Abstract:
A sugar cane harvester for harvesting two rows of cane stalks is equipped with a pair of endless track assemblies which each include a track frame suspended from the main frame of the harvester by a four-point suspension including tilt and elevation cylinders that permit side-to-side tilting, and elevation adjustments of the harvester main frame so as to place base cutters at the best attitude for cutting cane contained in the rows, even if the rows are at different elevations.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to tracked sugar cane harvesters and more particularly relates to a track frame and suspension for a two-row cane harvester. 
     It is known to equip a sugar cane harvester with track laying track assemblies for operation in soft or wet fields for floatation and so that undue compaction does not occur. 
     These track assemblies each include a track frames having a cross member extending between a rear portion of the tacks and mounted to a main support frame for tilting about a fore-and-aft axis located midway between the tracks. A pair of tilt cylinders are located at opposite sides of the vehicle and act between the main frame and the cross member so as to place the vehicle main support frame in various selected tilted attitudes relative to the track frames in order to compensate for sloping ground, for rows of cane of different heights and for situations where the cane stalks in one row may be bent over. The track frame cross member which contains the fore-and-aft pivot connection with the main frame also contains a horizontal transverse pivot axis structure about which the tracks are vertically pivotable for adjusting the elevation of the forward part of the main frame, and hence the height of the base cutters carried on the forward part of the main frame, relative to the tracks, this adjustment being done by a pair of elevation cylinders respectively located at opposite sides of the vehicle and mounted between the main frame and respective forward portions of the track frames. The part of the track frame to which the elevation cylinders are attached is a frame portion which straddles the top of the tracks themselves. An example of such a track frame assembly is disclosed in Australian Patent No. 574,871 granted to Paul Mizzi on Jul. 14, 1988. 
     This known track frame design is relatively heavy and the part that straddles the top of the track has a tendency to cause mud and debris to accumulate where the part passes over the tracks. 
     SUMMARY OF THE INVENTION 
     According to the present invention there is provided an improved track frame and suspension for a sugar cane harvester. 
     An object of the invention is to provide a track-supported sugar cane harvester having suspended track frames of a simple, light-weight design. 
     A more specific object of the invention is to provide track frames which are each coupled to the main vehicle frame by a ball joint permitting tilting and vertical adjustments of the track frame and to provide tilt and elevation cylinders which suspend the frame and serve to provide dampening of undercarriage vibrations due to the loads being carried by the hydraulic cylinders. 
     Yet another object of the invention is to provide a sugar cane harvester as set forth in the immediately preceding object wherein there are four points of suspension for each track frame. 
     A further object of the invention is to provide track frames suspended as set forth in one or more of the previous objects, with the suspension for each frame further including a longitudinally extending control arm that acts to transfer turning forces directly to the main frame of the machine. 
     Still another object of the invention is to provide a suspended track frame which is constructed so that it does not tend to accumulate mud and debris in the vicinity of the track. 
     These and other objects will become apparent from a reading of the ensuing description together with the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a right side elevational view of a track-supported sugar cane harvester of the type with which the present invention is particularly adapted for use. 
     FIG. 2 is a perspective view looking towards the left front of the right-hand track of the sugar cane harvester and showing the four-point connection of the track frame with the main frame of the harvester. 
     FIG. 3 is a left front perspective view of the left-hand track frame of the sugar cane harvester. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, there is shown a two-row sugar cane harvester  10  including a main frame  12  supported on right-and left-hand track assemblies, with only the right-hand assembly  14  being shown. An operator&#39;s cab  16  is mounted on a forward part of the main frame  12  just behind mountings on the frame  12  for, and in a position for observing the operation of, a cane topper  18  and sets of elongate, steeply inclined gathering rolls  20  having spiral lifting elements about their periphery. A base cutter assembly is provided for each row of cane stalks to be cut and comprises a pair of counter-rotating cutter blades (not shown) mounted in at a location beneath a rear portion of the cab  16  for severing the stalks of cane close to the ground and for feeding the cut stalks into a passage defined by upper and lower sets of conveyor rolls of a first conveyor (not shown) that conveys the cut cane stalks between a pair of rotary cutters (not shown) that cut the stalks into lengths or billets. A primary extractor  24  is mounted on a rear portion of the main frame  12  at a location behind the rotary cutters which discharge the billets into the primary extractor  24  which acts to separate leafy trash from the billets, the latter falling into a loading conveyor  26 , having its forward end mounted to the main frame  12  for slewing about an upright axis. A secondary extractor  28  is mounted at a rear discharge end of the conveyor  26  and acts to remove any remaining leafy trash from the stream of billets as the billets are deposited into a trailed container (not shown), or the like. 
