US1778250A - Method of and apparatus for treating flexible wood-veneered material - Google Patents

Description

Oct. H, 1930. A. ELM'ENDORF 1,773,250

I IBTHOD OY AW' FOR TREATING FLEXIBLE WOOD VENEERID IATERIAL Filed larch 27, 1929 2 Shoots-Sheet l 0d. 14, 1930. ELMENDQRF 1,778,250

METHOD OF AND APPARATUS FOR TREATING FLEXIBLE WOOD VENEHRBD MATERIAL Filed March 27, 1929 2 Sheets-Sheet 2 jzflenfai W MW/ fig; w gm,

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Patented Oct. 14, 1930 UNITED STATES PATENT OFFICE ARMIN ELMENDORF, OI CHICAGO, ILLINOIS, ASSIGNOR TO THE FLEXWOOD COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE METHOD OF AND APPARATUS FOR TREATING FLEXIBLE WOOD-VENEERED MATERIAL Application filed March 27, 1929- Serial No. 850,283.

In my prior application, Serial No. 334,865, filed January 24, 1929, I have disclosed a novel material comprising a flexible backing faced with thin wood veneer whose structure has been broken down to such an extent that the veneer will have no tendency, when dry, to curl up. The present invention has for its object to make it possible rapidly and at a small cost to treat the veneer so that it will possess theaforesaid characteristic.

The treatment of the veneer to place it in a condition such that it will have no tendency to curl under moisture and temperature changes or, in other words, to render it limp, because of the frail character of the veneer, can best be effected after the veneer has been glued to its backing. Therefore, viewed in one of its aspects, the present invention may be said to have for its object rapidly and economically to treat a flexible material faced with thin wood veneer so as to render the veneer limp or, in other words, destroy its capacity for curling, without marring the appearance of the surface of the veneer when the product is laid flat.

In carrying out my invention, beginning at one end of the sheet, I place the face of one narrow strip extending in the general direction of the grain after another undersuflicient tension across the grain to cause the veneer to split; thus progressively breaking .1 1p -.-or partially disintegrating the veneer. I'The narrower each individual section or strip is, the more numerous will be the breaks in the veneer and more truly limp will the veneer become. This may conveniently be done by simply bending the sheet, with a flexible backing on the inner side, in such a manner that the veneer must split.

The various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection wlth the accompanying drawings, wherein:

Figures 1, 3, 5, 7 and 9 are diagrammatic views illustrating the assembling of a flexible sheet, comprising a backing and a facing of wood veneer, and elements by means of which the splitting of the veneer ma be brought about in several different ways; igs. 2, 4, 6, 8 and 10, are views similar to Figs. 1, 3, 5, 7 and 9, respectively, illustrating a second step in the process; Fig. 11 is a side view of a machine for carrying out the method illustrated in Figs. 5 and 6; and Fig. 12 is a vertical section through the machine.

Referring to Figs. 1 and 2 of the drawings, A. represents a flexible backing faced with thin wood veneer B; both the backing and the veneer being shown on a greatly enlarged scale. 1 is a bar having at the top a more or less blunt edge 2; the thickness of the bar being also exaggerated. Laying the sheet on the bar, as shown in Fig. l, with the wood on top, and then pressing down on the sheet on opposite sides of the bar, a condition illustrated in Fig. 2 will be brought about. If the forces acting on the sheet are such that in the process of bending it over the edge, the outer face of the wood is stretched beyond the rupture point, the wood will split art way through or all the way through. T e veneer usually splits at a considerable number of places along the bar, because the grain seldom runs along straight parallel lines across the sheet; the more or less radial lines I) in Fig. 2 indicating such breaks in the veneer. Of course, when the curved part of the sheet is flattened again the breaks or slits will close and be invisible for all practical purposes. However, the veneer, so treated, has been rendered limp and impotent so far as the capacity to curl is concerned.

In practice, after the sheet has once been bent over the edge or bar, it need simply be pulled, while so bent, across the latter, so that the veneer will be progressively broken up from one end of the sheet to the other.

If desired, a belt or band of flexible mate rial may overlie the veneer while the bending is in progress. Such a belt or band is the veneered sheet from rubbing on the edge bar. As previously pointed out, the veneered sheet may be moved continuously so as proressively to draw it across the edge or ar. owever, an intermittent feed ma be employed. For example, as illustrate in Figs. 7 and 8, there may be placed above the edge or bar a vertical reciprocable plunger -having a concave bottom face 6. The veneered sheet being in osition between the members 1 and 5, as in icated in Fig. 7, the plunger is pressed down, bending the sheet over the edge or bar as shown in Fig. 8, producing the same effect as the operations illustrated in Fi s. 1 to 6. It will be seen that. initially the fi exible sheet is engaged, along three parallel lines, two separated lines on the upper face, and a single line on the under: face and half-way between the two upper lines. In other words, the section of the veneer spanned by the plunger has its exposed face'free, and unrestrained until the plunger has been forced clear down.

' In Figs. 9 and 10 there is illustrated a slightly different modification. The .bar 7 terminates at the top in a comparatively sharp edge 8. The plunger 9., above the bar, has a vertical openingor passage 10 registering with the bar. When the plunger is forced down upon a veneered sheetlying on the bar, it bends the sheet sharply over the edgeof the bar, causing the veneer to crack,

as indicated in Fig. 10. Here, also, there is a three-line contact between the bending members and the sheet; and, here also, the face of the veneer in the working zone is left free.

The sheet must be fed intermittently when it is treated in either of the ways illustrated in Figs. 7 to 10, the feeding of the sheet bein e ected while the plungers are up.

