Abstract:
A continuous tortilla chip cutting system where tortilla carried on a conveyor are continuously divided by a cutting mechanism into pre-cuts for frying into chips. A programmable controller drives a servo motor that moves an upper surface of the conveyor at a known velocity V, and a detector located above the conveyor at a known distance D from the cutting mechanism alerts the controller to the imminent arrival of the tortilla. The controller also controls a servo motor that actuates the cutting mechanism in a stop/start fashion. Based on the detection of the tortilla, the controller drives the servo motor associated with the cutting mechanism at just the right time and at just the right speed so that the cutter mechanism cuts each arriving tortilla into predictable sub-units called “pre-cuts” based on the velocity V of the conveyor belt, the detection of the flat bread unit carried by the conveyor, and the known distance between the moving flat bread unit and the cutter assembly.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This application relates generally to assembly line food production machinery and, more particularly, to a continuous tortilla chip cutter used, for example, for cutting tortilla chips from whole tortillas. 
         [0003]    2. Description of the Related Art 
         [0004]      FIGS. 1 to 5  show a flatbread unit  20  (i.e. a tortilla, pita bread, etc.), or a stack thereof, being processed into “pre-cuts”  21  that will be fried and served. Restaurants and families alike have long been using a knife to hand-cut corn tortillas to make old fashioned fresh-fried tortilla chips. The hand-cut method works by using a knife to cut a tortilla  20 , or short stack of tortillas (e.g. 5-7), into chip-shaped pieces  21  and then frying those pieces in hot oil.  FIG. 1  shows a traditional tortilla cut that forms substantially-rectangular chips.  FIG. 2  shows more closely spaced cuts that form thin strips that are suitable for tortilla soup. If done by hand, the cook would use a knife to make the parallel cuts, and then make a final perpendicular cut that divides the parallel strips into two groups. 
         [0005]    Hand-cutting is sometimes used to make triangular chips by using a knife to cross-cut the tortilla stack into four, six, or more pieces, as shown in  FIGS. 2 to 5 , but when cutting the tortilla into six or more pieces, which requires three or more cuts, it is somewhat difficult to get all of the cuts to go through a common center. It can be done, but it is a relatively laborious process and the result is substantially imperfect chips. 
         [0006]    In the snack food industry, manufacturers usually make production-line chips that are for sale to retail consumers by sheeting raw corn masa (or other dough) into a continuous dough sheet, cutting chip shaped dough pieces from the sheet, baking the dough pieces in an oven, frying the baked dough pieces in hot oil, cooling the fried chips, and then packaging the chips in retail bags for distribution. The cutting of chip-shaped pieces from a raw sheet of dough usually leaves a thickened border or “hem” on the uncooked, chip-shaped dough piece, and on the final product. The chips are consumed at room temperature sometime over the next several days or weeks. The chips made in this manner are ideal for sale in grocery stores, convenience stores, vending machines, and the like, but are less than ideal for restaurant use. 
         [0007]    Sheeted chips can be produced in mass quantities, but it is usually impractical to serve them fresh fried. Moreover, sheeted chis inherently have a relatively thick “hem” around the perimeter of the chip shapes due to the masa that is pushed aside by the cutting blades of the cutter roller. Because of the hem, many consumers place a premium on the higher-quality of tortilla chips that are made by starting with fully-cooked (baked) corn tortillas, cutting the tortillas into chip shaped pre-cuts (e.g. by hand, or by cutting stacks of tortillas with suitable machines called choppers), and then frying the pre-cuts. Restaurants prefer pre-cuts because they are fresh fried and promptly served. When compared with fresh fried chips, sheeted, pre-packaged chips have a thickened border, are not served warm, and have a different taste and texture. 
         [0008]    Some restaurants that serve fresh-fried tortilla strips prefer to buy boxes of ready-to-fry pre-cuts so that they can fresh-fly chips, on site and on demand, without having to hand-cut the tortillas. This approach is consistent with the higher volume demand of certain restaurants. There may also be a market for retail packaged chips that are made by frying pre-cuts and packaging them for retail sale. 
