Abstract:
A soil working tool, such as a cultivator tip, having a carrier which bears a primary cutting element and at least two secondary cutting elements on a cutter holder, wherein both the primary cutting element and the secondary cutting elements include a cutting edge. To optimize the penetration to achieve better cutting results, the cutting edges of the secondary cutting elements are arranged offset with respect to the cutting edges of the primary cutting element.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention relates to a soil working tool, in particular a cultivator tip, having a support which supports a primary cutting element and at least two secondary cutting elements on a cutter holder, wherein both the primary cutting element and the secondary cutting elements each has a respective cutting edge. 
     Discussion of Related Art 
     A soil working tool of this kind is known from German Patent Reference DE 10 2009 029 894.0, wherein the cutting elements are soldered to the cutter holder and the primary cutting element forms a cutting edge transverse to the advancing direction of the tool. The secondary cutting elements are set at an angle to the primary cutting element. 
     SUMMARY OF THE INVENTION 
     One object of this invention is to provide a soil working tool of the kind mentioned above that makes it possible to optimize penetration for the benefit of a better cutting result. 
     The above and other objects of this invention are attained with a soil cutting tool having cutting edges of secondary cutting elements situated so that they are offset relative to the cutting edges of the primary cutting element, with the cutting edges of the secondary cutting elements extending parallel to one another. 
     Because the cutting edges of the secondary cutting elements are no longer oriented obliquely and positioned in a V-shape relative to one another as in the prior art, a cleaner, straighter cut is produced, which produces a more definite cutting result and because of the shorter cutting edges, requires less tractive effort. This improves penetration into the soil. Furthermore, for the benefit of lower manufacturing costs, shorter lengths of hardened metal can also be used, making it possible to maintain the same plowshare width as in the prior art. 
     According to one embodiment of this invention, it is possible for the cutting edges of the secondary cutting elements to be arranged flush with one another. This produces a uniform tool load during the cutting engagement, which can prevent damage to the attachment of the cultivator tip. 
     It is preferable for the cutting edge of the primary cutting element to extend parallel to the cutting edges of the secondary cutting elements. This produces a stepped cutting engagement with clean, straight cuts. 
     In some embodiments, good cutting results can be achieved if the cutting edge of the primary cutting element is spaced at least 4 mm apart from the cutting edge of the secondary cutting element. This spacing achieves a stepped cutting engagement for the benefit of a lower required advancing power. This also avoids the formation of a trench bottom. 
     The cutting edge of the primary cutting element should be spaced a maximum of 15 mm from the cutting edge of the secondary cutting element in order to achieve a particularly stable tool design. 
     A soil working tool according to this invention can be embodied so that the cutter holder has cutting element mounts for the primary cutting element and the secondary cutting elements. The cutting element mounts have a seat surface and a contact surface situated at an angle thereto. The primary cutting element and the secondary cutting elements are each supported with a fastening section on the seat surface and with a cutting attachment on the contact surface. This achieves a mechanically stable cutting geometry. It is possible for the contact surfaces and/or the seat surfaces of the secondary cutting elements and of the primary cutting element to be oriented parallel to one another. This makes it possible to ensure a simple, exact, and reproducible orientation of the secondary cutting elements and the primary cutting element. 
     According to one embodiment of this invention, it is possible for the primary cutting element to protrude in the advancing direction relative to the secondary cutting elements or for it to be recessed relative to them. 
     Preferably, the seat surfaces are spaced apart from one another by a distance in the range from 8 to 14 mm. This produces stable tooth geometries on the cutter holder for accommodating the cutting elements. In this connection, it is also particularly possible for the contact surfaces to be spaced apart from one another by at least 4 mm, but preferably by a distance in the range from 15 mm to 30 mm. 
     If the diverting surfaces are oriented at an angle to one another, preferably by an angle in the range between 0.1° and &lt;90°, then the aggressiveness of the soil working tool can be adjusted by the way in which the diverting surfaces of the secondary cutting elements are set relative to the primary cutting element. More steeply angled diverting surfaces result in a more powerful displacement of material, while more gently sloped angles reduce the required traction force of the machine. 
     In another embodiment of this invention, both the primary cutting element and the secondary cutting elements have diverting surfaces that are situated so that they are parallel to one another and spaced apart from one another by at least 4 mm, but preferably by a distance in the range from 5 mm to 11 mm. The provision of parallel diverting surfaces makes it possible to convey the cut material away in a precise fashion. The diverting surfaces can also protect the steel body from erosion. 
     For the benefit of a symmetrical distribution of force, it is possible according to this invention for the secondary cutting elements to be arranged on the cutter holder symmetrical to the primary cutting element and on both sides of it. This produces an inward-directed flow of material from the secondary cutting elements to the primary cutting element. The secondary cutting elements are subjected to a greater level of abrasive wear, which is accompanied by the benefit of a lower stress on the primary cutting element. In addition, the inward-directed material flow subjects the cutter holder to less abrasive wear on the sides. 
