Abstract:
An apparatus for transfer of the weight from the plow to the tractor to improve the traction of the tractor for which the rotational axis  11  is arranged in such a way that the transfer of the weight, at the same time, also effects a required torque for the turning process and an increase in the stability of the tractor during the turning process.

Description:
This application claims the benefit of German Application No. 10 2010 019 819.6 filed May 8, 2010, and PCT/DE/2011/00104 filed May 6, 2011, International Publication No. WO 2012/006979, which are hereby incorporated by reference in their entirety as if fully set forth herein. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a semi-mounted reversible plow. 
     SUMMARY OF THE INVENTION 
     Such a semi-mounted reversible plow can be taken from the European patent specification EP 1 549 124. For this semi-mounted reversible plow there is an hydraulic cylinder placed between the attachment device and the plow frame. This hydraulic cylinder should contribute to improving the traction of the tractor. If the front axis of the tractor is to come under additional load, then a pressing force is generated via the hydraulic cylinder in the upper link of the tractor. If the rear axle of the tractor is to be put under load, EP 1 549 124 teaches that a tractive force must be generated in the upper link of the tractor. This prior art has the disadvantage that a high torque must be generated by the slewing gear during turning of the plow frame. The slewing gear must be designed to be appropriately extensive and heavy and is therefore also expensive. Also all neighboring components must be designed according to the forces arising there, which also has a negative effect on the manufacturing costs. One further comparable semi-mounted reversible plow can be taken from EP 2 033 503. There is also an hydraulic cylinder provided here, as for the semi-mounted reversible plow according to EP 1 549 124, with which the tractive force in the upper link must be generated if the traction of the rear axle of the tractor should be increased through transfer of weight from the semi-mounted plow to the tractor. This is where the disadvantages occur, described above, concerning the high rotational energy required to a high degree since this design of semi-mounted reversible plow with just one wheel as the travel gear on the side on the frame requires a significantly higher rotational energy. 
     The object of the invention is to create an apparatus which reduces the required rotational energy for turning the plow frame which holds the cost of the slewing gear within reasonable limits, which also increases the static stability of the tractor during the turning process and which also improves the traction of the tractor through transfer of weight from the semi-mounted plow to the tractor. 
     This object is achieved according to the embodiments disclosed for the present invention. 
     Since the rotational axis or the imaginary extension of the rotational axis crosses the plow frame in the operating position on the furrow side, at some distance from the center of gravity of the plow frame, the center of gravity of the plow frame lies between the rotational axis or the imaginary extension of the rotational axis and the rotational joint of the travel gear or wheel. Upon actuation of the hydraulic cylinder the weight of the semi-mounted reversible plow is transferred to the tractor and therefore a torque is applied onto the plow frame around the rotational axis. Since the center of gravity of the plow frame is arranged to the side of the rotational axis or the imaginary extension of the rotational axis between the wheel and the rotational axis or the imaginary extension of the rotational axis, actuation of the hydraulic cylinder causes turning of the plow frame if the tractive force in the hydraulic cylinder is made appropriately large. An appropriately low tractive force in the hydraulic cylinder does, on the other hand, only cause a reduction in the required torque which must be delivered by the slewing gear. The magnitude of the reduction in the required torque depends on the distance between the center of gravity of the plow frame and the imaginary extension of the rotational axis and the part of the weight taken on by the hydraulic cylinder. The required torque from the slewing gear and therefore also the size of the hydraulic cylinder of the slewing gear can then be reduced and the stability of the tractor during the turning process increased by this magnitude of the reduction in the required torque. In this way, on the one hand, a weight is transferred from the device to the tractor to obtain better traction and the torque from the slewing gear required for the turning process of the plow frame is reduced significantly. 
     The invention further provides that the rotational axis or the imaginary extension of the rotational axis is arranged to cross the plow frame in the front area in the operating position. Since the rotational axis or the imaginary extension of the rotational axis crosses the plow frame in the front area, the distance to the center of gravity of the plow frame is relatively large and therefore also the effective lever arm which, together with the lifting force of the hydraulic cylinder, causes reduction of the required torque of the slewing gear for the turning process of the plow frame. 
     An enlargement of the lever arm is achieved in such a way that the slewing gear or the imaginary extension of the rotational axis is arranged so as to cross the plow frame in the operating position in the area between the first plow body and the third plow body. The reduction in the required torque which must be delivered by the slewing gear for turning the plow frame is increased even further in this way. 
     According to the invention it is further provided that a draw frame is connected with the attachment frame or with the intermediate frame which is connected in the rear area of the plow frame indirectly or directly with the plow frame or the travel gear. The plow frame with the bodies arranged on it is therefore pulled over the connecting point of the turning arm of the slewing gear with the plow frame and the connecting point of the draw frame with the plow frame or the travel gear. This effects a favorable introduction of the tractive forces into the plow frame. 
