US2592578A - Concrete step form - Google Patents

Description

April 15, 1952 KOGL 2,592,578

CONCRETE STEP FORM Filed April 28, 1947 7 Sheets-Sheet 1 FIE l gwvexwtoa FRANK KOGL 5- April 15, 1952 F. KOGL CONCRETE STEP FORM 7 Sheets-Sheet 2 Filed April 28, 1947 FRANK KOGL mwww April 15, 1952 F. KOGL CONCRETE STEP FORM 7 Sheets-Sheet 3 Filed April 28, 1947 z 5 7 0 W v m 2H,. 4 9 I 4 a; H A a I u a 4 u o n n m 4 5 6 w o u n i m. L2 T4 2 m n A 4.. L (m a 8 ml: 9 w a GI 6 FRANK KOGL A ril 15, 1952 F. KOGL CONCRETE STEP FORM 7 Sheets-Sheet 4 Filed April 28, 1947 ZM/ 3 K M/ ma Q m April 15, 1952 F. KOGL 2,592,578

' CONCRETE STEP FORM Filed April 28, 1947 7 Sheets-Sheet 5 PIE 5 FRANK KOGL April 15, 1952 F. KOGL CONCRETE STEP FORM 7 Sheets-Sheet 6 Filed April 28, 1947 FRANK KOGL April 15, 1952 F. KOGL 2,592,578

CONCRETE STEP FORM Filed April 28, 1947 7 Sheets-Sheet '7 FIE 1E 63 gwue/wbo n FRANK KOGL MZLM+ A Q Patented Apr. 15, 1952 CONCRETE STEP FORM.

Frank Kogl, St. Paul, Minn., assignor of two and one-half per cent to Walter H. Carlson, tw'oand one-half per cent to Ora E; Carlson, West St. Paul, four per cent to Minnie M. Clark, four per cent to Genevieve Clark, South St. Paul, Minn.-, andten per cent'to Richard L. and Ruby S.- McBridev Flynn, Superior, Wis.

Application April 28, 1947, Serial No. 744,430

7.Claims. (Cl. 25.1'18.) 1

This invention relates to. improvements in forms for precastingmonolithic concrete 1 step structures.

The primary. object isto provide an improved form for this purpose which will permit con crete stairs or steps to be rapidly poured and cast as a unit and which formmay be readily used to cast different numbers of steps'or even several castings at a time. A further object is to provide a form which may be easily set upfor receiving the concrete and thenv taken down to remove the cast steps. Still a further object is to provideheating meansfor quickly and effectively curing the concrete to speed up the operation of the form. Another object is to provide a form which is designed to. cast a predetermined number of steps but which may be partially removed when a number of step structures having fewer steps are to be cast, or which.alternatively may be used without such disassembly to castfewer steps when only a few such.

structures are required. Another object is to provide a form which will make an improved product, easily handled, with provisions for.

lighting andheating and otherxadvantages as will presently appear.

These and other more: detailed and specificobjects will be disclosed in the course of the following specification, reference being had to the accompanying drawings, in which- Fig. 1 is a side view of the form in casting position, mounted upon a supporting frame or fixture and illustrating one manner in which the number of steps cast in the' f'orm maybe reduced.

Fig. 2 is an elevational. and sectional view taken substantially along the line 2-2 in Fig.1.

Fig. 3 is a vertical sectional view of the form in Fig. 1.

Fig. 4 is .a side elevation of the form supported ona skid in position for stripping it from a cast structure and showing this operation .in process.

Fig- 5 isa fragmentary sectional View of. the

. upper part: of l the form, inthis caseused for theiupper'part of. the form showing a different manner of cutting or stopping off the formto reduce the number ofsteps. cast therein.

Fig. 9 is an enlarged fragmentary detail sectional view of apart of the form ass'een in Fig. 8.

Fig. 10 is a sectional view along the line l0l0 in Fig.9..

