EP1864726A1

EP1864726A1 - Feed device for metal bars, and relative method

Info

Publication number: EP1864726A1
Application number: EP07109758A
Authority: EP
Inventors: Giorgio Del Fabro
Original assignee: MEP Macchine Elettroniche Piegatrici SpA
Current assignee: MEP Macchine Elettroniche Piegatrici SpA
Priority date: 2006-06-08
Filing date: 2007-06-06
Publication date: 2007-12-12
Also published as: ITUD20060148A1

Abstract

Device (10) and method to feed metal bars (12) wound in a roll (13) to an operating machine (11). The device (10) comprises a loading assembly (16) in which one or more rolls (13) of metal wire are provided, and a drawing and straightening assembly (15) mounted on the operating machine (11) in order to draw and straighten the metal wire and feed it to specific operating members of the operating machine (11). The operating members comprise a shearing assembly to prepare the metal bars (12) to a desired size. The device (10) also comprises selective feed elements (17, 19) disposed upstream of the drawing and straightening assembly (15), in order to automatically connect one or another of the rolls (13) to the drawing and straightening assembly (15) according to determinate operating requirements of the operating machine (11), so as to simultaneously feed a first of the metal bars (12) from a first roll (13), and prepare, in a stand-by condition, a second of the metal bars (12) from a second roll (13).

Description

FIELD OF THE INVENTION

The present invention concerns a feed device for metal bars, particularly for metal bars wound in a roll or coil, and fed to an operating machine, such as for example a bending machine, a stirrup-machine, a cage-making machine or other machine for working metal bars. In particular, the present invention allows to feed the operating machine automatically and substantially continuously, possibly changing the diameter or type of metal bar, and reducing to a minimum the manual intervention of the operator and loading downtimes.
A method and a device according to the preamble of the main claims are disclosed in EP-A1-564.445 .

BACKGROUND OF THE INVENTION

It is known that to feed a working machine with one or more metal bars from a roll, it is necessary to unwind the leading end of the roll and constrain it to a first drawing and straightening assembly of the working machine, so as to start the bar moving towards automatic working.
In the same way, if the roll is finished or the diameter of the bars to be worked is changed, a new roll is prepared and the procedure to constrain the leading end to the drawing and straightening assembly of the machine must be repeated.
These loading and roll-change operations are normally carried out manually, and require temporary interruptions to the functioning of the machine, thus entailing a reduced productivity.
Moreover, known machines need various workers to support the feeding operations, thus increasing both the costs and the risks of accidents, also due to the masses and weights involved.
One purpose of the present invention is to achieve a feed device which is simple and economical to make, and which allows to feed metal bars to a working machine substantially continuously, reducing to a minimum the stand-by downtimes of the machine and hence increasing the productivity thereof.
Another purpose of the present invention is to achieve an automatic loading device for metal bars which is safe for the workers and reduces the risk of accidents to a minimum.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the main claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.
A feed device for metal bars according to the present invention is applied to feed metal bars fed from a roll to an operating machine for working bars, the latter for example sheared to size with respect to the unwinding roll.
In accordance with the above purpose, the feed device according to the present invention comprises a store, or loading assembly, in which one or more rolls of metal wire are provided, and at least a drawing and straightening assembly mounted on the operating machine and configured to draw and straighten the metal wire unwound from the respective rolls in order to feed it to specific operating members of the operating machine, which provide at least a shearing assembly to prepare bars of the desired size.
According to a characteristic feature of the present invention, the feed device also comprises selective feed means disposed upstream of the drawing and straightening assembly and able to automatically and alternately connect one or the other of said rolls to the drawing and straightening assembly, according to determinate operating requirements, such as for example the state of fullness of the rolls and/or the type of metal bars to be fed to said operating members.
The selective feed means is also configured to simultaneously allow to feed to the machine a first metal bar from a first roll, and to prepare, in a stand-by condition, a second metal bar arriving from a second roll.
In this way, once the first roll is finished, the selective feed means switches the feed to the second roll, defining a substantially continuous feed to the machine.
Moreover, while the first metal bar supplied by the second roll is being fed, the selective feed means according to the present invention allows to load a new roll, when the previous one is finished, then keeping it in the stand-by condition until the second roll is finished.
According to a first form of embodiment of the present invention, the selective feed means comprises two or more mobile tubular elements or tubes, into which the metal bars to be fed are inserted axially.
In this way, while a first tubular element is kept in a feed condition in which it feeds the drawing and straightening assembly with a metal bar supplied by the first roll, the other tubular element is kept in the stand-by condition in which a metal bar supplied by the second roll is prepared inside it, having a diameter equal to or different from the first.
The present invention thus allows that, as soon as one of the rolls is finished, the two tubular elements are automatically moved, automatically varying the source of feed of the bars, in particular, taking the second tubular element to the feed condition and the first tubular element to the stand-by condition; this allows to ensure a substantially continuous feed to the operating machine or at least with a very extended duration without requiring interruptions for the roll-change.
Moreover, since the selective feed means functions substantially automatically, it is sufficient to provide a limited number of workers, possibly only for checking and for maintenance, and for the initial introduction of the leading end of the roll into the feed means.
Advantageously, each tubular element is provided with an inlet end and an outlet end, which can be moved by means of movement means, so as to selectively direct the metal bars fed by the rolls towards the drawing and straightening assembly, or keep them in the stand-by condition.
According to a variant, the inlet ends of the tubular elements are pivoted to a fixed structure, while the outlet ends are able to be aligned selectively and alternately with the drawing and straightening assembly by means of the movement means.
According to another variant, the feed device comprises a protection cabin structured so as to prevent access at least to the zone where the rolls are unwound and the zone where the bars enter the selective feed means, so as to prevent the workers in this way from approaching the metal bars at least during their feed to the shaping machine.
Advantageously, the protective structure is divided into isolated sectors, so that, while a first roll is unwound to feed the shaping machine, the worker can intervene on a second roll, isolated from the first, and load the leading end of the roll substantially continuously into the second tubular element.
Vice versa, when feed is made through the second tubular element, the worker can intervene in safety on the first roll in order to replace it and load the leading end of the roll into the first tubular element.
This solution allows the workers to work in substantial safety, protected from the bars being drawn, and allows to feed the metal bars continuously to the operating machine.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

