FIELD OF THE INVENTION
[0001] The present invention concerns a machine for bending a tubular product, for example
a metal tube for making fluid-dynamic pipes, conduits, plants or other.
[0002] In particular, the machine according to the present invention allows to bend tubular
products in an automated manner, to obtain them in an already finished or semi-finished
form.
[0003] The present invention also concerns the method for bending a tubular product.
BACKGROUND OF THE INVENTION
[0004] Machines for bending tubular products are known, which comprise devices to feed a
tubular product to a bending device.
[0005] In particular, the feed devices feed the tubular product, in the form of a straightened
segment or roll, to the bending device after possibly straightening it with suitable
straightening devices, for example of the type with rollers.
[0006] The feed devices are configured to feed the tubular product along a rectilinear axis
of feed of the machine.
[0007] The bending device is installed on a support arm with an oblong development which
is in turn installed on a support structure, parallel to the axis of feed of the tubular
product.
[0008] The support arm is also selectively rotatable around an axis of rotation substantially
coinciding with the axis of feed of the tubular product.
[0009] The rotation of the support arm allows to position the bending device on planes that
are angularly offset with respect to each other. It is therefore possible to bend
the tubular product on angularly offset bending planes, obtaining very articulated
configurations of the tubular product.
[0010] It is also known that bending machines are equipped with cutting devices to cut the
bent finished product from the tubular product.
[0011] For example, a first solution is known, in which the cutting device is installed
downstream of the bending device and cuts the tubular product by removing material,
for example with a circular saw.
[0012] This solution generates offcuts, waste of material and causes problems in recovering
the work chips.
[0013] Furthermore, for articulated conformations of the finished product, the cutting device
can interfere with curved portions of the tubular product.
[0014] A bending machine is also known, provided with a cutting device equipped with orbital
cutting incision blades, that is, which can be moved circumferentially around the
tubular product in order to cut it.
[0015] In this solution, the cutting blades are installed on a support with a fork conformation.
In order to cut the tubular product, the support is moved so that the arms of the
fork are positioned to partly surround the tubular product to be cut. Subsequently
the cutting blades are driven to incise and cut the tubular product in the desired
position.
[0016] This solution, although it solves the problem of generating chip, is not very versatile
since the cutting device is normally positioned at the side of the bending device
and the fork configuration of the support does not always allow to position the cutting
blades in the desired cutting position, for example due to a possible interference
with a bent portion of the product.
[0017] A solution is also known that provides to install the cutting device upstream of
the support arm and downstream of the feed devices. In this solution, the cutting
device is equipped with incision blades that incise the tubular product circumferentially
without effecting a real separation.
[0018] The incision obtained generates a preferential tearing line of the tubular product
along which, by the action of subsequent bending of the bending device, it is possible
to separate the finished product from the tubular product being worked.
[0019] However, this solution has the disadvantage that if the incision is made in direct
proximity to a bent portion of the finished product, the bending action, which also
determines the subsequent separation, can cause an unwanted deformation of the end
incised. For example, finished products may be obtained in which the terminal end
has a cross section that is inclined, not perpendicular, with respect to the axis
of the tube.
[0020] This deformation can cause an oval section of the finished product at least in the
end portion, which requires a subsequent finishing operation.
[0021] In a totally different field from that of bending tubular products, bending machines
are known for metal bars, such as reinforcement round pieces.
[0022] An example of this type of machine is described in
EP-A-0.419.443. However, these machines cannot be used for bending tubular products since a bending
action would entail generating a narrowing of the tubular cavity and therefore a reduction
in sizes of the passage cross section of the tube.
[0023] Document
EP-A-0.419.443 describes cutting shears which, due to the action of two blades moved sliding against
each other, generate a cutting by deforming the bar. Although using shears for cutting
bars is extremely effective, the same cannot be said for cutting tubular products.
[0024] Indeed, using shears for cutting tubular products generates in the cutting zone a
localized deformation of the tube and an occlusion of the tubular passage cavity.
[0025] This requires further finishing operations to finish the cut ends of the tubular
product, with connected times and costs.
[0026] It is therefore a purpose of the present invention to obtain a machine for bending
metal products that is extremely versatile and that allows to obtain tubular products
with shaped configurations, even very complex ones.
[0027] Another purpose of the present invention is to obtain a machine for bending metal
products that allows to limit, and even completely eliminate, all working offcuts.
