The present inventions relate to improvements in high speed production sheeting devices for comestible products (e.g., tortillas and tortilla chips). More specifically, the present inventions relate to sheeting devices with improved stripper wire assemblies.
Corn tortillas and tortilla chips are cut from a sheet of corn dough, called “masa,” and then baked and/or fried. In mass production, the sheeting and cutting stages are accomplished by a tortilla sheeter.
High production tortilla sheeters feed masa from a hopper between a pair of large, stainless steel rollers which roll the masa into a sheet of substantially uniform thickness. The rollers are spaced apart in production to form a gap, known as a “pinch point gap,” through which the masa passes. The masa adheres to the surface of one of the rollers, known as the exit roller, after passing through the pinch point gap. A third roller then cuts the masa into either tortillas or tortilla chips. The third roller, known as a “cutting roller,” commonly has either circular shaped (for tortillas) or triangular-shaped (for tortilla chips) cutting guides positioned on the cylindrical external surface of the cutting roller. The cut tortillas or chips then are stripped from the exit roller by a stripper wire and/or a blower, or by a similar device.
An aspect of at least one of the inventions disclosed herein includes the realization that the stripper wire of a dough sheeter is a limiting factor in the design of higher capacity and higher efficiency dough sheeter systems. For example, the stripping wire of a sheeter must be pulled against an outer surface of the front roller of a dough sheeter so as to cause cut pieces of dough to peel off of the front roller and fall onto an output conveyor. The stripping wire is subjected to wear by way of contact with the front roller, as well as contact with guide bands on the front roller. During operation, by way of frictional contact with the bands and front roller, the stripper wire is pulled upwardly and, due to contact with the bands and roller, the center of the stripping wire is pulled to a position higher relative to the ends of the stripper wire. Thus, the point of contact and thus the point of peeling away of cut dough pieces at the center of the roller is different than at the ends of the roller. This can cause problems with the output of the cut dough pieces. The stripper wire can be tensioned tightly against the outer surface of the rear roller so to pull it into a straighter configuration. However, the higher the tension in the stripper wire, the faster it will suffer failure from wear.
An aspect of at least one of the inventions disclosed herein includes the realization that adding a center support to a stripper wire assembly of a dough sheeter can provide the dual benefits of normalizing the point of contact between the stripper wire and the outer surface of the front roller and allow the stripper wire to be used on a much wider dough sheeter. For example, a stripper wire assembly can have a stripper wire mount disposed at each end of a front roller, as well as a stripper wire support member disposed at a location between the two ends of the front roller. As such, the central stripper wire mount can reduce the extent to which the stripper wire is pulled upwardly along the outer surface of the front roller and thus have a more uniform point of contact along the front roller. Further, secured as such, the same type of stripper wire assembly can be used on a wider sheeter. This can provide a more efficient design, significantly wider than known dough sheeters, for example, about twice as wide as known dough sheeters.
Thus, using known dough sheeters to provide the output of a dough sheeter in accordance with the present embodiments would require two or more dough sheeters. As such, there would be two drive systems, two front rollers, two rear rollers, two cutting rollers, twice as many bearings, two conveyor belt systems, etc. However, using the improved stripper wire assembly disclosed herein, a dough sheeter can be made much wider using only a single front, rear, and cutter roller as well as a single drive system, a single conveyor belt system, etc. Although these components would be larger, they would not be twice as expensive overall and result in fewer parts.
Another aspect of at least one of the inventions disclosed herein includes the realization that installation or replacement of broken stripper wires can be accelerated by forming the stripper wires with preformed, enlarged ends. For example, a stripper wire can include a preformed loop at one end with an enlarged object captured therein, such as a ring or small piece of rod. As such, a stripper wire can be more quickly replaced on a sheeter machine.
Another aspect of at least one of the inventions disclosed herein includes the realization that a sheeter machine can include a plurality of tension-controlled wire payout mechanisms mounted for paying out stripper wire across subportions of an output roller of a dough sheeting machine. For example, a sheeter can include one or more tension-controlled payout mechanisms mounted adjacent center support of the sheeter machine, each payout mechanism feeding stripper wire through a center support, then across a portion of an output roller. The sheeter machine can also include winding mechanisms, configured to pull the stripper wire from the payout mechanism, through the center support, and across a portion of the output roller in a continuous manner. As such, a sheeter machine can be operated in a more continuous manner with a reduced likelihood of breakage of stripper wire. With this type of system, the stripper wires usually do not break. Rather, the reels on the tension-controlled payout mechanism are emptied over time, in a predictable manner. Thus, replacement of stripper wire spools on the tension-controlled payout mechanisms can be predictably scheduled, thereby enabling the reduction of waste that can result from sudden an unexpected stripper wire failures.
The above-mentioned and other features of the inventions disclosed herein are described below with reference to the following drawings. The illustrated embodiments of the sheeter are intended to illustrate, but not to limit, the inventions.
The inventions disclosed herein have applicability to sheeters used in conjunction with continuously moving conveyor systems. However, an understanding of the inventions disclosed herein is facilitated with the following description of the application of the principles of the present inventions to dough rolling, and in particular, rolling dough into tortillas and tortilla chips. In some embodiments, the inventions disclosed herein can be used in conjunction with sheeters that have a sheet thickness control system, such as those disclosed in U.S. Pat. Nos. 5,470,599, and 8,740,602, the entire contests of both of which are hereby incorporated by reference.
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The roller drive assembly 14 also includes a generally cylindrical front roller 24 and a generally cylindrical rear roller 26. The rollers 24, 26 can have a slightly roughened surface (obtained, for example, with sandblasting). The rollers 24, 26 are rotated in opposite directions and can be driven at the same speed or slightly different speeds, depending on desired performance characteristics. The rollers 24, 26 are positioned generally parallel to each other.
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The front roller 24 also includes a plurality of grooves, in which bands 34 are disposed. The grooves have an inner surface that has a smaller diameter than the inner surface of the bands 34. The bands are sufficiently large that they can be pulled approximately parallel or slightly projecting from the outer surface of the roller 24.
A stripper wire 36 is secured to the roller assembly 14 at locations adjacent to both ends of the front roller 24 and downstream from the cutter roller 28. More specifically, the stripper wire 36 is mounted at the right end of the front roller 24 adjacent to the right-most point of contact 38 and secured at the left end of the roller 24 adjacent to the left-most point of contact 40. The stripper wire is threaded under the bands 34. As such, the stripper wire can strip off cut pieces of dough from the outer surface of the front roller 24 yet allow remaining pieces of dough, referred to as “rework”, to remain in contact with the bands 34 and be fed back into the hopper so as to become reworked with the dough 32 above the pinch point gap (
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When the distance 52 becomes too large, the cut pieces of dough can flip over, fold on top of themselves, or result in other configurations or orientations that are detrimental to the cooking procedure to follow. Although increasing the tension in the stripper wire 36 can reduce the height of the point of contact 42, the higher the tension in the stripper wire 36, the shorter the lifespan of its use. When a stripper wire breaks, the sheeter must be shut down and a new stripper wire installed. If the rollers 24, 26 were longer, requiring a longer stripper wire, then the central point of contact 42 would be even higher. Thus, the behavior and lifespan of the stripper wire 36 presents a limiting factor in the overall width of a sheeter 10.
An aspect of at least one of the inventions disclosed herein includes the realization that improving the stripper wire mount for a sheeter can accommodate longer rollers that can output a significantly higher amount of cut dough using the same roller speeds.
The drive 100 can include a front roller 102 and a rear roller 104 mounted adjacent and parallel to the front roller 102 and so as to define a pinch point gap therebetween (not shown). The roller drive 100 can include pinch point adjustment devices 110, 112 mounted at opposite ends of the rear roller 104. Other configurations can also be used.
The drive 100 also includes a hopper assembly 122. The hopper assembly 122 includes a right sidewall 124, a left sidewall 126 and a center dividing wall 128, which can be referred to as a “saddle”. The hopper 122 also includes a front wall assembly 130 and a rear wall assembly 132. The central wall 130 divides the hopper assembly into a right side hopper portion 134 and a left side portion 136. Thus, when dough, such as masa, is dropped into the hopper 122, it is divided into the right and left hopper portions 134, 136 by the center dividing wall 128.
In the illustrated embodiment, the roller drive 100 is configured for tortilla production, for example, round tortillas. Thus, the front roller 102 includes band grooves 140 and band 142 disposed within the grooves 140 and at the outer ends of the working surface of the front roller 102. The distance between the grooves 140 is sized to accommodate the desired diameter of a tortilla cut by the cutting roller (not shown). In this configuration, the front roller 102 is approximately twice as long as the front roller 24 of
The drive 100 also includes a stripper wire assembly 150. The stripper wire assembly 150 includes a right side mount 152, a left side mount 154 (not shown) and a central mount member 156. The central mount member 156 is aligned with the center divider 128 of the hopper assembly 122. Thus, during operation the center divider 128 prevents dough from the hopper assembly 122 from being fed into the area of the center mount 156.
The stripper wire assembly 150 also includes a stripper wire 160 extending from the right side mount 152 and the above side mount 158 and can be engaged with the central mount 156. In the context of a dough sheeter, the stripper wire 160 can be a thin wire, for example, but without limitation, 16 gauge, 18 gauge, 20 gauge, 22 gauge, or other thicknesses.
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The large portion 182 can be a channel or cylindrical bore having an inner dimension larger than the width of the slot 180. As such, when the stripper wire 160 is inserted through the opening 180 into the enlarged portion 182, the enlarged portion 182 can better capture the stripper wire 160 and secure it within the enlarged portion 182 whether the roller 102 is moving or stationary.
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During operation, when the front roller 102 is driven in the direction of the arrow 190, the stripper wire 160 is pulled upwardly. Thus, with the stripper wire 160 positioned within the enlarged portion of the mounting location 172, the stripper wire falls along a double-humped configuration having a first apex 192 on a right side portion of the front roller 102 and a left-side apex 194 on the left-side portion of the front roller 102. The maximum height of the apexes 192, 194 is significantly lower than what might result during operation of the roller assembly 100 without central mounting portion 156.
For example, the stripper wire 160 might tend to rise to a much higher apex 196 illustrated in phantom line in
The enlarged head 202 is formed of a length of the stripper wire 200 extending around the ring 204 into the groove in the outer surface thereof, then wound around itself forming a tightly wound portion 206 that is sufficiently tight for capturing the ring 204 in the enlarged head 202 of the stripper wire 200. This type of configuration for preformed thin wire is common in the guitar string industry.
In this configuration, the stripper wires 200A, 200B are captured within the mounting locations 178 and 176 because the diameter of the wires used to form the stripper wires 200A, 200B is smaller than the opening slot 180 and enlarged passages 182. However, the enlarged heads 202A, 202B are significantly larger than the enlarged passage 182. Thus, the enlarged heads cannot pass through the enlarged passage 182 and are thereby captured and held securely in place during operation. The free ends (not shown) of the stripper wires 200A, 200B can be secured to mounting locations 152, 154 as described above with reference to
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The first and second wire payout mechanisms 300, 302 can be in the form of spools of stripper wire connected to constant tension feed mechanisms. Many different kinds of constant tension wire feed systems can be used. For example, some commercially available systems are known as “constant tension payoff systems” that are configured to provide constant tension, regardless of spool diameter or wire speed. For example, such systems are commercially available from Magnetic Brake Systems, Inc., and other sources.
Generally, these types of systems include a controller, which can be in the form of a motor or brake system that controls the payout of a material such as a wire from a spool. Typically, these types of systems are adjustable and include a user input for adjusting the tension maintained in the spool during payout of material from the attached spool. Further, these types of devices can be configured to accommodate variable speed of payout while providing a constant tension.
The stripper wire arrangement 150C can also include stripper wire takeup devices 304, 306. The takeup mechanisms 304, 306 can each include a spool and a motor configured to rotate the spool so as to pull stripper wire 200Y, 200X from the corresponding payout mechanism 302, 300. In some embodiments, the takeup devices 304, 306 are configured to operate at constant speed. Such a configuration has long been known in many fields and can be provided by a simple controller (not shown) and an electric motor (not shown) configured to drive the electric motor at a constant speed.
As such, the controller modulates the total power, and in some devices, modulates the current at a constant voltage, to drive the motor at a constant velocity, modulating the power delivered to the motor to overcome variations in load. In this context, under normal operation, the payout devices 302, 300 would provide a constant or substantially constant tension in the stripper wires 200Y, 200X, which could be measured in the stripper wires near the spool payout devices 302, 300.
The stripper wires 200Y, 200X can be threaded through the center support 156C and to a corresponding takeup mechanism 304, 306. By way of contact with the center support 156C and the outer surface of the roller 102, additional friction and load might be imparted in the form of additional tension generated in the stripper wires 200Y, 200X at the takeup mechanisms 304, 306. Thus, conventional constant speed motors and controllers at the takeup devices 304, 306 can automatically apply additional power to overcome the additional tension thereby created.
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While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.
Number | Date | Country | |
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63002235 | Mar 2020 | US |