Patent Description:
They are known seeding machines of the pneumatic and/or electropneumatic type comprising a conveyor on which seeding trays filled with soil or loam are advanced, on which markers are firstly made by means of a marker roller and within each marker a seed is deposited by means of a seeding roller.

A first known type of seeding machines provides the use of a motorised belt conveyor on which the seeding trays advance. The marker roller and seeding roller are driven by respective motors that are independent of the conveyor motor and their rotation thereof is made synchronous to the conveyor motor by a suitable control system.

Such a type of machine, although high-performing, is rather complex and expensive and requires fine-tuning and continuous maintenance operations.

A second well-known type of seeding machines provides a "sleeper" conveyor, in which the conveyor consists of a fixed rest plane on which the trays, pushed at the back between sleepers, run. Such sleepers (with a fixed pitch) are driven by a motor, which by means of a suitable rigid transmission assembly also transmits the motion to the marker roller and seeding roller. The position of the sleepers is such that the rotation of the marker and seeding roller is synchronised with the advancement of the seeding tray.

Although this second type of seeding machines is simpler and more robust than the first type of seeding machines, it is not particularly suitable for use with particularly light or flexible seeding trays, which do not withstand a rear thrust.

A further known seeding machine according to the preamble of claim is disclosed in document: <CIT>.

An object of the present invention is to overcome the aforementioned drawbacks of the prior art, within the framework of a simple, rational and cost-effective solution, by creating a seeding machine that is as structurally simple as a seeding machine of the second type, with the consequent advantages of requiring less set-up and maintenance operations, and that is as versatile as the seeding machines of the first type described above.

These and other objects are reached by the characteristics of the invention as set forth in independent claim <NUM>.

The dependent claims outline preferred and/or particularly advantageous aspects of the invention.

The invention, in particular, makes available a seeding machine comprising:.

wherein the transmission assembly comprises a friction clutch configured to be selectively switched between a closed position, in which it allows the transmission of the rotary motion from the motor of the conveyor to the seeding roller, and an open position, in which it interrupts the transmission of the rotary motion from the motor of the conveyor to the seeding roller.

Thanks to this solution, the seeding roller may be driven by the same motor as the conveyor and, at the same time, may be synchronised thereto without the need for rear thrusting means physically acting on the seeding tray.

Advantageously, the machine may comprise a system for detecting a seeding tray resting on a section of the rest plane located upstream of the seeding roller along the advancement direction.

Furthermore, the machine may include an electronic control unit operatively connected to the detection system and to the friction clutch, wherein the electronic control unit is configured to:.

Advantageously, the electronic control unit may be configured to:.

Again, the electronic control unit may be configured to:.

According to one aspect of the invention, the machine may comprise an assembly for adjusting a distance between the seeding roller and the conveyor rest plane, wherein preferably the adjusting assembly is motorised.

Furthermore, the machine may also comprise a marker roller rotatably associated with the support frame, around a rotation axis parallel to the rest plane and to the rotation axis of the seeding roller, whereby the marker roller is arranged around the rest plane upstream of the seeding roller in the advancement direction. For example, the marker roller may also be associated with a further friction clutch, operating in the same way as described above for the seeding roller.

Within the context of this aspect, the machine may comprise a further transmission assembly interposed between the conveyor motor and the marker roller configured to transmit a rotary motion from the motor to the marker roller and equipped with a further friction clutch configured to selectively be switched between a closed position, in which it allows the transmission of the rotary motion from the motor of the conveyor to the marker roller, and an open position, in which it interrupts the transmission of the rotary motion from the motor of the conveyor to the marker roller.

According to a possible embodiment, the machine may comprise a plurality of seeding rollers (and/or marker rollers) with mutually parallel rotation axes arranged in succession on the rest plane along the advancement direction, wherein each seeding roller may be preferably driven selectively or simultaneously with respect to the other seeding rollers and/or is configured to seed a respective type of seeding trays or to seed in the same tray.

Further features and advantages of the invention will be more apparent after reading the following description provided by way of non-limiting example, with the aid of the accompanying drawings.

With particular reference to these figures, <NUM> globally indicates a seeding machine, in particular for seeding into seeding trays V previously filled with soil or loam.

The machine <NUM> is part of a seeding system that provides a machine filling the trays with soil/loam that is placed upstream of the machine <NUM> and from which it receives the seeding trays V filled with soil or loam.

The seeding tray V, for example, is divided into cells, each of which is filled with a respective portion of soil/loam and is intended to accommodate at least one seed (or a plurality of seeds) therein. A seeding tray, therefore, has a plurality of rows of cells, wherein the cells of each row are arranged side by side along a flanking direction and the rows of cells are parallel (adjacent) to each other and aligned along an alignment direction orthogonal to the flanking direction.

The machine <NUM> includes a conveyor <NUM>, which is configured to support at least one seeding tray V resting on a lower surface thereof opposite to the upper surface to be seeded.

The conveyor <NUM> comprises a support frame <NUM> provided with ground supports and a (single) conveyor belt <NUM> supported by the support frame <NUM>.

For example, the support frame <NUM> comprises two fork seats to be transported/moved using a fork vehicle.

The conveyor belt <NUM> is defined by a (single) flexible belt wrapped around itself in a loop around at least one drive roller <NUM> and at least one (end) driven roller <NUM>.

