Field of the Invention

The present invention relates to an automated assembly machine for manufacturing rebar structures, such as rebar cages or engineered meshes, in multiple dimensions. The assembly machine comprises at least one robot unit capable of moving along the production area, while the cage or mesh is preferably fixed in the longitudinal direc tion during the assembly process. The longitudinal rebar elements and the transverse rebar elements are preferably loaded into the assembly machine in an automated pro- cess.

Background of the Invention

During construction it is known to embed reinforcing rebar cages or engineered mesh es into the concrete to strengthen and hold the concrete structure in tension. Such re- bar cages or engineered meshes may be pre-fabricated at a production facility and then transported to the building site. This reduces the total assembly time and improves the quality of the assembled cage or mesh.

The rebar cages may be assembled manually using a jig system where the stirrups are individually positioned along the jig system after which the longitudinal rods or bars are fed manually through each of the stirrups. The worker then secures each longitudi nal rod to the stirrups by either spot welding, a mechanical connection or by tying a steel wire around the stirrup and longitudinal rod or bar at the crossings. However, this manual assembly process is highly labour intensive and time consuming. Today it may take several hours to few days to complete a cage structure for a team of 5-10 workers.

The rebar cages may instead be assembled using a semi-automated machine where the worker manually loads the stirrups into the machine and then manually feeds the lon- gitudinal rods trough the stirrups. Afterwards, the machine automatically welds the stirrup to the longitudinal rods in a pre-determined position and moves the structure to the next position where the next stirrup is welded in place. Alternatively, the rebar cages may be assembled using another machine where the worker initially positions the stirrups along a holding frame, and then manually feeds a first set of longitudinal rods through the stirrups. The longitudinal rods are resting on a number of supporting arms distributed along the holding frame. The worker then raises the support arms into a first vertical position relative to the stirrups and manual ly welds the longitudinal rods to each stirrup. The support arms are afterwards low ered and a second set of longitudinal rods are manually fed into the machine. The sup port arms are then raised to a second vertical position, and the worker then manually welds the longitudinal rods to each stirrup.

In above machines, the worker has to manually feed the longitudinal rods into the ma chine from one end. This requires a corresponding amount of free spacing in order to feed the rods into the machine as well as unloading the finished cage. A known prob lem with moving cages is that it is difficult maintain the precision as the cage is moved back and forth during the assembly process.

Instead of manually placing stirrups in the machine, a continuous wire may be auto matically welded onto the longitudinal rods via a robotic welding unit as the longitu dinal rods are rotated around a rotation axis. However, the longitudinal rods are still manually being fed into this machine.

The above machines are only capable of handling rods with a diameter less than 16 millimetres. Cages comprising thicker rods have to be assembled manually, typically by 4 to 10 workers. The above mentioned semi-automated machines are also not ca- pable, or very limited and restricted in terms of freely placing the stirrups next to each other with approximately zero spacing.

Engineered meshes may be assembled in a fully-automated machine where the longi tudinal rods are fed onto a loading table where the longitudinal rods are spaced apart. The arrangement of longitudinal rods is then transferred to a stationary welding sta tion. The transverse rods may be stored in a magazine above the welding heads and then continuously fed onto the longitudinal rod arrangement. Alternatively, the trans verse rods may be fed onto a second loading table where the transverse rod arrange ment is then transferred onto the longitudinal rods. The welding heads then weld the transverse and longitudinal rods together to form the engineered mesh as the longitu dinal rods are being pulled through the welding station and onto an unloading table. However, this machine takes up a lot of space in the production area, and is only able to handle rods with a diameter of 16 millimetres or less.

US 2008/0333764 A1 discloses an assembly machine, comprising a table for receiving two vertical rebar mats and a plurality of vertical spacers, a set of movable robotic arms arranged on either side of the receiving table, and a loading unit arranged at one end of the receiving table. The loading unit is used to load the vertical spacers from a separation or cutting station to a conveyor unit extending along a side of the receiving table. The rebar mats are loaded from a separate assembly station arranged parallel to the receiving table via the adjacent robotic arms or an overhead crane.

Object of the Invention

An object of the invention is to provide an assembly machine and method that solves the abovementioned problems.

Another object of the invention is to provide an assembly machine and method that reduces the total assembly time and is much less labour intensive.

Yet another object of the invention is to provide an assembly machine and method that take up less space in the production area.

A further object of the invention is to provide an assembly machine and method that allows for the manufacture of two- or three dimensional reinforcement structures us ing the same machine setup.

Description of the Invention

One object of the invention is achieved by an assembly machine for manufacturing of reinforcement structures, such as rebar cages or meshes, comprising:

- a production area extending in a longitudinal direction and in a transverse direction,

- a plurality of support arms arranged relative to the production area, each of the sup port arms extending the transverse direction,

- a first loading unit arranged relative to the support arms, the first loading unit being configured to load a number of longitudinal rebar elements onto the support arms in the transverse direction, wherein the longitudinal rebar elements are fixed in the longi tudinal direction by the support arms,

- at least one holding unit configured to hold a number of transverse rebar elements, the at least one holding unit being arranged relative to at least one moveable robot unit,

- where the at least one moveable robot unit comprises at least one robotic arm, wherein the at least one robotic arm is configured to be fitted with at least one tool, the at least one moveable robot unit is configured to move along the production area in the longitudinal direction so that the transverse rebar elements are moved along the longitudinal rebar elements during assembly.

This provides a compact assembly machine that has a smaller overall footprint com pared with conventional assembly machines. This also provides a multi-functional assembly machine capable of manufacturing two-dimensional as well as three- dimensional reinforcement structures using the same machine setup and space. The present assembly machine is able to manufacture cages or meshes with any kind of rod or bar diameter in a fully-automated process. Further, the cage or mesh structure is kept stationary in the present assembly machine thus fewer components are required compared to conventional assembly machines where the cage or mesh structure is moved through the machine. The cages and meshes may thus be manufactured with higher precision.

The present assembly machine comprises a production area extending in the longitu dinal direction and further in the transverse direction in which the cage or mesh is assembled. A plurality of support arms are distributed along the production area in the longitudinal direction. Each support arm is configured to provide support for all or some of the longitudinal rebar elements. The support arms may each extend partly or fully along the production area in the transverse direction. The support arms may fur ther be arranged at one or both sides of the production area.

