Abstract:
An articulated harvester includes a powered harvester having a pair of forward wheels or tracks, having a pair of rotatable rearward caster wheels, and carrying an on-board harvester grain bin for housing harvested grain. The harvester tows a grain cart, which carries a grain cart bin for housing harvested grain. A joint assembly interconnects the harvester and the grain cart. The joint assembly includes a grain cart tongue that mates with the harvester. An articulation cylinder assembly connects the harvester and the grain cart tongue in the region of the joint assembly. Bi-directional, biased guide rods connect between the grain cart tongue and the caster wheels. The grain car may be steerable and/or powered. The harvester may be steerable by its pair of forward wheels or tracks. A conventional harvester and grain cart assembly can be converted into the novel articulated harvester.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     None.  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH  
       [0002]     Not applicable.  
       BACKGROUND OF THE INVENTION  
       [0003]     The present invention generally relates to combines or harvesters that pull an integrated, often powered and steerable, grain trailer for extra storage capacity, and more particularly to a simple conversion thereof into an articulated harvester. For present purposes the term “harvester” will be used to include, inter alia, combines, corn pickers, harvesters, and like equipment that pick, harvest, or otherwise process grains in field. Often the term “combine” will be used herein; however, such use is by way of illustration and not by way of limitation.  
         [0004]     Modern grain combines, such as are used to harvest corn, wheat, soybeans, etc., and corn pickers, have significantly increased their throughput capability. These increases have resulted from improvements such as wider cutting heads and increased number of row units per machine in the case of row crops such as corn. The threshing and grain separating capacity of the machines has increased in parallel by building larger machines with higher horsepower engines.  
         [0005]     Concomitant therewith, the number of acres in the average North American farm has increased dramatically with crop fields becoming larger and longer. Fields with a row length of one-half mile have become quite common.  
         [0006]     The result of these simultaneous trends is that the amount of harvested crop or clean grain produced in one round or two lengths of the field has increased dramatically. The harvested grain must be carried along by the harvesting system until the end of the field is reached where it is transferred into a bulk transportation vehicle such as a truck (tractor-trailer or semi) or wagon. Combines have an onboard grain hopper in which to store the harvested grain until the end of the field has been reached. Seed corn pickers typically pull a trailer or wagon, or a truck is driven along side them to receive the grain.  
         [0007]     Due to increased combine throughput and long fields, virtually no combine commercially available today has sufficient capacity in its on-board hopper to store the corn harvested during one round of an 80 acre field or a field which is one-half mile in length with the crop yields typically found in the U.S. corn belt. The on-board primary storage hoppers are limited in capacity by the physical size of the machine and the total weight of the combine with a full hopper, which can be carried on 2 axles or 2 tracks in some cases.  
         [0008]     Farmers and farm equipment manufacturers have addressed this problem by developing intermediate transport grain carts or trailers, which are pulled by a separate tractor and operator. The grain cart/tractor combination is stationed at the opposite end of the field from the road transport (bulk storage) vehicle or along the length of the field to receive the grain from the combine when its primary hopper is full and before the combine reaches the end of the field where the road transport vehicle is located. The traditional grain cart has self-unloading capability usually in the form of an auger, conveyor, or side hydraulic dump mechanism, which receives power from the tractor. The grain cart/tractor combination typically carries the grain to the end of the field and loads it into the road transport vehicle, such as a semi-truck. Examples of such grain wagons can be found in U.S. Pat. Nos. 5,013,208, 5,340,265, and 5,409,344.  
         [0009]     Grain cart capacities typically vary from 400 bushels to 1000 bushels. Therefore, a loaded grain cart and pulling tractor may weigh as much as 90,000 pounds. Repeated trips across the field by this large vehicle combination can produce additional soil compaction, particularly in wet conditions, which reduces future crop yields. This method of intermediate storage and movement of grain with the field incrementally adds one operator and significant capital cost to the harvesting process.  
