US1985143A - Precast concrete step - Google Patents

Description

Dec. 18, 1934. E BUFFALO}: 1,985,143

PRECAST CONCRETE STEP Filed March 50, 1953 Patented Dec. 18, 1934 7 Benjamin E." Buffaloe, assignor Memphis,"

I f"'hpplication March30, 1 elg,- g 565 :v

I 6 Claims, (cl qzlg lt This invention relates: to precast ,concrete steps designed for :out doorv use although not restricted to suchlocation. Steps .constructed' as set .;forth herein, because of the simplicity of the design andthe. economical advantages in'manufracture and use, are particularly adapted for use as ground floor steps for tenement houses,,factories'and rear steps for any priced home;

; 1 :Aswill appear from the detailed description of the invention a stair, or set of steps,is made up of two carriages or jacks cast from concrete and having the. usual treads and risersqiThe step elements-or treads are simple concrete-slabs laid on the tread surfaces .of the; carriages or-jacks and attachedthereto by means-of reinforcing rods projecting from theytread surfaces into ppenings inithe :step' elements, and. cemented or grouted; therein. j; v y

P15111118 carriages arejcast of concrete in a single piece of :an open center, triangular form The base of, the triangle frests upontheground Zor on a; suitable concretefoundation, the upright meme ber of the triangle supports the upperend of the 'thirdside which constitutes a stringer for supporting the steps-and is cast to providetread surfacesforslabs to rest on. T

Fora: stair of any selected number-of steps only two molds are necessary'in making, one for thejacks oncarriages, and one for thesteppr tread members-.- -.The treads-are therefore uniform and the-.carriagesmay be cast for any number of treads up to: about-ten above which number :the economic value practically ceases.

Referring; tov the, drawing; -;;w hich is made} a part of; this applicationiandin:,which,similar reference characters indicate similar parts:

F'ig..1 isga-view in perspective of a construction showing four steps,

Fig. 2 is a view of one of the carriages or jacks shown in perspective,

Fig. 3 is an end view of a set of steps as shown in Fig. 1, with a part broken away to the reinforcing rod which fastens the tread to the jack,

Fig. 4 is a perspective view of one of the steps or treads shown in inverted position and,

Fig. 5 is a detail view in section showing the method of attaching the treads to the jacks.

In the drawing the jacks or carriages indicated at 1 are of unitary or monolithic construction being cast of concrete in a suitable mold. These jacks comprise a base portion 2, a vertical portion 3 and an inclined portion 4, which portions define a central triangular opening. This open construction contributes to lessening weight as well as saving material when more than two openings" steps. are. involved. ma struetureas the number forcingmeans'maybe efmployed The steps, or

treadsarexshown 'at38 .and each has .a, recessed or depressed portiori'ongthe-bottom side asindicat ed. at;9,a Fig'. :4, whichgives-a strong andcompar; atively lightl construction. '-I,he, treads; are pro.- .vided withgfrustro-conicalf openings near ;their ends which. are suitably spaced to come; directly overthe tread portions 5 of. the jacks when -,the

treads 8 are placed thereon; in assembly. fI'hfiSe openin s 10, have. their-larger. ends upon the up per surface of the treadsxandrwhen thel treads are in place on the jacks the smaller ends ,ofrthe "will-be closed: by the tread; surfaces 51";

1'..,Referring.abate-me seat for sesame treadsl to, the stringers .4 fat :the carriag.es, 'refer- 'en'ceimay behadatofliigss 3 and Sin which the reinforcing rod. zorrstud ,11 his: shown attached to the, rod 2'7 as by: a"; half: 1 turn therearound. and wrapped with wirenas at:: l2'.? rod 1-1:.ex- :tends:-. upwards through. th'esztread surface}, 5 a distance less than the vthicknessiof a stepvS and has its; upper; endaben't. rover-,3 distorted 1 omens;

larged as shown atji' lz3. to'sformLa headrorene largement which is -embedded in cement. I. or grouting; 14 packed in the' opening. :10; in assembly. The small end of the frustro-conical opening is of sufiicient size to pass over the upper end 13 of the rods 11 and being larger than the rods 11 admits of adjustment of the step 8 endwise for alignment of the ends of the steps and also for adjustment with respect to the risers 6 to properly position the steps on the carriages. In placing the steps in position on the carriages a thin layer of cement 15 is spread on the tread surface 5, and on the riser surface 6 as high as the step 8 will extend. This layer of cement serves not only to attach the steps to the carriages but also to compensate for inaccuracies in the castings and insures continuous contact of the treads with'the entire tread surfaces 5.

