Abstract:
A wholestalk sugar cane loader includes a piler for accumulating wholestalk sugar cane into piles, and a grab assembly mounted to the end of a boom assembly carried by the loader frame and having opposed tines operable for encircling a mass of piled wholestale sugar cane, with the boom assembly then being operated for lifting the mass of wholestalk cane and depositing it into a container of a haul vehicle. The piler and the grab assembly have respective surface structures which cooperate, when the grab assembly is being loaded with the mass of wholestalk sugar cane, so as to aid the operator in keeping the tines of the grab assembly out of soil contact so that no soil is carried into the mass of wholestalk cane by the tines.

Description:
FIELD OF THE INVENTION 
     The present invention relates to sugar cane loaders, and, more particularly, relates to a piler and grab arrangement for such a loader. 
     BACKGROUND OF THE INVENTION 
     Most modern sugar cane loaders have some method of piling cut sugar cane stalks. The device used for this purpose is referred to as a piler. There are various types of pilers such as push pilers, chain pilers, football pilers and star pilers. These pilers all have two things in common. They all push and pile the cane and all define a pocket into which one of the pair of grab tine arrangements sweep in order for the grab to close about piled or accumulated cane stalks. 
     A problem associated with the known sugar cane loaders is that they all tend to cause soil to be mixed with the gathered cane stalks due to the action of the piler sliding across the ground and/or due to the action of the grab tine arrangements as they close about the piled cane. Various inventions have been tried to reduce the amount of soil being included with the sugar cane stalks being loaded. See for example U.S. Pat. Nos. 4,609,318; 4,614,476; 4,878,341; 4,962,637; 5,193,873; and 5,285,856. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided an improved piler and grab arrangement for a sugar cane loader. 
     An object of the invention is to provide a sugar cane loader having a piler and grab arrangement which operates so as to prevent the grab from engaging soil and mixing it with gathered cane stalks during loading operation. 
     The above object is achieved by providing the piler and grab with cooperating surfaces which effect rotation of the grab arrangement as the boom arrangement is lowered so as to keep the grab tines from soil engagement during the operation of closing the tines upon a pile of cane stalks. 
     The foregoing object and other objects will become apparent from a reading of the ensuing description together with the appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1-9  are right side views of a sugar cane loader respectively depicting a sequence of different positions of the boom and grab arrangements during bringing the grab arrangement into engagement with a cane stalk pile created by the piler. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to  FIGS. 1-9 , there is shown a sugar cane loader  10  including a loader boom arrangement  30  and a piler arrangement  70 . 
     The sugar cane loader includes a main frame  12  supported on front and rear pairs of drive wheels  14  and  16 , respectively, with the rear wheels  16  being steerable, in a well known manner (not shown). Power for driving the wheels and for operating the various hydraulic functions of the loader  10  is supplied by an internal combustion engine  18  supported on a rear region of the frame  12 . Provided on a forward region of the frame  12  is an operator&#39;s cab  20  containing a seat  22  located within reach of various manually operated controls, of which only a steering wheel  24  is shown. 
     The loader boom arrangement  30  is mounted at a central region of the main frame  12 , just to the rear of the cab  20 . The loader boom arrangement  30  includes an upright mast  32  mounted to a pedestal  34  for being selectively rotated about a vertical axis, in a manner well known in the art. An inner boom  36  has a first end pivotally coupled, by a horizontal pivot arrangement  38 , to an upper end of the mast  32  for being swung vertically by a first extensible and retractable hydraulic boom cylinder  40 . The inner boom  36  has a second end pivotally coupled, by a horizontal pivot arrangement  42 , to a first end of an outer boom  44 , and a second extensible and retractable hydraulic boom cylinder  46  is coupled between the inner and outer booms  36  and  44  for pivoting the outer boom  44  about the pivot arrangement  42 . Pivotally mounted to a second end of the outer boom  46 , by a horizontal pivot arrangement  48 , is a grab assembly  50  including, as viewed in the drawings, a curved rear grab tine  52  and a curved front grab tine  54 . A cylinder mounting bracket (not shown) is carried on the pivot arrangement  48 . Mounted between the cylinder mounting bracket and the rear grab tine  52  is an extensible and retractable hydraulic rear grab tine cylinder  56 , and mounted between the bracket  50  and the front grab tine  48  is an extensible and retractable hydraulic front grab tine cylinder  58 . The grab tine cylinders  56  and  58  are selectively operated in concert so as to open the grab assembly  50 , when the cylinders are retracted, as shown in  FIG. 1 , for example, and to close the grab assembly  50 , when the cylinders are extended, as shown in  FIG. 9 , for example. The front grab tine  54  includes opposite sides which terminate in tine end sections  60  located for straddling an end section  62  of the rear grab tine  46  when the grab tine assembly  50  is completely closed, with the end sections  60  and  62  then overlapping. 
