US3099336A

US3099336A - Prefabricated stair

Info

Publication number: US3099336A
Application number: US69094A
Authority: US
Inventors: Floyd L Hawkins
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-11-14
Filing date: 1960-11-14
Publication date: 1963-07-30
Anticipated expiration: 1980-07-30

Description

July 30, 1963 F. L. HAWKINS 3,099,336

PREFABRICATED STAIR Filed NOV. 14, 1960 2 Sheets-Sheet l INVENTOR. Flo yd L. Haw Kins 27 Httarney:

F. L. HAWKINS PEFABRICATED STAIR 2 Sheets-Sheet 2 July 30, 1963 Filed Nov. 14. 1960 ,daAA Httorneys United States Patent Ofiice 3,099,336 Patented July 30, 1963 3,099,336 PREFABRICATED STAIR Floyd L. Hawkins, Rte. 1, Box 103, Montevallo, Ala. Filed Nov. 14, 1960, Ser. No. 69,094 Claims. (Cl. 189-43) This invention relates to a stair and more particularly to a stair that comprises a plurality of independent connected step units.

Heretofore, independent step units have normally been secured to a common support, such as a stringer. This has required the use of considerable materials and resulted in a relatively heavy structure as well as being costly since stair constructions have been custom made heretofore. In some instances, treads and risers have been placed on fixed supports so that the steps and supporting structure could not be dismantled andtransferred to other locations.

The present invention comprises a stair which may be easily prefabricated and brought to the site of use, and thereafter, it may be dismantled and transferred to another location. It does not employ common connecting stringers fof the independent step units and only requires the use of a vertical support adjacent the upper step unit or platform of the stair. 'In some instances, the step units may be secured directly to a wall of a building structure without the use of a vertical support.

It is the object of the present invention to provide a prefabricated stair structure comprising a plurality of independent vertically staggered step units which are secured in overhanging relation to each other without the use of a common connecting stringer or the like extending between the separate step units.

A further object of the present invention is to provide a metal stair comprising a plurality of independent step units with each of the steps comprising a pair of spaced generally parallel channel members with a tread member extending between the upper surface of each pair of channel members to form a supporting surface, the tread distance between adjacent step units being adjustable to varying distances thereby allowing the stair to be adaptable for use under varying conditions. A single design of the stair will thereby satisfy several conditions of use, so that a special design is not required for each building construction.

Apparatus embodying features of my invention is shown in the accompanying drawings, forming a part of this application, in which:

FIG. 1 is a side elevational view of the prefabricated stair comprising independent step units and an upper landing supported by vertical supports;

FIG. 2 is a front elevational view of the stair construction shown in FIG. 1 showing each step comprising a pair of channel members connected by a tread and riser member;

FIG. 3 is a perspective view of a stringer of one of the step units and having a slanted rear end thereon; and,

FIG. 4 is a perspective view of a tread and riser member which forms the supporting surface on each of the step units and has embossments on the upper surface of the tread to provide a non-slip surface.

Referring now to the drawings for a better understanding of my invention I show a prefabricated metal stair indicated generally by the numeral and comprising a plurality of independent vertically staggered step units '11 leading to a landing 12. Landing 12 may be suitably positioned outside an entrance to a building or the like (not shown). Vertical supports 13 are secured to each side of landing 12 by a securing plate 14. The lower ends of supports 13 are embedded in concrete indicated by the letter C. Thus, the only support required for my prefabricated stair is the support for the upper step or landing 12. If desired, and the building is of a construction to support the stair, the stair may be fastened to the building without any vertical support.

Each of the step units 11 comprises a pair of stringers 16 in the form of channel members. As shown in FIG. 3, each stringer 16 comprises a web 18 with an upper inturned flange 19 and a lower inturned flange 2.1.

Flanges

19 and 21 extend in a horizontal direction and have a plurality of openings 22 extending therethrough. It is understood that members other than channel memibers could be employed, such as Z-shaped members, or plate and clip members. An inturned clip 20 having openings therethrough is positioned on the forward end of stringer 16.

A tread and riser member indicated generally by the numeral 23 is shown in FIG. 4 and extends between a a pair of stringers 16. Each tread and riser member comprises a tread 24, an upwardly extending riser 26, and a downwardly extending flange 2.7. Embossments 28 extend upwardly from tread 24 and form a non-skid surface for the users of stair 10. Openings 31 extend through each end of tread 24 so that the tread and riser member 23 may be secured to stringer 16 by suitable securing means indicated generally by the numeral 32 and comprising a bolt and nut arrangement.

