US2913078A

US2913078A - Girder structure

Info

Publication number: US2913078A
Application number: US449147A
Authority: US
Inventors: Kaiser Willy
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-05-03
Filing date: 1954-08-11
Publication date: 1959-11-17
Anticipated expiration: 1976-11-17

Description

Nov. 17, 1959 w. KAISER GIRDER STRUCTURE 2 sheets-sheen `1 Filed Aug. 11. 1954 Nov. A11, 1959 w. KAISER 2,913,078

- GIRDER STRUCTURE I Filed Aug. 11, 1954 y A 2 Sheets-Sheet 2 United States Patent m GIRDER STRUCTURE Willy Kaiser, Frankfurt am Main, Germany Application August 11, `1954, Serial No. 449,147 Claims priority, application Germany May 3, 1954 1 Claim. (Cl. 189-37) The present invention relates to a girder, a concrete insert and like structures comprising at least two con tinuous, longitudinal booms and further strip-shaped struts interconnecting said booms.

It has been found that heretofore existing disadvantages inherent in known constructions of lattice girders are readily overcome in a simple manner, if the struts or webs are formed by punching and bending up striplike elements in corrugated fashion and at predetermined distances to form at least one strip-shaped boom. Each strip thereby embodies a lattice-shaped span stretching below a hollow space through which, if necessary, concrete aggregate may Vpass Vand may reach within the main girder area rapidly and directly both the strut and adjacent parts of said girder, so that the girder structure will be completely embedded in the concrete and undesirable cavities therein will be reliably avoided. The iron or other material used is effectively protected against corrosion.

It is, therefore, an object of the present invention to provide means facilitating the construction of a girder of increased strength and sucient resiliency, which is simple, easy and inexpensive to produce and lends itself to a great variety or applications.

It is a further object of the present invention to provide means affording strengthening of the girder by using a strip-shaped iron boom of high buckling resistance or a rod-shaped boom made, for instance, from Monier or reinforcing steel. The buckling resistance of the stripor band-shaped boom is produced, for example, by irnparting to the boom a special profile, possibly by longitudinally directed, corrugated impressions, headings and like formations or by edge curling.

It is another object of the invention to provide means affording strengthening the continuous strips of the boom which supports the struts, by longitudinal corrugations, marginal curlings or other profiles.

The above and other objects of the invention will become further apparent from the following detailed description, reference being had to the accompanying drawings showing preferred embodiments of the invention.

In the drawings:

Fig. 1 is a side elevation of a girder according to the invention;

Fig. 2 is a section taken along the line II-Il of Fig. 1;

Fig. 3 is aperspective view of the girder shown in Fig. 1;

Fig. 4 is an end elevation of a girder in modified form shown partly in section;

Fig. 5 is a side elevation of two girders symmetrically combined and with the top one in the inverted position;

Fig. 6 is a' section along the line VI--VI of Fig. 5;

lFig. 7 is a side elevation of four girders of Fig. 1 combined to form a box or column;

Fig. 8 is a section taken along line VIII-VIII of Fig. 7;

Fig. 9 is a view of a girder in perspective having a boom which is bent towards the struts;

2,913,078 Patented Nov. 17, .1959

Fig. 10 is an end elevation of a girder, partly in section, the edges of the boom forming the struts being provided with bent over flanges; l

Fig. li illustrates a girder wherein the struts are punched out of the two booms and are outwardlyl bent;

Fig. ll is an end elevation of another constructional form of a girder as fitted in the ceiling of an apartment;

Fig. 13 is a section taken along the line XlII-Xlll of Fig. 12.

Fig. 14 is a vertical section through a girder somewhat modified in regard to Fig. 3;

Fig. l5 is an end view of the girder ofFig. 14 partly shown in section; y

Fig. 16 is a section taken along line XVI-XVI of Fig. 14. s

Referring now more particularly to the attached drawings, there is disclosed a boom 1, which also serves, for example, as a support for bricks. Its center is provided with punched out apertures or slots 2 (Figs. 1 to 3) each of which is bridged by three angular legs or portions 3, 4, 5 produced by cutting, punching out and bending, 1 so that a closed eld of forces is obtained outside slots 2, as the remaining strips 6 and 7 (Fig. 2) of the boom 1 are uninterrupted. Between the root points, for example 8 and 9, of two consecutive legs or struts, 5, 3 a transverse web 1 is formed. The inclination of the struts or headings, their width and length, and also the width of the transverse web 1' of the boom between the aforesaid root points 3, 9 depend upon the requirements as to strength, upon the material used and also upon the application to which the girder is to be subjected. It is to be noted that struts or legs 3, 4, 5 are stretched an longer than the respective elongated slot 2.

