Patent Publication Number: US-2022210978-A1

Title: Support rail of an ear lifter for crops

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of International Application No. PCT/EP2020/061568, filed Apr. 25, 2020, claiming priority to Germany Patent Application No. 20 2019 102 446.1, filed Apr. 30, 2019. 
    
    
     TECHNICAL FIELD 
     The following disclosure relates to a support rail of an ear lifter for crops, with a major direction of extension, wherein a section formed as a skid is arranged between a first end and a second end of the support rail, wherein the section formed as a skid is configured to be guided with its outer side over a ground, and to an ear lifter for a mowing unit of a harvesting machine, with a stalk lifter and a support rail carrying the stalk lifter. 
     BACKGROUND 
     In known harvester mowing units, guard fingers are distributed along a cutter bar, which guide the cutter bar and form the counter-blades for the knife blades. In order to be able to mow kinked or laid stalks safely, ear lifters are used to lift the stalks. The ear lifters typically have a support rail and a stalk lifter. The support rail used to attach the ear lifter to the mower bar of the mower guides the stalk lifter, on the upper side of which the stalk material is lifted. When operating the harvester, the support rail must be guided a short distance above the ground surface so that the kinked or laid stalks can be lifted as completely and reliably as possible with the stalk lifter. The section of the support rail closest to the ground slides over the ground surface almost permanently, like a skid. Due to the increasing working speeds of the harvesters and the unevenness of the ground surface, the support rail is subject to considerable abrasive wear. 
     DE 101 23 248 C1 describes an ear lifter in which the support rail is made rigid in an area between the second end and a retainer by means of a profiled section. The section directly at the second end is itself sufficiently reinforced by the fastening of the stalk lifter to the support rail, so that the profiling extends to the adjoining section. These are, in particular, the slidingshoe-like section, with which the support rail rests on the ground, and the adjacent section reaching towards the retainer. For this purpose, the support rail is curved in cross-section in this section. 
     From the publication WO 2011/143681 A1, an ear lifter is known in which a surface is arranged in the front part of the downward-facing side of the ear lifter, which is configured to frequently slide on the ground during operation, wherein this surface is provided with a wear plating made of a material different from the material of the support rail, wherein the wear plating is formed by a plating part mounted replaceably on the ear lifter. 
     It is an objective to improve a support rail for an ear lifter with respect to at least one of the properties of wear, bending stiffness and torsional rigidity by means of an enhanced profiling compared to the prior art. 
     SUMMARY OF THE INVENTION 
     The objective is met by a support rail for an ear lifter and by an ear lifter according to the independent claims. In the dependent claims, embodiments and advantageous further developments are indicated. 
     The support rail of an ear lifter for crops has a main direction of extension, wherein a section formed as a skid is arranged between a first end and a second end of the support rail. The section formed as a skid is configured to be guided with an outer side over a ground. The major direction of extension is also referred to as the longitudinal axis, wherein this is not to be understood as a straight line, but is to be defined along the support rail, which is generally curved in the longitudinal direction. The section formed as a skid will also be referred to simply as skid in the following. The skid is formed, for example, by a section of the support rail itself, but can also be arranged as a separate component on the support rail. 
     It is provided that the section formed as a skid comprises a bar, wherein the bar extends in the major direction of extension on an inner side opposite the outer side. 
     An advantage of the support rail is that the bar provides a profile that is more resistant to bending than a single-curved profile and also has improved wear behavior. Furthermore, the support rail with the bar has a higher torsional stiffness than a single-curved profile. The advantageously improved wear behavior results from the fact that the support rail offers greater stability under increasing wear in the section of the skid and thus a longer service life until failure occurs. In support rails with a single curvature according to the state of the art, as the skid wears a hole forms in its centre. The hole becomes larger with wear and weakens the skid to such an extent that it must be replaced. In the event of failure, part of the skid or the ear lifter may get lost. Sharp-edged fragments stuck in the ground can then destroy a tire of the harvesting vehicle, for example. Another danger if the front part of the ear lifter is lost is that it can get into the cutting unit and subsequently pass through the entire threshing elements of the harvester, where it can cause considerable damage. This results in long downtimes and high repair costs. In the case of the disclosed skid, the bar remains in place to bridge and stabilize the hole even under increasing wear. This results in an advantageously longer service life of the support rail. Furthermore, increasing wear towards the flanks, i.e. the outer areas of the skid next to the bar, will soon result in deposition of soil and harvested material. This will be clearly noticeable to the user so that he can inspect the ear lifter for its wear limit without risking a loss due to excessive weakening of the worn section. 
