Abstract:
A front attachment for an agricultural harvesting machine operates independently of rows of stalk crop to be harvested. The front attachment includes harvesting devices for harvesting the stalk crop, intake conveyor mechanisms extending across a width of the harvesting devices, snapping devices located downstream of the intake conveyor mechanisms in the direction of the crop flow and a cross conveyor located downstream of the intake conveyor mechanisms and snapping devices. In the arrangement, the cross conveyor and snapping device driven by a common drive train, the front attachment is prefabricated to enable retrofitting with a second drive train and the second drive train functions as the drive for a retrofittable chopping device.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
       [0001]    The invention described and claimed hereinbelow is also described in German Patent Application DE 10 2012 10603.5, filed on Jul. 20, 2012. This German Patent Application, subject matter of which is incorporated herein by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d). 
       BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to a front attachment for an agricultural harvesting machine that operates independently of rows for harvesting stalk crop. 
         [0003]    Front attachments for agricultural harvesting machines are known. Document DE 102005021792A1, for example, describes a front attachment for use with a self-propelled harvesting machine such as a combine harvester or a forage harvester. The front attachment so discloses comprises intake conveyor and snapping units, which are disposed in pairs and are used to pick up and convey as well as harvest the stalk crop. A cross auger is disposed downstream of the intake conveyor and snapping units and feeds the crop to a feed rake, which feeds crop into the harvesting machine. A chopping device (designed as a cutting disc), is located underneath each of the intake conveyor and snapping units and separates the plant stalks from the stump, which remains in the ground. 
         [0004]    These components, i.e., the intake conveyor and snapping units, the cross auger and the cutting discs are driven by means of a common drive train. To this end, drive power provided by an internal combustion engine of the harvesting machine is transferred by a chain or a belt to a universal drive shaft of the front attachment. The universal drive shaft leads into a transmission housing (which houses a transmission), from which transmission the drive power is distributed to the components to be driven. The intake conveyor and snapping units are disposed in pairs and are connected to one another on the drive side by a continuous shaft extending across the width of the front attachment. Bevel gears branch off from the shaft to the respective intake conveyor and snapping units and to the particular cutting discs. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention overcomes the shortcomings of known arts, such as those mentioned above. 
         [0006]    In an embodiment, the present invention is a front attachment, which operates independently of rows, is characterized by simplified and cost-favorable design. 
         [0007]    In more detail, the inventive front attachment is prefabricated in such a manner that it can be retrofitted with a second drive train, which functions as a drive for a chopping device that can be retrofitted on the front attachment. The modularity is achieved by providing a second drive train and a chopping device, which can be retrofitted if necessary, resulting in a simpler and more cost-favorable design of the front attachment. 
         [0008]    This inventive front attachment so designed results in a high degree of flexibility in the use of the front attachment since, due to the modularity, the drive train comprising the chopping device is detachable in the same manner. The first drive train in particular (which is the common drive for the harvesting devices, i.e. the intake conveyor mechanisms, the snapping devices, and the cross conveyor) is dimensioned more cost favorably since the power requirement of the chopping device is disregarded in the design of the first drive train. The front attachment also displays a lower overall weight due to the elimination of the chopping device, which is not required in all harvesting conditions. 
         [0009]    A further advantage of the modularity of the inventive front attachment is that the basic output of the common drive train is lower for the intake conveyor mechanism, the snapping device, the cross conveyor and the second retrofittable drive train for the retrofittable chopping device than that of a single drive train for all components. 
         [0010]    Advantageously, the second drive train and the chopping device driven thereby can be designed as separate modules. The assembly and disassembly of the second drive train and the chopping device are thereby simplified. 
         [0011]    In particular, the first drive train and the second drive train comprise means for varying the speed that can be output to the driven assemblies. This feature enables separating the settability and adjustability of the drive speeds of the harvesting device and of the retrofittable chopping device, thereby improving the adaptability to changing harvesting conditions. 
         [0012]    The means for varying the speed that can be output to the driven assemblies permit a stepless or stepped adjustment of the speed. A variator transmission is preferably provided as the means for the stepless variation of the speed of the assemblies that can be driven separately by the first and second drive trains. As an alternative, a hydromechanical or electric drive solution that permits a stepless adjustment of the speed may be provided. For that matter, a manually adjustable belt drive may be provided to implement a stepped variation of the speed. The design of the drive trains having a means for the stepped or stepless adjustment of the speed permits flexible adaptation even to greatly varying harvesting conditions. 
