US2006929A - Grating and grating bar and method of fabricating gratings - Google Patents

Description

July 2, 1935'. NAGIN 2,006,929

GRATING AND GRATING BAR AND METHOD OF FABRICATING GRATINGS Filed May 24, 1954 $15 .6. fly. 2 .Fz'gS. 9.

Patented July UNITED STATES PATENT OFFICE My invention relates manufacture and is GRATIN G AND GRATI NG BAR AND METHOD OF FABRICATING GRATINGS Harry Nagin, Pittsburgh, Pa. Application May 24, 1934, Serial No. 727,259

17 Claims.

to gratings and their especially directed to a. grating of the type wherein cross bars are secured by welding to main supporting bar members, such as are used for covering all sorts of openings either in the floor, sidewalks, or over pits of various kinds, or in other places wherein a grating can be conveniently as a reinforcing an concrete structures.

used and which is also applicable d armoring means for use in The invention contemprovision and use of a cross ruction.

Ordinarily, gratings are formed from longitudinal girder bars able depth relative ,or hearing bars of considerto the cross bars which are secured transversely thereto to form the grating. In this type of grating, it is customary to notch the cross bars by removing a portion thereof from the underside thereof and to likewise notch the i top side of the bearing members and to fit these bars together with the notches of the cross bars registering with those of bearing bars to interlock the bars.

assembled are weld The various members after being ed by various methods. The

welds'resulting are of undesirable appearance due to excess that the joint metal, and it frequently happens is badly made.

Not infrequently the metalaround the edges of the bars is burned, presenting an unsightly appearance.

With the present invention,

notching need not tion contemplates upsetting the point where it is member in such manner that the the crossbar at this point is of but of increased width.

shaped that the or at the top of the proaches the lower It is further contemplated in the preferred manner of forming this method of to.- This invencross bar at the to the bearing cross section of reduced depth Moreover, the upset is so oss sectional area is greatest bar and decreases as it apend of the upset portion.

be resorted to be joined the cross bars, to form the upset portions so that the wide top surfaces of the upset portions are elevated slightly above the top surface of the bar in which they are formed to provide safety tread surfaces.

In the method of assembling the grating, the cross bars after they have been upset at predetermined points, are placed over the bearing bars. By pressure resistance electric welding the bars 50 are simultaneously heated and forced together,

resulting in a pressure welded structure of a. uniform and extremely strong character and of pleasing appearance.

In the accompan invention,

ying drawing, illustrating my Figure l is a perspective view of a grating made according to my invention;

Figures 2, 3, and 4 show other gratings embodying my invention;

Figure 5 shows a grating bar having reduced 5 portions;

Figure 6 is a cross sectional'view along the lines VIVI of Figure 5;

Figure 7 is va view of Figure 5;

Figures-8 and 9 show cross sections somewhat similar to that shown in Figure 7;

Figure 10 is a top plan view of the bar shown in Figure 5;

Figure 11 is a view through the welded joint along the line XIXI of Figure 2; and

Figure 12 is a section through the welded joint along the lines XIIXII of Figure 2.

In Figures 1, 2, 3, and 4, I have shown assembled gratings made according to my invention, having longitudinal bars or bearing members 2 and cross bars 3 secured to the bearing bars or bearing members at predetermined intervals 4.

Since the bearing bars carry most of the strain, they are usually of greater depth than the cross bars. The bearing bars may be of uniform cross section throughout, although they may be notched as has hitherto been done in the art.

In Figures 1 and 2, I have shown straight cross bars placed at right angles to the bearing bars. In Figure 3, the cross bars 311 are provided with offset portions and alternate bars have the offset portions turned in opposite directions. In Figure 4, the cross bars 31) are of slightly different shape from those shown in Figure 3, the offsets being turned in the same direction. In both Figures 3 and 4, adjacent bars are not directly opposite to one another. Either of these constructions is of advantage in gratings wherein the openings are to be of such size that a womans heel, for example, will not readily enter the space between the members composing the gratings.

