Abstract:
An agricultural working vehicle includes a working tool, a drive assembly for raising and lowering the working tool and a control element that is deflected from a neutral position in different directions. A speed (v) at which the drive assembly moves the working tool is a continuous function of a deflection (a) of the control element.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
       [0001]    The invention described and claimed hereinbelow is also described in German Patent Application DE 10 2012 002992.6, filed on Feb. 15, 2012. This German Patent Application, subject matter of which is incorporated herein by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d). 
       BACKGROUND OF THE INVENTION 
       [0002]    The invention broadly relates to an agricultural working vehicle such as a forage harvester or a combine harvester. 
         [0003]    The working tools of conventional agricultural working vehicles such as forage or combine harvesters are generally removable, whether to replace the working tool in order to adapt to work to be performed or because the dimensions of the working tool are so great that the working vehicle, with the working tool mounted thereon, is prohibited from traveling on public roads. In that case, the working tool must be delivered separately, e.g., on a trailer drawn by the working vehicle, to the site of use, where it must be lifted. 
         [0004]    The raising and lowering of a working tool requires a great deal of caution and practice on the part of a user. Mistakes can result in damage to the working tool, which are costly to repair. 
         [0005]    In order to control a drive assembly for raising or lowering the working tool, a conventional working tool comprises a toggle switch that is movable in two degrees of freedom. By swiveling the toggle switch in a first degree of freedom, the driver can select whether to raise or lower the working tool. By swiveling the toggle switch in the second degree of freedom, the driver sets the speed of the motion. In order to lift a working tool, a driver will generally drive the working vehicle toward the working tool with a greatly lowered, vehicle-side coupling and then raise the coupling at the slow speed for engagement thereof with a tool-side coupling. The further the vehicle-side coupling is lowered and the more slowly it is raised, the more certain it is that damage to the working tool will be prevented; however, it takes that much longer to raise the tool. 
         [0006]    An agricultural working tool comprising a such multifunctional handle, the diverse control elements of which facilitate such control of a working tool, is known from DE 10 2009 034 154 A1. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention overcomes the shortcomings of known arts, such as those mentioned above. 
         [0008]    In an embodiment, the invention provides an agricultural working tool that permits working tools to be handled rapidly as well as safely. 
         [0009]    In an embodiment, the invention provides a working tool, a drive assembly for raising and lowering the working tool and a control element that can be deflected from a neutral position in different directions in order to control the drive assembly. The speed at which the drive assembly moves the working tool is a continuous function of the deflection of the control element. This feature makes it possible for the user to flexibly adapt the speed of the drive assembly to the extent of the danger and, when setting down the working tool (e.g., to thereby lower the working tool rapidly at first), provided it is not close to a surface underneath and to reduce the speed upon approaching the surface underneath, in order to ultimately place the tool onto the surface underneath gently and safely. 
         [0010]    The speed is preferably controlled by deflecting the control element via rotation about an axis. 
         [0011]    To ensure safe handling, it is advantageous for the control element to have a corrugated circumferential surface. 
         [0012]    The axis about which the control element can be rotated is preferably oriented transversely to the direction of travel of the working tool so that, upon deflection, the circumferential surface of the control element is moved vertically or in the direction of travel, but not in the direction transverse to the vehicle. This makes it possible, even for an untrained user, to establish a logical connection between the direction of the deflection and the direction of the tool motion and to prevent the tool from inadvertently moving in the wrong, undesired direction. 
         [0013]    If only a portion of the surface of the control element is exposed and the rest is inaccessible, e.g., in a housing, then the exposed surface is preferably oriented such that deflection of the surface upwardly and/or in the direction of travel permits the working tool to be raised. Deflection thereof opposite the direction of travel and/or downward permits the working tool to be lowered. Thus, easy accessibility and convenient operability of the surface can be combined with a correlation, which is clearly intuitive to the user, between the direction of the deflection and the direction of the resultant tool motion. 
         [0014]    The control element is preferably disposed on a multifunctional handle along with control elements for other functions of the working vehicle. 
         [0015]    Such a multifunctional triol can have a gripping surface that is oriented to support at least a portion of the palm of a user&#39;s hand lying in an operating position and thereby permit operation for a long period of time without the operator becoming tired. The control element is placed on the multifunctional handle in order to reach the control element by a finger on the hand lying in the operating position. 
         [0016]    A surface of the multifunctional handle adjoins the exposed surface of the control element in a flush manner, preferably transversely to the deflection direction. Such a surface shape help prevents inadvertent deflection of the control element. 
         [0017]    To ensure that inadvertent, light contact with the control element does not result in unwanted movement of the tool, the control element is configured to be fixed in the neutral position by way of locking means. 
         [0018]    The position of the working tool being influenced by accidental, small deflections of the control element also can be prevented in that an interval of the deflection, in which the speed of the working tool is zero, extends on either side of the neutral position. The tool, therefore, does not begin to move until the control element is deflected out of said interval. 
     
    
     
         [0019]    Further features and advantages of the invention will become apparent from the description of embodiments that follows, with reference to the attached figures, wherein 
           [0020]      FIG. 1  shows a schematic view of a forage harvester as an example of an agricultural vehicle according to the invention; 
           [0021]      FIG. 2  shows a view of the head of a multifunctional handle used in the forage harvester depicted in  FIG. 1 ; 
           [0022]      FIG. 3  shows the head with a driver&#39;s hand resting thereon; 
           [0023]      FIG. 4  shows a control element of the multifunctional handle; 
           [0024]      FIG. 5  shows a graph that illustrates the correlation between the deflection of the control element and the raising and lowering speed of the tool of the forage harvester; 
           [0025]      FIG. 6  shows a variant of the control element; and 
           [0026]      FIG. 7  shows a perspective view of the head of a multifunctional handle according to a second embodiment; 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    The following is a detailed description of example embodiments of the invention depicted in the accompanying drawing. The example embodiments are presented in such detail as to clearly communicate the invention and are designed to make such embodiments obvious to a person of ordinary skill in the art. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention, as defined by the appended claims. 
         [0028]    A person skilled in the art is familiar with the basic features of the forage harvester, such as the forest harvester depicted in  FIG. 1 . Hence, this disclosure does not describe in detail known assemblies used in conventional harvesting machines, such as front harvesting attachment  1 , intake assembly  2 , chopping mechanism, and transfer bend  3 . What is important for an understanding of the present invention is that the front harvesting attachment  1  is removable for transport on a trailer on a public road, and permits selection and installation of the appropriate front harvesting attachment for the particular crop to be harvested. In order to remove the front harvesting attachment  1  from a non-illustrated trailer, for example, or to lower said front harvesting attachment onto said trailer after use, the height of the intake assembly  2  is adjusted with the aid of hydraulic cylinders that are driveable by a diesel engine of the forage harvester via a pump having a variable throughput rate. 
         [0029]    Control elements for controlling various functions, in particular for adjusting the height of the intake assembly  2 , are disposed in an instrument panel  4  of a driver&#39;s cab  5  and are situated there on a multifunctional handle  6 . The multifunctional handle  6  is displaceable relative to the instrument panel  4  to control the progressive motion of the forage harvester. The multifunctional handle can have a single degree of freedom for displacement, for controlling forward and reverse motions of the forage harvester, e.g., in the form of a gate guide of the type described in U.S. Pat. No. 6,715,269 B2. Preferably, however, the multifunctional handle  6  has two degrees of freedom for displacement, one in the direction of travel for controlling the forward and reverse motion and ground speed, and one in the direction transverse to the vehicle for controlling the direction of travel. 
         [0030]    The use of the multifunctional handle  6 , described in greater detail in the following, is not limited to a forage harvester, however, and may be used for any other type of agricultural vehicle such as a tractor or a combine harvester. 
         [0031]      FIG. 2  shows a perspective view of the head of the multifunctional handle, as viewed by the driver. A hollow neck  8  is integrally formed on the underside of the grip head  7 , and accommodates a shaft of the handle (which is not shown in  FIG. 2 ) and connects the head  7  to a joint in the instrument panel  4 . The grip head  7  is irregularly shaped. Consequently, sides of the grip head are not sharply delineated from each other and instead transition continuously into each other at edges that are rounded off to a greater or lesser extent. Yet, a continuous surface is identifiable that is curved relatively slightly, is disposed on a top side that is approximately diametrically opposed to the neck  8  and that includes a gripping surface  9  in the region thereof facing the driver that is adapted to the shape and size of a driver&#39;s palm. And, adjacent thereto in the direction of travel, the continuous surface includes a control field  10 . As shown in  FIG. 2 , the gripping surface  9  has small recesses distributed thereon. 