     The piler arrangement  70  includes a rearwardly opening U-shaped frame  72  including a pair of transversely spaced arms  74  joined at their forward ends to a cross member  76  and having rear ends pivotally mounted to a lower front region of the main frame  12  for swinging vertically about a horizontal axis defined by respective horizontal pivot assemblies  78 . A pair of upstanding brackets  80  are respectively joined to the pair of arms  74 , and coupled between each bracket  80  and one of a pair of brackets  82  joined to the main frame  12 , is an extensible and retractable, hydraulic piler lift cylinder  84 . Formed at a lower end of each of the brackets  82  is a chain mounting bracket  86  containing a key hole shaped opening receiving a chain  88  having an end fixed to the cross member  76  of the piler frame  72 , with a selected link of the chain being placed in the smaller section of the key hole shaped opening, whereby the chain  88  serves as a down stop for preventing the piler arrangement  70  from being lowered to the extent that it digs into the soil. The piler arrangement  72  includes a plurality of transversely spaced, vertical push plates  90  having rear portions joined to the frame cross member  74  and having generally C-shaped forward edges  92  adapted for engaging cut cane stalks lying on the ground and causing them to be pushed into a pile, as the loader  10  is driven forward. An adjacent pair of the push plates  90 , which are located so as to be disposed centrally relative to a pile of cane stalks pushed up by the piler arrangement  70  are spaced from each other by a distance slightly greater than the width of the grab assembly  50 . No structure is coupled between these adjacent push plates  90  in a zone extending forward from the cross member  76  to the forward edges  92  so that a piler pocket  94  is formed that is substantially free of cane stalks and through which the rear grab tine  52  may pass during grabbing piled cane stalks. Up to this point, the structure described is conventional. Joining rear regions of the adjacent push plates  90 , which form the piler pocket  94 , and forming part of the present invention, is a downwardly and forwardly inclined guide plate  96 , which engages a front region of the cross member  76 . Also forming part of the present invention are horizontal first and second rollers  98  and  100 , respectively, coupled to a back side of the rear grapple tine  52  in a region which constitutes approximately the lower third of a length dimension of the tine  52 , with the first roller  98  being located near a bottom end of the tine  52  and the second roller  100  being spaced above the roller  98 . 
     In operation, the piler arrangement  70  is lowered to a working height, as shown in  FIG. 1 , and the loader  10  is advanced forwardly along a windrow of cane stalks which have been cut and laid generally crosswise to a cane row or cane rows from which the cane stalks have been cut. The forward edges  92  of the push plates  90  contact the cane stalks and cause them to be pushed into a pile. Once a pile has been formed, as shown in  FIG. 1 , for example, the grab assembly  50  is opened fully, by completely retracting the actuators  56  and  58 , and positioned with the rear and front tines  52  and  54  arranged in fore-and-aft alignment with each other and with the piler pocket  94 . Because the grab assembly  50  hangs free at the pivot arrangement  48 , the lower ends of the tines  52  and  54  are disposed approximately at a horizontal plane. With the illustrated loader  10 , the initial positioning of the grab assembly  50  is accomplished by operating the first boom cylinder  40  so as to lower the inner boom  36  to an angle of about 23° to the horizontal and by operating the second boom cylinder  46  so as to dispose the outer boom  44  such that it makes an angle of approximately 99° with the inner boom  36 . A seated operator can easily see when the lower end of the rear grab tine  52  is adjacent an upper, forward end of the piler push plates  90 , which is the proper initial position of the grab assembly  50 . 