[0028] Another purpose of the present invention is to obtain a machine for bending metal
products that is particularly efficient and allows to obtain, directly in the finished
form, a final product that is already curved and cut to size.
[0029] Another purpose is to perfect a bending method for tubular products that is particularly
efficient and versatile.
[0030] 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
[0031] 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.
[0032] In accordance with the above purposes, a machine for bending a tubular product according
to the present invention comprises:
- a feed device configured to feed the tubular product along an axis of feed,
- a support arm with an oblong development and installed, on a support structure, parallel
to the axis of feed, the support arm being able to rotate with respect to an axis
of rotation coinciding with the axis of feed, and
- a bending device disposed downstream of the feed device, installed on the support
arm and configured to bend the tubular product.
[0033] According to one aspect of the present invention, the machine comprises a cutting
device configured to at least partly cut the tubular product, and installed aligned
with the axis of feed, upstream of the bending device and in a position comprised
along the longitudinal extension of the support arm.
[0034] According to another aspect of the present invention, the cutting device is of the
orbital type and comprises a support body installed aligned with the axis of feed
and on which at least one cutting tool is installed. In particular a drive member
is associated with the support body, configured to make the at least one cutting tool
rotate orbitally around the axis of feed, to perform the cutting of the tubular product.
[0035] In this way it is possible to obtain a machine able to obtain bent tubular products
of quality that, once bent, can be directly cut in line, without requiring lateral
movements of the cutting device, and preventing possible interferences with the latter.
[0036] This makes the machine extremely versatile since it allows to obtain bent tubular
products in direct proximity to the bend effected which do not need further finishing
operations.
[0037] Moreover, the use of a cutting device of the orbital type allows to carry out the
cutting of the tubular product without deforming, that is varying, the sizes and the
shape of the internal cavity of the tube. Moreover, the use of a cutting device of
the orbital type prevents generating cutting chips which become offcuts.
[0038] The present invention also concerns a method for bending a tubular product that comprises:
- feeding a tubular product along an axis of feed;
- positioning a bending device associated with a support arm with an oblong development
and installed on a support structure, parallel to the axis of feed, the positioning
providing at least the rotation of the support arm around an axis of rotation coinciding
with said axis of feed;
- bending the tubular product with the bending device.
[0039] According to a possible implementation of the present invention, the method comprises
cutting, at least partly, the bent tubular product with a cutting device installed
aligned with the axis of feed, upstream of the bending device and in a position comprised
along the longitudinal extension of the support arm.
[0040] According to another aspect of the present invention, the cutting of the tubular
product provides to make at least one cutting tool rotate orbitally around the axis
of feed and around the tubular product to perform the cutting of the latter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] These and other characteristics of the present invention will become apparent from
the following description of some embodiments, given as a non-restrictive example
with reference to the attached drawings wherein:
- fig. 1 is a perspective view of a machine for bending a metal product, in accordance
with a first embodiment;
- fig. 2 is a schematic section view of part of a machine for bending the metal product;
- fig. 3 is a view in section along the line III-III of fig.2;
- fig. 4 schematically shows a possible variant embodiment of fig. 2.
[0042] 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 embodiment can conveniently be incorporated into other
embodiments without further clarifications.
DETAILED DESCRIPTION OF SOME EMBODIMENTS
[0043] With reference to the attached drawings, a machine for bending a tubular product
P is indicated in its entirety by the reference number 10.
[0044] In the embodiments that follow, the representations are deliberately schematic, to
better comprise the characteristics of the machine according to the present invention.
[0045] Operating details such as, for example, the diameters of the tubes, the radii of
curvature made, the particular operating components, have been chosen deliberately
randomly so as not to limit the individual embodiments to specific operating solutions,
also considering the fact that one of the main advantages of the present invention
is that the machine has great operating applicability for bending substantially any
type of tube whatsoever, with any radius of curvature.
[0046] According to the present invention, the tubular product P can be supplied to the
machine 10 both in the form of roll or coil, and subsequently straightened, and also
in the form of a segment from which the final products are cut.
[0047] According to embodiments shown in figs. 1, 2 and 4, the machine 10 comprises a feed
device 11 to feed the tubular product P and a bending device 12 configured to bend
the tubular product P according to desired geometries.
[0048] The feed device 11 is configured to feed a tubular product P along an axis of feed
F.
[0049] According to possible embodiments the feed device 11 can be configured to feed the
tubular product P both toward the bending device 12 and also in the opposite direction.
