US95402A - Improved bridge - Google Patents

Description

'EDWARD WILLIAM YOUNG, or NEW STREET, SPRING' GARDENS;

GREAT BRITAIN.

'- Letters Patent .N g 95,402, lated September 28, I69; patented tn England, February 19,1868.

IMPROVE!) BRIDGE.

l The Schedule referred. to inthese Letters Patent and making part ef .the same.

To all whom 'lt may concern Be it known that I, EDWARD WILLIAM YOUNG, of

Newstreet, Spring Gardens, in the'county of Middlesex, Kingdom of Great Britain and Ireland, have invented a new and useful Improvement in the Construction of Bridges; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawing, and to the letters 'of reference marked thereon. Y'

y This invention consists ln the construction of bridges of a compound character, of which the essential characteristic is the supporting of a suspendedstructure or suspension-bridge by two cantilevers.

In such bridges, a portion of the superstructure at andlor a certain distance ori each side of the centre of the span, acts as a suspension-bridge, the parts between this and the piers acting as cantilevers.

Thecentral or suspension .part of the .structure 4dees not contribute in any way to the support of the side or cantilever portions.

In order to enable others skilled in the art to make and use my invention, I will now proceed to describe its construction and operation, reference being had tothe accompanying drawing, which forms a part of thi specification, and in which- Figure 1 is an elevation, and

Figure 2, a plan of a bridge of ,a single span of three hundred feet clear on my improved system.

Figures 3, 4, and 5, modifications of' the invention.

Ihe central part,'a a', is a suspension-bridge one hundred and twenty in length, a b and a b being the cantilever portions of the structure.

In this example, the suspensioneehains c c are braced lay-"means of diagonals, l (l, capable of acting v either as struts or ties.

ihe cantilever portions, 'a b and a b', are formed of vertical struts e e, inclined tiebars ff, a top member, g g, in tension, composed of metalin the form of links ,or plates, and abottom member, h lL,-in compression.

The cantilevers et b anda' b are supported by towers t' t, and are secured by back-ties le le, anchored in the ground.

lhe suspensions-chains are allowed to'bend freely at the points a a', where they join the eantilev'ers, and also at the point l, at the centre of 'the span.

The platform ofthe bridge is made capable of bending freely at points ,nl on and 11 Allowance for end motion, due tocontraetion and expansion, should be made at points m In.

'Ihe wind-ties n nfor th'e platform are shown in g. 2, on the left-hand half' of the figure, and the windties c o, for the top memberof the cantilever on the right hand.

Fig. 3 repesents a bridge on my improved system, with one centre and two side-spans. l

In this example, the'top member of the cantilever portions is curved, andthe strutsinclined at an angle with the vertical. Towers are also dispensed with.

p p, the suspended portion of the structure, is made vrigid by means of diagonal bracing, p q, and p q are system may be structure is formed of a bowstring truss, x az', the dead:

weight of which is either wholly or partially counterbalanced by the weight ofthe structure in the adjoining spans, the strain being communicated by means of the chain y y.

When the spans u t-n lw are'loaded, span tu being unloaded, the resistance of the -trnss' a; x' to upward transverse strainpenables it 'to perform the duty of an anchorage to these spans. n

Again, when span t n is loaded, spans e t-n w 'being unloaded, the resistance of the truss\a: :t to

downward transverse strain, prevents the superstructure of the spans v t-nw from being lifted out of:

position.

The method herein described of constructing the.'

span t n is not claimed by me.

The form and arrangement-of parts in the cantilever and suspended portions of the structure may be varied.

What I claim as my invention, and desire to secure by Letters Patent,is-

A bridge having two cantilever portions, and an in-I termediate suspended portion, all constructed substantially as described.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing Witnesses.

v EDWARD WILLIAM YOUNG.

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