REVERSIBLE PLOUGH WITH COMBINED WHEEL

Abstract

A reversible plough (1) including a frame (2) which is rotatable about a first axis (X1) between two opposite working positions, in which ploughing members which are mounted on the frame (2) are in a working position and in a rest position, respectively. The frame (2) is further rotatable about the first axis (X1) in a transport position which is angularly intermediate between the working positions. The plough further comprises a combined wheel adjustment device (6) configured to selectively take up, with respect to the frame (2), two working positions in which the device (6) adjusts the working depth of the respective ploughing members and a transport position, with which the device (6) at least partially supports the frame (2). The device (6) comprises an attachment member (7) with respect to the frame (2) and a support (20) which is secured to the attachment member (7) in a rotatable manner about a second axis (X2) and which carries at least one arm (40) for adjusting the working depth which is secured in a tilting manner about a third axis (X3) and a wheel (44) which is rotatably idle about a fourth axis (X4).

Description

[0001] Reversible plough with combined wheel

[0002] DESCRIPTION

[0003] The present invention relates to a reversible plough with a combined wheel which is preferably constructed according to the preamble of the main claim.

[0004] The invention particularly relates to a plough of the type which is carried during the work phase or integrally supported on the three-point linkage of a tractor and half-carried during the transport phase or pulled by the two lower points of the linkage.

[0005] Such ploughs are characterized by the presence of at least one wheel, particularly referred to as the combined wheel, which serves in the work phase to adjust the ploughing depth and in the transport phase to support the plough on the road at the distal side with respect to the three-point linkage. In a reversible plough, there is provided a frame which carries at least one pair, but preferably a plurality of pairs of opposite right and left ploughing members and a head of the plough which serves to engage the plough with the pulling apparatus (tractor). The combined wheel is mounted on the frame preferably but not necessarily at the opposite side to the head and is provided to take up two working positions, by rotating with respect to the frame at opposite sides depending on whether the right or left ploughing members operate and at least one transport position in which the frame and the ploughing members are supported in the transport phase above the wheel. In theory, this wheel should always be aligned with the travel direction of the plough in order to avoid wear and abnormal forces. As a result of the operation of the plough and in particular the adjustments thereof, however, the wheel cannot remain fixed at a predetermined angle to the frame. The problem is counter-acted by using wheels for adjusting the working depth which are secured to the frame via connecting rods, in accordance with a pattern which is generally similar to an articulated parallelogram, which serve to orientate the wheel so that it is always arranged parallel with the working plough body. However, this system provides only an approximate solution because it does not take into account an additional positioning variant of the plough in the work phase given by the heel setting of the plough which varies in accordance with the ground and the type of plough. The adjustment of the heel setting involves varying the geometry of the plough so that, in the work phase, it proceeds with a modest angulation with respect to the advance direction. However, it is important because it allows elimination of the lateral thrust, optimizing the arrangement of the traction points. This involves a series of disadvantages, all substantially correlating with the fact that the pulling of the depth adjustment wheel while it is also arranged only at a slightly oblique position with respect to the advance direction of the plough brings about sliding of the wheel on the support ground. This causes the wheel to be subjected to premature wear, to collect mud and crop residues which obstruct the free rotation thereof and does not take account of the heel setting of the plough at all. In particular, the wheel applies a reaction to the ground having a transverse component relative to the advance direction which, at most, can redirect the plough by urging it laterally with respect to the advance direction which is programmed by the adjustment of the geometry of the plough itself.

[0006] The problem is solved only in the devices in which the wheel allows only depth adjustment, allowing the support arm of the wheel a limited degree of freedom in terms of orientation about a vertical axis. In such devices, however, it is necessary to have a wheel dedicated only to transport on roads, it not being possible to use the depth wheel to this end. Therefore, the system is not used in combined wheel devices and it cannot be transferred in this context without substantially great changes to the same device.

