Abstract:
A press is provided with a feed channel, whose feed channel wall, in the event of overload, can be pivoted away from a feed rotor. The pivotal motion of the feed channel wall is realized about an upstream bearing, which, by means of a link, is itself moved away from the feed rotor in an upright guide. The motion within the guide is derived from the pivot motion of the feed channel wall away from the feed rotor. A hydraulic cylinder, working against a spring defined by an accumulator, is coupled to a downstream end of the channel wall and resists movement of the channel wall away from the feed rotor, but yields under a preselected crop load.

Description:
FIELD OF THE INVENTION 
   The invention relates to a feed channel wall having an upstream bearing and a downstream connector for a control apparatus which, on the other hand, can be attached to a machine, and having a line between the upstream bearing and a machine-side bearing, and further relates to an agricultural harvester. 
   BACKGROUND OF THE INVENTION 
   DE 198 41 598 A 1 shows a round baler having a cutting apparatus in a feed channel between a pick-up and a pressing chamber. The bottom of the feed channel can be lowered at both ends in order to prevent a clear crop jams. The upstream end is connected to the pick-up by means of links, which are controlled by a hydraulic cylinder. 
   The problem on which the invention is founded lies in the perception that the positioning control of the upstream end region is too complex. 
   SUMMARY OF THE INVENTION 
   This problem is solved according to the invention by the teaching of Patent Claim  1 , the other patent claims detailing features which advantageously refine the solution. 
   In this way, both end regions of the feed channel wall are controlled in their position by means of just one control apparatus. The use of two bearings at the upstream end region, which are connected on the machine side, produces a forced guidance, which is dependent on the position of the downstream end region. The bearing, as well as the guide, can be configured as plain or roller bearings and are located on the duct wall or the machine, i.e., for example, on the crop receiver or the frame of the machine, for example on a press or a loader wagon. The guide can be formed in a slot, a curved track, a rod system or the like. The adjustment on the basis of the guide can be made transversely to and/or along the feed flow, resilient elements or overload safety devices also being able to be used. 
   If the guide has a curvature, depending on the configuration of the curvature, a progressive or a regressive instead of a linear adjustment can be made, depending on the requirements. The curvature—even or uneven—also determines the direction in which the adjustment is made. 
   If the link to the straight line joining all the upstream bearings forms no angle or only a slight angle, it can brace itself against the influencing force of the feed flow and thus prevent friction against the guide, leading to a reduction in wear. In this case, the feed channel wall is in a very stable position, partly due to its bearing contact against the end of the guide. 
   A triangular arrangement of the upstream bearings has the result that the feed channel wall moves as far as possible away from the guide, i.e. widens the feed channel, in order to prevent crop jam problems. 
   An external-force-actuated control apparatus, for example a hydraulic cylinder or electric motor, can be easily driven via a switching circuit, which can be operated both from the press and from a towing vehicle. Such an external-force-control can be realized both manually and automatically. In simple construction, this adjustment could also however be performed by a rod system, a lever or the like. 
   The controlling of the control apparatus on the basis of parameters of the feed crop flow allows a rapid reaction to indications of a blockage. Thus, the pressure transversely to the feed flow, as well as a torque at the feed rotor, can form a suitable signal for the adjustment of the control apparatus. On the other hand, the crop density can also be detected with ultrasound or the like and converted into a signal. 
   The use of a spring (mechanical, pneumatic, pressure relief valve in a hydraulic circuit, etc.) has the advantage that load peaks can be absorbed without this immediately resulting in an adjustment of the feed channel wall. 
   Although there are many usage conditions in which crop is transported and can lead to a crop jam, for example in the transport of potential recyclables and waste in industry, of agricultural products in silos, in animal houses, etc., the danger of blockage in agricultural presses and loader wagons used in the field is particularly critical, since blockages are there difficult to clear and delay the harvest, which may lead to crop losses in poor weather. The use of the invention in the poorly accessible region between the crop receiver and the crop reservoir is therefore particularly advantageous. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     An illustrative embodiment of the invention, described in greater detail below, is represented in the drawing, in which: 
       FIG. 1  shows a press having a feed channel wall according to the invention in side view and in schematic representation, 
       FIG. 2  shows the feed channel wall in a position nearest to a feed rotor and having a hydraulic circuit for a control apparatus, 
       FIG. 3  shows the feed channel wall in a partly pivoted-away position, and 
       FIG. 4  shows the feed channel wall in a position full pivoted away from the feed rotor. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A press  10 , shown in  FIG. 1 , is of standard construction, i.e., it has a superstructure  12 , a chassis  14 , a drawbar  16 , a crop receiver  18 , a crop reservoir  20  and a feed apparatus  22 . 
