Abstract:
Cutting devices are known in rectangular baling presses that can be taken out of operation so that cut or uncut harvested material is selectively pressed. However, this is disadvantageous since it is difficult to hold cut harvested material together with binder twine under high tension. A rectangular baling press is proposed in which the cutting device is taken out of operation at least at the start and end of bale formation so that the twine presses only against uncut material at the end of the bale. The cutting device may additionally be taken in and out of operation during formation of the bale so that upper and lower layers of the bale are also formed by uncut material.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention concerns a rectangular baling press with a pressing area, a supply channel, a binding device and a cutting device upstream of the pressing area.  
         BACKGROUND OF THE INVENTION  
         [0002]    EP A2 11 33 914 discloses a rectangular baling press with a cutting device that can be taken out of operation so that cut or uncut harvested material can be selectively pressed.  
           [0003]    According to EP B1 341 508 the cutting device of a heavy-duty baling press is disabled at the end of the formation of a round bale in order that premature separation of the round bale does not occur after it leaves the pressing chamber.  
         SUMMARY OF THE INVENTION  
         [0004]    The invention is based on the problem that bales of cut harvested material are difficult to hold together with binder twine Under high tension.  
           [0005]    The invention solves this problem by providing a control so that the cutting device is entirely or partially disabled at the start and at the end of the formation of a bale.  
           [0006]    In this manner, the formed bale does consist substantially of cut harvested material but the binder twine rests on uncut sections so that the bale does not break apart under the high tension forces of the twine.  
           [0007]    There are various possibilities of forming a rectangular bale. Usually, several packets are pre-compressed and inserted as a stack into the pressing area. It is basically sufficient in this case if the first and last packet in a bale consist of uncut material. In other cases, material to be pressed is introduced continuously into the pressing area, e.g., when feeding takes place axially with a worm. In this case, the thickness of the uncut beginning and ending sections is proportional to the feed time of the material so that the cutting device is taken out of operation for a certain time, which corresponds to a certain thickness of the section of uncut material.  
           [0008]    Since the pressing operation is controlled or regulated on the basis of various constantly monitored parameters of the rectangular baling press, it is logical to also use these parameters, which are furthermore used for a synchronous flow of the movements of the pressing components, binding components and supply components, for the control or regulation of the cutting device. The activation and deactivation of the cutting device can accordingly take place either mechanically via a linkage or the like, or electrically by means of sensors, switches or the like. An optimization is achieved in particular in the case of a rectangular baling press without heap-like feeding of material by taking several parameters into consideration, e.g., a measuring wheel that determines the beginning of a bale and applied pressure that determines the approaching end of a bale.  
           [0009]    It is also conceivable, depending on the desired or acceptable proportion between cut and uncut harvested material, to collect uncut harvested material not only on the front surfaces of the bale but also on its top and its bottom. In this manner no harvested material is lost during the further handling of the bale, e.g. during transport or during winding. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The drawing shows an embodiment example of the invention described in detail below.  
         [0011]    The sole FIGURE of the drawing shows a rectangular baling press in a schematic side view. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0012]    The drawing shows a rectangular baling press  10 , for producing rectangular bales, that comprises a frame  12  supported on ground by a tandem arrangement of support wheels  14 . A draft tongue  16  is connected to the frame  12  and extends from the latter to the front and is designed in such a way that it can be connected to a towing vehicle such as a tractor, which is provided with a power take-off shaft for supplying power to drive various driven components of the rectangular baling press  10 . Pressing area  18  or a chamber with a rectangular cross section is partially formed by an upper housing part  20  and a lower housing part  22 . The lower housing part  22  is provided with material inlet  24 , to which a curved supply channel  26  is connected, which functions as a pre-pressing area as described in the following. A receiving device  28  includes a pick-up and a center-feed auger arranged upstream of the supply channel  26  in order to lift a swath of harvested material from the ground and deliver it to a compressing fork  30  that serves to compress harvested material into the supply channel  26  until a load with a determined density has collected upstream of fingers  32  of a retention device  34 . The retention device  34  is pivotably mounted to move between a retaining position, in which fingers  32  extend into supply channel  26  in the vicinity of material inlet  24 , and a supply position, in which the fingers  32  are retracted from the supply channel  26  in order to make it possible for the load of harvested material to be pushed through material inlet  24  into pressing area  18  by a loading fork assembly  36 . A spring-loaded flap  38  is pivotably mounted in a lower front position of the supply channel  26  and pivots as a function of the pressure from the harvested material present in supply channel  26 . Once the harvested material has reached the desired density, an electric control circuit (not shown) is supplied with current that produces appropriate drive connections that first causes retention device  34  to move in such a way that it retracts fingers  32  from the blocking position, as shown in the drawing, and then loading fork assembly  36  is activated in such a way that its forks  30  slide through supply channel  26  and move the load of harvested material into pressing area  18 . Once the load of harvested material has been pushed into pressing area  18 , a plunger mechanism  40  arranged in a forward location of the frame  12  is actuated in a controlled sequence according to the loading fork assembly  36  in order to move the harvested material to the rear into pressing area  18 , by way of a pressing plunger  48 , where it is compressed into a bale  46 , as is well known from the prior art. After the started bale  46  has reached a pre-selected length, a binding device  42 , that supplies binder twine and comprises several curved needles  68 , is activated in order to supply several strands of twine to an appropriate number of tying devices (not shown) that function in such a way that they place lengths of twine around the pre-selected length of the bale in order to form a bound bale  44  ready for unloading, which takes place when bale part  46  is pressed out of the rear part of pressing area  18  as new loads of harvested material are being pushed into pressing area  18 .  
