Abstract:
A round baler has a bale chamber surrounded by bale forming means running over stationary and moveable rollers. Some moveable rollers are carried by arms which are located outside opposite side walls of the bale chamber. This enables a bale to be formed within the spacing between the side walls and to be ejected by raising the arms carrying moveable rollers to open the bale chamber.

Description:
FIELD OF THE INVENTION 
     The invention refers to a round baler having a bale chamber covered at least substantially by side walls and flexible bale forming means. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 5,931,089 discloses a round baler having multiple rollers rotatably journalled in a chassis to carry a set of belts. An inlet to a bale chamber is provided downstream of a pick-up between two fixed rollers. A span of belts bridging this inlet is engaged by incoming crop and deflects towards the bale chamber to create a loop. The incoming crop increases the bale in said loop until it reaches a maximum diameter. As soon as the maximum diameter is reached, a gate carrying one of the rollers limiting the inlet is raised and the loop opens to the ground to dump the bale. 
     In “FMO 141 B D-00, Hay and Forage Harvesting” of Deere &amp; Company pages 153 and 154 is disclosed a type of round baler which had been common in the 1970&#39;s. This type had two spaced side walls each of one piece and a pair of arms to which is attached a frame carrying three rollers over which belts are trained. In the bottom area a bottom conveyor of a wide belt is provided, on which the bale is supported during formation. When the round baler is empty, a lower front roller assumes a position immediately above said bottom conveyor and close to an inlet of the bale forming chamber. The more the bale approaches its maximum diameter, the bigger will be a part of the bale, that extends over the rear edges of side walls. 
     The problem to be solved with respect to these prior art balers is either the weight of the gate which has to be handled in order to get the bale out of the bale chamber or the costs of a bottom conveyor. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a large round baler having an improved bale forming arrangement for overcoming the aforementioned problems associated with prior art balers. 
     The objectives of the present invention are accomplished by a structure including a roller located outside the bale chamber to train the bale forming means and to carry the bale, and for allowing just this roller to move in order to open the bale chamber at the rear of the baler to dump the bale onto the ground. Moving just one roller results in much less weight being moved than when moving a complete gate with several rollers and stiff side walls, as is the case with the prior art balers. Furthermore, a single roller may be moved on a quite complex track as opposed to a part of a circle as given by the movement of the gate. The arm supporting the single roller may be pivoted about a single axis or moved a long a path either defined by a guide or achieved by a multi-sectional arm having controls between the sections for varying their relative positions. A bottom conveyor is omitted, since the arms with the roller may be positioned under the bale and since the arm can slip under the side walls to the front and close to the center of gravity of the bale, the arms may carry the weight without being exposed to extreme bending forces. 
     Two rollers on the pair of arms permit a better routing of the bale forming means and to keep sections of the belts away from other moving parts. The distance between the rollers may be fixed or variable, whereas a variation of the distance may be achieved by power actuators like hydraulic motors or the like. 
     While in principle it would be possible to control the position of the arm manually by means of a link or the like, it is more convenient, more powerful, more flexible, and less dangerous to do it via a power actuator like a hydraulic motor or an electric motor and preferably either remote controlled or controlled by means of sensors, etc. 
     The routing of the bale forming means, the tension in them, and the location of the loop delimiting the bale chamber can be adjusted, modified, and controlled, if a second arm with one or more rollers is provided to train the flexible bale forming means. 
     While in general it would be possible to have an individual pivot axis for each pair of arms, both pairs of arms could be moved without limits and conflicts, if they are rotated or pivoted about the same axis, with different arm lengths preferably. 
     An overload as well as a high tension in the flexible bale forming means is achieved by a roller applied by an actuator, like a spring or any other tension means. Such an actuator or power actuator can be a gas spring, a mechanical coil or leaf spring or a hydraulic piston moved against a preferably variable pressure. Preferably this roller is kept in a guide to guarantee a roller movement and thus a tensioning or loosening of the bale forming means without canting or twisting. 