In Figs. 11 and 12 I have illustrated a machine for carrying out the process illustrated in Figs. 1 to 6, particularly Figs. 5 and 6. The machine comprises two parallel side frames 15 and 16. J ournalled in the frame, with their axes of rotation in the same vertical plane, are three long rollers 17 ,18 and 19. The roller 18 is driven in any suitable way as, for'example, by a belt passing over a suitable pulley 20 on theroller shaft 21. On the shaft 21 is a gear wheel 22 mesh ing with a similar gear wheel 23 on the shaft 24 of the roller 19; Consequently,

The veneered sheet AB when the roller 18 revolves, the roller 19 also revolves, but in the opposite direction. There are two other rollers, a hea roller 25 and a roller 26. The roller 25- as at its ends trunnions 27 that ride in long slots 28 inclined to the vertical. The high ends of the slots are nearest to the rollers, 17 to 19. The roller 25 will therefore position itself as far away from the rollers 17 to 19 as the slots 28 will permit, when free to do so.

The roller 26 is journalled at itsends in blocks 30 slidable in horizontal bearings 31; the blocks being adjustable toward and away from the rollers 17 to 19 by means of suitable screws 32. In the space between the rollers 17 to 19, on the one hand, and the rollers 25 and 26, on the other hand, and at a considerably higher elevation than the roller 21, is a long bar 33 parallel with the axes of rotation of the rollers. The bar is shown as mounted on suitable brackets 34 on the frame. .The bar is shown as being triangular. in crosssection, with the a exat the top:

A broad endless elt 35 extends aroundthe rollers 17, 18 and 25 extending, between the rollers 18 and 25, over the top of the bar. 36. extends over' -the A second endless belt rollers 19 and 26 and over the bar. The arts are so proportioned that those parts 0 the belts from a point near the roller 25 to the point where one of the belts passes under the roller 18 and the other passes over the roller 19, lie, parallel with each other and tend tov come into contact with each other.

is fed into the machine underneath the roller 25, and passes up between the belts over the bar and down underneath the roller 18 and over the roller 19. In passing-over the apex of the bar, the

veneer is partially disintegrated in the manner heretofore explained. Normally the trunnions on the roller 25 are at some distance from the lower ends of the slots, so that this roller may be said to be suspended in a loop of the belt 35, thereby kee ing this belt under a constant tension. 11 the other hand, the tension of the belt 36 may be adjusted by means of the screws 32.

In the drawing the thickness of the veneered sheet, as well as the radius of the edge over which the sheet is drawn are exaggerated as was the case in Figs. 1 to 10. If the radius of the edge on the bar is too great there will be no appreciable splitting of the veneer. With a very small radius, on the other hand, the breaks in the veneer will be many and they will be close together.

I do not wish to limit myself toany particular degree of fineness in the disintegra: tion of the veneer because for some uses the breaks may be farther apart than for others. It is possible, however, by making the radius of the edge over which the sheet is drawn small, to produce breaks that will be an average distance of a thirty-second of an inch or less apart.

I claim 1. The method of making pliable a sheet composed of a flexible backing faced with wood veneer, which consists in splitting the veneer to divide the face thereof into many narrow filaments whose long edges follow the grain of the wood.

2. The method of making pliable a sheet composed of a flexible backin faced w1th wood veneer which consists in breaking the veneer at least through the outer face along closely-spaced lines following the grain.

3. The method of treating a sheet composed of a flexible backing faced with wood veneer, which consists in manipulating the sheet so as progressively to stress the veneer across the grain past the rupture point.

4. The method of treating a sheet composed of a flexible backing faced with wood veneer, which consists in manipulating the sheet so as progressively to stress the veneer past the rupture point across a line extending in the general direction of the grain and moving across the sheet transversely of the gram.

5. The method of progressively partially disintegrating the veneer on a sheet, consisting of a flexible backing and a facing of wood veneer, so as to render the veneer limp, which consists in manipulating the sheet so as to place one narrow section of the veneer after another, under sufficient stress transversely of the grain to cause the veneer to split.

6. The method of treating a sheet consisting of a flexible backing faced with thin wood veneer, which consists in progressively placing narrow sections of the veneer extending in the general direction of the grain under sufficient tension to cause the veneer to split.

7. The method of treating a sheet consisting of a flexible backing faced with thin wood veneer, which consists in progressiveliy placing narrow sections of the veneer exten ing in the general direction of the grain uni der suflicient tension to cause the veneer to split and leaving the face of each section substantially free while that section is being placed under tension.

8. The method of treating a sheet consisting of a flexible backing faced with wood veneer, which consists in bending it forcibly over an edge extending in the general direction of the grain and engaging the backing.

9. The method of treatin a sheet consisting of 'a flexible backing aced with wood veneer, which consists in bending it forcibly over an edge extendin in thegeneral direction of the grain an engagin the backing, and moving the said edge an said sheet relatively to each other in the direction of the length of the sheet and repeating the bending operation.

between two flexible belts, and then drawing the composite member under tension across;

and at the same time bending it over the edge with the veneer lying outwardly from the backing.

12. In a machine for the purpose specified, a bar having an edge, two endless belts having sections in contact with each other passing across the bar and bent over said edge, and means for driving said belts so as to cause said sections to travel in the same direction.

13. In a machine for the purpose specified, a horizontal bar having an edge at the top, a long endless belt surrounding the bar and resting on said edge, the said belt extending downwardly on opposite sides of the bar, a, second endless belt above the bar, a portion of the second belt in the vicinity and on opposite sides of said edge resting on the first belt, and means for driving said belts so as to cause the contacting parts of the belts to move in the same direction.

In testimony whereof, I sign this specifica-

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