US2388479A - Veneer strip, coils thereof, and method of preparing same - Google Patents

Description

Nov. 6, 1945. P. RGOLDMAN COILS THEREOF, AND METHOD OF PREPARING SAME VENEER STRIP,

Filed Oct. 21, 1942 fnvenZors a PauZR. 6E0 Zziyman F r id/we,

aud/W i Patented Nov. 6,1945

UNITED STATES PATENT orr cs sisal-le I mean sramcons rnnnaor, AND a METHOD or rnsrAnmd SAME Paul R. Goldman, Andover, Mm, assignor to Plymold Corporation, Lawrence, Mara, a cor- I l Mration My present invention relates to the of thin wood stripping, wood veneer or plywood in strips of various widths and of indeterminate Application October 21, 1942, w No. 462,800

, 4 Claims. (Cl. 144-409) pre tion 1 represents a typical coil or roll of veneer strip in accordance with the invention, as seen in its package form ready for shipment or use. The illustration is not to scale, and is atio as to thickness of the wood strip and as to the diameter of the 0011. both or which may vary within wide limits. In this packaged form, the

' coil, indicated as a whole by the numeral 5, comproved process and means for producing the 7 same.

In the drawing illustrating by way of example one form of the article and of means for carrying out the manufacturing process:

Fig. '1 shows in elevation and somewhat diagrammatically a package of coiled veneer stripbut is particularly adapted for use in forming spirally wrapped pipe, tubing, conduit and the like. In the formation of such tubular and other cylindrical structures the length of the veneer strip, to be continuous from end to end of the structure and unless laid parallel to the structure axis, must be greater than that of the structure, the more so where the strip is applied in a lengthwise progressive close spiral. The required strip length frequently therefore is greater than that ordinarily available in a single natural piece of thin wood material, whether cut spirally from the log or stock or otherwise.

Accordingly the invention provides for preparing a supply of thin wood or veneer stripping of indeterminate extensive length, adequate to run continuously in a spiral from end to end .of the given cylindrical or tubular structure. At the same time the invention also makes possible the utilization of relatively small or short logs and timber stock for forming the veneer stripping, including what otherwise would be waste material for veneer-forming purposes. Also under the invention odd lengths of veneer, including left-over and even scrap pieces may be used in preparing the coils of tape-like veneer or thin wood strip.

Referring to the drawing in more detail, Fig.

prises a continuous length of the veneer strip designated generally at I.

The continuous strip of the coil is composed of a number of relatively short lengths of the thin flexible wood united endwise. This material usually is of the hard wood class, including such woods as birch, maple, mahogany, poplar, walnut and others. but for some purposes softer woods as for example some of the firs and even some varieties from the general class of soft woods may be used. The thin sheets and strips of the wood may be out from the log or stock in any preferred manner including slicing or knife-cutting, as well as rotary cuttins. As towidth, this thin flexible wood material for forming the coiled package may vary within a considerable range, according to the size of the tubing or other article to be manufactured, the coiled stripping being supplied in the various widths as appropriate to the particular manufacture. Thus the strip width may range from a relatively nan-ow tape of about inch or even less, for the smaller articles, up to widths of 4 to 10 inches or more for the larger diametered manufactures. Likewise the gauge or thickness of the wood strip may range from an extreme thinness of about &0 to .400 of an inch up to the heavier veneers of inch and more, again largely depending on the particular article of ultimate manufacture. Generally the strip or tape as presented in the coiled package consists of a single ply or thickness of the wood, but in some cases it may comprise two or more wood plies superposed and suitably bonded together prior to coiling. In such plural'ply forms the end unions of individual plies, to be described, may coincide in the different plies or may be differently spaced along the strip as a whole.

As above indicated the flexible wood strip 8 of any particular coil or package 5 is continuous. In a given coil the total strip length may run into-hundreds or even a thousand feet or more,

there being no definite limit in this respect other than that of theweight and diameter desired for any given coiled package, and the capacity of any apparatus for preparing and handling it. Further, it is important that this wood strip or tape, especially with reference to its use for wind in into tubing and cylindrical structures, shall be of substantially uniform thickness throughout. To provide such uniformity in a continuous strip formed of a considerable number of relapurpose may be employed. This includes not only such medium lengths as 6 to feet and thcreabouts but also much shorter sections, somemajority of subsequent tubular applications of the strip, contributing both to radial or crushnot more than a foot or so long- Under the invention, by reason of the uniform and otherwise improved end jointing of the numerous component pieces, and whereby a relatively large and the leading end of a next piece 8. These.

pieces l and 8, representative of any two lengths to be joined, whether the same or different'wood stock, have been slit or trimmed to uniform width and preferably are of substantially the same gauge or thickness. "In connecting the adjoining ends of any two strip pieces such as I and 8- the latter are substantially overlapped at a joint or union area as at 9, a bonding agent being supplied at the contiguous faces of the overlapped portions.

Desirably the transverse edges of the pieces to be joined are cut or trimmed on a bias, disposing them nonperpendicularly to the side edges of the strip, as at la, 8a, Fig. 2. The terminal edge of each piece is thus extended lengthwise of the,

strip, thereby reducing the chances of havin transverse imperfections in the wood material presented along any considerable part of the terminal edge. Also, in the subsequent use of the strip, such diagonal terminal edge is caused to.

aline generally with the axis of the tubular structure to which the strip is applied by spiral winding, so subjecting the material to less tencloning and internal stress along such terminal line of a component piece of the strip.

The union as a whole, such as at 5, may be further improved and tendency of cracking or frayin thereat reduced by spacing one end of the diagonal terminal line of a given piece 1 or ii inwardly from the side edge with which such linc,'i extended, would define an internal acute angle. From such inset point, as indicated at lb, ill) for example the terminal line extends perpendicularly, or more nearly so, to the adjacent side edge, a at 1c, 8c. Thus any acute projection at the end of a piece is avoided, while retaining the advantages of the diagonal terminus.

In addition to the foregoing, in the preparation oi the strip to be coiled, the several successive pieces desirably are so selected and so slit or trimmed to width that the wood graining will be parallel or substantially so in the succeeding in Fig. 2. Such arrangement is well suited to a resisting strength and to axial strength Or rigidity. In some instances, however, the predominant grain direction may be at right angles to desirable that the granular formation at the overlapping end portions of successive pieces to be joined shall have an approximate mutual parallelism, thereby facilitating the bonding and to some extent an actual inter-penetration of the body substance of the overlapped pieces; see Fig.4.

In Fig. 5 I have illustrated, largely diagram-- matically, one form of apparatus suitable for practicing the method involved. The comparatively short portion of a wood strip 6 there shown includes a zone 8 of juncture of two successive pieces such as 'I and 8. These strip pieces have been prepared, cut and trimmed in the mannot such as described in connection with Figs. 2 and 3, and their end joint areas, with the adhesive or other bonding agent applied, have been placed in mutually overlappin relation. Such agent may be any of various known plastic glues,

cements and the like, including those of the urea formaldehyde type and those of the Tego' type as used in aircraft construction, such agent being adapted for setting under pressure, whether with 01 without the application of heat. The strip pieces thus preliminarily connected are then subjected to substantial pressure, particularly at the region of juncture. Such pressure may be variously applied, in some cases before the pieces are connected and as a. step preparatory thereto, but is conveniently accomplished at a compressing station from which the strip is advanced to a coiling means.

In Fig. 5 for example I have shown upper and lower rolls ll, l2 rotatively supported in opposed relation on a frame it. The upper roll H is joumaled in a bearing block H verticall slidable in a guide ii on an arm IS, the latter pivoted as at I! on the frame It. Thus the arm l6 and upper roll H as a whole are subject to vertical adjustment, and the roll I I is independently movable for loading and pressure adjusting purposes. This roll ll, desirably of a heavy construction, is urged into pressing engagement with the wood strip 8 passing below it, as by strong springs I. held under compression in the bearing guides ll at the respective ends of the roll. The pressure of these springs may be regulated as by means of threaded plungers i9 adapted to be turned down against them as by hand wheels 20. I

At its end remote from its pivotal supp rt the arm 18 is provided with a finely adjustable positive stop means illustrated as a stud 2| extending down through and having threaded engagement with the arm [8. The lower end of this stud extends through a fixed abutment 22 on the frame and has collars 23 fixed on it, one above and one below the abutment. In this manner the degree of approach for the pressure rolls II and I! may be positively set to limit the same in accordance with the gauge or thickness desired for the particular strip 6. This setting of the rolls may be facilitated as by mean of a stationary scale 24 graduated in small fractions of an inch or calibrated in terms of pressure, with a cooperating index 25 on the adjustable roll-carrying arm I.

A already pointed out, the resultant continuous strip 6 is of uniform thickness, without objectionable thickening at the joined zones or areas such as 9. If for example the component pieces such as! and 8 are ,6 in. thick, the several joint areas 9 likewise are but little if any over V in. thick instead of twice that thickness or more.

For a strip of 3 in. thickness, merely as an example, the limiting stop 22, Fig. 5, is set to space the rolls ii, i2,\by exactly la in. or in some cases slightly less, for example l in., when it is desired to exert some ironing or compressive action on the portions of the strip 8 between joints 8 in addition to the heavy compressive action at the latter. These joints or juncture zones 8, comprising overlapped end portions of two separate pieces ordinarily would be at least twice as "thick as the non-lapped body portion of either piece such as I or 8. But as the'connected pieces are advanced between the rolls H, ii any such excess thicknes is compressively reduced. The

i adequate to reduce them to the /54 in. thickness selected in the illustrative example, rendering them substantially uniform with the remainder of the strip. The pressure thus applied is regulated to be such that" the wood substance of the previously separate pieces at the overlapped areas I is to a considerable extent inter-penetrated and product, is not limited to the particular steps,

means and structure as herein illustrated or de scribed by way of example, its scope being pointed which comprises forming and assembling a plu- ,rality of elongated wood pieces of the width and thickness desired for the strip in a manner to present the graining predominantly in mutual parallelism, applying a bonding agent at end areas of pieces to be connected end to end, lapping said areas, subjecting the lapped areas to substantial pressure adequate to compress them to a thinness uniform with that of the individual component pieces, repeating said steps-with successive pieces as facilitated by said mutually parallel graining arrangement to provide a continuous strip of indeterminate length, and freely coiling the strip into roll package form for subsequent off-feeding rotatively in any desired'length thereof.

compressed into a unitary mass. as facilitated by a be applied over the whole length of the strip,

with some corresponding compressive and unifying eifect also on the portions between joints. By

2. A thin flexible wood strip for manufacturing purposes, said strip havin an indeterminate con tinuous length and being of substantially uniform thickness of the order of about 0 to, in., said strip comprising a plurality of component pieces of like thickness disposed in longitudinal series and with their graining in approximate mutual parallelism, such pieces having end areas compressively reduced to approximately-but onehalf the initial thickness of the given piece, said areas of trailing and leading ends of successive pieces being overlapped and bonded together to provide an integrated joint of a thickness not substantially exceeding that of the component strips and the transverse edges of the jointed ends ofthe successive pieces being for a substantial portion of their extents non-perpendicular to their 40 longitudinal side edges.

controlling the pressure, as by the described posilappedportions between Joints. If desired the strip may be passed successively through one or more additional pressure-applying stations such as that represented at the right in Fig. 5, or the ends of pieces to be overlapped may be compressively reduced preparatory to interconnecting them.

The connected strip 6 is advanced to a suitable winding core,'reel or other coiling means, not shown but indicated by the arrow at the left in Fig. 5, for winding the strip into the coil package form such as that of Pie. 1. Prior to coiling the strip may be subjected to a burnishing, polishing or abrading action, such for example as by passage through sanding Or other abrasive wheels 26, 21. These are shown as driven differentially or oppositely to the direction of travel of the strip, to apply a rubbing, burnishing or like action upon one or both faces of the latter. 7 In this manner any rough or irregular areas, whether at the Joints or elsewhere are smoothed, reduced or removed. It will be understood that travel of the strip to the coiler, and at other stages of the disclosed continuous process, is effected by feeding or advancing means, as for example pairs of opposed feed rolls as at 28, 28.

My invention, as to method, apparatus. and

3. A thin flexible wood strip-according to claim 2 wherein the transverse edges of the jointed ends of the successive pieces are diagonally disposed over a portion of their extent, and along their remaining extent are more nearly perpendicular to the longitudinal side edges of the strip.

4. As a new product of commercial manufacture, a supply roll package of wood veneer for shipment, storage and use by feeding ofl' therefrom rotatively in the manufacture of lamillar veneer articles and the like, said package comprising a continuous strip of thin flexible wood veneer of indeterminate length and of substantially uniform thickness, said strip composed .of a plurality of individual relatively shorter thin flexible single-ply wood veneer pieces of like thickness and of uniform width throughout and having'their predominant direction of graining' substantial multiple of any initial individual veneer piece.

PAUL R. GOLDMAN.

CERTIFICATE'OF CORRECTION. Patent No. 2,588,l1.79; V November 6, 19L5. PAUL R. 001mm.

It is hereby certified that error appears in the printed. specification of the above numberedpatent-requiring correction as follows: Page 3, sec- 0nd column, lines 18 and '19, elaim f, strike out the words "as facilitated by said mutually parallel greiining arrangement" and insert the same after "pieces" first occurrence, line 17; and. that the said Letters Patent should be read. with this correction therein that the same may conform to the record of the case in thePetent Office.

Signed and sealed this 29th day of January; A. D. 191%.

Leslie Frazer (Seal) First Assistant Commissioner of Patents.

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