US76041A - Charles bender - Google Patents

Description

`in the currents of the rivers.

, @uiten gratta atwt @fitta CHARLES BENDER, OF IIESSE DARMSTA T, GERMANY.

.Batters Patent lo. 76,041, dated lmc/L 3l, 1868.

IMPROVED WIRE-TRUSS BRIDGE.

TO ALI.'- WHOM IT MAY CONCERN:

Be it known that I, CHARLES BEND'ER, citizen of the Grand Duchy of IIesse Darmstadt, inGermany, nowresident of the city ofNew York, in the county of New York, in the State of New York, have invented a new Construction of a Wire-Truss Bridge; and I do hereby declare Vthat the following is a-full and exact description ofthe same. l

The nature of my bridge-consists in the application of wire cables for truss-bridges, to gain the advantages of the cheapncss, homogeneousness,-and strength of wire, as well as Vto secure that cheap method of putting up the bridges, as used for suspension-bridges, which is dispensing with expensive pile-driving and scaffold-work To gain all said advantages in the cheapest and least complicated manner, I divide each of the lower chords or cables of the bridge in three pieces, one unbroken main cable and two smaller'side cables, the latter consist' ing of as many piecesl as there are'panclsf; further, 'I construct adjustable joints to connect the main and side cables with the uprights and diagonals; and lastly, I apply a suitable saddle io support the forces acting in the cables, and to connect the upper aud'lower chords in the very simplest way.

My bridge consists of a straight or curved upperchord of wood, iron crsteel; of a bottom chord, made of iron wire, in form of a curve; of vertical posts, and diagonal ties.

My bottom chord is constructed in such a way that'the strains in all the cross-sections are equal when'the `bridge is uniformly loaded; the greatest savings of material are consequently made possible, the .cross-sections being, according to the nature of wire, the same.

The lower chord, if no tl'unifortnly loaded, shows' diil'erent'strains in its'diii'erent points. The greatest dierf' ence of the strains is observed when the heaviest possible load is brought on one side of the bridge, the other half of the same being unloaded. In these cases the diagonale are-exerted in their maximum, and their strains are necessary to restore the equilibrium at each knot of the lowcrvchord. To transfer thesefstrains to the lower chordfii separate such a part of its whole cross-scction as to stand the greatest difference ofthe cable strains. I

.divide -the separated amount of the lower chord in two ropes of equal cross-section, each of those ropes consisting `of as many single cables as there are panels. Each of these cables is provided with coaches on both ends, by

whicharrangemcnt the connection with uprights and diagonale is made possible. Hereby thccross-section of the lower chord is not enlarged, the sum of the cross-sections of all three cables being exactly the same as is necessary to stand the highest possible strain by loading the whole bridge.

If these smaller cables or side cables, calculated accordingtto the considerations above mentioned, might not he separated, it would be required to stiffentlie bridge by another separate truss, so as to transfer perfectly the weights from the points of' loading to the support-s of thc bridger I Y By applying the diilerent short cables, it is possible to connect the lower chord with the diagonals; another method of connecting the latter, as by friction, Ste., not being Asecure enough for the use of bridges.

By the unbroken main cable, the advantage is secured of putting up the bridge in that manner used on suspension-bridges, dispensing with pile-driving and scafoldwvork in the current of the river.. I lay the middle lines lof main and side cables in the same' horizontal cylindrical surface, and place the main cable between the side cables. By this arrangement, I facilitate the calculation, and avoid dic'ulties arising from unequal expansion in the case that the curves of the cables might not be of similar form.

Tof-asten the pieces of side cables, as well as the diagonals and vertical posts, to the main cable, and to correct the position of the latter, I have invented castings, the construction of which I will proceed to describe.: They consist of two iron plates, C, between which runs the main cable. Erich of these plates is provided with four pegstwo to fasten the side cables, and two to fasten thc diagonals.

At the lower part of the inside, each plate is provided with two ears, through which pass iron bolts E. At the upper ends of thc inside, each plate is provided with several teeth, Fitting exactly in respective holes of the covering-plate which serves to fasten the vertical posts.

Pieces of wrought iron', bent according to the shape of the cable, andV provided with screw-bolts on both ends, as shown by Figures l, 2, E, serve to changeA and correct thepositionv of the cable, and byicreating friction, help tojoin the whole casting with the cnible. Two o'fthese iron pieces :1re banging on the cable, .1nd vthe deseendinfr bolts :1re missin# thronfvh the ears above mentioned fastened b nuts and thus reventimr the risiui1 D D n 1 1 n l D of the cable. 'lwo other iron pieces of this kind 'embrace the cble from below.- Their four screw-bolts ure passing through four 1n'oles of the covering-pluto, und are fastened by nuts.' These bolts prevent u slipping (lown of the cable. Thin wedges of iron, bentaround tbe cable, ure applied beneuth these bolts to secure their vertid Cnl position, as shown by figs. 1, 2, m m. vWhere bottom und upper chords join,- a casting has been usefl in form i of :L saddle, offering to tbe cable a large, broad bed, :is shown inFigures 6, 7.

According to the nature of the valley or the river, across which the bridge is to be built, the Hoor may be laid on the upper chord or suspended ontbe cable by iron rods. I

Wbut'I Claim :1s my invention, :mil desire to secure by Letters Patent,is the following: 1. I claim uubottom chord, consisting of un'unbroken main cable and side cables, the latterconsisting of as ina-ny pieces as there are panels, substantially :is and for the purpose specified.

2. I claim the joints of the'bottorn chord, consisting of two si'de plates and a covering-plnte, as shown in figs. 1, Z, 3, LL, 5, the several parts being construetednnd userl as und'for the purpose herein specified.

3. I claim the saddle joining, the bottom und upper chords, in connection with bottom chords of truss-bridges constructed of wire cables, substantially as set forth. i

New York, November 3, 1867.

CHARLES BENDER.

Witnesses:

CHARLES Fnnzrsn, Guo. W. SACKETT.

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