Patent Publication Number: US-2023157213-A1

Title: Knife insert and retract with independent knife protection of agricultural baler

Description:
FIELD OF THE INVENTION 
     The present invention pertains to an agricultural baler, and, more specifically, to a crop cutting assembly of the agricultural baler. 
     BACKGROUND OF THE INVENTION 
     Agricultural harvesting machines, such as agricultural balers (which can be referred to as balers), have been used to consolidate and package crop material (which, depending upon the application, can also be referred to as forage, forage material, or forage crop material) so as to facilitate the storage and handling of the crop material for later use. Often, a mower-conditioner cuts and conditions the crop material for swath or windrow drying in the sun. When the cut crop material is properly dried (depending upon the application), an agricultural harvesting machine, such as an agricultural baler, which can be a round baler, travels along the swath or windrows (hereinafter, collectively referred to as windrows, unless otherwise specified) to pick up the crop material. In the case of round balers, the crop material is formed into cylindrically-shaped round bales. 
     More specifically, pickups of the baler gather the cut and windrowed crop material from the ground, and then convey the cut crop material toward a bale-forming chamber within the baler (that is, the bale chamber). A drive mechanism operates to activate any pickups, augers, and/or a rotor of a feed mechanism (which can also be referred to as a feeder system). A pickup can convey crop material in an overshot manner, while a rotor can convey crop material toward or into the bale chamber in an undershot manner. A conventional bale chamber may include a pair of opposing sidewalls with a series of rolls (which can be referred to as rollers) and belts that rotate and compress the crop material into a cylindrical shape. When the bale has reached a desired size and density, a wrapping assembly, which includes wrap material, may wrap the bale to ensure, at least in part, that the bale maintains its shape and density. The wrap material can include a film (such as a flexible plastic wrap) or a net (which can be referred to as net wrap). For example, wrap material may be used to wrap the bale of crop material. After wrapping, a cutting or severing mechanism of the wrapping assembly may be used to cut the wrap material once the bale has been wrapped. The wrapped bale may be ejected from the baler and onto the ground by, for example, raising a tailgate of the baler. The tailgate is then closed, and the cycle repeated as necessary and desired to manage the field of cut crop material. 
     The feeder system can include not only the rotor but also a floor and a cutting assembly. The rotor, which is downstream of the pickup, can be positioned above the floor which the crop material traverses prior to entering the bale chamber and can work in conjunction with, and cooperatively with, the cutting assembly. The rotor can include a rotor shaft (extending transversely) and a plurality of tines (which can have a generally triangular or star-shaped configuration) spaced apart across the transverse extent of the baler. The tines are configured to engage and thereby to push the crop material towards the bale chamber and can be grouped in pairs, with a relatively short distance between the tines of a given pair. The floor can include a plurality of slots across the transverse extent of the floor, each slot extending longitudinally in the floor (that is, parallel or otherwise aligned with a direction of crop flow). The cutting assembly can include a plurality of knives (which can also be referred to as cutters) which are selectively received in the slots of this floor, respectively. When inserted through the slots so that the knives extend at least partially above the floor, each respective knife (depending upon the design) can extend between a pair of tines of the rotor, as the rotor shaft rotates the tines. Further, the knives, as they extend through the slots above the floor are configured to cut the crop material to a predetermined length, as the crop material passes by the knives prior to the crop material entering the bale chamber. By cutting the crop material into smaller lengths prior to entering the bale chamber, a denser bale can be formed in the bale chamber, which advantageously provides more crop material per bale, enables less wrap material to be used to wrap the bale, and enables better stacking of bales during storage and/or transit. 
     When a foreign object, such as a rock, is taken up by the pickup and conveyed towards the bale chamber, the foreign object can encounter one or more knives. To prevent or otherwise mitigate damage to the knives, the knives can have overload protection by way of an overload protection mechanism, which can include a spring which urges one or more knives to extend at least partially above the floor and allows the one or more knives to drop down at least partially below the floor when the foreign object strikes the one or more knives. Individual knife overload protection is known to use a spring for each knife. Having such overload protection for each knife (which can be referred to as individual knife overload protection) is advantageous. Overload protection is also known, not using springs, that is not assigned to individual knives but to an entire bank of knives of the feeder system. 
     During use, knives can become jammed or otherwise stuck with respect to the slots in the floor, which can inhibit servicing and/or replacing of respective knives. That is, dirt and debris can collect around or enter into the slots, thereby causing at least two problems. First, knives already deployed at least partially above the floor can become stuck in their respective slots because of the dirt and debris and thus unable to retract back down through the slots upon encountering a foreign object or otherwise needing to be retracted or serviced. Second, knives not yet deployed at least partially above the floor can become unable to progress through the respective slots because of the dirt and debris that has collected at the slots and/or on the knives, blocking the knives from deploying through the slots into position for cutting; for, the spring force urging the knives into a deployed position (and thus providing the overload protection) is not strong enough to burst through this blockage. To clear a blockage, for example, that is preventing an individual knife from inserting up through the slot, it is known to use a hydraulic linear actuator to push on the spring of the individual knife overload protection mechanism; but, this design is often not strong enough to push through the blockage. 
     In the current state of the art, feeder systems include either an individual knife overload protection mechanism with a hydraulic linear actuator to push through a spring of the individual knife overload protection mechanism to clear a blockage, or the ability to force all knives to be inserted or retracted. Neither option is fully satisfactory, and the former can be improved upon. 
     What is needed in the art is a simple and effective way to have, simultaneously, both individual knife overload protection and an effective way to forcibly insert and to forcibly retract the knives of a feeder system. 
     SUMMARY OF THE INVENTION 
     The present invention provides an agricultural baler with a feeder system including individual knife overload protection that is spaced apart from an engagement apparatus configured for forcibly inserting and retracting all or a group of knives of the feeder system. 
     The invention in one form is directed to a feeder system of an agricultural baler, the feeder system being coupled with a frame of the agricultural baler, the feeder system including: a cutting assembly coupled with the frame and including: at least one knife configured for cutting a crop material; an engagement apparatus configured for: being spaced apart from at least one overload protection mechanism individually associated with a single one of the at least one knife; selectively engaging with the at least one knife and thereby for forcing the at least one knife to occupy a first position; and selectively engaging with the at least one knife and thereby for forcing the at least one knife to occupy a second position. 
