EP2739413B1

EP2739413B1 - Method and apparatus for making concrete reinforcement cages and product obtained thereby

Info

Publication number: EP2739413B1
Application number: EP12750345.6A
Authority: EP
Inventors: Anton Massimo Galluccio
Original assignee: Schnell SpA
Current assignee: Schnell SpA
Priority date: 2011-08-03
Filing date: 2012-08-03
Publication date: 2018-07-25
Anticipated expiration: 2032-08-03
Also published as: ES2692273T3; WO2013017684A2; WO2013017684A3; ITBO20110483A1; EP2739413A2

Description

Technical Field

The present invention concerns a method and apparatus for assembling reinforcements for reinforced concrete, as well as the product obtained thereby.

Background Art

It has been known that, in order to perform the reinforcement of reinforced concrete pillars and beams, metal cages made by longitudinal iron rods linked by suitably spaced transverse rods are used.
In particular, it has been known that, in order to make transverse stirrups, machines which automatically perform the folding of metal rods according to a predetermined profile are used. The so-obtained stirrups generally shape a polygonal profile, for example quadrangular. Made stirrups are separated from the rod to be worked by means of cutting, performed by a suitable cutting device of the machine for making stirrups, then they are collected and transported to the following working stations.
The stirrups, technically defined as "transverse reinforcements", have a primary role in the endurance of buildings. Their number and their position are carefully defined through complex calculations, generally filed with competent offices for official controls, as an attachment to a detailed project, also as an anticipatory evidence of the due diligence in case of disputes.
Moreover, it has been known that the making of the above mentioned metal cages usually is rather complex and requires considerable production times, with a sensible waste of labour and proportionally high costs. As a matter of facts, it is still used to manually assemble the reinforcements, by assembling each stirrup with the respective longitudinal bars through binding or welding. It evidently causes long working times, since it is necessary to manually provide for the positioning of each single stirrup according to the required pitch.
It is to be observed that the endurance of the final product is strictly linked to the concurrence between the project and its execution. Therefore, it is important that the stirrups are in number and position indicated by the designer who checked the project.
Another problem is to be observed, as well, issued by the fact that the single flat stirrups used for assembling reinforcements have an open polygonal profile whose stability results actually weak. More precisely, such stirrups have end hooks suitable for being placed reciprocally overlapped at a vertex. As a consequence, the single stirrups result substantially open and, consequently, extremely deformable. Such circumstance obviously represents a critic factor, in particular for the fact that stirrups are produced with end arms which do not allow an overlapping resulting stable during the handling operations. On the contrary, stirrups tend to easily deform, distancing from the theoretical structure of the cited polygonal profile. Thus, the storage, the handling and the assembling of the transverse reinforcements result particularly hard.
It is as well to be observed that it is not currently possible to control the production and handling process of stirrups so as to provide for products which can perfectly be repeated and handled in the following assembling. In particular it is really difficult to perform the assembling of stirrups in automatic manner when the difference from the theoretical profile overcomes a determined tolerance limit.
Within the field, different solutions have been proposed, as for example the one disclosed in patent EP 0667195 B1 , forming the basis for the preamble of the claims 1 and 7, which provides methods and devices for making "preassembly" for reinforcement cages, made by transverse stirrups fixed in the project positions through the union of rigid auxiliary longitudinal wires. Such solutions solve only few specific problems of the reference field, in particular reducing the production times of the final product, but they do not specifically face the size and handling problems of the so-preassembled products which must be transported to the building site.
As another example patent FR 2 155 230 A1 , forming the basis for the preamble of the claim 17, discloses a preassembly for making reinforcements for reinforced concrete, said preassembly comprising plurality of transverse stirrups united by a plurality of flexible and inextensible longitudinal elements forming bights laying towards the outside of the preassembly. The handling of such a preassembly is unsafe and not convenient.