Fig. his a detail in elevation of one'of the removable cover or side plates, notched foruse in the form of Figs. 8 to 10.

Fig.12 is a vertical section illustrating still another use of the form.

This application discloses a form which is an improvement over :my prior Patents No. 2,161,822 issuedJunel'Bth, 1939; No. 2,281,698 issued May 5th, 1942; No. 2,331,701, issued October 12th. 1943, and No. 2,353,676 issued July 18th, 1944, and is in several respects quite similar to the form of the latter patent. The present form further is used in accordance with the casting methods taught. in my Patent. No. 2,289,439. issued July 14th, 1942. I

Referring now more particularly and by refer,- ence characters to the drawing, the form'constituting my present invention comprises basically an outer form indicated generally at A and an inner form indicated generally at B which is positioned within and spaced from the outer form to provide a casting cavity shaped and adapted to form a plurality of steps and sides therefor. In the present case the form'is made to cast a seriesof four steps having treads C and risers D and with a rearward extension of the, uppermost step forming a platform'E. In the. finished cast structure there will also be formed sides as indicated at F which extend downwardly from the platformv and steps so that the casting has an open bottom and back but theis otherwise completely hollow therewithin closed. The cast structure is thus substantially identical to that formed by the mold in my Patent No. 2,353,676.

The: outer form A comprises one piece side These members, I5 to [8, are all identical in construction and each comprises a riser forming plate I9 and a tread forming plate which, where they join, are forwardly bulged as indicated at 2| to form a nosing along the forward edges of the steps. It will be noted that the contiguous portions of the side panels ID are similarly formed as indicated at 22 so that this nosing extends also the full width of the treads C. The lowermost step forming member |5 has an angle iron 23 extending along its lower edge and corresponding in function to the angle irons l2 upon the side panels. This member I5 then extends not quite to the junction of the lowermost tread C with the next riser and this edge is also provided with an angle iron 24 adapted to fit against a similar angle iron 25 upon the forwardly turned edge portion 26 of the next step forming member IS. The upstanding webs of the angle irons 24 and 25 are secured together in any suitable manner such as by means of the bolts 21 and in a similar manner the step forming members l6, l1 and [8 are all joined together along corresponding edges and by corresponding parts as seen in Figs. 1 and 4. Thus, while all of the step forming members |5 to l8 are normally secured together as a unit, they may be each separated from the other whenever desired. The uppermost member I8 also has an angle iron 28 along its rear edge which fits against a similar iron 29 secured to a platform plate indicated at 30. These parts are connected by bolts 3| so that the plate 30 forms a rearward continuation of the upper step form to define the outer or upper surface of the aforesaid platform E. Preferably, the platform plate 30 is also divided into sections as clearly shown in Fig. 4 joined by angle irons 32 and bolts 33 so that a half or short platform may be cast when desired.

To hold the assembled step forming members I! to |8 in place on the outer form, I provide them at the ends of their vertical riser forming plates IS with fastening bars 34 which fit against the outwardly turned webs of short angle iron bars 36 welded to the adjacent vertical and forward edges of the side panels Ill. These bars are apertured to receive bolts 36 as seen in Fig. 1 which will anchor these parts of the form together. The horizontal tread plates 20 are also provided with end bars 31, which project far enough to clear the nosing forming bulges 22,

and which are notched as indicated at 38 for en" gagement by wing nuts 39 upon clamp bolts 40. These clamp bolts 40 are pivoted at 4| upon the side panels l0 and in normal position they extend upward so that when the wing nuts 39 are tightened the step forms will be pulled tightly to place. The end bars 38 are also apertured as indicated at 42 to fit d wnwardly over pilot or locating pins 43 welded to the side plates to fur ther anchor the step forms in place. The platform plate 30 is also anchored in place by the same means including the end bars 38 and the hinged clamp bolts 40 having wing nuts 38.

