Abstract:
A soil cultivation device drivable in a displacement direction relative to the soil and designed to break up sub-soil. The device has a chassis or frame, a row of support arms and a drive unit, respective cutting tool pivot units pivotally hinged on the support arms to pivot relative to the arms about a second pivoting axis, permitting a cutting tool fixed on the cutting tool pivot units to pierce the soil and the cutting tool pivot units to be pivoted in relation to the support arms. In addition, the device has at least one gear mechanism, which transmits the relative displacement of the cutting tool pivot unit and the support arm, which at least occurs when the cutting tool has pierced the soil and the soil cultivation device is traveling onwards in the displacement direction, to at least one unit not displaced up and down with the support arm.

Description:
This application is a §371 National Stage Application of International Application No. PCT/DE2006/000521, filed on 28 Mar. 2006, claiming the priority of German Patent Application No. 10 2005 015 068.3 filed on 1 Apr. 2005, German Patent Application No. 10 2005 015 422.0 filed on 4 Apr. 2005 and German Patent Application No. 10 2005 021 025.2 filed on 6 May 2005. 
     BACKGROUND 
     The invention relates to a soil cultivation device movable in a direction relative to the ground for subsoil loosening, having the features as set forth in the preamble of the attached claim  1 . 
     Such soil cultivation devices are marketed in a variety of different versions and known from a plurality of patent documents such as, for example, DE 196 55 123 C2, WO 98/05191, EP 1 040 741 A2, EP 0 853 869 B1 and also EP 0 037 595 A1, all of them incorporated herein by reference. 
     The basic principle of such soil cultivation devices is described, for example, in EP 0 853 869 B1. 
     These soil cultivation devices are, for example, movably mounted articulated on a tow vehicle for riding over the ground. For example, the soil cultivation device can be mounted articulated on a reciprocating three-point linkage of a tractor or hitched trailing a tow vehicle. Soil cultivation devices have as a rule a frame (also termed chassis) for riding the ground on wheels, rollers or cylinders. These soil cultivation devices include a series of tool units for soil cultivation oriented perpendicular to the forward direction (traveling direction). Each of the tool units has (at least) one supporting arm pivotally mounted on the device chassis for reciprocation via a driving means such as particularly a crank assembly. At the other end of the supporting arm a piercing or perforating tool is articulated, for which, as a rule, a tool holder is provided as a perforating tool articulating means in which a perforating tool such as for example a tine or tine assembly or a hollow spoon or perforating tool units in the form of a bed of nails can be fixedly secured. These tool holders are pivotally articulated at the supporting arm. 
     As evident from FIGS. 2 and 3 of EP 0 853 869 B1 and the description thereof, lowering the supporting arms causes the perforating tool to perforate the ground. When the soil cultivation device travels further forwards, the perforating tools initially remain in the ground in the down position of the supporting arm and are pivoted relative to the supporting arm by the resistance. In this arrangement the tool holder or more generally the perforating tool articulating means is pivoted relative to the supporting arm. In all currently known generic soil cultivation devices, a stop is provided for each perforating tool or for each perforating tool holder against which each perforating tool or perforating tool holder is biased by a biasing device. In the pivoting of the perforating tool articulating means relative to the supporting arm with the tool in the ground, further traveling of the soil cultivation device causes the tool holder or an element articulated thereto to leave the stop. Then, when the supporting arm is again lifted and the soil cultivation device travels further in the forward direction, the perforating tool is drawn out of the ground and the biasing device pulls the perforating tool articulating means against the stop. 
     These stops and biasing devices are designed differently in prior art. As it reads from EP 0 853 869 B1 and EP 0 037 595 A1 the biasing device and the stop are configured on a telescopic rod which changes its position in operation by being reciprocated parallel to the supporting arm. In the devices as known from DE 196 55 123 C2, WO98/05191 as well as EP 1 040 741 A2, separate springs bias the tool holders against a stop provided at a setting lever. 
     Various attempts have been made in prior art to handle the movement of the perforating tool articulating means relative to the supporting arm, namely to bias, damp or to control and set such relative movement. It is known in particular to adjust the position of each stop to thus set the angle at which the perforating tool perforates the ground. 
     Movement handling means known hitherto for handling such movements are complicated in design. In addition, such handling means are also exposed to heavy wear because of the considerable amount of dirt as may materialize, particularly in hollow spoon operation. Apart from this, there is a limit to the working speed of the known devices. 