     Here, it is provided for that the draw frame is connected cardanically with the attachment frame or with the intermediate frame and the travel gear and is designed to serve as a torsion resistant stabilizer for fixing the upright position of the wheel. In cases where the travel gear just consists of one wheel then the wheel can be fixed and guided in its upright position using the known method. 
     DETAILED DESCRIPTION 
     The invention alternatively also relates to a semi-mounted reversible plow with an attachment frame with a plurality of link points for attachment to the upper and lower link of a tractor as well as a plow frame carrying a plurality of plow bodies, which frame is supported via a travel gear with at least one wheel and is turned over the slewing gear with a rotational axis and turning arm into the respective operating position and is connected pivot-mounted with the attachment frame in a horizontal direction, for which the rotational axis of the slewing gear or the imaginary extension of the rotational axis crosses the plow frame in the operating position on the furrow side at some distance from the center of gravity of the plow frame and for which the upper link is designed as an hydraulic cylinder. For this solution, transfer of weight of the semi-mounted reversible plow to the tractor is not via an hydraulic cylinder integrated on the semi-mounted reversible plow but rather via an hydraulic cylinder designed as an upper link which is arranged between the attachment frame and the tractor. This solution somewhat simplifies the structure of the plow and also offers the option to achieve a comparable effect using less effort overall, as with the version with the hydraulic cylinder integrated in the semi-mounted reversible plow. It is also possible for this solution to have the position of the rotational axis or the position of the imaginary extension of the rotational axis similarly arranged on the furrow side to cross the plow frame at some distance from the center of gravity of the plow frame. 
     Further details and advantages of the subject of the invention emerge from the following description and the relevant drawings, which show two exemplary embodiments with the necessary details and single parts. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a side view of the semi-mounted reversible plow in its operating position, 
         FIG. 2  shows a view from above of the semi-mounted reversible plow in its operating position, 
         FIG. 3  shows a cut-out of the side view of the front part of the semi-mounted reversible plow according to  FIG. 1  and 
         FIG. 4  shows a side view of the semi-mounted reversible plow in its operating position with an hydraulic cylinder functioning as the upper link. 
     
    
    
       FIG. 1  shows a side view of the semi-mounted reversible plow  1  in its operating position. The semi-mounted reversible plow  1  comprises the main components attachment frame  5 , slewing gear  10 , travel gear  8 , draw frame  30  and plow frame  7  with the plow bodies  6 . The semi-mounted reversible plow  1  is connected with the three-point rod of a tractor via the attachment frame  5 . The upper link pivot  4  and the lower link pivots  2  and  3  are provided for this on the attachment frame  5 . The attachment frame  5  with its attachment tower  40  has the upright standing axis  41  with which the plow frame  7  and the travel gear  8  are connected pivotably via the intermediate frame  13 . The transverse axis  14  is provided on the intermediate frame  13  on the end-side via which the slewing gear  10  is connected pivotably with its cross-member  33 . The hydraulic cylinder  15  is connected at some distance from the transverse axis  14  with the cross-member  33  and the intermediate frame  13 . Upon actuation the hydraulic cylinder  15  transfers the weight of the plow frame  7  to the attachment frame  5  and therefore to the rear axle of the tractor (not shown). To this effect, the hydraulic cylinder  15  is fitted with one or a multiplicity of hydraulic accumulators (not shown here) which allow adaptation to the ground of the plow frame  7  with the plow bodies  6  while maintaining the transfer of weight of the plow frame to the tractor. The plow bodies  6  are led at operating depth, at the front, by means of the tracing wheel  39  and, at the rear, by means of the travel gear  8  with wheel  9 . The cross-member  33  receives the rotational axis  11  and the turning arm  12  which can be seen particularly clearly in  FIG. 2 . The travel gear  8  is in connection via the draw frame  30  with the attachment frame  5 . The draw frame  30  serves in this case as a torsion resistant stabilizer  32  which is connected cardanically via the intermediate link  36  and the intermediate frame  13  with the attachment frame  5 . The draw frame  30  or the stabilizer  32  are connected cardanically in the rear area  31  of the semi-mounted reversible plow  1  via the rear transverse axis  62  and the upright axis  63  with the wheel carrier  60 , which is pivoted via the hydraulic cylinder  64  around the rear transverse axis  62 , wherein the operating depth of the plow bodies  6 , amongst other things, can also be changed. The range of swivel of the wheel carrier  60  around the rear transverse axis  62  is limited by a dead stop  66  to secure clearance above the ground. The length of the draw frame  30  and therefore also the front furrow width of the semi-mounted reversible plow  1  can be altered by means of the actuator  65  in the normally known manner. The wheel carrier  60  has the wheel fork  61  in which the wheel  9  is mounted. 