The tread distance D (see FIG. 1) is the distance between the forward end of stringers 16 of one step unit and the forward end of stringers 16 of a superjacent step unit. Tread 24 extends forwardly of the forward end of stringers 16 to form an overlap or nose distance indicated by the letter N. Distance N is varied when tread distance D is varied. As an example, as shown in FIG. 1, if distance D is 10" then the overlap or nose distance N is /2 as the overall width of tread 24 is 10 /2. If the distance D were 8", the overlap N would be 2 /2. Thus, step units 11 may be adjusted relative to each other to vary tread distance D and thereby vary overlap distance N. This feature allows stair 19 to be adaptable for different spans.

Stringer 16 for step units 1.1 beneath landing 12 and the uppermost unit 11 have slanted rear ends indicated by numeral 35. The lower corner of rear end 35 is indicated by letter P and is positioned in direct vertical alignment with the forward ends 34 of the second superjacent step for the example above in which the maximum tread distance D of 10" is obtained. For tread distances under 10" the overlap of the superjacent steps would be even greater. Thus, the width of two stringers 16 is positioned beneath the width of each of treads 23-. Riser 2 6 may be secured by suitable securing means to clip members 20 by suitable securing means 30 (see FIG. 1).

Upper tread member 36 on landing 12 has a rear flange 37 thereon. Flange 3-7 may be secured directly to a building or joining structure and in some instances, the use of vertical supports may be elminated.

From the foregoing, it will be understood that I have provided a prefabricated stair comprising independent step units without the use of a common stringer or support The step units comprise a tread extending between a pair of stringers with each step unit superposed on a subjacent step unit. The independent step units may be moved horizontally relative to each other so that the tread distance and overlap or overhang of the tread may be varied. The step units are easily fabricated and may be erected in a minimum of time and without the use of any complicated tools. Further, the stair is light as there are no connecting members between each of the step units and since only a minimum of vertical support is required.

While I have shown my invention in but one form, it

will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modiflcations without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is:

1. A stair comprising a plurality of metal independent step units, each unit comprising a pair of channel shaped stringers spaced from each other and having horizontally extending flanges thereof contacting and overhanging horizontally extending flanges of the stringers of a subjacent unit, the overhanging flanges of the stringers having a plurality of vertically aligned openings therein whereby adjacent stringer-s may be adjusted relative to each other to vary the amount of overhang between adjacent stringers, and means passing through the aligned openings to secure the units together.

2. In a stair, a plurality of independent generally identical step units, each of said units comprising a pair of parallel spaced stringers of equal length, the stringers of each unit being supported on the rear portions of the upper horizontal surfaces of the stringers of a subjacent unit and overhanging said rear portions, a tread member extending between each pair of stringers on the contacting portions thereof, there being aligned openings in the stringers whereby the tread distance of the stair may be adjusted, and means passing through the openings to secure the units together.

3. A metal stair comprising a plurality of vertically staggered step units, each of said step units being substantially identical and comprising a pair of laterally spaced channel members having inturned facing horizontally extending flanges, a rear portion of the flanges on each channel member overhanging a rear portion of the flanges on the channel members of a subjacent unit, a tread member extending between and secured to the upper flanges of each pair of channel members on nonoverhanging portions thereof, said tread member being mounted for adjustment relative to the channel members, the overhanging flange portions having a plurality of vertically aligned openings therein whereby the tread distance between adjacent step units may be adjusted, and means to support the rear end of the uppermost step unit.

4-. The stair defined in claim 3 in which said tread member comprises a horizontal section with a flange on each side thereof and embossrnents on the upper surface thereof, the flange on one side extending in a direction opposite the flange on the other side.

5. In a stair, a plurality of vertically staggered independent generally identical step units, each of said units comprising a pair of parallel spaced stringers having upper and lower horizontally extending flanges, the stringers of each unit being disposed to contact the rear portions of the upper flanges of the stringers of a subja-cent unit and to overhang said upper flanges, a tread member extending between each pair of stringers on the contacting portions of the flanges, and means securing the flanges of contacting adjacent stringers to each other.

References (Iited in the file of this patent UNITED STATES PATENTS 2,593,683 Lyons Apr. 22, 1952

Claims

1. A STAIR COMPRISING A PLURALITY OF METAL INDEPENDENT STEP UNITS, EACH UNIT COMPRISING A PAIR OF CHANNEL SHAPED STRINGERS SPACED FROM EACH OTHER AND HAVING HORIZONTALLY EXTENDING FLANGES THEREOF CONTACTING AND OVERHANGING HORIZONTALLY EXTENDING FLANGES OF THE STRINGERS OF A SUBJACENT UNIT, THE OVERHANGING FLANGES OF THE STRINGERS HAVING A PLURLAITY OF VERTICALLY ALIGNED OPENINGS THEREIN WHEREBY ADJACENT STRINGERS MAY BE ADJUSTED RELATIVE TO EACH OTHER TO VARY THE AMOUNT OF OVERHANG BETWEEN ADJACENT STRINGERS, AND MEANS PASSING THROUGH THE ALIGNED OPENINGS TO SECURE THE UNITS TOGETHER.