Abstract:
A sheeter includes an internally grooveless front roller, a rear roller configured to rotate counter to the front roller, a partially spiraled stripper wire coupled across the front roller, and a conveyer belt connected to a proximal conveyer roller and a distal conveyer roller. The conveyer belt includes a landing zone configured to prevent damage to a received product. The conveyer belt includes a raised portion adjacent to the proximal end and flat portion towards the distal end.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a divisional application of U.S. patent application Ser. No. 12/730,044, filed on Mar. 23, 2010, now U.S. Pat. No. 8,434,404, which claims priority under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/162,618 filed on Mar. 23, 2009, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates generally to food production machinery and, more particularly, to an improved sheeter with spiraled stripper wire and conveyer belt with a landing zone. 
     2. Description of the Related Art 
     Machines called “sheeters” are routinely used in production lines that produce tortillas and tortilla chips. In general, as shown in  FIGS. 1-3  and  4 A- 4 D, a conventional sheeter consists of a pair of closely-spaced counter-rotating rollers  20 ,  30  that compress a mass of corn masa  11  (or other dough) into a sheet  12  within a gap between the two rollers. As the sheet  12  exits the gap, it is separated from the back roller  20  using a stripper wire stretched across its width or, more commonly of late and as suggested, by rotating the front and back rollers at slightly different speeds. Another approach to encouragins separation is using a coated back roller (e.g. coated with Teflon®) so that it has a lower coefficient of friction than the front roller (e.g. made with UHMW). The sheet  12  remains adhered to the front roller  30  and, at this point, a patterned “cutter roller”  40  forms shaped dough pieces  70  by cutting a pattern into the sheet  12  by rotating its patterned walls against the front roller  30  through the dough sheet  12 . After this, a stripper wire  50  stretched across the width of the front roller  30  strips the chip-shaped pieces and surrounding web of “re-works” (if any), after which the shaped dough pieces  70  land on a take-away conveyer belt  60  that moves the dough pieces  70  onward (e.g. into an oven, not shown). The excess dough  13  (called “re-work”) surrounding the shaped dough pieces  70  (between rows and/or between sequential ones of the shaped dough pieces, depending on the pattern) is rotated upward on the front-roller  30  to merge with the fresh masa located between the rollers. 
     In the prior art, typically, the front roller  30  is provided with a plurality of grooves that hold flat bands (e.g.  32 ) (sometimes collectively hereafter “band grooves”). The bands  32  generally serve two purposes. First, because the front stripper wire  50  is threaded beneath the bands  32 , the bands  32  help hold the wire  50  against the roller  30  to strip the shaped product pieces (see pieces  71 ) off of the front roller  30  and onto the conveyor belt  60 . The bands  32  also tend to pinch the re-work  13  that is located between product rows to help make that re-work  13  stay with the front roller  30 . As shown, these bands  32  are traditionally located between rows of the chip-shaped pieces to help pull the re-work  13  back onto the front roller  30  and rotate it up and around for recombination with the masa, rather than allowing it to land on the take-away conveyer  60  with the chip-shaped pieces  70 . When the bands  32  are used with certain product shapes, real estate on the front roller  30  that could otherwise be used for product rows is wasted. In  FIG. 4A , for example, there are only ten rows of triangular shaped dough pieces due to the interior band grooves  32 . Since the rows of this particular shape (and others) could be placed side-by-side without any unused dough, it is the band grooves  32  alone that are wasting space. 
     The prior art stripper wire  50  has traditionally had a slight spiral from one end  51  to another end  52 . However, due to drag-related forces, the frictional forces associated with the masa and the front roller  30  tends to pull the wire  50  upward to a central high spot  53 . 
     The industry has previously taken different approaches to try and eliminate all bands, or at least eliminate the intermediate bands  32  (leaving only the left-most and right-most bands  31 ,  31  to return the outer edges of re-work surrounding the product). The applicant&#39;s prior patent application Ser. No. 10/346,362 is an example of one such approach, the entire content of which is hereby incorporated by reference. It features a vibrating T-shaped blades rather than a stripper wire. The invention of Ser. No. 10/346,362 may well prove successful, but stripper wires remain popular such that there remains a need for an improved sheeter that uses a stripper wire without intermediate bands to maximize product efficiency. 
     BRIEF SUMMARY 
     One aspect of an embodiment of the invention includes a sheeter including an internally grooveless front roller, a rear roller configured to rotate counter to the front roller, a partially spiraled stripper wire coupled across the front roller, and a conveyer belt connected to a proximal conveyer roller and a distal conveyer roller. The conveyer belt includes a landing zone configured to prevent damage to a received product. The conveyer belt includes a raised portion adjacent to the proximal end and flat portion towards the distal end. 
     Another aspect of an embodiment of the invention provides a sheeter apparatus including an internally grooveless front roller, a stripper wire coupled across the front roller, a conveyer belt coupled to a proximal conveyer roller and a distal conveyer roller, and an elevation device disposed between the proximal conveyer roller and the distal conveyer roller. The conveyer belt includes a raised portion adjacent to the elevation device. The conveyer belt includes a landing zone configured to prevent damage to a received product. 
     Yet another aspect of an embodiment of the invention provides a method of manufacturing a plurality of product pieces using a sheeter device. The method includes providing a raw product mass to a cutter configured to shape the raw product into a plurality of product pieces, transferring the plurality of product pieces to a conveyer belt, pressing the plurality of pieces with an internally grooveless front roller, stripping the plurality of product pieces from the front roller, and catching the plurality of product pieces stripped by the front roller onto a landing zone of the conveyer belt. The landing zone spans the width of the conveyer belt and the conveyer belt includes a raised portion and a flat portion. The raised portion of the conveyer belt is configured to prevent damage to the plurality of product pieces. 
     Other aspects and advantages of the present invention will become apparent from the following detailed description, which, when taken in conjunction with the drawings, illustrate by way of example the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       For a fuller understanding of the nature and advantages of the invention, as well as a preferred mode of use, reference should be made to the following detailed description read in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates a typical prior art sheeter with a front roller that has left and right edge bands and a plurality (9) of intermediate band grooves that consume product space; 
         FIGS. 2 and 3  show a back view of the prior art sheeter of  FIG. 1  and, more specifically, the cutter roller that includes a plurality of annular gaps that correspond to the band grooves on the front roller; 
         FIG. 4A  shows the typical arrangement of the stripper wire stretched across the width of the front rollers in the prior art sheeter of  FIG. 1 . The wire may have a sheet spiral (as shown), but frictional forces tend to drag a center regions  53  of the wire upward relative to both ends; 
         FIG. 4B  is an end view of the prior art sheeter of  FIG. 4A ; 
         FIG. 4C  is an illustration of a prior art sheeter showing multiples rows of product and re-work adhered to the front roller via intermediate band grooves; 
         FIG. 4D  is an illustration of a prior art sheeter showing multiples rows of product formed by a dual front roller having end and central band grooves; 
         FIG. 5  illustrates a first portion of an improved sheeter according to one embodiment of the invention including a stripper wire with an exaggerated spiral; 
         FIG. 6  illustrates a sectional side view of the embodiment illustrated in  FIG. 5 ; 
         FIG. 7  illustrates the two heights Z 1  and Z 2  caused by the spiraled stripper wire, the latter tending to cause product defects if used as is with a conventional conveyor belt; 
         FIG. 8  is a sectional side view of a first preferred embodiment of the invention that includes the spiraled stripper wire of  FIGS. 5 and 6  in combination with a conveyor that includes a unique landing zone; 
         FIG. 9  is a perspective view of the embodiment of the invention illustrated in  FIG. 8 ; 
         FIGS. 9A to 9C  are views of a sheeter corresponding to the embodiment of the invention illustrated in  FIG. 9 ; 
         FIGS. 10-12  are views of another embodiment of the invention as an alternative to the embodiment illustrated in  FIGS. 9 and 9A  to  9 C; 
         FIG. 13  illustrates a side view of another sheeter including larger rollers and multiple landing zone magnetic rollers according to another embodiment of the invention; and 
         FIG. 14  illustrates a perspective view of the sheeter illustrated in  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION 
     The following description is made for the purpose of illustrating the general principles of the invention and is not meant to limit the inventive concepts claimed herein. Further, particular features described herein can be used in combination with other described features in each of the various possible combinations and permutations. Unless otherwise specifically defined herein, all terms are to be given their broadest possible interpretation including meanings implied from the specification as well as meanings understood by those skilled in the art and/or as defined in dictionaries, treatises, etc. The description may disclose several preferred embodiments for sheeter systems, devices, and methods, as well as operation and/or component parts thereof. While the following description will be described in terms of sheeter devices, systems and methods for clarity and placing the invention in context, it should be kept in mind that the teachings herein may have broad application to all types of systems, devices and applications. 
       FIG. 5  shows a first portion of an improved sheeter according to one embodiment of the invention. As illustrated, a stripper wire  150  is spiraled across the width of an internally grooveless front roller  130 . As shown in  FIGS. 5 and 6 , best viewed together, the stripper wire  150  runs from one end  151  located at about a “7 PM” position (i.e., if located on a dial of a clock) on the nearest-most end of the roller  130  and spirals to another end  152  located at about “4 PM” (i.e., if located on a dial of a clock) at a farthest-most end of the roller. While not shown, it is well-known in the art to tension the stripper wire  150  by affixing at one end (e.g., far end  152 ), and by attaching the near end  151  to a tensioning mechanism such as, for example, a guitar peg or a pneumatic cylinder that applies tension to the wire  150 . Continuous stripper wire systems with suitable tensioning mechanisms are known as well. The stripper wire may be a discrete segment or a portion of a longer wire used in a continuously or periodically moved wire feed system. 
     The spiral of  FIGS. 5 and 6  is exaggerated relative to ordinary spiral of the prior art. This beneficially allows the wire  150  to stay close to the roller  130  without the need for internal bands and also eliminates the central high spot  53  associated with the prior art arrangement. Now, however, as best shown in  FIG. 6 , the far end  152  of the wire  150  is quite high above the conveyor belt  160  relative to the rear end  151 . 
     The exaggerated spiral created by the relative high position of the wire&#39;s end  152  helps eliminate the need for the intermediate band grooves, but it means that the product  171  being stripped off the front roller in that region has a relatively long distance to travel before it lands on the conveyor belt  160 . Thus, if the spiral stripper wire  150  of  FIGS. 5 and 6  were simply combined the conventional take-away conveyor used in prior art sheeters, there is an increased probability that the product pieces in that zone would be damaged. 
       FIG. 7  shows how product near end  151  would fall a relatively small distance Z 1 , whereas product  171  at the far end would fall a relatively great distance Z 2 . The product is delicate at this point and the typical result would be damage or defects due to folding, wrinkling, tearing, stacking, flipping, etc. 
       FIG. 8  shows both aspects of the preferred embodiment of the invention. Here, the spiraled stripper wire  150  stretches across the face of an internally grooveless roller  130 , in combination with a special conveyor belt  260  that includes an extended landing zone  261  that generally conforms to the curvature of the front roller  130 . Through this unique arrangement, the travel distances Z 1 , Z 2  at the near and far ends  151 ,  152  of the spiraled stripper wire  150  are made to be about the same and are located close enough to the landing zone  261  at all points to minimize product damage. 
     As further shown in  FIG. 8 , the presently preferred conveyor  260  comprises a mesh belt  265  that rotates around a pair of end rollers  262 ,  263 . The belt  265 , of course, is driven at an appropriate location (not shown). Here, the embodiment further comprises an apex roller  264  that elevates the mesh belt  265  to create the landing zone  261 . The landing zone  261  is elevated and, preferably, as shown here, radiused. In other embodiments, the apex roller  264  might be replaced with a curved, but non-rotating surface, i.e. a curved “skid plate” formed from UHMW plastic or similar low-friction material. Other elevation mechanisms are possible. 
     The preferred embodiment of  FIG. 8  also includes a magnetic roller  266  located beneath the mesh belt  265  in the landing zone  261 . The magnetic roller  266  generally comprises a stainless steel shaft having a number of tubular magnets in an end to end arrangement. The tubular magnets attract the mesh belt  265  downward. The magnetic roller  266  helps maintain the curvature of the landing zone  261  relative to the roller  130 . In some situations, the magnetic roller  266  may be eliminated and in others there may be need or desire for multiple magnetic rollers or other mechanisms (e.g. inwardly extending guide tabs or hold-downs) that help maintain the curvature. 
       FIG. 9  is a perspective view of the first preferred embodiment of  FIG. 8 . As shown, the front roller beneficially requires no interior band grooves  132  (like those shown in  FIG. 4A ). As a result, the cutter roller  140  can be provided with a full pattern of shaped dough pieces. In this embodiment, for example, the sheeter could produce twelve (12) rows of triangular corn chips rather than only ten (10). This is a twenty percent (20%) increase in hourly output and a reduction in the amount of re-work which enhances overall product quality. 
       FIGS. 9A to 9C  are additional views of an actual sheeter corresponding to the preferred embodiment of  FIG. 9 . As shown, the front roller does not contain any interior band grooves and the product coverage is highly efficient. 
       FIGS. 10 to 12  illustrate another embodiment of the invention that varies a bit from, but is quite similar to the presently preferred embodiment of the invention illustrated in  FIG. 8 . The main differences are twofold. As further illustrated in  FIG. 13 , the apex roller  264  is larger diameter of about 6 inches rather than about 1 inch. It was discovered through experimentation that a larger diameter apex roller  264  is preferred because a smaller roller tended to accelerate the dough pieces off of its radius, resulting in occasional product defects. 
     As illustrated in  FIG. 13 , one embodiment includes a plurality of magnetic rollers  266 , such as 2, 3, 4, etc. In this embodiment of the invention, due to the larger apex roller, the additional magnetic rollers  266  are necessary for higher speeds of the mesh belt  265 .  FIG. 14  illustrates a perspective view of the embodiment shown in  FIG. 13 . 
     Reference in the specification to “an embodiment,” “one embodiment,” “some embodiments,” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments. The various appearances of “an embodiment,” “one embodiment,” or “some embodiments” are not necessarily all referring to the same embodiments. If the specification states a component, feature, structure, or characteristic “may,” “might,” or “could” be included, that particular component, feature, structure, or characteristic is not required to be included. If the specification or claim refers to “a” or “an” element, that does not mean there is only one of the element. If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element. 
     While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that this invention not be limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those ordinarily skilled in the art.