         [0013]    Preferably, the chopping device is configured to be shifted independently of the harvesting conditions. By separating the drive trains from intake conveyor mechanisms, snapping devices and cross conveyor and from the chopping device, it is possible to shift the harvesting devices and the chopping device in succession. This feature is advantageous in particular upon engagement of the front attachment. For example, the chopping device can be engaged first, before the remaining harvesting devices of the front attachment are engaged using the first drive train, or vice versa. The load on the drive assembly (typically an internal combustion engine of the harvesting machine that accommodates and drives the front attachment according to the invention), is thereby reduced. 
         [0014]    The second drive train is shifted by disengaging and engaging a universal drive shaft in a tool-free manner. 
         [0015]    Alternatively, the second drive train is shifted using a central clutch. As a result, the amount of time required is markedly reduced compared to the prior art, which prior art requires that each unit of the intake conveyor mechanism and of the snapping device be coupled manually in order to engage and disengage the chopping device. In addition, the handling of this solution is substantially more convenient. A further advantage of the use of a clutch is that the modular design of the drive trains makes it possible to utilize an additional start-up clutch for limiting the maximum torque upon engagement or disengagement. To this end, a friction coupling can be installed in the second drive train, for example, which absorbs the frictional energy dissipated during shifting. 
         [0016]    The shifting procedure, moreover, may be carried out automatically in the invention. The clutch can be shifted from the driver&#39;s cab, thereby permitting the operator of the harvesting machine to remain therein. To this end, the operator actuates a switch, for example, which controls an actuator system for operating the clutch. The procedure for engaging the front attachment is optimized in that the second drive train for the chopping device is engaged first, before the intake conveyor mechanisms, the snapping devices and the at least one cross conveyor are operated in a second step. The inertial forces that load the drive are reduced as a result. 
         [0017]    Furthermore, a central free wheel mechanism is provided in the second drive train. The central free wheel mechanism helps to lower costs and reduce installation space and weight of the front attachment. 
         [0018]    Preferably, the chopping device comprises a transmission housing, which extends substantially across the width of the front attachment, and into which vertically extending knife shafts extend in sections. Also, bevel gears driving the knife shafts are disposed in the transmission housing. The transmission housing comprises all essential components of the chopping device, which can be combined in this manner to form one retrofittable assembly. 
         [0019]    In particular, a main transmission (which is a component of the second drive train), is disposed at the transmission housing. The main transmission, which can be coupled to a main drive shaft of the chopping device, in combination with further drive components, forms a further retrofittable assembly. This greatly simplifies the procedure for retrofitting the front attachment, i.e. for installing and deinstalling the chopping device and the second drive train. 
         [0020]    The transmission housing is designed as a frame member comprising at least one upper shell and one lower shell, which has flange connections. 
         [0021]    Advantageously, the upper shell is a component of a frame structure of the front attachment. 
         [0022]    Alternatively, the upper shell is subsequently attachable to the frame structure of the front attachment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    Further features and advantages of the invention will become apparent from the description of embodiments that follows, with reference to the attached figures, wherein: 
           [0024]      FIG. 1  depicts a schematic representation of a modular front attachment constructed according to the inventive principles; 
           [0025]      FIG. 2  presents a top view of a thusly designed front attachment in a position installed on a feed rake of a combine harvester; 
           [0026]      FIG. 3  presents a schematic representation, in a view from above, of a front attachment fastened on a feed rake; and 
           [0027]      FIG. 4  presents a schematic partial view of a frame structure of a modular front attachment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    The following is a detailed description of example embodiments of the invention depicted in the accompanying drawing. The example embodiments are presented in such detail as to clearly communicate the invention and are designed to make such embodiments obvious to a person of ordinary skill in the art. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention, as defined by the appended claims. 
         [0029]      FIG. 1  shows a front attachment  1 , which comprises, inter alia, a snapping device  2 , at least one cross conveyor  3 , and a chopping device  4 . The snapping device  2  and the at least one cross conveyor  3  are components of a harvesting device of the front attachment  1 , which, in addition to the chopping device  4 , are driven by a combine harvester, which is not shown in greater detail. The snapping device  2  and the at least one cross conveyor  3  are driven by a first driven mechanism  5  of the combine harvester using a first universal drive shaft  6 . This first universal drive shaft  6  is selectively coupled to the first driven mechanism  5  using a form-locking clutch  7 . For example, when the front attachment  1  is installed on the combine harvester, the universal drive shaft  6  is connected in a driving manner to the first driven mechanism  5  via the form-locking clutch  7 . The first driven mechanism  5 , the first universal drive shaft  6  and the clutch  7  form a first output train  35 , via which both the snapping device  2  and the cross conveyor  3  are driven. 