     In particular, it is also possible for at least two secondary cutting elements to be provided on each side of the primary cutting element. This makes it possible to produce a plurality of cutting steps. 
     A good distribution of force on both the primary cutting element and the secondary cutting elements can be achieved in a simple way by embodying the width of the cutting edges of the secondary cutting elements to be at least 0.5 times the width of the cutting edge of the primary cutting element. 
     A soil working tool according to this invention can be embodied so that the cutting edge of the primary cutting element is arranged perpendicular to the advancing direction (V) and is offset in the direction of the force of gravity relative to the cutting edge of the secondary cutting element. This achieves a furrow-opening action and reduces the undesirable formation of a trench bottom. 
     In one embodiment, it is also possible for the support to have a raised breaking rib and/or a recessed breaking groove. This achieves a breaking up of clods and/or a displacement of soil. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This invention is explained in view of exemplary embodiments shown in the drawings, wherein: 
         FIG. 1  is a perspective depiction of a cultivator tip, according to one embodiment of this invention; 
         FIG. 2  is a sectional view of the cultivator tip from  FIG. 1 , viewed along the cutting line labeled II-II in  FIG. 1 ; 
         FIG. 3  shows another embodiment variant of a cultivator tip; 
         FIG. 4  is a sectional view along the cutting line labeled IV-IV in  FIG. 3 ; 
         FIG. 5  is a perspective view of another embodiment of a cultivator tip; 
         FIG. 6  is a sectional view taken along the cutting line labeled VI-VI in  FIG. 5 ; 
         FIG. 7  is a perspective view of another embodiment of a cultivator tip; 
         FIG. 8  is a sectional view taken along the cutting line labeled VIII-VIII in  FIG. 7 ; 
         FIG. 9  is a perspective view of another embodiment of a cultivator tip; 
         FIG. 10  is a sectional view taken along the cutting line labeled X-X in  FIG. 9 ; 
         FIG. 11  is a sectional view taken along the cutting line labeled XI-XI in  FIG. 9 ; 
         FIG. 12  is a perspective view of another embodiment of a cultivator tip; 
         FIG. 13  is a sectional view of the cultivator tip according to  FIG. 12 , viewed along the cutting line labeled XIII-XIII in  FIG. 12 ; 
         FIG. 14  is a perspective view of another embodiment of a cultivator tip; 
         FIG. 15  is a sectional view of the cultivator tip according to  FIG. 14 , viewed along the cutting line labeled XV-XV in  FIG. 14 ; and 
         FIG. 16  is a sectional view taken along the cutting line labeled XVI-XVI in  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a cultivator tip with a support  10  comprising of a steel body. The cultivator tip has a fastening section  11  with fastening mounts  12  in the form of through openings. The support  10  has a cutter holder  13  at one end, which is equipped with cutting element mounts  14 . 
     As clear from  FIG. 2 , the cutting element mounts  14  have a seat surface  14 . 1  that is oriented in the advancing direction V of the cultivator tip. This seat surface  14 . 1  is adjoined at an angle by a contact surface  14 . 2 . The cutting element mounts  14  accommodate a primary cutting element  20  and four secondary cutting elements  21 , as shown in  FIG. 1 . The primary cutting element  20  and the secondary cutting elements  21  can be embodied identically. If necessary, however, it is also possible for the secondary cutting elements  21  to have a narrower width transverse to the advancing direction V, but to otherwise be identical to the primary cutting element  20  so that they can be manufactured in the same tool mold equipped with sliding side walls. The principle cutting element  20  and the secondary cutting elements  21  have a fastening section  20 . 1 ,  21 . 1 , which is embodied as plate-shaped. The fastening section  20 . 1 ,  21 . 1  forms a support surface  20 . 6 ,  21 . 6 . The fastening section  20 . 1 ,  21 . 1  has a cutting attachment  20 . 2 ,  21 . 2  integrally formed onto it. The cutting attachment  20 . 2 ,  21 . 2  forms another support surface  20 . 7 ,  21 . 7 . The support surfaces  20 . 6 ,  20 . 7  and  21 . 6 ,  21 . 7  are oriented at right angles with respect to each other. The primary cutting element  20  and the secondary cutting elements  21  form a frontal diverting surface  20 . 4 ,  21 . 4  that tapers down to a rounded cutting edge  20 . 3 ,  21 . 3 . The cutting edge  20 . 3 ,  21 . 3  transitions into an open surface  20 . 5 ,  21 . 5  that faces toward the rear. 