     A carrier on the moveable arms with one or more rollers on it permits to bring the rollers in the right position and to route the bale forming means as needed. While the position of the carrier is fixed as opposed to moveable, it could be attached in different positions depending on the configuration of the baler or the like. 
     Fastening the carrier and the rollers with it moveably with respect to the arms allows the rollers to be brought into an optimum position during the movement of the arm about its pivoting axis. This could be helpful to change the tension in the bale forming means, to route the bale forming means through tights areas, etc. 
     In order to have an inlet of fixed width which corresponds to the infeed geometry of an upstream pick-up, two rollers of a fixed distance may be used, which rollers may be a support roller in the bottom and a stripper roller on the top. One of these rollers could be located on the arm and swing away, when the bale chamber is opened. 
     If the bale forming means are trained over the stationary roller kept rotatably by the chassis and delimiting the inlet on the side remote from the bale chamber, no starter roller is required and thus there is no risk of wrapping in that area. Furthermore the crop gets in immediate contact with the bale forming means and can start rolling. 
     In an embodiment, in which the flexible bale forming means are trained over the stationary roller(s) on the side facing the bale chamber, a small chamber is provided, which has a driven starter roller at one side, which assists in holding the crop and starting the bale core. 
     The path of the roller or the rollers on the arm(s) is predetermined and easy to achieve, if it follows the contour of the side walls, which may be formed such, that a certain routing of, and tension in, the bale forming means is achieved. 
     The possibility to change the distance between the side walls allows to produce bales of different size and volume and thus to accommodate to the dimension of a truck or the like. The distance can be varied if the side walls are moved on or with the shafts on which the arms are journalled. 
     Stops at the arms, roller or carrier fixed on the arms, are useful to act against the bending forces applied to the side walls by the crop. Thus the bale chamber retains a constant width even if it is filled completely. Such stops could contain rollers, gliders or the like. 
     Belts and chains with slats thereon are excellent bale forming means, since they can be trained in a very flexible way over rollers in different and even changing positions. 
     If the peripheral edges of the side walls are distant in the plane of their substantial extension from any adjacent or close component, like a frame, pick-up, etc., the rollers on the arms can be moved in a circular path around the side walls to perform an endless cycle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawing shows two embodiments of the invention explained in the description below. 
     FIG. 1 is a schematic depiction of an empty round baler constructed according to a first embodiment sectional view taken along line  1 — 1  of FIG.  2 . 
     FIG. 2 is a rear view of the round baler of FIG.  1 . 
     FIG. 3 is a view of the round baler of FIG. 1 showing a slightly filled bale chamber. 
     FIG. 4 is a view of the round baler of FIG. 1 showing a partially filled bale chamber. 
     FIG. 5 is a view of the round baler of FIG. 1 showing a filled bale chamber. 
     FIG. 6 is a view of the round baler of FIG. 1 showing the unloading of a bale. 
     FIG. 7 is a schematic depiction of an empty round baler constructed according to a second embodiment and having a cutting device upstream of the bale chamber. 
     FIG. 8 is a view of the round baler of FIG. 7 showing a slightly filled bale chamber. 
     FIG. 9 is a view of the round baler of FIG. 7 showing the unloading of a bale. 
     FIG. 10 is a schematic, side view of a round baler constructed according to a third embodiment. 
     FIG. 11 is a view of the round baler of FIG. 10 showing a slightly filled bale chamber. 
     FIG. 12 is a view of the round baler of FIG. 10 showing a filled bale chamber. 
     FIG. 13 is a view of the round baler of FIG. 10 showing the unloading of the bale. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, there is shown a round baler  10  comprising a chassis  12 , a set of fixed rollers identified more specifically below, a moveable roller  16 , an arm-and-roller assembly  18  and flexible bale forming means  20 . The round baler  10  is designed substantially in a mirror image with respect to a vertical center plane extending in the travel direction of the round baler  10 . 