Disclosure

The task of the present invention is that of devising a method and an apparatus which allows to perform in an easy and automatic way the union and the desired reciprocal positioning of stirrups for reinforcement of reinforced concrete, so as to obtain a preassembly, itself object of the invention, of simple handling, transport and final assembling at the building site.
Another scope of the present invention is that of providing an apparatus for the spacing and the fixing of stirrups used for the making of the cited preassembly, with an easy assembling and functional conception and with a surely reliable functioning, a versatile use as well as relatively economic cost.
A further scope of the present invention is that of providing a method as well as an apparatus able to make a preassembly for reinforcements for reinforced concrete, which definitely corresponds to the project requirements, in particular assuring an optimal endurance against the forecasted stresses.
The cited scopes are attained, according to the present invention, by the method and apparatus for the assembling of reinforcements for reinforced concrete, as well as by the so-made product according to the attached claims.
In particular the method and apparatus provide to make a preassembly being able to be uncompacted, wherein the stirrups made for making the reinforcement are spaced and reciprocally fixed according to the desired positioning. In fact, the stirrups of so-called "transverse" reinforcement are united with a plurality of longitudinal interconnection elements of easily flexible materials and substantially inextensible, that is able to assure that the distance of fixing between one stirrup and another will not substantially change during the following handlings of the preassembly for the transport and the preparing for the building site. As concerns the cited flexibility, the union between the stirrups and such interconnection elements enables to obtain a preassembly easy to compact in a compacted configuration wherein the stirrups are approached to each other, suitable to ease the handling, storing and transporting operations and able to be uncompacted from said compacted configuration to an uncompacted or outstretched configuration, wherein further to the extension of the interconnection means the stirrups result to be spaced according to the desired positioning, that is predetermined, thanks to the fixing to the cited interconnection means. Therefore such fixing simply imposes a maximum limit to the reciprocal spacing between the stirrups.
Such fixing preferably occurs out of such stirrup by means of welding, or through other fixing systems.
United stirrups then find the correct placement following to the outstretching which can be obtained through a determined external traction action.
The distance between united stirrups is determined in a definite way by the presence of control means associated with the feeding means of the interconnection means, which measure the extension of the fed tracts, that is of the tracts between a stirrup fixing and the following stirrup fixing. The pitch, or more generally the axial distance between correspondent portions of the stirrups is therefore controlled in a precise and repeatable way.
Moreover the method provides, in suitable step relationship, the relative operation of two planes: an interception plane, on which the correct positioning of the single stirrup is operated together with the union of this one with the interconnection element, and a mobile abutment plane in direction orthogonal to the interception plane, for enabling the placement of the united stirrups in a compacted configuration. Therefore, at the end of the operative steps the method allows to store on the abutment plane a preassembly, able to be uncompacted, in compacted configuration. The final product, obtained with the method, is therefore very easy to pick up from the apparatus, to handle and to transport.
More precisely, it is possible to uncompact the preassembly for its use at the building site, for example, by simply acting on the end stirrups of the compacted preassembly according to opposed directions of reciprocal spacing. The preassembly then acquires the outstretched configuration. In particular the outstretching of the interconnection elements of the preassembly, allowed by the flexibility of the same elements, arranges the stirrups in the position predetermined in the project and made during the assembling step through the controlled feed to the interconnection elements. The interconnection elements can be for example tape-shaped, that is with a flat section, of the so-called "strap" type, or with a circular section or different, anyway suitable to be united to the support stirrups without interruption and at reciprocal predefined distances.
The feature of the preassembly of being able to be uncompacted in particular is determined by the fact that the interconnection elements, as for example tapes, or metal wires of easy deformability or flexibility, or of other suitable materials compatible with concrete, for example carbon fibre, are easily led to form bights when the union zones of two correspondent consecutives stirrups are approached. Therefore, thanks to the "natural" bight-disposition, when the preassembly is in the compacted configuration, with approached stirrups, the interconnection element is easily led to arrange itself in the internal side of the preassembly. For the same cited mechanical properties, the interconnection element is as well suitable to outstretch in a configuration substantially rectilinear by means of a traction stress applied preferably by operating on the edge stirrups or directly on the same interconnection elements.
It is also useful the particular orientation of each tract folded or bended, comprised between two following fixings to the stirrups, inside the preassembly to be formed. In substance, in the assembling step, each tract comprised between a union point and a following one exceeds the distance between said stirrups in the compacted configuration. As a consequence, thanks to the cited flexibility of the interconnection elements, the exceeding tracts form bights inside the preassembly in the compacted configuration, for example by simply feeding the same interconnection elements towards the inside of the preassembly. Such arrangement is particularly advantageous, since it allows to obtain a compacted preassembly without protrusions external to the perimeter of the stirrups, so as to completely avoid to hold out the steps of handling and transport towards the building site and without needing to use further guide members. Moreover the inner arrangement of the interconnection elements does not compromise in a substantial manner the consistence of the concrete cover, since the shim of this one is minimally engaged by the presence of such elements when the preassembly is arranged in use in outstretched configuration.
According to a particular embodiment, it is possible to provide that at least one of the interconnection elements used for the making of the preassembly, able to be uncompacted, is united with each stirrup of the product at both open vertexes of each stirrup. Such arrangement is particularly advantageous since it stabilizes at the same time the shape of the single stirrups and the one of the whole preassembly. In the compacted configuration the shape of the preassembly able to be uncompacted is in fact principally issued by the shape of the single stocked stirrups. Therefore the closing of the open vertexes of the single stirrups determines a compacted preassembly minimally deformable by the handling and the transport.
Moreover, it is worth noting that the particular bight shape turned toward the inside of the fixing elements of the preassembly on compacted configuration assures that, also in the uncompacted or outstretched configuration and in absence of tractions operating on the preassembly, the fixing tracts are substantially oriented toward the inside of the structure. Therefore there is substantially no risk that the interconnection tracts could engage the space external to the concrete product where they could get, trigger or diffuse undesired corrosion occurrences.
Besides, an advantageous aspect of the invention consists of an uncompacted preassembly in the cited outstretched configuration and as well completed with a plurality of strengthening bars which constitute the longitudinal or main reinforcement, by means of turnable fixing means. Such turnable fixing means are suitable to perform the union of the stirrups with the above mentioned strengthening bars with a function similar to articulated junctions or hinges. In such way the so-made reinforced preassembly is suitable to be closed again in a flatten configuration, thanks to the cited articulated junctions. In such way it is possible to pre-assemble a structure which has all the necessary reinforcements or project reinforcements, which can be reduced to a closed configuration, flatten, which eases the transport, the handling, as well as its immediate use in the building site. As matter of facts, thanks to the cited function of the turnable junctions, the reinforced preassembly can be put again in its outstretched configuration directly at the building site for performing the accomplishment operations, exclusively related to the definitive blocking.

