WO2010139374A1

WO2010139374A1 - Device including quick feeder for rods and / or bars

Info

Publication number: WO2010139374A1
Application number: PCT/EP2010/000555
Authority: WO
Inventors: Claudio Bernardinis; Sergio Benedetti
Original assignee: A.W.M. S.P.A.
Priority date: 2009-01-29
Filing date: 2010-01-29
Publication date: 2010-12-09
Also published as: ITUD20090017A1; EP2382061A1

Abstract

The present invention relates to device including a single bar loader (6), a quick feeder unit (1) for rods and/or bars (7) arranged downstream and subjacent of the single bar loader (6), and a bar positioning and distribution unit (9) arranged downstream and subjacent of the quick feeder unit (1), the device operating with chains with articulated links in systems for forming electro-welded metallic nets. Moreover, the invention relates to a method for operating the device.

Description

DEVICE INCLUDING QUICK FEEDER FOR RODS AND / OR BARS

Technical field

The present invention relates to a quick feeder unit for steel rods and/or bars which works in cooperation and coordination upstream of a chain-type bar distribution and positioning unit for machines or systems for continuous forming and production of electro welded metal nets.

The quick feeder unit acts as an intermediate loading buffer between the unit that supplies the steel rods or bars individually, one after another, in succession, having identical or different diameters and lengths, and the chain-type positioning and distribution unit for exact downstream positioning, with the laying of a plurality of rods with set interspaces on the subjacent working surface simultaneously and instantaneously.

The invention is a machine constituted by a plurality of parallel rectilinear structures provided with adapted advancement chains or screw feeders or toothed belts or equivalent systems, which are capable of conveying with preset interspaces, perpendicularly, said steel rods and/or bars onto the (subjacent) gravity positioning and distribution unit. Said quick feeder unit conveys the various rods in a parallel arrangement and in correct position with preset interspaces and is lowered on command in an angular and/or parallel manner, below the upper receiving surface of the subjacent positioning and distribution unit. In this manner, the plurality of mutually parallel and spaced rods is simultaneously placed and inserted in the respective receiving seats of the subjacent positioning and distribution unit: therefore, the total loading of all the rods occurs in a small number of seconds, without having to wait for individual loading rhythms as occurs currently with known methods.

Background art

In the current background art, in the field of automated systems for forming electro welded metal nets, products used in the construction sector in general and in industrialized prefabrication for reinforcing concrete, various technical solutions are known for feeding the units for distributing and positioning metallic rods and/or bars.

In particular, Italian invention patent no. UD93 AOOO 170 and the corresponding European patent no. 669859 are known which have been filed by the same inventor as the present invention and in which the rod positioning and distribution unit, actuated by a plurality of chains which are arranged parallel and side-by-side and are provided with adapted movable automatic closure clamps for supporting rods transversely, is fed in a single point, where said clamps open, individually, and therefore a long loading time is needed to cover a specific and large surface. This operation in fact occurs by means of the stepwise advancement of the chains, depending on the intervals on which the individual bars or rods of different size and length are to be positioned. This way of proceeding is a considerable drawback, since it constitutes a production bottleneck, in particular in systems for the continuous forming of electro welded metal nets that are particularly fast and automated.

Therefore, the object of the present invention is to overcome the shortcomings of the current state of the art of feeder devices with such a repetitive waste of time in loading the positioning and distribution unit with a plurality of various types of rods, arranged parallel to each other (at right angles to the chains) and arranged variously on the surface. It has been thought to accelerate the production process and to make it more efficient, building an intermediate feeder which acts as a storage buffer capable of reducing the loading times of the subjacent positioning and distribution unit, which is already known in the field according to the two cited patents, since this step occurs simultaneously and instantaneously for all the rods.

