Patent Publication Number: US-2004050560-A1

Title: Tillage apparatus

Description:
[0001] The subject of the present invention is an apparatus for working the soil.  
       [0002] The apparatus concerned is intended in particular to work the soil in somewhat inaccessible regions such as trenches. This soil-working apparatus may be an apparatus which turns the soil over at the surface, or deeper down, so as to clean the surface that is to be worked, or to make it safe. This apparatus may also be used for neutralizing anti-personnel mines in regions to which access is difficult, such as trenches. Indeed, it is known practice for apparatuses to be used for detecting anti-personnel mines, these apparatuses working on relatively flat surfaces, detecting and exploding anti-personnel mines either by exerting pressure on or vibrating the ground, or by uncovering a layer of earth, for example using rotary implements. However, such apparatuses are not suited to working in sloping land or land with unevennesses.  
       [0003] The apparatus according to the invention comprises an arm mounted on a support at one of its ends and having several elements articulated to one another about horizontal axles. The support on which the arm is mounted may, for example, consist of a turret mounted to pivot about a vertical axis on the chassis of a vehicle. The free end of the arm is equipped with an implement holder.  
       [0004] The object of the invention is to provide an apparatus of this type which can work in sloping land or land exhibiting pronounced irregularities, such as in trenches.  
       [0005] To this end, in the apparatus to which it relates, of the aforementioned type, the free end of the arm is equipped with a rotary actuator the axis of rotation of which is transversal to the axles about which the elements of the arm are articulated and, on the lower part of which is fixed a unit containing a motor intended to drive an output shaft transversal to the axis of the rotary actuator and at the end of which an implement is mounted with overhang.  
       [0006] Advantageously, the output shaft at the end of which the implement is mounted is parallel to the ground.  
       [0007] The implement is therefore mounted with overhang at the end of the output shaft of the drive motor which is, for example, a hydraulic motor. As this implement is mounted to pivot about a horizontal axle, it will therefore work in a vertical plane. It is therefore possible to work in a very narrow region such as a trench by orientating the working plane in the direction of the trench or to work very close to an obstacle, such as a wall, by altering the position of the arm which is made up of several elements articulated to one another, and the angular position of the implement-carrying unit with respect to the end of the arm by virtue of the rotary actuator.  
       [0008] Advantageously, in this apparatus, the output shaft at the end of which the implement is mounted is equipped with means of displacement in translation along its axis. It is thus possible to widen the area of action of the implement by giving the output shaft a reciprocating movement. Thus, for example, if the width of the working region of the implement is 10 cm and the stroke of the ram is 30 cm, it will be possible, for the same position of the arm, to obtain a working of the land over a width of 40 cm.  
       [0009] According to one option, the means of displacing the output shaft in translation consist of a hydraulic ram.  
       [0010] According to one embodiment of the apparatus according to the invention, inside the unit mounted at the free end of the arm is pivotably mounted a bushing equipped at its periphery with a toothed annulus meshing with a pinion driven off the motor and inside which there is mounted, free to translate but locked in terms of rotation, a hollow shaft forming a cylinder for a piston fixed to the end of a rod integral with the unit.  
       [0011] According to one option in this case, the hollow shaft is rendered integral in terms of rotation with the bushing by a set of complementing splines formed in their contacting faces. Furthermore, advantageously, the ram supply circuit comprises ducts formed in the rod of the ram.  
       [0012] The implement mounted with overhang at the end of the output shaft of the motor may have various forms. It may, for example, be a hub to which are fixed the ends of chains, the other ends of which are equipped with bob weights, or a hub to which are fixed several radial arms the free ends of which are sharpened.  
       [0013] According to another embodiment, this implement comprises a disk or several parallel disks the center(s) of which is(are) fixed on the end of the shaft and the periphery(ies) of which comprise(s) teeth.  
       [0014] In another embodiment, the implement mounted with overhang at the end of the output shaft comprises a disk supporting, on a first angular sector, a portion of cylindrical surface, from which there extends at least one tooth able to penetrate the ground and, on a second angular sector, a number of rods able to move aside the soil displaced by the tooth.  
       [0015] As a preference, the orientation of the rods varies gradually from an orientation that is divergent with respect to rotation to an orientation of the rods parallel to the axis of rotation.  
       [0016] In addition, several teeth extend from the cylindrical portion, two of them situated near the front edge of the portion in the direction of rotation, the other teeth being situated near the rear edge. 
     
    
    
     [0017] In any event, the invention will be clearly understood with the aid of the description which follows, with reference to the schematic appended drawing which, by way of non limiting examples, depicts one embodiment of this apparatus and several forms of embodiment of implements:  
     [0018]FIG. 1 is an overall perspective view depicting the entirety of the apparatus;  
     [0019]FIG. 2 is a perspective view on an enlarged scale of the part of the apparatus equipped with the implement;  
     [0020]FIG. 3 is a view in longitudinal section and on an enlarged scale on III-III of FIG. 2;  
     [0021] FIGS.  4  to  8  are five schematic views depicting four types of implement with which this apparatus may be equipped. 
    
