Description:
This invention relates to concrete wall forming apparatus and to the method of constructing such walls.
Heretofore, precast concrete blocks have been used to construct ornamental walls, the blocks being placed in superposed rows on a concrete foundation. The laying of blocks for this purpose requires the services of a skilled mason for placing the blocks and applying mortar between the sides of adjacent blocks of one row as well as between the superposed blocks of two rows.
The main object of my invention is to produce an ornamental concrete wall simulating a block-laid wall by pouring concrete in a continuous operation around form units embodying my invention.
Another object is to provide form units which are self-contained and self-supporting and capable of being placed in side-by-side engagement to form a row and stacked in superposed engagement to form a plurality of rows of form units around which concrete may be poured to build a wall in successive rows, without requiring panels, blocks or framework to retain the forms in concrete confining positions.
Another object is to provide flexible joints in the form walls to facilitate withdrawal of the forms from the concrete after it has been poured and become set.
Another feature of the invention is to provide means temporarily and detachably connecting the forms of a pair in back-to-back abutment to form self-supporting units which produce a wall ornamental on both its front and rear faces, said means being quickly removable to permit separation of the forms and withdrawal in opposite directions from the formed concrete wall.
In the drawings:
Fig. 1 is an elevational front view of part of a concrete wall produced by the use of form units embodying my invention, showing six of the units in place as they appear during the pouring of the concrete and showing a portion of the finished wall as it appears after three of the form units have been removed.
Fig. 2 is a transverse, vertical sectional view in the plane of the line 2-2 of FIG. 1.
FIG. 3 is a perspective view of one of the forms of a unit embodying my invention.
FIG. 4 is a vertical sectional view, enlarged, in the plane of the line 4-4 of FIG. 3, showing one of several flexible joint constructions which may be employed in the forms.
FIG. 5 is an elevational view showing a connector, detached, used to temporarily connect a pair of oppositely facing forms during the placement of the form units and the pouring of the concrete around them in the production of a concrete wall.
FIG. 6 is a sectional view in the plane of the line 6-6 of FIG. 5.
FIG. 7 is a vertical sectional view of a pair of forms, temporarily connected back-to-back to make a unit, as they appear when concrete has been poured around them, showing the use of dissimilar contoured front and rear forms.
FIG. 8 is a view similar to FIG. 7 of a pair of forms and concrete around them, showing similar contoured front and rear forms in the unit.
FIG. 9 is a vertical sectional view of a pair of metal forms, temporarily connected back-to-back to make a unit, supporting a pair of forms of other material such as thermoplastic material, as they appear when concrete has been poured around them.
FIG. 10 shows a sectional view, enlarged, of the flexible joint construction which may be used in thermoplastic forms in place of the flexible joint shown in FIG. 4.
FIG. 11 is an enlarged transverse vertical sectional view similar to FIG. 2 showing the interfitting engaging means between the forms of superposed rows of forms which permit stacking of the forms and retaining them in stacked positions while the concrete is being poured and becoming set.
FIG. 12 is an elevational front view showing a modified form of connector which may be used in place of the one shown in FIG. 5.
FIG. 13 is a elevational end view of the connector of FIG. 12.
FIG. 14 is an enlarged sectional view showing the peripheral flanges surrounding the faces of adjacent and superposed forms for interfitting engagement with each other as also showing in FIG. 11.
In the embodiment of the invention shown in FIGS. 1--3, form units each consist of two forms 20 placed back-to-back. Each form 20 comprises four walls 21 preferably made of sheet metal or other suitable material, shaped to desired curved contour, and joined together at their proximate side edges to form corners. As shown in FIGS. 3 and 4, the edges are welded or otherwise connected together throughout part of their length, but are spaced apart slightly toward the inner or rearward portions which are joined together by a resilient member 22 connected to the walls 21 by adhesive 22'. The resilient members 22 may be made of sponge rubber or other suitable material and may be of tubular or other form to produce a flexible joint between the walls 21. The flexible joint 22 may be dispensed with if the concrete used in pouring the wall contains an expansible additive, or if the curve of the walls 21 is quite shallow, in which case the forms can be withdrawn from the set concrete without relying on the flexible joint to give resiliency to the forms 20 to facilitate withdrawal.
Due to the shape of the individual forms 20, in which the inner or rearward portions of the walls 21 are narrower than the face or outer portions, the form members 20 alone are not self-supporting in the position required for producing an ornamental concrete wall. Two such forms 20, when placed back-to-back, with flanges 25 abutting each other and temporarily connected by a connector 26, as shown in FIGS. 5 and 6, or by a connector 27, as shown in FIGS. 12 and 13, produce a unit which is self-supporting and capable of standing on the parallel lower horizontal edges of the faces of the two forms 20 which constitute a form unit, with the front faces in vertical planes.
The connector 26 may be made of wood or other suitable material. It comprises two flat square pieces 28 with rounded corners 29, and an intermediate flat piece 30 which may be a separate piece or integrally formed with one of the pieces 28, providing a peripheral groove or recess 31 as shown in FIGS. 5 and 6. The connector 26 is placed into the space between the flanges 25 of the form walls 21 of two abutting forms 20 of a unit, and is manually rotated by means of the wing bolt 32 to cause the flanges 25 of the two forms 20 to enter the groove 31 in the corner portions of the connector 26, thereby drawing the two forms 20 together and frictionally locking them in the position shown in FIGS. 1 and 2.
The modified form of connector 27 shown in FIGS. 12 and 13 for the same purpose as the connector 26. The connector 27 may be made of two pieces 33 of metal, connected together in their central areas by a plate 34 and rivets 35. The pieces 33 are bent at 36 away from each other to provide a recess 37 between the facing areas 38. The pieces 33 are connected together by rivets 39 but spaced from each other in the areas 38. The connector 27 is placed in position between abutting flanges 25 of two forms 20 and then rotated less than 45° to cause the flanges to enter the recess 37 between the areas 38. Rotating of the device is conveniently done by placing fingers in the holes 40 in the pieces 33.
The forms 20 shown in FIGS. 1--3 can conveniently be made of metal due to the absence of sharp bends in the walls 21. However, it is practical to produce forms having more ornamental contours, such as the form 45 shown in FIG. 7, which may be coupled with similar form, or with differently contoured form such as 46. Forms such as indicated at 45 can be made of thermoplastic material by means of an injection mold. A self-supporting form unit can be made of two similar forms 45 coupled back-to-back, or form 45 coupled with a different form 46. Flanges 45 on the coupled forms 45, 46 are temporarily held in abutting relationship by connectors such as 26 or 27, as heretofore explained.
FIG. 8 shows another ornamental unit 50 consisting of two forms 51 held together, back-to-back, with flanges 52 abutting. When thermoplastic material is used, as is desirable for ornamental forms such as 45 and 50, the four walls comprising each form can be molded integrally instead of being joined together as described in connection with the metal forms 20. Flexibility can be provided in the molded forms by the construction of corners as shown in FIG. 10, where a tubular resilient corner 53 is molded into the form walls 51. The same may be applied to the walls 48 of the form shown in FIG. 7.
In order to use very light weight, thin thermoplastic material for producing ornamental forms, the construction shown in FIG. 9 may be employed, wherein two metal forms 55, similar to the forms 20 of FIGS. 1--3, are connected together by their abutting flanges 56 engaged by connectors such as 26 or 27, heretofore described. The ornamental forms 60 of thermoplastic material have smooth surfaces 61 complemental to the surfaces 62 of the metal forms 55 on which they are supported. The surfaces 63 opposite the smooth surfaces 61 are ornamental to produce the same ornamental effect in the concrete poured around them.
An important feature of my apparatus for producing ornamental concrete walls is the construction of the peripheral edges of the forms 20, 45, 46, 50, and 55, which are provided with inwardly turned flanges best shown in FIGS. 11 and 14 as applied to superposed forms of two rows of forms designated 70 and 70'. The flanges designated 71 and 72, respectively, are shaped to have interfitting engagement by means of the projections or tongues 73 on flange 71, and 74 on flange 72. When the flanges and tongues are in engagement with each other, the superposed forms 70, 70' are supported in concrete receiving positions without the aid of panels, blocks or framework, and maintain the positions required for confining the concrete which is poured around the forms in the construction of an ornamental wall. After the concrete has become set, the forms of the lowermost row can be withdrawn, and the forms of successive rows can be withdrawn, leaving grooves 75 in the finished wall to simulate the mortar grooves of a precast block laid wall.
The method of constructing the described wall made of poured concrete consists of the following steps: a concrete foundation F having a flat horizontal top is prepared as shown in FIGS. 1, 2 and 11; form units each comprising a pair of forms 20, or modifications thereof, held in back-to-back abutment by connectors 26 or 27, are placed side-by-side to form a first row on the foundation F; a double headed nail 76 with heads 77, 78, is driven through the lower wall of each form or some of them into the foundation F; concrete is poured around the forms of the first row of forms to fill the spaces surrounding the bottoms, sides and tops of the forms; a second row of form units is placed on top of the form units of the first row with the flanges 71 and tongues 73 engaging the flanges 72 and their tongues 74; concrete is poured around the forms of the second row of forms to fill the spaces surrounding the bottoms, sides and tops of the second row forms; the cycle of operations is repeated for the third and successive rows of forms; and the forms are withdrawn when the concrete has become set by first withdrawing the nails 76 (used only in the first row forms), and rotating the connectors 26 or 27 to disengage them from the flanges 25 of the abutting forms of a unit, removing the connectors, and then pulling the forms away by movements in opposite directions forwardly and rearwardly of the wall with the aid of the projections 24 on the forms 20, to disengage the interfitting flanges from each other, and separating the forms from the set concrete.
Withdrawal of the forms of the several rows leaves the grooves 75 between the rows and adjacent forms which simulate mortar grooves in block laid walls.
The rotating of the connectors 26 or 27, to engage the flanges 25 of the forms 20 when in rear abutment, to produce a form unit, has the effect of expanding the walls 21 if made of flexible material, such as metal or other yielding material. Rotation of the connectors to detach them from the abutting forms of a unit allows the walls 21 to contract and thus facilitates withdrawal of the forms from the set concrete.
The pouring of the concrete around the forms of a first row, followed by pouring concrete successively around superposed rows of forms instead of pouring concrete around all the forms of several rows in one operation is particularly desirably when the form units are made of relatively fragile material not designed to withstand excessive weight.
After the concrete of the entire wall has become set, the forms may be removed at will, but it is also practical to remove the forms from the lowermost row when the concrete has become set without waiting for complete setting of concrete in the next and other rows poured after the first row concrete has been poured. Thus forms can be used again for pouring upper rows of a long wall in which lower rows have already become set.