US2657160A - Veneer joining apparatus - Google Patents

Description

Oct. 27, 1953 E. L. cRosToN VENEER JOINING APPARATUS 5 Sheets-Sheet l Filed May 14, 1949 INVENTOR. fd/ward Crosfon ATTORNEYS REYNOLDS c5 BEACH Oct. 27, 1953 E. cRosToN 2,657,160

VENEER JOINING APPARATUS Filed May 14, 1949 5 Sheets-Sheet 2 lNvENToR.

` Edward L. Crosfcn ATTORNEY- REYNOLDS BEACH Y'MM-@MJ Oct. 27, 1953 lE. L. cRosToN 2,657,160

VENEER JOINING APPARATUS Filed May 14, 1949 5 sheets-sheet 3 INVENTOR. Edward L. fc4-:fon

ATTORNEYS BY REYNOLDS i BEACH Oct. 27, 1953 E. L. CROSTON VENEER JOINING APPARATUS Filed May 14, 1949 5 Sheets-Sheet 4 ggf@ A Oct. 27, 1953 E. L. cRosToN VENEER JOINING APPARATUS.

Filed May' 14, 1949 5 Sheets-Sheet 5 INVENTOR.

ATTOKNEYS REYNOLDS BEACH MAJ M [c7/ward L Crosio/2 Patented Oct. 27, 1953 Edward L. Croston, Dash Point,Wash/., -assignoni to. American. Manufacturing-r Company, Inc., Tacoma, Wash., a' corporation .ofl'Washington..

Application May14, 1949; Serial No. 9322544 4.01aims. (Cl. 154-116)- This inventionnrelates to af method and. appa--r ratus' for'adhesively edge-joining veneer-.cr .similanmaterialsfor use in making. plywood, furniture, .and for otherV purposes. Its principal ob,-

jectristo avoid the dificultypreviously experi-y enced, namelythat of the joints'separating or drawing apartfrom shrinkage of the veneer becausefof unavoidable drying thereof during application of heat to set the adhesive.

I-n-.someprior types of veneer joining apparatus veneerv strips` wereY advanced together edgewise continuously throughthe apparatus and between heatedsurfaces Whileheld in. edge-to-edge relationship-.-v To keep.. adjoining edges. incontact during suchmovement. clamping pressure Wa-s applied to opposite'facesof theradvancing veneer strips by the opposed conveyor elements. Such pressure vwas sufficientv to hold the pieces coplanar and flat;v however, it did not exert suicient pressure to hold the veneer against edgewise shrinkage-from heat-drying. Moreover, because offthis clamping pressure, applied `to all veneer strips alike, it wasI not possible to compensate for veneer shrinkage byv setting. up relative motion of the pieces, againstfriction, so. as to continually urge each veneer strip toY press its edge against the adjacent edge of the strip next preceding it..

In accordance With myinvention the veneer strips arewpreferably stopped completely during the.' actualbonding operation, and at'that time their opposite faces are subjected tohpressures suiiiciently well. distributed and great enough to prevent separation of. the. abuttingv edges. WhileV the. process is intermittent, movement.. of the veneer stripsfbeingarrested during b'ondingperiods to set the joints between thestripsin batches, andnot continuously, the-joined veneer emerges from the vmachine in a continuous ribbon. ata. production rate which is superior to thatobtained.

heretofore with-continuous movement machines. Thelength ofv joined veneergribbon produced each cyclefin-a-particular caseA is. limited onlybyI themaximum .practical length. of the machine which advances and. holds then individual strips. for.

bonding.

