Methods for handling masa

Abstract

masa handling methods for the continuous processing of masa type dough in conjunction with commonly available feed processing equipment, such as a masa extruder, an oven, or cooling apparatus. One masa handling method includes a masa separator having a pair of opposed, endless belt conveyors having facing surfaces spaced apart to receive a generally continuous masa stream output from a nozzle on the masa extruder. When the masa stream moves between the conveyors, it is gripped by their facing surfaces and moved away from the nozzle, causing the masa to be separated into individual pieces, or logs. The masa handling method can also include feeding the masa to masa hoppers fed by at least two endless belt conveyors arranged in upstream and downstream positions relative to each other. The masa is transported along the conveyors and is automatically diverted into one masa hopper by a diverter gate operated by a controller that receives a signal from a sensor sensing a masa level within an associated one of the hoppers. The hopper has one or more rotating shafts having projections to remove gas bubbles from the masa and force it toward the sheeter rollers. A pair of primary rollers with scrapers can be provided within the hopper to roll the masa to an intermediate thickness before it passes between the sheeter rollers.

Description

This application is a division of application Ser. No. 08/192,458, filed Feb. 7, 1994adetector deflector plate 41 guides the masa logs 74 onto the horizontal portion 38 of the "L" shaped separator conveyor 24. The masa logs 74 then move towards the selectively operable diverter gates 42. The photo-sensor 106 mounted adjacent to each masa hopper 40 senses the level of masa 74 therein. If the level of the masa 74 within any one masa hopper 40 drops below a predetermined level, the sensor 106 associated with that masa hopper 40 changes the state of its signal which is sent to the PLC 104. The PLC 104 then commands the pneumatic cylinder 102 to retract the diverter gate 42 located above that masa hopper 40. That diverter gate 42 pivots into an open gap position and the masa logs 74 then fall into that the intermediate masa hopper 40. The photo-sensor 106 then signals the PLC 104 when the level of masa 74 within that masa hopper 40 rises above a certain predetermined level. The PLC 104 then commands the pneumatic cylinder 102 to extend, thereby closing that diverter gate 42 and allowing the masa logs 74 to travel on to the next masa hopper 40 48.

An advantage associated with the diverter gates 42 is the corresponding labor savings due to their automatic operation. Normally, human attendants would be necessary to ensure that the masa hoppers 40 each had a proper supply of masa 74. By utilizing the photo-sensors 106, the PLC 104, and the pneumatic cylinders 102, the diverter gates 42 operate automatically and the supply of masa logs 74 within each masa hopper 40 is maintained without costly human labor. It should be understood that, while a PLC 104 is preferably used to control the diverter gates 42, a corresponding logic system having electronic relays could also be used to perform the same control functions as the PLC 104. Once the masa logs 74 have been fed to the appropriate masa hopper 40, they must be compressed to remove gas bubbles which cause voids in the rolled masa (not shown).

The self feeding masa hopper 40 compresses and removes the unwanted gas bubbles from the masa 74. The masa is fed, via gravity, to the rotating shafts 52. The projections 122 on the rotating shafts 52 compress the masa 74 and force it through the slot 116 towards the primary rollers 54. The projections 122 on the rotating shafts 52 advantageously remove gas bubbles by compressing the masa 74 without requiring any human labor. Accordingly, the costs associated with the human attendants required by the prior art masa hoppers are avoided. Once the gas bubbles are removed from the masa 74, the masa must be rolled into a generally uniform curtain (not shown).

The primary rollers 54 compress the masa 74 into the generally uniform curtain suitable for feeding to the sheeter rollers 56. Both primary rollers 54 are driven by the masa hopper A/C motor 148 and have different sized drive gears 120 so the primary rollers 54 rotate at different speeds. This arrangement is especially advantageous because, as compared to rollers driven at the same speed, the masa 74 is less likely to stick to the lower surface of the primary rollers 54 when they rotate at different speeds. If the masa 74 sticks to the lower surface 136 of one of the primary rollers 54, it is carried around and will not be fed into the sheeter rollers 56. Accordingly, it is desirable to prevent the masa 74 from becoming stuck to the lower surface of the primary rollers 54. However, if, despite the differential speed, the masa 74 becomes stuck to one of the lower surfaces 136 of the primary toilers 54, it must be removed.

The scrapers 130 will advantageously separate the masa curtain if it becomes stuck to the lower surface 136 of one of the primary rollers 54. The springs 144 bias the blades 132 so that they ride on the lower surfaces 136 of the primary rollers 54. Accordingly, when the masa curtain becomes stuck to the lower surface 136 of one of the primary rollers 54, the blade 232 scrapes it off and it continues to travel towards the sheeter rollers 56.

