Abstract:
The expansible baling chamber of a large round baler is constructed so as to have chamber-forming elements that act to bias a forming bale away from the chamber inlet so that harvest entering the inlet will be more easily wrapped onto the bale, these chamber-forming elements, in some embodiments, also acting to increase the tension of tensioning mechanism forming part of the baling chamber. Also aiding in the delivery of harvest to the baling chamber is a conveyor having portions located within the chamber inlet.

Description:
FIELD OF THE INVENTION 
     The invention pertains to a round baler having an expansible baling chamber, and more specifically relates to the arrangement of various components forming the baling chamber. 
     BACKGROUND OF THE INVENTION 
     DE-A1-198 10 074 discloses a round baler having a baling chamber, the size of which can be varied due to the fact that belts are compliantly supported on rollers, with the belts forming a loop between two rollers situated on the sides of an inlet, and with the baling chamber being formed in said loop. A two-armed carrier that can be pivoted about the rotational axis of a lower roller is provided above the inlet. As the bale diameter increases, a central roller is pressed away from the baling chamber such that a third, upper roller tensions the belts to a certain degree and thus increases the density of the round bale. 
     A comparable arrangement for tightening belts of this type is disclosed in DE-A1-198 51 470. However, only one roller is arranged on a pivoted carrier in this case, with the pivoting movement of the carrier being controlled by the tensioning arm of the belts. 
     According to EP-A1-0 339 730, a baling chamber is surrounded by belts and rollers, with four rollers being arranged on a pivoted carrier and partially encompassing the baling chamber. The belts extend through a gap between a roller situated farthest from the pivoting axis of the carrier and a roller situated adjacent thereto. Due to these measures, the walls surrounding the baling chamber are coupled to one another and a high tension is exerted upon the round bale. 
     The problem to be solved with the invention can be seen in the fact that the supply of new material is difficult to introduce into the baling chamber when the forming bale has a high density. 
     SUMMARY OF THE INVENTION 
     According to the present invention there is provided an improved structure for defining an expansible baling chamber of a large round baler. 
     An object of the invention is to provide a large round baler having an expansible baling chamber that is constructed so as to facilitate the feeding of harvest into the baling chamber. 
     A more specific object of the invention is to provide a large round baler having an expansible baling chamber having a forward part partially defined by a plurality of rolls mounted to a carrier pivotally mounted to the opposite side walls of the baling chamber, with one or more of the rolls having a flexible tension means, that forms part of the baling chamber, engaged therewith such as to cause the carrier to pivot to press the other roll(s) against the forming bale so to force it away from the bale chamber inlet so as to create a space for allowing the ingress of the harvest. 
     A further object of the invention is to provide a large round baler as defined in the immediately preceding object, wherein the carrier is so shaped and the roll(s) engaged by the tension means are so located that the carrier causes an increase in the tension of the tension means as the bale increases in size. 
     Yet another object of the invention is to provide a large round baler as defined in the immediately preceding object, and further including a harvest conveyor which is located partially within the baling chamber inlet for positively delivering the harvest through the inlet. 
     These and other objects will become apparent from a reading of the ensuing description together with the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic, left side view of a large round baler having a baling chamber, formed in accordance with a first embodiment of the invention, and shown in a condition at the beginning of the baling process. 
     FIG. 2 is a view like that of FIG. 1, but showing the baling chamber in a condition at the end of the baling process. 
     FIG. 3 is a schematic, left side view of a large round baler having a baling chamber, formed in accordance with a second embodiment of the invention, and shown in a condition at the beginning of the baling process. 
     FIG. 4 is a view like that of FIG. 3 but showing the baling chamber in a condition at the end of the baling process. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, there is shown a large round baler  10  having a front frame  12  and a rear discharge gate  14 . The baler  10  conventionally serves for receiving a mowed harvest and compressing this harvest into round bales of variable size. 
     The frame  12  includes an axle  16  on which is 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 , deflection rollers  36 , a tensioning device  38  and tension means  40 . The frame  12  is supported on the ground by means of the axle  16  and the wheels  18  such that the round baler  10  can be towed over a field by a not-shown towing vehicle. 
