US2615325A - Precast sectional concrete stairs - Google Patents

Description

Oct. 28, 1952 D. s. SEEBER 5 PRECAST SECTIONAL CONCRETE STAIRS Filed Aug. 6, 1948 INVENTOR. Ba. 12 SS eeber- Patented. Oct. 28, 1952 v 31.7.:

UNITED 9 2,615,325 i '7 PRECAST SECTIQ-NAL ooNoeE'rE "Dales. SeebemHillsboro, Oreg. N Applicationdugiust 6, 194,8, Serial No. 42,359;

401mm. (cheat-9 6) l I My invention pertains to precast sectional concrete structures, and relatespai icularly to'conf crete stairs constructed of precast sections which are joined detachably for ready assembly and dis assembly. I I l It is a principal object of my invention to provide concrete stairs formed of sections which are precast in molds at a. factory for subsequent assembly at the site of installation.

Another object is the provision of novel means STAIRS These dowels serve also to join the base plates for joining together recast concrete sections de invention will appear from the following detailed description taken in connection with the accompanying drawing in which:

Fig. 1 is a perspective view 'of a stairs constructed of precast'concrete sections embodying my invention, and showing in dotted outline meansby which said sections are joined together; Fig. 2 is a side elevation of the stairs shown in Fig. 1 and illustrating in dotted outline am'odifled form of means for joining the"precast sec tions together; I

Fig. 3 is a fragmentaryelevation'ofthe'strucf ture shown in Fig. 2 as 'viewe'din the'direction of arrow 3; and 'f Fig. 4 is a fragmentary se'ctionalview of 'the step sections embodying myinvention'and showing a further modificationof means for joining 'said'sections together. r I f In the stair construction embodying my invention plates l and 2 form a base'upon which' the sidewalls 3 and the lowermostof the :step units 4 are detachably mounted. Although I'h'aveshown plates 2 as being of narrow'slab' constructioriand arranged'individually under each ofthesidewall's 3, it is understood that a'plate having thesame lateral dimension as plate [may be used."- In fact, a single base plate may be used to advantage in some constructions in place'of the plural plates ii I and 2. A recess is formed in the base-plate! and extends laterally thereacross a distance equal to the length of a step unit 4. Said recess is triangular in cross section and functions to secure the lower step unit in position, as is more fully explained hereinafter. I. v

The sidewalls 3 are mountedin spaced relation upon the base'plates l and "2. As'shown in the drawing, the sidewalls are of trapezoidal'shapc, the-shorter of thetwo parallel sides being providedfor mountinga platform' i adjacent the uppermost step 4. In the-event that said platform is not desired, the sidewalls may be of triangular shape. In either case a sloping edge is provided for mounting the step units position. The sidewalls may be secured detachably to the base plates 1 and- 2'by-means of doweljs 6, (as is illustrated in Fig- 2) which are imbedded in the sidewalls and project from the lower edge thereof into .wells formed in the base plates.

together inab'utting relationshipf i I g Each'of the step units 4, which includes the riser portion f! of 'each step, is substantially trapezoidal in profile. The sloping edgeof the stepunit rests upon the sloping edge of the side"- walls 3, thereby forming a horizontal-stepping surface 8 which is parallel withthe base plates land 2. Y W The platform'5, if provided, preferably isof the same thickness-as the-thinner end of the step unit against which it abuts. Th e stepping surface 8 of the step and the upper surface-of the platform thus lie in a common plane to form an upper landing onthe stairs." we

i A portion of the riser adjacent the sloping-side of the stepis cutaway longitudinally to form a squared notch. 'On the step units above'the' lowermost step,=this notch overlaps therear edge of the step immediately below it, and the portion of the unit adjacent the notch serves as a key'by which the step units are held releasably in assem bled condition. Onthebottom step the key por'-' tion adjacent the notch is received in the triangular recess formed in the base plate I.

It is to be noted that the floor of the recess forming the hypotenuse of the triangle is an extension of the-upper face of sloping'edge of the sidewalls 3. In this manner the-lower step-rests agains the sloping edge of the recess and the side- 1 walls and is detachably locked-to the-base plate whereby it-is prevented from being displaced laterally or; longitudinally therefrom. -Althougli the-step units arranged above the lowermost step cannot move longitudinally with respect to the sidewalls- 3, they may, if not restrained, be displaced laterally thereof. I prevent this lateral displacement by any of the various means illustrated in-the drawing and now to be described.

