US2470690A - Concrete step form - Google Patents

Description

May 17, 1949.

F. A. DAHLE CONCRETE STEP FORM Filed Sept. 23, 1946 Patented May 17, 1949 UNITED vS'I'A'IIEIS PATENT OFFICE "CONCRETE STEP FORM Frederick A. Dahle', Los Angeles, Calif.

Application September 23, 1946, Serial '310,698,765

(Cl. V.Z5-118) 8 Claims. 1

This invention is a form for the casting of ceh ment stairway steps, one at a time completely.

It is an `object of this invention to provide a simple, substantial, practical and low-cost casting orrn in the matrix of which there maybe thoroughly tamped a suitable Portland cement mix for the production of a single, Icomplete step unit for a iight of duplicate-steps in a proposed structure.

Also. an object of the invention is to `provide a step casting .form in which there is a 'combination of elements cooperative to provide 'the'necessary matrix 'chambers to giveto the cast step the desired limbs and tread, and to provide 'a form in which several ofthe combination elements `are adapted for ready adjustment 'as to eachother and as to a main core body for making steps having various length, tread and riser dimensions.

Further, .a purpose of the invention is Vto pro vide a compact andbodily portable steptorm, .and

whichincorporates matrix making features which can be readily manipulated to quickly release lthe cast and hardened, monolithic step as produced in the form.

The invention resides in -certainadvancements l in this art asset forth in the ensuing disclosure and having, `with `the above, additionalobjects and advantages as will be made manifest xin the `following `description of the herewith illustrative `form and its mode lof operation; it being undostood that modifications, variations and adaptations may be resorted to within the scope, spirit and principles of the invention as vit is claimed in conclusion hereof.

Figure 1 is a perspective of a monolithic step as produced by the form here set forth.

Figure 2 is a broken-away, sectional plan of the form.

Figure 3 is a detail, longitudinal Isection of abutted nose channels of the form.

Figure '4 is fa broken-away -front elevation o the form.

Figure 5 is a cross-sectionlon line 5-5,\oi 2. Figure 6 is a vertical section of the tread wing matrix parts.

lFor nomenclature it is desirable to rei-er to thei cast stepshown in Fig. 1 and which has atread T of desired thickness with a front nose FNand an 'end nose EN for nish effect, and the opposite lend `of the tread has a, vertical Wing W with forwardly vshown in cross-section in the form matrix (the step 'being v'castin the inverted position in the instant method); where it will be seen that the :front nose is considerably deeper than the thicknesslof the tread perse.

As clearly shown in Fig. 5, the form embodies a stimpreferably hollow, thin walled core -2 stably supported fon any suitable bench or platform B. The core has an elongate, flat and smooth top 3 onto Iwhich a batch .of plastic cement is poured to Aform the desired tread T whose iront, longitudi- :nal 'nose :is molded `in a .semicylindricaL elongate Iforwardly faced channel l which is removably clinched frmly .to the core top `as by a set-of clamps f5. The channel 4 ymay beof any suitable cross-section.

To form the end nose EN of the tread -a like, semicylindrical'transverse channel `extends forwardly from its .abutting junction, Fig. 3, with the backchannel 4 and has a flat, end sheet 'l which depends in front of the ffront or .riser wall .21' of the vcore which it vertically .abuts for the creation of a matrix pocket 8 in which to form the riser wing RW. The opposite side of this pocket 8 is yprovided by Way of -a vertical, transverse flange 9 which is a partei an adjustable means forming van elongate riser pocket I0 in front of the riser wall @Zrof the core.

This adjustable means consists of a frontal'wa-ll including a set of mutually overlapped plate sections yl l, t2 and L3 longitudinally, relatively adjustable -on clamp bolts I4 whereby to enable the 'casting of steps of different lengthsat will in this vform. As shown "in Figs. 4 Aand `5, the top edge )el Ithelsectional Wall (Il, i2, I3) projects above the .top lplane of the ferm top 3 to the llevel of the horizontal axes ofthe coplanar nose channels and'this `determines the thickness of the `tread plaster which :is compacted .and dressed by sweeping a transverse smoothing 'bar B longitudinally of the form; Fig.-5. Thislbar also pressesexcess plaster-out into the fixed nose -dening channels mentioned.

The depth of the riser pocket I0 is fixed by a vertically adjustable, .longitudinally disposed, spacing strip 1I 5 xedzat :the desired -level between the frontwall r2rof the -core and the riser panel or frontal iwall lH-l3; lFlugs. 'land 5. Likewise the-depth-of the Wingfpocket `8 is regulated by a lforwardly projecting spacing strip I6 abutting `'the positionedlstrip l5 fand xedbetween the "outer Asheet f1-fand to companion flange Fil of the panel 0r wall I I-I3.

To fix the front to rear length of the riser wing pocket 8 a vertical block or stud I1, Figs. 2 and 4,

is clamped between the outer ends of the sheet l and the flange 9, and extends up from the rim shaping face Ilia of the bottom strip I6 to the level of the top edge of the panel Wall II-I3, Fig. 4.

