US2558615A - Mold for concrete steps - Google Patents

Description

June 25, 1951 E. J. JOHNSON MOLD FOR CONCRETE swaps 4 Sheets-Sheet 1 Filed Nov. 26, 1947 N s N g M ,A a

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June 26, 1951 JOHNSON 2,558,615

MOLD FOR CONCRETE STEPS Filed Nov. 26, 1947 4 Sheets-Sheet 2 I N V EN TOR. EM/L J. JOHN-501v Wig Wm A ITOENE Y:

June 26, 1951 E, JOHNSON 2,558,515

MOLD FOR CONCRETE STEPS Filed Nov. 26, 194'? 4 Sheets-Sheet 5 23 y' n F26}? ATTORNEYS E. J. JOHNSON MOLD FOR CONCRETE STEPS June 26, 1951 '4 Sheets-Sheet 4 Filed Nov. 26', 1947 INVENTOR. f'M/l. J; JTofi/vaolv ATTOENEYS Patented June 26, 1951 UNITED STATES PATENT OFFICE MOLD FOR CONCRETE STEPS Emil J. Johnson, Minneapolis, Minn.

Application November 26, 1947, Serial No. 788,284

3 Claims. 1 This invention relates to new and useful improvements in concrete molds or forms for making pro-fabricated reinforced concrete steps, each including tread and riser portions.

Concrete stairways, as now commonly constructed, are usually erected or formed with the use of temporary molds constructed of lumber, and which must be set up for each job and may therefore require considerable labor, as each job requires the erection of a new form.

An object of the present invention is to provide a cement or monolithic stairway constructed of preformed spaced side members and a plurality of preformed combination tread and riser units which may be quickly assembled to provide a substantial and rugged stairway having the appearance of solid concrete.

A further object is to provide a novel mold or form for molding conventional tread and riser step units, and suitable stepped side wall members adapted to be arranged in spaced relation to provide supports for the tread and riser units, and a series of grooves and tongues being provided in said end walls and tread and riser units adapted for interlocking engagement to prevent relative displacement of the parts when assembled, whereby once the tread and riser units have been secured in position upon the end walls and to each other by a plastic bonding cement or plaster, a substantial stairway is provided which will be extremely neat in appearance and will oiier the utmost in the way of stability and ruggedness in an apparatus of this general type.

Other objects-of the invention reside in the formation of the first or ground step, which comprises two risers, one for spacing the tread portion of said first step from the ground surface, and the other riser extending upwardly from the tread portion of said step to support the tread portion of the next succeeding step, the second, third and succeeding step units being so arranged until the flight of steps has been completed; in the provision of a mold havin means therein for forming complemental grooves and beads adapted for interlocking engagement to retain said step and end wall units in proper position relative to one another; in the simple construction of the various parts of the mold whereby they may readily be manufactured at low cost and also'whereb-y the parts of the mold may be quickly assembled or taken apart; and in the manner of constructing the interlocking beads or ribs whereby said beads or ribs may be made in quantity production at low cost, after which they may be quickly bonded to the bottom faces of the treads of the step units with a minimum of efiort and bonding cement, whereby a complete stairway may be quickly constructed in a very short time and at minimum cost; and in the provision of a mold of the class described having means whereby it may readily be adjusted for steps of different sizes, particularly in the height of the risers.

Other objects of the invention will appear from the following description and the accompanying drawings and will be pointed out in the annexed claims.

In the accompanying drawings there has been disclosed a structure designed to carry out the various objects of the invention, but it is to be understood that the invention is not confined to the exact features shown, as various changes may be made within the scope of the claims which follow.

In the drawings:

Figure 1 is a plan view of my improved mold partially broken away to more clearly disclose the construction thereof;

Figure 2 is a front view of Figure 1;

Figure 3 is an end view thereof;

Figure 4 is a cross sectional view on the line 4-4 of Figure 1 with some of the parts omitted;

Figure 5 is a view similar to Figure 4, but showing the form filled with concrete;

Figure 6 is a plan view of one end of Figure 5, showing the arrangement of the interlocking beads on the bottom face or" the tread portion of each tread;

Figure 7 is a perspective view of one of the bead elements prior to being secured to the cement in the mold, as shown in Figure 5;

Figure 8 is a View similar to Figure 4 with the parts separated to more clearly illustrate their relationship;

Figure 9 is a perspective view of one of the end walls of the tread form;