     The round baler  10  serves to receive crop lying on the ground and to form a cylindrical bale  22  (see FIG. 5) therefrom. The round baler  10  may be of the pulled type, as shown, or of the self-propelled type. In order to gather crop from the ground, a pick-up  24  is provided, which delivers crop directly (see FIGS. 1 and 3 to  6 ), or indirectly via by means of an intermediate conveyor  26  (see FIGS. 7 to  9 ), to a bale chamber  28  (see FIG.  3 ), which is variable in size. A finished bale  22  is delivered to the ground by means of a ramp  30 . The round baler  10  may also be provided with a twine tying or a net or plastic wrapping device, which is not shown however. Finally, the round baler  10  is equipped with a drive, not shown, receiving power from a prime mover, like a tractor, not shown. 
     The chassis  12  comprises a frame  34 , a tongue  36 , an axle  38  and side walls  40 . 
     The frame  34  is understood to be the rigid welded and bolted carrying part of the round baler  10  including shielding and the like. The frame  34  carries, in an usual manner, the pick-up  24  and, if present, the intermediate conveyor  26  as well as the ramp  30  and the drive. 
     The tongue  36  is attached to the front of the frame  34  and extends forwardly to be coupled to the prime mover. 
     The axle  38  is attached in the bottom area of the frame  34  and journals wheels  42  at each lateral end to support the round baler  10  on the ground. The wheels  42  are shown as single wheels, but tandem wheels could also be used. 
     The side walls  40  are spaced inwardly from the frame  34 , as best seen in FIG.  2 . The side walls  40  are each carried on a shaft  44  fixed with its outer end to the frame  34 . The side walls  40  include peripheral edges  46  that are free, that is to say, not connected to the frame  34  or to any other component. Moreover a gap is provided between the peripheral edges  46  of the side walls  40  and components in the vicinity of the side walls. The shape and size of the side walls  40  corresponds at least to the maximum cross section of the bale  22 . As shown in FIG. 1, the shape of the side walls  40  follows substantially a circle. All in all, the side walls  40  are fixed to the frame  34  in a cantilevered fashion and are reinforced sufficiently to withstand the pressing forces in the direction of the longitudinal axis of the bale  22 . The side walls  40  leave a distance between them in which the bale chamber  28  is created. While in general the side walls  40  extend parallel to each other, there may be a slight divergence towards the rear. 
     The set of fixed rollers include four idler or drive rollers  50  and two starter rollers, which fixed rollers are all made of steel possibly covered partly or totally with a rubber coating or rubber sleeves, not shown. Shafts  48  are provided to journal the set of fixed rollers for rotation in the frame  34  by means of bearings, not shown. All of the fixed rollers run parallel to each other. The idler or drive rollers  50  are located in lower front, upper front, upper rear, and rear positions. As can best be seen in FIG. 6, the upper rear roller  50  is located so as to be vertically above a bale  22  rolling down the ramp  30 . The starter rollers  52  are located above the delivery end of the pick-up  24  or of the intermediate conveyor  26 , if any. The centers of the starter rollers  52  lie in a plane, which has an inclination to the ground of about 45 degrees. Only a small gap is provided between the starter rollers  52 . In a not shown embodiment, more or less than two starter rollers  52  may be provided. In this specific embodiment, the starter rollers  52  are of a bigger diameter than the drive or idler rollers  50 . Preferably both starter rollers  52  are driven, whereas it is sufficient if only one of the idler or drive rollers  50  is driven. 
     The moveable roller  16  is received in a track or on a guide, not shown, and is biased upwardly by an actuator  54 , which is shown as a coil spring. Instead of a coil spring, a leaf spring, a gas accumulator or a hydraulic cylinder with a throttle or the like may be used to yieldably resist upward movement of the moveable roller  16 . While in the preferred embodiment the moveable roller  16  is located in the front part of the frame  34 , it could be located at any other suitable place. It is the purpose of this moveable roller  16  to keep a minimum tension in the bale forming means  20 . In order to provide for the proper tension, more than one moveable roller  16  could be provided, and the movement of the actuator  54  could be controlled as a function of signals of the belt tension and/or of the status of the bale forming process. 
