Abstract:
A folding frame for an agricultural implement such as a wheel rake. The frame includes ground engaging wheels and two toolbars foldable for operation and for transport. The folding frame is provided flexibility to conform to uneven surfaces, yet stability against the torques and forces of operation. A slidable tongue provides folding action between the transport position and the operating position. A spacing between rear ends of the two toolbars may be altered hydraulically for wider or narrower windrows. A novel caster wheel provides support for the toolbars and is located so that the implement&#39;s transport position is narrower than the prior art&#39;s.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a Continuation-in-Part of U.S. patent application Ser. No. 12/482,567, filed Jun. 11, 2009, now U.S. Pat. No. 8,267,186 and which also claims benefit of U.S. Ser. No. 61/313,398, filed Mar. 12, 2010. 
    
    
     Priority is claimed from both of the above identified applications and both are incorporated herein by reference in their entirety. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO MICROFICHE APPENDIX 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an agricultural implement including a folding toolbar. More particularly, the present invention relates to an improved method and apparatus for providing stability for the folding toolbar as well as flexibility when operating on uneven terrain. 
     2. Background Art 
     As farm implements are made to cover greater areas in a single pass, components of those implements become longer and, thus, exhibit greater tendencies to flex, twist, and generally deform. Incorporating appropriate flexibility of farm implement frames—to conform to uneven terrain—while maintaining adequate stability—that is, resist flexing, twisting, and deforming—are challenges faced by implement designers. 
     Many types of agricultural implements include folding toolbars, including, but not limited to, agricultural wheel rakes. The folding toolbars may be supported at an end farthest from a tongue by a ground engaging wheel or wheels, such as that shown in  FIGS. 2   a  and  2   b . Due to the distance between the ground engaging wheel and the rear end of the toolbar, impulses to the ground engaging wheel because of uneven ground and obstacles can result in damage to the toolbar and other parts of the implement. 
     In the past, the ground engaging wheel attached to the toolbar has been mounted on the side of the toolbar away from the tongue of the implement as seen in  FIG. 1 . The width of the implement when folded for transport is greater due to the location of the ground engaging wheel. Other choices of location, while narrowing the folded implement have proved untenable because of interference between the ground engaging wheel and other moving parts of the implement. 
     An improvement to the former problem—that of impulses to the ground engaging wheel  10 —can be made by increasing the diameter of the ground engaging wheel. However, it has been found, increasing the diameter of the ground engaging wheel requires an increase in an offset  240 , which is the horizontal distance between a substantially vertical axis  230  and a substantially horizontal axis  220  as seen in  FIG. 2   a . If the offset  240  is not increased with tire diameter, instability results, with a symptom of shimmy. The combination of the increased wheel diameter and the requisite increased offset  240  results in a much greater clearance requirement. The ground engaging wheel must be disposed adequately far from the parts of the implement with which the wheel may interfere. 
     Forces due to obstructions in the path of the ground engaging wheel, as well as forces due to operating the implement in the field, can result in deformations of the folding toolbar. Prior art implements have utilized joints with limited degrees of freedom to provide rigidity to resist these deformations. However, the joints with limited degrees of freedom have not permitted the folding toolbars to adequately conform to uneven terrain. 
     The must be foldable between a transport configuration, sufficiently narrow to pass through a gate or traverse public roadways, and a broadened operating configuration. It is also desirable to provide varying windrow widths. 
     Most folding wheel rakes on the market today that fold by changing the tongue length, do so by using folding arms or telescoping frame members. This causes the working or operational length to be unnecessarily longer, making it more difficult for the operator to turn the tractor and rake at the end of each windrow. 
     There is, therefore, a need for an agricultural implement including a folding toolbar having ground engaging wheels at outboard ends of the toolbars mounted so as to reduce the folded width of the implement. There is an additional need for the ground engaging wheel to reduce impulse on the toolbar due to uneven ground or obstacles. There is also a need for a folding toolbar providing both conformability to uneven field surfaces and stability under the influence of the loads realized in use of the implement. There is a further need for a folding toolbar wherein the overall length of the implement remains short. There is also a need for a folding toolbar on a wheel rake providing for varying windrow widths. 