The inner form B also has side panels 44 with stiffening bars 45 and 43 around its lower and rear edges, but in this case the transverse portions of the form comprising the tread forming plates 41, riser forming plates 48 and platform plates 49, are all welded or otherwise rigidly secured to the side panels. Thus, the inner form is effectively a one piece affair and it is, of course, so shaped and sized that, when inserted into the outer form with lower and rear edges aligned, there will be formed a casting space which not only is shaped to mold the desired component parts of the monolithic stair structure, but is of the desired width at all points to provide adequate strength. It will further be understood, as has been pointed out in my previous patents, that this inner form will have a slight taper or draw so that it may be readily withdrawn from the cast structure after the casting operation is completed.

In the casting position the assembled form is supported in an erect position upon its forward end as seen in Figs. 1, 2 and 3 so that the open rear end of the casting cavity between the inner and outer forms is turned uppermost. To support the form in such position, I provide a frame or fixture indicated generally at G having a base 50 from opposite ends of which are erected irregularly shaped end frames 5! across which are secured a plurality of horizontal supports 52 and vertical supports 58. These supports 52 and 53 may be lumber of a common dimension and are adapted, respectively, to engage the now downwardly turned riser forming plates Hi and the vertically turned tread forming plates 20. The supports 52-53, may, of course, be recessed whenever necessary to clear bolts and other projecting parts. The supports 52, of course, thus support the weight of the form, and to hold the form in place I provide draw bolts 54 which are adapted at one end to be fitted to brackets 55 upon the side panels l0 and at their other ends are placed through brackets 56 extending from the vertical supports 53. When these draw bolts 54 are drawn up tight, they will obviously securely anchor the form to the fixture G. The two uppermost vertical supports 53 engage and support the sectional platform plate 30 as clearly shown.

In casting position the normally lower edge of the form is positioned vertically and this edge is closed by a U-shaped cover plate indicated generally at 51, the width of which is sufficient to overlap the inner and outer angle irons l2 and the corresponding angle irons 23 and 58 upon the inner and outer forms. The plate 51 has a plurality of openings to pass pilot or locating pins 59 extending from the angle irons and the plate is held to the angle irons at a plurality of points by means of clips indicated generally'at G6 which may be drawn tight and hooked over the edges of the plate and irons. These clips and their uses are described in greater detail in my Patent No. 2,353,676 and will not be further described herein. Ordinarily, the plate 57 will extend to the top of the form in its casting position but the plate is made in sections along its vertical portions as seen in Fig. 2 so that it may be applied to the form to any desired level for purposes presently to appear.

To hold the forms in their assembled position and support the inner form in properly spaced relation to the outer, I provide hanger bars 6| which extend across the top of the form in its casting position and which are bolted to the angle irons l3 on the outer form and to corresponding angle irons 62 upon the inner form. When so mounted, these hanger bars 6| will obviously largely support the weight of the inner form but I also provide the bars with cranked, threaded studs 63 which are threaded downwardly through the ends of the bars in position to engage the outermost form. Thus, as has been pointed out in my prior patent just referred to, it is possible by removing the bolts connecting the cross bars to the outer form to elevate the inner form merely by turning the studs 63 downwardly so that they bear downwardly on .the outer form. This is oi. advantagein breaking the inner'form loose from the cast structure when the form is stripped from. thecasting as will later appear,

In the" use of the form as thus far described, it

willbeapparent that the. casting cavity, may be.

The .vibration imparted to the-mold by operation.