     The roller-and-arm assembly  18  in the embodiments of FIGS. 1 to  9  comprises two sets of arms  56  and  58 , carriers  60  and  62 , rollers  64  and  66  and drives  68  and  70 . 
     Each arm  56 ,  58  has an inner end rotatably journalled on the shafts  44  by means of a bushing  72  and  74 , which is rotatably fixed with a drive wheel  76  and  78 . The outer end of the arms  56 ,  58  respectively bear the carriers  60  and  62 . The arms  56 ,  58  extend through the space between the side walls  40  and the frame  34  and have a length such, that the rollers  64 ,  66  at least partially are located outside the side walls  40 . In the shown embodiments, the arms  56 ,  58  are straight and extend radially. However, it would be possible to make each of the arms  56 ,  58  of two or more sections, which are moveable with respect to each other. 
     The carriers  60 ,  62  are here shown supporting respective pairs of rollers  64  and  66  on shafts  67  extending between the carriers  60 ,  62 , but the carriers may be designed to support one or more than two rollers, over which the flexible bale forming means  20  is trained, whereas the location of these rollers  64 ,  66  defines the path of the runs of the bale forming means  20 . The position of the carriers  60 ,  62  with respect to the arms  56 ,  58  is preferably fixed, although it would be possible to make it adjustable, too, either remote controlled or controlled by a spring or similar actuator. As to be seen in FIG. 1, carrier  62  is inclined with respect to the arm  58  and carrier  60  makes a right angle with the arm  56  to which it is attached. 
     The rollers  64 ,  66  are rotatably received in or on the carriers  58 ,  60  and extend at least over the full width of the bale chamber  28 . In a case in which the distance between the side walls  40  can be varied, the rollers  64 ,  66  and preferably the carriers  60 ,  62  extend laterally beyond the side walls  40 . According to FIG. 2, stops  80  are provided on shaft  67  of one of the rollers  64 , which stops are axially fixed on the shaft  67  and act against an outward movement of the side walls  40 . In the preferred embodiment, the rollers  64 ,  66  rotate with their shafts  67  in the carriers  60 ,  62 . Contrary, each roller  64 ,  66  could consist of a drum rotating on its respective shaft  67 , which itself is rotatably fixed in the respective carrier  60 ,  62 . 
     The drives  68 ,  70  each comprise a gear or transmission  82  (see FIG. 2) with two output shafts  84 ,  86 , which each is connected to the drive wheels  76 ,  78  by means of a drawing means  88 , like a chain or a belt. In other not shown embodiments, the transmission  82  or a motor could be attached directly to the drive wheels  76 ,  78  or to the bushings  72 ,  74  connected to them. The drives  68 ,  70  do not perform a constant movement of the arms  56 ,  58  but perform a stop-and-go movement, i.e., the arms  56 ,  58  are moved between positions which correspond to the status of the baling cycle. Each drive wheel  76 ,  78  is connected rotatably fixed to the respective bushing  72 ,  74  and latter to the respective arm  56 ,  58 . As a result, each pair of arms  56 ,  58  will rotate as soon as the drive wheel  76 ,  78  is driven through the pulling means  88  by the respective output shaft  84 ,  86 . While FIG. 2 shows only one transmission  82  and one set of output shafts  84 , the side view figures disclose the arrangement and location also of the second set of output shafts  86 . While it is convenient to have both transmissions  82  and sets of output shafts  84 ,  86  close to each other, it is not really necessary. In an alternative arrangement, the drive wheels  76 ,  78 , the bushings  72 ,  74 , the output shafts  82 ,  84  and the pulling means  88  could be replaced by hydraulic cylinders and/or levers being directly connected to the arms  56 ,  58 , especially as long as the arms  56 ,  58  perform only a limited pivot movement. 