     According to an embodiment, it is provided that the bar is connected on the inner side to the section formed as a skid. In this way, two elongated slots will form under the wear described above, the combined width of which is less than the width of the single hole, and the area of which is less than the area of the hole. For example, the bar is joined to the section formed as a skid by material bonding, in particular by welding. Alternatively, the bar can be riveted and/or glued to the section formed as a skid. 
     According to a further embodiment, the bar is inserted into a recess in the section formed as a skid. The recess is designed in particular as a continuous slot along the main extension direction, into which the bar is inserted. The bar projects, for example, on the inner side beyond the section formed as a skid. A slot has an extension along the major direction of extension, which is at least twice as large, for example at least five times as large, as in other directions of extension. 
     According to a further embodiment, it is provided that the bar is made of a different material than the section formed as a skid, or than the rest of the support rail. A different material in the sense of the disclosure is also to be understood as an identical starting material with different material properties, which result, for example, from a treatment of the material. This includes in particular a hardness and/or a strength of the material, which can be influenced, for example, by a heat treatment. Hardness is the mechanical resistance of a material to the mechanical penetration of an indenter. Strength is the resistance of a material to deformation and separation. Hardness and strength can be determined by material testing methods known to the skilled person. For example, the bar is made of a material that has a greater hardness and/or strength than the material from which the skid section is made. 
     According to a further embodiment, it is provided that the bar is formed in the shape of a rib, so that the bar together with the section formed as a skid has a T-shaped cross-section in a section transverse to the major direction of extension. For example, the section formed as a skid has lateral flanks, wherein the lateral flanks are angled towards the inner side. For example, the section formed as a skid is concavely curved on the inner side, so that the T-shape is not to be understood in the sense that the skid must be straight in cross-section. 
     Along the major direction of extension, an extension of the bar in a secondary direction of extension may be constant or may vary, for example decreasing from a central area toward both sides. For example, the bar has a curvature along the major direction of extension that corresponds to a curvature of the section formed as a skid. The bar is thus advantageously adapted to the contour of the section formed as a skid. 
     According to a further embodiment, it is provided that the bar has a base plate, wherein the base plate is connected to the section formed as a skid. The base plate advantageously facilitates the connection of the bar to the section formed as a skid, in particular if the latter is not inserted in a recess. Advantageously, the base plate provides a surface for making an adhesive connection or a riveted connection. 
     The disclosure is not limited to a support rail having only one bar. The skilled person will recognize that an embodiment is conceivable in which the section formed as a skid has on the inner side, in addition to the bar, at least one further bar extending in the major direction of extension, wherein the bars are arranged in particular parallel to one another. 
     A further aspect relates to an ear lifter for a mower unit of a harvesting machine, which meets the above-mentioned objective. The ear lifter comprises a stalk lifter and a support rail supporting the stalk lifter, as previously described. 
     The stalk lifter is arranged, for example, at the second end of the support rail, wherein the section formed as a skid joins the second end and wherein the bar extends to the stalk lifter. The stalk lifter may have a V-shaped profile in cross-section, wherein the bar extends into the V-shaped profile such that one end of the bar is disposed between the legs of the V-shaped profile. The bar may be connected to the stalk lifter. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       In the following, further features and advantages will be explained in more detail by means of exemplary embodiments with reference to the accompanying drawings. The explanations are merely exemplary and do not limit the general idea of the invention. 
       In the Figures show 
         FIG. 1  a perspective view of an embodiment of the ear lifter with a support rail; 
         FIGS. 2 a  and 2 b    two detailed perspective views of an embodiment of the support rail; 
         FIGS. 3 a  and 3 b    two perspective detail views of a further embodiment of the support rail; 
         FIGS. 4 a  and 4 b    two detailed perspective views of yet a further embodiment of the support rail. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an exemplary embodiment of an ear lifter with a support rail  5 . A first end  8  of the support rail  5 , which is made from a flat material as the starting material, is provided for attachment to a mower bar of a harvesting machine, which is not shown. At a second end  9  remote from the first end  8 , a stalk lifter  10  is attached to the support rail  5  to form an acute angle with the support rail  5 . The support rail  5  comprises a retainer  11 , which is configured to rest on a finger guard, which is not shown. The support rail  5  extends along a major direction of extension X from the first end  8  to the second end  9 , with an outer side  15  facing the ground during operation on a harvesting machine. The section  12  of the support rail  5 , formed as a skid, is configured to slide over the ground, which is not shown, and is accordingly subject to considerable wear. Viewed from an inner side  18 , the support rail  5  is concavely curved in the section of the skid  12 , so that flanks  17  of the skid  12  enclose an acute angle with the ground during operation. 
