Abstract:
A baler includes a baling chamber configured for forming parallelepiped bales. The baling chamber has a top wall that is adjustable toward and away from a bottom wall of the chamber. The top wall is provided with a plurality of transversely spaced, parallel slots extending lengthwise of the chamber. A baling piston is mounted for movement within the baling chamber and includes an upper part which is defined by a plurality of transversely spaced ribs that are respectively received in the slots in the top wall and accommodate the movement of the latter during adjustment.

Description:
FIELD OF THE INVENTION 
     The invention concerns a baler with a parallelepiped or slab-shaped baling chamber and a baling piston enclosed in it that is free to move. 
     BACKGROUND OF THE INVENTION 
     The prospectus “GREENLAND Large Baler Vario Industry”, no publication date, discloses a large baler with a baling channel that can be adjusted in 5 cm. steps between a height of 0.65 m. and 0.8 m. In this way bales of different dimensions can be produced. 
     The problem underlying the invention is seen in the fact that the conversion to a different channel cross section requires approximately one day. Furthermore at present a greater range of channel cross sections is being demanded. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a baler for making parallelepiped bales and having an easily adjustable baling chamber. 
     A broad object of the invention is to provide a baler having a baling chamber for forming parallelepiped bales and the cross section of which can be easily changed as desired and made to conform to the size, particularly the height, of the transport vehicle available for the particular field. 
     Another object of the invention is to provide an adjustable baling chamber, as set forth in the preceding object, together with an adjustable needle arrangement whereby the needles and with them the entire tying arrangement is located on a movable upper chamber housing part, so that the spacial arrangement of the needles relative to the tying arrangement does not change when this part is repositioned, so that a secure engagement of the needle points in the knot tying device is assured. 
     Another object of the invention is to provide an adjustable baling chamber, as set forth in the foregoing objects, and together with this to incorporate structure providing the ability to reposition a drive, for example, a flywheel drive with a crank arm or a hydraulic motor together with the repositioning of the upper chamber part such that the force of the driver is always applied to the center of the baling piston so that it occupies a secure and centered end position. 
     A more specific object is to provide spindles, spreader linkages and the like as possible actuators for the repositioning of the upper chamber part, or more advantageously to use of motors, particularly remote controlled motors since these are simple devices which can transmit large forces. 
     Another specific object is to construct the side surfaces of the baling channel such as to cover the entire height, so no crop to be baled can escape and cause jams. If the side walls extend in one-piece configuration from above or below, a smooth surface results with low frictional resistance; if upper and lower walls are provided, that overlap vertically, then the entire side walls do not project either at the top or at the bottom. Depending on the dimensions selected such a large vertical repositioning movement can be attained so that an access from the outside into the baling chamber is possible. 
     A light-weight configuration of the baler can be attained by arranging the large components, particularly the cover or top and the bottom, as well as the side walls of the baling chamber, as a light-weight design so that the forces are absorbed by a few massive components, for example, the repositioning arrangement, which surround the baling chamber and carry and reposition the chamber top and portions of the side walls. 
     Another object of the invention is to configure an upper region of the baling piston as a collection of ribs such that a generally closed baling surface of the baling piston results, which leads to a uniform compression. The baling piston can be subdivided actually, not only conceptually, into an upper and a lower part. Slots in the chamber top or cover, for example, as an alternative to a large opening have the advantage that the ribs can extend through them and that the cover encloses the baling chamber at the sides as much as possible. The change of the cross section of the baling chamber can then be performed by lowering or raising the cover and letting the ribs extend to a greater or lesser distance through the slots. 
     The actual subdivision of the baling piston into two parts leads to a simplification of the manufacturing process. 
     The covering of the baling chamber at its sides does not stand in the way of a repositioning in height if the side walls extend into slots in the moving or the stationary part of the housing and are able to penetrate more or less deeply into the slots. 
