Abstract:
A self-propelled windrower includes a rear axle having end sections which are adjustable to vary the tread width of caster-mounted rear wheels having upright spindles mounted for swiveling within cylindrical receptacles defining outer ends of the axle end sections. Front wheels of the windrower are steerable and a steering assist is provided including right and left steering cylinders having barrels respectively mounted to right and left reaction arms by a mounting permitting the cylinder to pivot vertically and horizontally, with the rods being coupled to respective steering arms fixed to the top of the spindles. In a first embodiment, right and left brackets are respectively fixed to forward surfaces of opposite end regions of a tubular center section of the rear axle in which the axle end sections are received for telescopic adjustment. The right and left reaction arms are respectively mounted to the right and left brackets when the end sections are in inward narrow tread width positions, and are respectively mounted to forward surface locations of outer end regions of the axle end sections when the latter are in outward wide tread width positions. In a second embodiment, the reaction arms are mounted to spindle receptacles at the outer ends of the axle sections such that the reaction arms may be secured in an infinite number of angular positions about the spindle receptacles so as to accommodate different tread widths of the steered rear wheels and/or different machine configurations and/or improved access to the machine without interference with other parts, other attachments, or for any other reasons.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to steering cylinder mountings and more specifically relates to such mountings as are applied for steering wheels at the opposite ends of an axle which is adjustable to vary the tread of the vehicle. 
       BACKGROUND OF THE INVENTION 
       [0002]    Self-propelled windrowers typically include a main frame supported on a pair of front wheels, which are separately driven hydrostatically so as to afford steering to the windrower by driving the wheels at different speeds, and a pair of rear wheels which are mounted to opposite ends of a rear axle so that they pivot about an upright caster axis. Some windrowers are capable of delivering conditioned crop to one side of the vehicle to form a windrow in a region which may be located at least partially in the track behind the front wheel at that side of the vehicle in order to group the windrow with a previously formed windrow laid down along a path at the center of the vehicle between the front and rear pairs of wheels. The axle sections to which the rear wheels are telescopically mounted within a remaining middle section of the rear axle and are fixed in selected positions so as to change the distance between the rear wheels, with the rear wheel on the discharge side of the vehicle being adjusted inwardly towards the center of the vehicle so that the adjusted wheel will not run upon the crop windrow. An example of such a self-propelled windrower is disclosed in U.S. Pat. No. 7,028,459. 
         [0003]    A hydraulic steering assist system (see U.S. patent application Ser. No. 11/957,800, filed on 17 Dec., 2007 and assigned to the assignee of the instant application) has been developed for steering the rear wheels of a self-propelled windrower in conjunction with the steering of the driven front wheels in order to give an operator more control over the self-propelled windrower when operated at relatively high road or transport speeds. The steering cylinders of this steering assist system are respectively secured to cylinder mounting assemblies respectively fixed at opposite end locations of a tubular middle section of the rear axle and into opposite ends of which opposite end sections of the axle are telescopically received for adjustment, with the rod ends of the cylinders being coupled to steering arms respectively fixed to top end regions of the upright spindles of the caster-mounted wheels. A drawback of this assist system is that, while the rear axle is disclosed as being adjustable in length, no provision is made for adjusting the position of the steering assist cylinder in order to accommodate for the change in axle length, and, hence, the change in the distance between the steering arm at the top of the caster spindle and the fixed steering cylinder. 
         [0004]    The problem to be solved is to provide a simple cylinder mounting structure for resisting steering assist cylinder reaction loads and for also allowing the cylinder to be repositioned for maintaining steering function when the axle length has been adjusted. 
       SUMMARY OF THE INVENTION 
       [0005]    According to the present invention there is provided a mounting assembly for a hydraulic steering cylinder coupled for effecting steering movements of a caster-mounted rear wheel, and more specifically there is provided a mounting assembly which overcomes the aforementioned drawbacks of the prior art mounting assembly. 
         [0006]    A broad object of the invention is to provide a steering cylinder mounting assembly comprising a reaction arm mounted for movement with the adjustable section of the fixed rear axle so that the distance between the actuator and the steering arm remains constant and with the reaction arm being adjustable to any angular position about the caster-mounted wheel spindle so as to accommodate different track positions of the steered rear wheels and/or different machine configurations and/or improved access to the machine without interference with other parts, other attachments, or for any other reasons. 
