Abstract:
An agricultural boom is made up of two sections connected together, including an inner boom section and an outer boom section that are joined together with a hinge assembly in mid portions of the boom. The outer boom section is mounted to the inner boom with a linkage and control cylinder that provides for a knee action, that permits the outer boom section to be raised and lowered. The boom sections are both mounted about upright axes, and are supported against downward loads by separate pairs of cables that have ends joined at the base of the respective boom section at spaced points and connected to the outer or free ends of the respective boom sections at common points. The cables permit the boom sections to pivot about their respective upright axes with one of the cables carrying tension loads and causing the outer or free ends of the boom sections to raise while the other cable becomes slack.

Description:
This application refers to and claims priority from U.S. Provisional Application Ser. No. 60/347,632, filed Jan. 11, 2002, the content of which is incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a foldable elongated agricultural sprayer boom for field spraying applications, which provides reliable breakaway structure for permitting an outer section of the boom to pivot relative to an inner section to clear obstructions. The outer section also can be folded back alongside of the inner section. The entire boom will fold forwardly for transport. The inner section of the boom is a composite structure that is lightweight, torsion resistant, and high strength. 
     Foldable field sprayer boom assemblies used for spraying fields have been used for many years. With larger and larger fields, it is desirable to have the booms as long as possible. Problems are inherent in using such booms since there are obstructions that the outer sections of the boom might strike, so the booms generally are made in more than one section with outer sections being capable of pivoting out of the way of obstructions. Also, the outer sections fold back along the inner sections and the entire boom then folds for transport. 
     Also, when long booms are used, torsional rigidity is from shock loads caused by uneven ground and the like. 
     Many agricultural sprayers use breakaway sections for hinging the outer boom section to the inner boom section, for example, U.S. Pat. No. 5,428,091 illustrates such a breakaway boom. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an agricultural sprayer boom made in at least two separate boom sections, which are hinged together at a desired location. The hinge between the inner section of the boom and the outer boom section is provided with a hydraulic cylinder control that is mounted to a floating or knee action linkage that permits the outer section boom to be raised and lowered at the mid point of the boom, and which will dampen the shock loads from the vehicle traversing rough or uneven ground. The hinge used for coupling the boom sections and mounting the hydraulic cylinder that controls the pivoting of the hinge permits folding of the outer boom section. The outer boom section folds back along side the inner boom section. 
     The outer end of the outer boom section is also supported on the inner boom section in a manner which permits the outer boom section to pivot to clear obstructions that it may strike, by utilizing a pair of suspension cables extending from a T-shaped upright bracket at the hinge at the inner end of the outer boom section. The cables carry tension load, and prevent the outer boom section from sagging when in use, and will maintain the outer boom section in a horizontal position. When the outer boom section engages an object during travel, the outer boom section will pivot about an upright axis, and as it pivots, one of the cables will be placed under greater tension, and the other cable will become slack, automatically. As the outer boom section pivots about the upright axis, the geometry is such that the outer end of the outer boom section will be caused to rise by the cable as the outer end moves through an arc about the upright pivot axis at its inner end. In this manner, the outer boom section will slide around and tend to rise over obstructions at the same time. The outer boom section will pivot to clear an obstruction a full 90° while supported by one or the other of the cables. 
     The spray boom is mounted onto a frame on a movable support, which can be a self-propelled vehicle or a towed trailer. The frame that mounts the boom can be raised and lowered so that the inner boom section will be raised. When the boom sections are to be folded for transport, the outer boom section is folded back alongside the inner boom section, using the hydraulic cylinder that controls the hinge that permits such pivoting. Also a second hydraulic cylinder is used for moving the inner boom section about an upright pivot to a folded position. The inner boom section also has a tension cable support connected from the frame to the T-bracket at the outer end. The cable is mounted so it causes the outer end of the inner boom section to tilt upwardly so that it nests close to the side of the supporting frame and vehicle. 
     It is also to be understood that there are folding boom sections extending from opposite sides of the supporting frame or vehicle, and each one is a mirror image of the other. Stated another way, there are two of the inner boom sections and mounted to the opposite sides of the support frame, and each of the inner boom sections will support an outer boom section as described. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary schematic top plan view of a field sprayer having a boom made according to the present invention installed thereon; 
     FIG. 2 is a fragmentary rear view of the outer boom section of FIG.  1  and its support shown schematically; 
     FIG. 3 is a perspective view of a base end of an inner boom showing a hydraulic cylinder for controlling pivoting of the boom for transport; 
     FIG. 4 is a perspective view of the hinge region between the inner and outer boom sections made according to the present invention; 
     FIG. 5 is a perspective side view of the outer end of the inner boom section after the outer boom section has been folded back adjacent the inner boom section; 
     FIG. 6 is a perspective view of the outer end of the inner section of the boom assembly from the front side of the hinge between the inner and outer boom sections; 
     FIG. 7 is a perspective view of the mounting of the inner boom section relative to the support frame; 
     FIG. 8 is a top view showing the inner boom mounting in a forward folded position; 
     FIG. 9 is a perspective view of the hinge between the inner boom section and the outer boom section similar to FIG. 6; 
     FIG. 10 is a view of the hinge similar to FIG. 9 but with the outer boom section folded rearwardly against the inner boom section; 
     FIG. 11 is a sectional view of the inner boom section taken on line  11 — 11  in FIG. 9; 
     FIG. 12 is a fragmentary perspective view of the support frame raised and the boom folded; 
     FIG. 13 is a schematic view of a bracket for supporting the inner boom section support cables on the support frame; and 
     FIG. 14 is a schematic representation of the frame for supporting the boom and support cables for the inner boom section. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An agricultural sprayer indicated generally at  10  is mounted on a trailer or a self-propelled vehicle  11  that supports a main support frame  12  that has a rear portion. The rear portion of frame  12  supports a pair of foldable boom assemblies  14 , shown extended on the right hand side of the vehicle  11  and folded for transport on the left hand side. The direction of travel of the vehicle is indicated by the arrow  16 . 
     The right hand foldable boom assembly  14  will be explained. The left hand boom assembly is a mirror image of the right hand boom assembly. The boom assembly  14  has an inner boom section  20 , and an outer boom section  22  that are hinged together with a controllable hinge assembly  24  in the central portions of the boom assemblies. The inner boom section  20  is mounted for pivotable movement about an upright pivot  26  at its base end, and it is controlled for pivoting about this axis with a hydraulic cylinder and link assembly  28 . 
     The folding of the hinge for outer boom section  22 , as well as providing the ability of the outer boom section to “float” is controlled with a hydraulic cylinder assembly  30  that is mounted onto a type of linkage frame  32  (FIG. 2) that acts as a control of a four bar linkage as shown in FIG.  2  and in other figures. The mounting to the rear of frame  12 , which can be raised and lowered as shown, permits raising and lowering the boom assembly while the boom assembly remains parallel to the ground. 
     The inner boom section  20  is made of three tubes  34 A,  34 B and  34 C stacked together so their central axes form a triangle in cross section (see FIG.  11 ). The tubes  34 A,  34 B and  34 C are welded together with welds shown at  35 A,  35 B and  35 C, respectively, so that the tubes make a very rigid assembly, that is lightweight, and can withstand high torsional loads for the amount of weight. The triple tube inner boom section can withstand loads so that it can have lengths in the range of 25 feet or more. As can be understood, the torsion loads on the inner boom section become high when the outer boom section is extending perpendicular to the length of the inner boom section as the outer boom section is being folded back to be parallel to and adjacent to the inner boom section. 
     As shown in FIGS. 3,  7  and  8 , and FIGS. 13 and 14 schematically, the main support frame  12  has front and rear upright corner posts  12 A (four posts), and horizontal side members  12 B that are pivoted to the posts  12 A on both sides of the frame. The posts at the front and rear are joined together with cross members  12 C. The front posts are fixed to the trailer or vehicle frame  12 V. The pivoting side members  12 B of frame  12  permits the rear of the frame to be raised and lowered like a four-bar linkage or parallelogram linkage, through the use of hydraulic cylinders, as shown schematically in FIGS. 12 and 13. One cylinder is shown at  12 F, and while the particular main support frame for mounting the folding boom does not form any part of the invention, the raising of the frame as shown in FIGS. 12 and 13 will provide for raising and lowering the boom assembly when spraying and provide clearances when the boom sections are folded forward. The frame  12  can be a fixed frame for a truck mounted sprayer and the showing of frame  12  is only one example of the support frames that can be used. 
     The inner boom section  20  is welded to an end plate  40  adjacent pivot  26 , and plate  40  is also welded to side plates  42  (see FIG. 8) that are welded to the inner boom  20 . The side plates  42  have openings that align with a pivot tube  44  that is welded to a pivot plate  46 . A pin  42 A is used for pivotally mounting the inner boom to the pivot plate  46  about a generally horizontal axis. 
     The inner boom is held in a generally horizontal position through the use of a pair of cables  48 F and  48 R (shown partially in FIGS. 1 and 6) that are both connected to a chain  48 C and to a bracket  48 P on the inner boom section, as shown in FIG.  14 . The cables  48 F and  48 R are connected to a suitable bracket  48 Y having arms  48 X and  48 Z extending upwardly from the frame  12  to support points that are spaced in fore and aft directions as shown schematically. 
     FIG. 8 shows the pivot plate  46  in place between two support plates  50  that are fixed to the frame  12 , and the pivot plate  46  has an outwardly or laterally extending arm  52  that supports a cylinder mounting leg  54  which is also part of and moves with the pivot plate  46 . The mounting leg  54  extends alongside of the inner boom section  20  and has an upright support  56  at its outer end (FIG.  7 ). An adjustable threaded rod  58  extends through an opening in the support  56  and carries a clevis type bracket  60  into which the rod end fitting  62  of a hydraulic cylinder or actuator  64  is mounted. The actuator  64  has a base end bracket  66  that fits between a pair of arms  68  that in turn are fixed to the frame  12 , and extend laterally outwardly therefrom at an angle, as can be seen in FIGS. 1,  7  and  8 . The pivot bracket  46  is mounted with a pin  50 A to the plates  50 . The pin  50 A forms the pivot  26 . Cylinder  64  is a double acting hydraulic cylinder that can retract and extend a rod and the cylinder  64  controls the position of the inner boom section about the pivot  26 . 
     The outer end of the triple tube inner boom section  20  supports the hinge assembly  24  for connecting the outer boom section to the inner boom section. Referring to FIGS. 4,  5 ,  6 ,  9  and  10 , the specific arrangement of this hinge assembly  24  can be seen. The inner boom section  20  has a fixed end bracket  70  at its outer end that is welded to the ends of the tubes  34 A,  34 B and  34 C, and the bracket  70  extends between the legs  71  of a channel shaped “knee action” link or plate  72 . The plate  72  is pivotally mounted with pins  74  to the end bracket  70  and thus to the inner boom section. The plate  72  forms the base for the hinging support for the outer boom section  22 . The channel shaped plate  72  has a control link  76  pivotally mounted thereto with pins  78 , for pivoting about axis parallel to the axis of pins  74 , and on the same legs  71  of the channel  72 . The control link  76  is a wishbone shaped link, and has a base end  80  that has a depending arm  82  that is pivotally mounted with a pin  84  to a pivoting link  86 . The link  86  is pivotally mounted with a pin  88  to the upper tube  34 A of the triple tubes of the inner boom section  20 . 
     The plate  72 , as can be seen in FIG. 10 for example, has a hinge member  90  that is used for supporting a T-shaped upright cable anchor bracket  92  that has an upright post  93  and a top cross member  112 . The post  93  of bracket  92  is fixed to hinge members  94  that mate with the hinge  90  and a hinge pin or bolt  96  is used for forming a pivot for hinge member  94  and the bracket  92  about a generally upright pivot axis. The axis of bolt  96  has an axis parallel to the plane of the main portion of the plate  72 . As can be seen in FIG. 10 an adjustable stop bolt  98  is threaded into a nut welded to plate  72  and can be used for limiting or adjusting the stopped position of the hinge member  94  about the upright axis of pivot pin  96  relative to plate  72  to keep the outer boom section oriented. 
     The T-shaped bracket  92  is used for mounting the outer boom section  22 . As can be seen in FIG. 9, the lower end of upright post  93  of bracket or support  92  has a pair of straps or arms  100  extending outwardly therefrom, and these arms  100  in turn pivotally mount a outer boom support hub  102  about a horizontal pivot using a pivot bolt or pin  104 . 
     The hub  102  also has spaced arms such as that shown at  106 , and the arm  106  receives the single tube outer boom section  22  and pivotally mount the outer boom section about an upright axis with a pin  108 . The outer tube section  22  can have a reinforcing or backbone tube  22 A thereon, but it is a relatively lightweight square tube as shown. 
     The T-shaped support or bracket  92  has a cross member  112  at the upper end of the post  93  thereof, and the cross member  112  extends in a direction perpendicular to the extension of the outer boom section  22 . The cross member  112  is positioned in a desired location relative to the central axis of the upright post  93  of the T-shaped support  92 , so that ears  114 A and  114 B are at the outer ends of the cross member  114  at the desired locations relative to the outer boom section pivot axis. The outer end of the outer boom section is supported about the pivot bolt  104  by cables  116 A and  116 B that are attached to the ears  114 A and  114 B through suitable fittings  118 A and  118 B (FIG.  9 ). The cables  116 A and  116 B are tension carrying cables, and are secured in a suitable manner to the outer boom section at a point  120  shown in FIG.  2 . The connection point  120  is spaced inwardly a desired distance from the extreme outer end of the outer boom section. The cables  116 A and  116 B are of size so that they will support the weight of the outer boom. The weight or moment of both the inner and outer boom sections about the pivot  42 A is carried back to the main support frame  12  by the pair of cables  48 F and  48 R, which are connected by a chain to a bracket on the inner boom section  20  as shown at  48 A. The cables  48 F and  48 R are oriented like the cables  116 A and  116 B so when the boom is pivoted forwardly on about the pivot  26 , the outer end of the inner boom will raise. 
     An additional cable  49  (FIG. 9) is connected from frame  12  to help control the plate  72  as shown by connecting the outer end t the top center of post  93 , at  48 A. This cable  49  forms a top link of a four bar linkage support for the boom assembly. The inner boom section  20  forms one bar between pivot pin  42 A and pivot  74 , where the inner boom section connects to the plate  72 , and thus to the post  93  and top cross member  112 , which together form a second link. The plate  72  and post  93  of bracket  92  are controlled as to their pivoting about pivot bolt  74  by the cable  49  which forms the top link, between frame  12  and plate  72 . The vertical members of frame  12  form the base link between pivot  42 A on the bracket  46 , and the top of frame  12  where the inner end of cable  49  is secured. 
     The vertical position of the boom assembly  14  is controlled by raising and lowering frame  12 . The orientation of the inner boom section, the plate  72  and cable  49  relative to the support frame  12  causes the boom to remain parallel as it is raised and lowered. The cable  49  is in addition to cables  48 F and  48 R. When the boom is extended and strapped out, the cables  48 F and  48 R do not affect the linkage action of cable  49 . The cables  48  and  49  tend to keep the inner boom section extending outwardly perpendicular to the frame  12 . 
     The pivoting of the bracket or support  92  about the axis of the pivot pin or bolt  96  is controlled with a folding linkage indicated generally at  124  (FIGS. 4,  5  and  10 ). The folding linkage  124  includes a bell crank  126 , a connecting link  128 , and a bracket  130  that is attached to the upright post  93  of the bracket  92 . The bell crank  126  is pivoted as at  126 A to a cross plate  132  at the upper end of the knee action plate  72 , and is also pivoted to one end of link  128  with a pin  126 B (FIG.  10 ). The opposite end of link  128  is pivoted to the ears or bracket  130  with a pin  128 A. 
     The linkage that is shown is made with suitable length links so that the bracket  92  can be rotated 180° from the position of FIG. 9 with the outer boom section extending straight out from the inner boom section, to a position where the outer boom section is folded alongside the inner boom section as shown in FIG.  10 . 
     The cylinder assembly  30  includes a hydraulic actuator or cylinder  134  that is used for controlling the linkage. The cylinder  134  has a base end connected as at  136  to a bracket  138  fixed to the wishbone control link  76 , and has its rod end mounted with a pin  140  to the bell crank  126  at a location spaced from both the pivot pin  126 A and the pivot pin  126 B. 
     When the cylinder  134  is retracted, the outer boom section is folded to the position shown in FIG.  10  and extends back along the inner boom section  20 , so that the outer end of the outer boom section is adjacent to the support frame. When the cylinder  134  is extended partially, it will pivot the hinge member  94  and the support  92  to a position shown in FIG. 9, with the outer boom section  22  extending essentially along the same axis as the inner boom section  20 , which is the working position for the sprayer boom  14 . 
     The boom assembly will be able to move between a position contacting the ground by lowering frame  12 , to a normal operating position where the inner boom section is raised above growing crops. 
     When the outer boom section  22  is folded back, to be parallel to and adjacent the inner boom section  20  as shown generally in FIG. 10, by retracting the rod of the cylinder  134 , then the inner boom section can be folded forwardly along the sides of frame  12  and vehicle or trailer  10  as well, by operating the actuator or cylinder  64 . When the cylinder  64  has its rod end extended, the entire boom, including both the inner and outer boom sections will pivot about the post axis  26  formed by the pin  50 A, and the pivot plate  46  will move to a position substantially 90° from the normal working position. As this is done, the cable  48 R will cause the outer end of the inner boom section to raise since it is anchored on an arm  48 X that extends to the rear of the pivot axis  26 . The cable  48 F will slacken. The boom assembly tilts up about the pivot axis of pin  42 A (FIG.  8 ). At the same time, the frame  12  can be lifted as shown in FIGS. 12 and 13, to provide for clearance of wheels or the like on the supporting vehicle. The boom can be moved to overlie a mechanical rest frame and then by lowering the frame  12  the free end of the boom will rest on a fixed support for transport. 
     Again, the showing of FIG.  13  and other showings of the frame are illustrative only and many other types of supporting frames can be used. 
     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.