The drive roller <NUM> is configured to move/rotate the conveyor belt <NUM> along a closed annular path, so that an upper branch of the conveyor belt <NUM> moves in a horizontal plane along (a single forward direction of) a preset advancement direction A (while an opposite lower branch moves in a parallel horizontal plane in an opposite return direction of the same advancement direction A).

The rotation speed of the drive roller <NUM> controls the advancement speed of the seeding tray V (which rests on the rest plane defined by the conveyor belt <NUM>) along the advancement direction A, which may be set and adjusted according to processing requirements.

For example, the advancement speed is adjustable, normally within a range between <NUM> and <NUM> trays/hr (thus, considering each tray/pitch having a length, along the advancement direction A, of <NUM>, the advancement speed is between 240mt/hr - i.e. <NUM> mt/min - and <NUM> mt/hr - i.e. <NUM> mt/min - ).

The (upper branch of the) conveyor belt <NUM> defines (and coincides with) a (horizontal) rest plane B on which the seeding trays V, with their lower surface, are intended to rest (stably).

The support frame <NUM> has two side panels (parallel to the advancement direction A), whose distance from each other defines the (maximum) width of the rest plane B.

The conveyor belt <NUM> has a width that is essentially equal to (or slightly less than) the (maximum) width of the rest plane B.

The conveyor belt <NUM> is made of a synthetic material, e.g. rubber, polyvinylchloride (PVC) or polyurethane (PU).

The drive roller <NUM> is driven in rotation by an (electric) motor <NUM>, for example, equipped with a gearbox, which is preferably supported (laterally) by the support frame <NUM>.

The machine <NUM> further comprises a seeding roller indicated with reference number <NUM>, which is configured to release a predetermined amount of seeds into the seeding tray V resting and moving on the (rest plane B of the) conveyor belt <NUM>.

The seeding roller <NUM> is arranged above the (rest plane B of the) conveyor belt <NUM>, e.g. at a certain (non-zero) distance from it, so that a seeding tray V to be seeded may be fitted (with a clearance) between the seeding roller <NUM> and the (rest plane B of the) conveyor belt <NUM>.

The seeding roller <NUM> is rotatably associated with the support frame <NUM> and comprises a (horizontal) rotation axis R1 essentially orthogonal to the advancement direction A.

The seeding roller <NUM> comprises at least one insert bar <NUM> equipped with a series of suction holes aligned along an alignment direction parallel to the rotation axis R1, preferably equally spaced from each other.

Preferably, the seeding roller <NUM> comprises a plurality of said insert bars <NUM> circumferentially spaced by a predetermined circumferential distance (or pitch), for example equal to the distance between (the centre of) two adjacent and aligned and/or side-by-side cells of the seeding tray V to be seeded by said seeding roller <NUM>.

Each insert bar <NUM> is connected, in a way known in itself, to a suction circuit (at least partially inside the seeding roller <NUM>) and is configured to pick up by suction one seed at a time from a seed reservoir <NUM> arranged tangentially to the seeding roller <NUM> and to release the picked-up seed into a respective seed cell of a seeding tray V advancing on the (rest plane B of the) conveyor belt <NUM>.

For example, the seeding roller <NUM> comprises a central shaft, which defines said rotation axis R1, and an outer jacket, e.g. made of light metal (such as aluminium).

Longitudinal grooves parallel to the rotation axis R1 (spaced from each other by said circumferential distance) are made on the outer jacket, which, for example, extend along the entire length of the outer jacket along respective generatrices thereof. Within each longitudinal groove a (hollow) full-length insert bar <NUM> is fitted, the inner axial cavity of which defines a suction pipe. The outer face of each insert bar <NUM> comprises sets of suction holes, e.g. defined by calibrated (radial) holes, which are aligned along the alignment direction parallel to the rotation axis R1.

A first end of each insert bar <NUM> is closed by a (fixed) closure element and a second end of the bar communicates with a distribution flange, which is configured to selectively connect and disconnect the plurality of insert bars <NUM> from the suction circuit.

For example, the distribution flange comprises a first opening (elongated along an arc of circumference) that communicates with a suction system of the suction circuit. In addition, the suction flange comprises a second opening that communicates with an exhaust system (at atmospheric pressure or compressed air).

The seeding roller <NUM> (i.e. its axial end equipped with the second ends of the bars) is rotatably (and tightly) associated with the distribution flange around the rotation axis R1, so that each second end of the bars is selectively located at the first opening (for an arc of rotation) and at the second opening, during rotation.

In practice, when the second end of the insert bar <NUM> is at the first opening, each suction hole of said insert bar <NUM> is in fluid communication with the (suction system of) suction circuit which allows to pick up from the reservoir <NUM> and retain, during said arc of rotation, a seed for each suction hole of the insert bar <NUM>, when, by contrast, the second end of the insert bar <NUM> is at the second opening, each suction hole of said insert bar <NUM> is in fluid communication with the discharge system which allows to discharge the previously picked-up seed.

The second opening is arranged in such a way that the insert bar <NUM> that is in communication with it is arranged at the bottom, in a seed-release position, i.e. vertically aligned with the rotation axis R1 and interposed between the rest plane B and the rotation axis of R1 itself.

The first opening is by contrast arranged so that it has a first circumferential end aligned (along a direction parallel to the rotation axis R1) with the reservoir <NUM> and a second end proximal (a few centimetres away) to the second opening.