Summary of the invention

The aim of the present invention is therefore to provide a quick feeder unit of an automated type with high productivity, having following main characteristics:

- having a function of intermediate buffer or storage, which cooperates in coordination upstream with a single bar loader and downstream with a chain-type unit for distribution and positioning bars, rods, in particular different types of metal bars or the like on an subjacent working surface;

- a chain-type bar or rod feeder unit capable of receiving adapted bars individually upstream, arranging them on an upper surface, by means of advancement in programmed steps of chains until all or part of the upper travel surface is covered, operating continuously even during operation of the subjacent positioning and distribution unit;

- a chain-type feeder unit, capable of performing an angular movement or of moving in a parallel manner on command so as to move downward with respect to the level of the upper surface of the subjacent chain-type positioning and distribution unit; with this movement, all the sorted rods are placed simultaneously and instantaneously on the upper surface of the positioning and distribution unit, which is provided with chains with particular receiving seats with automatic closure for its subsequent translational motion and exact positioning by vertical fall, by gravity, of the rods onto the subjacent working surface; - a quick feeder unit provided with chains with a large surface for receiving metallic rods or bars, generally larger than the surface of the subjacent positioning and distribution unit to be fed, in order to provide a capacious bar magazine that is ready for their programmed transfer in order to reduce loading times;

- the chains with articulated links used to transport the bars can be replaced with other means suitable for the purpose, such as for example: screw feeders, toothed belts and the like, side- by-side pairs of toothed rods, one of which is movable with an eccentric element; which are moved synchronously in order to move all the bars forward in a parallel manner, maintaining their arrangement on the surface.

Essence of the invention

The aim and objects of the invention are achieved according to claim 1 and the dependent claims, providing a quick feeder unit for rods or bars, in particular for metal bars, that can act as a buffer or as a storage unit receiving the individual-type metal bars and distributing the metallic bars correctly gathered onto a large upper surface, in particular a bar supporting chain-type band, which can move in an angular or parallel way with respect to the receiving surface of the subjacent chain band-conveyor of an automatic positioning and distribution unit to be fed instantaneously with a plurality of metal bars.

According to the present invention, the quick feeder unit receives the straight metal bars, having appropriate dimensional characteristics, which arrive one at a time from an adapted upstream automatic single bar loader. The straight bars are placed on adapted U-shaped or V-shaped receiving seats, parallel to each other, with constant interspaces or not, depending on the planning requirements for forming electro welded metal nets or on other needs. Said receiving seats are connected directly or indirectly to one or more articulated chains, which are arranged parallel to each with a direction that is perpendicular to the metallic bars, thus forming an upper bar supporting chain-type band. The articulated chains, by moving synchronously with respect to each other, move forward the U-shaped or V-shaped receiving seats, which are provided or not with bars, thus providing a large surface for the distribution of variously positioned mutually parallel metal bars.

Said collection surface for the various mutually parallel metal bars arranged with mutually constant interspaces or not, with an adapted supporting frame and with movement members, is rendered able to move in an angular or parallel fashion with respect to the receiving surface of the articulated chain assembly of the subjacent positioning and distribution unit, which is made in a known manner according to the Italian patent no. UD93 AOOOl 70 and European patent no. 669859. The bar supporting chain-type band of the quick feeder unit, as mentioned, is constituted by a plurality of mutually parallel articulated chains, each of which supports multiple U-shaped or V- shaped bar supporting seats, and the entire surface is moved back downward on command, in an angular manner or in a manner that is parallel to the subjacent reference and receiving plane of the positioning and distribution unit, whose chains are offset with respect to those of the quick feeder unit. In this manner, the bars carried by the bar supporting chain-type band of the quick feeder unit are all simultaneously rested on the respective upper receiving seats of the chains, in particular on the upper receiving and holding units of the subjacent automatic positioning and distribution unit. The latter, in an extremely rapid manner by means of the chains, transfers all the gathered bars from an upper position to a lower position, to then place them by gravity on the working surface. During the rapid movement of the bars of the subjacent positioning and distribution unit, the feeder is in a lowered position but it can still be fed, continuing to receive individual loading upstream. The inactivity time of the feeder, which is estimated as approximately three seconds, is only the time related to the step for the passage of the metal bars of the quick feeder unit to the subjacent positioning and distribution unit. Once the subjacent positioning and distribution unit has transferred all the metal bars from an upper position to the lower position, the movable quick feeder unit rises back to the higher position again over the upper surface of the subjacent positioning and distribution unit, continuing to receive the individual loading of the metal bars until completion of the upper bar distribution surface is achieved, and is then ready for a new feeding cycle for the subjacent positioning and distribution unit.

