US146425A - Improvement in connections for suspension-rods of iron truss-bridges - Google Patents

Description

A. BONZANU. m Connections for Suspension-Rods of lronn'l'lruss- Patentedlan-13Q1 874.

Bridges.

AM PHDM-Uf/MGMFH/G 04% K lasso/1M3 Muss) AnoLrnUs BONZANO, or PH(ENIXVILLE, ASSIGNOR TO HIMSELF, THOMAS o. oLAEKE, or PHILADELPHIA, JOHN GRIFFEN AND DAVID EEEvEs, or PmENIXVILLE, PENNSYLVANIA.

IMPROVEMENT IN CONNECTIONS FOR SUSPENSION-RODS OF IRON TRUSS-BRIDGES.

Specification forming part of Letters Patent No. 146,425, dated January 13, 1874 application filed December 16, 1873.

A through the medium of plates or links A.

( Shown in the side view, Figure l, and sectional view, Fig. 2, of the accompanying drawing.)

The character and advantages of my invention can be best explained by comparing it with the oldplan of connecting suspension-rods to upper chords, as shown in the side View,

Fig. 3, and sectional view, Fig. 4, in which B represents part of the tubular upper chord of a bridge, and D part of the end post, both being fitted to the connecting-piece E of castiron, through which passes the pin G, for receiving the eyes forged on the end of the suspension-rods H. In a truss-frame bridge of extended span these rods must be both numerous and substantial, the pin Gr being of proportionate strength, so that the eyes at the end of the rods must necessarily be of large diameter.

It is well known to those engaged in structures of this class, that to make large eyes trustworthy demands elaborate, exact, and costly forged work, to dispense with which is one of the main objects of my invention.

Instead of concentrating all the suspensionrods at the pin G, I fit to the latter two plates or links, A, above referred to, one plate on each side of theconnecting-piece E, and to these plates I connect the eyes of all the suspension-rods H, there being in the present instance sixteen rods, four on each side of each plate, one connecting pin or bolt, to, serving for the attachment of two rods. These bolts or pins are comparatively small, and the eyes of the suspension-rods are of correspondingly small diameter, and. can be forged at much less expense than the larger eyes shown in Fig. 3, while they are much better adapted than the latter for resisting the strains to which they are subjected.

As regards the plates or links themselves, it will scarcely be necessary to remark that the simplest forging work is demanded inmanufacturing them.

It will be observed that the eyes of the sen cral snspensioirrods are attached to theplates or links at points so far apart from each other that no material weakening of the said plates can result from the holes bored for the reception of the pins a. i

In some cases it may be desirable to connect more than eight suspension-rods to one of the plates A. This may be accomplished without boring additional holes in the plates by the use of a supplementary link, A, Fig. 5, which may be attached to the main link or plate A in place of one of the suspension-rods-the rod B, Fig. 1, for instanceand to these supplementary links may be connected the four suspensionrods shown, in which case ten suspension w crowded together, a considerable length of pin G is required for their reception. The longer this pin is the more substantial it must be to resist the leverage to which it is subjected by the strain of the outer rods, and the more these rods are dispersed over the pin G the more unequal will be the strain which they have to re sist, whereas the employment of the links A results in concentrating the resisting medium as close to the upper chords as possible, and

within limits which render the resisting medium more effective.

These advantages will be readily understood by comparing my improvement, (shown in Fig. 2) with the old plan. (Illustrated in Fig. 4.)

The same plan of thus concentrating the resisting mediums may be employed at other points in the bridge than where the upper chord is connected to the end posts. Iii-Fig (3, for instance, where two lengths of chordtnbe, B B, and Vertical post K join the con necting-pieee E, at intermediate points in the truss-frame between the opposite end posts, I connect two links, A one on each side of the connecting-piece, to the transverse pin M, and to eaeh link I connect two suspe11sion-rods,H A much better result is attained by this employment of the links, for the reasons above given, than if all four, suspension-rods were connected directly to the pin M.

I claim as my invention- 1. In a truss-frame, the combination, substantially as described, of plates or links A with the upper chord and suspension-rods.

2. The combination, with the upper ehorc1,of'

plates or links A, any desirednnmber of supplementary links A and the suspension-rods.

In testimony whereof I have signed my name to this specification in the presence of two snb scribing witnesses.

AD OLPHUS' BONZANO.

Witn esses:

1. G. CAREY, JEROME JOHN.

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