         [0010]     In the field of trailers or wagons that are towed by a farm tractor or over-the-road tractor-trailers (so-called “semis”), U.S. Pat. No. 2,667,028 shows a towable combine with an attached grain cart. U.S. Pat. No. 4,460,193 shows a pull type swather assembly, which can be crabbed. U.S. Pat. No. 4,359,854 shows a tractor drawn combine, which also can be crabbed. U.S. Pat. No. 5,412,929 shows the ability to steer a pair of rakes being towed by a tractor. U.S. Pat. No. 5,579,228 shows a servo steering control system for a non-powered trailer that includes forward and backward motion. U.S. Pat. No. 5,209,320 shows an articulated crop pesticide sprayer adapted to be pulled. U.S. Pat. No. 4,740,006 proposes to retrofit existing tractor-trailers with a remote-control steering system. Finally, U.S. Pat. No. 5,329,451 proposes a steerable trailer and steering apparatus, which includes a servo control.  
         [0011]     A significant advance in grain carts is disclosed in U.S. Pat. No. 5,904,365. Disclosed is a powered towing vehicle having steering wheels and a wheeled trailer is connected to the vehicle for its towing. The wheels of the trailer are connected to a source of power for generating forward and rearward movement of the trailer. These wheels also are connected to a source of power for turning such wheels in order to steer the trailer. These wheels further are connected to a sensor to sense the position of the trailer wheels as they are being steered. The steering wheels of the towing vehicle also are connected to a sensor to sense the position of the vehicle wheels as they are being steered. The trailer steering wheel sensor is displayed to an operator of the vehicle so that the vehicle operator knows the relative position of each of the steering wheels. The trailer steering power source is connected to the vehicle so that an operator of the vehicle can remotely steer the wheels of the trailer. Unloading of the grain takes place separately from both the combine hopper and from the grain cart.  
         [0012]     An improved grain handling assembly for a combine and grain cart combination is disclosed in application Ser. No. 10/247,249, filed on Sep. 19, 2002, the disclosure thereof being expressly incorporated herein by reference.  
         [0013]     Articulated combines can be found in U.S. Pat. Nos. 6,012,272, 6,125,618, 6,339,917, and subsequent divisional patents therefrom. Implementation of these articulated combines commercially requires new tooling and market acceptance; yet, the advantages of articulated vehicles is well known. The present invention, then, is addressed to retrofitting harvester/grain cart assemblies and converting them into articulated harvesters with the advantages attendant therewith. The present invention also is addressed to manufacturing (from scratch) such an articulated harvester as an original equipment item.  
       BRIEF SUMMARY OF THE INVENTION  
       [0014]     An articulated harvester includes a powered harvester having a pair of forward wheels or tracks, having a pair of rotatable rearward caster wheels, and carrying an on-board harvester grain bin for housing harvested grain. The harvester tows a grain cart, which carries a grain cart bin for housing harvested grain. A joint assembly interconnects the harvester and the grain cart. The joint assembly includes a grain cart tongue that mates with the harvester. An articulation cylinder assembly connects the harvester and the grain cart tongue in the region of the joint assembly. Bi-directional, biased guide rods connect between the grain cart tongue and the caster wheels. The grain car may be steerable and/or powered. The harvester may be steerable by its pair of forward wheels or tracks. A conventional harvester and grain cart assembly can be converted into the novel articulated harvester.  
         [0015]     The corresponding method for converting a combination of a powered harvester and a grain cart towed with the harvester into an articulated harvester commences by providing a combination of a powered harvester having a pair of forward wheels (or tracks) and a pair of rearward wheels, and a powered grain cart towed with the harvester. The harvester carries an on-board harvester grain bin for housing harvested grain and the grain cart carries a grain cart bin for housing harvested grain. The harvester rearward wheels are replaced with a pair of rotatable caster wheels. The harvester and the grain cart are interconnected with a joint assembly. The joint assembly includes a grain cart tongue that mates with the harvester. The harvester and the grain cart are connected with an articulation cylinder assembly in the region of the joint assembly. Finally, the grain cart tongue and the caster wheels are connected with bi-directional, biased guide rods.  