Referring to Fig. 1 of 'the drawing, the base plate l,'the step units! and the platform 5 are provided with holes which aline vvith each other when-the'sectionsare arranged together to form the-stairs, A'length'of wire 9 i s passed through said alined-holes during assembly of thesections andis-there'after joined at its ends to form a closed loop. Wire"9' maybe formed integral with base'pla'te; I. as shown in Fig. -1, or may be threadedtherethro igh; as above described; a1 thoughthelatter procedure would, of course, 'require the preformed hole in base plate I to be rounded to facilitate easeof assembly. Y A groove ljlis formed longitudinally in the rear edge ofth'e platfor n to receive the 'wire therein and conceal itfrom view. The rea-r edge ofthe platform thus presents a flat surface forfabutment' against structures onwhich the stairs'areto be'installed; The modi ficationillustrated in Fig. 4 "of the drawing difiers from the'construction shown in 1- only in the provisionof elongated tubes; in place "of the holesformed the concrete' r tions during the casting operation, and thus form v A an integral part of each unit. 'In addition to providing the necessary aperture through which the wire may be threaded, the tubes enhance the structural strength of the sections in which they are secured. Spike-like extensions Ila are inserted in one end of each of the tubes and slidabl engage the bore of adjacent tubes. 1

In the modification illustrated in Figs. 2 and 3, the step units 4 are provided with dowels 92 which extend parallel with the sloping side of the former and project outwardly from the squared notch. These dowels are received in wells formed diagonally in the rear corners of the step units and in the base plate [adjacent the triangular recess. As eachstep unit is slid downwardly, along the sloping edges of the sidewalls 3, the dowels, ['2

enter the complementary wells provided, and the units thus become locked detachably .in assembled arrangement. U-shaped dowels I3 embedded adjacent each end of the platform 5 pro-, ject into cooperating wells formed inthe upper shorter edges of the sidewalls for-securing th platform removably thereon;

Although the sections comprising the stairs of my invention may be constructed of various ma-. terials, I prefer to cast them of reinforced concrete in molds of desired shape; The preformed sections. may thereafter be shipped to the site where installation is to be made, and assembled in the manner described hereinbefore.

I claim:

1. A stairway constructed of preformed sec;

tions comprising a flat base having spaced wells open to theupper surface thereof, spacedsidewalls mounted .detachably on-v said base and having protruding dowels resting onein each of said wells, said sidewalls having complementary surfaces comprisingflat tops andslopingedges, a recess extending laterally in said base. andopen to said upper surface thereof, one side of said recess forming an extension of thesloping edges of said sidewalls, a plurality of abutting step units each having a riser,- a stepping surface and a slop ing side, said slopingside resting upon thesloping edges of said sidewalls, a portion of said riser being cut away longitudinally adjacent said sloping side forming. a notch with the reariwall of said notch acting as a depending key, the key of the bottom step engaging the recess in; the base, the key of intermediate stepsabutting-against adjacent steps along the side opposite said riser, a platform member resting on said sidewall flat top and abutting the topmoststep to form a level surface therewith, and means between abutting sections detachably securingthe latter together.

2. A stair constructed of precast sections com,- prising a base, spaced sidewalls mounted detachably on and abutting said base, saidv sidewalls having complementary sloping sides, a recess extending laterally in said base, a plurality of abutting steps units each having a riser, a stepping surface and a sloping side, said sloping side resting upon the sloping edges of said sidewalls, a portion of said riser being cut away longitudinally adjacent said sloping side to form a notch with the rear wall of said notch acting as a depending key, each such key extending the full width of one step unit, the key of the bottom stepengaging the recess in the base, the key of other units abutting against adjacent units along the side opposite said riser, a platform member abutting base, step and platform sections having hollow tubes therein alined with each other, and spikelike connecting means extending through each abutting'pair of 'said hollow tubes and releasably securing said precast sections together.

3. A stair constructed of precast sections comprising a base, spaced sidewalls mounted on said base,'said sidewalls having complementary surfaces comprising flat tops and sloping edges, a recess extending laterally in said base, a plurality of step units each having a riser, a stepping surface and a sloping side, said sloping side resting upon the sloping edges of said sidewalls, a portion of said riser being cutaway longitudinally adjacentsaid sloping side to form a notch with the rear wall of said notch acting as a depending key, the key of the bottom step engaging the recess in the base, the key of intermediate units abutting against adjacent units along the side opposite said riser, a platform member resting on said sidewall flat top and abutting the topmost step to form a level surface therewith, said base, platform, and step sectionshaving passages therein alined with each other, the back of said platform member having an open-faced longitudinal groove therein, a flexible connecting means extending along said platform member groove and through said alined passages and joined at its ends to form a closed loop releasably securing said sections together, and pin means detachably securing said sidewall and base to complete 1 the joinder of all elements into an integral stair structure.

4. A stair constructed of precast concrete-sections comprisinga base section, spaced sidewall sections mounted detachably upon and abutting said base, said sidewalls, having complementary sloping edges, a recess extending laterally in said base, a plurality of abutting step sections each having a riser, a stepping surface and a sloping side, said slopingside resting upon the sloping edges of said sidewalls, a portion of said riser being cut away longitudinally adjacent said sloping side to form a notch with the rear Wall of saidnotch acting as a depending key, the key of the bottom step engaging and abutting the recess in the base, .the key of intermediate steps abutting against adjacent steps alongtheside opposite said riser; a platform section resting uponand' abutting said sidewalls and abutting the top step, and pin means between said abutting base and sidewall, between said abutting bottom step and base, between said abutting platform and sidewalls, and between said abuttingsteps detachably securing the same together as a structural unit. 1

- DALE S. SEEBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

Images