Abstract:
A large round baler is equipped with an enveloping arrangement that moves a run of enveloping material to the circumferential surface of a bale with a pivot arm including a driver having projections in the form of teeth that can be caused to penetrate the enveloping material to cause a positive locking with the run of enveloping material so that the enveloping material may be selectively inserted into the baling chamber at the beginning of a wrapping cycle and engaged with a contact plate to effect separation of the enveloping material once a predetermined number of wraps have been applied to the circumference of the bale.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention concerns a large round baler with a baling chamber that is partially surrounded by baling elements, and with an enveloping arrangement with a separating arrangement and with a withdrawal arrangement to grasp and insert a run of enveloping material in the shape of a broad band into the baling chamber.  
         BACKGROUND OF THE INVENTION  
         [0002]    U.S. Pat. No. 5,581,973 discloses a large round baler with an enveloping arrangement that withdraws net from a net roll by means of a pivot arm and introduces it through a slot between the baling elements into a baling chamber. The pivot arm is equipped with a spring loaded jaw in which the net is guided and retained on the basis of friction.  
           [0003]    The problem underlying the invention is seen in the fact that the friction force originating in the net varies on the basis of the condition of the material and is higher or lower with another enveloping material and hence that the material gripping device of the prior art is such that a reliable supply of enveloping material cannot be guaranteed.  
         SUMMARY OF THE INVENTION  
         [0004]    According to the present invention, there is provided an improved device for delivering enveloping material to the baling chamber of a large round baler.  
           [0005]    An object of the invention is to provide an enveloping arrangement including a device for grasping a run of enveloping material in a positive safe lock and hence safely, where the run of enveloping material may be a net or foil and where moisture, applied adhesive films, unevenness, and the like do not detract from the reliability of the enveloping arrangement.  
           [0006]    Drivers are particularly effective and are configured as teeth, points or the like and thereby can easily penetrate into the run of the enveloping material, or act as a fork in the case where the enveloping material is a net.  
           [0007]    If the drivers are configured as suction nozzles, the retaining force as well as the amount of the run of the enveloping material that is drawn into the suction nozzles and the timing of the grasping and release can be varied. If necessary, the release can also be accelerated by compressed air.  
           [0008]    Few process steps are required if the take-up of the run of the enveloping material is performed at the same point in time and by the same movement as that which effects its separation from the supply roll at the end of the enveloping process.  
           [0009]    If the withdrawal arrangement can be repositioned between a position facing away from the baling chamber and a position facing towards the baling chamber, there is an assurance that it will not be loaded in the non-operating position by material to be baled. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The drawing shows an embodiment of the invention that shall be described in greater detail in the following.  
         [0011]    [0011]FIG. 1 is a left side perspective view of a large round baler equipped with an enveloping arrangement constructed in accordance with the principles of the present invention.  
         [0012]    [0012]FIG. 2 is an enlarged side view of the enveloping arrangement shown in FIG. 1.  
         [0013]    [0013]FIG. 3 is a view similar to that of FIG. 2, but showing a second embodiment of the enveloping arrangement.  
         [0014]    [0014]FIG. 4 is a perspective view of the withdrawal device of the enveloping arrangement.  
         [0015]    [0015]FIG. 5 is a perspective view of the withdrawal device of FIG. 4, but showing a different driver construction. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]    [0016]FIG. 1 shows a large round baler  10  with a frame  12 , running gear  14 , a towbar  16 , a baling chamber  18 , baling elements  20 , a harvested crop inlet  22 , a take-up arrangement  24 , a supply arrangement  26 , and an enveloping arrangement  28 .  
         [0017]    Except for the enveloping arrangement  28 , the large round baler  10  is of a conventional configuration in which in a baling chamber  18  is defined by the baling elements  20  and the side walls  30 , and in which a bale  32  of harvested crop, tobacco, industrial garbage, precious material, etc. is formed and subsequently wrapped with a run of enveloping material  34  configured of net, foil or the like.  
         [0018]    The frame  12  holds together the running gear  14 , the towbar  16 , and the side walls  30 , and carries the baling elements  20 , the take-up arrangement  24 , the supply arrangement  26 , and the enveloping arrangement  28 .  
