US1447257A - Bridge construction - Google Patents

Description

Mar. 6,1923,

G. LJNDENTHAL BRIDGE CONSTRUCTION Filed Dec. 2?, 1921 {i am 85 Mom r Patented ar. 6, 1923..

'* e i Q BRIDGE CONSTRUCTION.

Application filed December 27,1921. Serial no. 524,849.

To all whom it may concern:

Be it known that I, GUSTAV LINDENTHAL, a citizen of the United States, residing at Metuchen, in the county of Middlesex and State f New Jersey, have invented certain new and useful Improvements in Bridge Construction, of which the following is a specification.

My invention relates to girders, and their use in bridge construction. My invention has more especial reference to plate girders provided with openings-in the web which openings may be either square, oblong or round. These so-called open work girders are known as Vierendeel irders and are described and shown in the Tatent No. 639,320 issued on December 19th, 1899 to Arthur Vierendeel. These girders, however, have been used heretofore only for loads moving on top f the girder in the longitudinal direction of the same, the girder being supported at each end on masonry or a metal tower. The object of my present invention is to use such a girder in the construction of metal bridges as a cross-beam so that loads can move transverse to the girder on top of the same as well as through the openings in the web. By using the girders in this manner I can produce a metal bridge of reat strength having two decks, an upper eck supported by the tops of the cross-wise girders and a lower deck formed on the bottoms of the said openings.

In the drawing illustrating my inventions, Fig. 1 is an elevational view of an open work girder diagrammatically indicating the use of the same for a double-deck bridge construction; Fig. 2 shows two cross sections through such a girder, one section being through a girder having one web andthe other section being through a girder having two webs. Fig. 3 is a similar view as Fig. 1 showing a girder for a bridge construction of greater carrying capacity and the manner of suspending such a girder.

According to Fig. 1, the girder 1 is provided with two oblong openings 2, 3 in its web 4. The web, as shown in Fig. 2 can be either single or double depending on the strength and carrying capacity of the bridge construction. The girder as illustrated, is arranged cross-wise, and may either be suspended at its ends, as shown at 5, on the right in Fig. 1, or it can be connected to a vertical truss, as shown at 6, on the left in Fig. 1. As indicated in Fig. 1, the tops of these cross-wise girders form the support for the upper deck 7 of the bridge, whereas the bottoms of the openings 8 form the support. for the lower deck 8, the girders, as shown, supporting longitudinal beams or girders 9 for carrying tracks (lower deck) or aroadway (upper deck). Tracks, of course, may be provided both on the lower and the upper deck.

shown in Fig. 1, having four openings, two oblong openings 10, 11 in the middle portion of the web and two square openings 12, 13, one" at eachend. This girder is shown suspended at it and 15, the top of the girder supporting a roadway and the bottom of,

the openin s each supporting a track. Longrtudinad girders 9 as in Fig. 1 are provided on the cross-wise girders to carry the tracks roadway.

It will be readil seen that this. use of open work girders or a bridge construction with an upper and lower deck formed bying bending stresses which with this form of girder when used for a double deck bridge are smaller than where two separate. girders of smaller depth are used, i. e. one girder for the upper deck and another girder for the lower deck. Moreover, the use. of such open work girders will result in economy of labor and time.

I claim as my invention.

' 1. In bridge construction with two decks a deep metal girder having a number of wide openings in the web, and means for supporting the said girder at right angles to the bridge, the top of the'girder supporting the upper deck andv the bottom of the openings supporting the lower deck of the bridge.

2. In bridge construction with two decks a deep metal girder having a number of wide 85 I Fig. 3, shows a 'wider girder than that i openings in the Web, means for supporting the said girder at right angles to the bridge, longitudinal been 1s supported by the said girder, and tracks carried by said beams.

3. In bridge construction with two decks a deep metal girder having a number of Wide openings in the WBb,II1ElDS for supporting the said girder transverse to the bridge the top of the girder supporting the upper deck and the bottom of the said openings 10 supporting the lower deck, and longitudinal beams supported on said girder for carrying loads moving transversely to the said girders.

In testimony whereof I affix my signature. 15

GUSTAV 'LINDENTHAL.

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