fig. 1 is a schematic view from above of a feed device according to the present invention associated with a machine for working metal bars;
fig. 2 shows an enlarged detail of the device in fig. 1 in a first operating condition;
fig. 3 shows an enlarged detail of the device in fig. 1 in a second operating condition
fig. 4 is a front view of an enlarged detail of the feed device in fig. 1.

DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF EMBODIMENT

With reference to the attached drawings, a feed device 10 according to the present invention is applied to an operating machine 11, such as for example a bending machine, a stirrup-machine, a cage-making machine or other machine, for shaping metal bars 12 fed from a roll 13.
In this case, the operating machine 11 can be selectively fed with four different types of metal bars 11 supplied by respective rolls 13, and the bars 11 are loaded to the operating members of the machine 11 by means of a drawing and straightening assembly 15 of the feed device 10.
In particular, the feed device 10 according to the present invention also comprises a loading cabin 16, in which the four rolls 13 are disposed, two feed tubes, respectively a first 17 and a second 19, which connect the rolls 13 alternately to the drawing and straightening assembly 15, and a movement assembly 20 disposed upstream of the drawing and straightening assembly 15 and able to move the feed tubes 17 and 19 alternately, to selectively switch the feed of the metal bars 12 between one and the other of the rolls 13.
The loading cabin 16 substantially consists of a plurality of protective panels 21 disposed annularly around the rolls 13, and around a segment of the two feed tubes 17 and 19.
Some of the protective panels 21 comprise an inlet door 22 which allows access inside the loading cabin 16, so as to allow the worker to perform the usual operations of maintenance and equipping.
Advantageously, the loading cabin 16 also comprises a plurality of median panels 24 which separate the inner area of the loading cabin 16 into two distinct and isolated zones.
In this solution, the four rolls 13 are disposed in twos in the two distinct and isolated zones of the loading cabin 16, so as to allow the worker to intervene in safety on a first pair of rolls 13, also while feed continues to the shaping machine 11 using the other pair of rolls 13.
Each of the two feed tubes 17 and 19 comprises an inlet end 23, facing towards the rolls 13, and an outlet end 25 facing towards the shaping machine 11.
In particular, each inlet end 23 is housed inside a respective one of the two distinct and isolated zones, and is pivoted to a fixed structure 26. Each outlet end 25 is associated with the movement assembly 20.
In this way, each feed tube 17, 19 can be selectively rotated between a first feed condition, in which it is substantially aligned with the drawing and straightening assembly 15 and feeds the latter with a metal bar 12 arriving from a first roll 13; and a second stand-by condition, in which it is dis-aligned from the drawing and straightening assembly 15, and keeps the leading segment of a second roll 13 inside it.
Advantageously, inside every feed tube 17, 19 a plurality of guide rollers 30 are provided, which stabilize and improve the sliding conditions of the metal bars 12 inside the respective feed tubes 17, 19.
On the fixed structure 26, immediately upstream of the inlet ends 23 of the two feed tubes 17 and 19, two respective drawing assemblies with rollers are provided, respectively 27 and 29, which unwind the rolls 13 and insert the relative metal bars 12 into the respective feed tubes 17 and 19, during the feed steps of the shaping machine 11.
In an initial feed step, the leading segments of the rolls 13 are inserted into the two drawing assemblies with rollers 27 and 29, and from here sent to the respective feed tubes 17, 19.
The movement assembly 20 comprises a loading carriage 31, mobile by means of a hydraulic motor 34 on mating guide bars 32, in a direction substantially transverse to the loading direction of the metal bars 12 into the shaping machine 11.
