DEVICE TO COMPLETE REINFORCEMENT CAGES AND RELATIVE METHOD

Abstract: Device (10) and method to complete reinforcement cages, used to insert a desired number of longitudinal rods (13) inside the perimeter of stirrups (12) of a pre-cage (11); the device (10) comprises at least a supporting plane (24), on which the pre-cage (11) is made to progressively advance and on which the rods (13) to be inserted are able to be arranged, lifting means (32) separated at intervals along the supporting plane (24) and able to assume a first low position ("I") located below the plane (24) and a second high position ("II") wherein they are able to lift the rods (13) above the lower edge of the stirrups (12), and a fixed abutment element (39) against which the front ends of the rods (13) are able to abut, the supporting plane (24) is able to move forwards, together with the pre-cage (11), from a first position ("A") to a second position ("B"), to progressively insert the rods (13) into the perimeter of the stirrups (12) and then, with the pre-cage (11) stationary, from the second position ("B") to the first position ("A").

Description: "DEVICE TO COMPLETE REINFORCEMENT CAGES AND RELATIVE METHOD" ■ & ■ - - "k -k FIELD OF THE INVENTION The invention concerns a device and a method to complete reinforcement cages made with round .pieces or metal profiles in general, used in reinforced concrete structures such as beams, pillars or foundations. To be more exact, the invention is used to insert a desired number of longitudinal completion rods inside the perimeter of the stirrups of a pre-cage during the step when the pre-cage itself is made. In the invention, the term "pre-cage" indicates a partly assembled cage, both as a structure formed by stirrups and a desired number of longitudinal rods according to the design project, and also as a structure formed by stirrups and auxiliary rods with the function of maintaining the stirrups joined together during the pre-assembly step. BACKGROUND OF THE INVENTION Metal cages used for reinforcement purposes in reinforced concrete structures comprise a plurality of longitudinal rods to which stirrups are associated, separated lengthwise at intervals. The cages can be assembled manually or automatically, by means of suitable machines known as cage-forming machines, which allow to make good quality cages with less workforce required. In the state of the art, the cages are assembled in two successive steps: firstly, a substantially standardized pre- cage is prepared by attaching auxiliary longitudinal profiles to the stirrups, the function of which is to keep the stirrups joined together; subsequently the cage is completed with the longitudinal rods according to the design project, mostly attached inside the perimeter of the stirrups . Although conventional procedures simplify some steps in making the cages, they have the serious problem of inserting the longitudinal rods inside the closed perimeter of the stirrups once the pre-cage is complete. This operation is very difficult, especially if the cages, and hence the relative longitudinal rods, are very long; it therefore entails risks to the safety of the workers, a numerous workforce, particular equipment and risk of damage to the material. Various solutions have been proposed which provide to keep the longitudinal rods raised with respect to a supporting plane on which the pre-cage is progressively formed and advances; although these solutions are satisfactory, in general, they can cause in some cases the partial deformation of and damage to the perimeter edges of the stirrups or the auxiliary profiles . The present Applicant has devised and embodied this invention to overcome these shortcomings and to obtain further advantages. SUMMARY OF THE INVENTION The invention is set forth and characterized in the main claims, while the dependent claims describe other characteristics of the invention. The purpose of the invention is to achieve a device and a method suitable to automate the operation of inserting a desired number of longitudinal rods inside the perimeter of the stirrups of a pre-cage while the latter is being formed, without risks of deformation or damage to the components of the cage . Another purpose is to achieve a device suitable to facilitate the discharge of the finished pre-cage, with the longitudinal rods located inside the perimeter of the stirrups. The device according to the invention comprises at least a supporting plane, arranged downstream of a cage-forming machine and on which the pre-cage is able to advance while it is progressively formed; the longitudinal rods to be inserted inside the perimeter of the stirrups are arranged on the supporting plane . According to one characteristic of the invention, the supporting plane is able to move cyclically, in a longitudinal direction and in a manner mating with the advance movement of the pre-cage being formed and for a travel substantially mating with the interaxis (step) of the relative stirrups . In cooperation with the supporting