An important. advantage of the invention re.- sults from the mechanism vfor andthe method of automatically advancing andpressing. together.

edgesof the successive veneer strips between press platens, andmaintaining. such edgewise pressure until. the press is closed Thisis accomplished into the press and pressing them together;

the dischargesideofithe:.press; it isfstoppedzposi.-

tively. and; held against the frictional force-,onits-'f surface tending; to advance it. f arther. It.A is: im-

portant .to-.note that although the unit pressure.

exerted: onvits 'surface'. is. suicient to hold* the veneer strip flat, the area engagedis. compara-y tively small,l soi that theV frictional force tending.

to'urgeV the veneeraheadv is overcome by. the positive arresting. force;

As the.A strip-of veneer nearest to the exit ,side

of the pressis-stop-ped, thesucceeding: piecescon.- tinue to be advanced by the frictionalforceexerted on their surfaces until the next piecexinvv turn. is: stopped. by. abutmentawithzthe Yfirst .piece already stopped.: In. turn. each succeeding. ,pieceis brought to a stop as:it overtakes andengages theY piece next' preceding. itV which. hasbeen stopped. When -the growing. series.` of contacting' ly. ofthe grain sufficientlytoA Withdraw -the4 edges f from. abutment An importantadvantage' of the foregoing procedureI isfthe continual .application to the strips, though stopped, rof a forceurging fthenr forward, thereby continuously maintaining the contacting edgesof adjacent pieces in.close abuttingrelationship:` until. the.- press= closed.

veneer, full and` uniform contact between adjoining ,edges of. the-vencen; when .the lpress is. finally`r closed, is-insured; even though the veneer maybe lwarped or its edges be not precisely parallel. To insure suchr operation.. the-leading veneer strip is held clamped. individually at least untilful'l.

closure of the press. Whenthe pr'essfis later openedfand thezi-lrstv strip has been. unclamped the new continuous veneer sheet is discharged from the'press: by applicationto it of* surface` frictional membersl moved .inthe same direction of advancaasftherstrips moved insbeingffedfinto' Simultaneously' additional. strips of'A veneenare fed into .thepress'for. joiningiitogether."

the press;

and. .to the. trailing edge.; of the-composite veneer sheet alreadyproduced..

A related; ,featureeof zmeehanismzcapafbleof ef yfectmgf.- the:procedura` describedV above: resides'rin Because zthef zones offrictional pressure, though-narrow, are comparativelyclosely spaced lengthwise: of .the

an arrangement of opposed platens of sectional construction to deine parallel grooves spaced at intervais across their widths and aligned with the direction or" veneer travel, and conveyor belts or chains operatively mounted in the grooves between such platen sections. During advancing and locating of the veneer strips in abutment in the press initially, the platens are held apart to allow the veneer to slide freely between them. However, the amount of separation of the platens at this time is limited, thereby restricting the space available for warp-age of the veneer and preventing the edge of one veneer strip overrunning the strip ahead which is stopped, because of the now coplanar relationship of succeeding strips. Such conveyors exert frictional pressure on the surfaces of the veneer strips of substantially equal predetermined value, and such pressure is approximately equal to that exerted by the press platens over a like area. Thus when the `platens are closed the pressure applied by them and by the conveyors is controlled such that the veneer is subjected to substantially equal unit pressure over its entire area within the press.

These and further objects, features and advantages of the invention will become apparent from the following detailed description of its preferred form, based upon the accompanying drawings.

Figure l is a plan View of my improved machine for joining veneer and similar materials, showing fragmentary portions of feed and discharge conveyors operating in conjunction therewith.

Figure 2 is a corresponding side elevation View, additionally showing a veneer clipper at the discharge end of the machine.

Figure 3 is an end elevation view of the feed end of the machine, with parts broken away.

Figure 4 is a vertical section through one end of the press showing part of a clamping conveyor and the press platens, taken in a plane parallel to the direction of veneer travel on the section line l-fi of Figure 5.

Figure 5 is a fragmentary vertical section through the press taken in a plane transversely of the direction of veneer travel on the section line of Figure li, and showing one pair of clamping conveyors and immediately surrounding fragmentary portions of the press platens.

Figure 6 is a vertical section through the discharge end of the press taken on the line 6 6 of Figure 'l and showing veneer arresting mechanism.

Figure 7 is a fragmentary vertical section through the press taken on line 1 1 of Figure 6 and illustrating the arresting mechanism, the press platens and clamping conveyors.

Figures 8, 9 and l0 are fragmentary diagrammatic vertical sectional views through the press illustrating successive stages in the joining operation.

Considered generally,` the principal operating components of the machine include the coacting upper and lower press platens l and I2, the plurality of coacting upper and lower feed conveyor belts or chains I and I5 arranged in laterally spaced parallel relation extending in the direction of veneer advance, and the veneer arresting mechanism i8. The pressure faces of the platens are sectional, as shown in Figure 3, defining between such sections grooves receiving the stretches of chains lll and i6. These chains frictionally engage the upper and lower surfaces of the veneer and by such engagement exert the tractive force eiective to'feed the veneer tlllQllgh the press. The clamping mechanism I8, operable to overcome the frictional grip of the feed conveyors lll and l and to arrest motion of the trailing edge of the veneer sheet emerging from the press, is conveniently mounted directly on the discharge end or" one of the press platens, such as upper platen Eil, rather than on a separate mounting, as shown in Figures 6 and 7. In such case it coacts with the lower platen i2, or with an end extension l of it, against which it presses to clamp positively the trailing edge of the veneer sheet.

In order to advance the veneer strips into and feed them through the space between the upper and lower platens each strip is inserted by a supply conveyor 22 between the enactingY pairs of upper and lower feed conveyor belts l and l, which are driven to move the veneer' vstrips on through the press.

These conveyors extend at least from one end of the press to the other, and preferably somewhat beyond such ends to facilitate loading and discharge of veneer. Discharge conveyor 213 taires the veneer from the discharge end of the feed. conveyors Il@ and I6. As shown in Figure l, conveyors 22 and 2d are preferably of the multiple belt type.

Figure 2 illustrates a typical working arrangement whereby the veneer strips V, advanced in the direction of the arrows, pass rst from the supply conveyor 22 to the feed conveyors lli and it, between the press platens, where they are clamped and edge-joined, and iinally the veneer is delivered as a continuous, composite sheet from the discharge end of the press to the discharge conveyor 24 which carries it to suitable cutting means, shown diagrammatically as the veneer clipper blade 26 and cooperating work support 253 located in shearing relationship beneath it, which cuts the sheet into the desired lengths.

The present invention is concerned only with the method and apparatus by which the veneer is handled from the time it is delivered to the feed conveyors until it leaves such conveyors at the discharge end. of the press. During that period the adhesively coated edges of the veneer strips are brought together uniformly, while such strips are ilattened into a common plane through-out, heated to set the adhesive, held against shrinkage during such heating, and iinally released for discharge from the press by the feed conveyors ld and l. rlhe veneer strips are so urged together edgewise and thereafter held that at no time during the edge-joining operation are the abutted edges of the veneer allowed to separate for any reason, and they also are prevented from overlapping.

In its preferred and illustrated form, as shown generally in Figures l, 2 and 3, the machine includes a central base Sil, a supply-end base Si supporting supply conveyor 22, and a dischargeend base 6B supporting the discharge conveyor 24. Upon the four corners of the central base 30 are mounted vertical posts 32 which fixedly support the upper press platen lil at its corners a convenient distance above such base. As shown in Figure 3, these posts have reduced upper ends received in apertures in the upper platen to form shoulders on which such platen rests, and their projecting ends are anchored to the platen by nuts 34, threaded onto such'posts to prevent such platen being lifted by pressure exerted on it by the movable lower platen I2 when the latter is urged upwardly in closing the press. Such corner posts 32 extend through apertures in the lower platen, guiding it for vertical reciprocatio'n.

In appropriate cases thev lowc-n,v platen might.- be fixed and the upper pla-ten movable, instead of' the upper platen being fixed and the lower platen movable, withoutv departing from theA essentials of' this invention.

Several hydraulic rams 3B are mounted in laterally spaced relation widthwise of the press on-base 30, as shown in Figures land 3', toraise and lower press platen in closing the press'. The individual rams, each comprising' a fluid cylinder and a coacting piston of any suitable construction, are spaced in the manner illustrated inorder to distribute their force reasonably uniformly over the platen for transmission to the veneer by pressing it against the upper platen. Any tendency of the lower platen to bend under load is minimized by using several rams in such an arrangement, so that the pressureL on the veneer is more uniform. Also with thisarrangement the platen itself need not be excessively massive to resist bending. The rams 38 are of course conjointly actuated by` pressure fluid,

controlled by suitable meansy not shown, and

stops limitdownward movement of the platen appropriately so that the relative separation of the platens when the press is' fully open leaves an opening betweenthe platens only sufiicient for the feed conveyors to advance a single layer of veneer through it, thus preventing overlap of adjacent edge portions of two sheets or veneer.

Since the veneer. is usually anything but uniformly nat when ready for joining, because of its invariable tendency to warp when notV forcibly held, it is advantageous to limit opening of the press in order to restrict the amplitude of veneer warpage permitted. when the veneer is being advanced through the press. The veneer edges thus cannot depart' far from lcoplanar registry, and since the feed conveyors pressI the adjacent edges of the veneer strips-togetl'ier in the desired relation at locations spaced' rather closely lengthwise ofthe strips, the edges of the intermediate portions between such conveyors are brought readilyA into uniform contact when the press platens are closed' to press'the veneer strips into planar condition.

The upper and lower press platens I t and I 2 arerpreferably of similar box girder' construction, and may be cast or fabricated from plate stock. As shown in Figures 3 and 5, each includes such a girder unit 40, constituting its principal structural portion, and' spaced, parallel facing strips preferably formed as the exposed surfaces of fiat tubesY lltv extending parallel to the feed conveyors f4 and It' and adaptedto engage and press the veneer; In the narrowgrooves or channels in the press platens formed between adjacent facing strips pass the work-engaging'or inner stretchesI of the feed conveyor chains, such alternately located strips' and chains cooperatively forming the working faces of the respective upper and lower platens. The girder portion lil of eachplaten preferably isformed with tunnels i2 through which the outer or return stretches of the feed conveyor chainsV may pass in traveling from the discharge end to thesupply end of the press outwof contact with the veneer.

It is to be understood that other forms of platen may be used. Instead of the conveyor chains-passing through the platens they may be guided to pass over their outer faces. Separately attached hollow facing tubes are not essential since the platens maybe of integral construction'. The: hollowsf-inthe facing tubes; or 1in theplaten if suchtubes are not used, serve conveniently for passage of steam to. heat the platen for setting the: glue between abutting edges of the-veneerA strips'in the press. Other heating arrangements; however', maybe employed. The essential feature'. of myv press is the alternate ar'- rangementof comparatively narrow, spaced feed conveyors and the platen pressure strips combining to'forrna platen surface which will applyr uniform pressure to substantially the entire surface of the: veneer: received in the press when the pressv isv closed. Moreover; the feed conveyors preferably are arranged to applyv substantially the: :samel unit pressure to veneer between them at all other: times, softhat` only the unclamped zones between conveyors experience a substantial pressure change to flatten them outl and hold them against shrinkage when the press platens are closed.

Whilethe feed conveyors may vary in form, I prefer-thatthey bechains or link beltscarrying or constituting the. moving support for an endlessseriesof work-engaging treads tt. ter; preferably of metal and, for example, sledlike inform, are free to slide over the surface of veneerv which is heldy positively against movement, without damaging the veneer or greatly loading the conveyor drive means. Yet under normal resistance to advance of the veneer through the press', with the latter open as previously described, these feed chain treads will have suili'cient frictional engagement with the veneer surface to effect impositive advance of such veneer, and of all strips alike, between the platens.

The feed conveyor chains it and It pass over sprockets 54 (Figure 4) mounted for' rotation on drive shafts 56 which are journaled at opposite ends` of the respective press platens. As shown in Figuresl and 3, these shafts are carried byv brackets 511 projecting from the end faces of such platens, to support the shafts 5t horizontally in perpendicular relation to the desired line of advance of the veneer through the press. One of the these shafts is driven by a chain and sprocket drive 58 from power means (notshown) housed within the discharge end frame section t0 (Figure 2l. Conveniently the corresponding shaft of' the opposed clamping conveyor derives its rotation from a gear connection 59 with the driven conveyor, as shown in Figure 1. The same power means driving the feed conveyors may be used to drive the supply and discharge conveyors 22 and 24, although a separate drive for the supply conveyor is indicated in Figure l of the drawings.

In order that the fee-d conveyors may be pressed firmly against the veneer at all times the opposed stretches of the conveyor chains are urged continuously toward each other. Moreover, it is desired to maintain the pressure of the conveyor chains at a predetermined value, or within a predetermined range of pressures, sulciently high that the zones of the veneer engaged by them will be held nat between the conveyor chains, but not so high that the resulting frictional force between the conveyor treads and the veneer surfaces will be excessive when edgewise movement of the veneer is positively arrested, insuring that the veneer will not be buckled and split by advance of the feed conveyors when thus held against movement.

The pressure with which the respective conveyor stretches engage the veneer is determined by` resilient connectionsV between the conveyors The lat-y and the press platens. resilient means employed are such that when the platens are open the resilient means will continue to urge the conveyor treads against the veneer with a force which does not differ appreciably from that exerted by them when the press is closed. In the preferred embodiment, each clamping conveyor is provided with a vertically yieldable, spring-urged bearing element such as the track d8 which bears against the back sides of the conveyor stretches engaging the veneer faces, to urge the conveyor treads against the veneer. 1f a single track is provided for each conveyor chain, such track will extend substantially the iull length of the press, although shorter tracks mounted end to end may be employed for the same purpose.

As shown in Figure 5, the tracks 48 are of T-bar shape, having a rib projecting vertically downward in the case of the upper track and upward in the case of the lower track along which the chain link spacers i3 roll or slide as the conveyor chains are driven. Compression springs 52 received in recesses in the anges of the tracks 58 bear against the adjacent faces of the platen structures. Normally, with the press open, the springs are compressed, combining to provide a force which produces the desired unit pressure against the veneer uniformly along the entire working stretch of the conveyor. The spring pressure does not change substantially during closure of the press because of the small amplitude of the lower platen movement effecting further compression of the springs. As has been explained, the hydraulic pressure exerted by the rams 38 is controlled by suitable means (not shown) to produce a pressure of the platen face strips le against the veneer which is substantially equal to that applied by the conveyor treads. Such pressure of the feed conveyors and closed press platens is preferably about 10 pounds per square inch.

It will be evident that the feed conveyor treads on the working stretches project somewhat beyond the general plane of the platen faces when A the press is open. Upon closure of the press the tracks backing such conveyor stretches must yield. To allow movement of the conveyor stretches from the planes of their respective platen faces into projecting position when the prees opens, the conveyors have a slight amount of slack. The tracks et are provided with ears at their ends, as shown in Figure e, embracthe respective press platens between them and sliding the platen end faces to guide the tracks for vertical reciprocation.

The remaining principal operating element is the recher-arresting or clamping mechanism i8, which is illustrated generally in Figure 2 and particularly in Figures 6 and 7. Such mechanism comprises a clamping bar S2 conveniently mounted slidably on the end face 68 of one of the press platens, such as the upper platen IS,

at the discharge end of the press. Such clamping' bar is guided for vertical reciprocation by the sides of elongated vertical slots titl in the bar coacting with machine screws E56 passing through the slots and threaded into the platen face at E8. The bar is notched or recessed at suitable intervals to accommodate the upper feed conveyor chains ll which extend beyond the discharge end of the press as shown best in Figure 7.

Normally the clamping bar 52 is raised from the work, allowing the veneer to be advanced through the press without resistance other than The characteristics of thel that of friction incurred by the warped veneer rubbing against the platen faces. At the proper point in the `advance of the veneer the bar is actuated manually or automatically to clamp the outwardly moving, continuous sheet of Veneer positively against further movement. Preferably the bar is actuated by pneumatic means such as the pair of cylinders i8 spaced endwise of the bar and carried by brackets 'l2 on the end face of the upper platen. As shown in Figure 6, each pneumatic cylinder actuator has a piston rod T4 connected to a lever 'l5 by a link i8. The lever is fulcrumed about a fixed pivot i9 on the press platen and is pivotally connected between its fulcrum and piston rod- 'M to an ear 8i! xed to the side of the clamping bar t2.

It will be evident from Figure 6 that downwardl movement of the piston rods 'ld effects clamping of the veneer by producing descent of the bar 62 pressing the veneer against the underlying end projection 2B of the lower press platen. The bar is raised by retraction of the piston rods 'ill into the cylinders it. If desired, the uid pressure in the cylinders may exert a force on the bar in the downward direction only, it being raised by spring means. Such spring means may be incorporated within the pneumatic cylinders and normally urge the pistons upwardly therein, or the cylinder may be of the double-acting type having ports in both ends to exhaust and deliver pressure uid to them. The cushioning effect or" air in the pneumatic cylinders allows the bar 62 to yield upward immediately when the lower platen moving upwardly is pressed against the lower side of the veneer beneath it, thereby permitting the veneer to be forced into uniform engagement with the upper press platen.

An operation cycle of the machine carrying out the general method of the invention is illustrated in Figures 8 to 10, inclusive, wherein the machine is shown diagrammatically, greatly simplified by omitting the conveyors and press details. lin Figure 8 a plurality of veneer pieces edge-coated with adhesive are being advanced in the direction of the arrow into the space between the press platens l@ and l2. Initially, when locating the pieces on the conveyors for delivery to the press, the operator will arrange the successive strips with gaps between their adjacent edges, to insure that the strips will not overlap before entering the press.

Just before the trailing edge of the leading strip has been advanced to the discharge end of the press the clamping mechanism i3 is actuated to pin such strip against the lower platen, or its extension 20, to stop movement of the veneer. This stage is illustrated in Figure 9. Thereafter succeeding strips of veneer entering the press continue to be advanced toward the stopped strip by the frictional engagement of the feed conveyor shoes with them until, one after another, they are each crowded successively edgewise against the next preceding strip. Close edgewise abutment of the strips is thereafter maintained by continued movement of the feed conveyors slipping across the strips until the press is loaded, at which time, without stopping the conveyors and without releasing the clamping mechanism I8, the press is closed upon the veneer. In the ensuing period, during which the adhesive in the veneer joints is being both heated and pressed by the press platens, the clamping mechanism I8 may be released. Preferably the feed conveyors are stopped as well, although they may be kept in motion continu- .its entire area within the press .because lt-he 'feed conveyor treads are very close togetherfalongfthe length of the conveyor chains and the pressure strips lof -the platens lie close alongside fthe rows yof feed Aconveyor treads.

An important feature of yfthe inventionfwhich should be noted in summarizing its principles is the combination of friction feed conveyor mechansim, operable to advance the veneer impositively, and positive arresting means to stop a leading veneer strip and hold it against the force applied to it by the feed conveyor mechanism. Another feature is the combination of feed conveyor mechanism in the form of several narrow conveyors arranged in spaced parallel relationship and press means composed of elements fitting between the conveyors and substantially filling the intervening spaces to press the areas of veneer between the feed conveyor elements for exerting a uniform pressure on the veneer over substantially the entire area in the press.

Moreover, although the unit pressure applied against the surface of the veneer by the feed conveyors when the press is open and the arresting mechanism has stopped the outgoing sheet is comparatively great, sufficient to flatten those portions of the veneer engaged by the conveyors, still the force exerted parallel to the surface of the veneer by the feed conveyors, tending to advance the veneer clamped against edgewise movement by the mechanism IB, is slight because the contact area of the feed conveyor treads is comparatively small and they have smooth metal surfaces. It is this arrangement which makes possible the effective use of pressure in bonding the veneer high enough to prevent shrinkage or contraction thereof during heating, since such high pressure in no wise interferes with the initial operation of locating the pieces edge to edge. As a result it is possible to obtain veneer joints which are improved over those previously obtainable 'and at improved rates of production and lower cost.

The use of a number of comparatively closely spaced feed conveyor chains, rather than a few widely spaced chains, is preferred. Even if the veneer strips are quite warped, they will nevertheless be flattened sufficiently by the feed con- Veyors so that, after being pressed together edgewise, no appreciable shifting of any edge portion of a strip will be effected by the press platens in closing, so the friction between the abutting sheet edges will neither prevent accurate registry of them nor cause damage to them, such as splintering.

I claim as my invention:

1. In the method of adhesively edge-joining strips, the steps which comprise advancing such strips successively along a predetermined path with their edges to be joined disposed transversely of such path, frictionally engaging simultaneously several of such strips substantially throughout a plurality of parallel, narrow areas extending entirely across such strips transversely of their edges to be joined and parallel to the direction of strip advance and spaced transversely of the direction of strip advance and by such engagement exerting laterally against the faces of such strips a force flattening them into faces '-of lsuch `strips advancing them -conjointly toa bonding station, halting the y.advance -ofthe leading strip while continuing to apply thereto -such lateral and parallel friction .forces to such strip .and .by :application of such forces continuing to advance .succeeding strips until each Iof such .strips edge-"abuts 4,the strip ahead of it and is thereby held against further advance, while continuing to apply such advancing and attening forces throughout such spaced, parallel, narrow areas applying distributed attening pressure laterally against -the 'faces of the strips in substantial continuity Ventirely across such strips in areas located transversely of the direction of strip movement between such spaced, parallel, narrow areas of the order of intensity or' the lateral force against the strips in such spaced, parallel, narrow areas, thereafter interrupting the advancing force applied to such spaced, parallel, narrow areas while still maintaining the iiattening force therein, and, while maintaining the attening force in such spaced, parallel, narrow areas and the -iiattening pressure in the areas therebetween, setting adhesive on the veneer strip edges.

2. Apparatus l'or adhesively edge-joining veneer pieces and the like, comprising upper and lower press platens guided for relative opening and closing movement and when open defining a passageway for the progressive edgewise advancement of edge-abutted veneer strips therebetween, the adjacent faces of said platens having work-engaging portions separated by open channels extending parallel to the direction of advance of the strips, including a iirst channel in the upper platen located in direct superimposed relation to a second, corresponding channel in the lower platen, a pair of endless, elongated, clamping conveyors including an upper conveyor having a lower, work-engaging stretch received in and movable lengthwise along said first channel and a coacting lower conveyor having an upper, work-engaging stretch received in and movable. lengthwise along said second channel, said clamping conveyor work-engaging stretches having substantially continuous, workengaging tread surfaces spaced from the press platen work-engaging portions transversely thereof when the press platens are open and operable cooperatively to fiatten the edgeabutted veneer strips therebetween substantially uniformly over the length of such stretches and thereby prevent overriding of one veneer edge relative to an abutting veneer edge, resilient means continuously pressing said conveyor workengaging stretches against the respective opposite veneer faces engaged thereby substantially independently of press opening and press closing movements, and power means driving at least one of said conveyors to effect advancement of edge-abutted strips through said passageway between the platens.

3. The apparatus defined in claim 2, and work arresting clamp means at the discharge edge of the press platens and operable independently of movement of the platens to clamp and hold a leading veneer strip against further advance through the press passageway, the conveyor tread surfaces being formed to slide harmlessly on the respective veneer strip faces while maintaining abutment of adjacent strip edges during interruption of veneer strip advance by said arresting clamp means.

4. The apparatus defined in claim 2, wherein coplanar relationship and a force parallel to the the resilient means comprise spring members 11 carried by the respective press platens and reacting therefrom to press the respective conveyor work-engaging stretches against the veneer faces when the press is open While yielding to permit recession of such stretches into the channels upon closing of the press.

EDWARD L. CROSTON.

UNITED STATES PATENTS Name Date Mell Apr. 26, 1927 Number Number i2 `Nanne Date Weber Feb. 12, 1929 Perry Mar. 17, 1931 Goss Nov. 3, 1942 Irwin et al Mar. 13, 1945 Pfenning June 12, 1945 Hall Sept. 24, 1946 Bolling Feb. 17, 1948 Blhuber Nov. 9, 1948 Bolling Nov. 22, 1949

Claims (1)

1. IN THE METHOD OF ADHESIVELY EDGE-JOINING STRIPS, THE STEPS WHICH COMPRISES ADVANCING SUCH STRIPS SUCCESSIVELY ALONG A PREDETERMINED PATH WITH THEIR EDGES TO BE JOINED DISPOSED TRANSVERSELY OF SUCH PATH, FRICTIONALLY ENGAGING SIMULTANEOUSLY SEVERAL OF SUCH STRIPS SUBSTANTIALLY THROUGHOUT A PLURALITY OF PARALLEL, NARROW AREAS EXTENDING ENTIRELY ACROSS SUCH STRIPS TRANSVERSELY OF THEIR EDGES TO BE JOINED AND PARALLEL TO THE DIRECTION OF STRIP ADVANCE AND SPACED TRNASVERSELY OF THE DIRECTION OF STRIP ADVANCE AND BY SUCH ENGAGEMENT EXERTING LATERIALLY AGAINST THE FACES OF SUCH STRIPS A FORCE FLATTENING THEM INTO COPLANAR RELATIONSHIP AND A FORCE PARALLEL TO THE FACES OF SUCH STRIPS ADVANCING THEM CONJOINTLY TO A BONDING STATION, HALTING THE ADVANCE OF THE LEADING STRIP WHILE CONTINUING TO APPLY THERETO SUCH LATERIAL AND PARALLEL FRICTION FORCES TO SUCH STRIP AND BY APPLICATION OF SUCH FORCES CONTINUING TO ADVANCE SUCCEEDING STRIPS UNTIL EACH OF SUCH STRIPS EDGE-ABUTS THE STRIP AHEAD OF IT AND IS THEREBY HELD AGAINST FURTHER ADVANCE, WHILE CONTINUING TO APPLY SUCH ADVANCING AND FLATTENING FORCES THROUGHOUT SUCH SPACED, PARALLEL, NARROW AREAS APPLYING DISTRIBUTED FLATTENING PRESSURE LATERALLY AGAINST THE FACES OF THE STRIPS IN SUBSTANTIAL CONTINUITY ENTIRELY ACROSS SUCH STRIPS IN AREAS LOCATED TRANSVERSELY OF THE DIRECTION OF STRIP MOVEMENT BETWEEN SUCH SPACED, PARALLEL, NARROW AREAS OF THE ORDER OF INTENSITY OF THE LATERAL FORCE AGAINST THE STRIPS IN SUCH SPACED, PARALLEL, NARROW AREAS, THEREAFTER INTERRUPTING THE ADVANCING FORCE APPLIED TO SUCH SPACED, PARALLEL, NARROW AREAS WHILE STILL MAINTAINING THE FLATTENING FORCE THEREIN, AND, WHILE MAINTAINING THE FLATTENING FORCE IN SUCH SPACED, PARALLEL, NARROW AREAS AND THE FLATTENING PRESSURE IN THE AREAS THEREBETWEEN, SETTING ADHESIVE ON THE VENEER STRIP EDGES.

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