US2317174A

US2317174A - Grating structure

Info

Publication number: US2317174A
Application number: US381014A
Authority: US
Inventors: Herbert H Bunker
Original assignee: KERLOW STEEL FLOORING Co
Current assignee: KERLOW STEEL FLOORING Co
Priority date: 1941-02-28
Filing date: 1941-02-28
Publication date: 1943-04-20
Anticipated expiration: 1960-04-20

Description

April 1943- H. H. BUNKER 2,317,174

GRATING STRUCTURE Filed Feb. 28, 1941 INVENTOR.

10 4/ if) 50 10 6 flerzri/Zfiunlar Patented Apr. 20, 1943 UNlTED STATES PATENT QFFICE GRA'IING STRUCTURE He bert H- un J sey City, N- J assignor to e ow Ste Fl o Compa rsey City. J-, a o p r tion of New Jers y Appiication February 28, 1941, Serial No. 381,014

3 a m lCl- 189* This invention relates to grating structures for open flooring and particularly to grating suitable for walkways, running boards, catwalks and the like.

Among the objects of this invention is to provide a grating structure suitable for walking upon under conditions which are ordinarily considered as requiring the exercise of caution and the need of complete confidence in the underfoot security provided by the walking surface. While a grating surface composed of metallic bars spaced from one another makes a good floor surface, the general utility of such a surface construction is sometimes restricted because the edges of the bars become smoothened by erosion under certain conditions of use. Gratings Sub-.- ject to weathering, Walkways about industrial plants and on shipboard, and running boards and steps on freight cars are examples of grating surfaces which are particularly subject to une desired alteration of their surfaces from rusting and other causes of erosion. An object of the i nstant invention is directed to producing a suitable grating for these and kindred uses which possesses slip-proof qualities capable of retention as part of the structure throughout its life and under severe conditions of erosion.

In the grating of the present invention, the bars which correspond to the longitudinallyrextending girder bars on the common grating are interrupted by a series of cut-out portions which operate to eliminate the continuity of the upper edges of these bars and thereby materially diminish the hazard of slipping inherent in a continuous straight bar. At the same time the frictional coefiicient of the entire grating surface is further increased by projections or offsets which extend laterally of the girder bars and above the surface defined by the upper surfaces of their sup-. porting girder bars. The drawing shows by way of illustration a preferred embodiment and the principle of my invention and what I now consider to be the best mode for applying that principle. Other embodiments of the invention employing the same principle may be used and structural changes made as desired by those skilled in the art within the spirit of the appended claims and without departing from the present invention.

In the drawing,

Fig, l is a plan of a section of the grating.

Fig. 2 is a side elevation on line 22 of Fig. 1.

Fig. 3 is an end elevation on line 3-3 of Fig. 1.

The grating is an assemblage of longitudinallyextending girder bars Ill spaced from one another and secured together by cross-bars l I. The girder bars are made from strip material, rectangular in cross-section. They are designed for load bearing purposes and are supported by beams upon which they rest, or upon the crossbars, as will be explained hereinafter. The girder bars of the instant invention have ofisets or pro- J'ections l2 which are punched out of the flat strip which forms each girder bar. It is apparent that the configuration of these punched cut projections may take various forms, it being important, so far as the present invention is concerned, that they provide oifset surfaces which extend laterally to the girder bars and also above the straight edges of the girder bars from which they are punched.

I he punching is accomplished by a cutting and die operation which severs the offset l2 from the girder bar along lines [3, M and I5 (Fi 2). Immediately upon severance, or by independent following operations, the offset is bent out from the girder bar, either in a single twist bend or by a double bending. As shown in the drawing, it is preferably bent along two lines which converge with respect to each other in the plane of the bar. One of these lines aa,, Fig. 2, is at an angle to the vertical and marks the line of folding between the girder bar and the offset. Its angularity causes the offset to be projected above the horizontal plane of the portions l6 of the girder bar which remain in alignment as discontinuous upper edges of the girder bar, as illustrated in Fig. 2. The amount of elevation of the offset above the top edges I6 is a function of the angue larity of the fold line aa with the vertical, and this may be varied in accordance with the res s desire to be a e e it b n un r to that the drawing is for the purpose of illustratns the prin e o y.

he s nd i e f mm b .s1 a d b tw the fi st ne of ld a o and the free nd o t e Offs t. T is s ond. l ne. o f l 2- is ao u a l disposed with reference to the top edges of the ofiset and has the effect of bringing the portion of the offset adjacent its free end into a horizontal position so that all of the upper edges of the offsets outward from the line bb are in a common horizontal plane above the plane of the portions I6 of the girder bars, as illustrated in Figs. 2 and 3.

It is apparent from this construction that the offsets provide, together with the remaining portions of the girder bars, a broken or discontinuous undulating surface which has a large number of relatively sharp edges and corners at right anboard gratings and is a desirable material.

gles and oblique to one another. The effect of this is that the bearing surface under the foot of a pedestrian is broken in a sufficient number of places adequately to obstruct slipping in any direction. The girder bars provide longitudinal edges l1, l8, which prevent side slipping; the offsets provide edges I9, 20, at right angles thereto for preventing slipping along the girder bars and also oblique edges 2|, 22, 23 and 24 with the girder bars which restrain slipping in those directions.

istics of the grating surface. It is apparent that the offset may be bent in a continuous curve either in whole or in part instead offorming two distinct planes, as shown in Fig. 1. Also, if desired, every alternate girder bar could be placed in a direction reversed to that shown in the draw ing whereby the pattern produced by the difierent dispositions of the offsets would be different from that shown in Fig. 1, although similar antislip characteristics would still be present.

Steel is commonly used for forming running Qrdinary wear of sharp or square edges results from abrasion through constant use, but rust flakes off and pits the metal and the disintegration caused thereby 'quickly'rounds off all natural edges which normally retard slipping. Superposed bosses or impressed indentures designed to prevent slipping also have their purpose adversely affected by the same cause. The present construction, while being exposed to the same deleterious wear, nevertheless will retain high non-slipping characteristics because of the permanency of its floor pattern;

The features of the invention thus far described are applicable for use with cross-bar gratings having cross-bars in which the crossbars have their upper edges in the same plane as the upper edges of the girder bars. It is intended that in such a structure the offsets be made in the manner and for the uses previously described. Particularly with reference to the use of the invention for fabricating running boards for freight cars, there is advantage in providing the cross-bars in the manner illustrated in the drawing. In this construction the cross-bars are notched at intervals (at 30) along their top edges and the girder bars are notched at intervals (at 3|) along their lower edges so that the notches of each set of bars may snugly engage the bars of the other set of bars in a double tongue'and groove joint. As illustrated in Figs. 2 and 3, the depths of the notches are so proportioned that after the bars are engaged the cross bars extend below the girder bars. The security of the engagement may be increased by providing dovetailed ends 32 at the bottoms of the notches in the girder bars which receive material forced therein from the cross-bars as the cross-bars are forced into engaged. With the lower edges of the girder bars elevated above The

end edges

25, 26, 21 and 28 add, to the tractional effect and anti-slip character-' the lower edges of the cross-bars, space is provided beneath the grating structure which prevents entrapment of water or other material in the interstices of the grating when the grating is laid upon a flat solid surface.

When exposed to rainand salt air, the metallic grating designed for use as a running board is likely to have its usefulness impaired by excessive erosion sooner than by either abrasive wear or impact effects produced by walking thereon. This is because such a grating usually has more material in it and therefore possesses more strength than is actually required for its service. While its margin of strength is sufficient to counteract any weakness which may develop from loss of material through corrosion, if the edges become rounded and its slipperiness increases, its efiicaciousness is seriously impaired; The grating of the present invention discounts the effect of the wear upon the edges by providing a large number of edges and discontinuous bars in the walking surface with some of these bars elevated with respect to the others.

What is claimed is:

1. A grating structure formed of intersecting and joined girder bars and cross-bars, said girder bars; having laterally extending ofl'sets spaced at intervals along the girder bars and extending upwardly above the 'planeof the upper edges of the girder bars to form an undulating floor surfacefor the grating structure, said offsets being bent out from the girder bars on substantially vertical lines of fold.

2. A fioorgrating structure comprising intersecting and joined girder bars and cross-bars pro viding open spaces in the floor area of the grating structure, each of said girders having a discontinuous upper edge provided by a series of notches, a plurality of projections extending sidewise from said girder bars and terminating in free ends in the spaces between adjacent girder bars, each projection being an integral part of a girder bar to which it is joined at one of the edges of a. notch and said projection having a portion thereof extending above the plane of the upper edges of the girder bars and substantially at right angles to the longitudinal direction of the girder bars. 7 a 3. An anti-slip open grating structure comprising intersecting girder bars and cross-bars standing on edge and joined together at their intersections by notches in the respective bars, said bars having their flatwise dimensions perpendicular to the plane of the grating, means carried by said girder bars for providing an undulating contour for the top surface of the grating, said means comprising cantilever projections bent from the girder bars and having their free ends projecting into the spaces between the girder bars and above their floor surfaces so as to provide anti-slip elements in the top level of the grating within the spaces between the girder bars.

HERBERT I-I. BUNKER.