     The accommodation of the position of the needles to the knot tying devices can be accomplished easily if openings are provided in the base body through which the needle support arms and journals connected to the movable part of the repositioning arrangement can extend. 
     If instead of a change in the height of the bale, its width can be varied, not only the height of the platform of the transport vehicle can be accommodated, but its length and width can be accommodated as well and an optimum loading can be achieved. In principle the repositioning arrangement would only need to be rotated through 90° and extended in the horizontal direction. The piston ribs would then not be extended vertically, but horizontally. If the supply channel is made to accommodate the cross section or is equipped with guide vanes a uniform supply across the entire width is assured. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic left side elevational view of a baler having a baling chamber constructed for adjustment in accordance with the invention. 
     FIG. 2 is a schematic left side view of a baling chamber of the baler shown in a maximum height condition. 
     FIG. 3 is a schematic left side view like that of FIG. 2, but showing the baling chamber adjusted to a minimum height condition. 
     FIG. 4 is a vertical sectional view taken along line  4 — 4  of FIG. 1, and showing the baling chamber in its maximum height condition. 
     FIG. 5 is a view similar to that of FIG. 4, but showing the baling chamber in its minimum height condition. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a baler  10  in the form of a large baler for the production of parallelepiped or slab-shaped bales, that includes a frame  12  supported on the ground by support wheels  14  in a tandem arrangement. A towbar or tongue  16  is connected to, and projects forwardly from, a front end of the frame  12  and is configured in such a way that it can be connected to a towing vehicle, such as an agricultural tractor, not shown, which is equipped with a power take-off shaft in order to deliver power to drive various components of the baler  10 . A baling chamber  18  or an enclosure of rectangular cross section is formed partially by an upper housing part  20  and a lower housing part  22 , where the lower housing part  22  is equipped with a crop inlet  24  which is connected to a curved supply channel or duct  26 , that is used as a pre-compression chamber, as is described in the following. A take-up arrangement  28  in the form of a pick-up together with a center-feed screw conveyor is arranged ahead of the supply channel  26 , in order to take up a swath or windrow of crop from the ground and to deliver it to a compression fork  30 . The fork  30  is used to compress crop in the supply channel  26 , until a load of pre-selected density has collected downstream of fingers  32  of a retaining arrangement  34  mounted so as to pivot between a retaining position in which the fingers  32  project into the supply channel  26  in the vicinity of the crop inlet  24 , and a supply position, in which the fingers  32  are retracted from the supply channel  26 , as shown, in order to make it possible for a load of crop to be forced into the baling chamber  18  through a crop inlet  24  by means of a loading fork assembly  36 . At a forward lower position of the supply channel  26 , a spring-loaded flap  38  is mounted, free to pivot, that pivots as a function of crop contained in the supply channel  26 , until this reaches a desired density, in order to effect activation of a circuit to supply current to an electrical control circuit, not shown, which establishes corresponding drive connections which initially have the effect that the retaining arrangement  34  moves in such a way that it retracts the fingers  32  from the retaining position into the position shown in FIG. 1, and then activates the loading fork assembly  36  in such a way that thereupon the compression fork  30  is slid through the supply channel  26  and moves the load of crop into the baling chamber  18 . Once the load of crop has been forced into the baling chamber  18 , a piston mechanism  40 , that is mounted to a forward location of the frame  12 , is actuated in a controlled sequence after the loading fork assembly  36 , in order to move the crop to the rear into the baling chamber  18 , where it is compressed in a stack, as is well known in the state of the art. After the stack of compressed material has reached a predetermined length, a needle assembly  42 , which includes several separate curved needles  68 , is actuated in order to deliver binding twine to a corresponding number of knot tying devices, not shown, that operate in such a way that they lay lengths of twine about the predetermined length of the stack in order to form a bale  44  that is ready for unloading, which occurs when it is forced out of the rear end region of the baling chamber  18  by a part of a bale  46 , when its length is increased by new loads of crop being forced into the baling chamber  18 . Since the invention concerns the repositioning of the baling chamber  18 —as is explained below—the amount of the crop supplied could be made to conform to the immediate size of the baling chamber  18 . 
