[0001] The present invention concerns an element for a screening fence.
[0002] The invention further relates to a method for realising screening fence elements.
In particular the device is applicable in the realising of screening fences in all
situations in which an area is to be fenced with a complete or partial prevention
of a view of the area delimited by the fence.
[0003] In the prior art it is usual to predispose a delimiting fence around an area, for
example a work-site, which offers a practically-complete covering of the view, which
is destined to prevent outsiders from viewing whatever is inside the delimited area.
[0004] The solutions available on the market for this type of application have necessarily
to surrender to compromise in relation to two aspects which are in contrast with one
another: the screening capacity and the lightness of the product, together with the
ability to offer a resistance to wind which is as low as possible.
[0005] Screening solutions in which the percentage of screening is 100% or nearly so are
constituted by panels, either continuous or beams of wood, metal or plastic material
textile netting, with a warp or weft which leave no space between the elements constituting
the material. Other known solutions offering a partial screening are constituted by
netting made of a plastic material with meshes that can be more or less tight according
to needs.
[0006] As mentioned above, the two types of products have positive characteristics which
are in contrast to one another; the first provide a total screening but are very sturdy
and heavy to set up on-site; the others give excellent manageability, set-up and costs,
but their true screening capacity is moot.
[0007] Other systems are realised by a netting coupled with material or panels which give
a better concealment from sight; this solution requires the use and acquisition of
two different products for obtaining a specific aim, beyond the difficulty of uniting
the two products to form one final product. This latter solution is typical of characteristic
zones where it is necessary to signal, in a typically orange colour, the presence
of a worksite, while it is also required to prevent outsiders from observing the inside
of the work-site.
[0008] Document
CH963931 describes realising a modular screening structure, particularly suited to delimiting
areas where a road accident has occurred, such that the area can be hidden from general
view. Each of the modules of the screening barrier exhibits a support structure provided
with a base and a plurality of vertical uprights which delimit a support frame on
which a predetermined number of flexible sheets provided with respective semicircular
openings is mounted, which sheets exhibit respective semi-circular openings defining
tabs that are openable by the action of the wind.
[0009] The main aim of the present invention is to obviate the problems encountered in the
prior art. An aim of the present invention is therefore to provide an element for
screening fences which is able to provide a high screening capacity and at the same
time a lower resistance to wind.
[0010] A further aim of the present invention is to provide an element for screening fences
which offers complete coverage.
[0011] A further aim of the invention is to make available an element for screening fences
which is light, easy to handle and to apply.
[0012] A further aim of the present invention is to make available an element for a screening
fence which exhibits easiness of setting up and which is economical. A further aim
of the present invention is to provide an element for screening fences which does
not require a reinforcing structure in order to resist the action of the wind.
[0013] A still further aim of the invention is to provide a method for realising elements
for screening fences which is simple, rapid and easy to industrialise.
[0014] A further aim is to make available a production method which makes the handling of
the product before use easier and simpler.
[0015] These aims and others besides are substantially attained by an element for screening
fences and a method for realisation thereof, in accordance with what is expressed
in one or more of the accompanying claims, taken alone or in combination.
[0016] The invention further relates to an element of one or more of the accompanying claims,
in which a tape body is provided with a plurality of additional second through-openings
that are without covering elements.
[0017] The invention further relates to an element of one or more of the accompanying claims,
wherein the covering elements are defined by means of the same cutting operation which
defines the corresponding opening.
[0018] The invention further relates to an element of one or more of the accompanying claims,
wherein the covering elements cover corresponding openings more in a second operating
position than in a first operating position.
[0019] The invention further relates to an element of one or more of the accompanying claims,
wherein the covering elements are displaceable between a plurality of distinct operating
positions.
[0020] The invention further relates to an element of one of more of the accompanying claims,
wherein each covering element exhibits a connecting portion with the tape body and
in which the cuts are larger in size than the corresponding and contiguous connecting
portion.
