Abstract:
A baling chamber for a large round baler includes a discharge gate having opposite side walls which meet respective side walls of the main frame along a line of separation that inclines downwardly and to the rear from top to bottom. The bottom of the baling chamber is defined in part by a bottom conveyor which slopes downward to the rear from a front end which delimits a lower side of an inlet through which crop is fed into the baling chamber. The discharge gate carries a lower front roll that supports an endless tension element arrangement and that is itself supported on a tensioning arm arrangement that pivoted to the discharge gate for movement against the resistance of a yieldable spring arrangement so as to permit the lower front roll to move rearwardly from a first position adjacent the inlet, which it occupies at the beginning of bale formation, as the bale grows.

Description:
FIELD OF THE INVENTION 
     The invention pertains to a round baler with a frame and a cover plate attached thereto in a vertically pivoted fashion, with a baling chamber being formed in said components that is partially encompassed by a tension means that is guided over several rolls. 
     BACKGROUND OF THE INVENTION 
     DE-A1-43 08 646 discloses a round baler with a baling chamber of variable size which is formed by a frame on the front side and a housing at the rear side that is hinged so that it can be opened. A substantially vertical plane of partition results between the frame and the housing. The hinged housing is pivoted away from this plane of partition in order to allow a round bale that has been formed in the baling chamber to be ejected from the baling chamber. An axle for supporting the round baler on the ground is situated behind the plane of partition. 
     The above-identified German patent typifies the prior art and exhibits the drawback of requiring the housing to be swung a significant angle about its hinge joint to, and hence in requiring an excessively long time for the housing to be swung open about the hinge joint to, a position at which the round bale, which may reach a height up to 1.8 meters, can be ejected from the baling chamber and for the round baler with the raised housing to be additionally advanced without causing a collision between the housing and the round bale. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided an improved large round baler baling chamber arrangement. 
     An object of the invention is to provide a large round baler having a baling chamber defined by components which cooperate to permit a bale formed in the baling chamber to be quickly discharged. 
     A more specific object of the invention is to provide a large round baler including a baling chamber defined in part by cooperating opposite side walls of the main frame and of a discharge gate that is mounted for pivoting between a lowered, closed position and a raised discharge position, the respective side walls of the main frame and discharge gate meeting at a line of separation which is inclined to the rear from top to bottom to a location near the rear of the baler. 
     A further object of the invention is to provide a baler, as defined in the immediately preceding object and further including a bottom conveyor which serves to support the bale during its formation and which is inclined downwardly from front to rear to a location near the rear of the baler. 
     Yet another object of the invention is to provide a baler, as defined in one or more of the foregoing objects, wherein a lower front roll for supporting a tensioning means, that forms a further portion of the baling chamber, is mounted to a lower end of a tension arm that is pivoted such that the tension means supported by it remains in contact with a lower rear location of a bale being formed and moves to the rear as the bale grows. 
     These and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is schematic, left side elevational view of a large round baler constructed in accordance with a first embodiment, wherein a partially filled baling chamber is surrounded by a tension means and stationary rollers. 
     FIG. 2 is a view like that of FIG. 1 but showing a completely filled baling chamber. 
     FIG. 3 is a schematic, left side elevational view showing the details of a forward end of a large round baler constructed in accordance with a second embodiment, wherein a partially filled baling chamber is surrounded by a tension means and rollers that are mounted on a pivoted carrier. 
     FIG. 4 is a schematic, left side elevational view showing the details of a forward end of a large round baler constructed in accordance with a third embodiment, wherein the bottom conveyor is constructed of a plurality of support rolls. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, there is shown a large round baler  10  including a frame  12  and a rear discharge gate  14 . 
     The round baler  10  conventionally serves to receive a mowed crop and compress it into round bales of variable size. 
     The frame  12  includes an axle  16 , on which are mounted wheels  18 , a hitch  20  and side walls  22 , with the frame carrying a pick-up  24 , a conveyor  26 , a cutting mechanism  28 , a bottom conveyor  30  and a carrier  32  with rollers  34 , rolls  36 , a tensioning device  38  and tension means  40 . The frame  12  is supported on the ground by the axle  16  and wheels  18  such that the round baler  10  can be towed over a field by a not-shown towing vehicle. 
     The hitch  20  is positively, non-positively or adjustably arranged on the frame  12  and serves to connect the round baler to the towing vehicle. The side walls  22  are rigidly mounted on the frame  12  and laterally limit a baling chamber  42  for a round bale  44 . 
