US1784969A - Top for desks and the like - Google Patents

Description

Dec. 16, 1930. R. H. MCLEOD 1,784,969

TOP FOR DESKS AND THE LIKE Filed Jan. 5, 1928 W I W INVENTOR Raymond/7f McLeod %MMMI ATTORN EY so as to have asoft, agreeable effect on the Patented Dec. 16, 193 0 UNITED, 8mm

RAYMOND H. McLEOi), OELAUREL, MISSISSIPPI, ASSIGNORY T0 MoLEOD runnirunn COMPANY, or LAUREnMIssIssIPrI, A oonronArioiv or ivrIssIssIPrr Tor Eon nEs s aim rnnmxn Application filed i'fanuaryi, 1928, 7 Serial No, 2{14,5 88."

'My present invention is shown as embodied in a wooden top for desks, tables and the like,- but certain featuresof the invention may be used for other purposes a My invention is particularly applicable to the construction of a table or desk top of the type intended to be finished or painted in solid colors rather than varnished or polished to bring out the grain of the Wood. For instance, a top for a tableor desk-made in accordance with my present invention maybe stained or painted a suitable shade of green eyes of the user; ora solid paint back-ground of any desired color maybe further decorated with a suitable pattern or picture applied by handpainting, printing or well known transferprocess; In either case, the

color coating may be protected by pyroxylin and, if desired, the gloss of the latter may be dulled by applying floor wax or similar material.

As concerns the use of solid color paints restful to the eye, my invention may be con-V sidered as an improvement over the linoleum topped desks and tables which are now much In vogue. As now made, such tops are expensive, not only on account of the cost of by what is called cross-banding by gluing sheets of veneer to oppositefaces of the core, the grain of'the veneer running widthwise 0f the table, that is, at right angles-to the grain of said'core- Over this again there is another layer of veneer, usually thinner, having the grain running the same direction as the grain of the core. This makes what is called a five-ply built-up'top. ,VVhen the core is carefully made and-the twolayers of veneer thus applied to both "faces thereof, a'fairly nonwarping structure is produced, onfthe upper fa'ce 'of which is applied the sheet of linoleum of the desired color. This product is of course expensive, and also, as I have discovered, is unsatisfactory because, although the two plies or even one ply of veneer on each face of the core may be adequate to prevent warplng, the non-warping effect isdueto'the symmetry of the tensionapplied by the tensile strength of the veneer on the 7 top surface being exactly equal to the'tension on't-he bottom surface But when linoleum is subsequently cemented to one of these surfaces and not to the other, the equality of tension 'isupset. Such equality might be re stored bygluing a similar layer-of linoleum on the bottom face of the structure,but the expense would be prohibitive.

By my invention, I am able to produce a table or desk top farsuperior to those of the prior art as concerns non-warping quality and Wear resisting quality and affording a painted surface which'may imitate linoleum or may be ornamentally painted to afford yet more original and pleasing effects. Y 7 According to my preferred method, Isub stitute forthe top layers-(one or two layers of veeneer' andone layer of linoleum) a sin glelayer of a dense composition of a peculiar kind having a practically negligible temperature expansion and substantially no humidity expansion, the: principal reason :for the lat-' ter being that the composition, is non-'hygror scopic besides being substantially waterproof under the conditions ofuse.

While there may beothercompositions hav ing the above qualities, I prefer, to use a-composition made of long fiber, resinous wood pulp, the, natural lignins or resins of the wood, preferably constituting the binder. The pulp is preferably that produced by a wellknown processfof subjecting woodenchips to the action of steam or water under suitable pressures whereby the wood is charged with Water superheated to a high temperature without burning the fiber or its natural binder material, whereupon the pressure-being abruptly released, the fibers are tornapart by the explosive effect of the instantaneously' released steam.- By suitable ,7

methods, such shredded lfiber pulp can be less than water.

felted and then formed into dense sheets by applying heavy follow-up pressure of, say 400 lbs. to 600 lbs. or more per square inch, with a suitable degree of. heat to expel water and weld the fibers by the natural gums or resins of the wood as the binder. In the preferred product, the natural wood constituents in the pulp have been compressed to a specific gravity which may be and preferably is greater thanthatof water, eventhough the i wood emp loy ed'be of specific gravity-much Its peculiarity is remark- V able tensile strength combinedwithremarkable stiffness and limited elasticity, that is to say, it iselastic under slight deflection, but .if its limited flexing elasticity be; exceeded, it snaps after the manner of a brittle substance. These qualities peculiarly adapt this composition for use-as a tensile and compression cross-banding material for a composite core in place of the veneers'heretofore used. Moreover, as the product is un1- for both faces of the core.

As before stated, the materialis practically without expansion or ClOIlllIilClllOIlLlIlClGI ordinary ranges of atmospheric heat and member or platen, and is finished to great den- According to my preferred method, aboardcold and dryness or humidity. V

When made by the preferred process, one

face of the composition,preferably the upper surface, contacts with a smooth compression sity and smoothness either with or without a lubricant or finish such-as parafline. Preferably, thesurface in contact with theothercompression member, is carried by or com pressed against some sort of reticulated sur-',

face such as a fine wire netting on which it has been felted. The surface being marked or grooved by the reticulation is peculiarly adapted to take the glue which must be .used for securing it to the core or filler. v

lVith the'above or similar sheet composition for cross-banding, I have discovered 1 that it is .not'necessary to build up a core by glued tongue andgrooveor dovetail joints.

like sheet of thecomposition of the proper size for the table top is laid on the assembly table, with aqwire-m a'rkedor raw surface V upward,"and the filler strips corresponding twelve hours. The long staple, natural wood to the ,core are simply coated with glue on their opposite faces and laid on the board until the area is filled up with such strips, whereupon asimilar board of the composition is laid overtheupper surfacesfof said strips, preferably smooth face upward. This threeplystructure is placed in clamps, subjected togreat pressure and so remains for,say,

composition described above is peculiarly adapted to absorb considerable quantities of assured, 7

tailed or glued to one another. Short pieces with irregular ends and wood having worm holes or similar defects-may bev used if the major portion of it is sound. 7

The composite material being thus built up, the rough edges 'm'ay be sawed and smoothed to precise surface dimensions required for the. top and'a protecting edge strip or molding glued against said edges. An ornamental molding may be used for this purpose. V Y 1 i The top and bottom may then be finished bygrinding off its upper surface to atrue plane exactly parallel with its lower surface, care, being taken tofleave the composition board facings of substantially the same thickness; This -has the advantage of removing the planished surface of the comg position to'expose arelatively raw surface that will take stain, paint or the like, as may be'desired. For the color, :I may use-oil .penetrate the fibers and give the desired color. The colorsurface maythen be covered with a thin,t'ransparent coat of pyroxylin,

the gloss'of whichmay be removed by wax,

as above described. Also, as above described,

any desired pictures or ornamentationsmay dicatecertainfeaturesof my method and;

lit

the productthereof. In these drawings,

Fig. 1 is aplanview of atop made in accordance with my;invention;,

filler strips may be assembled and glued to the face. of a board of the wood pulp com up beforehand .Fig. 3 is an enlarged sectional detail of I the complete product as, for instance, on the 7 line 3'3, Fig. 1.

the completed topof which only the upper composition layer 2 is'visible. 1 -Figs; 1 andl2 ind'cate the simplest and mixed with pigment and benzol which will accompanying drawings, which are Fig.2 is a schematic view indicatinghow In Fig. 1, itnwill be understood that 1 is V the molding or frame glued to theedges of lac cheapest method of assembling. As before stated, the essential for the filler strips, as

4, 5, 6, 7, 8, etc. is that they be uniformly kiln dried and that they be planed to ex sheet 3, on which are assembled strips enough to cover itand preferably to overlap the edges both at the sides and ends. While the material and size may be the same for all the filler boards, miscellaneous scrap is preferably used because it is cheaper. .As an illustration, the piece 4, Fig. 2, may be or dinarily kiln dried wood from a southern gum tree, say 4 inches wide and 3 feet long.

