EP1396296A1

EP1396296A1 - Method for cropping to size and optionally bending profiled elements with bending and shaping machines, particularly profiled elements supplied in bar form

Info

Publication number: EP1396296A1
Application number: EP02019774A
Authority: EP
Inventors: Gianfranco Terenzi
Original assignee: Schnell SpA
Current assignee: Schnell SpA
Priority date: 2002-09-04
Filing date: 2002-09-04
Publication date: 2004-03-10
Anticipated expiration: 2022-09-04
Also published as: EP1396296B1

Abstract

A method for cropping to size and optionally bending profiled elements, particularly for cropping and optionally bending profiled elements supplied in bar form, with bending and shaping machines of the type that comprises at least: an upstream feeder assembly (1), which can be actuated to produce the advancement of the profiled element (2) along its axis; a bending assembly (4), which is arranged downstream of the upstream feeder assembly; cropping means (5), which are interposed between the upstream feeder assembly (1) and the bending assembly (4); and a downstream traction assembly (6) of the roller type, arranged downstream of the bending assembly (4). The method entails, only in the recoverable trailing portion of the profiled element (2), after a step for the advancement of the profiled element along its own axis, which is performed by way of the upstream feeder assembly (1), and after an optional step for bending the leading portion of the profiled element (2) by way of the combined actuation of the upstream feeder assembly (1) and of the bending assembly (4), engaging the profiled element (2) by means of the downstream traction assembly (6) and pulling it, by way of the traction assembly, until a chosen length is reached along the advancement direction. The profiled element (2) is then cropped to size by way of the cropping means (5) and is then subjected to optional bending of its trailing portion by way of the combined actuation of the downstream traction assembly (6) and of the bending assembly (4).

Description

The present invention relates to a method for cropping to size and optionally bending profiled elements with bending and shaping machines, particularly for cropping and optionally bending profiled elements supplied in bar form.
Bending and shaping machines for bending profiled elements provided in coil or bar form, particularly for producing reinforced concrete frames, are known.
Machines of this kind and the associated methods for bending profiled elements are disclosed for example in Italian patents No. 1,235,176, 1,235,177, 1,242,690, 1,252,962 and 1,252,984.
These machines are generally constituted at least by: an upstream feeder assembly, which can be actuated to produce the advancement of the profiled element along its axis; a bending assembly, which is arranged downstream of the upstream feeder assembly along the advancement direction imparted to the profiled element by the upstream feeder assembly; cropping means, which are interposed between the upstream feeder assembly and the bending assembly, and a downstream traction assembly of the roller type, which is indeed located downstream of the bending assembly and in axial alignment with the preceding assemblies and with the direction of advancement of the profiled element being processed.
These machines generally work by performing, by way of the cropping means, an optional first cropping of the profiled element, so as to define the leading end of the profiled element, and by then performing one or more bends in the leading portion of the profiled element by way of the combined actuation of the upstream feeder assembly and of the bending assembly.
Then the profiled element is made to advance, by means of the upstream feeder assembly, by a preset extent and is then cropped, by way of the cropping means, so as to define the trailing end of the profiled element.
With this cropping, the part of the profiled element that lies downstream of the cropping means is disengaged from the action of the upstream feeder assembly. After cropping, the trailing portion of the profiled element is subjected to one or more bending operations, engaging the profiled element with the downstream traction assembly and actuating, in an appropriately combined manner, said downstream traction assembly and the bending assembly.
In some of these machines the cropping means are constituted by shears that can move on command along the advancement direction of the profiled element in order to crop the trailing portion of the profiled element to the intended length in order to form the required bends along said portion.
In the above cited machines, the various elements of the machine are supported by a structure that forms a worktable that is generally substantially vertical, subvertical or otherwise tilted and on which the profiled element is bent, and a support on which the profiled element is made to advance.
In some cases, the shears can be retractable with respect to said worktable.
It is also possible to provide additional elements or assemblies that take part in the process, such as supporting means and channel guides, supporting redirection elements, et cetera, which can assume different positions that are however compatible with the method according to the present invention but are scarcely relevant in terms of the description of the present invention.
The bending assembly, in these machines, can be able to move at right angles to the worktable as well as at right angles to the axis of the profiled element, in order to engage or disengage the profiled element. The downstream traction assembly is composed of one or more pairs of rollers, between which the profiled element being processed passes. Also the downstream traction assembly can be movable at right angles to the worktable, optionally on three different levels, in order to engage or disengage the profiled element and optionally lift the profiled element.
Further, the rollers of each pair of rollers of the downstream traction assembly can be movable toward or away from each other in order to engage or disengage the profiled element.
Although these machines, by way of the adoption of the traction assembly arranged downstream of the bending assembly, have solved the problem of bending the trailing portion of the profiled element by means of a single bending assembly, they have not solved, in many operating situations, the problem of containing the waster produced by cropping the profiled elements to size in the recoverable end portion of the profiled element when it originates from a coil and even more so if it originates from a bar.
This problem, which affects the entire category of these machines, is scarcely important when the profiled element is provided to the machine in coils, since the problem arises only when the coil of profiled element is used up, and the length of the coil is on the order of thousands of meters.
The problem is instead very important if the profiled element is provided to the machine in bar form (usually with a length of 12-18 m, exceptionally 24 m), since waste is produced for each bar.
In this case, in view of the fact that the upstream feeder assembly cannot be moved closer to the cropping means or vice versa beyond a certain limit, due to dimensional problems, the length of the profiled element being processed that is actually usable is reduced by an extent at least equal to said limit.
For this reason, if one has a trailing portion of a bar that nominally could be used to produce a finished part (understood as the product of the machining of the machine, being it a stirrup, a bent part or a simple straight bar cropped to size or simply extracted from a bundle without performing any cropping), in practice it is not possible to use it if the length of the end segment is not at least equal to the sum of the length required for the finished part and the distance between the upstream feeder assembly and the cropping means.
Otherwise, the upstream feeder assembly would in fact cease producing the advancement of the bar segment before the intended length of profiled element, for obtaining another finished part, has passed through the cropping means.
This fact inevitably forces to reject the entire trailing portion of the bar, which does not meet this size requirement, thus increasing waste considerably.
The aim of the present invention is to solve the above described problem, by providing a method for cropping to size and optionally bending profiled elements, particularly for cropping and optionally bending profiled elements supplied in bar form, with bending and shaping machines, particularly of the type described above, that allows to reduce waste considerably.
Within this aim, an object of the invention is to provide a method that allows to utilize, for production purposes, the entire length of the profiled element fed to the machine.
Another object of the invention is to provide a method that can be performed without requiring substantial structural modifications with currently commercially available bending and shaping machines, particularly of the type described above.
This aim and these and other objects that will become better apparent hereinafter are achieved by a method for cropping to size and optionally bending profiled elements, particularly for cropping and optionally bending profiled elements supplied in bar form, with bending and shaping machines of the type that comprises at least: an upstream feeder assembly, which can be actuated to produce the advancement of the profiled element along its axis; a bending assembly, which is arranged downstream of said upstream feeder assembly along the direction of the advancement of the profiled element by way of the action of said upstream feeder assembly; cropping means, which are interposed between said upstream feeder assembly and said bending assembly; and a downstream traction assembly of the roller type, arranged downstream of said bending assembly; the method comprising at least one step for the advancement of the profiled element along said advancement direction, which is performed by way of said upstream feeder assembly, and being characterized in that it comprises sequentially, for the end portion of the profiled element, the steps of:

engaging the profiled element by means of said downstream traction assembly after the profiled element, pushed by said upstream feeder assembly, has arrived with at least one of its portions at said downstream traction assembly;
pulling the profiled element, by means of said downstream traction assembly, for a present length along the advancement direction;
cropping the profiled element by way of said cropping means.

Further characteristics and advantages of the present invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of the method according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
Figures 1, 3, 5, 7 and 9 are sequential views of the various steps of the method according to the invention with a bending and shaping machine, shown only schematically and in front view;
Figures 2, 4, 6, 8 and 10 are views of the same steps of the method according to the invention shown in the preceding figures, with the bending and shaping machine shown schematically in cross-section.
With reference to the figures, the method according to the invention is meant to be performed by way of bending and shaping machines of the type that comprises, in a per se known manner, at least: an upstream feeder assembly 1, which can be actuated in order to produce the advancement of the profiled element 2, preferably in bar form, along its axis in an advancement direction 3; a bending assembly 4, which is arranged downstream of the upstream feeder assembly 1 along the advancement direction 3; cropping means 5, which are interposed between the upstream feeder assembly 1 and the bending assembly 4; and a downstream traction assembly 6, which is indeed located downstream of the bending assembly 4.
The various elements of the machine are all axially aligned along the advancement direction 3 and are supported by a structure that forms a worktable 20, which is generally vertical or inclined but might also be horizontal.
The upstream feeder assembly 1 can be constituted, in a per se known manner, by pairs of rollers 7 that have mutually parallel axes which are generally horizontal and are pressed against each other in order to engage the profiled element 2, which passes between them, and can be actuated at least partially with a rotary motion about their respective axes in order to produce the advancement of the profiled element 2 along the direction 3.
The upstream feeder assembly 1, as an alternative to what has been shown, can be constituted in a per se known manner by a plurality of separate units instead of a single unit, for example a unit arranged proximate. to the insertion region of the profiled element 2 and a unit adjacent to the cropping means 5.
The cropping means 5 can be constituted by shears 8 that are stationary or movable, in a per se known manner, along the direction 3 and may also retract with respect to the worktable 20.
The bending assembly 4 can be constituted by a central pin 9 and by a bending pin 10 that can rotate around the central pin 9.
As an alternative, the bending assembly can be provided according to other known configurations, such as for example a bending disk on which a central roller and a bending pin are fixed, or, as another alternative, a shaped channel that acts as an abutment and as a central bending mandrel, and a movable disk that supports the bending pin. Moreover, the bending assembly 4 can be movable, in a per se known manner, both at right angles to the worktop 20, i.e., generally in a substantially horizontal direction, in order to engage or disengage the profiled element 2, and parallel to the worktop 20, i.e., generally in a substantially vertical direction, in order to engage in a different manner the profiled element 2 depending on the direction of the bending to be performed and/or in order to lift the profiled element 2, i.e., by using the multiple operating levels according to the known art or in the most appropriate combinations in relation to the type of finished part and to the shape of the machine.
The downstream traction assembly 6 is of the roller type and is constituted, in a per se known manner, by one or more pairs of rollers 11 that have mutually parallel axes, are generally perpendicular to the worktop 20, and are pressed against each other in order to engage the profiled element 2, which passes between them, and can be actuated at least partially with a rotary motion about their respective axes in order to produce the advancement of the profiled element 2.
Both the bending assembly 4 and the downstream traction assembly 6, as described by the cited patents, may assume three different positions according to requirements: a first normal position for working at the level of the worktable 20; an optional second position in which they are retracted fully or partially below the worktable, also referenced as retracted position, in order to avoid interfering with the profiled element being processed; and a third elevated position above the worktable 20 in order to allow some processes without interfering with the physical dimensions of the cropping means and the upstream feeder assembly.
The downstream traction assembly 6 can be movable, in a per se known manner, substantially at right angles to the worktable 20 in order to engage or disengage the profiled element 2.
The method according to the invention is now described in its embodiment as regards the trailing portion of a profiled element 2 supplied in bar form.
For the sake of simplicity it is assumed that a single profiled element at a time is fed to the bending and shaping machine, without altering the fact that the method according to the invention can also be performed by feeding simultaneously a plurality of profiled elements in bars arranged side by side.
Moreover, the expression "profiled element" is used to designate a profiled element having any cross-section, either solid or hollow according to requirements, particularly a steel rod for reinforced concrete.
For the sake of greater clarity in exposition, it is deemed useful to clarify the expressions "recoverable trailing portion of the profiled element" and "finished part" that will be used in the description of the method according to the invention.
The expression "finished part" is used to reference the product of the treatment of the machine, be it a bracket, a bent part or a simple straight bar cropped to size or simply extracted from a bundle without performing any cropping.