     The flexible bale forming means  20  are in the form of endless belts trained over the rollers  16 ,  50 ,  64  and  66  and driven by frictional contact between the bale forming means  20  and these rollers  16 ,  50 ,  64 ,  66 . In the embodiment of FIGS. 1 to  7 , the bale forming means  20  touch the starter rollers  52  tangentially on their inner side only, as long as the bale chamber  28  is empty, as it is shown in FIG.  1 . As soon as crop is fed into the bale chamber  28 , the bale forming means  20  are deflected opposite and away from an inlet  90  formed between the forward roller  64  of the rear arm  56  and the lowermost starter roller  52 . The bale forming means  20  form a loop, the ends of which are located at the forward roller  64  of the rear arm  56  and at the rear roller  66  of the forward arm  58 . As soon as the bale  22  reaches its maximum diameter, its cross section is aligned with the major portion of the side walls  40  (see FIG.  5 ). It can be seen in FIG. 5 that a full sized bale rests with a portion of the bale forming means  20  on the rollers  64  of the rear arms  56 . In this situation, the front part of the bale  22  is supported on the starter rollers  52 . When no crop is in the bale chamber  28 , as shown in FIG. 1, the bale forming means  20  extend in a substantially straight line from the forward roller  64  of the rear arm  56  to the forward roller  66  of the front arm  58  via the starter rollers  52 , from where it is routed to the moveable roller  16 , to surround it by about 180 degrees, before it reaches the front lower roller  50 . In this situation, the moveable roller  16  is in its home position, in which no or almost no force is applied to it by the actuator  54 . This is in contrast to the situation illustrated in FIG. 5, wherein the bale chamber  28  is filled completely, with the moveable roller  16  being pulled by the bale forming means  20  to its other extreme end position, in which the maximum force is applied by the actuator  54 . As it is apparent from FIGS. 1 to  6 , all rollers  50 ,  64 ,  66  stay in their position from the beginning to the end of the baling process, only roller  16  is moved to accommodate for the growing bale  22 . In the embodiment according to FIGS. 1 to  6 , the bale forming means  20  moves clockwise. 
     The bale  22  is made from straw, hay, cotton, tobacco, any other crop or industrial material like plastic, garbage, paper, clothing, etc. After the bale  22  has attained its desired diameter, which usually, but not necessarily, is its maximum diameter, it is tied with twine, wrapped with net or plastic, and ejected to roll onto the ground via the ramp  30 . Since this round baler  10  is of the variable chamber type, the density of the bale  22  is more or less the same throughout the full radius. However, the position of the moveable roller  16  could be controlled such, that different tension is applied to the bale forming means  20  during the baling cycle to achieve a soft core and hard outer layers. 
     The pick-up  24  is of conventional construction and is attached to the frame  34  by means of lifting means, as this is known. 
     The intermediate conveyor  26  is of a known type as well, either as a cutting unit or as a mere undershot or overshot conveying rotor, which both deliver the crop from the pick-up  24  to the inlet  90 . 
     The bale chamber  28  is covered on its circumference by the flexible bale forming means  20  and the starter rollers  52  and is open only in the area of the inlet  90 . Laterally the bale chamber  28  is covered by the side walls  40 . 