         [0030]    The first universal drive shaft  6  drives a hydraulic pump  9  via a belt drive  8 , wherein this hydraulic pump supplies pressure medium within the front attachment  1 . To this end, non-illustrated hydraulic circuits are provided, via which control functions are performed at the front attachment  1  using appropriate hydraulic valves. 
         [0031]    The universal drive shaft  6  is connected to a primary disc  10  of a variator transmission  11 , the variator transmission having a secondary disc  12  and a drive belt  13 . An output shaft  14  of the variator transmission  11 , which extends from the secondary disc  12 , extends to a first traction mechanism drive  15  comprising a belt drive  16 , which drives the snapping device  2 , and a chain drive  17 , which drives the cross conveyor  3 . An overload clutch  18  is disposed in the drive of the at least one cross conveyor  3 , wherein the overload clutch automatically interrupts the drive of the cross conveyor  3  when a torque value is exceeded. Further overload clutches  19  are assigned to individual snapping rollers of the snapping device  2 . 
         [0032]    A second drive mechanism  21 , at which a second universal drive shaft  22  engages, is provided opposite the above-described first drive mechanism  5 . This second universal drive shaft  22  is selectively coupled via a form-locking clutch  21   a  to the first driven mechanism  21 . The second universal drive shaft  22  drives the chopping device  4  via a belt drive  23  and a main transmission  24 . The second driven mechanism  21 , the clutch  21   a,  the second universal drive shaft  22 , the belt drive  23  and the main transmission  24  form a second output train  36 . The second output train  36  is used exclusively to drive the chopping device  4 . 
         [0033]    As shown in  FIG. 1 , main drive shafts  25  extend from the main transmission  24 , wherein these main drive shafts drive knives  20  of the chopping device  4  via vertically extending knife shafts  59 . Overload clutches  26  are located at the drives of the knife shafts  59 , which are in the form of bevel gears. Activation of the overload clutches  18 ,  19  or  26  is detected via a sensor system , thereby signaling a failure of individual snapping rollers, individual knife drives of the chopping device  4 , or the at least one cross conveyor  3  to the driver in the cab of the combine harvester. The main transmission  24  may comprise a steplessly variable transmission and alternatively, as a multistage transmission. 
         [0034]    The front attachment  1  is coupled to a feed rake  29  of the combine harvester. The feed rake  29  comprises a feed rake shaft  30 , which is driven via a main belt drive and drives conveyor chains in the interior of a feed rake housing  31 . The feed rake shaft  30  protrudes from the feed rake housing  31  on both sides and forms the driven mechanisms  5  and  21 . 
         [0035]      FIG. 2  also depicts the front attachment  1  with crop dividers  27 , downstream of which intake conveyor mechanisms  28  are disposed. The intake conveyor mechanisms grasp and guide the corn stalks. The intake conveyor mechanisms comprise conveyor discs  29  equipped on the circumference thereof with conveyor tines  31  and, are driven in pairs in opposing directions of rotation. The conveyor tines  30  move the corn stalks grasped by these conveyor tines through a conveyor channel  31 , at the end of which the corn stalks are received by snapping devices  2  extending transversely to the direction of travel of the combine harvester.  FIG. 2  shows the arrangement of the chopping device  4 . 
         [0036]      FIG. 2  also shows the front attachment  1  coupled to a feed rake  32  of a combine harvester. The feed rake  32  comprises a feed rake shaft  33 , which is driven via a main belt drive  33   a  and drives conveyor chains in the interior of a feed rake housing  34 . The feed rake shaft  33  protrudes from the feed rake housing  34  on both sides and forms the driven mechanisms  5  and  21 . The first universal drive shaft  6 , which extends to the primary disc  10  of the variator transmission  11 , is fastened at the driven mechanism  5  via the form-locking clutch  7 . Proceeding from this primary disc  10 , the drive torque is transferred via the drive belt  13  to the secondary disc  12 . The secondary disc is connected via the output shaft  14  to a drive pinion  37  of the chain drive  17 , which extends to the cross conveyor  3 . A chain  38  of this chain drive  17  drives a shaft  40  of the cross conveyor  3  via a driven pinion  39 . The belt drive  16  extends parallel to this chain drive  17 . The belt drive comprises a drive pulley  41 , which is connected in a rotationally fixed manner to the output shaft  14 , a drive belt  42  and a driven pulley  43 . The driven pulley is connected to a drive shaft  44  of the snapping device  2 . 
         [0037]    A second end of the feed rake shaft  33  protrudes beyond the feed rake housing  34  and is connected to a drive of the chopping device  4  (as described with reference to  FIG. 1 ). To this end, the corresponding second driven mechanism  21  is connected via the second universal drive shaft  22  to a drive pulley  47 . Drive pulley  4  drives the transmission  24  via a drive belt  48  and a driven pulley  49 . The transmission  24  is connected to the main drive shaft  25  of the chopping device  4 , which extends transversely to the direction of travel of the combine harvester (as described with reference to  FIG. 1 ). 
