tip.

The advantage in the type of tip construction shown is that a stiff and permanent lead-gripping point may be made without the use of excessively thick material'in the remainder of the tip. The greater wall thickness of the part 3| at the closed end insures additional wall thickness of the slit end through which the lead projects.

It is obvious that the construction may be utilized in other modifications than those shown and I do not wish to be limited except as indicated in the appended claims.

VI claim:

1. The method of making pencils which consists in providing a relatively short tube having one end closed, then swedgin`g the closed end to provide a taper therein, thereby somewhat elongating the tube, then positioning an elongated tube axially within the swedged member, then swedging the cylindrical portion of the member into close contact with the exterior of the elongated'tube, then cutting off the closed tapered end and providing longitudinal slits in said tapered end, and then forming a nonmetallic moldable material over the swedged cylindrical portion of the assembly in order to provide a complete tip portion for a pencil.

2. The method of forming pencil tips with attached lead feeding mechanism consisting of the. steps of swedging the closed end of a cylinder to provide a tapered portion and a cylindrical portion, then swedging the cylindrical portion over a threaded tube, then cutting off the closed tapered end, slitting said end and providing a transverse notch in the swedged cylindrical portion, then molding a non-metallic material over said swedged portion, the material entering the notch therein.

3. The method of forming pencil tips having an attached lead projecting mechanism, consistingfof swedging a cylinder having a closed end to provide a tapered portion on the closed end and a cylindrical portion of a diameter less than the largest diameter of the tapered portion,

the swedging operation by which the cylindrical portion is formed serving to confine a tube within said cylindrical portion, then cutting oi and slitting the extreme end of the tapered portion, then providing a transverse notch in the cylindrical portion, then molding a tip portion over said cylindrical portion and forcing a quantity of the material into the notch.

4. In a pencil tip, the lower end of which is tapered and the upper end of which is cylindrical and 'of less diameter than the large diameter of the tapered portion, a threaded tube anchored within said cylindrical portion, registering notches being provided in the cylindrical portion and'said'tube, anon-metallic tip portion being overy said cylindrical portion and projecting into said notch and shaped to correspond to theA taper of the metal tip portion.

5. In combination, a pencil tip consisting of metallic and'non-metallic portions, the metal portion consisting of an element having a tapered lower end, the lead outlet end being of greater Wall thickness than the remaining portion,v the element having a cylindrical portion of less diameter than the largest diameter of the tapered portion, a :tube confined within the cylindrical portion, the cylindrical portion and tube having a registering transverse notch, the non-metallic portion of the tip being formed over the cylindrical portion and projecting into the notch therein.`

6. In combination, a pencil tip consisting of metallic and non-metallic portions, the metal portion consisting of an element having a tapered lower end, the leadoutlet end being of greater wall thickness than theremaining portion, the element having a cylindrical portion of less diameter than the largest diameter of the tapered portion, a tube confined within the cylindrical portion, the cylindrical portion and tube having a registering transverse notch, the non-metallic portion of the tip being formed over the cylindrical portion and projecting into the notch therein.

FRANK C. DELI.

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