Patent Description:
More particularly, the present invention concerns perfected selector rollers, as well as selector machines that use said rollers.

The rollers of the present invention can be both keyed onto a shaft equipped with motion and, therefore, also individually replaceable, and also obtained integrally with the shaft itself.

The rollers are installed staggered on parallel shafts to constitute a non-linear path.

By chipboard panels we mean those panels, consisting of wood shavings, bonded by suitable glues, and normally hot pressed.

Such panels can be characterized by a single-layer structure, by a multi-layer structure, or by a structure defined as "with continuous variable grain size", or other type.

To obtain the panels, by industrial methods, the shavings are generically obtained from a heterogeneous mass of chips which are selected in various fractions, each of which is treated (clean, refined, etc.) to obtain suitable quality shavings.

A fundamental element that determines the quality of the panels is the "workability" of the panel itself, and this parameter is related to the duration of the cutting tools and abrasive belts used.

The systems for removing contaminants from the chips of recycled wood are complex and normally provide, at the beginning of the cleaning cycle, roller-type screens to divide the incoherent mass into various homogeneous fractions.

Each of the fractions is then advantageously cleaned with suitable specialized systems to treat the specific grain sizes of each fraction.

In the case of thin or fine chips or of particular wood, the current technology is not able to obtain an optimal average result.

It is also true that when thin or fine chips or particular wood are present in the mass to be selected, they are not selected in an optimal manner.

Current technology is not even able to adequately select, with a single type of roller, materials such as thin wood chips, humus, earth and/or inert materials in general.

Selector rollers of a known type are disclosed in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

<CIT> discloses a selector roller provided with a circumferential protrusion, wherein the circumferential protrusion is provided with an apical annular surface, wherein on opposite sides of the circumferential protrusion there are indentations protruding with respect to said opposite sides.

Non-optimal results affect the quality and qualification of the final product.

In fact, the quality of a panel is not only defined by the presence of impurities but also by the quality of the chips used.

To solve these and other problems that affect the quality and workability of the panels, Applicant has carried out studies and research on a large number of profiles of the selector rollers and their customizations.

From this long and complex and very expensive research work, Applicant has identified a selector roller as shown below.

This roller not only allows an excellent selection of the usual chips, but this result is also obtained with thin chips and/or wood material or not and/or with materials such as humus, earth or inert materials in general.

Applicant has studied a roller suitable to solve the problems caused by thin or inconsistent chips, provided that specific previously unknown dimensional ranges are adapted.

This definition also allowed the roller, improved and modified as indicated below, to solve the problem of chip selection very well, with the wide range of problems that they have.

It is therefore a purpose of the present invention to obtain selector rollers which improve and complete the selector function.

Another purpose of the present invention is to improve the powerful selection capacity of any selector machine with rollers positioned on adjacent axes and facing each other, either separated or not, of the type identified above, as well as similar and comparable rollers.

Another purpose of the present invention is to provide rollers that allow to optimize the selection process in terms of time, cost and energy.

These purposes are achieved by means of the selector roller in accordance with claim <NUM>.

In accordance with the above purposes, according to the invention a roller to select chips of wood material or suchlike, humus, soil, inert materials or comparable materials, has two annular lateral shoulders and a circumferential protrusion contiguous to the lateral shoulders.

According to the invention, the circumferential protrusion has a trapezoidal cross-section defined by a smaller side, a larger side, parallel and opposite to the smaller side, and two opposite sides joining together the smaller side and the larger side.

In preferred embodiments, the trapezoidal cross-section can be an isosceles, or scalene, or again rectangular trapezoid with one of either the opposite sides substantially orthogonal to the larger and smaller sides.

The Applicant has found that particular shapes of the trapezoid adapt to different types of material. Hereafter in the description, we will refer to "chips" as comprising different types of loose materials such as humus, soil, inert materials or thin chips of wood and non-wood material and other similar and comparable materials. In this way, the roller allows an excellent selection not only of the usual materials but also, and above all, of the thin chips of wood or non-wood material and of other types of materials as listed above, guaranteeing optimal results for the final product in terms of quality and optimizing the selection process in terms of time, cost and energy.

Based on the diameter of the lateral shoulder, that is, of the circumferential base of the roller from which the circumferential protrusion starts, the Applicant has identified precise reference measures to increase the capacity to select the chips and, therefore, the quality of the material selected for the final product.

According to the invention, preferably the height of the trapezoidal section, that is, the distance between the larger side and the smaller side, is between <NUM> and <NUM> times the diameter of the lateral shoulder. Advantageously but not restrictively between <NUM> and <NUM>.

The invention also provides that preferably the larger side of the trapezoidal section ranges from <NUM> to <NUM> times the diameter as above, advantageously between <NUM> and <NUM>.

The smaller side of the trapezoidal section ranges from <NUM> to <NUM> times the diameter as above, advantageously between <NUM> and <NUM>.

The values above vary proportionally as the real diameter of the lateral shoulder varies according to the relations above.

For example, if the diameter of the lateral shoulder is <NUM>, that is, <NUM> meter, the height of the trapezoidal section is comprised between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

These values, however, can vary further since they depend on the type of material worked, and on the quantity and quality of the heavy contaminants present.

According to the invention, the circumferential protrusion is provided with an apical circumferential surface on which substantially symmetrical teeth are disposed.

Such teeth promote a rapid selection of the wood material by arranging the latter into the position suitable to pass this selection step.

According to a variant suitable for particular types of flakes/wood, not forming part of the present invention, the teeth do not have a symmetrical shape.

According to one variant, the dissymmetry can be in phase analogy or in phase contrast with the rotation according to the type and sizes of the material to select.

The symmetrical teeth are disposed sequentially in a regular manner along the circumferential protrusion.

According to another variant, the symmetrical teeth are disposed sequentially, alternating with non-symmetrical teeth along the circumferential protrusion.

The variants above are actuated according to specific types of materials to be selected and/or of specific impurities to be eliminated.

According to one variant, the opposite side or sides have indentations that can occupy the whole side, or reach the base of the indentations, or affect one part of the side free of the teeth, until possibly reaching the apical circumferential surface. This being dependent on the physical and/or morphological characteristics of the chips.

Such indentations cooperate with the teeth as above during the rotation of the selector rollers to obtain a more powerful and rapid selection of the material to be selected, optimizing the selection process in terms of time and energy and, therefore, cost.

According to the invention, a machine to select chips of wood material or suchlike, humus, soil, inert materials or comparable materials comprises at least two parallel shafts. Each shaft comprises one or more rollers, as described above, disposed interspersed and cooperating with rollers present on the opposite parallel shaft.

Furthermore, the rollers as above have respective circumferential protrusions and lateral shoulders disposed in such a way that the circumferential protrusions of one shaft are facing in correspondence with the shoulders of the other adjacent shaft and vice versa.

In this way, circumferential protrusions and lateral shoulders of opposite rollers cooperate with each other to define a passage gap for material of desired sizes, increasing the selection capacity of the selector machine and consequently its efficiency. In particular, such desired sizes are coherent with the sizes of the gap.

Hereafter in the description, we will describe by way of example the case of single rollers keyed onto a drive shaft. In accordance with the disclosure it is provided to produce the individual rollers in the drive shaft and integrally therewith.

Not in accordance with the invention, elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

Embodiments of the present invention are described here with reference to figs. from <NUM> to <NUM> attached and concern selector rollers <NUM>, hereafter also referred to as "rollers", suitable to select shavings and flakes of fibrous material, advantageously wood, but not only, but also of humus, soil and other comparable materials in order to divide them on the basis of sizes and granulometries. Hereafter in the description, as mentioned above, the term "chips" encompasses all the possible variants mentioned of materials to be selected.

Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants insofar as these are within the scope of the invention which is delimited by the appended claims.

The rollers <NUM> have an annular shape, which develops around a central axis X, defining the axis of rotation.

As shown by way of example in <FIG>, the rollers <NUM> are suitable to be keyed onto a shaft <NUM>, for example a drive shaft.

In accordance with the disclosure, the rollers can be obtained in a single body with the shaft <NUM>.

By way of a non-limiting example, the rollers <NUM> can be obtained by knurling on a shaft <NUM> that is axially symmetric to the central axis X.

In particular, <FIG> shows two facing shafts <NUM>, <NUM>' which carry a plurality of selector rollers <NUM>.

The selector rollers <NUM> are disposed aligned side by side coaxially along each shaft <NUM>, <NUM>' defining a selector profile.

In a selector machine, there are supplied parallel arrays of rollers <NUM> which are associated with respective shafts <NUM>, <NUM>', the series of rollers <NUM> present on one shaft <NUM> cooperating with a series of rollers <NUM> present on another shaft <NUM>' parallel to the first.

As a function of the shape of the rollers <NUM> on one shaft <NUM>, these may or may not be interspersed with rollers <NUM> present on the parallel shaft <NUM>'.

According to one variant, the shafts <NUM>, <NUM>' can be provided, for example alternatively, lying on parallel planes.

Such variant is suitable to exert a greater action of selection or transport of the material located on the rollers <NUM>.

Between the selector rollers <NUM>, disposed interspersed on two facing shafts <NUM>, <NUM>', a passage gap <NUM> is left which is suitable to select the material to be screened, for example thin chips, with an elongated or small size.

The plurality of selector rollers <NUM> side by side on one shaft <NUM> defines a selector profile mating with the selector profile defined by another plurality of selector rollers <NUM> side by side on the adjacent shaft <NUM>', said profiles being distanced by a distance equal to the passage gap <NUM>.

The passage gap <NUM> is advantageously, but not necessarily, uniform in accordance with the size and type of the material to be screened.

In fact, only the particles and shavings that have a thickness smaller than the gap can pass through the passage gap <NUM>.

According to one example embodiment, the rollers <NUM> according to the invention have a truncated cone annular conformation defined by a circumferential protrusion <NUM> that has a trapezoidal diametrical section <NUM> (<FIG>).

By diametrical section we mean the section along a plane transverse and parallel to the oblong development of the shaft <NUM> and containing the axis X.

In <FIG>, possible variants of the trapezoidal section <NUM> of a roller <NUM> keyed onto a shaft <NUM> are shown by way of example.

In accordance with the disclosure, these variants of the trapezoidal section <NUM> are also applicable to rollers <NUM> made in a single body with the shaft <NUM>.

In particular, <FIG> shows side by side, for illustrative and descriptive clarity and by way of example only, two possible alternative variants of a roller <NUM> with a trapezoidal section <NUM> in which one variant provides the roller <NUM> keyed onto a shaft <NUM> (indicated as A in <FIG>) and the other variant provides the roller <NUM> made in a single body with the shaft <NUM> (indicated as B in <FIG>). It is not excluded that these variants can also be made with rollers <NUM> with trapezoidal sections <NUM> such as those shown in <FIG>.

The trapezoidal section <NUM> is defined by a smaller side <NUM>, a larger side <NUM>, parallel and opposite the smaller side <NUM>, and two opposite sides <NUM> joining together the smaller side <NUM> and the larger side <NUM>.

The size of the smaller side <NUM> is smaller than the larger side <NUM>.

The opposite sides <NUM> can be oblong, equal, differentiated, or at least one orthogonal to the smaller <NUM> and larger <NUM> sides.

The trapezoidal section <NUM> can be an isosceles (<FIG>), rectangle (<FIG>) or scalene (<FIG>) trapezoid.

The circumferential protrusion <NUM> is provided with an apical annular surface <NUM> defined by the circumferential succession of the smaller sides <NUM>.

The rollers <NUM> can have, or not have, circumferential selector throats on the sides of the circumferential protrusion <NUM> and/or at the base of the latter.

With reference to <FIG>, the roller <NUM> also has in the axial endings of two lateral shoulders <NUM> suitable to cooperate, during use, with respective lateral shoulders <NUM> of side by side rollers <NUM> keyed onto the same shaft <NUM>. Such lateral shoulders <NUM> are disposed laterally and contiguously to the circumferential protrusion <NUM> and can be made in a single body with the latter so as to guarantee a longer useful life for the roller <NUM>.

According to some embodiments, the circumferential protrusion <NUM> can be knurled, or obtained by means of a machine tool for knurling starting from the shaft <NUM>.

According to one embodiment, the lateral shoulders <NUM> can be made in a single body with the shaft <NUM>.

Such lateral shoulders <NUM> are cylindrical. The facing lateral shoulders <NUM>, in accordance with the type of heavy contaminants to be eliminated, can be flat cylindrical, conical, or determine a throat connected to the base of the circumferential protrusion <NUM>.

The larger side <NUM> of the trapezoidal section <NUM> is in line with the upper surface of the lateral shoulders <NUM>.

According to one embodiment, the height of the trapezoidal section <NUM>, that is, the distance between the smaller side <NUM> and the larger side <NUM>, will be coherent with obtaining an equal or differentiated continuous passage gap <NUM> between the smaller side <NUM>, the lateral shoulder <NUM> and the opposite sides <NUM> in accordance with the type of selection to be obtained.

When two rollers <NUM> are side by side, the lateral shoulders <NUM> of two rollers <NUM> of one shaft <NUM> create a circumferential ring <NUM> which cooperates with the apical annular surface <NUM> of the circumferential protrusion <NUM> of the opposite and offset roller <NUM> (<FIG>) present in the adjacent shaft <NUM>'.

This conformation allows to obtain on the plane that contains all the axes X, X' of the shafts <NUM>, <NUM>' a slit or passage gap <NUM> with a zigzag shape that has desired characteristics.

According to some embodiments, the lateral shoulders <NUM> can also be variously shaped and possibly provide ridges or hollows to facilitate the discharge of impurities or heavy contaminants.

According to some embodiments, the perimeter conformation of the apical annular surface <NUM> is determined by the drawing action that has to be exerted on the chips, shavings and on the heavy contaminants.

The apical annular surface <NUM> advantageously has teeth <NUM>, uniform and balanced with respect to the radius, configured to actuate the desired selection of the chips, facilitating the advancing and drawing action thereof between facing rollers <NUM> alternated on contiguous shafts <NUM>, <NUM>'. Such action is further facilitated by the trapezoidal section <NUM> which allows to accompany the material to be screened in the desired direction and in the correct position.

The teeth <NUM> are provided with two bases <NUM> made inside the circumferential protrusion <NUM>, with an apical portion coinciding with a portion of the apical annular surface <NUM> and comprised between the two bases <NUM>, and with two sides <NUM> joining the apical portion respectively with the two bases <NUM>.

The teeth <NUM> are trapezoidal in accordance with the sizes and types of material to be screened.

With reference to <FIG>, on the opposite sides <NUM> of the trapezoidal section <NUM> of the circumferential protrusion <NUM> there are indentations <NUM> protruding with respect to the opposite sides <NUM> which are suitable to facilitate the drawing of the chips toward the passage gap <NUM>.

The indentations <NUM> have an oblong shape substantially parallel to the opposite sides <NUM> suitable to dispose the chips with an elongated shape parallel to the opposite sides <NUM>. Such indentations facilitate the advancing and drawing action between successive rollers <NUM> on a same shaft <NUM>, and between interspersed facing rollers present on two contiguous shafts <NUM>, <NUM>'.

In this way, the chips are accompanied and disposed in the correct position for entry into the passage gap <NUM>, reducing the time needed to screen the material to be selected.

Such indentations <NUM> can affect the whole opposite side <NUM> or only part of it.

According to some embodiments, the indentations 19a (<FIG>) can extend from the larger side <NUM> up to the base <NUM> of the teeth <NUM>, that is, they can be of a length comprised between the larger side <NUM> and the base <NUM> of the teeth <NUM>.

According to some embodiments, the indentations 19b (<FIG>) can extend from the larger side <NUM> up to the smaller side <NUM> of the trapezoidal section <NUM>.

According to some embodiments, the indentations 19c (<FIG>) can extend from the larger side <NUM>, and partly on the lateral shoulder <NUM>, up to the smaller side <NUM> of the trapezoidal section <NUM>.

According to some embodiments, the indentations 19c (<FIG>) can extend from the larger side <NUM> up to the smaller side <NUM> of the trapezoidal section <NUM> and affect the entire width of the teeth <NUM>, that is, extend from side <NUM> to side <NUM> of the teeth <NUM>.

According to some embodiments, the indentations <NUM> can extend from at least one side <NUM> of the teeth <NUM> up to the smaller side <NUM> of the trapezoidal section <NUM>, or up to the lateral shoulder <NUM>.

According to some embodiments, the indentations <NUM> can be inclined in the sense of rotation of the roller <NUM> or in the sense opposite this rotation.

According to some embodiments, the indentations <NUM> can have a rectangular, or triangular, or wavy, or serrated shape along the opposite side <NUM> in accordance with the type of material to be selected and eliminated.

According to some embodiments, the indentations <NUM> on one roller <NUM> are offset, or aligned with respect to the indentations <NUM> of an adjacent roller <NUM>.

All the possible embodiments above advantageously offer a wide range of solutions for different operating cases of moving and selecting wood chip materials or suchlike that have different conformations and different intended use, and are able to increase the selection capacity of each roller <NUM> and, in general, of the selector machine.

The teeth <NUM> are also made so as to dispose and accompany the chips with their larger elongated size parallel to the passage gap <NUM>.

At the same time, the indentations <NUM> and the teeth <NUM> are suitable to channel impurities, in accordance with their greater weight, respectively toward the lateral shoulders <NUM> and the bases <NUM> of the teeth <NUM> so that they can be eliminated.

It is clear that modifications and/or additions of parts may be made to the selector roller <NUM> as described heretofore, without departing from the scope of the present invention which is delimited by the appended claims.

Claim 1:
Selector roller suitable to select chips of wood material or suchlike, humus, soil, inert materials or comparable materials, provided with a circumferential protrusion (<NUM>) having a trapezoidal cross-section (<NUM>) defined by a smaller side (<NUM>), a larger side (<NUM>), parallel and opposite to the smaller side (<NUM>), and two opposite sides (<NUM>) joining together the smaller side (<NUM>) and the larger side (<NUM>) and with two cylindrical annular lateral shoulders (<NUM>) disposed laterally and contiguously to the circumferential protrusion (<NUM>), wherein the circumferential protrusion (<NUM>) is provided with an apical annular surface (<NUM>), defined by the circumferential succession of the smaller sides (<NUM>), on which symmetrical trapezoidal teeth (<NUM>) are present, uniform and balanced with respect to the radius wherein on the opposite sides (<NUM>) of the trapezoidal section (<NUM>) of the circumferential protrusion (<NUM>) there are indentations (<NUM>) protruding with respect to said opposite sides (<NUM>) and having an oblong shape substantially parallel to said opposite sides (<NUM>).