US1772309A - Pencil - Google Patents

Description

Aug. 5, 1-930.

III

V. H. FORSSMAN PENCIL Filed Deo...20, 1929 //7 venfor V 4 7arssm n the cutting in one direction. only when being" Patented Aug. n

first Unis sT Application filed December 0,'192-9,Serial No.

The object ofjthe present invention is to provide lead pencils. or the like with strong wood coverings adaptedto be satisfactorily sharpened, by employing any desired unseasoned timber and obtaining avery high yield therefrom. It is based upon the discovery that the great stiffness in the longitudinal di rection of the lead pencils ofselected high grade timber that have hitherto been satis factory, and also their inclination tofavour sharpened, are based upon'the arrangement of the wood cells'in these coverings Cells of wood are-elongated,spindle-shaped hollow beamsof great elasticity and strength in relation to their size. In these good pencils they. alllie very approximately in the direc- 'tion of thelead, and therefore have a stiffen- .ing effect, and furthermore almost entirely guide the knife, according ,to their form and arrangement,when cutting in the desired direction.

The invention consists in the manufacture of protective coverings from wood foils with a large number of uncut cells lying in the plane of the foils and of cells lying in other directions mostly out, these foils being so ar* ranged round the lead, by winding them round it for example, that the direction of the fibres is at least approximately the same as that of the lead. 7

Such wood foils are delivered, as is known,

by a peeling machine for'example, with a very large yield, even when preference is given to fresh unseasoned trunks of all kinds of timber. It has been found advantageous to peel roughly, that is to say, to turn thepeeling knife to the trunk at quite a large angle to thetangent tothe trunk so that it partly cuts and partly shaves. Underthese circumstances-it pushes the wood fibres still more into the right direction, namely,'the direction of the cutting edge. Moreo'ver the foils are then softer and more porous, as a result of which they admit of being coiled better, and subsequently shrink more, thatis, form a firmer stick. Timbers orpa'rts thereof which are too hard are thereby equalized. i The invention is illustrated by way of ex- "as applied to a tree trunk,

wood-has here to be ping the foil 2 round the lead 4: a protective and in Germany November. 192:7;

ample in the accompanying drawings in which Figure 1 illustrates the peeling operation Figure 2 shows a off a trunk, and v Figure 3 a pencil lead wound round-with such afoil. V y i Figure 4: is a plan view'of the lead pencil, shown in Figure 3.

InFigures 5 and 6 are illustrated devices for shaping andhardening the lead pencil coverings. I 1 The fresh trunk 1 of any desired kind of regarded as being clamped in a peeling machine and a foil 2 as being taken off by a peeling knife 3. The grain therefore runs transversely to the direction of movement of the sheet of wood, and the great majority of the cells, provided the thickness of the foil isadapted to the kind of timber, are not cut through, and liein the plane of the foil, while cells extending in other directions are cut through. By wrappart of a wood foil peeled covering 5 is obtained. This protective covering may of course also be produced in other wayswith the same result, for instance two or more foils may first be assembledwith the grain in the same direction to form a thicker sheet of wood, and thereupon formed into a covering.

In order further to enhance the strength of the 7 covering 5 the latter may be passed through a pressing device, which may for example be constructed in the manner of a nozzle, or consists of a plurality of heated rollers 6 (Figures 5 and 6) ,the' working surfaces of which unite at their positions of contactwith the wood covering 5 to form the desired cross-sectional shape. It is also possible to employ a plurality of roller stages'in series This manufactureof pencil coverings per mits of the employment of-almost any kind of timber. Hard woods can be made porous by into strong coverings with very m0 What I claim is v 1. A lead pencil comprising a graphite core and a Wrapping of Wood f0il, the breadth of the Wood foil being equal to the length of the pencil. v

2. A lead pencil comprising a graphite core, and a wrapping of Wood foil, 7 the breadth jof the weed foil being equal to the length of'the pencil, 'the cells ofthe, Wood foil that are substantially parallel t0""the core I not being cutthroughg, and the cells that are not substantially parallel to the core'being cut through. Y

In testimony whereof I have signed iny 7 name to' thi specification.

E AD HENRIK FORSSMAN.

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