     It is a common practice to grow cane in raised rows or ridges. For various reasons the cane stalks in one row may be at a different elevation relative to cane stalks in an adjacent row. It is desirable to have the base cutters for the adjacent rows operate to cut the cane as close to the ground as possible so that the maximum amount of stalk is harvested, especially in view of the fact that the sugar content of the lower part of the stalk is higher than in other parts. Therefore, provision is made for side-to-side tilting of the harvester  10 . This is accomplished by the track frame and suspension structure described below. 
     Specifically, referring now to FIG. 2, it can be seen that the right-hand track assembly  14  includes a track frame  30  mounted to the main frame  12  of the cane harvester  10 . The left-hand track assembly includes a track frame  32 , shown only minimally in FIG. 2 but in its entirety in FIG. 3, is mounted to the frame  12  in a manner similar to the track assembly  14 . The right- and left-hand track frames  30  and  32  are mirror images of each other, with like parts being given the same reference numeral followed by an R or an L to differentiate between the opposite sides. For the sake of brevity, only the track assembly  14  and its frame  30  are described in detail with it to be understood that the other track assembly is similar. Further, although only the right-hand track assembly  14  is shown, it is to be understood that absent members of the left-hand track assembly are the same or mirror images of those of the track assembly  14 . 
     The track frame  30  includes a longitudinally extending side member  34 R having a front end defined by a yoke or fork  36 R and a rear end defined by a ring-like housing  38 R. The track frame  30  further includes an A-frame structure projecting inwardly from the side member  34 R and defined by a transverse member  40 R joined to an inner surface of the side member  34 R, at a location just ahead of the ring-like housing  38 R, and by a diagonal brace  42 R having its front end joined to the frame  30 , at the rear of the yoke  36 R, and its rear end joined to an inner end of the transverse member  40 R. A ball (not visible but see ball  46 L in FIG. 3) is welded to a plate  48 R that is in turn welded to an inner end of the transverse member  40 R and an inner surface of a longitudinally extending rear end portion of the diagonal brace  42 R, the ball then projecting inwardly from the plate  48 R. 
     Opposite sides of the yoke  36 R are respectively disposed on opposite sides of an idler wheel  5 OR that is rotatably mounted in a pair of transversely spaced bearing blocks (not shown) mounted for sliding fore-and-aft in a pair of guides (not visible but see one guide  52 L visible in FIG. 3) provided at respective inner surfaces of the yoke sides. The housing  38 R at the rear of the frame  30  serves to support a right-hand hydrostatic transmission drive motor and planetary final drive gear set (not shown) whose output is coupled to a drive sprocket  54 R (FIG. 1) that is aligned with the idler wheel  50 R. An endless track  56 R extends about the drive sprocket  54 R and idler wheel  50 R. A plurality of track rollers  58 R are mounted to the longitudinal member  34 R, with two being shown mounted to the top of the member  34 R and engaging a bottom surface of a top run of the track  52 R and with the remainder being shown mounted to underside locations of the frame member  34 R and engaging a top surface of a bottom run of the track  52 R. A track tensioner (not shown) of a well known construction is coupled between the longitudinal member  34 R of the frame  30  and the idler wheel  5 OR for forcing the wheel against the track  40 , but being able to recoil to permit obstacles to pass between the track  56 R and the idler wheel  50 R or drive sprocket  54 R. 
     The right- and left-hand track frames  30  and  32  are both suspended from underside locations of the main frame  12 . With reference to FIG. 2, it can be seen that the main frame  12  includes a longitudinally extending right-hand side rail  60 R that is inclined upwardly from front to rear, this side rail being just inwardly of the track  56 R. A corresponding left-hand side rail (not shown) is provided just inwardly of the track at the left-hand side of the cane harvester  10 . A cross beam, not shown, joins rear portions of the side rails. The main frame  12  includes a horizontal platform  62  located on the longitudinal center of the harvester  10  adjacent and above rear ends of the right- and left-hand track frames  30  and  32 , respectively. A centrally located post  64  extends between and has its opposite ends joined to the cross beam and the platform  62 . A right-hand side post  66 R extends between and has it opposite ends respectively joined to a right-hand forward corner of the platform  62  and the side rail  60 R, the post  66 R being angled upwardly and outwardly from the platform  62 . A support member  68 R, in the form of a right triangle, has its hypotenuse fixed to the outer surface of the side post  66 R, its base extending horizontally at a level above that of the top of the track  52 R and its remaining side located in a first longitudinally extending vertical plane spaced inwardly from a second longitudinal vertical plane containing inner ends of the upper and lower runs of the track  52 R, as considered when the latter is resting on a horizontal surface. Fixed to and projecting downwardly from an outer location of the base of the triangular support member  68 R is a pair of longitudinally spaced mounting lugs or ears  70 R having a purpose explained below. The main frame  12  further includes a front brace  72 R having an upper end fixed to the side rail  60 R and a rear brace  70 R having an upper end joined at the junction of the side post  66 R and the side rail  60 R, the front and rear braces  72 R and  74 R converging downwardly and being joined together at a reinforcing member  76 R located inwardly from, and about half way between opposite ends of, the track frame member  34 R. A pair of transversely spaced plates  77 R extend beneath and are fixed to the reinforcing member  76 R, the brace  72 R and a portion of the side rail  60 R leading up to the brace  72 R. Converging toward and being joined to each other and to the reinforcing member  76 R, at a location adjacent the rear brace  74 R, are inner and outer, generally horizontal beam members  78 R and  80 R which have their rear ends respectively fixed to forward central, and right front locations of the platform  62 . A left-hand inner beam member  78 L is also partly visible. A mounting lug  82  has a rear end joined to a front, central location of the platform  62  between the rear ends of the inner beam members  78 R and  78 L and extends downwardly and forwardly from the platform  62  to a location at a level below that of the bottom of the platform  62 , and hence, below the bottoms of the beam members extending from the platform. 
     The track frames  30  and  32  are coupled to the frame  12  in a manner presently described. Specifically, the lower end of the mounting lug  82  is provided at its opposite sides with ball receptacles of which only the left-hand receptacle  84 L is shown. The right-hand ball of the track frame  30  is captured for universal movement in the right-hand receptacle while the left-hand ball  46 L of the track frame  32  is captured for universal movement in the left-hand receptacle  84 L. Spaced a short distance inwardly on the rear transverse member  40 R from the longitudinal member  34 R and fixed to top and front surfaces of the member  40 R are a pair of transversely spaced plates  86 R. 
     An extensible and retractable hydraulic tilt cylinder  88 R has a lug at its cylinder end which is received between and pinned to the pair of plates  86 R by a transverse pin  90 R while a terminus of the rod end of the cylinder  88 R is defined by an eye that is located between the mounting lugs  70 R and coupled thereto by a longitudinal pin  92 R. 
     A longitudinal control arm or link  94 R has a rear end located between and coupled to forwardly projecting portions of the plates  86 R by a transverse pin  96 R, and has a front end received between the plates  77 R, at a location below the reinforcing member  76 R, and are coupled to the plates by a transverse pin  98 R. 
     Mounted to the top of the diagonal member  42 R of the track frame  30  at a location in longitudinal alignment with the tilt cylinder  88 R and control arm  94 R is an extensible and retractable hydraulic elevation cylinder  100 R. The cylinder  100 R has its lower end coupled to the top of the member  42 R by a ball joint connection  102 R. The upper end of the cylinder  100  is received between the plates  77 R, at a location below the junction of the rail  60 R and brace  72 R, and is coupled to the plates by a transverse pin  104 R. 
     It will be appreciated then that the track frames  30  and  32  are each suspended from the main frame  12  at four points, namely the connection at the ball joint at the inner rear corner of each of the frames (see ball joint  46 L of the frame  32 ), the connection at the top of the tilt cylinder  88 R or  88 L, the connection at the front end of the control arm  94 R or  94 L and the connection at the top of the elevation cylinder  100 R or  100 L. It is here noted that the pins  96 R and  96 L respectively coupling the control arms  94 R and  94 L to the track frames  30  and  32  are aligned with the ball joints defined by the balls carried by the frames  30  and  32  and the ball receptacles carried by the main frame member  82  so as to define respective transverse pivot axes about which the track frames  30  and  32  are pivotable in response to extension or retraction of the elevation cylinders  30  and  32 . Ideally, the pivot connections of the lower ends of the tilt cylinders  88 R and  88 L would respectively be on the same axis as the pins  96 R and  96 L but such would require special clevis ends to be fashioned for the tilt cylinders. 
     The operation of the suspension of the track assembly  14  shown in FIG. 2 is stated below with it to be understood that the left hand track assembly operates in a similar fashion. If the operator desires to elevate the right-hand side of the cane harvester  10  relative to its left-hand side, the operator will effect extension of the tilt cylinder  88 R. This will cause the main frame  12  to pivot upwardly about the ball joint (not shown) that is fixed to the plate  48 R. Contraction of the left-hand tilt cylinder  88 L will create an even more difference in the elevation of the opposite sides of the frame  12 . Tilting the frame  12  in the opposite direction is accomplished by extending the left-hand tilt cylinder  88 L and/or contracting the right-hand tilt cylinder  88 R. 
     Raising or lowering of the front of the main frame  12  of the harvester  10  is effected by respectively extending or contracting the elevation cylinders  100 R and  100 L so as to pivot the frame  22  vertically about the transverse axis defined by the ball joints respectively at the inner rear of the frames  30  and  32  and the pivot pins  96 R and  96 L. The location of the elevation cylinders  100 R and  100 L on the diagonal members  42 R and  42 L allows forces to be applied directly on the longitudinal center of the diagonal members which are supported at their rear ends by the main frame  12 . This minimizes twisting loads from being imposed on the diagonal members  42 R and  42 L and transferred to the longitudinally extending side members  34 R and  34 L is important since they carry the track rollers  58 R that keep the tracks in proper alignment. With the elevation cylinders  100 R and  100 L so connected to the track frames  30  and  32 , no straddle frame over the tracks is required, such straddle frames inherently causing mud build-up problems and increasing the weight and complexity of the track frames. 
     When the harvester  10  is being turned to the right, loads imposed by the earth on the outer side of the track  52 R will be transferred in compression through the control arm  94 R to the main frame  12  while loads imposed by the earth on the inner side of the left-hand track will be transferred through the control arm  94 L in tension to the main frame  12 . Reverse loading of the control arms  94 R and  94 L will occur during a left-hand turn. While the control arms  94 R and  94 L are preferably located as disclosed, there are other ways of keeping the track frames  30  and  32  parallel with a longitudinal centerline of the vehicle  10  when side loads are imposed on the tracks. For example, while the plates  86 R are here shown projecting forwardly to provide a location for the connection  96 R, the geometry of the track frame  30  could be modified slightly by shifting the transverse member  40 R forwardly far enough to permit the plates  86 R to extend to the rear with the pivot  96 R being provided there and still aligned with the ball joint axis. In such a construction, the control arm  94 R could be modified so as to extend rearwardly and inwardly from the connection  96 R, with the connection  98 R then being relocated to a position on platform  62  rearwardly of the ball joint support  82 . Another alternative could be to dispense with the control arms  94 R and  94 L altogether and to perform the controlling function with the elevation cylinders  100 R and  100 L. In this case, the cylinders  100 R and  100 L and their end connections would be of a more robust construction so as to withstand side loads imposed on the tracks. Still another possible alternative to using the control arms  94 R and  94 L would be to provide the main frame  10  with a pair of transversely spaced restraining plates for each track frame that straddle a specially shaped bumper structure forming part of an adjacent track frame, this arrangement permitting the track frames to freely elevate and tilt while having their sideways movement restrained. 
     The hydraulic actuators  88 R,  88 L,  100 R and  100 L serve to carry loads imposed on the track assemblies and thus also serve to dampen vibrations transmitted through the track assemblies. This of course is the preferred embodiment, however, other powered extensible and retractable devices, such as powered screw jacks, for example, could be used instead of hydraulic cylinders. Yet another alternate construction would be to substitute powered crank arms coupled between the main frame  12  and the track frames  30  and  32  at the locations occupied by the cylinders  100 R,  100 L and  88 R,  88 L, and arranged to produce a mainly vertical movement of the track frame at its points of connection with the crank arms.