         [0038]      FIG. 3  presents a schematic view from above of a front attachment  1  fastened to a feed rake  29 . The  FIG. 3  representation shows the first drive train  35  only in part and shows the second drive train  36  in its entirety. As explained above, the snapping device  2  and the cross conveyor  3  are both driven via the first drive train  35 . The snapping device  2  comprises a snapping roller shaft and first snapping rollers  53  disposed thereon. These first snapping rollers  53  are connected in a driving manner via a gear pair  45  to second snapping rollers  54 . These second snapping rollers  54  are equipped at the ends thereof with auger sections for drawing in corn stalks and the like. 
         [0039]    The second drive train  36  can be retrofitted if necessary and is used exclusively to drive the chopping device  4 . The chopping device  4  comprises a transmission housing  50 . The transmission housing extends substantially across the width of the front attachment  1  and in which the main drive shaft  25  is disposed. The vertically extending knife shafts of the knives  20  extend into the interior of the transmission housing  50 , in which the particular drives of the knives  20  also are disposed, in the embodiment shown, the particular drives are designed as bevel gears. 
         [0040]    The transmission housing  50  forms a retrofittable assembly. The retrofittable assembly is installed onto or removed from the front attachment  1  in a relatively short period of time. The main transmission  24  is coupled to the main drive shaft  25  of the chopping device  4 , in combination with the second driven mechanism  21 , the clutch  21   a,  the second universal drive shaft  22  and the belt drive  23 , forming a further retrofittable assembly. This construction markedly simplifies the procedure for retrofitting the front attachment  1 , i.e., installing and deinstalling the chopping device  4  and the second drive train  36 . 
         [0041]    The transmission housing  50  is designed as a frame member  56  comprising at least two shells, i.e. a lower shell  58  and an upper shell  57  (as shown in  FIG. 4 ). The upper shell  57  is preferably a component of a frame structure  55  of the front attachment  1  or alternatively, can be configured to be subsequently fastened to the frame structure  55 . The lower shell  58 , in combination with the bevel gears, the knife shafts  59  and the knife carriers  69 , forms one unit that attaches at the upper shell  57 . The particular bevel gear is connected to the lower shell  58  via a flange connection  59 , thereby enabling the bevel gears to be replaced individually if necessary. The design of the part of the transmission housing  50  that carries the bevel gears has the advantage that components of the chopping device  4  are no longer installed individually. In addition, alignment errors of the shafts are reduced. 
       LIST OF REFERENCE SYMBOLS 
       [0000]    
       
           1  front attachment 
           2  snapping device 
           3  cross conveyor 
           4  chopping device 
           5  first driven mechanism 
           6  first universal drive shaft 
           7  form-locking clutch 
           8  belt drive 
           9  hydraulic pump 
           10  primary disc 
           11  variator transmission 
           12  secondary disc 
           13  drive belt 
           14  output shaft 
           15  traction mechanism drive 
           16  belt drive 
           17  chain drive 
           18  overload clutch of  3   
           19  overload clutch of  2   
           20  knife of  4   
           21  second driven mechanism 
           21   a  form-locking clutch 
           22  second universal drive shaft 
           23  belt drive 
           24  transmission 
           25  main drive shafts of  4   
           26  overload clutches of  4   
           27  crop divider 
           28  intake conveyor mechanisms 
           29  conveyor discs 
           30  conveyor tines 
           31  conveyor channel 
           32  feed rake 
           33  feed rake shaft 
           33   a  main belt drive 
           34  feed rake housing 
           35  first drive train 
           36  second drive train 
           37  drive pinion of  7   
           38  chain 
           39  driven pinion of  7   
           40  shaft of  3   
           41  drive pulley of  16   
           42  drive belt of  16   
           43  driven pulley of  16   
           44  drive shaft of  2   
           45  gear pair 
           47  drive pulley 
           48  drive belt 
           49  driven pulley 
           50  transmission housing 
           51  auger section 
           52  snapping shaft of  2   
           53  first snapping rollers 
           54  second snapping rollers 
           55  frame structure 
           56  frame member 
           57  upper shell 
           58  lower shell 
           59  knife shaft 
           60  knife carrier 
       
     
         [0103]    As will be evident to persons skilled in the art, the foregoing detailed description and figures are presented as examples of the invention, and that variations are contemplated that do not depart from the fair scope of the teachings and descriptions set forth in this disclosure. The foregoing is not intended to limit what has been invented, except to the extent that the following claims so limit that.