The reservoir <NUM> is, for example, defined by a hopper supported by the support frame <NUM> in a tangential and overhanging position with respect to the seeding roller <NUM>.

For example, the seeding roller <NUM> is supported by the support frame <NUM> in a height-adjustable manner.

For this purpose, the machine <NUM> comprises a first assembly <NUM> for adjusting the distance between the seeding roller <NUM> and the rest plane B.

The first adjustment assembly comprises a support sub-frame <NUM> rigidly attached to the support frame <NUM> of the conveyor <NUM>.

The support sub-frame <NUM> comprises a vertical guide <NUM>, which is for example defined by two columns rising from the support sub-frame <NUM>.

In addition, the first adjustment assembly <NUM> comprises a movable sub-frame <NUM>, which is slidably associated with the vertical guide <NUM>, along an adjustment direction orthogonal to the support plane B, i.e. vertical.

The movable sub-frame <NUM> comprises, for example, a pair of cylindrical (through-hole) seats adapted to be fitted onto the columns defining the vertical guide <NUM>, so as to define a prismatic connection with them.

The movable sub-frame <NUM> comprises a rolling seat within which an axial end (of the central shaft) of the seeding roller <NUM> is accommodated in rotation, e.g. by interposing a special bearing.

Preferably, the axial end (of the central shaft) of the seeding roller <NUM> axially protrudes from the movable sub-frame <NUM>.

The movable sub-frame <NUM> is driven to axially slide along the vertical guide by an actuator.

In a simplified embodiment, the actuator is of the manual type, such as a hand crank.

In a preferred and advantageous embodiment shown in the figures, the actuator is motor-driven.

Specifically, the actuator comprises an electric motor <NUM> attached to the support sub-frame <NUM> to whose drive shaft a worm screw <NUM> is associated which rises from the support sub-frame <NUM> and screwed into a lead screw made in the movable sub-frame <NUM>.

A rotation of the worm screw <NUM> corresponds to a vertical sliding of the movable sub-frame <NUM> along the adjustment direction and, with it, of the seeding roller <NUM>.

The reservoir <NUM> is supported by the movable sub-frame <NUM>, e.g. with the possibility to slide (swing) along a sliding direction parallel to the rotation axis R1 of the seeding roller <NUM>.

For example, the reservoir <NUM> is connected to a transmission cable, e.g. of the Bowden cable type (equipped with spring return means), which switches, by means of a special crank rotatably associated with the movable sub-frame <NUM>, a rotation imposed (directly or indirectly) by the motor <NUM> of the conveyor, into an alternating sliding motion of the reservoir <NUM>, which is for keeping the seeds in movement inside therein.

The seeding roller <NUM> may also have a release doctor blade (attached to the movable sub-frame <NUM>) that is designed to slightly touch the insert bar <NUM> to ease the release of the seeds in the release position.

The seeding roller <NUM> is configured to be driven in rotation around its rotation axis R1, for example, at a predetermined and constant rotation speed.

In particular, the seeding roller <NUM> is driven in rotation by the motor <NUM> of the conveyor <NUM>.

For this purpose, the machine <NUM> comprises a transmission assembly <NUM> interposed between the motor <NUM> of the conveyor and the seeding roller <NUM> configured to transmit a rotary motion from the motor <NUM> to the seeding roller <NUM>.

For example, the transmission assembly <NUM> is a flexible member, i.e. a chain (or belt).

In particular, the transmission assembly <NUM> comprises a drive gear <NUM> (or drive pulley), which is rigidly connected to the drive shaft of the motor <NUM>, e.g. it is rigidly connected to the drive roller <NUM> of the conveyor.

Preferably, the drive gear <NUM> is keyed to a shaft parallel to the drive roller <NUM> and made integral in rotation with it by a pair of meshing toothed wheels.

In addition, the transmission assembly <NUM> comprises a driven gear <NUM> (or driven pulley), which is connected to (the central shaft of) the seeding roller <NUM>, for example at the axial end (of the central shaft) of the seeding roller <NUM> which protrudes axially from the movable sub-frame <NUM>.

The transmission assembly <NUM>, moreover, comprises at least one flexible member <NUM>, for example a chain or belt, configured to transmit the rotary motion from the drive gear <NUM> to the driven gear <NUM>.

For example, the transmission assembly <NUM> comprises an intermediate gear <NUM>, which is rotatably coupled to the support sub-frame <NUM> around a rotation axis parallel to the rotation axis R1 of the seeding roller <NUM>.

In one possible configuration, the flexible member <NUM> is wound around the drive gear <NUM>, driven gear <NUM> and intermediate gear <NUM>.

In an alternative and advantageous embodiment shown in the figures, the transmission assembly comprises two flexible members <NUM>, one of which is wound around the drive gear <NUM> and the intermediate gear <NUM> and the other one wound around a further intermediate gear <NUM> (parallel, concentric and integral with said intermediate gear <NUM>) and the driven gear <NUM>.

For example, the transmission assembly <NUM> has a transmission ratio of <NUM>:<NUM>.

The transmission assembly <NUM> also comprises one or more belt tensioners adapted to compensate for the pull of the flexible element <NUM> depending on the distance set between the seeding roller <NUM> and the rest plane B.