Therefore, the considerable time saving during the loading of the final positioning and distribution unit is evident, since it is not fed individually, with one bar at a time, as hitherto known technically, but by using the present quick feeder unit, the loading time of this step is reduced considerably because laying and distribution are almost instantaneous for the entire surface of the upper part of the chain band-conveyor of the positioning and distribution unit, which is of course constituted by a plurality of parallel bars with the same time for positioning as a single one.

In accordance with what has been described above, it is possible to use, in the construction of the quick feeder unit, as a replacement of the chains with articulated links with bar supporting receiving seats adapted for parallel transport, also other similar technical solutions, such as for example screw feeders or worm screws, or also toothed belts provided with automatic clamps for carrying the bars, or also toothed rods arranged side-by-side with a relative movement of the eccentric type, which perform the same functions, i. e., the parallel movement of the metal bars. Said metal bar transport means are moved synchronously with respect to each other and are arranged parallel to each other, and at the same time, at right angles to the metal bars, do not interfere with the subjacent positioning and distribution unit but cooperate in coordination. The loading of individual metal bars upstream of the quick feeder unit in fact occurs continuously and is interrupted only for a short time, the time needed to unload cyclically and alternately all the metal bars instantaneously onto the upper surface of the subjacent positioning and distribution unit.

The frame of the quick feeder unit has a plurality of parallel chain supporting arms for transport in a parallel and transverse manner of the metal bars. All the chains are actuated by the same shaft at one end of the arms, and said arms constituting an arm frame are arranged like the teeth of a comb and enter partially in a laterally adjacent and parallel manner to the chains of the subjacent positioning and distribution unit to be fed.

The upward and downward angular movement of the arm frame with respect to the upper level of the subjacent positioning and distribution unit occurs according to a third-class lever, i. e., with the fulcrum at one end, proximate to the upstream loading, and the actuation force along said arm frame leaves the end free to operate within the operating area of the subjacent chain band- conveyor positioning and distribution unit.

According to a variation of the present invention, the quick feeder unit, instead of performing an angular and parallel movement within the contour of the subjacent positioning and distribution unit, might be moved in a parallel manner, by virtue of suitable means, downward from above and vice versa with respect to the upper surface of the positioning and distribution unit in order to allow the passage of all the metal bars from the quick feeder unit to said positioning and distribution unit.

The invention fully achieves the intended aim, i. e., to minimize the feeding time of the bar positioning and distribution unit that acts on the subjacent working surface. The quick feeder unit is in fact loaded constantly, while the unloading of a plurality of parallel metal bars occurs instantaneously. The advantage provided in terms of time to the global cycle in the apparatus for forming electro welded metal nets is considerable, by largely reducing the production bottleneck caused by the insertion of the metal bars in the correct position during the step for forming and welding the metal bar nets.

The above objects as well as further objects that will become apparent hereinafter are achieved by a quick feeder unit as defined in claim 1.

Further advantageous aspects of the invention are set out in the dependent claims.

One solution of a preferred embodiment according to the present invention is disclosed in the following drawings with description but shall not be limiting to the invention. Brief description of drawings

Fig. l is a side view of a bar feeding and positioning arrangement for a continuous forming of electro welded metal nets, wherein a quick feeder unit is placed between a single bar loader on the right side and an subjacent chain-type bar positioning and distribution unit.

