Volumetric metering unit for particulate and powder substances

Abstract

A volumetric metering unit for supplying a particulate and / or powdered substance in a metered manner comprises a housing (1) comprising a chamber (10), an inlet opening (11) and an outlet opening (12). The metering unit (100) further comprises: a rotating dispensing drum (2) comprising a shaft (20) having a first end (21) and a second end (22) which are axially opposite; and a motorized unit (3) connected or connectable in a rotational manner to the second end of the shaft in order to rotate the drum. A connection device (4) is provided which is configured to rotationally connect the second end (22) of the shaft (20) to the motorized unit (3). The connecting means (4) are configured to engage and disengage by means of movement along the axis of rotation of the drum (2). The metering unit (100) further comprises a flanged element (5) which supports the shaft (20) and is applied to the first wall (13) of the chamber (10) via a bayonet-type connection means (6).

Description

Technical Field

[0001] The present invention relates to a volumetric metering unit for particulate and / or powdered substances, and more particularly to a machine for dispensing such substances. Background Art

[0002] Volumetric dispensers of this type are widely used in agricultural seeders in order to dispense particulate substances, such as seeds, fertilizers and / or additives such as disinfectants or pesticidal substances associated with the seeds, in a metered manner during the seeding operation. These dispensers are also known as granulators or microgranulators, especially when they are used to dispense additives. In addition to this preferred use, these dispensers are further used in all fields where a metered supply of product is required.

[0003] An example of a volumetric dispenser constructed according to the prior art is described in the document WO2004015378A1 in the name of the same applicant. The dispenser includes a box-like structure in which a dispensing drum is rotatably supported.

[0004] The first problem is the difficulty of cleaning or replacing the dispensing drum. Replacement is particularly necessary in order to be able to equip the dispenser with different drums suitable for the substance to be dispensed. This involves removing the transmission means that rotate the drum, opening a suitable port of the dispenser, removing the existing drum and introducing the required drum. All these steps require a high degree of dexterity. In fact, a disadvantage of the known structures is that they contain a large number of parts that must be assembled in the correct order and manner using connecting tools, screws, flanges and other items. This concept is not very suitable for the case of agricultural machinery, because many interventions must be carried out in the field, and thus the need to remove and handle different parts may result in these parts being lost or incorrectly assembled.

[0005] The second problem is related to the fact that the handling of the drum involves a high risk for the operator, since the seeds, fertilizers and additives dispensed on the ground may often have a certain degree of toxicity due to the composition of the product itself or the composition of the chemical products associated therewith. Usually, seeds are treated with tanning substances or fungicides, which are harmful both for contact and inhalation. Fertilizers and additives may release dangerous powders or at least irritating powders, or powders containing dangerous products themselves. Therefore, it is preferable to avoid direct contact with such substances. A possible solution is to use protective gloves, but this is not ideal because the protective gloves limit the possibility of effectively and easily handling the above-mentioned small mechanical parts.

[0006] Another example of a volumetric dispenser constructed according to the prior art is described in DE102007034997A1. The dispenser includes a housing for a hollow drum-shaped member, in which the hollow drum-shaped member is axially assembled on a drive shaft, and the drive shaft is mounted in the housing in an axially removable manner. In order to remove the drum-shaped member from the housing, it is therefore necessary to remove the drum-shaped member from the shaft, and the disadvantage is that due to the presence of powder between the drum-shaped member and the shaft, the drum-shaped member may be stuck in the housing.

[0007] Another example of a known volumetric dispenser is described in DE102020002763A1.

[0008] In different technical fields, an example of a connection system between a rotor and a drive shaft is described in US4602727, which particularly relates to a rotary medical valve.

[0009] Therefore, the problem solved by the present invention is to provide a volumetric metering unit for particulate and / or powdered substances, which is structurally and functionally configured to at least partially overcome one or more of the disadvantages listed in the referenced prior art.

[0010] Another object of the present invention is to provide a volumetric metering unit for particulate and / or powdered substances, in which the removal and possible replacement of the rotor can be carried out in a simplified manner, usually only requiring the removal of a limited number of connecting parts and components.

[0011] Another object of the present invention is to provide a volumetric metering unit for particulate and / or powdered substances, in which the risk of an operator coming into contact with the substances contained in the metering unit is significantly reduced.