         [0007]    A more specific object of the invention is to provide a reaction arm, as stated in the previous object, which, when the axle is adjusted to a narrow track position, is mounted in a first orientation to a bracket fixed on the fixed section of the axle, and which, when the axle is adjusted to a wide track position is mounted directly to the adjustable section of the axle in a second orientation, disposed 45° from the first orientation, with the first and second orientations so that the reaction arm and supported steering cylinder is located, for example, for avoiding interference, for being in an aesthetically pleasing position, or for any other reason. 
         [0008]    In accordance with a second embodiment, it is an object to mount the reaction arm to the spindle of the steered wheel in a manner which permits the reaction arm to be placed in an infinite number of positions about the spindle so as to provide improved access to other parts and/or avoid interference with other parts as changes are made in the track width of the steered rear wheels and/or to adapt to different machine configurations. 
         [0009]    The object(s) pertaining to the first embodiment (is) are achieved by constructing the reaction arm so as to have one end defined by a mounting surface which disposes the reaction arm substantially fore-and-aft when the mounting surface is secured against a mounting surface of a bracket fixed to the fixed axle section, and which disposes the reaction arm at an angle of about 45° from fore-and-aft when the reaction arm mounting surface is secured against the moveable axle section. 
         [0010]    The object(s) pertaining to the second embodiment (is) are achieved by providing a reaction arm having an end defined by a clevis which is clamped to top and bottom regions of a cylindrical spindle receptacle at the end of the axle which has the steerable wheel spindle located therein. 
         [0011]    These and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic top view showing a self-propelled windrower with a cab and front section of a main frame removed revealing a windrow accumulator suspended from the frame for delivering crop to a location behind a right front, steerable drive wheel, and with rear wheels being shown caster-mounted to opposite ends of a fixed rear axle and coupled for being steered by hydraulic steering assist cylinders. 
           [0013]      FIG. 2  is a schematic top view with parts broken away showing the fixed rear axle with the right caster wheel being shown in an inner adjusted position and the reaction arm being positioned so as to extend fore-and-aft, and with the left caster wheel being shown in an outer adjusted position and the reaction arm being positioned so as to extend transversely at an approximately a 45° degree angle to the axle. 
           [0014]      FIG. 3  is an enlarged right rear perspective view showing the right caster wheel and reaction arm positioned as depicted in  FIG. 2 . 
           [0015]      FIG. 4  is a perspective view similar to that of  FIG. 3 , but showing a second embodiment wherein the reaction arm is mounted to the spindle receptacle at the end of the right adjustable axle section cylinder to the reaction arm and a steering arm fixed to the top of the caster spindle. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0016]    Referring now to  FIG. 1 , there is shown a self-propelled windrower  10  including a main frame  12  supported on a pair of driven front wheels  14  and on a pair of rear ground wheels  16  located at the opposite ends of an axle  18  located at the rear of the frame  12 . A header  20  is suspended at a forward end of the frame  12  in a well known manner (not shown), with the header being equipped with crop cutting and conditioning arrangements (not shown), with the cutting arrangement being operable for severing stems of the crop at ground level and for feeding the severed crop into the conditioning arrangement which conditions and then propels the conditioned crop to the rear. A cross-conveyor  22  is suspended from the frame  12  in a conventional manner (not shown) so as to extend obliquely to a longitudinal center line of the windrower  10  from a location just inside the left front wheel  14  to a location just to the rear of the right front wheel  14 , the conveyor  22  being mounted for selective movement between a lowered working position and a raised stand-by position. When in the lowered working position, the cross-conveyor  22  is disposed for receiving conditioned crop discharged rearwardly from the conditioning arrangement and for conveying this crop laterally to form a windrow of crop behind the right front wheel  14 . When the cross-conveyor  22  is located in the raised, stand-by position, crop discharged from the conditioning arrangement is deposited on the ground beneath the cross-conveyor  22  so as to form a windrow extending along the longitudinal center line of the windrower  10  between the sets of wheels  14  and  16 . In a manner known in the art, two crop windrows can be bunched together by first placing the cross-conveyor  22  in its raised position, and operating the windrower  10  to cut a swath of crop at the left side of a field of standing crop, thus forming a first windrow which lies along the longitudinal center of the windrower  10 . Once this pass is completed, the cross-conveyor  22  is lowered and the windrower is driven in the opposite direction to cut a swath which, from the perspective of the operator, is located at the right side of the field of standing crop, the cross-conveyor then acting to deposit crop to the rear of the right front wheel  14  so as to form a second windrow alongside the first-formed windrow. 