         [0009]    Tortilla factories have been serving their commercial restaurant customers by taking the same cooked tortillas that they might otherwise package and sell as whole tortillas, and cutting them into so-called “pre-cuts”  21  for delivery to the restaurant in suitable boxes for later, on demand frying at the restaurant. Typically, a factory making pre-cuts operates by cooking the tortillas in a normal manner, and then proceeds by aligning a number of them into a stack, and by cutting the stack to create the pre-cuts  21 . Some machines operate by pushing the stack through one or more stationary cutting blades. Others operate by pushing one or more cutting blades through a stationary stack of tortillas. In either case, a single complex cutting blade may be used (e.g. an X-shaped blade), or a single blade may be used and the blade or stack of tortillas is rotated between cuts. 
         [0010]    The conventional approach to making pre-cuts requires many steps that are spread over many hours, sometimes as many as 24 hours, for example 
         [0011]    1. Make the raw tortillas (prepare the masa by cooking raw corn or mixing water with corn flour and then sheet the masa into a sheet and cut tortilla shapes from the sheet) 
         [0012]    2. Cook (bake) 
         [0013]    3. Cool 
         [0014]    4. Count 
         [0015]    5. Stack by hand (e.g. on racks or in boxes) 
         [0016]    6. Store them to cool (maybe overnight) so that they stick together less when cut 
         [0017]    7. Cut pre-cuts from the stacks by manually placing the stacks on a cutter (with some requiring hand rotation) 
         [0018]    8. Convey the pre-cuts 
         [0019]    9. Tumble the pre-cuts (to separate the many pre-cuts that are stuck together) 
         [0020]    10. Weigh 
         [0021]    11. Box 
         [0022]    12. Deliver to restaurants 
         [0023]    The prior art contains numerous tortilla cutters that are suitable for cutting pre-cuts from a stack of tortillas (step 7 above), but they exhibit certain deficiencies that are addressed by the present invention. 
         [0024]    U.S. Pat. No. 6,318,225, entitled Tortilla Cutter, invented by Longoria, describes an automatic tortilla cutter that uses a piston-driven cutter that is formed from two vertically-oriented blades that arranged in an X-configuration. In operation, an operator manually loads a stack of tortillas below the X-shaped cutter, and then the apparatus drives the X-shaped cutter down through the stack. This cutter requires the extensive manual labor and prevents full automation, a key characteristic that food production businesses aim to achieve. 
         [0025]    U.S. Pat. No. 5,148,655, entitled Slicer and Bagger for Substantially Flat Food Products, invented by Salinas, shows a stack of of food products manually placed on top of an X-shaped slicing blade. When pressed downward by a ram member, the food products are divided into smaller segments that fall into a bag located below the blade. At least one drawback of this device is its complexity and its inapplicability to a continuous and automated cutting operation. 
         [0026]    U.S. Pat. No. 4,978,548, entitled Method and Apparatus for Continuous 
         [0027]    Production of Tortilla Chips, invented by Cope et al., describes a method for producing tortilla chips where a stack of tortilla shapes is refrigerated before being pushed through the knife blades of a chip cutter. 
         [0028]    Shortcoming of the Prior Art Cutters 
         [0029]    Many different kinds of machines have been designed to make tortilla chips from whole tortillas. The task generally involves three successive operations: (1) stacking tortillas vertically, one on top of another; (2) cutting through the tortillas with a vertical blade making a motion downward and through the stack of tortillas; and (3) separating the chopped tortillas from each other through an industrial tumbling dryer. 
         [0030]    When the task of cutting whole tortillas into tortilla chips is used as described above, the machine is sometimes known as a “tortilla chip chopper” or simply a “chopper.” When the process is performed using the system as described below (as the exemplary tortilla production environment), the system is usually known as a continuous tortilla chip cutter. Regardless of the method, both systems are part of a much larger food production system of producing tortilla chips and packaging them for further processing or consumption. 
         [0031]    That being said, the ultimate goal of a chopper/continuous tortilla chip system is to cut tortillas chips from whole tortillas to create a tortilla chip without a “hem.” A hem is a thick notch at the point of cutting that provides additional structural reinforcement to the chip, creating a harder and “stronger” chip. The benefit of creating a chip without a hem is that the chip is more tender and fragile. As a result, the fragile chip does not require as much pressure or effort to chew (because it breaks inside the end user&#39;s mouth more easily) and is less likely to cause oral lacerations. An additional benefit is that tortilla chips made through this method, without a “hem,” represent more authentic or old fashioned chips where restaurants would cut day-old-tortillas, fry them, and serve them to their customers. On the other hand, tortilla chips with a hem are preferred “scooping” chips. 