     A soldered connection is used to fasten the primary cutting element  20  and secondary cutting elements  21 , which are of a hard material, in particular a hard metal. It is also possible to use an adhesive connection to enable a more advantageous manufacture. The primary cutting element  20  and the secondary cutting elements  21  are placed with their support surfaces  20 . 6 ,  20 . 7  and  21 . 6 ,  21 . 7  against the corresponding seat surfaces  14 . 1  and contact surfaces  14 . 2 . The integrally joined connection occurs or takes place on these surfaces. When mounted, the cutting edges  20 . 3 ,  21 . 3  of the primary cutting element  20  and secondary cutting elements  21  are oriented parallel with respect to one another. In this position, the cutting edges  21 . 3  of the secondary cutting elements  21  are situated flush with one another in pairs. In addition, the diverting surfaces  20 . 4  and  21 . 4  and the open surfaces  20 . 5  and  21 . 5  are respectively situated parallel to one another, as clearly shown in  FIG. 2 . The diverting surfaces  20 . 4  and  21 . 4  and/or the open surfaces  20 . 5  and  21 . 5  can also be situated at an angle with respect to one another, as shown in the exemplary embodiment according to  FIGS. 5 and 6 .  FIG. 2  also shows that the seat surfaces  14 . 1  are adjoined at right angles by flanks  14 . 3  of the cutter holder  13 . The fastening sections  20 . 1  of the primary cutting element  20  and the secondary cutting elements  21  cover the seat surfaces  14 . 1  in a direction transverse to the advancing direction V so that the relatively softer material of the cutter holder  13  is protected. 
       FIGS. 3 and 4  show another embodiment of a cultivator tip of this invention. In this case, a primary cutting element  20  and two secondary cutting elements  21  are built into a cutter holder  13 . The design of the primary cutting element  20  and the secondary cutting elements  21  essentially corresponds to that shown in  FIGS. 1 and 2 , thus permitting reference to the preceding explanations. In addition, the embodiment of the cutting element mounts  14  essentially corresponds to that of the cultivator tips shown in  FIGS. 1 and 2 . To this extent, reference is also made to the preceding explanations. By contrast with the cultivator tips according to  FIGS. 1 and 2 , in the present case, only two secondary cutting elements  21  are provided, whose cutting edges  20 . 3  are oriented parallel to each other and are flush with each other. It is also possible for the cutting edges  20 . 3  to be parallel but offset from each other. In addition, the cultivator tip according to  FIGS. 3 and 4  has a rib structure formed onto it at the front, which facilitates the penetration of the cultivator tip into the soil. In addition, excavated material can be compressed in the recesses between the ribs. This results in a “natural” wear protection. 
     The cultivator tip according to  FIGS. 5 and 6  is a modification of the cultivator tip according to  FIGS. 3 and 4 . As mentioned above, the diverting surfaces  21 . 4  and the open surfaces  21 . 5  of the secondary cutting elements  21  are oriented at an angle relative to the diverting surface  20 . 4  and open surface  20 . 5  of the primary cutting element  20 . The primary cutting element  20  in this case is in a flatter orientation relative to the advancing direction V than the secondary cutting elements  21 . As a result, the primary cutting element  20  bites into the soil more sharply, while the secondary cutting elements  21  provide a greater displacement. 
       FIG. 6  shows that the cutting edges  21 . 3  of the secondary cutting elements  21  are offset transversely to the advancing direction V and opposite the force of gravity relative to the cutting edge  20 . 3  of the primary cutting element  20 . This produces less of a tendency to form a trench bottom because the primary cutting element  20  opens deeper furrows. 
     The same effect can also be achieved if the cutting edges  21 . 3  of the secondary cutting elements  21  are lower than the cutting edge  2 . 3  of the primary cutting element  20 .  FIGS. 7 and 8  show such an embodiment where the support  10  is again provided with a breaking rib  16  on its side oriented in the advancing direction V. This breaking rib  16  forms the cutting element mount  14  for the primary cutting element  20 . Starting from the primary cutting element  20 , the breaking rib  16  continuously widens in the direction toward the end of the support  10  oriented away from the primary cutting element  20 . This achieves a structure that is optimized in terms of stress. In addition, the breaking rib  16  also reinforces the support  10  and increases the section modulus in opposition to flexion in the main direction of force.  FIG. 10  shows that a breaking groove  17  is recessed into the back of the support  10 . Once again, this groove extends starting from the primary cutting element  20  in the direction toward the rear end of the support  10 , as shown in  FIGS. 9 and 10 . 
     The above-mentioned breaking rib  16  breaks up clods in a favorable manner and a certain amount of material flow into the breaking groove  17  can be produced for the benefit of a lower required traction force. In addition, this design also counteracts the undesirable formation of a trench bottom. 
     The same effect can also be achieved if on the contrary, a breaking groove  17  is formed into the front of the support  10  and a breaking rib  16  is formed onto the back. Such a design is featured in the exemplary embodiment shown in  FIGS. 13 through 15 . 
       FIGS. 7 and 8  and  FIGS. 11 through 15  show exemplary embodiments in which the primary cutting element  20  is recessed relative to the secondary cutting elements  21  in the opposite direction from the advancing direction V. Consequently, the front pair of secondary cutting elements  21  always engages the soil first, producing an initial separating action. Then, the second pair of secondary cutting elements  21 , such as shown in  FIGS. 11 and 12 , and then the primary cutting element  20  dig in. More of the wear is thus distributed onto the two secondary cutting elements  21 . As a result of this wear-optimized tool design, it is in particular also possible to use the same parts for the secondary cutting elements  21  and the primary cutting element  20 .