NEST-CASTING OF CONCRETE ELEMENTS

Abstract: Method of and apparatus for nest-casting of generally large elements (12, 14, 16) formed of multiple angular surfaces including a side forming element (16) of concrete used as a mold form together with a spaced repositionable mold form used as a side forming element (20) for forming therebetween another large element (18) of concrete. Successive cast forming operations by repositioning the side forming element (20) provide cast elements of concrete. The repositionable side forming element (20) is constructed from an assemblage of interchangeable modular structural components some of which are hingedly connected, adjustable in length, and demountable from the assemblage. Heater elements (140) and vibrating energy sources (120) may be severally applied to the appartus for compaction of the cast material and accelerating the cast process.

Description: Description NEST-CASTING OF CONCRETE ELEMENTS BACKGROUND OF THE INVENTION The present invention relates to casting of panels in successive or sequentially formed self-forming mold forms and more particularly the invention is directed to casting of concrete wall elements formed and molded directly against a previously cast element on the side and with a spaced repositioned element on the other side. Field of the Invention The apparatus and method of the invention provide for use of a folded concrete element as a stable molding form against which to cast another element employing only one-half of the form otherwise required and successively or subsequently casting another similar element against a previous folded concrete element using only a half form without dismantling the same and including means for its movement after a cast concrete element is set so that it in itself forms a mold surface. Included in forming the half form are a series or system of triangulated supporting structures composed of a rigid assemblage of interchangeable modular structural elements securely hinged to each other OM -2- forming a half form while a mold facing previously molded and cured forms the other mold side. The ends are formed by modular section that are reciprocably or parallelly adjusted along a given dimension at the ends of the mold form and thus repeated casting of an indefinite variety of nestable wall elements as well as repeated castings of a predetermined wall element are provided, in any of the general forms of "I", "L", "M", and "N" as well as any conventional zigzag form. Other and further details that are provided in forming the casting element are included and described in further detail below, such as providing compaction by a vibrator element, heating means for accelerating the curing process, wheel mountings on the half frame or form structures hydraulically controlled as well as the concept of providing demolding oil, wax, rubber and the like between layers of panels and concrete molded elements formed in their nesting relation. Description of the Prior Art Concrete precast elements for walls, floors and composite sections of buildings, whether flat-shaped or of folded shapes and constructions involving slabs jointed end on end and at an angular relation into a common or singular element such as in the form of an "L" have been known to be cast in batteries, that is, a simultaneous casting process or simulcast. Such batteries consist of *» olds made of several horizontally spaced upstanding shutter rings or mold forms temporarily secured to each other for casting of the concrete therein and which are subsequently detached for 5 allowing removal of the cast concrete elements. One such known structure is a battery of molds shown in the Cross patent listed below. Another patent of some interest having pivotal end members for the assembly of concrete blocks is Torricelli. 10 Such various disclosures as are known are shown by the representative. U.S. Patents listed as follows: 2,314,468 . E. Urschel 3,307,821 D. Torricelli 3,618,181 M. E. Veale 15 3,701,508 Walter Peter Cross 3,844,524 Howard M. Fisher et al 3,859,021 Ar in Kleiber 4,191,521 Hendrikus Muldery Whether taken singly or viewed in 20 combination with each other, none of these patents is believed to have a bearing on the patentability of any claim of this invention. SUMMARY OF THE INVENTION A primary and significant object of the 25 present invention is to provide method and apparatus of casting concrete element of the folded type, as well as simple slab elements, such as by casting a subsequent panel directly upon and against a previously cast element for one side of 30 the mold and using a same set of form or forms, O herein called "system forms" for completing the mold cavity for such casting. Thus a cast product is to be formed having a contoured surface form generated on one side by surface forming means that is to form an image of the contoured surface form on the other side of the product. Another object of the present invention is to provide a method and apparatus forming concrete elements in sequence where there is provided a surface forming member generating one side of a contoured element and an image surface member generated by the surface forming member forming the other side of the contoured element. Yet another object of the present invention is to provide structural concrete elements in which there are contoured surfaces disposed to have a plurality of vertically defined planes. A further object