         [0016]     Advantages of the present invention include the ability to convert a harvester and grain cart into an articulated harvester. Another advantage is that the conversion is simple and straightforward. A further advantage is that the conversion is not expensive. Yet another advantage is that the inventive conversion can be accomplished by ordinary mechanics in the harvester field. A yet further advantage is that such inventive design can be manufactured as an original item of manufacture. Another advantage is that that harvester can be disconnected from the grain cart and driven around separately. A further advantage is that owner of the modified harvester can sell it as a stand-alone harvester by simply installing a conventional axle and wheel assemblies in place of the caster wheel assemblies. These and other advantages will be readily apparent to those skilled in the art based on the disclosure set forth herein. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     For a fuller understanding of the nature and advantages of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:  
         [0018]      FIG. 1  is a side elevational view of the novel converted articulated combine (or harvester), which was formed from a conventional combine and towed grain cart;  
         [0019]      FIG. 2  is an overhead view of the novel articulated combine illustrated in  FIG. 1 ;  
         [0020]      FIG. 3  is an overhead view of the novel combination when the articulated combine is making a right turn;  
         [0021]      FIG. 4  is an overhead view of the novel combination when the articulated combine is making a left turn;  
         [0022]      FIG. 5  is partial cut-away side elevational view of the joint connecting the forward bogey (former combine) with the rearward bogey (former grain cart) of the novel articulated combine;  
         [0023]      FIG. 6  is an overhead view of the articulation joint assembly connecting the joint connecting the forward bogey (original combine) with the rearward bogey (original grain cart) of the novel articulated combine;  
         [0024]      FIG. 7  is an overhead view of  FIG. 6  while the articulated combine is being turned to the left;  
         [0025]      FIG. 8  is a side elevational view of the combine of  FIG. 1  detached from the grain cart;  
         [0026]      FIG. 9  is a overhead view of the joint assembly configured for the combine to be mobile detached from the grain cart;  
         [0027]      FIG. 10  is an overhead view like that in  FIG. 9  with the combine being turned to the left;  
         [0028]      FIG. 11  is a partial cut-away side elevational view of an alternative hitch design; and  
         [0029]      FIG. 12 a  side elevational view of the trunnion mount for the vertical auger located within the grain cart bin.  
         [0030]     The drawings will be described in detail below. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]     The present invention improves upon the grain cart and combine combination disclosed in U.S. Pat. No.  5 , 904 , 365 . It also can employ the novel grain unloading and handling system disclosed in application Ser. No. 10/247,249 (cited above). Advantageously, the invention also can improve upon other prior art grain cart/combine combinations. Accordingly, the grain cart bogey of the novel articulated combine for present purposes comprehends a grain cart that is unpowered, is powered only, or is both powered and steerable. The harvester likewise may or may not be steerable, but is powered.  
         [0032]     Referring initially to  FIG. 1 , an articulated combine,  8 , is seen formed from a grain cart,  10 , and a combine,  12 , which are mechanically interconnected by a joint assembly,  14 . Combine  12  generally includes a cab,  16 , in which the operator is seated, a cornhead,  18 , a drive wheel pair,  20 , a caster wheel pair,  22  (only one of each set of wheels being depicted in  FIG. 1 ), a primary grain hopper or combine grain bin,  24 , and an auger assembly,  26 , for unloading hopper  24 . Such combine is a modern combine with all of the appurtenances and features that combine manufacturers provide today, but for caster wheels  22 , which replace a set of conventional wheels. Similarly, grain cart  10  is conventional in construction in that it includes a wheel pair,  28  (see  FIG. 2  to view both wheel pairs  28 a and  28 b), a secondary grain hopper or grain cart bin,  30 , and joint assembly  14 , which is different than a conventional tongue that typically connects combine  12  with grain cart  10 . Grain cart  10  is powered, preferably by extending the hydraulics from combine  12  to wheel pair  28 . Wheel pair  28  optionally could be steerable, such as in the manner taught in U.S. Pat. No. 5,904,365.  
