US2114773A - Grid or grating structure - Google Patents

Description

April 19, 1938. c. l. AUTEN ET Ax.

` GRID OR GRATING STRUCTURE Filed March 24, 1936 V2 Sheets-Sheet 2 7 Q36) Zz,

bww/l .lluutgr Zie 'rE 150 ha,

R TVZz Patented pr. 19, 13

it R GRATIING STRUCTURE Claude I. Auten, Robert l). Snodgrass, and Walter F. Schulz, Youngstown,

Ohio, assignors to 'lruscon Steel Company, Youngstown, Ohio, a

corporation of Ohio Application March 2d,

8 Claims.

This invention relates to improvements in grid or grating structures of the general type described and claimed in Schulz Patent No. 2,031,007, dated February 18, 1936; also, to concrete structures reinforced by said grid or grating structures, and involves a Welding process as described and claimed in Schulz Patent No. 1,973,113, dated September 11, 1934.

Grid or grating structures of the general type described and claimed ln Schulz Patent No. 2,031,007 are characterized by a series of bars, usually of inverted T- shape or L-shape in cross section, disposed in side to side relationship with their flanges abutting to provide closed-bottom spaces between their webs for the reception of concrete and having their webs connected together at their tops by transversely disposed spacing bars. Such grid or grating structures, when employed in the production of certain structures, such as bridge oors and the like, wherein they are subjected to heavy loads, are not, as a rule,

supported from beneath throughout their extent, but only at spaced points. They must,

therefore, be inherently strong in order to supo port the heavy superimposed loads to which they are subjected. At the same time, it is extremely desirable that they shall be of minimum Weight for light weight installation and especially from an economical production standpoint.

Accordingly, one important object of the present invention is to provide a grid or grating structure of the general type described and claimed in Schulz Patent No. 2,031,007, but including bars having generally the sectional shape of railwayrails with consequent high resistance to bending under superimposed los. Requisite strength thereby is obtained with comparatively few bars and the weight of the structure is correspondingly reduced, with resultant reduction in production costs. l

The use of comparatively few bars in a grid or grating structure of any given size means, of course, that the distance between adjacent bars is increased, and that, since the base flanges of the bars are only of normal width, they do not abut at their edges and close the bottoms of the spaces between the bars. Accordingly, another special object of the present invention is to provide novel means for closing the bottoms of the spaces between adjacent bars.

For various reasons as set :forth in .the aforementioned Schulz patents it` is desirable to connect the bars at their tops by cross members of V-shape in section welded to the bars by a process as set forth in the earlier of said patents. That 1936, Serial No. '10,692

process involves passing an electric current through the bars and the cross members to bring them to fusion temperature at the points Where they are in contact, and in applying pressure to the cross members to cause them to become em- 5 bedded in and united with the bars. For the successful practice of said process it is desirable that there shall be relatively small areas of metal at the points where the cross members contact with the bars, which would not be the case if the present cross members directly engaged the enlarged or bulbous heads of the present bars. Accordingly, another important object of the present invention is to provide bars of generally the sectional shape of railway rails, but having top :formations especially designed to oder small areas of contact with the cross members, so that the welding process described in Schulz Patent No. 1,973,113 may advantageously be employed to connect said cross members with said bars, and 20 so that when the spaces between the bars are lled with concrete to the level of the tops of the top formations and the cross members the heads of the bars are completely covered and protected by the concrete. In addition, e. further object of the invention in this connection is to provide top formations on the bars for the purpose stated, which formations may be economically formed on the bars during rolling thereof.

With the foregoing and the other objects in view, which' will become more fully apparent as the nature of the invention is better understood, the same consists in the novel features of combination and arrangement as will be hereinafter more fully described, illustrated in the accompanying drawings and dened in the appended claims.

In `the accompanying drawings:

Figure 1 is a perspective view of a portion oi a grid or grating structure embodying the features of the invention; and

Figures 2 and 3 are detail longitudinal and transverse sections, respectively, through the structure shown in Figure 1.

A grid or grating structure or unit constructed in accordance with the present invention includes in its organization a plurality of bars i@ disposed in side to side relationship, and a plurality of cross members il connecting said bars i0 together at their tops. In 'this connection and as will be understood, any particular section or unit may be of any desired length, breadth and depth and may include any desired number of the bars t@ and. cross members ll spaced any desired distances apart, depending upon the strength required in the sectionor unit and various other considerations.

As illustrated, the present bars I0 have generally, the sectional shape of railway rails. 'I'hat is to say, each bar comprises a vertical web I2, base flanges I3 extending laterally from the bottom of said web, and a relatively heavy, bulbous head I4 formed at the top of said web and constituting a compression member effective in itself and especially in conjunction with the bottom tension member constituted by the base flanges I3 to resist downward bending or deflection of the bar under superimposed load. As to the physical properties of the bars l0, these may be varied within considerable ranges, depending upon the particular use to which any particular grid or grating structure or unit is to be put.

The bars I0 are disposed in side to side relationship and may be spaced any desired distances apart; depending upon the strength required in any particular structure. 'They are joined together and maintained in properly spaced relationship by any desired number of rods I4 extending at any desired points through openings I5 in the Webs I2 and welded to said webs as indicated at I6. They are additionally maintained properly spaced apart and upright by the cross members Il.

Regarding the cross members II, it would be impractical to weld these directly to the heads I4 of the bars I0 by a. welding process as described in Schulz Patent No. 1,973,113 because of the large areas of metal in the heads Il. Accordingly, a special feature of the present invention resides in forming narrow upwardly projecting ribs I1 on the bar heads I4, preferably medially of said heads, to provide relatively small areas of metal through the instrumentality of which the cross members II may advantageously be welded to the tops of the bars I0 by a welding process as described in said Schulz patent.

