US2431353A - Apparatus for bending - Google Patents

Description

Nov. 25, 1947.

A. E. VARNER ET AL APPARATUS FOR BENDING Filed Jul 29, 1944 3 Sheets-Sheet l INVENTOR ATTOR EY Nov. 25, 1947.

' A. E. VARNER ET AL APPARATUS FOR 'BENDING Filgd uly 29, 1944 s Sheets-sheaf 2 ATTOR EY Nov. 25, 1947. A. E. VARNER ET AL APPARATUS FOR BENDING Filed July 29, 1944 s Sheets-Sheet :5

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Patented Nov. 25, 1947 APPARATUS FOR BENDING "Alvie Evans Varner and Fred assignors to Masonite Corpora- Laurel, Miss.,

Merritt Pettingill,

tion, Laurel, Miss .a corporation of Delaware Y Application July 29, 1944'Q'Serial o. 547,212

2 Claims. (o ls-i9) The present invention relates to apparatus for manufacturing integral fiber hardboard products which are of angular cross-section.

The principal object of the invention is the provision of an apparatus whereby such products, hereafter designated angular products for short, can be manufactured substantially free from cracking, breakage, and the like. A further object is the provision of such an apparatus whereby such angular hardboard products can be made from originally flat sheets. A further object consists in the provision of apparatus for carrying into effect the process claimed in the copending application-of Alvie E. Varner, Serial No. 547,211, filed on even date herewith.

In order to afford a better understanding of the present invention, the process claimed in said copending application will first be outlined, to be followed by a description of the apparatus of the present-invention, which may be used to carry out such process and for other purposes. I

- While the apparatus of the present invention can be used for making angular products from fiber boards which have been previously consolidated or from sheets'in several laminations, it is preferably applied to manufacture angular hardboard products from relatively porous blanks which, although preferably dried nearly or completely dry, have not been previously subjected to consolidating pressure and heat, and which will be considerably reduced in thickness by conversion to hardboard product-s through application of heat and pressure.

The first application of the process of said copending application to blanks such as described above consists in hot-pressing and thereby consolidating the blank locally along a narrow substantially linear region or line where the apex of the angular formation is to be located. This initial hot-pressing along such substantially linear region or line is preferably performed in such manner as to leave the outer surface of the blank substantially flat or plane in the neighborhood of such line, while forming a substantially V-shaped indentation at the surface which will be the interior surface of the product. The material is thus reduced in thickness to about the thickness it will have in the final product and is correspondingly consolidated, strengthened, and densified locally along the desired line (see Fig. 8).

The consolidated and densified linear portion produced by such local hot-pressing treatment is so located that it will be at and near the exterior surface of the product, with the interior-side indentationopposite such outer consolidated line portion In performing the linear densification along such line with the consolidated portion confined principally to that part of the blank which will beat the exterior of the product and in forming the interior-side indentation opposite such locally densified linear portion, the lateral or "leg portions of the blank on each 'side of such line may be slightly-cocked or bent into-angular or V-formationWithan interior angle of slightly less than 180 (seeFigs. 4 and 8). This slight cooking or bending is favorable in that it is in the same direction that the further bending will be performed later on.

"The linear consolidation treatment which has been described is preparatory for bending along the densified line portion so provided. This treatment has the effect of providing a comparatively thin, densified linear exterior portion between the lateral or leg portions extending outwardly therefrom at either side, onwhich thin linear densified-portion the lateral or leg portions can be turned or bent toward one another with' practical absence of stretching at the exterior surface. I approachment of the lateral portions toward one another'inthe bending operation, and this will; avoid interior leverage effects beingcreated in; bending adjacent to the consolidated linear por-' tion which otherwise would tend to produce stretching of the material at the exterior surface."

When such linear consolidation has been performed, the lateral parts or leg portions of the blank at each side of such linear indentation are bent'or brought toward each other into angular formation with the apex of the angle along the previously-consolidated line portion. The combination of interior-side indentation with exterior-side consolidation having served to bring all the blank'material in this region into a dense, I

strong, thin portion located at and near the exterior surface, it becomes practicable to accomplish such bending with practically complete absence of stretching or rupture of the exterior surface of the material along or adjacent to the apex line.

In performing the bending operation, the blank is held solidly at the line of first consolidation,

and the lateral or leg portions of the blank on each side of such line brought toward one another into angular formation in such manner that each a of these portion-s is kept substantially fiat or plane and will remain so in the final product.

'The bent angular structure so produced is next hot-pressed to thereby obtain a final angular fiber hardboard product which is permanently con The interior indentation will permitweights instead .of. springs,-

Figs. 8 and 9 are perspective views with parts broken away of a partly converted blank and of a finished angular hard fiber-board product respectively.

The interior or male die bar l shown in the drawings of the elongated press apparatus is adaptediorzuse inmaking angular products havsolidated and densified throughout (see Fig. 9).

It is not necessary ordinarily to chill the finished product before it is released from consolidating pressure and it may be released while hot. 1 The steps of this process may be separate and distinct, or may merge into one another in the making of the product -byzthe apparatus of the present ine; vention, particularly when done rapidly. ing.a .90. opening: This-:die. bar lll is' illustrated -A final interior angle of 90 opening in the as being fixed and with other parts moved up pro-duct is ordinarily desirable for purposes suchTrIOiatoward it, but other arrangements may be reas mentioned below, but such angle maybe more, sorted to if desired. Provision is made for heatthan 90 or slightly less than 90 as maybecalld ing; cavities l2 for steam or for electrical heatfor (see Fig. 9). ing elements or the like being indicated.

With use of relatively porous:.;bla-nks'madei0f3- The exterior. die; arrangement consists of two hydrolyzed wood fiber produced..-by-treatmentmhwsfemale die'bars l 4 |4 which are pivoted or hinged wood chips with steam and explosive disruption. together as.by..one thereof having at each end into fiber, as by means of the gun" describediri (one end only shown) a stud shaft l6 secured to U. S. patent to Mason #1324221, and thezresult-.,-., it;;and;extending through a journal [8 in the ing fiber somewhat refined, and its content of second die bar of the pair. The axes of stud water solubles preferably reduced as by; washing shafts I 6. are in alignment with the, meeting formed into sheets;.containing1, ab0ut 2%-3% of edgesof the upperfacesof die bars;l 4,- so-that; preferably petrolatum for. sizing. purposes, and movement of the die bars {4, 5l l 'takesplace with-,,= d-ri-ed in a hot air drier-withoutmaterial'pressure, outany substantial opening. being formed therethe describedoperatiQns canbe performed and. between. The stud, shafts 16, I6 extend through good sound products madezwithoutneedof addislots-20.in brackets 22',-thuspermitting.vertical; tion of other materials for;bo nding.or plasticizmovement; of die bars l4, l4-at their meeting. ing purposes; In the case ofusing such blanks edges. The: die bars- I4, M are provided on their; the linearconsolidation an-dthe bending and the under sides with reenforcing parts I4,- I l to be. later consolidation; throughout are preferably referred tolater. Dielbars I4, 14 are-supported performed at atemperatureof about 200-220 C. neantheirouteredges onledges 24- at each side; lf these blanks t i some. oisture, as, say,. of the. angular-.recessor v trough-like depression about 5%l0%, the pressure,.used:in hot-pressing. 26in the heated,. vertically movable press bar fill. the bentblanks. ispreferably-releasedone; or Theinner edgeso-i 'diebars I4, i4earesupported more. times to permit; breathingor escape .of 5 upon headed push rodss 30- extending through;- vapors. bores inv press barrlfltand urged upwardly by In case of blanks madeprground wood it is ad-- springs 32.- The springs 32- are: preferably ens vantageous to add a small proportion of resinous closed in. short tubular guar a h material, such as about-10%30=%-. of, a thermothe heads 3| .of push. rods.30,-and-serving-topreplastic resinous materialfforexample; since other- Vent collection.'offoreign materials-byv the springs wise;some rupture oftheproductmaybe caused 4.0 us h -eans may be provided to. at the exterior and adjacent torth'e line of bendpz fi r the functions of spr n -32 F m l ing... Addition of plasticizers, as about 5%-10% of Fig. 6 shows the --weights- '35 .-for -;,this .--pu p moisture or a like percentage of alcohol, is. v use- Nu s; 3 L ve 110- limit the. :upward -movemen1-,--ofg ful toward makingggoodbendsras.described- Inpu h rods 3B- asrshown,in.1 ?ig-..;3. Elevation@ofi-;.. caseof-.,incorporationof. such added,,resinous-4 nressbar zfiaby.thespreferably-hydraulic-rams: material, somewhat lower hot-.pressing-ltempera- 35; serves to bring. the. apparatus spartseshowm from .th .open .position shown; in: Fig-.13 .;to g the:

p t o vand t0-@1118 ClOSBdrFPOSHI-iOIUQf';

tures may -be-.used,- as..about :150 C. forexample- Eig.. .5lrespectively. Diebar. I man-dpress b ar 28,

In case .of .usingvolatile.alcohols for. plasticizing; breathing. is ordinarily unnecessary; but. may, be... 7

5 are. preferably heat-insulatedfrom adj-acent bodies. of metal..asindioated at 38....

resorted .to if desired-.2 I

Use of woodfiber is. preferred,-. andespeci-ally With the parts in the position; of;Fig;;s ithee lower part of. blank Am which -1wi1-l.;beamthe-zexhardwood. However, ;wood-y materials of annual:

terior-of .th'e-productwill be consolidated by'heata grbwthrmay b r d as asource of. lignpce11u1ose fiber if desired..

The accompanying drawingssillustratesnap-- ndpressu-re alon a longitudinal linen-42 hence.

shown asthe .longitudinalicenter lin'egoi fthGFblfiI-E .yi'i. while the nose-A t-of the interior-diebar lflziorms i. an indentation 46 in that facerof theblanlewhic willsbeatthe interior ,0fthe produch... (Seeqalsoii Fig. -8.). During".thishperation; the exterior din: bars 14,114 are, supported by. thespringsfltso-as to..present a fhtprsubstantially: flat, Flipper sure? Figs. 3, 4, and 5 are transverse views with thee, J U- g? f: th mress :bar .22 3315? elongated idi sbars .in .open-- Pa tially,closeds-and d Q t 'f53' t fliOrrd iWarSfi :l4-: closed positions.re s-pectively, .and .illustrating ,the wil1be..forced to therclosedzapositionispringsqflri blank and product instages ofq'the sai -d processes. c m pushiro fimd re s d v carried out with.. the apparatus of the .present. t ma or-f v f t r ms iifis Atethi sem invention. outside -diesbars l 4,-- l 4 will @become :substantiallyi:v

Fig. 6. is autransverse v viewsshowing us of linersior ,the-etrough-like:depression-=26in. the

press. .bar. 28-, -with..their, :exten-dingreenforcing parts. I 4.2, l 4 4 beingzreceivedq; in! seats 26%, '2 fil'r'piifl-ix; vided. for-.- that-purpose. Ina-this wayisaid:..'die;e rs r-" %arefirmlyvand' solidly:supportedzrbyzi press bar 28 to resist the application of the final paratus which can beusedfor. carrying out i said: process and for other-purposes; and alsostages in. the conversion of ablank to a-final angular hard-= 1 board. product by use-of the. apparatus @of -the present invention. p

Insuch drawingsEig; 1 is .a-sideiview partly broken away, andFig. 2. anaendmview .-of an elongated press. apparatus Fig. 7 is atransversesection of separatefinishing, dies, which may ,be :used for- .eifecti-ngsthefinal consolidation. .of. the .blankto make .thex-produ'ct in a separate step or stage; and

consolidating pressure, are prevented from spreading apart or opening up, and are well heated from the internally heated press bar 28. The die bars may be directly heated if desired. When die bars l4, M are thus depressed by raising press bar 28, they form a female die corresponding to the interior or male die bar I9.

With the parts in the position of Fig. 5, the final consolidating hot-pressing operation can be completed with the production of a finished angular fiber-board product 48. However, if desired, this hot-pressing and consolidating operation may not be completed in the apparatus used for bending, and in such case the bent and partlypressed angular product can be transferredto separate finishing press dies l and 59 (Fig. 7), and the hot-pressing completed by means of such dies I0, 59 if desired. In this way the bending press cycle can be considerably shortened. The female die 50 may be made with a Slight fillet, as indicated at so as to slightly round off the apex line if desired. If the blank 40 contains some moisture or other vapor-forming material, the pressure on the dies may be intermittently released in the early part of the operation of hot-pressing the previously bent blank to permit moisture or vapor escape.

The hot-pressing consolidation is preferably applied progressively and gradually from the line 42 of first compaction outwardly. This is accomplished with the apparatus of the present invention by the die-closing movement taking place against the resistance of the springs 32 as will be readily understood.

Integral angular fiber-board products made from fiat sheet blanks with the apparatus of the present invention are strong and substantial, and are practically free from breakage or cracking due to conversion from original fiat blank formation to their final state. Being solidly held between dies during the final hot-pressing operation, the final products hold their angular shape and are substantially free from tendency to open or spread. Made smooth or with design impressed on surfaces on each or either side, they are adapted for many uses, such as wall surfacing at either inside or outside corners, counwith an angular recess having flat walls and a recessed seat at the bottom portion thereof, a pair of pivotally connected substantially fiat female die members having reinforcing projections on the under surface extending along the adjacent edges thereof, said projections having a shape complementary to that of said recessed seat, means for yieldingly supporting said female die members in substantially horizontal alignment over the angular recess of the press member, and an angular male die member opposite the recess of the press member, said male member adapted to coact with the aligned female members to move the female members downwardly into the recess in the press member so that the said projections form a complementary fit with the recessed seat and said female members lie flat against the Walls of the angular recess.

2. In apparatus for making angular shaped fiber board products, a press member provided with an angular recess having flat walls and a recessed seat at the bottom portion thereof, a pair of female die members hinged together with pivoting means and having reinforcing projections on the under surface extending along the adjacent edges thereof, said projections having a shape complementary to that of said recessed seat, slotted guide members positioned at opposite ends of the press member and adapted to slidably receive the pivoting means, means for yieldingly supporting said female die members in substantially horizontal alignment over the angular recess of the press member, and an angular male die member opposite the recess of the press member, said male member adapted to coact with the aligned female members to move the female members downwardly into the recess in the press member so that the said projections form a complementary fit with the recessed seat and said female members lie flat against the wall.

3. Apparatus as described in claim 2, and wherein the pivoting means of the female die members are positioned at opposite ends of these members and at points in alignment with their adjacent edges and with their outer faces.

ALVIE EVANS VARNER. FRED MERRITT PETTINGILL.

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

UNITED STATES PATENTS Number Name Date 548,895 Staples Oct. 29, 1895 529,192 Remus Nov. 13, 1894 1,512,916 Elmendorf Oct. 28, 1924 541,890 Stickley July 2, 1895

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