Figure 10 is a fragmentary detail plan view showing a portion of the upright wall which cooperates with the vertical Wall of the main body portion of the mold to form the riser of a step unit;

Figure 11 is a view similar to Figure 6, but showing the form filled with concrete and a pair of spaced upright wall members being positioned on top of the mold to provide the ground riser of the first step, shown in Figure 17 Figure 12 is a cross sectional view on the line I2--l2 of Figure 11;

Figure 13 is a plan view of one end of a mold Figure 19 is a perspective view of a mold utilized for making the end wall sections;

Figure 20 is a perspective view of a completed end wall member;

Figure 21 is a perspective view showin a flight of stairs partially completed; and

Figure 22 is a detail sectional view on the line 22-22 of Figure 18, showing the interlocking of the tread portions of the step units with the upper edges of the end wall members.

The novel concrete form herein disclosed is shown comprising a main body portion, best shown in Figures l, 5 and 8, including an up right wall 2, a horizontal Wall 3 and cross walls 4. The walls 2 and 3 form wall surfaces of the mold cavity, whereas the cross walls 4 serve to provide supports for the walls 2 and 3. The walls 2, 3 and A may be secured together by suitable means such as welding to provide, in effect, a unitary structure. If necessary, a third cross wall t may be interposed between the cross walls 4 shown in Figure 2, to further strengthen the structure.

A seat-forming member 5 is shown seated against and secured to the bottom face of the horizontal wall 3 with its outer marginal edge portions extending outwardly beyond the corresponding edge portions of the horizontal wall 3, thereby to provide aseat 6 which extends along the front side of the mold and the two ends thereof, as shown in Figure 1. It is to be noted by reference to Figure 1, that the member prises an elongated front portion b and laterally extending end portions 0 which cooperate to form the seat The seat 6 is adapted to receive and support a plurality of edge wall members i and 8, the edge walls I constituting the end walls of the form for a given size tread, and the edge wall 8 forming the front wall of the form. The seat 6 is spaced downwardly from the top surfaces of the horizontal wall 3 whereby the outer edges of the wall 3 will provide abutments to facilitate accurately positioning the edge Wall members l and 8 with respect to one another in the setting up of the form. The edge walls l and 8 may be secured in position upon the seat 6 by suitable means such as C-clamps 9, such as shown in Figures 2 and 3.

An important feature of the invention resides in the construction of the upright walls '5 and 3 of the mold. As shown in Figures 4, 5, 8 and 9, the inner faces of the edge wall elements 7 and 8 are provided with longitudinally extending grooves which constitute portions of the mold cavity and serve to provide the rounded edges of the treads, shown at H in Figure 18. The ends I2 of the end walls 1 are shaped to conform to the configuration of the adjacent face of the side wall 8, as shown in Figure 8, whereby one end of each end edge wall 1 may be interlocked with the front edge wall 8, as will be understood by com- 4 reference to Figure 8. The height of the edge walls I and 8 from the top surface of the horizontal wall 3 of the main body of the form determines the thickness of the tread of the step to be formed in said mold.

To complete the mold, a back upright wall I3 is shown mounted in spaced relation to the upright Wall 2 of the main body portion of the mold, and is spaced from the wall 2 by an angle iron 14 secured to the plate is. The angle iron l4 constitutes the lowermost wall of the mold cavity, and forms the top edge E5 of a step unit, as shown in Figures 16 and 17. A cleat i5 is shown secured to the inner face of the rear wall or plate 13 at each end thereof, and preferably extends slightly beyond the end edge walls l, as shown at the lefthand end of Figure l. The cleats !6 preferably extend to the top edge of the baci; wall l3 whereby they may provide upright recesses ii in the riser is of each step unit, as clearly illustrated in Figures 16 and 17.

Filler blocks it are secured to the back wall 13 by bolts it, at the ends thereof, and constitute the end Walls of the cavity forming the riser of each step unit. The upper ends of the blocks l6 are disposed in the plane of the seat 6, whereby they are engaged by the end edge wall members l', as shown at a in Figure 4.

The rear wall 53 may be removably secured to the upright wall 2 of the main body member of the mold by C-clamps 9, similar to those which secure the end and side edge walls "I! and 8 in position with respect to the horizontal wall 3. Angle brackets i ii are shown secured to the lower end of the back wall i3 and have adjusting screws 2! mounted therein to facilitate vertically adjusting the plate IS with respect to the horizontal plate 3 of the main body of the mold. Such vertical adjustment of the back wall 13 also changes the position of the horizontal wall i l and thereby varies the height of the riser it of a step unit, as will be understood. The main body of the mold and the rear wall or plate it may be supported upon suitable base members 22, as clearly illustrated in Figures 3 to 8, inclusive.