     BRIEF SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a method and apparatus for mounting a caster wheel to a toolbar, such as that used on wheel rakes, that results in a narrower folded width. 
     For the purposes of the present disclosure, including the claims, a caster wheel is defined as a wheel assembly,  10 ,  100 , as shown in  FIGS. 1   a - 2   c , the wheel  210  having a substantially horizontal axis of rotation  220  substantially at a center of area of the wheel  210 , and about which the wheel  210  rotates. The wheel assembly  10 ,  100 , further has a substantially vertical axis  230  of rotation providing steering of the wheel  210 . The wheel assembly  10 ,  100  rotates about the substantially vertical axis  230  of rotation relative to the implement toolbar (not shown in  FIGS. 2   a - 2   c ). The substantially horizontal axis of rotation  220  rotates about the substantially vertical axis of rotation  230 . The wheel assembly  10 ,  100  may, optionally, be locked so the wheel assembly  10 ,  100  will not rotate about the substantially vertical axis  230  for some of the operation of the implement. However, to meet the definition of a caster wheel, the wheel assembly  10 ,  100  must include a substantially vertical axis of rotation  230  and the wheel assembly  10 ,  100  must rotate about said substantially vertical axis of rotation  230  during at least some of the caster wheel&#39;s operation. The definition of the caster wheel also demands the caster wheel include a load bearing, ground engaging wheel  210 . Specifically, a rake wheel, with tines about its periphery for engaging forage material and applying it to a windrow, does not satisfy the definition of a caster wheel, for the purposes of this document, regardless of the rake wheel&#39;s axes of rotation. 
     To effect the above object, the toolbar of the implement includes a first portion, pivotally attached to a main frame of the implement and extending generally forward from the pivotal connection. A second portion of the toolbar is parallel to, but not collinear with, the first portion of the toolbar. The second portion of the toolbar is set inward—that is, toward the tongue—from the first portion of the toolbar, and comprises a forward end of the toolbar assembly. The caster wheel may then be disposed such that the substantially vertical axis of rotation of the caster wheel assembly lies between the first and second portions of the toolbar. 
     Because of the offset of the second portion of the toolbar inward from the first portion of the toolbar, a spacing between the rake wheels must be increased, thus providing room for the caster wheel assembly. 
     An additional object of the instant invention is to provide a suspension system for the caster wheel providing support for an agricultural implement toolbar. Torsion axles are used for axles for wheels that are not caster wheels. An example use is on trailer axles. Application of the torsion shaft to a caster wheel is novel. The torsion shaft provides a substantially horizontal axis of pivot about which forks pivot. Pivoting the forks permits the toolbar to which the caster wheel assembly is pivotally attached to raise and lower while the ground engaging wheel of the caster wheel engages the ground. Due to the effect of the torsion axle, these movements—raising and lowering—are damped, thus reducing accelerations and consequent forces. 
     Still another object of the present invention is to provide a folding toolbar assembly having sufficient rigidity to resist the deformations of its members due to operation while at the same time, providing the flexibility of the assembly to conform to uneven and varying terrain. 
     Fold arms extending between a joint operatively attached to the tongue and a joint operatively attached to the toolbars provide resistance to moments produced when the rake wheels are engaged to forage material in the field. In addition, due to the novel use of a ball joint for the fold arms at the tongue, each fold arm has three degrees of rotational freedom at the tongue. A novel joint also providing three degrees of rotational freedom connects a rear end of each toolbar to a frame. Thus, torsional loads to the toolbars must be supported by the fold arms. The joint between each fold arm and the respective toolbar provides only a single degree of rotational freedom—in a substantially vertical direction. So torsional loads on the toolbars are resisted by the fold arms. 