[0007] EP 4147547 describes a reversible plough with a combined wheel, wherein the wheel is carried by a pivotable arm in the three positions indicated but secured to the frame in a rigidly parallel manner with respect to the presumed advance direction of the plough during the work phases. In practice, in the two working positions, the wheel does not have the freedom to take up an advance orientation which is completely parallel with the work direction, this orientation being rigidly predetermined by the securing action between the carrying structure of the wheel and the frame.

[0008] EP2875707 describes a combined wheel with a different rotation mechanism between the three possible operating positions, meaning two positions for adjusting the ploughing depth and one transport position, but it is also rigidly secured to the plough frame and is therefore subject to the same disadvantages indicated above.

[0009] The problem addressed by the present invention is therefore to configure a reversible plough with a combined wheel which is structurally and functionally constructed to at least partially overcome the disadvantages set out with reference to the cited prior art.

[0010] In the context of this problem, an object of the invention is to provide a plough in which, besides the benefits of working depth and transport adjustment, provided by the structure of the combined wheel device, it is possible to obtain a situation in which the wheel itself, in the working depth adjustment phase, is advantageously slidable and does not involve wear or accumulations of earth and residual crops.

[0011] Another object of the invention is to provide a plough in which there are provided means for blocking the wheel in the working and / or transport positions which are particularly advantageous and efficient.

[0012] This problem with these and other objects which will be better appreciated below are solved and achieved by the invention by a reversible plough which is constructed according to one or more of the following claims.

[0013] In a preferred embodiment, a reversible plough comprises a frame which is rotatable about a first axis between two opposite working positions, in which ploughing members which are mounted on the frame and which are opposite in pairs are in a working position and in a rest position, respectively. The geometry of the ploughing members and the frame together defines an advance direction of the plough.

[0014] Preferably, the frame is further rotatable about the first axis in a transport position which is angularly intermediate between the working positions.

[0015] In a preferred exemplary embodiment of the invention, the plough comprises a combined wheel adjustment device configured to selectively take up, with respect to the frame, two working positions in which the device adjusts the working depth of the respective ploughing members and a transport position, with which the device at least partially supports the frame, depending on the angular position of the frame with respect to the first axis.

[0016] Preferably, the combined wheel device comprises: an attachment member with respect to the frame, a support which is secured to the attachment member in a rotatable manner about a second axis and which carries at least one arm for adjusting the working depth which is secured in a tilting manner about a third axis to the support.

[0017] Preferably, the arm for adjusting the working depth carries a wheel which is rotatably idle about a fourth axis, the third axis and fourth axis being substantially perpendicular to the second axis and the second axis constituting a reversal axis of the wheel with the relevant arm and support as a result of the effect of its own weight between the working position and transport position.

[0018] There are preferably provided blocking means for blocking the rotation of the support about the second axis in the respective working positions and in the transport position.

[0019] In one embodiment of the invention, the support is secured to the attachment member in a freely rotatable manner about a fifth axis in such a manner that the wheel is freely able to be orientated with respect to the frame about the fifth axis which is substantially perpendicular to the advance direction at least for a limited angular path which is not zero, in the two working positions, so as to be arranged in a self-aligned manner with respect to the advance direction.

[0020] In one embodiment of the invention, the support is connected with the attachment member to the frame through a first hinge joint which is rotatable about the fifth axis and there are provided travel limiting means between the joint and the attachment member for limiting the swinging of the joint about the fifth axis.

[0021] According to a preferred embodiment, the first joint comprises a first hinge element which is fixedly joined to the attachment member and a second hinge element which is mounted on the support, the first and second hinge elements of the first joint being secured about the fifth axis, the support being secured to the second hinge element of the first joint through a second hinge joint which is rotatable about the second axis.

[0022] According to a preferred aspect, the second hinge joint comprises a pin which extends from the second hinge element of the first joint perpendicularly to the fifth axis and which is received in a rotational seat in the support.

[0023] Preferably, the blocking means are provided between the pin and the support in order to block the rotation of the support on the pin in predefined angular positions.

