Abstract:
A grasping mechanism for an agricultural bale wagon has a fixed grasping arm and a movable grasping arm. The movable grasping arm is translatable toward and away from the fixed grasping arm. The movable grasping arm can be rotated to define varying angular relationships between the fixed grasping arm and the movable grasping arm. Rotation and translation of the movable grasping arm are effected by an actuator. A resilient bumper between the fixed grasping arm and movable grasping arm is adjustable automatically to span the adjusted width between the fixed grasping arm and movable grasping arm.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to self-propelled agricultural bale wagons and, more particularly, to bale wagons of the type adapted to pick up large crop material bales of different sizes and to form stacks of the bales. 
         [0003]    2. Description of the Related Art 
         [0004]    Present day crop harvesting practices include the formation of large bales of crop material, such as hay or other crops, which are dropped in the field. Bale wagons are used to pick up the bales from the field, form the bales into a composite stack on the bale wagon and subsequently discharge the entire stack into a storage area. It is known for such bale wagons to include a first table which receives bales from a bale loader or pick up device mounted on the bale wagon. The first table accumulates a predetermined number of bales with the bales being arranged in a row in a pattern determined by a computer on board the bale wagon. A second table receives the rows of bales from the first table and accumulates several such rows. This group of rows is commonly referred to as a “tier”. A third table or load bed then receives the tiers from the second table and accumulates these tiers to form a “stack” on the load bed. Once the stack has been accumulated on the load bed, it may be unloaded by pivoting the load bed 90 degrees and depositing the stack on the ground or other surface so that the first tier of bales which was accumulated on the second table is now the lowermost tier of the stack on the ground surface. 
         [0005]    Current bale collecting systems on self-propelled bale wagons for large bales include a clamp that grasps the bale, lifts the bale, and deposits the bale on a first collecting table. Large bales can be formed in different sizes, such as, for example, bales that are three feet wide and bales that are four feet wide. When changing from collecting bales of one size to collecting bales of another size, known bale wagon systems require that the operator make manual adjustments to the bale wagon, such as changing the general spacing between the opposed clamp arms, and/or changing a cushioning bumper between the arms. For example, some bale wagons have a single rotational clamp arm that is actuated by a cylinder. The rotational arm rotates away from a rigid clamp arm in order to provide a large aperture to receive bales. By taking advantage of geometric relationships, only a short stroke of a cylinder is needed to actuate the mechanism. However, with this type of structure, changing from collecting bales of one size to collecting bales of another size requires the operator to adjust the overall width of the clamp by removing a hydraulic cylinder mount, pulling a pin and sliding the frame to the desired position for the new size bales to be collected. Then, the pin has to be reinserted, and the cylinder mount reconnected before bale pickup can be started. This is problematic if the operator inadvertently adjusts the mechanism incorrectly, or forgets to make a required adjustment. The time required for making the mechanical adjustments prolongs the time required to complete the pickup task. 
         [0006]    Another type of pickup mechanism on a bale wagon engages the bales with a translational system, such as a simple, laterally sliding mechanism that extends and retracts to allow bales to enter the opening. While these mechanisms may be operable with bales of multiple widths, they cannot provide a wide aperture for bale entrance without providing an excessively long translational element for clamping the bales. For example, to provide a 6 foot wide opening for picking up 4 foot wide bales, the translational element must have a cylinder with 2 feet of extra travel. The extra length can result in increased weight, and can require extra structure, larger packaging and increased cycle time due to the extra stroke of the cylinder. Further, for the clamp to adjust down to 3 feet for small bales or lesser widths for transport, the length of the cylinder becomes prohibitively expensive. 
         [0007]    What is needed in the art is a bale wagon system that can pick up bales of multiple sizes without the need for making manual adjustments to the mechanism. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a pickup system that uses a combination of translational and rotational elements to provide a wide aperture for bale entrance while using very little stroke to achieve a wide opening. 
         [0009]    The invention in one form is directed to an agricultural bale wagon with a chassis, an articulating mechanism coupled to the chassis and a bale grasping mechanism coupled to the articulating mechanism. The bale grasping mechanism includes first and second grasping arms; a translational mechanism for moving one of the first and second grasping arms towards the other of the first and second grasping arms; a rotational mechanism rotating one of the first and second grasping arms relative to the other of the first and second grasping arms; and an actuator operatively connected to the translational mechanism and the rotational mechanism. 
         [0010]    The invention in another form is directed to an agricultural bale wagon provided with a chassis, an articulating mechanism coupled to the chassis and a bale grasping mechanism coupled to the articulating mechanism. The bale grasping mechanism includes a fixed grasping arm and a movable grasping arm, a translational mechanism connecting the fixed grasping arm and the movable grasping arm and configured for moving the movable grasping arm toward and away from the fixed grasping arm, a rotational mechanism connecting the fixed grasping arm and the movable grasping arm and configured for rotating the movable grasping arm relative to the fixed grasping arm, and an actuator operatively connected to the translational mechanism and the rotational mechanism. 
         [0011]    The invention in still another form is directed to an agricultural bale wagon provided with a bale grasping mechanism including a fixed grasping arm and a movable grasping arm. A translational mechanism connects the fixed grasping arm and the movable grasping arm. The translational mechanism includes a sliding member movable along a fixed member. A rotational mechanism connects the sliding member and the movable grasping arm, and the movable grasping arm is rotatably carried on the sliding member. An actuator is operatively connected to the fixed member and the sliding member. 
         [0012]    An advantage of the present invention is that the bale grasping mechanism can accommodate bales of different sizes without the need for manually adjusting the bale grasping structure. 
         [0013]    Another advantage is that a wide entrance opening is provided at the distal ends of the bale grasping arms. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0015]      FIG. 1  is a side perspective view of an agricultural bale wagon that uses an embodiment of a system for the detection of the sizes of the bales it picks up of the present invention; 
           [0016]      FIG. 2  is another view of the bale wagon of  FIG. 1  before it encounters a bale; 
           [0017]      FIG. 3  is a perspective view of the grasping mechanism of the present invention used with the bale wagons of  FIGS. 1 and 2 ; 
           [0018]      FIG. 4  is a closer perspective view of the grasping mechanism of  FIG. 3 ; 
           [0019]      FIG. 5  is another perspective view of the grasping mechanism of  FIGS. 3 and 4 ; 
           [0020]      FIG. 6  is a view of the grasping mechanism of  FIGS. 3-5  grasping a 3 foot bale; 
           [0021]      FIG. 7  is a view of the grasping mechanism of  FIGS. 3-6  grasping a 4 foot bale; 
           [0022]      FIG. 8  is a perspective view of the grasping mechanism adjusted for receiving a bale; 
           [0023]      FIG. 9  is a perspective view similar to that of  FIG. 8 , but illustrating the grasping mechanism adjusted for transport; 
           [0024]      FIG. 10  is a flowchart depicting the logic of an embodiment of the grasping system of the present invention; and 
           [0025]      FIG. 11  is a schematical block diagram of the grasping system that carries out the method of  FIG. 10 . 
       
    
    
       [0026]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    Referring now to the drawings, and more particularly to  FIGS. 1-9 , there is shown a bale wagon  10  having a chassis  12 , wheels  14 , an articulating mechanism  16 , and a grasping mechanism  18 . Wheels  14  are coupled to chassis  12  and provide support to chassis  12 . Articulating mechanism  16  is coupled to chassis  12  and to grasping mechanism  18 , and provides the lifting, orientating and stacking functions of a bale that is grasped by grasping mechanism  18 , to position bales on bale wagon  10 . 
         [0028]    Grasping mechanism  18  includes grasping arms  19  and  20 , a translational mechanism  21  including a clamp cylinder or actuator  22 , a bumper  24 , springs  26 , a sliding member  28 , a bumper sensor  30 , a transport sensor  32 , a three foot sensor  34 , a four foot sensor  36  and a fixed plate or channel  42 . Grasping arms  19  and  20  are arranged to engage and hold a bale B in a squeezing, grasping or clamping fashion. Accordingly, grasping arm  19  is in a fixed position, and grasping arm  20  is movable relative to grasping arm  19 . Translational mechanism  21 , through the operation of actuator  22  and the guidance of sliding member  28  in, on or against channel  42 , moves grasping arm  20  by causing sliding member  28  to move so that arm  20  moves toward or away from arm  19 . 
         [0029]    Grasping mechanism  18  further includes a rotational mechanism  48  that includes, in addition to the aforementioned actuator  22 , an upper rocker arm  50 , a link  52  and a lower rocker arm  54  connecting upper rocker arm  50  and link  52 . Actuator  22  can be a hydraulic cylinder and is held by a pivotal connection  56  to a frame member  58  that is fixed relative to arm  19 . At the opposite end, actuator  22  has a pivotal connection  60  to one end of upper rocker arm  50 . Upper rocker arm  50  is a curved, somewhat boomerang shaped body of plate steel or the like. Lower rocker arm  54  is generally straight. A shaft  62  extends through upper rocker arm  50  near an end thereof opposite to connection  60 . Shaft  62  also extends through one end of lower rocker arm  54 . Upper rocker arm  50  and lower rocker arm  54  are arranged with respect to shaft  62  so that upper rocker arm  50  projects laterally from shaft  62  in one direction and lower rocker arm  54  projects laterally from shaft  62  essentially in opposite direction from upper rocker arm  50 . Shaft  62  extends through upper rocker arm  50  and lower rocker arm  54 , and outwardly extending end portions of shaft  62  are held pivotally in a bracket  64  that is attached to sliding member  28 . Upper rocker arm  50  and lower rocker arm  54  are rigidly held to shaft  62  by welding or the like so that the assembly of upper rocker arm  50 , shaft  62  and lower rocker arm  54  are rigidly held one with respect to the others. Shaft  62  is rotationally held by bracket  64 . At an opposite end of lower rocker arm  54  from shaft  62 , lower rocker arm  54  forms a pivotal connection  66  with one end of curved link  52 . The opposite end of link  52  from pivotal connection  66  forms a pivotal connection  68  at a proximal end portion of grasping arm  20 . Grasping arm  20  has a pivotal connection  70  to sliding member  28 . 
         [0030]    Bumper  24  is positioned between arms  19  and  20  and is configured to move as it contacts a bale. Springs  26  bias bumper  24  outward and are compressed when a bale contacts bumper  24 . The movement of bumper  24  is detected by the activation of bumper sensor  30 , thereby indicating the presence of a bale between arms  19  and  20 . Sensors  32 ,  34  and  36  are mounted to fixed plate or channel  42 , with sliding member  28  sliding along triggering sensors  32 ,  34  and  36  dependent upon whether sliding member  28  is proximate to sensors  32 ,  34  and  36 , this triggering then providing feedback to detect the position of sliding member  28  and thereby whether a bale has been dropped, or if the bale is three feet wide or four feet wide. 
         [0031]    In looking at  FIGS. 3 and 4 , it can be seen that with no bale in  FIG. 3  bumper  24  is biased outward. With a bale present, bumper  24  is pushed back with a portion of bumper  24  extending back as can be seen in  FIG. 4 . This triggers sensor  30  to indicate the presence of bale B being between arms  19  and  20 . Sequentially looking at  FIGS. 5-7  sensors  32 ,  34  and  36 , which are mounted to plate  42 , are shown as though looking through sliding member  28 , with the left portion of sliding member  28  shown in some of the Figs. The position of sliding member  28  relative to sensors  34  and  36  determine the width of bale B. For example in  FIG. 4 , bale B has contacted bumper  24  and sliding member  28  is to the right not covering any of sensors  32 ,  34  and  36 , with arms  19  and  20  fully open. In  FIG. 5  arms  19  and  20  are positioned in a transport mode and sliding member  28  completely encompasses sensors  32 ,  34 ,  36 . In  FIG. 6  sensors  34  and  36  are beneath sliding member  28  causing them to be triggered, and sensor  32  is not triggered indicating that a three foot bale is present. In  FIG. 7  sensor  36  is triggered by the proximity of sliding member  28  with sensors  32  and  34  being not triggered to then indicate that a four foot bale B being present. 
         [0032]    Bumper  24  reduces shock from bale contact because of the resilient yielding of springs  26 . Further, bumper  24  extends across the full width of the opening between grasping arms  19  and  20  for all adjusted widths between the arms. Bumper  24  includes a laterally fixed plate  72  connected to fixed channel  42  and a laterally translatable plate  74  which slides over laterally fixed plate  72  and is connected to sliding member  28 . Accordingly, as grasping arm  20  is move toward or away from grasping arm  19 , laterally translatable plate  74  slides along laterally fixed plate  72 , to increase or decrease the overlap of the plates. Thus, the width of bumper  24  is adjusted together with adjustment in the spacing between grasping arms  19  and  20 , all through the operation of the single actuator  22 . 
         [0033]    Through the operation of translational mechanism  21 , grasping arm  20  is caused to translate toward and away from grasping arm  19  as actuator  22  is withdrawn or extended. Sliding member  28  moves along channel  42  under the operation of actuator  22 . Additionally, however, rotational mechanism  48  causes grasping arm  20  to pivot about the pivotal connection  70  between grasping arm  20  and sliding member  28 . When actuator  22  is being extended, the interconnection of upper rocker arm  50 , lower rocker arm  54 , link  52  and the pivotal connections to grasping arm  20  cause grasping arm  20  to rotate outwardly, so that distal ends of grasping arms  19  and  20  are more distantly spaced than proximal ends of grasping arms  19  and  20 , as shown in  FIG. 8 . When actuator  22  is being retracted, the resistance from encountering the bale causes the translational action to stop, at which time only rotational action can continue. Arm  20  continues to rotate inwardly until arms  19  and  20  engage the bale along the full extent of the bale, as shown in  FIGS. 6 &amp; 7 . Still further, with no bale present between arms  19  and  20 , actuator  22  can be fully retracted such that grasping arm  20  closely approaches grasping arms  19 . Fixed plate  72  fully covers translatable plate  74  therebehind, and rotational mechanism  48  has rotated grasping arm  20  to be parallel to or slightly inwardly directed at the distal ends of the arms. This transport position is shown in  FIG. 9 . 
         [0034]    Now additionally referring to  FIGS. 10 and 11 , there is shown a method  100  to control grasping mechanism  18  and a structure of the system to carry out method  100 . Proposed here is an algorithm  100  to use feedback from the bale clamp position in order to determine the size of a bale and thus determine the tier stack pattern. Method  100  also provides automatic clamp initiation when bale B contacts bumper  24  thereby activating sensor  30 . 
         [0035]    The system executes method  100  as follows: 1. The control system  40  senses that a bale B has been engaged by the bumper  24  of the clamp  18  (see step  102 ). This is accomplished by the bumper  24  being pushed back, with respect to the clamp frame, and tripping a frame mounted sensor  30  (see step  104 ). If no bale is sensed method  100  proceeds to step  106 . 2. Upon sensing bale B, the control system  40  by way of controller  38  retracts clamp cylinder  22 , which squeezes bale B. 3. When the pressure in the cylinder reaches a predetermined set point (see step  108 ), as a pressure adequate to clamp and hold bale B, the system  40  determines the width of bale B based on the position of the translational element  28  of the clamp. 4. If only the four foot (first) sensor  36  is tripped (see steps  110  and  112 ), the bale is four feet wide (step  118 ), then the system  40  determines that two bales are to be placed per tier (step  124 ). If the first sensor  32  and three foot sensor  34  (second sensor) are tripped (see steps  110  and  114 ), the system  40  determines that bale B is three feet wide (step  120 ) and that three bales are to be placed per tier (step  126 ). If the four foot sensor  36 , three foot sensor  34 , and transport sensor  32  are all tripped (see steps  110  and  116 ), the clamp  18  has retracted to the transport position and there is not a bale in clamp  18  (either a false reading on bumper sensor  30  or a dropped/broken bale has occurred). In this case, the clamp cylinder  22  is extended and the system  40  re-sets to clamp another bale, no bales are added to a tier. The logic controlling tier formation, i.e. bale count, will be used after the bale size has determined the stack pattern by the present invention. 
         [0036]    Advantageously, with the present invention an operator can enter a field and not have to consider bale size when collecting bales, rather, the operator can simply begin picking up bales, and grasping mechanism  18  will adjust automatically to the new size bales. 
         [0037]    This system will eliminate the very likely scenario where the operator has been collecting bales of one size, and goes to another field to collect bales of another size but forgets to set the controller to the new size, as is required with prior art systems. 
         [0038]    While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.