US2454787A - Process for dry expansion of wood veneer - Google Patents

Description

Nov. 30, 1948. FRANCEK 2,454,787

PROCESS FOR DRY EXPANSION 0F WOOD VENEER Original Filed Aug. 18, 1943 3 Sheets-Sheet 1 INVENTOR.

NOV. 30, 1948. FRANEK 2,454,787

PROCESS FOR DRY EXPANSION OF WOOD VENEER Original Filed Aug. 18, 1943 s Sheets-Sheet 2 l I 4/ 4 7 l 4 i 4 5- i 4 6 I /3 E 1 ,73 N I /5 a 52 /Z 20 IN V EN TOR.

$53 k 560W I 0/19 'Nov. 30, 1948. J. R. FRANCEK PROCESS FOR DRY EXPANSION OF WOOD VENEER Original Filed Aug. 18, 1945 3 Sheets-Sheet 5 N VEN TOR Patented Nov. 30, 1948 PROCESS FOR. DRY EXPANSION OE WOOD VENEER Joseph R. Francek, Fox River Grove, 111., assignor to Edmund. J; Sheehan; Chicago; Elli Original application. August 18, 1943, Serial No. 493.079.. Divided and thisapplication.Schism: her 28, 1944*, Serial No. 556 3854 1 The present inventionrelates' to wood veneers and more particularly to an improved wood veneer for covering Walls or the like for purposesof decoration or finishand to anew and improved process for manufacturing wood veneers: of the class described.

The-present application is-a division of application, Serial No; 3991079, filed; August 18, 1943, which is a continuation-impartof Letters Patent No; 2,347,820 for the- Dry expansion of wood veneer, reference to which is hereby'made.

It has been long desirable tohave an wood-I veneer which could" be applied to a Wall surface or the like as easily as wallpaper and which,

would simulate paneling and'be just as enduring.

Wood veneering isiproduced in. one: of; the well known manners by rotating: a. log: against; a: cutter toshavea thin layer: from. the log in. a; manner that provides the best? grain effect: possible with each-log. In many: woodsx the grain: isheavypinothers light. To bring: out the-grain, the lathe cut is preferably at an acute. angleto and through the grain rather: than vertical to.

5.:(3laims: (Cl. 144-309) looking along the-face of a wall to catch the re or along the grain, thereby providing a decorative.

effect in which alt'ernatie portions: of grain; are; separated by Wood fiber;

This provides in thegrain. alternate: portions. of. strong wood capableof bending and buckling and. weak portions which yield to the. action". of the stronger parts and cause buckling, splitting and splintering.

It has been the practice, in. some instances; to; fracture the veneer before applying, tothewall so that the predisposition: to fracture is, accomplished or taken careof before application to a wall and thereby the effect of. an ultimate, warping or curling of. the=grain is reduced; Such a process is. one wherein. the veneer is torn or;

split along lines extending along or followingthel grain as by drawing the. veneer across theblunt. edge to break it.

Such a flexing, however, merely augments the weakness of the veneer. whereit; is already the; weakest and does little if anything-to the stronger, parts of the: wood to process. them. After such veneer has. been. installed; for a; time=,-.. a person.

Ill;

fractionvoilight will see that thestrong parts are; left to and do buckle and spoilthe desired mirror smoothness that: is attained with veneer board" p ne-line:

Further-more; with such a process; the veneer is not expanded enough, toprevent absorbeddampmess" expanding it further after installation andcausing-- itto buckle:

Care of the objects of the presentrinvention is to flex the veneei"unifermly throughout its ex pause andto =expand i-twithout placing: a strain on the"Weaker-portions or the wood fiber which: would cause the Wood tosplit; along grainlines;

Another object of theinvention resides in a process treating sheetsof wood veneer or the: like so as to-preventthesameiromcontracting, expanding or war-ping after beingapplied-4 to. the walls.