    
     [0022] The apparatus depicted in the drawing comprises a motorized vehicle  2  on the chassis of which a turret  3  is mounted to pivot about a vertical axis. Mounted to pivot about a horizontal axis on this turret  3  is an arm  4  comprising three elements  5 ,  6 ,  7  articulated to one another about two horizontal axles  8  and  9 . Angle sensors provide the position of the elements relative to one another and allow a mounting plate  10  belonging to the element  7  to be kept in a position parallel to the ground. Mounted on this mounting plate  10  is a rotary actuator  12  the upper part  13  of which is fixed to the mounting plate and the lower part  14  of which is mounted to pivot on the upper part  13 . The part  14  is secured to a unit  15  acting as an implement holder.  
     [0023] Mounted in the unit  15  is a hydraulic motor  16  the output shaft of which is equipped with a pinion  17  meshing with a pinion  18  of parallel axis. This pinion  18  meshes, for its part, with an toothed annulus  19  secured to a bushing  20  mounted to pivot about a horizontal axis in the unit via bearings  22 . This bushing  20 , driven in rotation, is prevented from translation in the unit. Mounted inside the bushing  20  is a hollow shaft  23  comprising, on its outer face, male splines  24  collaborating with female splines  25  of the bushing  20  to prevent the shaft  23  from rotating with respect to the bushing  20  while at the same time allowing this shaft a translational movement with respect to the bushing. The shaft  23  protrudes beyond the unit and its free end has an end wall  26  allowing this shaft  23  to act as a cylinder. This cylinder is engaged on a fixed rod  27 , the widened end  28  of which forms a piston. The cylinder is equipped, at its rear end, with an annular element  29  providing sealing around the rod  27 . Formed in the rod  27  are ducts  30  for the circulation of a hydraulic fluid, supplying and emptying chambers delimited between the hollow shaft  33  on the one hand and the rod and the piston  28  on the other.  
     [0024] Depending on the way in which hydraulic fluid is supplied to these chambers, the shaft  23  can slide relative to the bushing  20  while being made to rotate by the latter.  
     [0025] The end  26  of the shaft  23  is equipped with implement securing means. In the embodiment depicted in FIGS.  1  to  3 , this implement comprises a hub  32  for attachment to the shaft and from which there extend three chains  33  to the end of each of which a bob weight  34  is fixed. When the shaft  23  is rotated, the chains  33  will adopt a radial position and the bob weights will strike the ground, making a groove of some depth therein.  
     [0026] In the embodiment depicted in FIG. 4, the implement comprises a hub  35  from which there extend three radial arms  36  at the ends of each of which a sharpened part  37  is mounted.  
     [0027] In the embodiment depicted in FIG. 5, the implement has the overall shape of a disk  38 , the center  39  of which serves for the attachment to the shaft and the periphery of which has several teeth  40  uniformly distributed.  
     [0028]FIG. 6 depicts an alternative form of embodiment of the implement of FIG. 5, this implement then consisting of three disks  38  arranged parallel to one another and secured in terms of rotation with the interposition of spacer pieces which have not been depicted in the drawing.  
     [0029]FIGS. 7 and 8 show a third embodiment of the implement, in which embodiment a disk  41  is extended axially on an angular sector by a cylinder portion  43  and on a second annular sector by a number of rods  44 .  
     [0030] As is apparent from FIG. 8, the orientation of the rods  44  varies gradually in the direction of rotation of the implement from an orientation of the rods  44  that is divergent with respect to the axis of rotation to an orientation in which the rods  44  are parallel to this axis.  
     [0031]FIG. 7 shows that three teeth  45  offset from one another extend from the outer face of the cylinder portion  43 .  
     [0032] From a practical point of view, the vehicle is first of all positioned so that the end of its arm  4  can reach the region in which the ground is to be worked. This region is reached by altering the articulation of the various elements  5 ,  6 ,  7  of the arm relative to one another and by rotating the unit with respect to the mounting plate  10  so that the implement can describe a working sequence that is predetermined and controlled by a computer or can describe a working sequence simply under the initiative of the operator. This working sequence may involve combined movements of displacing the arm and translating the implement-bearing shaft with respect to the unit in which it is mounted. The stroke and the frequency of displacement of the shaft can be controlled by a sequencer.  
     [0033] As is evident from the foregoing, the invention provides a great improvement to the known art by supplying an apparatus for working the soil that allows this work to be performed systematically, even in highly inaccessible regions.  
     [0034] When the vehicle is equipped with the implement depicted in FIGS. 7 and 8, when the implement rotates the teeth  45  enter the ground and, in particular, when the ground is hard, tear out clumps. These clumps then drop into the rods  44  which, on the one hand, have a sifting action and play a part in breaking these clumps up and, on the other hand, have an action of moving these clumps aside onto a region of the ground which has already been worked. The latter action makes it possible in particular for the implement not to pick back up clumps which have already passed through it.  
     [0035] As goes without saying, the invention is not restricted to the sole embodiment of this apparatus which is described hereinabove by way of example or to the sole embodiments of the implements which have been disclosed; on the contrary, it encompasses all alternative forms thereof. Thus, in particular, the ram for the reciprocating translational movement of the implement could comprise a cylinder or a rod depending on which way round it is mounted, receiving, at its end, a thrust roller bearing allowing the ram to be kept fixed in terms of rotation without thereby in any way departing from the scope of the invention.