US2246216A

US2246216A - Grating

Info

Publication number: US2246216A
Application number: US229895A
Authority: US
Inventors: Harry S Nagin
Original assignee: Reliance Steel Products Co
Current assignee: Reliance Steel Products Co
Priority date: 1938-09-14
Filing date: 1938-09-14
Publication date: 1941-06-17
Anticipated expiration: 1958-06-17

Description

Jude 17, 1941. H. s. NAGIN 2,246,216

GRATING Filed Sept. 14, 1958 l 2 INVENTOR L v .Harr SCNQ 7J2 U L1: 5 11 g Patented June 17, 1941 GRATING Harry S. Nagin, Pittsburgh, Pa., assignor to Reliance Steel Products Company, RankimPa a corporation of Pennsylvania Application September 14, 1938, Serial No. 229,895

Claims.

This invention relates to ratings and is particularly directed to gratings which have a skid proof or skid resistant surface and a method of making the same.

Gratings comprising longitudinal bearing bars and cross bars extending laterally between and secured to the bearing bars are in common use for providing a traffic supporting surface for both pedestrian and vehicular traffic. The tops of said bars lie in substantially the same plane. The surface presented to the traflic by said structures is fairly skid resistant to some kind of traffic. The object of this invention is to enhance the skid resistant properties of the gratings.

I have found that the skid resistant properties of a grating to all sorts of trafiic may be greatly increased by serrating or indenting the tops of the bearing bars and the cross bars which comprise the trafiic supporting surface. This is preferably done by a knurling or rolling operation performed on the assembled grating after the grating has been fabricated and While it is cold.

In the accompanying drawing, which illustrates the present preferred embodiment of my invention:

Figure 1 is a diagrammatic top plan View of a portion of a typical grating without serrations;

Figure 2 is a plan of ,a portion of a grating showing one form of serrations;

Figure 3 is a plan View of a portion of a grating showing another form of serration;

Figure 4. is a section along the line IV-IV of Figure 2; s

Figure 5 is a plan of a portion of a grating showing still another form of serration; and

Figure 6 is a diagrammatic view in elevation of a suitable serrating apparatus.

In the drawing, there is illustrated a grating unit which consists of a desired number of longitudinal bearing bars or bearing members 2 of predetermined dimensions which are assembled in spaced apart parallel relationship. At suitable intervals the bearing members v2 are secured to one another adjacent their tops by cross bars 3 which extend transversely to the bearing members and are secured thereto in any convenient manner, preferably by pressure electric resistance welding. The tops of .the bearing members 2 and the tops of the cross bars 3, when joined, are in substantially the same plane and together form a structure presenting a reticulated traffic bearing surface. The bearing surfaces of all the bars have serrations or indentations 4 thereon preferably formed after the grating unit has been assembled and welded. All

t xposed ops of th be ri m mb s a the ad a nt ross ba ar s rate he in en tions may all run in a common direction and uniformly over the bearing member and the cross bar as shown n igu 2. o t r a s may run n on direct on a o bea member and t e ad acent ha 91" the c o s r and in a ferent direction on the adjoining bearing members and the halves of the cross bars adjacent to them, as shown Figure 3. Again, the bearing members and the cross bars may each be knurled to form pyramids or like projections or indentations. The prime object to provide some sort of serrations on the top exposed surfaces of the bearing members and the cross bars to increase the skid resistant Properties of the grating.

It will be observed that the top surfaces of the bars are slightly widened at the top '5 by the serrating operation. This is shown, for example, in Figure 4, where it will be observed that the top surface of the cross bar is wider than the adjacent portion of the cross bar. This gives a slightly wider metal surface to be presented to the trafiic and retards wear of the surface.

In making my grating unit I first assemble the bearing bars 2 and the cross bars 3 of the desired dimensions and in the desired relationship and thenunite them, preferably by pressure electric resistance welding. This part of the process is old. I then pass the welded unit between a pair .of rollers, the surface .of the rollers in contact with the .top surfaces of the unit being suitably shaped so as to impressor roll the desired serrations onto the bearing bars and the cross bars.