         [0032]    Chopping 
         [0033]    There are many different types of choppers (also known as slicers or cutters) that have been used for some time. In a high-speed production environment, the traditional method has been to stack tortillas by hand (or using an automated counter/stacker system), place them in a vertical tunnel-like structure, and cut them using a mechanical blade which travels downward through the stacked tortillas. In a typical tortilla chip chopper, the chopper apparatus is a mechanical blade (usually manufactured in an X formation) which chops through a stack of tortillas by forcefully moving downward through the stack of tortillas. In another embodiment, the stack can be placed on top of a fixed, stationary blade (usually manufactured in an X formation) whereas a flat piece of metal pushes the stack of tortillas downward against the blade, slicing the tortillas and pushing the pieces into a compartment below. 
         [0034]    Separating/Freeing From Adhesion 
         [0035]    At the point of chopping, the tortillas are stacked vertically, one on top of another. Unfortunately, due to the moisture content of the tortillas at the time of chopping (which is usually about 30%), the tortilla pieces “stick” together as the blade applies pressure and these pieces must be freed so that no two chips are “stuck” together. This process is generally known as freeing the chips from adhesion. 
         [0036]    Tumbling 
         [0037]    That being said, due to the adhesive properties of the tortilla&#39;s moisture content, the tortilla chips need to be freed from adhesion and to perform this, an industrial tumble dryer is often employed. The use of an industrial tumble dryer serves two functions: First, the tumbling movement tends to separate the chips from each other; and second, the heat helps to evaporate the moisture content of chips, removing the “stickiness” of the chips. In another embodiment a vibrating conveyor may be used instead of a tumbling conveyor. 
         [0038]    The prior art chip cutters operate on a stack of tortillas, in batches. As a result, they generally require the counting and stacking of the tortillas, and they generally require the tortillas to be more fully cooled (or even refrigerated) to reduce sticking caused by the blades compressing the tortillas into one another at the cut lines. Nonetheless, even with extensive cooling, sticking continues to be a problem due to the moisture content of the stacked tortillas and tumblers or shakers are often used to separate the pre-cuts from one another. In addition, many of the prior art systems require manual placement of the stacks. There remains a need, therefore, for a continuous tortilla chip cutting system that improves on the prior art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]      FIGS. 1 to 5  are, for context, top plan views showing how a tortilla or other flatbread unit  20  may be sliced into pre-cuts  21  of various desired shapes for frying; 
           [0040]      FIGS. 6 and 7  are schematic top and side views of a first preferred embodiment of a continuous flat bread cutting apparatus  10  for cutting flat bread units  20  into pre-cuts  21 , shown here as comprising a conveyor  40 , a detector  50 , a generic cutting mechanism  60  that can take on any suitable construction or manner of operation that is consistent with the present invention, a conveyor motor M 40 , a cutter motor M 60 , and a controller  70 ; 
           [0041]      FIGS. 8 and 9  are schematic top and side views of a second preferred embodiment of a continuous flat bread cutting apparatus  210  that is similar to the first preferred embodiment, but comprises a cutting mechanism  260  more specifically formed from a pair of counter-rotating rollers  262 ,  264 ; 
           [0042]      FIG. 10  is a perspective view of the cutting mechanism  260  used in the second preferred embodiment of  FIGS. 8 and 9 ; 
           [0043]      FIG. 11  is an isolated perspective view of the rotating die, or cutter roller  264 , showing how its blades  265  will divide a tortilla  20  into four triangular pre-cuts  21  if its rotation is timed such that that the central portion  266  is aligned with the center of the tortilla  20  as it passes through the cutting mechanism  260 ; 
           [0044]      FIG. 12  is a dimensioned plan view of the cutter roller  264  showing its general construction; 
           [0045]      FIG. 13  is a perspective view of a third preferred embodiment that has two parallel rows or lanes; 
           [0046]      FIGS. 14 to 16  are top, input end, and output end views, respectively, of the third preferred two-row embodiment of  FIG. 13 ; 