In particular, the respective outlet ends 25 of the feed tubes 17 and 19 are attached to the loading carriage 31, so as to selectively move the two feed tubes 17 and 19 between the two conditions, fed and stand-by.
The loading carriage 31 also comprises two insertion channels 33 and 35, facing respectively the outlet end 25 of the feed tube 17, and the outlet end 25 of the feed tube 19.
Each insertion channel 33 or 35, in this case, consists of a plurality of pairs of rollers 38 able to direct the metal bars 12 fed by the rolls 13 to the shaping machine 11.
In particular, in the feed condition, the insertion channels 33 or 35 direct the relative metal bar 12 towards the drawing and straightening assembly 15, while in the stand-by condition the insertion channels 33 or 35 direct the leading segment of the relative roll 13 towards a pivoting lever 36 which, once activated under pressure, signals the presence of the leading segment of the roll 13.
In this case, a linear position transducer 37 is associated with the loading carriage 31, and slaves the hydraulic motor 34 in order to regulate the movement of the loading carriage 31 with precision, possibly as a function of predetermined and standardized movements.
In this case, the loading carriage 31 also comprises two insertion holes 39 which allow to feed the metal bars 12 supplied by the rolls 13 in a substantially traditional manner.
The feed device according to the present invention functions as follows.
First of all the respective leading segments of two of the four rolls 13 are loaded by the worker into the respective drawing assemblies with rollers 27 and 29.
The two drawing assemblies with rollers 27 and 29 unwind the rolls 13 progressively, making the relative metal wires slide inside the respective feed tubes 17 and 19, until they reach the loading carriage 31.
The loading carriage 31 is positioned initially so as to configure the first feed tube 17 in the feed condition, so that the leading end of the roll 13 is gripped in the drawing and straightening assembly 15. At this point, the drawing assembly with rollers 27 is released from the first roll 13, so that feed to the shaping machine 11 is effected only by the drawing and straightening assembly 15.
At the same time, the second feed tube 19 directs the relative leading end of the roll 13 in the stand-by condition, in which it contacts under pressure the pivoting lever 36, generating a signal of its presence.
Once the first roll 13 has been finished, the loading carriage 31 rotates the two feed tubes, automatically taking the first 17 to the stand-by condition, and the second 19 to the feed condition, so that the leading end of the second roll 13, prepared inside it, can be taken and gripped by the drawing and straightening assembly 15, and then fed to the shaping machine 11.
At this point the worker enters the isolated zone of the loading cabin 16 where the first, finished roll 13 is to be found, and he replaces it, possibly loading the leading end of the new roll 13 into the relative drawing assembly with rollers 27, in order to dispose it inside the first feed tube 17. As we said, this operation is performed simultaneously with the feed of the second metal bar 12, in safe conditions for the worker.
Once the second roll 13 is finished, the loading carriage 31 rotates the two feed tubes 17 and 19, to feed the new leading end of the roll 13 prepared in the first feed tube 17 to the operating machine 11.
At the same time, the worker replaces the second finished roll 13, possibly loading its leading end into the relative drawing assembly with rollers 29.
It is clear, however, that modifications and/or additions of parts may be made to the feed device 10 as described heretofore, without departing from the scope of the present invention.
It is also clear that, although the present invention has been described with reference to specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of feed device for metal bars, and relative method, having the characteristics as set forth in the claims and hence all coming within the scope of protection defined thereby.