Description of Drawings

Details of the invention shall be more apparent from the detailed description of a preferred embodiment of the apparatus for assembling reinforcements for reinforced concrete according to the invention, illustrated for indicative purposes in the attached drawings, wherein:

figure 1 shows a perspective view of the apparatus for assembling reinforcements for reinforced concrete according to the invention;
figures 2 and 3 show a perspective view of a unit used in the apparatus in following operative steps;
figure 4 shows a schematic perspective view of the unit shown in figures 2 and 3, together with the preassembly, able to be uncompacted, which can be obtained thereby;
figures 5, 6 and 7 show schematic views of further advantageous configurations of the product object of the invention.

Best Mode

With particular reference to such figures, the apparatus for assembling reinforcements for reinforced concrete according to the invention is indicated in its entirety with 1.
The apparatus 1 comprises a fixed frame 2 suitable to shape in its inside a storage housing 3 for a preassembly, able to be uncompacted. For example, such housing 3 can substantially have parallelepiped-shape structure and in such case the fixed frame 2 comprises a plurality of vertical rods 4, arranged at the vertexes of a correspondent base rectangle. The vertical rods 4 are stably linked through crossbars 5. Obviously it is possible to provide many other shapes for the storage housing and then for the fixed frame 2.
The storage housing 3 shaped by the frame 2 is suitable to receive the stirrups 6 to be assembled at an inlet zone 7 and more precisely on a plane delineated by a centering device, as better described hereinafter. In the disclosed case, the frame 2 is arranged leant on suitable feet 8 and the inlet zone 7 is shaped at the top of the pillars 4, being circumscribed by the correspondent top crossbars 5 of the frame 2. As an alternative, the frame 2 can be oriented in a different way, for example vertically, with its inlet zone 7 arranged vertically on a respective side of the frame.
The storage housing 3 is as well equipped with a mobile abutment plane or support plane 9, for example pierced-platform-shaped, assembled slidable on suitable sliding guides 10 preferably placed at the vertical rods 4. Such mobile support plane 9 is horizontally arranged in figure 1, but it can be differently placed, for example in vertical manner according to the orientation of the apparatus, as previously specified.
In particular, the support plane 9 is mobile about the cited sliding guides 10, that is in the approaching and spacing direction of the inlet zone 7 to the storage housing 3.
At the inlet zone 7 and, in the illustrated case, at the crossbars 5, the apparatus 1 comprises the above mentioned centering device 11 for the stirrups 6 to be assembled, a union device 12 for the union of a stirrup 6 received from the centering device 11 with at least one interconnection element 13 of flexible and substantially inextensible material. The apparatus comprises as well a feeding unit 14 of the interconnection element or elements 13 to be united with the stirrups 6.
The interconnection elements 13 are preferably metal elements of tape, wire or tubular type. Different elements or elements of different materials can also be provided, as long as they are provided with the cited mechanical characteristics. As concerns the technical meaning of such mechanical characteristics, the flexibility is to be intended so that such elements are suitable to freely assume a non-rectilinear shape, in particular folded, by means of approaching two spaced portions of the same element. On the contrary, the same property of the flexibility is to be intended so as that the interconnection element can on the contrary freely assume a shape substantially rectilinear coming from a bight-shape, when the above mentioned spaced portions are spaced in measure substantially equal to the extension of the tract, in the case defined by the structural project, which is interposed between them. Moreover, the cited inextensibility characteristic refers to the fact that the correspondent tracts of the interconnection elements keep, both in the free bight-configuration and in the rectilinear one, a constant extension, that is able to assure in a reliable manner a predetermined spacing of the stirrups united with them, as described hereinafter.
More precisely the centering device 11 preferably comprises a plurality of centering units independently mobile about the inlet zone 7 for allowing the correct positioning of a single stirrup 6 fed to the apparatus 1 and possibly the re-establishment of the correct shape of the stirrup 6 in case, because of an imprecision in the making or the deformability of row materials, it does not match the desired shape. The disclosed case provides a first centering unit 110a, a second centering unit 110b and a third centering unit 110c, each of them cooperating with a correspondent union unit 120 and with a respective feeding unit 140 of a correspondent interconnection element 13 (see figure 2).
For example it is possible to provide that the first centering unit 110a and the second centering unit 110b are carried mobile along the direction of a crossbar 5 of the fixed frame 2, for example for intercepting a respective couple of adjacent vertexes of a stirrup 6 and that the third centering unit 110c is, on the contrary, carried mobile along a direction parallel with respect to the preceding one, for intercepting an opposed portion of the same stirrup 6, so as to enable the positioning of a stirrup 6 on a determined interception plane. More precisely each centering unit 110 comprises a support arm 15 assembled slidable on at least one crossbar 5. In particular in the illustrated case the first support unit 110a and the second support unit 110b are slidably assembled, in an independent manner, on a same crossbar 5 of the fixed frame 2 through respective support arms 15a, 15b, while the third centering unit 110c comprises a support arm 15c assembled slidable and on a respective transversal element extended between a couple of crossbars 5 substantially parallel, perpendicular to the direction in which the remaining centering units are slidable. As an addiction and as an alternative, the cited arms can be provided turnable with respect to the crossbar on which they are assembled.