The next piece, 5, may be 3 inches wide of tupelo and it may be only 15 inches or so long, the remainder of the length being filled out by an entirely separate piece, 5a. 6 may be oak, 7 may be a 2-inch width of beech, etc., etc. The assembler simply has a stack of these fillers of proper thickness. He takes them one at a time and applies the opposite surfaces to the glue applying apparatus, not caring whether or not any glue gets on the side edges. Tests seem to show that the lengthwise strength is as great or even greater when the strips are not glued together laterally, but they may be so glued if desired. Preferably all the strips extend beyond the margin ofthe composition sheet both at the ends and at the sides. It is immaterial if there be quite substantial spaces up to a quarter of an inch or more between strips, as at 10, Fig. 2. V 7

After the sheet or board 00 is thus covered with filler strips, a similar board as 2, is applied in registry with x, whereupon clamps are adjusted to apply great pressure and so remain for the time necessary to allow the glue to set, say 12 hours. This is facilitated by the nature and depth of the composition employed.

Thereupon the completed structure is removed from theclamps and is sawed along or, preferably, slightly within the line a, m, to form a perfectly true rectangle with vertical edges. Thereupon the frame or molding strips 1 are glued about the edges and held in clamps until the glue is set. Finally, the entire top and bottom are sanded. off to true parallel planes, removing any slight projections of the molding 1. Preferably, a week or ten days are allowed for the struc turc to set and temper, before the final grindof'the surfaces in the sandpapering ma chine.

The resulting "product" is perfectly non;

warping and has remarkable transverse stiffness. While thestiffnessis naturally greater, the greater the total thickness of the slab, it will be found that for equal thicknesses my simple three-ply topv is stiffer and stronger than the expensive jointed and built-up fiveply tops of the prior art. I The stiffness,

density'and lue receptive quality of the top and bottoms ieets and probably also the pre-' cise uniformity of thickness of filler strips,

structure. I u i V, 4

' Inthe specific embodiment shown n F g.

, contribute toproduce a remarkably rigid 3, the composition sheets 2, 3, are e-achsubstantially one-eighth inch in thickness and the filler core three-fourths of aninch, mak

ing the total thickness of the slab one inch.v While precise dimensions are not the essence of invention and while the thickness of the core may be increased asmay be desired for the most massive table top and'mayfbe decreased to three-eighths or one-fourth inch or'less, for a card table,.it is desirable that the composition sheets bekept thick enough to ensure board-like stiffness anda tensile strengthsufficient to completely control thewarping tendencies ofthe core.

lVhile I prefer to use composition boards made by the above described process, I do not wish my invention to be limited to this pre- 7 cise material. Moreover, while the extremely simple, almost haphazard method of assembling described in connection withFig.

2 is very inexpensive and entirely satisfactory, it is evident that the same boards similarly applied to a previously built-up core In the particular case shown, most of the v filler strips are through-extending and run lengthwise of the completed top, but this is not at all necessary. Frequently, the waste end of furniture wood used for this purpose are of short irregular lengths, say 15 inches to 30 inches and it is often desirable to lay them widthwise of the completed top, instead of lengthwise as,ifor instance, in the case of a large table top, say, 36 inches by 7 2 inches. Obviously, board sheets of maximum length, say 48 inches by 96 inches, may be used to build up a single large unit which may be either used as a unit or may be sawed up into smaller units.

While I have referred to the preferred" thatis one of the reasons why it is highly desirable, if not absolutely necessary, to com- 7 day of January, A. D. 1928.

pletely protect the edges by Waterproofing expedient-s. In the present case the "med-on molding serves this purpose perfect y.

i A' raw'top orbottom surfaceexposed'by the sanding machine will take Water or La benzolstain or glue but does not soak or transmit it in the direction in which the sheet Was compressed. Consequently, any stain or filler, particularly when protected by pyroxylin as above described, makes the'eX-,

posed surfacesabsolutely proof against moisture. 1 a

I claim:

A fabricated three ply panel comprisinga sheet'of the long fiber, grainless composition produced by the high compression of steam exploded wood, reinforcing members below' said sheet and in the form of Wooden strips of uniform "thickness spaced apart Within limits which will require a minimum of material while leaving no part of said sheet unsupported through an area great enough to permit a flexure suificient to overcome the elastic limits of said sheet, a second sheet similar in size and composition to said first sheet below said reinforcing members, the

Whole united by glue and pressure into a unitary structure. a H V Signedat New York city, in the county vof New York, a nd State of New York this 4th 1-1 MC E D,

AYMOND

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