[0050] According to a possible embodiment shown for example in fig. 1, the feed device 11
can comprise at least a pair of drawing rolls 13, between which the tubular product
P is made to pass and advance.
[0051] According to a variant embodiment shown in figs. 2 and 4, the feed device 11 can
comprise vise elements 14 configured to grip a portion of the tubular product P and
to make it advance along the axis of feed F by means of an alternate gripping and
releasing motion in a direction parallel to the axis of feed F.
[0052] According to embodiments shown in figs. 2 and 4, the bending device 12 comprises
a contrast element 15 and a bending element 16 configured to bend the tubular product
P around the contrast element 15. The bending element 16 can be configured to grip
the tubular product P on the contrast element 15 and is rotatable around the latter
to bend the tubular product P.
[0053] It is quite clear that the bending device 12 can also have different configurations
from those described here, for example it can be provided with a plurality of contrast
elements 15 and bending elements 16, possibly also made in a single body, and each
suitable to define a predefined radius of the final product.
[0054] The machine 10 according to the present invention comprises a support structure 17
on which a support arm 18 is installed, with an oblong development and disposed with
its oblong development parallel to the axis of feed F.
[0055] The support arm 18 is selectively rotatable with respect to an axis of rotation coinciding
with the axis of feed F of the tubular product P.
[0056] In particular, it is provided that, during rotation, the support arm 18 keeps itself,
with its oblong development, substantially parallel to the axis of feed F.
[0057] According to the solution shown in figs. 1, 2 and 4, the support arm 18 has a first
end 19 associated with the support structure 17, and a second end 20, opposite the
first end 19, and positioned cantilevered with respect to the support structure 17.
[0058] The bending device 12 is installed on the support arm 18.
[0059] The rotation of the support arm 18 around the axis of feed F allows to position the
bending device 12 on different planes, reciprocally angled with respect to each other.
In this way it is possible to bend the tubular product P on different planes, reciprocally
angled with respect to each other.
[0060] According to the solution shown in figs. 1, 2 and 4, the bending device 12 is installed
in correspondence with the second end 20 of the support arm 18.
[0061] According to possible solutions, the support arm 18 is installed on a rotation member
21 associated with the support structure 17 and configured to make the support arm
18 rotate around the axis of feed F.
[0062] The rotation member 21 can comprise a discoid body 22 in correspondence with which
the support arm 18 is installed with its first end 19.
[0063] The discoid body 22 is connected to drive members, not shown in the drawings, suitable
to make the discoid body 22 rotate, and also the support arm 18 associated with it,
around the axis of feed F.
[0064] According to possible solutions, shown for example in figs. 1, 2 and 4, the support
arm 18 and the rotation member 21 can comprise radial positioning devices 23 configured
to position the support arm 18 radially with respect to the axis of feed F. In this
way it is possible to move the support arm 18 closer to/away from the tubular product
P being worked, in order to dispose it for example in a position where it does not
interfere with the work in progress, or to position the bending device 12 in a suitable
position for working the tubular product P.
[0065] The radial positioning devices 23 can comprise, merely by way of example, guides,
racks, drive members.
[0066] According to one aspect of the present invention, the machine 10 comprises a cutting
device 24 configured to at least partly cut the tubular product P.
[0067] The cutting device 24 is installed upstream of the bending device 12, in a position
comprised along the longitudinal extension of the support arm 18 and aligned with
the axis of feed F of the tubular product P.
[0068] Here and hereafter in the description and the claims by "position comprised along
the longitudinal extension" we mean a position of the cutting device 24 between the
first end 19 and the second end 20 of the support arm 18.
[0069] According to a possible solution, the cutting device 24 comprises a support body
25 installed aligned with the axis of feed F and on which at least one cutting tool
27 is installed, in this specific case two cutting tools 27, configured to at least
partly cut the tubular product P.
[0070] A drive member 28 can be associated with the support body 25, and is configured to
make the at least one cutting tool 27 rotate around the axis of feed F. In this way
it is possible to define a cutting device 24 of the orbital type.
[0071] According to a possible embodiment, the support body 25 can be provided with a through
cavity 26 through which, during use, the tubular product P is made to pass. The through
cavity 26 is therefore aligned with the axis of feed F of the tubular product P.
[0072] The support body 25, or at least part of it, can be selectively movable radially
toward/away from the axis of feed F, to control the depth of the cut on the tubular
product P.