The expression "recoverable trailing portion of the profiled element" is understood to reference the trailing part of the profiled element that is the residue of preceding processes and whose residual length is at least equal to the length required to produce another "finished part".
As shown in Figures 1 to 4, in the presence of a recoverable trailing portion of the profiled element 2, the profiled element is made to advance by the upstream feeder assembly 1 through the cropping means 5 and is subjected to optional bending by way of the combined actuation of the upstream feeder assembly 1 and of the bending assembly 4.
Then, as shown in Figures 5 and 6, the profiled element 2 is made to advance by the upstream feeder assembly 1 by an extent that is at least sufficient to engage the downstream traction assembly 6 on a portion of profiled element that has not been bent. During this advancement, in particular during the initial step of this advancement, the downstream traction assembly 6 can be spaced, or better still retracted, under the worktable 20 to avoid hindering the advancement of the profiled element 2.
The downstream traction assembly 6 is then moved so as to engage the profiled element 2 and is then actuated so as to perform a step for pulling the profiled element along the advancement direction 3 in cooperation or not with the upstream feeder assembly 1, in order to obtain the useful length for forming the finished part, as shown in Figures 7 and 8. What characterizes the method according to the invention is that the final part of this traction is performed in any case by the downstream traction assembly 6 alone, since the profiled element has at this point exited from the rollers 7 of the upstream feeder 1.
As a whole, the advancement imposed to the profiled element 2 by the upstream feeder assembly 1 and by the downstream traction assembly 6 is equal to the overall extension that one wishes to obtain for the finished part to be produced, both when said advancement is achieved with the separate and successive intervention of the assemblies 1 and 6 and when there is a moment of cooperation of the assemblies 1 and 6.
At this point the cycle continues in a per se known manner, for example as described in the above cited patents. More specifically, the cropping means 5 are actuated, cropping the trailing end of the profiled element 2; as shown in Figures 7 and 8, by way of the combined actuation of the downstream traction assembly 6 and of the bending assembly 4, the optional bending (one or more bends) of the trailing portion of the profiled element 2 is performed and the profiled element is then unloaded from the machine. During this last bending step, or simultaneously with such step, it is possible, if necessary, for the bending assembly 4 and/or the downstream traction assembly 6 to move into a raised position above the worktable 20 in order to allow the trailing end bends without interfering with the physical dimensions of the upstream feeder assembly 1 and of the cropping means 5, which protrude from the worktable 20 and are usually also protected by movable coverings.
It should be noted that the downstream traction assembly 6 can be engaged with the profiled element 2 before the advancement action produced by the upstream feeder assembly 1 ends. In this case, during the simultaneous actuation, the upstream feeder assembly 1 is synchronized with the downstream traction assembly 6. What characterizes the invention, however, is the fact that the downstream traction assembly 6 is the only one responsible for moving the profiled element 2 in the trailing portion, when the end of the profiled element has left the upstream feeder assembly 1.
In any case it is possible, by virtue of measurement means of a known type, to monitor the overall length of the profiled element 2 that passes through the cropping means 5, so as to crop the profiled element 2 to the intended length.
Clearly, if the length of the recoverable trailing portion of the profiled element coincides with the length of the finished part to be obtained, the cropping means 5 are not actuated.
In the most extreme case, if the length of the bar coincides with the length of the required finished part, the cropping means 5 are never actuated; moreover, if in this last case the bending of the profiled element is also not required, the machine operates like a simple unit for extracting bars from a bundle of bars.
Moreover, it should be noted that the downstream traction assembly 6 can be used to extract from the machine the "unrecoverable trailing portion", i.e., the final portion of the bar that is shorter than the length required for the finished part, so long as said unrecoverable trailing portion has a length that is sufficient to reach the downstream traction assembly 6.
By comparing the method according to the invention with known methods, it can be noted that the downstream traction assembly 6 is used in two different situations: not only to move axially the profiled element 2 after cropping in order to position the profiled element at the level required to perform the bend or bends of the trailing end, as provided by the background art, but also to complete the advancement of the profiled element 2 in its recoverable end portion before performing said cropping. It is therefore possible to utilize practically all the length of the profiled element fed to the machine despite the inevitable distance between the upstream feeder assembly 1 and the cropping means 5.
The present invention therefore allows to obtain a waste that is shorter than the distance between the upstream feeder assembly 1 and the cropping means 5, or even no waste at all; this is absolutely not possible with the methods currently in use.
The reduction in waste entails significant economic advantages particularly if the profiled elements are fed to the bending and shaping machine in bar form.
In practice it has been observed that the method according to the invention fully achieves the intended aim and objects, since it allows to reduce significantly the waste produced by the cropping of the profiled elements.
Although the method according to the invention has been conceived particularly for bending and shaping machines supplied with profiled elements in bar form, it can in any case be used advantageously also for cropping and optionally bending profiled elements fed in coils.
The method thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; all the details may further be replaced with other technically equivalent elements.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

