Abstract:
An arrangement is proposed that responds to the upward movement of a discharge gate, which forms a rear housing section of a baling chamber to the cylindrical bale in such a way that contact elements of the arrangement are pressed into the surface of the cylindrical bale, preferably by means of a servo motor, in order to reliably grasp the cylindrical bale and move it together with the gate until the bale is free of a fixed forward section of the baling chamber.

Description:
FIELD OF THE INVENTION 
   The invention concerns an arrangement to support the ejection of a cylindrical bale from a large round baler and a large round baler equipped with such an arrangement. 
   BACKGROUND OF THE INVENTION 
   DE-A1-32 47 661 discloses a large round baler with a plunger that is inserted into the forward housing section when the rear flap is opened, in order to force out a cylindrical bale located in the baling chamber. 
   DE-A1-32 34 748 reveals a large round baler with plates in the forward lower regions of the inner surfaces of the opposite side walls of a rear discharge gate that should reduce the friction between the cylindrical bale and the forward side walls of the baling chamber as well as increase the friction between the cylindrical bale and the rear side walls, whereby the ejection of the cylindrical bale is to be improved. 
   The problem underlying the invention is seen in the fact that the first noted arrangement is too costly and the second is too ineffective. 
   SUMMARY OF THE INVENTION 
   According to the present invention, there is provided an improved structure for aiding in the discharge of a large round bale from the baling chamber. 
   An object of the invention is to provide the rear, movable discharge gate section of the baling chamber of a large round baler with a contact element or device used to grasp the cylindrical bale actively, particularly beyond the friction already existing, and to pull it out of the forward housing section. The contact element may be configured selectively and even adjustable in its shape, its ability to pivot and in its contact force or the depth of its penetration, and thereby conform to the weight of the cylindrical bale or to the resistance of the bale to movement. Here consideration must be given to the fact that a bale composed of straw weighs considerably less than a bale composed of silage. The secure grasping of the cylindrical bale also avoids the possibility that the bale remains caught during the ejection on rotating baling components, for example, rollers, and that a net or the like applied to the bale is damaged. The contact element may be configured in the form of a tooth, a tine, a barb, or the like, in such a way that the contact element presses against and penetrates into the end face or circumferential surface of a bale. The adjustment path of the device may amount to approximately 5 cm. to 15 cm. depending on the weight or the resistance to movement of the cylindrical bale. This dimension is selected in such a way that the cylindrical bale is no longer retained by the discharge gate and falls to the ground on the basis of its weight or under some control after a certain path of the discharge gate has been covered that corresponds to a safe movement of the cylindrical bale out of the baling chamber. Such an arrangement can be subsequently applied to existing large round balers after their manufacture or may be integrated into the production of new large round balers. 
   In its simplest form, the contact element may be configured as a barbed hook that grasps or clamps the cylindrical bale, particularly its end face or circumferential surface, when the discharge gate is raised and thereby carries the bale along. If the movement is performed under outside force, for example, a spring, a motor, or actuated by an operator or as a result of linkages actuated by movement, the force as well as the time of actuation can be influenced or controlled. The surface of the contact element that touches the cylindrical bale may be smooth, coated or even profiled, in order to obtain an optimum contact with the cylindrical bale. 
   If the contact element can be brought into contact with the cylindrical bale or penetrate the bale by means of a servo motor, the path over which the cylindrical bale is carried along can be controlled extremely well. If necessary, the servo motor may also be moved in both directions so that a net extending partially over both end faces of the cylindrical bale is not damaged when the bale slides out of the discharge gate. 
   The servo motor may be configured as a hydraulic, pneumatic or electric motor, which depends on the forces that must be transmitted and which sources of force are available. 
   The clamping or retaining effect can be increased by the provision of several contact elements, for example, one on each side and/or several per side. 
   If a large round baler is equipped with at least one contact element in at least one side wall of a rear pivoted discharge gate, a reliable emptying of the baling chamber at the end of the baling process is assured. 
   The use of a common energy source and particularly a common control of the servo motor for the contact element or elements and the discharge gate has several advantages. On the one hand, its own energy source, that is, an additional energy source and/or control arrangement is avoided, which reduces the cost. On the other hand, then an increased contact force can be applied, if both servo motors are included in a series or a parallel circuit and the resistance to movement of the discharge gate is in direct proportion to the weight of the cylindrical bale and its clamping force on the side walls of the discharge gate. Hence, if the cylindrical bale is clamped strongly in the forward housing section of the baling chamber and/or is particularly heavy, then the contact elements will apply increased force to the cylindrical bale or penetrate into it and assure its being carried along by the movable housing section or discharge gate. 
