EP0888042A1

EP0888042A1 - An agricultural machine

Info

Publication number: EP0888042A1
Application number: EP97909751A
Authority: EP
Inventors: Cornelis Johannes Gerardus Bom; Adrianus Petrus Maria Brabander
Original assignee: Maasland NV
Current assignee: Maasland NV
Priority date: 1996-10-25
Filing date: 1997-10-20
Publication date: 1999-01-07
Also published as: NL1005026C1; AU4728097A; WO1998018309A1; AU724560B2

Abstract

The invention relates to an agricultural machine, in particular a soil cultivating machine, such as a seed drill whether or not combined with a cultivator, which agricultural machine is provided with a supporting implement (1) for coupling to the front lifting hitch of a tractor, which implement, for the pupose of being supported on the ground, is provided with a roller (2) that is connected with a frame (3), while there are provided suitable supporting means (18; 19 - 21, 23, 24) between the frame (3) and the roller (2) for a mutual pivoting movement about an imaginary or real axis (20) which is at least orientated in the direction of travel (A).

Description

AN AGRICULTURAL MACHINE

The present invention relates to an agricultural machine, in particular a soil cultivating machine, such as a seed drill whether or not combined with a cultivator, which agricultural machine is provided with a supporting implement for coupling to the front lifting hitch of a tractor, which implement, for the purpose of being supported on the ground, is provided with a roller that is connected with a frame.

Such machines are generally known. They are in- tended for further crumbling of soil which has been worked primarily, usually by ploughing, at least in the upper part of the primarily worked soil layer. As the primary cultivation has particularly for its object to turn the upper soil layer, the latter is usually broken up roughly and the contact with the soil layer which has not been touched is considerably reduced. The known machines are intended to press the primarily cultivated soil, prior to crumbling, in such a manner that the contact between soil which has been turned and soil which has not been touched is re-established at least to some extent. This contact is required for the growth of plants in view of the capillary supply of water from relatively deep soil layers. During pressing, considerable forces may occur in the frame of the machine or in the connection thereof with the tractor. This often leads to a relatively heavy construction of the frame. The present invention has for its object to obtain a construction in which such forces are avoided or in which such forces act on the construction to a lesser degree.

In accordance with the invention, this aim is achieved when there are provided suitable supporting means between the frame and the roller for a mutual pivoting movement about an imaginary or real axis which is at least orientated in the direction of travel . With such a construction it is usually possible for the roller to follow uneven- nesses in the field without torsion forces occurring between the tractor and the. frame or in the frame itself. The construction also facilitates the movement of the tractor during operation. Moreover, by avoiding to a significant extent torsion forces occurring in the implement, a relatively lighter and consequently cheaper construction of the frame will be possible.

In a favourable embodiment, the supporting means comprise a real pivotal axis, at whose ends roller bearings are provided, which roller bearings are included in the frame with little clearance between an upper and a lower horizontal guide face. In an alternative embodiment, the frame is supported on the roller via at least two spring elements, such as compression springs or shock absorbers whether or not produced as hydraulic ones, each disposed on a lateral side outside the transverse centre of the roller.

According to a further aspect of the invention, the pushing forces of the tractor are transferred to the roller via the frame of the implement by means of arms arranged between the frame and the roller construction, which arms, in connecting points, are provided with ball-and-socket joints. In accordance with the invention, in view of the forward movement of the roller, the arms may be included in the machine both in a pushing and in a pulling position.

A further particular aspect of the invention relates to an implement in which such arms extend for the greater part above the roller, substantially horizontally, and from the frame towards the roller whilst having a downward directional component. Such a machine is compact in height in the direction of travel, so that manoeuvring the machine is facilitated and the centre of gravity will be located close to the tractor.

