US3024712A

US3024712A - Grating

Info

Publication number: US3024712A
Application number: US688263A
Authority: US
Inventors: Gerald G Greulich
Original assignee: KERRIGAN IRON WORKS Co
Current assignee: KERRIGAN IRON WORKS Co
Priority date: 1957-10-04
Filing date: 1957-10-04
Publication date: 1962-03-13
Anticipated expiration: 1979-03-13

Description

March 13, 1962' G. G. GREULICH 3,024,712

GRATING Filed Oct. 4, 1957 FGJ.

INVENTOR GERALD G. GREULICH ATTORNEY;

United States Patent 3,024,712 GRATING Gerald G. Greulich, Fort Lauderdale, Fla., assignor, by mesne assignments, to Kerrigan Iron Works Company, Nashville, Tenn., a corporation of Tennessee Filed Oct. 4, 1957, Ser. No. 688,263 4 Claims. (Cl. 94-30) This invention relates to load carrying metallic structures and more particularly to load carrying open metallic gratings, such as commonly used for walkways, manhole covers, platforms, stair treads, catwalks, sidewalks, runways for vehicles, bridge floors and the like.

Heretofore, such gratings have been made by piercing some of the components and lacing other components through the pierced holes. Other constructions embody spacer members placed between parallel load carrying members, such spacer members being riveted or welded to the load carrying members. One particular arrangement illustrating the use of spacer members embodies dovetail faces on the spacer members corresponding to dovetail grooves in the sides of the load carrying members. In constructing a grating from such members, it is necessary to insert the spacer members at the ends of the load carrying members and then move them along the length thereof to the proper locations. After all of the spacer members have been properly located, deformations are formed to prevent longitudinal movement.

Still other gratings are assembled by placing reticulated or alternately bent members ,between adjacent straight load carrying members, with the assembly fastened into a rigid unit by bolts, rivets or welds at the points of contact or engagement. Sometimes, such structure may embody notching or interlocking crossed-over members and often the crossed bars are weld-forged into surfaces or edges of the load carrying members. Still another method of constructing `a grating of the type described involves the formation of suitable longitudinal Sections, as by extruding or the like, and subsequently piercing the upper portions so as to allow the passage of air and the like through the openings. Many forms of gratings have also been made by means of casting molten metal in molds of the nal shape of grating desired. Expanded metal is also utilized to a considerable extent for certain grating applications.

The present invention is more particularly concerned with improvements in gratings made up of individual sections to a desired size. In accordance with the principles of the present invention, assembly of the individual sections into a rigid unit is accomplished without the necessity of welding or other analogous procedures and without the necessity of piercing t-he metal sections so as to remove substantial portions thereof and thereby reduce its strength.

In general, the present invention utilizes an arrangement of opposed flanges on one element of the assembly and spaced faces or portions on t-he adjacent element arranged to enter between the flanges. One of the flanges is undercutpto receive one of the faces, while the other flange is straight so as to permit each pair of adjacent elements of the grating to be assembled without the necessity of a longitudinal sliding movement throughout their length, but rather by a simple lateral and arcuate relative movement between the two. The elements may be readily locked into their assembled position by deforming the straight `flange over the other face.

Accordingly, it is an object of the present invention to provide a method of assembling a grating of the type described which effects a saving in the time and effort heretofore required to effect assembly of prior art gratings.

Still another object of the present invention is the provision of a grating assembly of the type described having individual elements of the assembly.

Still another object of the present invention is the provision of a grating of the type described, which is pleasing in appearance, sturdy in construction and economical to assemble.

These and other objects of the present invention will become more apparent during the course of the following detailed description and appended claims.

The invention may best be understood with reference to the accompanying drawings wherein `an illustrative ernbodiment is shown.

In the drawings:

lFIGURE l is a fragmentary top plan view of a grating embodying the principles of the present invention;

FIGURE 2 is an enlarged cross-sectional view taken along the line 2 2 of FIGURE 1;

'FIGURE 3 is a fragmentary perspective view of a portion of the grating; and

FIGURES 4 and 5 are vertical cross-sectional views illustrating the manner in which adjacent bars of the grating are assembled.