[0073] As described hereafter, the cutting device 24 can also make only an incision, or
a complete cut, on the tubular product P.
[0074] According to embodiments shown in figs. 2-4, the cutting tools 27 can comprise cutting
blades with a disc conformation. Cutting blades with a disc conformation are advantageous
in that they do not cause any offcuts, with their consequent problems of disposal
and recovery, and the cut is performed only by the penetration of the blade.
[0075] According to a possible embodiment, the cutting device 24 is installed on a support
element 29 attached to the rotation member 21 and configured to support the cutting
device 24, keeping it aligned with the axis of feed F.
[0076] The support element 29 can have an oblong development, and is installed substantially
parallel to the axis of feed F.
[0077] According to embodiments shown in figs. 1, 2 and 4, the support element 29 is defined
by a tubular body 30 provided with an axial cavity, aligned with the axis of feed
F and inside which, during use, the tubular product P is made to pass. In this way,
when the rotation member 21 makes the support arm 18 rotate around the axis of feed
F, the cutting device 24 remains always aligned with the latter, and therefore with
the tubular product P being worked. This condition ensures that the cutting device
24 does not interfere with portions of the tubular product P that have been bent.
[0078] According to a possible embodiment, the tubular body 30 is attached with a first
end to the rotation member 21, while the other end is located cantilevered with respect
to the latter and is configured to support the cutting device 24.
[0079] According to one embodiment, shown schematically in fig. 4, the cutting device 24
can be connected to movement members 31 configured to move the cutting device 24 parallel
to the axis of feed F. In this way it is possible to move the cutting device 24 toward/away
from the bending device 12, to define for example the correct position to make the
cut on the bent tubular product P, or to take the cutting device 24 to a position
where it does not interfere with the bending operations performed.
[0080] Merely by way of example, the movement members 31 can be chosen from a group comprising
a linear actuator, a rotary actuator, an articulated mechanism, one or more movement
guides or a possible combination thereof.
[0081] A possible solution can provide that the movement members 31 are associated with
the cutting device 24 and with the support element 29, for example it can be provided
that a ball bearing mechanism can be installed on the support element 29, along which
the cutting device 24 is selectively translatable.
[0082] According to a possible variant embodiment shown in fig. 4, the machine 10 according
to the present invention can comprise at least a gripping device, different from the
possible feed device 12 described with reference to figs. 2 and 4, and configured
to grip a longitudinal portion of the tubular product P.
[0083] The gripping device, combined for example with the action of the feed device 11 and/or
with another gripping device as described hereafter, generates an axial tension on
the tubular product P being worked, parallel to the axis of feed F, such as to detach
a tubular portion of the tubular product P if the latter has been incised by the cutting
device 24.
[0084] In the case shown in fig. 4, the machine 10 comprises a first gripping device 32
and a second gripping device 33, disposed upstream and downstream of the cutting device
24 and each configured to grip a respective portion of the tubular product P.
[0085] At least one of either the first gripping device 32 or the second gripping device
33, in the case shown here the second gripping device 33, can be associated with a
translation member 34 configured to move the respective gripping device 32, 33 in
a direction parallel to the axis of feed F.
[0086] In this way, once at least a pre-incision of the tubular product P has been made,
the first gripping device 32 and the second gripping device 33 grip respective portions
of the tubular product P located upstream and respectively downstream of the pre-incision
made. By activating the first gripping device 32, the second gripping device 33 and
the translation member 34, it is possible to generate a traction on the tubular product
P and consequently a separation thereof.
[0087] According to possible variant embodiments of the present invention, shown for example
with reference to figs. 2 and 4, the machine 10 can comprise a bending core 35 positionable
inside the tubular product P to contrast the action of the bending device 12 from
the inside, and to conform as desired the bending of the tubular product P.
[0088] Holding devices 36 can be associated with the bending core 35, to keep it in a predefined
position inside the tubular product P.
[0089] The holding condition of the holding devices 36 is such that when the feed device
11 feeds the tubular product P to the bending device 12, and the latter is driven,
the bending core 35 is kept in a predefined position with respect to the bending device
12.
[0090] This working condition allows to feed the tubular product P substantially continuously.
[0091] According to a possible and non-restrictive embodiment of the present invention,
the holding devices 36 comprise magnetic elements 37, disposed on the perimeter around
the tubular product P and in a position coordinated with that of the bending core
35. The magnetic holding action carried out by the magnetic elements 37 allows to
keep the bending core 35 in the predefined position for making the bend.
