Abstract:
An agricultural baler includes a main bale chamber, needles, knotters, a triggering system, a knotter lock, a blow-off mechanism, and a monitoring system. The needles are coupled to the main bale chamber and thread twine around a formed bale. The knotters receive the twine from the needles and tie the twine. The triggering system is for activating the needles and the knotters. The knotter lock is a manual lock of the triggering system thereby preventing the needles and the knotters from being triggered. The blow-off mechanism directs a flow of air at the knotters and the needles. The monitoring system has a single sensor that provides signals indicating a normal operation of the knotters, and whether the knotter lock is engaged.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to Belgium Application No. 2015/0181, filed Jul. 8, 2015, the contents of which are incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to agricultural balers, and, more particularly, to agricultural square balers having a monitoring system for the knotting/triggering systems. 
       BACKGROUND OF THE INVENTION 
       [0003]    Agricultural harvesting machines, such as balers, are used to consolidate and package crop material so as to facilitate the storage and handling of the crop material for later use. In the case of hay, a mower-conditioner is typically used to cut and condition the crop material for windrow drying in the sun. In the case of straw, an agricultural combine discharges non-grain crop material from the rear of the combine defining the straw (such as wheat or oat straw) which is to be picked up by the baler. The cut crop material is typically raked and dried, and a baler, such as a large square baler or round baler, straddles the windrows and travels along the windrows to pick up the crop material and form it into bales. 
         [0004]    On a large square baler, a pickup unit at the front of the baler gathers the cut and windrowed crop material from the ground. The pickup unit includes a pickup roll, and optionally may include other components such as side shields, stub augers, wind guard, etc. 
         [0005]    A packer unit is used to move the crop material from the pickup unit to a duct or pre-compression chamber. The packer unit forms a wad of crop within the pre-compression chamber, which is then transferred to a main bale chamber. (For purposes of discussion, the charge of crop material within the pre-compression chamber will be termed a “wad”, and the charge of crop material after being compressed within the main bale chamber will be termed a “flake”). Typically such a packer unit includes packer tines or forks to move the crop material from the pickup unit into the pre-compression chamber. Instead of a packer unit it is also known to use a rotor cutter unit, which chops the crop material into smaller pieces. 
         [0006]    A stuffer unit transfers the wad of crop material in charges from the pre-compression chamber to the main bale chamber. Typically such a stuffer unit includes stuffer forks which are used to move the wad of crop material from the pre-compression chamber to the main bale chamber, in sequence with the reciprocating action of a plunger within the main bale chamber. 
         [0007]    In the main bale chamber, the plunger compresses the wad of crop material into flakes to form a bale and, at the same time, gradually advances the bale toward the outlet of the bale chamber. The plunger reciprocates, back and forth, toward and away from the discharge end of the baler. The plunger may include a number of rollers, which extend laterally outward from the sides of the plunger. The rollers on each side of the plunger are received within a respective plunger slot formed in the sidewalls of the bale chamber, with the plunger slots guiding the plunger during the reciprocating movements. 
         [0008]    When enough flakes have been added and the bale reaches a full (or other predetermined) size, a number of knotters and needles are actuated which wrap and tie twine, cord or the like around the bale while it is still in the main bale chamber. The twine is carried to the knotters by the needles that pivot through the bale chamber to the knotters. The twine is grasped, cut and tied, and the formed baled is ejected out the back of the baler as a new bale is formed. 
         [0009]    In EP1066747 a baler is disclosed having a sensor and timer operations, including a trip arm related to a stuffer mechanism that activates the sensor. However, the sensor is not for a knotter mechanism. 
         [0010]    In EP2011385 it is disclosed that a blast of air can be delivered at the tip of the needles to dislodge crop material as they arrive at the knotters having passed through the bale chamber. 
         [0011]    In U.S. Pat. No. 465,235 there is disclosed a monitoring system for detecting the malfunctioning of a knotting mechanism of a baler. However the system does not monitor or control multiple features. 
         [0012]    In EP2803259 a tractor and baler combination is shown where a control unit is able to control the drive connection between the tractor and baler when a critical operating state of the pickup or knotting mechanism of the baler is detected. 
         [0013]    What is needed in the art is an agricultural baler that can effectively monitor multiple functions of the knotting system in an efficient manner. 