of the present invention is to provide vertical end stops for closing off ends between a form defined by a contour surface forming member and a contour image surface forming member and in which the vertical end stops adjustably pass through parallel planes until a desired dimensional position is achieved. An additional object of the present invention is to provide stiffening structures for end stops that improve the method and construction of large concrete elements according to the present invention. Still another object of the present invention is to provide by vibration the compaction of the casting material as it is cast in the forms. Another and additional object of the present invention is to provide heating structures and methods for improving the curing of the cast material, improved methods of feeding the material into the contoured forms, providing spacer elements and support structures comprising an assemblage of interchangeable modular structural components some of which are hingedly connected, adjustable in length, threadedly engaging each other, and demountable from the assemblage. An object of the invention also is to provide a coating of form oil between the image contoured surface and the cast element so that the cast element is not adhered or cohered onto the image contoured surface material. An additional and further object of the invention is to provide a hydraulic ram system with retractable wheel assemblages for moving the contoured surface forming means away from a set cast element for inspection and also to reposition it for sequential casting where the contoured surface member is then used for a new side of a cast element while the previously formed cast element provides an image surface contour forming another side of the cast form. Particularly, it is an object an advantage and feature of the present invention to provide surface forming means generating a side of a contoured element and a contoured image surface means generated by the surface forming means forming the other side of the contoured element. Another object and advantage of the invention is to obviate over the prior art method and apparatus of casting elements in arrays or batteries even though such battery casting affords good designed dimensioning, high and rapid production and, some economic features; known battery casting provides disadvantages that are not present in the practice of the invention. Less space and movement of equipment for concrete casting of elements is available in the present invention since there is no dead space disposed between individual concrete elements formed by the sequence formed structures. Battery arrangements also have the disadvantage that the molds are not capable of being rapidly and easily alterable so dimensions of the resulting concrete element may be varied if desired. Battery assemblies are not easily mobile and access to the concrete element so formed is often difficult. The sequential arrangement of a one-contourned form surface for construction of concrete elements against a mirror or image of a previously contoured surface by means of an assemblage of the present invention provides more uniformity, improved strength and dimensional characteristics of the final concrete product. It is an object and advantage of the present invention to provide an arrangement or assemblage of forms called a "system form" that enables one to provide a sequential set of formed concrete elements. This is a method of nest-casting and is uniquely adapted for contoured and folded type of concrete constructions for walls and similar structural components. A final and additional object of the present invention is to provide a system of forms, thoroughly flexible and versatile for allowing a great variety of shapes, dimensions and contour surface finishes of a sequence or nesting of precast elements, each of which is used as part of a cast for a nest formed concrete element. The "system forms" are fractionalized and modularized into standard interchangeable components and supporting an adjusting configurations of the structure forming the mold facings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS Figure 1 is a plan view of a concrete casting assemblage illustrating method and apparatus for nest casting of concrete elements according to a preferred embodiment and best mode of the present invention. Figure 2 is an elevational view of a side taken on an enlarged scale. Figure 3 shows a typical sectional view of the embodiment shown in Figure 2 but on an iRE OM -8- enlarged scale. Figure 4 is an enlarged view taken along line 4—4 of Figure 2. Figure 5 shows an enlarged view of a detail of an assembly connecting two various components of a main structural frame. Figure 6 is a sectional view taken along line 6—6 of Figure 5. Figure 7 is an alternate detailed view of the assembly shown in Figure 6. Figure 8= is a plan and broken away view on an enlarged scale of an end stop assembly. Figure 9 shows detail of an assembly coupling system. Figure 10 shows in an enlarged scale details of an inclined top mold having apertures for inserting and pouring concrete material there¬ through. Figure 11 shows a modification of an arrangement shown in Figure 8 for constructing a series of contoured end stop surface elements. Figures 12-18 show component assemblage elements some of which are interchangeable modular structural components, some of which are hingedly connected, adjustable in length, and demountable from the assemblage as desired. Figures 19, 20 and 21 show improved contour concrete elements of configurations attained by the method and apparatus of the present invention. Figure 22 is a plan view similar in some features to the plan view of Figure 1 but illustrating the method and apparatus of the invention for nest casting of concrete elements in the shape of "N" and "M", respectively. Figures 23 and 24 are sectional views taken along lines 23—23 and 24—24, respectively, of Figure 1 and contain details of stiffening assemblies. Figure 25 is a plan view showing the casting of an inclined assembly and for casting flat elements. Figure 26 is a sectional view thereof taken along lines 26—26 of Figure 25. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, there is shown apparatus 10 for casting a nest of panels of generally large concrete elements, concrete elements 12, 14, 16 having previously been cast and, as shown in Figure 1, a concrete element 18 in the process of being formed. Nest casting of these concrete elements may proceed as shown from a cast concrete element 12 and the sequential process of casting proceeding on each side thereof and in which prior casts fold concrete elements such as concrete element 16 forming one side of a mold form 18 for casting a concrete element while a sequentially repositionable mold form 20 forms the other side of the mold form. Sequentially repositionable mold form 20 previously had formed S s E concrete element 12, 14, 16 and may now form the other side of the mold form 18 for concrete element. Similarly, folded concrete element 12 which is shown as an L-shaped configuration, but may as well be an I, M, N, zigzag, flat, or other folded concrete elements, comprise a predetermined side of the cast folded concrete element 14 forming one side of the mold form therefor, with the mold form 22 forming another side of the mold form 14, it having formed the predetermined side of the folded concrete element 12. This is continued as will be described hereinbelow for forming the nest casting of generally large concrete elements, particularly the several concrete elements configured as I, L, M, N, or other flat or zigzag configurations. Form assembly 10 is initially used together with assembly 20 to mold a first concrete former. Subsequently, assembly 20 is relocated to mold a subsequent element, whereas assembly 10 remains in place or may be discarded. The concrete element 18 being cast or formed may also be identified herein as a sequentially casting folded concrete element space 18 formed by a last, prior or image forming element 16 having a surface generated by a sequentially repositionable or image forming surface mold form 20. These are comprised of a series of mold facings or sheet steel facings 30, behind which there may be provided cold rolled stiffeners 32 held in place and supported by stiffener beams or fra es 34 as is particularly shown in Figures 3, 23 and 24. Secured behind these frame structures are further framing supports and structures 36 and are held in place by stays 38 and stays 40 which may comprise a triangulated support frame or stays 42 and which may be connected by a hinged clevis 44. The structures of stays 42 may be of various constructions and design as particularly shown generally in Figure 2 and more specifically in Figures 12-15. Spacers 46, pivot receiving elements 48 and pin receiving elements 50, 52, 54, are exemplary shown in Figures 16-18 for receiving shafts or pins 60 shown in Figure 12. Also supported as part of the frame 34 is a retainer beam 62 having its swivel head 64 and a rotating jack screw 66, which provide support for end casting form structures 70 as shown in each end of the concrete element 18. A perforated stiffening beam 74 is shown supported from a foot attachment fitting 54 shown in Figure 3 and the entire assemblies 10 and 20 are raised by a beam supported hydraulic ram 80 shown connected to hydraulic lines 84 in Figure 3. The hydraulic ram 80 is supported by a swivel wheel assembly 82. The stays 38 support in horizontal relation any number of walking support surfaces or walking planking elements 86 which are cooperatively disposed with safety railings 88. The base floor or shoe fittings 54 are precisely held in stabilized O position by an arrangement including a jack screw 90 coupled to a hinged hasp assembly 92, all of which may be raised temporarily from the anchored position shown in Figure 3 when the hydraulic ram 80 and swivel wheel assembly 82 is capable of removing or displacing the mold form outwardly to a new given or predetermined position. The hinged hasp assembly 92 is connected to an anchor assembly 94. Jack screw spacer arrangements 100 are separately provided as shown in Figures 1 and 3, among other Figures, so that a top fixed relationship that corresponds with the fixed relationship of the anchor assembly 94 is similarly achieved as desired for maintaining precise dimensional relationships. Anchor details are shown in Figure 6 and when an anchor arrangement is not in use or needed, the assembly 94 is removed from fixed position 104 and a cover plate 106 is placed to hide or cover the opening left by the anchor assembly. Modification of an end stop assembly is shown by end stop assembly 110 in Figure 11 having a similar type retainer beam 62 and a swivel head 64 with a rotating jack screw 66. Where