Fig. 2 is a schematic plan in top view on to the quick feeder unit, illustrating an arrangement of metal bars on a surface of a bar supporting chain-type band of the quick feeder unit with respect to structures that constitute the subjacent bar positioning and distribution unit;

Fig. 3 is a side view of a right part of Figure 1 in larger scale, illustrating an arrangement of functional main parts of the quick feeder unit and it illustrates an angular movement of the quick feeder unit, which moves upward and downward around a fulcrum driven by a hydraulic cylinder;

Fig. 4 is a side view of the positioning and distribution unit of Figure 1 but in larger scale, illustrating open receiving and holding units on the surface of the chain band-conveyor.

Fig. 5 is a side view of the receiving and holding units in an open metal bar receiving state;

Fig. 6 is a side view of the positioning and distribution unit of Figure 4 but with closed receiving and holding units on the surface of the chain band-conveyor.

Detailed description of the invention :

Fig. 1 gives an overview of a bar feeding and positioning arrangement for bars 7, in particular for metal bars 7 in order to automatically produce electro welded metal nets, comprising mainly a single bar loader 6, a quick feeder unit 1 downloading at its first end the metal bars 7 from the single bar loader 6 on to a bar supporting chain-type band 2, a positioning mechanics 3 for controlling a vertical position of the quick feeder unit 1, a positioning and distribution unit 9 downloading simultaneously a plurality of metal bars 7 from the quick feeder unit 1 and conveying and releasing them simultaneously on to a working surface 12 for welding purposes.

Fig. 3 shows the single bar loader 6 providing repetitively and in an appropriate rate metal bars 7 onto a first end of a bar supporting chain-type band 2 with U-shaped or V-shaped receiving seats 2.2 which are mounted along the conveying chain-type bands 2 in order to receive and to keep the metal bars 7 in place on the so bar supporting chain-type band 2 of the quick feeder unit 1. The receiving seats 2.2 are mounted parallel inline with the supported metal bar 7 as well as there are mounted also multiple pairs of receiving seats 2.2 along the chain-type bands 2 with defined interspaces between the receiving seats 2.2 along the chain-type bands 2.

The so repetitively placed metal bars 7 on the bar supporting chain-type band 2 get conveyed by the moving chain-type band 2 from its first end adjacent and subjacent to the single bar loader 6, towards a second end at a transporting cogwheel arrangement 5 of the bar supporting chain-type band 2. Each of the bar supporting chain-type bands 2 is clamped on a respective supporting arm 2.3 between a cogwheel arrangement 4 and the cogwheel arrangement 5, wherein one of said cogwheels is a controlled driven cogwheel, so that the bar supporting chain-type band 2 is continuously moving around these shafts and horizontally in direction of the horizontal arrow. The supporting arms 2.3 constitute an arm frame. The supporting arm 2.3 between the cogwheel arrangement 4 and the cogwheel arrangement 5 is at the first end pivot-mounted at the cogwheel arrangement 4 which acts as well as a fulcrum for said supporting arm 2.3. The position of the supporting arm 2.3 can become elevated and lowered around said fulcrum within a vertical upper and lower position, indicated by an angle ALPHA in the drawings Fig.l and Fig. 3. The vertical elevation and lowering of the supporting arms 2.3 is driven by a positioning mechanics 3 connected to a part of the supporting arm 2.3 between its first and the second end whereas the positioning mechanics 3 is also actuated by an actuator 11 , which is in particular a hydraulic cylinder. But the kind of vertical movement of the supporting arm 2.3 shall not be limited to the above mechanism and it is also imaginable that it is supported and elevated/lowered by other suspension and/or actuating means.