The height of the ribs I1 approximately equals the depth of the cross members I I. Therefore, when said cross members are sunk into said ribs and are united therewith by the welding process, they are disposed substantially entirely, and at least in major part, above the bar heads I4. Consequently, when the spaces/between the bars vIIJ subsequently are filled with concrete I8 to the level of the preferably flush or substantially ush tops of the cross members I I and the ribs I1, the bar heads I4 are completely embedded in and covered by the concrete and thereby are effectively protected against corrosion and deterioration and remain embedded and protected until the ribs and the cross members and the concrete above the heads become substantially completely worn away. In this connection it is apparent that due to the sectional V-shape of the cross members II and to said cross members and the ribs I1 being disposed above the tops of the bar heads I4, there are avoided any thin lips of concrete likely to become spalled or broken away.

Since the bars I0 primarily are required to support superimposed loads, their base flanges I3 may be relatively narrow, and since said bars are specially designed to support superimposed loads, they may be spaced such comparatively wide distances apart that their base flanges do not cooperate to close the bottoms of the spaces between the bars. Therefore, another special feature of the present invention resides in the pro- .vislon of means in the form of plates I9 to close the bottoms of the spaces between the bars I 0 for the reception of the concrete I8. These plat are directed upwardly near their side edges, as at 20, to provide shoulders to engage the edges of the bar anges I3, thus to hold the plates against lateral movement, and from the tops of their up- Wardly directed portions they are extended outwardly, as indicated at. 2l, to rest upon the bar flanges thus'to support the plates in position spanning the spaces between the bar flanges. Preferably the portions 20 are of such height that the bottoms of the plates are disposed substantially flush with the bottoms of the bars I0. Said plates I9 thus constitute simple, inexpensive and effective means to retain poured concrete within the spaces between the bars I0 entirely to the bottoms of said bars.

At each side of the present grid or grating A structure or unit, alternate cross members II are,

or may be, directed downwardly, as indicated at 22, for the purposes set forth in connection with the cross members of Schulz Patent No. 2,031,007. Moreover, if a crowned road or oor surface is desired, the bars I0 may be bent to conform to the desired crowning.

Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention or scope of th'e appended claims.

We claim:

1. A surface reinforced concrete structure comprising a plurality of bars disposed in 4side to side relationship, each bar comprising a concrete surface reinforcing rib having a subjacent hd and a depending web, other concrete surface reinforcing cross members extending across and press welded into said ribs to the depth of the subjacent head thereof, means 'closing the spaces between the depending webs of the bars and a concrete fill in said spaces covering the heads of the bars and also having the surface reinforcing ribs and cross members embedded' therein.

2. A reinforced concrete structure including an exposed surface grid work consisting of metallic bars welded at spaced intervals, one of said bars having an enlarged bulbous subjacent compression chord embedded in the concrete below the surface and the other of said bars extending into the concrete substantially to the top plane of the bulbous compression chord.

3. A reinforced concrete structure including a plurality of main load carrying members including a web and a top portion of substantially cruciform shape, and cross bars welded into the said top portions to the depth of the beginning of the laterally extending portions of said shape to pro- 'vide an exposed wear resisting surface gridwork and subjacent compression chords encased in the concrete ll.

4. A grid for concrete structures comprising a plurality of main bars disposed in side to side relationship, said bars each comprising a web, a base, an enlarged head at the top of the web, a combined welding and wear resisting n'b of metal extending upwardly from the head, and members extending across and entirely above the heads of said bars and sunk into and welded to said ribs to thetop plane of the said head to provide a surface gridwork lying wholly above the plane of the enlarged headof each bar for shielding the same from weather and wear.

5. A reinforced concrete structure comprising a plurality of bars disposed in side to side relationship, said bars each comprising a. web, a chord in the form of bulbous head at the top of the web, a rib of metal extending upwardly from said head, members extending across and press welded into said ribs to the depth of a. plane common to the tops of said heads, and concrete within the spaces between the bars and covering the bulbous heads thereof and rods extending through the webs of said bars below the bulbous heads thereof.

6. A grid for concrete structures comprising a plurality of bars disposed in side to side relationship, said bars each comprising a web having a compression head at the top thereof and a combined Welding and wear resisting rib of metal extending upwardly from the head, cross members press welded into said ribs to substantially the plane of the compression head, means supported above the bottom extremities of the bars for closing the spaces therebetween and members extending through the webs of said bars above the said last named means.

7. A grid structure for bridge floors and the like comprising a. plurality of rolled sections of substantially I-beam formation, each including' base flanges and a bulbous head connected by a continuous vertical web, an integral upstanding welding and wear resisting rib on the bulbous head, cross members press welded at spaced intervals into said ribs, plates supported on the upper faces of the base flanges, and a cementitious ll poured in the space above the said flanges and plates and extending to the tops of the cross bars and ribs to cover the bulbous heads and providing maximum compression strength in the top of the concrete fill while protecting the effective load carrying bulbous heads from Weather and Wear.

8. A reinforced concrete structure for maintaining maximum compression. strength Vin the top section thereof, comprising a wear resisting 15 surface exposed to traflc loads including cross cated beneath the surface plane of the cross Webs 20 and the exposed concrete thereby to protect said bulbous compression members from abrasive wear,

C. I. AUTEN. ROBT. D. SNODGRASS.

WALTER F. SCHULZ.

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