     An additional object of this invention is to provide a sliding tongue that effects the folding of the toolbar. The folding toolbar is adapted to be operatively attached to a prime mover such as a farm tractor for towing from place to place. First and second toolbars, attached to and moved by the tongue member, are pivotally attached to linkage members and pivotal joints permit the folding toolbar apparatus to be moved between a narrow and longer transport position and a shorter and wider working position, while at the same time retaining flexibility in use. The rear end of the tongue member extends behind the frame in the operating position, making the folding toolbar apparatus shorter than conventional folding toolbars in the operating position. 
     Another object of the present invention is to provide variable windrow widths. To effect this object, the rear end of each toolbar is operatively, pivotally attached to the frame in a slidable fashion. A spacing between the rear ends of the first and second toolbars may be made greater or smaller via this sliding function, which is preferably carried out hydraulically. 
     Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of an agricultural wheel rake of the prior art; 
         FIG. 2   a  is a side elevation view of a caster wheel assembly of the prior art; 
         FIG. 2   b  is a front elevation view of the caster wheel assembly of the prior art; 
         FIG. 3  is a top plan view of an agricultural wheel rake in operating position; 
         FIG. 4  is a top plan view of the agricultural wheel rake in transport position; 
         FIG. 5  is a first front elevation view of an agricultural implement frame in operating position; 
         FIG. 6  is a second front elevation view of the agricultural implement frame in operating position on uneven ground; 
         FIG. 7  is a side elevation view of the agricultural implement frame; 
         FIG. 8  is a detail of a fold arm of the agricultural implement; 
         FIG. 9  is a detail of a center fold arm joint; 
         FIG. 10  is a detail of a fold arm and caster wheel pivot axis; 
         FIG. 11  is a detail of a rear toolbar connection point of the agricultural implement; 
         FIG. 12  is a detail of a hanger used at the rear toolbar connection point of the agricultural implement; 
         FIG. 13  is a detail of a ball joint between a tongue and the fold arm of the agricultural implement; 
         FIG. 14  is a top plan view of an agricultural implement frame in operating position showing an axis of rotation for a narrow disposition of the toolbars; 
         FIG. 15  is a top plan view of an agricultural implement frame in operating position showing an axis of rotation for a wide disposition of the toolbars; 
         FIG. 16  is a top plan view of the agricultural wheel rake in operation raking forage and pulled by an agricultural tractor; 
         FIG. 17  is a side elevation view of a caster wheel assembly of the present invention; 
         FIG. 18  is a side elevation view of the caster wheel assembly of the present invention showing a torsion shaft; 
         FIG. 19  is a front elevation view of a caster wheel assembly of the present invention; 
         FIG. 20   a  is an internal view of a first form of the torsion shaft; 
         FIG. 20   b  is an internal view of a second form of the torsion shaft; 
         FIG. 20   c  is an internal view of a third form of the torsion shaft; 
         FIG. 21   a  is an exploded view of the first form of the torsion shaft; 
         FIG. 21   b  is an exploded view of the second form of the torsion shaft; 
         FIG. 21   c  is an exploded view of the third form of the torsion shaft; 
         FIG. 21   d  is a perspective view of the first form of the torsion shaft, assembled; 
         FIG. 22  is a top plan view of one toolbar in unfolded or operating mode showing rake wheel spacings; and 
         FIG. 23  is a top plan view of one toolbar in folded or transport mode showing rake wheel spacings. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings wherein like reference numerals indicate identical or corresponding parts throughout the several views, the implement  20  of the present invention is shown in  FIG. 3 , including a plurality of rake wheels  630 ,  830  operatively, rotatably attached to a left toolbar  200  and a right toolbar  300 . The implement  20  is depicted in the operational position and towed by a tractor  80  in  FIG. 3 . In  FIG. 4 , the same implement  20  is depicted in a transport position and towed by the tractor  80 . 
     An elongated tongue member  100  is shown in  FIGS. 3 ,  4  and  7 , operatively attached at a front end to a hitch structure  22  while at a rear end the elongated tongue member  100  is disposed in and extends through a slide box  106 . The slide box  106  is operatively, rigidly attached to a frame  107 . The frame  107  comprises downwardly depending portions for rotatably mounting ground-engaging transport wheels  102 . 
     The tongue includes a hitch  104 . The hitch  104  is supported by a drawbar of the agricultural tractor  80 . 
     A hydraulic cylinder  108 , best seen in  FIGS. 3 ,  4  and  7 , is attached at a joint  34  on a substantially horizontal axis to the elongated tongue member  100  and is attached at the other end to the frame  107 , supported by the transport wheels  102 . It is the lengthening or shortening of the hydraulic cylinder  108  that moves the tongue member  100  between the transport position shown in  FIG. 4  and the operational position shown in  FIG. 3 . In the transport position of  FIG. 4 , the implement  20  may pass through farm gates and travel on a road or highway and be sufficiently narrow to avoid extending into adjacent lanes of traffic. Once the folding implement  20  is pulled into a field by the tractor  80  shown in  FIG. 3 , the hydraulic cylinder  108  is shortened causing the frame  107  to move with respect to the elongated tongue  100  to the position shown in  FIG. 3  which is the working or operating position of the toolbars  200 ,  300 . In  FIG. 16 , cut crop material  1610 , such as hay, shown in front of the folding implement  20  with rake wheels  630 ,  830  is shown being raked by the implement  20  into a windrow  1620  as the rake moves forwardly over the cut crop  1610 . Of course when the task of windrowing the entire field has been completed and it is desired to go back through a gate and onto a public road or highway, the hydraulic cylinder  108  is lengthened to the position shown in  FIG. 4  thus moving the folding implement  20  to the transport position shown in  FIG. 4 . 
     Another aspect of the present invention comprises a caster wheel assembly  1700  shown in  FIGS. 17-19 . The caster wheel of the instant invention includes the substantially horizontal axis of rotation  220  about which the wheel  210  turns, and the substantially vertical axis of rotation  230  about which the entire caster wheel assembly  1700  rotates. The substantially vertical axis may exist by virtue of a stem  1740 , fitted into bearings in the implement. 
     The caster wheel of the present invention also includes a novel use of a torsion shaft assembly  1820 . The forks  1730  are permitted to pivot relative to the stem  1740  about a substantially horizontal pivot axis  220 . 
     Several variations of torsion shaft assemblies  1820  are shown in  FIGS. 20   a - 21   d . Torsion shaft assemblies  1820  comprise an outer housing  2010 , usually being formed from material generally known as square tubing; an axle  2020 ,  2025 , sometimes in the form of square stock as in  FIGS. 20   a - 20   b ,  21   a - 21   b , and  21   d  or round stock with a key  2070 , as shown in  FIGS. 20   c  and  21   c ; and at least one elastic member  2040 ,  2050 ,  2060 . 
     The at least one elastic member  2040 ,  2050 ,  2060  may comprise a plurality of separate elastic members  2040 , or a single elastic member  2050 ,  2060 , molded to fit into the outer housing  2010  and to receive the axle  2020 ,  2025 . The at least one elastic member  2040 ,  2050 ,  2060  is usually made of an elastomer, and commonly referred to by those of ordinary skill in the art as rubber. 
     The axle  2020 ,  2025 , besides being either square or round stock, has splines  1750  machined or attached onto the ends as shown in  FIGS. 21   a - 21   d . The splines  1750  engage apertures in the forks  1730  while the outer housing  2010  is stationary with respect to the stem  1740 . In this way, when the forks  1730  are rotated relative to the stem  1740 , a resisting torque is generated in the torsion shaft assembly  1820 . 
     Regardless of the configuration, when the axle  2020 ,  2025  is rotated relative to the outer housing  2010 , the at least one elastic member  2040 ,  2050 ,  2060  is deformed, resulting in a resistance, in the form of a torque, to the rotation. A resisting torque results from rotation of the axle  2020 ,  2025  in either direction from a neutral position. In the neutral position, either there is no deformation of the at least one elastic member  2040 ,  2050 ,  2060  or any deformation is axisymmetric about an axis of rotation of the axle  2020 ,  2025 . In either case, no torque is sustained about the axle  2020 ,  2025  in the neutral position. 
     An alternative to the common torsion shaft assemblies  1820  shown in  FIGS. 20   a - 21   d  is the use of a torsion spring—a coiled spring that is deflected by the axle  2020 ,  2025  when the axle  2020 ,  2025  rotates relative to the stem  1740 . 
     The present invention is not limited to any one form of torsion shaft assembly. 
     The housing  2010  of the torsion shaft assembly  1820  is rigidly attached to the caster wheel assembly&#39;s stem block  1760 , which remains stationary relative to the stem  1740 . The forks  1730  of the caster wheel assembly  1700  are rigidly attached to the axle  2020 ,  2025  of the torsion shaft assembly  1820  via the splines  1750 . Therefore, the forks  1730  are permitted to pivot relative to the stem block  1760 , with the dampening effect of the elastomer  2040 ,  2050 ,  2060 . 
     The caster wheel assembly  1700  with a torsion shaft assembly  1820  as shown in  FIGS. 20   a - 20   c  provides a dampening of forces to the toolbar  200 ,  300  from irregularities in the ground surface, hit by the wheel  210  of the caster wheel assembly  1700  in motion. Dampening these forces reduces noise, vibration, and fatigue. 
     An additional aspect of the present invention is shown as applied to an agricultural wheel rake shown in  FIGS. 3 and 4 . The caster wheel assembly  600  of either  FIGS. 2   a - 2   b    10  or  FIGS. 17-19   1700  is disposed inward on the toolbar  200 ,  300  compared to the prior art (contrast  FIG. 1  to  FIG. 3 ). The inward placement of the caster wheel assemblies  600  exhibits the advantages of better supporting the force due to the moment applied to the toolbar by virtue of the raking process, and a narrower implement profile when the implement is folded to its transport mode as shown in  FIG. 4 . 
     For the purposes of the present document, including the claims, the term inward is defined as toward a longitudinal centerline  310  shown in  FIG. 3 . For example, the caster wheel assemblies  600  in  FIG. 3  are disposed inwardly compared to the caster wheel assemblies  10  of  FIG. 1 . A distance inward from the toolbar is a distance inward from a nearest point on an imaginary line  320  passing through a middle of the toolbar toward the longitudinal centerline  310 . For this definition, the imaginary line  320  shall be considered infinite in length, so this inward distance from the toolbar may be defined forward and rearward of the toolbar in question. 
     For the purposes of the present document, including the claims, the term forward is defined as the usual and general operating direction  330  as shown in  FIG. 3 . The term rearward is defined as opposite forward. Similarly the term front is defined as the forward-most portion of the implement. Rear is defined as opposite the front. 
     For the purposes of the present document, including the claims, the term towed agricultural implement is defined as an agricultural implement with ground engaging means, for example wheels, independent of the source of motive power, for example a farm tractor. Therefore, a towed implement is pulled by the source of motive power and may use the source of motive power&#39;s hydraulic system for raising and lowering, but does not make use of lift arms usually attached to a farm tractor. 
     For the purposes of the present document, including the claims, the adjective narrow is defined as a reduced distance between extreme outer points of the implement from the longitudinal centerline  310 . Narrow refers to a distance measured perpendicular to the longitudinal centerline  310 . The verb narrow is defined as the operation of reducing the distance between extreme outer points of the implement from the longitudinal centerline  310 . Specifically, the verb narrow is not synonymous with shorten, which means a reduction in a length measured parallel to the longitudinal centerline  310 . 
     For the purposes of the present document, including the claims, the transverse direction is hereby defined as a direction perpendicular to the forward direction, and lying in a plane substantially parallel to the ground on which the implement is disposed. Equivalently, the transverse direction is the direction parallel to an axis of rotation of the ground engaging rear wheels  102  shown in  FIGS. 3 and 4 . 
     For the purposes of the present document, including the claims, an axial distance is hereby defined as a distance measured along a line parallel to the axis of rotation of the rake wheels  630 ,  830  (see a, b, and c in  FIG. 9 ). The rake wheels  630 ,  830  can be for example of the type shown as rake wheel 32 in U.S. Pat. No. 6,945,924, which patent is incorporated herein by reference in its entirety. 
     To provide adequate clearance between each caster wheel  600  and the nearest rake wheels  630 , each toolbar  200 ,  300  includes a forward section  202 ,  302 , rigidly attached to the toolbar  200 ,  300 . Furthermore, the forward section  202 ,  302  is parallel to and inwardly offset from the respective toolbar  200 ,  300  to which it is attached. 
     Due to the inward offset of the forward rake wheels  630 ,  830 , a distance between the rake wheels  630  nearest each caster wheel  600  must be increased to provide appropriate spacing for operation. This is illustrated in  FIGS. 22 and 23 . In the operating position (unfolded) shown in  FIG. 22 , the rake wheel hubs are transversely equidistant—distance x—from one another so no forage is missed in the raking operation. As seen in  FIG. 23 , the axial distance between the rake wheels  630 ,  830 , indicated as a, and b, varies. Distance a is the standard distance, and the distance used in the prior art. The distance b is the increased spacing required for caster wheel  600  clearance. The increased spacing b is necessary for achieving the equidistant spacings x when points of attachment of the rake wheel pivot arms to the toolbar  200 ,  300  have been offset inward in the vicinity of the caster wheels  600 . 
     Unlike the toolbar of the prior art,  FIG. 1 , where the substantially vertical axis of rotation  230  of the castor wheel assembly  10  is disposed outwardly from the toolbar, the axis of rotation  230  of the castor wheel assembly  600  the instant invention is located at or near the line  320  passing through the middle of a center portion of the toolbar section  200 ,  300 . One advantage realized from this arrangement is better support of the moment applied to the toolbar  200 ,  300  by the raking action. An additional advantage is realized by a narrower frontal profile when the implement is folded for transport, as shown in  FIG. 4 . 
     Another aspect of the present invention comprises a frame and mechanical linkage for supporting a toolbar in a configuration that allows it to follow the terrain while minimizing strains in the toolbar and frame. The components may be simplified and the resulting product can be manufactured in a cost effective manner while providing high reliability and durability. 
     For the preferred embodiment, the wheel rake, two types of assemblies are connected to the toolbar: rake wheel assemblies and a caster wheel. Both create a torque load or moment on the toolbar due to the fact that the weight and operating loads are applied at points offset from the centerline of the toolbar. The torque load is counteracted by the supporting linkage. Many prior art rakes have utilized the linkage at the rear of the toolbar to provide the requisite capability to counteract this torque and hold the toolbar from rotating at the rear connection to the frame. In the prior art as shown in  FIG. 1 , the rear connection is used to counteract this torque and position the rear of the toolbars, to set the width of the resulting windrow. A linkage at the front, the fold arm, is then used to position the front of the toolbar. These configurations have been adequate, and successful in managing deformations of the frame members. However, when encountering variations in terrain, the relative positions of the front and rear of the toolbar need to change to follow the terrain as seen in  FIG. 6 . Mechanisms have been developed with relatively complicated designs, including complicated fold arms, to attempt to allow the necessary movement of the toolbar without inducing binding situations in the linkages. 
     The present invention utilizes a relatively simple fold arm  400 ,  500 , configured to position the front of the toolbars  200 ,  300  between an operating position ( FIG. 3 ) and a transport position ( FIG. 4 ) while a rear support, connected to the main frame  107 , sets the position of the rear of the toolbar  200 ,  300 . The rear mechanism of this invention is configured to provide three degrees of rotational freedom in a novel combination with the front fold arm  400 ,  500  serving as the only means of rotationally positioning the toolbar  400 ,  500  about its centerline as required to counteract the offset load of the rake wheels  630 ,  830  and the caster wheel  600 . As a result, the assembly can be optimized and the size of the components minimized, while maintaining or increasing expected durability. 
     As explained above and shown in  FIGS. 3 and 4 , includes the elongated tongue member  100 , supported by the ground engaging wheels  102  rotatably mounted to the frame  107 , the slide box  106  and the hitch  104 . The frame  107  and slide box  106  support the left toolbar  200  and the right toolbar  300 , each having a first end at the front,  202 ,  302 , and a second end at the rear,  204 ,  304 . The frame  107  supports both toolbars  200 ,  300  at the second end  204 ,  304  as illustrated in more detail in  FIG. 11  where the support structure for the second end  204  of the left toolbar  200  is shown. The support structure includes a cylinder  110 , comprising a cylinder ram  112  extending from the slide box  106  to the frame  107  and a body  114 . The cylinder ram  112  defines a first axis of pivot  160  about which the respective toolbar  200 ,  300  may pivot. The cylinder&#39;s  110  body  114  is slidable relative to the ram  112  using common cylinder components, well known by those of ordinary skill in the art, such that the body  114  may slide longitudinally along the ram  112  as pressurized fluid is directed to either a first port  116  or a second port  118 . When fluid is directed into the inner port  116 , the cylinder body  114  will slide away from the tongue  100 . Alternately, when fluid is directed to the outer port  118 , the cylinder body  114  will slide toward the tongue  100 . These movements allow the distance between the ends  204  and  304  of the toolbars to be altered as shown in  FIGS. 14 and 15 . In  FIG. 14 , the ends  204  and  304  have been moved toward the center as would be required to form a narrow windrow, while  FIG. 15  shows the ends  204  and  304  moved apart, as would be required to form a wider windrow. In addition to moving longitudinally relative to the ram  112 , the body  114  is able to freely rotate about the centerline of the ram  112 , about the first pivotal axis  160 . 
     The body  114  includes a block  120  comprising a bored hole defining a second axis of pivot  162 . The block  120  supports a mounting bracket  122 , via a first pin  124  as shown in  FIG. 12 . The mounting bracket  122 , in turn, supports the second end  204  of the toolbar  200  via a second pin  126 , passing through holes in the mounting bracket  122  and through ears  206 , welded to the toolbar  200 . The centerline of the joint defined by the second pin  126 , ears  206 , and mounting bracket  122  defines a third axis of pivot  164 . 
     The toolbars  200 ,  300  rotate about the second pivotal axis  162  when moved from the operating or raking configuration shown in  FIG. 3  to a transport position shown in  FIG. 4  as the cylinder  108  extends, moving the slide box  106  relative to the tongue member  100 . 
     The first axis of rotation  160  allows the front end of the toolbar  202 ,  302  to move freely to follow the terrain, as shown by the front end  202  of the left toolbar  200  in a raised position, and the front end  302  of the right toolbar  300  in a lowered position in  FIG. 6 . 
     The front ends  202 ,  302  of the toolbars  200 ,  300  are positioned by fold arms  400 ,  500  shown in  FIG. 3 , with the rake in the operating position, and in  FIG. 4  with the rake in the transport position. The toolbars  200 ,  300  are moved between these two positions by the cylinder  108  and the two fold arm cylinders  610 , one of which is depicted in  FIG. 9 . The cylinder  108  may be extended or retracted via the hydraulic system of the tractor  80  to move the slide box  106  relative to the frame  107 , and subsequently the rear portions of the toolbars  204 ,  304  relative to the front connection point of the fold arms  402 ,  502 . This relative movement results in a rotational movement of the toolbars  200 ,  300 . 
     The left fold arm  400  can be seen in  FIG. 8  to include a first end  404  attached to the tongue  100  at a connection point  402 , via a ball joint, detailed in  FIG. 13 . Ball joints are known to provide three degrees of rotational freedom, and zero degrees of translational freedom. The opposite end  406  of the fold arm is connected to the left toolbar  200  at a joint providing one degree of rotational freedom, such as a cylindrical joint. In the preferred embodiment, as shown in  FIG. 10 , the connection is robust and includes a top plate  408  and a bottom plate  410  connected to the fold arm  400 , configured to straddle the left toolbar  200 . The top plate  408  and bottom plate  410  include holes aligned to define an axis of rotation  412 . The caster wheel assembly  600  is includes the stem  1740  that passes through a first ear  410 , left toolbar  200 , and a second ear  408  in a manner that the left fold arm  400  directly supports the left caster wheel assembly  600 , while using the same joint to support the left toolbar  200 . With this configuration, the forces from the left caster wheel assembly  600  are transferred directly to the left fold arm  400 . 
     Each of the fold arms  400 ,  500  positions the front end of the toolbar  200 ,  300  by changing length as provided by a joint rotating about a substantially vertical pivot axis  414  ( FIGS. 8 and 9 ), provided on both fold arms  400 ,  500 , which allows the fold arm  400 ,  500  to pivot in a substantially horizontal plane and controls the rotational position of the entire toolbar  200 ,  300  by pivoting about the substantially vertical pivot axes  412 ,  414 . Because these substantially vertical pivot axes  412 ,  414  disallow rotation about any other axis, the orientation of the left toolbar  200  relative to the left fold arm  400  is maintained rigid to the limits of the deformation of the materials used to manufacture the implement. This can be seen by comparing  FIGS. 5 and 6 . In  FIG. 6  the front of the left toolbar  200  has climbed onto a slight hill causing the left fold arm  400  to rotate about the connection  402  to the elongated tongue member  100  on a substantially horizontal pivot axis as enabled by the ball joint in a counterclockwise direction. Since the pivot axis  412  does not permit rotation about a substantially horizontal axis at the left toolbar  200 , the pivot axis  412  is thus likewise pivoted in a counterclockwise direction. Hence, the left toolbar  200  is also rotated through an equal angular displacement in the counterclockwise direction. The rear connection to the main frame, as described earlier and depicted in  FIGS. 11 and 12 , will allow this angular displacement by allowing free angular movement about both the first pivot axis  160  and the third pivot axis  164 . 
     This novel combination provides a fold arm  400 ,  500  configured to control the position of the front of a toolbar  200 ,  300  by folding in the substantially horizontal plane between an operating position and a transport position, while remaining rigid in a vertical plane. During mower operation, the fold arm  400 ,  500  is essentially a rigid member in any plane, positioning the front of the toolbar in the substantially horizontal plane. The fold arm  400 ,  500  also positions the toolbar  200 ,  300  in a vertical plane, controlling the toolbar&#39;s  200 ,  300  position as the offset load of the caster wheel assembly  600  and rake wheel assemblies  630 ,  830  induce a torque load on the toolbar  200 ,  300  generally about its longitudinal axis. The rear support for the toolbar provides three degrees of rotational freedom allowing the fold arm  400 ,  500  to exclusively counteract this induced torque in the toolbar  200 ,  300 . 
     In the operating position, the fold arms  400 ,  500  act as rigid members connected to the tongue with ball joints at their respective pivots  402 ,  502 , and to the front end of the toolbars  200 ,  300  at uniaxial cylindrical pivots. The toolbars  200 ,  300  are connected on their opposite ends to the frame  107  with a system of pivoting joints as shown in  FIGS. 11 and 12  for the left toolbar  200 , free to rotate about the first, second, and third pivot axes  160 ,  162 , and  164 . The toolbars  200 ,  300  will pivot about axes of rotation as shown in  FIGS. 7 ,  14  and  15 , where only one axis  166  for the left toolbar  200  is shown. This axis of rotation passes through the pivot  402  and the rear connection to the frame. Due to the fact that the ball joint at pivot  402  is higher than the rear connection at axes  160 ,  162  and  164 , and the resulting orientation of the axis of rotation  166 , the caster wheel assembly  600  will tend to move generally forward and out as the caster wheel assembly  600  is raised up, for instance when traveling over an obstruction. 
     It is to be understood, the explanations of the present invention for the left members of the apparatus are also applied to the right members. 
     The embodiments of the novel suspension system herein described may be utilized for many implements making use of a toolbar. The invention is not intended to be limited to forage wheel rakes. 
     The above embodiments are the preferred embodiments, but this invention is not limited thereto. It is, therefore, apparent that many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.