The longitudinal rebar elements are preferably fixed in the longitudinal direction by the support arms. This may simply be achieved by the design of the support arms, such as by integrated recesses or teeth where each recess or pair of adjacent teeth is shaped to hold one or more longitudinal rebar elements. This may also be achieved by mechanical means arranged on the support arms, such as described later.

A first loading unit is arranged relative to the production area, e.g. at one side, and extends in the longitudinal direction. The first loading unit is configured to load the longitudinal rebar elements onto all or some of the support arms. The first loading unit may further be configured to separate a bundle of longitudinal rebar elements and to load the longitudinal rebar elements individually. The longitudinal rebar elements may thus be automatically loaded into the assembly machine in a transverse direction, thereby providing a more compact footprint. Alternatively, the longitudinal rebar ele ments may be automatically loaded onto the respective support arms from one end of the production area in the longitudinal direction. This setup may be suited for slim production halls as it takes up less space in the transverse direction. A cutting unit may be arranged relative to the first loading unit for cutting each longi tudinal rebar element into the desired length. Alternatively or additionally, a bending unit may be arranged relative to the first loading unit for bending the longitudinal re bar elements into the desired profile. The longitudinal rebar elements may thus be cut and/or bend in a fully-automatic step as they are fed into the first loading unit.

Instead of automatically bending and/or cutting the transverse elements and/or the longitudinal rebar elements, this may be done manually or semi-automatically in a cutting or bending area. After the cutting and/or bending process, the respective ele ments may then be transferred to the loading unit(s). This may be desired for cages or meshes having a complex profile.

According to one embodiment, the at least one moveable robot unit comprises a first moveable robot unit with a first robotic arm and a second moveable robot unit with a second robotic arm, the first robotic arm being configured to be fitted with a first tool and the second robotic arm being configured to be fitted with a second tool.

The present assembly machine comprises at least one moveable robot unit with at least one multi-axial robotic arm which may be fitted one or more tools for performing different tasks, such as welding or binding. The robot unit may be arranged on a base moveablely connected to a rail, a track or a frame, wherein a local drive unit, e.g. a motor, may be configured to move the base with robot along the rail, track or frame. Optionally, the robot unit may be moveably connected to a further rail or frame, wherein another local drive unit, e.g. a motor, may be configured to further move the base with robot along that further rail or frame. The robot unit may thus be moved in at least one direction, preferably in the transverse direction, the longitudinal direction and/or an orthogonal direction perpendicular to the transverse and longitudinal direc tion. The cage or mesh structure is thus kept stationary while the robot unit is moved back and forth during the assembly. Whereas in conventional assembly machines, the robot unit is kept stationary while the cage or mesh is moved back and forth during the assembly.

In example, the robot unit(s) may be arranged on a rail, track or frame positioned on one or both sides of the production area. Alternatively, the robot unit(s) may be sus- pended from a frame, track or rail positioned a distance above the production area. The position of the robot units may thus be adapted to the layout of the manufacturing facility.

Preferably, a first moveable robot unit with a first robotic arm and a second moveable robot unit with a second robotic arm are arranged relative to the production area. The first and second moveable robot units may be connected to individual rails or frames or a common rail or frame. Optionally, the first and second robots may be arranged on a common base and driven by a common drive unit. This saves time and allows differ ent task to be performed at the same time. This further allows the robot units to be moved individually or synchronously.

The first and second robotic arms may be fitted with different types of tools used dur ing the manufacture of the cage or mesh. In example, the first and second tools may be a welding tool, a binding tool, a gripping tool or another suitable tool. The first tool and/or the second tool may be adapted to fit the profile of the cage or mesh structure and/or the individual rebar elements. The first and/or second tool may also be a multi tool, e.g. a welding and gripping tool, configured to add multi-functionality to the ro bot unit without having to change tools or wait for another robot unit to assist with a specific task. Each robot unit may be fitted with one or more sensors or cameras which are connect ed to a controller. The controller may be configured to control the movement of the robotic arm based on the input signals from the sensors. This allows the tool to be positioned correctly relative to the cage or mesh. Optionally, the controller may use the input signals from the sensors to compensate for misalignment between the respec tive longitudinal and transverse rebar elements.

According to one embodiment, the plurality of support arms comprises a first set of first support arms and at least a second set of second support arms, wherein at least one of the first and second support arms is configured to move between a retracted position and at least a loading position or a holding position.

One or more sets of support arms may be distributed along the production area, wherein each set may be arranged to support a dedicated number of longitudinal rebar elements. Preferably, a first set of first support arms for supporting a first set of longi tudinal rebar elements and a second set of second support arms for supporting a sec ond set of longitudinal rebar elements. Optionally, additional sets of support arms may be distributed along the production area for supporting additional sets of longitudinal rebar elements.

Each of the first and second support arms may comprise a first part that may extend in the transverse direction on which the longitudinal rebar elements may rest. The first part may be connected a second part providing support for the first part and the longi tudinal rebar elements. The second part may comprise support feet, plates or legs.

Preferably, the first support arms and/or the second support arms may be configured so that the entire support arm, or at least a part thereof, may be moved between a re tracted position, a holding position and optionally a loading position. In example, the first and/or second support arm may be arranged on a rail so that it is able to move in the transverse direction. Alternatively, the first and/or second support arm may rotate in transverse plane around an axis perpendicular to the transverse and longitudinal directions. The respective support arms may thus be placed in different positions dur ing the assembly process. According to one embodiment, the at least one of the first and second support arms comprises at least one moveable part configured to move, e.g. extend, in at least the transverse direction or in an orthogonal direction perpendicular to the transverse and longitudinal directions and/or to rotate or pivot around a rotation or pivot point on the first or second support arm.

The first and/or second support arm may alternatively or additionally comprise at least one moveable part, e.g. the first part, which may be moved relative to another station ary part, e.g. the second part. This allows only a part of the support arm to be moved relative to the rest of the support arm.

