US339199A - Compound lumber - Google Patents

Description

(No Model.)

J. MARIS.

GOMPOUND LUMBER.

4 Patented Apr. 6, 1886.

WITNESSES N. PETERS. Plwmulm mr, Wishingion. D. t:v

STATES PATENT Orricn.

JARED MARIS, OF PHILADELPHIA, PENNSYLVANIA.

COMPOUND LUMBER.

SPECIFICATION forming part of Letters Patent No. 339,199, dated April 6, 1886.

Application filed May 15, ISES. Serial No.165,023. (No model.)

To all whom it may concern.-

Beit known that I, JARED lVIARIS, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Methods of Manufacturing Compound Lumber from which Articles or Structures are Formed; and

'I do hereby declare the following to be a full,

clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improved method of manufacturing compound lumber from which articles or structures are formed, the object being to strengthen or stiffen or lighten such articles or structures and regulate the expansion thereof; and it consists, first, in removing portions of the wood from the piece from which the structure or article is to be formed and introducing into the recesses or cut-away portions separate and independent strips or pieces of wood or material of such form and character as will serve to strengthen or stiffen or lighten the completed article or structure or to regulate the expansion thereof 5 second, in removing portions of the wood from the piece from which the structure or article is to formed and introducing into the recesses or cut-away portions separate and independent strips of wood or material in such manner that they will break joints one with another; third, in removing portions of the wood from the piece from which the article or structure is to be formed and introducing into the recesses or cut-away portions very thin strips of wood or material, in such a manner that they will break joints one with another and allow of the employment of a great number of re-enforcing or supplemental strips in a comparatively small space; fourth, in removing portions of the wood from one side or face of a piece from which the article or structure is to be formed and introducing into such recesses or cut-away portions separate and independent strips of wood or material, so as to extend only partly through the main piece; fifth, in bending a piece of wood into any desired form, and then cutting or forming recesses therein and introducing into said recesses separate and independent strips of wood or material, for strengthening or lightening or regulating the expansion of the completed structure or article; sixth, in certain other features of invention in the method of forming structures or articles from wood, as will be hereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure l is a plalrview of a straight piece of wood having strips of wood inserted therein in accordanee with my invention. Fig. 2 is alongitudinal section, and Fig. 3 is a transverse section, of the same. Figs. 4, 5, and G are similar views of a straight piece of wood having strips of wood inserted therein from its oppo site sides. Fig. 7 is a detached view of one of the strips for insertion into the piece. Fig. 8 represents a bent strip of wood having pieces inserted therein from one side. Fig. 9 is a similar view showing the pieces inserted from opposite sides. Fig. 10 is a cross section of a piece of wood having strips inserted from its sides so as to intersect one another. Fig. 11 is a cross-section of a square piece of wood having strips of wood inserted in its sides, and Fig. 12 is a crosssection of a round piece of wood with strips of wood inserted in its periphery.

In Figs. 1, 2, and 3, A represents a piece of wood having elongated slots a formed therein by means of a circular saw or by other means. These slots are preferably made very narrow and extend only partly through the piece, so that the side opposite the saw kerfs or slots remains undisturbed and uncut. The slots are also preferably formed so as to break jointsin the manner shown. \Viihin each slot is inserted a thin strip of wood made in the form illustrated in Fig. 7, the curved edge of the strip being cut so as to conform in shape to the bottom of the saw-kerf and fit snugly therein. To retain the strips against displacement, they are secured within the slots by means of glue or other cement. By making the saw-kerfs very narrow and inserting correspondingly thin strips therein and arranging the latter so as to break j oints,as described, I am enabled to materially strengthen the piece and increase its elasticity without adding to its size or weight. Instead of forming the saw-kerfs in one side only of the piece, they may be formed in opposite sides thereof, as shown in Figs. 4, 5, and 6, and in some kinds of work this plan may be'the preferred one.

In Fig. 8 I have represented a piece of wood which is bent into any desired form, after which recesses or slots are formed thereinand the strips of wood inserted within the recesses.

In Fig. 9 the piece is bent and the stripsinsert-ed into the opposite sides of the piece that is to say, into the concave and the convex surfaces of the strip.

- in slots extending around the entire circumference of the piece, such methodbeing resorted to in articles of sufficient size to admit of the insertion of the strips on all sides or within the entire periphery of the piece of wood of which it is to be formed.

Many important advantages are derived from my improved method of manufacturing articles or structures from wood, and of the number the following are enumerated: In such articles or structures as require to be compact in form and size and of maximum strength the insertion of thin strips within correspondingly narrow slots in the piece of wood, so that the strips shall overlap and break joints, enables me to greatly enhance the strength of the piece, as it allows of the employment of any suitable kind of wood, and to re-enforce and strengthen it by the thin strips,which are arranged so as to conform as nearly aspossible to the arrangement of the natural fiber of .the wood, and as the re-enforcing or supplemental strips may consist of very hard, tough, and elastic wood, they serve to add very materially to the strength of the piece so re-enforced. Again, the elasticity of a piece of wood may be greatly increased by resorting to my improved process, as a piece of wood having a limited amount of elasticity, when re-enforced by thin strips of tough and elastic wood inserted therein in the manner described, is rendered exceedingly resilient and strong, and thereby adapted to many uses for which it could not be used in its natural state. Again, by inserting-the thin strips of wood within thenarrow slots in such a manner that the grain of the strips will intersect or be arranged across the grain of the piece, the latter will be stiffened. and prevented from cracking or splitting; also, the expansion and contraction of a piece of wood may be increased or decreased or equalized by the employment of there-enforcing or supplemental strips.

It is well known that wood expandsin a direction transverse to the length of its fiber and not in a line therewith. Hence by inserting the thin strips of wood so that the grain of the strips shall be arranged at right angles to the grain of the piece the tendency of the piece to expand or contract will be in a great measure counteracted by the tendency of the fiber of the strips to expand in an opposite direction. By a proper location and arrangement of the thin strips the expansion of the piece of wood may be regulated and controlled as desired.

In many instances a cheap grade of wood may be utilized by properly re-enforcing its strength or stiffness or elasticity by the employment of the supplemental strips, as described, and also a structure of minimum weight may be secured by this process, as it allows of the use of the lightest species of wood, which may be properly strengthened and stiffened throughout its length, or at any point where it may be subjected to heavy strain or weight.

In the manufacture of articles from bent woodthe process described is of value and importance, for the following reasons among others that might be cited:

It is well known that the tensile strength of wood exceeds its collapsing or crushing strength. Thus, for example, when a piece of wood is bent, the fibers on the inside of the curve will fold onto themselves, while the fibers on the outside of the curve will retain their normal position, or nearly so. N ow, when a piece of wood thus bent into curved form is allowed to absorb moisture from an source, the lateral expansion of the folded fibers will tend to lengthen the inner face of the curve, and hence to straighten it. This change of curve is a serious objection in all cases where symmetry or joints are affected thereby. By inserting the thin strips of wood into the narrow saw-kerfs on the inside of the curve, the grain of the strips being arranged in line with the grain of the curved piece, the tensile strength of the strips is utilized in counteracting the tendency of the crowded fibers on the inside of the curve to expand, and thereby retains the piece in its curved form.

As my improved process is applicable to a great variety of special purposes, I do not restrict myself to any particular purpose for which it may be used.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A strip or piece of wood having a series of short narrow strips or pieces, substantially as described, secured within short narrow slots formed with the strip or piece, substantially as and for the purpose set forth.

2. The method of manufacturing compound lumber, consisting, essentially, in forming a series of narrow slots in one or more faces of a piece of wood and securing withinlsaid slots thin strips or pieces of wood, the said thin strips being arranged to break joints with one another.

3. The method of manufacturing articles or structures of bent wood, consisting in first bending the wood into the desired form, and then forming narrow slots therein and inserting within the slots thin strips of wood, substantially as set forth.

IIS

4-. A piece of wood provided with narrow 6. A piece of wood having narrow semicirslots arranged to break joints one with ancular grooves therein and thin strips of wood other, and thin strips of wood secured within semicircular in shape inserted in said grooves. said slots so as to break joints, substantially In testimony whereof I have signed this 5 as set ;|:'orth. specification in the presence of two subscrib- I 5 5. A piece of wood provided with narrow ing witnesses. slots extending partly through the piece, and JARED MAR-IS. narrow strips of material secured within said \Vitnesses: slots so as to break joints, substantially as set G130. L. MARIs, 1o forth. ARTHUR M. \VARE.

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