Another important feature of the present invention resides in longitudinally grooving the top edge 15 of the riser of each step unit, as shown at 23 in Figures 16 and 17. To thus groove the upper edges of the risers, a longitudinally extending bead or half oval as is shown seated upon and secured to the upper horizontal web of the angle iron it which spaces the back wall i3 from the upright wall 2, as best shown in Figures 4, 5 and 8. By thus securing the bead 2d to the angle iron 16, it becomes an integral part of the mold and results in the production of the groove 23 in the upper edge of each step riser.

A bead 25 is provided on the bottom face of the tread portion intermediate of each step unit 26, as clearly illustrated in Figure 18. To provide the beads 25 on the bottom faces of the step units 26, longitudinally extending bead elements 25 may be pro-formed of concrete or some similar material, as shown in Figure 7. After the mold has been filled and packed with concrete, as illustrated in Figure 5, a bead element 25 is placed upon the surface of the wet concrete in parallel relation to the front edge of the mold, whereupon it becomes bonded to the concrete, as the latter sets, thereby to become, in effect, an integral part of the concrete forming the body of the tread being molded. Similar cement beads 26' are provided adjacent to the ends of each tread adapted to be received in longitudinally extending grooves 21 provided in a pair of stepped end wall members 28, subsequently to be described.

The bottom step unit, generally designated by the numeral 29, differs somewhat from the intermediate step units 20 in that in addition to the riser I8 provided at the rear thereof, it also has integrally formed therewith a riser 3i located adjacent to its forward edge and adapted'to rest upon a suitable foundation, not shown, or upon the ground surface, as Indicated in Figure 18.

To form the dependin riser 3| on the first step unit 29, spaced wall members 32 and 33 are shown secured to the main body of the form in spaced relation, as shown in Figure 12. The walls 32 and 33 are spaced apart by suitable spacing blocks .34 secured in position between the walls 32 and 33 by such means as bolts 35, and may be supported directly upon the end edge walls I, as will be understood by reference to Figure 11 and 12. The wall members 32 and 33 may be secured to the main body portion of the form by suitable c-clamps, not shown in the drawings.

The top step 36, as shown in Figures 15 and 18, also varies somewhat from the intermediate steps 20 in that it may not have a riser extending upwardly from the rear edge portion thereof, but in lieu thereof may be provided with a downwardly extending riser 37, shown integrally formed with the tread portion 36.

To construct the top step 35, a separate mold is used comprisin a base plate, generally designated by the numeral 38 having a seat 39 at each end thereof and along the front side thereof which corresponds to the seat 6 shown in Figures 1, 4 and s. The base plate as is shown composed of two plates 4i and 42 suitably secured together in fixed relation with the edge of the top plate 4| at the ends of the mold and at the front side thereof bein spaced inwardly from the corresponding edges of the bottom plate 42 to provide the seat 39. If desired the base plate 38 may be made from a single piece of metal, but for economical reasons, it is preferably made from two pieces of metal, as shown in Figure 14, to facilitate formation of the seat 39.

End walls 43 and a side wall 44 are supported upon the seat 39 in a manner similar to the corresponding end and edge Walls 7 and 8, respectively, of the form shown in Figures 1 and 2. The wall members 43 and i4 may be secured in position upon the seat 39 by suitable c-clamps 9.

The rear wall 45 of the form illustrated in Figures 13 and 14 is shown comprising an angle iron having its lower horizontal flange suitably secured to the base plate 38 by such means as welding or, if desired, it may be adjustably secured to the plate 32 by a C-olamp 9 whereby the width of the tread may be varied by increasing the length of the end walls 43.

The top edge of the rear wall 45 is preferably disposed in the plane of the front wall 44. Auxiliary walls 46 and 47 are provided at the rear of the mold to form the riser portion 31 of the top step unit 36, as shown in Figures 15 and 18. The walls 46 and! correspond to the walls 32 and 33 shown in Figure 12, and the wall 46 may be sup ported upon the top edge of the wall 45 and the wall member 4! upon the end wall members 43' of the mold. Suitably spaced blocks 48 are interposed between the wall members 43 and 41 to retain them in spaced relation, as will be understood. Bolts 49 secure the spacers to the wall member 46, and said wall members are secured in position on the form by suitable C-clamps 9.

Pre-formed bead elements 25' and 26 are placed upon the fresh concrete in the mold, as shown in Figures 13 and 14 to provide, in effect, integral beads adapted to be received in the complemental grooves 23 provided in the risers l8 of adjacent step units 20, as shown in Figure 18.

The forms shown in Figures 1, 2, l3 and 14, are utilized to complete the formation of the step units illustrated in Figures 15, 16 and 17, and which are utilized in a flight of steps as illustrated in Figure 18. To support the steps 29, 20 and 33 in proper relation, a shown in Figure 18, suitable end wall members 28, shown in Figure 20, are utilized. The end wall members 28 have their upper edges stepped as shown in Figure 20, and their horizontal and vertical edges, with the exception of their rear edges, are grooved to receive a bondin cement, as will be understood.

The end walls 28 are made in a mold or form such as illustrated in Figure 19. This mold comprises abase plate if having a stepped wall member, generally designated by the numeral 52, secured to the top surface thereof by suitable means such as clamps, or if the mold is to be used for makin a standard size set of steps, as shown for example in Figure 18, the wall member 52 may be secured to the plate 5! by welding, if so desired.

, A bottom wall 53 in the form of an angle iron is also secured to the base plate 5|, and a similar wall member 5% is shown secured to the rear edge portion thereof to form the rear edge of the side wall member 28, as will be understood. The upper edges of the stepped wall member 52, bottom wall 53, and rear wall 54 are disposed in a common plane to facilitate forming the end wall so that such wall edges may be utilized for determining the thickness of the end wall 28. In other words, when constructing an end wall, the form shown in Figure 19 is filled with plastic or fresh concrete which may be tamped or otherwise packed therein to remove all voids of water and air and produce a solid, dense mass of concrete, after which the surface of the concrete is smoothed over with a straight edge which may be slid over the top edges of the wall members 52, 53, and 54, as is well known in the art. The stepped wall member 52 is formed with bead elements 55 which form grooves 27 and 53 in the end wall members 28, as shown in Figure 20. After the concrete has set in the form, the bottom and rear wall members 53 and 54 may be removed from the base plate 5| after which the slab of concrete forming an end wall 28 may readily be moved from the form to condition the form for receiving another charge of fresh concrete.

The mold or form shown in Figure 19 is so constructed that the grooves 21 formed in the top edge portions of the finished end wall 28 by the beads 55, are symmetrically disposed on the top edge portions of wall member 28, as shown in Figure 20, whereby the same mold may be used for making the two end supporting walls of a given set or flight of steps. If desired, the end wall members 23 may be suitably reinforced by placing conventional reinforcing rods in the form before pouring the concrete therein. In like manner, suitable reinforcing rods may be utilized in the formation of the steps 29, 26 and '36, as is well known in the art.

From the foregoing, it will be noted that the various step elements required in the erection of a flight of stairs may be pre-formed and stocked for future use. When erecting a set or flight of steps comprising, for example four steps, as

attacii shown in Figure 18, a pair of end wall members 28, such as shown in Figure 20, are erected upon suitable foundations, in proper position relative to a doorway or platform. The end walls 28 are spaced apart to correspond to the length of the step to be used, and whereby the beads 26' provided on the bottom surfaces of the treads of the step units will register with the grooves 21 provided in the upper horizontal edge portions of the end wall members 28. The grooves 23 in the risers of the steps and also the grooves 21 in the upper horizontal edge portions of the end wall members 28 are made slightly larger than their complemental bead elements 25' and 26. thereby to provide a gap between the surfaces of the grooves and said bead elements for receiving a bonding cement in the erection of the steps, as shown at in Figure 18.

The operation of erecting a flightof steps made in accordance with the present invention is extremely simple, once the end wall members 28 have been properly aligned with one another upon suitable foundations. It is to be understood that the bottom edges 58 of the end wall members Zsare suitably secured to their respective foundations by such means as cement, and the rear edges 59 of said end wall members may be similarly secured to the foundation of a building whereby the end wall members may be rigidly supported with respect to one another.

After the end wall members 28 have thu been erected and are securely supported upon their respective foundations, the bottom step 29 is placed in position upon the end wall members as shown in Figure 22, and suitably secured thereto by the application of cement in the grooves of the end wall members 28 and in the riser is of the first step. The ends of the risers are also bonded to the upright edge portion 56 of the end wall members 28 by applying soft cement between said edges and the recessed ends ll of the risers, as will be understood. The same operation is repeated for each step until the entire flight of steps has been completed, and after the bonding cement has become thoroughly set, the resultant stairway or flight of steps will provide a very rugged and substantial structure which will be very neat and attractive in appearance, and wherein all steps will be symmetric and uniform in configuration.

By the employment of the novel forms herein disclosed, a contractor engaged in the erection of concrete stairways may, at times when business may be slack, manufacture individual steps 20 and 29, as shown in Figures 16 and 17 and carry such steps in stock for future use, as they may readily be nested together for storage. It is assumed, of course, that the steps may be made to a standard size which will meet the requirements of most building structures. If not, the forms may readily be altered to meet conditions, or they may be made adjustable, whereby the width of the treads and height of the riser may be varied, and, if necessary, the length of each tread may be Varied.

The various forms utilized in the construction of the steps and end members 28 are extremely simple and inexpensive in construction, and may be made of stock parts such as boiler plate angle irons and strap or bar stock metal. The end edge walls l and 43 of the molds shown in Figures 1 and 13, respectively, and the front edge walls 8 and 44, respectively, of said forms, may require some special treatment to provide the longitudinally extending grooves in the inner faces thereof which form the rounded edges H of the treads, as shown in Figure 18.

The operation of pouring the concrete in the forms is extremely simple as the entire tops of each of the forms shown in Figures 1, 13 and 19, are open, and the side walls thereof provide means for supporting a straight edge which may be utilized to level the plastic concrete in the forms as is well known. This is made possible as a result of the bead elements 25 and 26 being preformed, and subsequently bonded to the surface of the fresh cement by placing them directly in the freshly poured cement after filling and troweling the cement in the form, as hereinbefore described.

It will be apparent to those skilled in the art that I have accomplished at least the principal objects of my invention, and it will also be apparent to those skilled in the art that the embodiments herein described may be variously changed and modified without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described; hence it will be appreciated that the herein disclosed embodiments are illustrative only, and that my invention is not limited thereto.

I claim as my invention:

1. In a mold for making concrete steps, a main body portion including an upright wall adapted to form one side face of a riser and a horizontal wall adapted to form the face of the tread of a step, edge wall members removably secured in fixed relation to said horizontal Wall and defining the side and front edges of the tread, a plate secured in spaced relation to said upright wall and cooperating therewith to provide a riser cavity in the mold, said mold being open at the top to facilitate filling with wet cement, a member of angular cross=section interposed between the upright wall and the plate, said member being carried by said plate and forming the bottom wall for the riser cavity, means for vertically adjusting said plate with respect to said horizontal wall whereby said member is correspondingly adjusted to vary the height of the resultant riser, and a protuberance on the bottom wall of the riser cavity for forming a longitudinal groove in the upper edge of the riser of each step made in the mold.

2. In a mold for making concrete steps, a main body portion includin an upright wall adapted to form one side face of a riser and a horizontal wall adapted to form the face of the tread of a step, edge wall members removably' secured in fixed relation to said horizontal wall and defining the side and front edges of the step tread, a plate secured in spaced relation to said upright wall and cooperating therewith to provide a riser cavity. in the mold, said mold being open at the top to facilitate filling with wet cement, and a member of angular cross-section interposed between the upright wall and said plate, said member being carried by said plate and forming a bottom Wall for the riser cavity, and means for vertically adjusting said plate with respect to said horizontal wall whereby said member is correspondingly adjusted to vary the height of the resultant riser.

3. In a mold for making concrete steps, a main body portion including an upright wall adapted to form one side face of a riser and a horizontal wall adapted to form the face of the tread of a step, edge wall members removably secured in fixed relation to said horizontal wall and de-.

9 fining the side and front edges of the tread, a plate secured in spaced relation to said upright wall and cooperating therewith to provide a riser cavity in the mold, said mold being open at the top to facilitate filling with wet cement, an angle iron interposed between the upright wall and said plate and disposed in horizontal position to provide a bottom wall for the riser cavity, means for securing the angle iron to said plate, and threaded means for vertically adjustin the angle iron relative to said horizontal Wall to vary the height of the riser of the resultant step.

EMIL J. JOHNSON.

REFERENCES CITED The following references are of record in the 5 file of this patent:

UNITED STATES PATENTS

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