Abstract:
An offset header for attachment to a grain harvester includes a body having a back and a bottom which form a collection trough extending the length of the body. The back further defines at a first proximal and an opening for receiving and for attachment to a grain conveyor of a grain harvester. A mechanism is located at the bottom for removing and collecting a crop from an agricultural field, and a transfer mechanism is operationally positioned in the collection trough to transf&#39;s er the collected crop toward the opening. A drive unit at a second distal end of the body supports and propels the second distal end of the body in cooperation with a grain harvester.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This Non-Provisional Utility application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/960,439 filed on Sep. 18, 2013, which is incorporated herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure generally relates to apparatuses and methods for harvesting agricultural grain. More particularly, the present disclosure relates to a header for a combine wherein the header is offset from the centerline of the combine. 
     BACKGROUND OF THE INVENTION 
     The agricultural industry consistently searches for methodologies to improve the yield of field crops. While new and improved varieties of corn, wheat, and soybeans have contributed greatly to increased yields at harvest, methodologies of field preparation and harvest can also impact crop yields either positively or negatively. The impact to the soil of crop harvesting operations is magnified for both grain and biomass when producers feel the need to harvest under less than optimum weather and/or soil conditions. Operation of combines to harvest the agricultural crops and the concurrent use of grain carts in the field have been identified as major contributors to soil compaction across agricultural fields as both combines and grain carts have both high gross and high axle weights. 
     Attempts have been made to control compaction during harvest through the use of controlled traffic lanes or designated tramlines for the harvesting equipment to traverse the field with little resulting impact because of operational issues. The major drivers of compaction are the use of grain carts used to speed harvest and the use of a grain harvester more commonly referred to as a combine. At the same time, farmers have attempted to address compaction issues by switching to radial tires, use of agricultural tracks, running dual/triple wheels, etc. However, when virtually the entire field is trampled by the combination of the grain cart and the combine, tramlines provide limited benefit. 
     Recognition of the impact of soil compaction on grain and biomass yields is rapidly growing, leading to interest in tramlines, both permanent and temporary, to create controlled traffic paths across fields. Effective use of tramlines can minimize the percentage of a field&#39;s surface which is impacted by soil compaction during grain harvest and other field operations. For example, by operating a grain cart in the travel tracks of the combine during a previous harvest pass, a temporary tramline can be created which exhibits some of the benefits of a permanent tramline, but that approach leaves significant room for improvement. 
     Soil scientists believe that there are conceptually two types of soil compaction. Deep compaction is driven by axle weight and near surface compaction is driven by ground pressure. While agricultural tracks have a conceptual advantage over tires, poor track design can result in an advantage for tires relative to compaction. One of the problems with agricultural tracks is the ground pressure peak that corresponds to the leading and trailing edge of poorly supported or improperly tensioned tracks. 
     Tramlines both minimize and control soil compaction in agricultural fields. Minimizing compaction increases the yield of both grain and associated biomass. Tramlines also minimize the run-down of biomass leading to enhanced biomass yields and higher biomass quality. The adoption of tramlines maximizes the quantity and quality of biomass that can effectively be removed from a field and hence the value of the biomass co-product produced by an agricultural field. At the same time, the routine use of tramlines minimizes soil compaction across a field and hence increases the production of both grain and associated biomass within a field. Concurrently, tramlines minimize the quantity of crop residue which is “run-down” during grain harvest—an important issue in maximizing the efficiency of biomass harvesting, maximizing biomass yields and optimizing biomass quality. 
     Increased biomass yields within a field reduces the harvest radius around a biomass processing plant, and correspondingly reduces harvesting and associated logistics costs. Further, increased biomass quality allows the operating processes of the biomass processing plant to be optimized. 
     Tramlines also makes feasible the harvesting of certain crops such as hay, crops grown for their chemical, food, nutraceutical or pharmaceutical properties such as oregano, at multiple times during the growing season. These multiple passes may be timed according to calendar, convenience, the plants&#39; growth stage, etc. Multiple passes may also be used to harvest specific parts of a plant such as seed from two or more varieties/strains, etc. with different growth characteristics. For example, harvesting seed from two grass species where one species is short and the second tall; or where one forms seed early and the second one late in the growing season. 
     The appropriate harvesting of biomass can eliminate the need for deep tillage at the end of a crop cycle (which minimizes the oxidation of soil organic carbon which is also a factor in soil compaction) and allows adoption of no-till production in high residue crops which can also reduce compaction (and enhance soil organic carbon levels in soil). Both changes can concurrently reduce crop production expenses. 