     The invention in another form is directed to an agricultural baler, including: a frame; a feeder system coupled with the frame and including: a cutting assembly coupled with the frame and including: at least one knife configured for cutting a crop material; an engagement apparatus configured for: being spaced apart from at least one overload protection mechanism individually associated with a single one of the at least one knife; selectively engaging with the at least one knife and thereby for forcing the at least one knife to occupy a first position; and selectively engaging with the at least one knife and thereby for forcing the at least one knife to occupy a second position. 
     The invention in yet another form is directed to a method for using an agricultural baler, the method including the steps of: providing a frame and a feeder system coupled with the frame, the feeder system including a cutting assembly coupled with the frame and including at least one knife and an engagement apparatus, the at least one knife configured for cutting a crop material, the engagement apparatus being configured for being spaced apart from at least one overload protection mechanism individually associated with a single one of the at least one knife; engaging selectively, by way of the engagement apparatus, with the at least one knife and thereby forcing the at least one knife to occupy a first position; and engaging selectively, by way of the engagement apparatus, with the at least one knife and thereby forcing the at least one knife to occupy a second position. 
     An advantage of the present invention is that it provides individual knife overload protection. 
     Another advantage is that it provides a way to forcibly insert and retract the knives. This may be done to clear blockage of the knives due to dirt and debris, to raise or lower the knives for servicing, or to run the baler with the knives down so as not to cut the crop material. 
     Yet another advantage is that it provides a way to have individual knife overload protection employing a spring while being able to selectively engage and thereby force the knives up or down. Thus, a mechanism is provided that forces knives to insert and to retract when needed (that is, the knives are positively inserted and positively retracted) and that allows a respective knife to fall away in an overload event. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For the purpose of illustration, there are shown in the drawings certain embodiments of the present invention. It should be understood, however, that the invention is not limited to the precise arrangements, dimensions, and instruments shown. Like numerals indicate like elements throughout the drawings. In the drawings: 
         FIG.  1    illustrates a schematic side view of an exemplary embodiment of an agricultural vehicle, formed as a tractor, and an agricultural baler, the agricultural baler including a feeder system, in accordance with an exemplary embodiment of the present invention; 
         FIG.  2    illustrates a perspective view of the feeder system of the agricultural baler of  FIG.  1   , the feeder system including a cutting assembly including a knife, with portions broken away, in accordance with an exemplary embodiment of the present invention; 
         FIG.  3    illustrates a schematic perspective view of the cutting assembly of  FIG.  2   , with portions broken away, the cutting assembly including an engagement apparatus, in accordance with an exemplary embodiment of the present invention; 
         FIG.  4    illustrates a schematic side view of the cutting assembly with the engagement apparatus of  FIG.  3   , with portions broken away, the engagement apparatus being in a home position and the knife being in a normal operating position, in accordance with an exemplary embodiment of the present invention; 
         FIG.  5    illustrates a schematic side view of the cutting assembly with the engagement apparatus of  FIG.  3   , with portions broken away, the engagement apparatus being in a first position, which forcibly places the knife in an insertion position, in accordance with an exemplary embodiment of the present invention; 
         FIG.  6    illustrates a schematic side view of the cutting assembly with the engagement apparatus of  FIG.  3   , with portions broken away, the engagement apparatus being in a second position, which forcibly places the knife in a retraction position, in accordance with an exemplary embodiment of the present invention; 
         FIG.  7    illustrates a schematic side view of the cutting assembly with a second embodiment of the engagement apparatus, with portions broken away, in accordance with an exemplary embodiment of the present invention; and 
         FIG.  8    illustrates a flow diagram showing a method for using an agricultural baler, in accordance with an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The terms “forward”, “rearward”, “left” and “right”, when used in connection with the agricultural vehicle, agricultural baler, and/or components thereof are usually determined with reference to the direction of forward operative travel of the agricultural vehicle and/or agricultural baler, but they should not be construed as limiting. The terms “longitudinal” and “transverse” are determined with reference to the fore-and-aft direction of the agricultural vehicle and/or agricultural baler and are equally not to be construed as limiting. The terms “downstream” and “upstream” are determined with reference to the intended direction of crop material flow during operation, with “downstream” being analogous to “rearward” and “upstream” being analogous to “forward.” 
     Referring now to the drawings, and more particularly to  FIG.  1   , there is shown an embodiment of an agricultural vehicle  100  (which can be referred to as a work vehicle  100 ) towing an agricultural baler  101 , in accordance with the present invention, to perform a baling operation within a field. As shown, work vehicle  100  can be configured as an agricultural tractor, such as an operator-driven tractor or an autonomous tractor. However, in some embodiments, the work vehicle  100  may correspond to any other suitable vehicle configured to tow a baler across a field or that is otherwise configured to facilitate the performance of a baling operation, including an autonomous baling vehicle. Additionally, as shown, baler  101  can configured as a round baler configured to generate round bales. However, in some embodiments, baler  101  may have any other suitable configuration, including being configured to generate square or rectangular bales. It should be further appreciated that baler  101 , while shown as being towed by tractor  100 , may also be a self-propelled baler that does not rely on a separate vehicle for propulsion and/or power to function. 
     Work vehicle  100  includes a pair of front wheels  102 , a pair of rear wheels  103 , and a chassis  104  coupled to and supported by the wheels  102 ,  103 . An operator&#39;s cab  105  may be supported by a portion of the chassis  104  and may house various input devices for permitting an operator to control the operation of work vehicle  100  and/or baler  101 . Additionally, work vehicle  100  may include an engine and a transmission mounted on chassis  104 . The transmission may be operably coupled to the engine and may provide variably adjusted gear ratios for transferring engine power to wheels  103  via a drive axle assembly. 
     As shown in  FIG.  1   , work vehicle  100  may be coupled to baler  101  via a power take-off (PTO)  106  and a tongue  107  to a hitch of work vehicle  100  to allow vehicle  100  to tow baler  101  across the field. As such, work vehicle  100  may, for example, guide baler  101  toward crop material  136  deposited in windrows on the field. As is generally understood, to collect the crop material  136 , baler  101  includes a feeder system (which can be referred to generally as a crop collector) mounted on a front end of baler  101 . Feeder system  108  may, for example, include a pickup  111 , a rotor  121 , and a cutting assembly  128 . Pickup  111  includes a rotating wheel with tines that collect crop material  136  from the ground and direct the crop material  136  toward a bale chamber  109  of baler  101  in an overshot manner (rotating clockwise in  FIG.  1   ). Rotor  121  includes a rotating shaft (rotor shaft) and a plurality of generally triangular or star-shaped tines (rotor tines) mounted to the shaft (as described above) that push or otherwise move crop material  136  towards or into bale chamber  109 , in an undershot manner (rotating counter-clockwise in  FIG.  1   ). Feeder system  108  can also include a rotating shaft (not shown) generally between pickup and rotor  121  that includes side augers for moving crop material  136  inwardly prior to entering bale chamber  109 . Cutting assembly  128  is disposed generally below rotor  121  and includes a floor  131  and a plurality of knives  129 . 