In one example, the second part may be a telescopic part which may be extended or retracted in the orthogonal direction. This allows the support arm to be raised or low ered into a particular holding position so that the longitudinal rebar elements may be placed correctly inside the stirrups in order to form the desired cage structure.

In one example, the first part may be rotated in the transverse plane around an axis in the height direction. Alternatively, the first part may be a telescopic part which may be extended or retracted in the transverse direction. This allows the first part to be rotated or telescoped away from the cage or mesh structure.

In one example, the first part may be pivoted in the orthogonal plane around an axis in the longitudinal direction. This also allows the first part to be pivot away from the cage or mesh structure.

Preferably, the first and/or second support arm may be configured to be moved in multiple directions, i.e. at least two directions. This provides a more flexible move ment of the support arm relative to the cage or mesh structure. In conventional assem bly machines, the support arms are only able to move in the height direction (i.e. the orthogonal direction).

According to one embodiment, at least the first or second support arms further com prises means for locally moving at least one of the longitudinal rebar elements in at least one transverse direction relative to the transverse rebar elements. The support arms, e.g. the first or second support arms, may be fitted with local moveable means for moving the longitudinal rebar elements in one or both transverse directions. The moveable means may be a transport chain or belt, but other types of mechanisms may also be used. The chain or belt may be fitted with teeth or fingers for separation of the longitudinal rebar elements. The local moveable means may prefera bly be arranged on the first part of the respective support arm. This allows the longitu dinal rebar elements to be moved into any transverse holding or installation position relative the transverse rebar elements. When combined with raised or lowering the support arms, the longitudinal rebar elements may thus be moved freely relative to the transverse rebar elements. In particularly, enabling the longitudinal rebar elements to be positioned in any transverse position within the enclosed spacing of the stirrups.

The local moveable means may extend continuously along the first part, or be split into sections. Alternatively, one or more stop elements may be arranged relative to the chain or belt, wherein the stop element may be used to hold the longitudinal rebar el ement in place relative to the transverse rebar element. The stop element may be a moveable pin or tap. This allows the longitudinal rebar elements to be moved into a holding position as well as into position relative the transverse rebar elements In one embodiment, the local moving means comprises at least one open-ended space configured to receive multiple longitudinal rebar elements, the multiple longitudinal rebar elements being arranged in at least one layer and/or in at least one column.

The local moveable means may preferably comprise a plurality of open-ended spaces defined by a plurality of projecting teeth or fingers. Each open-ended space has a pre determined profile shaped to receive and hold one or more longitudinal rebar ele ments. The width and depth of the profile may be selected so that at least two longitu dinal rebar elements may be arranged in at least one layer and/or in at least one col umn within that space. A local clamping or gripping mechanism may be used to hold the longitudinal rebar elements in place. This allows the local moveable means to hold multiple sets of longitudinal rebar elements. According to one embodiment, at least the first support arms or the second support arms are configured to be moved individually and/or synchronously relative to each other. The support arms within one set may be moved, e.g. raised or lowered, in synchro nously or individually, as described later. Further, the first set of first support arms and the second set of second support arms may be moved synchronously or individu ally. The controller or a local control unit may control the movement of first and sec ond support arms. This allows the support arms to be moved together into a loading position. This also allows the individual support arms to be moved away from the cage or mesh structure to enable the transverse rebar elements (e.g. stirrups) to be moved along the longitudinal rebar elements.

According to one embodiment, the at least one holding unit is a magazine for storing a predetermined number of transverse rebar elements, the magazine being configured to move together with the at least one moveable unit.

The holding unit may be connected to the first and second moveable robot units so that it moves together with the first and second robots. The holding unit may extend over or under the cage or mesh structure in the transverse direction. The holding unit may simple be a magazine adapted to hold a plurality of transverse elements. This allows the transverse elements to be loaded in a bundle.

Alternatively, the holding unit may be connected to only one of the moveable robot units and extend in the longitudinal or transverse direction. The holding unit may then be loaded or re-loaded as the robot unit is moved along the production area.

According to one embodiment, the magazine is adjustable to hold transverse elements of different sizes and shapes.

The magazine may preferably be adjustable so that it can be adapted to hold transverse rebar elements of different sizes and shapes. The magazine may comprise a number of clamps, fingers or hooks for holding the individual transverse rebar elements. Other holding means may also be used. This increases the versatility of the magazine. Further, the holding means may be configured to guide the transverse rebar elements in the orthogonal plane during the longitudinal movement. In example, these holding means may be two sets of clamps, fingers or hooks arranged relative to each other. One set of clamps, fingers or hooks may be kept stationary while the other set of clamps, fingers or hooks may be adjustable to bring them into contact with the trans verse rebar elements. Alternatively, the holding means may comprise one or more telescopic arms which may be extended into contact with the transverse rebar ele ments. This prevents the rebar elements, e.g. the stirrups, from moving uncontrollable as the robot units are moving along the production area.

Alternatively, the assembly machine may comprise a set of magazines each adapted to a particular size and shape of the transverse rebar elements. The magazine on the as sembly machine may thus be interchanged with another magazine during the assem bly.

According to one embodiment, the assembly machine further comprises a second loading unit configured to load the transverse rebar elements into the at least one hold ing unit, preferably, the second loading unit is configured to move in and out of alignment with the at least one holding unit.

A second loading unit may further be arranged relative to the production area, e.g. at one end. This second loading unit may be configured to automatically load the trans verse rebar elements into the holding unit, e.g. the magazine, of the assembled ma chine. Alternatively or additionally, another bending unit may be arranged relative to the production area. The bending unit may be configured to automatically bend the transverse rebar element elements, e.g. stirrups, into the desired profile. This further reduces the number of manual steps and allows the workers to perform other tasks. This setup may be suited for slim production halls as it takes up less space in the transverse direction.

The second loading unit may be a moveable loading unit configured to move in and out of alignment with the holding unit or magazine. In example, the second loading unit may be arranged on a base moveably connected to a rail, track or frame, wherein a local drive unit, e.g. a motor, is configured to move it along the rail, track or frame. The second loading unit may be arranged relative to the robot unit(s) so that it may be aligned with the holding unit or magazine in the transverse or longitudinal direction. The transverse rebar elements may thus be loaded into the magazine, e.g. using the first and second robot units or via the second loading unit. This increases the versatili ty of the present machine setup compared to conventional assembly machines where the rebar elements are fed manually or directly from a payoff station.