The sheeter rollers 56 counter rotate at the same speed and compress the masa into its final thickness. The rotary cutter (not shown) cuts circular tortillas 60 from the masa on the underside of one of the sheeter rollers 56. The tortillas 60 then fall onto the tortilla conveyor 58 and are moved towards other food processing equipment, such as an oven.

It should be appreciated from the foregoing description that the present invention provides a masa handling system 10 having the following features: the safe separation of the masa stream 20 into individual logs 74; the automatic distribution of those logs 74 to the masa hoppers 40 requiring resupply; the automatic removal of gas bubbles from the masa within the masa hoppers; and the prevention of the masa curtain from becoming stuck to the primary rollers 54.

While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended than the invention be limited, except as by the appended claims.

Claims

1. A method for handling masa within a food processing system having a pair of aligned, opposed separator conveyors having facing surfaces, the longitudinal ends of the separator conveyors positioned adjacent to a nozzle connected to a masa producing device, the food processing system further having at least two masa hoppers including an end mass hopper and an intermediate masa hopper, the masa hoppers and the separator conveyors connected by at least two endless belt feed conveyors having upper surfaces moving that are movable in the same direction, the feed conveyors positioned in an upstream and downstream relationship relative to each other when the feed conveyors are moving in the same direction, at least one feed conveyor positioned adjacent to the other longitudinal ends of the separator conveyors, each of the masa hopper hoppers having an associated sensor for sensing, the a level of mass and masa therein, the intermediate masa hopper having an opening positioned below a diverter gate located between the feed conveyors, each diverter gate connected to gap located between the upstream and downstream feed conveyors, the gap being controlled by an associated mechanism and pivotable between an open that provides a closed gap position, where the masa is guided from the upstream feed conveyor to the downstream conveyor, and a closed an open gap position, where the masa is guided from the upstream conveyor into the intermediate masa hopper positioned below the gap, each masa hopper located adjacent to a pair of aligned, opposed sheeter rollers, the sheeter rollers located adjacent to a masa hopper having side walls and a bottom wall defining a slot, the masa hopper also having at least one shaft above the bottom wall, each shaft having projections, the method comprising the steps of:

moving the facing surfaces of the separator conveyors at equal speed away from the nozzle;

feeding a generally continuous masa stream through the nozzle such that the masa stream contacts at least one of the facing surfaces of the separator conveyors and is guided between the facing surfaces of the separator conveyors;

gripping separating the masa stream between both facing surfaces of the separator conveyors pulling the masa stream such that the masa stream is separated into masa logs;

feeding the mass masa logs onto the upstream end of a feed conveyor; moving the masa logs from the separator conveyors along the upper surfaces of the feed conveyors;

moving the masa logs along the upper surfaces of the feed conveyors;

sensing the level of masa within an associated masa hopper;

causing a signal to change its state when the level of masa within the associated masa hopper is below a predetermined level;

selectively opening and closing the diverter gate gap with the associated driving mechanism to control the flow of masa logs to the associated masa hopper in response to said change in signal;

placing the masa logs through the opening of one of the masa hoppers;

feeding the masa logs to at least one shaft within the masa hopper; rotating the shaft;

removing gas bubbles from the masa with the projections on at least one shaft; and

forcing the masa through the slot, toward the sheeter rollers, with the projections on at least one shaft.

2. The method as defined by claim 1, wherein the method further comprises the steps of; step of:

arranging the facing surfaces of the separator conveyors to curve toward each other such that a cradle is formed to securely grip the masa.

3. The method as defined by claim 1, wherein the method further comprises the step of;

adjusting the speed of the facing surfaces of the separator conveyors to change the length of the masa logs. PAR

4. The method as defined in claim 1, wherein the mechanism is a pneumatic cylinder connected to a controller, the method further comprising;

programming the controller to compare said signal to a predetermined value,

selectively commanding the operation of the pneumatic cylinder to control said selective opening and closing of the diverter gate.

5. The method as defined in claim 1, wherein said step of feeding the masa logs to at least one shaft within the masa hopper is accomplished by gravity.

6. The method as defined in claim 1, wherein said step of rotating the shaft is accomplished by an A/C motor.

7. The method as defined in claim 1, wherein the masa hopper also has a pair of opposed, horizontally, aligned primary rollers between the slot and the sheeter rollers, the primary rollers each having a generally cylindrical surface and two ends, the method further comprising the steps of;

rotating the primary rollers;

drawing the masa between the primary rollers;

compressing the masa into a generally uniform curtain; and

feeding said uniform curtain into the sheeter rollers.

8. The method as defined in claim 7, wherein the masa hopper also has two endcaps, each endcap mounted around the ends of the primary rollers, the method further comprising the step of;

preventing the generally horizontal movement of the masa past the ends of the primary rollers.

