FIELD OF THE INVENTION

The present invention concerns a perfected curving machine, and also the corresponding method for curving reinforcement rods.

The perfected curving machine and the corresponding method serve to make curved reinforcement rods with desired radiuses of curvature.

BACKGROUND OF THE INVENTION

Curving machines for reinforcement rods are known, that is, rods used to reinforce reinforced concrete.

It is known that, in the case of circular or semi-circular platforms, the reinforcement rods must be shaped in direct coordination with the profile of the platform to be made.

Reinforcement rods can have a round section, a round section with ridges or ribs able to reinforce the anchorage with the concrete, a square or similar section, or a rectangular section.

Reinforcement rods are usually connected to each other by stirrups to create the desired reinforcement structures.

It is also known that for curved reinforcement structures with a big diameter, segments of reinforcement rods are shaped to create, for example by stirrups, in loco or in the place of shaping, the reinforcements to be anchored or integrated in the cast of concrete.

Curving machines are known with a substantially horizontal flat panel, but these have problems in manipulating both the segments of rod to be curved and also the forming arcs of the circle.

These problems affect both the safety of the operators and also the physical condition of the bars, which are subjected to possible deformations. It has also been tried to solve these problems by disposing a plurality of benches at entrance to and exit from the curving machine.

On the one hand this strategy solves some problems, such as those connected with supporting the stirrups shaped as an arc of a circle, but on the other hand it is not easily practicable when two or more bars are being worked simultaneously. In this case, the bars remain reciprocally positioned only in cooperation with the bending unit, but downstream and upstream they tend to collapse.

If one or more bars collapse upstream of the bending unit, there can easily be a twisting of the bars in the bending unit. In this case, problems can be created both for the bending unit, and for the operator, and for the bars involved.

The present invention has been devised, tested and embodied in order to simplify the operations of shaping one or more bars in an arc of a circle, or in other curves.

In fact, the present invention allows to obtain bars shaped in an arc of a circle, or with rectilinear segments and curved segments, or spiral or elliptical or in an arc of a circle with at least two diameters.

The purpose of the present invention is therefore to simplify the production of shaped bars conformed as an arc of a circle or as a circle, preventing dangers for the operators, organizational and operating complications, quality and constancy of the product and variability of the curvature.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

According to the invention, a perfected curving machine provides a support bench, with a mainly longitudinal development, on which the bars to be worked are disposed.

Clamping means are provided in a desired position on the bending bench, and are configured to selectively clamp the position of the bars to be worked.

The support bench can have a length substantially coordinated with the length of the bars that are worked on each occasion.

The perfected curving machine comprises at least one bending unit associated to the support bench and configured to bend the bars.

The support bench can be equipped with guides that cooperate at least with the at least one bending unit, which is equipped to move along the support bench in a desired and controlled manner.

When the clamping means are located centrally with respect to the length of the support bench, they can be substantially stable and suitable to clamp the bars. According to a variant the clamping means can be totally or partly retracted with respect to the support bench.

According to another variant it can be provided that it is a bending unit that performs the function of the clamping means, at least temporarily. In this case, the bending unit can be located centrally to the support bench, or in a desired position, even terminal.

The bending unit has two contrast rolls between which the bars are gripped.

The bending unit also comprises a curving roll that cooperates with guide means and with a positioning device, in order to selectively position, either continuously or point-by-point, the curving roll on the bar or bars to be processed.

In particular, the curving roll acts on the bar, thrusting it to bend it around one of the contrast rolls.

A programmable computerized system controls, commands and manages the whole.

BRIEF DESCRIPTION OF THE DRAWINGS

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

- fig. 1 shows a perfected curving machine according to the invention;

- fig. 2 shows the curving machine of fig. 1 in a first operating position;

- fig. 3 shows the curving machine of fig. 1 in a second operating position;

- fig. 4 shows the curving machine of fig. 1 in a third operating position;

- fig. 5 shows the curving machine of fig. 1 in a final operating position;

- fig. 6 shows a variant of the curving machine of fig. 1 in a first operating position;

- fig. 7 shows the curving machine of fig. 5 in a second operating position;

- fig. 8 shows the curving machine of fig. 5 in a third operating position;

- fig. 9 shows the curving machine of fig. 5 in a fourth operating position;

- fig. 10 shows a possible operating position of the curving machine of fig. 1.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one form of embodiment can conveniently be incorporated into other forms of embodiment without further clarifications.

DETAILED DESCRIPTION OF FORMS OF EMBODIMENT

We shall now refer in detail to the various forms of embodiment of the present invention, of which one or more examples are shown in the attached drawing. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one form of embodiment can be adopted on, or in association with, other forms of embodiment to produce another form of embodiment. It is understood that the present invention shall include all such modifications and variants.

In accordance with the present invention, a perfected curving machine 10 is shown schematically in fig. 1 and is configured to curve, shape or bend bars 12 with different characteristics and nominal diameters.

The curving machine 10 is configured to operate on one or more bars 12 according to the particular working needs required.

Here and hereafter in the description reference will be made to the working of a single bar 12 although it is clear that the curving machine can work more bars 12 at the same time.