of the vibratoris very effective in causing the material to properly settle and distribute itself and in theuformation of a. dense,- smooth surface in casting. When the mold has been filled, it must,.of course, be left in position untilthe casting cures. to a point permitting the mold. to be removed without breakage and to speed up this curing operation, which obviously controls the time between casting operations, I provide in the'fixture G heating means in the form either of a steam coil or helix, 68 or electric lamps 69, or both. Thus, as soon as the casting has been completed, a canvas or the like may be thrown over the entire form and the heat provided by the element 68 or 69 will materially advance and. speed up the curing cycle. Another steam coil 68 may be placed in theform as seen in Fig. 2 upon a fitting 68 When ready, the entire form is lifted from the fixture G and for this purpose I provide, asin my earlier patents, a bail indicated generally at 10, whichis pivotally attached at H to opposite sides of the outer form. The pins 1| forming this pivot connection are adjus -ably mounted in angularly extending guideways 12 secured to the side panels Ill. and by proper adjustment thepivot axis may! be so located with the respectxto the center of gravity of the form that it will be nicely balanced.- in the bail 10. The entire inner form B may be pulled as aunit from the inside of the casting after the clips 60 are removed in an upward direction while the form is still supported in the fixture G and to then hold the casting in.

place in the outer form cross bars (not shown here) may be temporarily fastened between the side panels I after which the outer form with its enclosed casting may be rested upon a skid or. structure indicated at 13 as seen in Fig. 4. By then removing the bolts 36 and loosening the wing nuts 39, the transverse platform and step forming portions of the outer form may be lifted up and swung clear as seen in Fig. 4 and when the side panels ID are pulled away, the casting will be left supported upon the skid and may be moved away thereon for further curing and maturing. These form assembly and disassembly operations and methods have all been pointed out in great detail in my earlier patents and should require no further description herein.

As thus far described, the form casts four steps, a platform and sides, all in an integral unit and is thus used to full capacity. Frequently, however, it is desirable to cast a structure having fewer than four steps, and often as few as. just one, and in some cases the platform is not desired or a shortened platform is desirable. Inl my previous patents I have disclosed forms which may be partially taken down and adapted by such operation to casting less than the full number of steps or for eliminating the platform. extension, but in the. present instance I provide-means which will permit my form to be used for this purpose without disassembly. As shownin. Figs. 1 to 4, I accordingly provide the side panels) of.

the outer form with openings 74 adjacent the junction of the treads andrisers of the four steps,-

and these openings are thus threein'number for each side panel. The openings '14 are located iminediately adjacent the points at which theitreadsi 0 meet the risers Dand thelower edgesof the openings are exactly horizontally ali ned with these points as seen in Fig. 1. Around the openings I then provide stiffening frame bars andthese frames are spaced outwardly from the ad jacent edges of the openings as shown both: in-

Fig. l and Fig. 7. Normally fitted in the openings 14 are closure or cover plates TBwhich alsohave stiffening frames 1! extending beyond the edges of the plates and adapted to nicely fit with in the frame 75 as well as to overlie the exposed edges of the side panels I 0 and so bring the plates. exactly flush on the inside with the inner surfaces of the panels. The plates are held'in place by tapered keys 78 which are passed througlj loops 19 on the opposite sides of the frame-"l5 and which when driven home bear inwardly upon the frame 1'! to securely lock the plates. Thus. so long as the openings 14 are covered, they will interfere in no way with the normal operation; of the form in casting to its full capacity as will be understood.

Now, for example. if it should be desired to cast a few structures having only three steps without the platforms, the uppermost plates 16 may be removed, as shown in Figs; 1 and 2, and thus the casting cavity between the forms will be exposed at this level so that the cementitious material may be poured only into the lower part of the form up to about the level of the lower edges of the openings. When the material reaches this level it may be surfaced off at what will then be the rear edge of the uppermost tread by the introduction through the openings 14 of a striking or scraping bar 80 which will then extend transversely through the form and may be worked back and forth to smooth off the material. When the form is so used, the upper few sections of the upright parts of the plate 51 will also be removed as in Figs. 1 and 2 and it will be noted that these sections are of such length that when removed in proper units the remaining upper edges of the plate will line up nicely with the lower edge of the opening (4. To then strike off the rear edge of the shortened sides F of the casting the striking bar 80 or a shortened var-- sion thereof may be guided in between the sides of the inner and outer forms and when rested upon the upper edges of the plate 51 and'upon the uppermost riser forming plate I!) the bar will be so guided thatthis edge will be struck off at the proper right angle with respect to the bottom of the casting. Thus, it will be seen that for any number of steps from one to three, the form may be readily put to use merely by removing the appropriate cover plat-es I6 and filling the form to that point after which the material is struck off to provide the necessary smooth edge.