         [0019]    The baling chamber  18  is covered at its end faces by the side walls  30 , and except for the inlet  22  and an opening  36  in its upper forward region, is enclosed around its circumference by the baling elements  20 . The opening  36  is provided adjacent to the enveloping arrangement  28  and provides an access to the baling chamber  18  for receiving the enveloping material  34 . The bailing chamber  18  can be opened for the delivery of the bale  32 , in a known manner, whereby a rear section of the side walls  30  is pivoted upward about an upper bearing, not shown, while a forward section remains rigid. In the embodiment shown, the baling chamber  18  is provided as fixed in its size. Instead, a baling chamber  18  that is variable in its size could also be used, as is also well known.  
         [0020]    In this embodiment, the baling elements  20  are configured as steel rolls that can rotate about horizontal axes extending transverse to the direction of operation and arranged along a circular arc. The baling elements  20  border very close to each other, and in the region of the inlet  22  and at the opening  36 , there is a spacing that corresponds approximately to the diameter of a baling element  20 . Nine baling elements  20  are supported in bearings, free to rotate, in the rear section of the side walls  30  that can be pivoted upward, and seven baling elements  20  are supported in bearings in the forward rigid section, free to rotate. This arrangement of the baling elements  20 , however, is meant only as an example. In place of the baling elements  20 , belts, bar chain conveyors or a mixture of these and the like could be used in order to surround a fixed or a variable baling chamber  18 .  
         [0021]    The inlet  22  is used for receiving the supply of the crop to be baled from the take-up arrangement  24 , or if available, from a conveyor arrangement that glides further into the baling chamber  18 .  
         [0022]    The supply arrangement  26  is used only selectively and may be configured as a conveyor as well as a cutting arrangement.  
         [0023]    In their forward region  92 , the side walls  30  are spaced at a greater distance from each other than in the region of the baling chamber  18 .  
         [0024]    The large round baler  10  described so far is of conventional configuration.  
         [0025]    The enveloping arrangement  28  is used to support, supply, and separate the run of the enveloping material  34  that is applied to its circumferential surface of a formed bale  32 , so that the bale  32  does not fall apart after leaving the baling chamber  18 . For this purpose, the enveloping arrangement  28  contains a support  38 , an enveloping material feed roll  40 , a guide arrangement  42 , a withdrawal arrangement  44 , an actuating arrangement  46 , steering arms  48 , a contact pressure arrangement  50 , and a covering  52 .  
         [0026]    In this embodiment, the support  38  is configured as a simple sheet metal plate extending in a horizontal plane in the transverse direction in the forward region  92  of the side walls  30  on which a supply roll  54  of the run of enveloping material  34  rests. The support  38  can also be configured in such a way that it can support several supply rolls  54  that it is provided with steps or depressions for their retention in position and the like.  
         [0027]    On its circumferential surface, the feed roll  40  is provided with a coating having a high coefficient of friction and can be brought into rotation by means of a drive derived from a baling element  20  or by means of its own drive, for example, by means of an electric or hydraulic motor. Initially, rotation of the feed roll  40  helps to withdraw the run of enveloping material  34  from the supply roll  54  and build up a tension in it during the enveloping process due to a limited rotational movement. The feed roll  40  is located between the support  38  and the opening  36  and rotates about an axis located at a level above the support  38 . The supply roll  54  can be brought into contact in its operating position with a region of the roll  40  in the 6 to 9 o&#39;clock position, as seen in FIG. 2, and is held into contact with it by the contact pressure arrangement  50 .  
         [0028]    The guide arrangement  42  is provided with two arms  56  that are mounted, as by bearings  58  provided in the forward region  92  of the side walls  30 , for pivoting vertically about a horizontal axis that is parallel to the axis of rotation of the bale  32 . Secured to a lower end region the arms  56  is a contact plate  60  that bridges the entire distance between the arms  56 . The contact plate  60  is stiff in bending and forms a part of a separating or cut-off arrangement  94 . The spacing between the arms  56  in the sideways direction is large enough for the roll  40  to be accommodated between them. A lower end region of the contact plate  60  is bent towards the baling chamber  18  so as to define a 90° angle, and with its upper edge, maintains a spacing to the circumferential surface of the roll  40 . At a point approximately in alignment with a top surface of the roll  40 , the arms  56  are bent so that their lower section, in the non-operating position shown in FIG. 2, extend generally in the vertical direction, while the upper section extends at an angle of approximately 30° to the vertical to the rear and inclined towards the bearing  58 . The guide arrangement  42  is located in such a way that, particularly in the non-operating condition, it is able to accept the run of the enveloping material  34  arriving over the roll  40  between the arms  56  and permit it to slide over the contact plate  60  to the baling chamber  18 .  
         [0029]    The withdrawal arrangement  44  is shown in an enlarged view as an individual part in FIGS. 4 and 5 and includes two arms  62  and a sheet metal driver  64 .  
         [0030]    The arms  62 , located at the sides of the withdrawal arrangement  44  generally in the same plane as the arms  56 , extend parallel to each other and are provided with two legs extending at an angle of approximately 90°. This means that the arms  62  move outside of the side walls  30  in the region of the baling chamber  18 . In the sharp bend between the two legs, the arms  62  are engaged in a bearing  66  at the side walls  30  with a horizontal bearing axis, so as to pivot vertically. In an end region of the arms  62  facing the baling chamber  18 , a further bearing  68  is provided, and in the end region facing away from the baling chamber  18 , the sheet metal driver  64  is rigidly attached to the arms  62  at an angle of approximately 75°. In the side view of FIG. 2, the arms  62  and the sheet metal driver  64  generally follow the shape of an “S”.  
         [0031]    The sheet metal driver  64  extends over the entire region between the side walls  30 , is configured rigidly in itself, and is at least generally level. The width of the sheet metal driver  64  corresponds to the width of the baling chamber  18 . As can best be seen in FIG. 4, the forward side of the driver  64 , that is, the side facing the contact plate  60 , defines an edge  70  provided with projections  72  having a toothed, a zig-zag or comb-shaped profile. In FIG. 5, a generally equal sheet metal driver  64  is shown that differs from that shown in FIG. 4, only in the shape of the projections  72 . Although the sheet metal driver  64  shown in FIG. 5 has two shapes of projections  72 , and these may be possible, it is unlikely that such a construction would be used, since it would be more efficient to cut out only one shape of driver. The projections  72  are worked into the sheet metal driver  64  by means of a stamping process, a laser cutting process or other form-giving operating process. The spacing of the projections  72 , their width and shape are selected in such a way that they can easily penetrate into a run of enveloping material  34  configured as foil or between the threads of a run of enveloping material configured as net, and can free this after it is supplied into the baling chamber  18 . The sheet metal driver  64  forms a second part of the separating arrangement  94 .  
         [0032]    The arrangement of the sheet metal driver  64  is selected in such a way that the points of the projections  72  come to lie on the contact plate  60  close to its sharp bend when the enveloping arrangement  28  is in its non-operating or waiting position shown in the drawing in solid lines.  
         [0033]    In the embodiment shown, the actuating arrangement  46  is configured as an electrically or hydraulically operated linear motor that is supported in bearings at one end on the side walls  30  and that engages with its other end in a bearing  74  on the arms  56  of the guide arrangement  42 .  
         [0034]    The steering arms  48  are configured as straight struts or rods that extend between a bearing  76  in the region of the sharp bend in the arms  56  and the bearing  68  on the end of the arms  62 , and in each case are connected with these, free to pivot.  
         [0035]    The contact pressure arrangement  50  and the covering  52  are described in great detail in U.S. patent application Ser. No. 10/377,961, filed 28 Feb. 2003, and are used to retain the supply roll  54  at all times in contact with the feed roll  40  by means of the weight of the covering  52  and to protect the enveloping arrangement  28  against the dirt-laden surroundings.  
         [0036]    A sheet metal covering extends between the side walls  30  over a part of the opening  36  that prevents any of the crop to be baled from escaping from the baling chamber  18  during the baling process, but permits the access of the run of enveloping material  34 .  
         [0037]    On the basis of the foregoing description, the enveloping arrangement  28  according to the invention operates as follows.  
         [0038]    Starting with a fully formed bale  32  being located in the baling chamber  18 , as shown in FIG. 1, an enveloping process can then begin. The enveloping arrangement  28  assumes the solid-line position shown in FIG. 2, but is not yet operating. The run of enveloping material  34  is wrapped around a supply roll  54  resting on the support  38 , and a partial section withdrawn from it lies upon the feed roll  40  and the contact plate  60 , and reaches slightly beyond the contact plate  60 . The points of the projections  72  engage the contact plate  60  and penetrate through the run of enveloping material  34 . The actuating arrangement  46  is extended and the feed roll  40  is not in operation.  
         [0039]    If the enveloping process is to be initiated from this non-operating condition, the actuating arrangement  46  is retracted, which has the effect that the guide arrangement  42  pivots downward in counterclockwise direction about the bearing  58  and thereby moves the contact plate  60  away from the projections  72 . Due to the connection over the steering arms  48 , the withdrawal arrangement  44  will also pivot downward in the clockwise direction about the bearing  66  and carry along the run of the enveloping material  34  it was hooked into. Simultaneously, the roll  40  is brought into rotation and thereby supports the advancing movement of the run of the enveloping material  34 . Following this, the roll  40  is braked so that it applies a braking force to the run of the enveloping material  34  in order to apply tension to it during the process. When the withdrawal arrangement  44  or the points of the projections  72  have reached their end position, the end of the run of enveloping material  34  is in the region of the circumferential surface of the bale  32  that is rotating in the baling chamber  18 , by which it is grasped and is carried along. This end position is made clear by the thin dashed lines in the drawing. As soon as the run of enveloping material  34  is grasped by the stalks projecting above the circumferential surface of the bale  32 , it is carried along by it until an adequate covering is attained. This is the case after approximately two rotations of the bale  32 . The wrapping or enveloping process is ended by extending the actuating arrangement  46 , whereby the withdrawal arrangement  44  moves towards the contact plate  60  in the counterclockwise direction, which then pivots in the clockwise direction. Thereby, the edge  70  or the projections  72  formed in it presses the run of enveloping material  34  against the surface of the contact plate  60 , retains it there, and produces a tension in it that finally leads to its tearing off. In this situation the contact plate  60  and the sheet metal drivers  64  interact and operate as the separating arrangement  94 . The run of enveloping material  34  will tear along an irregular line and will hang over the edge of the contact plate  60 . In this condition, the drive of the feed roll  40  is also turned off again.  
         [0040]    [0040]FIG. 3 shows an embodiment of the enveloping arrangement  28  that deviates slightly from that shown in FIG. 2, but follows the same principle. In place of the steering arm  48 , a steering arm system  80  is provided that includes a first steering arm  82  and a second steering arm  84 , and that can be loaded by a driver  86 .  
         [0041]    A further difference lies in the fact that the contact plate  60  contains an L-shaped retaining angle  88  that extends parallel to its lower edge, and that lies upon the lower bent leg of the contact plate  60  at an angle of approximately  450  so that its corner touches the contact plate  60 .  
         [0042]    The first steering arm  82  engages with one end in the region of the sheet metal driver  64 , free to pivot, with the shortened arms  62  that furthermore can pivot about the bearing  66 . At its other end, the first steering arm  82  is connected in a joint in a bearing  90  with an end region of the second steering arm  84 . The other end region of the second steering arm  84  engages the bearing  58 , free to pivot, about whose region the guide arrangement  42  pivots.  
         [0043]    The driver  86  is connected, torsionally rigid, with the guide arrangement  42  and is in contact with the underside of the second steering arm  86  between its end regions. Accordingly, a downward pivoting movement of the guide arrangement  42  also brings about a downward movement of the driver  86 , which the second steering arm  84  can follow about the bearing  58  on the basis of the force of gravity acting on the withdrawal arrangement  44 . On the other hand, at the end of the enveloping process and during the separation, there occurs an active effect of the driver  86  upon the underside of the second steering arm  84  which forces the latter to pivot upward and thereby to bring the withdrawal arrangement  44  into contact with the contact plate  60 .  
         [0044]    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.