US1789969A

US1789969A - Stair construction

Info

Publication number: US1789969A
Application number: US376340A
Authority: US
Inventors: William A Davis
Original assignee: BABCOCK DAVIS CORP
Current assignee: BABCOCK DAVIS CORP; BABCOCK-DAVIS Corp
Priority date: 1929-07-06
Filing date: 1929-07-06
Publication date: 1931-01-27
Anticipated expiration: 1948-01-27

Description

Jan. 27, 1931. w. DAVIS 1,789,969

sum cdnswnuc'rwn Filed July 6. 1929v rza Wi'bzeas T Patented Jan. 27, 1931 UNITED srn'rrs WILLIAM A. DAVIS, OF MALDEN, MASSACHUSETTS, ASSIGNOB TO BABCOCK-D'AV IS COR- 2 PORATION, OF BOSTON, MASSACHUSETTS, ACORIORATION OF MASSACHUSETTS STAIR CONSTRUCTION Application filed July 6, 1929. Serial No. 376,340.

The present invention relates to stair con-, struction, and more particularly to metallic stairs of the general form commonly employed in industrial institutions and public buildings.

of which will be obvious to'those skilled in the art from the following description.

In the accompanying drawings illustrating the preferred form of the invention, Fig. 1v represents a side elevation, partially diagrammatic, of a stair embodying the improved features of the'invention; Fig. 2 is a detail illustrating a section in elevation of my improved stair construction; and Fig. 3 is a section on the line 33, Fig. 2.

The stair shown in the illustrated embodiment of the invention comprises parallel stringer members 10 having upper and lower flanges 11 and 12, with the stringers mounted in such a manner that the lower'flanges are directed inwardly and toward one another to serve as a. support for the stair treads. The stringers are supported at the upper and lower ends in any conventional or desired manner.

Each tread and riser comprises essentially a sheet-metal member 14, having a tread portion 16 and a riser portion 18, with an outwardly turned nosing 20 at the upper end adapted to act as a reinforcement and support for the next adjacent tread. The individual stair member is rigidly connected at the junction of the tread and riser to the flange 12 by means of a bolt or similar connection 22. The outwardly projecting ledge formed by thenosing is also rigidly con nected to the next adjacent tread 16 through securing bolts 24. In addition, each tread member is rigidly connected to the face of the stringer at a point adjacent the upper end of the tread through the employment of a supporting angle 26, which may be welded to the treadportion 16 at 28. After the individual stair member has been assembled between the stringers, the angle is bolted rigidly to the face of the stringer by connections 30, all as indicated in Fig. 3. It-w'ill be evident that a securing angle is provided at opposite sides of each tread for connec tion to both stringer members, one only of a these angles being indicated in Fig. 3. By virtue of this construction not only are the individualstair elements rigidly connected together at the outerportion of the tread, but in addition each stair element is rigidly connected to the stringer members, both at the junction of the tread and riser and at points adjacent the outer end of the tread. After assembly of the metallic portion of the stair structure with the stringer members, the tread is conveniently filled to a level gauged by the height of the nosing 20 with a cementitious mixture 32, as indicated in Fig. 2, this mixture providing the necessary tread wearing surface covering the metal support.

With this construction it will be evident, furthermore, that the securing angles,due to their location in proximity to the faces of the stringers 10, leave a completely unobstructed and unbroken tread space for the reception of the cementitious mixture, and

permit the formation of a homogeneous mass of necessary depth which is not intersected by securing bolts or other similar constructions which might conceivably weaken and cause premature cracking and failure of the mixture forming the tread.

I claim:

A stairway comprising opposed stringer members, sheet metal stair elements each comprising a tread and riser interposed between the stringer members, an upwardly extended nosing at the front portlon of each tread, a cementitious mixture covering the tread to the approximate depth of the nosing, and supporting angles Welded to the upper face of each sheet metal tread element and at opposite sides of the tread element adjacent the front portion, and connections between the angles and stringers for rigidly supporting the tread elements therefrom, the supporting angles being embedded Within the cementitious mixture covering the sheet metal tread.

' WILLIAM A. DAVIS.