Patent Description:
In agriculture, and in particular in the viticulture industry, it is well known to provide support structures for plants consisting of rows of posts driven into the ground so as to form rows. The posts are spaced from each other and they are interconnected in their parts protruding from the ground by a horizontal wire, called a "load-bearing wire", which is fixed and tensioned on said posts at an appropriate height from the ground surface. Furthermore, at least one pair of wires parallel to each other and arranged on respective sides of each post of the row shall be fixed and tensioned on the two posts which are located at the ends of each row, called "head posts". These wires are commonly referred to as "containment wires" or "movable wires" given that, during the various stages of plant cultivation, they are moved to different heights from the ground to contain and organise the growing vegetation according to a desired configuration. As a matter of fact, in winter, when vine shoots are very short or are completely absent, pairs of movable wires are arranged close to the ground. In the spring and summer, when the plants produce ever more luxuriant vegetation, each pair of movable wires is placed progressively further away from the ground in the direction orthogonal to the ground, harnessing the vegetation between the wires of each pair, therefore organising the development thereof according to a desired configuration. This operation is commonly carried out to ensure an increasing exposure of the foliar surface and the fruits of the plants to the sun and wind. Furthermore, this facilitates vegetation treatment operations such as clipping, plant protection treatments and other fully conventional treatments.

In particular, the tensioning of fixed or movable wires is carried out by means of tensioning elements or wire tensioners generally represented by rollers. These rollers shall consist of a rod with a cylindrical cross-section and/or at least partly solid or hollow polygonal and provided with transversal holes for engagement with one or more ends of metal wires to be tensioned. In general, when there is a pair of parallel wires to be tensioned, there are two holes positioned at the ends of the roller. Further holes are provided to allow the engagement with locking pins so as to block the rotation of the roller in the wire unwinding direction.

These rollers have been used for a long time and are usually associated with a head post, as described for example in the patent application <CIT>, or combined with elastically compensating devices, as described in patent <CIT>. Another state of the art wire tensioning device is known from <CIT>.

Although these elements perform their function without any particular drawbacks, it has been observed that given that the two parallel wires are tensioned simultaneously by acting with a suitable tool at one end of the roller, the wires could be wound at their respective ends asymmetrically. This is due to the fact that, on the one hand, it may be difficult to set the engagement of each wire to its corresponding end of the roller in a perfectly symmetrical manner and, on the other hand, the action of the rotation tool may nevertheless tend to incline the roller with respect to its ideal transversal winding position with respect to the straight extension of the wires, even when the roller is supported by holes on a support post.

Furthermore, even were the tensioning to be carried out optimally, the two wires could easily be stressed naturally or by an operator differently or by accidental impacts with the operating equipment when running the vineyard, therefore causing an asymmetrical extension/stretching with respect to the roller. This drawback results in an even significant displacement of the two wires such to lose their parallelism and/or positioning in a single horizontal plane, therefore negatively affecting the function of containment and correct support of the vegetation during the growth of the plants along the row.

Therefore, the task of the present invention is to provide a wire tensioning element or roller that avoids the aforementioned risk of misalignment of the two wires tensioned differently.

In the context of the task outlined above, an object of the present invention is therefore to provide a wire tensioning element with a structure which allows to separately adjust the tension of the two wires.

A further object is to provide a wire tensioning element that is easy to use for adjusting the individual tension of the wires.

A further object is to provide an elastically compensating device comprising the aforementioned wire tensioning element, as well as a system for supporting rows of plants comprising the aforementioned wire tensioning element.

The task and objects outlined above are attained by a wire tensioning element, whose body comprises two rotatably connected portions. Characteristics and advantages of the invention will be apparent from the following description, provided by way of non-limiting example, with reference to the attached drawings, wherein:.

<FIG> shows a wire tensioning element <NUM>, according to the present invention, formed by two portions, first <NUM> and second <NUM>, which can be assembled together along a common rectilinear axis X-X.

The first portion <NUM> is generally cylindrical bar-shaped comprising a first end <NUM> and a second end <NUM> opposite the first.