The uppermost portion 4 of the struts is rigidly connected to a round iron bar 10, for example by welding, but, instead of a welded connection, it is also possible to embed the round iron bar inthe topmost portion of the strut 4, whereby the latter is trough-shaped, as at 11, shown in Fig. 4. The girder is preferably so used that the strips 1', 6, 7 supporting the struts 3, 4, 5 serve as the structure lower boom and the round iron bar 10 as the* upper boom.

In the girder according to Figs.v 5 and 6, two booms bearing struts are so combined that the apexes of the struts abut one another, this abutting occurring in the constructional example via a continuous piece of strip iron 12. The legs 3 4, 5 of the strut ofthe lower boom are placed symmetrically in inverted form relative to the

legs

13, 14, 15 of the corresponding strut of the upper boom 16 which is identical with the lower boom in other respects.

The box or column structure, shown in Figs. 7 and 8, is made up from four strutted booms of the type shown in Figs. l to 3. since the apexes, for example, 17, 18 of each two diametrically abutting

struts

19 and 20 respectively, are

directly interconnected by welding. The apexes 21 and 22 of the struts 23 and 24, respectively, which are 1ocated at transversely to the -

struts

19 and 20, re-A spectively, are also directly welded together, but the crete owing through the apertures rapidly and uniformly without hindranceand fully covering all iron parts.

The girder according to Fig. 9 is also a box girderv having the particular advantage that, while being relatively rigid, it is very narrow, requires only little material and is simple to produce. The

flanges

25, 26 of the strip-like No special opposite boom is present,`

3 boom 27 are bent right on to the legs 3, 4 and 5 of the strut supported by the strip and, for example, are welded to the said legs. A special opposite boom can be provided but is omitted as the

bent flanges

25, 26 which lie adjacent the apex 4 of the struts, form a reliable substitute Vfor the upper boom.

ln the embodiment of the invention according to Fig. 10, which in other respects corresponds to that as shown in Figs. 1 to 3, the edges 2S, 29 of the continuous strips of the boom bearing the struts are bent into one quarter of a circle. The bending can also be etected in the direction of the struts, as indicated by the dotted lines.

In the embodiment of the invention according to Fig. 11, the lengths a and the half-spans between struts are o f different sizes in the two booms so that unequal spacing exists. Into a long space, for example a, of the lower hoorn 33 there engages the shorter strut 34 of the other boom 35, this engagement being similar as in toothed racks and being of such type that the legs of the struts, for example, 36, 37, of the two booms 35 and 33, respectively, extend parallel to one another.

The girders for a ceiling shown in Figs. 12 and 13 comprise two proled

steel strips

41, 42 which form the lower and upper boom, respectively, and from which bridge-

like strips

43, 44 are struck out and bent outwardly. The

strips

43, 44 are Welded together with a steel strip 45 therebetween or are interconnected in any other suitable manner. The strip 42 forming the upper boom is strengthened by a round iron 46 fitted to the strip 42 and rigidly connected thereto.

The intermediate layer or strip 45 is wider than the width of the bridge-like outwardly

bent parts

43, 44 and serves as a bearing surface for flat-surface cover plates 47. Only a small quantity of concrete mixed in situ is required, since it is unnecessary to ill right down to the lower boom 41 which can be provided in known manner with means for suspending a plaster support.

Apart from the simpler construction of the cover plates 47 and due to economies derived when concrete is mixed in situ, the new construction has the further advantage that a genuine twin-slab ceiling is formed which has all improved properties of heat and sound insulation as compared with a single-slab solid ceiling.