Where a considerable number of one, two, or three step castings are to be made, itmay be preferable, as seen in Fig. 5, to remove the upper part of the outer form and the platformplate 3d and any one of the step forming members the angle iron 24 of the uppermost remaining step forming member to thus form the tread surface straight and even back to the point at which it is cut off. Without the provision of some such means it is obvious that the uppermost tread would be difficult to form to full width and the oar 82 overcomes this while providing a guide by which the rear edge of the tread may be readily troweled or smoothed off.

It is possible also to form a false bottom for the forms in order to reduce the number of steps cast and thus permit the casting of one or more steps with the integral platform E. This arrangement is shown in Figs. 8 to 10 and is used in connection with a form construction identically as just described. In this case, however, at the point at which it is desired to out off the form the adjacent openings 14 are exposed by removing the cover plates T6 thereat and a cross bar 84 is inserted endwise through these openings so that it crosses the bottom of the form exactly at the bottom of the lowermost riser D. This cross bar 8 is trussed as indicated at 85 to prevent it from bending under the weight of the material and it is held in place by replacing the cover plate 56 with plates 86 having notches 81 to exactly fit and engage the bar. The bar 84 will, of course, be wider than the overall width of the assembled form in order to project outwardly through the notches 8? and when the plates 86 are installed and the key 18 is driven home, the bar will be held firmly in the lower corners of the openings 14. See Fig. 10. To form and define the lower edges of the step sides I" in alignment with the lower edge of the lowermost riser D, I then provide vertical bars 90 which extend downwardly through the spaces between the inner and outer form sides and are trussed as indicated at 9!. The lower ends of the bars 96 are provided with depended pins 88 welded at 89 and the cross bar 84 has loops 88 to receive the lower ends of these pins to thus anchor the lower ends of the bars against displacement in any except an upward direction. The upper ends of the bars 90 are joined to angle irons 93 which may then be bolted across the top of the form as indicated at 94. Bars 84 and 90. when thus installed, form a U-shaped cut off or false bottom for the form allowing it to be filled to any desired level and as seen in Fig. 8, it is installed for casting a two step structure with platform. Obviously, where three steps are cast, the bars 8!) will be replaced by others of the proper length to fit.

In each outer riser forming plate ii], I provide one or more openings through which may be introduced cap screws 95 for anchoring tapered plugs 96 in the space between the forms. When these plugs 35 are used there will obviously be formed in. the risers D an equal number of inwardly tapering openings 9'! as best seen in Fig. 6. These openings 91 provide convenient means for the installation of electric bulbs 98 for lighting the treads at night and as here shown, the bulbs 98 are installed in sockets 99 secured within the step structure and the bulbs are protected by transparent lenses N10. The installation also lends itself to the use of conventional resistance wire heating units IUI in the inside of the step structure by the use of which the steps may be warmed in winter to prevent the accumulation of ice or rid the steps thereof. When this is not desired in the castings, the plugs may, of course, be omitted and the openings for the cap screws plugged up in any suitable manner.

Also, as seen in Fig. 3 I may employ a plug 96 at each upper side of the form in order to provide transversely aligned openings I02 in the sides F immediately beneath the uppermost step. These openings may be desirable to facilitate the handling of the castings since a pipe or other tool may be readily thrust therethrough to facilitate carrying, as will be readily apparent. These openings Hi2 also provide a very desirable ventilation for the hollow inside of the steps.