   The press  10  is represented as a drawn press  10  having a size-variable crop reservoir  20 ; it could equally well be a self-propelling press  10  and/or one having a constant-size crop reservoir  20 , the type of (non-detailed) press elements being immaterial. 
   The superstructure  12  rests on the chassis  14  and bears the crop receiver  18  and the feed apparatus  22  and forms the crop reservoir  20  between (non-detailed) side walls. 
   The chassis  14  contains a rigidly or resiliently fitted axle and wheels. 
   The drawback  16  is connected in a rigid, or a vertically pivotable, manner to the superstructure  12  and serves for the connection to a towing vehicle (not shown). 
   The crop receiver  18  is also referred to as a pick-up and is connected in a vertically movable manner to the superstructure  12 , as is likewise known. 
   The crop reservoir  20 , at a front, lower region, has an inlet  24  for the fed crop, which connects directly to the feed apparatus  22 . 
   The feed apparatus  22  can be rigidly or movably connected to the crop receiver  18  or the superstructure  12  and contains, inter alia, a feed rotor  26 , a feed channel wall  28 , a control apparatus  30  and, in this illustrative embodiment, a hydraulic circuit  32  for the control apparatus  30  and, as indicated in  FIG. 2 , a cutting apparatus  34 . The feed apparatus  22  has the function of accepting crop brought up from the crop receiver  18  and of transporting it cut, or uncut, into the crop reservoir  20 . According to the nature of the crop per se or the density of the crop flow, there is always the danger of blockages, in the zone ahead of which an increased pressure may develop upon the feed channel wall  28 . The region between the crop receiver  18  and the inlet  24  includes a feed channel  36  defined by the feed channel wall  28 , the feed rotor  26  and side walls (not shown). 
   The feed rotor  26  can be driven in both directions and has drivers  38 , which convey the fed crop against the blades  40  of the cutting apparatus  34 , if such are present. In the position of the feed channel wall  28  according to  FIGS. 1 and 2 , the drivers  38  reach close up to these. 
   The feed channel wall  28  extends between the crop receiver  18  and the inlet  24  and follows essentially the periphery of the feed rotor  26  over about a quarter of its circumference. Whilst the drawing shows an undershot feed apparatus  22 , the invention could similarly be used on an overshot feed apparatus  22 . On the side remote from the feed rotor  26 , there is located on the feed channel  28  at its downstream end region a connector  42 , at its upstream end region a first bearing  44 , and in the vicinity of the latter a second bearing  46 . In this specific illustrative embodiment, the first and the second bearing  44  and  46  are located on a support  48 , which can simultaneously serve as a reinforcement for the feed channel wall  28 . If perpendiculars are drawn onto the surface of the feed channel wall  28  and through the first and the second bearing  44 ,  46 , these are spaced mutually apart, the second bearing  46  being located closer to the upstream end than the first bearing  44 ; moreover, the first bearing  44  has a greater distance to the feed surface of the feed channel wall  28  than does the second bearing  46 . The connector  42  and the bearings  44  and  46  can be configured both as pins, screws and as a continuous rod, etc. Although the connector  42  and the bearings  44 ,  46  are placed beneath the feed channel wall  28 , i.e. on its side remote from the feed rotor  26 , since this is easier to manufacture and install, the connector  42  and the bearings  44 ,  46  could also, however, be provided on its other side. At the upstream end region of the feed channel wall  28  there is a guide  50 , which receives the second bearing  46  slidably within it. In this illustrative embodiment, the guide  50  is configured as a slot in a plate attached to the crop receiver  18  or to the superstructure  12 . The guide  50  is of substantially kidney-shaped configuration and is vertically disposed. At least on each side of the feed apparatus  22 , a guide  50  is provided. 