The metal bars 7 get placed on at least two receiving seats 2.2 on the bar supporting chain- type band 2 carrying the metal bars 7. Fig. 2 shows from a top side view a schematic arrangement of the metal bars 7 on the bar supporting chain-type band 2 with a first end at a cogwheel arrangement 4 and a second end at the cogwheel arrangement 5, with the subjacent positioning mechanics 3, with an axis position at rolls 10 of the positioning and distribution unit 9. The bar supporting chain-type band 2 with its provided in the currently described preferred embodiment with four receiving seats 22 (not directly shown) per metal bar 7 that hold the metal bars 7 on four horizontal chains 2 with rectilinear U- or V-shaped vertical teeth so that the metal bars 7 can be taken over by the parallel chain-type conveyors of the positioning and distribution unit 9 with receiving and holding units 20 (Fig. 4). The parallel chain-type conveyors of the positioning and distribution unit 9 are arranged in a comb like configuration between the chain-type bands 2 (thus in between and parallel to the chain- type combs 2), such that upon moving the chain-type bands 2 vertically upward (orthogonally in respect to the drawing surface) the metal bars 7 can be taken over by the positioning and distribution unit 9.

During the feeding of the quick feeder unit 1 with metal bars 7 the supporting arm 2.3 remains in an upper position, as shown in Fig. 1. When the first metal bar 7 reaches then the second end of the bar supporting chain-type band 2 at cogwheel arrangement 5, the feeding process is stopped for a short period of time, the supporting arm 2.3 is then lowered to the lower position of the angle ALPHA which is not shown but indicated in Fig. 1 and Fig. 3, so that the receiving and holding units 20 of the positioning and distribution unit 9 can take over the plurality of metal bars simultaneously and rapidly from the receiving seats 2.2 of the chain-type band 2 of the quick feeder unit 1. After the metal bars 7 have been taken over by the receiving and holding units 20 of the positioning and distribution unit 9, carried in open retaining spaces 25a (Fig. 5) of the receiving and holding units 20, the closing and holding elements 21 are closed simultaneously. Then the metal bars 7 get transported rapidly from position A (Fig. 4) in arrow direction B towards position C and further until the last metal bar 7 passed position C within the positioning and distribution unit 9. Then all metal bars 7 are out of the subjacent space of the underneath receiving seats 2.2 of the lowered supporting arm 2.3 of the quick feeder unit 1. After the metal bars 7 are transported away as described above the supporting arm 2.3 is elevated again into the upper position and the process of feeding the bar supporting chain-type band 2 with metal bars 7 from the single bar loader 6 continues and the process reiterates.

Fig. 4 shows an arrangement of the positioning and distribution unit 9 as a derivative of the "bar introduction device" regarding the Italian patent UD93A000170 from the same inventor, whereas the visible chain band-conveyor 13 engages and moves around an actuation shaft 8 and rolls 10, having an upper horizontally part A to C substantially parallel to the adjacent bar supporting chain-type bands 2 of the quick feeder unit 1 and having a lower bottom part D adjacent above and parallel to the working surface 12. The chain band-conveyors 13 are in a controlled way rotating around the actuation shaft 8 and the rolls 10 and contain on their respective surfaces multiple receiving and holding units 20 which are placed along a chain band-conveyor 13 next to each other and inline with a clearly defined interspace, adapted to the defined bar interspace of the electro welded metal net, which gets produced. The distance of the receiving and holding units 20 must fit of course also to the interspace of the metal bars 7 of the receiving seats 2.2 of the bar supporting chain-type bands 2, which have to become adapted to the defined interspace of the metal net to be produced.