The curving machine 10 comprises a support bench 14 provided to support the bar 12 during working.

The support bench 14 has a mainly oblong development and a length substantially equal to the length of the bars 12 that it has to support.

The support bench 14 can be located substantially horizontal or sub-horizontal, although a vertical orientation thereof is not excluded.

The curving machine 10 also comprises at least one bending unit, in this case two bending units 15a and 15b configured to bend the bar 12 to the desired shape.

The bending units 15a and 15b are installed on respective movement carts 18 which are configured to move the bending units 15a and 15b along an axis of movement X. In the form of embodiment of figs. 1 and 2, the bending units 15a and 15b are disposed aligned along the axis of movement X and can be moved reciprocally nearer to and away from each other.

The axis of movement X develops substantially along the longitudinal development of the support bench 14.

The carts 18 can be moved on the support bench 14 in a desired and controlled manner, each cart 18 being managed by itself or in relation to the other cart 18.

In accordance with a possible solution, the curving machine 10 comprises movement members associated to the carts 18 to allow the latter to move on the support bench 14.

The movement members, not shown in the drawings, can include grub screw mechanisms, rack or chain mechanisms.

In accordance with a possible form of embodiment, the curving machine 10 comprises guides 17 disposed substantially parallel to the axis of movement X and on which the carts 18 are installed sliding.

Each bending unit 15a and 15b comprises two contrast rolls 20a and 20b, located in a position opposite each other and during use, the bar 12 is made to pass between them.

At least one of the contrast rolls, in this case the contrast roll 20a is provided with positioning means 22 configured to allow contrast roll 20a to move selectively nearer to/away from contrast roll 20b, in order to adjust the gap of the bar 12 and hence the pressure that the contrast rolls 20a and 20b exert on the bars 12. The pressure exerted on the bars 12 can be intended to draw the bar 12 or, in a possible variant, to exert a holding or clamping action on the bar 12.

In possible solutions, at least one of the bending units 15a, 15b, in this case both, also perform the function of clamping means on the bar 12.

In this form of embodiment, it is provided to constrain the rotation of the contrast rolls 20a and 20b and to press them one against the other to exert a holding action on the bar 12.

According to a possible solution, at least one of the contrast rolls, in this case the contrast roll 20b, is motorized. This solution allows to move the respective bending unit 15a or 15b along the extension of the bar 12 in order to allow the bends to be made, as will become clear hereafter.

In this solution, it may not be necessary for the cart 18 to be motorized, at least during the working step of the bars 12, since the action of the motorized contrast roll 20b on the bars 12 determines the controlled and desired advance of the cart 18.

Indeed, the contrast roll 20b, acting on the bar 12, exerts a friction action with the contrast roll 20a on the bar 12 and draws with it the corresponding bending unit 15a and 15b and the cart 18.

The bending units 15 also comprise, in cooperation with the contrast rolls 20a and 20b, at least a curving roll 24 configured to exert a predefined deformation on the bar 12 comprised between the contrast rolls 20a and 20b. The curving roll 24 is located in an external position with respect to the contrast rolls 20a and 20b. In particular, the curving roll 24 determines a predefined curvature of the bar 12 around at least one of the contrast rolls 20a, and 20b.

The curving roll 24 can be associated to guide means 25 and to a positioning device 27, configured to move the curving roll 24, with respect to the contrast rolls 20a, 20b, on the guide means 25.

The guide means 25 can be disposed with an orientation incident with the axis of movement X, that is, incident with the bar 12 so as to allow the curving roll 24 to exert the desired curving action.

The positioning of the curving roll 24 can be continuous and/or discrete.

The position of the curving roll 24 with respect to the contrast rolls 20a and 20b determines the curvature of the bar 12.

Indeed the curving roll 24 can remain fixed with respect to the contrast rolls 20a and 20b all the time the bar 12 is worked, or, according to a variant and in the case of curvatures with different radiuses, the position of the roll 24 is updated on each occasion, with respect to the contrast rolls 20a and 20b, by commands imparted by the positioning device 27 of the curving roll 24.

The position of the curving roll 24 can be fixed, for example orthogonal to the bar 12, or inclined with respect to it by a different and variable angle in relation to the desired radius of curvature of the bar 12. In other variants of the invention, the position of the curving rolls 24 is the same for both bending units 15a and 15b, or different from each other, for example to obtain an arc of a circle with different curvature values.

In other variants, the position of the curving rolls 24 is variable in a discontinuous manner during the shaping operations.

In the form of embodiment shown in figs. 8 and 9, the position of the curving roll 24 is variable in continuous manner during the working of the bars 12.

In accordance with one possible implementation, each of the bending units 15a and 1 b can comprise an abutment roll 34, disposed with respect to the bar 12, on the same side on which the curving roll 24 is located.

The abutment roll 34 is positioned in a fixed position with respect to the cart 18 for moving the bending unit 15a, 15b.