     According to the description above and starting with FIG. 1 in the initial phase, the rear arms  56  are oriented more or less vertically, such that their front roller  64  is spaced to the rear from the starter roller  52  to form the inlet  90 . In this position, both rollers  64  are almost in the same horizontal plane and form a substantial part of the bottom of the bale chamber  28 , on which the bale  22  may rest. The front arms  58  extend substantially in a nine o&#39;clock position, such that the rollers  66  are located above the starter rollers  52  and a plane through their longitudinal axles is inclined at about 45° degrees to the ground. The flexible bale forming means  20  bridge the inlet  90 . The position of the arms  56  and  58  remains substantially unchanged until the bale chamber  28  is filled completely, as shown in FIG.  5 . The only exception is a movement of the front arms  58  counterclockwise so as to move the lower or rear roller  66  very close to the upper starter roller  52  in response to crop being fed into the bale chamber  28 . This is to avoid a gap between the upper starter roller  52  and the rear or lower roller  66  of the front arms  58  through which crop could escape. In order to eject the bale  22  from the bale chamber  28 , the rear arms  56  are raised, i.e., they are swung counterclockwise with respect to FIG. 1 into the position shown in FIG. 6, in which the rollers  64  are above the bale  22 . In this position, the flexible bale forming means  20  is biased by the force of the actuator  54  such that a span of the bale forming means  20  tends to extend along a straight line between the rear roller  66  of the forward arm and the rear fixed roller  50 . Since the rear fixed roller  50  is located relatively high, the bale  22  can roll out of the bale chamber  28  and down the ramp  30 . As soon as the bale  22  is ejected, both pairs of arms  56 ,  58  are returned to their home positions, as shown in FIG.  1 . 
     The embodiment according to FIGS. 7 to  9  is very similar to the embodiment of FIGS. 1 to  6 . However, in these figures, an intermediate conveyor  26  is provided downstream the pick-up  24 , which replaces the lower starter roller  52 . As a consequence thereof, only one starter roller  52  is provided, and the carrier  60  on the rear arms  56  provides for a greater distance between the rollers  64 , such that the front roller  64  comes close to the delivery end of the intermediate conveyor  26 . Furthermore, in an empty state of the round baler  10 , the front arms  58  are raised to a higher position than in FIG. 1, such that the upper roller  66  comes very close to the moveable roller  16 . Finally, the direction of movement of the flexible bale forming means  20  is contrary to the embodiment in FIGS. 1 to  6 , i.e., counterclockwise. 
     Disregarding these differences, the round baler  10  according to FIGS. 7 to  9  is designed and acts in the same way as the one in FIGS. 1 to  6 . 
     The round baler  10  according to FIGS. 10 to  13  is substantially of the same design as the round baler  10  according to FIGS. 1 to  6  with the following exceptions: the front pair of arms  58  is missing, the starter rollers  52  are replaced by two additional fixed rollers  92 , the span of the bale forming means  20  engages the outer side of the additional fixed rollers  92  and the pick-up  24  as shown or an intermediate conveyor  26  are of a heavy design, which is useful to deflect the strand of the bale forming means  20  between the front roller  64  and the rear additional fixed roller  92 . The advantage of this design is to have less components. 
     The additional fixed rollers  92  are of the same design as the remaining idler or drive rollers  50  and stay in place during the full baling cycle. A rear additional roller  92  assumes the place of the rear starter roller  52  and is located within the boundary of the side walls  40 . The second and forward additional roller  92  is located in front of the side walls  40  outside the boundary or periphery of the side walls  40  in a plane slanted about 45° to the ground. 
     The bale forming means  20  circulate in a clockwise direction with respect to the drawing. Contrary to the routing of the embodiment in FIGS. 1 to  6 , in which the bale forming means  20  touch the side of the starter rollers  52  facing the bale chamber  28 , in this embodiment the bale forming means  20  touch the side of the additional rollers  92  remote from the bale chamber and adjacent the pick-up  24  to form a wedge with it, in which the crop is rolled counterclockwise. As soon as the crop enters this wedge, a bale core is started and rolled and the bale forming means  20  deflect inwardly to form a loop, as seen in FIG. 11, which grows until it reaches a size as shown in FIG.  12 . During the bale forming process, the bale  22  rests with its front part on the rear additional roller  92  and with its substantial part on the rolls  64  on the moveable arms  56 . 
     The pick-up  24  is of such a stability and power, that incoming crop can be pushed sufficiently against the bale forming means  20  to start forming a bale core. 
     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.