[0092] Thanks to the magnetic elements 37 it is therefore possible to dispose the bending
core 35 in correspondence with the central zone of magnetic equilibrium, thus remaining
in a substantially suspended condition inside the space defined by the magnetic elements
37.
[0093] This allows to eliminate the production of offcuts since, once a first portion of
the tubular product P has been bent according to the desired pattern, the tubular
product P itself can be cut exactly to size, only separating the bent portion and
avoiding on each occasion having to remove the bending core 35.
[0094] According to embodiments shown in figs. 2 and 4, the bending core 35 comprises a
support element 38 cooperating with the holding devices 36 and provided to hold the
bending core 35 in the correct bending position.
[0095] According to a possible solution, the holding device 36 can be selectively movable
in a direction parallel to the axis of feed F to modify the position of the bending
core 35 inside the tubular product P.
[0096] According to possible solutions, for example if the tubular product P is supplied
from a roll, the machine 10 can be provided with straightening devices 41 configured
to straighten the tubular product P and supply it in a straight configuration to the
bending device 12.
[0097] According to a possible solution of the present invention (figs. 1, 2 and 4), the
straightening devices 41 can be positioned upstream of the feed device 11 to supply
to the latter the already straightened tubular product P.
[0098] It is quite clear that the straightening device 41 can be positioned in any position
whatsoever upstream of the bending device 12.
[0099] The straightening devices 41 can be defined by a plurality of straightening rollers
42, between which the tubular product P is made to pass.
[0100] According to the embodiment shown in fig. 2, we will now describe a possible functioning
mode of the machine according to the present invention.
[0101] The tubular product P is fed along the axis of feed F toward the bending device 12,
possibly subjecting it to a straightening action by means of the straightening devices
41.
[0102] During this step, inside the tubular cavity of the tubular product P, the bending
core 35 can be disposed and kept in position. The bending core 35 is positioned in
correspondence with the bending device 12 to control the bending of the tubular product
P.
[0103] In this condition, the support arm 18 is positioned, with the radial positioning
devices 23, so as to dispose the bending device 12 in correspondence with the tubular
product P.
[0104] Then one or more bending operations are performed on the tubular product P according
to one or more radii of curvature depending on the specific bending requirements.
[0105] Subsequently, the tubular product P is cut by the cutting device 24, to separate
the bent product.
[0106] In this condition, it can be provided that the cutting device 24 is moved along the
axis of feed F to position it in the correct position with respect to the bent product,
to perform the cut.
[0107] Alternatively, or in combination, it can be provided that the feed device 11 makes
the tubular product P retreat or advance, to position the bent product in a correct
position with respect to the cutting device 24.
[0108] The cutting of the tubular product P can be the through type, that is, the cutting
device 24 performs a complete separation of the bent product directly, cutting its
thickness completely, or it can be a partial cut, that is, making only a pre-incision
on the tubular product P which does not completely cut through its thickness. Making
only a pre-incision on the tubular product P avoids generating deformations of the
cut end which extend toward the inside of the tubular product P, which reduce its
diameter and which can require further operations, for example socketing, in order
to restore the diameter of the bent product.
[0109] In this last condition it can be provided that the separation of the bent product
is performed by the bending device 12, which generates the axial tearing tension sufficient
to separate it. For example, it can be provided that the tearing action is performed
with the last bending operation, which is provided for the bent product to be obtained.
[0110] According to a possible variant embodiment, described with reference to fig. 2, it
can be provided that the axial tearing tension on the tubular product P is conferred
by the combined cooperation of the bending device 12 and the feed device 11. For example,
once the tubular product P has been bent, the bending devices 12 can keep it gripped
between its components, the cutting device 24 makes the pre-incision, and the feed
devices 11 are driven in the opposite direction to the normal feed direction so as
to generate, together with the bending devices 12, the tension needed to make the
separation.
[0111] According to another variant embodiment, described with reference to fig. 4, the
action of separating the tubular product P is performed by the combined action of
the first gripping device 32 and the second gripping device 33 which, when the cut
is being performed, or once the pre-incision has been made, grip the tubular product
P, and at least one of them, in this specific case the second gripping device 33,
is moved axially to generate the tension needed to make the separation.