The cross bars, as shown in Figures 5 through 10, have at predetermined spaced apart points, deformed portions 5 which have a different cross section from the remaining undeformed portion of the bar. The spacing apart of these deformed portions is governed by the desired spacing of the bearing bars in the completed grating. The cross bar is deformed at these points by an upsetting operation or by a rolling operation or by any other convenient manner. At each of the welding points 4, the cross bar has a raised portion 6 preferably of modified diamond shape, as shown in Figure 10. This portion extends prefalong the section VII-VII erably' about th of an inch above the top surface of the bar to form a safety tread or wearing surface. The width of the deformed portion is greatest at the top, as shown in Figures 7, 8, and 9, and the width decreases downwardly. The contour of the finished deformed surface is preferably parabolic with the apex of the curve at the bottom of the deformed portion, although it may take other forms as, for example, those shown in Figures 8 and 9, but, in any case, the bottom of the deformed portion is above the lower edge of the bar.

In fabricating the'gratings, the bearing bars are assembled and spaced apart the predetermined distance, and a pair of cross bars shaped as I have described above are placed thereon at predetermined welding points 4. By suitable pressure electric resistance welding means each pair of cross bars is welded to the bearing bars at all of the welding points or joints throughout the whole length ofthe cross bars in one operation, although if desired one bar or one joint thereof may be welded inany one operation.

The pressure electric welding method that I employ is widely known to those skilled in the art and forms no part of the present invention, per se. In this method of welding, one electric terminal is laid along the cross bar throughout its length and another electric terminal is laid along the adjoining cross bar throughout its length. The current is then turned on, whereupon at the points of contact or welding points, themetal is heated, and, when it attains the proper temperature, pressure is applied to the electric terminals which forces the cross bars down on the bearing bars and welds them together at the welding points. In this operation, the upset portion of the bar is actually sunk down into and fused with the bearing bar. In the finished grating, the top of the cross bar is fiush with the top of the bearing bars, except that the raised portion or projection 6 extends above the top of the cross bar to form gripping surfaces, if such are desired. When desired, the cross bars may be made without the projection'li and the cross bars themselves allowed to project in the finished grating a desired distance above the top level of the bearing bars.

Figures 11 and 12 show the cross bar 3 welded in place to the bearing bar 2. The metal from the bearing bar fills in the reduced portion of the cross bar and forms a uniform weld, as shown in Figure 12. This weld is an exceedingly strong one and neat in appearance. Figure 11 shows the approximate contour of the cross bar after the weld to the bearing bar.

My invention provides an extremely neat appearing welded grating, the welds of which are exceedingly strong and the grating is one that is capable of rapid and economical fabrication as only the cross bar is deformed and the bearing members are ordinary rectangular bars of the desired size. The upset portion of the cross bars is so designed that the excess metal of the bearing bars fills out the deformed portion of the cross bars and produces a strong economical and sightly weld. The expense of slotting the hearing members is entirely obviated and the weakening of the metal which results from slotting is avoided while an improved grating structure is produced.

While I have illustrated and described, by way of example, a preferred embodiment of my invention, it will be understood that the invention is not limited thereto but may be otherwise embodied within the scope of the following claims:

I claim:

1. The method of forming gratings which comprises forming cross bar members in the form of narrow vertical strips having regularly positioned wide portions therein of less depth than the normal depth of the strip, said wide portions being of downwardly decreasing cross sectional width, thereafter assembling the bars so formed over the bearing bars with the bottoms of the wide portions contacting with the top edges of the bearing bars, and then heating the contacting portions of the cross bars and bearing bars and pressing them together to simultaneously weld the contacting surfaces and force the wide portions of the cross bars into the top edges of the bearing bars.

2. A reticulated grating composed of a number of parallel spaced apart bearing members, and a plurality of spaced apart intersecting cross bars, each cross bar having spaced apart upset portions of greater maximum width and less depth than the main portion of the bars, the cross bars being welded to the bearing members.