The first end <NUM> is provided with means <NUM> for engagement with a tool (not shown) for driving the first portion in rotation around the axis X-X. Preferably, such means are a hexagonal surface which can be engaged by a corresponding hollow hexagon head tightening wrench. Alternatively, the engagement means may be a through hole which can be engaged by a rod, such as the shank of a screwdriver. Near the first end <NUM>, in the direction of the second end <NUM>, the first portion <NUM> comprises a through hole <NUM> for engagement with an end segment of a wire to be tensioned, as explained below.

The second end <NUM> is a pin which extends axially and represents a first means for engagement with a complementary second engagement means obtained on the second portion <NUM>, as described below. In particular, the pin <NUM> has a radial extension that is smaller than the rest of the first portion <NUM> so as to create a radial ring <NUM>.

Advantageously, such ring <NUM> shall be serrated and shaped so as to cooperate with a corresponding complementary serrated ring entirely obtained on the second portion <NUM>, so as to allow the rotation of each of the portions, first <NUM> and second <NUM> around the axis X-X only in one direction, clockwise or counter-clockwise, this however preventing the mutual rotation in the opposite direction, counter-clockwise or clockwise. Therefore, the two serrated rings of the respective first <NUM> and second <NUM> portions of the roller <NUM> face for an axial engagement, as explained in greater detail below. Preferably, teeth <NUM> of the ring <NUM> are radially inclined in a single direction to form a ring in which there are alternated a shoulder 25A of a tooth and a ramp 25B of an adjacent tooth. In other words, the teeth are inclined with respect to the direction orthogonal to the axis X-X. Furthermore, the number of teeth may vary depending on particular needs or preferences. Preferably, there are six of them, they have a radial extension of <NUM>° and a <NUM>°-<NUM>° degree of inclination with respect to the X-X axis.

Then, the radial surface <NUM> of the teeth <NUM> extends axially towards the first end <NUM> with a polygonal shape, preferably hexagonal, followed by an annular seat <NUM> for engagement with a portion of an elastically compensating device, as explained below, or with the edge of a hole of a post (not shown) for supporting a row of plants. This seat enables the roller <NUM> of the invention to be rotatably supported on said elastically compensating device or on said support post, when provided for.

The second portion <NUM> of the roller <NUM>, as shown in <FIG>, has a shape generally identical to that of the first portion <NUM>, with a first end <NUM> and a second end <NUM>.

The first end <NUM> is provided with means <NUM> for engagement with a tool (not shown) for driving the second portion in rotation around the axis X-X. Preferably, such means are a hexagonal surface which can be engaged by a corresponding hollow hexagon head tightening wrench. Alternatively, the means may be a through hole which can be engaged by a rod, such as the shank of a screwdriver. Near the first end <NUM>, in the direction of the second end <NUM>, the second portion <NUM> comprises a through hole <NUM> for engagement with an end segment of a wire to be tensioned, as explained below.

The second end <NUM> comprises a cylindrical cavity <NUM> which is axially open and with a closed bottom which extends axially and represents a second means for engagement with the aforementioned first complementary engagement means represented by the pin <NUM> of the second end of the first portion <NUM>. In particular, cavity <NUM> has a serrated annular radial edge <NUM> which surrounds the opening of the cavity. The teeth <NUM> of the annular edge are arranged in a mirror-like fashion with respect to the teeth <NUM> of the annular radial ring <NUM> of the first portion <NUM>. Therefore, also these teeth <NUM>, preferably are radially inclined in a single direction to form a ring in which there are alternated a shoulder 36A of a tooth and a ramp 36B of an adjacent tooth. In other words, the teeth are inclined with respect to the direction orthogonal to the axis X-X. Furthermore, the number of teeth may vary depending on particular needs or preferences. Preferably, there are six of them, they have a radial extension of <NUM>° and a <NUM>°-<NUM>° degree of inclination with respect to the X-X axis.

Then, the radial surface <NUM> of the teeth <NUM> extends axially towards the first end <NUM> with a polygonal shape, preferably hexagonal, followed by an annular seat <NUM> for engagement with the edge of a hole of a post (not shown) for supporting a row of plants. Said seat allows the roller <NUM> of the invention to be rotatably supported by a support post, when provided for, also at its second portion <NUM> for greater stability.

As shown in <FIG>, when the first <NUM> and second <NUM> portions are assembled together to form the roller <NUM>, the outer surfaces <NUM>, <NUM> respectively of teeth <NUM> of the first portion <NUM> and the teeth <NUM> of the second portion <NUM> respectively are co-planar. As a matter of fact, the two portions are assembled by inserting the pin <NUM> of the first portion into cavity <NUM> of the second portion so that the annular step <NUM> and the radial edge <NUM> come into contact with the ramps and shoulders of the respective teeth in complementary contact.

In particular, it should be observed that with the aforementioned contact there is formed a zig-zag broken line <NUM> along the circumference of contact between said first <NUM> and second <NUM> portions. This line shows long sections <NUM> inclined with respect to the axis Y-Y orthogonal to the longitudinal axis X-X of the roller, interspaced by short sections <NUM> parallel to said longitudinal axis, the former corresponding to the inclined ramps of the teeth and the second at the shoulders. In this manner, it is clear that the gear-like engagement allows the mutual rotation of the two first <NUM> and second <NUM> portions only in one direction, but it is prevented on the other direction, as explained in detail below.

According to a second object of the invention, <FIG> shows an elastically compensating device <NUM> or damper comprising the tensioning element <NUM> described above.

The elastically compensating device <NUM> is substantially a device like the one described for example in patent <CIT> and it comprises an elastic element <NUM> which extends along a rectilinear axis Z-Z between a first <NUM> and a second <NUM> hook-like element.

The elastic element <NUM> is preferably a compressible spring between said first <NUM> and second <NUM> hook-like elements, which extends between a first <NUM> and a second <NUM> end.

The first hook-like element <NUM> comprises a first end <NUM> for fixing to a post (not shown) of a row head, a second end <NUM> for retaining the second end <NUM> of the elastic element <NUM> and a straight section <NUM> which connects said ends and it is such to be inserted into the internal space defined by said elastic element. In particular, said first hook-like element is formed by a metal wire folded to form a U shape in which the first end <NUM> protrudes from the first end <NUM> of the elastic element <NUM>, it is closed and variously shaped to be connected directly around said post or indirectly using a collar or further connection means such as for example a chain, or using a screw transversal to the post. The second end <NUM> of said first hook-like element comprises two portions of wire <NUM> which are folded divergently so as to create two hooks for engagement with at least one turn of said second end <NUM> of the elastic element.

The second hook-like element <NUM> comprises a first end <NUM> for supporting the wire tensioning element <NUM> of the invention, a second end <NUM> for retaining the first end <NUM> of the elastic element <NUM> and a straight section <NUM> between said first and second end adapted to be inserted into the internal space defined by said elastic element. In particular, said second hook-like element is formed by a metal wire folded to form a U shape in which the first end <NUM> forms two parallel foldings <NUM> each for engagement with an annular seat <NUM>, <NUM> respectively of the first <NUM> and second <NUM> portion of the wire tensioning element <NUM>. The second end <NUM> comprises two portions <NUM> (only one visible in <FIG>) of a wire folded divergently so as to create two hooks for engagement with at least one turn of said first end <NUM> of the elastic element <NUM>.

With reference to the <FIG>, now, described below is the operation of the wire tensioning element <NUM> of the present invention.

First and foremost, the wire tensioning element <NUM> is fitted, for example, to the first end <NUM> for supporting the second hook-like element <NUM> of an elastically compensating device <NUM> so that the parallel foldings <NUM> each engage a seat <NUM>, <NUM> respectively of the first portion <NUM> and of the second portion <NUM> of the wire tensioning element (<FIG>).

Then, as shown in the detail of <FIG>, a metal wire (and not only, for example also plastic) W is inserted into each through hole <NUM>, <NUM> respectively of the first <NUM> and second <NUM> portion.

At this point, one of the two portions of the wire tensioning element <NUM>, for example the second <NUM> as shown in <FIG>, is driven in rotation by engaging with an appropriate tool (not shown) which acts on the first end <NUM> thereof. The engagement described above allows to wind the wire W on the second portion, leaving the first portion <NUM> still, preferably held still using a further tool which engages the first end <NUM> thereof, for greater safety, bringing the wire to the desired tension.

Upon reaching the desired tension of the wire W on the second portion <NUM>, the first end <NUM> of the first portion <NUM> can be adjusted to wind and therefore tension another wire W thereon (<FIG>). Obviously, in this case, thanks to the aforementioned gear-like engagement, the rotation occurs is in the opposite direction with respect to the rotation direction of the second portion <NUM>.

It should be borne in mind that during the second rotation of the first portion, a tool (not shown) must be kept engaged on the first end <NUM> of the second portion <NUM> so as to counteract the driving force which may however also involve the second portion in the unwinding direction, specifically due to the fact that the two first and second portions are in close contact.

Advantageously, as shown in <FIG> and <FIG>, the wire tensioning element <NUM> of the invention is mounted on the aforementioned elastically compensating device <NUM> so that, during the tensioning of the wires (<FIG> and <FIG>), the elastic element <NUM> is partially compressed. However, this completely conventional operation can be carried out separately for the two wires so as to adjust not only the tension individually but also as a result any asymmetries which can easily appear between the two wires W. In other words, the wire tensioning element <NUM> may be arranged inclined with respect to the longitudinal extension of the wires W, both on the vertical and horizontal plane. As a result, also the elastic element <NUM> of the elastically compensating device <NUM> could easily twist with greater shortening of the turns on one side with respect to the other and, therefore, negatively affect its correct functionality.

The possibility to adjust the tension of the two wires W separately, allows to prevent this event from occurring.

Furthermore, the wire tensioning element <NUM> can be mounted, for example, directly on a support post thanks to the engagement between the edges of two holes on opposite walls and the two circular seats <NUM> and <NUM> respectively of the first <NUM> and second <NUM> portion.

According to a further object of the invention, <FIG> schematically shows a system <NUM> for supporting the vegetation of a fruit-bearing plants-row, preferably for a vineyard, comprising two head posts P fixed into the ground with suitable fixing means F known in the industry, such as tensioners and the respective anchors. Driven into the ground between said head posts are intermediate posts I arranged in line and evenly spaced apart from each other so as to form a row. A plurality of wires are fixed to the head posts P and they are generally divided into fixed wires W1 and movable wires W2. Both the fixed and movable wires can be tensioned using the tensioning element <NUM> of the present invention. As described above, the movable wires are fixed to the head posts using elastically compensating elements <NUM>.

In the light of the above, it is clear that the drawbacks noted above have been overcome while major advantages have been achieved.

As a matter of fact, the tensioning element of the invention allows to adjust - in a differentiated manner - the tension of the wires so as to compensate especially the extension changes that the two wires are easily subjected to when handled from the two opposite sides of the row when handling the vegetation.

The differentiated adjustment avoids or readily corrects the inclinations of the tensioning element from the optimal transverse position with respect to the rectilinear direction of the wires. As a result, also the elastically compensating element is kept straight so that it works in the best conditions.

Furthermore, a further advantage of the wire tensioning element of the invention lies in the fact that the assembly thereof is significantly simplified, given that a single operator can do so without involving a second operator, as is currently the case with conventional wire tensioners and without using fasteners.

Numerous variants to the wire tensioning element <NUM> of the invention can be adopted by the person skilled in the art, without departing from the scope of protection defined by the attached claims.

Claim 1:
Agricultural wire-tensioning element (<NUM>) comprising a first portion (<NUM>) assembled to a second portion (<NUM>) along a common rectilinear axis (X-X) in order to allow the mutual rotation around said axis, wherein said agricultural wire-tensioning element is characterized by the fact, that said rotation being constrained in a single direction for each portion by means of an engagement between a toothed radial ring (<NUM>) of said first portion and a mirror-like toothed radial ring (<NUM>) of said second portion, whose respective teeth (<NUM>;<NUM>) are radially inclined with respect to said axis (X-X) according to a single direction so as to form a shape coupling between the teeth of the first (<NUM>) and of the second (<NUM>) portion.