Referring now more particularly to the drawings, there is shown in FIGURE 1 a grating assembled in accordance with the principles of the present invention. The grating includes a plurality of straight load bearing members or bearer bars 10 and reticulated connector bars or members 12 secured between adjacent bearer bars to maintain the same in spaced parallel relation.

Preferably, the reticulated connector bars 12 are bent to provide a plurality of longitudinally extending bearer bar engaging portions 14 interconnected by transversely extending diagonal portions 16.` Alternate bearer bar engaging portions 14 are disposed in the same general plane and successive bearer bar engaging portions are spaced apart laterally.

Grating assemblies of alternate straight bars maintained in parallel relation by reticulated connector bars are known. The present invention is more particularly concerned with a novel method of assembling such bars and a novel structure for rigidly securing the same in assembled position. In general, the securing means of the present invention embodies the provision on one of the bars of a straight flange and a spaced opposed undercut flange. The adjacent bar or member has spaced portions thereon engageable between Ithe opposed flanges by relative lateral and arcuate movements between the adjacent bars so as to initially insert one of the portions within the undercut flange and subsequently move that portion and the undercut flange into registering engagement and the opposite portion and the straight flange into contact. In this initial position of assembly, the bars are readily retained together and may be readily locked into rigid engagement by deforming the straight flange, as by bending or the like, over the other portion.

With the above in mind, the structure illustrated in the drawings to exemplify one embodiment of the principles outlined above will now be described. Both the bearer bars 10. and the connector bars 12 are preferably initially constructed so that they have a uniform cross-sectional configuration throughout their longitudinal extent. It is preferable to utilize extruded aluminum, although it will be readily understood that other materials may be utilized which are either rolled, extruded or otherwise fabricated. Each bearer bar is generally I-shaped in cross-section and includes a central web 18 having a pair of flanges 20 on its upper end extending from opposite sides thereof and a pair of flanges 22 on its lower end extending from the opposite sides thereof. Each of the upper flanges 20 includes a lower connector bar engaging surface 24 which is undercut so that the lowermost point along a line formed by the intersection of a transverse plane therewith is disposed on the outer end portion of the flange and all points along such line inwardly of the lowermost point are disposed thereabove. As shown, the lower connector bar engaging surface 24 of each flange 20 constitutes a flat dovetail face which is disposed at an angle between approximately 30 and 40 with respect to the horizontal.

Each lower flange 22 constitutes a straight flange having an upper connector bar engaging surface 26 arranged so that no points along a line formed by the intersection of a transverse plane therewith are disposed above a horizontal plane touching any point along the line adjacent the inner end portion of the flange. As shown, the flanges 22 have the usual configuration of a conventional l-beam. ln addition to the

flanges

20 and 22, each bearer bar has its upper surface provided with a series of ridges 28, which serves not only to enhance the appearance of the grating, but also to improve its anti-slip characteristics.

Each connector bar 12 is preferably also of general I-shaped configuration in cross-section and includes a central web 30 having a pair of upper flange engaging portions 32 on the upper end thereof extending from opposite sides thereof and a pair of lower flange engaging portions 34 on the lower end thereof extending from opposite sides thereof. Each of the upper portions 32 constitutes a flange extending outwardly from the web 30 of the connector bar and includes an upper bearer bar engaging surface 36 arranged to engage the lower surface 24 of an adjacent upper flan-ge 20 of an adjacent bearer bar. Preferably, the outer end of each flange portion 32 terminates in a vertical surface 38 arranged to be parallel to and to be almost or in actual contact with the web of an adjacent bearer bar adjacent the associated flange surface 24. Preferably, the web 30 has an extension 40 disposed above the portions 32 and provided with a single ridged upper surface 42 corresponding to the multiple ridged upper surface 28 of the bearer bar. The extension 40 includes vertical side walls 44 arranged to abut the outer ends of the flanges 20 of the bearer bar.

Each lower portion 34 also constitutes a flange extending from the web 30 and includes a lower edge or surface 46 arranged to engage the upper surface 26 of an adjacent lower flange 22 of an adjacent bearer bar. Extending upwardly from each edge 46 is a locking surface 48. ln addition, each lower flange portion 34 also includes an outer edge or surface 50 arranged to engage the web of an adjacent bearer bar at a position adjacent the lower flange thereof.

As noted above, each connector bar 12 is of substantially uniform cross-sectional configuration throughout its longitudinal extent and is bent transversely to provide the longitudinally extending bearer bar engaging portions 14. In assembling adjacent bearer bars and connector bars, the upper portion 32 of the longitudinally extending portions of the connector bar extending toward the assoelated bearer bar, are arranged to be inserted within the upper undercut flange 20 of the associated bearer bar extending toward the connector bar. It will be noted, however, that since the transversely extending portions 16 of the connector bar cross the undercut flange 20, the upper flange engaging portions of the longitudinally extending portion of the connector bar cannot be inserted within the undercut flange. Therefore, in order to permit entry, either the flange of the bearer bar or the portion of the connector bar at the junctures between the longitudinally extending portions and transversely extending portions thereof must be interrupted. As shown, the outer junctures between the longitudinally extending portions 14 and transversely extending portions 16 of the connector bar flange portions 32 are cut out as indicated at 52. In addition, to facilitate the transverse bending of the connector bar to form the reticulated configuration, the lower flange portions 34 are eut away, as indicated at 54, at the outer junctures between the longitudinally extending portions 14 and transversely extending portions 16. The cutouts 54 are not essential, since the flange portions may be moved into lateral engagement with the straight lower flanges 22 of the bearer bars without interference.

With the connector bars 12 cut away and bent in the manner indicated above, the grating is assembled by effecting a relative lateral and arcuate movement between a bearer bar 10 and a connector bar 12 sufficient to initially insert the adjacent flange portion 32 within the adjacent undercut flange 20 of the bearer bar, as shown in FIGURE 4, and to subsequently move the surface 36 into registering engagement with the surface 24 and the lower flange portion into engagement with the lower flange of the bearer bar, as shown in FIGURE 5. It will be noted that the cutouts 52 enable the connector bar and bearer bar to be moved longitudinally so that they can be properly positioned. Next, the outer end of the lower flange 22 is deformed upwardly, as indicated at 56, into engagement with the surface 48 to lock the two bars against lateral separation. It will be noted that the upward bending of the lower flange 22 deforms the metal such that it is disposed in the longitudinal path of movement at the junctures between the longitudinally extending portions 14 and transversely extending portions of the associated flange portion 34 of the connector bar to thereby also prevent relative longitudinal movement between the two bars. By this simple expedient, the two bars are rigidly interconnected with a minimum amount of time and effort.

It Will be understood that the grating may be progressively built up, in the manner indicated above, to any desired size. In this regard, it will be noted that the bearer bars in the intermediate portion of the grating contact portions 14 of adjacent connector bars on both sides thereof and, preferably, the adjacent longitudinally extending portions 14 of the connector bars on both sides thereof contact the bearer bars at the same longitudinal positions so that `both lower flanges 22 may be deformed upwardly in one operation. This materially reduces the time required in assemblage.

It can thus be seen that there has been provided a grating assembly which may be readily constructed of individual bars of uniform cross-sectional configuration throughout their longitudinal extent. The cross-sectional configuration of the bars is such that adjacent bars may be interconnected by the simple expedient of effecting a relatively lateral and arcuate movement therebetween so as to initially insert a first portion on one of the bars within a first undercut flange on the other bar and, subsequently, move the one portion and undercut flange into registering engagement and a spaced second portion on one of the bars and a spaced straight flange on the other bar into engagement. Where a reticulated connector bar is utilized, the undercut flange engaging portion is cut away, which permits the two bars to be readily adjusted longitudinally with respect to each other. Finally, the two bars are rigidly interconnected against both lateral and longitudinal movement by deforming the straight flange over the portion engaged thereby.