     BRIEF SUMMARY 
     The object of the invention is thus to improve a soil cultivation device having the features as set forth in the preamble of the attached claim  1  such that a design is now made available which has a longer useful life and with which higher working speeds are nevertheless attainable whilst maintaining full handling for biasing, checking, setting and similar handling movements in pivoting the supporting arm relative to the perforating tool. 
     This object is achieved by a soil cultivation device having the features of claim  1  and by a soil cultivation device having the features of claim  23 . 
     Advantageous embodiments of the invention form the subject matter of the sub-claims. 
     Accordingly, the soil cultivation device for loosening the subsoil in accordance with the invention has, for providing a plurality of perforating tool units, a plurality of reciprocatingly actuated supporting arms articulated directly or indirectly at the device frame or chassis to pivot reciprocatingly about a first pivot axis. Furthermore, a perforating tool articulating means is articulated at each supporting arm for pivoting about a second pivot axis relative to the supporting arm. A perforating tool can be fixedly secured at the perforating tool articulating means, i.e. secured immovably relative to the perforating tool articulating means. The perforating tool may be formed for example integral with the perforating tool articulating means or, in other words, pivotally articulated at the supporting arm directly. Alternatively, as is well known in prior art, the perforating tool articulating means may be configured as perforating tool holders or the like for releasably securing various kinds of perforating tools. 
     The supporting arms are pivotally articulated at the frame or chassis at a first portion that may be a first end portion. The perforating tool articulating means is articulated at a second portion spaced away from the first portion and which in particular may be the other end portion of the supporting arm. 
     It is this articulation of the perforating tool articulating means that enables the perforating tool to perforate the ground when the supporting arm is lowered and pivoted relative to the supporting arm in further device travel so that the subsoil, for example beneath turf, is loosened. When the supporting arm is lifted during further travel of the soil cultivation device a perforating tool as a component of the perforating tool articulating means can be retracted from the ground and pivoted back to its starting position relative to the supporting arm about the second pivot axis. 
     The perforating tool articulating means is thus pivotable relative to the supporting arm at least with the tool perforating the ground and on further forward travel of the soil cultivation device. The basic subject of the invention is handling this movement of the perforating tool articulating means relative to the supporting arm which movement is forced by the further device travel. Preferably also the pivoting position of the perforating tool articulating means relative to the supporting arm is to be handled during the performance of the perforating. It is particularly in a parallelogram handling—known for example from EP 0 853 869 B1 and EP 0 037 595 A1—that, due to this parallelogram handling, the perforating tool articulating means and supporting arm become pivoted relatively to a certain extent also when the supporting arm is lifted. Since, however, with the supporting arm lifted the corresponding perforating tool is not active in ground cultivation, these further relative pivoting movements due to the way in which the perforating tool articulating means is guided are of lesser interest. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims, and accompanying drawings where: 
         FIG. 1  is a schematic side view of one embodiment of a solid cultivation device for subsoil loosening; 
         FIG. 2  shows a schematic illustration of a second embodiment of a soil cultivation device; 
         FIG. 3  shows a schematic illustration of a third embodiment of a soil cultivation device; 
         FIG. 4  shows a schematic illustration of a fourth embodiment of a soil cultivation device; 
         FIG. 5  shows a schematic illustration of a fifth embodiment of a soil cultivation device; 
         FIG. 6  shows a schematic illustration of a sixth embodiment of a soil cultivation device; 
         FIG. 7  shows a schematic illustration of a seventh embodiment of a soil cultivation device; 
         FIG. 8  shows a schematic illustration of a eighth embodiment of a soil cultivation device; 
         FIG. 9  shows a schematic illustration of a ninth embodiment of a soil cultivation device; 
         FIG. 10  shows a schematic illustration of a tenth embodiment of a soil cultivation device; and 
         FIG. 11  shows a schematic illustration of a eleventh embodiment of a soil cultivation device; 
       It should be understood that the various embodiments are not limited to the arrangements and instrumentality shown in the drawings. 
     
    
    
     DETAILED DESCRIPTION 
     In accordance with a first aspect of the invention a gear mechanism is provided at at least one, preferably on several, most preferably on all tool units for communicating the movement of the perforating tool articulating means relative to the supporting arm to units or assemblies not reciprocating with the supporting arm. The gear mechanism thus receives the pivotal movement of the supporting arm relative to the perforating tool articulating means and communicates it to at least one assembly which, at the time, is not reciprocating with the supporting arm. 