In Fig. 1 the dash lines indicate that portion of the structure below ground level in out door construction. In this figure the portion 2 rests on a concrete base 16 which is poured in place after the carriages have been assembled in position on temporary blocks.

In assembling the structure described the carriages are placed in position in parallel or temporary blocks ,and the concrete bases poured underthe portions 2 'as indicated in Fig. 1-. This operation may be made very quickly by using quick setting cement in the concrete for,

the bases 16. The layers 15 of cementare then applied as indicated in Fig. 5. The slabs or treads 8 are next placed imposition with the ends 13 of rods 11 extending-into the openings}- 10. The treads may be properly aligned at their ends by adjustment permitted by reason of the difference in size of the openings 10 and the rods 11. g The treads may also be adjusted,

in position with respect tothe risers 6. The cement l5 ensures continuous contact between the treads 8 and the surfaces 5. When the treads are in position grouting or cement is packed in the openings 10 from the top and is leveled off even with the-upper surface of the tread providing a continuous cement tread surface, and securely locking the treads to the carriages through the rods 11 which rods also serve to reinforce the stringers 4. v w

The construction described'is simple in line, economical in manufacture and enduring in use. Only one mold is needed for the treads of a given desigmand' only one mold is necessary for the carriages for a selected number of steps. There are only two distinct elements necessary to be cast, the carriage which is used in duplicate and the treads or slab steps of which any desired number may be used. in setting up the steps, the operation is simple and can be rapidly performed. This involves merely setting "up the carriages, pouring the concretebases and putting the step treads'in position and filling the openings with cement.

What I claim'is: r 1. A stair composed of pre-ca'st concrete members, comprising a pair of carriages having reinforcing rods disposed therein with themfree ends of certain of said rods extending through the tread surfaces of said carriages and distortedto form a head Jportion thereon; a series of concrete steps having frustro-conical openings therein near their free ends to pass over the head portions of said rods whenlthe steps are placed in position on said tread "portions and a filling of concrete inisaid openingsto lockthe steps to the'ends of the rods.

2.'A stair composed of pre-cast concrete members, comprising'a pair of reinforced jacks having an open center and the usual treads and risers, a reinforcing rod disposed in the base, upright and inclined portions of each jack, a series of reinforcing studs attached to said rod and extending therefrom through the treads of said inclined portion of the jack, the free ends of said studs being distorted to form a head, a

series of steps disposed on -the said treads and having .openings therein? for v-reception. of the heads of said studs, and a concrete filling in said openings to lock the steps to the studs.

, 3. In a concrete stair construction a pre-cast carriage having a base portion, an upright portion anda n inclined portion provided with the usualtreads and risers, all cast in one piece with an open center, said inclined portion provided with reinforcing means comprising a reinforcing rod and a plurality of reinforcing studs attached thereto, said studs extending from said rod through the surfaces of the treads and distorted at their free ends.

4. In a concrete stair construction, a pair of pre-cast carriages, having the usual treads and risers, rods-With distorted ends fastened in said carriages and a series of steps of cast concrete having openings therein to cooperate with the rod ends and disposed on the treads of the carriages and a filling of ;concrete in said openings and surrounding the distorted ends of said rods and permanently attachingsaid steps to said a treads.

' 5. In a concrete stair constructiom'a pair of pre-cast carriages having the usual treads and risers, rods'with enlarged head portions cast in the tread portions of said carriages and a series of concrete steps having openings extending through the entire thickness of the step-near pre-cast carriages having the usual treads and risers, rods with enlarged head portions cast in the tread portions of said carriages-and a" series of concrete steps having openings extending through the entire thickness of the step near their free ends to pass over the head portions of said rods when the steps are placed in position on said tread portions and a filling of concrete in said openings to lock the steps to the head portions of the rods, said head portions extending into the step a'distance less than the thickness of the step.

,. r I BENJAMIN E. HBUFFALQE.

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