     Sizing crop production equipment such as planters, sprayers, etc. to maximize the efficiency of tramlines is relatively easy, up to a point. Tramway layout and use is driven by equipment size. However, as combines and similar pieces of equipment get larger, the use of tramlines is thwarted by size. With a 30′ combine header, it is barely possible to run a combine down one tramway while unloading grain into a catch cart running down the next tramway over. With a 40′ header, it takes extraordinary extensions to the combine&#39;s unload auger and modifications to the catch cart to effectively utilize a tramway system. A 60′ header is in commercial use outside of the USA and there is a movement to develop a 60 foot corn head to match the size of current planters available from multiple manufacturers covering 24 rows at 2.5 feet per row (i.e., 60 feet in width). For these, full use of a tramway is physically challenging. 
     However, 48 row planters at 2.5 feet per row planters (i.e., 120 feet in width are commercially available from multiple manufacturers. To match the combine and the planter to a common set of tramlines would require a 120 foot header. To build such a system in a conventional way is near impossible as the engineering on the header would be complicated and heavy; and the combine used to process the grain would be significant in size leading to unique compaction issues. Therefore, a header for use on a grain harvester is needed wherein a maximum field area can be covered with minimal soil compaction. 
     SUMMARY OF THE INVENTION 
     The present disclosure is generally directed to a header for use on a grain harvester wherein the header is offset from the centerline of the harvester. The offset header for attachment to a grain harvester includes a body having a back and a bottom which form a collection trough extending the length of the body. The back further defines at a first proximal end an opening for receiving and for attachment to a grain conveyor of a grain harvester. A mechanism is located at the bottom for removing and collecting a crop from an agricultural field, and a transfer mechanism is operationally positioned in the collection trough to transfer the collected crop toward the opening. A drive unit at a second distal end of the body supports and propels the second distal end of the body in cooperation with a grain harvester. 
     In another aspect, the header includes a plurality of resilient mounts at the opening for attaching the offset header to a grain harvester. Further, the resilient mounts are self-severing at a pre-defined force applied thereto. 
     In still another aspect, the drive unit is unpowered. 
     In yet another aspect, the drive unit includes a power source, a traction member, and a frame securing the drive unit to the body. 
     In a still further aspect, the traction member is selected from a group consisting of an agricultural track and a wheel. 
     In another aspect, the power source is selected from a group consisting of a hydraulic motor, an electric motor, pneumatic motor, and a mechanical drive. 
     In another aspect, the drive unit includes a positioning system. 
     In a still further aspect, the header includes at least a second drive unit mounted to the body at an intermediate point therealong. 
     In yet another aspect, a grain harvesting system comprises a grain harvester having a grain conveyor at a front thereof and an operator&#39;s cab including interactive controls for steering, regulating propulsion, and harvesting operations by an operator occupying the operator&#39;s cab. An offset header is attached to the grain conveyor and includes a body having a back and a bottom forming a collection trough extending the length of the body. The back further defines at a first proximal end an opening for receiving and for attachment to a grain conveyor of the grain harvester. A mechanism at the bottom removes and collects a crop from an agricultural field, and a transfer mechanism is operationally positioned in the collection trough to transfer the collected crop toward the opening A drive unit at a second distal end of the body propels the second distal end of the body in cooperation with the grain harvester. A control system includes a central processing unit having an associated memory, a display, a user input device, and an instruction set resident in the memory and executable by the central processing unit wherein the instruction set when executed functions to integrate and control the drive unit for maintaining the header in a desired alignment with the grain harvester in response to an operator&#39;s interactive control inputs. 
     In another aspect, the header includes a plurality of resilient mounts attaching the offset header to the grain harvester wherein the resilient mounts permit vertical and longitudinal movement of the offset header with respect to the grain harvester. Further, the resilient mounts are self-severing at a pre-defined force applied thereto. 
     In still another aspect, the drive unit includes a power source, a traction member, a steering function, and a frame securing the drive unit to the body. The motor and steering function are responsive to inputs from the central processing unit. 
     In yet another aspect, the traction member is selected from a group consisting of an agricultural track and a wheel. 
     In another aspect, the motor is selected from a group consisting of a hydraulic motor, an electric motor, pneumatic motor, and a mechanical drive. 