     Referring now to  FIG. 2 , the next step in the operation is to lower the inner boom  36  by about 10°, which causes the rear tine  52  to enter the piler pocket  94 . Proceeding to  FIG. 3 , the next step is to lower the inner boom  36  yet a few more degrees which brings the lower roller  98 , carried at a lower rear region of the rear tine  52 , into contact with the guide plate  96 . The force imposed on the roller  98 , as the boom  36  is lowered, causes the grab assembly  50  to start rotating clockwise, or forwardly, about the pivot arrangement  48 . As soon as the operator sees the grab assembly  50  start to undergo this clockwise rotation, further lowering of the inner boom  36  is immediately stopped. The operator then causes the outer boom  44  to pivot to the rear about the pivot arrangement  42  by controlling the second boom cylinder  46  so that it contracts, with the interaction between the lower roller  98  and the guide plate  96  then being such that the reaction force is directed below the pivot arrangement  48  so as to cause the grab assembly  50  to rotate approximately 27° counterclockwise, or rearwardly, about the pivot arrangement  48  in response to the outer boom  44  being pivoted approximately 3° to the rear, as shown in  FIG. 4 . Going on to  FIG. 5 , the operator continues to lower the outer boom  44  by continuing to pivot it to the rear about the pivot arrangement  42  through approximately another 3°, this resulting in the grab assembly  50  undergoing approximately 17° of additional counterclockwise rotation about the pivot arrangement  48 , which results in the lower roller  98  rolling off the bottom of the guide plate  96  and the upper roller  100  coming into engagement with the guide plate  96 . The operator continues lowering the outer boom  44  by operation of the second boom cylinder  46  to effect rearward rotation of the outer boom  44  about the pivot arrangement  42  through another 3° increment, as shown in  FIG. 6 , which causes the grab assembly  50  to undergo approximately another 15° of counterclockwise rotation, with this lowering of the boom  44  resulting in the lower roller  98  coming into ground contact and in the lower end of the rear tine  52  being disposed approximately at ground level. At this point, the second boom cylinder  46  is fully retracted making it unnecessary for the operator to guess where to stop lowering the outer boom  44 . 
     Once the lower roller  98  is resting on the ground, the front grab assembly  50  is closed by operating hydraulic controls so as to route pressure fluid for effecting the extension of the tine cylinders  56  and  58 , as shown by the sequence of positions illustrated in  FIGS. 7-9 . It will be appreciated that during this closing operation neither of the grab tines  52  or  54  come into ground contact. Therefore, no soil will be mixed with the piled cane stalks due to the operation of the grab assembly  50   
     Once the tines  52  and  54  are closed sufficiently for the grab assembly  50  to hold a gripped mass of the piled cane stalks, the booms  36  and  44  are raised by extending the cylinders  40  and  46 , and the mast  32  is rotated so as to dispose the loaded grab assembly  50  over a mobile container (not shown) for hauling cane stalks. The tine cylinder  58  is then contracted so as to open the tine  54  and release the gripped mass of cane stalks into the mobile container. The operator then drives the loader  10  ahead so as to pile more cane stalks while once again lowering and swiveling the boom assembly  30  so as to position the grab assembly  50  for picking up the piled cane stalks. 
     While the planar guide plate  96  of the piler arrangement  94  and the rollers  98  and  100  of the rear grab tine  52  are preferred interacting parts of the piler and grab tine for causing a desired rotation of the grab assembly  50  for orienting the grab assembly for being closed upon a pile of cane stalks without the tines of the grab assembly coming into contact with the soil, the guide plate  96  could take other shapes, and, in lieu of using rollers, the back side of the rear grab tine  52  could be shaped for cooperating with the guide plate so as to create the desired rotation of the grab assembly  50  during loading it with piled cane stalks. 
     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.