It is possible with my present form to cast a plurality of separate structures each operation. Referring to Fig. 12 I show therein a lower easting having two steps indicated generally at I and J with integral sides K. and an upper casting having two steps L and M, with platform extension N and integral sides 0. The form itself is identical to that previously described and for this use the form is first filled to the level of the middle openings 14 from which the cover plates 16 are removed and the upper edges then finished off by the striking bars Bil as in Fig. 3. The bars 84 and 90 are then installed at these openings, as described and as shown in Fig. 8, after which the form is filled to the top as will be readily apparent. Thus, the form is at all times worked to full capacity.

It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described my invention, what I claim to be new and desire to protect by Letters Patent is:

1. In a form for casting a series of concrete steps and sides therefor in a monolithic unit, inner and outer spaced forms having portions for shaping the treads and risers of the steps and the sides therefor, the said form while casting being supported on end with its rear end uppermost for pouring the material downward into the space between the forms toward the front end or lowermost step, the sides of the outer form having openings through which material may be poured and a tool introduced to surface oil the material, and cover plates removably mounted over the openings.

' 2. In a form for casting a series of concrete steps and sides therefor in a monolithic unit, inner and outer spaced forms having portions for shaping the treads and risers of the steps and the sides therefor, the said form while casting being supported on end with its rear end uppermost for pouring the material downward into the space between the forms toward the front end or lowermost step, the sides of the outer form having openings through which material may be poured and a tool introduced to surface off the material, cover plates removably mounted over the openings, and the said openings being located adjacent the junction of the tread and riser forming portions of the outer form.

3. In a, form for casting a series of concrete steps and sides therefor in a monolithic unit, inner and outer spaced forms having portions for shaping the treads and risers of the steps and the sides therefor, the said form while casting being supported on end with its rear end uppermost for pouring the material downward into the space between the forms toward the front end or lowermost step, the sides of the outer form having openings through which material may be poured and a tool introduced to surface ofi the material, cover plates removably mounted over the openings, and the said openings being located adjacent the junctions of the tread and riser forming portions of the outer form and the lower edges of the openings being horizontally aligned with the junctions of the treads and risers.

4. In a form for casting a series of concrete steps and sides therefor in a monolithic unit, inner and outer spaced forms having portions for shaping the treads and risers of the steps and the sides therefor, the said form while casting being supported on end with its rear end uppermost for pouring the material downward into the space between the forms toward the front end or lowermost step, cut-off means positioned in the space between the forms for forming a false bottom at the level of any selected step to reduce the capacity of the form, the said cut-off means comprising a U-shaped assembly hung at its upper ends from the top of the form when it is in casting position and secured at its lower corners to the sides of the outer form.

5. For casting concrete steps with sides in monolith, a form structure of the character described having inner and outer forms respectively having tread and riser forming portions and sides for forming the sides of the cast structure, means for supporting the forms in spaced relation with an intervening casting cavity, and a U-shaped member positioned in the form at the level of a selected step to reduce the capacity of the casting cavity and cast fewer steps than the full capacity of the form.

6. For casting concrete steps with sides in monolith, a form structure of the character described having inner and outer forms respectively having tread and riser forming portions and sides for forming the sides of the cast structure, means for supporting the forms in spaced relation with an intervening casting cavity, and a U-shaped member positioned in the form at the level of a selected step to reduce the capacity of the casting cavity and cast fewer steps than the full capacity of the form, said U-shaped member having a cross bar to close the space between the tread and riser forming portions of the forms and connected bars for closing the spaces between the sides of the forms. I

7. For casting concrete steps with sides in monolith, a form structure of the character described having inner and outer forms respectively having tread and riser forming portions and sides for forming the sides of the cast structure, means for supporting the forms in spaced relation with an intervening casting cavity, a U-shaped member positioned in the form at the level of a selected step to reduce the capacity of the casting cavity and cast fewer steps than the full capacity of the form, said U-shaped member having a cross bar to close the space between the tread and riser forming portions of the forms and connected bars for closing the spaces between the sides of the forms, and means separably connecting the respective bars making up said U -shaped member.

FRANK KOGL.

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

UNITED STATES PATENTS

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