         [0033]     It will be observed that the novel articulated combine, then, can be made by conversion of a combine/grain cart combination by replacing the combine rear wheels with caster wheels and by replacing the simple grain cart tongue with a joint assembly. Such simplicity adds to the value of the invention, as it is relatively easy to undertake such conversion.  
         [0034]     The grain transfer assembly,  32 , depicted in  FIG. 1  is that novel grain transfer assembly as disclosed in application Ser. No. 10/247,249 (cited above). It will be appreciated that grain could be off-loaded separately from the combine grain bin  24  and from grain cart bin  30 , such as is disclosed, for example, in U.S. Pat. No. 5,904,365. The particular method by which grain is off-loaded from articulated combine  8  is not a limitation on the present invention.  
         [0035]     As disclosed in application Ser. No. 10/247,249, it will be observed that generally horizontal first grain transfer assembly  32  runs between combine grain bin  24  and grain cart bin  30 . A generally vertical grain transfer assembly,  34 , is seen to be located within grain cart bin  30  and is interconnected with first grain transfer assembly  32 . Horizontal grain transfer assembly  32  is seen to extend into combine grain bin  24  through its rear wall (see  FIG. 5 ) and vertically at about its midpoint. A canvas, rubber, or other suitable material seal,  33 , keeps the harvested grain from spilling out, yet permits movement of assembly  32  during turning of the combine, as will be described below in connection with  FIGS. 3 and 4 . This location means that as soon as combine grain bin  24  is about one-half full, harvested grain housed in bin  24  can be withdrawn and transferred into grain cart bin  30 . Conversely, by reversing the direction of travel of transfer assembly  32  grain can be transferred from grain cart bin  30  back into combine grain bin  24  for its unloading via unloading mechanism  26 .  
         [0036]     While the grain transfer assemblies can be conveyors, augers, or similar known devices (e.g., auger, bucket conveyor, cleated conveyor, or the like), the present invention will be specifically illustrated with (and not limited to) augers. Generally, a hydraulic motor assembly,  36 , powers horizontal harvested grain transfer assembly (auger)  32  and is composed of a suitably sized hydraulic motor, chain, sprocket, and bearings. Auger assembly  32  is supported at its grain cart end by a joint,  38 , and at its combine end by a joint,  40 . Auger assembly  32  also is provided with a grain cart discharge door,  42 , which is actuated by a hydraulic cylinder,  43 , and with a rear discharge,  44 , and with a shroud rotate joint,  46 . Auger assembly  32  is shrouded or covered from joint  46  forward to combine grain bin  24  and is an open trough,  48 , from joint  46  rearwardly. Harvested grain can be discharged from auger assembly  32  into grain cart bin  30  via discharges  42  and  44 . Discharge of harvested grain into grain cart bin  30  is facilitated by this dual discharge scheme. Such scheme also means that discharge  44  is disposed rearwardly of vertical auger assembly  34 .  
         [0037]     A hydraulic motor assembly,  50 , powers vertical auger assembly  34  and generally is composed of a suitably sized hydraulic motor, chain, sprocket, and bearings. Harvested grain housed in grain cart  30  is withdrawn from grain cart bin  30  by auger assembly  34  and discharged from a spout,  52 , into open trough  48 . Hydraulic motor  36  is reversible so that harvested grain can be reciprocally transported between combine grain bin  24  and grain cart bin  30 , including the transfer of harvested grain from grain cart bin  30  back to combine grain bin  24 . Vertical auger assembly  34  is mounted to grain cart bin  30  with a trunnion mount,  54  (see  FIG. 12 ). Trunnion mount  54 , composed of trunnion mount portions  54   a  and  54   b,  permits auger assembly  34  to be rotated rearwardly to rest on a side of grain cart bin  30  for storage.  
