US2994417A - Stair treads - Google Patents

Description

1961 H. NAGIN 2,994,417

STAIR TREADS Filed March 25, 1958 2 Sheets-Sheet 1 E'*i a Z I INVENTOR.

HAROLD NAGIN.

ATTORNEYS.

' Aug. 1, 1961 H. NAGIN 2,994,417

STAIR TREADS Filed March 25, 1958 2 Sheets-Sheet 2 INVENTOR.

HAROLD NAGIN.

ATTOR N EYS United States Patent 2,994,417 STAIR TREADS Harold Nagin, Pittsburgh, Pa., assignor to Reliance Steel Products Company, McKeesport, Pa., a corporation of Pennsylvania Filed Mar. 25, 1958, Ser. No. 723,712 4 Claims. (Cl. 189-43) This invention relates to stair treads and is for a metal stair tread of a type commonly used for industrial and commercial purposes.

Metal stair treads are made in varying sizes, depending upon the width of the stairway, and treads of the type to which this invention pertains commonly have the main area of the tread formed of metal grating with a nosing at the front that is generally impervious, and often of an abrasive or non-slip character. The construction heretofore generally employed has been such that the main bearing bars of the grating extend in an end-toend direction, with the less closely spaced cross or connecting bars extending crosswise. This construction is one that not only requires a great deal of welding and is therefore expensive, but it requires that the grating, generally made in large panels of standard size, be cut to the exact dimension of the tread. It so happens, however, that in the manufacture of grating there are often scrap ends and pieces resulting from the cutting down of the standard size panel to an exact length, or cutting out the good areas from a defective panel.

The present invention has for its principal object to provide a stair tread of an improved construction which can be more economically constructed, and which enables short scrap lengths of grating to be employed.

My invention may be more fully understood by reference to the accompanying drawings, in which:

FIG. 1 is a plan view of a stair tread embodying my invention, parts being broken away for clarity of illustration;

FIG. 2 is a transverse vertical section in the plane of line II-II of FIG. 1;

FIG. 3 is a view similar to FIG. 2 with a different nosing;

FIG. 4 is a view similar to FIG. 1 of slightly modified construction;

FIG. 5 is a transverse section in the plane of line VV of FIG. 4; and

FIGS. 6 and 7 are fragmentary sectional views in the same plane as FIG. 5, showing still other forms of nosings.

Referring first to FIG. 1, the tread is made with a main front section formed of light plate or heavy sheet metal, this plate being designated generally as 2, and it has a wide vertical front web or panel 3 to give it rigidity, and at the lower edge the panel has an inwardly or rearwardly-turned lip 4 at its bottom edge to also strengthen it. The top of the plate is bent inwardly to provide a horizontal nose portion 5, and it is turned downwardly at the rear of the nose portion to provide a second narrower vertical web 6. At the lower edge of the second vertical web is a rearwardly-turned flange 7 constituting a supporting ledge. This forms a strong, rigid main supporting member for the tread.

At each end of the vertical panel is welded the front end of a rearwardly-extending bar or plate 8 of rectangular section with its long direction vertical, the weld being indicated at 9. The top edges of these side plates or panels 8 are substantially flush with the top of the ledge 7.

The two side bars 8 are connected at their rear ends by a cross bar 10. As shown in FIGS. 1 and 2, the side bars and cross bars constitute an integral U-shaped member.

A piece or pieces of grating 11 are set on the ledge 7 and welded thereto, the wide or heater bars extending from front to back, the rear ends of the grating resting on and extending beyond the cross bar 10. This piece or these pieces of grating may be odd pieces of scrap cut to a uniform length in a fore-and-aft direction, and can be of odd Widths so long as they cover the tread space from side to side. For purposes of appearance, a strip 12 may be welded to the projecting rear ends of the bars 11' of the grating.

The top of the grating is above the top of the nose 5, and a nosing strip 13 is welded, bolted, or formed from resin and abrasive in situ on the part 5 so that the top of the nosing strip .13 is flush with the top surface of the grating. This nosing can be replaced from time to time if necessary. In FIG. 2 the nosing is indicated as being of a plastic nature with abrasive granules therein.

In FIG. 3 the nosing designated 14 is indicated to be of channeled cast metal. Also the tread in this figure is of lighter construction and the front panel is less deep, with the flange 4 being omitted, and the bottom of the side pieces 8 and back cross piece 9 are flush with the bottom of the front panel.