[0021] The following is a detailed description, by way of non-limiting example, of a preferred
embodiment of an element for screening fences and a method for realisation thereof,
wherein:
figure 1 is a perspective view of an element for screening fences, in accordance with
the present invention;
figure 2 is a perspective view of a detail of the element of figure 1, in which covering
elements are arranged in a first operating position;
figure 3 is a second perspective view of a detail of the element of figure 1, in which
covering elements are arranged in a second operating position;
figure 3 a is the same view as in figure 3, in relation to a first variant;
figure 3b is the same view as in figure 3, in relation to a second variant;
figure 4 is a perspective view of a further variant of an element for screening fences,
with a different distribution of openings, in accordance with the present invention;
figure 5 is a schematic illustration of a machine and the relative production method
of the element for screening fences of figure 1;
figure 6 is a detailed view of the element of figure 1;
figure 7 is a variant of the view of figure 6; and
figure 8 illustrates the stages of setting up the element 1 produced with the device
of figure 5.
[0022] With reference to the figures, 1 denotes in its entirety an element for screening
fences of the present invention. The element 1 comprises at least a tape-form body
2 provided at least with a plurality of first through-openings (visible in figure
3). The element 1 further comprises a plurality of covering elements 4, each of which
is coupled to the tape body 2 at a corresponding opening 3 of the first through-openings
3.
[0023] Each covering element 4 is mobile at least between a first operating position (illustrated
in detail in figure 2) in which it at least partially covers the corresponding opening
3 and a second operating position (illustrated in detail in figure 3) in which it
is displaced with respect to the first operating position. In the invention, the covering
elements 4 are displaceable from the first operating position to the second operating
position by a gust of wind when the covering element 4 is set up on-site, such as
to reduce the resistance of the covering element 1 to the wind. A greater thrust of
the wind corresponds to a more greatly-displaced position of the covering elements
4, and a more exposed area of the openings 3, which leads to a lower wind-resistance
of the fence. The covering elements 4 are afforded in the tape body 2, each by a through-cut
5 in the tape body 2 itself. The covering elements 4 defined thus consist in effect
of mobile tabs made in a single piece with the tape body 2. In particular, the covering
elements 4 are defined by the cut defining the corresponding opening 3. The covering
elements 4 exhibit a connecting portion 6 with the body 2. The covering elements 4
are made in a single piece with the tape body 2.
[0024] The cuts 5 exhibit a greater extension than the connecting portion 6, such as to
be able to define the covering elements 4. The extension of the cuts 5 is at least
1.5 times the extension of the corresponding connecting portions 6. The covering elements
4 exhibit substantially complementarily-shaped forms to the shapes of the corresponding
openings 3 at which they are coupled to the tape body 2.
[0025] As can be seen in figure 2, the covering elements 4 in the first operating position
substantially completely close the corresponding through-openings 3 at which they
are coupled to the tape body 2. The covering elements 4 are substantially coplanar
with the tape body 2 in the first operating position and are inclined in the second
operating position with respect to the tape body 2. Of importance is the fact that
in practice the covering elements 4 can be partially displaced with respect to the
coplanar position with the tape body 2, for example due to the properties of the material
the tape body 2 is made of.
[0026] The covering elements 4 reveal corresponding openings 3 more greatly in the first
operating position than in the second operating position. The covering elements are
displaceable among a plurality of distinct operating positions, not illustrated in
detail in the figures.
[0027] In an alternative embodiment (not illustrated) the covering elements 4 could be made
independently of the tape body 2 and be applied at the portion 6 to the tape body
2 at the first openings 3. This solution however leads to greater costs and production
times with respect to the first above-illustrated solution.
[0028] The tape body 2 can be made of a plastic material, but could also be realised in
other materials that are appropriate for the purpose. The openings 3 and the tilting
covering elements 4 made in the tape body 2 facilitate external use of the fencing
element 1 without its being necessary to provide a reinforcing structure in order
for it to resist the action of the wind, as the covering elements 4 displace at the
passage of the breeze, thus defining windows which can guarantee a lower resistance
to the wind.
[0029] The tape body 2 can be provided with a plurality of additional second through-openings
7 (for example holes) which are not covered. The second through-openings 7 can be
defined by small-diameter holes (such as not to allow vision of the delimited area)
and can enable a further reduction in wind-resistance of the fencing element 1. The
dimensions and shapes of the openings made in the tape body 2, as well as the weight
of the body 2 itself can be varied such as to obtain a product having different characteristics
and fields of application.
[0030] Of significance is the fact that the invention is very flexible and adaptable to
the various needs. For example, the capacity of the covering elements 4 to bend under
the thrust of the wind can be varied by changing the extension of the connecting portions
6, as the smaller the length of the connecting portion 6 the more easily the covering
elements 4 can bend (as illustrated for example in the first variant of figure 3a
in which the connecting portions 6 are shorter than those of figure 3). Also, the
connecting portion 6 can be perforated in order to further reduce the thrust required
for bending the covering elements 4.
[0031] It is also worthy of note that it is possible to vary the extension surface of each
covering element 4 in order to vary the thrust necessary for bending the elements
4. The greater the extension of each covering element 4, the greater the overall thrust
exerted by the wind on the element 4 will be.
[0032] Further, the shape of the covering elements 4 can be any, according to requirements
(see for example the second variant of figure 3b).
[0033] It is also possible to vary the overall resistance of the element for screening fences
by changing the overall number of covering elements 4 and corresponding openings 3
provided in the fencing element.
[0034] The invention further relates to a method for realising an element for screening
fences comprising at least the stages of providing a tape body 2 and coupling a plurality
of covering elements 4 to the tape body 2 at a plurality of first openings 3 of the
tape body 2 such that the covering elements 4 are mobile at least between a first
operating position in which they at least partially cover the corresponding first
openings 3 and a second operating position which is displaced with respect to the
first operating position. The stage of coupling a plurality of covering elements 4
to the tape body 2 is performed by realising the covering elements 4 directly on the
tape body 2 by means of a stage of realising the through-cuts 5 of the tape body 2,
such that the cuts define the first through-openings 3 and the covering elements 4
at the same time.
[0035] Observing figure 5 in particular, a schematic illustration of a machine for producing
a screening fence element is provided, according to what has been described herein
above.
[0036] In particular, the plastic material defining the whole structure of the screening
fence element is brought to the molten stage and then extruded by means of an extruding
head 9. Figure 5 schematically represents a linear extruding head 9 which shows the
tape body 2 already in its flat form in output.
[0037] Alternatively rotary extruding heads can be used, giving a tubular product made of
plastic which is then cut along the extruding direction and flattened such as to reach
exactly the flat configuration illustrated in figure 5, immediately downstream of
the extruding head.
[0038] In particular, the material exits the extruding head 9 along an extrusion direction
denoted in the figures with the arrow MD.
[0039] The material used will usually be a thermoplastic polymer.
[0040] Preferably the polymer will be polyethylene and in general a high-density polyethylene,
with an appropriate addition of colorants, for example in order to give it the typical
orange colour used for work-site fencing, and for example with inclusion of further
additives such as UV protection agents.
[0041] Note that the tape body 2 in exit from the extruding head can already be provided
with the second openings 7.
[0042] Alternatively the second openings 7 can also be made after the extrusion stage, for
example during the stage of realising the through-holes or also at different times,
with separate devices.
[0043] In general, the second through-holes 7, typically though not necessarily circular-shaped
(slightly irregular if realised during the extrusion stage with the material still
in the plastic state) are used for guiding the tape body 2 in the movement along the
extrusion direction MD.
[0044] In still other terms, the second through-holes 7 constitute the reference that guarantees
the correct positioning of the tape body 2 during the stages of movement on the production
machine.
[0045] On this subject, and merely by way of example, the second openings 7 can be arranged
along a predetermined number of rows 13, 14 that are substantially parallel to the
extrusion direction MD.
[0046] From the point of view of distribution, too, the through-holes 7 can be equidistanced
or not, according to needs, without forsaking the inventive concept of the present
invention.
[0047] A cutter 10 is located downstream of the extruding head 9, for realising the plurality
of through-holes 5 which define the first openings 3 and the covering elements 4.
[0048] As can also be seen from figure 5, there exists a very precise arrangement relation
of the covering elements 4 with respect to the extrusion direction MD. In general,
in the cutting operation, covering elements 4 are defined which develop substantially
entirely in a transversal direction TD with respect to the extrusion direction MD.
[0049] Looking in particular at figure 6, it can be seen how the covering element 4 exhibits
a transversal prevalent development direction, which is substantially perpendicular
to the extrusion direction MD.
[0050] In particular, the covering element illustrated in figure 6 is symmetrical with respect
to the prevalent development direction 8.
[0051] Generally speaking, the covering element 4 is joined to the tape body 2 along at
least the connecting portion 6 and at least a portion 4a of the covering element 4
develops in a direction TD which is transversal to the extrusion direction MD and
external of the extension of the dimension 11 of the connecting portion 6 in the extrusion
direction MD.
[0052] This situation is clearly illustrated in figure 7, where the extrusion direction
MD and the transversal direction TV thereto have been indicated.
[0053] The covering element 4 represented exhibits a connecting portion 6 which is slightly
inclined with respect to the extrusion direction MD and the dimension 11 has been
illustrated with an area of grey background which the connecting portion identifies
along the extrusion direction MD.
[0054] As can be seen, the covering element 4 is arranged at least partly externally of
the dimension 11.
[0055] In general, the portion 4a external of the dimension 11 will be greater than the
portion 4b internal of the dimension 11 and in general at least twice larger in terms
of surface.
[0056] The foregoing determines in general terms that the connecting portion 6 is positioned
during use superiorly of the furthest free portion of the covering element 4 which
is thus maintained in a closed position by its own weight once the screening fence
element is set up in working position.
[0057] In still other terms, it is extremely relevant that covering elements 4 can be realised
which in the absence of wind are maintained in the closed position, or the substantially
closed position, thanks to their own weight.
[0058] Further, and as will be clarified herein below, this orientation is also extremely
advantageous in the stage of packing the roll 15 constituted by the tape body 2 wound
about an axis 12.
[0059] A different orientation of the covering elements 4 from the one illustrated in figure
5, i.e. a configuration of the covering elements 4 in such a way as to present a prevalent
axis of development parallel to the extrusion direction MD would lead to the opening
of the tabs themselves if the tape body 2 were rolled; this would lead to problems
in correcting predisposition and positioning of the roll 15 itself.
[0060] Note also how the connecting portion 6 extends generally substantially parallel to
the extrusion direction MD (see figure 6) or in any case is slightly inclined with
respect thereto (see figure 7).
[0061] In general, the angle of inclination with respect to the extrusion direction MD will
less than 30% and preferably less than 15°.
[0062] A further important characteristic is the presence of the cuts 5 having an extension
(perimeter) of at least 2.5 times, and usually at least 3 times the extension of the
connecting portion 6.
[0063] Because of the plastic material used (thermoplastic polymer, in particular polyethylene)
it is necessary to give the covering element particular geometric characteristics
such as to enable them to be opened in the presence of wind.
[0064] The extension of the perimeter is one of the characteristics to be taken account
of. The present of a semi-circular opening or in any case an opening having a perimeter
which is at least 2.5 times the length of the connecting portion determines a not-easy
opening of the openings 3 and a good level of resistance even in the presence of wind.
[0065] Obviously the maximum distance of the cut with respect to the connecting portion
6 is also of considerable importance.
[0066] In fact, the dynamic pressure exerted by the wind generates a torque about the hinge
defined by the connecting portion 6.
[0067] It is clear that the zones of areas further from the connecting portion 6 are those
which, given a same dynamic pressure, develop a greater torque.
[0068] Further, the length 1 of the connecting portion 6 determines an effective resistance
to the opening of the covering element 4.
[0069] In other terms, at least a zone of the cut 5 defining the covering element 4 must
exhibit a distance d from the connecting portion which is greater than 1/2 and in
particular at least 0.81.
[0070] Preferably this distance d will be at least 1 (see once more figures 6 and 7). Obviously
also the surface or area of the covering element 4 has an importance to the ability
thereof to open in the presence of wind of the other tabs.
[0071] The covering element must in general define an area of surface which is at least
1.5 times the length predefined by the connecting portion 6 squared. In other words,
the ratio must be at least A>1.5·1
2.
[0072] Looking once more at figure 5, in the production process the tape body 2 is cooled
and thus can be wound in a roll 15 about a winding axis 12 up to the desired dimensions
of the roll 15.
[0073] At this point a transversal cut is made and a new roll is commenced.
[0074] Thus the fencing element in the final realisation thereof is constituted exclusively
by a sheet made of an extruded plastic material wound in a roll and exhibiting cuts
5 on its surface.
[0075] In general, in terms of weight per unit of length, it is more than 200 grams per
square metre and in particular more than 650 grams per square metre in order to guarantee
minimum resistance performance levels in the face of atmospheric agents once set up
in the worksite.
[0076] The procedure for setting up the fencing element comprises predisposing the roll
15, still wound up, and then constraining a most-external first portion 16 of the
tape body 2 to a first support 17, for example by means of constraining elements 18
such as strings or bands passing through the first or second openings 3, 7. As can
be seen in figure 8, the roll 15 is unwound about the winding axis such as to be able
to fence-in a predetermined area 19.
[0077] A further portion 20 of the tape body is constrained to a further support 21 and
the stages are gradually repeated up until they completely conceal the area 19 of
interest.
[0078] Note in particular that by its nature the tape body can be positioned following any
path and in particular areas that are not flat and/straight.
[0079] Obviously the length L of the roll will be a number of times the height H thereof.
[0080] In general the length L of the roll will be at least 10 times the height H, in particular
it will be between 20 and 70 times the height H of the roll.
[0081] Purely by way of non-limiting example, the height of the tape body 2 can be comprised
between 1 and 2 metres, while the lengths can be any as the length coincides with
the extrusion direction.
[0082] Standard lengths will generally be comprised between 30 and 50 metres.
[0083] The present invention provides important advantages. Firstly, the above-described
element enables problems encountered in the prior art to be solved. In particular,
a screening fence element of the invention is able to provide high screening capacity
while at the same time offering only a low resistance to wind. In particular, a fencing
element of the invention does not require a reinforcing structure for resisting the
action of the wind. An element of the invention can offer a complete coverage of the
delimited area and is light, easy to handle and to apply. A fencing realised as in
the invention is economical and is very easy to set up in the worksite.
[0084] With the present invention a fenced perimeter can be completely screened with a much
lighter product that is easier to handle with respect to wooden panels or aluminium
alloy panels of known type. The fencing element of the element, for example orange
in colour, can be used to delimit work-site areas where the complete screening of
the working area is required.
[0085] The device of the invention is also simple and economical to realise, and the method
for realising the screening fence elements of the invention is simple, rapid and economical.
1. A method for realising an element for screening fences, comprising at least a tape
body (2) provided with at least a plurality of first through-openings (3) and a plurality
of covering elements (4), each of which is coupled to the tape body (2) at a corresponding
opening (3) of the through-openings (3) and is mobile at least between a first operating
position in which it at least partially covers the corresponding opening (3) of the
first through-openings (3) and a second operating position in which it is displaced
with respect to the first position and in which it covers the corresponding opening
(3) less than in the first operating position, the method comprising following stages:
extruding the tape body (2) made of plastic material along an extrusion direction
(MD), by means of an extruding head (9);
realising a plurality of through-cuts (5) for defining the first openings (3) and
the covering elements (4).
2. The method of the preceding claim, wherein the covering element (4) is joined to the
tape body along at least a connecting portion (6), the stage of realising the through-cuts
(5) determining at least a portion (4a) of the covering element (4) which portion
(4a) develops in a transversal direction (TD) to the extrusion direction (MD) and
externally of a dimension (11) of the connecting portion (6) in the extrusion direction
(MD).
3. The method of one of the preceding claims, wherein the stage of realising the cuts
(5) defines a connecting portion (6) which extends substantially parallel to the extrusion
direction (MD).
4. The method of one or the preceding claims, wherein the stage of realising the cut
defines a cut (5) having an extension which is at least 2.5 times, and in particular
at least 3 times greater than an extension of the connecting portion (6).
5. The method of one or more of the preceding claims, wherein the stage of realising
a plurality of cuts defines a covering element (4) which develops substantially entirely
in a transversal direction (TD) with respect to the extrusion direction (MD) and externally
of the dimension (11) of the connecting portion (6) in the extrusion direction (MD).
6. The method of one or more of the preceding claims, wherein the stage of realising
the cuts defines a connecting portion (6) exhibiting a predefined length (1), the
covering element (4) having a surface area which is at least 1.5 times the predefined
length (1) of the connecting portion squared: A≥1.5·12
7. The method of one or more of the preceding claims, wherein the connecting portion
exhibits a predefined length (1), at least a zone (22) of the cut (5) defining the
covering element (4) having a distance (d) from the connecting portion which is greater
than ½*1 and in particular which is at least 0.8*1 and still more in particular is
1.
8. The method of any one of the preceding claims, wherein the covering element (4) exhibits
a transversal prevalent development direction (8), in particular substantially perpendicular
to the extrusion direction (MD).
9. The method of any one of the preceding claims, comprising following stages:
perforating the tape body in order to fashion a plurality of second through-openings
(7); and
guiding the tape body (2) in the movement along the extrusion direction (MD), by using
the reference determined by the second openings (7), in particular the second openings
(7) being arranged along a predetermined number of rows (13, 14) which are substantially
parallel to the extrusion direction (MD); and
in particular winding the tape body (2) in a roll about a winding axis (12) that is
perpendicular to the extrusion direction in order to define a roll (15).
10. An element for screening fences comprising at least a tape body (2) provided at least
with a plurality of first through-openings (3) and a plurality of covering elements
(4), each of which is coupled to the tape body (2) at a corresponding opening (3)
of the first through-openings (3) and is mobile at least between a first operating
position in which it at least partially covers the corresponding opening (3) and a
second operating position which is displaced with respect to the first position and
in which it covers the corresponding opening (3) less than in the first operating
position, the tape body exhibiting a height (H) along a transversal axis which is
defined between two parallel opposite sides (22, 23) and a length (L) along a prevalent
development axis (24), characterised in that the length (L) is at least 10 times greater than the height (H) and in particular
it is comprised between 20 and, for example 70, times the height (H).
11. The element of the preceding claim, wherein the tape body (2) is entirely made of
a plastic polymer being polyethylene and in particular high-density polyethylene,
the tape body exhibiting a weight per unit of length which is greater than 200 grams
per square metre and in particular is greater than 350 grams per square metre.
12. The element of claim 10 or 11, wherein the covering element (4) is joined to the tape
body along at least a connecting portion (6), at least a portion (4a) of the covering
element (4) developing in the height direction (H) of the tape body (2) externally
of the dimension (11) of the connecting portion (6) in a direction of the length (1)
thereof.
13. The element of any one of claims from 10 to 12, wherein the cut (5) has an extension
of at least 2.5, and in particular at least 3 times the extension of the connecting
portion (6), in particular the connecting portion exhibiting a predefined length (1)
and at least a zone (22) of the cut (5), defining the covering element (4), exhibiting
a distance (d) from the connecting portion (6) which is greater than ½*1, and in particular
at least 0.8*1 and more in particular 1, the covering element (4) optionally defining
a surface area (A) of at least 1.5 times the predefined length (1) of the connecting
portion squared: A≥1.5·12
14. The element of any one of claims from 10 to 13, wherein the covering element (4) exhibits
a transversal prevalent development direction (8), and in particular perpendicular
to the prevalent development direction (24) of the tape body (2), the covering element
(4) optionally developing entirely in the direction of the height (H) and externally
of the dimension (11) of the connecting portion (6) along the prevalent development
axis.
15. A process for setting up an element for screening fences, as in any one of claims
from 10 to 14, comprising stages of:
predisposing a roll (15) constituted by a tape body (2) wound in a roll;
constraining a first portion (16) of the tape body (2), which first portion (16) is
most external of the roll, to a first support (17), for example by means of a constraining
element (18) such as strings or bands passing through the first and/or second opening
(3, 7);
unwinding the tape body from the roll (15) along the winding axis (12) in order
to fence off a predetermined area (19);
constraining at least a further portion (20) of the tape body (2) to a further support
(21) for defining a perimeter positioning of the tape body (2) about the area (19)
to be fenced off, with a non-flat progression and in particular a curved progression
along the prevalent development direction (24) of the tape body.