         [0017]    Referring now to  FIG. 2 , the rigid rear axle  18 , which is incorporated in the frame  12 , includes a tubular fixed central section  24  having right and left end sections  26  and  28 , respectively, telescopically received in opposite ends of the central section  24 . Each of the axle end sections  26  and  28  is secured in a desired adjusted location by a pair of bolts  30  which pass through a pair of holes (not shown) provided in an end region of the central axle section  24  and a pair of aligned ones of a plurality of adjustment holes  32  (two shown in end section  26  in  FIG. 3 ) spaced lengthwise along the adjustable axle end sections  26  and  28 . The outer ends of each of the end sections  26  and  28  of the rear axle  18  is defined by a substantially cylindrical, upright spindle receptacle  34  ( FIG. 3 ). 
         [0018]    The rear wheels  16  are respectively caster-mounted to the spindle receptacles  34  by right and left wheel support arm assemblies  36  and  38 , which are mirror images of each other. Referring also to  FIG. 3 , it can be seen that each of the arm assemblies  36  and  38 , as viewed with the wheels  16  oriented for traveling straight ahead as shown in  FIG. 2 , includes an upper mounting member  40  including a rear portion  42  containing a vertical cylindrical through bore provided with splines, with the through bore having a splined lower end of a spindle  44  received therein and held in place by a threaded bolt  46  on which a washer is received, the bolt being received in a threaded bore extending axially into a bottom end of the spindle  44 . The spindles  44  of the arm assemblies  36  and  38  respectively project upwardly through the receptacles  34  at the ends of the axle sections  26  and  28 . Upper ends of the spindles  44  are splined and a pair of steering arms  48  respectively contain splined openings in which the splined upper ends of the spindles  44  are respectively received, the arms  48  being held in place by circlips  50  received in grooves provided in upper end regions of the spindles  44 . The arm assemblies  36  and  38  further include right and left, L-shaped wheel arms  52 R and  52 L, respectively. The wheel arms  52 R and  52 L each include an upper horizontal section  54  which extends in front of a respective one of the wheels  16  and is joined to a downwardly and rearwardly inclined section  56  such that the arms  52 R and  52 L respectively curve around to the right side of the right wheel  16  and to the left side of the left wheel  16  so that the wheels are approximately in fore-and-aft alignment with the spindles  44 . The lower ends of the inclined arm sections  46  are respectively defined by cylindrical tubes  58  in which a stub shaft (not shown) is fixed, the stub shafts projecting inwardly from the tubes  58  and having respective hubs of the wheels  16  received thereon for rotation thereabout, as is well known in the art. 
         [0019]    The arms  52 R and  52 L are respectively coupled to the upper mounting members  40  by a pair of suspension arrangements  60 , which are each similar to that disclosed in U.S. patent application Ser. No. 11/968,759 filed 3 January and having the same assignee as does the instant application. The suspension arrangements  60  each include a horizontal shaft  62  extending axially through a tube (not shown) having a square cross section and being disposed in parallel relationship to, and above, the horizontal section  54  of the wheel arms  52 R and  52 L. Opposite ends of the shaft  62  are fixed to the associated arm section  54  by clamp arrangements  64  with a central part of the shaft  50  being tightly engaged with resilient elastomeric members (not shown) located within the tube receiving the shaft  62 . This tube is clamped to the upper mounting member  40  by a set of four, generally U-shaped bolts  66  located adjacent each end of the tube and which embrace the tube and have threaded ends projecting through holes provided in the upper mounting member  40  and receiving respective nuts  68 . 
         [0020]    With reference to  FIGS. 2 and 3 , it can be seen that right and left arm support brackets  74 R and  74 L, respectively, are mounted to right and left end regions of the central axle section  24 . The support bracket  74 R is a weldment comprising an inverted U-shaped channel member  76 , which, in  FIG. 2 , extends rightwardly and rearwardly at an angle of 45° to a straight forward direction of travel and having a rear end joined to a vertical rear mounting plate  78  and a front end joined to a vertical front mounting plate  80 . The bottoms of the opposite sides of the channel member  76  are fixed to a horizontal plate  82 . The rear mounting plate  80  is clamped to a forward surface of the right end region of the central axle section  24  in sandwiching relationship to a spacer plate  84  by a pair of the bolts  30  which extend through aligned holes provided in the axle sections  24  and  26  and in the mounting and spacer plates  80  and  84 , respectively. 
         [0021]    The support bracket  74 L is a mirror image of the support bracket  74 R and includes an inverted U-shaped channel member  86  which extends leftwardly and rearwardly at an angle of 45° to a straight forward direction of travel, has front and rear ends respectively joined to vertical front and rear mounting plates  88  and  90 , respectively, and has depending sides joined to a horizontal plate  92 . The vertical front mounting plate  88  is clamped to the rear surface of a left end region of the central axle section  24  in sandwiching relationship to a vertical spacer plate  94  by the mounting bolts  30 . 
         [0022]    Right and left steering reaction arms  96 R and  96 L are respectively provided for supporting right and left, hydraulic steering cylinders  98  for steering the right and left rear wheels  16 . The reaction arm  96 R is defined by a weldment including a U-shaped channel member  99  which increases in height and width from front to rear, with the channel being closed by a top plate  100  fixed to the tops of opposite sides of the channel member, and has a bottom plate  102  extending beneath, and fixed to, a forward region of the web of the channel member  99 . A forward end of the channel member  99  and the plates  100  and  102  define a vertical L-shaped upright edge assembly, as viewed from the top in  FIG. 2 , to which an L-shaped mounting plate  104  is fixed. Welded in place within circular openings provided in the top plate  100  and the web of the channel member  99 , in a forward region of the reaction arm  96 R, is an upright cylindrical mounting yoke stem receptacle  105  (only visible in  FIG. 3 ). 
         [0023]    When the axle section  26 , together with the right wheel  16 , is adjusted to an inner narrow track position as shown in  FIG. 2 , the long leg of the mounting plate  104  is clamped to the mounting plate  78  of the support bracket  74 R in sandwiching relationship to a spacer plate  106  by a pair of bolts  108  respectively extending through aligned holes provided in opposite ends of the plates  78 ,  106  and  104 . As can best be seen in  FIG. 3 , the short leg of the mounting plate  104  is clamped, as by vertically spaced bolts  110 , to an upright plate  112  forming part of a U-shaped mounting bracket  114  having vertically spaced legs supported by the spindle receptacle  34 . When the axle section  26 , together with the right wheel  16  is adjusted to an outward wide track position, the L-shaped mounting plate  104  of the reaction arm  96 R is secured to a front outer end region of the axle section  26  in sandwiching relationship to the spacer plate  106  by the bolts  108 . 
         [0024]    The reaction arm  96 L is a mirror image of the bracket  96 R and includes a channel member  116  which is visible through a hole provided in a top plate  118  fixed across the tops of opposite sides of the channel member. A bottom plate  120  is fixed across a forward region of the bottom of the channel member  116 . A vertically oriented, L-shaped mounting plate  122  joins a complimentary-shaped forward end arrangement of the channel member  116  and plates  118  and  120 . A left upright, cylindrical mounting yoke stem receptacle (not visible) is provided in a front end region of the reaction arm  96 L. 
         [0025]    When the axle section  28  is adjusted outwardly with the left wheel  16  to establish a wide track position, as shown in  FIG. 2 , the long leg of the L-shaped mounting plate  122  is clamped in sandwiching relationship to a left spacer plate  106  by a left pair of bolts  108 , while the short leg is clamped, as by a left pair of vertically spaced bolts  110 , to an upright plate  124  forming part of a U-shaped mounting bracket  126  having vertically spaced legs supported by the left spindle receptacle  34 . In the case where the axle section  28  is placed in an inward position along with the wheel  16  to establish a narrow track position of the left wheel  16 , the long leg of the L-shaped mounting plate is clamped to the mounting plate  90  of the support bracket  74 L in sandwiching relationship to the left spacer plate  106  by the left pair of bolts  108 . 