3. A reticulated grating composed of a number of parallel spaced apart bearing members, and a plurality of spaced apart intersecting cross bars, each cross bar having spaced apart upset portions of greater maximum width and less depth than the main portion of the bars, the cross bars being welded to the bearing member, the crossing points on each bearing member being staggered with the crossing points of the adjoining bearing member.

4. A reticulated grating composed of a number of parallel spaced apart bearing members, and a plurality of spaced apart intersecting cross bars, each cross bar having spaced apart upset portions at their points of contact with the bearing members of less depth than the intervening portions of the bars, and having a cross sectional area substantially equal to the cross sectional area of the remainder of the bar, the cross bars being welded to the bearing members.

5. A reticulated grating composed of a number of parallel spaced apart bearing members, and a plurality of spaced-apart intersecting cross bars, each cross bar having spaced apart upset portions of less depth than the main portion of the bars, and having a cross section at least substantially equal to the cross section of the remainder of the bar, the cross bars being welded to the bearing members, the crossing points on each bearing member being staggered with relation to the crossing points of the adjoining bearing member.

6. A reticulated grating composed of a number of parallel spaced apart bearing members and a plurality of intersecting cross bars each having spaced apart upset portions of less depth than the main portion of the bars, the upset portion of the bar being widest at the top and of substantially the same cross sectional area as the remainder of the bar.

7. A reticulated grating composed of a number of parallel spaced apart bearing members and a plurality of intersecting cross bars each having spaced apart upset portions of less depth than the main portion of the bars, the upset portion of the'bar being widest at the top and of substantially the same cross sectional area as the remainder of the bar, and being substantially embedded throughout the greater portion of its height in said bearing member.

- 8. A bar for use in gratings and the like, having spaced apart wide portions, each wide portion being of less depth than the rest of the bar.

9. A bar for use in gratings and the like, having spaced apart wide portions, each wide portion being of less depth than the rest of the bar and the cross sectional area vf the wide portion being at least substantially as great as the cross sectiona] area of the intervening portion of the bar.

19. A bar for gratings having spaced apart upset portions, the bar at each upset portion being of less depth than the rest 01' the bar and wider at the top than the intervening portion of the bar and than the remainder of the upset portion.

11. A bar for gratings having spaced apart upset portions, the bar at each upset portion being of less depth than the rest of the bar and wider at the top than the intervening portion of the her and than the remainder of the upset portion, the cross sectional area of the upset portion being at least substantially equal to that of the remaintier oi the bar.

12. A bar for gratings having spaced apart upset portions, the bar at each upset portion being of less depth than the rest of the her and wider at the top than the intervening portion of the bar and than the remainder of the upset portion, the top of the upset portion projecting above the upper surface of the cross bar.

13'. A grating bar having spaced apart upset portions, the bar at each upset portion being of less depth than the rest of the bar and wider at the top than the intervening portion of the bar and than the remainder of the upset portion, the

top or the upset portion having a projection thereon which projects above the upper surface of the cross bar and being of a uniform shape.

14. A bar for gratings having spaced apart upset portions of less depth than the main portion of the bar, the upset portion of the bar being widest at the top and of constantly decreasing width from the top to the bottom.

15. A bar for gratings having spaced apart upset portions oi less depth than the main portion of the bar, the upset portion of the bar being widest at the top and of constantly decreasing width from the top to the bottom, and a projection on said upset portion which extends above the upper surface or the main portion of the bar.

16. A her for gratings having spaced apart indentations therein, of iess depth than the intervening portions of the bar and having said indented portions of a width greater than the width oi the intervening portions of the her.

17. The method of rushing a grating, which comprises distorting cross-bar elements in such manner as to form regularly positioned wide portions on the upper edge thereof and recesses on the bottom edge thereof, assembling said crossbar elements on hearing hers with said hearing bars received in the recesses, and then heating the contacting portions or the cross-bars and bearing bars and pressing them together, utilizing the distorted portions of the cross-bars to effect the flowing of the metal of the bearing bars.

HARRY NAGIN.

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