For the purposes of the present invention, the transmission assembly <NUM> comprises a friction clutch <NUM> configured to selectively be switched between a closed position, wherein it allows transmission of rotary motion from the motor <NUM> of the conveyor <NUM> to the seeding roller <NUM>, and an open position, wherein it interrupts the transmission of the rotary motion from the motor <NUM> of the conveyor <NUM> to the seeding roller <NUM>.

In particular, the friction clutch <NUM> is configured to (temporarily) couple and decouple at least one of the drive roller <NUM> or motor <NUM> from the seeding roller <NUM>.

In the example shown, the friction clutch <NUM> is interposed between the seeding roller <NUM> and the driven gear <NUM>.

For example, the friction clutch <NUM> comprises a first body <NUM> rigidly connected to (the central shaft of) the seeding roller <NUM>, for example keyed to the central shaft of the seeding roller itself, and a second body <NUM> rigidly connected to the driven gear <NUM>, wherein the driven gear <NUM> is for example keyed to such second body <NUM>.

The first body <NUM> and the second body <NUM> are selectively mutually coupled and decoupled, so that it is possible to selectively switch between the closed position, in which the first body <NUM> and the second body <NUM> are made integral with each other in rotation (by friction), and the open position, in which the first body <NUM> and the second body <NUM> are disengaged from each other (and a mutual rotation with respect to the rotation axis R1 of the seeding roller <NUM> is allowed).

When the friction clutch <NUM> is in the closed position, the rotary motion imparted by the motor <NUM> of the conveyor <NUM> is transmitted (integrally) to the seeding roller <NUM> via the transmission assembly <NUM>.

When the friction clutch <NUM> is in the open position, the seeding roller <NUM> is decoupled from the motor <NUM> of the conveyor <NUM> and, therefore, remains stationary, e.g. it stops/is instantly braked by appropriately calibrated frictions on the central shaft thereof and/or by a braking assembly (while the flexible member <NUM> and the driven gear <NUM> continue to rotate with the drive gear <NUM> and the motor <NUM> of the conveyor <NUM>).

For example, the friction clutch <NUM> is of the pneumatic and/or electropneumatic type.

For example, the friction clutch <NUM> is fluidically connected to a compressed air pumping system (e.g. a compressor) via a solenoid valve.

If the solenoid valve is in an open/activated position, the pumping system is configured to hold/bring the friction clutch <NUM> to the closed position, if the solenoid valve is in a closed/deactivated position, the pumping system is disconnected from the friction clutch <NUM> and it moves to the open position.

It is not excluded, however, that the friction clutch <NUM> may be arranged in a different location on the transmission assembly <NUM>.

The machine <NUM> further comprises a detection device configured to detect a position assumed by the seeding roller <NUM>.

The detection device comprises, for example, a proximity sensor S1 associated, e.g. in an integral manner, with the support sub-frame <NUM> configured to detect a detection member D1 associated integrally (in an eccentric manner) with (the central shaft of) the seeding roller <NUM> (e.g. at the free end thereof protruding from the first body <NUM> of the friction clutch).

The proximity sensor S1 is configured to detect the passage of the detection device D1 when the seeding roller <NUM> is placed in a (single) predetermined angular position, preferably end-of-stroke/stop position, and generate an (electrical) signal representative of such angular position.

When the seeding roller <NUM> is in the angular end-of-stroke/stop position, no insert bar <NUM> is in the seed release position.

In addition, the machine <NUM> comprises a system for detecting a seeding tray V resting on a section of the rest plane B located upstream of the seeding roller <NUM> along the advancement direction A.

For example, the detection system is configured to detect the front end (in the advancement direction along the rest plane B) of the seeding tray V at a predetermined axial position of the rest plane along the advancement direction A.

For example, the detection system comprises an optical assembly, which has, for example, a photocell S2 and a respective reference body (aligned to the photocell along a direction horizontal and orthogonal to the advancement direction).

When the front end of the seeding tray V encounters the light beam emitted by the photocell S2, it interrupts it, and the detection system is configured to generate an (electrical) signal indicative of a predetermined axial position of the seeding tray V on the rest plane B.

For example, the optical assembly is associated with the support frame <NUM> of the conveyor <NUM>, preferably in an adjustable (i.e. sliding) manner along the advancement direction A.

The machine <NUM> comprises an electronic control unit <NUM> configured to control the operation of the machine <NUM> in an automatic and/or semi-automatic manner.

The electronic control unit <NUM> comprises a processor and a memory unit.

In addition, the electronic control unit <NUM> includes a user interface (equipped with a screen and/or buttons, if any) for receiving information from an operator and/or issuing signals or information that may be perceived by the operator.

The electronic control unit <NUM> is operatively connected to the detection system in order to receive the signal emitted by it.

The electronic control unit <NUM> is also operatively connected to the detection device so as to receive the signal emitted by it.

The electronic control unit <NUM> may be operatively connected to the motor <NUM> of the conveyor <NUM>, e.g. so as to control start and stop thereof.

The electronic control unit <NUM> may also be operatively connected to the electric motor <NUM> to control start and stop thereof, and thus to adjust the distance of the seeding roller <NUM> from the rest plane B.