         [0038]     Attachment of auger assembly  32  at either end requires pivoting capability in order for the combine and towed cart to turn. This can be seen by reference to FIGS.  3  (right turn) and  4  (left turn). It will be apparent that if grain transfer assembly  32  cannot pivot that turning of articulated combine  8  cannot be accomplished. The flexibility of seal  17  also enables auger assembly  32  to pivot as it extends through the hole in the side of combine grain bin  24 . Such pivoting also requires the hole in grain transfer assembly  32  to be large enough to accommodate turning of articulated combine  8  with consequent pivoting of auger assembly  32 .  
         [0039]     Ball hitch assembly  15 , illustrated in  FIG. 5 , enables articulated combine  8  to articulate. While a variety of hitches can be envisioned, ball hitch assembly  15  includes a tow ball,  56 , with a threaded end,  58 , retained by a nut,  60 , to a bracket assembly,  62 , attached to axle  66  at the rear of combine  10 . Correspondingly, tongue  70  attached to grain cart  10  at its forward end carries a bracket assembly,  64 , having a cavity that mates over tow ball  56  with a suitable locking mechanism to guard against the premature or unwanted separation of the hitch assembly  15 . It will be appreciated that ball hitch assembly  15  may be require additional reinforcement in order to withstand the torque and moment placed on it when articulated combine  8  turns. Such design is well within the skill of the artisan with the particular design in  FIG. 5  being for illustrative purposes only.  
         [0040]      FIG. 6  shows joint assembly  14  along with caster wheels  22   a  and  22   b.  It will be observed that each caster wheel  22   a / 22   b  is connected to an axle,  66 , by a U-shaped wheel mounts,  68   a  and  68   b  (see also  FIGS. 14 ). In particular, wheel mounts  68   a  and  68   b  are pivotally mounted to axle  66  to permit each caster wheel  22   a / 22   b  to freely rotate 360°. Each caster wheel assembly  22   a / 22   b  can be fitted with a suitable tire, such as, for example, a used aircraft tire.  
         [0041]     It will be observed that hitch assembly  15  is connected to a tongue,  70 , of grain cart  10 . A drive around stub also could replace tongue  70 , as will be described below in connection with  FIGS. 8-10 . Wheel mounts  68   a / 68   b  are seen connected to tongue  70  via a pair of bidirectional, biased guide rods,  72  and  74 , respectively, biased with springs  71  and  73 , respectively. Such guide rod springs bias caster wheels  22   a / 22   b  to be oriented for straight-line movement of articulated combine  8  and generally confine caster wheels  22   a / 22   b  to match the articulation angle. Biased guide rods  72  and  74  preclude combine  8  from jack-knifing, especially when backing up. The attachment points of guide rods  72  and  74  do not necessarily comply with the Ackerman Steering design rules as shown, but such attachment point locations, if necessary, can be calculated by the skilled artisan. Thus, the attachment points of guide rods  72  and  74  in the drawing is for illustration and teaching purposes and should not be taken as a limitation on the present invention. Also, biasing means other springs could be used as is necessary, desirable, or convenient.  