     The hitch  20  is unyieldingly, compliantly or movably connected to the frame  12  and serves for connecting the round baler  10  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 has the same width or a greater width than the baling chamber  42 . The pick-up  24  collects the harvest that lies on the ground with prongs  46  that convey in an overshot fashion and moves the harvest to a cutting mechanism  28  along a transport surface that is not illustrated, with the harvest being fed into the baling chamber  42  from the cutting mechanism. 
     The conveyor  26  operates in an undershot fashion and is constructed in the form of a rotor that assists in feeding the harvest delivered by the pick-up  24  into the cutting mechanism  28 . The conveyor  26  may have a smooth surface or be equipped with drivers, prongs teeth, ribs, screws or the like. 
     The cutting mechanism  28  customarily contains 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 is only cited as a supplement for 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 for comminuting the harvest 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  24  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  32  or a roller  34  arranged on the lower end region of the carrier, respectively. 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 thereto. 
     The rotor  52  includes a central tube  60  and drivers  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 by means of a not-shown drive when viewing the round baler  10  from the left side. The drivers  62  essentially have a triangular shape, the tip of which extends almost to the bottom  48  and the cover  50 . A total of five rows of drivers  62  are welded or screwed onto the central tube  60  along helical lines, with the drivers  62  being spaced apart from one another in the axial direction of the rotor  52 . The rotor  52  has a significant diameter of approximately 0.6 m. 
     The knives  54  are constructed 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 drivers  62  through slots in the cover  50  that are not visible in the figures. The knives  54  are held by a commonly adjustable carrier that is not illustrated in the figures and may extend up to the central tube  60  in one end position and up to the inner side of the cover  50  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 only acts as a conveying rotor  52 . The knives  54  are situated above the rotor  52  and upstream of the inlet  58 . 
     The strippers  56  are situated upstream of the knives  54  and also arranged in the intermediate spaces between the drivers  62 . An upper edge of the drivers  62  extends in a slightly descending fashion toward the cover plate  14  and is slightly bent. The strippers  56  border the central tube  60  on one side and the bottom conveyor  30  on the other side, with the strippers very closely following their contour. The position of the strippers  56  is chosen such that the round bale  44  is able to partially support itself on the strippers in the initial phase of the baling process, with the strippers consequently covering a certain part of the inlet  58 . 
     In this embodiment, the bottom conveyor  30  is formed by two rollers  64  that are mounted stationary in a rotatable fashion in the frame  12  or its side walls  22 , respectively, and have a relatively large diameter. The rear roller  64  is arranged lower than the front roller  64  and situated directly above the axle  16 . A descending transport surface is thus created on the two rollers  64 . Instead of using two rollers  64 , it would also be conceivable to provide a larger or smaller quantity of rollers, a chain conveyor, a conveyor belt or the like. The bottom conveyor  30  limits the baling chamber  42  in its lower region with part of its circumference. The rollers  64  are preferably driven. 
     The carrier  32  is constructed in the form of a rail that is resistant to bending and provided twice, namely on each side wall  22 . In this case, sufficiently known reinforcing elements that are not illustrated in the figures are provided between the two carriers. The carrier  32  can be pivoted vertically about a horizontal pivoting 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 , namely approximately in its center in this particular embodiment, such that it is able to move similar to a rocker. 
     Assuming three rollers  34  are provided, which is not absolutely imperative, the rollers  34  consist of a lower roller, a central roller and an upper roller  34 . The rollers  34  are rotatably accommodated between the two carriers  32  and extend over the entire width of the baling chamber  42 . The arrangement is chosen such that, once the round bale  44  essentially has reached its full size, the surfaces or edges facing the round bale  44  lie on a curved surface that follows the diameter of the round bale  44 . The diameters of the lower roller and the central roller  34  are greater 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  simultaneously 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 harvest being baled therein directly acting upon said rollers. 
     Several deflection rollers  36 , of which at least one is driven, extend between the side walls  22 , with said deflection rollers partially being rotatably supported in said side walls parallel to the rollers  34 . According to FIG. 1, four deflection rollers  36  are arranged essentially in the corner points of a trapezoid, about which the tension means  40  revolves in an endless fashion. Three of the four deflection rollers  36  are stationarily supported on the intermediate walls  22 , with one deflection roller being movably supported on the tensioning device  38 . 