     In still another aspect, the grain harvester includes a first positioning system, and the drive unit at the distal end of the header includes a second positioning system. The first and second positioning systems are interactive to establish a position of the distal end of the header with respect to a position of the grain harvester. 
     In yet another aspect, the first and the second positioning systems are selected from a group consisting of strain gauges, laser measurement sensors, and radio frequency sensors. 
     In a still further aspect, the first positioning system is a global positioning system for determining a position of the grain harvester and the second positioning system is a global positioning system for determining a position of the distal end of the header. The central processing unit determines, as a function of the determined positions, speed and steering control inputs to the drive unit to maintain the distal end of the header in a desired orientation with a grain harvester. 
     In another aspect, the drive unit speed is independent of the speed of the grain harvester and is variably controlled by the central processing unit. 
     In another aspect, the header includes at least a second drive unit mounted to the body at an intermediate point therealong. 
     In a still further aspect, a method of harvesting grain from an agricultural field to minimize soil compaction includes acquiring a grain harvesting system of the type including a grain harvester having a header operationally mounted thereto. The header is offset from a centerline of the grain harvester and has a proximate end mounted to a grain conveyor of the grain harvester and a distal end extending away from the grain harvester. The distal end is supported and propelled by a drive unit affixed to the distal end of the header. Tramlines are established in the agricultural field wherein adjacent ones of the tramlines are separated by a distance of approximately twice the width of the header. The grain harvester is operated on a first pass of a first tramline to harvest the grain on a first side of the tramline. The grain harvester executes a 180° turn at the end of the tramline and is then operated on a second pass along the first tramline in an opposite direction to harvest the grain on a second side of the tramline. The bidirectional grain harvester operations are repeated on subsequent tramlines. 
     These and other features, aspects, and advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described, by way of example, with reference to the accompanying drawings, where like numerals denote like elements and in which: 
         FIG. 1  presents a front isometric view of an offset grain harvester header embodying the present invention, wherein the header includes a mount for attaching to a harvester offset from the harvester centerline; 
         FIG. 2  presents a rear isometric view of the offset header; 
         FIG. 3  presents a top front isometric of the offset header mounted to a grain harvester; 
         FIG. 4  presents a right side elevation view of the grain harvester and header of  FIG. 3 ; 
         FIG. 5  presents top front isometric view of an extended length offset header mounted to a grain harvester; 
         FIG. 6  presents a system block diagram of an operational system of a grain harvester having an offset header mounted to a front thereof.  FIG. 7  presents a top plan view of a grain harvester and offset header utilizing tramlines in a field to minimize soil compaction; 
         FIG. 8  presents an alternate embodiment header having each end thereof mounted to a grain harvester wherein each harvester is operating on a tramline. 
     
    
    
     Like reference numerals refer to like parts throughout the various views of the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word “exemplary” or “illustrative” means “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” or “illustrative” is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. For purposes of description herein, the terms “upper”, “lower”, “left”, “rear”, “right”, “front”, “vertical”, “horizontal”, and derivatives thereof shall relate to the invention as oriented in  FIG. 1 . Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     There are several approaches as potential solutions to the problem of undesired excessive soil compaction in agricultural fields during the harvesting phase. First, the span of a header can be increased wherein the attachment point for the header to harvester interface is centered on the header. Additional independent supports such as wheels, tracks, etc. can be added at the outer ends of the header and at any necessary intermediate points. Ideally, these independent supports would be powered and steerable. The stresses placed on the harvester would be substantial. Moving a long header between agricultural fields presents substantial challenges and the physical size needed to harvest 48 rows of high-yielding crop is substantial. However, large headers have difficulty in following the contours of the ground being harvested. Consequently, rigid headers have access to crop losses and are susceptible to harvest damage. Therefore, large headers require a degree of built-in flexibility, thus making design and wait a significant issue. 
     Second, a long header frame can be built which spans the space between two tramlines, with one or both frame supports at either end of the frame being powered and steerable. One or both ends of the frame are attached to one or more combines operating in the same tramlines. The grain header of selectable with is moved along the length of the frame to harvest the field in a sequential fashion. 