[0024] According to an aspect of the invention, the blocking means comprise a collar which is mounted in a fixed manner in terms of rotation on the pin so as to rotate together with the second hinge element and at least one angular abutment, and preferably two angular abutments, which is / are diametrically opposite and which are formed on the collar, a stop member being mounted on the support and being able to be connected to the at least one angular abutment in the respective working positions.

[0025] Preferably, the stop member comprises a peg which is movable away from and towards the at least one angular abutment counter to a spring.

[0026] Alternatively, the blocking means comprise a second hydraulic actuator which is active between the second hinge element and the support.

[0027] In this case, it is preferable for the second hydraulic actuator to be of the singleaction type.

[0028] Preferably, the blocking means comprise a form-fitting connection between the attachment member and the support so as to fixedly join the attachment member and the support in terms of rotation about the second axis when the plough is half-carried in a transport position. Preferably, the form-fitting connection is formed between respective walls of the attachment member and at least one runner which is mounted on the support in such a position as to be interposed between the walls of the attachment member when the frame of the plough is in the transport position.

[0029] According to an advantageous aspect, a first actuator is interposed between the support and the at least one arm of the combined wheel device for adjusting the working depth of the plough through the combined wheel device. Preferably, this first actuator is a hydraulic actuator.

[0030] Preferably, a pressure accumulator is connected to the first hydraulic actuator in order to use the first actuator so as to act as a hydraulic damper when the plough is in a transport position.

[0031] In this case, there is preferably provision for interception valve means to be interposed in the connection between the first actuator and the pressure accumulator.

[0032] According to another aspect of the invention, these valve means are actuated by the attachment member when it is engaged in the form-fitting connection.

[0033] The features and advantages of the invention will be better appreciated from the following detailed description of two preferred embodiments thereof which are illustrated by way of non-limiting example with reference to the appended drawings, in which:

[0034] Figures 1 and 2 are side views of a plough according to the invention in a transport position and a working position, respectively;

[0035] Figures 3 and 4 are side views of a combined wheel adjustment device in a transport position and a working position, respectively;

[0036] Figure 5 is a side view of the combined wheel adjustment device of Figure 3; Figures 6, 7 and 8 are a side view, a cross-section and a detail of a first exemplary embodiment of the invention, respectively;

[0037] Figures 9 and 10 are a side view and a cross-section of a second exemplary embodiment of the invention, respectively.

[0038] In the Figures, there is generally designated 1 a reversible plough which includes a frame 2 which carries at one end a head 3 and which carries a plurality of pairs of opposite and symmetrical right 4d and left 4s ploughing members. By a reversal mechanism which is integrated in the head 3, the frame 2 is rotatable about a first axis XI between two working positions which are opposite each other at approximately 180° and an intermediate transport position which is rotated by approximately 90° with respect to the preceding two positions.

[0039] In the working positions, one series of ploughing members is working in order to turn over the earth while the other series of ploughing members is vertically opposite in a rest position. In the transport position, the ploughing members are horizontally opposite and the frame 2 is supported at one end by two lower attachments 5 of a three-point linkage and at the opposite side by a combined wheel adjustment device 6.

[0040] The combined wheel device 6 serves to adjust the working depth of the ploughing members when they are in a working position, alternating at one side and the other of the frame 2 in accordance with the position taken up by the frame and that of the ground support system of the plough in the transport position. It is caused to rotate between the above-mentioned positions as a result of the effect of its own weight following the rotation imposed on the frame 2.

[0041] This device 6 comprises an attachment member 7 with respect to the frame 2, preferably including a plate 8 which is provided to be rigidly fixed to the frame by screws 9 and which has an opening 17 in a central position. The attachment member 7 is provided, at one side thereof, opposite the frame 2, with two walls 11 which are bored for the passage of a pin 12 so as to constitute a first hinge element of a first hinge joint which is generally designated 13. The axis of the pin 12, or the axis of the joint 13, is indicated below as the fifth axis X5.