     The tensioning device  38  conventionally includes an arm  68 , a bearing  70  and an energy storing device  72 . The arm  68  is formed by a massive steel rail and provided twice analogous to the carriers  32 , i.e., in the region of both side walls  22 . The arm  68  extends almost over the entire length of the side wall  22  and is provided with two deflection rollers  36  in the end region that is situated distant from the bearing  70 . These two deflection rollers are spaced apart from one another in the radial direction. One of the deflection rollers  36  is situated in an interior space that is surrounded by the tension means  40 . The arm  68  extends beyond the bearing  70  in the end region that is situated proximal to the bearing  70  and slightly angled so as to form a lever arm  74 . The bearing  70  accommodates the arm  68  in a vertically pivoted fashion with the end region situated opposite to the deflection rollers  36 . For this purpose, a separate bearing  70  may be respectively provided on each end wall  22  or one bearing may extend between the side walls  22 . 
     The energy storing device  72  is constructed 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 storing device  72  is mounted on the lever arm  74  with one end and on the holder  76  with the other end, with the holder stationarily engaging on the frame  12  or the side wall  22 . The energy storing device  72  normally is at least slightly pre-stressed. However, it would also be possible to construct an embodiment in which the resistance of the energy storing device  72  can be varied, e.g., by means of a controllable throttle, such that a different compaction is realized over the diameter of the round bale  44  and a soft core is achieved. The effective direction of the storing device  72  is chosen such that the arm  68  with its deflection rollers  36  is always pressed toward the inlet  58 , i.e., in the sense of the smallest baling chamber  42  possible. 
     The tension means  40  is conventionally formed of several narrow belts that extend parallel to one another in this embodiment. The tension means  40  that is assigned to the frame  12  represents a closed tension means and is provided separately of a tension means provided in the discharge gate  14 ; however, this is not absolutely imperative. It would also be conceivable to utilize only one tension means  40  in the frame  12  and the discharge gate  14 . Beginning at the deflection roller  36  situated on the arm  68 , the tension means  40  extends in a clockwise direction through the gap between the upper and central roller  34  arranged on the carrier  32 , over a lower front deflection roller, an upper front deflection roller and an upper rear deflection roller  36  in the frame  12 . Due to the ability to pivot the arm  68  and the carrier  32 , the section of the tension means  40  which extends between the gap and the movable deflection roller  36  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 harvest situated in the baling chamber  42 . 
     The baling chamber  42  has a variable size and is bordered by its inlet  58 , the rollers  34  arranged on the carrier  32 , the part of the tension means  40  which extends between the gap and the movable deflection rollers  36 , a tension means section in the discharge gate  14 , and the bottom conveyor  30 . On the end faces, the baling chamber  42  is essentially closed by the side walls  22 . 
     The round bale  44  is formed of the harvest that is wound up in a helical fashion and ultimately reaches 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 and then onto the ground. The density of the round bale  44  is attained with the tension of the tension means  40  which is generated by the energy of the energy storage device  72 . 
     The discharge gate  14  is connected to the frame  12  in a vertically pivoted fashion by means of a bearing  78  with the pivoting movement being caused by sufficiently known hydraulic cylinders that are not illustrated in the figures. The discharge gate  14  includes opposite side walls  80 , several deflection rollers  82  and a closed, endless tension means  84 . The side walls  80  respectively extend in the same planes as do the side walls  22  of the frame  12  and close the baling chamber  42  on its end faces. Conventional, not-shown reinforcing elements extend between the side walls  80 . 
     The four deflection rollers  82  used in this embodiment are mounted in fixed locations, but accommodated in the side walls  80  in a rotatable fashion, with the deflection rollers extending over the entire width of the baling chamber  42  parallel to the deflection rollers  36 . The deflection rollers  82  consist of an upper front deflection roller, an upper rear deflection roller, a lower rear deflection roller and a lower front deflection roller. The lower front deflection roller  82  lies in the immediate vicinity of the rear lower roller  64  of the bottom conveyor  30 . A deflection roller  82  that is carried by the arms  68  and situated in the immediate vicinity of the corresponding deflection roller  36  arranged on the arms  68  is provided between the lower front deflection roller and the upper front deflection roller  82 . The vertically movable deflection roller  82  subjects the section of the tension means  84  which extends between the upper front deflection roller and the lower front deflection roller  82  to a forward excursion in the direction of the inlet  58 . 