   In addition, on each side of the crop receiver  18  or the superstructure  12  there is provided a machine-side bearing  52 , and between this machine-side bearing  52  and the first bearing  44 , respectively a link  54 , which is accommodated such that it is pivotably movable at both ends. The link  54  is dimensioned such that it lies essentially on a straight line which extends through the machine-side bearing  52 , the first bearing  44  and the second bearing  46  when the feed channel wall  28  is in its position nearest to the feed rotor  26 , in which the second bearing  46  bears against the upper end of the guide  50 . When the feed channel wall  28  is in its lowered position, the machine-side bearing  52 , the first bearing  44  and the second bearing  46  form essentially a right-angled triangle, one side of which is formed by the link  54 . 
   The downstream connector  42  is located close to the feed surface of the feed channel wall  28  in a straight-ending portion. The feed channel wall  28  is provided in the curved region with slots (not shown), through which the blades  40  can extend. 
   The control apparatus  30  is configured in this illustrative embodiment as a double-acting hydraulic cylinder having its rod end coupled to the downstream connector  42  and it cylinder end connected to the superstructure  12 . The control apparatus  30  extends essentially vertically and is connected to the hydraulic circuit  32  (shown purely in simplified representation), which, inter alia, has a spring  56  in the form of a gas pressure accumulator coupled to the piston rod side of the cylinder. This spring  56  is loaded so as to resist downward movement of the feed channel wall, but, when an excessive amount of feed crop is drawn into the feed channel  36  a pilot-operated relief valve  57  opens and permits the feed channel wall  28  to move away from the feed rotor  26 . 
   The hydraulic circuit  32  is conventionally configured and can be operated manually or automatically such that it moves the feed channel wall  28  away from the feed rotor  26  or up to the latter. The hydraulic circuit  32  is shown only in  FIG. 2 , purely for the sake of simplicity, but otherwise, in this illustrative embodiment, is constantly included. In principle, a mechanical or electrical adjustment could also, however, be chosen. 
   The cutting apparatus  34  is likewise conventionally configured and is represented only by the blades  40 . According to this, the blades  40  are mounted in a frame and can both deflect counter to spring load in the event of overload and be deliberately pivoted out of the feed channel  36  or disassembled in order to free the feed channel  36 . The blades  40  reach quite close up to the feed rotor  26 . 
   According to all that, the following function based on a normal operating mode, as shown in  FIGS. 1 and 2 , is obtained. 
   According to  FIG. 2 , the feed channel wall  28 , both at the upstream and at the downstream end region, is in the position nearest to the feed rotor  26 , and the second bearing  46  bears against the upper end of the guide  50 ; the control apparatus  30  is retracted and the blades  40 —insofar as present or installed—reach through the slots in the channel wall  28 . In a case in which the amount of crop which makes its way into the feed channel  36  and is pressed by the feed rotor  26  against the feed channel wall  28  is such that the control apparatus  30  is moved counter to the force of the spring  56 , the following occurs. The pressure exerted on the rod end of the piston of the control apparatus  30  surmounts the force of the spring  56  resulting in the feed channel wall  28  pivoting away from the feed rotor  26 , to be precise about an imaginary pivot point obtained from the interaction of the first bearing  44 , the link  54 , the machine-side bearing  52 , the second bearing  46  and the guide  50 . During this pivotal motion, the link  54  leads the second bearing  46  in the guide  50 , so that the said second bearing cannot fall there, but rather can only slide in a controlled manner. The connection by means of the link  54  leads also to a forced motion of the second bearing  46  and thus of the upstream end of the feed channel wall  28  away from the feed rotor  26 . This forced motion derives from the fact that the link  54  is deflected out of the straight line connecting all the bearings  44 ,  46 ,  52  a triangle is formed, the hypotenuse of which extends between the second bearing  46  and the machine-side bearing  52  and becomes shorter the further the feed channel wall  28  pivots away from the feed rotor  26 . In this case, the guide  50  also acts as a lateral bearing contact for the second bearing  46 , so that the triangle must be formed. In  FIG. 3 , an intermediate step is represented, whilst in  FIG. 4  the second bearing  46  bears against the lower end of the guide  50  and essentially a right-angled triangle has been formed. 
   Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.