Abstract:
A crop harvesting mechanism having a reel assembly with a reel that is rotatably supported at each end by a respective reel support. A reel carrier arm is provided for each of the reel supports and the supports are movable along the reel carrier arm. A horizontal adjustment actuator moves the reel support along the reel carrier arms over an adjustment range. The reel carrier arms are constructed with an upward or downward oriented curve, inside of the adjustment range over which the reel holding devices can be shifted by the actuator. The reel operates below a cutting bar in its forward position and in a position moved further back that is above and behind the cutting bar so that collisions are avoided.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to a harvesting mechanism with a reel assembly that is rotatably supported at each end on curved reel carrier arms. Each of the reel carrier arms is pivotably mounted. A horizontal adjustment actuator moves reel supports along the reel carrier arms to provide an enhanced adjustment range.  
       BACKGROUND OF THE INVENTION  
       [0002]     Harvesting mechanisms are used for grain harvesting with self-propelled combines. They usually have a horizontally orientated cutter bar for cutting crop stalks and a transverse conveying auger that feeds the cut crop to the feederhouse of the combine. A pickup reel is located above and in front of the cutter bar to gather the crop to be harvested and to direct crop to the cutter bar and the transverse conveying auger. The pickup reel rotates around a longitudinal axis and is provided with horizontal tine carriers distributed around the longitudinal axis. The tine carriers carry tines that engage the crop stalks.  
         [0003]     The reel is usually rotatably mounted on reel supports that are provided on reel carrier arms. The carrier arms are pivotably mounted behind the cutter bar on the frame of the harvesting mechanism and pivot around a horizontal axis transverse to the direction of forward movement. The angle of the reel carrier arm is adjusted by a hydraulic cylinder around the axis, and thus adjusts the height of the reel relative to ground level and the cutter bar. An additional hydraulic cylinder shifts the reel along the reel carrier arm. The position of the reel can thus be varied in the forward and backward direction.  
         [0004]     The reel carrier arms are usually straight over their entire length, as shown in the prior art in GB 1 501 639 A, GB 1 574 033 A and WO 03/049532 A. Alternatively, reel carrier arms are provided with bends or angles. Usually the part of the reel carrier arm that cooperates with the reel support is straight, as shown in U.S. Pat. No. 4,800,711, U.S. Pat. No. 6,029,429, DE 195 08 887 C, and DE 195 29 067 A. Therefore, when the reel is shifted along the reel carrier arm, the reel moves in a straight line. The angle or slope of the reel carrier arm relative to the horizontal depends on the pivoting angle of the reel carrier arm around the horizontal axis.  
         [0005]     Additionally, some harvesting mechanisms have a two part intake mechanism. A front bottom part carries the cutter bar and is movable in the forward direction. A rear bottom part is fixed solidly to the harvesting mechanism frame. In order to adapt the harvesting mechanism to a crop such as rapeseed, for example, the front bottom part is moved forward. Problems can arise in adjustment of the reel position because collisions between the reel and cutter bar are possible when the front bottom part is adjusted forward. Specifically collisions happen in the area of the cutter bar if the reel is adjusted forward or is lowered too far.  
         [0006]     Thus, precautions are taken to prevent such collisions. In U.S. Pat. No. 4,800,711 a mechanical coupling is provided between the cutter bar and the reel carrier arm by a lever mechanism that automatically moves the reel carrier arm vertically as a function of the horizontal position of the cutter bar. A similar mechanical coupling between the reel carrier arm and cutter bar which has a radial cam and a guide roller is described in WO 03/049532 A. To prevent collisions of the reel with the cutter bar, DE 195 08 887 C provides an electronic coupling for positioning the cutting bar via a connection to a sensor that controls an actuator.  
         [0007]     The known coupling between the position of the cutting bar and the vertical reel position is disadvantageous in that the operator cannot switch to certain reel positions in a manner that is easily known to him because certain reel positions are blocked mechanically or electronically. Furthermore, the above mechanical and electronic components are relatively expensive and are susceptible to fouling and damage.  
         [0008]     Potential collisions between the reel and cutter bar also arises in other types of harvesting mechanisms, especially those with conveyor belts that transport the crop back to a transverse conveying auger which then feeds the crop to the feederhouse of a combine, as described in GB 1 501 639 A, GB 1 574 033 A and GB 1 602 067 A. A sufficiently long horizontal adjustment path of the reel is required to be able to move the reel far enough forward to receive laid crop, and also to be able to move the reel far enough backward for rapeseed harvest to press the crop mat under the transverse conveying auger. The reel should operate below the cutting bar in the forward position but not lie on the conveyor belt in the rear position. This problem could be resolved by a mechanical arrangement, similar to the previously described couplings between the position of the cutter bar and the vertical adjustable reel position, which automatically raises the reel arm when it is moved backward. However, this configuration also has the above-described shortcomings.  
