METERS, PHOTO LTHOGRAF WASHINGTON n C dimite-d tttrt parte entre Letters Patent No. 111,855, dated February 14, 1871.
IMPROVEMENT IN MACHINES FOR BENDING WOOD.
The Schedule referred to these Letters 1 atent`axxd making p axt o the same.
To all whom it may concern :v Be it known that I, OBADIAH MARLAND, of Boston, in thc county of Suffolk and State of Massachusetts, have 'invented an Improvement in Chains for Bending Wood; and I do hereby declare that the following, taken in connection with the drawing which accompanies and forms part of this speciication,.is a description of my inventionsucient to enable those skilled in the art to practice it.'
. Prior-to my invention wood has been bent by first confining it to a iiat Aband of ironor toQa fiat thin chain, the baud or chain having thereon at one end a chock, and .at the other a piece with set-screws, which- `were adjusted tightl'yragainst one end of the timber,
forcing the other end solidly against thelchock; then. both the timber and the band or chain were bent by suitable application of force.
In bending Atimber the end sought is to keep the fibers of the extrados of the wood while exing, and
when' dexed 'in their natural condition as to extension or compression', as if they are extended they will rupture, and if they 'are compressed then the amount of compression will be inj nrions and unnecessary.
When tw'opieces of material in paralleifstraight lines Aare bent into parallel curves, with their ends so secured together' that they cannot move relatively toV eachother, the `tendency will-be toelongate the outer lines of the combination and to-shorten the inner lilies,- and there will be one'line betweenfthe extrados and intrados of the curve whichwvill remain of the same length which it had beforebending, which line may he termed the neutrailine'.
New when, as before my invention, a flat meta band or a dat chain has beeny used the neutral line has been about in the center of the thickness. of the band or inline ofthe pivots of the chain, and the timber has been compressed on the extrados, though not of course to the same extent as at the intrados, and the exteriors of the band and chain have been elongated and their interiors have been compressed, resulting in breaking the band and in shearing oi the chainpivots.
In practice I am informed that chains so appliedhave been destroyed at the first bending with a timber, and the bands break upon the second or third bending.
My invention consists in details of construction and arrangement, hereinafter described, of chains for bending timber, in which chains one surface of each link- 'oar bonds or turns practically in a iine or surface coinciding with lines drawn across the back or outer surface ot' the timber to bo bent, Y
Of the drawing- Figure l shows, in plan, a timber-bending chain illustrating my invention.
Figure 2 is a central longitudinal` section of the x same, th'e section being taken in the piane of the line s s fio'. y 7 D Figure 3 is a side view of the chain.
Figures 4, 5, 6, and 7. are' sectional views of portions of chain embodying my invention as they appear when bent or curved, each viw exhibiting a modification in the detail of construction, though all of them shows that the bending takes place in lines coincident (or substantially so) with the back of the timber to be bent-,in combination with thechain.
Included with each of figs. 4, 5, and 6 is a longitudinal sectional view of one end of'one bar of the chain.
Figure 7 includes a plan as weli as a longitudinalV sectional view. of one end of a bar.
. Figure S includes three .views of pieces used with the chain, as shown inhg. 6, which pieces .I term Spanner-bars. r
Figure 9 shows a detail of construction. Figure l0 shows, in end view, three bars of a chain, each witha half pivot on each side', `and with awhole reinforcingpivot 'located near lthe back and in the ccntrallongitudinal plane of the bar..
The chain shown at fig. 7 corresponds, substantially, with that part ofA thechain shown in' iig. 2, where marked 2 1 2. A
'Iihe chain shown in fig. 6 corresponds, substantially, with 'that part ofthe chain shown'in iig. 2, where marked 3'4 5.
The'chan shown in iig. 5 corresponds, substantially, with that part of thechain shown Anfig. 2, where marked 6. In practice I-prefer to make the bars'of my chain of uniform width, as seen in ig's. 4, 5, 6, and 7, and n ot as seen inv igs.l 1, 2, and 3, where the variations in width were made merely to enable me to pass in one chain from bars of one kind to bars of another kind while keeping radius links, c, of the same length.
The bars lt are made with flanges, b, oneach end,
projecting beyond the neutral piace or'the draft-piane toward the centers of. the curves to be formed, these anges serving to keep the timber from spreading sidewise as it is bent; for it' the timber is too narrow to iill the. space between the anges, then. side pieces are driven between the angesV on one side of the chain and the side of the timber.
The chain has secured to il, at' suitable apart, two-.stout chocks or clamps, one or both of which are provided with set-screws, so that by adjustmentthereof no endwise movement of the whole timber, vwith relation to the chain, can take place.
This is not shown, as it does not differ from the provision heretofore used with metal bands for the same purpose.
Each bar, et, is made with projecting pivots, by which it is secured to the bars adjacent by suitable The bars 2 l 2, in figs-1, 2, and 3, and the bars seen in gs. 7 and 10 have on each edge a half pivot, the axes of. which are in lines formed bytheinterdistances v as before described. v
The chain shown in g. 4 is like'that seen in iig. 6,:
. sections of the sides ofthe bars with the timber faces thereof', and it will be seen that all parts of my chain,
seen .inig 3, vto'strengthen the chain when used for heavy work.
It will-be seen that the line a; cr, which is in the.
timber-face of the chain and is the neutral'line and the line of draft, is ofthe same length whetherexed orstraight.-
The chain shown in g.'6.is substantially the same 'as that part of the chain shownat 3 4 5, g. 2,Y except where the construction in'g.2 is modified to enable me to pass from one forni to another. Here, the flanges b extend further from the bodies of the bars c than they do in fig. 6. This'enables me to make use of" Spanner-bars d, which span or break the joints between the bars d, 'and are of such thickness that they form the timber-face in the line of' the axes of the pivots, which pivots are whole and are located with their axes in the central planes of each bar denotedfby the line y y.
' Where heavy bending is to' b edone, two pivots may bemade on each end ,of said` bars andunited bylinks, as seen at 3 and 4 in iig. 3, for the purpose of strengthening the chain.
The Spanner-barsl d are made onf-the timber-face, between the lines d 11. of a width equal to the dis# Ytance fot' the pivots apart, and are so, located on the bars a. as to .bring the lines d (Z into continuation of 4-the axial lines of the pivots.y
. The edges of the Spanner-baremo beveled and notched, as shown most clearly in Iig. 8, and the parts c, and the edges of the end Spanner-bars abut against suitable formations in or on the chain, as seen in g.2, so that the spanner=bars 'dc not move reiativelyv to the length of the chain.
The chain shown in fig. 5 is made up of "bars substantially like those shown at 6 6, iig. 2.
The pivots on these b ars have their axes at or very ,near theintersections of the faces of the bars be tween the i'anges 11, and sections taken in planes indicated by the line w w.
With a'chain vs o'niade, a thin metal band may be laid' between the' timber and the bars, where it wil,.
if carefnll y proportioned as to thickness, with reference to the 'curve to be'bent andthe exact relation of the axes of the pivots to the' faces of bars a, average the spaces between the angles of 'the the bai-sa and the inscribed curve.
f This band does not receive either compression or extension in the act of beiiding, as its ends are not fixed, and as it is simply flexed it will last almost indenitely.
If used for heavy bending, the bars maybe made deep and with reinforcing pivots and connecting-links,
except'that Spanner-bars are not used, and on each polygon formed -by bar a filling-piece, f, is used, the face of which is brought into the line of the axes of the pivots.
lhese piecesfmay be curved on the face to suit the curvel to be formed on the timber, `and chains lso made, or asy shown in4 fig. 5are best adapted to light work.
to suit larger orisriialler curves, and by slight changes arranged to be flexed, and to said parts are secured the chocks, clamps, or pieces which take the end-th rust of the timber when it is bent.
The end'bars at 6 6 'in fig. 2 have-their pivots connected by links, c, to pivots 'on the pieces g, whichpivots are strengthened by connectinglinks taking hold-of their outer ends and extending over other short pivots or studs formed on said pieces g at h.
In the centei` of each piece g is formed a bearing inay extend outwadbeyond the trnnnions as fitras required for convenience in manipulating and securing the timber.
It is tothese pieces j' that the clamps, which secure the timber ends, are fixed, and as the pieces j can turn will thereby be equalized between the pivots and links ou both sides of the chain. w g" l The outer lines of -links c connecting the pivots are made' in halves, and enter grooves turned near the eudsof the pivots, and said halves being screwed-together prevent all or any oil the links c from becoming detached.
In fig. 9 is seen one of the short pivots on the piece g', seen at h, iig. 1, showing a convenient way of sec ur;- ing the link on the pivot.
In the pivot a groove is turned beyond the link, into are secured by an outer ring p, the space between said outer ring'and the capover the end of the pivot being filled bythe ring q, the cap fr being secured to the pivot by a central screwi- The trunnion i. is secured in place `by a cap, u, which 'tits in a recess turned to receive it, the cap being held ing through the trunni'on.
I claimf v 1. lhe combination of bars a, by means of ha'lf pivots and links, substantially as described.
2. The combination, with bars a, of ltwo sets of piv- :ots and links, one on which/the bars turn, and the other for reinforcing the'fformer.
3. The combination, --with the bars met' Spanner-bars or pieces j, substantially asandfor the purpose speci- 4. The spanner-bars al, with notched and beveled edges, and 'with their backs curved at the edges, substantially as shown in g. S.'
5. '.lhe combination, with a chain made up of bars c connected at their'ends, of clamp-bearing pieces j, by means of trunnions, arranged substantially as and for the purpose set forth.
OBADIAI-I MARLAN D.
tothe trunnion byscrews entering it, or by bolts pass- Witnesses J. nossrmn,
J. B. CROSBY.
The pieces f can be changed for others having faces in the thickness may bechanged slightly in position receive and support -the timber, which, parts are not l for a trunuion, i, which is. made on the piece j, which onvtheirtrnnnious it will be obvious that the strain:
which groove hall' rings, o, are placed, which haii" rings