US2593709A - Veneer handling apparatus - Google Patents

Description

April 22, 1952 R. N. WARE, JR., ETAL 2,593,709

VENEER HANDLING APPARATUS original Filed July 16, 1947 2 SHEETS--SHEET l ,Tiki

fn I/En ZUP5 y Eazy/ard N Ware d?? Reginald 7a/272072 1; /@HZEE April 22, v1952 R, N WARE, 1R` ETAL 2,593,709

VENEER HANDLING APPARATUS Original Filed July 16. 1947 2 SHEETS--SHEET 2 fnf/EHZDPE Ric/zaini JVM/4e (//f Regina/Z U01/272072 Patented Apr. 22, 1952 VENEER HANDLING APPARATUS' Delaware Crignal application July 16, 1947, Serial No.

761,188. Divided and this application December 4, 1948, Serial No. 63,564

1 Claim.

This invention relates to apparatus for continuously producing paper-covered wood veneer from green,A undried wood and moistened stretched paper.

Specifically, the invention deals with apparatus which will reel veneer as it is' peeled from a log to form wound veneer rolls and to steam these rolls and to feed the steamed rolls to conveyors which form an elongated ribbon composed of stitched-together veneer from successive rolls.

This application is a division of our copending application, Serial No. 761,188, led July 16, 1947, entitled: Method of Making Paper Covered Veneer, now U. S. Patent No. 2,521,554, issued September 5, 1950.

The apparatus of the present invention winds freshly peeled veneer into relatively tight rolls and then heats these rolls with wet steam to raise their temperature without drying the wood.

The logs from which the wood is peeled are preferably in a green, undried condition. The hot steamed rolls of veneer are unreeled as needed to form ribbons. The ribbons of each successive roll are stitched together in. end to end relation to form a continuous ribbon. This continuous ribbon, while still in a hot condition, is advanced between the adhesive coated faces of wet stretched paper webs. The adhesive on the stretched paper webs is of a type adapted to suciently bond the paper to the wood so that relative slippage therebetween cannot occur even before the wood and the paper are dried. The bond thus created is sufficiently strong so that the paper will hold the wood against shrinkage during the subseouent drying operation. At the same time, the relatively small degree of shrinkage occurring during the drying operation will not cause a puclrering or wrinkling of the paper, because it is in a stretched condition and has substantially the same coeiiicient of shrinkage as the wood thatV is bonded thereto.

An important object of the present invention is to reel the freshlv peeled veneer sheets so that they can be handled in rolled-up form.

Another feature of the invention'resides in the wet steaming of the veneer reel to uniformly heat the Wood for producing a hot veneer that will speed up subsequent setting and drying. We have found that certain species of wood, such as Cottonwood, cannot be. satisfactorily peeled into veneer sheets from heated logs because the wood bers fuzz up when lathe cut in a hot condition.

Another feature of the invention resides in the provision of continuously operating apparatus which will handle successive rolls of freshly peeledA veneer through a steaming operation and will also piece together by stitching operations the short broken veneer sectionsl obtained in peeling a log to produce an elongated ribbon that is connected to the unreeled veneerf ribbons in producing a continuous ribbon for the paper covering step.

A further feature of the invention resides in the provision of tensioned driven press rolls yfor securing the paper sheets to the wood veneer while maintaining tension on the paper to 1nsure a good bond between the paper and wood and a smooth paper surface. v

An object of the invention is to provide apparatus for forming paper covered wood veneer and including devices for reeling veneer and for feeding wound veneer rolls through ak steam chamber.

Other and further objects of this invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of a preferred example, illustrate one embodiment of the invention.

On the drawings:

Figure 1 is a fragmentary broken' diagrammatic side elevational view of the first portion of the apparatus of this invention for forming rolls of veneer for steaming the wound veneer rolls, and for unreeling the wound steamed rolls.

Figure 2 isa View similar t0 Figure'l but illustrating a successive portion of the apparatus including the structure for covering` the wood veneer with paper.

