US349468A - Bridge - Google Patents

Description

(No Model.) 2 Sheets--Sheet 1.

J. TOMLINSON.

' BRIDGE. N0. 349,4 w P tented Se 21, 1886.

9 $3 m 7 N w (No Model.) 2Sheets-Sheet 2,

J. TOMLINSON.

BRIDGE. No. 349,468. Patented Sept 21, 1886.

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UNITED STATES.

PATENT OFFICE.

JOSEPH TOMLINSON, OF ELY, IOWA.

BRIDGE.

SPECIFICATION forming part of Letters Patent No. 349,468, dated September 2]., 1886.

Application filed November 12, 1885. Serial No. 182.633.

(No model.) Patented in England April 14, 1886, No. 5,206.

To all whom it may concern: Be it known that I, JOSEPH TOMLINSON, a citizen of the United States, and a legal resident of Ely, in the county of Linn and State of Iowa, but temporarily residing at Ottawa, Canada, have invented certain new and use ful Improvements in Bridges, of which'the following is a specification.

This invention has been secured to me in Great Britain by Letters Patent No. 5,206, dated April 14, 1886.

My invention relates to bridges and like structures in which chords formed of eye-bars connected by pins are employed; and the invention consists in a compound chord formed of two or more such single chords placed one above another, and connected by upright eyebars, but otherwise unconnected; in providing compound posts, each member carrying an independent set of suspenders, and each system of suspenders having an independent anchorage or attachment; in a novel arrangement of the connections between the main truss or trusses and the intermediate truss, by which expansion and contraction are provided for, and in various other features and details, hereinafter pointed out and explained.

In the accompanying drawings, Figure 1 is a side elevation of a portion of a bridge constructed in accordance with my invention. Fig. 2 is a top plan of the same; Fig. 3, an enlarged view of the upper and central portion of Fig. 1, showing more plainly the details of construction; Fig. 4, a section on the line :0 x of Fig. 3; Fig. 5, a section on the line y y of Fig. 3; Fig. 6, a plan view of the chords and saddle; Fig. 7, a side elevation of the shore end of the truss; Fig. 8, a view illustrating the connection between the main trusses and the intermediate truss.

The primary object of my invention is to secure the efficient action of a greater number of eye-bars in the chords and suspenders of long-span bridges than has been practicable under any construction hitherto known; and

in the attainment of this end in the manner I am about to describe I also incidentally secure a more-compactand effective arrangement of the chords than heretofore. I

In all prior constructions, so far as I am aware, wherein the chords have been formed of eye-bars and pin-connections, the only mannor in which adequate strength could be at tained has been by making the eye-bars wide and heavy, or by building upthe chords of many eye-bars placed side by side, and consequently producing a chord of very great width, requiring wide saddles and bearings, and otherwise adding to the difiiculties of construction and impairing the appearance of the finished work. These difficulties and objections are obviated by making a compound chord composed of pin-j ointed eye-bar chords arranged in series or tiers, one tier above another. This will be better understood upon referring to the drawings, in which A B indicate piers, the latter carrying pier posts or columns C,which support the chords D.- g

The posts or columns 0 each consist of four posts, a I) a 1), arranged in pairs, the two posts of each pair connected by diagonal bars or latticing e, and the two compound posts thus formed being connected by ties d, which also form spacing-pieces. By this construction a very strong tower or support is produced, and one which affords a wide footing and wide seats orbearingsurfaces for the saddle, thus insuring the distribution of the superposed weight over a large surface or area.

As shown in Fig. 3, the outer columns, I) b, are made somewhat shorter than the intermediate colu1nns,a a, in order to produce the necessary curvature or arching form at the top of the compound post or cfilumn for the saddleE to rest upon. 7 As best shown in Figs. land 3, the chords D consist each of a series of eye-bars, fiarranged side by side in groups, the ends of the bars of one group extending between those of the adjoining groups, and joined thereto by pins j, passing through the eyes of the overlapping ends, as usual, and two or more of such single chords, placed one above another, as in Fig. 3, to produce the compound chord D. Y

from the saddle on the pier-posts to different distances, as shown in Fig.1, the upper chord extending to the ends of the main truss, the second one to points nearer the pier-posts,and the lower one to points still nearer the pier- The different tiers of single chords extend 5 posts, thus proportioning the strength of the chord as a whole to the load or stress it has to carry at different points in its length. The number of tiers or single chords may of course be varied as required, three being represented in the drawings.