In FIG. 4 the main front piece is of the same construction as that shown in either of the preceding figures, it being shown to be like FIG. 2, and corresponding reference numerals have been used. However, in this case the side plates 15, corresponding to 8 in the previous figures, are wider and have their top edges extend above the level of the nose 5 of the member 2 so as to be flush with the grating designated 16. These plates are also longer than those shown in FIGS. 1, 2 and 3, being long enough to extend beyond the ends of the grating bars 16'. A cross piece 17 with an inwardly-turned ledge 18 connects the rear ends of these two plates, with the ledge 18 providing a support for the rear ends of the grating bars. The top edge of the cross piece 17 extends above the top of the grating, making a projecting edge or guard.

The nosing .19 in this figure may be of any suitable type or like any of those shown or described. It is here shown the same as in FIG. 2, but with openings in the top portion 5 into which the resin-abrasive material is keyed.

FIG. 6 shows a corrugated cast metal nosing 20 welded in place by metal in holes 21 in the portion 5. FIG. 7 shows a metal nosing strip 22 with a knurled top surface bolted to the nose 5 by threaded studs 23.

It will be understood that I have shown different nosings only for purposes of illustration, and a wide variety of arrangements such as those shown may be used, it being desirable, however, that the surface 5 be lower than the top of the grating, and that the nosing strip be thick enough to be level with the top of the grating.

While the grating sections 16 in FIGS. 4 and 5 are lightly tack-welded in place, actually they would be retained in place by merely setting them on the ledges 7 and 18, and they would be confined by the side plates 15 from displacement at the ends of the tread.

I claim:

1. A stair tread comprising a main tread member consisting of a panel of grating having intersecting cross bars and bearing bars with the top edges of both sets of bars being in a common plane and the bottom edges of the bearing bars extending below the level of the bottom edges of the cross bars, the cross bars extending in the direction of the length of the stair tread and the bearing bars extending crosswise of the tread from the front to the rear, a vertical panel of the full length of the stair tread forming the front of the stair tread, said panel having a top horizontal portion turned inwardly toward the grating at a level below the top of the grating, said top portion having a turned-down flange confronting the ends of the bearer bars of the grating, said flange having a ledge at the bottom under the front ends of the bearer bars of the grating for supporting the grating panel, end plates attached to the vertical panel extending rearwardly from the panel at the ends of the grating, a cross support connecting the two end plates and providing a support under the rear ends of the bearing bars of the grating, and a nose piece secured to the top of said horizontal portion of the vertical panel having its top surface level with the top of the grating.

2. A stair tread as defined in claim 1 wherein the end plates have their top edge portions confronting the ends of the cross bars of the grating and forming an end framing at each end of the grating panel parallel with the bearing bars, the cross support connecting the end panels having a vertical web against which the rear ends of the bearing bars terminate and having a horizontal ledge on which the rear ends of the bearer bars are supported.

3. A frame structure to be used with a panel of grating to form a stair tread, said frame comprising a vertical front panel of the overall length of the stair tread and of greater depth than the grating with which it is to be combined, said panel having at the top thereof a rearwardly-extending horizontal portion, the rear edge of the horizontal portion being turned downwardly, the turned-down portion having a rearwardly-extending ledge at the bottom thereof for supporting a panel of grating, a rearwardly-extending end plate at each end of the vertical panel rigidly attached thereto, a cross piece rearwardly of the front panel rigidly connecting the two end plates,

4 said cross piece having a grating supporting area at the same level as said ledge whereby a panel of grating may be placed on said ledge and on the supporting area of the cross piece and secured thereto to provide a horizontal tread surface.

4. A frame structure to be used with a panel of grating to form a stair tread as defined to in claim 8 wherein the side plates have their top edges extending above the level of said horizontal portion of the front panel, the cross piece connecting the end plates comprising a vertical strip against which the rear of a panel of grating may be confined, the grating supporting area of the cross piece comprising a forwardly-extending flange at the lower edge of said strip, said horizontal portion of the front panel being below the top edges of the end plates so that a nose piece may be placed thereon and secured thereto with the top of the nose piece in the plane of the top edges of the end plates and flush with the top of a grating which the frame is designed to receive and support.

References Cited in the tile of this patent UNITED STATES PATENTS 1,134,032 Clarke Mar. 30, 1915 1,557,287 Hughes Oct. 13, 1925 1,655,769 Lerner Jan. 10, 1928 2,006,929 Nagin July 2, 1935 2,572,432 Bates Oct. 23, 1951 FOREIGN PATENTS 361,649 Great Britain 1931

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