         [0032]    While the gripping surface  9  is sized to support the metacarpal bones of the second to fifth fingers along the entire length thereof, the width of the control field  10  is designed only for the index and middle fingers. Therefore, the remaining fingers can grip a steeply slanted flank  11  on a side of the grip head  7  that faces away from the driver and not shown in  FIG. 2 . And, the driver can pull the grip head  7  toward himself using the fingers, even if the index and middle fingers are substantially extended on the control field  10  and are unable to pull. 
         [0033]    In the  FIG. 2  embodiment, the control field  10  comprises three control elements  12 ,  13 ,  14 . The control element  12  adjusts the height of the intake assembly  2  and the front harvesting attachment  1 ; but the control elements  13 ,  14  can be dedicated to other functions of the front harvesting attachment  1 . The two control elements,  13  and  14 , are placed on the front end of the control field  10  such that, when the driver&#39;s hand rests on the gripping surface  9  ( FIG. 3 ) and the index finger is extended, the tip thereof can touch one of the two control elements  13 ,  14  (which are designed as buttons), and depress them. The control element  12  is located closer on the gripping surface  9 , and therefore, the user must curve the index finger in order to touch and deflect said control element using the fingertip. 
         [0034]    The control element  12  comprises a knurled wheel  15  having a flat, cylindrical shape. The wheel can be rotated about an axis  16  extending substantially through the grip head  7  transversely to the direction of travel of the forage harvester. The greatest portion of the knurled wheel  15  is housed in the grip head  7 . An exposed part of the circumferential surface  17  thereof is elongated on both sides in the direction of the axis  16  via arched housing segments  18  of the grip head  7 . The housing segments  18 , therefore, together with the exposed circumferential surface  17 , form a substantially flat, lenticular projection on the control field  10 . 
         [0035]      FIG. 4  shows the knurled wheel  15  in a schematic side view in the direction of the axis  16 . The control field  10 , into which the knurled wheel  15  extends, rises slightly in the direction of travel, i.e. toward the left in  FIG. 4 . In order to turn the knurled wheel  15 , therefore, the user&#39;s finger (which is in contact with the exposed circumferential surface  17 ), must make a motion in the direction of a double arrow labeled with reference numeral  19  in the figure. That is, the point on the circumferential surface  17  contacted by the driver&#39;s fingertip is deflected substantially in the direction of travel and, simultaneously, slightly upward, or is deflected opposite the direction of travel and slightly downward. It is understood to be clearly intuitive to the driver that deflection in the direction of travel triggers an upward motion of the intake assembly  2 , and motion opposite the direction of travel triggers a downward motion. 
         [0036]    To ensure that accidental contact of the circumferential surface  17  does not result in deflection and, therefore, a change in height of the intake assembly  2 , the knurled wheel  15  is locked in the neutral position thereof. Such locking can be accomplished with the aid of a leaf spring  20 . In this case, the ends of said leaf spring are fixed in the grip head  7 , the leaf spring comprising an elastically deflectable projection  21 , which engages in a notch  22  of the knurled wheel  15  when in the neutral position. 
         [0037]    In order to convert the position of the knurled wheel  15  into a signal that can be used to control the speed of the intake assembly  2 , a potentiometer is coupled to the knurled wheel  15 . By way of the design thereof, such a potentiometer generally limits the freedom of rotational motion of the knurled wheel  15  to approximately half of one revolution. By way thereof, a linear correlation between the deflection of the control element  13  and the displacement speed of the intake assembly  2  can be easily achieved. 
         [0038]    The invention further contemplates use a digital angle-of-rotation sensor that converts rotation of the knurled wheel  15  into a pulse train comprising a number of pulses that is proportional to the angle of rotation that was passed through. Such an angle-of-rotation sensor is particularly suitable for attaining any type of interrelationship between the deflection α of the control element  13  and the displacement speed v of the intake assembly. That approximate interrelationship is shown as a solid curve in  FIG. 5 , in which small deflections about the neutral position  0  do not result in motion and only those deflections that exceed a threshold +ε or −ε result in a displacement speed v that increases linearly depending on the deflection α. 