a top surface of a mold frame 18 is designed to have a nonlevel resulting surface, an initial former 114 shown in Figure 10 is provided so that concrete is cast and poured therein by pumping, such as through a canvas chute (not shown), OM elephant trunk or the like, extended so that the pouring device is extended as deeply into the mold as possible to overcome splashing and clinging of concrete from removing the molding oil, wax or the like, as described below, which is applied to the initial or forming surfaces. The oil or wax performs its function and is not removed which would occur quite easily with splashing the damp structure of the poured concrete. While the concrete is increasing in depths during pouring within the mold form 18, external vibratory mechanisms or vibrators 120 are activated to insure compaction and early settling of the wet concrete so that an excellent surface finish is achieved, even though the fresh concrete is fairly thick. Thus a satisfactory concrete surface finish free of depressions is produced. Within the frame arrangement and stays 42 and interspersed at variously desired distances apart throughout a length of the form 20, there are a plurality of heater assemblies such as electric or gas operated heaters 140. Convection and radiated heat energy are applied against the metal forms, the heat being applied during molding and allowed to rise between the stiffeners, which may be directed along a controlled path by an insulating canvas 144, Figure 3, fastened to a rear and top arrangement of a mold facing section so that hot air is distributed and energy is transferred in the form of heat unto the metal form. Because of the I nature of sequential molding to be performed by the mold structure 20, it is possible that the arrangement of heaters 140 and the canvas 144 are not removed during the restaging of the form 20. The system of the present invention is capable of being used to precast flat I-shaped panels and even relatively large floor slabs where they are erected in a vertical or generally vertical array. As has been referred to above, it is appreciated that the system of cement forms and uses of the present invention may be used to form the various constructions, shapes or sizes of I, L, M and N or zigzag configurations 212, 214, 216 illustratively shown in Figures 19, 20 and 21. Also, it is within the purview of the inven¬ tion to provide that the assemblies may be staged at a slight inclination from the vertical. This form of the invention is illustrated and described in connection with Figures 25 and 26. It is also appreciated that the elements 18 need not be finished at a top at an exact level orientation of the mold facing and can therefore be screeded at a lower level whether horizontal or even slightly inclined. It is further seen that nested elements 12-18 are finished at the top by screeding flush with the tops of the preceding elements, such tops providing further a convenient area to stand or work from. An element can be cast on a base elevated from and supported upon a base floor 160 (Figure 3) and fitting in the casting cavity, OM so that such element, while matching the nest top may be of less height if desired than other elements of the same nest. New concrete against a fresly cast element tends to maintain to a higher or highest degree of both water and heat in the elements, thereby enhancing a proper curing without the use of special curing compounds or other conventional and routine methods of the prior art. It should be noted that before the pouring and dispensing of the concrete mix into the forms, that the prior or image mold form is prepared throughout its surface by being treated with release oil applied by brush or spray. The casting face of the form 16 is coated with form oil or wax, the floor area in front of the assembly being likewise treated with oil or wax. The materials which may be used for this purpose are de olding oil or soft wax and the like which is extended to such widths that it will be covered throughout by a bottom seal to form the assembly of the cast element 18 when in place. A few hard rubber or wooden blocks 180 are set on the floor against the assembly preventing it from being accidentally imparted by assembly 20 when being placed. The assembly of the mold form 20 may then be rolled into position in front of the set assembly and after removal of the safety blocks, if desired, the assembly is slowly pushed within millimeters of its final OMP position. The arrangement is then connected to the anchor assembly 90, 94 and the form 20 is then lowered onto the base floor 160 whereby tightly compressing the bottom seal 182 as well as the seal under the end stop assembly. This assembly is then slowly moved into its final position by adjusting the jack screw spacer 90 while keeping a correct and proper distance between the assemblies by removable spacers at the bottom and with the jack screw spacers 100 along the top shown in Figure 3. The jack screws 102 and their corresponding bracket assemblies are installed on the fittings 38, 40 and are operated to pull the assemblies tightly against each other and squeezing any seals along the end stop assemblies 70. Stiffening assemblies associated with the connection are then tightened by actuating the jack screws 210 shown associated with the members 212, and ladders 200 shown in Figures 4 and 23 are installed. Spacer blocks at the bottom of the