[0112] According to a possible variant embodiment, not shown, the function of one of either
the first gripping device 32 or the second gripping device 33 can be performed by
the feed device 11, for example by the vise elements 14, or the drawing rollers 13,
allowing to reduce the operating members of the machine 10.
[0113] During the cutting or separation operations, a radial distancing of the support arm
18 can be provided, to dispose it in a position where it does not interfere with the
operating components in action.
[0114] It is clear that modifications and/or additions of parts may be made to the machine
10 and method for bending a tubular product as described heretofore, without departing
from the field and scope of the present invention.
[0115] For example, it can be provided that the cutting device 24 is disposed in direct
proximity, that is, at a distance of less than 150mm, from the bending device 12.
In this way it is possible to optimize the process times of the machine 10 and cut
the bent product also in direct proximity to the curve just made.
[0116] 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 machine and method for bending a tubular product,
having the characteristics as set forth in the claims and hence all coming within
the field of protection defined thereby.
1. Machine for bending a tubular product (P) comprising:
- a feed device (11) configured to feed said tubular product (P) along an axis of
feed (F),
- a support arm (18) with an oblong development and installed, on a support structure
(17), parallel to said axis of feed (F), said support arm (18) being able to rotate
with respect to an axis of rotation coinciding with said axis of feed (F), and
- a bending device (12) disposed downstream of said feed device (11), installed on
said support arm (18) and configured to bend said tubular product (P),
characterized in that it comprises a cutting device (24) configured to at least partly cut said tubular
product (P), and installed aligned with said axis of feed (F), upstream of said bending
device (12) and in a position comprised along the longitudinal extension of said support
arm (18),
in that said cutting device (24) is the orbital type and comprises a support body (25) installed
aligned with said axis of feed (F) and on which at least one cutting tool (27) is
installed, and
in that a drive member (28) is associated with said support body (25), configured to make
the at least one cutting tool (27) rotate around said axis of feed (F), to perform
the cutting of said tubular product (P).
2. Machine as in claim 1, characterized in that said support arm (18) is installed on a rotation member (21) associated with the
support structure (17) and configured to make the support arm (18) rotate around said
axis of feed (F).
3. Machine as in claim 2, characterized in that said cutting device (24) is installed on a support element (29) attached to the rotation
member (21) and configured to support the cutting device (24), keeping it aligned
with said axis of feed (F).
4. Machine as in claim 3, characterized in that said support element (29) is defined by a tubular body (30), provided with an axial
cavity aligned with said axis of feed (F) and inside which the tubular product (P)
is made to pass.
5. Machine as in claim 3 or 4, characterized in that said cutting device (24) is connected to movement members (31) configured to move
the cutting device (24) parallel to the axis of feed (F).
6. Machine as in any claim hereinbefore, characterized in that it comprises at least a gripping device (32, 33) configured to grip a longitudinal
portion of the tubular product (P).
7. Machine as in claim 6, characterized in that it comprises a first gripping device (32) and a second gripping device (33) disposed
upstream and downstream of said cutting device (24) and each configured to grip a
respective portion of said tubular product (P), and in that at least one of either said first gripping device (32) or said second gripping device
(33) is associated with a translation member (34) configured to move the respective
gripping device (32, 33) in a direction parallel to said axis of feed (F).
8. Method for bending a tubular product (P) that comprises:
- feeding a tubular product (P) along an axis of feed (F);
- positioning a bending device (12) associated with a support arm (18) with an oblong
development and, installed on a support structure (17), parallel to said axis of feed
(F), said positioning providing at least the rotation of said support arm (18) around
an axis of rotation coinciding with said axis of feed (F),
- bending said tubular product (P) with said bending device (12),
characterized in that it comprises cutting, at least partly, the bent tubular product (P) with a cutting
device (24) installed aligned with said axis of feed (F), upstream of said bending
device (12) and in a position comprised along the longitudinal extension of said support
arm (18), and
in that the cutting of the tubular product (P) provides to make at least one cutting tool
(27) rotate orbitally around the axis of feed (F) and around the tubular product (P),
to perform the cutting of the latter.
9. Method as in claim 8, characterized in that it comprises moving said cutting device (24) parallel to the axis of feed (F), and
keeping it aligned with the latter.
10. Method as in claim 8 and 9, characterized in that said cutting device (24) performs a pre-incision of said tubular product (P), and
in that it provides to generate an axial tension at least in the pre-incision zone of said
tubular product (P) to separate the bent product.