Apparatus suitable for serrating the top surfaces of the grating is shown in Figure 6. The apparatus consists of an upper roll 6 which may be solid .or may be made .up of discs fixedly mounted on a shaft 1, and a lower roll 8. The upper roll 6 has surface projections thereon for serrating the grating. The lower roll 8 has an ordinary cylindrical surface.

Gratings so formed are highly skid resistant; are inexpensive to manufacture, since the increased cost involved in serrating the surface is but very little. By rolling in or pressure forming the indentations, the original skin on .the bar edges is not injured and this original skin is more resistant to wear and to corrosion than is a surface which has been broken or cut. The'rolling in of the indentation also produces the flare at the upper edge of the grating bars, and avoids the formation of sharp cutting edges such as might injure one who might fall on the grating. The serrated surface is preferably such that the While my grating is particularly useful as an open type grating, it can be used to advantage as a reinforcing unit for a cementitious body. The armoured surface of the completed cementitious body is rendered somewhat more skid resistant by the use of grating units having skid resistant properties of the character imparted to it according to my invention. It is to be understood that the bearing bars and cross bars could be serrated before being assembled in the "unit, but this type of construction is somewhat more expensive and a less satisfactory joint results.

WhileI have illustrated and described certain preferred embodiments of. my invention, it is not limited thereto, but may be otherwise embodied and practiced within the scope of the following claims:

I claim: 1. Agrating or the like fabricated from continuous separate bars of metal having fiat surfaces, comprising wrought metal bearing members and cross bars rectangular in cross section disposed angularly with respect to said bearing members and secured thereto by pressure electric resistance welding, the top edges of said members and of said bars constituting tread surfaces throughout their lengths and being indented to provide serrations, the tops of the serrations lying insubstantially the same plane, said serrations being angularly disposed to the longitudinal axis of the bearing'members and to the longitudinal axis of. the cross bars, the serrations of adjoining parts continuing uninterruptedly from a bearing member into an adjoining cross bar.

2. A grating or the like fabricated from continuous separate bars of metal having flat surfaces, comprising wrought metal longitudinal bearing members, wrought metal cross bars rectangular in cross section disposed angularly with respect to said bearing members and secured thereto by pressure electric resistance welding,

the top edges of said members and of said bars constituting tread surfaces throughout their lengths and being provided with rolled serrations, the tops of the serrations lying in substantially the same plane, said serrations being angularly disposed to the longitudinal axis of the bearing constituting tread surfaces throughout their lengths and being slightly widened at the top and of substantially constant thickness throughout the remainder of their sections, and being serrated, the tops of the serrations lying in substantially the same plane, said serrations being angularly disposed to the longitudinal axis of the bearing members and the longitudinal axis of the cross bars, the serrations of adjoining parts continuing uninterruptedly from one bearing member into an adjoining cross bar.

4. An assembled grating comprised of two sets of angularly disposed contacting bars fixedly joined at their points of contact and having their top surfaces in a plane, all of the bars being serrated over their entire top surface, there being laterally extending portions along the top edges of. the bars, the grooves between the serrations at the junctions of the bars being in register and continuing uninterruptedly across the area of the junction and intothe adjoining bars and being angularly disposed to the longitudinal axes of both sets of bars.

5. A grating or the like fabricated from continuous separate bars of metal having flat surfaces, comprising wrought metal longitudinal bearing members, Wrought metal cross bars rectangular in cross section disposed angularly with respect to said bearing members and secured thereto by pressure electric resistance welding, the top edges of said members and of said bars constituting tread surfaces throughout their lengths and being indented to provide serrations, the tops of the serrations lying in substantially the same plane, said serrations being" angularly disposed to the longitudinal axis of the bearing members and to the longitudinal axis of the cross bars, the serrations on alternate bearing members and the adjoining portions of. the cross bars running inone direction and continuing uninterruptedly from one member into the adjoining portions of the cross bars, while the serrations on the bearing members intermediate the alternate members and on the portions of the cross bars adjoining the intermediate members run in another direction.

HARRY S. NAGIN.