Not applicable.
Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates generally to an agricultural implement, including a work tool. More particularly, the present invention relates to an improved suspension system for agricultural implements having one or more floating work tools.
2. Background Art
Ground on which forage crops or other mowable foliage is grown is rarely smooth. Such ground essentially always varies in level both in a direction of travel of the mowing machine or harvester, and in a transverse or lateral direction.
Mowing machines having a variable height cutter have been available for decades. Mounted sickle mowers used in the mid-twentieth century could be raised and lowered using the tractor lift system. Towed mowers, by necessity, were made so the work tool could be raised and lowered, at least between an operating position and a transport position.
U.S. patent application Ser. No. 11/927,866 to Thompson et al. filed Oct. 30, 2007 is incorporated herein by reference in its entirety, relates to the field of this invention and is prior art to the instant application at this time.
In U.S. Pat. No. 6,250,055, a mower header suspension system is disclosed and is incorporated herein by reference. The suspension system comprises a pair of lower linkage arms and a single upper suspension arm. Provision for changes in ground elevation in the direction of travel is disclosed.
Disclosed in U.S. Pat. No. 6,055,800 is a mower header suspension system providing a variable header angle compared to the longitudinal direction and is incorporated herein by reference. The disclosed mechanism comprises two lower linkage arms and a single upper linkage arm.
The above described header suspension systems provide for changing the height of cut relative to the ground surface supporting the ground engaging wheels of the tractor or towed mower, but do not provide for a consistent cut height on ground that varies in level both in the direction of travel and in the lateral direction.
There is, therefore, a need for a method and apparatus for providing flexibility in header position to permit the header to raise and lower as ground elevation changes, and to rotate to adjust to lateral variations in ground surface levels.
There is an additional need for a header suspension system providing self-leveling, in the transverse direction, when the header is positioned in its transport mode.
An object of the present invention is to provide a work tool suspension system that enables a header or work tool of a towed implement to be raised and lowered so mowing height can be varied. Another object is to provide a work tool suspension system permitting the header or work tool to follow the variable ground contour—both in the direction of travel and transverse to the direction of travel, resulting in a consistent cut height despite the variability of the ground elevation. Still another object is to provide a work tool suspension system providing for self-leveling in the transverse direction when the header or work tool is raised to its transport height.
For the purposes of this document, including the claims, a towed implement is an implement with ground engaging wheels or the like, independent of the source of motive power, for example a farm tractor; additionally, the towed implement has a frame or other component that may be raised and lowered relative to the ground engaging wheels independent of a lift, such as a standard three-point or two-point lift system, of the source of motive power. Therefore, a towed vehicle is pulled by the source of motive power. The towed vehicle may make use of the source of motive power's hydraulic system for raising and lowering, but does not make use of lift arms usually attached to a farm tractor.
The mower comprises two integrated frames connected by two sets of linkages to create a four-bar linkage. As with any four-bar linkage, the two sets of linkages are maintained parallel to one another, so that the two frames are maintained at a known orientation to one another as the header is raised and lowered.
The lower linkage set preferably comprises two links oriented at angles with respect to a longitudinal axis of the mower such that they connect to the sub-frame at points nearer the longitudinal axis than those points at which they connect to the main frame.
In contrast, the upper links are angled such that they connect to the sub-frame at points farther from the longitudinal axis than those points at which the upper links connect to the main frame.
A spherical bearing provides a joint between two links, the joint having a pivot point. In other words, there is no unique axis of rotation. In contrast, a cylindrical bearing disposed between two links provides an axis on which the links pivot relative to one another. Rotation about any other axis requires straining of the cylindrical bearing or the links.
Spherical bearings are used to connect each independent bar of the upper linkage set to the main frame and to the sub-frame. As well, spherical bearings are also used to connect the lower linkage bars to the sub-frame. The lower linkage bars are pivotally attached to the main frame by cylindrical bearings.
In a first embodiment, the lower linkage bars are affixed to one another where the lower linkage bars converge at their sub-frame ends, and are subsequently connected to the sub-frame using a single spherical bearing. In an alternative embodiment, the two lower linkage bars are not directly connected to one another, but are pivotally connected to the sub-frame by independent spherical bearings in the same manner as the upper linkage bars.
The linkage arrangement herein described allows the sub-frame the ability to rotate about an axis of rotation parallel to the longitudinal axis of the mower. This ability is called “float” and refers to the capability of the mower to adjust itself automatically to a ground slope perpendicular to the direction of travel.
An additional feature of the above-described arrangement of links is self-leveling. Due to constant tension in the upper links and constant compression in the lower links, the work tool or header will level itself when drawn up to its uppermost, or transport position.
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.
a is a side elevation of an agricultural mower;
b is a side elevation of the agricultural mower in an operating configuration;
a is a top plan view of the sub-frame in a transport configuration showing arms of the working tool rotated inward toward the longitudinal axis, narrowing the implement, for transport;
b is a top plan view of the sub-frame in an operating configuration showing the working tool arms rotated outward from the longitudinal axis in an operating configuration;
a is an isometric view of the mower in the transport configuration;
b is an isometric view of the mower in operational configuration;
a is a rear elevation view of the mower in a second embodiment having individual links at a bottom of the four-bar linkage system;
b is a rear elevation view of the mower in a third embodiment having individual links at a bottom of the four-bar linkage system;
Referring now to the drawings wherein like reference numerals indicate identical or corresponding parts throughout the several views, the present invention in its preferred embodiment comprises a suspension system for an agricultural mower 1, shown in its entirety in
The tongue 2 is preferably drawn by an agricultural tractor 100 as shown in
A front of the mower 1 is likewise hereby defined as the general portion of the mower 1 in the lead as the mower 1 is drawn in the forward direction. A rear of the mower 1 is hereby defined as the general portion of the mower 1 seen when viewed from the end of the mower 1 opposite the tongue and facing in the forward direction.
A longitudinal direction is hereby defined as a direction parallel to the forward direction. A transverse direction is hereby defined as a direction perpendicular to the longitudinal direction, and parallel to an appropriate average of a slope of the ground surface in the vicinity of a header 6.
The verb, narrow, is defined herein as a reduction in a width of the implement in the transverse direction. The implement is narrowed for transport. Narrow does not imply shorten, which is a reduction in length in the longitudinal direction.
The above definitions are defined for the purposes of this document, including the claims.
The present invention comprises a four-bar linkage system including an upper set of linkages 12 and a lower set of linkages 11, each comprising two bars as illustrated in
Each independent bar of the upper linkage set 12 is pivotally connected to the main frame 15 by a spherical bearing, also known as a ball joint, at a first point and is pivotally connected to the sub-frame 10 by a spherical bearing at a second point. The use of ball joints on the upper linkage set 12 permits the sub-frame 10 to sway transversely at its top, hence providing float for the header 9 as can be seen in
As illustrated in
The use of cylindrical bearings between the lower linkage members 12 and the main frame 15 restricts the lower linkage arms 11 to a pivot on a single axis of rotation. The spherical bearing or bearings at the connecting point between the sub-frame 10 and the lower linkage arms 11 permit the sub-frame to rotate about an axis parallel to the longitudinal axis 52, as well as an axis perpendicular to the longitudinal axis 52. Hence, the header 9 may be raised and lowered between the transport and operational positions, as well as float while in the operational mode.
The linkage arrangements described above allow the sub-frame 10 to rotate about an axis of rotation parallel to the longitudinal axis 52 (see
As illustrated especially in
Skid shoes, attached to the two header sections 9, operatively engage the ground and provide the forces required to cause the two header sections 9 to pivot about the cylindrical bearings 4 to conform to the ground contour. In conforming to the ground contour, cut crop height may be maintained more evenly, and there is less chance of engaging the cutters to the soil.
The two arms 8, pivotally mounted to the top of the forward portion of the sub-frame 10, also rotate about vertical axes of rotation. Consequently, the cutter bars 9 suspended from these arms 8 pivot toward or away from the longitudinal axis 52. As shown in
The sub-frame 10 is mounted on the suspension system in such a way as to give the sub-frame 10 a multidirectional freedom of motion. Hence, the underside of the cutter bar 9 is allowed to more consistently engage the ground surface 65 as the ground surface 65 varies. This results in benefits of a more consistent cut height, less crop wastage, and less frequent engagement of the cutters into soil.
Another significant benefit is realized by the converging and diverging arrangements of the lower linkage bars 11 and the upper linkage bars 12, in combination with the illustrated connection of the sub-frame lift cylinder 14 to the sub-frame 10. Due to the lower linkage bars 11 being in compression and the upper linkage bars 12 being in tension whenever the sub-frame lift cylinder 14 carries any of the header's 6 weight, the header 6 is self-leveling, as shown in
The point at which the sub-frame lift cylinder 14 connects to the sub-frame must be above the connection point of the lower linkage arms 11 to the sub-frame and below the connection point of the upper linkage arms 12 to the sub-frame in order to effect the compression of the lower links 11 and tension of the upper links 12 explained above.
An additional leveling feature is illustrated in
The embodiments of the novel suspension system herein described may be utilized for any implement making use of a floating work tool. The invention is not intended to be limited to agricultural mowers.
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.
Number | Name | Date | Kind |
---|---|---|---|
3517491 | Harer et al. | Jun 1970 | A |
3592106 | Baughman | Jul 1971 | A |
4177627 | Cicci | Dec 1979 | A |
4207802 | Homuth | Jun 1980 | A |
4286423 | Caldwell et al. | Sep 1981 | A |
4343138 | Neuerburg | Aug 1982 | A |
4506609 | Fuss et al. | Mar 1985 | A |
4599852 | Kerber | Jul 1986 | A |
4676053 | Pruitt | Jun 1987 | A |
4719742 | Ermacora | Jan 1988 | A |
4723396 | Ermacora | Feb 1988 | A |
4723401 | Webster | Feb 1988 | A |
4724661 | Blakeslee | Feb 1988 | A |
4970848 | Neuerburg | Nov 1990 | A |
5060462 | Helfer | Oct 1991 | A |
5107663 | Wattron | Apr 1992 | A |
5193330 | Nusser | Mar 1993 | A |
5203154 | Lesher | Apr 1993 | A |
5337544 | Lauritsen | Aug 1994 | A |
5417042 | Walch | May 1995 | A |
5566535 | Pruitt | Oct 1996 | A |
5566536 | Krafka | Oct 1996 | A |
5737859 | Tardif | Apr 1998 | A |
5992133 | Walch | Nov 1999 | A |
6035478 | Miller et al. | Mar 2000 | A |
6055800 | Walch | May 2000 | A |
6076341 | Gummerson | Jun 2000 | A |
6085501 | Walch | Jul 2000 | A |
6125619 | Wolff | Oct 2000 | A |
6186043 | Callies | Feb 2001 | B1 |
6238170 | Pingry et al. | May 2001 | B1 |
6250055 | Franet | Jun 2001 | B1 |
6269619 | Walch | Aug 2001 | B1 |
6308504 | Walch | Oct 2001 | B1 |
6345490 | Wolff | Feb 2002 | B1 |
6360516 | Harkcom | Mar 2002 | B1 |
6381935 | Wattron | May 2002 | B1 |
6655118 | Thompson | Dec 2003 | B1 |
6662540 | Harkcom | Dec 2003 | B1 |
6666010 | Beaufort et al. | Dec 2003 | B2 |
6698113 | Jones | Mar 2004 | B1 |
6758031 | Franet | Jul 2004 | B2 |
6782680 | Viaud et al. | Aug 2004 | B2 |
6907719 | Ligouy | Jun 2005 | B2 |
7024844 | Schlesser | Apr 2006 | B2 |
7047714 | Stephenson | May 2006 | B1 |
7596935 | Bollinger et al. | Oct 2009 | B2 |
7658056 | Thompson et al. | Feb 2010 | B2 |
7726109 | Thompson et al. | Jun 2010 | B2 |
7958707 | Thompson et al. | Jun 2011 | B2 |
7996794 | Kobayashi et al. | Aug 2011 | B2 |
20030221401 | Ligouy | Dec 2003 | A1 |
20040035288 | Hawthorne | Feb 2004 | A1 |
20060248870 | Geiser | Nov 2006 | A1 |
20070144130 | Geiser | Jun 2007 | A1 |
20090107097 | Thompson | Apr 2009 | A1 |
20090107100 | Bollinger et al. | Apr 2009 | A1 |
Number | Date | Country |
---|---|---|
456900 | Nov 1991 | EP |
0642731 | Mar 1995 | EP |
Number | Date | Country | |
---|---|---|---|
20110047948 A1 | Mar 2011 | US |