The receiving and holding units 20 can have each an open state, a closed/holding state and a bar releasing state which can be set mechanically, electrically or magnetically. In the upper horizontally part A to C all receiving and holding units 20 have to be in a bar receivable open state, ready for taking over metal bars 7 from the bar supporting chain-type band 2. Then after the metal bars 7 are carried in the open retaining spaces 25a, the closing and holding units are closed, preferably simultaneously, by a controllable closing mechanism (Fig. 6) in order to hold the metal bars 7 in a retaining space 25b while they are rotating sidewards and upside-down in direction B towards and above the working surface 12 where they stop at a defined position. Above the working surface 12 the receiving and holding units 20 with still held metal bars 7 (not shown) get opened by a release control unit 18 and are brought into an open releasing state again (Fig. 4), so that the metal bars 7 fall out of the receiving and holding units 20 by gravity force onto the working surface 12 and can become welded. It is also imaginable that in order to release the metal bars 7 onto the working surface 12 the receiving and holding units 20 get not opened totally but only so wide, that the closing and holding elements 21 are used as guiding elements for a better positioning of the falling out metal bars 7 onto the working surface 12.

As soon as the unloading of the metal bars 7 from the quick feeder 1 is finished and the supporting arm 2.3 is in the upper position again, the individual loading upstream restarts. Once the entire surface of the upper part of the bar supporting chain-type band 2 of the quick feeder unit 1 has been loaded again, the whole cycle reiterates. The reduction of the repetitive loading time of the positioning and distribution unit 9, since its feeding does not occur metal bar by metal bar 7 but simultaneously with multiple metal bars 7, gets evident and leads to a considerable time saving.

Fig. 5 shows a receiving and holding unit 20 in more detail comprising base elements 23 with an integrated opening and closing mechanism, connected movable closing and holding elements 21 in order to close (25b) or to open again (25a) a retaining space 25a for readiness to receive metal bars 7 again. The opening and closing of the closing and holding elements 21 is controlled by a mechanical opening/closing control element 24, getting controlled from outside.

It is imaginable that said opening/closing control element 24 can be of a mechanical wheel type, that it can comprise electrical contacts and/or that it can comprise a magnetic sensor/actuator or the like. Furthermore it has not necessarily to be placed where it is drawn.

Another imaginable arrangement connected to this invention is that the release control unit 18 comprises an electronic control together with a mechanical interspace device which allows computerized programmable and even individual interspaces of adjacent receiving and holding units 20 like what is also known from ski lifts of the state of the art.

The present invention is not limited to the use of chain band-conveyors and other chain- type feed band solutions described above, it shall also cover a possible use and substitution by similar functional devices as screw feeders, worm screws, toothed belts provided with automatic clamps, toothed rods moved back and forth with an eccentric element and the like.

The present invention shall also not be limited to metal bars as it is also imaginable to use it for plastic bars which get welded by liquids or by heat.

The present invention is also not limited to the examples of the embodiments described above as it can also comprise additional supporting embodiments, other forms and the like.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included just for the sole purpose of increasing intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

List of Reference Numerals

1 quick feeder unit

2 bar supporting chain-type band

2.2 receiving seats (on the bar supporting chain-type band 2)

2.3 supporting arm

3 positioning mechanics

4 cogwheel arrangement

5 cogwheel arrangement

6 single bar loader

7 metal bars

8 actuation shaft

9 positioning and distribution unit

10 rolls

11 actuator (in particular a hydraulic cylinder)

12 working surface

13 chain band-conveyor 18 release control unit

20 receiving and holding units

21 closing and holding elements

23 base elements (of the receiving and holding unit)

24 opening/closing control element

25a open retaining space (of the receiving and holding unit 20)

25b closed retaining space (of the receiving and holding unit 20)

25c guiding openings (of the receiving and holding unit 20) ALPHA angle (moving angle of the supporting arm 2.3)

