High mobility agricultural implement

An implement supports several ground cultivating tools on a main toolbar and at least one wing toolbar. The two are coupled together by two pivot brackets attached to the outer end of the main toolbar and the inner end of the wing toolbar. The pivot brackets are coupled to the main toolbar and the wing toolbar to permit the wing toolbar to pivot upwardly and downwardly with respect to the main toolbar. When the wing toolbar pivots upwards with respect to the main toolbar, it pivots about an upper point or axis and when it pivots downwards with respect to the main toolbar it pivots about a lower point or axis below the upper point or axis.

BACKGROUND OF THE INVENTION
 With the increasing horsepower of modern tractors and the constant
 pressures of agricultural efficiencies, agricultural implements such as
 plows, rakes, harrows, disks, planters and the like have been increasing
 in their lateral dimensions. With the increased horsepower of the pulling
 implement of the tractor, more rows in a field can be cultivated
 simultaneously. Unfortunately, agricultural fields are uneven. As the
 implements increase in their lateral dimensions they do not follow the
 changing contours of the ground as accurately, leading to over- or
 under-penetration by ground-cultivating devices attached to the implement.
 For this reason in recent years the implements have been designed in
 several sections disposed along a line perpendicular to the direction of
 travel and connected to each other through generally flexible couplings
 disposed between the sections. The flexible couplings allow small upward
 or downward deflections between the sections of the implement as it
 travels over the ground, thus permitting each section to follow the
 contours of the field more accurately, and providing more even ground
 penetration by the attached devices.
 There has been a trend in recent years to plant crops in rows spaced ever
 more closely together. As a result, each of the ground-cultivating devices
 such as row units for planting seed are spaced closer together on each
 section of the implement's tool bar. Given row spacings of fifteen inches,
 for example, the row units on a planter would be spaced fifteen inches
 apart, thereby providing a gap of only one to two inches between adjacent
 row units on adjacent sections of the tool bar. If such a coupling is
 used, there is a real danger that as one section of the tool bar is flexed
 upward or downward over a ground contour that it will cause adjacent row
 units to contact each other and break. What is needed, therefore, is an
 improved agricultural implement that will permit greater relative motion
 between adjacent sections of the implement while reducing the risk of
 damaging ground cultivating devices, such as row units, mounted on those
 sections. It is an object of this invention to provide such an implement

Before explaining at least one embodiment of the invention in detail it is
 to be understood that the invention is not limited in its application to
 the details of construction and the arrangement of the components set
 forth in the following description or illustrated in the drawings. The
 invention is capable of other embodiments or being practiced or carried
 out in various ways. Also, it is to be understood that the phraseology and
 terminology employed herein is for the purpose of description and should
 not be regarded as limiting.
 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 Referring to FIG. 7, a tractor 10 is shown towing an implement 12 that is
 comprised of three tool bars, a main tool bar 14 and two wing tool bars 16
 and 18 that are coupled to the main tool bar via flexible couplings 20 and
 22, respectively. Several row units 24 (exemplary of the wide variety of
 ground cultivating devices that could be attached to the sections of an
 implement) are mounted on each of the tool bars. These row units are
 aligned on fifteen inch centers across the width of the three tool bars to
 thereby define several equally spaced rows 26 that are cultivated in the
 field. These row units typically have a width of ten to fourteen inches,
 thereby typically providing a gap 28 between each adjacent pair of row
 units of one and three inches.
 Prior art flexible couplings 20, 22 have been made with a single pivot
 point 30 as shown in FIG. 8. This pivot point 30 was typically defined by
 a steel pin passing through holes in the ends of the tool bars to permit
 slight upward or downward pivoting of the wing tool bars 16, 18 with
 respect to the main tool bar 14. Due to their fixed pivot position, they
 permit adjacent row units (not shown) mounted on either side of the pivot
 30 to collide when wing tool bar 18 is moved upward or downward with
 respect to main tool bar 14. Leading links 32 and 34 are coupled to wing
 tool bar 16 and 18, respectively, and to tongue 36 of implement 12 to
 prevent the wing tool bars from being bent backwards as the implement is
 towed through the field.
 FIG. 9 shows a high mobility flexible coupling 22' for joining the ends of
 main tool bar 14 and wing tool bar 18 that improves upon the prior art
 coupling of FIG. 8 by providing a plurality of pivot points. This coupling
 includes elongate members 38 and 40 extending upward from tool bar 14 and
 elongate members 42 and 44 extending downward from wing tool bar 18.
 Elongate members 38 and 40 have holes through an upper portion that define
 and support pin 46 and elongate members 42 and 44 have holes to a lower
 end thereof that define pin supports for pin 48. An elongate link 50
 extending approximately perpendicularly to the longitudinal extent of main
 tool bar 14 and wing tool bar 18 is disposed between main tool bar 14 and
 wing tool bar 18 and is coupled to the elongate members. Pin 46 passes
 through elongate members 38 and 40 and through a hole in the upper end of
 link 50 to define a pivotal relationship between link 50 and main tool bar
 14. The axis of relative rotation defined by this pivot is substantially
 horizontal. Pin 48 similarity passes through the holes in the lower ends
 of elongate members 42 and 44 and through a hole in a lower end of link 50
 to define a pivotal relationship between the lower end of link 50 and wing
 tool bar 18. The axis of relative rotation defined by this pivot is
 substantially horizontal. Recesses 52 and 54 are provided between elongate
 members 42 and 44 and 38 and 40 on the ends of tool bars 18 and 14,
 respectively, to support the sides of link 50 which is sized to fit into
 these recesses when main tool bar 14 and wing tool bar 18 are
 substantially parallel. FIGS. 2, 4 and 6 show that the assembly pivots
 about a top and a bottom pivot point when wing tool bar 18 is pivoted
 upward or downward with respect to the main tool bar 14.
 FIGS. 1, 3 and 5 illustrate a rear view of implement 12 in the vicinity of
 the flexible coupling 22' (as shown in FIG. 7) and show a portion of main
 tool bar 14, wing tool bar 18 and two row units 24, one mounted on each of
 main tool bar 14 and wing tool bar 18. In FIG. 1, the position of the
 flexible coupling is shown when main tool bar 14 and wing tool bar 18 are
 parallel and colinear. FIG. 2 shows the relative positions of main tool
 bar 14 and wing tool bar 18 when an outer end of wing tool bar 18 is
 pivoted upward with respect to main tool bar 14. FIG. 5 illustrates the
 relative positions of main tool bar 14 and wing tool bar 18 when an outer
 end of wing tool bar 18 is pivoted downward with respect to main tool bar
 14. As can be seen in these three views, when wing tool bar 18 is pivoted
 upward with respect to main tool bar 14 (FIG. 3) the two tool bars pivot
 with respect to each other around a top pivot. By pivoting relative to
 each other about a top pivot point disposed above the center line of main
 tool bar 14 and wing tool bar 18, wing tool bar 18 can rise higher in the
 air, and be disposed at a greater upward angle with respect to main tool
 bar 14 without causing contact between the two adjacent row units 24 as
 compared to the prior art pivot of FIG. 8. In a similar manner, FIG. 5
 shows that wing tool bar 18 pivots with respect to main tool bar 14 a
 pivot point below the top pivot point when an outer end of wing tool bar
 18 is lowered. By pivoting with respect to each other about a pivot point
 disposed below the top pivot point, wing tool bar can rotate downwardly
 with respect to main tool bar 14 without causing interference or contact
 between the two adjacent row units 24 to a greater extend than provided by
 the prior art flexible coupling of FIG. 8. In this manner, a high mobility
 agricultural implement employing high mobility flexible coupling 22'
 provides superior performance and ground contour following ability than an
 implement equipped with the coupling of FIG. 8.
 The flexible coupling of FIGS. 1-6 and 9 can be used in implement 12 in
 place of couplings 20 and 22, instead of the prior art coupling shown in
 FIG. 8. The example described above shows upwardly extending members from
 tool bar 14 and downwardly extending members from the wing tool bar
 connected to it. The coupling could as easily be made with downwardly
 extending members from main tool bar 14 and upwardly extending members
 from the wing tool bar to which it is connected. The spacing of the row
 units is not critical. While the benefits of the flexible coupling are
 most clear when the row units 24 are spaced on fifteen inch centers,
 nonetheless, the same benefits can be provided when the row units are
 spaced farther apart, for example, on twenty to thirty inch centers.
 The description above was directed to "row units." Nonetheless, the high
 mobility flexible coupling described herein is of similar benefit for any
 implement having different ground cultivating devices coupled to its
 flexibly coupled sections. For example, disks, rakes, harrows, chemical
 applicators or other tool bar mounted devices could be substituted for the
 row units illustrated in the figures.
 Thus, it should be apparent that there has been provided in accordance with
 the present invention a high mobility agricultural implement that fully
 satisfies the objectives and advantages set forth above. Although the
 invention has been described in conjunction with specific embodiments
 thereof, it is evidence that many alternatives, modifications and
 variations will be apparent to those skilled in the art. Accordingly, it
 is intended to embrace all such alternatives, modifications and variations
 that fall within the spirit and broad scope of the appended claims.