Abstract:
A belt tracking control device for a conveyor device is provided, in particular for agricultural round balers, having at least one roller and at least one traction element which is guided over the roller and having at least one edge region which extends from the side edge of the traction element in the direction of the width thereof. At least one guide roller is provided through which the edge region can be deflected from the movement plane of the traction element.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a belt tracking control device, in particular for round balers, having at least one roller and at least one traction element which is guided over the roller and having at least a first edge region which extends in a transverse direction with respect to the longitudinal direction of the traction element. 
       BACKGROUND OF THE INVENTION 
       [0002]    Conveyor devices with traction elements are used, in particular, for transporting loose conveyed material, such as bulk piece goods. For this purpose, the conveyor devices have traction elements, in particular flat belts, warp knit fabrics or the like which carry the conveyed material or acts on it or picks it up. The traction element is guided or deflected by way of rollers. 
         [0003]    Such conveyor devices are used, for example, in agricultural round balers which pick up straw or hay as the conveyed material, in order to wind the material into the shape of a round bale. 
         [0004]    In particular in round balers, it is necessary to feed the conveyed material uniformly, since the external shape of the round bale is dependent upon the uniformity of feeding of the material to be pressed. 
         [0005]    When the conveyed material is fed in a non-uniform way, the traction element is loaded on one side. In addition to the movement component in the running direction of the traction element, one-sided loading also results in a movement component which runs transversely with respect to the direction of movement and by which the traction element is moved on the roller in the direction of the rotational axis thereof. This oblique running of the traction element can lead to tearing of the traction element or to crossing over of adjoining traction elements which run parallel to one another. 
         [0006]    In order to avoid oblique running of the traction elements it is known from the prior art to arrange, at the side edges of the traction elements, guide strips which extend in a direction parallel to the running direction of the traction elements and prevent a movement of the traction elements which are directed transversely with respect to the latter. 
         [0007]    Owing to the friction between the side edge of the traction elements and the guide strip, the traction elements are subject to more rapid wear than would be the case without the guide strips. Furthermore, guide strips also generally constitute collecting points for circulating conveyed material, and this can lead to blockages. 
       SUMMARY OF THE INVENTION 
       [0008]    The object of the present invention is therefore to provide a belt tracking control device which loads the traction elements mechanically only to a small extent and prevents blockage of conveyed material. 
         [0009]    The belt tracking control device comprises at least one roller and at least one traction element which is guided over the roller. In this context it is known, in particular because of round balers, that the traction element is guided over the roller from a first movement plane into a second movement plane. 
         [0010]    According to the invention, the traction element has a first edge region which extends from the first side edge of the traction element in a longitudinal transverse direction with respect to the latter. The longitudinal direction of the traction element corresponds here essentially to the running direction provided for the traction element. 
         [0011]    According to the invention, at least one guide roller is provided by which the first edge region can be deflected out of the respective movement plane of the traction element. The guide roller acts on the surface of the traction element in the edge region thereof. 
         [0012]    The deflection of the edge region causes the side edge of the traction element to be offset in the axial direction of the roller as the edge region runs onto the roller. As a result of this offset of the side edge, the traction element is pushed in the axial direction of the roller as it runs onto the roller, as a result of which the course of the traction element is corrected by means of the roller and oblique running of the traction element is prevented. 
         [0013]    Furthermore, the deflection by the guide roller causes the tensioning in the edge region of the traction element to be increased. In an effort to reduce the tensioning, the traction element therefore moves in the axial direction of the roller in order to reduce the magnitude of the deflection of the edge region. 
         [0014]    In addition to essentially cylindrical casing shapes, the roller can also have other shapes such as, for example, a convex shape. Since belt-like traction elements tend to run over the highest point of a roller, a convex section on the roller causes the traction element to be centered on the roller. 
         [0015]    The traction element may be, for example, a flat belt or ribbon belt on a rubber basis with one or more layers of plastic fibers and preferably having a patterned surface. 
         [0016]    According to the invention, the guide roller can be mounted in a cantilevered fashion, as a result of which circulating conveyed material is prevented from collecting and a self-cleaning effect is brought about. 
         [0017]    According to a further embodiment of the invention, the guide roller is arranged upstream, i.e. in front of the roller in the movement direction of the traction element. As a result of this arrangement, a small deflection of the edge region is already sufficient to correct the course of the traction element over the roller. 
         [0018]    According to the invention it is possible to provide that the guide roller can be moved relative to the roller. As a result, the magnitude of the deflection of the edge region of the traction element can be varied. The magnitude of the deflection of the edge region determines the offset of the side edge as it runs onto the roller in the axial direction thereof. 
         [0019]    The adjustment of the guide roller relative to the roller can be carried out manually from an active position into an inactive position, wherein in the inactive position the edge region of the traction element is not deflected out of the movement plane of the traction element. Furthermore, the adjustment of the guide roller can also be carried out as a function of the course of the traction element on the roller, as a result of which, when a control device is used, there is the possibility of automatically correcting the course of the traction element during the operation of the conveyor device. 
         [0020]    According to the invention, the casing shape of the guide roller can be essentially cylindrical or conical. A conical casing shape, the diameter of which becomes smaller from the side edge over the width of the traction element, causes the magnitude of the deflection of the traction element to decrease continuously from the side edge in the direction of the width thereof. 
         [0021]    According to the invention, the rotational axis of the guide roller can extend at an angle in a range from 20° to 45° relative to the movement plane of the traction element. As a result, the edge region is deflected to the greatest extent at the side edge, and the magnitude of the deflection of the traction element therefore decreases continuously in the direction of the width thereof toward the center. 
         [0022]    According to a further embodiment of the invention, the axis of the guide roller extends in a plane parallel to the movement plane of the traction element at an angle in a range from 5° to 15° with respect to the axis of the roller. 
         [0023]    Since multi-dimensional deflections with small radii always constitute increased material loading, the service life of the traction element is increased as a result of a continuous decrease in the magnitude of the defection of the traction element in the direction of the width thereof. 
         [0024]    Both the conical casing shape of the guide roller and the pivoting of the rotational axis of the guide roller with respect to the rotational axis of the roller cause the side edge to have a larger offset in the axial direction of the roller than the remaining edge region. 
         [0025]    Instead of the pivoting with respect to the rotational axis of the roller, the axis of the guide roller can, according to a further embodiment of the invention, extend in a direction parallel to the axis of the roller. 
         [0026]    According to one embodiment of the invention, the guide roller extends over at least a third of the width of the traction element. The guide roller can extend up to the center of the traction element here. 
         [0027]    According to the invention, the guide roller and the roller can be arranged on opposite sides of the traction element, as a result of which the guide roller and the roller are each assigned to opposite surfaces of the traction element. The edge region of the traction element runs onto the roller here before the rest of the section of the traction element comes into contact with the roller. 
         [0028]    Alternatively, it is also possible to provide for this purpose that the guide roller and the roller are arranged on the same side with respect to the traction element. As a result, when the traction element runs onto the roller the edge region is lifted therefrom. 
         [0029]    According to a further embodiment of the invention, it is possible to provide that the traction element has a second edge region which extends from the second side edge of the traction element transversely with respect to the longitudinal direction thereof, i.e. in the direction of the first side edge, and is deflected by a second guide roller. 
         [0030]    The deflection of the second edge region by the second guide roller causes the second side edge of the traction element to be offset in the axial direction of the roller as the second edge region runs onto the roller. As a result of this offset of the second side edge, the traction element is displaced in the axial direction of the roller as it runs onto the roller, as a result of which the course of the traction element over the roller is corrected and oblique running of the tension element is prevented. 
         [0031]    The deflection of the first and second edge regions on the traction element causes the course of the traction element to be corrected in both directions axially with respect to the roller. 
         [0032]    Where at least two traction elements which are guided largely parallel one next to the other are used, the second guide roller can be provided between the traction element, wherein the second guide roller deflects the edge regions, guided one next to the other, of the two traction element. According to the invention, the second guide roller can, for example, be in the shape of a double cone, with the edge regions of each traction element which run one next to the other each being assigned a conical section. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    Exemplary embodiments of the invention are described in detail below with reference to the accompanying drawings, wherein: 
           [0034]      FIG. 1  is a perspective schematic illustration of a traction element which is guided over a roller and is deflected by a guide roller; 
           [0035]      FIG. 2  is a lateral view of the traction element, the roller and of the guide roller from  FIG. 1  with a second roller; 
           [0036]      FIG. 3  is a plan view of the device from  FIG. 2 ; and, 
           [0037]      FIG. 4  is a plan view of two traction elements which are guided largely in parallel over two rollers the edge regions of which are deflected by respective assigned first and second guide rollers. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0038]      FIGS. 1 ,  2  and  3  show a traction element  10  with an edge region  16  which extends from the side edge  18  in the width direction, a first roller  12 , a second roller  26  and a guide roller  14 . For purposes of better illustration, the second roller  26  is not shown in  FIG. 1 . 
         [0039]    The traction element  10  is deflected over the second roller  26  and the first roller  12  in the direction of the arrow  20 . The rollers  12 ,  26  determine the movement plane of the traction element  10 , wherein the traction element  10  is pre-stressed by the rollers  12 ,  26 . In the illustration according to  FIG. 2 , the movement plane of the traction element  10  corresponds to the tangential plane which is formed by the rollers  12 ,  26  and which is indicated in  FIG. 2  by the dashed line  38 . 
         [0040]    In the movement direction of the traction element  10  in front of the first roller  12 , a guide roller  14  is arranged, the guide roller  14  acting on the surface of the traction element  10  in the edge region  16  thereof and deflecting the edge region  16  out of the movement plane  38  of the traction element  10  before the traction element runs onto the first roller  12 . The traction element  10  runs through here between the guide roller  14  and the first roller  12 . 
         [0041]    The guide roller  14  has a conical casing shape, wherein the diameter decreases in the width direction of the traction element  10 . The axis  24  of the guide roller  14  extends at an angle relative to the axis  22  of the first roller  12 , with the result that the magnitude of the defection of the edge region  16  decreases continuously starting from the side edge  18  thereof. The width of the deflected edge region  16  is determined by the width of the contact face of the guide roller  14  with the traction element  10 . 
         [0042]    As is apparent from  FIG. 2 , the edge region  16  is deflected out from the movement plane of the traction element  10 , with the result that the traction element  10  runs onto the first roller  12  starting from the first side edge  18 . 
         [0043]    Furthermore,  FIGS. 1 and 3  show that a lateral offset of the side edge  18  in the direction of the axis  22  of the first roller  12  additionally results from the deflection of the edge region  16  via the guide roller  14 .  FIG. 3  shows in this connection oblique running of the traction element  10  which is corrected by the deflection of the edge region  16 . 
         [0044]    In order to illustrate better the magnitude of the lateral offset  42  of the side edge  18 ,  FIG. 3  shows a dashed line  40  which indicates the course of the side edge  18 , as it would be if not for the deflection of the edge region  16  by the guide roller  14 . 
         [0045]    As can also be discerned from the illustration in  FIG. 3 , the first roller  12  and the second roller  26  are mounted so as to be rotatable between two side elements  28 ,  30 . The guide roller  14  is, on the other hand, mounted in a cantilevered fashion on just one of the side elements  28 . 
         [0046]    The side elements  28 ,  30  can, for example, be components of a frame of a round baler (not illustrated). 
         [0047]      FIG. 4  shows a further embodiment of the device which is illustrated in  FIG. 3  and in which, in addition to the traction element  10 , a second traction element  110 , a second guide roller  36  and a third guide roller  120  are also provided. 
         [0048]    The traction element  10  has, in addition to the edge region  16 , a second edge region  32  on the opposite side, which second edge region  32  extends from the second side edge  34  of the traction element  10  in the direction of the width thereof or in the direction of the side edge  18 . 
         [0049]    The second traction element  110  and the third guide roller  120  are arranged in mirror-symmetrical fashion with respect to the traction element  10  and the guide roller  14  in  FIG. 4 , wherein the second traction element  110  also has two edge regions  112 ,  116  which extend from the side edges of the traction element  110 . The edge region  112  of the second traction element  110  is assigned here to the third guide roller  120 , wherein the latter is deflected by the third guide roller  120 , like the edge region  16  of the traction element  10 . In order to avoid repetitions, reference is therefore made to the description of  FIGS. 1 to 3 . The function of the guide roller  14  which extends along the axis  24  and deflects the edge region  16  of the traction element  10  corresponds here to the function of the third guide roller  120  which extends along the axis  124  and which deflects the edge region  112  of the second traction element  110 . 
         [0050]    The second guide roller  36 , which is in the shape of a double cone, is arranged between the two traction elements  10 ,  110 . 
         [0051]    Each of the traction elements  10 ,  110  is assigned here a conical section  44 ,  122 , wherein the conical section  44  deflects the second edge region  32  of the traction element  10 , and the second conical region  122  deflects the second edge region  116  of the second traction element  110 . The axis  46  of the second guide roller  36  extends here essentially parallel to the axis  22  of the first roller  12 . 
         [0052]    The adjacent second edge regions  32 ,  116  of the traction element  10 ,  110  which run one next to the other are deflected by the second guide roller  36  in the same way as the edge region  16  of the traction element  10 . Reference is made in this respect to the description of  FIGS. 1 to 3 . 
         [0053]    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.