In each bending unit 15a and 15b, the abutment roll 34 is disposed so that the contrast rolls 20a, 20b are interposed between the abutment roll 34 and the curving roll 24. In this way, when the bar 12 is bent by the curving roll 24, the portion of bar located upstream of the curved portion that is made does not move, rendering the action of the curving roll 24 null.

According to a possible variant, not shown in the drawings, at least one of the bending units 15a and 15b is provided with clamping means installed on board the respective cart 18 and configured to constrain the position of the bar 12 to that of the respective bending unit 15 a, 15b.

According to a variant of the invention (fig. 6), the curving machine 10 comprises clamping means 16 interposed between the bending units 15a and 15b and configured to clamp the bar 12 at least during shaping.

The clamping means 16 can comprise a vise for example.

According to the invention, the action of the clamping means 16 can be regulated depending on the desired clamping.

According to a possible solution, the clamping means 16 can be vertically fixed or retractable with respect to the support bench 14, to move to a position of non-interference with a possible movement of the bar 12 during loading or discharge of the shaped bar 12. According to the forms of embodiment shown in figs. 1 - 5, the curving machine 10 comprises bending units, respectively 15a and 15b, which alternately perform the function of clamping means.

In this solution, the following operating modes can be achieved:

- the bending unit 15a remains stationary at one end of the guides 17 and acts as a vise while the bending unit 15b advances (fig. 2) at least as far as half the bar 12, bending it into one or more predetermined bends, and then stops to assume the function of the clamping means (fig. 3). When the bending unit 15b is stationary, the bending unit 15a advances (fig. 4), possibly bending the bar 12 until it substantially comes into contact with the bending unit 15b (fig. 5). In this way, both the bending units 15a and 15b obtain the corresponding bent portions of the bar 12;

- the bending unit 15a moves to an intermediate position along the extension of the bar 12 and acts as a vise, and the bending unit 15b advances along the bar 12, bending it in a desired manner until it almost comes into contact with unit 15a. After this, it will be the bending unit 15a, possibly and if required, to move to the desired position to perform another bend.

In the solution shown in figs. 6-7, the clamping means 16 are disposed in an intermediate position along the longitudinal extension of the support bench 14. In this solution, the bending units 15a and 15b advance simultaneously from the ends of the support bench 14 toward the clamping means 16, where they stop (fig. 7). During their movement, the bending units 15a and 15b perform the corresponding curving operations, since the bar 12 is clamped by the clamping means 16.

By suitably regulating the action of the bending units 15a, 15b, it is possible to obtain bars 12 shaped in a circle (fig. 8) or, if the reciprocal position between the curving roll 24 and the contrast rolls 20a and 20b is continuously modified, for example a spiral shape is obtained (fig. 9).

In the form of embodiment in fig. 1, the curving machine 10 comprises a bar feed unit 29, in which the bars 12, pre-cut or not, are disposed in the form of bundles. The bar feed unit 29 can also comprise an extractor 30 to take one or more bars 12 from the bar feed unit 29 to then make them available on the support bench 14 to the bending units 15a and 15b.

Downstream of the extractor 30 there is a cutting element 31, such as a shear, to selectively cut the one or more bars 12 to a desired length.

Subsequent to the cutting element 31 a feed bench 32 is disposed, which develops longitudinally and adjacent to the support bench 14 to feed the bars 12 to the latter.

A drawing unit 33 is also associated with the feed bench 32, operating in cooperation with the extractor 30, and provided to extract the individual bars 12 from the bar feed unit 29.

The drawing unit 33 is selectively mobile with respect to the feed bench 32 to take the bars 12 extracted by the extractor 30 and take them to the feed bench 32.

A measuring device can cooperate with the drawing unit 33, for example integrated with the cutting element 31 or, alternatively, with the drawing unit 33. The measuring device is configured to selectively command the functioning of at least one of either the extractor 30, the cutting element 31 or the drawing unit 33.

It is clear that modifications and/or additions of parts may be made to the perfected curving machine 10 and the corresponding method as described heretofore, without departing from the field and scope of the present invention.

For example, as shown in fig. 10, it can be provided that in at least one of the two bending units 15a and 15b, the curving roll 24 and the contrast roll 20a adjacent to it, and located on the same side with respect to the bar 12, are selectively movable away from the other contrast roll 20b.

In this way, in the condition where the first bending unit 15a and the second bending unit 15b are in contact with each other, the curving roll 24 and the contrast roll 20a of one of the bending units, in this case the first bending unit 15a, moves away from the contrast roll 20a. In this condition, the rolls of the other bending unit 15b are activated and in particular the motorized contrast roll 20a determines an advance of the bar 12 in order to complete the bending of the segment of bar 12 that is comprised between the first 15a and the second bending unit 15b. According to a possible formulation of the present invention, it can be provided that, once bending has been completed, and if it has not been done correctly, the curving rolls 24 are taken to a position of non-interference with the bar 12 and the bending units 15a and 15b are moved reciprocally away from each other, keeping the respective contrast rolls 20a and 20b in contact with the bar 12. In this way, it is possible to straighten the bar 12 already bent, so as to possibly perform the bending operation again.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of perfected curving machine 10 and the corresponding method, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.