US2721472A - Stairway - Google Patents

Description

Oct. 25, 1955 w. J. MOAVER 2,721,472

STAIRWAY Filed March 22, 1952 INVENTOR. WALTER J. McAVER ATT'YS United States Patent STAIRWAY Walter James McAver, Chicago, Ill.

Application March 22, 1952, Serial No. 278,056

2 Claims. (Cl. 72-96) This invention relates to molded concrete stairways and is particularly directed to improvements in metal frames for stairway structures of the general type disclosed in my Patent No. 2,150,586 for Concrete Stair, issued March 14, 1939.

The main objects of this invention are to provide an improved form of skeleton frame structure adapted for prefabrication as a complete unit for use as a container and reinforcing structure for a molded concrete stairway; and to provide in such a structure improved means for simplifying the erection procedure and improved means for supporting reinforcing bars.

A specific embodiment of this invention is shown in the accompanying drawings in which:

Figure 1 is a fragmentary, perspective view of the skeleton frame for the improved concrete stairway.

Fig. 2 is a sectional detail taken on the line 22 of Fig. 1, showing how the bracket members connect the longitudinal and transverse reinforcing bars to the riser plates.

Fig. 3 is a fragmentary, longitudinal vertical section of the completed stairway with concrete filling in place, the section being taken on a vertical plane through the line 33 of Fig. 1.

Fig. 4 is a transverse section taken on a plane at right angles to the stringer members of a modified form of the invention for use in cases where the stairway is provided with concrete balustrades along its sides.

In the form shown in Figs. 1, 2 and 3, a pair of stringer bars of channel section are connected in parallel relation to each other by a series of riser face plates 11 disposed so as to stand vertically when the stringers are inclined parallel to the pitch line of the finished stairway for which they are intended. As shown in Figs. 2 and 3 the riser plates 11 are offset to form a nosing 12 and tread flange 13. The ends of the riser plates are Welded to the stringer bars.

Intermediate between the stringer bars 10, each riser plate 11 has attached thereto one or more depending bracket members 14 which support a system of reinforcing members. Each bracket 14 comprises a rod bent to an inverted V-shape, providing a straight middle portion 15 disposed vertically and welded to the riser with terminal arms 16 and 17 extending downward from its ends, the arm 16 having a hook 18 formed at its lower end to support a transverse reinforcing bar 19 and the arm 17 being directed rearward from the riser plate 11, approximately at right angles to the longitudinal reinforcing bars 20 which extend parallel to the stringers 10 and are spaced apart at equal intervals.

The ends of the bracket arms 17 are welded to the longitudinal reinforcing bars 20. The books 18 on the bracket arm 16 are welded to the transverse reinforcing bars 19, each longitudinal reinforcing bar 20 is also welded to each transverse reinforcing bar 19 at their intersections. Preferably there is a welded joint at every place where there is a metal-to-metal contact between elements of frame structure.

In the modified form shown in Fig. 4, the stringer bars 21 may be of angle section with an outwardly directed flange 22 along the upper edge thereof and with its vertical leg of sufiicient width to extend down to or below the tread surfaces 23 of the steps formed by the masses of concrete 24 in the final form as shown in Fig. 3.

In the form shown in Fig. 4, the reinforcing bars 20 are connected to the riser plates 13 by brackets 14 in the same manner as is indicated in Fig. 3; but the transverse reinforcing bars 25 differ from the bars 19 in having upstanding end portions 26 to connect and reinforce the balustrade.

For molding the concrete aggregate in the form shown in Fig. 3, it is only necessary to provide a temporary form member for the sofiit surface 27; whereas, in the form shown in Fig. 4, it is necessary to provide forms for the sides 28 in addition to the sofiit surface 27.

Although an illustrative structure has been specifically defined in the foregoing description, it will be understood that numerous details of the structure shown and described may be modified or omitted Without departing from the spirit of the invention as defined by the following claims.

I claim:

1. A stairway comprising a continuous unitary concrete body of stepped form reinforced by a pair of laterally spaced longitudinal stringer bars, riser plates extending between and having their ends attached respectively to said stringer bars, a series of longitudinal reinforcing rods laterally spaced at substantially uniform distances from said stringer bars and from each other below said riser plates and extending substantially from end to end of the stairway, a series of transverse reinforcing rods, and bracket arms attached to said riser plates, some of said arms being attached to respective said longitudinal rods and others being attached to respective said transverse rods.

2. A stairway comprising a continuous unitary concrete body of stepped form reinforced by a pair of laterally spaced longitudinal stringer bars, riser plates extending between and having their ends attached respectively to said stringer bars, a series of longitudinal reinforcing rods laterally spaced at substantially uniform distances from said stringer bars and from each other below said riser plates and extending substantially from end to end of the stairway, a series of transverse reinforcing rods, and bracket arms attached to said riser plates, some of said arms being attached to respective said longitudinal rods and others being attached to respective said transverse rods, certain of said bracket arms terminating in hooks embracing the respective rods.

References Cited in the file of this patent UNITED STATES PATENTS 760,752 Peterson May 24, 1904 932,679 Coleman Aug. 31, 1909 1,753,234 Cope Apr. 8, 1930 FOREIGN PATENTS 242,988 Great Britain Feb. 11, 1926

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