       FIG. 2  shows a view from above of the semi-mounted reversible plow  1  in its operating position. The semi-mounted reversible plow  1  is overall freely connected around the upright standing axis  41  trailing with the tractor via the attachment frame  5  and the upper link pivot  4  and the lower link pivots  2 ,  3 . The intermediate frame  13  is connected with the upright standing axis  41  which receives the cross-member  33  of the slewing gear  10  with the rotational axis  11  and the turning arm  12 . Owing to the particular arrangement of the slewing gear  10 , the rotational axis  11  is in a position which ensures that the imaginary extension  16  of the rotational axis  11  crosses the plow frame  7  on the furrow side at some distance  17  from the center of gravity  18  as seen in the direction of the extension  16  of the rotational axis  11 . In order to achieve the effect of reducing the required rotational energy, the imaginary extension  16  of the rotational axis  11  must cross the plow frame  7  in the front area  20 . In the example according to  FIG. 2  the imaginary extension  16  of the rotational axis  11  crosses the plow frame  7  in the area  21 , between the first plow body  22  and the third plow body  23 . The semi-mounted reversible plow  1  is a semi-mounted reversible plow  1  with a variable operating width adjustment plow body  6 . Actuation of the hydraulic cylinder  42  causes the operating width of the individual plow bodies  6  to be altered via the control gear  59 . Here, also the wheel arm  57  with the pivot bearing  58  and therefore also the travel gear  8  are adjusted with the wheel  9  in a direction parallel to the direction of operation. The wheel arm  57  with the pivot bearing  58  is connected at the rear of the plow frame  7  with the plow frame  7  via the console  55 . Actuation of the hydraulic cylinder  42  causes both the position of the plow frame  7  and the position of the draw frame  30  and the intermediate frame  13  to change. This change in the position of the intermediate frame  13  also causes a change in the position of the imaginary extension  16  of the rotational axis  11  and therefore also the distance  17  of the imaginary extension  16  of the rotational axis  11  to the center of gravity  18 . One ensures that the imaginary extension  16  of the rotational axis  11  is always on the furrow side some distance  17  from the center of gravity  18  in every operating width setting. The reduction in the required rotational energy for the slewing gear  10  is optimal if the distance  17  is very large and the lifting force of the hydraulic cylinder  15  is also very large. Conversely, the reduction in the required rotational energy for turning the slewing gear  10  is lower if the lifting force of the hydraulic cylinder  15  is reduced and the distance  17  is smaller. A reduction in the required rotational energy is not possible if the lifting force of the hydraulic cylinder  15  is zero or if the imaginary extension  16  of the rotational axis  11  runs through the center of gravity  18  or on the land side of the center of gravity  18 . On the land side means the area  43  which is in the right turning plow position of the semi-mounted reversible plow  1  on the left of the center of gravity  18  of plow frame  7 . 
       FIG. 3  shows a cut out of a side view of the front part of the semi-mounted reversible plow  1 . The hydraulic cylinder  15  is, on the one hand, connected to the mounting point  35  of the cross-member  33  and, on the other hand, with the mounting point  34  of the intermediate frame  13 . The hydraulic cylinder  15  is arranged here at some distance from the transverse axis  14 . The greater the distance apart, the more the weight can be transferred from the plow frame  7  to the tractor for the same lifting force or tractive force of the hydraulic cylinder  15 .  FIG. 3  also clearly illustrates the arrangement of the intermediate link  36  which connects the draw frame  30  or the stabilizer  32  cardanically with the intermediate frame  13 . To this effect, the intermediate link  36  has the vertical axis of traction  37  and the horizontal axis of traction  38 . 
       FIG. 4  shows an alternative solution, without the hydraulic cylinder  15  according to  FIG. 1 . A trailing arm  52  is used here instead of the hydraulic cylinder  15  which blocks a movement around the axis  14  of the intermediate frame  13  to the cross-member  33 . The intermediate frame  13  and the cross-member  33  can also form a unit permanently attached to each other so that the transverse axis  14  and the trailing arm  52  are not needed. Then, the transfer of the weight of the plow frame  7  to the tractor takes place via the upper link which, in this case, is designed as an hydraulic cylinder  50 . The lower links  51  are integral parts of the tractor. The hydraulic cylinder  50  is an integral part of the plow. Movability of the hydraulic cylinder  50  can be achieved via the hydraulic accumulators (not shown here), wherein an adaptation to the ground can be secured between the tractor and the semi-mounted reversible plow  1  while maintaining the tractive force in the hydraulic cylinder  50 . 
     The lifting force or the tractive force of the hydraulic cylinders  15  or  50 , both for the design according to  FIG. 1 to 3  and also the design according to  FIG. 4 , can be controlled using a control apparatus, for example dependent on the slip of the drive wheels on the tractor or with a pre-set regulating variable for the tractive force or the lifting force of the respective hydraulic cylinder  15  or  50 .