       SUMMARY OF THE INVENTION 
       [0014]    In accordance with an aspect of the present invention, there is provided an agricultural baler with an efficient usage of a single sensor relative to knotter functioning. 
         [0015]    In accordance with another aspect of the present invention, there is provided an agricultural baler including a main bale chamber, needles, knotters, a triggering system, a knotter lock, a blow-off mechanism, and a monitoring system. The needles are coupled to the main bale chamber, and thread twine around a formed bale. The knotters receive the twine from the needles and tie the twine. The triggering system activates the needles and the knotters. The knotter lock is a manual lock of the triggering system thereby preventing the needles and the knotters from being triggered. The blow-off mechanism directs a flow of air at the knotters and/or the needles when moved to the knotters. The monitoring system has a single sensor that provides signals indicating a normal operation of the knotters, an engagement of the knotter lock, and a time to trigger the blow-off mechanism for a predetermined amount of time. 
         [0016]    An advantage of the agricultural baler is that it is able to monitor several functions using one sensor. 
         [0017]    Another advantage is that the engagement of the knotter lock is detected to help prevent operation of the baler when the knotter lock is engaged. Then, a knotter locked operation message can be send to a display, warning the operator of a traction unit (e.g. a tractor) that the knotter lock is engaged. Alternatively or additionally, a sound can be heard or a light can be flashed in the operators cab to warn the operator. When the knotter lock is disengaged, normal working of the knotters and needles is possible, and operation of the baler and traction unit can now continue. 
         [0018]    Yet another advantage is that the agricultural baler times the blowing off of the knotters and the needles at the appropriate time. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    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 embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0020]      FIG. 1  is a perspective cutaway view showing internal workings of a large square baler comprising a monitoring system, in accordance with an exemplary embodiment of the present invention; 
           [0021]      FIG. 2  is a side partial view of the baler of  FIG. 1  illustrating an embodiment of a sensor used in cooperation with a triggering system, in accordance with an exemplary embodiment of the present invention; 
           [0022]      FIG. 3  is another side view of the triggering system of  FIG. 2 , when a bale knotting operation is being triggered, in accordance with an exemplary embodiment of the present invention; 
           [0023]      FIG. 4  is yet another side view of the triggering system of  FIGS. 2 and 3  with a knotter lock engaged, in accordance with an exemplary embodiment of the present invention; and 
           [0024]      FIG. 5  is a block diagram illustrating connections and functions of the monitoring system using the sensor with the triggering system of  FIGS. 2-4  in the baler of  FIG. 1 , in accordance with an exemplary embodiment of the present invention. 
       
    
    
       [0025]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    Referring now to the drawings, and more particularly to  FIG. 1 , there is shown a perspective cutaway view showing the internal workings of a large square baler  10 , in accordance with an exemplary embodiment of the present invention. The baler  10  operates on a two stage feeding system. Crop material is lifted from windrows into the baler  10  using a pickup unit  12 . The pickup unit  12  includes a rotating pickup roll  14  with tines  16  which move the crop rearward toward a packer unit  18 . An optional pair of stub augers (one of which is shown, but not numbered) are positioned above the pickup roll  14  to move the crop material laterally inward. The packer unit  18  includes packer tines  20  which push the crop into a pre-compression chamber  22  to form a wad of crop material. The packer tines  20  intertwine the crop together and pack the crop within the pre-compression chamber  22 . The pre-compression chamber  22  and the packer tines  20  function as the first stage for crop compression. Once the pressure in the pre-compression chamber  22  reaches a predetermined sensed value, a stuffer unit  24  moves the wad of crop from the pre-compression chamber  22  to a main bale chamber  26 . The stuffer unit  24  includes stuffer forks  28  which thrust the wad of crop directly in front of a plunger  30 , which reciprocates within the main bale chamber  26  and compresses the wad of crop into a flake. The stuffer forks  28  return to their original stationary state after the wad of material has been moved into the main bale chamber  26 . The plunger  30  compresses the wads of crop into flakes to form a bale and, at the same time, gradually advances the bale toward an outlet  32  of the main bale chamber  26 . The main bale chamber  26  and the plunger  30  function as the second stage for crop compression. When enough flakes have been added and the bale reaches a full (or other predetermined) size, knotters  34  are actuated which wrap and tie twine around the bale while it is still in the main bale chamber  26 . Needles  36  bring the lower twine up to the knotters  34  and the tying process takes place. The twine is cut and the formed bale is ejected from a discharge chute  38  as a new bale is formed. 
         [0027]    The plunger  30  is connected via a crank arm  40  with a gear box  42 . The gear box  42  is driven by a flywheel  44 , which in turn is connected via a drive shaft  46  with the power take-off (PTO) coupler  48 . The PTO coupler  48  is detachably connected with the PTO spline at the rear of the traction unit, such as a tractor (not shown). The PTO coupler  48 , the drive shaft  46 , and the flywheel  44  together define a portion of a driveline  50 , which provides rotative power to the gearbox  42 . The flywheel  44  has a sufficient mass to carry the plunger  30  through a compression stroke as power is applied to the drive shaft  46  by the traction unit (not shown). 
         [0028]    Now, additionally referring to  FIGS. 2-5 , there are shown side views of a triggering system  52  and a monitoring system  58  (shown schematically in  FIG. 5 ) associated therewith and located on the agricultural baler  10 , in accordance with an exemplary embodiment of the present invention. The triggering system  52  is generally located on a top of the main bale chamber  26  along with a knotter lock  54  and a blow-off mechanism  56  (shown schematically in  FIG. 5 ). The monitoring system  58  interacts with elements of the triggering system  52  and part of the monitoring system  58  may be located in a traction unit, such as a tractor (not shown) that is pulling and providing power to the agricultural baler  10 . 
         [0029]    The triggering system  52  includes a star wheel  60 , a coupling wheel  62 , a pivoting gauge  64 , a trip lever  66 , and a spring  68 . The star wheel  60  engages the crop material along a top side of the bale as the bale is moved in the main bale chamber  26 . The star wheel  60  moves proportionally with the length of the bales causing the coupling wheel  62  to move the pivoting gauge  64  in an upward direction. When the pivoting gauge  64  is raised to a release point  70  (as seen in  FIG. 3 ), the tension on the spring  68  causes the bottom portion of the trip lever  66  to be pulled to the right and the triggering event occurs for the bale tying sequence to begin. This is precluded from happening if the knotter lock  54  is engaged (as shown in  FIG. 4 ), where a handle  72  is moved in a clockwise direction causing a locking portion  74  to engage part of the triggering system  52 . The knotter lock  54  is engaged for purposes of safety when maintenance is being done to the baler  10  to preclude the triggering of the operation of the needles  36  and the knotters  34 . If the knotter lock  54  is left engaged and the agricultural baler  10  is operated then no knotting operation takes place and the operator may have compressed a significant amount of crop material and wasted twine and time, and a need to then re-bale the crop material. 
         [0030]    The monitoring system  58  includes a sensor  76 , a controller  78 , and a display  80 . The display  80  may be part of the traction unit and in an operator cab of the traction unit for conveying information to the operator. The controller  78  may be a standalone unit or its functions may be carried by another controller on the agricultural baler, or by way of dedicated circuits. The controller  78  executes software instructions to perform the functionality of the controller  78  described herein. Such software instructions are stored on a computer-readable tangible medium, either internal to the controller  78  or external thereto. The controller  78  loads such software instructions and executes them to perform the functionality described herein. The sensor  76  is a single sensor that carries out several functions because of its positioning and the data available to it as a result of its desirable positioning. The sensor  76  may be a proximity sensor, an optical sensor, a contact sensor, a magnetic sensor, or other type of sensor that can serve the purposes discussed herein. The sensor  76  provides a signal or signals to the controller  78  based on a sensed parameter or parameters. The controller  78  interprets the signal or signals received from the sensor  76 . 
         [0031]    In  FIG. 2 , the knotter lock  54  is in an unengaged position with locking portion  74  apart from the sensor  76 , and the trip lever  66  is also apart from the sensor  76 . This results in either a non-signal provided from the sensor  76  to the controller  78  or a signal indicating that there is nothing detected proximate to the sensor  76 , so that the controller  78  would interpret this signal as the knotter lock  54  being disengaged and no warning would be sent to the display  80  by the controller  78 . When the star wheel  60  is advanced and the pivoting gauge  64  is advanced, as shown in  FIG. 3 , this causes the trip lever  66  to move proximate to the sensor  76  and the proximity of the trip lever  66  is detected and a signal is generated by the sensor  76  and transmitted to the controller  78 . Meanwhile the needles  36  move through the main bale chamber  26  and the twine is conveyed to the knotters  34  and the bale is tied. As this is happening the triggering system is reset with the trip lever  66  being pulled back allowing the pivoting gauge  64  to pivot downwardly until the top of the pivoting gauge  64  settles against the coupling wheel  62 . This movement of course causes the trip lever  66  to move away from the sensor  76 , back to a position as shown in  FIG. 2 . Since the trip lever  66  is no longer proximate to the sensor  76 , the signal generated by the sensor  76  and provided to the controller  78  indicates to the controller  78  that a momentary presence, of less than one second to a few seconds in duration, has occurred and that the detection is of a normal operation of the baler  10  and more specifically of the knotter system composed of the knotters  34 , the needles  36 , and the triggering system  52 . 
         [0032]    When the signal sent by the sensor  76  is representative of the movement/presence of the trip lever  66 , not only is a signal indicating a normal operation of the baler  10  sent to the display  80  by the controller  78 , but also a count that another bale has been completed can be sent. Yet further, when the triggering event occurs the controller  78  sends a signal to the blow-off mechanism  56  to cause air to flow on the knotters  34  and/or a distal end of the needles  36  as they become proximate to the knotters  34  having traveled through the main bale chamber  26 , and they may have become fouled with some crop matter, which needs to be removed. This airflow or blast of air helps to ensure a cleaning action and a resulting reliable handoff of the twine to the knotters  34  so that they can tie the knots and cut the twine of the completed bale. 
         [0033]    When the knotter lock  54  is in the locked position, as shown in  FIG. 4 , the sensor  76  provides a constant signal indicating the proximity of the knotter lock  54  to the controller  78 . The constant signal is interpreted by the controller  78  as the knotter lock  54  remaining in an engaged position and hence information to that effect is sent to the display  80  by the controller  78 . It is also contemplated that an alarm signal may be initiated by the controller  78  in the event that movement of the traction vehicle takes place while the indication of the engagement of the knotter lock  54  continues. The controller  78  may transmit the alarm signal to the display  80  for display thereon, or it may alternatively transmit the alarm signal to a speaker (as a sound alarm), to a lamp (as a (flashing) light alarm), or a combination of them in the operator cab to warn the operator that the knotter lock  54  is still in the engaged position and that forward driving of the traction vehicle should be stopped. 
         [0034]    The triggering system  52 , specifically the controller  78 , detects the normal operation of the knotter  34  mechanism, and transmits a warning signal in case the knotter lock  54  is activated. (Without this advantage there is nothing on the machine to warn the operator if the lock  54  is still activated after servicing the knotters  34 . This is disadvantageous since a very long bale will be produced until the operator notices that the knotters  34  are not functioning.) Further, the triggering system  52 , specifically the controller  78 , transmits a signal to the blow-off mechanism  56  to operate the blow-off mechanism  56  of the knotters  34 . (Advantageously the blow-off system  56  does not need to be constantly operable.) When the signal of the tripping is used to also operate the blow-off mechanism  56 , it will be able to blow air on the knotters  34  when the needles  36  are coming up (operated by the tripping mechanism  52 ) and will clean the needles  36  when it is actually needed (which is just before the needles  36  reach the knotters  34 ). 
         [0035]    Stated in another way, the desirable positioning of the sensor  76  allows the sensor  76  to detect three different things and allows the controller  78  to control various aspects of the monitoring system  58  accordingly. The sensor  76  looks for the trip lever  66  movement in the knotter cycle. If the trip lever  66  is activated it would pass the sensor  76  for about one second. The sensor  76  generates a signal that can be used by the controller  78  to set/reset the knotter cycle. So the software executed by the controller  78  knows it is a knotter cycle (and displays this on the monitor  80 ). If someone activates the knotter lock safety  54 , a portion  74  comes in front of the sensor  76 . The sensor  76  generates a signal that lasts longer than the one second. The software executed by the controller  78  knows now it is the knotter lock safety  54 , which is activated, and provides a warning signal to the display monitor  80 . If the operator forgets to reset the knotter lock safety  54 , he would see the warning on the monitor  80 . He will know that he should reset or disengage the knotter lock safety  54  first before he drives on to create an extremely long bale, which will have to be re-baled. The first signal (the short one, activated by the trip lever  66 ) generated by the sensor  76  can also be used by the controller  78  to activate the blow-off mechanism  56 . This ensures that the knotters  34  will be cleaned just before a knot is made. 
         [0036]    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.