US2054995A - Bridge tower construction - Google Patents

Description

p 2,1936. J. B. STRAUSS BRIDGE TOWER CONSTRUCTION 7 Filed March 2, 1935 2 Sheets-Sheet l FIG.

smu BY W INVENTOR IOSCPKD.

n-r-rnRNEY Patented Sept. 22, 1936 7 UNITED STATES PA -TENT OFFICE,

BRIDGE TOWER CONSTRUCTION Joseph B. Strauss, San Francisco, Calif. Application March 2, 1935, Serial No. 9,047

I m 4 Claims. (o1. ii-'21)" This invention relates to improvements in Patent No. 1,967,381. Extending between the bridges and has particular reference to cross legs 5 and 6 are the transverse members 8, 9, I0, braces for the legs of the bridge tower. andl I. These transverse members are made up The principal object of the invention is to proof preferably a series of parallel cross girders l2 5 vide means for connecting the cross bracing in and- I3. These cross girders are in turn attached 5 such a manner as to'distribute various stresses to-gusset plates M, which gusset plates are in from the transverse members of the bridge tower turn secured to strain equalizer plates l6, which to the cells composing the legs of the tower. plates also form the side walls of the central cells.

A further object is to produce a device of this The gusset plates M are connected to these strain 10 character wherein the stresses will be transmitequalizer plates Icy-overlapping joining plates l1, l0

ted both horizontally and laterally with respect to which are riveted as best shown in Fig. 4. the transverse members without weakening the The construction thus far would only dissipate cellular construction at the point of connection. strains through the cells in a horizontal direction,

Other objects and advantages will be apparent as for instance, from right to left, or vice versa,

during the course of the following description. as viewed in Fig. 2. In order to transmit the 5' In theaccompanying drawings forming a part strains in a plane, at an angle of 90 degrees to the of this specification and in which like numerals plates l6, it is necessary to tie the end cells of the are employed to designate like parts throughout towerleg to the central cells, but without weakthe same, 1 ening the structure. 7 This I have accomplished g0 Fig. 1 is a side elevation of a bridge tower conby inserting tension plates l8 at spaced intervals 0 structed in accordance with my invention, through the plates l6. These plates are in turn Fig. '2 is an enlarged fragmentary cross secriveted to the side walls'of the adjacent cells and. tional view on the line 22 of Fig. 1, consequently when the plates [6 transmit strains Fig. 3 is a cross sectional view taken on the from the tower to the transverse members, or vice line 3-4: of Fig. 2, and versa, then these strains will be dissipated 25 Fig. 4 is a fragmentary perspective view partly throughout all of the cells, which would not be in cross section and looking in the direction of possible Without the employment of the plates l8, the arrows 4-4 of Fig. 3. for the reason that the cells'at the sides of the Fig. 5 is a fragmentary detailed view showing center portion of the tower would only be riveted the manner in which the tie plate is secured. to the cells in the center portion and conse- 30 In building bridges it has been common to conquently there would be a tendency for the rivet struct towers, which towers consist of a pair of heads to pull off, while with my structure all of spaced uprights or legs. These towers are usually the strain upon the rivets holding the various connected together by lateral members commonly cells together becomes a shearing strain, which called cross braces. These cross braces are usthe bolts or rivets are well able to stand. It is of 35 ually riveted to the uprights, and for ordinary great importance that in structures of great small bridges sufficient strength is possible, but height, .a certain resiliency must be provided but with exceedingly large bridges where great that the strains incident to this resiliency must heights are necessary, it is very important that be dissipated throughout the entire structure so the cross braces shall be tied in to the legs of that movement of the structure comes entirely 40 the tower in such a manner that the various from the resiliency of the material of the strucstresses which may be caused by wind, earth ture without causing undue strain at any particushock and the like, will be properly dissipated lar point. throughout the entire structure so that no dam- Referring to Fig. 1, it might be said that the age will occur to the bridge. I have, therefore, only flexing of a tower of this character would be devised a means of tying the cross members into the movement of the top in bending toward or the legs of the tower in such a manner that no away from the observer. A side movement would weakness will occur which might be detrimental be arrested by the cross pieces connecting the two and cause the bridge to be unsafe. legs of the tower. Now as these cross pieces are Referring to the drawings, it will be noted that secured to the plates !6 all stresses tending to 50 the legs of my tower as a whole are designated by resist side sway will pass through these cross the numerals 5 and 6 and that each of the these pieces and the plates i 6, which plates are riveted legs is built up of a series of rectangular cells 1 to the center cells of the tower and so connected arranged parallel with each other and one upon by the rivets that only a shearing action takes the other. This construction is covered in my place, and while it is true that in the drawings 55 corner angles are shown, these angles are only used for building up the cell units in assembling and to keep out the weather when the cells are in assembled position in the towers. In order to provide for the flexing strain of the tower in the direction parallel to the bridge proper and to not introduce any pulling strain on the rivets connecting the cells in side to side relation and in a direction transverse to the plates I6 it is necessary to tie the sides of the cells that are on the same plane together through the plates l6, and it is by the use of the plates I8 that I accomplish this tie. The plates l8 are riveted to the last mentioned sides of the cells and these rivets are under shearing strain when the tower flexes in the direction of the bridge proper. Therefore, it will be apparent that no matter in which direction the tower tends to move, the cells and connecting parts are held by rivets under a shearing strain only, thus taking off any tension strain which would otherwise be applied to rivets in the structure.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same and that various changes relative to the material, size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention or scope of the subjoined claims.

Having thus described my invention, I claim:-

1. In a device of the character described, the combination of a pair of parallel cellular vertically disposed tower legs, transverse members connecting said legs at intervals, said transverse members comprising a plurality of cross girders centrally connected to said tower legs, and means for distributing stresses from the cells of said tower legs to the transverse members, whereby said tower legs and said transverse members act as a unit for distributing stresses.

2. In a device of the character described, the combination of a pair of parallel cellular vertically disposed tower legs, transverse members connecting said legs at intervals, said transverse members comprising a plurality of cross girders centrally connected to said tower legs, means for distributing stresses from the cells of said tower legs to the transverse members, whereby said tower legs and said transverse members act as a. unit for distributing stresses, said means comprising a series of vertically disposed plates connecting the adjacent tower cells together, said plates being connected to said transverse members.

3. In a device of the character described, the combination of a pair of parallel cellular vertically disposed tower legs, transverse members connecting said legs at intervals, said transverse members comprising a plurality of cross girders centrally connectedto said tower legs, means for distributing stresses from the cells of said tower legs to the transverse members, whereby said tower legs and said transverse members act as a unit for distributing stresses, said means comprising a series of vertically disposed plates connecting the adjacent tower cells together, said plates being connected to said transverse members, and tension plates extending through said last mentioned plates and connecting the adjacent cell sections one to the other.

4. In a bridge tower, a pair of spaced parallel legs, each of said legs including a plurality of vertically and horizontally disposed cell sections secured one to the other so as to form a unitary structure, transverse members spaced at intervals between said tower legs, plates connecting the adjacent faces of said tower legs with said transverse member, said plates extending between the centrally disposed cells of said legs, and tension plates disposed at right angles to said first mentioned plates and extending therethrough, said tension plates being connected to their engaging cell structure.

JOSEPI-IVB. STRAUSS.

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