     The tension means  84  is constructed analogous to the tension means  40  in the frame  12  and extends over all aforementioned deflection rollers  82  in the discharge gate  14 . The section of the tension means  84  which extends between the movable deflection roller and the lower front deflection roller  82  forms a length-adjustable part of the wall of the baling chamber  42 . 
     According to the previous description, the round baler  10  according to FIGS. 1 and 2 functions as described below. 
     In a not-shown situation in which the arm  68  is situated in its lowest position due to the effect of the energy storing device  72 , the carrier  32  approximately assumes the position shown in FIG.  1  and the sections of the tension means  40  between the upper roller  34  arranged on the carrier  32 , the movable deflection roller  36  or the movable deflection roller  82 , respectively, and the lower front deflection roller  82  essentially lies in a plane that extends from the front toward the rear at an incline of approximately 45°. In this case, the baling chamber  42  assumes a 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 harvest is, for example, arranged in swaths, with the harvest being collected by means of the pick-up  24  and fed to the cutting mechanism  28 . The rotor  52  conveys the harvest into the baling chamber  42  in an overshot fashion and, if applicable, past the knives  54 . In the baling chamber, the harvest comes in contact with the sections of the tension means  40  and  84  which revolve in the same direction. Due to the cooperation between the rotatable support and, if applicable, the drive of the rollers  64  and the rollers  34  and the packing surface of the tension means  40  and  84 , the harvest begins to rotate once it reaches a sufficient volume, namely in the counterclockwise direction in the figures. In another embodiment, the round bale  44  may also be wound up in the clockwise 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  is slightly moved upward against the force of the energy storing device  72 . This causes the sections to be subjected to an upward excursion such that they are displaced out of the common plane and assume the shape of an obtuse roof. The carrier  32  is slightly pivoted in the counterclockwise direction about the pivoting axis  66  such that its lower roller  34  moves into the baling chamber  42 . In this position, the round bale  44  is supported on the front roller  64  of the bottom conveyor and on the strippers  56 . 
     As the baling process progresses, the round bale  44  reaches a size shown in FIG.  2 . In this operating state, the arm  68  is completely pivoted upward and the energy storing device  73  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, the round bale  44  is built up toward the top such that its circumferential surface presses against the upper roller  34  and pivots the carrier  32  about the pivoting axis  66  in the counterclockwise direction. Since the pivoting axis  66  is situated between the ends of the carrier  32 , this pivoting movement causes the lower end region of the carrier  32  to move into the baling chamber  42  with the lower roller  34  such that the round bale  44  is displaced toward the rear and now only supported on the bottom conveyor  30  and the lower front deflection roller  82  in the discharge gate  14 . Since the round bale  44  no longer slides directed past the inlet  58 , the process of feeding additional harvest into the baling chamber  42  is simplified. Since three rollers  34  press against the circumferential surface of the round bale  44  in the region of the carrier  32 , superior guidance of the round bale  44  and high compaction are achieved. 
     FIGS. 3 and 4 show an embodiment of the invention which largely corresponds to the embodiment according to FIGS. 1 and 2 and also fulfills the same function. However, the carrier  32  in this embodiment according to FIGS. 3 and 4 contains an arm  86  with one additional roller  88 . 
     The arm  86  essentially protrudes from the carrier  32  perpendicularly, namely in the direction toward the lower front deflection roller  36  in the frame  12 . The arm  86  is rigidly connected to the carrier  32  in the region of the upper roller  34 . The alignment is chosen such that the roller  88  carried by the arm  86  always adjoins the inner side of the tension means  40 . The length of the arm  86  is chosen such that a lever arm is formed which, when pivoting the carrier  32  in the counterclockwise direction, subjects the section between the movable deflection roller and the lower front deflection roller  36  in the frame  12  to a noticeable additional excursion. Due to the excursion of this section, the tension in the tension means  40  is additionally increased at the end of the baling or winding process. 
     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. 
     ASSIGNMENT 
     The entire right, title and interest in and to this application and all subject matter disclosed and/or claimed therein, including any and all divisions, continuations, reissues, etc., thereof are, effective as of the date of execution of this application, assigned, transferred, sold and set over by the applicant(s) named herein to Deere &amp; Company, a Delaware corporation having offices at Moline, Ill. 61265, U.S.A., together with all rights to file, and to claim priorities in connection with, corresponding patent applications in any and all foreign countries in the name of Deere &amp; Company or otherwise.