[0042] A second hinge element 14 of the joint 13 is hinged to the pin 12 so as to be able to rotate about the axis X5. The rotation is free (that is to say, it is not opposed by anything) but limited to a small angle through the interaction of an extension piece 16 which is fixed to the second hinge element and which interacts in the opening 17 of the plate 8 in accordance with the angular travel limiter of the joint 13. This function can further be performed via travel limiters of another type which are known to the person skilled in the art.

[0043] Therefore, the joint 13 allows the second hinge element 14 to freely take up any angular position about the axis X5 within the abutment limits of the extension piece 16 between the longitudinally opposite shoulders of the opening 17.

[0044] The combined wheel device 6 further comprises a support 20 which is preferably of the box-shaped type and which is in turn rotatably hinged (for example, through bearings 23 or bushes) about a second axis X2 on a pin 21 which extends radially from the second hinge element with the axis X2 perpendicular to the axis X5. The assembly of the pin 21 and the bearings 23 is received in a tubular sleeve 24 or other structure suitable for constituting a rotation seat of the pin 21 and a second hinge joint 22 between the support 20 and the first joint 13.

[0045] Blocking means 25, 26 are provided between the pin 21 and the support 20 in order to block the support 20 on the pin 21 and, consequently, the second joint 22 in predetermined angular positions. The blocking means 25 comprise a collar 27 which is mounted so as to be fixedly joined in terms of rotation on the pin 21 so as to rotate together with the second hinge element 14 and at least one angular abutment 28 and preferably two abutments 28 which are formed on the collar 27 in diametrically opposite positions.

[0046] It may be understood that the function of the collar 27 is only to carry the angular abutments 28. Therefore, it may take up any formation and arrangement suitable for maintaining a predetermined angular position between the angular abutments 28, for example, may be an integral part of the pin 21. The angular abutments 28 are angularly spaced apart by approximately 180° relative to each other in order to allow the positioning of the system 6 in the two working positions of the ploughing members.

[0047] The angular abutments 28 are preferably in the form of flared and rounded holes (in practice, half-dome-like) which are suitable for abutting, while receiving it, a stop member, for example, formed by a stop peg 30, preferably having a rounded or conical head.

[0048] The peg 30 is preferably guided in a bush 31 and is urged to engage with the abutments 28 by a fluid-dynamic cylinder 32 which, when it is pressurized as explained below, urges the peg 30 radially towards the collar 27, overcoming the counteraction provided by a disengaging spring 33. Conversely, when the fluid-dynamic cylinder 32 is connected for release, the spring 33 gives way to the hydraulic thrust of the cylinder 32, extracting the peg 30 from the annular abutments and allowing the rotation of the support 20 about the second axis X2. It may be understood that the peg may be integrated in the rod of the cylinder 32.

[0049] Furthermore, there is hinged to the support 20 an arm 40, the fulcrum of which is formed by a pin 41 which defines a third axis X3 which is perpendicular to the axes X5 and X2.

[0050] The arm 40 preferably comprises two flanks 42 and has at the end distal from the pin 41 a fourth pin 43 which defines a fourth axis X4 which is preferably parallel with the third axis X3 and on which a wheel 44 is mounted in a rotatably idle manner. The wheel 44 performs both the function of adjustment of the ploughing depth and the function of supporting the plough during the transport phase. As a result of these two functions, it is called a combined wheel.

[0051] Each flank 42 of the arm 40 comprises an extension 53. A first actuator 45, which is preferably hydraulic (but where applicable also manual, with a simple screw coupling) is interposed between a pin 46 which is mounted between the extensions 53 and the support 20, where it is anchored by a pin 47. The first actuator 45 serves to tilt the arm 40 about the third axis X3 during the ploughing depth adjustments. The adjustment imposed is where applicable displayed by a slider 57 which is associated with the first actuator 45. There is further preferably provided a pressure accumulator 48 which is connected to the first actuator 45, if a hydraulic actuator is used, which allows use of the first actuator 45 itself as a damper according to what is described below. The hydraulic connection between the accumulator 48 and the hydraulic circuit of the first actuator 45 is controlled by interception valve means 61. Preferably, these interception valve means 61 may comprise a valve 49. The valve 49 can be both a manual control valve (mechanical or electrical) and an automatic control valve, in this second case a valve with push-button control 50 preferably being used, the valve being of the normally closed type and mounted, for example, on one of the extensions 53 in such a position as to interact with one of the walls 11 or another component fixed to the frame in the transport position of the plough in order to place the first actuator 45 in hydraulic connection with the pressure accumulator 48 when the attachment member is pivoted about the fifth axis X5 towards the support 20 in the transport position of the plough.

