US 2337792 A
Description (OCR text may contain errors)
Dec. 28, 1943. F. A. YoKELl. 2,337,792
ARTICLE OF MANUFACTURE AND PROCESS FOR- MAKING SAME Filed Feb. 1o. 1942 l a ,l
/f YOA/fL 5)/ Patented Dec. y
MANUFACTURE aan raooass Foa MG SAME Frank A. Yokell, Gresham, Greg. 'A'ppueadon February 10,1942, semi No. 430,134
` 4 Claims.
This invention relates generallyl to the woodworking art and particularlywto-'the plywood industry and a special referenceto forming of plywood and the method ,ofv producing same.
Before entering into anveiql'anation of this invention, it must be understood that plywood is constructed of a plurality lof sheets of veneer glued in a superimposed relationship to form a board in which the grain in ther-various layers is normal to the grain in the :next adjacent layers.
It is a well known fact thatwith the increasing scarcity of suitable Veneer-logs, increasingly greater percent of thelogsiar'eused up in the making of plywood, which means that in order to obtain a good face oneachply board that a clear veneer must be used or it must be slit to remove the knots or defects, o ij,the defects mal be cut out and patched as fispornmonly the case so that when the board is`nally finished, it will present a complete and new appearance.
Owing to the cost of labor and materials, the patching of plywood haslbeen practically abandoned on at least one sideofytheboard, and when knots occur on one face ofthe board, they must either be patched or allowed to remain vacant in case the knot should fall out. This limitsP the use o the board to one side and the board is sold at a reduced rate and known as a reject Recently, there has been a marked increase in the adoption of knotty lumber for home finishing purposes and although plywood i s commonly used for interior finish, 'it is difiicultto maintain the knots therein owing to the fact that the veneer is thin and is caused to bend considerably before it is fabricated into plywood boards.
It is therefore the main object of my invention to construct a plywood board vwhich will utilize the knotty portion of a veneer log and yet produce a finished lumber without danger of having the knots fall out afterl the fabrication thereof. j
I accomplish these andother objects in the manner set forth in thefollowing specification,
as illustrated in the accompanying drawing, in which:
y Fig. 1 is an enlarged, fragmentary view through a piece of plywood from which a knot has fallen out.
Fig. 2 is a plan of Fig. 3 is a View similar to Fig. l showing the knot hole filled with a suitableplastic.
Fig. 4 is a plan of Fig, 3.
Fig. 5 is a side elevation of a piece of transfer paper.
Fig. 6 is a plan 'of Fig. 5.
Fig; 'I is a section 'through the plywood after the imitation knot and its surrounding surface have been sanded.
5 Fig. 8 is a plan of Fig. '7.
Fig. 9 is a fragmentary view showing a` mallet having a rubber stamp mounted on each of its heads.
Fig. 10 is a plan of the mallet head showing the rubber stamp making the annular rings.
Similar numbers refer to similar parts throughout the several views.
Referring in detail shown a piece of plywood consists of three plies of veneer I2, I3 and IS.
In Figs. 1 and 2 is shown a vacant space I5 formerly occupied by a knot which had fallen out either during the cutting of the Veneer from the log, or in the handling thereof.
In Figs. 3 and 4, which are similar to Figs. 1 and 2, is shown a plug I6 of plastic material to the drawing, there is II which in this case such as sawdust, preferably of a dark or stained wood, or of pulverized knots themselves; the binder employedbeing preferably of a resinous nature which will become effective in the presence of heat.
It will be noticed in Fig. 3, that the surface il of the plug l5 is left somewhat rounded.
Zin Figs. 5 and 6 is'shown a paper transfer i8 upon which are printed with transfer ink the lines 9 which represent the annular rings of the limb which form theiknot. The ink, or stain, employed to make the lines IS may be of the ordinary 'transfer variety or of one which will readily penetrate the plastic material IG when l heat is applied thereto.
It is important to note that before filling the space i5 with the plastic I6, it is necessary to coat the interior of the space I5 with an adhesive 2E 'to insure the imitation knot remaining in position.
In the formation of the imitation knot by the means thus far set'forth, it is desirable to have on hand various sizes and types of transfer papers it in order to` avoid any objectionable similarity in the knots. Itwiil be noted that if the rings i9 on the transfer I@ are larger than the opening I5, that there will be no transferring action upon the wood since there will be a lack of moisture, but where the moist plastic occurs, the coloring matter will extend well into the material and will not be'removed by the subsequent sanding thereof, although such sanding would remove any such stain as might be produced by the over-hanging rings It.
A further advantage arising from the use of the transfers I8 exists'in the prevention of a gluing action taking place between the boards themselves wherever an imitation knot is located.
In some instances, it will be found desirable to employ a mallet 2| upon whose striking faces 22 are mounted the rubber stamps 23 which are formed to resemble the annular'rings of a knot. The stamp is preferably pressed against an ink pad, and then the mallet 2i is used to strike over the plastic plug I6 causing any surplus plastic to be squeezed out laterally while the stamp itself presses `slightly into the space i5 forming slight annular rings which will not be .obscured by the sanding process.
I am aware that it has long been the practice to illl defects in wood by means of what is known as plastic wood. It is therefore not my intention to cover such 1actions broadly, but I do intend to cover all such forms and modications of the article and the method for making same, as fall fairly within the appended claims.
, I claim: l
1. An article of manufacture `consistirig of a plywood board from a i'lat side of which knots have been removed and the knot holes lled with soft plastic, and a plurality of annular rings formed in thebody of said plastic whereby the plastic material may be sanded` flush with the surface of `the board without removing said rings.
2. An article of manufacture consisting of a plurality of plies of veneer united by adhesive to form a single board, an outermost face of which has knot holes formed therein caused by the removal of the knots during fabrication, a. layer of adhesive extending across the bottom of the knot hole and around the sides-thereof, a plug fox-said knot-hole of plastic wood extending outwardly from the board, said plug having concentric rings formed therein simulating the annular rings of a limb, and extendingwithin that portion of the plug which is within the knot hole itself.
3, A method of treating plywood consisting of coating the knot holes therein with adhesive, then lling the holes Awith a plastic material which is darker than the surrounding wood, then forming substantially concentric rings in said plastic in imitation of a knot, and then sanding the surface of the plywood and plastic without removing the rings therefrom.
4. VA method of forming imitation knots inv Wood, consisting of progressively coating the sides of a knot hole with adhesive, then filling the knot hole with a plastic wood resembling in color a natural knot, then forming in the plastic material concentric rings, the marks of which extend beneath the surface of the board, and then sanding the board and knot to a common face.
FRANK A. YOKELL.