For example, the electronic control unit <NUM> is configured to receive (e.g. via the user interface) information regarding the type/height of the seeding tray V or detect (via a special sensor) the height of the seeding tray V and control the electric motor <NUM> (e.g. equipped with an encoder) so that the seeding roller <NUM> is placed at a predetermined distance H from the rest plane B, for example where H is equal to H1 + k, where H1 is the height of the seeding tray and k is a calibrated seeding height (greater than or equal to <NUM>).

In addition, the electronic control unit <NUM> is operatively connected to the friction clutch <NUM> of the transmission assembly <NUM> (i.e. to the solenoid valve connected thereto) to control its switching, alternately, between the closed position and the open position.

In a simplified embodiment of the invention, the machine <NUM> could have a single seeding roller <NUM>.

In this embodiment, the system could provide, upstream of the machine <NUM> (i.e. of the conveyor <NUM>), a piece of equipment (independent of the machine <NUM>) configured to make seeding markers in the soil/loam that fills the seeding trays V.

For example, such equipment could provide a marker pad (with alternating vertical motion), configured to make seeding markers in the soil/loam that fills each cell of a seeding tray V (during a stationary step of the latter).

Alternatively, in the embodiment shown, the machine <NUM> comprises a marker roller <NUM> which is configured to make a plurality of seeding markers (or recesses) within the soil or loam filling the seeding tray V resting and transiting on the (rest plane B of the) conveyor belt <NUM>.

The marker roller <NUM> is rotatably associated with the support frame <NUM>, around a rotation axis R2 parallel to the rest plane B (i.e. horizontal and essentially orthogonal to the advancement direction A) and the rotation axis R1 of the seeding roller <NUM>.

The marker roller <NUM> is arranged above the rest plane B (at a non-zero distance from it) upstream of the seeding roller <NUM> (in the advancement direction imposed by the conveyor <NUM>) in the advancement direction A, so that between the marker roller <NUM> and the (rest plane B of the) conveyor belt <NUM> a seeding tray V to be seeded may be fitted (with interference from the soil/loam arranged therein).

The marker roller <NUM> comprises at least one set of (conical) reliefs aligned along an alignment direction parallel to the rotation axis R2, preferably equally spaced from each other.

Preferably, the marker roller <NUM> comprises a plurality of said sets of reliefs circumferentially spaced by a predetermined circumferential distance (or pitch), for example equal to the distance between (the centre of) two adjacent and/or aligned cells of the seeding tray V to be dug with said marker roller <NUM> and seeded with the seeding roller <NUM>.

For example, each row of reliefs has an arrangement of reliefs such that it enters a respective cell of a row of cells (orthogonal to the advancement direction A) of a seeding tray V.

The marker roller <NUM> comprises a number of sets of reliefs equal to (or greater than) the number of sets of rows of cells (in the advancement direction A) present in the seeding tray V.

For example, the reliefs are made in a jacket associated, e.g. permanently with the marker roller <NUM>.

For example, the marker roller <NUM> comprises a central shaft, which defines said rotation axis R2 on which said jacket with reliefs is wound.

Preferably, the marker roller <NUM> is keyed/fitted onto the central shaft removably (e.g. axially extractable), so that it may be replaced as required.

For example, the marker roller <NUM> is supported by the support frame <NUM> in a height-adjustable manner.

For this purpose, the machine <NUM> comprises a second adjustment assembly <NUM> (preferably identical to the first adjustment assembly <NUM>) of the distance between the marker roller <NUM> and the rest plane B.

The second adjustment assembly <NUM> comprises a support sub-frame <NUM> rigidly attached to the support frame <NUM> of the conveyor <NUM>.

In addition, the second adjustment assembly <NUM> comprises a movable sub-frame <NUM>, which is slidably associated with the vertical guide <NUM>, along an adjustment direction orthogonal to the rest plane B, i.e. vertical.

The movable frame <NUM> comprises, for example, a pair of cylindrical (through-hole) seats adapted to be fitted onto the columns defining the vertical guide <NUM>, so as to define a prismatic connection with them.

The movable sub-frame <NUM> comprises a rolling seat within which an axial end (of the central shaft) of the marker roller <NUM> is accommodated in rotation, e.g. by interposing a special bearing.

Preferably, the axial end (of the central shaft) of the marker roller <NUM> protrudes axially from the movable sub-frame <NUM>.

In particular, the actuator comprises an electric motor <NUM> fixed to the support sub-frame <NUM> to whose drive shaft an endless screw <NUM> is associated which rises from the support frame <NUM> and screwed into a nut made in the movable sub-frame <NUM>.

A rotation of the endless screw <NUM> corresponds to a vertical sliding of the moving sub-frame <NUM> along the adjustment direction and, with it, of the marker roller <NUM>.

The marker roller <NUM> is configured to be driven in rotation around its rotation axis R2, for example, at a predetermined rotation speed relative to the advancement speed of the seeding tray V set by the conveyor <NUM>.

Preferably, rotational drive of the marker roller <NUM> is independent of or disengageable from the rotational drive of the seeding roller <NUM>.

In particular, the marker roller <NUM> is driven in rotation by the motor <NUM> of the conveyor <NUM>.

For this purpose, the machine <NUM> comprises a further transmission assembly <NUM> interposed between the motor <NUM> of the conveyor <NUM> and the marker roller <NUM> and configured to transmit a rotary motion from the motor <NUM> to the marker roller <NUM>.

The further transmission assembly <NUM> is, for example, a flexible member, i.e. a chain (or belt).

In particular, the further transmission assembly <NUM> comprises a drive gear <NUM> (or drive pulley), which is rigidly connected to the drive shaft of the motor <NUM>, e.g. it is rigidly connected to the drive roller <NUM> of the conveyor.

In the example illustrated, the drive gear <NUM> is indirectly connected to drive roller <NUM> and made integral thereto in rotation via the transmission assembly <NUM> of the seeding roller <NUM>.

In particular, the drive gear <NUM> is keyed to the support shaft on which the intermediate gear <NUM> of the transmission assembly <NUM> of the seeding roller <NUM> is also keyed.

In practice, the drive gear <NUM> of the further transmission assembly <NUM> is parallel, coaxial and integral to said intermediate gear <NUM> of the drive unit <NUM>.

In addition, the further transmission assembly <NUM> comprises a driven gear <NUM> (or driven pulley), which is connected to (the central shaft of) the marker roller <NUM>, for example at the axial end (of the central shaft) of the marker roller <NUM> which protrudes axially from the movable sub-frame <NUM>.

The further transmission assembly <NUM>, moreover, comprises, at least, a flexible member <NUM>, for example a chain or belt, configured to transmit the rotary motion from the drive gear <NUM> to the driven gear <NUM>.

For example, the further transmission assembly <NUM> comprises an intermediate gear <NUM>, which is rotatably coupled to the support sub-frame <NUM> around a rotation axis parallel to the rotation axis R2 of the marker roller <NUM>.

In one possible configuration, the flexible member <NUM> is wound around the drive gear <NUM>, the driven gear <NUM> and the intermediate gear <NUM>.

In an alternative and advantageous embodiment shown in <FIG>, the further transmission assembly <NUM> comprises two flexible members <NUM>, one of which is wound around the drive gear <NUM> and the intermediate gear <NUM>, and the other one is wound around a further intermediate gear <NUM> (parallel, coaxial and integral with said intermediate gear <NUM>) and to the driven gear <NUM>.

For example, the further transmission assembly <NUM> has a transmission ratio of <NUM>:<NUM>.

The further transmission assembly <NUM> comprises one or more belt tensioners to compensate for the pull of the flexible member <NUM> depending on the distance set between the marker roller <NUM> and the rest plane B.

For the purposes of the present invention, the further transmission assembly <NUM> comprises a friction clutch <NUM> (identical to the friction clutch <NUM> of the transmission assembly <NUM>) configured to selectively be switched between a closed position, in which it allows the transmission of rotary motion from the motor <NUM> of the conveyor <NUM> to the marker roller <NUM>, and an open position, in which it interrupts the transmission of the rotary motion from the motor <NUM> of the conveyor <NUM> to the marker roller <NUM>.

In particular, the friction clutch <NUM> is configured to couple and decouple (temporarily) at least one of the drive roller <NUM> or motor <NUM> from the marker roller <NUM>.

In the example shown, the friction clutch <NUM> is interposed between the marker roller <NUM> and the driven gear <NUM>.

For example, the friction clutch <NUM> comprises a first body <NUM> rigidly connected to (the central shaft of) the marker roller <NUM>, for example keyed to the central shaft of the marker roller itself, and a second body <NUM> rigidly connected to the driven gear <NUM>, wherein the driven gear <NUM> is for example keyed to said second body <NUM>.

The first body <NUM> and the second body <NUM> are selectively coupled and decoupled from each other, so that it is possible to selectively switch between the closed position, in which the first body <NUM> and the second body <NUM> are made integral with each other in rotation by friction or by gear/teeth/helical connection, and the open position, in which the first body <NUM> and the second body <NUM> are disengaged from each other (and mutual rotation with respect to the rotation axis R1 of the marker roller <NUM> is allowed).

When the friction clutch <NUM> is in the closed position, the rotary motion imparted by the motor <NUM> of the conveyor <NUM> is transmitted (in full) to the marker roller <NUM> via the further transmission assembly <NUM>.

When the friction clutch <NUM> is in the open position, the marker roller <NUM> is decoupled from the motor <NUM> of the conveyor <NUM> and, therefore, remains stationary, e.g. it stops/is instantly braked by suitably calibrated friction on the central shaft thereof and/or by a braking unit (while the flexible member <NUM> and the driven ring gear <NUM> continue to rotate with the driven gear <NUM> and the motor <NUM> of the conveyor <NUM>).

It is not excluded, however, that the friction clutch <NUM> may be arranged at a different location on the further transmission assembly <NUM>.

The machine <NUM> further comprises a cleaning device <NUM>, which is configured to clean the marker roller <NUM> (i.e. its reliefs) of any residual soil or loam.

For example, the cleaning device could comprise a (fixed) brush rigidly attached to the movable sub-frame <NUM> and arranged with its longitudinal axis parallel to the rotation axis R2 of the marker roller <NUM>, preferably above it. The brush is configured to brush (along one directrix of the marker roller <NUM>) the marker roller <NUM> while the latter is rotating.

In an alternative embodiment shown in the figures, the cleaning device <NUM> comprises a brush roller <NUM>, which is rotatably associated with the support frame <NUM>, around a rotation axis parallel to the rest plane B (i.e., horizontal and substantially orthogonal to the advancement direction A) and the rotation axis R2 of the marker roller <NUM>.

The brush roller <NUM> is arranged above the marker roller <NUM> (in contact with it).

For example, the brush roller <NUM> comprises a central shaft, which defines said rotation axis.

For example, the brush roller <NUM> is supported by the movable sub-frame <NUM>.

The brush roller <NUM> is configured to be driven in rotation around its rotation axis, for example, at a predetermined and constant rotation speed, e.g., at a different speed from the marker roller <NUM> and/or in the reverse rotation direction from the marker roller itself.

In particular, the brush roller <NUM> is driven in rotation by the motor <NUM> of the conveyor <NUM> (i.e. it is driven by the driven gear <NUM>, which takes the motion from the intermediate gear <NUM> connected to the drive gear <NUM>, in turn driven by the motor <NUM>).

For this purpose, the machine <NUM> comprises a (belt) transmission connecting a toothed ring gear keyed on the central shaft of the brush roller <NUM> with a toothed ring gear keyed on the central shaft of the marker roller <NUM>.

The machine <NUM> also comprises a further detection device configured to detect a position assumed by the marker roller <NUM>.

The further detection device comprises, for example, a proximity sensor S1 associated, e.g. in an integral manner, with the support sub-frame <NUM> configured to detect a detection member D1 associated integral (eccentrically) with (the central shaft of) the marker roller <NUM> (e.g. at the free end thereof protruding from the first body <NUM> of the friction clutch).

The proximity sensor S1 is configured to detect the passage of the detection member D1 when the marker roller <NUM> is placed in a (single) predetermined angular position, preferably end-of-stroke/stop position, and generate an (electrical) signal representative of such angular position.

When the marker roller <NUM> is in the angular end-of-stroke/stop position, for instance, no set of reliefs is in the position proximal to the rest plane B (with longitudinal axis orthogonal to the rest plane B).

In addition, the machine <NUM> comprises a further system for detecting a seeding tray V resting on a section of the rest plane B located upstream of the marker roller <NUM> along the advancement direction A.

For example, the further detection system is configured to detect the front end (in the advancement direction along the rest plane B) of the seeding tray V at a predetermined axial position of the rest plane along the advancement direction A.

For example, the further detection system comprises an optical assembly, which has, for example, a photocell S2 and a respective reference body (aligned to the photocell along a direction horizontal and orthogonal to the advancement direction.

When the front end of the seeding tray V encounters the light beam emitted by the photocell S2 of the further detection system, it interrupts it and the detection system is configured to generate an (electrical) signal indicative of a predetermined axial position of the seeding tray V on the rest plane B.

The electronic control unit <NUM> is operatively connected to the further detection system so as to receive the signal emitted by it.

The electronic control unit <NUM> is also operatively connected to the further detection device, so as to receive the signal emitted by it.

The electronic control unit <NUM> may be operatively connected to the motor <NUM> of the conveyor <NUM>, e.g. so as to control start and stop and (possible) speed variation thereof.

The electronic control unit <NUM> may, in addition, be operatively connected to the electric motor <NUM> to control start and stop thereof and, therefore, to adjust the distance of the marker roller <NUM> from the rest plane B.

For example, the electronic control unit <NUM> is configured to receive (e.g., via the user interface) information regarding the type/height of the seeding tray V or detect (via a special sensor) the height of the seeding tray V and control the electric motor <NUM> (e.g., equipped with an encoder) so that the marker roller <NUM> is placed at a predetermined distance from the rest plane B.

Furthermore, the electronic control unit <NUM> is operatively connected to the friction clutch <NUM> of the further transmission unit <NUM> (i.e. to the solenoid valve connected thereto) to control its switching, alternately, between the closed position and the open position.

According to one embodiment (shown in the figures), the machine <NUM> comprises a plurality of seeding rollers <NUM> (as described above) arranged in succession along the advancement direction A.

For example, the seeding rollers <NUM> differ from each other only in the arrangement of the insert bars <NUM> and/or the arrangement of the suction holes along them (and their axial position along the advancement direction A).

For example, each seeding roller <NUM> is associated with the support sub-frame <NUM> via a respective first adjustment unit <NUM>, as described above.

Furthermore, preferably, each seeding roller <NUM> takes the rotary motion from the motor <NUM> of the conveyor <NUM>, e.g. via a respective transmission assembly <NUM>.

Although it is possible that each transmission assembly <NUM> has a respective drive gear <NUM> rigidly connected to the drive shaft of the motor <NUM>, as described above, it is nevertheless possible to provide - as in the case illustrated in the figures - that the drive gear <NUM> of the transmission assembly <NUM> connected to the seeding roller <NUM> closest to the motor <NUM> is keyed to a shaft parallel to the motor roller <NUM> and made rotationally integral with it by means of a pair of meshing toothed wheels, whereas the drive gear <NUM> of each transmission shaft <NUM> connected to seeding roller <NUM> distal from the motor <NUM> is indirectly connected to the motor roller <NUM>, i.e. it is keyed to the support shaft on which the intermediate gear <NUM> of the transmission assembly <NUM> of the seeding roller <NUM> proximal thereto and closer to the motor <NUM> is also keyed (i.e. it is parallel, coaxial and integral with said intermediate gear <NUM>).

In any case, each transmission assembly comprises a respective friction clutch <NUM> that may be driven independently of the other friction clutches <NUM> of the other transmission assemblies <NUM>.

Again, the machine <NUM> comprises a plurality of detection systems, as described above, one for each seeding roller <NUM>.

In addition, the machine <NUM> comprises a plurality of detection devices, as described above, one for each seeding roller <NUM>.

The electronic control unit <NUM> is operatively connected to each detection system so as to receive the respective signal emitted by it.

The electronic control unit <NUM> is also operatively connected to each detection device so as to receive the respective signal emitted by it.

The electronic control unit <NUM> may also be operatively connected to each electric motor <NUM> to control start and stop thereof, and thus to adjust the distance of the respective seeding roller <NUM> from the rest plane B.

In addition, the electronic control unit <NUM> is operatively connected to the friction clutch <NUM> of each transmission assembly <NUM> (i.e. to the solenoid valve connected thereto) to control its switching, alternately, between the closed position and the open position.

For example, each seeding roller <NUM> may be driven selectively in relation to the other seeding rollers <NUM> to seed a respective type of seeding tray V.

Alternatively or additionally, each seeding roller <NUM> may be driven at the same time as the other seeding rollers <NUM> in order to seed into the same seeding tray, for instance more seeds into the same cell.

The electronic control unit <NUM> is configured, as mentioned, to control and monitor the operation of the machine <NUM>, e.g. by operating as described hereinafter.

Referring to a working sequence, wherein a seeding tray V is fed onto the conveyor <NUM> (from its upstream end) and passes through the rest plane B along the advancement direction A, the operation of the machine <NUM> controlled and monitored by the electronic control unit <NUM> is described hereinafter.

Firstly, where the marker roller <NUM> is present, the electronic control unit <NUM> is configured to receive a signal from the further detection system (when the seeding tray intercepts the light beam of the respective photocell S2).

At this point, the electronic control unit <NUM>, with a predetermined delay, is configured to control the friction clutch <NUM> of the further transmission assembly <NUM> so as to switch it to its closed position based on the received signal.

As the seeding tray V passes underneath the marker roller <NUM>, the latter is controlled to rotate around its rotation axis R2 (at a rotation speed equal to the advancement direction of the conveyor belt <NUM>).

In practice, the marker roller <NUM>, while rotating (perfectly phased with the advancement of the seeding tray V), makes a seeding marker in each cell of the seeding tray by sinking into the soil or loam present therein.

For example, the electronic control unit <NUM> is configured to hold the friction clutch <NUM> in the closed position for a predetermined number of complete revolutions of the marker roller <NUM>, e.g. for a single revolution of the marker roller.

In particular, the electronic control unit <NUM> is configured to receive the signal emitted by the detection device (at each complete revolution made by the marker roller <NUM>) and control the friction clutch <NUM> so as to switch it to its open position after a predetermined number of revolutions made by the marker roller <NUM>, for example each single complete revolution made by the marker roller <NUM> (detected by the detection device).

Subsequently or simultaneously, the electronic control unit <NUM> is configured to receive a signal from each detection system (when the seeding tray intercepts the light beam of the respective photocell S2).

At this point, the electronic control unit <NUM>, e.g. with a predetermined delay, is configured to control the friction clutch <NUM> of the respective transmission assembly <NUM> so as to switch it to its closed position based on the respective signal received.

As the seeding tray V passes under the respective seeding roller <NUM>, the latter is controlled to rotate around its rotation axis R1 (at a rotation speed equal to the advancement speed of the conveyor belt <NUM>).

In practice, the seeding roller <NUM> during its rotation (perfectly in phase with the advancement of the seeding tray V) releases a seed in each seeding cell (previously made in each cell) of the seeding tray V.

For example, the electronic control unit <NUM> is configured to hold the friction clutch <NUM> of each transmission assembly <NUM> in the closed position for a predetermined number of complete revolutions of the seeding roller <NUM>, e.g. for a single revolution thereof.

In particular, the electronic control unit <NUM> is configured to receive the signal emitted by each detection device (at each complete revolution made by the respective seeding roller <NUM>) and control the friction clutch <NUM> so as to switch it to its open position after a predetermined number of revolutions made by the seeding roller <NUM>, for example each single complete revolution made by the seeding roller <NUM> (detected by the respective detection device).

Claim 1:
A seeding machine (<NUM>) comprising:
- a frame (<NUM>);
- a conveyor (<NUM>) defining a rest plane (B) for seeding trays (V) and equipped with a motor (<NUM>) configured to advance the seeding trays (V) resting on the rest plane (B) along an advancement direction (A);
- a seeding roller (<NUM>) rotatably associated with the frame, around a rotation axis (R1) parallel to the rest plane (B), and arranged above the rest plane (B);
- a transmission assembly (<NUM>) interposed between the motor (<NUM>) of the conveyor (<NUM>) and the seeding roller (<NUM>) configured to transmit a rotary motion from the motor (<NUM>) to the seeding roller (<NUM>);
characterised in that the transmission assembly (<NUM>) comprises a friction clutch (<NUM>) configured to be selectively switched between a closed position, in which it allows the transmission of the rotary motion from the motor (<NUM>) of the conveyor (<NUM>) to the seeding roller (<NUM>), and an open position, in which it interrupts the transmission of the rotary motion from the motor (<NUM>) of the conveyor (<NUM>) to the seeding roller (<NUM>).