     The pick-up  24  is conventionally constructed, and may have the same or a wider width than the width of the baling chamber  42 . The pick-up  24  collects the crop that lies on the ground with prongs  46  that convey in an overshot fashion, and moves the crop to a cutting mechanism  28  along a transport surface that is not illustrated in greater detail, with the crop being fed into the baling chamber from the cutting mechanism. 
     The conveyor  26  operates in an undershot fashion and is realized in the form of a rotor that assists in feeding the crop delivered by the pick-up  24  into the cutting mechanism  28 . The conveyor  26  may have a smooth surface or be equipped with dogs, prongs, teeth, ribs, worm screws or the like. The cutting mechanism  28  customarily has a bottom  48 , a cover  50 , a rotor  52 , knives  54  and strippers  56 . The cutting mechanism  28  is not important for the invention and only is cited as a supplement to this embodiment; it is in particular, possible to omit the knives  54  such that the rotor  52  simply acts as a conveyor. If the cutting mechanism  28  is provided, it serves to comminute the crop delivered by the pick-up  24  such that it can be better compacted in the baling chamber  42 . 
     The bottom  48  extends between the pick-up and the bottom conveyor  30 , and has a curvature that essentially follows the radius of the rotor  52 . 
     The cover  50  has the same curvature and extends between the conveyor  26  and the carrier or a roller  34  arranged on the lower end region of the carrier. The bottom  48  and the cover  50  form a receptacle opening upstream of the rotor  52  and an inlet  58  of the baling chamber  42  downstream of the rotor, with the inlet simultaneously being limited by the lower roller  34  and the bottom conveyor  30 . When viewing the round baler  10  from the left, the inlet  58  is situated in the first quadrant of the rotor  52 , and is consequently arranged essentially laterally to it. 
     The rotor  52  includes a central tube  60  and dogs  62  that are attached to the central tube  60  such that they are curved in a trailing fashion. The central tube  60  is driven in the clockwise direction, when viewing the round baler  10  from the left side, by means of a not-shown drive. The dogs  62  have an essentially triangular shape, the tip of which extends almost to the bottom  48  and the cover  50 . A total of five rows of dogs  62  are welded or screwed to the central tube  60  along helical lines, with the dogs  62  being spaced apart from one another in the axial direction of the rotor  52 . The diameter of the rotor  52  is of considerable size, and occupies approximately 0.6 m. 
     The knives  54  are realized conventionally and can preferably be locked in different positions, with the knives also being able to yield in case of an overload. The knives  54  extend into all or only a few of the intermediate spaces between the dogs  62  through slots in the bottom  48  that are not visible in the figures. The knives  54  are held by a common adjustable carrier, not illustrated in the figures, and may extend up to the central tube  60  in one end position and up to the inner edge of the bottom  48  in the other end position. As mentioned previously, the knives  54  can also be omitted such that the rotor  52  does not perform a cutting function, but rather acts only as a conveying rotor  52 . The knives  54  are situated below the rotor and upstream of the inlet  58 ; they may, however, also be arranged above the rotor  52  if the rotor conveys in an overshot fashion. 
     The strippers  56  are situated downstream of the knives  54  and are also arranged in the intermediate spaces between the dogs  62 . An edge of the dogs  62  that faces the baling chamber  42  extends nearly vertically and is slightly curved. The strippers  56  border the central tube  60  on the one side and the lower roller  34  on the other side, with the strippers very closely following their contours. The position of the strippers  56  is chosen such that the round bale  44  is able always to support itself on the strippers against a forwardly directed movement, with the strippers consequently covering a certain part of the inlet  58 . 
     The bottom conveyor  30  in the embodiment according to FIGS. 1-3 is formed by two support rolls  64  that are stationarily, rotatably mounted in the frame  12  or in its side walls  22 , with a tension means  82  being looped around the support rolls. The rear support roll  64  is arranged lower than the front support roll  64 , but is still situated above the axle  16 . A descending transport surface is thus created on the two support rolls  64  and the tension means  82 . Instead of using the two support rolls  64  and the tension means  82 , it would also be conceivable to provide a larger or smaller number of support rolls, a chain conveyor, a conveyor belt or the like (see FIG.  4 ). The bottom conveyor  30  limits the baling chamber  42  in its lower region with part of the periphery, with said part of the periphery increasing as the size of the round bale  44  increases. The support rolls  64  are preferably driven. 