It will be understood that the cross-sectional conguration of the bars can `be varied considerably from that shown without departing from the principles of the present invention. The essential feature is the provision on one member of a pair of spaced flanges, one of which is undercut and one of which is straight, and the provision on the cooperating member of portions arranged to engage between the flanges by relative lateral and arcuate movement so as to bring one portion into registering engagement with the undercut flange and the other portion into initial contact with the straight flange so that the latter can be subsequently deformed thereover. The exact bar engaging surfaces of the

flanges

20 and 22 are not limited to the straight dovetail surfaces shown.

It thus will be seen that the objects of this invention have been lfully and eifectively accomplished. It will be realized, however, that the foregoing specific embodiment has been shown and described only for the purpose of illustrating the principles of this invention and is subject to extensive change without `departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

I claim:

l. In a grating assembly having a plurality of straight bars and intermediate connector bars extending in the same longitudinal direction with said straight bars substantially parallel, each straight bar having a web and spaced pairs of opposite flanges extending laterally therefrom, and each of one of said pair of flanges being provided with an undercut forming with said web an undercut opening toward the other pair of flanges, and each connector bar having alternate oppositely laterally displaced straight portions each provided with spaced pairs of opposite outwardly diverging flanges adjacent and extending toward the straight bar flanges, each of one pair of said outwardly diverging connector bar flanges `snugly lockingly inter-fitting into corresponding undercuts of adjacent straight bar anges and the corresponding anges vof the other pair of said straight bar anges being bent over the adjacent diverging flange of said connector bar.

2. In a grating assembly having a plurality yof straight parallel bars with longitudinally extending intermediate connector bars between them, each straight bar having a web and spaced pairs of opposed flanges extending laterally therefrom and each connector bar being formed with alternate oppositely laterally displaced straight portions having a web and spaced pairs of opposed lateral flanges extending therefrom toward the `adjacent straight bar flanges, the flanges of one of said bars diverging from its web to form outwardly open recesses, and each of one of the pairs of flanges of the other bar being provided with an undercut forming with the web of said other bar an inwardly open recess interlocking with the corresponding `outwardly diverging flange orf said one bar, and corresponding flanges of the other pair of flanges of said other bar being 4bent over the other outwardly open diverging flange of said one bar whereby to retain said bars in assembled interlocked relationship7 3. In a grating assembly having a plurality of straight bars and intermediate laterally zig-zag connector bars extending in the same longitudinal direction with said straight bars substantially parallel, each straight bar having a web and Ispaced pairs of opposed flanges extending laterally therefrom and each of one of said pair of iianges being provided with an undercut forming with said web an undercut having an inclined surface and each connector bar having alternate oppositely laterally displaced straight portions each provided with spaced pairs of diverging flanges adjacent and extending toward the straight bar anges, each of one pair of said outwardly diverging flanges inter-fitting with a corresponding said undercut surface and substantially conforming in angularity with said surface, and corresponding flanges of the other pair of flanges of said straight bar being crimped over the other adjacent diverging anges of said `c011- nector bar to hold said straight bars and said connector bars rigidly interlocked.

4. In a grating assembly having a plurality of straight bars and intermediate laterally zig-zag connector bars extending in the same longitudinal direction with said straight bars substantially parallel, each straight bar having a web and spaced pairs of flanges extending laterally therefrom and each of one of said pair of anges being provided with an undercut forming with said web an undercut opening toward the `other pair of flanges and each connector bar having alternate oppositely laterally displaced straight portions each provided with spaced pairs of outwardly extending flanges adjacent land extending toward the straight bar flanges forming outwardly extending undercuts opening away from each other, each of one pair of said outwardly extending anges `of said connector bar snugly lockingly interftting with ya corresponding inwardly opening undercut surface of straight bar ange and corresponding anges of the other pair of anges of said straight bar being bent over the other out-A wardly extending ange of said connector bar.

References Cited in the lile of this patent UNITED STATES PATENTS 727,234 Walker May 5, 1903 1,344,882 Goldie June 29, 1920 1,865,059 Ragsdale Iune 28, 1932 2,302,586 Thalen Nav. 17 194g