US3316684A - Plywood panel construction - Google Patents

Description

y 2, 1957 D. A. PROUDFOOT PLYWOOD PANEL CONSTRUCTION Filed May 8, 1964 FIG. 2

FIG. 3

I30 M m mm W HOA INVENTOR DON A. PROUDFOOT 9' fir ATTORNEYS United States Patent 3,316,684 PLYWOOD PANEL CONSTRUCTION Don A. Proudfoot, Cedarwood Drive, Greenwich, Conn. 06830 Filed May 8, 1964, Ser. No. 365,896 4 Claims. (Cl. 52--615) This invention relates to plywood panel constructions, and more particularly to such constructions for interior and decorative finish uses. It is principally concerned with the problems attending the use of low grade wood veneers with stained finishes, for interior plywood panelling. Even more specifically, the invention evolves around the use of comparatively, structurally weak, low grade veneers for interior plywood panel facing.

A prime example of a low-grade wood veneer, previously considered as fit only for interior ply or crossbanding use is a very low-grade Douglas fir veneer, known as white-pocket veneer and so called because of depressions and holes in the veneer, the surfaces of which are white, the condition arising because of a fungus, Fom-es pini, which infects a good quantity of Douglas fir trees.

Previous attempts have been made to use white-pocket veneer as the face stock for interior plywood panels. These attempts have failed as it is a practical impossibility to obtain either rotary cut or sliced white-pocket veneer in commercial quantities with a uniform enough field of infestation over the face of a 4 x 8' sheet and between one sheet and another. Furthermore, as rotary cut fir veneer is literally peeled from lo-gs roughly parallel to the annual growth rings, it presents a most unattractive facing material because of the great contrast in density and appearance between spring and summer wood, resulting in wild and non-uniform configurations of grain. Sliced veneer of the white-pocket variety although presenting a better grain appearance, has still been considered undesirable because of infestation non-uniformity.

Two further problems have kept low grade wood veneer of the white-pocket variety from any appreciable use as interior plywood facing material. The first is that due to lower density characteristics of such veneers, as opposed to the higher grade woods, and due to the weakening of the veneer because of the fungus infestation, a panel with a facing of such a veneer would be structurally unbalanced if merely replacing the normally higher grade or uninfected facing with the lower grade infected wood were attempted.

The second further problem which has kept low grade wood veneers of the white-pocket variety from use as interior plywood facing material arises because of the usual veneer strip construction of plywood panels. In laying up plys of wood veneers, the better grades of wood yield approximately 6 to 20 inch width strips which are joined along their sides to make up the normal four foot width of the standard 4' X 8' panel. White-pocket, in such widths presents an aggravated, undesirable picture of non-uniform fungus infestation, knots and wild configurations of grain. To merely use lesser width strips of the low grade veneer would not solve the appearance problem appreciably as the use of even the selectively available 3 to 8 inch width strips, of white-pocket do not sufficiently minimize the infestation nonuniformity and undesirable grain configurations. Furthermore the appearance of so many smaller width veneer strips as a facing creates its own unattractive results.

It is an object of the present invention to permit the use of low grade wood veneer as face stock by overcoming the appearance and structural problems just discussed.

In a practical embodiment of the invention there is provided a decorative plywood panel having a back ply of low grade but sound wood, a center ply of any acceptable grade and in accordance with the invention, a stained facing ply comprised of comparatively narrow side by side, edge joined veneer strips of low grade wood having commercially intolerable appearance and structural characteristics, such as wild grain configuration, and in the case of white-pocket veneer, non-uniform fields of fungus infestation, the grain configurations and fields of infestation differing appreciably in each strip and from strip to strip. In .further accordance with the invention, strips of decorative and structural media, preferably of a density and strength greater than that of the facing veneer, and comparatively thin in thickness and sometimes in width relative to the facing veneer strips, are laid up on the facing veneer, preferably overlying the veneer joints from the top edge to the bottom edge of the panel.

The strip media, which can be made of metal, plastic, or any other material compatible with the appearance and structural demands of the decorative panelling, constructed .as described, accomplishes two aims when used in this environment. First it breaks up the unattractive grain and infestation patterns so that wildness and nonuniformity, respectively, are lost in the overriding design of finished, albeit infested, wood sections alternating with strips of media having a contrasting design impact. Just as importantly, the addition of the structurally stronger strips to the weakened facing of the infected veneer, restores balance to the otherwise unbalanced panel so that warpage and other distortions due to hu .midity changes, for instance, which would seriously affect a panel having a weak face veneer on one side and not on the other, are kept within acceptable tolerances.