           [0047]      FIG. 17A  is a perspective view of a fourth presently preferred continuous flat bread cutting system  410  that features a frame  420  carrying six independently driven conveyors  40 ; 
           [0048]      FIG. 17B  is a view of the graphical interface to the preferred controller  70 ; 
           [0049]      FIG. 17C  is a screen used to adjust the home positioning that accurately and repeatedly positions the cutter roller  464  in the center of the tortilla  20 ; 
           [0050]      FIG. 17D  is a perspective view of the electrical box  415  on the lower exit side of the system  410 ; 
           [0051]      FIG. 18  is a close-up view of the output end of the six conveyors  40 , with the protective cover  411  lifted open, to reveal six corresponding sensors  450 ; 
           [0052]      FIG. 19  is a close-up view looking inward toward the sixth or right-most sensor  450  in  FIG. 18 ; 
           [0053]      FIG. 20  is a close-up view of the output side of the same row shown in  FIG. 19 , but looking back in an opposite direction; 
           [0054]      FIG. 21  is a view of the output side of the system  410 , like  FIG. 20 , but with the protective cover  412  rotated upward about its hinges in order to reveal more details; 
           [0055]      FIG. 22  is a perspective view of a modular cutting mechanism cartridge  460 , shown in isolation for clarity of construction and overall operation; 
           [0056]      FIG. 23  is a close-up view of the non-geared side the modular cutting mechanism cartridge  460  of  FIG. 22 , showing the bearings and positional adjustment mechanism; 
           [0057]      FIG. 24  is an even closer view of the interface between the aperture  466  in the side plate  461  and the carrier  485  that supports the bearings  484  that hold the cutter roller  464 ; 
           [0058]      FIG. 25  shows how the cutting blades  465  of a cutter roller  464  (here a 6-chip cutter) intersect in a central portion  466  of substantial area; 
           [0059]      FIG. 26  is a schematic representation of the cutter roller  464  of  FIG. 25 , including its cutting blades and central portion  466 ; 
           [0060]      FIG. 27  is a schematic representation of an improved cutter roller  564  where the cutting blades  565  are arranged to be close enough to cut the tortilla  20  into the pre-cuts  21  of desired shape without creating a dense central section as in  FIG. 25 ; and 
           [0061]      FIGS. 28 and 29  relate to alternative cutter roller  664  that uniquely cuts several similar shaped pre-cuts  21  from a larger tortilla 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0062]    The present invention can reside in many possible embodiments, but the presently preferred embodiments reside in a Continuous Tortilla Chip Cutter that is part of a tortilla chip cutting environment as follows 
       Exemplary Tortilla Chip Cutting Environment 
       [0063]    In an exemplary tortilla chip cutting environment there are five successive operations: (1) the transportation of the tortillas directly from the cooling conveyor to the Continuous Tortilla Chip Cutter; (2) the acceleration of the tortillas creating distance between tortillas/physical separation; (3) the cutting of the tortilla; (4) discharge; and (5) cooling. Furthermore, as compared to the prior art described above, the exemplary tortilla chip-cutting environment requires less manual labor, provides a safer environment, and requires less energy be consumed. 
         [0064]    Transportation. The exemplary tortilla chip cutting environment is one which eliminates the need for counting and stacking and automatically transports the tortillas to the cutter, providing the food production manufacture the ability to become fully automated. From where the tortillas are being cooled, they can be routed to an additional transporting belt leading to the Continuous Tortilla Chip Cutter System. An additional transporting belt is directly attached to the cooling conveyor where tortillas are cooled, allowing the cooled tortillas to be chopped shortly after being produced. 
         [0065]    Acceleration. Once the tortillas have been transported, they reach another conveyor belt leading directly to the cutter. This additional conveyor travels at a rate of speed higher than the previous conveyor so that distance (physical space) is created between each of the tortillas. As the tortillas travel upward through the high-speed conveyor they pass through a tunnel-like enclosure which contains a robotic eye. This robotic eye performs a visual inspection that notifies an on-board computer of the tortilla&#39;s presence and the length of time before the tortilla reaches the cutter. Moreover, with this robotic eye, the cutting apparatus is activated only at the time the tortilla reaches the cutter. 