[0012] The object of the present invention is also to provide to the art a volumetric metering unit for particulate and / or powdered substances, which allows for the improvement of known technical solutions in the case of a simple and reasonable technical solution with a relatively limited cost. Summary of the Invention

[0013] By means of the present invention, the problem is solved and these objectives are at least partially achieved by a volumetric metering unit for metering the supply of particulate and / or powdered substances, which includes a housing.

[0014] Preferably, the housing includes a chamber, an inlet opening and an outlet opening, and a first wall and a second wall opposite each other, and a flow direction of particulate and / or powdered substances is defined between the inlet opening and the outlet opening.

[0015] Preferably, the metering unit includes a rotary dispensing drum which is supported rotatably about a rotation axis in a housing. Preferably, the drum includes a shaft having a first end and a second end, the first end and the second end being axially opposite and supported respectively on a first wall and a second wall.

[0016] Preferably, the metering unit includes a motorization unit which is rotationally connected or can be connected to the second end of the shaft so as to rotate the drum.

[0017] Preferably, the metering unit includes a connecting device which is configured to rotationally connect the second end of the shaft to the motorization unit. Preferably, the connecting device is configured to be able to engage and disengage by means of a movement along the rotation axis respectively towards the second wall and away from the second wall through a seating formed in the first wall of the chamber.

[0018] Preferably, the metering unit includes a flange element that supports rolling elements, and the first end of the shaft is rotatably supported by the rolling elements, and the flange element is applied to the first wall of the chamber.

[0019] Preferably, the flange element is connected to the first wall via a bayonet-type connection device which is configured to selectively close and open the seating by means of a combined movement of rotation about the rotation axis of the flange element and translation along the rotation axis.

[0020] It will be understood that the metering unit according to this first aspect allows the rotor to be simply removed and subsequently repositioned in the relevant housing without disassembling the motorization unit and with a simple rotational-translational movement.

[0021] Furthermore, due to the specific connection method, the rotor can also be unblocked without disassembling the components, thus reducing the risk of dropping components on site or, in any case, limiting the manual operations required by the operator.

[0022] Furthermore, the unblocking of the drum can be achieved by rotation, and due to this configuration, this operation can be performed by acting on a flange element independent of the shaft, and thus this operation is performed in a manner independent of the connection to the motorization unit.

[0023] In this way, it is not necessary to rotate the motorization unit to remove the characteristic drum, which also helps to avoid any disassembly of the motorization unit in order to perform the removal of the drum.

[0024] Therefore, generally speaking, the complexity of the operation can thus be reduced, and the consequent risk of contact with the substances present in the metering unit can also be reduced.

[0025] In addition to the above features, the present invention may further have one or more of the following preferred features.

[0026] Preferably, the motorized unit is located in a remote position relative to the first wall of the chamber and in a close position relative to the second wall of the chamber.

[0027] Thus, the extraction area can be kept away from the components of the motorized unit, further facilitating the operation.

[0028] In some embodiments, the connecting device includes a movable part and a fixed part, which are respectively formed on the second end of the shaft and on the motorized unit. Preferably, the connecting device is configured to be engaged and disengaged by the movable part moving relative to the fixed part along the rotation axis.

[0029] Preferably, the connecting device includes a connecting pin and a part bifurcated into two tips, the tips and the connecting pin are respectively formed on the second end of the shaft and on the motorized unit, or the tips and the connecting pin are respectively formed on the motorized unit and the second end of the shaft, and the tips are configured to receive the connecting pin between the two tips.

[0030] This configuration allows the connecting device of the present invention to be simply and reliably realized.

[0031] It should be understood that in some embodiments, the fork-shaped part and the connecting pin respectively define the movable part and the fixed part, or the fork-shaped part and the connecting pin respectively define the fixed part and the movable part.

[0032] Preferably, the connecting device is configured to be engaged and disengaged by moving the drum and the shaft together along the rotation axis towards and away from the second wall respectively through the seating portion.

[0033] Preferably, the motorized unit includes a hollow shaft, and the connecting pin is formed on the hollow shaft.

[0034] Preferably, the motorized unit includes a pulley, the hollow shaft is rotatably connected to the pulley, and the pulley is configured to transmit the rotational movement to an additional rotating component via a transmission belt.

[0035] Due to this feature, a high level of secure connection can be ensured and it is easy to assemble without removing the components of the motorized unit.

[0036] In addition, the present invention advantageously allows the drum to be removed without having to remove the transmission belt from the pulley.

[0037] Preferably, the seating portion is configured to allow the drum to move towards and away from the housing, thereby allowing a high level of accessibility within the housing.