mold may then be removed and this completes the readiness of the mold cavity for receiving concrete for casting in the mold form 18. Concrete used or poured for the initial former and as required in subsequent elements is of relatively high strength such that compaction by the vibrators insures full contact of the concrete with all surfaces of the forms resulting in the satisfactory concrete surface finish free of depressions. The concrete can be fed by skip from O above through a hopper or by pumping. While the concrete continues to be poured, vibrators and heater elements are activated as necessary to insure perfect casting. When the concrete reaches near a top of the forms, screw jacks 102 remain firmly in place until stripping is being performed and spacers 100 may be removed and the top of the cast element is then screeded at a required or desired level. When the concrete has sufficiently set and hardened, the stiffening assemblies of connections are respectively slackened by actuating corresponding jack screws 210, and other with corresponding brackets being released, removed or rotated upwards on hingedly fittings 48, 50 and then the form assembly 20 is removed. This is referred to further in connection with Figures 22-26. Jack screws closest to being perpendicular to the mold are loosened enough that their hasp may be removed from the anchor assembly 90, 94 and these jack screws are then rotated above the clevis and brought to rest in their non-active position. Subsequently, the remaining jack screws 90, more or less set at 45° to the mold faces, are then activated so as to pull the form assembly, sliding it on the floor a few millimeters. Once the assembly is sufficiently freed from the concrete element, it is raised by depressing the wheel assemblies 82 while disengaging the last jack screws 90 from the anchor assemblies and folding OM them to non-active position. The form assembly is then rolled away, thoroughly cleaned and prepared or transformed for another and subsequent casting. The operation of cleaning the surfaces and preparing for another casting may include first an inspection of the newly stripped prefabricated concrete element surface for possible defects such as cavities formed by entrapped air bubbles, slight honeycomb effects or any other defects which in the first instance should have been avoided. Such defects, if any, are carefully corrected with an application of cement grout finished by steel trowel or putty knives, following the hardening of which the concrete surface is thoroughly brushed or preferably vacuum cleaned and coated with a quick setting cement slurry applied preferably with a rubber squeegee to fill up all minute cavities or seal the pores of the cast element surface. Then prior to the next and sequential step of molding, the surface is prepared by an oil or wax being applied thereupon. If the next element is to receive reinforcing steel, lifting lugs, blocking for lift hook cavity or to include prescribed contrivances such as electrical conduit, electrical boxes, templates, template mounted piping assemblies or the like to be be embedded therein, these are fitted into mold assemblies 10 or 20 after the surfaces of such assemblie, are properly oiled with the oil or wax treatment as is the base floor, earlier described and outlined above. Building elements are cast such that the initial and starting building element is the largest element and sequentially the elements are progressively cast to smaller sizes as is consistent with established general production schedules. Once the nest becomes sufficiently heavy to withstand thrust of the concrete, the initial former is relocated on the base floor and set on a felt pad cut flush with the casting surface of the former, which is subsequently strutted at the reverse face by wooden blocks 190 which may be attached to the stiffening beam 74 being held by jack screws 90 anchored to the assemblies 94. In this manner, a new nest is started. As nests are increasing at one end, the older or oldest elements at the other end, insofar as needed, are removed by whichever moving device is available and immediately set on trailers, for example, and then directly transported to their ultimate erection site. It is appreciated that in this process there is no storage handling at all, while the storage as well as curing occur at no additional expense within the nest which in turn require the smallest possible grouping area for this comprehensive single production, curing, and stocking process. In permanent or semi-permanent installations, the lifting devices are preferably movable by gantries on rails or the like. For less permanent installations including the fortuitous temporary utilization of floors of buildings at the project site, the lifting of building elements as well as relocating the initial former is done by mobile cranes. Lifting may generally be required and is realized by means of spread beam with close perforations serving to engage upper hooks of lifting chains with lower hooks strung through the lifting lugs of the formed elements 12, 14, 16, 18. The lifting lugs are cast in a vertical plane, passing through the center of gravity of the elements, members so cast that the latter may be lifted and most importantly be then set, in a perfectly vertical position. The distance between the lugs are so arranged and constructed between the perforations of the spread beam that the