     Inside bale chamber  109 , rollers, belts, and/or other devices compact the crop material  136  to form a generally cylindrically-shaped bale  110 . Bale  110  is contained within baler  101  until ejection of bale  110  is instructed (e.g., by the operator and/or a baler controller  123  of baler  101 ). In some embodiments, bale  110  may be automatically ejected from baler  101  once bale  110  is formed, by baler controller  123  detecting that bale  110  is fully formed and outputting an appropriate ejection signal. Further, work vehicle  100  includes a control system  114 , which includes a controller  115 , which includes a processor  116 , memory  117 , data  118 , and instructions  119 . Control system  114  can further include an input/output device  120  such as a laptop computer (with keyboard and display) or a touchpad (including keypad functionality and a display), device  120  being configured for a user to interface therewith. 
     As shown in  FIG.  1   , baler  101  may also include a tailgate  112  movable between a closed position (as shown in the illustrated embodiment) and an opened position via a suitable actuator assembly. Tailgate  112  and/or the actuator assembly may be controlled to open and close by baler controller  123 . In the closed position, tailgate  112  may confine or retain bale  110  within baler  101 . In the open position, tailgate  112  may rotate out of the way to allow bale  110  to be ejected from the bale chamber  109 . Additionally, as shown in  FIG.  1   , baler  101  may include a ramp  113  extending from its aft end that is configured to receive and direct bale  110  away from baler  113  as it is being ejected from bale chamber  109 . In some embodiments, ramp  113  may be spring loaded, such that ramp  113  is urged into a raised position, as illustrated. In such embodiments, the weight of bale  110  on ramp  113  may drive ramp  113  to a lowered position in which ramp  113  directs bale  110  to the soil surface. Once bale  110  is ejected, bale  110  may roll down ramp  113  and be deposited onto the field. As such, ramp  113  may enable bale  110  to maintain its shape and desired density by gently guiding bale  110  onto the field. Further, baler  101  includes a control system  122 , which includes controller  123 , which includes a processor  124 , memory  125 , data  126 , and instructions  127 . Controller  123  can communicate with controller  115 , so that controller  115  outputs information to the display of input/output device  120  of work vehicle  100 , thereby informing a user of various conditions of baler  101  and bales  110  forming or formed therein. Further, baler  101  includes a frame  130  to which all of the components of baler  101  are directly or indirectly coupled. Thus, feeder system  108 , and thus also cutting assembly  128 , are coupled with frame  130 . 
     It should be appreciated that the configuration of work vehicle  100  described above and shown in  FIG.  1    is provided only as one example. Thus, it should be appreciated that the present disclosure may be readily adaptable to any manner of work vehicle configuration. For example, in an alternative embodiment, a separate frame or chassis may be provided to which the engine, transmission, and drive axle assembly are coupled, a configuration common in smaller tractors. Still other configurations may use an articulated chassis to steer work vehicle, or rely on tracks in lieu of wheels  102 ,  103 . Additionally, as indicated previously, work vehicle  100  may, in some embodiments, be configured as an autonomous vehicle. In such embodiments, work vehicle  100  may include suitable components for providing autonomous vehicle operation and, depending on the vehicle configuration, need not include the operator&#39;s cab  105 . 
     Additionally, it should be appreciated that the configuration of baler  101  described above and shown in  FIG.  1    is provided only as one example. Thus, it should be appreciated that the present disclosure may be readily adaptable to any manner of baler configuration. For example, as indicated previously, baler  101  may, in some embodiments, correspond to a square baler configured to generate square or rectangular bales. It should be further appreciated that the illustration of baler  101  in  FIG.  1    is schematic. 
     Further, in general, controllers  115 ,  123  may each correspond to any suitable processor-based device(s), such as a computing device or any combination of computing devices. Each controller  115 ,  123  may generally include one or more processor(s)  116 ,  124  and associated memory  117 ,  125  configured to perform a variety of computer-implemented functions (e.g., performing the methods, steps, algorithms, calculations and the like disclosed herein). Thus, each controller  115 ,  123  may include a respective processor  116 ,  124  therein, as well as associated memory  117 ,  125 , data  118 ,  126 , and instructions  119 ,  127 , each forming at least part of the respective controller  115 ,  123 . As used herein, the term “processor” refers not only to integrated circuits referred to in the art as being included in a computer, but also refers to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits. Additionally, the respective memory  117 ,  125  may generally include memory element(s) including, but not limited to, computer readable medium (e.g., random access memory (RAM)), computer readable non-volatile medium (e.g., a flash memory), a floppy disk, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disc (DVD), and/or other suitable memory elements. Such memory  117 ,  125  may generally be configured to store information accessible to the processor(s)  116 ,  124 , including data  118 ,  126  that can be retrieved, manipulated, created, and/or stored by the processor(s)  116 ,  124  and the instructions  119 ,  127  that can be executed by the processor(s)  116 ,  124 . In some embodiments, data  118 ,  126  may be stored in one or more databases. 
     Baler controller  123 , herein, is assumed to be the primary controller for controlling operations of baler  101 . However, controller  123 , as indicated in  FIG.  1   , can be in communication with controller  115  of work vehicle  100 , such that any or all information associated with either controller  115 ,  123  can be shared with the other controller  115 ,  123 , and either controller  115 ,  123  can perform the functions of the other controller  115 ,  123 . Controllers  115 ,  123  can communicate with each other in any suitable manner, such as a wired connection or a wireless connection, such as radio signals (RF), light signals, cellular, WiFi, Bluetooth, Internet, via cloud-based devices such as servers, and/or the like. Further, while not shown, both controllers  115 ,  123  can communicate with a remotely located data center, which controllers  115 ,  123  can communicate with by any suitable way, such as those just referenced. Such a data center can include its own controller (and thus processor(s), memory, data, and instructions, substantially similar to that described above with respect to controllers  115 ,  123 ) which can be configured to perform any of the functions associated with controllers  115 ,  123 . Controllers  115 ,  123  and the data center can be a part of any network facilitating such communication therebetween, such as a local area network, a metropolitan area network, a wide area network, a neural network, whether wired or wireless. 