         [0066]    Cutter/Slicer Mechanism. As previously mentioned, there are many different types of cutters (sometime also known as slicers or choppers) that have been known for used for some time. In a high-speed production environment, the traditional method has been to stack tortillas by hand, place them in a vertical tunnel-like structure, and cut them using a blade which travels downward through the stacked tortillas. However, the continuous tortilla cutter system uses a rotating die (or cutter) that captures each individual tortilla and rotates over the tortilla, cutting it into quarters, eighths, or whatever size a food producer desires. The benefit of this is that each tortilla is cut separately with pieces being ejected from the cutter in a manner where the pieces are not placed on top of each other and pressed together with force. If these pieces were placed on top of each other and sliced with force, the moisture would make them “stick” together and require them to be separated through a tunnel dryer. This cutter/slicer mechanism makes this step (separating the pieces through a tunnel dryer) unnecessary as the pieces are separated at the time of cutting. 
         [0067]    Discharge. After the tortillas have been cut to create tortilla chips, the chips are discharged from the cutter to the cooling conveyor belt. 
         [0068]    Cooling. An exemplary cooling conveyor belt may be four (4) to eighteen (18) rows in height, allowing chips to begin at the top and make their way down, row-by-row, so that the chips may be cooled and to assist in evaporating any additional moisture prior to packaging. A blower is usually associated with the cooling conveyor belt to blow cool air throughout the belt to ensure temperature cool down. 
       First Preferred Embodiment 
     General Operation 
       [0069]    There are many possible embodiments of a Continuous Tortilla Chip Cutting System according to the present invention.  FIGS. 6 and 7 , for example, are schematic top and side views of a first preferred, albeit simplified embodiment of a Continuous Tortilla Chip Cutting System  10  for cutting tortillas  20  into pre-cuts  21 . As shown in  FIGS. 1 and 2 , the system  10  receives the tortillas  20  from an upstream flatbread production line  30  which may be fully automated, manual, or some combination thereof. As shown, the system  10  comprises a conveyor  40  that is driven by a conveyor motor M 40 , a detector  50 , a cutting mechanism  60  that is driven by a cutter motor M 60 , and a controller  70 . 
         [0070]    The goal is to form pre-cuts  21  that are distinct from one another, undamaged, and of consistent shape. The pre-cuts  21  formed by the system  10  are usually intended for frying, after further cooling or at some time in the future. For example, the producer may sell the box  80  of pre-cuts  21  to a restaurant, bar, or the like, who will fry a portion of the pre-cuts  21  on demand, in order to serve the retail customer with hot, fresh-fried, tortilla chips. 
         [0071]    In the illustrated embodiment, the pre-cuts  21  are discharged directly into a box  80  (usually lined with plastic) for hypothetical sale to a customer of the producer, but it should be understood that it may be desirable to further cool the pre-cuts by transporting them on a cooling conveyor, or equivalent, before stacking and packaging them into a box  80 . 
         [0072]    In the preferred embodiment, as best shown in the side view of  FIG. 7 , the preferred cutting mechanism  60  accelerates the pre-cuts  21  upward, through an arc, so that they are discharged and tend to separate from one another. The preferred conveyor  40  has an upper surface  41  that moves upward at an angle, with its input end  42  lower than its output end  43 , but other arrangement and orientations are possible for both the conveyor  40  and the cutting mechanism  60 . 
         [0073]    The cutting mechanism  60  of  FIGS. 1 and 2  is illustrated as a black box that can take on any suitable construction or manner of operation that is consistent with the present invention. It can be roller-based, guillotine-like, etc., without departing from the presently intended scope of the embodiments encompassed by the invention. 
         [0074]    In operation, the production line  30  delivers flat bread units  20  to the input end  42  of the conveyor and the conveyor  40 , driven by the conveyor motor M 40  under the control of the controller  70 , transports the flat bread units  20  on its upper surface  41 , from the input end  42  to the output end  43 , at a known, controlled, velocity V. Along the way, as it moves at velocity V, the detector  50  detects the leading edge (or other suitable datum) of each flat bread unit  20  and outputs a detection signal  51  to the controller  70 . At the output end  43 , each successive flat bread unit  20  is fed to the cutting mechanism  60  that is driven by a cutter motor M 60 . The controller  70  controls the cutter motor M 60 , based on the detector  50 &#39;s detection of the flat bread unit  20 , the speed V, and the distance D, in order to actuate the cutting mechanism  60  at just the right time and at just the right speed in order to consistently, repeatedly cut each flat bread unit  20  into a substantially identical plurality of “pre-cuts”  21 , flat bread unit after flat bread unit. 