The second loading unit may comprise a second magazine configured to hold a plural ity of transverse rebar elements. This second magazine may be pre-loaded before moving the second loading unit into alignment. The second loading unit may be con figured to transfer the transverse rebar elements from the second magazine and into the magazine of the holding unit, once the two magazines are aligned. This allows for quick loading and re-loading of the transverse elements.

According to one embodiment, the longitudinal rebar elements and/or the transverse rebar elements have a diameter of 16 millimetres or more.

The present assembly machine setup is particular suited for the manufacture of 3D reinforcement structures, such as rebar cages, and also 2D reinforcement structures, such as engineered meshes. The transverse elements may be shaped as stirrups or transverse rods or bars. The longitudinal rebar elements may be shaped as longitudinal rods or bars. Unlike conventional assembly machines, the present assembly machine is able to handle longitudinal rods and/or transverse rods having a diameter between 6-55 millimetres, preferably of 16 millimetres or more. Further, conventional assem bly machines are specifically designed for just one type of reinforcement structure.

Another object of the invention is achieved by a method of manufacturing reinforce ment structures, such as rebar cages or meshes, comprising:

- providing an assembly machine, the assembly machine comprising a production area extending in a longitudinal direction and in a transverse direction, the assembly ma chine further comprises a plurality of support arms distributed along the production area and at least one moveable robot unit with at least one robotic arm arranged rela tive to the production area, the at least one robotic arm being configured to be fitted with at least one tool, - loading a plurality of longitudinal rebar elements onto the support arms of the as sembly machine in the transverse direction,

- further loading a plurality of transverse rebar elements into at least one holding unit of the assembly machine,

- moving the transverse rebar elements along the longitudinal rebar elements to indi vidual installation positions via the at least one moveable robot unit, in which each transverse rebar element is secured to at least one of the longitudinal rebar elements, e.g. by a welding or binding process. The present method provides an automated process for the manufacture of rebar cages as well as engineered meshes. Further, it allows the cage or mesh structure to be man ufactured with a higher precision as the cage or mesh structure is kept stationary while the robotic arm is moved along the production area. The present method is particularly suited for the manufacture of cages or meshes where at least the longitudinal rods have a diameter of 6-55 millimetres, preferably 16 millimetres or more.

The finished cage or mesh may be transferred out of the present assembly machine in the transverse direction or in the longitudinal direction dependent on the particular configuration. In conventional assembly machines, the finished cage or mesh is only able to be unloaded in the longitudinal direction.

The longitudinal rebar elements are initially transferred into the first loading unit. This may be done automatically via a cutting unit, or manually. The longitudinal rebar el ements may then be loaded onto all support arms, e.g. the first and second support arms, via the first loading unit. Alternatively, the longitudinal rebar elements may be loaded onto selected support arms, e.g. the first or second support arms. Alternatively, first longitudinal rebar elements may be loaded on the first support arms, second lon gitudinal rebar elements may be loaded on the second support arms, and so on. This allows the support arms to be selectively loaded, if needed.

After the longitudinal rebar elements have been transferred, the first loading unit may be moved towards the support arms in the transverse direction. The longitudinal rebar elements may then be loaded, e.g. individually, onto the support arms, after which the first loading unit may be moved away from the support arms. This allows the robot unit(s) to move back and forth along the production area without the first loading unit blocking the movement. The first loading unit may thus move in or out of position relative to the support arms, unlike conventional assembly machines where the load ing unit is stationary.

The transverse rebar elements, e.g. the stirrups, may be loaded directly into the hold ing unit of the assembly machine at this stage. This may be done by the robotic arm, e.g. using a gripping tool, or via a second loading unit, as described later. Alternative ly, the transverse rebar elements may be pre-loaded into a magazine which is then mounted in the assembly machine.

According to one embodiment, a number of first support arms with a number of first longitudinal rebar elements is moved into a first holding position before the transverse rebar elements are moved into their individual installation positions and secured to the first longitudinal rebar elements.

After loading at least the set of first longitudinal rebar elements, the first longitudinal rebar elements may then be moved in the transverse direction via local moveable means on the first second support arms to their respective transverse positions. Alter- natively, the first longitudinal rebar elements may be loaded directly into their trans verse positions. The first set of first support arms may then move the first set of longi tudinal rebar elements into a first holding position in the orthogonal direction.

Alternatively, all longitudinal rebar elements may be loaded onto the second support arms in one step. Local moveable means on the second support arms are then used to move the set of first longitudinal rebar elements into position relative to the first sup port arms which then moved the set of first longitudinal rebar elements into the first holding position. Once the first longitudinal rebar elements have been moved into the first holding posi tion by the first support arms, the process may optionally be repeated for another set of longitudinal rebar elements. The remaining longitudinal rebar elements may then be moved to a temporary trans verse position on the second support arms relative to the set of first longitudinal rebar element. In particular, this allows the stirrups to be moved longitudinally while the longitudinal rebar elements are positioned within the stirrups.

The transverse rebar elements may afterwards be moved along the longitudinal rebar elements together with the robot unit(s) to a first installation position where a first transverse rebar element or a first set of transverse rebar elements may be secured to the first longitudinal rebar elements, e.g. using a welding or binding tool on the robot- ic arm. The remaining transverse rebar elements may then be moved to a second in stallation position together with the robot unit(s) where a second transverse rebar ele ment or a second set of transverse rebar elements is secured to the first set of longitu dinal rebar elements. The steps are repeated for the remaining transverse elements. In the above first forward run, the transverse rebar elements may not be secured all to the longitudinal rebar elements in each installation position. The robot unit(s) may then be moved back along the cage or mesh structure to complete the securement of each transverse rebar element in each installation position. Similarly, the robot unit(s) may in this first backwards run also complete the securement of a set of transverse elements relative to each other and/or to the longitudinal rebar elements.

According to one embodiment, the method further comprises the step of:

- moving at least a number of second support arms with a number of second longitu dinal rebar elements into at least a second holding position, the at least second holding being different from the first holding position, and

- further securing the transverse rebar elements to at least the second longitudinal re bar elements.