     Referring again to the piston mechanism  40 , it can be seen that the latter includes a baling piston  48  that is arranged for a back and forth movement in the baling chamber  18  between a retracted position ahead of the crop inlet  24  and an extended position beyond the crop inlet  24  (see FIG.  1 ). This movement of the baling piston  48  has the result that loads of harvested crop, that are introduced from the supply channel  26  into the baling chamber  18 , are compressed against a stack of harvested crop, which includes the partially formed bale  46  and/or the complete bale  44 . Furthermore the piston mechanism  40  contains a driver  50  configured as an actuating arrangement, that can be extended and retracted, which is shown here as a double-acting hydraulic cylinder-piston unit, whose cylinder end is anchored with a pin  52 , free to pivot, on the frame  12  at a point above the compression fork  30 . The piston end of the drive  50  is connected at a connecting point  54  to a device such as a pin at a location between opposite ends of a first steering arm  56  used as a crank arm, whose forward end region is connected, free to pivot, at a bearing location  58  on the frame  12 . A rear end region of the first steering arm  56  is connected at a bearing location  60  to a device such as a pin on a forward end region of a second steering arm  62  operating as a connecting rod, whose rear end region is connected at a bearing location  64  by means of a device such as a pin with the baling piston  48 . It should be noted here that the connecting pins of the bearing locations  58  and  64  are arranged along a line of centers that lies along or approximately along a longitudinal centerline of the baling chamber  18 . This has the result that the reacting force of the harvested crop that acts upon the baling piston  48 , is substantially absorbed by the driver  50 , when the first and the second steering arm  56  and  62  are located along a line, which is the case when the baling piston  48  is located in its rear end position. Furthermore it should also be noted that the two steering arms  56  and  62  could be configured in each case as a pair of steering arms spaced at a distance to each other in the transverse direction. The driver  50  would then be connected at the connecting point  54  (pin) at a point between the pair of steering arms  56 , that form the first steering arm  56 . It can therefore be recognized that the baling piston  48  forms the slider of a slider crank mechanism that includes a first steering arm  56  as the crank arm, and a second steering arm  62  and the steering arms  94  as connecting rods. Although the linkage formed by the steering arms  56 ,  62  and  64  does not move beyond a dead center position, it could be characterized as a toggle link mechanism or a toggle link. Although the preferred embodiment shows a driver  50 , that is connected to the first steering arm  56  at a point between opposite ends of the first steering arm  56 , the driver could be connected at any point between the bearing location  58  and the bearing location  64 ; for example, the driver  50  could be connected to the pin  60  or at a point along the length of the second steering arm  62 , where the operation is in a better condition than that of the known arrangement, in which the actuation arrangement is connected directly to the baling piston  48 . 
     Further details of this baler  10  are described in EP-A2-0 940 072, whose disclosure is hereby incorporated herein. It should be noted that in place of this special drive with a hydraulic motor, a conventional crank drive can be applied equally well. 
     FIGS. 2 through 5 refer only to the configuration of the baling chamber  18  and the baling piston  48  that is guided in it. The uniqueness of this invention lies in the fact that the cross section, in particular the height, of the baling chamber  18  can be varied in order to produce bales  44  of differing heights and thereby also of differing mass. 
     For this purpose the upper part of the housing  20  is arranged so as to be repositioned in height, as will be explained below on the basis of FIGS. 4 and 5. 