Figure 3 is a View similar to Figures 1 and 2 but illustrating the third or last portion of the apparatus which serves to dry thepaper covered veneer product'. y

Figure 4 is a plan view of a veneer sheet, onehalf of which is covered with paper in accordance with this invention, and illustrating the manner in which the paper holds the Wood against aeavoe 'l l. I I

Figure 9 is a fragmentary plan view showing adjoining stitched-together veneer sheets.

As shown on the drawings:

As shown in Figure l, the reference numeral I9 designates generally a log-peeling lathe commonly used for cutting veneers from wooden logs. The lathe I9 includes a driven log support I I and a cutting blade I2. The support II drives a log I3 in the direction of the arrow against the blade l2 and a veneer ribbon i4 is peeled or cut from the log. In accordance with this invention a reeling stand I5 is mounted adjacent the lathe I and drivingly supports a shaft I6 on which the veneer I4 is reeled to form a roll I'I.

Uprights I8 carry three superimposed pairs of tracks or rails I9 to provide a roll-handling stand 29 in front of the reeling stand I5.

The axles or shafts I6 for the rolls Il, as best shown in Figure 6, have flanged rollers Ia on the ends thereof for riding on the tracks I9. The flanges overlie the outsides of the tracks I9 to hold the rolls between the rails.

The reeling stand I is adapted to raise a wound roll II to the two upp'er tracks I9 for depositing rolls Il on these tracks. The rolls are advanced along the stand 20 to a steam chest 2l having inlet doors 22 adapted to be opened to permit entry of the rolls I'I while still supported on the tracks I9. A plurality of rolls are accommodated at the same time in the steam chest 2l. A steam inlet pipe 23 supplies wet steam at about 4 to l5 lbs. per square inch pressure to the steam chest 2I for saturating the chest. Wet steam circulates all around the rolls I'I in the steam chest and heats these rolls without drying the veneer. The length of the heat treatment will vary, depending upon the thickness of the veneer and the size of the rolls. It is preferred that the rolls do vnot exceed 30 inches in diameter and that they be Wound tight enough so as to be evenly disposed around the shaft. Under such conditions the steam treatment may vary from 30 minutes to two hours. The temperature of the steam is preferably maintained around 225 to 249 F. The

wood becomes heated to less than the temperature of the steam or to about 160l to 225 F.

wound rolls Il out through exit dams 24 of. the -steam chest.

The Atop rails I9 have spring-pressed or counter weighted end sections 25 pivoted thereon and adapted to mate with a reel support 26 at the end of the reel section 2D. A spring 2Ior counterweight normally holds the pivoted sections 25 in a raised position to open up a gap 29 between the reel support 26 and the rail section 25. When a roller I6a rides up to the rail sections 25, the weight of the roll Il will depress the springs or counterweights so that the sections 25 will mate with the reel support 26 and the roll I'I is there- Vby fed to an unreeling stand designated generally by the reference 29.

'I'he rails I9 beneath the top rails terminate in pivoted end sections 39 pulled upwardly to the inclined position of Figure 1 by springs such as 3| or counterweights (not shown). When rollers carrying rolls II are advanced on the rails I9 to the pivoted sections 36, these sections 39 will be depressed to mate with extension rails 32 of a second unreeling stand,33 and the roll Il will be deposited into this unreeling stand without lifting it off of the rails. y

The unreeling stand 29 has inclined extension rails 34 extending downwardly from the rails 26 thereof to spring-pressed or counterweighted pivoted sections 35 held by springs 36 or counterweights (not shown) above the rails 32. When the roll I1 is unwound from a' shaft and its rollers in the unreeling stand29 the rollers can carry the shaft down the inclined rails 34=to the spring-loaded or counterweighted rails 35 whereupon the weight of the shaft will depress these rails into registration with an inclined set of rails 31 communicating at their lower ends with the bottom rails I9. When a roll Il in the unreeling stand 33 is completely unwound from its shaft, the rollers on this shaft will be guided back along the rails 32 to the inclined rails 3l without interference because the rail sections 39 and 35 will be raised by thesprings 3| and 36 to an out of the way position as shown in Figure 1. The shafts I5 are thereby returned along the bottom set of rails I9 to the winding reel stand I5. The two top sets of rails: I9 are preferably inclined downwardly toward the reel stands 29 and 33l while the bottom set of rails I9 is preferably inclined downwardly toward the winding reel stand I5 so that the wound rolls I1 will gravitate toward the unreeling stands 29 and 33 while the shafts I6 will gravitate toward the reeling stand I5.

Beneath the bottom rails I9 there is provided a conveyor system for handling short pieces .of veneer which are not wound into rolls I'I. As shown in Figure l, an inclined conveyor 38 of the belt or tape type extends from under the lathe knife I2 to a horizontal conveyor 39 beneath the bottom rails I9. This conveyor 39 feeds through a clipper 39a which trims the edges of the veneer pieces to form straight ends. The conveyor 39 discharges into a sewing machine 49. As shown in Figure 8, the sewing machine 40 has a head 4I carrying a plurality of needles 42 at spaced intervals across the width of a veneer sheet I4 fed therethrough. As illustrated in Figure 9,`pieces of veneer I4 are stitched together by rows of stitches 43 spaced at intervals across their Width. The stitched pieces of veneer I4 can fall by gravity out of the machine 40 to be picked up by an inclined conveyor 44 which raises them to an elongated horizontal conveyor 45. The horizontal conveyor extends to another horizontal conveyor 46 beyond the unreeling stand 29. Alternately, as shown in dotted lines, the stitched together pieces of veneer from the conveyor 44 can be wound into a roll on a reeling stand 45a and moved up to the rails I9 for a steam treatment in chest 2|. I

A conveyor 4T is provided to receive veneer unwound from a roll Il on the unreeling stand 29 to convey this venee1` to the conveyor 46. Another conveyor 4=8 is provided to convey veneer unwound from a roll on the unreeling stand 33 to the conveyor 4|6. Therefore, all veneer sheets are eventualy fed to the conveyor 46.

The conveyor 45,'as indicated above, receives stitched' together short veneer pieces. These stitched-together pieces eventually form a ribbon of appreciable length that can be selectively fed to the conveyor 46 for attachment to the trailing end of a veneer sheet I4 from an unwound roll I'I, if desired.'

As shown in Figure 2, a second sewing machine 49 similar to the machine 40 of Figure 1 receives 'the veneer I4 from the conveyor 46 and stitches veyor "45. `rThe 'continuous ribbon is 'fed to VIVan inclined yconveyor 50 lonto lafhorizontal conveyor -`5| 'tThe continuous ribbon 'of veneer 'I4 on the conveyor `5I is next fed between adhesive coated faces `of paper webs in awet stretched condition. The paper webs are preferably composed of tough kraft paper.

As 'shown in Figure 2, a roll of paper `5I is mounted vabove the apparatus for covering the top vface of the veneer ribbon. lA paper webW from this roll is guided under va guide ro11^53 lto awetting rolly 54 contacting the underface of the web and rotatably mounted in a suitable coating pan A55. The pan preferably contains water at temperatures raround 180 1F'.Y Alternately, the pan can contain a water emulsion of a paraffin' wax capable o'f imparting a smooth wax iinish on the paper while lat the same time having 'the water thereof penetrate into the paper for wetjting it. The wet paper web then passes under a guide roll v'.58 and isfed to a coating machine having a fountain roll 451applyv a coating of adhesive tothe topface of the web opposite the face engaged by the wetting roll 54. The adhesive is `oi' a type capable of creating a lrm bond before it is thoroughly dried, so that no slippage will occur between the paper and wood as the wood begins to shrink during a drying operation. A vegetable protein glue is suitable.

After receiving the adhesive coating, the web is directed overa guide roll 58 and around a turny ing roll 59 so that its adhesive-coated face will overlie the top face of the veneer ribbon discharged oi of the conveyor 5 I.

A second roll cf paper 60 is mounted beneath the apparatus and feeds a second web W over guide rolls 6I to a turning roll 182 for providing a reverse run of the web over a wetting roll 63 operating in a pan 84 to wet the web with hot water or with a water-wax emulsion as described in connetionwith the web from the roll 52. vThe web from the wetting roll 83 then passes around another/turning roll 65 to again have its direction of travel reversed. Guide rolls 68 direct the web to a'coating apparatus 61 which applies the same type of adhesiveto the opposite face of the webv as is applied to the other web byjthe coating apparatus 51. The adhesive-coated vweb is then passed under a guide roll 68 andv around a turning roll 68 which directs the adhesivecoated face of the web under the ribbon of veneer v I4 discharged from the conveyor 5 I It will be noted that the web runs between the wetting rolls and the adhesive coating machines areappreciably long so that the water can pene- I trate into the webs and permit them to stretch. The wet webs are placed under tension by the coating machines 51 and 61 so that the adhesive is applied to the wet webs in` a stretched condition on-the faces of the webs opposite the` faces engaged by the wetting rolls. The adhesive itself preferably has a water base so that the opposite faces of the webs are :also wet with water. The runs of the webs beyond the adhesive coating machines are also of considerable length so that further stretching of the webs is possible! The adhesive-coated faces of the webs are guided by the turning rolls 59 and 69 in spaced relation above and below the Veneer ribbon fed from the conveyor 5I.

The webs 4with the veneer ribbon therebetween are fed through a first press 10 composed of top and bottom rollers yspring loaded toward each other by a spring such as 1I. The chamber 12 contains a number of press rolls 13 composed of attachment Sto permit. threading lof paper covered veneer through the: machine. The chamber also contains ta series of drivenpress rolls T4. T-hus, as'shown, 'the last three sets of rolls are .positively driven-land are spring `loaded Yas at 15 to exert lincreased pressures on the paper and 'veneer assembly received therebetween. The press 10 advances the webs and veneer ribbon to the press rolls 14 through the idler rolls 13 and, when the 'assemblyl is completely threaded through the rolls 14, the 'drive on the press 10 is released Vso that the rolls .14 become the main driving rolls for pulling the paper and `veneer through the idler rolls 13. The rollers coactr for ironing the paper webs on the wood ribbon sandwiched therebetween teinsure a 'good iirm vcontact tov create a thorough lad hesive bond. The tension pull established by the rolls 14 keeps. the papery webs in stretched condition and the lidler rolls 13 maintain somewhat of a dragging action on the paper.

The chamber 12 is heated to temperatures around 120 to 180 F. by a steam coil 16 extending through the chamber. The steam coil heats air in the chamber and the heated air starts to remove some of the moisture from the webs and veneer without, however', drying the veneer to its shrinking point, which is usually below 30% moisture content. Moistened air is exhausted from the chamber by a blower 11.

By the time the paper and veneer reach the discharge vend of the chamber 12, the adhesive bond between the paper andthe wood is sufficiently strong so that the slippage cannot occur when the wood starts to shrink. While the adhesive may not yet be in its iinal setfstate, it is,

nevertheless, strongl enough to hold the wood in its expanded or swollen condition even when the moisture is dried from the wood and the wood tends to shrink. The heated veneer from the steaming operation is soit and pliable and facilitates drying and setting of the adhesive. The adhesive itself can be applied in a heated condition if desired. The paper, of course, is heated from the application of the hot water or wax emulsion. These heatvtreatments speed up the operation.

The paper covered wood veneer isdepositedV on another conveyor 11 as it leaves the chamber 12 and this conveyor feedsa iiyin'g shears 18 which cuts the material into the desired length segments. The shears 18 includes a tiltable cutting section 19 rocked by an eccentric 80 so as to move the cutter blades withthe advancing material at a correlated speed thereby preventing buckling of the advancing material during the cutting operation.

The cut product is deposited on another conveyor 8|.

'Ihe conveyor 8 I, as shown in Fig. 3, discharges to a tipple 82 which selectively supplies superimposed conveyors 83 extending through a drying kiln 84. The kiln 8 4 is quite long and has a blower 85 mounted on top thereof for receiving air from an inlet duct 86 and .discharging the air through a distributor duct 81 to an inlet duct 88 at the discharge end of the kiln. The air and kiln are heated by steam pipes or other heating means (not shown) so that the kiln will have an inlet temperature around 250 F. and an outlet temperature around 375 F. The circulating hot air in the kiln drives the moisture out of the paper and wood to produce the nal dried product which still contains enough moisture so that it will not warp -`when exposed to the atmosphere. The conveyors 83 extend beyond'the discharge end of the kiln so that the product can cool down sufliciently to a temperature convenient for handling.