Referring now more particularly to Figs. 14 to 16, there is shown a girder 50 having a proled corrugated base plate or boom 51 and a corrugated upper boom 52 of similar prole in cross section (Fig. The width of base boom 51 is considerably larger than the width of upper boom 52, although the latter may be of the same width as the base boom 51.

The base boom has the lateral, somewhat inwardly bent flange portions 51a, Slb from which extend the median profiled portion 53 provided with a center groove 54. From the median portion 53 there extend, longitudinally of said boom in serpentine fashion, twostruck-out pairs of

struts

55, 56 and 57, 58, each pair terminating in a substantIally horizontal apex or intermediate portion 59. A recessed web 60 is provided between struts 56, 57 of two adjacent pairs of struts 55, 56 and 57, 5S which web Iis of greater length than the length of each apex portion 59.

It will be observed that the length of each pair of struts 55, 56 and S7, 58 is greater than the length of the respective slots 61, 62 which are provided in the rolll median portion 53, as it is well apparent from From upper boom 52 there extend similarly struck outpairs of

struts

63, 64 and 65, 66 which formed originally the grooved part 67 of the median profiled portion 68 of upper boom 52. The web 70 remaining e.g. between struts 64, 65 of the aforesaid upper pairs of

struts

63, 64 and 65, 66 is of greater length than web 60 of the base boom 51, while horizontal intermediate portions 59a of the pairs of

upper struts

63, 64 and 65, 66 coincide with the respective apex portions 59 of the lower pairs of

struts

55, 56 and 57, 58. These apex portions 59 and 59a are welded together along seams 69a and leave a circular opening 69 therebetween, which is formed by upwardly and downwardly directed half-grooves 54 and 67 of the struck out upper and lower struts, e.g. struts 66 and 58, as seen in Figs. 15 and 16. All the struts, and as seen in respect to struts 66 and 58, have further lateral flange parts 71, "i2 and 73, 74.

lt will be observed that due to the fact that the respective median prolile portion 53 of the base boom and median profile portion 68 of the upper boom 52 are grooved at 54 and 67, the respective struck out and consequently grooved pairs of struts although somewhat stretched in length offer a considerable resistance against bending and buckling, so that a girder 50 is obtained which is not only light in weight, but also of considern able strength, which may be readily employed for various building and construction purposes.

It will be noted that, as seen in Figs. 14 to 16, the upper and

lower booms

51, 52 are preferably made from rolled-steel shapes or strip material of a thickness Varying approximately from 1.5 to 4 rn./m. The length of portions 59, 59a of the latticed girder 50 is about 2 cm. While the length of webs 60 and 70' is approximately 3 cm. and 4.5 cm., respectively. The length of each of the slots 61 and 62 is about 15 cm.

The pairs of struts, as above indicated, may be obtained by punching or like severing operations either in cold or warrn state from the respective booms and will then be stretched to about 15 to 20% in their respective positions,as shown in Fig. 14.

Slots 61, 62, as well as the hollow profiled booms may be used to accommodate insulated electric wiring or any known other structural parts for use in connection with girders.

Various changes and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modiiications be embraced by the annexed claims.

Having thus described my invention, what is claimed as new anddesired to be secured by Letters Patent, is:

A girder structure comprising a corrugated base boom having a central arcuate upwardly extending grooved portion, a corrugated upper boom spaced a predetermined distance from said base boom, said upper boom having a medial arcuate downwardly extending grooved portion, saidV arcuate portions being opposed to each other and being slit along opposed side portions thereof at spaced intervals, said slit portionsin said upper boom and said base boom` being stretched from their respective booms to form a plurality of spaced substantially V- shaped projecting web members of arcuate cross-section, the apices of said web members of said upper boom and said base boom beingl in abutment and being welded together defining tubular openings between the abutting surfaces thereof.

References Cited in the tile of this patent UNITED STATES PATENTS 1,090,843 Golding Mar. 24, 1914 1,311,820 Jones July 29, 1919 1,565,879 White Dec. 15, 1925 1,604,375 Bates Oct. 26, 1926 1,788,145 Bates Jan. 6, 1931 1,804,132 Tashjian May 5, 1931 2,089,023 Hahn Aug. 3, 1937' FOREIGN PATENTS 112,021 Austria Ian. 10, 1929 601,441 Great Britain May 5, 1948