A-C upper horizontally part

D bottom part

Claims

1. A device including a single bar loader (6), a quick feeder unit (1) for rods and/or bars (7) arranged downstream and subjacent of the single bar loader (6), and a bar positioning and distribution unit (9) arranged downstream and subjacent of the quick feeder unit (1), the device operating with chains with articulated links in systems for forming electro-welded metallic nets, wherein the quick feeder unit (1) comprises a plurality of supporting arms (2.3) shaped like the teeth of a comb, which are pivoted at a first end, leaving the second end free to oscillate in an angular direction with respect to a fulcrum at the first end, upward from below and vice versa, the supporting arms (2.3) being actuated synchronously by actuator means (11) such as hydraulic cylinders (11) and corresponding positioning mechanics (3), the supporting arms (2.3) being arranged parallel and partially laterally adjacent to chain band-conveyors (13) of the bar positioning and distribution unit (9), with mutually opposite combs, so that the second ends of the supporting arms (2.3) can move from a position above the bar positioning and distribution unit (9) to a lower position which is contained within the contour or region of operation of the bar positioning and distribution unit (9), each supporting arm (2.3) being equipped with a bar supporting chain-type band (2) provided with receiving seats (2.2) for receiving from the upper side from the single bar loader (6) the rods and/or bars (7) arranged transversely, the bar supporting chain-type bands (2) being actuated synchronously by means of a shaft (4), arranged at the first end of the supporting arms (2.3) which also acts as the fulcrum for the angular movement of the supporting arms (2.3), the bar supporting chain-type bands (2) forming on the upper side thereof a plane or surface for resting the rods and/or bars (7), the second end of the supporting arms (2.3) of the quick feeder unit (1) extending substantially up to the downstream remotest end of the bar positioning and distribution unit (9), the single bar loader (6) being arranged proximately to the shaft (4) and adapted to load the individual rods and/or bars (7) and to place them automatically, one by one, on the bar supporting chain-type bands (2) which advance toward the second end of the supporting arms (2.3), all the rods and/or bars (7) being thus arranged parallel to each other and with preset interspaces or distances in the receiving seats (2.2), the device being further adapted to both halt the single bar loader (6) and to halt the advancement of the bar supporting chain-type bands (2), the device being further adapter to lower the bar supporting chain-type bands (2) angularly with respect to the fulcrum and simultaneously, such that all the conveyed rods and/or bars (7) that affect the area of the subjacent bar positioning and distribution unit (9) are placed simultaneously on respective receiving and holding units (20) of the subjacent bar positioning and distribution unit (9), the receiving and holding units (20) being operable to close and lock the received rods and/or bars (7), the bar positioning and distribution unit (9) being adapted to convey the rods and/or bars (7) which are positioned and locked in the receiving and holding units (20) to a lower position.

2. The device according to claim 1, wherein the supporting arms (2.3) of the quick feeder unit (1) are provided, for the individual movement of the rods and/or bars (7), with the bar supporting chain-type bands (2) with adapted U-shaped and/or V-shaped receiving seats (2.2) which are directed upward and are suitable for receiving transversely the rods and/or bars (7) from above or laterally.

3. The device according to claims 1 or 2, wherein supporting the arms (2.3) of the quick feeder unit (1) are provided, for the individual conveyance of the rods and/or bars (7) in position on the upper surface, with screw feeder devices at right angles to the rods and/or bars (7).

4. The device according to one or more claims 1 to 3, wherein the arms (2.3) of the quick feeder unit (1) are provided, for the individual conveyance of the rods and/or bars (7), with toothed- belt devices provided with suitable bar receiving seats or other equivalent devices suitable for the purpose, arranged at right angles to the bars to be conveyed.

5. The device according to one or more claims 1 to 4, wherein the arms (2.3) of the quick feeder unit (1) are provided with pairs of laterally adjacent toothed rods, one rod being fixed, the other one being movable back and forth with a movement derived from the rotation of an eccentric element.

6. The device according to one or more claims 1 to 5, wherein the arms (2.3) of the quick feeder unit (1) are moved angularly like a third-class lever, i. e., with the fulcrum (4) at the first end, the actuation force along the actuator means (11) and the corresponding positioning mechanics (3) leaving the second end (5) to protrude within the contour of the subjacent positioning and distribution unit (9).

7. The device according to one or more claims 1 to 6, wherein, the supporting arms (2.3) of the quick feeding unit (1) for positioning with preset interspaces the individual bars can be moved, by means of suitable devices, in a parallel manner, downward from above and vice versa, with respect to the bar receiving surface of the subjacent positioning and distribution unit (9) in order to be able to discharge all the bars instantaneously.