In this last respect the invention contemplates that the material for the strip media can be such that its dimensions will be relatively stable regardless of moisture content or environment. Thus, materials which are comparatively non-porous and non-absorbent of water are well suited for use as strip media.

The application of the strip media to may be by gluing and may take the form or inlay, either within into the veneer.

Because of the comparatively small widths of low grade veneer which results from selecting the stock to eliminate knotes, for instance, and to attain a reasonable degree of uniformity of pocketing, it is desirable to lay up the strip media along the veneer joints to eliminate the appearance of the joint and where larger widths occur over any particular veneer strip, a strip of the media may be placed intermediate the edges for appearance or balancing purposes.

In carrying out the objects of the invention it has been found that where metals are concerned, strip media made of copper metals are particularly compatible with the structural and appearance characteristics of the invention. Copper, brass and bronze provide very desirable architectural results. Other metals such .as aluminum are also considered quite compatible.

The above and further objects of the invention are deducible from the following description of a specific embodiment thereof when taken in conjunction with the drawings, of which:

FIG. 1 is a perspective view of panel incorporating the invention;

FIG. 2 is a magnified, transverse section through a portion of the FIG. 1 panel; and

FIG. 3 is a transverse sectional view of a pair of panels incorporating the invention and showing an edge joint between the two panels.

The plywood panel 10, shown in FIGS. 1 and 2 represents a one quarter inch, three-ply panel having a back ply 11 of low grade but uninfested wood (which may be the facing veneer of face mounting pre-formed grooves, or pressed an interior plywood grade D for instance), a cross band ply 12 which may be of any suitable grade, and a facing ply 13, made up of side by side and conventionally edged joined strips ISA-ilSAA of white-pocket Douglas fir, rotary cut veneer. The plys are glued together in conventional fashion and, as is usual, the grain, not shown, except for grain configurations g in facing ply 1 3, in any one ply runs generally perpendicularly to the grain of each adjacent It should be understood that a panel having five or more plys can be readily adapted to incorporate the invention so long as it includes the low grade facing veneer and strip media as described.

The fungus infection of the veneer strips 13A 1 3AA is shown by the presence of depressions and holes 14 in the body of the consequently weakened veneer strips.

It can be appreciated that the areas of fungus infestation in the facing ply 13 would, over wider areas, present an intolerable blotchy appearance in a panel made up only of edged joined facing veneer strips.

It can be appreciated too, that the wild grain configurations due to the rotary cutting of the fir log parallel to the annual growth rings and through spring and summer wood, if carried through in larger width areas, such as are available in uninfected wood veneers, would be extremely unattractive as indeed they are, though minimized, even in the smaller, 38 inch width areas which are available, through selection, in white-pocket veneers.

Furthermore, the extra number of joints in a veneer facing of the white-pocket fir, resulting because of strip selection would result in another impossible appearance characteristic in that too many veneer strips, as against the normal number of strips required where 6-20 inch conventional strips of veneer are used, are apparent on the face of the panel.

In order to overcome these appearance problems and in order to add strength to the weakened, infested facing ply to restore balance between the back and facing plys, the strip media of the invention is applied to the facing ply.

As shown in the drawing, strips 13A include in their outer faces grooves 15, pre-formed by sanding or routing at the veneer joints 16 and penetrating the bodies of ad jacent veneer strips so that the strip media can straddle adjacent veneer strips and cover the veneer joints.

Grooves, such as 17 (FIG. 2) intermediate the edges of a comparatively wider veneer strip 13AA are provided to receive the strip media for appearance purposes or for structurally balancing the facing panel 13 as against the back panel 11.

In accordance with the invention, strips of metal 18 are inlaid within the pre-formed grooves 15, resulting in a design of laterally spaced parallel strips of alternating finished wood and metal. The facing ply 13 is thereby strengthened and a most attractive design impact is provided by the breaking up of the grain and infestation patterns in the veneer strips 13A-13AA with interspaced strips of metal.

The strips 18 are shown in the drawings to be fabricated of metal, and in practice, copper metals have been found to be structurally and architecturally very compatible with wood finishes. It can be appreciated, however, that many different metals, for instance, aluminum, can be used for the strip media.

Furthermore, the strip media need not be restricted to metals but should preferably be fabricated of a material which is comparatively non-porous and non-absorbent of water, as well as structurally sounder than the low grade veneer strips 13A, so that it will not only add strength to the facing ply for balancing purposes, but will also be such as not to be subject to dimensional changes due to changes in moisture environment.

It should also be understood that the strip media need not be inlaid in groove b t m y be face mounted. The

structural and appearance advantages have also been obtained in this manner.

In accordance with what particular materials are used for the strip media, the staining or other finishing of the wood can be done before or after the laying up of the strip media, and the affixing of the media upon the facing ply or within the grooves can be accomplished by well known adhesives, the choice of which will depend upon whether metal, as shown, is used for the strip media or whether other types of materials are used.

To facilitate the utilization of panels constructed in accordance with the invention, it is contemplated that the side edges of such panels may be provided with mating grooves to accommodate strip media at the edge joint. Thus the design effects of the alternating wood and strip media are carried through from one panel to the next. Also a facile and undetectable edge joinder operation, in situ, with more permissible alignment tolerances than is the case with conventional panels, is permitted.

As can be seen in the FIG. 3 presentation, the edges of panels 101 and 111 are provided with complementary L grooves 26 within the facing plys 130 along their laterally joined edges at edge joint 25. The panel back plys 110, A are, for purposes of illustration, laid flush against studs such as stud 27 and fixed in place via nails 28. The metal strip media 30 at the edge joint is set in place via any of the well known adhesives for fixing metal to wood and can be of the pressure sensitive variety.

Now it should be understood that the invention provides a most decorative interior plywood panel which utilizes for its facing ply, extremely low grades of wood and even such structurally weakened grades of wood as whitepocket, Douglas fir. Even though such facing material is structurally weaker than the back ply of the panel, the invention provides for a balanced panel because of the fact that the strip media used adds strength to the facing ply. In this last respect, the invention also contemplates the use of strengthening decorative strip media on both sides of a decorative panel in a custom situation when both sides are to be viewed.

It should be understood that although a specific embodiment of the invention has been shown and described, the scope of the invention is to be limited only by the scope of the appended claims.

What is claimed is:

1. A plywood panel for interior decorative use comprising a plurality of plys including at least a back ply and a facing ply, said facing ply being constituted by edge joined strips of a low grade wood veneer of a strength and appearance unsuited for use as a facing ply and having an outer surface, and strips of material of higher strength characteristics than said low grade wood veneer of said facing ply, said strips of said material being secured to said outer surface of said veneer strips of said facing ply and strengthening said facing ply and improving the appearance thereof to render said low grade wood veneer suitable for use as a facing ply.

2. The plywood panel of claim 1 wherein grooves are formed in and extend only partly into said facing ply at its outer surface and said strips of said material are secured within said grooves.

3. The plywood panel of claim 2 wherein said grooves are formed along the joined edges of said veneer strips.

4. The plywood panel of claim 1 wherein said low grade wood veneer is of the white-pocket variety.

References Cited by the Examiner UNITED STATES PATENTS 2,090,529 8/1937 Gram 52-622 X 2,253,667 8/1941 Warner 52622 X 2,315,967 4/1943 Knowlton 161--36 X HARRISON R. MOSELEY, Primary Examiner.

P. M. CAUN, Assistant Examiner.

Claims (1)

1. A PLYWOOD PANEL FOR INTERIOR DECORATIVE USE COMPRISING A PLURALITY OF PLYS INCLUDING AT LEAST A BACK PLY AND A FACING PLY, SAID FACING PLY BEING CONSTITUTED BY EDGE JOINED STRIPS OF A LOW GRADE WOOD VENEER OF A STRENGTH AND APPEARANCE UNSUITED FOR USE AS A FACING PLY AND HAVING AN OUTER SURFACE, AND STRIPS OF MATERIAL OF HIGHER STRENGTH CHARACTERISTICS THAN SAID LOWER GRADE WOOD VENEER OF SAID FACING PLY, SAID STRIPS OF SAID MATERIAL BEING SECURED TO SAID OUTER SURFACE OF SAID VENEER STRIPS OF SAID FACING PLY AND STRENGTHENING SAID FACING PLY AND IMPROVING THE APPEARANCE THEREOF TO RENDER SAID LOW GRADE WOOD VENEER SUITABLE FOR USE AS A FACING PLY.

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