The present invention is particularly advantageous when the agricultural machine is constituted by a combination of a cultivator and a sowing or broadcasting machine, whose hopper is supported on the frame of the implement. With such an agricultural machine, by means of the construction according to the present invention, the advantage is obtained that in case of a local unevenness or a local slope in the soil surface, the frame and the hopper will be able to maintain their position relative to the lifting hitch of the tractor. In particular when the hopper is completely filled, this has the advantage that no additional forces as a result of tilting of the hopper will occur in the construction. The invention furthermore comprises a construction in which the ventilator is arranged in the immediate vicinity of the trestle of the implement, the drive shaft thereof being orientated in the direction of travel and the shaft of the ventilator, via transmission means, being in driving connection with a drive shaft which is located in the transverse centre of the implement. Such a construction is very compact and advantageous because of the possibility of a relatively short and simple transmission via a universal joint shaft which is connected to the front power take-off shaft of a tractor.

The invention further comprises an agricultural machine including a metering device whose discharge opening is released by means of a sliding device, e.g. for testing purposes . For a better understanding the invention will further be described with reference to the accompanying drawings, in which:

Figure 1 shows in rear view an implement pertaining to the agricultural machine according to the invention; Figure 2 shows in side view the implement of

Figure 1;

Figure 3 is a vertical cross-section taken on the line III-III in Figure 1, which line coincides with an imaginary centre plane M of the machine; Figure 4 is a view of part of the implement according to the arrow IV in Figure 3;

Figure 5 is a cross-section taken on the line V-V in Figure 4;

Figure 6 is a side view according to Figure 2 of part of the implement in an alternative embodiment;

Figure 7 is a partial front view of a second alternative embodiment of the implement;

Figure 8 is a front view of part of the machine and shows a third alternative embodiment of the implement, and

Figure 9 is a view of a cross-section taken on a line IX-IX in Figure 8.

Corresponding elements in the drawings are indicated by the same reference numerals. The invention is by no means restricted to the embodiments shown and described; they only serve to illustrate the inventive idea.

Figure 1 shows an implement 1 supported on the ground via a roller 2. The implement 1 constitutes part of a (non-shown) agricultural machine, in the present embodiment a machine for broadcasting granular material, such as a seed drill or a fertilizer broadcaster. For that purpose, in this embodiment, the implement is provided with a hopper 10. The roller 2 and the hopper 10 are interconnected via a frame 3. The implement 1 is intended for coupling to the front lifting hitch of a tractor. To that end, the implement 1 comprises a trestle 4 provided with the required coupling means, which are known per se. The shown trestle 4 is a so-called quick- coupling trestle. The frame 3 comprises a pair of lower girders 5 and an upper girder 6, extending substantially horizontally and forwardly from the trestle 4. The upper girder 6 is designed in this case as a plate part which, in a cross-sectional view, is bent into a V-shape and the lower girders 5 are designed as hollow right-angled profiles. The longitudinal girders 5, 6 are coupled near their front ends with a frame work consisting of a lower transverse girder 7 and an upper transverse girder 8, which are intercoupled by a pair of struts 9 converging in upward direction. The frame work is included in the frame at an angle of approximately 45° for a proper abutment and a proper connection with the rear wall of a hopper 10 which is V-shaped in side view. The hopper 10, having a shape which is known per se, comprises a larger lower part including two right-angled funnel-shaped portions whose inner side walls, extending in the direction of travel A, are interconnected at least near their upper edges . Below the lower longitudinal girders 5 the frame 3 is provided with two horizontal U-sections 11 extending transversely to the direction of travel and facing each other with their open sides. The foremost one of these U-sections 11 is located substantially over the front boundary of the roller 2 and is connected with the lower transverse girder 7 via supporting lugs 12 closing off the ends of the U-section. In an analogous manner, via supporting lugs 13, the rearmost U-section 11 is connected with a cross-beam 14 provided between the lower longitudinal girders 5. The legs 15 and 16 of the U-sections 11 extend horizontally. The U-sections 11 are both included in the implement 1 at equal level. The roller 2 is supported against the U-sections 11 inter alia via a central support 18. For this purpose the roller 2 comprises a supporting element 19, which, in the present embodiment, is designed as a single, vertically arranged plate at whose upper side there are provided axle portions 20 extending transversely to the lateral direction of the roller to between a lower leg 15 and an upper leg 16 of the U- sections 11. Around the axle portions 20, substantially between the lower leg 15 and the upper leg 16 of a U-section 11, there are provided fitting bearings 21. In the embodiment shown, the front and the rear axle portions 20 constitute an integral whole, so that there is obtained a reinforcement of the supporting element 19, which is plate-shaped in the present embodiment. For that purpose the central portion is thicker than the end portions on which the bearings 21 are disposed. In a non-shown embodiment, the supporting element 19 is constituted by two plate parts disposed in an inverted V-shaped arrangement. In side view, a supporting element 19 has a substantially triangular shape, the rear and lower angle coinciding with a horizontal cross-beam 23 pertaining to the roller frame. The cross-beam 23 is included in the machine in the imaginary plane outside the upper and rear quadrant of the roller 2, and is connected with the axis 25 of the roller 2 via roller frame portions 24 extending towards the axis 25 of the roller. According to the invention, any roller may be applied. The embodiment shown in Figure 1 comprises a packer roller, whereas Figure 7 shows an embodiment comprising a so-called segment roller. In the preferred embodiment of Figure 7 comprising roller segments 22, in this case in the form of tyres, the frame portions 24 extend between the segments 22 towards the axis 25. In an embodiment in the form of e.g. a packer roller, i.e. a roller having a closed cylindrical circumferential wall on which there are provided, wreath-wise, protrusions for the purpose of a favourable running out of the roller, the frame portions 24 are passed along the ends of the roller 2. The roller 2 is furthermore connected with the frame 3 of the implement 1 via a quadrangle hinge construction having substantially upwardly directed pivotal axes 29. To this end, in the present embodiment on the outside of the supporting lugs 12, the frame 3 is provided with pairs of lugs 27 in which there may be included a pivotal axis 29 at an angle of approximately 15° upwards and rearwards as well as upwards and sidewards. In an analogous manner, the roller frame 23, 24 is provided with pairs of lugs 28, e.g. disposed on the inside of a roller frame portion 24. Between a foremost pair of lugs 27 and a rearmost pair of lugs 28 provided on the relevant side of the machine, there extends a connecting arm 30. Near its two ends, an arm 30 is coupled with the pivotal axis 29 via a ball-and-socket joint 26. The two arms 30 extend downwards in rearward direction, which enables a mutual pivoting movement of the frame 3 and the roller 2 about the pivotal axis 20: the front sides of the arms have a fixed position just below the frame 3, whereas the rear ends of the arms 30 have to be located at some distance from the frame for being able to pivot along with the roller 2. This construction favours the compactness of the implement and forms a separate subject of the invention. For limiting the mutual pivotability, the frame 3 is provided with stops 31 constituted by plate parts which extend from a lower longitudinal girder 5 in outward direction and which are reinforced by means of at least one rib 32. The stop 31 being made of plate material ensures the stop of a rear pivotal axis 29 in any position of the roller 2 relative to the frame 3.

The function of the machine will be explained in what follows.

During operation, the frame 3 is pushed forward by the front lifting hitch of a tractor and the lifting hitch is fixed in a position in which the weight of the front side of the tractor, and that of the implement 1, is distributed over the roller 2 and the front wheels of the tractor. In particular when for example after a primary soil cultivation, such as ploughing, the soil is crumbled in a secundary working run by means of e.g. a rotary harrow to a depth which is for cereal crop usually relatively small, this results in that the lower layer of primarily cultivated soil is properly pushed against the uncultivated underlayer for the purpose of capillary supply of water. Nevertheless, for example when the primary objective is to support the weight of the implement 1 including the hopper 10 only to a minimum extent on the ground via the tractor, it is possible to fix the lifting hitch of the tractor in a floating position.

The specific supporting means in the machine, constituted by the guide faces 15, 16, the axle 20, the bearings 21 and the quadrangle hinge construction 29, 30, enable in a favourable manner a simultaneous pivoting movement of the roller 2 relative to the frame 3 about an imaginary vertical pivotal axis when steering the front tractor wheels. Such a construction facilitates the steering of the tractor-machine combination during operation, in particular when the latter comprises a soil cultivating implement, such as the combination of a rotary harrow or cultivator with a seed drill.

During operation, the roller 2 adapts itself to unevennesses in the soil surface by pivoting about the horizontal axis 20, which pivotal movement is also allowed by means of the ball-and-socket joint constructions 26 near the pivotal axes 29 of the connecting arms 30. In view of an ample fitting in the connecting points of the quadrangle hinge construction, which also allows such a mutual pivotability of the roller 2 and the frame 3, a ball-and- socket joint 26 has the advantage that the bearings 21 are positioned exactly relative to the guide faces 15 and 16, thus enabling a minimum width thereof. In a more expensive embodiment, the guide faces 15 and 16 perform a curved path equal to the curve defined by the quadrangle hinge construction. The shown construction comprising a standard U-section 11 having relatively wide legs 15, 16 has the advantage of being able to be produced in a quick and cheap manner. The pushing force of the tractor is substantially transferred to the roller 2 via the steering arms 30, while the two bearings 21 and the supporting element 19 ensure a fixed and correct position of the roller 2. Due to the indicated position of the bearings 21, both the foremost and the rearmost bearing 21 are supported against the upper guide face 16 during operation. Upon lifting of the machine, the bearings 21 rest on the lower guide faces 15. In a non-shown alternative for the guide faces 15, a support 18 is suspended in the frame 3 by means of one or more flexible connecting elements, such as chains. The position of the bearings 21 near the front, respectively the rear boundary of the roller 2 also constitutes a favourable compromise between the moments occurring when the implement 1 is being supported on the one hand, and the magnitude of the curve described by the bearings 21 when the roller 2 is being operated on the other hand. The mutual pivotability of the roller 2 and the frame portion 3 has the advantage that torsion forces, occurring during operation in the implement 1 and in the connection thereof with the tractor, are limited.

In the specific embodiment of the invention in which the implement 1 constitutes part of an agricultural machine designed as a sowing or broadcasting machine, the implement 1 is provided with a hopper 10 including metering devices 34 connected to the outlets thereof. Said metering devices 34, driven by means of an electromotor 35, supply the metered sowing seed to a venturi-device 36 by means of which the metered seed is fed to an air current for the purpose of transport to sowing or broadcasting elements. Figure 4 shows a metering wheel 33 and a rebound plate 47, via which metered seed is fed to an air current supplied via a supply hose 37 and accelerated by means of a venturi-element 48. The air-seed mixture is supplied via a discharge hose 38 to a non-shown sowing or broadcasting unit. The discharge hose 38 is connected to a discharge cone 49 constituting part of the venturi-device 36. The supply opening of the discharge cone 49 is located at some distance from the discharge opening of the venturi-element 48 in a housing 50 which constitutes partially a unit with the discharge cone 49. The housing portion connected with the discharge cone 49 is capable of being removed via clamping elements 51 from the housing portion which is connected with the venturi-element 48, after detaching the clamping elements 51 and after displacement of the housing portion connected with the discharge cone 49 through a right-angled open slotted hole 52. The housing portion connected with the venturi-element 48 is rigidly connected to the metering device 34 by means of clamping elements disposed at the points 53. For the purpose of a correct mutual positioning of the housing portions, the detachable housing portion is provided with a stop 54 disposed on a bottom plate of the housing 50. The release of the discharge opening of the metering device 34 described in the foregoing serves a simple calibration of the metering device 34 by means of a test.

Figure 6 shows an alternative construction for the release of said opening with the aid of a horizontally disposed pivotal axis 56. For this purpose, in an alternative construction, a venturi-element 57 is provided with a flange 58 which is pivotable on one side about a horizontal pivotal axis 56, orientated transversely to the direction of travel, relative to a flange disposed on the metering device 34. During operation, the venturi-element 57 is capable of being fixed to the metering device 34 by means of the clamping element 58 which can be pivoted from a clamping position about a pivotal axis 59, which is also disposed horizontally and transversely to the direction of travel. The alternative construction 57 has the advantage that the release can be effected quickly and without the risk of contamination of a venturi-portion and that a correct and quick mutual positioning of the metering device 34 and a venturi-device 57 is guaranteed.

For generating the air current for the purpose of the transport of the metered seed, the machine is provided with a ventilator 40 constituting part of a ventilator unit including a carrier 41 on which the ventilator 40 is arranged. The carrier 41 extends transversely to the drive shaft of the ventilator or air pump 40, which, with an outer end and near its drive shaft, is connected in the connecting point 42 via lugs, with the upper transverse girder 8 and, with the other end near the vertical imaginary centre plane M of the machine extending in the direction of travel, is connected in the connecting point 43, also via lugs, with the cross-beam 14. The ventilator unit 39 comprises a bearing supported drive shaft 44 which intersects the said centre plane M of the machine and which is connected via a support 45 with the carrier 41. Via a grooved end, the drive shaft 44 is capable of being coupled with a universal joint shaft for being driven from the front power take-off shaft of a tractor. In a stable initial position, the drive shaft 44 is located over the pivotal axis 20. Via driving wheels accommodated in a guard element 46 and one or more endless drive elements, preferably V-belts, disposed therebetween, the drive shaft 44 is in a driving connection with the ventilator 40. The carrier 41 has such dimensions that the ventilator 40 can be arranged on a lateral side of the coupling trestle 4, even when the dimensions of the ventilator 40 are relatively large, i.e. equal approximately the height of the coupling trestle 4. This has the advantage that, when the drive shaft of the ventilator and the drive shaft 44 are orientated in the direction of travel A, the most rearwardly located tangents of the ventilator 40 and the coupling trestle 4, extending transversely to the direction of travel, can coincide, thus enabling a minimum distance from the centre of gravity of the implement 1 to the tractor. Nevertheless, the shown construction provides a simple and effective drive of the ventilator 40. The ventilator 40 pumps air, sucked in via a central opening covered with gauze, through a flexible line 37, which is split up via at least one non-shown T-piece, to the venturi-devices 36 or 57. According to a preferred embodiment, the venturi-devices 36 or 57 are mounted in the machine so as to extend horizontally and transversely to the direction of travel A and debouch into conveyor hoses 38, which extend along the tractor in rearward direction and debouch into a sowing or broadcasting unit included in the machine.

Figures 8 and 9 illustrate a second alternative construction for releasing a discharge opening 61 of the metering device 34 known per se, e.g. for a test. By means of a test the metered quantity of seed is calibrated at a given number of revolutions of the metering wheel 33. The metering wheel 33 constitutes part of the metering device 34. During the rotating movement, the metering wheel 33 takes along seed, e.g. between its radial blades, which seed, at the level of the right under quarter of the shown wheel, falls down in the direction of an opening 61 giving access to a venturi-device such as the venturi-device 36 described in the foregoing.

Figure 8 shows in a front view the left one of at least two discharge openings in the hopper 10. In the present embodiment, the housing 50 of the venturi-device 36 is not detachable and the venturi-device 36 is connected with the slidable portion of a sliding device 62. The sliding device 62 comprises a fastening plate 63, which is provided near its lower side with guide strips made of synthetic material, and a recess in which a slide 65, made e.g. of metal plate material, is capable of being guided. The slide 65 is provided with a handle 66 and bears preferably with only four ridge-shaped protrusions 67 on the recesses in the guide strips 64 constituting a straight guide means for the slide 65. The recess in the guide strips preferably equals the thickness of the material of which the slide 65 is made. Near the rear side the fastening plate 63 is provided with a rear lug 68 at whose lower side there is provided a stop for the slide 65, e.g. in the form of a nutted bolt connection or which lug 68 constitutes a stop itself by being bent over 90° in downward direction. Both the slide 65 and the fastening plate 63 are provided with an aperture which equals the opening 61 in the metering device 34. More in particular the slide 65 and the fastening plate 63 may be designed as rectangular frame works made of plate material. Halfway the frame work of the carrier there is disposed a transverse connecting means including an opening 69 through which a locking pin can be passed for locking the slide 65 into the operative position, e.g. by means of a locking pin 70. Near its front end the fastening plate 63 is still provided with a foremost stop 73 which prevents the slide 65 from being pulled from the straight guide means 64 when releasing the discharge opening 61.

The length of the fastening plate 63 and the guide strips 64 equals double the length of the slide 65. There is obtained a proper guiding or supporting upon moving to a foremost position of the venturi-device, in which the discharge opening 61 in the metering device 34 is released. Figure 9 shows the slide in the operative position in which the opening in the housing of the venturi-device 36 is located under the opening 61.

In the present embodiment, a carrier 72 is disposed against the venturi-device 36, which carrier 72 supports the discharge hose 38 of the venturi-device under the right discharge opening of the machine. In the present embodiment, the carrier is ring-shaped and the discharge hose 38 is passed through the ring. As a result, upon release of the discharge opening 61, making use of the clearance or movability in the discharge hose 38, the discharge hose of the neighbouring discharge opening is moved along, so that the space under the metering device 34 remains available for disposing a receptacle, a measuring cup or a bucket.

The present embodiment has furthermore the advantage that the opening can be opened by the user in a simple manner in that the handle 66 is or may be provided at a small distance from the front side of the machine and in that upon replacement of the venturi-device there is no need to work against the gravity acting on the venturi-device and the supply and discharge hoses 37 and 38 connected thereto. This applies all the more since the venturi-device because of its position under the hopper will necessarily be at a relatively large distance from the body of the user when said hopper is being manoeuvred. The slide 65 bears preferably with only four ridges 67 on the guide strips 64, so that it will be possible to reduce friction, occurring as a conse- quence of contamination of the strips, to a minimum and to counteract same in an effective manner during operation of the slide.

The invention is not restricted to the aforementioned description, but also relates to all the details in the drawings, in particular also to the components contributing to the invention. The invention further relates to all sorts of alternatives in the construction, of course, being within the terms of the following claims.

Claims

1. An agricultural machine, in particular a soil cultivating machine, such as a seed drill whether or not combined with a cultivator, which agricultural machine is provided with a supporting implement (1) for coupling to the front lifting hitch of a tractor, which implement, for the purpose of being supported on the ground, is provided with a roller (2) that is connected with a frame (3), characterized in that between the frame (3) and the roller (2) there are provided suitable supporting means (18; 19 - 21, 23, 24) for a mutual pivoting movement about an imaginary or real axis (20) which is at least orientated in the direction of travel (A).

2. An agricultural machine as claimed in claim 1, characterized in that the supporting means

(18; 19 - 21, 23, 24) comprise a real pivotal axis (20).

3. An agricultural machine as claimed in claim 1 or 2 , characterized in that one or more front support points (21) are located between the roller (2) and the frame (3) in front of the centre line of the roller, and one or more rear support points (21) are located behind the centre line of the roller (2 ) .

4. An agricultural machine as claimed in claim 3, characterized in that the supporting means (18; 19 - 21, 23, 24) comprise a roller bearing.

5. An agricultural machine as claimed in any one of the preceding claims, characterized in that the supporting means (15 - 24) are limitedly movable across or along a guide face (15, 16) included in the frame (3) or in the roller construction (2; 23 - 25).

6. An agricultural machine as claimed in claim 5, characterized in that a guide face (15, 16) constitutes part of a U-profile (11).

7. An agricultural machine as claimed in any one of the preceding claims, characterized in that the roller (2) is connected with the frame (3) via a quadrangle hinge construction (29, 30) having substantially upwardly directed pivotal axes (29).

8. An agricultural machine as claimed in claim 7, characterized in that a guide face (15, 16) is disposed between the imaginary pivotal axes (29) of the quadrangle hinge construction (29, 30), which imaginary pivotal axes (29) are located on a transverse line in the implement.

9. An agricultural machine as claimed in claim 7 or 8, characterized in that the quadrangle hinge construction (29, 30) is constituted by a trapezium construction having two arms (30) converging in forward direction.

10. An agricultural machine as claimed in claim 9, characterized in that, relative to the usual direction of travel of the agricultural machine, the arms (30) are disposed so as to extend downwards in rearward direction.

11. An agricultural machine as claimed in claim 9 or 10, characterized in that the arms (30) are connected with a pivotal axis (29) via a ball and socket joint (26).

12. An agricultural machine as claimed in any one of claims 7 - 11, characterized in that the supporting implement (1) comprises a hopper (10) having one or more outlets (17) debouching in front of the foremost pivotal axes (29).

13. An agricultural machine as claimed in any one of claims 7 - 12, characterized in that the foremost pivotal axes (29) are disposed in front of the roller (2) and the rearmost pivotal axes (29) are arranged behind the roller (2).

14. An agricultural machine, in particular as claimed in any one of the preceding claims, characterized in that the frame (3) comprises a substantially triangular coupling trestle (4) for coupling to the front lifting hitch of the tractor, to which trestle (4) there are mounted lower and upper arms (5, 6) extending substantially horizontally in forward direction, which arms (5, 6) form the connection of the coupling trestle (4) with a foremost frame work of two horizontal carriers (7, 8) interconnected by struts (9).

15. An agricultural machine as claimed in any one of the preceding claims, characterized in that the roller (2) is provided with a horizontal roller frame beam (23) which, via arm portions (24) is connected with the axis (25) of the roller (2), to which roller frame beam (23) there is mounted a support (18) extending upwards and forwards for supporting supporting means (15, 16, 21, 22) disposed between the frame (3) and the roller (2).

16. An agricultural machine as claimed in any one of the preceding claims, characterized in that the roller (2) comprises a central axis (25) on which there are disposed roller segments (22), such as tyres, and that the supporting means (18) provided between the frame (3) and the roller (2) comprise at least one support (24) extending between the roller segments towards the axis (25).

17. An agricultural machine as claimed in any one of the preceding claims, characterized in that the supporting means (15, 16, 19, 20) comprise at least one U-shaped section (11) in which a bearing (21) rotatable about an axis (20) is capable of performing a curved path, defined by the quadrangle hinge construction (29, 30) and caused by a mutual pivoting movement .

18. An agricultural machine as claimed in any one of the preceding claims, characterized in that two U-shaped sections (11) facing each other are included in the frame (3), at least substantially at equal height, and the relevant bearings (21) are coupled with the roller (2) via an axis (20).

19. An implement (1) for coupling to the lifting hitch of a tractor, in particular to the front lifting hitch, as described in any one of the preceding claims.

20. A roller (2), in particular as described in any one of the preceding claims, adapted to be applied in a machine as claimed in any one of the preceding claims.

21. An agricultural machine provided with a supporting implement (1) as claimed in any one of the preceding claims and provided with a hopper (10) which is connected to the frame.

22. An agricultural machine as claimed in claim 21, characterized in that the implement (1) is provided with a ventilator (40) for pneumatic transport of granular material present in the hopper (10), which ventilator (40) is connected, via an endless transmission element, with a drive shaft (44), adapted to be driven via a coupled axle, provided in the transverse centre of the implement.

23. An agricultural machine as claimed in particular in claim 21 or 22, characterized in that the implement (1) comprises a metering device (37) which debouches into a ven- turi-device (36) for mixing the metered seed in an air current, which venturi-device can release the outlet of the metering device (37) by pivoting about a horizontal axis (56).

24. An agricultural machine, in particular as claimed in any one of the preceding claims, comprising a sliding device (60) for releasing, by sliding parts in the machine, the discharge opening (61) under a metering wheel (33) of a metering device (34).

25. An agricultural machine as claimed in claim 24, characterized in that the sliding device (62) is provided with a handle (66) near the front side of the machine.

26. An agricultural machine as claimed in claim 24 or 25, characterized in that the sliding device (62) is provided with straight guide means (64) for guiding a slide (65) in forward direction in the machine to the place where the discharge opening (61) of the metering device (34) is located during operation.

27. An agricultural machine as claimed in claim 26, characterized in that the length of the straight guide means (64) at least approximately equals double the length of the slide ( 65) .

28. An agricultural machine as claimed in any one of claims 24 - 27, characterized in that the machine parts (36) to be displaced are provided with a carrier (72) for displacing, together with the machine parts (36), a discharge hose (38) which is connected to a second machine part (36) in the machine .

29. An agricultural machine or part thereof, as described in any one of the preceding claims.