Abstract:
A bale shape monitoring system for round balers includes first and second indicator lights, and bale shape monitor apparatus for alternately generating signals in the indicator lights in response to predetermined expansion of the baling chamber of round balers. Typically round balers are operated in a manner whereby crop material is fed into only one side of the baling chamber at a time. The signals generated in the indicator lights are used by the operator of a round baler as an indication of when to weave the baler to feed crop material into the other side of the baling chamber. Proper use of the disclosed system prevents the formation of poorly shaped bales while reducing operator fatigue.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to round balers and, in particular, to a system for monitoring bale shape in round balers. 
     During operation of a round baler, it is often necessary to weave the round baler back and forth in a zigzag pattern on the windrow of crop material being picked up and baled. This is because the windrows of crop material are typically much narrower in width than the pickups and the baling chambers of round balers. Without the weaving action, there is a tendency for the bales formed in round balers to be barrel-shaped or egg-shaped instead of uniformly cylindrical. Although the proper weaving of a round baler in a zigzag pattern overcomes the problem of poorly shaped bales, it requires that the operator constantly remember when to weave the baler. This causes operator fatigue. 
     It is an object of the present invention to provide a bale shape monitoring system for round balers which prevents the formation of poorly shaped bales while reducing operator fatigue. The monitoring system of the present invention comprises single bale shape monitor means as contrasted with prior art systems which use plural bale shape monitors. 
     SUMMARY OF THE INVENTION 
     A bale shape monitoring system according to the present invention is intended for use in a round baler having a bale forming apron defining an expandable bale forming chamber. The system includes first and second indicator means and bale shape monitor means which generates a signal in one of the indicator means in response to a predetermined expansion of the bale forming chamber. The bale shape monitor means subsequently generates a signal in the other indicator means in response to a further predetermined expansion of the bale forming chamber. 
     In the preferred embodiment of the present invention, the bale shape monitor means is connected to an arm means which supports the bale forming apron and which is movable as the bale forming chamber expands. The bale shape monitor means generates the signals in the indicator means in response to predetermined movements of the arm means. The bale shape monitor means includes a link connected at one end to the arm means and at the other end to a plate. The plate is rotatably mounted and carries a plurality of magnets. A magnetically activated switch is disposed for activation by the magnets in order to generate the signals in the indicator means. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a right side elevation view of a round baler embodying a bale shape monitoring system according to the present invention; 
     FIG. 2 is an enlarged view of a portion of the round baler of FIG. 1 illustrating bale shape monitor apparatus in accordance with the present invention; 
     FIG. 3 is a further enlarged view of the bale shape monitor apparatus illustrated in FIG. 2; 
     FIG. 4 is a sectional view taken along lines 4--4 in FIG. 3; 
     FIG. 5 is a schematic view of a bale shape monitoring system according to the present invention; and 
     FIGS. 6 and 7 are diagrammatic plan views of a round baler during operation thereof utilizing the system illustrated in FIG. 5. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a round baler 10 is generally of the type disclosed in U.S. Pat. No. 4,426,833, incorporated herein by reference. The round baler 10 includes a base frame 12 supported by a pair of wheels 14 and an auxiliary frame or tailgate 16 pivotally connected to the base frame 12 by stub shafts 18. A pickup mechanism 20 is mounted on the base frame 12 for picking up windrowed crop material, and a tongue 22 provided on the base frame 12 is adapted for connection to a tractor. 
     A floor roller 24 and guide members 26,28,30 are rotatably mounted on the base frame 12, and guide members 32,34,36,38 are rotatably mounted in the tailgate 16. An arm assembly 40 is rotatably mounted on the base frame 12 for rotational movement between a forward position shown in FIG. 1 and a rearward position shown in FIG. 2. The arm assembly 40 carries further rotatable guide members 42,44. 
     A flexible bale forming apron 46 is movably supported on the aforementioned guide members. The apron 46 may be of the chain and slat type as illustrated in FIG. 1 or the flat belt type. Since both of these apron types are well known, no further description thereof will be provided. The apron 46 has an inner course extending between the guide members 30 and 38 to define a bale forming chamber 48 which is expandable during bale formation. When the baler 10 is empty, the apron inner course is disposed in a wedge-shaped bale starting position 48a and the arm assembly 40 which assists in supporting the apron 46 is disposed in its forward position shown in FIG. 1. As a bale is formed in the baler 10, the bale forming chamber 48 expands while the apron inner course expands in length around the bale and the arm assembly 40 is moved toward its rearward position. When a full size bale has been formed in the baler 10, the apron inner course is disposed in the full bale position 48b and the arm assembly 40 is moved to its rearward position shown in FIG. 2. Air spring assemblies 50 are connected between the base frame 12 and the arm assembly 40 to urge the arm assembly 40 toward its forward position of FIG. 1. This maintains a predetermined amount of tension in the apron 46 during bale formation in order to control the density of bales formed in the round baler 10. 
     According to the present invention, bale shape monitor apparatus 52 includes a link 54 pivotally connected at one end 54a to the arm assembly 40. The other end 54b of the link 54 is pivotally connected to a lever 56 as best seen in FIGS. 3 and 4. The lever 56 is fixed to a sleeve 58 which is rotatably mounted on a stub shaft 60. The stub shaft 60 is fixed to a bracket 62 that is bolted to the base frame 12. The flange portion 64 of the bracket 62 supports a magnetically activated switch 66 such as part No. 103SR12A-1 manufactured by Microswitch Inc. This particular type of switch 66 is commonly referred to as a hall effect switch. A plate 68 is fixed to the sleeve 58 and the arcuate flange portion 70 thereof supports a plurality of magnets 72a-72j. 
     Referring to FIG. 5, a system which incorporates the bale shape monitor apparatus 52 includes a time delay 74 such as part No. KD118 manufactured by Instrumentation and Control Systems Inc., a latching relay 76 such as part No. S89R11DBD1 manufactured by Potter and Brumfield, and an operator panel 78 with left and right indicator lights 80 and 82, respectively. The time delay 74 may be provided with an adjustable resistor 84 to allow adjustment of the time delay 74 in a preselected range of, for example, 0.1 second to 10 seconds. The input of the time delay 74 is connected to the switch 66 by wiring 86, and the output of the time delay 74 is connected to the latching relay 76 by wiring 88. One terminal 76a of the latching relay 76 is connected by wiring 90 to the left indicator light 80 on the control panel 78 while the other terminal 76b of the latching relay 76 is connected by wiring 92 to the right indicator light 82 on the operator panel 78. 
     When the inner course of the apron 46 is in its bale starting position 48a and the arm assembly 40 is in its forward position as shown in FIG. 1, the various parts of the bale shape monitor apparatus 52 will be disposed in the positions shown in full lines in FIG. 3. The plate 68 will be positioned so that the first magnet 72a is in alignment with the switch 66. The clearance between magnet 72a and the switch 66 is preferably between 1/16 inch and 1/4 inch. Activation of the system of FIG. 5 causes the right indicator light 82 to be illuminated while the left indicator light 80 is extinguished. 
     The operator then starts towing the baler 10 across a field along a windrow of crop material with the pickup 20 aligned to feed crop material into the right side of the bale forming chamber 48 as illustrated in FIG. 6. As the crop material is formed into a roll bale in the bale forming chamber 48, the inner course of apron 46 expands in length and the arm assembly 40 rotates from its forward position shown in FIG. 1 toward its rearward position shown in FIG. 2. This rotation of the arm assembly 40 causes rotation of the plate 68 carrying the magnets 72a-72j in a counterclockwise direction in FIG. 3. When the plate 68 is rotated far enough so that the second magnet 72b (to the right of magnet 72a in FIG. 3) becomes aligned with the switch 66, a signal is sent via the wiring 86 to activate the time delay 74. If the second magnet 72b remains aligned with the switch 66 during the entire period of time (for example, 1 to 2 second) for which the time delay 74 is set, a signal is sent via the wiring 88 to actuate the latching relay 76. The latching relay 76 will then toggle from terminal 76b to terminal 76a thereby illuminating the left indicator light 80 via the wiring 90 and simultaneously extinguishing the right indicator light 82. 
     The operator then weaves the baler 10 toward the right along the windrow of crop material so that the pickup 20 is aligned to feed crop material into the left side of bale forming chamber 48 as illustrated in FIG. 7. As bale formation continues in the bale forming chamber 48, the arm assembly 40 continues to rotate toward its rearward position shown in FIG. 2 thereby causing further rotation of the plate 68 which is connected to the arm assembly 40 by the link 54 and the lever 56. This further rotation of the plate 68 results in the third magnet 72c (to the right of magnet 72b in FIG. 3) becoming aligned with the switch 66. A signal is again sent via the wiring 86 to activate the time delay 74. Should the third magnet 72c remain in alignment with the switch 66 for the duration of the setting of the time delay 74, another signal will be sent via the wiring 88 to cause the latching relay 76 to toggle back from terminal 76a to terminal 76b. This results in reillumination of the right indicator light 82 and simultaneous extinguishing of the left indicator light 80. The operator subsequently weaves the baler 10 back toward the left along the windrow of crop material so that the pickup 20 is again aligned to feed crop material into the right side of the bale forming chamber 48. 
     As bale formation continues in the bale forming chamber 48, the arm assembly 40 will continue to be rotated toward its rearward position shown in FIG. 2. This rotation of the arm assembly 40 will cause the left and right indicator lights 80 and 82, respectively, to be alternately illuminated by the bale shape monitor apparatus 52. Consequently, the operator will be given an indication or signal when to weave the baler 10 to feed crop material into the other side of the bale forming chamber 48 of the baler 10. It will be understood that proper use of the system shown in FIG. 5 results in the formation of bales which are uniformly cylindrical. Accordingly, the present invention prevents formation of poorly shaped bales while reducing operator fatigue. 
     The purpose of the time delay 74 is to prevent a false signal which may be caused by a bouncing motion of the arm assemlby 40. During bale formation, the arm assembly 40 normally rotates smoothly from its forward position shown in FIG. 1 toward its rearward position shown in FIG. 2. However, under adverse conditions such as in the event of an egg-shaped bale, the arm assembly 40 may bounce back and forth during its rotational movement. In order to insure that the arm assembly 40 has rotated to a new position and is not in a bouncing motion, each of the magnets 72a-72j must remain aligned with the switch 66 for the entire duration of the time setting of the time delay 74 or the time delay 74 will be automatically reset and there will be no change in the indicator lights 80 and 82.