[0038] Preferably, the flanged element has a hole, and the flanged element is axially assembled on the shaft through the hole at an axial intermediate position between the first end of the shaft and the blade of the drum. The first end of the shaft axially protrudes away from the flanged element through the hole to the outside of the chamber and has a groove, which is preferably annular, and the groove can be grasped to move the drum and the flanged element axially away from the second end of the chamber.

[0039] Therefore, the groove can be used with a tool that can engage in the appropriate groove to grasp the drum.

[0040] Preferably, the bayonet-type connecting device includes at least one through groove formed on the flanged element and having a widened portion and a narrowed portion. The widened portion is configured to allow a blocking element supported on the first wall to pass through the groove, and the narrowed portion is configured to prevent the blocking element from passing through the groove.

[0041] These features provide a solid solution, especially suitable for use in the agricultural field, where components also need to be able to withstand high stresses.

[0042] Preferably, the through groove is in the form of a circumferential arc that is coaxial with the axis of rotation.

[0043] To achieve the connection, by means of a rotational movement around the axis of rotation, a simple structural solution can be adopted, which is still beneficial to the structural stability.

[0044] Preferably, the connecting device includes a plurality of through grooves distributed non-uniformly around the axis of rotation, and at least one of the grooves includes a pair of widened portions.

[0045] In this way, the connection can be made asymmetrically by rotating in the clockwise direction in one case and in the counterclockwise direction in another case, so that the flanged element is suitable for connection in two different positions, for example, one on the right side of the machine and the other on the left side of the machine.

[0046] Preferably, the metering unit includes a calibration port for calibrating the material flow.

[0047] Preferably, the metering unit includes at least one movable wall supported in the housing to selectively direct the material flow towards the outlet opening or towards the calibration port.

[0048] Preferably, the metering unit includes a rod-shaped member adapted to control the movement of the movable wall.

[0049] It should be understood that the simplified removal system of the present invention is particularly highly applicable in the case where there is a calibration port, which actually simplifies the accessibility inside the housing and thus also the possibility of reaching the calibration port, for example, for cleaning or maintenance.

[0050] In particular, this feature is particularly advantageous if there is a movable element inside the housing, such as the wall described above.

[0051] According to another aspect, the invention also relates to an agricultural distribution machine, in particular a spreader and / or a seeder, comprising at least one volumetric metering unit and at least one hopper, the volumetric metering unit having one or more of the above-described features, the hopper comprising a lower part having a supply opening, and the inlet opening of the volumetric metering unit being adapted to the lower part.

[0052] According to another aspect, the invention also relates to a kit, which comprises a volumetric metering unit having at least one rotary distribution drum supported in a housing in a rotatable manner about a rotation axis, the drum comprising a shaft carrying axially opposite first and second ends, the first end of the shaft having a groove and one or more of the above-described features, and a calibration tool engaged in the groove.

[0053] The tool preferably comprises attachment means with respect to the calibration port of the metering unit and a collection device for the calibration substance fixed to the attachment means. Preferably, the attachment means comprises an engagement member arranged to be removably engaged in the groove of the shaft of the drum to facilitate the movement of the engagement member.

[0054] Preferably, the collection device for the calibration substance comprises a calibration bag having an opening, the calibration bag being fixed to the connecting means in a position such that when the tool is applied to the calibration port, the calibration bag is positioned to be supplied with the substance falling from the calibration port.

[0055] Preferably, the tool comprises a handle fixed to the attachment means.

[0056] Preferably, the handle is fixed to the attachment means on the opposite side of the engagement member.

[0057] Preferably, the attachment means comprises: a pair of walls arranged at intervals; a transverse member extending between the walls; and first engagement means on the walls at the opposite side of the collection device, the first engagement means being capable of connecting to a corresponding first engagement counter-means provided on the calibration port.

[0058] Preferably, the engagement member comprises second engagement means located on the transverse member, the second engagement means being capable of connecting to a corresponding second engagement counter-means provided on the distribution drum.

[0059] Preferably, the second engagement means comprises a recess formed in the transverse member.

[0060] Preferably, the recess opens towards the collection device.

[0061] Preferably, the wall has a cam-shaped profile portion that extends beyond the transverse member on the side opposite to the handle.

[0062] Thus, the same advantages associated with the first aspect can also be achieved by an agricultural machine and a kit constructed in this way.

[0063] Additional preferred aspects are also defined in the appended claims and the description below.

[0064] In this specification and the appended claims, and more generally in the context of the present invention, unless otherwise explicitly stated, many terms and expressions are considered to have the meanings expressed in the following definitions.

[0065] In particular, the term "bayonet-type connection" is intended to be understood as an actual bayonet-type connection and different types of connections, where the connection is achieved by a mechanical connection that is generated by relative movement between two components, and the relative movement includes both rotation and translation, preferably including translation along an axis parallel to the axis along which the rotation occurs.

[0066] These movements can be performed in any order, and can also be performed partially or completely simultaneously. Description of the Drawings

[0067] The features and advantages of the present invention will be better understood from the following detailed description of a plurality of exemplary embodiments of the present invention shown by way of non-limiting examples in the accompanying drawings, in which:

[0068] Figure 1 is a perspective view of the volumetric metering unit of the present invention;

[0069] Figure 2 and Figure 3 are respectively cross-sectional views of the horizontal plane of the metering unit and related details relative to Figure 1 ;

[0070] Figure 4 is a cross-sectional view of the volumetric metering unit of the present invention taken in a vertical plane;

[0071] Figure 5 is a perspective view of the rotary drum-like member and related flange-type elements and components of the volumetric metering unit of the present invention; and

[0072] Figure 6 is a schematic view of an agricultural machine including the volumetric metering unit of the present invention. Detailed Description of the Embodiments

[0073] Referring to Figure 6, generally, the dispensing machine for particulate matter is designated by 200. This dispensing machine can be used for sowing, as well as for dispensing fertilizers, disinfectants, etc.

[0074] The machine 200 includes: one or more hoppers for containing the material to be dispersed; a fan that supplies an air stream under pressure to an air injector; at least one volumetric metering unit 100 that supplies a metered amount of the material present in the hopper to the air stream generated by the fan, and a dispenser that dispenses the mixed air stream and the material to be conveyed to a dispensing duct.

[0075] Now refer to Figure 1 and Figure 2 , the volumetric metering unit 100 generally includes a housing 1, and a rotary dispensing drum 2 is accommodated in the housing 1 so as to be rotatable about a rotation axis X.

[0076] As Figure 3 and Figure 4 more particularly shown in, the housing 1 includes a chamber 10, an inlet opening 11, and an outlet opening 12, and a flow direction F for particulate matter and / or powder matter is defined between the inlet opening 11 and the outlet opening 12.

[0077] There are also a first wall 13 and a second wall 14. The first wall 13 and the second wall 14 are opposite to each other and define a space in which the rotary dispensing drum 2 can be received.

[0078] Advantageously, the rotary dispensing drum 2 includes a shaft 20 having a first end 21 and a second end 22. The first end 21 and the second end 22 are axially opposite and are respectively supported on the first wall 13 and the second wall 14.

[0079] The rotation of the drum 2 is achieved by means of a suitable motorization unit 3 which is rotationally connected to the second end 22 of the shaft. For example, the motorization unit 3 is rotationally connected to the second end 22 of the shaft by means of a gear system 30 or a step down system.

[0080] Therefore, by rotating the drum 2, particulate matter and / or powder matter can be conveyed in a metered manner from the inlet opening 11 to the outlet opening 12 according to the flow direction F. For this purpose, the drum 2 has blades 8 which allow the material to be metered according to the formation of the material and the rotational speed of the drum 2 itself.

[0081] A calibration port 16 can also be provided for calibrating the flow rate of the material. Advantageously, the flow can be redirected by a movable wall 7 supported in the housing 1 so as to selectively direct the material flow towards the outlet opening 12 or towards the calibration port 16.

[0082] As can be observed in the figure, advantageously, the motorized unit 3 is located in a position remote from the first wall 13 of the chamber and in a position close to the second wall 14 of the chamber.

[0083] In some embodiments, the motorized unit 3 includes a pulley configured to transmit a rotational movement to an additional rotating component of the dispenser via a transmission belt 31.

[0084] The rotation between the motorized unit 3 and the drum 2 is transmitted by a suitable connecting device 4, which is shown in more detail in the Figure 3 exemplary embodiment.

[0085] In particular, the connecting device 4 is configured to rotatably connect the second end 22 of the shaft 20 to the motorized unit 3.

[0086] Preferably, the connecting device 4 includes a connecting pin 41 and a portion bifurcated into two tips 42, the two tips 42 and the connecting pin 41 being formed on the second end 22 of the shaft 20 and on the motorized unit 3 respectively, preferably in a region of the associated hollow shaft 33 that can be advantageously connected to the pulley 32 itself.

[0087] Advantageously, when the end 22 of the shaft is inserted into the hollow shaft 33, the tips 42 and the connecting pin 41 formed on the hollow shaft 33 hold the pin 41 between the hollow shaft 33 and the tips 42.

[0088] In this way, the connecting device 4 can be configured to be able to engage and disengage by moving the drum 2 along the axis X in the direction towards the second wall 14 and away from the second wall 14 respectively through the seating portion 15 formed in the first wall 13 of the chamber 20 without removing the pin 41. Thus, it will be understood that preferably, the connecting device 4 is configured to be able to engage and disengage by means of the movement of the drum 15 and the corresponding shaft 20 along the axis X.

[0089] Therefore, preferably, the seating portion 15 is configured to allow the drum to move away from the housing and towards the housing.

[0090] In any case, it should be understood that the positions of the pin and the tips can be reversed, and alternative embodiments of what has been described can also be provided, where the connection is achieved by different components but always by a movement of approaching / away along the axis X.

[0091] On the side opposite to the connecting device, a flanged element 5 is provided, which supports the rolling elements 50, and the first end 21 of the shaft 20 is in turn rotatably supported by means of the rolling elements 50.

[0092] The flanged element 5 is advantageously applied to the first wall 13 of the chamber 10 via a bayonet-type connection device 6 which is configured to selectively close and open the seating 15 by means of a combined movement of rotation about the axis of rotation X of the flanged element 5 and translation along the axis of rotation X.

[0093] Preferably, the flanged element 5 has a hole 50 through which the flanged element 5 is axially fitted onto the shaft 20 and is located at an intermediate axial position between the first end 21 of the shaft and the blade 8 of the drum. The first end 21 of the shaft projects axially away from the hole 50 and away from the flanged element to the outside of the chamber, and the first end 21 has a groove 23 which is preferably annular and can be gripped to move the drum axially away from the second end of the chamber together with the flanged element.

[0094] In some embodiments, the bayonet-type connection device includes at least one through slot 51 formed in the flanged element, and the through slot 51 has a widened portion 52 and a narrowed portion 53. The widened portion 52 is configured to allow a blocking element 54 supported on the first wall 13 to pass through the slot 51, and the narrowed portion 53 is configured to prevent the blocking element 54 from passing through the slot 51.

[0095] For example, the blocking element 54 can be formed by a nut which can be provided with a washer or a wing nut or other elements having dimensions that allow passage through the widened portion 52 but not through the narrowed portion 53.

[0096] In this way, the connection can be achieved by a combined translational and rotational movement, and in the applicable case, a more stable blocking effect can be obtained by tightening the nut / wing nut.

[0097] It will also be understood that the slot 51 can be in the form of a circumferential arc having an extension coaxial with the axis of rotation X.

[0098] As can be more clearly observed in Figure 6 According to another aspect, the connection device 5 includes a plurality of through slots 51 distributed non-uniformly about the axis of rotation X, and at least one of the slots 51 includes a pair of widened portions 52.

[0099] This allows the use of the same components to be connected at different positions. For example, as can be observed in Figure 6 the first widened portion can be used to fix the flanged element to the first metering unit, and the second widened portion can be used to fix the second metering unit.

[0100] Therefore, the present invention solves the posed problems while providing a number of advantages. In fact, the metering unit of the present invention allows for the easy removal of the rotary drum-shaped member, which facilitates both the replacement of the rotary drum-shaped member, for example, and the provision of different vanes, as well as for the inspection and maintenance of the housing.

[0101] Furthermore, the connection produced by means of the flanged element has been found to be particularly versatile and practical.

Claims

1. A volumetric metering unit (100) for metering the supply of particulate and / or powdered substances, the volumetric metering unit (100) comprising: A housing (1), the housing (1) comprising a chamber (10), an inlet opening (11) and an outlet opening (12), a first wall (13) and a second wall (14) opposite each other, and a flow direction of particulate and / or powdered substances being defined between the inlet opening (11) and the outlet opening (12); A rotary distribution drum (2), the rotary distribution drum (2) being supported in the housing (1) in a rotatable manner about a rotation axis (X), the drum (2) comprising a shaft (20) having a first end (21) and a second end (22), the first end (21) and the second end (22) being axially opposite, and the first end (21) and the second end (22) being supported on the first wall and the second wall respectively; A motorization unit (3), the motorization unit (3) being rotationally connected to the second end (22) of the shaft, or the motorization unit (3) being capable of being rotationally connected to the second end (22) of the shaft to rotate the drum (2); Connecting means (4), the connecting means (4) being configured to rotationally connect the second end (22) of the shaft (20) to the motorization unit (3), the connecting means (4) being configured to: be able to engage and disengage by moving along the rotation axis (X) towards and away from the second wall (14) respectively through a seating portion (15) formed in the first wall (13) of the chamber (20); A flange element (5), the flange element (5) supporting rolling elements (50), the first end (21) of the shaft (20) being rotatably supported via the rolling elements (50), the flange element (5) being applied to the first wall (13) of the chamber (10) via a bayonet-type connecting device (6), the bayonet-type connecting device (6) being configured to selectively close and open the seating portion (15) by a combined movement of rotation about the rotation axis (X) of the flange element (5) and translation along the rotation axis (X).

2. The volumetric metering unit (100) according to the previous claim, wherein, The motorization unit (3) is located in a remote position relative to the first wall of the chamber and in a proximal position relative to the second wall of the chamber.

3. The volumetric metering unit (100) according to any one of the preceding claims, wherein, The connecting means (4) includes a connecting pin (41) and a portion bifurcated into two tips (42), the tips (42) and the connecting pin (41) being formed on the second end of the shaft and the motorization unit respectively, or the tips (42) and the connecting pin (41) being formed on the motorization unit and the second end of the shaft respectively, the tips being configured to receive the connecting pin between the two tips.

4. The volumetric metering unit (100) according to the previous claim, wherein, The motorized unit includes a hollow shaft (33) on which the connecting pin (41) is formed.

5. The volumetric metering unit (100) according to the preceding claim, wherein, The motorized unit includes a pulley to which the hollow shaft (33) is rotatably connected, and the pulley is configured to transmit rotational movement to an additional rotating component via a drive belt.

6. The volumetric metering unit (100) according to any one of the preceding claims, wherein, The seating portion (15) is configured to allow the drum-shaped member to move towards and away from the housing.

7. The volumetric metering unit (100) according to any one of the preceding claims, wherein, The flanged element (5) has a hole (50) through which the flanged element (5) is axially assembled on the shaft (20) and is located at an axial intermediate position between the first end (21) of the shaft and the blade (8) of the drum-shaped member. The first end (21) of the shaft axially projects out of the chamber away from the flanged element through the hole (50), and the first end (21) of the shaft has a groove (23), preferably an annular groove (23), and the groove (23) can be grasped so that the drum-shaped member and the flanged element move axially away from the second end of the chamber together.

8. The volumetric metering unit (100) according to the previous claim, wherein, The bayonet-type connection device (6) includes at least one through groove (51) formed in the flanged element, and the through groove (51) has a widened portion (52) and a narrowed portion (53). The widened portion (52) is configured to allow a blocking element (54) supported on the first wall (13) to pass through the groove (51), and the narrowed portion (53) is configured to prevent the blocking element (54) from passing through the groove (51).

9. The volumetric metering unit (100) according to the previous claim, wherein, The through groove (51) is in the form of a circumferential arc that is coaxial with the rotational axis (X).

10. The volumetric metering unit (100) according to claim 8 or 9, wherein, The connection device (5) includes a plurality of through grooves (51) distributed non-uniformly around the rotational axis (X), and at least one of the grooves (51) includes a pair of widened portions (52).

11. The volumetric metering unit (100) according to any one of the preceding claims, the volumetric metering unit (100) comprising: A calibration port (16) for calibrating the material flow; and at least one movable wall (7) supported in the housing (1) to selectively direct the material flow towards the outlet opening (12) or towards the calibration port (16).

12. The volumetric metering unit (100) according to any one of the preceding claims, wherein, The connection device (4) includes a movable part and a fixed part formed on the second end (22) of the shaft and the motorized unit (3) respectively, and the connection device (4) is configured to be engaged and disengaged by moving the movable part relative to the fixed part along the rotational axis (X).

13. The volumetric metering unit (100) according to any one of the preceding claims, wherein, The connection device (4) is configured to be engaged and disengaged by moving the drum-shaped member (2) and the shaft (20) together along the rotational axis (X) towards and away from the second wall (14) respectively through the seating portion (15).

14. An agricultural dispensing machine, in particular, the agricultural dispensing machine is a spreader and / or a seeder, the agricultural dispensing machine comprising at least one hopper and at least one volumetric metering unit according to one or more of the preceding claims, the hopper comprising a lower part having a supply opening, and an inlet opening of the volumetric metering unit being applied to the lower part.

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