As explained above, theA adhesive bond between the paper and the wood is sufciently strong in a partially set condition so that relative slippage between the paper and wood will not occur when the wood is dried.

' As illustrated in Figures4 and 5, the product 89 of this invention is composed of a wood veneer lcore 90, adhesive bonds 9| on each face of the core, and paper covers 92. The wood 4core 90 is held in an expanded swollen condition such as it assumes when it is saturated with moisture. Even though the moisture content of the product is reduced materially beneath the shrinking point of the wood, the paper is strong enough to hold the Wood against shrinking. This is illustrated in Figure 4, wherein only half of the woodI is covered with paper. The exposed half 90a is in a shrunken, dried condition, while the covered half 90 is just as dry, but in its original expanded condition. As illustrated, considerable shrinkage normally occurs upon the drying of the wood veneer, and this shrinkage frequently produces checks andcraoks 93 between fiber bundles of the wood. A dried veneer sheet is therefore usually full of checks and holes such as 93. The grain 94 of the wood extends longitudinally or across the width of the veneer ribbon and in the dryingr of the uncovered veneer the pith or soft wood between the harder fiber bundles will tear apart to produce the checks and holes. This condition does not occur in the paper covered portion of the wood, where the grain 94 remains in its expanded condition and the fiber bundles are not allowed to pull the softer pith apart to create open holes or checks.

Some slight shrinkage, in the nature of l to 2%, does occur as the green wet wood is dried down to the finished condition wherein its moisture content is about 6 to 12%. This shrinkage takes place without puckering or wrinkling the paper bonded to the wood because the paper is also in a stretched condition and shrinks coexvtensively with the wood. Any shrinkage of the wood thereby merely permits simultaneous shrinkage of the stretched paper which in no event reaches the stage where the paper becomes compressed to wrinkle or pucker.

The paper sheets, by being bonded to the green, undried wood inits swollen condition, with a bond that is strong enough to resistrelative slippage between the paper and wood even before the wood is dried, will save as much as 10 to 25% of shrinkage loss heretofore attendant with the drying of wood. The undried green wood contains about 120 to 130% moisture by weight, and this moisture content can be reduced to about 30% by weight before shrinkage of the wood begins.

According to' this invention, the adhesive bond is sufllciently set before the wood is reduced to a moisture content of 30% to prevent relative slippage between the paper and the wood when the assembly is dried below 30%. The adhesive thus has a strong wet strength setting capacity.

From the above descriptions it will be understood that the invention provides apparatus which will form paper-covered Wood Veneer and which includes reels for winding veneer sheets into rolls,`a steam chest for steaming the rolls to uniformly heat the veneer sheet and apparatus for covering the hot Veneer sheet with heated, moisture-saturated paper to bond the paper to the veneer before the veneer is dried to its shrinkingpoint, and apparatus for drying the papercovered product to a moisture content between 6 and 12% where it will not warp in any atmosphere.

It will, of course, be understood that various details of the apparatus may be varied through a wide range without departing from the princi-` ples of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise thannecessitated by the scope of the appended claim.

We claim as our invention:

Veneer handling apparatus comprising an elongated rack having superimposed tracks including roll conveying tracks and empty Winder shaft conveying tracks, movable track sections accommodating passage of rolls in one direction, means for swinging said movable tracks to an out of the way position after passage of said rolls for accommodating movement of `unwound shafts back to the shaft tracks, and an unreeling stand at the end of the track for receiving wound rolls from one set of tracks and for discharging empty shafts back to the other tracks. f

' RICHARD N. WARE, JR.' REGINALD CANNON.

REFERENCES CITED The following references,` are of record in the le of this. patent:

UNITED STATES PATENTS Germany of 1937

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