plane there is at least a fixed retaining and abutment element on which the front ends of the longitudinal rods to be inserted are able to abut; the longitudinal position of the abutment element is advantageously adjustable according to the length of the rods . The device according to the invention also comprises lifting means, arranged substantially transverse and at intervals along the supporting plane, able to keep the longitudinal rods at least temporarily raised to allow them to be inserted inside the perimeter of the stirrups . To be more exact, the lifting means are able to assume at least a first position, wherein they are arranged below the surface of the supporting plane, and a second position wherein they are raised with respect to the surface for a value at least such as to allow the rods resting on them to pass over the lower side of the stirrups. In a preferential embodiment, the lifting means consist of oscillating arms. According to a variant, the lifting means consist of arms movable vertically. According to another variant, the device according to the invention comprises a command and control unit able to govern the cycle of moving the supporting plane and the lifting means, according to the work cycle of the cage- forming machine to which the device is associated. According to the invention, the longitudinal completion rods are arranged on the supporting plane and then the pre- cage is begun. With every forward step of the pre-cage, there corresponds first a correlated forward movement of the plane, and then the plane retreats by the same value. When the plane advances together with the pre-cage, the lifting means are active, that is to say, raised, so that the longitudinal rods, which are held stationary with respect to the plane by the abutment element, are progressively inserted into the perimeter of the stirrups; when the plane retreats, the lifting means are de-activated, that is, lowered, so that the plane can return to the original position without interference between the lifting means and the stirrups, with the rods resting on the lower side of the perimeter of the stirrups . In the case where the oscillating lifting arms are used, they are activated, when the pre-cage is complete, to overturn the pre-cage on one side to allow it to be discharged. According to a variant, before the pre-cage is discharged, the plane advances slightly to free the rear end of the pre- cage from interference with the operating assemblies and with the structure of the cage-forming machine. BRIEF DESCRIPTION OF THE DRAWINGS These and other characteristics of the invention will be clear from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached drawings wherein: Fig. 1 is a view from above of a device according to the invention in association with a cage-forming machine suitable to produce pre-cages; Fig. 2 is a longitudinal section of the cage-forming machine shown in Fig. 1; Fig. 3 is an enlarged scale transverse section of the device according to the invention; Fig. 4 shows a variant of Fig. 3; Figs. 5a-5h show some steps in the method according to the invention. DETAILED DESCRIPTION OF PREFERENTIAL EMBODIMENT In the attached Figures, the number 10 denotes in its entirety a device able to insert longitudinal completion rods 13 inside the closed perimeter of stirrups 12 of a pre- cage 11. The device 10 is arranged downstream of a cage-forming machine 15 able to produce pre-cages 11 consisting, in the embodiment shown here, of two auxiliary profiles 14 and a plurality of stirrups 12; in this case, the auxiliary profiles 14 are shaped like a loop in correspondence with the points where they are attached to the stirrups 12 and are associated outside with the latter. The cage-forming machine 15 comprises a frame 22 on which, for each of the auxiliary profiles 14, a drawing assembly 16, a first 17 and second straightening assembly 18, a shaping assembly and a welding assembly 20 are assembled. Every drawing assembly 16 is able to make a relative auxiliary profile 14 advance, possibly unwinding it from a reel located upstream of the cage-forming machine 15; the straightening assemblies 17 and 18 serve to straighten the profile 14 respectively on the horizontal plane and on the vertical plane, the shaping assembly 19 is able to achieve relative loops along the profile 14 and finally the welding assembly 20 is able to attach the auxiliary profile 14 to the stirrups 12 which are located one after the other in the attachment position. The welding assembly 20 can include retaining means able to keep the stirrups 12 in position during the attachment operations . The cage-forming machine 15 also comprises tubular guide elements 21 inside which the auxiliary rods 13 are able to slide. The assemblies 16-20 acting on an auxiliary rod 14 are assembled on a slider 23 able to move with respect to the frame 22, so as to adjust the position thereof with respect to the assemblies 16-20 acting on the other auxiliary profile 14. The device 10 according to the invention