     The carrier  32  is realized in the form of a rail that is resistant to bending and is provided twice, namely on each side wall  22 . In this case, sufficiently known reinforcing elements that, however, are not illustrated in the figures, are provided between the two carriers. In the embodiment according to FIGS. 1 and 2, the carrier  32  is realized rigidly and is slightly inclined toward the front, with the carrier according to FIG. 3 being pivoted in a vertical plane about a horizontal pivot axis  66  that extends transverse to the driving direction of the round baler  10 . The pivoting axis  66  is situated between the ends of the carrier  32 , and in this particular embodiment, approximately in its center such that it is able to move similarly to a rocker. In another embodiment that is not illustrated in the figures, the carrier  32  can be pivoted about a pivoting axis that coincides with the rotational axis of the lower roller  34 . 
     Assuming three rollers  34  are provided, which, however, is not absolutely imperative, the rollers  34  consist of a lower, a central and an upper roller  34 . The rollers  34  are rotatably accommodated between the two carriers  32  and extend across the entire width of the baling chamber  42 . The arrangement is chosen such that the surfaces or boundaries facing the round bale  44  lie on a curved surface, with this curved surface following the diameter of the round bale  44  once the round bale  44  has essentially reached its full size. The diameters of the lower roller and the central roller  34  are smaller than the diameter of the upper roller  34 . The lower roller  34  is always situated near the rear edge of the cover  50 . The rotational axis of the central roller  34  also forms the pivoting axis  66 . However, this is not absolutely imperative, and may be achieved differently in other embodiments. The pivoting axis  66  may, in particular, be offset toward the bottom, toward the top, toward the front or toward the rear. A gap through which the tension means  40  extends is formed between the central roller and the upper roller  34 . The lower roller and the central roller  34  directly form part of the wall of the baling chamber  42 , with the crop being baled therein directly acting upon said rollers. Instead of using the carrier  32  with its rollers  34 , it would also be possible to provide only one roller  34  or only one deflection roller  36 , around which the tension means  40  extends. 
     Several rolls  36 , of which at least one is driven, extend between the side walls  22 , and are, in part, rotatably supported in these parallel to the rollers  34 . According to FIG. 1, four rolls  36  are provided about which the tension means  40  revolves in an endless fashion. Two of the four rolls  36  are stationarily supported in the side walls  22 , with the other two rolls being movably supported on the tensioning device  38  such that they are able to move together with the tensioning device. 
     The tensioning device  38  conventionally includes an arm  68 , a bearing  70  and an energy storage device  72 . The arm  68  is formed by a massive steel rail or tube and provided twice, analogously to the carriers  32 , i.e., in the vicinity of both side walls  22 . The arm  68  extends almost over the entire length of the side wall  22  and is provided with two rolls  36  in the end region that is situated distant from the bearing  70 . These two rolls are spaced apart from one another in the radial direction. These rolls  36  are situated in interior spaces that are surrounded by the tension means  40 . The arm  68  extends beyond the bearing  70  in the end region that is situated near the bearing  70  and is slightly angled so as to form a lever arm  74 . The bearing  70  accommodate the arm  68  in a vertically pivoting fashion at the end region situated opposite to the rolls  36 . For this purpose, a separate bearing  70  may be respectively provided on each side wall  22 , or one bearing may extend between the side walls  22 . 
     The energy storage device  72  is realized in the form of a helical tension spring in this embodiment; alternatively, it would be possible to utilize a hydraulic cylinder with a gas pressure accumulator or a throttle, a different type of spring, a combination thereof or the like. The energy storage device  72  is mounted at one end to the lever arm  74  and at the other end to the holder  76 , with the holder acting stationarily on the frame  12  or the side wall  22 . The energy storage device  72  normally is at least slightly pre-stressed. However, it would also be possible to realize an embodiment in which the resistance of the energy storage device  72  can be varied, e.g., by means of a controllable throttle, such that a different degree of compaction is realized across the diameter of the round baler  44 , so-called soft core is achieved. The effective direction of the energy storage device  72  is chosen such that the arm  68  with its rolls  36  is always pressed toward the inlet  58 , i.e., in the direction of the smallest possible baling chamber  42 . 
     The tension means  40  is conventionally formed of several narrow belts that extend parallel to one another in this embodiment. The tension means  40  represents a closed tension means and extends through the frame  12  and the discharge gate  14 . It would also be conceivable to conventionally provide two separate tension means in the frame  12  and the discharge gate  14 . Beginning at the front roll  36  on the arm  68 , the tension means  40  runs through the gap between the upper and the central roller  34  on the carrier  32 , over a lower front roll  36 , an upper front roll  36  and on into the discharge gate  14  via an upper central roll, an upper rear roll, a lower rear roll, a movable roll, the rear roll on the arm  68 , an upper roll  36 , with the movable roll being identified by the reference symbol  90  and described in greater detail below. Due to the ability to pivot the arm  68  and the carrier  32 , the section of tension means  40  which runs between the gap and the roll  36  on the arm  68  can be subjected to an excursion, and varied with respect to its size. This section represents part of the wall of the baling chamber  42 , and is directly acted upon by the crop situated in the baling chamber  42 . 
     The baling chamber  42  has a variable size and is surrounded by the inlet  58 , the rollers  34  on the carrier  32 , the section of the tension means  40  runs between the gap and the roll  36  on the arm  68 , a tension means section between the rear roll  36  on the arm  68  and the movable roll  90 , and the bottom conveyor  30 . On the end faces, the baling chamber  42  is partially closed by the side walls  22 . 
     The round bale  44  is formed of the crop that is wound up in a helical fashion and ultimately reached the size indicated in FIG.  2 . In order to unload the round bale  44  from the baling chamber  42 , the discharge gate  14  is raised such that the round bale  44  is able to roll along the bottom conveyor  30  and onto the ground. The density of the round bale  44  is obtained by means of the tension means  40 , which is generated by the energy storage device  72 . 
     The discharge gate  14  is connected to the frame  12  in a vertically pivoting fashion in a bearing  78 , with the pivoting movement being caused by sufficiently known hydraulic cylinders that, however, are not illustrated in the figures. The discharge gate  14  has two side walls  80 , the aforementioned rolls  36 , a section of the endless tension means  40 , two arms  84  and the movable roll  90 . The side walls  80  extend in the same plane a the side walls  22  of the frame  12  and close the baling chamber  42  on its still-open end faces. Known reinforcing elements that, however, are not illustrated in the figures, extend between the side walls  80 . The four rolls  36  used in this embodiment are stationarily accommodated in a rotatable fashion in the side walls  80  an extend over the entire width of the baling chamber  42 , parallel to the rolls  36  in the frame  12 . Each arm  84  is connected in a vertically pivoting fashion in the vicinity of the upper edge of the discharge gate  14 , and approximately centrally, in bearing  92 , with the arms having a trough-like or U-shaped form when viewed from the side of the round baler  10 . The interior space of the arm  84  resulting from this particular shape is large enough that it can accommodate part of the circumference of the round bale  44  once it has reached its maximum size, i.e., the “trough” is open toward the front. 
     The arm  84  rotatably carries the roll  90  on its lower end, with the movable roll traveling along the surface of the bottom conveyor  30  as the diameter of the round bale  44  increases. The tension means  40  is guided over the movable roll  90  such that the movable roll  90  and the tension means section extending over it are always indirect or indirect contact with the round bale  44 . Another energy storage device  94 , which may be realized analogously to the energy storage device  72 , i.e., in the form of a helical tension spring, a hydraulic cylinder with a throttle or a pressure accumulator, etc., engages the arm  84  between the bearing  92  and the movable roll  90 . The energy storage device  94  is mounted, at the end that is situated distant from the arm  84 , to a holder  96 , with the holder being mounted on the side walls  80 . The energy storage device  94  is pre-stressed in such a way that it always presses the arm  84  toward the inlet  58 . 
     The side walls  22  and  80  abut one another in a plane of partition  98  that extends from the bearing  78  to the rear support roll  64 , from the upper front toward the lower rear, with an incline of approximately  600  with reference to the horizontal. 
     According to the previous description, the round baler  10  of the embodiment illustrated in FIGS. 1 and 2 functions as described below. 
     In a not-shown situation in which the tension arm  68  is situated in its lowest position due to the effect of the energy storage device  72 , the arm  84  and the movable roll  90  assume approximately the position shown in FIG  1 . The sections between the upper roller  34  on the carrier  32  and the rolls  36  on the arm  38  or the movable roll on the arm  84  extend essentially from the upper front toward the lower rear in a plane inclined by approximately 45°. In this case, the baling chamber  42  assumes a nearly triangular shape, the hypotenuse of which is formed by the two aforementioned sections, with the triangle almost standing on one of its tips. The baling chamber  42  has the smallest possible volume in this instance. 