In this disclosure the set up form is provided with a matrix pocket 261, Figs. 4 and 5, to produce the tread Wing W on the right-hand end, and means are provided whereby to readily change the tread length and the riser height dimensions as desired for a given step to be cast, and at the same time maintain the end jointing faces J I and J2 always in parallel, one to the other. To that purpose a vertical wing wall 2| extends down from the top edge of the front panel Wall II-I3 to a plane below the bottom of the longitudinal strip I5, Fig. 4, and is spaced from the near end face of the core 2 by a pocket bottom forming spacer device composed of a pair of side lapped slides 22 and 23, Fig. 6. The slide 23 has a horn 23a. rigid with its upper end bridging the companion slide 22 and hinged at 23h, Fig. 5, to the bottom edge of the longitudinal nose channel 4; this horn defining the front joint face J I of the tread wing W, when plastic cement is poured into the pocket 20.

Likewise the lower end of the slide 22 has a horn 22a fixed thereon and bridging the cooperative slide 23 so as to define the back joint face J2, in casting the step. The horn 22a is hinged to the contiguous inner face of the spacer strip I5, Fig. 5. Therefore, as either or both of the tread and the riser widths are preset for a given step monolith the two slides 22-23 (determining the width of the pocket 20) can relatively longitudinally shift, on mutual guides 24, still keeping effective faces of their horns lparallel.

It is understood that either right-hand or lefthand steps (as to the wings W and RW) can be cast in this form by mere selection of right or left, hand elements; a right-hand set being here shown as assembled onto the core 2. The frontal corners of the core are suitably rabbeted at 2c to produce corner fillets F on the cast step.

In Figs. 4 and 6, is shown a cement stop lug Zia, on the upper rear corner of the wing panel 2|, matching the inner face of the nose channel Il; to terminate the relative end of the front nose of the step.

Any suitable and practical means may be employed for temporarily securing the various adjustable pocket forming parts as to the main core 2, and to each other. The nose channel 4 is held to the top of the core as by simple C-strap clamps, and the rear end of the transverse nose channel 6 has a hook 25 interlocking with the channel 4. A spring C-clamp 26 clinches the sheet 'I and the flange 9 onto the interposed spacer strip I6. Suitable spring, Cclamps 21 hold the front panel wall II-I3 to the strip I5 and to the front wall of the core 2. And one or more clamps 28 fix one end of the front wall section I3 to the near, ver tical, Wing Wall 2|.

What is claimed is:

1. A concrete step form having, in combination, a block-shaped core presenting a step tread top face and a riser face along one longitudinal side, and right and left end step Wing faces for molding a wing on either end of a proposed step a forwardly facing longitudinally extending nose` depth channel bodily shiftable on the said top face toward or from said riser and whose bottom 4 edge stands on said top face and means for fixedly holding the channel to the said top face, a step end nose channel coplanar with and normal to and abutting the concave side of the longitudinal channel and bodily shiftable on said top face and means for holding the end nose channel on said top face and to the longitudinal channel; a riser panel parallel to and spaced from the said riser face of the core, an elongate riser rim strip forming the bottom of the form space between the core and said panel; a tread wing form Wall spaced from an adjacent Wing face of the core and abutting the riser panel to close the riser form space and means for holding tread Wing Wall and said panel in adjusted position on the core, a wing rim form device forming the bottom of the space between the core and said wall; the said panel and said Wing wall extending to a desired height above the plane of the said core top and below the top edge of said channels to determine the thickness of the said tread and produce a nose deeper than the tread thickness.

2. The form of claim 1; and means at the opposite end of the tread panel and in front of the riser face of the core box for forming a mold pocket for a back turned riser wing.

3. The form of claim 1; the said riser panel being composed of relatively longitudinally adjustable plates for the casting of steps of dilferent length at will and the end nose channel being adjustable along the longitudinal channel complementally.

4. The form of claim 1; the said riser rim strip being adjustable between the core and said panel toward or from the core top face to produce risers of different heights.

5. The form of claim 1; the said rim device including longitudinally lapping relatively longitudinally adjustable slide sections which are respectively hinged to the top nose channel and to the said strip for concurrent compensating shift during change of tread and riser dimensions.

6. The form of claim 1; the two channels interabutting in a miter, concave joint to point up the intersecting step noses.

7. The form of claim 1; the said device having parallel, wing-facing horns xed on distal ends of a pair of cooperative, side lapping slide members, and the horns being respectively hinged to the top nose channel and to the said riser rim strip.

8. The form of claim l; said wing wall having a cement stop lug oifset to terminate the frontal nose of the step short of the step riser wing.

FREDERICK A. DAHLE.

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

UNITED STATES PATENTS Number Name Date 863,760 Schachner Aug. 20, 1907 875,113 Schachner Dec. 31, 1907 1,012,735 Smock Dec. 26, 1911 1,555,750 ODonnell Sept. 29, 1925 1,963,866 Peterson June 19, 1934 1,984,087 Scheel Dec. 11, 1934 2,155,908 Samonds Apr. 25, 1939 2,281,698 Kogl May 5, 1942 2,353,676 Kogl July 18, 1944

Images