[0052] Preferably, an additional blocking means 26 of the combined wheel device 6 according to the invention is used exclusively in the transport position of the plough 1, blocking the rotation of the combined wheel about the second axis X2. The blocking means 26 comprises a form-fitting connection between the attachment member 7 and the support 20 so as to fixedly join in terms of rotation about the second axis X2 the attachment member 7 and the support 20 when the plough is half-carried in the transport position.

[0053] This form-fitting connection is brought about between at least one runner 60, preferably a pair of runners 60 (where applicable, which can be combined to form a single block-shaped member). These runners 60 can be positioned in such a manner as to be interposed between the walls 11 of the attachment member 7 when the frame of the plough is in the transport position. In this manner, when the wheel 44 is supported on the ground during the transport phase and the arms of the combined wheel device are pivoted about the third axis X3, the runners 60 are gradually inserted between the walls 11 of the attachment member, blocking the rotation about the second axis X2 and fifth axis X5.

[0054] It may be observed that the axis of the pin 12 of the attachment member moves from a vertical arrangement with respect to the ground, corresponding to the working condition of the plough 1, to a substantially horizontal position which blocks the plough 1 in the transport position via the form-fitting connection between the runners 60 and the walls 11.

[0055] A construction variant of the invention, which is generally designated 101, relates to the configuration of the blocking means. Similar or technically equivalent details are indicated with the same reference numerals as the preceding example.

[0056] In this case, a second hydraulic actuator 102 is used, preferably and advantageously of the single-action type, which is active between the second hinge element 14 and the support 20. A rod 103 of the second actuator 102 is hinged to an arm 104, preferably fixed so as to project radially from the second hinge element. A cylinder 105 of the second actuator 102 is in turn secured to the base of the support 20, preferably in a central position thereof. This means that, when the cylinder 105 is pressurized, the second actuator 102 is blocked in terms of extension, thereby preventing the rotation of the support 20 about the fifth axis X5, while, when the cylinder is connected for release, rotation is possible. There is provided between the support 20 and the attachment member 7 a rotation limiter 108 (in particular, rotation about the axis X2) which is formed between an abutment surface 109 of the support and an abutment 110 which is fixedly joined to the pin 21. The two are in a mutually abutting state when they are in a working position and the cylinder 105 is pressurized.

[0057] The operation of the plough is described below.

[0058] Starting from a working condition, for example, in which the ploughed ground is turned over to the right with respect to the advance direction of the plough (example of Figure 2) in one travel path, wishing to reverse the plough in order to arrange it so as to plough the ground "evenly", that is to say, by turning over the earth in the same manner during the return path, it is necessary to actuate the mechanisms which are provided for reversing the ploughing members 4d, 4s which are mounted on the head 3. The frame 2 is thereby rotated by 180° and the combined wheel device 6, remaining practically stopped, rotates in fact with respect to the frame under the action of its own weight, thereby being brought from the same side of the ploughing members, opposite the ploughing furrows.

[0059] If there is no intervention in the ploughing depth adjustment by adjusting the first actuator 45, the previously imposed depth is also repeated during the return path. In all these steps, the plough is completely carried by the three- point linkage of the agricultural tractor and the combined wheel performs only the function of depth adjustment. The setting through the first actuator 45 is intuitive per se and is demonstrated by the position of the slider 47.

[0060] In order to change from the working position of the frame 2 to the transport position, initially there is actuated the device of the tractor which governs the raising of the plough. Therefore, the plough 1 is provided to be rotated through 90° with respect to the working position.