     At the beginning of the baling process, the round baler  10  is moved over a field on which the crop is, for example, arranged in windrows, with the crop being collected by means of the pick-up  24  and fed to the cutting mechanism  28 . The rotor  52  conveys the crop into the baling chamber  42  in an under shot fashion, if applicable, past the knives  54 . In the baling chamber  42 , the crop comes in contact with the strands of the tension means  40  that revolve in the same direction. Due to the cooperation between the rotatable support, and optionally the drive of the support rolls  64  and the rollers  34 , and the packing surface of the tension means  40 ,  82 , the crop begins to rotate once it reaches a sufficient volume, namely in the clockwise direction in the figures. In another embodiment, the round bale  44  may also be would up in the counterclockwise direction. 
     As the baling process progresses, the round baler  10  reaches the operating state shown in FIG. 1, namely the operating state in which the arm  68  has been moved slightly upward against the force of the energy storage device  72  and consequently subjects the strands to an upward excursion such that they are displaced out of the common plane and assume the shape of a blunt roof. In the embodiment according to FIG. 3, the carrier  32  is slightly pivoted about the pivoting axis  66  in the counterclockwise direction, such that its lower roller  34  moves into the baling chamber  42 . In this position, the round bale  44  is essentially supported on the front support roll  64  of the bottom conveyor  30 . 
     As the baling process progresses, the round bale  44  reaches the size shown in FIG.  2 . In this operating state, the arm  68  is completely pivoted upward and the energy storage device is completely tensioned, such that the highest density possible is achieved on the circumferential surface of the round bale  44 . Since the bottom conveyor  30  is unable to yield and the carrier  32  with its rollers  34  is either realized stationarily or can, according to FIG. 3, pivot only to a limited degree, the round bale  44  is built up toward the top and the rear such that its circumferential region acts upon the section between the rear roll  36  on the arm  68  and the movable roll  90  or upon the movable roll  90  itself, although only indirectly. The arm  84  retreats in opposition to the force of the energy storage device  94 , and starting from a position near the inlet  58 , moves backward up to the plane of partition  98  and slightly into the discharge gate  14 , into a position situated distant from the inlet  58 . During this process, the round bale  44  is increasingly supported on the bottom conveyor  30 . 
     In order to eject the round bale  44 , the discharge gate  14  and consequently the arm  84 , are raised in the counterclockwise direction in the figure such that the round bale  44  is able to roll, on the surface of the bottom conveyor  30  that is inclined toward the rear, out of the region of the baling chamber that is situated in the frame  12 . It is quite obvious that an opening through which the round bale  44  can be ejected is produced more rapidly, and with a shorter adjusting distance of the discharge gate  14 , due to the inclined plane of the partition  98 , as well as to the fact that the movable roll  90  moves toward the rear. Both measures make it possible to attain the objective of the invention independently of one another, and can be carried out independently of one another. However, the described combination improves the respective effect. Due to the nearly triangular shape of the discharge gate  14 , an interfering front edge is reduced to a minimum, and the discharge gate  14  does not have to be raised as high in order to be moved over the round bales  44  lying on the ground when the round baler  10  is advanced in order to continue the baling process. 
     FIGS. 3 and 4 show embodiments of the invention which largely correspond to the embodiment according to FIGS. 1 and 2, and also fulfill the same function. 
     The difference between the embodiment according to FIGS. 1 and 2 and the embodiment according to FIG. 3 can be see in the fact that the carrier  32  is movable about a horizontal pivot axis  66  in FIG.  3 . 
     The difference between the embodiment according to FIGS. 1 and 2 and the embodiment according to FIG. 4 can be seen in the fact that the bottom conveyor  30  in FIG. 4 does not consist of two support rolls  64  and an endless tension means  82  that extends over these two support rolls, but rather of a series of support rolls  64  that lie parallel to one another and exhibit the same surface that descends toward the rear. This is, among other things, achieved by means of diameters that decrease toward the rear. 
     In a not-shown embodiment, the bottom conveyor  30  can be pivoted downward about the rotational axis of the front support roll  64  on the rear side. This can be controlled by means of a hydraulic cylinder. Consequently a third measure is made available for rapidly realizing the required opening cross section. 
     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.