Another object or the invention is-- tozunifor-mly flex the-wood throughout-- its expanse andtexpand; it beyond its; natural wet expansion limit.-

A fur-then object of the invention isto: render. the sheet or veneer: flexible; and. cxpandibla enough to allow ion: wall; depressions: and-1 raises;

normally experienced with; hand: trawledplasten walls or floors. 1

Another object: of the .imientionl s to flexaan expand sheets; of: wood veneer," in: a dry: process prior to installation;

Another objector; the invention is to, perforate; the: wood-veneer. according to;- a; predetermined. pattern; to flex and; expaudl it nd; ca se. the: grain. to. recover; itselil bye dampenin the; surface. to A be finished-i enough. that; it: cart; be; sandedfwithrout splinteri'ngr the; fiber; and when. ins alled with.- a moistcsadhesive the rain ett es. p rmanently into: its expanded. position. for final finishing. I

A further object. O fil ihisj invention is o dry: expand sheets. of, wood veneer Without destroying; the; grain oi. the: sheets...

Another-object; oflthis intention; resides in. the particular manner or spreadin the: ar sur ace. of; theveneen sheets by forcing pinpoints, into or. through; the; wood: according; to; a predetermined,

pattern:

These being" among thev object-s. oi th pr sent. muentionbther andiurther Objects will become apparent; from. the; drawings the: dessripvion-l re.- lating; thereto; and. the; appended claims.

Referring now to. the; drawin s;

Eiga. Lissa sideelevation partly iii-sect on taken somewhat obliquely to a working table and illus-L tratinsr a machine. by which. the. process: is practicedi;

Fig. 2 is a top plan View of a device illustrated in Fig. 1;

Fig. 3 is an enlarged vertical section taken upon the line 3--3 in Fig. 2;

Fig. 4 is a plan View of a sheet of fabricated veneer partly processed according to the teachings of the present invention;

Fig. 5 is a vertical section through a device illustrating the manner in which a sheet of veneer is prepared for processing according to the teachings of the present invention;

Fig. 6 is a section taken upon the line 36 in Fig.

Fig. 7 is a vertical section illustrating the manner in which the sheet of veneer shown in Fig. 6 is processed; v

Fig. 8 is a section of veneer as it appears after being processed in the manner shown in Fig. 7, and

Fig. 9 is a vertical section through the sheet of veneer diagrammatically illustrating the character of the sheet when it is ready for use.

In the practice of the present invention, the wood veneer, such as that illustrated at H] in Fig. 5, is preferably backed with a sleazy fabric l I, such as cheese cloth, which is intimately adhered to the wood by an adhesive l2, preferably having a latex base. The back of the veneer is then perforated from the back through the cloth by means of a plurality of elements 13 so designed and located as to spread the fibers of the wood at predetermined places without regard to the grain or the presence or absence of hard portions in the wood at these places.

In adhering the fabric H to the veneer by means of the flexible adhesive I2 the adhesion is preferably made under pressure, and heat, if desired, byrollers I4 such as those illustrated diagrammatically in Fig. 5.

The resulting product is indicated generally by the numeral l5 and will hereinafter be referred to as the veneer, the veneer 15 having a back surface it and a face I! with the length of the veneer considered that dimension running with the grain and the sides of the veneer those edges which are disposed opposite to each other transversely of the grain.

' Although the backing II is shown as cheese cloth, it may comprise felted fibers or other fabricated material having the characteristic of being sleazy enough to yield or permit the expansion of the veneer as accomplished by the process described herein without being weak beyond this expansion, the intimate adhesion provided and described being helpful in maintaining strength in the veneer along with the fiber or fabric. The felted fibers or fabric will serve successfully for the purposes contemplated when spread evenly, since it is desired that the backing be of a substantially uniform thickness throughout.

Although the Veneer may be processed by hand with a single element or a plurality of elements carried by a hand driven block, it is preferred that this process be carried out by a machine as more particularly shown in the drawings wherein the preferred way of practicing the invention is illustrated as representative of others which persons skilled in the art may use for the same purpose. In processing the veneer 15 by a power, a bar carrying a plurality of elements is reciprocated up and down to perforate the Veneer in a predetermined manner as the veneer is fed under the bar.

For this purpose, as shown in Fig. 1, a bed is supported by side frames 2| upon a floor 22 to 4 which the frames are secured by bolts 23. A shaft 24 is journalled in the side frames by bearings 25 and is driven by a motor 26 through a motor pulley 21, a V belt 28 and a shaft pulley 30. The shaft 24 extends beyond the side frames 2| to receive crank wheels 3| having crank pins 32 and counter-weights 33.