[0061] This type of plough is generally fitted in a manner known per se with a hydraulic alignment device for the frame which automatically intervenes, before starting the rotation of the frame, in order to reduce the spatial requirement of the plough with respect to the rotation axis and thereby to facilitate the rotation of the frame, particularly preventing impacts with the ground.

[0062] In the first embodiment of the invention, the one provided with an unblocking system of the rotation via the disengaging spring 33, the cylinder 32 is preferably connected to the hydraulic alignment device in such a manner that, during the alignment step of the plough which precedes the rotation thereof, the cylinder 32 is depressurized and moved into an unblocking condition by disengaging the abutment peg 30 from the angular abutments 28 in response to the action of the spring 33. In this manner, the collar is free to rotate together with the pin 21 about the second axis. When the plough is rotated following, for example, the reversal of the travel direction, the wheel 44 remains substantially stopped as a result of the effect of its own weight while the frame 2 of the plough moves at the opposite side of the wheel with respect to the preceding position. The peg 30 is urged towards the collar as a result of the effect of the spring 33 until it is facing the angular abutment which is diametrically opposite, engaging with it and therefore blocking the rotation of the support 20 about the second axis X2.

[0063] In the second embodiment of the invention, the one provided with an unblocking system of the rotation via the second actuator 102, it is also controlled by the hydraulic alignment device but the second actuator 102 is depressurized for the entire rotation step of the plough and pressurized only afterwards, in order to achieve the desired positioning.

[0064] The plough is thereby rotated through 90° with respect to the working position. Therefore, by the combined wheel 44 being placed on the ground and by the frame 2 of the plough being lowered, there is carried out the release of the third point of the three-point linkage with methods to which the present invention does not relate. When the combined wheel 44, which has taken up the transport orientation, is supported on the ground, there is initially an approach movement of the runners 60 towards the walls 11 of the attachment member 7. Continuing the descent, the walls 11 wrap around the runners 60 and the descent finishes when the support 20, through the runners 60 or otherwise, moves into support on the attachment member 7. There contribute to securing the combined wheel of this invention both the mass itself of the plough and the interlocking connection condition between the runners and the walls of the respective supports 20 and 7. In this manner, the second axis X2 and the fifth axis X5 remain blocked.

[0065] The invention thereby achieves the objects proposed, further affording important advantages including: - allowing elimination of the tie rods and connecting rods normally provided for the alignment of the wheel with the travel direction,

[0066] - obtaining the automatic engagement of the combined wheel with the frame in the transport phase,

[0067] - allowing damping of the stresses resulting from the transport phase, - obtaining a positioning of the combined wheel in the different, completely automatic phases.

Claims

1. A reversible plough (1; 101) comprising a frame (2) which is capable of rotation around a first axis (X1) between two opposite working positions, in which the plough elements (4d, 4s) mounted on the frame (2) and arranged opposite each other in pairs are in the working and non-working positions, respectively, wherein the geometry of the plough elements (4d, 4s) and the frame (2) together determines the direction of movement of the plough (1), wherein the frame (2) is also designed with the possibility of rotation around the first axis (X1) in the transport position, which is an angular intermediate position between the working positions, a combined wheel adjustment device (6) configured to selectively adopt two working positions relative to the frame (2), in which the device (6) regulates the working depth of the corresponding arable elements (4d, 4s), and a transport position, in which the device (6) at least partially supports the frame (2), depending on the angular position of the frame (2) relative to the first axis (X1), wherein the combined wheel device (6) comprises: fastening element (7) relative to the frame (2), a support (20) which is attached to the fastening element (7) with the possibility of rotation around the second axis (X2), wherein the support (20) carries at least one lever (40) for adjusting the working depth, which is attached in an inclined manner around the third axis (X3) to the support (20) and which carries a wheel (44) configured to rotate idly around a fourth axis (X4), wherein the third axis (X3) and the fourth axis (X4) are substantially perpendicular to the second axis (X2), the second axis (X2) forms the axis of reversal of the wheel (44) with its lever (40) and the support (20) as a result of the action of its own weight between the working and transport positions, locking means (25, 26) for locking the rotation of the support (20) around the second axis (X2) in the corresponding working and transport positions, characterized in that the support (20) is fixed to the fastening element (7) in a freely rotating manner around the fifth axis (X5) in such a way that the wheel (44) is capable of freely orienting itself relative to the frame (2) around the fifth axis (X5), which is essentially perpendicular to the direction of advancement, at leaston a limited angular path, different from zero, in two working positions with a self-aligning arrangement relative to the direction of advancement., 2. A reversible plough (1; 101) according to claim 1, in which the support (20) is connected by a fastening element (7) to the frame (2) by means of a first articulated joint (13) made with the possibility of rotation around a fifth axis (X5), and between the joint (13) and the fastening element (7) travel limiting means are provided for limiting the swing of the joint (13) around the fifth axis (X5).

3. A reversible plough (1; 101) according to claim 1 or 2, in which the first connection (13) comprises a first hinge element rigidly connected to the fastening element (7), and a second hinge connection (14) mounted on a support (20), wherein the first and second hinge elements (14) of the first connection (13) are secured around the fifth axis (X5), and the support (20) is secured to the second hinge element (14) of the first connection (13) by means of a second hinge connection made with the possibility of rotation around the second axis.

4. A reversible plough (1; 101) according to claim 3, in which the second hinge joint (22) comprises a kingpin (21) which extends from the second hinge element (14) of the first joint (13) perpendicular to the fifth axis (X5) and which is placed in a rotating socket in the support (20).

5. A reversible plough (1; 101) according to claim 4, in which locking means (25, 26) are provided between the kingpin (21) and the support (20) for locking the rotation of the support (20) on the kingpin (21) in given angular positions.

6. The reversible plough (1) according to claim 5, in which the locking means (25) have a ring (27) which is mounted fixedly relative to rotation on the kingpin (21) so as to rotate together with the second hinge element (14) and at least one angular stop (28), preferably two angular stops (28) which are diametrically opposed and which are formed on the ring (27), wherein the locking element is mounted on the support (20) and is designed with the possibility of connection with at least one angular stop (28) in the corresponding working positions.

7. A reversible plough (1) according to claim 6, in which the locking element comprises a rod (30) which is designed to move from and to at least one angular stop (28) against a spring.

8. The reversible plough (101) according to claim 4, in which the locking means (25) comprises a second hydraulic actuator (102) which is active between the second hinge element (14) and the support (20).

9. The reversible plough (101) according to claim 8, wherein the second hydraulic actuator (102) is a single-acting actuator.

10. A reversible plough (1; 101) according to one or more preceding claims, in which the locking means (26) comprise a tight connection between the fastening element and the support (20) so as to ensure a rigid connection of the fastening element and the support (20) in terms of rotation around the second axis (X2) when the plough (1) is in the semi-hitched transport position.

11. The reversible plough (1; 101) according to claim 10, in which a tight connection is formed between the corresponding walls (11) of the fastening element (7) and at least one guide element (60), which is mounted on the support (20) so as to be located between the walls (11) of the fastening element (7) when the frame (2) of the plough (1) is in the transport position.

12. A reversible plough (1; 101) according to one or more preceding claims, in which the first actuator (45) is located between the support (20) and at least one lever (40) of the combined wheel device (6) for adjusting the working depth of the plough (1) by means of the combined wheel device (6).

13. A reversible plough (1; 101) according to claim 12, wherein the first actuator (45) is a hydraulic actuator.

14. A reversible plough (1; 101) according to claim 13, in which a hydraulic accumulator (48) is connected to the first actuator (45) to use the actuator (45) as a hydraulic damper when the plough (1) is in the transport position.

15. A reversible plough (1; 101) according to claim 13 or 14, in which an intercepting valve means (61) is inserted into the connection between the first actuator (45) and the hydraulic accumulator (48).

16. A reversible plough (1; 101) according to claim 15, in which the valve means (61) is actuated by the fastening element (7) when it is engaged in a tight connection.