US1854905A - Pencil and method of making pencils - Google Patents

Description

April 19, 1932.

Filed Nov. 25, 1929 FIGJ.

Patented A 19, 1932 UNITED STATES,

PATENT OFFICE CHARLES KAISER, SR.) OF GARLS'IA'D'JI, JERSEY, ASSIGNOR '1'0 EAGLE PENCIL COMPANY, OF NEW YORK, N. Y.,- A CORPORATION-OF DELAWARE I PENCIL AND .METHOD OF MAKING PENOILS Application filed November 25, 1929. Serial No. 409,447.

This invention relates generally -to the manufacture of pencils, and has particular reference to the manufacture of pencils of the kind having the marking material surrounded by a sheath of wood or other fibrous material.

One object of the invention is to provide a. sheath of the materials indicated which will be stronger than prior sheaths of the 1 same material. The manner in which this is efi'ected and the advantages accruing will be explained in detail later on. It is suflicient at this point to say that the sheath is reinforced against breaking and splitting stresses in such a way that the likelihood of breaking the'marking material is reduced and, if the marking material does break accidentally or because of excess writing pressure, the piece broken off is shorter than with prior articles of the kind.

Another object of the invention is to provide a. method of reinforcing pencil sheaths which will accomplish satisfactorily the purposes desired and which will nevertheless not greatly increase the manufacturing cost.

The invention has other objects and advantages which will become apparent from the statement of a preferred practice hereinafter contained, said statement containing references to the drawings which accompany and form a part of this specification.

In said drawings:

Fig. 1 is a perspective view of a portion of one of the wood blanks used in making pencils which has been prepared according to the invention.

Fig. 2 is a perspective View of an assembled pencil containing the invention.

Fig. 3 represents the nature of the usual break of a prior pencil.

.Fig. 4 represents the nature of a break of the marking-material in apencil made according to this invention. 1

The drawings show the. manner'in which the inventions are employed in the manufacture of lead: pencils having a sheath of cedar or other wood. In the manufacture of such pencils it has long been customary to prepare slabs or blanks of substantially the length of the finished pencil and wide enough to make on its plane surfaces adjacent its grooves, is

fitted 1n position in such a way that its grooves will receive the sticks of marking material resting in the grooves of the first blank. The assembled unit is subsequently cut up into pencils of the desired exterior shapes by tools applied tothe faces of the blank. One of the pencils produced in this waiy is illustrated in Fig. 3 of the drawings.

t has for many years been observed that when one of the prior pencil points breaks, the break is within the sheath and the sheath splintered or split around the point of breakage. In sharpening the pencil the sheath has had to be cut away to remove the splintered portions as well as to expose enough of the lead to form a satisfactory writing point. I This trouble results largely from the fact that the material of the sheath is not strong enough to support the lead properly against stresses. This weakness of the material also results in wastage when sharpening pencils in the ordinary sharpeners, as the material of the sheath twists oif of the lead, often throwing a strain-on the lead which causes the lead to break off and thereby making necessary a continuation of the sharpening process.

Pencils made according to the present invention do-- not have these objections, as the wood sheaths support the lead firmly even though the sheath is, in sharpening, reduced to a quite thin edge around the writing point; the thinned material does not twist off in sharpening with-the usual machine and does not split or s linter when the writing point breaks off. s one result of this, when the lead doesbreak the piece broken ofi' is substantially only the portion which isclear of the sheath.

These and other advantages are obtained by,-in effect, reinforcing the interior of the sheath around the lead. In the preferred practice the grooves 11 in the blanks 10 are each given an application of a material WhlCll will penetrate the fibers of the wood to a certain extent and which will form a thin shell reinforcement and others did not, showed that the reinforced pencils given a pressure test at a 45 angle stood an average of 1.7 kilo rams pressure before the break occurred, an that the break occurred at the thin edge 13 (Fig. 4:); while pencils which had not been reinforced, when subjected to the same pressure tests, broke at an average of 1.1 kilogram pressure; and far enough up in the sheath to produce the splintered eifect illustrated at 14 in Fig. 3.

The reinforcing material may be any one of a number suitable for the purpose and may be applied in any way which will produce the desired effect. The best results are obtained by using a material which will be tenacious and relatively hard when set; and

applying it in such a way as to penetrate between the fibers sufiiciently to bind the fibers together after it sets and form a Very thin shell on the interior of the sheath. A good material for the purpose is what may, for convenience, be called a varnish containing any one of a number .of gums common in the varnish or lacquer field. .A varnish containing copal has proven highly satisfactory.

The varnish should contain a thinner in sufficient quantity to serve as a vehicle to carry the gum (or equivalent) into the wood fibers. A convenient way of applying the varnish is to employ a gang of spreader tools to which the varnish is supplied in any desired way, each of the spreaders operating to apply the varnish to the entire interior of one of the grooves 11.

After the grooves have been supplied with the varnish the blanks 10 may be dried in a dry room, but the best results seem to be obtamed if the drying is done on racks at about room temperature.

After the drying is completed, the fibers of the wood on the interior of the sheath will be bound together and the interior of the groove covered by a thin shell. This is represented in a somewhat diagrammatical wa'yih'oundin'g a marking material,

at 15 in the drawings. After the varnish has set, the leads are supplied to the grooves, the blanks secured together and cut into pencils just as in the prior practice. ,The grooves 11 in the blanks may be made slightly larger than a thin varnish in such a quantity as not to materially restrict the sizes of the grooves.

While the inventions have been explained in connection with the manufacture of a certain kind of pencil, it is obvious that they may be employed with other manufactures. It is also obvious that the preferred practice may be varied from in certain respects. It is, therefore, the desire not to be limited by anything stated with respect to the method or the product, except as set forth in the claims which follow.

What is claimed is-- 1. As a new article of manufacture, a pencil comprising a stick of marking material, and a wooden sheath for said stick composed of fibrous material havin the portion engaging the marking materlal treated with a tough, hard varnish in such a manner as to serve as a binder for the fibers and as a reinforcement for the sheath.

2. The method of manufacturing pencils which includes forming from a fibrous material pieces which when assembled will form a sheath for marking material, treatin with a thin gum varnish the portions of said pieces which will engage the marking material when the pieces are assembled into a sheath, allowing the varnish to dry, and then securing the pieces together around the marking material.

3. A method of manufacturing pencils and the like which includes treating portions forming the interior of the sheath with a varnish thin enough to penetrate the material of the sheath and form a tough and relatively hard shell around'the marking material, allowing suflicient time for the varnish to penetrate the material and harden, and then applying the sheath to the marking material.

4. The method of manufacturmg pencils which includes reparingpieces of wood to closely surround and form a sheath for a marking material, and treating with a relatively thin copal varnish the portions of said pieces which will engage the marking material when the pieces are assembled to form the sheath, allowing the varnish to dr and then securing the pieces together aroun the marking material.

5. The method of manufacturing pencils which includes grooving pieces of wood in such a way as that when the pieces are assembled they will form a sheath completely sura plying to the grooves a varnish thin enough to enetrate between the fibers of the wood an containing a material which will be tough and relatively hard when the varnish is dried, allowing the varnish to dry, and then -ass'embling the grooved pieces to form a sheath on themarking materlal.

6. vAs a new article of manufacture, a pencil comprising a stick of marking material, and a wooden sheath for said stick having an interior surface which has been treated with a tough, hard varnish and the varnish dried before the sheath was assembled around the marking material.

In testlmony whereof I hereto aflix my signature.

CHARLES KAISE-R, SR.

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