         [0026]    The right and left hydraulic steering cylinders  98  each include a rod  128  projecting axially through a barrel  130  in which is located a piston (not shown) which is fixed to the rod for reciprocation within the barrel. A forward end of the cylinder rod  128  is connected to the right steering arm  48  by a coupler  132  which includes a stem that projects downwardly from a ball section and is received in a hole provided in the arm  48  and secured in place by a nut (not visible) received on threads at the bottom of the stem. The barrel of each hydraulic cylinder  98  has a cylindrical collar  134  received on, and fixed to a front end thereof. A pair of horizontal, axially aligned trunnions  136  are fixed to opposite sides of the collar  134 . Right and left, generally Y-shaped mounting yokes  138  are respectively provided for mounting the right and left cylinders  98  to the reaction arms  96 R and  96 L. Specifically, each mounting yoke  138  includes a pair of upright limbs  140  containing aligned holes respectively receiving the pair of trunnions  136  of an associated one of the cylinders  98 . The upright limbs  140  of each of the mounting yokes  138  have lower ends joined to an upright stem (not visible) received for rotation within the left upright receptacle  105  of the associated reaction arm  96 R or  96 L. The stem is retained in place by a bolt  142  carrying a washer  144  and being received in a threaded opening extending axially into the yoke stem. 
         [0027]    It will be appreciated that the alternate mounting positions for the reaction arms  96 R and  96 L make it possible to locate the right steering cylinder  98  in a protected location wherein it extends along side the frame of the windrower  10  without the frame interfering with the operation of the cylinder when the right wheel  16  is located in its narrow track position, as shown in  FIGS. 1 and 2 , and makes it possible to locate the left steering cylinder  98  in a protected location wherein it extends along the axle  18  without the axle or the frame of the windrower interfering with the operation of the steering cylinder. Further, it will be appreciated that reaction forces imposed on the steering cylinders  98  during steering operations will be transferred to the barrel of the cylinder, and from there through the yoke and associated reaction arms  96 R and  96 L. During operation, the cylinders  98  will pivot at the trunnions  136  received in the yoke  138  and/or about the yoke stem, thus preventing undesirable side loads on the cylinder rod  128 . 
         [0028]    Referring now to  FIG. 4 , there is shown a reaction arm  200 R constructed in accordance with a second embodiment of the invention and illustrated in a position corresponding to that when the right wheel  16  is located in its narrow track position, as shown in  FIGS. 1 and 2 . The reaction arm  200 R includes an elongate body  202  which is T-shaped in cross section throughout a substantial portion of its length and includes an inner end defined by a clevis  204  including upper and lower limbs  206  and  208 , respectively, having removable ends  210  and  212  secured with capscrews  214  securing the ends to a remaining portion of the limbs, so as to releasably secure the upper and lower limbs respectively to upper and lower regions of the right spindle receptacle  34 . An upright cylindrical receptacle  216  is welded within a circular opening provided in an outer end region of the elongate body  202 , and the upright stem of the yoke  138  is received for swiveling within the receptacle  216 , just beyond an outer end of a vertical leg which forms the stem of the T-shaped cross section. The steering cylinder  98  has its rod end coupled to the steering arm  48  at the top of the wheel spindle and the barrel of the steering cylinder  98  is located between and mounted to the limbs  140  of the yoke by trunnions  136  joined to the barrel of the cylinder and establishing a horizontal pivot axis about which the cylinder may pivot. 
         [0029]    With the right wheel  16  being in its narrow track position, as illustrated, the reaction arm  200  is disposed substantially parallel to the forward direction of travel of the windrower  10 , and when the right wheel  16  is in a wide track position, the reaction arm  200  will preferably be placed in a position wherein it extends substantially parallel to the rear axle  18 . However, this need not be the case since the structure of the clevis  204  makes it possible to adjust the reaction arm  200  to an infinite number of angular positions about the spindle receptacle  34 . 
         [0030]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.