lifting chains also are nearly vertical during the lift while the main hook of the crane is on a vertical through the center of gravity of the total element. The removal of an element can be further aided at the moment of lifting by pushing or pulling such element sidewise using a lever pinned into the orifice of a cover plate 106, which orifice is in the first instance intended for removal of the cover from the collar 108. The illustration of stiffening assemblies including stays 208 such as in Figures 23 and 24 are totally flexible and adjustable and allow for usage of additional jack screws 210. The stiffening assembly also carries the ladder 200. A longer ^13 O ladder 202 is required for use in Figure 24. The jack screws are generally of the same construction throughout where possible. They are composed of the jack bolt and a corresponding short initial body section having at one end a quick acting screw-and-lock nut combination and at the other end a standard threaded cavity for enabling the jack body to be lengthened by one or more extension sections likewise provided with a standard threaded cavity and at the other end a threaded pin fitting the standard cavity. The combination allows the initial jack body and the extension bodies to be coupled to each other as well as to the hinged clevis 44 by a tailend 220, as shown in Figure 5 or any similar fittings. The jack bodies are also perforated in order to be keyed to fitting 221 or bracket 222, or the swivel head 64, or the like. It is further appreciated that the system of the method and apparatus of the invention and new form of casting is also used to precast flat "I" panels even for relatively large floor slabs. As a way of example, form assemblies 240, 250 are staged at a slight inclination * ' from the vertical, see Figures 25 and 26. The mold facing assemblies are set on a face spreader 254 while the screws 256 are adjusted to fully bear the form assemblies and anchorage to the base floor is realized in the manner described above. A matching form assembly composed of a number of assemblies 240 fastened to O

Claims: CLAIMS 1. Method of nest-casting of generally large concrete elements having at least two sides comprising the step of sequentially casting folded concrete elements between a first predetermined prior cast folded concrete element forming one side of a mold form and a repositionable mold forming another side of the mold form having previously formed said first predetermined side. 2. The invention of claim 1 wherein the method includes the step of moving end stops through parallel planes and fixedly securing the vertical end stops for closing off opposite ends of the mold form between the predetermined side and the other side thereof. The invention of claim 1 wherein the other side is essentially constructed and arranged from an assemblage of interchangeable modular structural components some of which are hingedly connected, adjustable in length and demountable from said assemblage. Method of nest-casting of generally large concrete elements having at least two sides comprising: casting a second folded concrete element between a first prior cast folded concrete element forming one side of a mold form and a repositionably mounted mold form having previously formed said first side now forming another side of the mold form; and casting a third folded concrete element between the second prior cast folded concrete element forming one side of a third mold form and the repositionably mounted mold form having previously formed said second side now forming another side of the third mold form. 5. Nest-casting of generally large concrete elements comprising: a folded concrete side forming means for a mold form; and movable means mounted on the side forming means for successively forming another side forming means. 6. The invention of claim 5 wherein the side forming means is furnished with retractable wheel assemblages actuated by hydraulic ram systems for repositioning of the side forming means selectively to an inspection position and then to a next sequential casting position. O 7. The invention of claim 5 wherein the side forming means is essentially constructed and arranged from an assemblage of interchangeable modular structural components some of which are hingedly connected, adjustable in length and demountable from said assemblage. 8. The invention of claim 5 wherein a fitted top stop mold element bridges the casting element to the side forming means for fixedly forming an inclined top edge surface, said top stop mold element having a series of casting material openings along its length for filling and thereafter closing off in steps from a lower opening and lastly to an upper opening. 9. Nest-casting of contoured concrete elements comprising: surface forming means generating one side of a contoured element; and means forming a mirror image surface generated by the surface forming means for forming the other side of the contoured element. 10. A nest-casting of concrete elements comprising: a product having a contoured surface on one side generated by surface forming means that formed an image of the contoured surface on the other side of the product; and end surfaces of the product formed by parallelly positioned end surface forming means. -^URE

Inventors: SCOTT GEO A, SCOTT, GEO, A.
Applicants: TOPLAND NV, TOPLAND N.V.
Application year: 1982
Main classification: B28B7
IPC codes: B28B7