A cross member 34 interconnects the uprights 2B of the frames near their upper end and to this member is secured the bed 20 by bolts 35, the side frames 2! extending above the bed upon opposite sides thereof in the form of bifurcated ends 36. As seen in Fig. 2, it is important to note that the bed is disposed obliquely to the cross member 34, the shaft 24 and the cross member 34 being much longer than the bed 20 is wide so that the bifurcated ends 36 may be located at points disposed diagonally across the bed.

The reciprocating bar already mentioned is indicated at 40 as mounted for vertical reciprocation in the bifurcated ends 36. For this purpose a follower portion 4! (Figs. 2 and 3) is provided at each end of the bar, and these followers are supported in sliding relationship between guides 42 held in place in the bifurcated ends 36 by means of bolts 43. Take-up for wear between the guides and followers is provided for in any suitable manner.

The bar 46 comprises two elements, the main element 44 and a secondary element 45 co-extensive with the main element at its lower edge 43. The secondary element 45 is pivoted to the main element 44 as at 4'! along a line spaced from the edge. Bolts 48 are employed to secure the two parts of the bar 40 together, as shown in Fig. 3, at spaced points throughout the length of the elements to establish a clamping relationship between the elements at the edge 46.

The construction of the bar will be better understood by understanding the manner in which it is made ready for use in the machine. The two parts 45 and 44 initially are clamped together with a spacer (not shown) filling the space 50 between them. With the spacer in place the bar 40 has drilled in the lower edge 46 thereof a series of holes, which holes are of a predetermined diameter and of a uniform depth. The spacer is then removed and replaced by the pointed elements l3, already mentioned, which have a diameter substantially identical with the diameter of the holes originally drilled. With this arrangement the elements I 3 are held in place by the clamping effort exerted by the bolts 48 to be carried by the bar 40 as a unitary part thereof as the bar is reciprocated, the reciprocation of the bar being accomplished by the crank pins 32, pitmans 5| interconnecting the crank pins 32 and the extension 49 upon the bar 40, as more particularly shown in Fig. l.

The throw upon the crank 36 is sufficient to drive the elements I3 as deeply into the bed, as represented by the perforation 52 made in the bed 20 beyond the veneer face I! of the veneer I5, so that maximum penetration may be had if desired, and the bed 20 is supported against this drive by the cross member 34.

Extension devices 53. (Fig. 1) are provided for the pitmans 5! to adjust the height of the bar 43 above the table to change the amount of penetration that the elements I3 will make in the veneer l5.

The veneer I5 is fed between the bar 40 and bed 23 with the back It thereof disposed towards the elements l3. In accomplishing this feed, a double feed effort is exerted upon the veneer l5 to force it along the bed under the elements .I 3 so that the amps-r elements 13 do-not strike the veneer necessarilylln the same place twice. The feed arrangement which has worked-successfully is one "wherein a very slow speed mot-or 353 or transmission is mounted under the bed34 .by means of a bracket E l-secured to-the bed by bolts 55. Two shafts .58 and '5 are journalled by bearings 5'81above the level of the bed with one of the shafts 56"locate'd transversely of the bed-in front' o f thebard o and the other shaft 5 located itransverselybeyond the bar 40. These shafts are propelled by means of pulleys 60, a countersh-aft 6-], and bolts 62, and have mountedupon them rollers B3'which are disposed in frictional contact 'with-the ba'ck- 45 of the veneer 15.

It is desired that the rollers upon the shaft 5'6 be smaller than those uponsh-a'fti'lor that the shaft 56 be rotated slightly slower than the -shaft 51 so that "there "is a slight slippage between the feed effort of the two shafts which tends to keep 1 theveneer stretched, when feeding "it the-direction indicated by the numeral 73.

In the feed operation, the veneer is fed minder the rollers $3 on shaft 56 until the reciprocating elements l3 begin to engage one corner ofthe which then takes over the process of 'pulling'the' Veneer enough to keep the 'feed'tight. At this time it will be well to note that successive-sheets of veneer are preferably tiedend'to end in one continuous strip if theveneer is backedby fabric; With such a tying together the f-eed'through the machine continues Without need for feeding successive sheets by hand.