     The upper part of the housing  20  is equipped with a cover  21 , that is configured in conventional manner as a heavy sheet metal component, that is relatively stiff in bending and preferably extends as a one-piece component over the entire length of the baling chamber  18 . On the upper side of the upper part of the housing  20  and to the rear of the supply channel  26 , a knot tying device assembly  66  is provided in known manner, into which the needles  68  of the needle assembly  42  can penetrate. Each side of the needle assembly  42  includes a needle support arm  70 , that can be pivoted in a vertical plane and moves the needles  68  through the baling chamber  18  with the twine, not shown, to the knot tying device assembly  66 , as soon as a bale  44  is to be bound. The cover  21  is carried at various points along its length by a yoke  72 , which forms a part of a repositioning arrangement  74  located at each point and that also includes a base body  76 . Slots  82  are provided in the cover  21  in the path of movement of, and extend in the direction of movement of the baling piston  48 . In order to insure that the stiffness of the cover  21  is adequate in this region, the cover  21  is configured with relatively thick walls or it could be constructed with reinforcing sheet metal components or the like. 
     The housing bottom  23  is formed in conventional manner from steel sheet metal that may be profiled, as shown, if necessary, and which extends over the entire length of the baling chamber  18  and is in contact, without movement, with the base body  76  of each repositioning arrangement  74 . While the cover  21  is generally closed, the bottom  23  is interrupted by the crop inlet  24  for the supply channel  26  and the inlet opening (not shown) for the needles  68 . The cover  21  and the bottom  23  extend generally parallel to each other. Nevertheless, in the rear outlet region for the bale  44 , adjustable flaps are provided, that are not shown but are well known, which give the bale  44  a certain resistance to movement. 
     The piston mechanism  40  includes the baling piston  48 , that can be shifted between two end positions by means of the driver  50  as is described in EP-A2-0 940 072. In the preferred embodiment, the baling piston  48  is subdivided into an upper part  78  and a lower part  80 , that are either configured separately from each other and are rigidly connected to each other or are formed as a one-piece component, as illustrated. 
     The upper part  78  is composed generally of transversely spaced, parallel, upright ribs  84 , that extend principally in the direction of movement of the baling piston  48 . The height of the ribs  84  is dimensioned in such a way that in every position of the cover  21  they extend through the slots  82 . The number of ribs  84  is selected in such a way that a relatively closed conveying surface of the baling piston  48  results and the spaces between the ribs  84  are relatively small. In the selected embodiment, nineteen ribs  84  are present. In other embodiments, there could be more or fewer. The width of the ribs is selected in such a way that they can be engaged in the slots  82  with relatively little play. 
     The lower part  80  is configured as a completely closed box. As a deviation from this configuration the lower part  80  may also be open downward and/or on the left side as seen in FIG.  1 . On the side walls of the lower part  80 , journals  88  are provided with rolls  90  supported in bearings, free to rotate, on the journals, in particular several in a row at equal heights. On the side of the piston  40  facing the crop to be baled, i.e., the rear side, compression means, not shown, channels for the penetration of the needles or the like can be provided. The steering arm  62  preferably engages in a joint at the center of the lower piston part  80 . The bearing location  58  that connects the first steering arm  56  in a joint is configured to be adjustable in height as well as in the longitudinal direction of the baling chamber  18 , for example, on an inclined plane in such a way that both steering arms  56  and  62  in their extended position extend in the longitudinal center plane of the baling chamber  18 . Nevertheless, this is only one preferred embodiment, that can frequently be omitted. Depending on the configuration of the guidance of the baling piston  48 , the steering arms  56  and  62  can also engage off center of the baling chamber  18 , that is, the bearing location  58  of the steering arm  56  remains unchanged. 
     On each side, a side wall  96  extends between the cover  21  and the bottom  23 , which engages a slot  98  in the side legs of the yoke  72 , so as to be able to slide vertically. The side walls  96  extend, fixed rigidly or removable, to the side outside of the cover  21  and are connected to the base body  76 . 
     The yoke  72  is configured as an inverted “U” and manufactured from tubing material or as a weldment. Each vertical leg of the yoke  72  is provided with a slot  98  and is rigidly connected over a bridge  86  with the other vertical leg. At the lower end of each leg of the yoke  72 , a connection  104  is provided for a servo motor  106 , that will be described in greater detail below. In place of the servo motors  106 , other repositioning mechanisms could be used, for example, levers, threaded spindles etc. The cover  21  is rigidly attached to the inside of the legs of the yoke  72 . 
     The base body  76  is configured in the shape of a “U”, whose legs extend upward alongside the legs of the yoke  72 . Between the legs of the base body  76 , the bottom  23  is in contact with, and connected to, the base body  76 . At approximately half the height of the legs, a guide  108 , configured as a “U”-shaped rail, is attached on each side on or in the legs, which extends parallel to the bottom  23 . These guides  108  receive the rolls  90  of the lower part  80  within themselves, free to rotate. The side walls  96  extend upward erect above the guides  108 . In the upper region of the legs openings  92  are provided through which journals  94  extend that engage the needle support arm  70  on the yoke  72 , free to move. While the bottom of the base body  76  can also be formed from a tube, a rail, a weldment or the like, its legs are configured as vertical guides that contain an interior space  110 . At the bottom of each interior space  110 , a connection  104  is also provided for the other end of the servo motor  106 . In the region of the interior space  110  located above it the legs of the yoke  72  are engaged so as to slide, free to move vertically. 
     The servo motors  106  extend between the bottom of the interior space  110  and the lower end of the legs of the yoke  72  and are connected over each of the connections  104  to these in a positive lock. The servo motors  106  may be configured as hydraulic motors or as electric motors, which, however, may depend on the forces to be transmitted, the space available and the like. It is necessary, however, to guarantee that during a repositioning process all servo motors  106  cover exactly the same path, so that there is no warping between each of the yokes  72 . The servo motors  106  are remotely controlled, for example, from the vehicle towing the baler  10 . While in the present embodiment the servo motors  106  are assumed to be double acting hydraulic motors, in other embodiments single-acting servo motors  106  could also be used, that are again retracted downward either on the basis of spring force or the force of gravity acting on the yokes  72 . 
     On the basis of the above description the result is the following configuration and the following operation. 
     The bottom  23  and the guides  108  are inserted and fastened to the base body  76 . Following this the servo motors  106  are inserted into the interior spaces  110 , connected with the base body  76  and connected to a hydraulic system, not shown. Then the baling piston  48  with its rolls  90  is slid into the guides  108  and the steering arm  62  is connected with the baling piston  48 . Following this, the cover  21  is laid upon the baling piston  48 , so that the ribs  84  extend through the slots  82 . Subsequently, the yoke  72  is slid into the interior spaces  110  and connected to the cover  21  and the servo motors  106 . Finally the journals  94  are inserted through the openings  92  and fastened to the yoke  72  and connected to the needle support arms  70 . 
     According to FIGS. 2 and 4, the baling chamber  18  can be adjusted so as to occupy a maximum height condition, and, according to FIGS. 3 and 5, it can be adjusted to occupy a minimum height condition. 
     The further description begins with the assumption that it is desired to adjust the baling chamber from its maximum height condition, shown in FIGS. 2 and 4, to its minimum height condition, shown in FIGS. 3 and 5, this being performed as follows. 
     The servo motors  106  are retracted synchronously and pull the yokes  72  downward, whereby the baling chamber  18  is lowered. Simultaneously the bearing location  58  is shifted, so that the stroke of the baling piston  48  and the position of the steering arm  56 ,  62  remains unchanged with respect to the baling piston  48 . 
     As a result of the attachment of the needle assembly  42  to the yoke  72  or the upper housing part  20 , the former also moves upward or downward and maintains the spacial relationship to the knot tying device assembly  66 . 
     While the present embodiment is initially based on the assumption that the upper housing part  20  is movable and the lower housing part  22  is fixed, this could also be the reverse, where then nevertheless the supply channel  26  and the components connected to it would have to be modified accordingly. Finally all side walls, the cover  21  and the bottom  23  could also be repositioned individually or in unison. 
     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.