         [0042]     In order to turn articulated combine  8 , a pair or articulation cylinder assemblies,  76  and  78 , are connected between grain cart tongue  70  and combine  12  (preferably to the axle/frame of combine  12 ). In order to accommodate the expected turning forces exerted by articulation assemblies  76  and  78 , a pair bracket assemblies,  80  and  82 , have reinforced tongue  70 . Other reinforcing assemblies can be envisioned and are appropriate for use, as those skilled in the art will appreciate. While the rods of articulation assemblies  76  and  78  are seen connected to the frame of combine  12  and their corresponding cylinders to tongue  70 , the reverse arrangement also can be used. Desirably, articulation assemblies  76  and  78  are hydraulically powered from the hydraulics typically provided for operation of combine  12 . Suitable sizing of the hydraulic valve permits articulation assemblies  76  and  78  to be added to the hydraulic scheme, with perhaps increasing of the size of the hydraulic pump carried aboard combine  12 . Also, control of articulation assemblies  76  and  78  has been extended into cab  16  for integration into the steering hydraulics. Suitable integration must account for any steering provided by wheel pair  28  of grain cart  10  and by wheel pair  20  of combine  12 . Such integration can be accomplished, for example, by suitable hydraulic or electronic controls.  
         [0043]     In  FIG. 7 , articulation cylinder assembly  78  is seen extended and articulation cylinder assembly  76  is seen retracted in order for articulated combine  8  to turn to the left. It will also be observed that caster wheels  22   a / 22   b  have rotated to the right with guide rods  72  and  74  biasing their orientation to be the same with respect to tongue  70 .  
         [0044]     In summary, then, in order to convert combine  12  and towed grain cart  10  into articulated combine  8 , the rear axle and wheels of combine  12  need to be replaced with axle  66  and wheel pair  22  carried by wheel mounts  68 . Next, joint assembly  15  needs to be added along with articulation cylinder assemblies  76  and  78 , and any required reinforcement of tongue  70 . Of course, the drawings show two articulation cylinder assemblies for illustrative purposes only. Finally, the control of articulation cylinder assemblies  76  and  78  needs to be integrated into the steering control system for combine  12 . With these few simple operations completed, an articulated combine has been manufactured from an existing combine and grain cart combination. As stated above, such harvester design also can be an original equipment manufacture.  
         [0045]     Since the inventive articulated harvester design has rear caster wheel pair  22 , it would be advantageous if grain cart  10  could be uncoupled from combine  12  and combine  12  still driven around, at least for short distances.  FIGS. 8-10  detail how this can be accomplished. Referring initially to FIGS.  8  (in which the joint area is cut-away) and  9 , in order to uncouple grain cart  10  from combine  12 , tongue  70  first is uncoupled from hitch assembly  15  and replaced with a stub tongue,  84 , whose free end carries a capture plate,  86 . The free ends of cylinder assemblies  76  and  78  are attached to capture plate  86  so that the free ends of stub tongue  84  and cylinder assemblies  76  and  78  moved in unison about their respective pivotal attachments to combine  12 . Biased guide rods  72  and  74  are disconnected from tongue  70  and re-connected to stub tongue  84 . Next, a support ring,  88 , is attached to axle  66  to provide support for stub tongue  84 , biased guide rods  72  and  74 , and cylinder assemblies  76  and  78 . A roller,  90 , is attached to the bottom of stub tongue  84  and it rides on the top surface of support ring  88 . Such support and motion will be seen in  FIG. 10  in which combine  12  is being turned to the left.  
         [0046]      FIG. 11  depicts an alternative hitch,  91 , design in which tongue  70  has an apertured U-shaped bar stock,  92 , which accepts an apertured plate,  94 , carried by and gusseted to combine axle  66 . A through bolt,  96 , and nut,  98 , secure bar stock  92  to plate  94 . The aperture in plate  94  carries a spherical bearing,  100 , such as an Aurora LCOM 24 spherical bearing (Aurora Bearing Company, Aurora, Ill.), which allows about ±7° roll and pitch to through bolt  96 . Rotation about through bolt  96  adds the third degree of movement about hitch  91 .  
         [0047]     While the invention has been described with reference to preferred embodiments, those skilled in the art will understand that various changes may be made and equivalents may be substituted for elements thereof without departing from the precepts of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. In this application all units are in the metric system and all amounts and percentages are by weight, unless otherwise expressly indicated. Also, all citations referred herein are expressly incorporated herein by reference.