     Referring now to  FIG.  2   , there is shown a perspective view of feeder system  108 , with portions broken away. Shown are pickup  111  (with tines), rotor  121 , and cutting assembly  128 . Rotor  121  is shown to include rotor shaft  233  and rotor tines  234  mounted to rotor shaft  233 . Rotor tines  234  are spaced apart transversely from one another and, as shown in  FIG.  2   , can be grouped in pairs. As rotor shaft  233  rotates, a given pair of rotor tines receive therebetween a respective upstanding knife  129 . Cutting assembly  128  is shown to include floor  131  and a plurality of knives  129  extending transversely across the front of baler  101 . Floor  131  includes a plurality of longitudinally extending slots  232  (running generally in the flow direction of crop material  136 ) through which a respective knife  129  can extend when deployed. That is, each slot  232  allows a respective knife  129  to project and to pass therethrough; any suitable number of slots  232  can be provided in floor  131 .  FIG.  2    shows several such knives  129  already having been inserted through respective slots and thus deployed and ready to encounter crop material  136 . Knives  129  are configured for cutting crop material  136  as crop material  136  is urged in the direction of flow  237  of crop material  136 . Knives  129  cut crop material  136  to a predetermined length, such as two-and-one-half inches, for example and not by way of limitation. 
     Referring now to  FIG.  3   , there is shown a perspective view of a portion of feeder system  108 , which includes cutting assembly  128 . Cutting assembly  128  includes floor  131 , knives  129  (not shown in  FIG.  3   ), and further includes an engagement apparatus  340 . Engagement apparatus  340  includes a pivot bar  341 , an engagement rod  342 , a joining mechanism  343 , and an actuator  344 . Floor  131  includes slots  232  and is coupled with frame  130  (as shown schematically in  FIG.  3   ). Pivot bar  341  (which can be formed as a tube) can be rotatably coupled with frame  130  so as to pivot about pivot axis  345  in either direction, as indicated by double-arrow  347 . Pivot bar  341  can be made of any suitable material, such as steel. Pivot bar  341 , as shown in  FIG.  3   , can extend the transverse width of floor  131  and beyond (or, alternatively, within) the lateral sides of floor  131 . Engagement rod  342  (which can be formed as a tube) can be made of any suitable material, such a steel. Engagement rod  342  extends substantially parallel to pivot bar  341  and can be substantially the same length as pivot bar  341 . Joining mechanism  343  can be formed as a linkage  343 , as shown in  FIG.  3   , and can be made of any suitable material, such as steel. Two such linkages  343  are provided and disposed at each lateral end of pivot bar  341  and engagement rod  342 , such that each linkage  343  is fixedly attached (such as by welding, pinning, or the like) to respective lateral ends of pivot bar  341  and engagement rod  342 . Linkages  343  pivot together with pivot bar  341 , causing engagement rod  342  to revolve around pivot bar  341  (thus, substantially in a circle) and thus be angularly displaced about pivot bar  341 ; this angular displacement of engagement rod  342  relative to pivot bar  341  is only partial—less than 180 degrees (for example, 170 degrees). The limitation of such angular displacement can be controlled by actuator  344  and/or any associated control system. Actuator  344 , as shown in  FIG.  3   , can be formed as a linear actuator  344 , such as a cylinder assembly  344 , including a cylinder  348  (housing a piston) and a rod  349  that is moved linearly by the action of the piston. As a linear actuator, cylinder assembly  344  can be, for example, a hydraulic cylinder assembly, a pneumatic cylinder assembly, or an electrically actuated cylinder assembly (which can include gearing and/or screws). If cylinder assembly  344  is a hydraulic cylinder assembly  344 , for example, then cylinder assembly can be controlled by suitable valving and can include fluid lines which fluidly communicate an interior of cylinder  348  with a pump and a reservoir of hydraulic cylinder fluid, such as hydraulic oil; this pump and reservoir can be maintained on work vehicle  100  and/or on baler  101 . 
       FIG.  3    shows that two such actuators  344  are provided, each associated with respective lateral ends of pivot bar  341  and engagement rod  342 , as well as a respective linkage  343 . A proximal end of cylinder  348  (left-most end in  FIG.  3   ) is pivotably mounted, so as to be coupled with frame  130  (this coupling with frame  130  is shown schematically in  FIG.  3   ); cylinder  348  pivots about a pivot axis  350 . Cylinder  340  pivots about pivot axis  350  as rod  349  extends and retracts, because rod is connected to linkage  343 . More specifically, a distal end of rod  349  is rotatably connected to a side (such as a lateral outboard side) of linkage  343  about pivot axis  352 . As rod  349  extends and retracts, rod  349  causes linkage  343  to rotate with pivot bar  341  about pivot axis  345 . As will be explained (below), engagement rod can engage with and thereby contact a surface (a bottom surface) of each respective knife  129  and thereby move (that is, forcibly insert and forcibly retract relative to slots  232 ) the knives  129  altogether as a group. Alternatively, engagement apparatus  340  can be formed in segments—each segment including each element of engagement apparatus  340 —such that groups of knives  129  less than the total number of knives  129  can be moved together as a group. Alternatively, engagement apparatus  340  can be formed in segments—each segment including each element of engagement apparatus  340 —such that each segment corresponds to a single knife  129  and individually moves knives  129 . 