         [0013]    Reference to the details of the plunger mechanism  40  shows that it comprises the pressing plunger  48  arranged for a back-and-forth motion in the pressing area  18  between a withdrawn position in front of material inlet  24  and an extended position above material inlet  24 . This motion of the pressing plunger  48  causes loads of harvested material from the supply channel  26  to enter the pressing area  18  and be compressed against previously introduced harvested material, including partially formed bales  46  and/or complete bales  44 .  
         [0014]    A cutting device  50  is provided between the receiving device  28  and the compressing fork  30  in a known manner. In the present embodiment example, the cutting device  50  is designed in such a way that it transports in an undershot fashion, however, this is not obligatory. This cutting device  50  comprises a comb rotor  52  and knives  54  that can be brought, preferably together, into or out of engagement with comb rotor  52  by a positioning device  56 .  
         [0015]    Finally, a control device  58  is provided that is connected on the one hand for receiving input signals from a sensor  59  at a measuring wheel  60 , and to a sensor  61  at the loading fork assembly  36 , and on the other hand for delivering a control signal to the positioning device  56 . The measuring wheel  60  is used for determining the length of a bale  46  being formed with the sensor  58  sensing the movement of the wheel  60 . The sensor  59  senses the position of the loading fork assembly  36 . Instead of, or in addition to, the measuring wheel  60  and loading fork assembly  36 , the control device  58  could also be connected to (not-shown) sensors for determining the pressure of the plunger mechanism  40  and the position of flap  38 , or to other sensors that could furnish information about the formation of the bale  46 .  
         [0016]    The following operation results from the foregoing.  
         [0017]    It is assumed that the control device  58  is adjusted in such a way that the first and last sections of bales  44  and  46  should not consist of cut harvested material. In this case, the measuring wheel  60  or a sensor (not shown) arranged thereon supplies a signal to the control device  58 , after which the formation of a new bale  46  begins. This signal is processed by the control device  58  and output to the positioning device  56 , which retracts the knives  54  from the supply channel  26  to an inactive position so that the comb rotor  52  only advances but does not cut the received harvested material. As soon as this uncut harvested material is introduced into the pressing area  18  and is pressed by the pressing plunger  48  against the already formed bale  44 , the measuring wheel  60  rotates, thereby indicating to the control device  58  that the end section is formed by uncut harvested material. The control device  58  then actuates the control device  56  so that the knives  54  move into the supply channel  26  and cut all received harvested material. The supplying of cut harvested material takes place until it is determined on the basis of the revolutions of the measuring wheel  60 , or on the basis of another sensor, that the formation of bale  46  is reaching its final phase. When it does, the control device  58  again supplies the signal to the positioning device  56  to remove the knives  54  from the supply channel  26  so that even the last section consists of uncut harvested material.  
         [0018]    If it is desired to place uncut crop on the top and bottom of the bale  46  as well as on both ends of the bale  46 , the signals from the sensors  59  and  61  are processed by the control device  58  in such a way that after the initial layer of uncut crop is formed at the beginning of the new bale  46 , the positioning device  56  is caused to keep the knives  54  in their inactive position so that uncut crop will initially be conveyed into the supply channel  26  which now has its upper end closed by the retaining device  34 . After a short delay, the positioning device  56  will be actuated to move the knives  54  into their operating position for cutting the crop. This will continue until just before the crop collected in the supply channel reaches the predetermined density for effecting operation of the loading fork assembly  36 , as determined by the flap  38 . A signal generated by a sensor there (not shown) will then cause the control device  58  to actuate the positioning device  56  for withdrawing the knives  54 . This will result in uncut crop being loaded into a lower part of the channel  26  below a layer of uncut crop. When the predetermined density is reached, the retaining device  34  will retract and the loading fork assembly  36  will sweep the charge of crop into the pressing area  18 , with the process repeating until the control device  58  receives a signal from the sensor  59  indicating that the bale  46  is almost finished. The control device  58  will then cause the positioning device  56  to withdraw the knives  54  to their inactive position so that the forward end of the bale  46  is supplied with uncut crop. Then the entire procedure is repeated during the formation of the next bale.  
         [0019]    Alternatively to the embodiment example presented, the cutting device  50  can also be designed in such a way that not all of the knives  54  but only a few of them are removed from the supply channel  26 .  
         [0020]    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.