Abstract:
An apparatus and method are disclosed for separating a pile of tortillas and individually depositing the tortillas on a conveyor to form a row of tortillas. The apparatus may include an accumulating device, an elevating device that is operable to remove a pile of tortillas from the accumulating device and elevate the pile of tortillas towards a vacuum conveyor. The vacuum conveyor is operable to continuously remove an uppermost tortilla from the pile of tortillas and transport the separated tortillas to a receiving conveyor. The separated tortillas are deposited on the receiving conveyor and may be transported to a subsequent processing operation.

Description:
BACKGROUND 
       [0001]    In the manufacture of tortillas, when the tortillas have been formed, the general tendency is to pile up the tortillas at different heights. Therefore, an apparatus that separates and individually places the tortillas on a band or conveyor is thus needed in order to prepare the tortillas for a subsequent processing operation, such as baking, frying, tearing the tortillas into strips, etc. Present automated techniques used to make tortillas require complex machines to replace the traditional manual production method or hinge press. Complex machines are also necessary to accumulate a certain quantity of tortillas to be used in subsequent processes or to separate the tortillas. Separating tortillas after manufacture and before storage is important since, without separating, storing the tortillas causes the tortillas to adhere to neighboring tortillas. Such adhesion diminishes the totillas&#39; quality, creating a problem for the consumer. 
         [0002]    Several techniques have been developed, such as the technique described in U.S. Pat. No. 5,494,398 by Montemayor et al. The Montemayor technique describes an apparatus used to separate the tortillas contained in piles, where the tortilla at the top of a tortilla pile is removed by a drilled cylinder. A suction is produced in the interior of the drilled cylinder by a fan, causing the tortilla located at the top of the tortilla pile to adhere to an exterior surface of the drilled cylinder. The tortilla can then be subsequently deposited on a band or conveyor. However, the technique described in Montemayor is deficient because the described technique is based upon the use of a single cylinder, which is unworkable at a wide transfer station because the size of the drilled cylinder becomes critical. Additionally, the Montemayor technique does not provide a flexible and soft delivery onto the band or conveyor, which may damage the tortillas. 
         [0003]    U.S. Pat. No. 5,531,156 by Brummett describes an apparatus to bend tortillas and make tacos with soft tortillas as well as “tostadas” (fried tortillas). Brummett describes an apparatus that accumulates the soft tortillas as well as the tostadas, which travel on a “V” conveyor. The tortillas are then taken from tortilla piles by a hollow head deposited between a pair of plates where the tortillas are compressed and heated. A mechanical finger moves downward to bend the tortillas and push the tortillas through the “V” conveyor. The Brummett apparatus also includes hot and cold food dispensing stations. As the tortilla travels on the conveyor, the tostadas are taken from piles. Particularly, a tostada is removed from the pile by a scraper that is inserted between a tostada at the bottom of the pile and the tostada thereabove. The lower tostada is released while the remainder of the pile remains supported. The released tostada travels through the “V” conveyor and passes under the hot and cold food dispensers. Therefore, Brummett describes taking a top tortilla from a tortilla pile by a hollow head. However, Brummett fails to describe a band that efficiently transfers individual tortillas from a tortilla pile and softly deposits the tortillas onto a conveyor. 
       SUMMARY 
       [0004]    An object of the present disclosure is to provide a tortilla transfer device that provides improved handling of flat food items, such as tortillas, and transportation of the tortillas to an additional processing operation after manufacturing the tortillas. For example, after being made, the tortillas may be transported to an operation that transforms the tortillas into tostadas or a fried food. Due to the large number of tortillas to be processed and the need to separate the tortillas from each other, the present disclosure describes a tortilla transfer apparatus. Tortillas may be fed from a conveyor to a post-processing feeder. The tortilla transfer apparatus may be fed by a band (interchangeably referred to as “conveyor”) or may be manually fed from a transfer table containing piles of tortillas. The piles of tortillas may have been formed by an operator. Alternately, an accumulating device may produce the piled tortillas. The piles of tortillas may be formed in such a way that the tortilla piles are substantially uniform. When the accumulating device is full, a button may be pressed, causing an electric controller (PLC) to execute a previously programmed routine. As a result, the accumulating device is horizontally displaced towards and engages an elevating table. The accumulating apparatus and the elevating table are formed from a plurality of vertical walls. The vertical walls of the accumulating apparatus are offset from the vertical walls of the elevating table. Consequently, the vertical walls of the accumulating apparatus and the vertical walls of the elevating table intermesh. The horizontal displacement is achieved by actuation of a piston and a plurality of slides. When the accumulating device and the elevating table are coupled together, the tortilla piles are transferred onto the elevating table and the accumulating device is withdrawn. As a result, a number of tortilla piles ordered by an operator are made to reside on a surface of the elevating table. A piston controlled by a servo valve may then cause the tortilla piles arranged at a top of the elevating table to be elevated until an upper band or conveyor with hollow vents removes the tortilla located at the top of the tortilla piles. The tortilla at the top of a tortilla pile is made to temporarily adhere to the conveyor due to vacuum communicated through the vents formed in the conveyor. The tortilla remains adhered to the conveyor until the vents are passed over rollers of such vacuum conveyor, which seals the vents causing the loss of vacuum. As a result, the tortillas fall from the conveyor due to gravity onto a conveyor. The conveyor transports the separated tortillas in ordered rows to a subsequent process, such as baking, frying, grinding, etc. 
         [0005]    The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0006]      FIG. 1  is a perspective view of a tortilla transfer apparatus; 
           [0007]      FIG. 2  is another perspective view of the tortilla transfer apparatus of  FIG. 1 ; 
           [0008]      FIG. 3  is a side view of the tortilla transfer apparatus of  FIG. 1 ; 
           [0009]      FIG. 4  is a top view of the tortilla transfer apparatus of  FIG. 1 ; 
           [0010]      FIG. 5  is a front perspective view of the tortilla transfer module of  FIG. 1  without guards or a supporting frame; 
           [0011]      FIG. 6  is another perspective view of the tortilla transfer apparatus of  FIG. 1  with a front guard but without a right-side supporting frame; and 
           [0012]      FIG. 7  is a further perspective view of the tortilla transfer apparatus without guards or the right-side supporting frame. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIG. 1  shows a tortilla transfer apparatus  18  with tortilla piles  10  in different stages of formation. A tortilla arriving band or first conveyor  11  on rollers  14  transports tortillas to the tortilla transfer apparatus  18 . The tortilla transfer apparatus  18  includes an accumulating device  37 , a second conveyor  25 , an elevating table  38 , a vacuum band or conveyor  20  having a plurality of vents  21 , and a supporting frame  12  that supports the vacuum conveyor  20 . The first conveyor  11  transports tortillas to the tortilla transfer apparatus  18 . An operator may transfer to the tortillas being conveyed by the first conveyor  11  to the tortilla piles  10 . The vacuum conveyor  20  resides at an upper portion of the tortilla transfer apparatus  18  and travels over a pair of rollers. The vents  21  formed in the vacuum conveyor  20  provide communication with a suction formed therein and the tortilla provided at a top of the tortilla piles  10 . The suction causes the uppermost tortilla in an individual pile  10  to adhere to the vacuum conveyor  20 , allowing the uppermost tortilla to be transported horizontally to the second conveyor  25 . The second conveyor  25  may be formed from metal. 
         [0014]      FIG. 2  is another view of the tortilla transfer apparatus  18  showing the accumulating device  37 , and the elevating table  38 . The elevating table  38  and the accumulating device  37  are formed from a plurality of vertical walls, the upper edges of which support tortilla piles  10 . The vertical walls of the elevating table  38  and the accumulating device  37  intermesh allowing the tortilla piles  10  disposed on the accumulating device  37  to be transferred to the elevating table  38 . As also shown, tortillas transported by the vacuum conveyor  20  are individually deposited on the second conveyor  25 . 
         [0015]      FIG. 3  shows a side view of the tortilla transfer apparatus  18 . The first conveyor  11 , which may be formed from a polymer such as a vinyl covered fabric, transports the tortillas to the tortilla transfer apparatus  18 . However, the first conveyor  11  need not be used. The first conveyor  11  may transport the tortillas from a previous processing operation, such as a tortilla forming operation, or from storage. The accumulating device  37  includes a plurality of vertical walls whose upper edges form a support surface for the tortilla piles  10 . In some instances the accumulating device  37  may be constructed of stainless steel in order to provide improved corrosion resistance as well as to facilitate cleaning. For example, stainless steel provides resistance to microorganisms. The accumulating device  37  may also include stabilizing guards  39 , which provide stability to the tortilla piles  10  so that the tortilla piles  10  do not collapse as a result of motion or from the height of the tortilla piles  10 . A piston  33  is operable to extend and retract the accumulating device  37 . The piston  33  may be hydraulic or pneumatic. Further, the piston  33  is operable to extend and retract at a rate to prevent the tortilla piles  10  disposed on the accumulating device  37  from collapsing. 
         [0016]    In operation, the elevating table  38  is lowered to a bottom position and the piston  33  is actuated, extending the accumulating device  37  until the vertical walls of the accumulating device  37  are intermeshed with the vertical walls of the elevating table  38 . The elevating table  38  may then be raised to effect a successful transfer of the tortilla pile  10  from the accumulating device  37  to the elevating table  38 . In some instances, a hydraulic or pneumatic piston  34 , controlled, for example, by a servo valve, may be used to raise and lower the elevating table  38 . The elevating table  38  raises the tortilla pile  10  so that an uppermost tortilla of the pile of tortillas  10  lies closely adjacent to the vacuum conveyor  20 . Because maintaining a defined distance between the uppermost tortilla and the vacuum conveyor  20  is important and because a thickness of the tortilla  16  is not uniform, the distance between the uppermost tortilla and the vacuum conveyor  20  is controlled by the rate at which the elevating table  38  is raised along with a proximity sensor that detects a distance between the uppermost tortilla and the vacuum conveyor  20 . This control is operable to maintain a desired distance between the uppermost tortilla and a vent  21  on the vacuum conveyor  20 . 
         [0017]    The elevating table  38  may also include a slide system and a stabilizing guard  39 . The stabilizing guard  39  may include a piston, such as a hydraulic or pneumatic piston, to extend and/or retract the stabilizing guard  39  to provide more stability to the tortilla piles  10 . The stabilizing guard  39  counteracts a force along a vertical axis of the tortilla piles  10  that may cause the tortilla piles  10  to collapse. A suction maintained through the vents  21  causes the uppermost tortilla to temporarily adhere to the vacuum conveyor  20 . The vacuum conveyor  20  transports the tortillas to the second conveyor  25  onto which the tortillas are delicately placed in rows. Consequently, the tortilla transfer apparatus  18  is operable to transform the tortilla piles  10  into rows of tortillas formed on the second conveyor  25 . The rows of tortillas formed on the second conveyor  25  may then be transported to a subsequent processing operation. 
         [0018]      FIG. 4  shows a top view of the tortilla transfer apparatus  18 . As shown in  FIGS. 4 and 5 , the tortilla piles  10  are transported to the tortilla transfer apparatus  18  by the first conveyor  11 . However, in some instances, the first conveyor  11  may be eliminated. For example, a layout of a manufacturing process may eliminate a need for the first conveyor  11 . That is, the tortilla piles  10  may be provided directly to the tortilla transfer apparatus  18  by an adjacent machine or process operation without the need for the first conveyor  11 .  FIG. 4  shows the vacuum conveyor  20  as well as the vents  21  formed therein. A flow of air through the vents  21  produces a suction or vacuum that holds the uppermost tortillas of the tortilla piles  10  against the vacuum conveyor  20   
         [0019]    As shown in  FIG. 6 , for example, the supporting frame  12  provides rigidity to the vacuum conveyor  20 , alignment for rollers  14  on which the vacuum conveyor  20  travels, and a vacuum system. The supporting frame  12  may be formed from tubular steel. In some implementations, the vacuum system includes a motor or engine, a suction hose  27 , and a vacuum apparatus  24  for generating a vacuum. In some implementations, the vacuum apparatus  24  may be a compressor and a Venturi system, which may reduce a size of the tortilla transfer apparatus  18  and, thus, save space. In other instances, the vacuum apparatus  24  may be a suction pump or extractor. In still other instances, the vacuum apparatus  24  may be a ventilator incorporated into or used in combination with a compressor or a compressor jointly with a storage tank and flow regulating system. The rollers  14  may be coupled to an electric motor, which rotates the rollers  14  and causes the vacuum conveyor  20  to travel. The electric motor may be controlled to control a speed of the vacuum conveyor  20 . In some instances, the vacuum system may be located at a top of the supporting frame  12  and coupled to a suction plate  23 . As shown in  FIG. 5 , the vacuum conveyor  20  circumscribes a central volume, and the suction plate  23  is disposed in the central volume. The suction plate  23  may include a plurality of openings, and air flow from the vacuum system may be drawn in through the plurality of openings formed in the suction plate  23 . Thus, the vacuum apparatus  24  may produce a suction airflow through the suction hose  27 . As a result, the airflow passing from an exterior of the vacuum conveyor  20 , in through the vents  21  formed in the vacuum conveyor  20 , into an interior volume of the suction plate, and through the suction hose  27 , thereby forming a vacuum for the transporting tortillas  16 . In other instances, the interior volume may be isolated and the rollers  14  may include a plurality of openings through which an air flow is produced to form a suction through the vents  21 . The tortillas  16  are exposed to the generated vacuum at the vents  21  in the vacuum conveyor  20 . The generated vacuum is operable to hold the tortillas  16  to the, vacuum conveyor  20  as the tortillas  16  are being transported from the tortilla piles  10  located on the elevating table  38  to the second conveyor  25 . 
         [0020]      FIG. 6  is another view of the tortilla transfer apparatus  18  showing a portion of the supporting frame  12  removed. As a result, the rollers  14  supporting the vacuum conveyor  20  and the suction plate  23  can be viewed. The second conveyor  25 , onto which the tortillas  16  are deposited from the vacuum conveyor  20 , is also shown. A separation distance between the vacuum conveyor  20  and the second conveyor  25  is controllable. As shown in  FIGS. 6 and 7 , this separation distance may be adjusted with elevating mechanism  28 . The elevating mechanism  28  includes a pair of handles connected to a screw mechanism and bushing nut. Operating the elevating mechanism  28  enables the second conveyor  25  to be placed at a desired elevation.  FIGS. 6 and 7  also show a top cover  29  on which the vacuum apparatus  24  is located. As also shown, the suction hose  27  is coupled to the vacuum apparatus  24  at a first end while an opposite end of the suction hose  27  is coupled to a suction plate  23 . Thus, suction hose  27  provides for the generation of a vacuum within the suction plate  23 . 
         [0021]    Referring again to  FIG. 7 , a transfer zone where the tortillas  16  are transferred from the vacuum conveyor  20  to the second conveyor  25  is shown. Again, the elevating mechanism  28  is also shown. The elevating mechanism  28  is provided on the supporting frame  12  at each side of the second conveyor  25  permitting alignment of the second conveyor  25  and adjustment of the separation distance between the vacuum conveyor  20  and the second conveyor  25 . The suction hose  27  extending between the vacuum apparatus  24  and the suction plate  23  is also shown. The tortillas  16  are released from the vacuum conveyor  20  when the tortillas  16  reach the roller  14  disposed over the second conveyor  25  because, as the belt or band of the vacuum conveyor  20  passes over the roller  14 , the roller  14  seals off the vents  21  from the suction airflow. As a result, the vacuum at the vents  21  is lost and the tortillas  16  fall from the vacuum conveyor  20  onto the second conveyor  25 . 
         [0022]    A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.