comprises a supporting plane 24 extending lengthwise as an extension of the cage-forming machine 15; the pre-cage 11 as it progressively forms is able to advance thereon. The longitudinal completion rods 13 to be inserted inside the perimeter of the stirrups 12 are also able to be arranged on the supporting plane 24. The supporting plane 24 is made of several elements 24b and is assembled on a relative frame 26, together with which it can move lengthwise with respect to two bases 25 resting on the floor; one of them is visible in Figs. 2, 3 and 4. The frame 26 comprises two longitudinal profiles 26a, extending lengthwise substantially for as long as the plane 24; wheels 30 able to slide inside guides 31 solidly associated with the bases 25 are assembled on said profiles 26a. In this case, the frame 26, and hence the supporting plane 24, is moved by a motor reducer unit 27 assembled on one of the bases 25; the motor reducer unit 27 is able to make rotate, selectively in both directions, a pinion 28 engaged on a rack 29 associated with a longitudinal profile 26a of the frame 26, causing the supporting plane 24 to move forwards or backwards with respect to the cage-forming machine 15. To be more exact, the supporting plane 24 can move from a first retracted position, wherein it is closer to the cage- forming machine 15, to a second advanced position; the travel of the supporting plane 24 is advantageously equal to the interaxis "i" between the stirrups 12 of the forming pre-cage 11. The device 10 also comprises a command and control unit of the programmable type, not shown here, able to govern the cycle of the motor reducer unit 27 to define the travel "c" according to the work cycle of the cage-forming machine 15. Along the frame 26 there is a plurality of arms 32, arranged substantially transverse with respect to the longitudinal profiles 26a and separated at intervals along the supporting plane 24. The arms 32 are housed in corresponding slits 33 made between the elements 24b of the supporting plane 24; the arms 32 are able to assume at least a first lowered position "I", wherein they are arranged below the upper surface 24a of the supporting plane 24, and a second raised position "II", wherein they are arranged substantially horizontal. In the raised position "II", the upper edge 32a of the arms 32 is located at a height "h" from the surface 24a of the plane 24 which is greater than the diameter of the stirrups 12, so as to allow the progressive insertion of the rods 13 into the perimeter of the stirrups 12 without knocking or getting stuck. The arms 32 are arranged in positions such that they never interfere with the stirrups 12 of the forming pre-cage 11; in a preferential embodiment, the distance "d" between the arms 32 is an integral multiple of the interaxis "i" between the stirrups 12. In this case, in the retracted position of the supporting plane 24, the first arm 32, that is, the one nearest the cage-forming machine 15, is located at a distance "e" from the vertical plane "Y" on which the stirrups 12 are attached, equal to the sum of the interaxis "i" and an additional offset value "x" . In the embodiment shown in Figs. 1-3, the arms 32 are associated with a longitudinal bar 34 arranged next to the supporting plane 24 and able to be made to rotate, when so commanded by the command and control unit, by actuators 35 associated with the frame 26. The actuators 35 have their stems 35a pivoting on relative levers 36 solid with the longitudinal bar 34; by activating the actuators 35 the longitudinal bar 34 is made to rotate causing the arms 32 to oscillate between the first position "I" and the second position "II" . As can be seen in Fig. 3, the arms 32 can assume a third position "III", raised and inclined with respect to the supporting plane 24, which is assumed in order to laterally discharge the finished pre-cage 11, with the rods 13 inside it. In the variant shown in Fig. 4, the arms 32 are attached to a connection beam 38, with which the stems 37a of vertical axis actuators 37 are associated at the lower part; by activating the actuators 37, the arms 32 are able to be arranged either in the first position "I" or in the second position "II", remaining substantially horizontal. In cooperation with the supporting plane 24, in a substantially terminal position thereof, there is a fixed abutment element 39, against which the front ends of the longitudinal rods 13 are arranged; the position of the abutment element 39 is advantageously adjustable according to the length of the longitudinal rods 13 to be used. The device 10 according to the invention functions as follows. First, the longitudinal rods 13 are arranged on the supporting plane 24, then on the arms 32 too, adjusting the position of the element 39 so that it serves as an abutment for the ends of the rods 13. In this step, the supporting plane 24 is in its first retracted position "A", while the cage-forming machine 15 attaches a first stirrup 12 to the auxiliary profiles 14 (Fig. 5a) . When the