     The section  12  formed as a skid is configured to be guided over the ground with the outer side  15 . The section  12  formed as a skid comprises a bar  14 , wherein the bar  14  extends in the major direction of extension X of the support rail  5  on the inner side  18  opposite the outer side  15 . Since the major direction of extension X of the support rail  5  coincides with that of the bar  14 , the term major direction of extension X hereinafter refers to both components. A secondary direction of extension Z of the bar  14  in the form of a rib is oriented substantially orthogonal to the major direction of extension X. The directional arrows are not to be understood as Cartesian coordinate axes, but are merely intended to illustrate the directions of extension in the slightly perspective view. In the further Figures, no direction arrows are indicated. The directions given in  FIG. 1  apply mutatis mutandis to all Figures. 
     In the exemplary embodiment of the ear lifter according to  FIG. 1 , the stalk lifter  10  is arranged at the second end  9  of the support rail  5 , wherein the section  12  formed as a skid is arranged adjacent to the second end  9  and wherein the bar  14  extends all the way to the stalk lifter  10 . The stalk lifter  10  has a V-shaped profile in cross-section, wherein the bar  14  extends into the V-shaped profile. 
       FIGS. 2 a  and 2 b    show two partial views of an embodiment of the support rail  5  for an ear lifter according to  FIG. 1 , of which the section  12  formed as a skid is shown in detail. Both Figures are described together. An extension of the bar  14  along the major direction of extension X in a secondary direction of extension Z (cf.  FIG. 1 ) is constant. The bar  14  has a curvature along the major direction of extension X, which is adapted to the section  12  formed as a skid. In the embodiment shown, the bar  14  has a base plate  16  which is connected to the section  12  formed as a skid. The base plate  16  serves to connect the bar  14  to the section  12  formed as a skid, which is realized here by fasteners in the form of rivets  19 . 
       FIGS. 3 a  and 3 b    show two partial views of a further embodiment of the support rail  5  for an ear lifter according to  FIG. 1 , of which the section  12  formed as a skid is shown in detail. Both Figures are described together. The embodiment differs from the embodiment shown in  FIGS. 2 a  and 2 b    in that the base plate  16  is connected to the section  12  formed as a skid in a different manner, namely without fasteners. The base plate  16  is connected to the section  12  formed as a skid, for example, by an adhesive connection, a soldered connection or by a welded connection. 
       FIGS. 4 a  and 4 b    show two partial views of a further embodiment of the support rail  5  for an ear lifter according to  FIG. 1 , of which the section  12  formed as a skid is shown in detail. Both Figures are described together. The embodiment differs from the embodiment shown in  FIGS. 2 a  and 2 b    in that the bar  14  is connected in a different manner to the section  12  formed as a skid. The bar  14  does not have a base plate, but is inserted into a slot-like recess  6  of the section  12  formed as a skid. The recess  6  runs along the major direction of extension X (cf.  FIG. 1 ) and is provided through from the inner side  18  to the outer side  15 . The bar  14  is flush with the outer side  15 , for example. On the inner side  18  the bar  14  protrudes therefrom, for example. 
     The bar  14  is joined to the section  12  formed as a skid, for example by a welded connection (not shown). Alternatively, in the embodiment according to  FIGS. 4 a  and 4 b   , there is also the option of attaching the bar  14  to the section  12  formed as a skid by means of a riveted connection. For example, the rivets (not shown) are prefabricated as protruding portions on the bar  14 . After the bar  14  is inserted into the recess  6 , the protruding rivets are machined from the outer side  15  so that the bar  14  is firmly connected. In particular, the rivets are provided at the ends of the bar  14 , which are driven into the ends of the recess  6  under deformation to form the connection. Another alternative is not to make the recess slot-like, but instead to provide a plurality of bores, wherein the rivets prefabricated as projecting portions on the bar  14  are inserted into the bores and riveted therein. In that case, with the exception of the rivets, the bar  14  is arranged on the inner side  15 . 
     A further alternative of the embodiment according to  FIGS. 4 a  and 4 b    is that the bar  14  protrudes on the outer side  15 , in particular in the same way as on the inner side  18 , so as to advantageously further reduce wear on the outer side  15 . 
     REFERENCE NUMERALS 
     
         
           5  Support rail 
           6  Slot-like recess 
           8  First end of support rail 
           9  Second end of support rail 
           10  Stalk lifter 
           11  Retainer 
           12  Section designed as skid 
           14  Bar 
           15  Outer side 
           16  Base plate 
           17  Flank 
           18  Inner side 
           19  Rivet 
         X Major direction of extension, longitudinal axis 
         Z Secondary direction of extension