       Second Preferred Embodiment 
       [0075]      FIGS. 8 and 9  are schematic top and side views of a second preferred embodiment of a continuous flat bread cutting apparatus  210  that is similar to the first preferred apparatus  10 , but more specifically comprises a cutting mechanism  260  that formed from a pair of counter-rotating rollers  262 ,  264 . As suggested by  FIG. 9 , the preferred upper roller  262  has a substantially smooth surface for cutting against (made e.g. of UHMW polyethylene), and the lower roller  264  has a plurality of blades  265  that rotate against the upper roller  262  (made e.g. of stainless steel). The key to consistent operation is to have the cutter roller  264  in a known starting position prior to the detection of each subsequent flatbread unit  20 , and then to start its rotation at just the right time to cut each flatbread units  20  into correctly shaped pre-cuts  21 . 
         [0076]      FIG. 10  is a perspective view of the cutting mechanism  260  used in the second preferred embodiment of  FIGS. 8 and 9 . As shown, the upper roller  262  and rotating die or cutter roller  264  are driven in a counter-rotating fashion through a mechanical arrangement comprised of a servo motor M 60 , a servo gear box M 61 , a sprocket M 62 , a belt M 63 , a driven gear M 64  on one end of the cutter roller  264 , a driving gear M 65  on an opposite end of the cutter roller  264 , and a driven gear M 66  on the upper roller  262 . In operation, the rotating die (or cutter)  264  captures each individual tortilla  20  and rotates its blades  265  through the tortilla, against the upper roller  262 , cutting it into quarters, eighths, or whatever size a food producer desires. 
         [0077]      FIG. 11  is an isolated perspective view of the rotating die or cutter roller  264 , showing how its blades  265  are arranged to form a pattern that will, in this particular case, divide a tortilla  20  into four triangular pre-cuts  21 , as shown in  FIG. 3 . Note that the blades  265  cross over at a central portion  266 . As already alluded to, the key is to time the rotation of the cutter roller  264  such that the central portion  266  is aligned with the center of the tortilla  20  as it passes through the cutting mechanism  260 . 
         [0078]    In the second preferred system  210 , as with the others, this timing is accomplished by using a controller  70  that controls the velocity V of the conveyor belt  40  through a conveyor motor M 40 . Preferably, the conveyor motor M 40  is controlled so as to drive the conveyor belt  40  at a rate of speed V that is higher than the previous conveyor (e.g. from a cooling conveyor) so that distance (physical space) is created between each of the tortillas  20 . 
         [0079]    As the tortillas  20  travel further on the upper surface  41  of the high-speed conveyor  40 , it passes beneath a sensor  50  (e.g. a robotic eye, or light sensor, or other suitable sensor) that sends a detection signal  51  to the controller (or on-board computer) regarding the tortilla&#39;s presence and imminent arrival at the cutting mechanism  260 . In operation, the length of time before the tortilla  20  reaches the cutting mechanism  264  is a function of the distance D and the velocity V, i.e. T=V/D. As a result of this arrangement, the controller  70  drives the cutting mechanism  160  at just the right time, when the tortilla  20  arrives, so that the cutting mechanism  160  ejects four substantially identical pre-cuts  21 . 
         [0080]      FIG. 12  is a dimensioned plan view of the cutter roller  264  showing its general construction in more detail and, based on the 7″ width of the central cylinder that supports the cutting blades  265 , the fact that it is designed to cut 6″ diameter tortillas into pre-cuts  21 . The presently preferred cutter roller  264  is formed by CNC milling a stainless steel cylinder to leave behind the cutting blades  265 , but other methods of manufacture may be employed. 
       Third Preferred Embodiment 
       [0081]      FIG. 13  is a perspective view of a third preferred embodiment that is like the second preferred embodiment, but comprises a suitable frame  320  that supports two parallel conveyor belts  40  and two corresponding cutting mechanisms  260  for providing increased throughput when fed by a two-row tortilla production line. 
         [0082]      FIGS. 14 to 16  are top, input end, and output end views, respectively, of the third preferred embodiment of  FIG. 13 . 
       Fourth Preferred Embodiment 
       [0083]      FIG. 17A  is a perspective view of a fourth presently preferred continuous flat bread cutting system  410  that features a frame  420  carrying six independently driven conveyors  40  for receiving tortillas  20  discharged in a corresponding number of lanes at the output end of an upstream production system (e.g. from a cooling conveyor or the like). In this embodiment, the six conveyors  40  are slanted upward, as with the earlier embodiments, and they are driven by servo motors to rapidly transport tortillas  20  toward modular cutting mechanism cartridges  460  (described more fully below) that feature a pair of counter-rotating rollers like the cutting mechanism  160  mentioned above. A protective cover  411  is provided for safety purposes. A controller  470  is accessible via a control box mounted to the side of the system  410 . Six pairs of adjustment handles  486 ,  486  are present, as explained further below with respect to  FIG. 23 . 
         [0084]      FIG. 17B  is a view of the graphical interface to the preferred controller  70 , an Allen Bradley® Panel View Plus  600 , a programmable unit that can accurately drive servo motors to control the velocity V of each conveyor belt  40  and then, based on the input of a detection signal from the optical detector  450 , can accurately control the exact turn-on time and speed of the servo motors that run each corresponding cutting mechanism  460 . 
         [0085]      FIG. 17C  is a screen used to adjust the home positioning that accurately and repeatedly positions the cutter roller  464  in the center of the tortilla  20 . The inventors contemplate the use of servo motors that are self-homing in future embodiments. 
         [0086]      FIG. 17D  is a perspective view of the electrical box  415  on the lower exit side of the system  410  where one finds the six variable frequency motor drivers that, under the direction of a suitable program running on the controller  70 , drive the six corresponding cutting mechanisms  460 . 
         [0087]      FIG. 18  is a close-up view of the output end of the six conveyors  40 , with the protective cover  411  lifted open, to reveal six corresponding sensors  450  that detect the tortillas  20  that are being independently transported at high speed by each of the six conveyors  40 . 
         [0088]      FIG. 19  is a close-up view looking inward toward the sixth or right-most sensor  450  in  FIG. 18 , at the top of the sixth conveyor belt  40 , and reveals the conductors  451  that transmit the sensor  450 &#39;s detection signal to the controller  470 . Looking closely, one can see the input to the associated cutting mechanism  460 , including a substrate roller  462  made of UHMW, and a cutter roller  464  that is made of stainless steel and has had cutting blades  465  milled into its periphery. 
         [0089]      FIG. 20  is a close-up view of the output side of the same row, looking back in a direction opposite to that of  FIG. 19 . Another protective cover  412  is provided for safety purposes. As shown, the cutting mechanism  460 &#39;s substrate roller  462  and cutter roller  464  are connected to one another by corresponding gears  472 ,  474 . The construction of the cutting mechanism  450  will become clearer from further description. 
         [0090]      FIG. 21  is a view of the output side of the system  410 , like  FIG. 20 , but with the protective cover  412  rotated upward about its hinges in order to reveal more details. One can now begin to see the modularity of the cutting mechanisms  460 . First, for purposes of modularity, the system frame  420  includes a number of vertical divider walls  421  (seven in total for six lanes) and, as suggested by the one hand bolt  480  that has been unscrewed from the divider wall  421  next to the right side of the left-most cutting mechanism  460 , each cutting mechanism cartridge  460  is detachably secured, as desired, between an adjacent pair of vertical divider walls  421  by four hand bolts  480 , two extending to the left and two extending to the right. By using modular cutting mechanism cartridges  460 , it is a relatively simple matter to repair or replace any given cutting mechanism  460 . 