9. The method as defined in claim 7, wherein there is a scrapper for each primary roller, each scrapper having a blade pivotally mounted and biased to longitudinally ride on the lower surface of its associated primary roller, the method further comprising the step of:

separating masa from the lower surface of each of the primary rollers.

10. A method for separating a stream of masa utilizing a pair of aligned, opposed separator conveyors having facing surfaces, the longitudinal ends of the separator conveyors positioned adjacent to a nozzle connected to a masa producing device, the method of separating the masa stream comprising the steps of:

moving the facing surfaces of the separator conveyors at equal speed away from the nozzle;

feeding a generally continuous masa stream through the nozzle such that the masa contacts at least one of the facing surfaces of the separator conveyors and is guided between the facing surfaces of the separator conveyors; and

gripping the masa stream between both facing surfaces of the separator conveyors, pulling the masa stream such that the masa stream is separated into masa logs.

11. The method as defined by claim 10, wherein the method further comprises the step of:

arranging the facing surfaces of the separator conveyors to curve toward each other such that a cradle is formed to securely grip the masa.

12. The method as defined by claim 11, wherein the method further comprises the step of:

adjusting the speed of the facing surfaces of the separator conveyors to change the length of the masa logs.

13. A method of feeding masa to a masa hopper within a food processing system, the food processing system further having a masa producing device and at least two masa hoppers an intermediate masa hopper and end masa hopper, the masa hoppers and the masa producing device connected by at least two first and second endless belt feed conveyors having upper surfaces moving that are movable in the same direction, the first and second feed conveyors positioned in an upstream and downstream relationship relative to each other each masa hopper when the feed conveyors are moving in the same direction, at least one of the masa hoppers having an associated sensor for sensing the level of mass and a level of masa, the intermediate masa hopper having an opening positioned below a diverter gate positioned gap located between the feed conveyors, each diverter gate connected to upstream and downstream conveyors, the gap being controlled by an associated mechanism and pivotable between an open driving mechanism that provides a closed gap position, where the masa is guided from the upstream feed conveyor to the downstream conveyor, and a closed an open gap position, where the masa is guided into the masa hopper, from the upstream feed conveyor into the intermediate masa hopper positioned below the gap, the method comprising the steps of:

moving masa logs, previously separated from a stream of masa produced from the masa producing device, along the upper surfaces of the feed conveyors;

sensing the level of masa within an associated masa hopper;

causing a signal to change its state when the level of masa within the masa hopper is below a predetermined level; and

selectively opening and closing the diverter gate gap with the associated driving mechanism to control the flow of masa logs to the masa hopper in response to said change in signal. PAR

14. The method of feeding masa as defined in claim 13, wherein the mechanism is a pneumatic cylinder connected to a controller, the method further comprising the steps of:

programming the controller to compare said signal to a predetermined value; and

selectively commanding the operation of the pneumatic cylinder to control said selective opening and closing of the diverter gate.

15. A method for feeding masa to a pair of aligned, opposed sheeter rollers, the sheeter rollers located adjacent to a masa hopper having an opening for receiving masa and side walls and a bottom wall defining a slot, the masa hopper also having at least one shaft above the bottom wall, each shaft having projections, the method comprising the steps of:

placing the masa through the opening in the masa hopper;

feeding the masa to at least one shaft;

rotating the shaft;

removing gas bubbles from the masa with the projections on at least one shaft; and

forcing the masa through the slot, toward the sheeter rollers, with the projections on at least one shaft.

16. The method for feeding masa as defined in claim 15, wherein said feeding is accomplished by gravity.

17. The method for feeding masa as defined in claim 15, wherein said rotating is accomplished by a motor.

18. The method for feeding masa as defined in claim 17, wherein there is a scrapper for each primary roller, each scrapper having a blade pivotally mounted and biased to longitudinally ride on the lower surface of its associated primary roller, the method further comprising the steps of: separating masa from the lower surface of each of the primary rollers.

19. The method for feeding masa as defined in claim 15, wherein the masa hopper also has a pair of opposed, horizontally, aligned primary rollers between the slot and the sheeter rollers, the primary rollers each having a generally cylindrical surface and two ends, the method further comprising the steps of:

rotating the primary rollers;

drawing the masa between the primary rollers;

compressing the masa into a generally uniform curtain; and

feeding said uniform curtain into the sheeter rollers.

20. The method for feeding masa as defined in claim 19, wherein the masa hopper also has two endcaps, each endcap mounted around the ends of the primary rollers, the method further comprising the step of:

preventing the movement of the masa past the ends of the primary rollers.

21. The method as defined in claim 1 wherein the upstream and downstream conveyors are operating in a fixed location and wherein the step of selectively opening and closing the gap with the associated driving mechanism comprises the step of moving a driven structure that is separate from the upstream and downstream feed conveyors.

22. The method as defined in claim 21 wherein the driven structure is a diverter gate positioned in the gap between the upstream and downstream feed conveyors, and wherein the step of moving the driven structure comprises moving the diverter gate between an open gap position and a closed gap position.

23. The method as defined in claim 21 wherein the associated driving mechanism is a pneumatic cylinder connected to the driven structure, the method further comprising the steps of:

connecting a controller to the pneumatic cylinder;

programming the controller to compare the signal to a predetermined value; and

selectively commanding the operation of the pneumatic cylinder to control the selective opening and closing of the gap.

24. The method of feeding masa as defined in claim 13 wherein the step of selectively opening and closing the gap with the associated driving mechanism comprises the step of moving a driven structure that is separate from the feed conveyors.

25. The method of feeding masa as defined in claim 24 wherein the moveable structure is a diverter gate positioned between adjacent ends of the upstream feed conveyor and the downstream feed conveyor, and wherein the step of moving the driven structure comprises the step of moving the diverter gate between an open gap position and a closed gap position.

26. The method of feeding masa as defined in claim 24 wherein the associated driving mechanism is a pneumatic cylinder connected to the driven structure, the method further comprising the steps of:

connecting a controller to the pneumatic cylinder;

programming the controller to compare the signal to a predetermined value; and

selectively commanding the operation of the pneumatic cylinder to control said selective opening and closing of the gap.

27. A method for handling masa within a food processing system having a source of masa logs positioned adjacent to a nozzle connected to a masa producing device, the food processing system further having at least two masa hoppers including an end masa hopper and an intermediate masa hopper, the masa hoppers and the source of masa logs connected by a first and second endless belt feed conveyor having upper surfaces, the feed conveyors positioned in an upstream and downstream relationship relative to each other, each masa hopper located adjacent to a pair of aligned, opposed sheeter rollers, the sheeter rollers located adjacent to a masa hopper having side walls and a bottom wall defining a slot, the masa hopper also having at least one shaft above the bottom wall, each shaft having projections, the method comprising the steps of:

feeding the masa logs from the source of masa logs onto the first feed conveyor;

moving the masa logs along the upper surface of the first feed conveyor;

selectively controlling the flow of masa logs to an associated masa hopper;

placing the masa logs through the opening of the associated masa hopper;

feeding the masa logs to at least one shaft within the associated masa hopper;

rotating the shaft;

removing gas bubbles from the masa with the projections on at least one shaft; and

forcing the masa through the slot, toward the sheeter rollers, with the projections on at least one shaft.

28. The method as defined in claim 27 wherein the step of selectively controlling the flow of masa logs to the associated masa hopper comprises opening and closing a gap between the first feed conveyor and the second feed conveyor; the gap positioned above the intermediate masa hopper.

29. The method as defined in claim 28 wherein the step of opening and closing the gap between the first and second feed conveyor comprises moving a driven structure that is separate from the first and second feed conveyor.

30. The method as defined in claim 29 wherein the driven structure is a diverter gate positioned between adjacent ends of the first and second feed conveyor, and wherein the step of moving a driven structure comprises opening and closing the diverter gate.

31. The method as defined in claim 27 further comprising the step of sensing a level of masa within the associated masa hopper.

32. The method as defined in claim 31 further comprising the step of causing a signal to change its state when the level of masa within the associated masa hopper is below a predetermined level.

33. The method as defined in claim 32 wherein the step of selectively controlling the flow of masa logs to the associated masa hopper comprises the step of selectively opening and closing a gap positioned between the first and second feed conveyor and above the intermediate masa hopper, said opening and closing of the gap resulting from said change in signal.

34. A method of feeding masa to a masa hopper within a food processing system, the food processing system further having a masa producing device, an intermediate masa hopper, and an end masa hopper, the masa hoppers and the masa producing device connected by an upstream and a downstream endless belt feed conveyor, each conveyor having an upper surface, the intermediate masa hopper positioned below a gap defined between the upstream and downstream feed conveyor, the gap being adjustable between a closed gap position where the masa is guided from the upstream conveyor to the downstream feed conveyor, and an open position where the masa is guided into the intermediate masa hopper below the gap, the method comprising the steps of:

moving masa logs along the upper surface of the first feed conveyor; and

selectively opening and closing the gap to control the flow of masa logs to the intermediate hopper positioned below the gap.

35. The method as defined in claim 34 further comprising the step of sensing a level of masa within an associated masa hopper.

36. The method as defined in claim 35 further comprising the step of causing a signal to change its state when the level of masa within the associated masa hopper is below a predetermined level.

37. The method as defined in claim 36 wherein the step of selectively opening and closing the gap comprises selectively opening and closing the gap in response to said change in signal.