US634026A

US634026A - Trussed suspension-bridge.

Info

Publication number: US634026A
Application number: US71873299A
Authority: US
Inventors: William H H Pittman
Original assignee: Individual
Current assignee: Individual
Priority date: 1899-05-29
Filing date: 1899-05-29
Publication date: 1899-10-03
Anticipated expiration: 1916-10-03

Description

Patened 'Oct'. 3, |899.

' w. H. H. PITTMAN.

TRUSSED SUSPESIUN BRIDGE.

(Application Hay 29, 1899.)

2 sheets-shan; l.

(N0 Modal.)

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EAA..

Patented Dot. 3,1899.

' W. H. H PlTTMAN.

TRUSSED SUSPENSE!!! BRIDGE.

ApplicMiion Bled 15129, 1599.)

. 2 Sheets-Sheet 2 inl nden.)

....lltilllllllllilll i UNITED* STATES PATENT OFFRE'.

y WILLIAM "n, n." -PITTMAN, orsrILLwArEnoKLAHoMA TERRITORY.

fTRussEo sUsPNfsfoN-BRIDGE.

sPEcIrIA'rIoN forming part of Letters Patent No. 634,026, dai-.ed 'october e, 1899.

at Stillwater, in the county of Payne and Ter-- ritory of Oklahoma, have invented a new and useful Trussed Suspension-Bridge, of which the'following isa specification. Y My invention relates to improvements ink trussed suspension-bridges designed to makel the parts strain eachother mutually, so as to attain the desired camber on the longitudinal stringersand to increase the resistance of the parts to strain in proportion to the load imposed upon the structure; and the object in view is to provide a simple structure adapted tobe easily and readily erected across a stream or chasm. v

With these ends in view the invention consists in the novel combination and construc- .representing the flooring applied to the stringere. Fig. 3 is a vertical transverse section on the line '3 3 of Fig. 1, showing one method of bracing the inclined depending struts. Fig. 4 isa similar transverse section on the`line et 4 of Fig. 1, illustrating another construction of braces -for the struts. Fig. 5

is an enlarged detail section on the line 5 5.

of Fig. 2, showing the means by which each deflected cable is confined in position on one of the struts.

The same nu merals of reference are used to denote like and corresponding parts in each of the several iigures of the drawings.

- In carrying my invention into practice I employ a pair of head-beams 10 11, which are seated upon the piers or abutments 12, the latter being erected on opposite sides' ot' the stream 'or chasm across which it is desired to erect the improved suspension-bridge. In connection with the head-beams 10 11 l ernploy a series of longitudinal stringers 13, which are seated in recesses 14:, provided in the opposing edges of the head-beams 10 11.V

Said beams are arranged in horizontal positions on the piers or abutments, s o'as to -lie parallel one withitheother, and 'said beams 1399.` Serin Nu. `mense. du modem,

.are couiined in place by being buried in the embankments or by any other suitable means. The seats 14 are produced in the opposing edges offthe head-beams, and the series of seats in each beam are spaced correspondingly to the intervals between the series of stringere. 'Asshown by Figs. 1, 3, and 4, a series of four stringere are employed to extend continuously `from one head f beam to the other, and these stringere are fitted in the recesses ofthe head-beams so as to be exposed to endwise pressure `from the solid faces on the head-beams, whereby thestringers are kept-in' the arched condition represented by `Fig. 2 in order to produce the desired camber in the structure. y

Below the series of arched longitudinal stringers are arranged the transverse beams 15, which are spaced at suitable intervals one from the other and which lie parallel to the head-beams and to each other. These crossbearns engage directly with the lower faces of the series of longitudinal stringers,.and from the ends of the cross-beams depend the struts 16, which are inclined outwardly, as shown by Figs. 3 and 4. A pair-of these depending inclined struts are provided on each' cross-beam l5 near the ends thereof, and the struts on the middle cross-beainare somewhat longer than the struts on either of the cross-beams which lie on opposite sides ofthe middle crossbeam. (See Fig. 2.) i

In order to strain the head-beams lO 11 to produce the endwise pressure of the longitudinal stringers, I employ the cables 17 1S, which are connected operatively with the head-beams and are engaged with the'lower ends of the series of struts that depend from the cross-beams. These cables are disposed at opposite sides of the bridge to extend the full length thereof, and each end of each cable is looped around one end ot' one head-beam, said loops being indicated by the numeral 19. The free end of the bight or loop of the cable is conned in vplace by means of the clip 20 of. any suitable construction. VTo prevent the cable from being displaced relatively to the inclined struts, a series of yokes 21 are fastened to the lower ends of the struts in positions to embrace the cables. Said lower ends of the struts are provided (See Fig. 2.)

with recesses 22,adapted' to receive'the cables, f

as shown by Figs. 3 and 4 and more clearly represented by Fig. 5. lEach yoke is littcd to one of the struts to embrace opposite side faces thereof and to confine the cable in the recess 22, and said yoke is fastened to the strut by the transverse bolt 223, which passes through the strut and the arms of the yoke. (See Fig. 5.)