first stirrup 12 has been attached to the profiles 14, the pre-cage 11 advances by one step equal to the interaxis "i" and simultaneously the supporting plane 24 moves into its second, advanced position "B" with the arms 32 in the second raised position "II" (Fig. 5b) . Since the rods 13 are held stationary by the abutment element 39, the advance of the plane 24 causes the rods 13 to be progressively inserted into the perimeter of the first stirrup 12. Subsequently, while the cage-forming machine 15 attaches a second stirrup 12 to the profiles 14, the supporting plane 24 retreats until it returns to its first position "A", as the pre-cage 11 is stationary because it is held by the assembly 16; in this condition, the arms 32 are lowered into the low position "I", so that they can slide below the lower side of the stirrup 12 (Fig. 5c) . The cage-forming machine 15 then provides to make the pre- cage 11 advance again, and the supporting plane 24, on which the first stirrup 12 is also resting, moves in mating manner, moving to the advanced position "B", while the arms 32 are again raised to their second position "II" to continue the insertion of the rods 13 into the second stirrup 12 too (Fig. 5d) . Then, while the cage-forming machine 15 attaches the third stirrup 12, the supporting plane 24 again retracts towards its position "A" , after having again lowered the arms 32 (Fig. 5e) . This cyclical movement is repeated for every stirrup 12 (Figs. 5f, 5g, 5h) , until the longitudinal rods 13 are inserted into the perimeter of all the stirrups 12 of the pre-cage 11. When the work cycle has been completed, the cage to be made can be completed by welding the longitudinal rods 13 to the pre-cage 11, without needing complex and difficult operations of inserting the longitudinal rods 13. This operation can be made directly on the supporting plane 24 or in another suitable site. As we have said, the finished cage or pre-cage 11 with the longitudinal rods 13 inserted can be laterally discharged by first making the plane 24 advance slightly to free the pre- cage 11 from interference with the operating assemblies of the cage-forming machine 15, and then moving the arms 32 to their third position "III" . It is obvious, however, that modifications and/or additions can be made to the device 10 and the method as described heretofore, without departing from the spirit and scope of the invention. For example, the means to move the supporting plane 24 and the arms 32 can be of a different type from that shown here. The supporting plane 24 can extend as far as in correspondence with the vertical plane "Y" where the stirrups 12 are attached. The supporting plane 24 can also rest directly on the floor, and be equipped with wheels, pads or similar, without requiring the base 25 and the movement system shown above. The abutment element 39 can be associated with its own movement means on the ground, and possibly be shaped to cooperate with rods 13 of a particular section, other than round. It is also obvious that, although the invention has been described with reference to specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of device and perfect identical methods, all of which shall come within the field and scope of the invention.

Claims: CLAIMS 1 - Device to complete reinforcement cages, used to insert a desired number of longitudinal rods (13) inside the perimeter of stirrups (12) of a pre-cage (11) while the pre- cage (11) is being formed, said device comprising at least a supporting plane on which the pre-cage (11) is made to progressively advance and on which said rods (13) to be inserted are able to be arranged, the device being characterized in that it comprises lifting means (32) separated at intervals along said supporting plane (24) and able to assume a first low position ("I") located below said plane (24) and a second high position ("II") wherein they are able to lift said rods (13) above the lower edge of said stirrups (12), and a fixed abutment element (39) against which the front ends of said rods (13) are able to abut, and in that said supporting plane (24) is able to move forwards, together with said pre-cage (11) , from a first position ("A") to a second position ("B"), with said lifting means in the high position ("II"), to progressively insert the rods (13), held by the element (39), into the perimeter of the stirrups (12) and then, with said pre-cage (11) stationary and with said lifting means (32) in the low position ("I"), from said second position ("B") to said first position ("A"), to return to start-of-cycle position. 2 - Device as in Claim 1, characterized in that the position of said abutment element (39) can be adjusted lengthwise along said supporting plane (24) . 3 - Device as in Claim 1, characterized in that the travel of said supporting plane (24) from said first position ("A") to said second position ("B") mates with the interaxis ("i") between the stirrups (12) of said pre-cage (11) . 