         [0091]      FIG. 22  is a perspective view of a modular cutting mechanism cartridge  460 , shown in isolation for clarity of construction and overall operation. As shown, the cutting mechanism  460  comprises left and right side walls  461 ,  461  that, for rigidity, are braced to one another by four transverse connecting members  471 . The backing roller  462  and cutter roller  464  are supported between the side walls, with their shafts supported by suitable bearings (described further below). The rollers  462 ,  464  are operatively connected to one another by gears  472 ,  474 . Each side wall includes two pairs of holes  481  and, as best shown by  FIG. 21 , the hand bolts  480  extend through the holes  481  in order to secure the overall cutting mechanisms  460  to the divider walls  421  of the system&#39;s frame  420 . Because the side walls  421  are relatively thin, each side plate  461  has two holes on one side and two holes on the other side, and there are corresponding holes in the dividing walls  421 . That way, the threaded tips of two nearby hand bolts  480  that are threaded toward one another are vertically spaced and do not interfere. 
         [0092]      FIG. 23  is a close-up view of the non-geared side the modular cutting mechanism  460  of  FIG. 22 , showing the bearings and positional adjustment mechanism. As shown, the backing roller  462  has a shaft (not visible) that rotates in a bearing  482  that is fixed to the side plate  461 . The cutting roller  464 , by contrast, has a shaft (also not visible) that rotates in a bearing  484  that is connected to a carrier  485  that slides within an aperture  466  in the side wall  461 , and is vertically adjustable therein through the operation of a handle  486  (see  FIG. 17 ) that turns a threaded adjustment rod  486  connected to the carrier  485 . Through this arrangement, the operate can carefully adjust the cutter roller  464 &#39;s proximity to the backing roller  462 , making it close enough to provide quality cutting, but not in direct contact therewith in order to extend the life of the cutting blades  465 . 
         [0093]      FIG. 24  is an even closer view of the interface between the aperture  466  in the side plate  461  and the carrier  485  that supports the bearings  484  that hold the cutter roller  464 . As shown, the carrier  485  has notches  488  in its parallel sides (only one is shown in this view) and each notch  488  receive the edge  489  of a retention plate  490  that is bolted to the side plate  461 . As a result, the carrier  485  is restrained within the aperture  466 , but it can move vertically up and down along the edges  489  of the retention plates. Many other constructions are possible. 
         [0094]    Improved Cutter Roller Blades 
         [0095]      FIG. 25  is a close-up that is best understood by briefly returning briefly to  FIG. 23  where one sees a cutter roller  464  that has been CNC-milled to provide three intersecting cutting blades  465  that, as shown in  FIG. 4 , will divide a tortilla  20  into six segments.  FIG. 25  is a close-up of the three cutting blades  465  that intersect in a central portion  466 . Due to manufacturing limitations associated with the CNC milling process (i.e. the finite size of the milling bit that removes material to leave behind the cutting blades  465 ), the center portion  466  takes on a star-shape of finite area. This phenomenon occurs even with a 4-chip pattern, but is most predominant with a pattern of 6-chips or more. As a result of this star shaped central portion  466 , when the cutter roller  464  is used to cut each tortilla  20  into a number of pre-cuts  21 , the central portion  466  will crush a corresponding area of the tortilla  20 , rather than cleanly cut that area into one of the pre-cuts. As a result, the cutting mechanism  460  creates and debris and powder that builds up over time and must be cleaned. It is also possible that the pre-cuts  21  will have a slightly misshapen tip. 
         [0096]      FIG. 26  is a schematic representation of the cutter roller  464  of  FIGS. 23 and 24 , including its cutting blades and central portion  466 .  FIG. 27  shows an improved cutter roller  564  where the cutting blades  565  are arranged to be close enough to cut the tortilla  20  into the desired pre-cuts  21  of triangular shape, but notably, do not intersect one another and form a dense central section as in  FIG. 26 . 
         [0097]      FIGS. 28 and 29  relate to alternative cutter roller  664  that uniquely cuts several similar shaped pre-cuts  21  from a larger tortilla, e.g. a 12″, 14″ or 16″ tortilla, for example, rather than from a smaller 6″ tortilla. As suggested by  FIG. 29 , the cutting pattern used with a larger tortilla can take on a variety of different configurations (e.g. concentric rings cut along radii of differing angular spacing) so that many more pre-cuts of similar shape can be provided by the larger tortillas. The result would be a more efficient and higher through-put production line. 
         [0098]    The embodiments disclosed herein have largely focused on corn tortilla systems. However, the underlying concepts can be applied to other production systems that produce flatbread units such as flour tortillas, pita bread, etc.