Each centering unit 110, in particular each support arm 15, carries a mobile support frame 16 suitable to be alternatively operated by respective operating means 17, mobile between an active advanced position, for intercepting at least one stirrup 6 and an inactive rear position for releasing the same stirrup. In the disclosed case each support frame 16 has a couple of lateral protuberances 18 suitable to intercept, through the cited alternative movement, respective portions of one end of the stirrup 6 or of sides adjacent to a same vertex of a stirrup 6.
In the cited advanced active position, the frame 16 intercepts a correspondent portion of the stirrup 6, holding up or blocking the passage to the inside of the storage housing 3, while, in the cited inactive rear position, the mobile frame 16 of the arm 15 frees the passage to the stirrup 6 of the inlet zone 7 towards the storage housing 3. It is to be observed that the interception portions of the respective frames 16 of the support arm 15 of the centering units 110 are preferably coplanar, that is in any case arranged in such way to delineate the cited interception plane for each stirrup 6.
Each centering unit 110 comprises as well auxiliary abutment means 19 suitable to enable the centering of a stirrup 6 and the re-establishment of the correct shape within the cited interception plane. In the disclosed case the auxiliary abutment means 19 comprise for each centering unit 110 a couple of abutment bodies. For example the abutment bodies 19 can be cylindrical and can be arranged on the cited lateral portions for the interception of the mobile frame 16 of the support arm 15 (see figures 2 and 3).
Each union unit 120 comprises union means for performing the union of a portion of a stirrup 6 intercepted and centred with respect to the abutment bodies 19, with a correspondent portion of an interconnection element 13. The unit comprises as well a tightening member 20 suitable to tighten the portion of stirrup 6 to be united with a portion of an interconnection element 13. The tightening member 20 shapes a jaw articulated to a pin 21 fixed transversally to the frame 16 of the support arm 15. The jaw 20 is articulated to operating means 22 suitable to allow its tilting about the transversal pin 21. Therefore the jaw 20 is suitable to be alternatively operated between an opening position, wherein the portion of the stirrup 6 intercepted by the centering unit 110 is free from the tightening (see figure 3), and a closing position, wherein the portion of the stirrup 6 is blocked by the jaw 20 (see figure 2).
In the disclosed case the provided union means are welding means, therefore the tightening member 20 serves also as welding electrode, cooperating with a conjugated body 23 suitable to serve as opposed polarity electrode, being opposed to the jaw 20 with respect to the portion of the intercepted stirrup 6. The conjugated body 23 (see figure 2) is preferably carried by the support frame 16. The conjugated body 23 is preferably shaped so as to provide a curved operating surface 24 suitable to receive in unwinding the interconnection element 13 dragged by the feeding unit 140. The operating surface 24 is shaped so as to progressively orient the interconnection element 13 in a direction substantially perpendicular to the interception plane of the stirrup 6. In other words, the conjugated body 23 leads the interconnection element 13 to arrange itself according to a direction longitudinal with respect to the reinforcement to be assembled, in which the stirrups 6 represent the transversal reinforcement elements. As an alternative it is possible to provide union means of different kind, for example of mechanical union through crimping, riveting or sticking.
The feeding unit 140 comprises dragging means 25, suitable to feed in controlled way tracts of the interconnection element 13 of predetermined extension. Such dragging means 25 can be made for example by a couple of dragging wheels, smooth, worked or suitably covered, suitable to drag while dragging the interconnection element 13. In substance the element 13, preferably made by metal tape, is interposed among the wheels 25 for being dragged with precision by the rotating motion of this one.
The dragging means 25 are advantageously operated through control means, for example of encoder type. Such control means are suitable to drive the unwinding of a determined extension of tape 13, so as to assure that a quantity of tape or similar element 13 that is unwound between a union point and the following one is equal to the pre-established one. As far as it is concerned, it is necessary to underline that in the structural project extension of the tape of different length between two following stirrups 6 can be provided, in order to allow the structure, in its entire, to have profiles suitable to different shapes or structural requirements. For example through non-rectilinear crossbars or fan-shaped stirrups or anyway inclined for optimizing the endurance against cutting stresses.
The wheels 25 are preferably aligned to the conjugated body 23 and to the actuation direction of the support frame 16, that is transversally to the portion of the intercepted stirrup 6 and to the articulation pin 21 of the jaw 20. Therefore the dragging made by the wheels 25 drives the tape 13 firstly on the operating surface 24 of the conjugated body 23 and then in the passage channel between the same body 23 and the stirrup 6 to be united.
In figures 2 and 3 the first centering unit 110a is illustrated during the steps of respectively tightening interception and release. It is important to observe that the first centering unit 110a intercepts in this case a portion of the stirrup 6 which corresponds to the overlapping vertex of the end hooks 6a, while the remaining centering units 110b, 110c respectively intercept a second vertex and a middle portion of an opposed end of the same stirrup 6, as shown in figure 1.
Such arrangement is particularly advantageous since the first centering unit 110a is suitable to cooperate with the union means 120 for performing the union of both overlapped ends of the stirrup 6 with correspondent portions of the interconnection element.
It allows to stabilize in considerable manner the structure of the stirrup 6, in particular by avoiding that not reciprocally united end hooks could allow an extreme deformability to such elements which indeed result open.
The functioning of the apparatus, as well as the steps of the method according to the invention are understandable though the preceding description.
In a starting step, an interconnection element 13, for example a metal tape, is prearranged at each feeding unit 140. Preferably the unwound tape tract is long enough to reach and overcome the operating surface 24 of the conjugated body 23. More precisely the exceeding tape or similar element beyond the operating surface 24 can contribute together with an opposed edge tract of tape or similar corresponding exceeding element to the final binding of the compacted preassembly.
In the same starting step, a first stirrup 6 is fed to the apparatus 1. For this scope the support frames 16 of the centering units 110 are prearranged in active advanced position. The first stirrup 6 is then fed and intercepted on the plane bounded by the side portions of the support frames 16, intercepting the tape or similar element 13 against the conjugated body 23.
Moreover the mobile support plane 9 is prearranged in a position close to the interception plane, in the storage housing 3 beyond the inlet zone 7.
Subsequently the tightening members 20 are operated for firmly tightening the portions of tape or similar unwound externally to the portions of stirrups intercepted by the centering units 110.
Then the union means are operated, performing the union of the tapes 13 or similar elements with the stirrup 6 in each of the intercepted positions. As previously disclosed, it is preferable that one of the unions with the fed stirrup 6 is made at the vertex of the stirrup comprising both overlapped portions of the hooks 6a, so as to assure a better structure endurance.
In a step following to the union, the tightening members 20 are driven back to the inactive open position, disengaging the intercepted portions of the stirrup 6 and of the belt 13.
The dragging means 25 are then operated in a controlled way, so as to unwind a tract of belt 13 of pre-established length. More precisely such extension corresponds to the distance between the first stirrup 6 and the following one according to the structural project. In case, for example, the project provides that the stirrups 6 are arranged in parallel manner, the measure of such unwinding is equal for each dragging element and corresponds to the projected step between the correspondent stirrups. As an alternative, the project could provide that the stirrups 6 are arranged within the reinforcement according to inclined laying planes, with the purpose of adapting their orientation to the distribution of the foreseen cutting loads. In such case the unwinding of tape 13 or of other similar element could be driven in a different measure for different feeding units 140. As well, it is possible to provide, and it is advisable, that in such case the fed stirrups 6 have different shape, for making a preassembly of parallelepiped shape also with stirrup orientations on incident planes. In this case is preferable that the apparatus for making stirrups linked to the apparatus according to the invention is connected to the same apparatus through electronic communication means suitable to transmit in input to the centering units 110 the geometrical parameters of the stirrups to be shaped, so as to automatically adapt the position parameters according to the variations of the production parameters.
It is to be noted that the tape 13 or similar element is arranged in this way toward the inside of the stirrup 6. Thanks to the flexibility of the same, the tape 13 or other similar element is arranged inside the stirrup 6 forming a bight.
In particular, using interconnection means 13 of the tape or strap type, that is with a substantially flat section, the flexibility is increased around the main axis of the section, therefore the unwinding of exceeding material entails the arrangement of the same element in bights toward the inside of the stirrups 6.
In a following step, or as an alternative before the previously described feeding step, the first stirrup 6 united to the tapes 13 or to similar interconnection elements is released by the centering units 110, through the displacement of the support frames 16 in the inactive position. The stirrup 6 is then transferred to the mobile support plane 9 prearranged close to the storage housing 3 for receiving the preassembly in formation.
Then a second stirrup 6 is fed for being united with the prearranged tapes 13, in the very same way of the preceding case. In particular it is necessary to underline that the controlled feed performed in the preceding step assures that the tract of tape 13 interposed between the just made union and the one to be made is equal to the distance pre-established by the project between the correspondent portions of the first and the second stirrup of the reinforcement to be formed. It is also to be noted that in such step, the first stirrup placed on the abutment plane and the second stirrup are preferably at an approached distance with respect the one of the project. Therefore the tract of the disengaged interconnection element 13 already united with one end of the first stirrup 6 arranged on the abutment plane forms the cited bight configuration turned inwards between the first and the second fed stirrup. Moreover it is to be noted that the positioning of the second stirrup 6 intercepts, between the same stirrup 6 and the union and tightening means 20, a determined portion of tape or similar fed element 13. The distance between such determined portion and the portion of the interconnection element 13 previously united with the first stirrup 6 corresponds to the distance established by the project between the same stirrups.
In the following operative step the union of the second stirrup 6 with different fed elements 13 is performed through the union and tightening means 20.
Further tracts of interconnection elements 13 of controlled extension are unwound by the feeding units 140. The mobile support plane 9 is suitably spaced from the interception plane of the centering groups 110, so as to create between them a space for the second stirrup 6 already united according to the thickness which it occupies and in suitable step relationship. Subsequently this second stirrup 6 is released towards the support plane 9 in contact with the already placed first stirrup. In this way a preassembly, able to be uncompacted, comprising the stirrups 6 and the interconnection tapes 13 is created on the above mentioned mobile support plane 9 (see figure 4).
It is to be noticed that in the particular case in which the apparatus 1 has an extension different than the vertical one, it is possible to provide that in the preassembly assemblage step, the stirrups 6 united in succession with the interconnection elements 13 are stored on the mobile support plane 9 in a not completely stacked configuration, that is maximally compacted, and that the complete compaction in instead performed in a final step, suitably approaching the mobile support plane 9 with the last stirrup 6 united with the preassembly.
The preassembly results anyway completed in the storage housing 3 when all the stirrups 6 provided by the project are united at the pre-established distances and approached to each other in a final compacted configuration.
As said before, the compacted preassembly preferably has exceeding corners of tape or similar element 13 exceeding from the edge stirrups. In a preparation final step it is possible to perform the tying of such terminal corners in order to assure the preassembly to be in the compacted configuration. Such preassembly is anyway easy to uncompact, by simply removing the cited tying, if provided, and performing a traction to the edge stirrups. It will be also easy to introduce the longitudinal strengthening bars when the assembled preassembly is still in compacted configuration. In the uncompacted configuration then the preassembly brings the stirrups back to the precise positions imposed in the preassembly production step as provided by the project, thanks to the inextensiveness of the interconnection element.
According to a further preferred embodiment of the disclosed assembling method, it is possible to obtain a preassembly 60, suitable to easily be re-compacted for easing the transport toward the building site.
Such preassembly 60, shown in figures 5, 6 and 7 is formed by means of the following union of longitudinal strengthening bars 61 with at least some stirrups of the preassembly. More precisely the longitudinal strengthening bars 61 are inserted inside the preassembly in the project positions, for example at the vertexes of the stirrups 6 with not tightened unions, that is rotatable bonds, so that they allow a minimum play and a correspondent articulation movement in the union points. In such way the preassembly can cinematically be represented by an articulated quadrilateral.
That means that also after having tightened the bars 61 to the stirrups 6, for example through tying or similar kind of junctions, it is possible to rotate the stirrups 6 around the union portions, so as to flatten the preassembly, able to be uncompacted, in flattered configuration, keeping the bars 61 placed in the inside (see figure 6).
The preassembly reinforced in flattered position 60a is then easy to transport to the building site, where it can easily be opened by picking up the longitudinal strengthening bars 61 arranged on the top. The reinforcement, that is the reinforced preassembly 60, comes then back to the initial configuration, represented in figure 4, ready for the concrete casting. For making the structure stable in use it is finally enough to tighten the ends of the longitudinal strengthening bars 61 with the reinforcements of the pillars in the correspondent junctions. In this way the reinforced preassembly keeps itself the characteristics of reduced dimensions, but its accomplishment requires less labour in the building site because the longitudinal bars 61 result already inserted and correctly positioned. Obviously in this specific case it is preferable that the flexible interconnection means 13 of the preassembly are previously arranged on same opposed sides for easing the flattering of the product.
In practice, the embodiment of the invention, the materials used, as well as the shape and dimensions, may vary depending on the requirements.

Claims

Method for preassembling reinforcements for reinforced concrete consisting of a plurality of transverse stirrups (6) suitable to be fixed to longitudinal bars (61) in order to shape a reinforcement cage, the method characterised by the steps of:
a. prearranging an interception plane associated with a centering device (11) for a stirrup (6)

b. prearranging a mobile support plane (9) for said stirrups (6), mobile in a direction perpendicular to said interception plane and cooperating with said centering device (11) associated with said interception plane

c. prearranging a device (14) for feeding at least one flexible and inextensible interconnection element (13)

d. feeding a said first stirrup (6) to said interception plane, centering it on said plane by means of said centering device (11)

e. uniting said interconnection element (13) to said first stirrup (6) by means of a uniting device (20)

f. performing the controlled feed of a predetermined extension tract of said interconnection element (13) by means of said feeding device (14)

g. in suitable step relationship with said step f. of performing the controlled feed of said interconnection element (13), releasing said first stirrup (6) united to said interconnection element (13) towards said mobile support plane (9)

h. repeating steps from b. to g. in order to unite further stirrups (6) to said interconnection element (13)

i. performing in suitable step relationship the operation of said mobile support plane (9) in a direction perpendicular to said interception plane, receiving by said operation said stirrups (6) united to said interconnection element (13) in condition of compacted preassembly, wherein said stirrups (6) united to said interconnection element (13) are approached to each other between said interception plane and said mobile support plane (9) and said interconnection element (13) is folded in bights towards the inside of said stirrups (6).
Method according to claim 1, characterized in that said step i. of performing the operation of said mobile support plane (9) in direction to said interception plane is carried out successively to said step e. of uniting a said first stirrup (6) to said interconnection element (13) and before said successive step of uniting a said second stirrup (6) to said interconnection element (13) fed in a controlled way, progressively taking away said abutment plane (9) from said interception plane, and receiving in accumulation said approached stirrups (6) of said compacted preassembly in formation.
Method according to claim 2, characterized in that said step e. of uniting a said first stirrup (6) to said interconnection element (13) is realized at one vertex of said first stirrup (6), said vertex comprising a first end hook (6a) and a second end hook (6b) substantially overlapped or approached, by means of a first union of said first hook (6a) to said interconnection element (13) and a second union of said second end hook (6b) to said interconnection element (13) carried out in the same operating union step or in two successive steps.
Method according to claim 2 or 3, characterized in that said step f. of performing the controlled feed of predetermined length tract of said interconnection element (13) is carried out by means of means (25) for dragging said interconnection element (13), orienting said feed towards the inside of said preassembly in formation, in such a way that said bight folding of said interconnection element (13) is directed inside said preassembly.
Method according to claim 4, characterized in that said step e. of uniting said stirrup (6) to said interconnection element (13) is carried out by means of sealer means (20, 23, 24) or sticking means or riveting means or crimping means.
Method according to one of the previous claims, characterized in that said interconnection element (13) is united externally to said stirrup (6).
Apparatus for preassembling reinforcements for reinforced concrete consisting of a plurality of transverse reinforcement stirrups (6) suitable to be united to a plurality of longitudinal strengthening bars (61), characterised by comprising a centering device (11) suitable to define an interception plane for one said stirrup (6), a device (14) for feeding at least one flexible and inextensible interconnection element (13) to be united to said stirrup (6) in order to make a preassembly designed to be completed with said longitudinal strengthening bars (61) to shape said reinforcement for reinforced concrete, a device (12) for uniting said stirrup (6) to said interconnection element (13), said feeding device (14) being adapted to feed said interconnection element (13) towards the inside of said stirrup (6) and being associated with means for controlling the extension of the fed portion of said interconnection element (13) and said apparatus comprising a support plane (9) mobile in direction perpendicular to said interception plane, for housing said preassembly between said interception plane and said mobile support plane (9) in a compacted configuration, wherein said stirrups (6) united to said interconnection element (13) are reciprocally approached and wherein said respective controlled extension of said interconnection element (13) are folded in bights.
Apparatus according to claim 7, characterized in that said centering device (11) comprises a plurality of centering units (110a, 110b, 110c) mobile on said interception plane at an inlet zone (7) for said stirrups (6), in a way as to perform the centering of a said stirrup (6).
Apparatus according to claim 8, characterized in that each of said mobile centering units (110a, 110b, 110c) carries a respective union unit (120) of said union device (12) and a respective feeding unit (140) of said feeding device (14) for one said interconnection element (13).
Apparatus according to claim 9, characterized in that said feeding unit (140) comprises a couple of counter rotating dragging wheels (25), associated with control means of the encoder type to drag controlled extensions of said interconnection element (13).
Apparatus according to claim 9, characterized in that said feeding unit (140) is oriented in a way as to drag controlled extensions of said interconnection element (13) towards the inside of said stirrup (6) intercepted on said interception plane, producing the cited bight folding of said interconnection element (13) inside said preassembly.
Apparatus according to claim 10, characterized in that said union unit (120) comprises a conjugated body (23) shaping an operating surface (24) suitable to abut said interconnection element (13) against one said intercepted stirrup (6), said operating surface (24) being shaped in a way as to orient progressively said interconnection element (13) in a direction substantially perpendicular to said plane for intercepting said stirrup (6).
Apparatus according to claim 12, characterized in that said union unit (120) comprises tightening means (20) suitable to tighten a portion of said stirrup (6) intercepted on said intercepted plane by means of said centering unit (110) against said conjugated body (23), said tightening means (20) being able to be tilted between an opening position and a closing position.
Apparatus according to claim 13, characterized in that said centering unit (110a, 110b, 110c) comprises a support arm (15a, 15b, 15c) carried mobile by a fixed framework (2) and a support frame (16) carried mobile by said support arm (15a, 15b, 15c), alternatively between an active position for intercepting said stirrup (6) and an inactive position for releasing said stirrup (6) to said mobile abutment plane (9).
Apparatus according to claim 14, characterized in that each said centering unit (110a, 110b, 110c) comprises auxiliary abutment means (19) shaping a couple of abutment bodies carried by said support arm (15a, 15b, 15c) in order to cooperate with said mobile support frame (16) in step of centering of said intercepted stirrup (6).
Apparatus according to one of the previous claims, characterized in that said union means (120) perform the union of said interconnection element (13) externally to said stirrup (6).
Preassembly for making reinforcements for reinforced concrete, comprising a plurality of transverse stirrups (6) united to a plurality of flexible and inextensible longitudinal interconnection elements (13), wherein said stirrups (6) are leaning against each other in compacted configuration and said interconnection elements (13) are arranged in bights between a union of a said stirrup and the successive union, said compacted preassembly being able to be uncompacted by means of traction in an outstretched configuration wherein said bights are outstretched and determine the desired distancing between said stirrups (6), characterised in that said interconnection elements (13) are arranged in bights fed towards the inside of said preassembly and are united to the said support stirrups (6) without interruption and at reciprocal predefined distances.