Once the transverse rebar elements have been secured to the set of first longitudinal rebar elements, the second support arms with at least the second longitudinal rebar elements may be moved to a second holding position.

The robot unit(s) may then be moved along the longitudinal rebar elements in a sec ond run and stopped at the individual installation positions where the transverse rebar elements are further secured to a set of second longitudinal rebar elements. This may also be done when the robot unit(s) are moved back along the cage or mesh structure in the first run, if the securement of the first longitudinal rebar elements is completed when the robot unit(s) was/were moving forwards.

Optionally, the second support arms may further be moved to another holding position and the robot unit(s) may be moved along the cage or mesh structure in another run, wherein the transverse rebar elements are further secured to another set of longitudinal rebar elements. The steps are repeated until all sets of longitudinal rebar elements have been secured to the transverse rebar elements. By repeating these steps, the indi vidual longitudinal rebar elements may thus be secured in any positions along the stir rups to form the cage structure.

The above first, second and another holding positions may differ from each other in the orthogonal direction. Preferably, the first holding position being located above the second holding position and, optionally, the second holding position being located above the another holding position.

According to one embodiment, the method further comprises the step of moving the transverse rebar elements, after being secured to the first or second longitudinal rebar elements, into placement on a plurality of additional support elements arranged in the production area.

After securing the transverse rebar elements to at least the first longitudinal rebar ele- ments, the support arms may be moved, e.g. lowered, until at least the transverse rebar elements are resting on the a number of additional support elements arranged in the production area. This allows the transverse rebar elements to be fixed in the orthogo nal plane during the rest of the assembly. The additional support elements each comprises an upper part adapted to receive and hold one or more of the transverse rebar elements. The upper part may comprise pro jecting teeth, fingers or pins between which the transverse rebar elements may be placed. The upper part may be adjustable or interchangeable so that it may adapted to the desired cage or mesh structure. One or more of the additional support elements may be fitted with supporting legs, plates or feet so it may be removed from the production area, when not being used. Alternatively, the individual support elements may configured as a dolly wagon, or be arranged on a set of rails, so that the finish cage or mesh structure may be removed while resting on the support elements. The dolly wagon may be a robotic dolly wagon.

In one embodiment, the method further comprises at least

- moving at least the first or second support arms to a first loading position before loading at least the first or second longitudinal rebar elements onto the first or second support arms, or

- moving the at least one holding unit to a second loading position before loading the transverse elements.

Prior to loading the longitudinal rebar elements, at least the second support arms are moved into a first loading position relative to the first loading unit. Preferably, both the first and second support arms are moved to the loading position. Preferably, the second loading position may be an orthogonal position located below the cage or mesh structure. The support arms may thus be loaded via the first loading unit and then moved into the respective holding positions.

Alternatively or additionally, the holding unit, e.g. the magazine, may be moved to gether with the robot unit(s) to a second loading position before loading the transverse rebar element. Preferably, the second loading position may be a longitudinal position located at a distance from the cage or mesh structure. The magazine may thus be load- ed via the second loading unit and then moved along the longitudinal rebar elements.

According to one embodiment, at least one of the second longitudinal rebar elements, before being secured to the transverse elements, is further moved in transverse direc tion into position relative to the one second longitudinal rebar element.

In one or more of the holding positions, all or some of the respective longitudinal re bar elements may be moved to transverse installation positions via the local moveable means. This may be done before the robot unit(s) are moved along the cage or mesh structure, or in a combined step. In example, one longitudinal rebar element may be moved to its transverse installation position and the robot unit(s) may be moved along the cage or mesh structure to se cure that longitudinal rebar element to the transverse rebar elements. Another longitu dinal rebar element may be moved to its transverse installation position and the robot unit(s) may be moved back along the cage or mesh structure to secure that longitudi nal rebar element to the transverse elements. The step is repeated until all longitudinal rebar elements are secured to the transverse rebar elements.

Alternatively, all longitudinal rebar elements may be moved into their respective transverse installation positions in one step. The robot unit(s) may then be moved along the cage or mesh structure to secure all longitudinal rebar element to the trans verse rebar elements.

According to one embodiment, the method further comprises the steps of:

- moving one first or second support arm from the first or second holding position to a retracted position,

- moving the robotic arm in the longitudinal direction past the one first or second sup port arm, and optionally

- further moving the one first or second support arm back into the first or second hold- ing position.

The support arms may be individually moved away from the longitudinal rebar ele ments as the robot unit(s) are moved along the cage or mesh structure. This is particu larly suited when installing stirrups.

Prior to moving the transverse rebar elements and robot unit(s), a selected support arm may be moved out of contact with the longitudinal rebar elements and away from the cage or mesh structure. The robot unit(s) and transverse rebar elements, e.g. the stir rups, may then be moved past the selected support arm in the longitudinal direction. The selected support arm may then be moved back into contact with the longitudinal rebar elements. The steps may be repeated for the next support arm. This allows the magazine with stirrups to be moved along the longitudinal rebar elements as the robot units install the individual stirrups. According to one embodiment, the assembly machine further comprises a first move- able robot unit with a first robotic arm, the first robotic arm being fitted with a first tool, and a second moveable robot unit with a second robotic arm, the second robotic arm being fitted with a second tool, wherein the first and second robot units are moved together along the production area.

The welding or binding process may preferably be performed by at least two robot units, each fitted with a tool at the end of the robotic arm. The first and second robot units may be fitted with different tools and perform different task as the robot units are moved along the cage or mesh structure. Alternatively, the first and second robot units may be fitted with the same tool and perform the same task.

One or both robotic arms may be used to grip and load the longitudinal rebar elements and/or the transverse rebar elements.

Alternatively or additionally, one robotic arm may grip a transverse rebar element from the holding unit and position it relative to the longitudinal rebar elements. The other robotic arm may then weld or bind the transverse rebar element together with the longitudinal rebar element. The robotic arm may clamp the two elements together before welding or binding the elements using a combined clamping and weld ing/binding tool.

Further, both the first and second robotic arms may be used to weld or bind the trans verse rebar element together with the longitudinal rebar element. The first and second robotic arms may both clamp the two elements together before welding or binding the elements together using the combined clamping and welding/binding tool.

According to one embodiment, a pre-loaded magazine with a number of transverse rebar elements are moved into alignment with the at least one holding unit, wherein the number of transverse rebar elements are transferred onto the at least one holding unit.

The second loading unit may be arranged on a rail, track or frame, as described earlier, so that the pre-loaded magazine may be moved into alignment with the magazine of the holding unit in the transverse or longitudinal direction. The pre-loaded magazine may then be moved towards the (empty) magazine of the holding unit so that the transverse rebar elements may be transferred onto the holding unit. This allows for a quick loading and reloading of the magazine.

The transfer may be done by moving one magazine relative to the other magazine in the orthogonal direction. Alternatively, mechanical means, such as an extendable arm or clamp, may be used to transfer the transverse rebar elements onto the holding unit. Other transferring means may be used.

According to one embodiment, the method further comprises the steps of:

- assembling a first part of the reinforcement structure, wherein one portion is left un assembled for assembling a second part of the reinforcement structure,

- moving the first part in the longitudinal direction from a first position to a second position,

- further assembling at least the second part of the reinforcement structure in continua tion of the first part, wherein the unassembled portion of the first part is integrated into the second part.

The present machine setup further enables larger reinforcement structures to be as sembled in a running process. Preferably, the larger reinforcement structure may be assembled in a fully-automated process using the present assembly machine. No mod ifications or extending of the production area is needed. This further increase the func tionality of the present assembly machine compared to the conventional assembly machines. This may be suited for slim production facilities where limited production area is available.

A first part of the large reinforcement structure may be assembled, as described earli er, wherein an end portion of the first part is left unassembled. The first part is then moved in the longitudinal direction partly out of the production area so that the end portion remains within the production area, e.g. using the above dolly wagon or rail system. Further longitudinal rebar elements and further transverse rebar elements are loaded into the present assembly machine, as described earlier. The further longitudinal may then be moved into position so that a corresponding end portion overlap the end por tion of the first part. Further, one or more transverse rebar elements may be positioned with the overlapping area. The rest of the second part is then assembled, as described earlier. The process may be repeated for additional parts of the larger reinforcement structure.

The finished larger reinforcement structure may then be moved out of the production area for storage and/or transport.

Description of the Drawing

The invention is described by example only and with reference to the drawings, wherein: Fig. 1 shows an exemplary embodiment of an assembly machine according to the invention,

Fig. 2 shows a first step of assembling a cage structure according to the inven tion,

Fig. 3 shows a second step of assembling the cage structure,

Fig. 4 shows a third step of assembling the cage structure,

Fig. 5 shows a fourth step of assembling the cage structure,

Fig. 6 shows a fifth step of assembling the cage structure,

Fig. 7 shows a sixth step of assembling the cage structure,

Fig. 8 shows a seventh step of assembling the cage structure,

Fig. 9 shows an eighth step of assembling the cage structure,

Fig. 10 shows a first step of assembling a mesh structure according to the inven tion,

Fig. 11 shows a second step of assembling the mesh structure,

Fig. 12 shows a third step of assembling the mesh structure,

Fig. 13 shows a fourth step of assembling the mesh structure,

Fig. 14 shows an exemplary embodiment of an adjustable magazine,

Fig. 15a-d show four exemplary embodiments of the support arm, Fig. 16 shows an exemplary embodiment of the support arm with local moveable means,

Fig. 17 shows another exemplary embodiment of the first loading unit moved away from the support arms,

Fig. 18 shows the first loading unit of fig. 17 moved into position relative to the support arms,

Fig. 19 shows an exemplary embodiment of the second loading unit,

Fig. 20 shows the second loading unit and the holding unit during transfer of the transverse rebar elements,

Fig. 21 shows the first and second robotic arms during the assembly,

Figs. 22-23 show the transverse rebar elements resting on additional support elements, Fig. 24 shows an exemplary embodiment of the support element, and

Fig. 25 shows a third embodiment of the local moveable means. In the following text, the figures will be described one by one, and the different parts and positions seen in the figures will be numbered with the same numbers in the dif ferent figures. Not all parts and positions indicated in a specific figure will necessarily be discussed together with that figure.

Reference list

1. Assembly machine

2. Production area

3. Loading unit

4. Longitudinal rebar elements

4a. First longitudinal rebar elements

4b. Second longitudinal rebar elements

5. Holding unit

5 a. Magazine

6. Transverse rebar elements

6a. First/secured transverse rebar element

6b. Remaining/unsecured transverse rebar elements

7. First robotic arm

8. Second robotic arm

9. Bending unit 10. First support arms

11. Second support arms

12. Adjustable magazine

13. Holding elements

14. Transverse direction

15. Height direction

16. First part

17. Second part

18. Local moveable means

19. Rail

20. Stop elements

21. Rail

22. Pins with spikes

23. Fingers

24. Second loading unit

24a.Holding unit

25. Magazine

26. Gantry unit

27. Support element

27a. Upper part

Detailed Description of the Invention

Fig. 1 shows an exemplary embodiment of an assembly machine 1 comprising a pro duction area 2 extending in the longitudinal direction and in the transverse direction. A first loading unit 3 is arranged relative to the production area 2 at one side, wherein the first loading unit 3 is configured to load longitudinal rebar elements 4 into the as sembly machine 1. A cutting unit is arranged relative to the first loading unit 3, as illustrated in fig. 1, and configured to receive the unprocessed longitudinal rebar ele ments 4’. The longitudinal rebar elements 4 are preferably cut into length and trans ferred to the first loading unit 3 in an automated process.

A holding unit 5 configured to hold transverse rebar elements 6 is arranged relative to a first moveable robot unit and a second moveable robot unit. The first moveable ro bot unit comprises a first robotic arm 7 which can be fitted with a first tool. The sec- ond moveable robot unit comprises a second robotic arm 8 which can be fitted a sec ond tool. Here, the holding unit 5 is configured as a gantry comprising a magazine 5a for holding the transverse rebar elements 6. An optional bending unit 9 is further arranged relative to a second loading unit (see fig. 1) that is arranged relative to the production area 2. The bending unit 9 is config ured to bend and cut the transverse elements 6 into the desired profile. A packoff sta tion is arranged relative to the bending unit 9, as illustrated in fig. 1, so that the unpro cessed transverse rebar elements 6’.

Fig. 2 shows a first step of a method of assembling a reinforcement structure in the form of a cage structure. Longitudinal rebar elements 4 are transferred onto the load ing unit 3 and transverse rebar elements 6 are loaded into the holding unit 5. Here, the transverse elements 6 are shown as stirrups. The magazine 5a is here shown as a mag- azine with two projecting fingers on which the stirrups are resting.

The first moveable robot unit comprises a rail extending along the production area 2 on which the first robotic arm 7 is arranged. Further, the second moveable robot unit comprises a rail extending along the production area 2 on which the second robotic arm 8 is arranged. The rails are arranged on opposite sides of the production area 2, thus allowing the first and second robotic arms 7, 8 to react the cage structure from both sides.

A set of first support arms 10 and a set of second support arms 11 are distributed along the production area 2. The first and second support arms 10, 11 each has a first part (see fig. 15a-d) extending in the transverse direction and a second part (see fig. 15a-c) extending in the orthogonal (height) direction.

Fig. 3 shows a second step of assembling the cage structure where the first and second support arms 10, 11 are moved to a loading position in the orthogonal direction. In the loading position, the first support arms 10 are further moved to a predetermined trans verse position.

A first set of longitudinal rebar elements 4a is loaded onto the second support arms 11. Fig. 4 shows a third step of assembling the cage structure, wherein local moveable means (see fig. 15a) on the second support arms 11 moves the set of first longitudinal rebar elements 4a into a transverse position relative to the first support arms 10. The first support arms 10 then moves the first longitudinal rebar elements 4a to a first holding position in the orthogonal direction.

A second set of longitudinal rebar elements 4b is afterwards moved to another trans verse position relative to the set of first longitudinal rebar elements 4a, as illustrated in fig. 5. The second support arms 11 are optionally further moved to a temporary hold- ing position in the orthogonal direction.

Fig. 5 shows a fourth step of assembling the cage structure, where the first and second robotic arms 7, 8 and the transverse rebar elements 6 are moved along the longitudinal rebar elements 4a, b.

A first transverse rebar element 6a is gripped by the first robotic arm 7 using a grip ping tool and positioned relative to the set of first longitudinal rebar elements 4a. The second robotic arm 8 secures the first transverse element 6a to the first longitudinal rebar elements 4a using a welding or binding tool.

Fig. 6 shows a fifth step of assembling the cage structure, where a selected first sup port arm 10’ is moved out of contact with the first longitudinal rebar elements 4a and away from the cage structure. The remaining first support arms 10 are still in contact with the first longitudinal rebar elements 4a.

The first and second robotic arms 7, 8 and the remaining transverse rebar elements 6b on the holding unit 5 are ready to move past the selected first support arm 10’.

Fig. 7 shows a sixth step of assembling the cage structure, where the first and second robotic arms 7, 8 and the remaining transverse rebar elements 6b on the holding unit 5 are moved past the selected first support arm 10’.

The selected first support arm 10’ is then moved back into contact with the first longi tudinal rebar elements 4a. Fig. 8 shows a seventh step of assembling the cage structure, where the second sup port arms 11 are moved in the orthogonal direction to a second holding position.

At least one of the set of second longitudinal rebar elements 4b is moved into a trans verse installation position via the local moveable means on the second support arms 11. The first robotic arm 7 then secures that second longitudinal rebar element 4b to at least a selected number of the secured transverse elements 6a as the first and second robotic arms 7, 8 are moved along the cage structure.

Another of the set of second longitudinal rebar elements 4b is moved into another transverse installation position via the local moveable means on the second support arms 11. The second robotic arm 8 then secures that second longitudinal rebar element 4b to at least a selected number of the secured transverse elements 6a as the first and second robotic arms 7, 8 are moved along the cage structure. Meanwhile, the first ro botic arm 7 secured the above one second longitudinal rebar element 4b to the rest of the secured transverse rebar elements 6a.

Alternatively, the above longitudinal rebar elements 4 are is secured to all transverse rebar elements 6 in one step as the first or second robotic arm 7, 8 moves along the cage structure.

Fig. 9 shows an eighth step of assembling the cage structure, where the second support arms 11 are moved in the orthogonal direction to another holding position.

In this holding position, the remaining longitudinal rebar elements 4 are positioned and secured to the secured transverse elements 6a, as described in relation to fig. 8.

Fig. 10 shows a first step of assembling the reinforcement structure in the form of an engineered mesh. Longitudinal rebar elements 4” are transferred to the first loading unit 3 and loaded onto the second support arms 11. Both the first and second support arms 10, 11 are moved to the loading position before loading the longitudinal rebar elements 6”. Fig. 11 shows a second step of assembling the mesh structure, where the longitudinal rebar elements 4” are moved into their respective transverse installation positions using the local moveable means (see fig. 15a).

The first robotic arm 7 grips a first transverse element 6a” and positions it relative to the longitudinal rebar elements 4”. Meanwhile, the second robotic arm 8 secures the first transverse element 6a’’ to at least a selected number of longitudinal rebar ele ments 4”. The remaining transverse rebar elements 6b” are arranged in a magazine 5a’ extending in the longitudinal direction. The magazine 5a’ is connected to the first robot unit, as illustrated in fig. 11.

Fig. 12 shows a third step of assembling the mesh structure, where the first robotic arm 7 grips a new transverse element 6b” while the second robotic arm 8 secures the current transverse element 6a” to the remaining longitudinal rebar elements 4”.

Fig. 13 shows a fourth step of assembling the mesh structure, wherein the first and second robotic arms 7, 8 are moved to the next installation position.

The next transverse element 6a” is positioned relative to the longitudinal rebar ele ments 4” by the first robotic arm 7 using a gripping tool. The second robotic arm 8 secures the next transverse element 6a” to the longitudinal rebar elements 4” using a welding or binding tool.

The steps are repeated until all transverse elements 6” are secured.