     Third, a header can be built which is one-half of the width of the field segments between adjacent tramlines. This header, instead of having a central mount to the harvester, would have a mount offset to one end of the header and the opposite end of the header being drive assisted. The offset nature of header induces corresponding offset loads exerted on the combine, therefore the outside and of the offset header must be supported. Ideally, such a support would comprise a powered, steerable wheel or track. Such a configuration permits the harvester and offset header to take one pass down one side of the tramline thereby harvesting one-half of the width of the field segment between the tramlines, and on a return pass harvesting one-half of the adjacent field segment. With current technology and tramline widths, this is the most effective approach, and one which can be immediately implemented for field segments of 120 foot widths between tramlines. As technology improves, the length of the headers can also increase thereby requiring fewer tramlines in the field. 
     Disclosed is a design for an offset, drive-assisted header to be used on a harvester such as a combine, forage harvester or similar agricultural implement used in crop production systems where controlled traffic practices (tramlines) are employed. By offsetting the header to the right or left (as opposed to the traditional centering), the effective width of the header is doubled. The harvester and a self-propelled close-coupled trailing grain cart move in the same set of tracks on both the forward and reverse traverse across a field. Each traverse processes a header&#39;s width of crop from alternating sides of a tramline. This approach significantly reduces the amount of land within a field which is allocated to tramline use. For example, in tramlines on 30 foot centers and a traditional centered 30 foot header, a 10 foot section or 33% of the surface area may be compacted by the harvester and another 10 foot section may be compacted by the grain cart while operating on a path parallel to the harvester during off-loading operations for a total compaction area of 67%. With 120 foot tramline centers, a 60 foot offset header, two passes to harvest the nominal 120 foot width of crop, and a close coupled grain cart, the impacted area is reduced to 8.3%. 
     In one exemplary implementation of the invention, a drive-assisted offset header  100  is shown in  FIGS. 1-2  illustrating its various components where a body  110  has a back  112  and a bottom  114  which in combination define a transfer trough  120 . A cutting mechanism  124 , such as a known movable sickle configuration, is positioned at a forward end of the bottom  114 . As illustrated, the header  100  is configured for harvesting corn and includes a plurality of snouts  126  between which respective rows of corn are guided for harvesting. Those practiced in the art, will readily recognize that the header  100  can also be configured for the harvesting of small grain such as wheat with the inclusion of a rotating reel in lieu of the snouts  126 . A grain transfer mechanism  122  is operationally positioned in the transfer trough  120  and can be of any known configuration such as an auger as illustrated or a conveyor belt or chain. As the width of a header increases, the header also has an increased need for flexibility since the field surface typically undulates rather than being flat. This requirement is of greater need for crops such as wheat and soybeans where the seed head or seed pods can often be close to the field surface. However, an auger is typically rigid, therefore, as flexure features are included in the header design, a belt conveyor to transfer the harvested crop along the header becomes increasingly attractive. The header  100  also includes a proximal end shield  116  at one end thereof and a distal end shield  118  at an opposite end thereof. The end shields  116 ,  118  can also have enclosed therein various drive mechanisms (not shown), bearings, and miscellaneous components known in the art and required for harvesting grain from an agricultural field. 
     Proximate to one end of the header, i.e. near proximal end shield  116 , the back  112  defines an opening  128  which is sized to receive the grain conveyor  184  ( FIG. 3 ) of a grain harvester to transfer the cut grain from the header to the grain harvester. Further, as is known in the art, the grain conveyor  184  also functions as the mount to which the header  100  is affixed for harvesting operations. A plurality of mounts  130  affix the header  100  to the grain conveyor  184 . Ideally, the mounts  130  between the header and the harvester at the proximal end of the offset header will be resilient, therefore allowing for minor mismatches in vertical and longitudinal orientations. 
     An assisted drive unit  140  is affixed to the header  100  and positioned on the outboard end proximate to distal end shield  118  of the offset header  100 . The drive unit may be affixed to the end at distal end shield  118  or affixed to the back  112  as illustrated. The positioning of the drive unit  140  is a tradeoff between simplicity in supporting the weight of the header at the distal end and the ability of the track  142  (or wheel) to move so as to follow the desired path during a turn. Positioning of the drive unit  140  will also be affected by crop row spacing and planting approach (i.e. solid as in seeded wheat vs. row crops such as corn and soybeans). The assisted drive unit  140  includes a support frame  146  affixed to the header  100 . The support frame  146  includes a traction member  142 , a power source such as drive motor  144 , and linkage (not shown) for steering the drive unit  140 . The power source  144  for the drive unit  140  positioned therealong may be of any type, such as mechanical, electrical, hydraulic, pneumatic, etc. However, hydraulic or electrical drive power is preferred since that approach typically results in a much simpler system than does a purely mechanical system. For shorter embodiments, the attachment to the grain harvester at opening  128  may be sufficiently rigid or a brace (not shown) extending from the distal area of the header  100  to the grain harvester may provide additional rigidity such that a powered drive unit is unnecessary. In such a case, an unpowered drive unit  140  (i.e. without a power source) utilized to support the distal end  118  of the header  100 . 