     This enables the movement of the supporting arm relative to the perforating tool, which movement is e.g. forced by further device travel with the tool perforating the ground, to be picked off at a location other than the supporting arm. On the other hand, a perforating position of the perforating tool relative to the supporting arm can be determined at a location other than that of the supporting arm because of the gear mechanism. This now makes it possible to do away with biasing means, stops, means for setting the stops, damping means, buffer stops and the like arranged to move with the supporting arm, i.e. all such handling means serving to handle the movement of the perforating tool relative to the supporting arm can now be arranged at a fixed location on the chassis or at a location at rest relative to the chassis of the device. 
     This has a number of advantages. For one thing, the mass moved together with the supporting arm can now be reduced. The individual handling means are no longer reciprocated together with the supporting arm and thus are no longer exposed to the jolting impact directly experienced by the supporting arm. In addition, significant space is now gained at the supporting arm since no room needs to be provided any more for the handling means in the space required for moving the supporting arms and/or the driving means. The perforating tools themselves can now be clustered denser and/or arranged lower overall relative to the ground so that the reciprocation amplitude may be reduced and the center of gravity may be lowered. 
     The handling means themselves can be sited where they are out of the way of being soiled, in thus enabling them to be configured no longer susceptible to dirt. 
     Now, because the handling means are no longer included in the movement a wealth of options are open for designing the handling means which hitherto were not available or only with considerable complications. 
     Thus, it is now possible to make use of far more sophisticated damping means including fluid dampers which can also be ported to a central fluid feed. 
     Again, because the handling means no longer needs to be configured slaved in the movement, the supporting arms can now be reciprocated faster without detrimenting the useful life of the handling means which in prior art are considerable larger and, above all, are continually exposed to acceleration forces. 
     The gear mechanism itself communicating the relative movement of each supporting arm from the system of coordinates slaved in the movement of the supporting arm e.g. into the system of coordinates of the device chassis at rest can be engineered differing completely. For instance, it could also take the form of a chain gear mechanism or a gear shaft located in or on the supporting arm. Preferably the gear mechanism is to be engineered so that the relative movement can be communicated as directly as possible and with minimum clearance from the system slaved in the movement of each supporting arm. 
     Thus, at this time, preference is given to a gear mechanism which is formed by a linkage articulatedly linked to the perforating tool articulating means for direct common movement together therewith. 
     For enabling the linkage to communicate the relative movement from the moved system with minimum influence by the movement of the supporting arms, the linkage should guide the movement as near as possible to the first pivot axis where the supporting arm is articulatedly linked to the device frame and thus interfaces the system at rest. It is here in this area near the pivot axis that the movement can be tapped for biasing, control, damping, setting and/or checking or like handling activities. 
     The gear mechanism for transferring or communicating the pivotal movement between supporting arm and perforating tool articulating means from or out of the system slaved in the movement of each supporting arm is preferably formed substantially of a rigid rod element acting roughly parallel to the supporting arm and a redirecting element. The rigid rod element is joined to the perforating tool articulating means by a first articulation point, preferably at an end portion in thus being able to fully communicate or transfer any movement of the perforating tool arranged thereon relative to the supporting arm without any losses. It is not necessary that the rod element is configured as a straight rod; only a rigid transmission between two articulation points is important. Any unit or assembly satisfying this requirement of communicating a movement of a first articulation point to second articulation point distanced away therefrom by essentially rigid ways and means is termed in the present context a rigid rod element. In operation the rod element is required to ensure rigid transmission between the articulation points. To permit adapting to the various requirements the rod element may also be designed so that its effective length, i.e. the length between the two articulation points, is adjustable selectively to be then fixed for operation. This may be done in various ways. For example, the rod element could be configured with multiple holes, each of which can serve optionally as articulation points in operation. It is just as possible to engineer the rod element as two elements in a telescopic arrangement each being fixed relative to the other in selectable length. As a further alternative, the rod element may take the form of a screw clamp comprising two threaded elements for fixing optionally selectable each relative to the other via a screw clamp. 
     The redirecting element is then articulated at the second articulation point of the rod element so that the redirecting element is slaved in the movement of the rigid rod element initiated by movement of the perforating tool articulating means relative to the supporting arm. 
     This relative movement can be tapped at this redirecting element, i.e. for example biased, limited by stops, damped, adjusted, checked, regulated or handled by some other ways and means. 
     Accordingly, the gear mechanism has preferably a redirecting element for redirecting the relative movements initiated in perforating, by further device travel and after the pulling of the perforating tool out of the ground. This redirecting element is preferably pivotable about a third pivot axis at the device frame or chassis in thus being mounted fixed to the frame. The third pivot axis is oriented approximately parallel to the first and approximately parallel to the second pivot axis. It is particularly preferred that the third pivot axis coincide with the first pivot axis about which the supporting arm is pivotally mounted at the frame, since the first pivot axis is the interface between the moved system and system at rest and a movement in the moved system can be communicated or transferred particularly simply by a redirecting element engaging this interface into the system at rest without being influenced by the movement of the supporting arm. 