       SUMMARY OF THE INVENTION  
       [0009]     Therefore, the reel carrier arms of the present invention are not straight but are curved and angled upward and/or downward. The reel carrier arms are curved or bent in the adjustment region or assembled from straight parts that enclose an angle to increase the adjustment range.  
         [0010]     Thus, during displacement of the reel support by the horizontal adjustment actuator in a manner defined by the curved arm, the reel is displaced not only along the reel carrier arm but also in a direction extending perpendicularly, upwards or downwards, to the direction of adjustment. The reel is moved by the horizontal adjustment actuator on a curved or angular path. The relationship between horizontal and vertical movement can be optimized for the specific circumstances of the harvesting mechanism so that undesirable collisions of the reel with the cutting mechanism parts can be avoided and the movement range of the reel can be optimized.  
         [0011]     In particular, a suitable curved shape of the reel carrier arms can enable the reel to operate in its front position below a cutter bar. Additionally, the reel can be shifted further back and located at a relatively small distance above and behind the cutter bar. The vertical adjustment actuator of the reel defines the pivoting angle of the reel carrier arm around the horizontal axis in its lowest position. The curved shape of the carrier arm is particularly advantageous in harvesting mechanisms with conveyor belt assemblies downstream from the cutter bar, which transport the crop backward and feed it to a transverse auger. The curved shape can also be expedient in other harvesting machines, such as in embodiments with a movable cutter bar or in grain harvesting machines with fixed cutter bars that are not equipped with conveyor belts. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  shows a schematic side view of a combine with a harvesting mechanism according to the present invention;  
         [0013]      FIG. 2  shows an enlarged side view of the reel support on the curved reel carrier arm; and  
         [0014]      FIG. 3  shows a partially cut-away side view of the harvesting mechanism, in which three different possible positions of the reel are indicated. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     An agricultural combine  10 , shown in  FIG. 1 , is supported on front driven and rear steerable wheels  12  and  14 , respectively. An operator cab  16  is provided from which the combine can be operated by a driver. A grain tank  18  is located to the rear of the operator cab and can discharge the grain deposited in it out through a discharge auger  20 . The grain tank  18  is supported on a frame  22 . The grain is broken down into its large and small constituents as it passes through a threshing cylinder  24 , a threshing concave  26  and a stripper beater  28 . A further separation of the harvested grain is effected on the shakers  30  connected thereto, and on a preparation pan  32  and sieve  34 . The threshed grain is conveyed into the grain tank  18 . The large portions of material other than grain are deposited on the ground by the shakers  30  and the light constituents are also blown onto the ground from the sieve  34  by a blower  36 . After the crop lying or standing on the ground has been picked up by a harvesting or cutting mechanism  42 , it is conveyed through a feederhouse  38  and a stone catching trough  40  to the threshing cylinder  24 . For the description presented below, the directions specified such as front, behind, above and below are relative to the forward direction V of the combine  10 .  
         [0016]     The harvesting mechanism  42  includes a frame that is assembled of side walls  46 , a back wall  48  with a cross beam  50  on its upper side, and a bottom  52 . The middle region of the cross beam  50  is suspended detachably on the feederhouse  38  by suitable means such as hooks. A cutting bar  54  with reciprocating knives is located at the front edge of the bottom  52 . Behind the cutter bar  54 , relative to the forward direction V, is a ramp  56  extending over the width of the harvesting mechanism  42  and inclined slightly toward the rear. Lateral spurs or side cutting mechanisms are arranged on the front side of the side walls  46 .  
         [0017]     Behind the ramp  56  there are several conveyor belt assemblies  58  arranged laterally alongside each other with the conveyor direction moving rearward, opposite the forward direction V. A transverse auger  60  is provided behind the conveyor belts and runs transverse to the forward direction V. The transverse auger  60  includes an auger tube with spirals welded on the tube and controlled collecting fingers provided in the tube middle section. The conveyor belt assemblies  58  rise slightly toward the back. Bottom plates  62  adapted in shape to the conveyor belt assemblies  58  and the transverse auger  60  are located at the mechanism underside. A number of conveyor belt assemblies  58  are arranged laterally side by side and is dependent on the width of the harvesting mechanism  42 .  
         [0018]     Above the cutter bar  54  and the conveyor belt assemblies  58  is a driven and rotatable pickup reel  44  that is adjustable in height and movable in the forward and backward direction. The reel is located on the harvesting mechanism frame, and extends transverse to the forward direction V. On both lateral ends of the frame of the mechanism  42 , a bracket  64  is welded on the front of the cross beam  50  and a reel carrier arm  66  is pivotably supported around a horizontal axis  68  running transverse to the forward direction V. The two reel carrier arms  66  are preferably identical or are mirror-symmetric across the longitudinal midplane.  
         [0019]     The reel carrier arms  66  extend from the axis  68  initially straight forward and then, at about one-third of its length, bend downward in a first bend angle  70 . Forward of the bend  70  in the forward direction V, the reel carrier arms  66  again extend straight forward and then bend downward, at about two-thirds of the arm length, in a second bend angle  72 . The reel carrier arms  66  again extend straight forward of the second bend  72 . As a result, the reel carrier arms  66  are somewhat bowed. In order to pivot reel carrier arm  66  about axis  68 , a vertical adjustment actuator  78 , such as a hydraulic cylinder, is positioned between an anchor device  76  located on the side wall  46  and a bracket  74  welded on the reel carrier arm  66  underneath the first bend  70 . Means for adjusting the distance between the piston rod of the vertical adjusting actuator  78  and the bracket  74  are provided in a known manner.  
         [0020]     The reel  44  is pivotably supported in a reel support  80  at both ends of curved arms  66 . The reel support  80  is in turn movably supported on the reel carrier arm  66  forward of the bend  72 . A horizontal adjustment actuator  82 , such as another hydraulic cylinder, is provided between the reel support  80  and the bracket  74 .  
         [0021]     The reel support  80  is shown in an enlarged view in  FIG. 2 . The reel support  80  includes vertically running side plates  90  between which the reel carrier arm  66  is located. The side plates  90  are joined above the reel carrier arm  66  by two bolts  92 , spaced apart in the forward direction. The bolts each rotatably support a hollow cylindrical roller  94 , which rolls on the upper side of the curved reel carrier arm  66 . An additional bolt  96  extends underneath the reel carrier arm  66  and carries another rotatable hollow cylindrical roller  98  that rolls on the underside of the reel carrier arm  66 . Alternatively, two bolts  96  with rollers  98 , one behind the other, could be provided on the underside of the reel carrier arm  66  to support the reel support  80  in a more stable manner. Thus the reel support  80  is movably supported on the reel carrier arm  66  by the rollers  92  and  98 . An opening  100  in the reel support  80  serves to support the axis of reel  44 . The piston of the horizontal adjustment actuator  82  is connected to the support  80  by a bolt  102  extending between the side plates. The bolt  102  can be inserted into any one of four holes  104  at the bottom of the side plates  90 . The adjustment range of the reel support  80  is thus extended for a given adjustment path of the horizontal adjustment actuator  82 .  
         [0022]     The reel  44  is rotated around its longitudinal axis by a hydraulic motor (not shown), which is preferably located on the right side of the reel viewed in the forward direction. During harvesting, the reel  44  rotates in the counterclockwise direction as viewed in  FIG. 1 .  
         [0023]     The reel  44  is equipped with six tine carriers  86  fastened on spiders  88 . The tine carriers carry tines  84  arranged alongside each other. The position of the tine carrier and the tines  84  is varied by conventional control mechanisms during the rotation of the reel  44  so that the tines  84  always extend approximately downward and slightly backward from the tine carriers. A control mechanism can involve eccentric levers, as described in the U.S. Pat. No. 4,008,558, or cams running in cam tracks, as disclosed in EP 1 048 199 A.  
         [0024]     The cam tracks or eccentric levers can be adjusted around the axis of the reel  44  to adjust the angular attitude of the tines  84  as required. The cam tracks or control elements for the eccentric lever do not rotate with the reel  44 , and are thus fastened on the reel support  80 , such as at a hole  106 . The reel support  80  changes its orientation during its movement along the curved reel carrier arm  66  due to the carrier arm curvature  72 . Thus, reel support  80  rotates around a horizontal axis oriented transverse to the forward direction V. Because the attitude of the tines  84  would thus change, a second support, which moves only between the curves  70  and  72  on the curved reel carrier arm  66  can be coupled with the support  80  and moves synchronously with it. The second support could be connected with the cam tracks or the control elements for the eccentric lever.  
         [0025]     The reel support  80  and respective lower sections of the reel  44  are shown in three positions in the  FIG. 3 . In the frontmost position, in which the reel is designated by  44  and the reel support by  80 , the reel  44  lies sufficiently far forward and the tines  84  are below the cutting bar  54  to pick up laid crop. At the rearmost position, in which the reel is designated by  44 ″ and the reel support by  80 ″, the reel  44 ″ lies sufficiently far back to press the crop onto the transverse auger  60  when harvesting a crop such as rapeseed. In the middle position, the reel  44 ′ is located above the conveyor belt assemblies  58 .  
         [0026]     The movement of the reel support  80  with the reel  44  effects a movement on a curved path along the curved reel carrier arm  66 , which first runs steeply from the front to the back and then runs flatter beyond the bend  72 . The shape of the reel carrier arm  66  is adapted to the cutting bar  54  and the conveyor belt assemblies  58 .