   The servo motor or motors for the contact elements are supplied together with the servo motors for the movable housing section or discharge gate but may be already deactivated at a point in time at which the first are still actuated. This is possible because the cylindrical bale need be moved only so far that is has been extracted from the forward fixed housing section. The control can be performed by means of a valve, by means of a mechanical overload protection device or the like. 
   If a wall of the large round baler that engages the contact element is configured in such a way that, in its non-operating position, the contact element does not project appreciably within the inner surface of the wall. This avoids any damage to the surface of the cylindrical bale, the net, the foil or the yarn during the baling process, the binding or the wrapping process. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawing shows an embodiment of the invention that shall be described in greater detail in the following. 
       FIG. 1  is a schematic, right side view of a large round baler with an arrangement to aid the ejection of a cylindrical bale from a baling chamber. 
       FIG. 2  is an enlarged, right side view of the arrangement of  FIG. 1  shown in an out-of-service position. 
       FIG. 3  is an enlarged perspective view of the arrangement of  FIG. 2  and showing the arrangement in an operating position. 
       FIG. 4  is a top view of the arrangement of  FIG. 2 , but showing the actuator in longitudinal section. 
       FIG. 5  is a top view of the arrangement of  FIG. 2 , but showing the arrangement in an operating position. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to  FIG. 1 , there is shown a large round baler  10  with an arrangement  12  for enclosing a cylindrical bale with wrapping material while the bale is located in the large round baler  10 . 
   The large round baler  10  includes a frame  14  that is supported by wheels  16  on the ground and that can be coupled by a towbar  18  to a towing vehicle. A baling chamber  20  is formed in the large round baler  10 , with the chamber  20  being defined by a plurality of rollers  22  arranged in a circular pattern. As seen in  FIG. 1 , an inlet  24  for harvested crop is located at a nearly five o&#39;clock position of the chamber  20  through which harvested crop is supplied. The frame  14  is subdivided into a rear housing section or discharge gate  26  that can be pivoted vertically, and a forward, fixed housing section  28 , each of which carries approximately one-half of the rollers  22  arranged around one part of a circle arc. The harvested crop is raised from the ground by means of a pick-up  30  and conveyed to the rear to the harvested crop inlet  24 . In this embodiment a cutter head  32  is provided between the pick-up  30  and the harvested crop inlet  24 , which, however, is not mandatory in any way. In place of the configuration shown, another could be selected in which the baling chamber  20  is not surrounded by pulleys  22 , but by belts, bar chains or a mixture of these two. Therefore the baling chamber  20  may be configured as variable or fixed in its size. 
   The arrangement  12  is representative of any possible arrangement for enclosing the cylindrical bale with yarn, net, foil or the like. 
   The baling chamber  20  contains a finished cylindrical bale  34  that is indicated by dashed lines. 
   Provided at each side of the large round baler  10 , for the purpose of raising the discharge gate  26  when a cylindrical bale  34  is to be ejected from the baling chamber  20 , is a servo motor  36  which extends between the forward, fixed housing section  28  and the discharge gate  26 . 
   So far the large round baler  10  described here corresponds to a conventional configuration. 
   Finally, and according to the invention, an arrangement  38  is provided for aiding in the ejection of the cylindrical bale  34  from the baling chamber  20 . The arrangement  38  is located in the rear housing section or discharge gate  26  in the lower front region of the discharge gate  26 . The arrangement  38  is described in greater detail in the following on the basis of  FIGS. 2–5 . 
   The arrangement  38  includes a retainer  40 , a first pin  42 , a second pin  44 , a servo motor  46 , a third pin  48 , a line  50 , an energy accumulator  52  and a contact element  54 . 
   Such an arrangement  38  can be provided a number of times per side or only once on a single side. 
   The arrangement  38  is attached to the outer side or surface of a side wall  56  of the rear housing section  26 , which, for this purpose is provided with an opening  58 . 
   The retainer  40  is defined by an outwardly opening channel member having spaced, parallel legs that are joined to a web fastened to the outer side or surface of the side wall  56 , for example, welded. The legs of the channel member are penetrated by two sets of bores, not described in any further detail, that are respectively used to receive the first and the second pins  42  and  44 . The bores or openings for the first pin  42  are located in a rear end region of the retainer  40  spaced rearward from the opening  58 , and the openings for the second pin  44 .are located in the region of the opening  58 . The bores are located on axes that extend generally vertically and parallel to the outside of the side wall  56  and parallel to each other. The retainer  40  is formed in such a way that the servo motor  46  can be mounted between its legs, free to move. 
   The first pin  42  is used as an axle or a shaft and is used to pivotally mount the servo motor  46  to the retainer  40 . The pin  42  is secured to the retainer  40  in the usual manner, for example, with cofter pins, threads or the like. 
   The second pin  44  is configured and secured in the same way as the first pin, but is used for the retention of the contact element  54 , so that it can move. Accordingly, the second pin  44  is engaged in bores that are adjacent one edge of the opening  58 . 
   In this embodiment, the servo motor  46  is configured as a single-acting hydraulic motor that is connected to the hydraulic system for the servo motor  36  of the rear housing section or discharge gate  26 . An energy accumulator  52  operates in the servo motor  46  which is pictured here as an internal helical compression spring. Since the contact element  54  can alone be brought into its out-of-service position as a function of the orientation of the contact element  54  and the direction of rotation of the cylindrical bale  34 , such an energy accumulator  52  is not always required. On the other hand, such an energy accumulator  52  may be configured as a pneumatic device or as an extension spring and/or be located on the outside of the servo motor  46 , or it may act upon the contact element  54  or the like. Finally, the servo motor  46  may also be configured as a double-acting servo motor  46 , in case this should be required. The only task consists of pulling the contact element  54  out of the baling chamber  20 , in case this should become necessary. The servo motor  46  is connected over the line  50  to a line  60  at the servo motor  36 , in particular in a parallel circuit; but a connection in a series circuit would also be possible under certain circumstances. The line  50  permits valve controlled pressurized fluid to flow into the servo motor  46 , which opposes the energy accumulator  52 . The task of the servo motor  46  is to press the contact element  54 , that is, its part in the baling chamber  20 , into the baling chamber  20  or into the end face of the cylindrical bale  34 . 
   The third pin  48  penetrates a piston rod  62  of the servo motor  46  parallel to the pins  42  and  44  and connects these, free to pivot, with the section of the contact element  54  located outside the baling chamber  20 . This pin  48  is also secured in a conventional manner and can be used as an axle or a shaft. 
   The contact element  54  is configured as a plate that is stiff in bending and is bent approximately at its middle through about  800 . The contact element  54  is supported in bearings, free to pivot, in the retainer  40  in the region of the bend by means of the second pin  44 . The contact element  54  includes a flat section located in the baling chamber  20 , that is engaged on the inner surface of the side wall  56  or in a pocket formed in it, and a section secured on the piston rod  62 , free to pivot. The section located in the baling chamber  20  is large enough to be forced into the end face of the cylindrical bale  34  to a depth, for example, of approximately  70  mm. In the region of its bend, the contact element  54  penetrates the opening  58 . 
   On the basis of the foregoing description the arrangement  38  operates as follows. 
   The arrangement  38  begins with a condition that is shown in  FIGS. 1 ,  2  and  4  and in which a cylindrical bale  34  is finally finished in the baling chamber  20  and awaits its ejection. 
   Beginning with this condition, pressure is applied to the line  60 , so that the associated servo motor  36  extends and pivots the rear housing section  26  upward. On the basis of the connection of the lines  50  and  60 , pressure is also applied to the servo motor  46  which thereby separates the contact element  54  from the second pin  44 , so that the section located in the baling chamber  20  moves away from the inner surface of the side wall  56  and is forced into the side surface of the cylindrical bale  34 . Hence, while the housing section or discharge gate  26  is being raised, the cylindrical bale  34  is grasped by means of the contact element or elements  54  and is pulled out of the forward housing section  28 . Thereby the supporting pressure of the cylindrical bale  34  on the rearmost lowest roller  22  of the forward housing section  28  is simultaneously reduced. At the same time, the same pressure is applied to both servo motors  36  and  46 . As soon as the cylindrical bale  34  has been pulled out of the forward housing section  28 , it can no longer be held by the contact elements  54  and falls to the ground out of the rear housing section  26 . In the one case in which the large round baler  10  is provided with a device, not shown, that permits the application of net or foil not only to the circumferential surface but also at least partially to the end face of the cylindrical bale, the servo motor  46  is preferably configured or controlled in such a way that it can withdraw the contact element  54  rapidly when the cylindrical bale  34  begins to slide. In this way any damage to the net or foil applied to the end face of the cylindrical bale  34  is avoided. 
   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.