         [0039]    Alternatively, a displacement speed that increases faster than linearly depending on the deflection can be implemented. Doing so makes it possible to precisely regulate a slow displacement speed and achieve rapid displacement via moderate deflection. 
         [0040]    Such a digital angle-of-rotation sensor does not necessarily limit the freedom of rotational motion of the knurled wheel  15 , and so it is basically possible to rotate the knurled wheel  15  to any extent, even by more than one revolution, toward the neutral position. In order to ensure that the driver can quickly return to the neutral position at any time, it is advantageous to limit the freedom of rotational motion of the knurled wheel  15 . A projection  23  of the knurled wheel  15  can be used for this purpose. For example (as shown in  FIG. 6 ), the projection is located in the neutral position centrally in the window  24  of the control field  10  filled by the knurled wheel  15  and is deflectable from there in the direction of travel or opposite the direction of travel until said projection impacts a front or rear edge  25  of the window  24 . 
         [0041]    As long as the user&#39;s fingertip is touching the projection  23 , the user can gauge the intensity and direction of the deflection without having to look at the control field  10 . The operator therefore always knows how he/she must move the control element  15  in order to stop the intake assembly  2 . In this embodiment, the knurled wheel  15  need not be circular; it is sufficient to provide a segment of a circle having a circumferential surface that is long enough to fill the window  24  in any reachable position. 
         [0042]    To enable the drive assembly to be stopped rapidly in an emergency, a return spring is dedicated to the knurled wheel  15  ( FIG. 6 ). The return spring is in the form of a hairpin spring  26  in this case. The two legs of the spring are immobilized in the head  7  at the interconnected ends thereof, and the free ends of which rest on either side of a peg  27  protruding eccentrically from the knurled wheel  15 . Any deflection of the knurled wheel  15  out of the neutral position results in deflection of a leg of the hairpin spring  26 . Hence, when the user releases the knurled wheel  15 , the knurled wheel is immediately forced back into the neutral position and the motion of the intake assembly comes to a standstill. 
         [0043]      FIG. 7  shows a perspective view (analogous to that of  FIG. 2 ), of a grip head according to another embodiment of the invention. The control element  12  (embodied as a knurled wheel  15  in this case), is disposed on a control field  28 . Control field  12  fills a lateral flank of the grip head  7  and is operated using the thumb. In accordance with the movability of the thumb, the knurled wheel  15  is rotated about an axis  16 . Axis  16  extends substantially parallel to the index finger resting on the control field  10  and extends approximately in the direction of travel of the forage harvester. The exposed circumferential surface  17  of the knurled wheel is therefore be moved up and down. An upward deflection of the circumferential surface results in an upward motion of the intake assembly  2 , and that a downward deflection of the circumferential surface  17  results in a downward motion of the intake assembly  2  conforms to the driver&#39;s intuition. 
         [0044]    The following list of reference signs of various elements mentioned above is included (as follows), for ease of explanation: 
       LIST OF REFERENCE CHARACTERS 
       [0000]    
       
           1  front harvesting attachment 
           2  intake assembly 
           3  transfer bend 
           4  instrument panel 
           5  driver&#39;s cab 
           6  multifunctional handle 
           7  grip head 
           8  neck 
           9  gripping surface 
           10  control field 
           11  flank 
           12  control element 
           13  control element 
           14  control element 
           15  knurled wheel 
           16  axis 
           17  circumferential surface 
           18  housing segment 
           19  double arrow 
           20  leaf spring 
           21  projection 
           22  notch 
           23  projection 
           24  window 
           25  edge 
           26  hairpin spring 
           27  peg 
       
     
         [0072]    As will be evident to persons skilled in the art, the foregoing detailed description and figures are presented as examples of the invention, and that variations are contemplated that do not depart from the fair scope of the teachings and descriptions set forth in this disclosure. The foregoing is not intended to limit what has been invented, except to the extent that the following claims so limit that.