     As illustrated in  FIGS. 3-4 , a harvester  180  in a typical self-propelled configuration has an operator&#39;s cab  182  at a front thereof and a centrally positioned grain conveyor  184  for interfacing with the proximate in  160  of the offset header  100 . The drive unit  142  is positioned at the distal end  118  of the offset header  100  to prevent undesired torquing about the grain conveyor  184 . The drive unit  142  is controlled by and coordinated with the operator controls within the operator&#39;s cab  182 . Additionally, in view of the header  100  being offset to one side or the other of the grain harvester  180 , the offset header  100  has an increased potential, if encountering an obstruction either in the forward or reverse direction or in the event of operational failure of the drive unit  140 , to induce considerable bending moments at the point of attachment to the grain conveyor  184 . Consequently, in order to prevent or minimize damage to the grain harvester  180  and the offset header  100  from these bending moments, the mounts  130  on the offset header include a ‘breakaway’ function wherein the mounts  130  will sever the attachment when subjected to a predefined force. 
     Turning now to  FIG. 5 , an alternate embodiment offset drive assisted header  200  is illustrated wherein the length of the alternate embodiment offset header  200  is approximately twice the length of the offset header  100  discussed above. Like features of the alternate embodiment offset header  200  have similar reference numerals preceded by the numeral “2”. A proximate end  216  of the offset header  200  is mounted to the grain conveyor  284  of the harvester  280  in a manner similar to the mounting of offset header  100  utilizing resilient, flexible mounts (not shown) which also have a ‘breakaway’ function to sever if a predefined force is exceeded at the mount. The offset header  200  has a plurality of snouts  256  for guiding rows of corn into the header for harvesting and can also be configured with a reel for harvesting small grain such as wheat and soybeans. Once the grain has been separated from the field, a grain transfer mechanism  222 , here shown as an auger, delivers the grain to the opening at the proximate end  216  of the header  200  so that the grain can then be directed through the opening  228  into the harvester via grain conveyor  284 . Again, the grain transfer mechanism  222  may be configured as a belt conveyor to accommodate flexibility feature incorporated into the header  200 . Because of its length, the offset header  200  includes a drive unit  240  mounted proximate to a distal end  218  and at least a second drive unit  240  positioned intermediately between the proximate end  216  and the distal end  218 . The header  200  can also include other configurations of supporting elements (such as wheels or rollers) between the grain harvester and the distal end  218  of the header  200 . Such multiple auxiliary supports facilitate flexibility aspects of the header  200 . 
     The outboard drive unit  140  and preferably any intermediate drive unit  240  is independently controlled for both speed and direction thereby allowing the outboard end of the header to trace any path defined by the primary harvesting system. This includes paths which require the outboard end of the offset header to follow an irregular pattern. 
     The ability to control the speed of individual drive units  140  mounted to the header on turns so as to account for differences in the turning radius and for drive unit slippage has significant benefits. This approach also satisfies the need to closely align the header with specific groups of rows for proper harvesting. Since the turn at the end of a set of rows in the field is seldom perfect, fine (and sometimes not so fine) adjustments are required for alignment. An independently powered and steered drive unit  140  can make the necessary adjustments without creating unnecessary forces on the offset header  100  or on the harvester  180 . Independently powered front (or rear) steering wheels can reduce actual turning radius and minimize rutting and burning by the drive unit. A short turning radius of the combined harvester  180  and the attached header  100  is important since it allows tramlines to be established on headlands as well as across the length of the field. Additional advantages are apparent when traction is impaired by mud, frozen ground, side slopes, ice, snow, etc. 