When the sheet is hit *by the elements 13, all the elements strike simultaneously along a line oblique to the sides and grain of the veneer. In providing this relationship by which the series of element-s13 strike the veneer along a line oblique to thegra-in, as compared with directlycross-wise of the grain, adjacent elements do not obstruct each other in expanding the grain, but rather the material is free to split and expand laterally at each element. Considered another way, if only one element 13 was employed to strike-the veneer at one time, thebody of Veneer proximate the split would be free to expand laterally under the splitting action of the element unopposed except by the strength of the remote wood to oppose. 0n the other hand, if a second-element l3was located next to the first element at a right angle" to the first, i. e. directly acros the grain, the freedom of the Wood to expand under the influence of one of the elements is opposed by the other as regards the displacement of the bodyof veneer between them. One element would prevent .the wood 'expanding towards it under the influence of t e other element, and vice versa. Of course, if the elements are spaced widely enough transversely of the grain expansion can be had, but the veneer would buckle between them and the efiiciency of the machine would be reduced for each stroke of the bar as compared with the preferred arrangement.

In the preferred arrangement the elements B are arranged in a: row disposed obliquely to the grain, thenvthe iwood adjacent and at right angles to each ielcmen'tis free to expand unhampered by adjacent elements, theexpansiomat one element taking place ahead-or behind adjacent elements. The more oblique, the row is arranged with regard to the grain, thegreat'er is this "freedom :to expand, it being a-corollary of the present invention that the degree of expansion imposed upon the veneer 15 can be controlled :by the degree of obliqueness at which the row of elementsstr'ike the wood. Although one row of elements has been shown, two or more rowson-a single bar or several-additional bars may be -employed solongas there is sufiicient space between elements which happens to be crosswise of the grain to permit expansion. Optimum-expansion isfound where veneer is fed sidew i-se under the bar.- However, due to some veneer being so long as to make it difficult to reciprocate a bar, the "relationship shown has been found to be quite satisfactory.

Although a bar has been shown with pointed elements thereon, pin wheels or a wheel or bar may be used which have short knives therein, provided the principle is adhered to of not having perforations made simultaneous in the veneer crosswise-of the grain --close enough for expansion to be opposed by adjacent-elements and provided, if knives are used, theyextend'generally in the direotion -of the grain. are preferred since they do not require the degree of obliqueness that knives would require.

partly processcdveneer piece is illustrated in Fig. 4 withthe perforations in thebaok indicated by the numeral H and the unprocessed portion by'the numeral 12, it being appreciated that the direction of obliqueness may beeither left hand or right hand without departing from the spirit of the invention,

Consequently, although it is old to perforate veneer, evenfrom the backside, the known methods of perforation do not expand the wood nor do they flex the wood as performed by the present invention since the perforations made conventionally were madetransversely of the grain, whereas in the present invention the perforations which are made inthe wood if made simultaneously in a seriesare spacedfrom one another longitudinally of the grain sufficient to permit the dry expansion of the veneer transversely ofthe grainto a degree controlled by the degree of obliqueness.

"Not onlymaythe degree of expansion be co-ntrolled by the angle of the obliqueness, but also itymay be controlled bythe speed of the feed as translatedl into the closeness of successive perforationsmade in the veneer, and also by varying the depth to which the elements are driven into the veneer, the elements l3 preferably being pointed with asemi-blunt taper.

Referring now to Figs. 7; 8 and9, it is indicated in Fig. 7 how the pointed elements 13 cause "a raising of wood fibre upon the face H as at It where the elements 1-3 pierce the veneer l5 to expand it; Then, when 'thepointed elements I3 are withdrawn, as indicated diagrammatically in Fig. 8,'this raised portion 10 is left asa roughening of the face H, and the perforation 11 left by the element l3 shows up as a pin hole through the veneer when the veneer is held between the observer and the light.

After expanding the wood by many of these perforations, the face I! of the wood is rough with portions 10 and covered with minute openings depending upon the depth to which the elements were driven, the texture of the wood, and. the

closeness of perforations. The face of the veneer is dampened slightly to swell the fibre enough to close the minute openings on the face and then faced by some suitable smoothing operations as by a very fine sand paper or rollers, after which the veneer is ready for installation upon a plastered wall or the like where, due to the flexing and expansion accomplished, as described, the veneer may easily be installed like wall paper and is not affected by humidity and temperature changes.

With the present process the veneer is expanded across the grain approximately /2 inch to a foot, depending upon factors already mentioned and this expansion is Well beyond the extent to which it would expand if soaked in water. Because of this, once the veneer is upon the wall, wetness other than humidity does not have a tendency to expand it. In fact, before applying to the wall, the veneer is dampened slightly to assist in handling and the veneer can dry then upon the wall without splitting.

The span of the bar 40 is reinforced suitably to carry the load involved in driving the elements I3 into the veneer l5. Springiness in the bar cannot be entirely eliminated so the weight in the center of the bar is so arranged that as the piercing load is picked up by the pins centrally of the bar the terminal flex of the bar on its down stroke under the weight of the bar carries the work load of the pinsand provides the effort necessary to drive the pins home, the speed of reciprocation and the weight of the moving masses being regulated for this purpose for optimum results.

The backing upon the veneer prevents the veneer from splintering and clogging the elements l3 and in order to free the elements from the veneer upon the up stroke of the bar 40 a combination shield and guide 13 holds the veneer 15 down after each perforation so that the veneer is free to be fed beneath the elements and have the perforations spaced according to any pattern that is predetermined by the speed of the feed, or, of the reciprocation in relation to the feed. The combination shield and guide 13 is illustrated in Fig. 3, whereas it is removed from the machine, shown in Figs. 1 and 2, so that the structure of the bar may be seen.

Consequently, although a preferred embodiment of the invention has been shown and described herein certain modifications and changes have been discussed and further modifications and changes may be apparent to those skilled in the art without departing from the spirit of the invention, the scope of which is commensurate with the appended claims.

What is claimed is:

1. The method of expanding and flexing a Wood veneer sheet backed with a sleazy material comprising piercing the veneer in a series of pier ings arranged along lines disposed diagonally to the grain while holding the fibers of the veneer in place upon one side with said backing closing the spaces caused by said sharp points.

2. The method of manufacturing a covering for a wall or the like comprising backing a wood veneer sheet Withan adhesive containing latex, pressing a sleazy material into intimate contact with the adhesive, perforating the wood veneer through the material at places spaced longitudinally of the grain to spread the wood fibers sidewise, and dampening the face of the wood veneer to close openings upon the face side caused by the perforations.

3. The method of expanding a fiber backed flexible sheet of wood veneer comprising backing veneer wood with a waterproof adhesive containing latex, pressing sleazy fibers into intimate contact with the adhesive, perforating the Wood veneer from the back in a series of successive pierces progressively made from one side of the sheet to the other, and dampening the face of the wood veneer to close openings upon the face side caused by the perforations.

4. The method of manufacturing a covering for a wall or the like comprising adhering a sleazy material to the back of a wood veneer sheet with an adhesive containing latex, piercing the wood veneer from the back through the material and adhesive with a series of simultaneously formed perforations spaced substantially longitudinally of the grain to expand the wood fibers in a direction crosswise of the grain, said material and adhesive permitting expansion of the wood fibers and holding them in their expanded position, repeating said series at points spaced laterally from preceding perforations, and closing openings left by said piercings upon the face side of said veneer.

5. The method of flexing and expanding a sheet of wood veneer crosswise of its grain comprising adhering a sleazy backing of fibers to the back of the sheet with a waterproof adhesive containing latex, piercing the sheet of wood veneer from the backed side thereof through the fibers and adhesive with a series of simultaneously formed perforations spaced substantially longitudinally of the grain, repeating said series at points spaced laterally from preceding perforations to spread the fibers at each perforation and r thereby expand the sheet transversely of the grain, and dampening the veneer to close the openings left by said piercings upon the face side of said veneer, while said backing and adhesive in cooperation with the wood fibers maintain the expanded condition of said sheet of wood veneer.

JOSEPH R. FRANCEK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

Images