4 - Device as in any claim hereinbefore, characterized in that said lifting means comprise arms (32) arranged transverse with respect to said supporting plane (24) and housed inside compartments (33) separated lengthwise along said plane (24) . 5 - Device as in Claim 4, characterized in that said arms (32) are associated with means (34) rotating in both directions and able to cause said arms (32) to oscillate between said first low position ("I") and said second high position ("II") and vice versa. 6 - Device as in Claim 5, characterized in that said arms (32) are able to assume a third position ("III") more raised with respect to said supporting plane (24) in which they are able to determine the discharge of the pre-cage (11) from said plane (24) onto one side. 7 - Device as in Claim 4, characterized in that said arms (32) are associated with a connection beam (38) able to move vertically to take them at least from said first low position ("I") to said second high posi.tion ("II") and vice versa . 8 - Device as in any claim hereinbefore, characterized in that said supporting plane (24) is associated with at least a relative fixed base (25) with respect to which it is movable 1engthwise. 9 - Device as in Claim 8, characterized in that it comprises motor means (27) able to act on at least a pinion (28) engaged on rack means (29) to move said supporting plane (24) with respect to said base (25) . 10 - Device as in Claim 8, characterized in that said supporting plane (24) is provided with sliding means (30) able to move inside mating guides (31) associated with said base (25) . 11 - Device as in any claim hereinbefore, characterized in that it comprises a command and control unit able to govern and control the movement cycle of said supporting plane (24) and of said lifting means (32) . 12 - Device as in any claim hereinbefore, wherein said device is located downstream of a cage-forming machine (15) defining a plane ("Y") for positioning the stirrups (12) to attach them to relative longitudinal connection profiles (14), characterized in that, in the first position ("A") of said supporting plane (24), the lifting means (32) nearest said cage-forming machine (15) is located at a distance ("e") from said plane ("Y") substantially equal to the sum of the interaxis ("i") between said stirrups (12) and an additional value ("x"): ( "e"= "i" + "x" ) . 13 - Method to complete reinforcement cages, used to insert a desired number of longitudinal rods (13) inside the perimeter of stirrups (12) of a pre-cage (11) while the pre- cage (11) itself is being formed, the method providing the following steps : - said longitudinal rods (13) are positioned on a supporting plane (24) with the respective front ends arranged against a fixed abutment element (39); - at least a first stirrup (12) is positioned in correspondence with a work plane ("Y"), and at least one auxiliary longitudinal profile (14) is attached to said stirrup (12) ; - said stirrup (12) and said at least one auxiliary profile (14) are fed forwards; - a new stirrup (12) is positioned in correspondence with the work plane ("Y") and the cycle is repeated, the method being characterized in that for every cycle to position, attach and feed every new stirrup (12) , it provides a first step wherein said supporting plane (24) advances in coordination with said at least one stirrup (12), and a second step wherein said supporting plane (24) retreats with said at least one stirrup (12) stationary, in said first advance step, wherein the supporting plane (24) is fed forwards, lifting means (32) being activated, arranged separated at intervals along said supporting plane (24) and able to hold said rods (13) raised, held stationary by the abutment element (39) , to allow said rods (13) to be inserted inside the perimeter of said stirrups (12), and in said second step, wherein the supporting plane (24) retreats, said lifting means (32) being lowered to allow them to pass below said stirrups (12). 14 - Method as in Claim 13, characterized in that it provides that said supporting plane (24) is moved for a travel ("c") mating with the interaxis between the stirrups (12) of said pre-cage (11) . 15 - Method as in Claim 13 or 14, characterized in that it provides, when the pre-cage (11) is complete, at least a step to laterally discharge said pre-cage (11) from the supporting plane (24) by taking said lifting means (32) to a third position ("III") raised higher with respect to said supporting plane (24) . 16 - Method as in Claim 15, characterized in that it provides, before the lateral discharge step, to advance the supporting plane (24) to free the rear end of the pre-cage (11) from interference with the assemblies which position, attach and advance the stirrups (12) .

Inventors: DEL FABRO GIORGIO, DEL FABRO MARCELLO, DEL FABRO, GIORGIO, DEL FABRO, MARCELLO
Applicants: DEL FABRO GIORGIO, FABRO MARCELLO DEL, PIEGATRICI MACCH ELETTR, DEL FABRO, GIORGIO, DEL FABRO, MARCELLO, M.E.P. MACCHINE ELETTRONICHE PIEGATRICI SPA
Application year: 2001
Main classification: B21F27
IPC codes: B21F27, B21F31, E04C5