       FIG. 6  illustrates in block format the operational system of a grain harvester  610  having mounted thereon an offset header  640  wherein the offset header  640  is configured with a drive assisted unit  650  at a distal end of the offset header  640 . The drive assisted unit  650  includes a motor  656 , a steering function  658 , and a position sensing system  652  which may further include an antenna  654 . Within the operator&#39;s cab (i.e. control cab  182 ,  FIG. 3 ) a control system comprises a central processing unit  612 , a display  616 , and an input device  614 . The input device  614  can be either a keyboard of known configuration or alternatively be incorporated into the display  616  wherein the display  616  includes a touch sensitive screen for receiving operator inputs in a manner known in the industry. The operating controls  618  includes a steering wheel, foot pedals, and operational levers and switches provide signal inputs to the central processing unit  612 . An executable instruction set within the memory of the central processing unit  612  then issues the required control commands to subsystems throughout the harvester  610 . Additionally, one or more of the operating controls  618  may be directly communicative in an analog fashion with subsystems of the harvester  610  and the offset header  640 . The central processing unit  612  is also communicative with one or more functions of the offset header  640  and the drive assisted unit  650 . Specifically, the central processing unit  612 , by executing the instruction set therein and in response to an operator&#39;s control inputs to the operating controls  618 , issues commands to the motor  656  and the steering linkage  658  of the assisted drive unit  650  to maintain the header  640  in a desired alignment with the harvester  610 . Maintaining this alignment can be enhanced through the integration of signals from the positioning system  652  and a known position of the harvester  610  as determined by a positioning system  620  resident on the harvester  610  and communicative with the central processing unit  612 . 
     Control of the outboard drive system  650  will typically be automated utilizing either close-coupling software which links the location of the outboard end of the header  640  to a reference point on the harvester. Such a positioning system could be constructed from a range of sensor systems and types (strain gauges, laser distance meters, radio frequency sensors, etc.) or be computed from GPS data received by and decoded by an antenna  654  on the outboard end of the offset header and a similar antenna  622  mounted in a known position on the harvester  610 . However, under certain circumstances such as short header widths with an additional added rigidity to the header frame, the combined outboard support  146  ( FIG. 1 ) and traction member  142  ( FIG. 1 ) could be a passive (unpowered) wheel or track. 
     In use, and as illustrated in  FIG. 7 , an agricultural field  190  can be subdivided by a plurality of tramlines  192  spaced at approximately twice the length of an offset header  100  according to the present invention and having a width approximating the width of the harvester  180 . The schematic of  FIG. 7  illustrates the tramlines  192  as having no agricultural crops growing thereon for the sake of clarity, however, it is anticipated that such tramlines  192  will also have crops planted thereon which are expected to have a lower yield as a result of the soil compaction occurring on the tramlines  192 . To harvest the grain from the agricultural field  190  the harvester  180  with an offset header  100  will make a first pass down a tramline  192  to harvest the grain on one side of the tramline  192  (harvested portion of the field is identified with the reference numeral  196 ), and at the end thereof execute a 180° turn with the traction member  142  maintaining the distal end of the header  100  in alignment with the harvester  180 . The harvester  180  then makes a second pass up the same tramline  192  to harvest the grain on an opposite side of the tramline  192 . As illustrated, the harvester  180  and offset header  100  have harvested the agricultural crop on the left side of the first tramline  192  and have partially completed its second passage along the first tramline  192  harvesting one half of the agricultural crop  194 . Upon reaching the end of the first tramline  192 , the harvester  180  and offset header  100  will execute another 180° turn to enter an adjacent tramline  192 . In this manner, soil compaction in the agricultural field  190  can be limited to the tramlines  192  and thereby maximizing crop yields in the non-traveled areas. It is also recognized that the harvester  180  and offset header  100  may adopt alternate patterns of crop harvesting in lieu of left to right sequencing. 
     The offset header concept can easily be extended to the concept where a header  300  is mounted to a system wherein the header is replaced by a truss  360  extending between a first harvester  380  to an independent carrier operating in an adjoining tramline such as a second harvester  380 . The independent carrier may also be a motorized device other than a second harvester. In this configuration, the header  300  may be attached directly to the truss  360  or supporting structure and moved along its length as sequential passes are made to harvest the land between two parallel tramlines  392 . The standing structure can be a simple metal beam or a more sophisticated support such as one or more trusses  360  which increases the strength and rigidity or provides for specific, components such as a conveyor to move materials or product along the length of the structure. Such a standing system can easily be structured for purposes other than harvesting such as supporting a spray boom, fertilizer distribution system, cultivator, or electronic sensor packages to monitor growth, diseases, insect populations, etc. This configuration also enables the selective harvesting within the field. 
     Since many modifications, variations, and changes in detail can be made to the described preferred embodiments of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents.