US 2577864 A
Description (OCR text may contain errors)
De. 11, 1951 J. w. THoRNToN ETAL STAIRS Sheets-Sheet l Filed Aug. 7, 1945 f o f/ f4 IBB- M1000 O O FIG. 2
RNW MOT NLN ENR Vmm w. .T DW. R
EN TH EO PJ ATTORNEY Dec. 11, :1951 J, w THORNTON r-:rAL 2,577,864
STAIRS 4 Sheets-Sheet 2 Filed Aug. '7. 1945 u.. ...w/ nl.
INVENTOR. PETER D. DONLON JOHN W. THORNTON ATTORNEY Dec. 11, 1951 1 W. THORNTON ETAL 2,577,864
STAIRS Filed Aug. 7, 1945 4 sheets-sheets INVENTOR. PETE R D. DONLON JOHN W. THORNTON AT TORNEY Dec. 1l, 1951 J, w, THORNTON ErAL 2,577,864
STAIRS Filed Aug. '7, 1945 4 Sheets-Sheet 4 FIG. 8
, NVENTOR. PETER D. DONLON JOHN W. THORNTON Mam/Mw ATTORNEY Patented Dec. 11, 195i STAIRS John W. Thornton, San Francisco, and Peter D. Donlon, Piedmont, Calif., assignors to Prefab Stairs .and Tile, Inc., a corporation of Cali- .ifernia Application August 7, 1945, Serial No. 609,400
This invention relates to improvements in the l I Iiemu.facturey `of stairs Aand particularly to a method which can be successfully utilized to provide a flight of stairs fabricated of separate ,units and made of concrete.
In dwellings and the like, straight rises of stairs are provided by cutting two or more stringers from heavy timbers, notching these to provide the outline of the stair treads and risers and placing these in position. Subsequently, risers and treads are secured in place. lf such stairs are exposed to weather, their life is relatively short and it is necessary to repair them at frequent intervals, for 4the stringers and the support members provided beneath the stringers rot away in a relatively few years. In accordance with the present invention, we have provided a successful method enabling stairs to be cast from concrete and faced as with tile or the like to provide a complete and a waterproof structure.-
The use of tile, bricks and the like for stairs is not, of course, new. However, these have heretofore only been employed in conjunction with wood supports, the usual practice being to build a wooden ramp and then to build the stairs up on this ramp. However, the weight of the tile o r brick presents a heavy load upon the wooden supports and, because the structure provided is not waterproof and cannot be made such, the life of the ramp is relatively short, particularly as compared to that of the tile.
In accordance with our invention, we precast a suitable stair form including the riser and tread facings.
When a turn is required in the stairs, some form of support is usualy improvised. Usually the final structure is a complicated maze of stringers and supports restricting the head room beneath the ,Stairs We have provided a novel stair structure in which precast concrete string.- ers, risers and treads are utilized. The stringersare supported from the side Walls and intermediate support columns -are not required. This is of great advantage for it ensures a maximum of head room under the stairs and at the same time shortening installation time and reducing the cost.
Another object of this invention is `to provide a novel stair Winder construction.
A11 additional object of the invention is to provide a, stair ,construction in Which precast units are employed and are-supported from the walls alone.
Further, it is an additional object of the present invention to provide a method of manufacture vfor a combination precast concrete stair in conjunction with a riser set of tiles and a tread set of tilesv or likel facing material'. y
Another lobject of the present invention -is to provide a novelprecast concrete stair structure. Referring@ the. .drawing eeeempenyipe end forming a part hereof, Figure 1 is a section through a suitable mold structure illustrating a mold and construction of the novel precast con crete stair structurey of .the present invention.
Figure 2 isa plan View of the mold structure illustrated in use in Figure 1.
Figure V3 1is a section illustrating thev lprecast .stairs supported on a .straight riser. l
Figure i is a plan view of `a stringerfinstallation.
Figure 5 isa View taken along the line ,ii-Bof Figure 4.
Figures 6 ,and 'l` ,are respectively views taken along the lines 6--6 and l-l of Figure 4, illustratins only the inside riser-Stringer about ,which the stair turn is made, Y
Figure 8 is a View, similar to Figure 4, 4ef .the completed stairs.
`Referring te the .drawing accompanyingand forming a vpart hereof. we rst provide a suitable meid inciudineside Wells lami .and epdwalls .9 and H. sidewalls l ands 4are spaced aparta distance sueiept to provide e .step of the. desired tread Width', well .l beine sherter 4than wall. ..8 to provide afell of .about Mi in each feet of tread width. The distance between the interedges of strips -tapiir. i .l eprresppridste the width 0f the. individuel .stair desired. ,A .betteln 1.2` is secured in position epd over a portieri Qi extends a cooperative .arcuate mold member i4. secured by nails ,I6 to one or more transverse supports I l. Along the inner face of strip l ,is mounted a short strip L8, the latter being posi.- tioned `directly upon bottom I2 to support the riser vfacing above the end of the riser. Member i4 is used to define the inside face of each stair; its ends ,26 and 25 each slope respectively toward the upper or outer edge of the mold so that, as will appear, mortar can be, placed between each stair and a supporting Stringer, Y f
To lend strength to the final structure, `suitab,le reinforcing elements such as structuralsteel reinforcing bars I9 are vpreferably positioned in the mold before the concrete Mis poured. One or more riser tiles, dependingupon the .depth Q.f themold..
such as that indicated at 2l, are positioned on strip I8. After this, a ,suitable concrete mixture is poured in the mold. and trowelled voff level with .edges l. 8,. 9 andy H.- As theeenerete eures. tread tiles indicated 'by numeral `22r are positioned directly .upen the ,GenerateV If desired, asheet metal Yiiashing plateale .is pesitioned over each meld endWe-ll agnelli .and beneath the edge 4of,
each border treadnle. The flashing is seemed to the adjacent. wallv structure which confinesl the sides of the stair (Figure .3) to complete-the' waterproofness .of the. structure and prevent water from leaking down alongside of each` of thestairs. ,Y
While. the precast-stairs described can be utilized on the ordinary and usual wood stringers, we prefer to err-rploy` these stair-s in r conjunction with the. novel, precast concrete stpingers which also iormfpart l.0f eur intention.
Referring particularly to Figures 4 and 5, we
wish to'point out that utilizationof precast, concrete stringers enables a simplified support structure to be utilized. Thus. as appears in Figures 4 and 5, it is only necessary to build a confining wall such as we have indicated generally at 4| and comprising sheathing 42 supported upon suitable studding or columns 43. The construction of the wall can be in any desired fashion usual in the art and as dictated by the needs and the details of the building under construction. In the construction illustrated in Figures 4 and 5` the stairway rises from the right-hand portion of 'Figure 4, making a full 180 turn, the rise continuing'on the left-hand portion of Figure 4, the stairway being confined by walls 6|, 62 and 63. To provide this, opposite Stringer pairs 46' and 41 are mounted on the opposite walls, Stringer 41 being suitably Supported by a plurality of clips 45 nailed to wall 6| while Stringer 46 is secured by like clips to a central column 48 about which the stair turn is made. The central column can be one member or can be fabricated of several; in any case, it is quite small and the turn about it is a tight one, requiring only a very small area as compared to that usually required. In reality, on a 180 turn column 48 is nothing more than a wall of minimum thickness, separating one stair run from another. Stringer 41 is continued by Stringers 49 and 50 secured to wall 62 on which they are also positioned by clips 45. Stringers 49 and 50 are preferably separate so that portion 5| of Stringer 5|) can overlap and extend along portion 52 of Stringer 49. In this way, minor adjustments in length to suit the length of the wall can be made.
The stair rise along the third wall 63 is'provided by Stringers 53, an oppositely positioned Stringer 54 on column 48 continuing the upward run of the stairs. The 180 turn about column 48 is effected by the novel Stringer structure illuStra-ted particularly in Figures 6 and '7 and indicated by numeral 1 I. This includes a first portion 12 continuing the rise of Stringer 46 along face 13 of column 48. A second portion 14 of the Stringer rests against face 18 of column 48,
" tioned end wall being in the same planes as the portion 14 being at 90 to portion 12 and including a plurality of angular-ly positioned seating surfaces 11, 18 and 18 thereon to support the inner edge of the several wedge-shaped stairs required to fit the turn and resting on Support faces 8|. 82 and 83 on Stringer 41 and Stringer 49. A third portion 62A of Stringer 1| fits against face 63A on column 48, this portion including seating surfaces 84. 85 and 86 for the remainder of the Stens on the turn. Beyond the turn, Stringer 54 and Stringer 53 provide for mounting of the further stairs vand risers.
The construction illustrated is designed for a 180 turn. from lStair |81 to stair |08, and made with six stairs IDI-|06, as appears in Figure 8. Those skilled in the art can readily adapt the structure to a turn of diierent extent and to accommodate a different number oi' rises in the' turn. The stairs utilized on the turn are basically like those Shown in construction in Figures 1-3, except that the molds are made of a suitable angularity to fit the angle of the tread. The Stringer 1| is preferably precast in one piece, suitable reinforcing being provided in the structure.
T0 facilitate assembly and securing of the precast steps in place. the forward corner of each riser and stair is relieved as at 9|. This permits mortar 92 to be inserted between the stair, the riser, and the Stringer as appears in Figure 3. In addition, the upward Slope on the inner face of the tread portion and the outward slope on rear face of the riser permits mortar to be inserted betwen these and the Stringer as at 96 and 81. Mortar iS also placed between the foot of the riser and the adjacent portion of the lower stair tread. as at 94.
With the stairs extended between risers secured only on the opposite sides of the confining walls, a maximum of head room is available. In some building designs this has enabled the overall height of the-building to be reduced as compared to that necessary when usual wood construction is employed.
1. A Stair construction comprising a iirst and a second Side wall in a spaced parallel vertical relationship; an end wall joining Said side walls and at substantially o to each of said side walls; an intermediate vertical column positioned substantially midway between and Substantially parallel to Said Side walls and in a spaced relation to Said end wall to provide a U-shaped Stair well; said intermediate column having a first column wall parallel to said iirst side wall, a second column wall parallel to said second side wall, and an end column Wall parallel to Said first mentioned end wall and joining said iirst and second column walls; a first stair Stringer extending upwardly and secured along said first side wall; a'second stair Stringer secured to said end wall andcontinuing said rst Stringer upwardly; a third Stair Stringer secured to said Second Side wall and continuing said second Stringer upwardly; a Stringer secured to said vertical column and consisting of a first portion extending upwardly along the rst column wall, a second portion extending along the end column wall and continuing Said rst portion upwardly, and a third portion extending along the second column wall and continuing the second portion upwardly, each Stringer being provided with spaced horizontal tread supports, the tread supports of the stringers on the Side walls and said iirst mencorresponding tread Supports of the column Stringer, and Stair treads extending between corresponding stair tread supports.
2. A stair construction, as in claim 1, wherein the column Stringer consists of pre-cast concrete.
JOHN W. THORNTON. PETER D. DONLON.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS y Number Name Date '705,794 Snider July 29, 1902 844,408 Schachner Feb. 19, 1907- 1,964,660 Buzby June 26, 1934 '2,330,148 Rogge Sept. 21, 1943 FOREIGN PATENTS l Number Country Date 31,163 France Sept. 7, 1926 124,457 Austria Apr. 15, 1931 162,398 Switzerland June 30, 1933 242,988 Great Britain Feb. 1l, 1926 463,389 France Feb. 20, 1914