     Referring now to  FIG.  4   , there is shown schematically a side view of cutting assembly  128 , with portions broken away. Cutting assembly  128 , in  FIG.  4   , is shown to include floor  131  (with portions broken away, such that only a top surface of floor  131  is shown), knife  129  (only one knife  129  being visible in  FIG.  4   ), pivot  451 , engagement apparatus  340 , and knife overload protection mechanism  455 . Floor  131  includes a slot  232  through which knife  129  extends in  FIG.  4    at least partially. Knife  129  includes a top surface which generally faces and thus encounters crop material  136  moving in flow direction  237 . Though not shown, this top surface can include a sharpened edge(s), serrations, and/or sharpened teeth configured for cutting through crop material  136 . Knife  129  is shown in its normal operating position, that being an insertion position. That is, knife  129  extends partially up through slot  232  so that the sharp top surface of knife can encounter and thus cut crop material  136 . Pivot  451  (which is coupled with frame  130 , as shown schematically in  FIG.  4   ) forms a pivot about which knife  129  can move and which knife  129  receives by way of a left-most mouth or cutout. Pivot  451  can be a bar, rod, or tube that extends substantially the transverse extent of floor  131  (like pivot bar  341 ) and can have any cross-section and/or positioning that allows for knives  129  to be removed during servicing; for example, when in their insertion position  562 ), knives  129  can be lifted out, or otherwise pivoted and lifted out, of the respective slot  232  and removed altogether from baler  101 . Engagement mechanism  340 , in  FIG.  4   , is shown to include pivot bar  341  (which pivots about pivot axis  345 ), linkage  343  which pivots with pivot bar  341 , engagement rod  342 , linear actuator  344  including cylinder  348  and rod  349 , cylinder  348  being able to pivot about pivot axis  350 , and rod  349  being able to pivot about pivot axis  352 . Engagement apparatus  340  is in its home position. That is, rod  349  is fully retracted, and engagement rod  342  is not engaged and thus not in contact with knife  129 . In this home position, linkage  343  can be said to point just above the 9 o&#39;clock position (for example, at about 275 degrees, with 0 degrees being directly upward, that is, the 12 o&#39;clock position). This home position is the normal operating position of engagement apparatus. For, engagement apparatus is primarily used to clear dirt and debris from slot  232  and/or knife  129  when knife  129  has become stuck and thus unable either to penetrate up through slot  232  so as to occupy the insertion position or to retract back down through slot  232  so as to occupy a retraction position. Thus, in normal operation of cutting assembly  128 , engagement mechanism  340  is not needed. 
     Regarding the knife overload protection mechanism  455 , this mechanism  455  includes rod  464 , a linkage  457 , an engagement shaft  458 , and a spring  459 . Though fixing mechanism  460  provides functionality for mechanism  455  and is coupled with frame  130 , fixing mechanism  460  is not included in mechanism  455 , as it can serve a series of mechanisms  455  assigned to a series of individual knives  129 . Rod  464  extends through a hole in fixing mechanism  460  and is coupled with linkage  457 , such as by a bolt, pin, or welding. Fixing mechanism  460  can be formed as a bracket  460  and is coupled with frame  130 , as schematically shown in  FIG.  4    (bracket  460  can be smaller than what is shown in the figures). Linkage  457  can be connected at its other end to engagement shaft  458 , which can engage a downstream surface of knife  129 . Engagement shaft  458  is normally in a notch of knife  129 , as shown in  FIGS.  4  and  5   . Spring  459  can surround and mount to rod  464  (as shown) and be braced at both ends to limit the extent of spring  459 , being limited at its left end (as viewed in  FIG.  4   ) by a ring fixed about the rod  464  and being limited at its right end by bracket  460  (another embodiment of the combination of rod  464  and spring  459  can provide that rod  464  has two parallel sides along its longitudinal extent and a reduced height portion along its longitudinal extent beginning near its distal end (opposite bracket  460 ) and running to its proximal end, with spring  459  surrounding this reduced height portion). Spring  459  can provide a compressive force to linkage  457 , which biases knife  129  in the up position (that is, its insertion position  562 ). Mechanism  455  is specific to each knife  129 , such that mechanism  455  is individually associated with a single knife  129 ; stated another way, a single one of overload protection mechanism  455  is assigned to and coupled with a single one of the knife  129 . Thus, each knife  128  has its own overload protection mechanism  455 . An actuator is not attached to mechanism  455  so as to push knife up or down, for example, so as to clear knife  129  of jams caused by dirt and debris relative to floor  131 . Overload protection mechanism  455  protects each knife from an overload situation, such as when a rock is taken up by the pickup  111  and fed in direction of travel  237  to floor  131 , with the result that this rock can strike one or more knives  129 , which can destroy or otherwise damage and thus hinder the functionality of the knives  129  that are struck. By having mechanism  455  assigned to only one knife  129 , only those knives that are struck by a foreign object will give way and thus retract under the force of the foreign object, rather than all of the knives, thereby allowing cutting to continue by those knives  129  that were not struck by the foreign object. In normal operation, the compressive force of spring  459 , together with the positioning of engagement shaft  458  in the notch of the downstream side of knife  129 , urges knife  129  in the insertion (up) position, as shown in  FIG.  4   . As indicated, when a knife  129  encounters the foreign object, knife  129  can retract momentarily all the way below the surface of floor  131  (alternatively, the retraction of knife  129  can be such that knife  129  does not completely retract under floor  131 , but partially). When such retraction occurs, engagement shaft  458  can exit the notch and ride up a downstream side of knife  129  as spring compresses (like in  FIG.  6   , though  FIG.  6    corresponds to when engagement mechanism  340  forces knife  129  to retract, not when a foreign object causes knife  129  to retract). Then, during normal operation, once the foreign object passes by knife  129 , spring  459  causes engagement shaft  458  of the individual knife overload protection mechanism  455  to press on knife  129  and thereby to cause knife  129  to spring back up into place, that is, into insertion position  562 , and engagement shaft  458  can slide back down knife  129  and return to the notch (as shown in  FIG.  4   ). This movement of knife  129  (retraction, and return to insertion position  562  under the force of spring  459 ) due to a foreign object (and removal of the foreign object) occurs only when engagement mechanism  340  is not engaged with knife  129  (as in  FIG.  4   ); only then can the individual knife overload protection mechanism  455  perform its primary function of allowing the individual knife  129  to retract and then forcing the knife  129  back to insertion position  562 . This ability of knife  129  to retract under the influence of a foreign object and to re-insert under the influence of overload protection mechanism  455  is shown by double-arrow  461 , in  FIG.  4   . 
     Further, knife overload protection mechanism  455  is spaced apart from engagement mechanism  340 . As shown in  FIG.  4   , knife overload protection mechanism  455  is positioned at a downstream end or portion of knife  129 , and engagement mechanism  340  is positioned generally at an upstream end or portion of knife  129 . Knife overload protection mechanism  455  and engagement mechanism  340  are discrete and distinct from one another. That is, overload protection to each knife  129  is provided by way of overload protection mechanism  455  apart from engagement mechanism  340 , and the upward force for insertion and the downward force for retraction of knives  129  is provided by engagement mechanism  340 . Thus, by way of overload protection mechanism  455 , overload protection is provided to each knife  129  individually (independent of the other knives  129 ); and, by way of engagement mechanism  340 , knives  129  can be forcibly moved and locked all at the same time (inserted or retracted) in order to service the knives, clear dirt and debris, or to remove knives  129  from operation without removing them from cutting assembly  128  (that is, moving knives  129  and locking them in a retracted position below floor  131 ). 
     Referring now to  FIG.  5   , there is shown a view similar to  FIG.  4   , with substantially similar structure. The primary difference between  FIGS.  4  and  5    is that engagement apparatus  340  has moved from its home position ( FIG.  4   ) to a first position ( FIG.  5   ). Correspondingly, engagement mechanism  340  is configured for selectively engaging with knife  129  and thereby for forcing knife  129  (positively pushing knife  129 ) to occupy a first position, which corresponds to the first position of engagement mechanism  340 . As shown in  FIG.  5   , this first position  562  of knife  129  can be the insertion position  562 , that is, a fully inserted position of knife. Further, when knife  129  is in this insertion position  562  by way of engagement apparatus  340 , knife  129  is locked into this insertion position  562  by way of engagement apparatus  340 . That is, knife  129  is not free to fall back down through slot  232 , because engagement apparatus  340  is pushing knife  129  up and engagement apparatus  340  is held in position, until adjusted. In operation, when engagement apparatus  340  is in its home position ( FIG.  4   ), cylinder  348  can receive hydraulic fluid, causing rod  349  to extend, which causes pivot bar  341  to rotate clockwise (as viewed in  FIG.  5   ), until engagement rod  342  is approximately in the 12 o&#39;clock position. In this movement, from the home position to the first position of the engagement apparatus  340 , engagement rod  342  engages and thus comes into contact with a bottom surface  453  of knife  129  and can forcibly raise knife  129  into its insertion position  562 , as shown in  FIG.  5   . For example, knife  129  could be stuck below or partially below floor  131  by dirt or debris  454 , and the forceful push of knife  129  by engagement rod will push knife  129  through this dirt/debris  454  (thereby clearing a jam caused by dirt/debris  454 ) and thus through slot  232  so as to be fully inserted. When engagement apparatus  340  is in its first position, this is not a normal operating configuration for cutting assembly  128 , and baler  101  should not be operated across a field in this manner; for, this position locks knives  129  into their insertion position  562  and thus unable to give way—under the influence of overload protection mechanism  455 —when struck by a foreign object. Using engagement apparatus  340  to force knife  129  into insertion position  562  enables the clearing of dirt and debris, and allows the user to remove the knives from their slots for servicing or replacement. From this first position of engagement apparatus  340 , engagement mechanism  340  has two options (beside remaining in this position). First, engagement mechanism  340  is configured for selectively disengaging from knife  129  and returning to its home position ( FIG.  4   ). In so doing, rod  349  retracts and linkage  343  pivots counter-clockwise (as viewed in  FIG.  5   ). Second, engagement apparatus  340  is configured for moving clockwise and thus for selectively engaging knife  129  and thereby for forcing knife  129  to occupy a second position  663 , namely, a retraction position  663 , which is also locked by engagement apparatus  340 . In proceeding to this second position  663 , thus forcing knives  129  fully up in their first position  562  and fully down in their second position  663 . This will provide a full “clean out,” wherein a clean-out cycle can be deemed to begin at the home position of engagement apparatus  340 , proceed to the first position of engagement apparatus  340  (corresponding to first position  562 ), then to the second position of engagement apparatus  340  (corresponding to second position  663 ), then back to the first position of engagement apparatus again (clearing out any remaining dirt or debris), and then back to the home position of engagement apparatus  340 . This second option  663  is discussed in reference to  FIG.  6   . Alternatively, engagement apparatus  340  can be configured to move from its home position ( FIG.  4   ) all the way to its second position ( FIG.  6   ) without stopping or otherwise pausing at its first position ( FIG.  5   ). 
     Referring now to  FIG.  6   , there is shown a view similar to  FIGS.  4  and  5   , in that substantially similar structure is employed. The primary difference between  FIGS.  5  and  6    is that engagement apparatus  340  has moved from its first position (its insertion position)( FIG.  5   ) to its second position (its retraction position). Correspondingly, engagement mechanism  340  is configured for selectively engaging with knife  129  and thereby for forcing knife  129  (positively pulling knife  129 ) to occupy the second position  663 , which corresponds to the second position of engagement mechanism  340 . As shown in  FIG.  6   , this second position  663  of knife  129  can be the retraction position  663 , that is, a fully retracted position of knife  129  (though retraction position  663  is shown (in  FIGS.  6 - 7   ) such that knife  129  is fully below floor  131 , this need not be the case; rather, the retraction position can be with knife  129  partially below floor  131 ). Further, when knife  129  is in this retraction position  663  by way of engagement apparatus  340 , knife  129  is locked into this retraction position  663  by way of engagement apparatus  340 . That is, knife  129  is not free to move back up through slot  232  (for instance, under the influence of knife overload protection mechanism  455 ), because engagement apparatus  340  is forcibly pulling knife  129  down and engagement apparatus  340  is held in position, until adjusted. In operation, when engagement apparatus  340  is in its first position ( FIG.  5   ), cylinder  348  can receive hydraulic fluid, causing rod  349  to extend even further (for instance, to its fullest extent), which causes pivot bar  341  to rotate clockwise (as viewed in  FIG.  6   ), until engagement rod  342  is approximately in the 2 o&#39;clock position. In this movement, from the first position to the second position of the engagement apparatus  340 , engagement rod  342  engages and thus comes into contact (or, remains in contact) with bottom surface  453  of knife  129  (for example, at the curve or notch of bottom surface  453  which is adjacent to linkage  343  in  FIG.  6   ) and can forcibly lower knife  129  into its retraction position  663 , as shown in  FIG.  6   . For example, knife  129  could be stuck fully or partially above floor  131  by dirt or debris  454 , and the forceful pull of knife  129  by engagement rod will pull knife  129  through this dirt/debris  454  and thus through slot  232  so as to be fully retracted. When engagement apparatus  340  is in its second position, this need not be but can be an operating configuration of cutting assembly  128 . That is, baler  101  can be run across a field and bale with knives  129  in their forcibly retracted position  663  (which may be advantageous for certain harvesting conditions), though this is not necessarily the normal operating configuration for cutting assembly  128 . Using engagement apparatus  340  to force knife  129  into retraction position  663  enables the clearing of dirt and debris that may be jamming knife  129  in the insertion position  562 , and/or allows the user to run the baler with knives retracted into retraction position  663 . From this second position of engagement apparatus  340 , engagement mechanism  340  (besides remaining in this position) can selectively return back to its first position ( FIG.  5   ) or its home position ( FIG.  4   ) by retracting rod  349  and thus causing pivot bar  341  and thus linkage  343  to pivot counter-clockwise (as viewed in  FIG.  6   ). 
       FIG.  6    further includes controller  123  and sensors  638 ,  639  operatively coupled with controller  123  (and also controller  115 )(for illustrative purposes controller  123  and sensors  638 ,  639  are shown in  FIG.  6    but not  FIGS.  4  and  5    as well, though they can be impliedly present). As indicate above, engagement apparatus  340  can be moved to different locations. For example, engagement apparatus  340  can be moved from its home position, to its first position, to its second position, back to its first position, and then back to its home position. Further, any other combination of movements can occur as well, for example, from the home position directly to the second position, without pausing at the first position, or the like. Engagement apparatus  340  can be so moved manually or by way of a control system, such by way of control system  122  of baler  101 . As described above, control system  122  includes controller  123 , and can include one or more sensors, such as sensor  638  and/or  639 , which are shown schematically (sensors can also be considered to be a part of control system  114 ). Sensors  638 ,  639  can be position sensors. Sensor  638  can be coupled with cylinder  348  (on an interior or an exterior of cylinder  348 ) and can be configured for sensing a position of rod  349  relative to cylinder  348 , thus sensing the position of rod  349  in terms of its stroke. Sensor  639  can be coupled with linkage  343  and can be configured for sensing a position of linkage  343 , a position of pivot bar  341 , and/or a position of engagement rod  342 . Position data sensed by sensors  638 ,  639  can be formed into position signals by sensors  638 ,  639  and outputted by sensors  638 ,  639  to controller  123 , which is configured for receiving the position signals from sensors  638 ,  639 . Upon receiving these position signals, controller  123  is configured for outputting this information to a display of input/output device  120  in cab  105  of tractor  100 , so that user can know this information. In this way, user can be informed about the position of engagement apparatus  340 , whether it is in its home position, its first position, or its second position and thus can know whether knives  129  are in their forced upward position  562  (first/insertion position) or their forced downward position  663  (second/retraction position). Further, these sensors  638 ,  639  or another sensor(s) can be configured for sensing a position of knives  129 , regardless of the position of engagement apparatus  340 , so as to inform the user whether knives  129  (individual, or as groups, or as the entire set of knives  129 ) are fully inserted, fully retracted, or at some intermediate position therebetween. 
     Further, a user (such as the operator of tractor  100 ), upon being informed of the position of engagement apparatus  340  and/or knives  129  by way of input/output device  120 , can issue a command to controller  123  by way of device  120  to move engagement apparatus  340  and thus knives  129  to a certain position, for example, to any of the positions of engagement apparatus  340  described above, namely, its home position, its first position, and its second position (or any intermediate position thereof). For example, user can issue a command to move engagement apparatus  340  from its home position to its first position (corresponding to insertion position  562  of knives  129 ). Upon doing so, controller  123  is configured for outputting a controller output signal to actuator  344 , for example, to extend rod  349  so that linkage  343  pivots to approximately the 12 o&#39;clock position. As sensors  638 ,  639  sense the position of rod  349 , linkage  343 , pivot bar  341 , and/or engagement rod  342 , controller  123  can be configured so as to know when to output a stop signal to actuator  344  so as to halt movement of engagement rod  342  at the first position of engagement apparatus  340 , such that knives  129  are in their insertion position  562 . Likewise, upon user command, controller  123  can output a signal so that actuator  344  further extends rod  349  to move engagement rod  342  to the second position of engagement apparatus  340 , and to output a stop signal to halt actuator  344  when sensors  638 ,  639  sense the position of rod  349 , linkage  343 , pivot bar  341 , and/or engagement rod  342 , corresponding to when engagement rod  342  reaches the second position of engagement apparatus  340  and knives are in their corresponding retraction position  663 . Further, a command can be issued to return engagement apparatus to its home position, and further commands can be issued by user, such that controller  123  and sensors  348 ,  349  act in corresponding ways, depending upon the specific command. 
     Referring now to  FIG.  7   , there is shown an alternative embodiment of the cutting assembly of the present invention, now labeled cutting assembly  728 .  FIG.  7    is similar to  FIGS.  4 - 6   , both structurally and functionally. Substantially similar structure, structurally and functionally, has the same reference character, or a reference character that is raised by a factor of 100, and will not be described again here, unless otherwise noted. The primary difference with  FIG.  7    relative to prior figures is the engagement apparatus, now labeled engagement apparatus  740 . Engagement apparatus  740  includes pivot bar  341 , joining mechanism  743 , engagement rod  342 , and actuator  744 . Pivot bar  341  includes pivot axis  345  and can pivot in either direction about pivot axis  345 . Joining mechanism  743  can be generally formed as a disc  743 , which functions similarly to linkage  343 . Disc  743  can be made of any suitable material, such as steel. Two discs  743  can be attached respectively to lateral ends of pivot bar  341  and lateral ends of engagement rod  342 , the attachments being by welding or pinning, or the like. Disc  743  pivots with pivot bar  341  and thus about pivot axis  345 . For illustrative purposes, in dash-dot-dot lines, a full 360 degree rotation of disc  743  (with respect to an outer perimeter of disc  743 ) about pivot axis  345  is shown; though a 360 degree path is shown, it can be appreciated that disc  743  may be limited to pivoting about a lesser angular extent, for example, less than 180 degrees, such as 170 degrees (such as just above the 9 o&#39;clock position to approximately the 2 o&#39;clock position, by way of the 12 o&#39;clock position). Engagement rod  342  engages a bottom surface  453  of knife  129 , as described above. Actuator  744  is shown schematically and, in this embodiment, is formed as a rotary actuator  744 . Rotary actuator  744  can be, for example, an electric motor or a hydraulic motor with a rotatable output shaft which can be connected to pivot bar  341  in any suitable manner, such as by a splined connection coaxial with pivot bar  341  (to either side of disc  743 , for example), or by a belt(s), a chain(s), and/or gearing. Control system  122  of baler  101  (and control system  114 ) can further include a sensor  739 , which is a position sensor and which is operatively coupled with, and thus communicates with, controller  123  (and controller  115 ); sensor  739  functions substantially similarly to sensors  638 ,  639 , unless otherwise noted. Sensor  739  can be attached pivot bar  741 , disc  743 , or other suitable structure, so as to be able to detect a position of pivot bar  741  and provide this position data in the form of position signals to controller  123 .  FIG.  7    supplies similar information to what is provided in  FIGS.  4 - 6    with respect to the first embodiment of the cutting assembly. That is,  FIG.  7    shows, in solid lines, engagement rod  342  in substantially the 6 o&#39;clock position (similar to  FIG.  5   ) and thus the first position of engagement apparatus  740 , with knife  129  in the insertion position  562 . Near the 9 o&#39;clock position (similar to  FIG.  4   ), engagement rod  342  is shown in dashed lines, to indicate the home position of engagement apparatus  740 . Near the 2 o&#39;clock position (similar to  FIG.  6   ), engagement rode  342  is shown again in dashed lines, to indicate the second position of engagement apparatus  740 , which corresponds to the retraction position  663  of knife  129 , shown in dash-dot-dot lines. 
     In use, a user of tractor  100  and baler  101  can bale crop material  136  (such as baling hay), using a cutting assembly  128 ,  728  as part of feeder system  108 . Cutting assembly  128 ,  728  has individual knife overload protection, by way of knife overload protection mechanism  455 . Further, cutting assembly  128 ,  728  includes a way to clear jams of knives  129  due to dirt and debris  454 , to otherwise service one or more knives  129 , and/or to run baler  101  with knives  129  forcible retracted and locked in retraction position  663 . In normal operation of baler  101 , user can run with knives  129  up and in their insertion position, held up by knife overload protection mechanism  455 , but not in any way by engagement apparatus  340 ,  740 . If a sensor detects, for example, that one or more knives  129  are jammed by dirt and debris from being able to insert fully up through slots  232 , or user otherwise wishes to ensure clearance of any possible dirt and debris, user can issue a command by way of input/output device  120  to cause control system  122  to move engagement apparatus  340 ,  740  from its home position to its first position (6 o&#39;clock position), so as to forcibly push knives  129  through any dirt and debris block slots  232  and to lock knives in the insertion position  562 . If user wishes to complete the clean-out or to otherwise retract knives  129  down to retraction position  663 , user can issue a command to move engagement apparatus  340 ,  740  to its second position (2 o&#39;clock position). User can also command engagement apparatus  340 ,  740  to return to its home position, the engagement apparatus  340  no longer being engaged with knives  129 , though knife overload protection mechanism  455  maintains its engagement with individual knives  129 . Thus, in accordance with the present invention, the user has positive engagement with knives  129  to raise or lower them on command, while maintaining individual overload protection by way of overload protection mechanism  455  using springs  459  as part of the individual overload protection mechanism  455 . 
     Referring now to  FIG.  8   , there is shown a flow diagram showing a method  865  for using an agricultural baler  101 , the method including the steps of: providing  866  a frame  130  and a feeder system  108  coupled with the frame  130 , the feeder system  108  including a cutting assembly  128 ,  728  coupled with the frame  130  and including at least one knife  129  and an engagement apparatus  340 ,  740 , the at least one knife  129  configured for cutting a crop material  136 , the engagement apparatus  340 ,  740  being configured for being spaced apart from at least one overload protection mechanism  455  individually associated with a single one of the at least one knife  129 ; engaging  867  selectively, by way of the engagement apparatus  340 ,  740 , with the at least one knife  129  and thereby forcing the at least one knife  129  to occupy a first position  562 ; and engaging  868  selectively, by way of the engagement apparatus  340 ,  740 , with the at least one knife  129  and thereby forcing the at least one knife  129  to occupy a second position  663 . The cutting assembly  128 ,  728  can further include the at least one overload protection mechanism  455 , a single one of the at least one overload protection mechanism  455  being assigned to and coupled with a single one of the at least one knife  129 . The method  865  can further include the step of disengaging  869  selectively, by way of the engagement apparatus  340 ,  740 , from the at least one knife  129 . The first position  562  can be an insertion position  562 , and the second position  663  can be a retraction position  663 , both the first position  562  and the second position  663  being locked. The at least one knife  129  can include a surface  453 , the engagement apparatus  340 ,  740  including an actuator  344 ,  744  and an engagement rod  342  configured for engaging the surface  453  of the at least one knife  129 . The actuator  344 ,  744  can be linear actuator  344  or a rotary actuator  744 . 
     It is to be understood that the steps of method  865  are performed by controller  115 ,  123  upon loading and executing software code or instructions which are tangibly stored on a tangible computer readable medium, such as on a magnetic medium, e.g., a computer hard drive, an optical medium, e.g., an optical disc, solid-state memory, e.g., flash memory, or other storage media known in the art. Thus, any of the functionality performed by controller  115 ,  123  described herein, such as the method  865 , is implemented in software code or instructions which are tangibly stored on a tangible computer readable medium. The controller  115 ,  123  loads the software code or instructions via a direct interface with the computer readable medium or via a wired and/or wireless network. Upon loading and executing such software code or instructions by controller  115 ,  123 , controller  115 ,  123  may perform any of the functionality of controller  115 ,  123  described herein, including any steps of the method  865 . 
     The term “software code” or “code” used herein refers to any instructions or set of instructions that influence the operation of a computer or controller. They may exist in a computer-executable form, such as machine code, which is the set of instructions and data directly executed by a computer&#39;s central processing unit or by a controller, a human-understandable form, such as source code, which may be compiled in order to be executed by a computer&#39;s central processing unit or by a controller, or an intermediate form, such as object code, which is produced by a compiler. As used herein, the term “software code” or “code” also includes any human-understandable computer instructions or set of instructions, e.g., a script, that may be executed on the fly with the aid of an interpreter executed by a computer&#39;s central processing unit or by a controller. 
     These and other advantages of the present invention will be apparent to those skilled in the art from the foregoing specification. Accordingly, it is to be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It is to be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention.