[0001] The present invention relates to an edging assembly for tubular elements in sheet
metal and similar materials: the assembly is suitable for the formation of shaped
edges (usually mutually complementary) on one or both ends of several tubular elements
that need to be mutually coupled in order to constitute a predefined pipe. The coupling
is usually achieved with the mutual seaming of the edges of two tubular elements which
are mutually inserted in each other.
[0002] Metallic pipes are usually used for the transport of exhaust gases, in heating and
air conditioning systems and, usually, in all cases in which gases need to be conveyed
along a preset path.
[0003] In particular it is necessary to provide specific forms of edgings in elements that
have a shape structure of the type of a section of cylindrical tubing, which are used
in order to provide curves in ducts.
[0004] Such elements are made starting from a sheet (generally made of metallic material)
which is cut according to a predefined shape, in which, once folded in order to make
the ends thereof meet, those ends are mutually coupled (usually by means of welding
processes).
[0005] The two lower and upper edges (with particular reference to a vertical orientation
of the axis of the tubular element) are subjected to an edging process that facilitates
their easy coupling with others (and mutually seamable) in the subsequent step of
making up the duct.
[0006] The edging process consists of the mechanical machining by cold deformation of each
edge using utensils of the type of contoured rollers.
[0007] In existing machines on the market for this type of machining, the piece is rotated
with respect to the motorized rollers which are fixed to the footing.
[0008] The tubular element, once arranged with an edge thereof between the rollers, while
it is being supported by an operator, is subjected to a rotary motion imposed by the
rollers, so that the rollers impress the desired shape (in relation to a force impressed
on at least one of them owing to their mutual approach) on the edge.
[0009] It is fundamentally important, in this step, that the operator facilitates the correct
alignment and arrangement of the tubular element, at least in the first moments of
the machining, in order to prevent the edge thereof from accidentally slipping out
from the contoured rollers.
[0010] Considering that the tubular elements are hollow cylindrical sections (in practice
portions of piping having at least one of the two edges cut along a plane that is
inclined with respect to the central/longitudinal axis), when these machining operations
are being carried out the hand of the operator (which has to hold the piece, which
rotates vortically, constantly pressed against the resting surface) rises and falls
to follow the inclination of the other, non-parallel, edge.
[0011] This manner of machining is dangerous for the operator who cannot handle a high rotation
speed of the pieces (otherwise he/she would be exposed to an extremely high risk of
injury). The execution time, because of the piece which rotates between the hands
of the operator, is very high.
[0012] The aim of the present invention is to solve the above mentioned drawbacks, by providing
an edging assembly for tubular elements that is particularly safe for the operator.
[0013] Within this aim, an object of the invention is to provide an edging assembly for
tubular elements that is fast and efficient.
[0014] Another object of the invention is to provide an edging assembly for tubular elements
that is versatile, for performing machining operations on tubular elements of different
sizes.
[0015] Another object of the present invention is to provide an edging assembly for tubular
elements that is low cost, easily and practically implemented, and safe in use.
[0016] This aim and these objects are achieved by an edging assembly for tubular elements
according to the present invention, characterized in that it comprises at least one
resting surface provided with at least one opening, said surface being provided with
coupling means for at least one annular abutment template, in which at least the inner
front is shaped and which is arranged so as to be substantially aligned with the at
least one respective opening, and at least one carousel, which can rotate and can
slide at least partially in a radial direction according to a preset stroke, with
respect to a central axis of the at least one respective opening, said carousel supporting
at least one corresponding complementarily shaped roller, the end edge of a tubular
element being arranged within said opening, between said shaped inner front of the
respective annular template and the corresponding complementarily shaped roller, for
the edging, i.e., deformation thereof according to preset shape and size standards.
[0017] Further characteristics and advantages of the invention will become better apparent
from the description of a preferred, but not exclusive, embodiment of the edging assembly
for tubular elements according to the invention, which is illustrated by way of non-limiting
example in the accompanying drawings wherein:
Figure 1 is a sectional view, taken along a transverse plane, of a first embodiment
of an edging assembly for tubular elements according to the invention;
Figure 2 is a view from above of the edging assembly in Figure 1;
Figure 3 is a sectional view, taken along a transverse plane, of a second embodiment
of an edging assembly for tubular elements according to the invention;
Figure 4 is a view from above of a portion of the edging assembly in Figure 3;
Figure 5 is a sectional side view of an additional portion of the edging assembly
in Figure 3;
Figure 6 is a sectional side view of an enlarged detail of an edging assembly for
providing a "female" edge;
Figure 7 is a sectional side view of an enlarged detail of an edging assembly for
providing a "male" edge".
[0018] With reference to the figures, the reference numeral 1 generally designates an edging
assembly for tubular elements A.
[0019] The edge that has to be provided on the tubular elements A can be of two different
types: a "male" edge constituted by a rim arranged radially with respect to the generatrices
of the pipe and a "female" edge also provided with a radial rim from which a further
tubular portion branches off having a larger diameter than that of the element A (and
larger also than the maximum space occupation of the radial rim present in the "male"
edge).
[0020] In this manner it is possible to carry out the seaming with other tubular elements
A simply by inserting the "male" edge of a first element A into the "female" edge
of another element A and then closing (by using specific folding devices) the tubular
portion of the "female" edge onto the rim of the "male" edge.
[0021] The edging assembly 1 comprises at least one resting surface 2 provided with at least
one opening 3: the surface 2 is for resting an edge of the tubular element A and thus
will comprise a rim of size adapted to accommodate and support the element A, and
inside such rim the central opening 3 that was defined previously will be provided.
[0022] The surface 2 is provided with coupling means 4 for at least one annular abutment
template 5, in which at least the inner front 6 is shaped.
[0023] The template 6 is arranged so as to be substantially aligned with the at least one
respective opening 3.
[0024] The assembly 1 comprises at least one carousel 7 which can rotate with respect to
a central axis of the at least one respective opening 3 (such central axis is the
center of rotation of the carousel 7).
[0025] The carousel 7 further can at least partially slide in a radial direction according
to a preset stroke, which depends on the dimensions of the edges ("male" and "female")
that it is necessary to provide.
[0026] The carousel 7 further acts as a support for at least one corresponding complementarily
shaped roller 8.
[0027] In the formation step, the end edge of a tubular element A will thus be arranged
inside the opening 3 (in substantial abutment against a limit rim of the resting surface
2), between the shaped inner front 6 of the respective annular template 5 and the
corresponding complementarily shaped roller 8: the pressure of the roller 8 on the
shaped inner front 6 will determine the deformation of the end edge of the interposed
element A, according to preset shape and size standards.
[0028] The assembly 1 according to the invention can comprise a plurality of different openings
3, inside each of which there is a corresponding carousel 7; on each opening 3 a corresponding
template 5 can be installed.
[0029] This makes it possible to simultaneously carry out multiple edging operations on
different tubular elements A, considerably increasing productivity.
[0030] Of particular practical and applicative interest is the adoption of an assembly 1
provided with two openings 3, two carousels 7 and respective templates 5.
[0031] Such assembly 1, while keeping dimensions down and space occupation to a minimum,
substantially makes it possible to double the speed of production of elements A provided
with an edge ("male" or "female") with respect to conventional devices, while ensuring,
with respect thereto, extremely high standards of safety in that the operator does
not have to support the element A during the machining and the element A proper remains
still during such process, thus not generating any potential danger for the operator.
[0032] It should be noted that the at least one annular abutment template 5 comprises two
complementary ring portions 5a and 5b: a first ring portion 5a can be rigidly coupled
to the resting surface 2, and a second ring portion 5b can be associated with a slider
that can perform a translational movement 9, by way of the action of a respective
actuator 10.
[0033] Such slider 9 can perform a translational movement between a first configuration
of maximum distance from the central axis of the respective opening 3 and a second
configuration of minimum distance from such axis, which corresponds to the mutual
abutment of the two ring portions 5a and 5b so as to form the template 5.
[0034] The arrangement of the end edge of a respective tubular element A within the opening
3 and its extraction from it are possible when the second ring portion 5b is in the
first configuration (the ring portion 5b is spaced from the ring portion 5a).
[0035] According to an embodiment of undoubted practical and applicative interest, the shaped
inner front 6 of each template 5 comprises at least two annular frames of different
diameter that define a contoured portion provided with at least one step.
[0036] It should be noted that each assembly 1 will be accompanied by a plurality of templates
5 of different inside diameters, to be used to provide edges on tubular elements A
of different diameters: in this manner the assembly 1 will be particularly versatile
and adapted to execute machining operations on all the commercial diameters for the
pipes with which a possible element A being machined is to be used.
[0037] If the assembly has a plurality of different openings 3, each one of them will preferably
be provided with a respective set of templates 5 in order to also enable the simultaneous
execution of many edging operations on different tubular elements A of the same diameter.
[0038] The carousel 7, which can rotate with respect to a central axis of the opening 3,
comprises a guiding block 11 coupled to a shaft 12 that is coaxial to the central
axis and is functionally associated with a respective motor.
[0039] Such carousel 7 further comprises a slider 13, which can slide on the guiding block
11 in a radial direction according to a preset stroke, by way of the action of a respective
movement element 14.
[0040] The movement element 14 comprises an apparatus for linear actuation 15 that is coaxial
to the central axis of the opening 3 and is provided, at its upper end, with an axially
symmetrical cam 16, the outer surface of which rests on a first face 17 of the slider
13.
[0041] In order to facilitate its installation, it is preferable to arrange the movable
stem of the linear actuation apparatus 15 inside an axial cavity of the shaft 12,
leaving the fixed body, which is more cumbersome, confined to its exterior.
[0042] The translational movements along the profile of the cam 16 of the first face 17
of the slider 13 force translational movements in a radial direction of the slider
13 proper: such translational movements determine the approach of the complementarily
shaped roller 8 to the shaped front 6 of the template, with consequent compression
between them of the interposed portion of tubular element A and its mechanical deformation.
[0043] It should be noted that, according to an embodiment of undoubted applicative interest,
the axially symmetrical cam 16 is frustum-shaped: interposed between the slider 13
and the guiding block 11 there are elastic means (usually an axially acting spring)
for forcing the first face 17 of the slider 13 on the outer surface of the cam 16.
[0044] It should be noted that the slideable association between the guiding block 11 and
the slider 13 can preferably be obtained by adopting a dovetail coupling.
[0045] The complementarily shaped roller 8 is pivoted freely on the slider 13 and comprises
at least one protruding annular band 18.
[0046] The profile of the roller 8 is thus substantially complementary to that of the inner
front 6 of the template 5.
[0047] In practice the roller 8 and the template 5 behave like the two halves of a mold
between which the piece being machined (in this specific case, the end portion of
a tubular element A) is interposed.
[0048] The slider 13 further comprises a plurality of accommodation holes 19, which are
distributed along a predefined direction, for the pivot 20 for the free coupling of
the roller 8, at different diameters of tubular elements A on which edging is to be
performed; such accommodation can be direct or indirect, i.e. auxiliary components
(such as for example in the embodiment shown in the accompanying figures) can be interposed
which can be fixed to the slider 13 according to a series of different arrangements,
in which case such auxiliary components will comprise a seat for the stable engagement
of the pivot 20. As explained previously, different abutment templates 5 are used,
the inside diameter of which is proximate to that of the corresponding tubular element
A at machining operations to be executed on tubular elements A of different sizes.
[0049] According to the template 5 adopted, it should be noted that the coupling pivot 20
will be engaged in a respective corresponding accommodation hole 19.
[0050] It should be noted that the carousel 7 (and therefore the shaft 12 as well) is mounted
on a supporting post provided with means for movement of a movable portion thereof
which is integral with the carousel 7, with respect to a fixed portion, which is integral
with the footing of the assembly 1: the stroke of such movable portion with respect
to the fixed portion is of the order of magnitude of the length of the edge to be
provided in the metallic element A.
[0051] Such axial movement makes it possible to vary the position of the roller 8 with respect
to the template 5, making it possible to obtain the two different edges ("male" edge
and "female" edge) on the tubular element A.
[0052] The lower height of the movable portion (with which the carousel 7 is associated)
ensures the provision of the "female" edge in that the portion of tubular element
A undergoes a deformation similar to the progression of the profile of the front 6
(or of the roller 8), while the greater height of the movable portion (with which
the carousel 7 is associated) ensures the provision of the "male" edge in that the
portion of tubular element A will see the creation of the radial rim only.
[0053] It should be noted that, with particular reference to an embodiment that is particularly
efficient, the movement means, the actuator 10 and the linear actuation apparatus
15 are selected preferably from hydraulic cylinders, pneumatic cylinders, devices
with threaded units and rack devices and the like.
[0054] If hydraulic cylinders are adopted, rapid response times and high levels of precision
can be achieved which will ensure a better operation of the entire assembly 1.
[0055] During the operation the idle roller 8 presses the sheet metal of the curve section
of the element A to be machined against the template 5 (which in fact behaves like
the matrix die of a mold), of the appropriate diameter, in order to execute the edging
machining.
[0056] The horizontal movement of the slider 13 with respect to the guiding block 11 (achieved
by fixing to the respective holes 19) and the substitution of the templates 5 are
the operations to be executed in order to switch from one diameter of a tubular element
A to another.
[0057] The slider 13 is pushed horizontally by the frustum-shaped cam 16 which descends
vertically by the action of the linear actuation apparatus 15 (which is preferably
constituted by a hydraulic cylinder). The descent of the cam 16 can be interrupted
and resumed, accelerated or slowed at any point of the entire work cycle (this can
be useful to adapt the machining cycle to the type of material that constitutes the
tubular elements A and its thicknesses).
[0058] The purpose of these variations of time and speed is to reduce the duration of the
cycle where and when this is possible.
[0059] In order to be capable of executing the "male" and "female" edgings one after the
other, with the same placing, without executing any assembly or disassembly of part
of the mechanism, the movable portion of the supporting post slides axially (with
respect to the fixed portion).
[0060] For machining different diameters, an additional movable component is provided which
makes a second roller 21 advance or retreat.
[0061] The second roller 21 is associated with the rotating carousel 7, with the interposition
of a respective linear actuator for its controlled translational movement in a radial
direction. Such translational movement in a radial direction occurs from a first,
retracted configuration, in which the second roller 21 is spaced from the first roller
8 and is arranged inside it, to a second configuration of substantial alignment of
the lateral surface of the second roller 21 with the lateral surface of the first
roller 8: such configuration is adapted for the abutment, on such aligned lateral
surfaces, of the end edge of the tubular element A being formed (in particular of
the "female" part of the coupling that is being formed).
[0062] The linear actuator with which the second roller 21 is associated is preferably of
the type of a hydraulic and/or pneumatic cylinder (although the possibility is not
excluded of using other types of actuators); it will thus be driven and powered by
a respective rotating distributor (connected to a hydraulic and/or pneumatic circuit)
which is also substantially integral with the carousel 7.
[0063] When this second roller is set beside the first roller, mentioned above, a "broader"
roller is created (in particular the overall height of their juxtaposed edges is such
as to abundantly exceed the maximum length of the edges to be provided on the tubular
elements A).
[0064] As previously mentioned, the "male" part of a curve section of a tubular element
A is a flanging, i.e. a 90° outward fold. The female part is a "bell socket", i.e.
a kind of outward step that accommodates the male part and which, in a subsequent
operation carried out on another machine, is folded back toward the center, thus making
the coupling of the two parts stable.
[0065] To make the "male" edge, a smaller quantity of material has to be machined than the
amount necessary to make the "female" edge. The quantity of material to be machined
depends, as noted, on the vertical position of the resting surface 2 (and as a consequence
on the position of the movable portion of the supporting post).
[0066] The movement means (preferably hydraulic and/or pneumatic cylinders) raise or lower
the edge of the tubular element A with respect to the rollers 8 (and 21) which, together
with the respective template 5, execute the two machining operations. Such movement
means thus have two configurations of operation, both of which are adjustable, a high
configuration (for making the "male" edge) and a low configuration (for making the
"female" edge).
[0067] In the high configuration, the second roller 21, which is arranged lower down, must
be withdrawn toward the center of rotation (central axis) in order to not interfere
with the resting surface 2. According to this arrangement, with the resting surface
2 high and the second roller 21 withdrawn, only the roller 8, the one which is fixed
rigidly to the slider 13, is operating.
[0068] When a "female" edge is to be executed, the resting surface is in the low configuration.
The second roller 21 is advanced and set vertically beside the roller 8 so as to form
an axially symmetrical component provided with a wider lateral surface.
[0069] The descent movement of the resting surface 2 and the advancement of the second roller
21 with respect to the roller 8 are connected so that no conditions of interference
ever occur.
[0070] The work cycle is as follows:
- the operator, by means of a button or by activating a sensor, selects whether to execute
a "male" edge or a "female" edge on the portion of tubular element A to be machined;
- the resting surface 2 is automatically positioned in the high configuration or in
the low configuration, as a consequence, and the second roller 21 advances or remains
withdrawn (again as a function of the type of machining selected). The mobile ring
portion 5b of the template 5 remains spaced from the fixed ring portion 5a;
- the operator places a tubular element A inside the template 5, on the resting surface
2;
- the operator activates the automatic sequence of the work cycle;
- the mobile template 5b touches the fixed template 5a. The shaft 12 is made to rotate;
the slider 13 advances radially, pushed by the frustum-shaped cam 16 which descends
vertically, pushing the roller 8 or, if execution of a "female" edge was selected,
the two rollers 8 and 21, outward;
- a processor (for example a PLC) governs the rotation speed of the shaft 12, the position
and the descent speed of the cam 16 and thus of the approach of the slider 13 to the
template 5.
[0071] After a set time everything returns to the rest position.
[0072] The processor (for example a PLC) that governs the assembly 1 is provided with memory
units in which machining cycle data can be stored for different tubular elements A
(different in terms of thicknesses, dimensions and types of material) and which, by
simply calling up a code associated with a specific item to be produced, provides
the elements of the assembly 1 with the speed, the times and any other information
relating to the different laws of motion.
[0073] The size and shape of the rollers 8 and 21 and the diameter of the templates 5 are
devised so that the machining is executed by the assembly 1 without any form of intervention
by the operator.
[0074] Advantageously the present invention solves the above mentioned problems, by providing
an edging assembly 1 for tubular elements A which is particularly safe for the operator:
the tubular element A in fact does not rotate about itself, but is substantially stationary
during the machining.
[0075] The only movements performed by the tubular element A are limited to small adjustments
of position which are caused by the minimum size tolerance that exists between each
template 5 and the respective tubular element A.
[0076] In any case it is not necessary for the operator to support the element A during
the machining (on the contrary, the assembly 1 can operate only when the operator
is outside a predefined perimeter around the element A).
[0077] Conveniently the edging assembly 1 according to the invention is particularly fast
and efficient, in that the operator can prepare the piece to be machined after the
piece that is already positioned on the assembly 1, since the assembly 1 does not
require direct intervention from the operator. This means that the preventive activity
of the operator makes it possible to reduce the dead times in operation.
[0078] Furthermore, for assemblies 1 provided with multiple openings 3 and carousels 7,
it will be possible to considerably increase the speed of production given the possibility
of executing multiple machining operations simultaneously.
[0079] If there are two openings 3 and carousels 7 in a single assembly 1, its dimensions
will still be very contained and thus its installation will be possible even in the
space usually occupied in conventional machines (in which however only one edging
operation is executed at a time, with the direct and continuous assistance of the
operator).
[0080] Conveniently, the assembly 1 is particularly versatile in that it can execute machining
operations on tubular elements A of different sizes simply by mounting the corresponding
template 5 and arranging the roller 8 in the corresponding position (using the adjustable
mounting made possible by the holes 19).
[0081] According to the type of practical implementation of the assembly 1, there can be
a roller 8 which is mounted directly onto respective holes 19 of the slider 13 or,
more conveniently, there can be interposed components onto which the roller 8 will
be fixed, again in a predefined position, and which can in turn be coupled to the
slider 13 according to a plurality of different arrangements thanks to the holes 19.
[0082] Conveniently the edging assembly 1 for tubular elements A is low cost, easily and
practically implemented and is safe in use.
[0083] The invention, thus conceived, is susceptible of numerous modifications and variations,
all of which are within the scope of the appended claims. Moreover, all the details
may be substituted by other, technically equivalent elements.
[0084] In the embodiments illustrated, individual characteristics shown in relation to specific
examples may in reality be interchanged with other, different characteristics, existing
in other embodiments.
[0085] In practice, the materials employed, as well as the dimensions, may be any according
to requirements and to the state of the art.
[0086] The disclosures in Italian Patent Application No.
BO2012A00063 from which this application claims priority are incorporated herein by reference.
[0087] 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.
1. An edging assembly for tubular elements (A), characterized in that it comprises at least one resting surface (2) provided with at least one opening
(3), said surface (2) being provided with coupling means (4) for at least one annular
abutment template (5), in which at least the inner front (6) is shaped and which is
arranged so as to be substantially aligned with the at least one respective opening
(3), and at least one carousel (7), which can rotate and can slide at least partially
in a radial direction according to a preset stroke, with respect to a central axis
of the at least one respective opening (3), said carousel (7) supporting at least
one corresponding complementarily shaped roller (8), the end edge of a tubular element
(A) being arranged within said opening (3), between said shaped inner front (6) of
the respective annular template (5) and the corresponding complementarily shaped roller
(8), for the edging, i.e., deformation thereof according to preset shape and size
standards.
2. The edging assembly according to claim 1, characterized in that said at least one annular abutment template (5) comprises two complementary ring
portions (5a, 5b), a first ring portion (5a) being rigidly associable with said resting
surface (2), a second ring portion (5b) being associable with a slider (9) that can
perform a translational movement, by way of the action of a respective actuator (10),
between a first configuration of maximum distance from the central axis of the respective
opening (3) and a second configuration of minimum distance from said axis, which corresponds
to the mutual abutment of the two ring portions (5a, 5b) so as to form said template
(5), the arrangement of the end edge of a respective tubular element (A) within a
said opening (3) and its extraction from it being possible when said second ring portion
(5b) is in said first configuration.
3. The edging assembly according to claim 1, characterized in that said shaped inner front (6) of said at least one template (5) comprises at least
two annular frames of different diameter that define a contoured portion provided
with at least one step.
4. The edging assembly according to claim 1, characterized in that said carousel (7) that can rotate with respect to a central axis of said opening
(3) comprises a guiding block (11), which is coupled to a shaft (12) that is coaxial
to said central axis, is functionally associated with a respective motor, and a slider
(13), which can slide on said guiding block (11) in a radial direction according to
a preset stroke by way of the action of a respective movement element (14).
5. The edging assembly according to claim 4, characterized in that said movement element (14) comprises an apparatus for linear actuation (15) that
is coaxial to said central axis of said opening (3) and is provided, at its upper
end, with an axially symmetrical cam (16), the outer surface of which rests on a first
face (17) of said slider (13), the translational movements of said first face (17)
along the profile of said cam (16) forcing translational movements in a radial direction
of said slider (13).
6. The edging assembly according to claim 5, characterized in that said axially symmetrical cam (16) is frustum-shaped, between said slider (13) and
said guiding block (11) there being interposed elastic means for forcing said first
face (17) of said slider (13) on the outer surface of said cam (16).
7. The edging assembly according to claim 1, characterized in that said complementarily shaped roller (8) is pivoted freely on said slider (13) and
comprises at least one protruding annular band (18), the profile of said roller (8)
being substantially complementary to the profile of the inner front (6) of said template
(5).
8. The edging assembly according to claim 1, characterized in that it comprises a second roller (21) that is associated with said rotating carousel
(7), with the interposition of a respective linear actuator for its controlled translational
movement in a radial direction from a first retracted configuration, in which it is
spaced from said first roller (8) and is arranged inside it, to a second configuration
of substantial alignment of the lateral surface of said second roller (21) with the
lateral surface of said first roller (8) for the abutment on said aligned lateral
surfaces of the end edge of a tubular element (A) being formed.
9. The edging assembly according to one or more of the preceding claims, characterized in that said slider (13) comprises a plurality of holes (19) for direct or indirect accommodation,
which are distributed along a predefined direction, for the pivot (20) for the free
coupling of said roller (8), at different diameters of tubular elements (A) on which
edging is to be performed, different abutment templates (5) being used the inside
diameter of which is proximate to that of the corresponding tubular element (A), and
said coupling pivot (20) being engaged directly or indirectly in a respective accommodation
hole (19).
10. The edging assembly according to one or more of the preceding claims, characterized in that said carousel (7) is mounted on a supporting post provided with means for movement
of a movable portion thereof which is integral with said carousel (7), with respect
to a fixed portion, which is integral with the footing of the assembly (1), the stroke
of said movable portion with respect to said fixed portion being of the order of magnitude
of the length of the edge to be provided in said tubular element (A).
11. The edging assembly according to one or more of the preceding claims, characterized in that said movement means, said actuator (10) and said linear actuation apparatus (15)
are selected preferably from hydraulic cylinders, pneumatic cylinders, devices with
threaded units and rack devices and the like.