A method for cropping to size and optionally bending profiled elements, particularly for cropping and optionally bending profiled elements supplied in bar form, with bending and shaping machines of the type that comprises at least: an upstream feeder assembly (1), which can be actuated to produce the advancement of the profiled element (2) along its axis; a bending assembly (4), which is arranged downstream of said upstream feeder assembly (1) along the direction (3) of the advancement of the profiled element (2) by way of the action of said upstream feeder assembly (1); cropping means (5), which are interposed between said upstream feeder assembly (1) and said bending assembly (4); and a downstream traction assembly (6) of the roller type, arranged downstream of said bending assembly; the method comprising at least one step for the advancement of the profiled element (2) along said advancement direction (3), which is performed by way of said upstream feeder assembly (1), and being characterized in that it comprises sequentially, for the end portion of the profiled element, the steps of:

engaging the profiled element by means of said downstream traction assembly (6) after the profiled element, pushed by said upstream feeder assembly (1), has arrived with at least one of its portions at said downstream traction assembly (6);

pulling the profiled element (2), by means of said downstream traction assembly (6), for a present length along the advancement direction (3);

cropping the profiled element (2) by way of said cropping means (5).
The method according to claim 1, characterized in that it comprises a step for bending the leading portion of the profiled element (2) by way of the combined actuation of said upstream feeder assembly (1) and of said bending assembly (4).
The method according to claim 1, characterized in that it comprises a step for bending the trailing portion of the profiled element (2) by way of the combined actuation of said downstream traction assembly (6) and of said bending assembly (4).
The method according to one or more of the preceding claims, characterized in that said downstream traction assembly (6) is engaged with the profiled element (2) before it is released by said upstream feeder assembly (1) and in that said downstream traction assembly (6) and said upstream feeder assembly (1) are mutually synchronized during their simultaneous action on the profiled element.
The method according to one or more of the preceding claims, characterized in that said downstream traction assembly (6) is engaged with the profiled element after said profiled element (2) has been released by said upstream feeder assembly (1).