8. The device according to claim 1, wherein the bar supporting chain- type bands (2) are provided with individual or multiple U-shaped and/or V-shaped receiving seats (2.2) which protrude and are directed upward and are each suitable to receive one or more bars (7) transversely.

9. The device according to claim 1, wherein, its loading occurs individually, i. e., one bar after the other, while the unloading of all or part of the bars that are gathered along the bar supporting chain type band (2) and affect the region of operation of the subjacent positioning and distribution unit (9) occurs instantaneously.

10. A method for operating a device including a single bar loader (6), a quick feeder unit (1) for rods and/or bars (7) arranged downstream and subjacent of the single bar loader (6), and a bar positioning and distribution unit (9) arranged downstream and subjacent of the quick feeder unit (1), the device operating with chains with articulated links in systems for forming electro- welded metallic nets, wherein the quick feeder unit (1) comprises a plurality of supporting arms (2.3) shaped like the teeth of a comb, which are pivoted at a first end, leaving the second end free to oscillate in an angular direction with respect to a fulcrum at the first end, upward from below and vice versa, the supporting arms (2.3) being actuated synchronously by actuator means (11) such as hydraulic cylinders (11) and corresponding positioning mechanics (3), the supporting arms (2.3) being arranged parallel and partially laterally adjacent to chain band-conveyors (13) of the bar positioning and distribution unit (9), with mutually opposite combs, so that the second ends of the supporting arms (2.3) can move from a position above the bar positioning and distribution unit (9) to a lower position which is contained within the contour or region of operation of the bar positioning and distribution unit (9), each supporting arm (2.3) being equipped with a bar supporting chain-type band (2) provided with receiving seats (2.2) for receiving from the upper side from the single bar loader (6) the rods and/or bars (7) arranged transversely, the bar supporting chain-type bands (2) being actuated synchronously by means of a shaft (4), arranged at the first end of the supporting arms (2.3) which also acts as the fulcrum for the angular movement of the supporting arms (2.3), the bar supporting chain-type bands (2) forming on the upper side thereof a plane or surface for resting the rods and/or bars (7), the second end of the supporting arms (2.3) of the quick feeder unit (1) extending substantially up to the downstream remotest end of the bar positioning and distribution unit (9), the single bar loader (6) being arranged proximately to the shaft (4,). the method comprising the steps of: loading the individual rods and/or bars (7), placing them automatically, one by one, on the bar supporting chain-type bands (2); and advancing them toward the second end of the supporting arms (2.3), all the rods and/or bars (7) being thus arranged parallel to each other and with preset interspaces or distances in the receiving seats (2.2), halting both the single bar loader (6) and the advancement of the bar supporting chain-type bands (2) when the supporting arms (2.3) of the quick feeder unit (1) are completely filled by the rods and/or bars (7) and occupy the upper surface of the bar supporting chain-type bands (2), lowering the bar supporting chain-type bands (2) angularly with respect to the fulcrum and simultaneously, such that all the conveyed rods and/or bars (7) that affect the area of the subjacent bar positioning and distribution unit (9) are placed simultaneously on respective receiving and holding units (20) of the subjacent bar positioning and distribution unit (9), the receiving and holding units (20) being operable to subsequently close and lock the received rods and/or bars (7), conveying by means of the positioning and distribution unit (9) the rods and/or bars (7) which are positioned and locked in the receiving and holding units (20) to a lower position; opening the holding units (20) to discharge the rods and/or bars (7), and leaving the supporting arms (2.3) of the quick feeder unit (1) free to rise and, at the same time, reactivating the single bar loader (6).

11. The method of claim 10, wherein the receiving and holding units (20) are operated to be closed or opened simultaneously and/or wherein the opening degree of the receiving and holding units (20) is controllable..