To brace thejoint between each cross-beam vand its depending struts, I employ braces, as

shown by Figs. 3 and 4. The short struts on the intermediate cross-beams are stayed by the diagonal braces 24C, shown by Fig. 4 as fitting in the space between the struts and the cross-beam; but with the long struts on the middle cross-beam I employ the tie-bar 25, as shown by Fig. 3. These struts are fastened in anysuitable way to the cross-beams, and the

braces

24 or 25 are secured either to the struts and cross-beam or to the struts themselves.

To further stay the struts and strengthen the bridge structure in its entirety, I employ the side truss-rods 26, which are arranged to cross each other and are fastened at 27 28 to the upper and lower parts of the series of struts on each side of the bridge, thus staying the struts against collapsing lengthwise of the bridge.

The stringers are stayed by the crossed truss-rods 2t), which extend diagonally from opposite ends of the cross-beams 15 and in the intervals between tlie same, and these horizontal truss-rods are fastened at 30 3l through opposite ends of the cross-beams in any suitableway.

The floor 32 is laid across the series of arched stringers. This iioor mayconsist of suitable plan ks laid crosswise u pon and firmly secured to the stringers; but the material of the floor and the method of fastening the same in. place may be varied within wide limits.

Thebridge is equipped with hand-rails 33 on each side thereof, and said rails are fastened to the posts Sel, which are secured to the cross-beams l5. The posts also support the guard-rails 35, and said posts are stayed by the braces 36.

From the foregoing description it will be noted that the side cables 17 1S are curved or inclined in an opposite direction to the camber of the stringers and 'the floor and that the cables tend to exert strain on the head-beams l0 11, so as to draw them toward each other in a direction to impose endwise pressure upon the stringers, the latter being conned against distortion or displacement by fitting the ends thereof in the seats of the head-beams. This arrangement and connection of the several elementscomposingtheimproved suspensionbridge strains the several parts to insure uniformity in the distribution of the load imposed upon the bridge-floor, and another-important advantage which is secured by the improved structure resides in the fact that the resistance of the stringers is increased in proportion to the load imposed upon the bridge. The side cables which strain the head-beams are confined in proper relation to the stringersby engagement with the struts, and displacement of the cables with relation to the struts is wholly overcome by the yokes which are fastened individually to the struts.

The several parts are of sim ple and durable construction, so that the bridge may be readily assembled and erected.

The parts may be made of either wood or metal, or a .combination of these materials may be adopted in the construction of the bridge; but itis preferable to make the cables of wire strands which are twisted or intertwined together.

As shown by Fig. 5, the lower recessed end of the strut may receive a metallicsaddle 22, against which the cable may bear, and this saddle is particularly .serviceable when the strut is made of wood, because it prevents the cable from cutting into the Wood.

Of course I will avail myself of the services of a skilled constructor in the selection of materials and in the number and arrangement of the parts. Thus the stringers may be seated on piling or any other suitable material in lieu of the piers or abutments, and the number of the stringers may be Varied according to the width of the bridge; also, in wide bridges the number of cables may be increased. The braces for the struts and for the stringers or door may be of cables, each composed of wire strands laid straight and Wrapped or twisted as desired; but, if desired, the braces for said parts may be of metallic -rods or even wood braces under certain conditions, the materials used being varied within the skill of the constructor. y

Changes may be made in the form and proportion of some of the parts while their essential features are retained and the spirit of the invention embodied. Hence I do not de- IIO vary therefrom.

Having thus described the invention, what l claim is l. A trussed suspension-bridge consisting of the head-beams, arched stringers seated on said head-beams and subjected to endwise pressure thereby, cross-beams engaging with the stringers and provided with depending struts, and cables engaging with said struts and with the head-beams, substantially as described.

2. A trussed suspension-bridge comprising the head-beams, the strin gers seated thereon, cross-beams engaging with said stringers, the struts depending from the cross-beams and provided with recesses in their lower edges, cables attached to the head-beams and fitted in the recesses of the struts, and yokes secured to the struts and engaging with said cables to confine the latter in the recesses of the struts, substantially 'as described.

3. In a trussed suspension-bridge, the decables against displacement 'witl relation to the struts, the truss-rods arranged at the sides I 3 of the bridge and engaging with the struts thereof, and the diagonal truss-rods united to the cross-beams, substantially as described.

In testimony that I claim the foregoing as my own I have hereto aixed my signature in zo the presence of two witnesses.

WILLIAM H. H. PITTMAN.

Witnesses:

C. W. McGR-AW, PERRY W. HAYES.