From each post a b a 1) independent sets of suspenders F run downward at proper angles to support the lower chord, G, and the compound posts H H. Each compound post or column H consists of two posts or columns, a b, latticedor connected by short diagonal braces or bars.

From the top of each single main member of the compound post or column 'aset of suspension rods, F, run downward to the lower chord, G, at the foot of the next post or column in the same system of bracing, and so on to the ends of the main truss on each side of the pier-posts.

The pierA has built in it a number of anch-- orages, J, sufficiently far apart to correspond with each set ofsuspenders at their connections with the shore end of the lower chord of the main trusses, as best shown in Fig. 7.

As shown in Fig. 3, the saddleE is composed of eye-bars g hi,extending over and formed to fit firmly on the fiat tops of the separate members I) a a I) of the pier-post. They are firmly connected together and to the suspenders by the pins j. The edges of the ends of each tier of eye-bars are formed to rest firmly on each ether, thus forming webs to sustain and distribute the stresses transferred to them from the eye-bar chords and suspenders over the top surfaces of the pier-posts, leaving the spaces usually required for the vertical extension of the posts to be occupied by eye-bars. arranging the tensile members over the pierposts their action is more direct and e'fiicient than it could be if separated, and so spread at greater distances apart. From the eye-bars g and i longer eye-bars f extend to connect with short eye-bars f, which connect the upper ends of the two members of the compound posts H, and also form members of the chord I). By this arrangement, and by passing the connecting-pins j through the vertical extensions of the members of each compound post or column H, as well as through the eye-bars, each member of each compound post is made to transmit the weight it has to carry independently of the other or others, and caused to adapt and adjust itself to the load or stress it is required to bear.

As illustrated in Fig. 2, thesaddles E of each of the main trusses are spread apart or separated more widely than the bodies of the chords, which is for the purpose of giving lateral strength and stability tothe structure. This separation is maintained by cross girders or stretchers K, extending; across the bridge from saddle to saddle, as indicated in Figs; 8 and 6.

In order to give the proper direction to the chords D from the saddles to the ends of the main trusses, the eye-bars h of the middle sec- By thus employ slotted filling-struts ew a tion of each saddle are bowed or curved, as illustrated inFig. 6, and to prevent collapsing under strain or tension filling pieces or blocks m are interposed between the respective eyebars h, as shown in said figure. The pier-posts and main trusses at both ends being thus constructed, an intermediate truss, L, is provided to fill the space between the ends of said main trusses. This intermediate truss may be of any approved construction. single or double, or single intersection.

The truss Lis connected to the main trusses in the manner illutrated in Fig. 8, to provide compensation for expansion and contraction, without the use of oblique posts, such as have been necessary under former constructions. As shown in said figure and in Fig. 1, the main truss terminates with the suspenders F and lower chord, G, the latter projecting beyond the last compression member or post,H,of the truss, and the suspenders running down to the outer end, as shown.

The central truss, L, is formed with its upper chord longer than the lower chord, and the suspenders M at each end run upward to the outer extremity of the upper chord at about the same angle as the suspenders F, or substantially so, thus giving the appearance of a continuous and uniform design.

The extremities of the two trusses-that is to say, the outer end of the lower chord of the main truss and the outer end of the top chord of the middle trussare connected by vertical posts N, connected to each with pin-connections and constituting movable compression members. It will thus be seen that instead of suspending the middle truss by vertical eye-' bars from the upper chords of the main trusses, as heretofore, I support the middle truss from the lower chords of the main trusses. Under this arrangement it is of course necessary to O to control or regulate the extent of movement of the end posts, N.

It will of course be understood that the curvature of the saddle is not an essential fea ture of my construction, and in some structures may not be desirable, and in structures of mod-' erate dimensions the saddle can be formed with one length of eye-bars.

Some features herein set forth are of course applicable to other structures.

I am aware that a trussed eye-bar chord has been proposed, in the end and middle portions of which the upper and lower series of eyebars are brought into the same plane and connected by the same through pin or bolt; but such construction I do not claim and do not use. By my plan I am enabled to greatly reduce the horizontal section of the cord, and at the same time distribute the load over different bolts or pins at the ends,where the need for such distribution is greatest.

I am also aware that it has been proposed to impart stiffness and immovability to the suspending-chains of suspension-bridges,piers,

of the bridge partly double and partly IOC and other similar roadways by the interposition between two sets of suspending-chains of diagonal braces, so arranged as to subdivide the intervening space between the upper and lower chain or sets of chains into a series of triangles having their apices pointing alternately upward and downward. Ihis, too, I disclaim. Such construction prevents the adaptation of each chain to the strain or load put upon it and makes a rigid truss, which I purposely avoid.

Finally, I am aware that two or more wholly independent eye-bar chords have been arranged one above another and the platform of a bridge suspended from each by independent rods orhangers. Such construction permits the structure to be materially thrown out of shape, and an undue load and strain to be brought upon any one chord of the compound chord, that, by reason of greater contraction or less expansion than another, may be raised or held above its normal relation to the other individual chord or chords of the compound chord. By my construction I secure under all circumstances and conditions a joint action of the individual chords or members of the compound chord, and yet permit each to adjust and adapt itself to the load independently of the other or others.

Having thus described my invention, what I claim is- 1. In a bridge or like structure, achord composed of two or more substantiallyparallel eyebar chords placed one above another and connected by upright eye-bars, but otherwise unconnected, whereby each separate chord is enabled to adj ustitself to strains, butis caused to receive its due portion of the load.

2. In abridge or like structure,a flexible chord composed of two or more eye-bar chords placed one above another, and connected only by links substantially perpendicular to said chords, whereby theindividual eye-bar chords and the compound chord are permitted to move and adapt themselves to strains.

3. In combination with a compound column or pier post consisting of posts b a a I),

i the saddle E, composed of eye-bars g h i, connected at their ends by pins, substantially as set forth.

4. In a bridge or like structure, the combination of a compound or double post and independent sets of suspenders running from eaehmain member of the compound post to the lower chord and vertical member to be sustained.

5. In a bridge or like structure, the combination of a series of sets of eye-bar suspendfor each series substantially as ers and a separate anchorage of sets of eye-bar suspenders, explained.

6. In a bridge, the combination of main trusses, an intermediate truss, and vertical posts connecting the lower chords of the main trusses and the upper chord of the intermediate trusses, and adapted to move with the chords to which they are connected as the longitudinal members of the bridge expand or contract.

7 In a bridge, the combination of pierposts, saddles composed of eye-bars or plates resting upon said posts and arranged in tiers, one tier above another, flexible compound chords composed of two or more eye-bar chords placed one'above another, connected by links substantially perpendicular thereto, and attached to the saddles, aplatform, and suspenders connecting the platform and the chords, all substantially as described and shown.

8. In a bridge, the combination of chords composed of two or more single eye-bar chords placed one above another, compression lower chords, compound posts extending from said lower chords to the eye-bar chords, and independent sets of suspenders extending from the top of each main member of the compound posts to the lower chords, substantially as set forth.

9. Ihe herein-described bridge, consisting of suitable piers, columns or posts mounted upon the piers, compound eye-bar chordsextending from the pier-posts in the direction of thebridge, compression-chords extending from the pier in the same direction, compound compression posts or members extending from compression-chords to the eye-bar chords, and suspenders extending from each main member of the compound posts to the chords, substantially as shown and described.

10. In combination with piers A B and posts 0, compound eye-bar chords D, saddles E, composed of eye bars or plates, suspenders F, lower chords, G, andcompound posts H,all combined and arranged substantially as set forth.

11. In a bridge such as described and shown, the combination of lower chords, G, compound posts H, having vertical extensions k, and chords D, composedof eye-bar chords joined together and connected with the vertical extensions by pins j.

. JOSEPH TOIVILINSON.

WVitnesses:

A. H. PICEHEY, Enwn. RAPER.

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