     In accordance with another aspect of the invention, a stop—as known per se in principle—reciprocating with the supporting arm is provided, wherein the stop can be adjusted via a gear mechanism to set a perforating angle for the perforating tool concerned. Furthermore, a biasing means slaved in the movement of the supporting arm is provided which biases the perforating tool articulating means against the stop. Although this configuration still has the same disadvantages as already explained in prior art as regards the handling means slaved in the movement, it is, however, already known to set the stops of a plurality of perforating tools in common via a central setting. For this purpose the gear mechanism is mounted with a redirecting element in the vicinity of the first pivot axis, each redirecting element of the perforating tools to be set in common engaging a common perforating angle positioning means. 
     The problem with such a configuration hitherto was that the bearings of such redirecting elements need to be replaced new after a relatively short time. On every working cycle the perforating tool was retracted against the stop impacting the redirecting element and its bearings. For this purpose plain bearings were employed hitherto, which however quickly became worn out and featured a corresponding high friction resistance right from the start. Bearings of this kind also require frequent maintenance. Tests with rolling contact bearings on existing structures proved to be a failure, the rolling contact members having become broken down after a relatively short time. All of these disadvantages can be avoided by mounting the redirecting element of the gear mechanism not only in the vicinity of the first pivot axis but pivotally mounted about the first pivot axis at the device frame, resulting in the redirecting element being pivotally mounted concentrically to the mount. In accordance with the invention one of the races or of the same bearing elements is now connected to be slaved in common in the movement with the supporting arms. In other words, this race or the like is slaved in the movement of the supporting arm and is thus continually turned about the bearing axis in a certain angular range. The rotational or pivotal bearing mounting the redirecting element is in movement all the time, resulting in each impact communicated via the perforating tool to the redirecting element now always occurring at a different location in the bearing. Each impact is now distributed about the bearing, and there is no danger that the bearing seizes up. This now makes it possible to employ rolling contact bearings such as ball bearings with no problem since no single rolling contact member is subject alone to impact. 
     In a preferred embodiment a pin fixedly connected to the supporting arm is configured concentrically jutting away from the first pivot axis for mounting a rolling contact bearing seating in turn the redirecting element of the gear mechanism. 
     This configuration now makes it possible to work at higher speed even in the otherwise conventional type in which the handling means are slaved in the movement whilst still achieving a longer life of the device in all with less need for maintenance. 
     Particularly preferred is a combination of both aspects of the invention in which a gear element of the gear mechanism communicating the relative movement of the perforating tool and perforating tool articulating means on the other hand, and supporting arm, on the other, from the system slaved in the movement of the supporting arm is mounted on the device frame by a rotary or pivot bearing, the bearing axis of which coincides with the first pivot axis about which the corresponding supporting arm is pivoted. One of these bearing elements of the rotary or pivot bearing is configured in a preferred embodiment slaved in the rotation with the supporting arm so that in the design in accordance with the second aspect of invention too, the aforementioned advantages of low bearing wear and a low maintenance requirement for the bearings are achieved. Due to the bearing axis coinciding with the first pivot axis, the gear element, particularly the aforementioned redirecting element, can also be mounted on the supporting arm without it being slaved in the reciprocation thereof. The movement of the supporting arm merely results in a relative rotation of the corresponding bearing elements with the advantages as commented above. However, even with movement of the supporting arm and despite mounting of the bearing on the supporting arm the position of the bearing in all remains stable in position relative to the device frame or chassis in thus enabling the pivoting of the perforating tool relative to the supporting arm to be picked off and handled at the gear element of the gear mechanism mounted in this way. 
     Further advantageous embodiments of the first aspect of the invention will now be detailed. 
     Particularly, when the gear mechanism is designed as a linkage, it is preferred that this linkage forms together with the supporting arm and the perforating tool articulating means a more or less parallelogram guide. As known basically from EP 0 037 595 A1 a parallelogram guide permits achieving, irrespective of the position of the supporting arm, a consistent angle between perforating tool and ground. This angle can be set by a redirecting element which acts parallel to the articulation of the perforating tool and is mounted articulated at the perforating tool articulating means by a rigid rod element guided parallel to the supporting arm. Correspondingly, automatic pivoting of the perforating tool articulating means results in corresponding pivoting of the redirecting element when the perforating tool perforates the ground and in further device travel. Due to the at least approximate parallelogram guide the position of the redirecting element remains independent of the position of the supporting arm and thus substantially independent of the movement of the supporting arm. Therefore, this relative movement can be handled at the redirecting element with the aid of an handling means arranged stationarily relative to the device frame or chassis. 
     The handling means serves particularly to return the perforating tool pulled out from the ground back into its original position. For this purpose, as happened before in the moved systems, a biasing means can be provided in the stationary system which biases the gear mechanism, for example the redirecting element, against a stop. The stop too, can then be arranged in the stationary system. The position of the stop itself is adjustable. Furthermore, buffers or more complicated damping means may be provided for damping. 
     It is particularly preferred to arrange this handling means in an area located, as viewed in the direction of forward travel, on the side opposite that of the supporting arms from the first pivot axis. In the example in which the soil cultivation device is hitched to the rear of a tractor and in which the supporting arms extend away from the first pivot axis against the direction of forward travel, it is preferred to attach the handling means to the front of the soil cultivation device, for example, to a front wall of the device chassis where there is enough room for various kinds of handling means. More sophisticated damping systems as well as fluid dampers, for example, hydraulic dampers, may be provided. It is also just as possible to apply various other connectors—for example fluid connectors and hydraulic or compressed air connection—to the handling means sited opposite the device frame or chassis in thus making for an enormous increase to the design options for biased means, stop assemblies, control elements, etc. 
     In any case, a gear mechanism in accordance with the invention can be provided with each perforating tool unit, i.e. each supporting arm assembly. In one preferred embodiment each of these gear mechanisms is mounted articulated at a separate handling means, for example, a separate bias means, a separate stop and/or a separate damper means. For each perforating tool unit a separate stop setting or other setting of the perforating angle can be provided. It is, however, just as possible to provide a central angle setting means with which all, or a group of the gear mechanisms can be set in common as regards the bearings for perforating angle. 
     Yet another advantage substantial to the invention is the possibility of improved noise damping when the movement of the perforating tool relative to the supporting arm is communicated from the system slaved in the movement of the supporting arm for example into an system at rest relative to the device frame. Since springs, dampers, stops and the like can be arranged at rest the means existing singly corresponding to each perforating tool unit can be grouped together in a module for noise damping in common. When, for example, such handling means are clustered on a front wall of the soil cultivation device, they could be covered in all by a hood lined with noise damping materials. 
     Example embodiments of the invention will now be detailed with reference to the accompanying drawing in which 
       FIGS. 1-11  are comparable side views of the salient components of eleven embodiments of soil cultivation devices for subsoil loosening showing part of the device frame and tool units with supporting arms for powered reciprocation with the perforating tool articulating means articulated thereto. 
     The FIGS. each show a side view transversely to the forwards travel direction illustrating the salient components of various embodiments of a soil cultivation device for subsoil loosening. Components typical to such devices as are well known from prior art—see for example the patents as cited in the background description—have been omitted to make for a better overview. As a rule the soil cultivation devices as involved feature a plurality of tool units arranged and distributed on the soil cultivation device perpendicularly to its forwards travel direction. A view in perspective of such a distribution is evident, for example, from the German patent application DE 10 2004 018 101 A1, incorporated herein by reference and to which express reference is made as regards further details of the soil cultivation devices concerned presently. 
     The  FIGS. 1 to 11  show all eleven embodiments of soil cultivation devices indicated in general with the reference numbers  1 - 11  respectively. Each soil cultivation device  1 - 11  has a device frame  20  for riding over the ground  22  in a forwards direction of travel  23  by means of rollers  21 . 
     A train of identically configured tool units  24  is provided into the plane of the illustration, only one of which is shown in each FIG. Each tool unit  24  has a supporting arm  25  which for example, may be a bar, but preferably, however, each supporting arm  25  is formed by a plurality of welded parallel bars each joined to the other. The supporting arm  25  is articulated to pivot about a first pivot axis  26  directly or indirectly at the device frame  20  such that the first pivot axis  26  is located stable attached to the device frame  20 . The supporting arm  25  is engaged by a driving means  27  with a crank assembly  28  and an driving rod  29  which pivotally reciprocates the supporting arm  25  about the first pivot axis  26 . A perforating tool articulating means in the form of a tool holder  30  articulated-mounted, pivotally relative to the supporting arm  25  about a second pivot axis  31 , to the free end of the supporting arm  25 . Accordingly, the second pivot axis  31  and the tool holder  30  move upward and downward together with the supporting arm  25 . Fixedly but releasably secured to the tool holder  30  is a perforating tool  32  for perforating the ground  22 . 
     Provided in the embodiments as shown in  FIGS. 1 to 10  is a gear mechanism provided in this case in the form of a first linkage  33 , transferring a relative pivoting of supporting arm  25  and tool holder  30  into the vicinity of the first pivot axis  26  for picking off there by a handling means  34  arranged stationarily relative to the device frame  20 . The linkage  33  comprises a rigid rod element, in this case in the form of a straight rigid rod  35 , the length of which cannot be varied having a first point of articulation  36  and a second point of articulation  37  spaced away from the first point of articulation in the longitudinal direction of the rod  35 . By its first point of articulation  36  at one end the rod  35  is fixedly but pivotally mounted articulated at the tool holder  30 . The pivot axis running through the first point of articulation  36  (into the plane of the drawing) about which the first point of articulation  36  can be pivoted to the tool holder  30  is located spaced away from and parallel to the second pivot axis  31 . The rod  35  runs approximately parallel to the supporting arm  25  and the spacing of the points of articulation  36 ,  37  roughly corresponds to the spacing of the first pivot axis  26  from the second pivot axis  31 . Thus, the second point of articulation  37  is located relative to the the first pivot axis  26  in a corresponding manner as the first point of articulation  36  is located relative to the second pivot axis  31 . In other words the points of articulation  36 ,  37  and the first and second pivot axis  26 ,  31  form at least approximately a parallelogram. 
     In the first to tenth example embodiment 1-10 the gear mechanism formed by the first linkage  33  further comprises a redirecting element  38  which is mounted pivotally about a third pivot axis  39  at the device frame  20 . In the embodiments 1-5, 7-10 with the exception of the sixth embodiment 6 the third pivot axis  39  coincides with the first pivot axis  26 , i.e. in this case the redirecting element  38  is mounted in this case concentric to the pivotal mount of the supporting arm  25 . In all embodiments 1-10 as shown in  FIGS. 1 to 10  the redirecting element  38  engages the handling means  34 . 
     In the first embodiment of a soil cultivation device  1  as shown in  FIG. 1  a rod  40  of variable length engages the redirecting element  38 . At the other end the rod  40  is biased by a biasing means in the form of a compression spring  41 . The compression spring  41  is supported at its other end by the device frame  20 . Provided furthermore at the support  42  is a damper in the form of a buffer  43 . The rod  40  is provided with a projection  44  or nose with which it is stopped by the buffer  43  acting as a stop. In the embodiments 1 and 2 this projection  44  is formed by nuts  44 ′. When the rod  40  contacts the buffer  43  the rod  40  is biased by the compression spring  41 . By a crank  45  a spindle  46  can be rotated in the interior of the rod  40  in thus setting the length of the rod  40 , as a result of which the location of the articulation A of the rod  40  at the redirecting element  38  is adjustable relative to the buffer  43 . This enables the resting position of the redirecting element  38  and thus the perforating angle of the perforating tool  32  to be set relative to the ground  22  so that the crank  45 /spindle  46  of the rod  40  acts as an angle setter. In operation the supporting arm  25  is moved up and down without influencing the location of the redirecting element  38 . But when the tool holder  30  is pivoted about the second pivot axis  31  this movement is communicated via the first linkage  33  to the rod  40  which can be moved downward contrary to the tension force of the compression spring  41  when the perforating tool is penetrating the soil and the soil cultivation device is traveling further in direction of travel. As soon as the perforating tool  32  is released the compression spring  41  pulls the rod  40  upward back into contact with the buffer  43  which cushions the impact. Although pivoting of the tool holder  30  occurs in the system slaved in the movement of the supporting arm  25 , the whole handling means  34  can be arranged stationarily relative to the device frame at the front wall of the device frame  20 . 
     Referring now to  FIG. 2  there is illustrated how in the second embodiment of a soil cultivation device  2  as shown therein, unlike in accordance with the first embodiment of the soil cultivation device as shown in  FIG. 1  in which the rigid rod  35  of the linkage  33  is arranged above the supporting arm  25 , this rod  35  is now located below the supporting arm  25 . In all other aspects, the second embodiment corresponds to the first embodiment. 
     Referring now to  FIG. 3  there is illustrated a third embodiment of a soil cultivation device  3  which as regards the location of the rod  35  of the linkage  33  again is based on that of the first embodiment from which it differs by the configuration of the handling means  34 . As evident from  FIG. 3  the handling means  34  includes in the soil cultivation device  3  as a biasing means a tension spring  47  biased between a holder  50  rigidly connected to the device frame  20  and the redirecting element  38  and, defined at a further location on the device frame  20 , a stop  48  for the redirecting element  38  directly. The stop  48  is in turn provided with a buffer  49  as a damping means located on a threaded pin  51  engaging a tapping in the device frame  20  so that the position of the stop  48  for setting the perforating angle is adjustable. 
     Referring now to  FIG. 4  there is illustrated a fourth embodiment of a soil cultivation device  4  which is very similar to the third embodiment, except that a compression spring  53  directly engaging the redirecting element  38  at one side of a projection, lever arm or extension  52  is provided as the biasing means urging the extension  52  in contact with the stop  48  engaging at the other side of the extension  52  known in principle from the third embodiment. 
     Referring now to  FIG. 5  there is illustrated a fifth embodiment of a soil cultivation device  5  in which no adjustment of the perforating angle is provided. This embodiment is of interest for simpler, more cost-effective versions. The redirecting element  38  is not mounted free to rotate but flexibly pivotally mounted. The redirecting element  38  is pivotally connected to the device frame  20  via an elastomer  54 . The elastomer  54  retains the redirecting element  38  in the position of rest as shown in  FIG. 5  whilst permitting pivoting of the redirecting element to both sides about the third pivot axis  39  to a certain extent. This pivoting happens, for example, every time the tool holder  30  is pivoted about the second pivot axis  31  in perforating. On release of the perforating tool  32  the elastomer  54  retracts the redirecting element  38  and thus the tool holder  30  back to the position at rest. 
     Referring now to  FIG. 6  there is illustrated a sixth example embodiment of a soil cultivation device  6  showing that the design principle as explained with reference to  FIG. 5  also functions when the redirecting element  38  is not pivotally articulated concentrically to the first pivot axis  26 . It is sufficient to flexibly mount the second point of articulation  37 . In the sixth example embodiment of the soil cultivation device  6  a lever element  55  as a redirecting element is mounted at an elastomeric mount  56  to a certain extent flexibly pivotable about the third pivot axis  39  running here above the first pivot axis  26 . 
     Referring now to  FIG. 7  there is illustrated a seventh example embodiment of a soil cultivation device  7  which is in turn based on the first embodiment from which it differs by instead of a separate angle setting for each tool unit  24  a central angle positioner  60  is now provided with which the perforating angle can be set in common for a plurality of tool units  24 . For this purpose the rod  40  whose length can be varied is replaced by a rod rod  61  which length cannot be varied and instead of the rigid support  42  a variable support  62  is now provided whose position relative to the device frame  20  is adjustable. Using an setting rod  63  extending crosswise to the direction of movement, the variable support  62  of a plurality of rods  61  can now be set in common. For this purpose, the setting rod  63  is pivotally mounted, for example cantilevered, at the device frame  20 , the pivoting angle being adjustable via a setting crank  64 . Otherwise this soil cultivation device  7  according to the seventh embodiment corresponds to soil cultivation device  1  according the first embodiment; also the stop buffer  43  is provided. 
     Referring now to  FIG. 8  there is illustrated a soil cultivation device  8  according to an eighth embodiment which is a sophistication over the seventh embodiment as explained above in that a flexible element  66  is now disposed at the rod  61  between the buffer  43  and the projection  44  formed in this case by a ring disk element  65 ; this flexible element  66  cushions the impact materializing on rebound of the perforating tool and particularly also when the perforating tool comes up against rocks or the like in the ground. 
     Referring now to  FIG. 9  there is illustrated a soil cultivation device  9  according to a ninth embodiment which is based on the seventh embodiment, wherein the connection of the rod  61  whose length can not be changed and the compression spring  41  is replaced by a telescopic rod  67  having an inner compression spring as is known, in principle from EP 0 037 595 A1, however, there, as a handling means, that is slaved in the movement. 
     Referring now to  FIG. 10  there is illustrated a soil cultivation device  10  according to a tenth embodiment which is a sophistication over the ninth embodiment in that the telescopic rod is now designed as a fluid damper  68  that can be controlled (pneumatically or hydraulically) via an external fluid port  69 . 
     Referring now to  FIG. 11  there is illustrated a soil cultivation device  11  according to an eleventh embodiment which differs from the embodiments 1 to 10 as described before in that—as is known—handling means slaved in the movement in the form of a biasing means  70 , a stop  71  and a multilayer damping member  72  accommodated therein are now provided, likewise provided is a linkage  73  with a redirecting element  74 . Different, however, to the first linkage  33  the linkage  73  of the eleventh embodiment is not rigidly mounted articulated at the tool holder  30  to be slaved in the movement thereof, but instead simply mounted articulated at the stop  71  for setting thereof. 
     According to the eleventh embodiment, the redirecting element  74  is seated on ball bearing  75  arranged concentrically to the first pivot axis  26  the inboard race of which is fixedly connected to the supporting arm  25  to be slaved in the rotation thereof when pivoted. For this purpose there is provided at the supporting arm  25  a pin (not shown) seating the ball bearing  75 . Thereby, a central angle positioner is located coaxially central into the first pivot axis. There is a bearing for this angle positioner at each supporting arm mount. The pin rotates with the supporting arm  25  and thus swings about a central axis. The ball bearing  75  is seated thereon. Seated on the ball bearing  75  is then the respective redirecting element  74 , in this case in the form of a small arm  76  at the protruding end of which an adjustment rod  77  is mounted acting in common on all redirecting elements  74 . This adjustment rod  77  can be pivotally adjusted centrally about the first pivot axis  26  by means of a crank  78 . 
     The reason for this configuration is that it allows use of rolling contact bearings such as the ball bearing  75 . Since the rolling contact bearings are always moved there is no longer always impact at the same location of the rolling contact bearing. With the impact as involved here quite considerable forces are communicated. If the rolling contact bearing were at rest the impact would always be at the same location which would result in the rolling contact bearing and/or its races being ruined. 
     In the soil cultivation device  11  the arms  76  seated at the ball bearing  75  concentric to the mounts of the supporting arm  25  protrude upwards. They are interconnected by a connection running transverse to the soil cultivation device  11 , which is here an approximately 10 cm wide rod  77  made of channel-section sheet metal. The complete adjustment rod  77  is angle adjusted via the crank  78 . The redirection occurs about these ball bearings  75 . A compression spring  79  contacting the crank  78  cushions the impacts caused by rebound in the tool holder  30  against the stop  71 . 
     Mounting the redirecting element  74  as explained for the eleventh embodiment can also be employed with the redirecting element  38  mounted concentrically to the first pivot axis  26  or with comparable elements of the gear mechanism in the first to tenth embodiment. 
     It is understood that the features explained specific to the example embodiments can, of course, be combined in further embodiments not detailed presently. 
     LIST OF REFERENCE NUMERALS 
       1  soil cultivation device (first embodiment) 
       2  soil cultivation device (second embodiment) 
       3  soil cultivation device (third embodiment) 
       4  soil cultivation device (fourth embodiment) 
       5  soil cultivation device (fifth embodiment) 
       6  soil cultivation device (sixth embodiment) 
       7  soil cultivation device (seventh embodiment) 
       8  soil cultivation device (eighth embodiment) 
       9  soil cultivation device (ninth embodiment) 
       10  soil cultivation device (tenth embodiment) 
       11  soil cultivation device (eleventh embodiment) 
       20  device frame 
       21  roller 
       22  ground 
       23  forwards direction 
       24  tool unit 
       25  supporting arm 
       26  first pivot axis 
       27  driving means or actuator 
       28  crank assembly 
       29  driving rod 
       30  tool holder (perforating tool articulating means) 
       31  second pivot axis 
       32  perforating tool or spike 
       33  linkage (gear mechanism) 
       34  handling means 
       35  rod (rigid rod element) 
       36  first point of articulation 
       37  second point of articulation 
       38  redirecting element 
       39  third pivot axis 
       40  variable-length rod 
       41  compression spring (biasing means) 
       42  support 
       43  buffer (damper device and stop) 
       44  projection 
       44 ′ nuts 
       45  crank (angle positioner) 
       46  spindle (angle positioner) 
       47  tension spring (biasing means) 
       48  stop 
       49  buffer (damper means) 
       50  holder 
       51  threaded pin (angle positioner) 
       52  extension on redirecting element 
       53  compression spring (biasing means) 
       54  elastomer (biasing means) 
       55  lever element 
       56  elastomeric mount 
       60  central angle positioner 
       61  variable-length rod 
       62  adjustable support 
       63  setting rod 
       64  setting crank 
       65  ring disk element 
       66  elastic element (damper) 
       67  telescopic rod 
       68  fluid damper 
       69  fluid connector 
       70  biasing means 
       71  stop 
       72  damping member 
       73  linkage 
       74  redirecting element 
       75  ball bearing 
       76  arm 
       77  variable rod 
       78  crank 
       79  compression spring 
       80  dirt region 
     A articulation