Fig. 14 shows an exemplary embodiment of an adjustable magazine 12 comprising a number of holding elements 13. Here, the holding elements 13 are shown as project ing fingers.

The position of each holding element 13 may be adjusted in the transverse direction (arrow 14) and, optionally, also in the orthogonal direction (arrow 15). The holding elements 13 are thereby able to be adapted to different sizes and shapes of the trans verse elements 6, 6”. Fig. 15a-d show four exemplary embodiments of the support arms 10, 11. In fig. 15a, the support arm 10, 11 is arranged on a rail (indicated by lowermost arrow) so that it is able to be moved in the transverse direction 14 relative to the rail 19 on which the robotic arms 7, 8 are placed.

The support arm 10, 11 comprises a first part 16 and a second part 17. Here, the sec ond part 17 is an extendable part so that the support arm 10, 11 is able to be move in the orthogonal direction 15.

The first part 16 extends in the transverse direction and comprises local moveable means 18. Here, the local moveable means is shown as a transport chain or belt. The local moveable means 18 is configured to move the longitudinal rebar elements 4, 4” into transverse installation positions (see fig. 16).

The support arm 10, 11 alternatively comprises a pivotal first part 16’, as illustrated in fig. 15b. The pivotal first part 16’ can pivot around a pivot axis.

The support arm 10, 11 alternatively comprises a moveable first part 16”, as illustrat ed in fig. 15c. The moveable first part 16” is able to move in the transverse direction 14.

The support arm 10, 11 alternatively comprises a rotatable second part 17”, as illus trated in fig. 15d. The rotatable second part 17” is able to rotate around a rotation ax is.

Common for the embodiments in fig. 15a-d is that at least a part of the support arm 10, 11 is able to be moved away from the cage or mesh structure.

Fig. 16 shows an exemplary embodiment of the support arm 10, 11 with local movea ble means 18. Here, only the first part 16 of the support arm 10, 11 and a sectional view of the transverse element 6, 6’ are shown.

The first part 16 comprises at least one stop element 20 arranged relative to the local moveable means 18. Here, two stop elements 20 are shown. The stop elements 20 are configured to hold the longitudinal rebar element 4 ,4” in a transverse installation position relative to the transverse element 6, 6”.

Fig. 17 shows the first loading unit 3’ as a moveable loading unit where the loading mechanism is arranged on a set of rails 21 extending in the transverse direction. The first loading unit 3’ is thus able to move in and out of position relative to the support arms 10, 11.

Here, the first loading unit 3’ is moved away from the support arms 10, 11 for loading the longitudinal rebar elements 4, 4”. The longitudinal rebar elements 4, 4” are load ed onto a transport chain comprising pins 22 with spikes.

Fig. 18 shows the first loading unit 3’ moved into position relative to the support arms 10, 11. The longitudinal rebar elements 4, 4” are loaded individually onto a local transport chain 18’ with projecting fingers 23 arranged on the support arms 10, 11.

Fig. 19 shows an exemplary embodiment of the second loading unit 24 configured to load transverse rebar elements 6, 6” into the magazine 5a of the holding unit 5. The second loading unit 24 comprises a gantry 24a moveable arranged on a rail extending perpendicular to the rails 19 of the first and second robot units, as illustrated in fig. 1. The gantry has another magazine 25 for holding a number of transverse rebar ele ments 6, 6”. Here, the transverse rebar elements 6, 6” are shown as a set of stirrups.

Fig. 20 shows the second loading unit 24 aligned with the holding unit 5 where the first and second robotic arms 7, 8 are used to transfer (indicated by arrow) the trans verse rebar elements 6, 6” from the magazine 25 of the second loading unit 24 to the magazine 5a of the holding unit 5.

The holding unit 5 and the first and second robot units are moved into a second load- ing position, as indicated in fig. 20. The second loading unit 24 is then moved from a further loading position (see fig. 1) and into alignment with the holding unit 5.

The transfer may also be done by moving the magazine 25 into the magazine 5a and lowering it so that the transverse rebar elements 6, 6” are resting on the holding ele- ments 13 of the holding unit 5. The magazine 24 is afterwards moved out of the mag azine 5a and away from the first and second robot units.

Fig. 21 shows the first and second robot units during the assembly, where the first robotic arm 7 is holding the next transverse rebar element 6, 6” in position relative to the longitudinal rebar elements 4, 4”. The second robotic arm 8 is securing that trans verse rebar element 6, 6” to the longitudinal rebar elements 4, 4”.

The first and second robotic arms 7, 8 are able to work together to perform a particular task, or independently to perform different tasks. While during so, the first and second robotic arms 7, 8 may move independently or synchronously in the orthogonal direc tion. One robotic arm may thus work from the bottom of the reinforcement structure while the other robotic arm may work from the top of the reinforcement structure. Figs. 22 and 23 show the transverse rebar elements 6, 6” after being secured to at least the first longitudinal rebar elements 4, 4”, where the transverse rebar elements 6, 6”are resting on additional support elements 27. The support elements 27 are config ured to fixate the transverse rebar elements 6, 6” in the orthogonal plane during as sembly.

The longitudinal rebar elements 4, 4” and transverse rebar elements 6, 6” is lowered onto the support elements 27 by the support arms 10, 11 and/or a gantry unit 26 with clamps, as illustrated in fig. 22. Multiple transverse rebar elements 6, 6” are resting on an elongated upper part 27a of the support element 27. The support elements 27 are distributed along the production area 2.

Fig. 24 shows the support element 27 with a generally L-shaped body where the lower part of the body acts as support feet for placement of the support element 27. The up per part 27a’ is here configured as an adjustable, e.g. telescopic, part for adjusting the position of the upper part 27a’ in the orthogonal direction. Fig. 25 shows a third embodiment of the local moveable means 18’” where the fin gers 23’ define an open-ended space having a local width and a local depth. The local depth and width are selected so that multiple longitudinal rebar elements 4, 4” is able to receive multiple longitudinal rebar elements 4, 4”.

Here, a single column of three longitudinal rebar elements 4, 4” are shown. However, the multiple longitudinal rebar elements 4, 4” may be arranged in multiple columns and/or multiple rows. Each row may comprise two or more longitudinal rebar ele ments 4, 4”.