Claims

Device to feed metal bars (12) wound in a roll (13) to an operating machine (11), said device (10) comprising at least a loading assembly (16) in which one or more rolls (13) of metal wire are provided, and at least a drawing and straightening assembly (15) mounted on said operating machine (11) and able to draw and straighten said metal wire in order to feed it to specific operating members of said operating machine (11), said operating members comprising at least a shearing assembly able to prepare said metal bars (12) to a desired size, the device also comprising selective feed means (17, 19) disposed upstream of said drawing and straightening assembly (15), and able to automatically connect one or another of said rolls (13) to said drawing and straightening assembly (15) according to determinate operating requirements of said operating machine (11), so as to simultaneously feed a first of said metal bars (12) from a first roll (13), and prepare, in a stand-by condition, a second of said metal bars (12) from a second roll (13), characterized in that said selective feed means comprises two or more mobile tubular elements (17, 19), into which the leading ends of said rolls (13) are inserted axially, and each of which is provided with an inlet end (23) and an outlet end (25), which inlet end (23) and outlet end (25) can be moved by means of movement means (20).
Device as in claim 1, characterized in that it also comprises protection means (16) structured so as to prevent access at least to a zone where said rolls (13) are unwound, and to a zone where the relative leading segments of said rolls (13) enter said selective feed means (17, 19).
Feed device as in claim 1 or 2, characterized in that said inlet ends (23) of each of said tubular elements (17, 19) are pivoted to a fixed structure (26) and said respective outlet ends (25) are associated with said movement means (20).
Device as in claims 2 and 3, characterized in that said inlet ends (23) are disposed inside said protection means (16).
Device as in any claim hereinbefore, characterized in that upstream of said inlet ends (23) respective drawing assemblies (27, 29) are provided, able to unwind at least the leading ends of said rolls (13) until they reach said drawing and straightening assembly (15).
Device as in any claim hereinbefore, characterized in that said movement means (20) comprises a loading carriage (31) movable by means of a drive member (34) on corresponding guides (32) in a direction substantially transverse to the direction of loading of said metal bars (12).
Device as in claims 1 and 6, characterized in that each of said respective outlet ends (25) of said tubular elements (17, 19) is attached to said loading carriage (31), so as to selectively move said two tubular elements (17, 19).
Device as in claim 6 or 7, characterized in that said loading carriage (31) also comprises two insertion channels (33, 35), facing the respective outlet ends (25) of said tubular elements (17, 19).
Device as in claim 8, characterized in that each of said insertion channels (33, 35) comprises a plurality of pairs of rollers able to direct said metal bars (12) towards said shaping machine (11).
Device as in any claim from 6 to 9, characterized in that said loading carriage (31) is associated with a position transducer (37), able to slave said drive member (34) in order to regulate precisely the movement of said loading carriage (31), possibly as a function of pre-determined and standardized movements.
Device as in any claim hereinbefore, characterized in that it also comprises at least a detection member (36), able to be activated under pressure by the leading end of the roll (13), in the stand-by condition, in order to signal the presence thereof.
Method to feed metal bars (12) wound in a roll (13) to an operating machine (11), comprising at least a first step of loading the leading end of a first roll (13) into selective feed means (17, 19) in order to feed a relative first metal bar (12) to said operating machine (11), and simultaneously loading a leading end of a second roll (13) into said selective feed means (17, 19) in order to prepare a relative second metal bar (12) in a stand-by condition, characterized in that it provides at least a second step in which, once said first roll (13) is finished, said selective feed means (17, 19) automatically connects said second roll (13) to said operating machine (11) in order to feed said second metal bar (12), and in which, simultaneously with the feed of said second metal bar (12), said first finished roll (13) is replaced by a new roll (13), in a zone of a loading assembly (16) of said rolls (13), isolated from said second roll (13).