Abstract:
A bun laner sorts buns into a predetermined number of lanes, for providing buns to a packaging unit. The bun laner detects when some lanes are filling faster than other and closes those lanes while the other lanes fill. A vacuum may be used to hold buns in a filled lane in order to close the lane. An optical detection unit may be used to determine when a bun has been stationary at a certain position in the lane for a predetermined amount of time.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not Applicable  
       STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable  
       BACKGROUND OF THE INVENTION  
       [0003]     1. Technical Field  
         [0004]     This invention relates in general to food packaging equipment and, more particularly, to equipment for sorting buns into lanes.  
         [0005]     2. Description of the Related Art  
         [0006]     Commercial bakeries use high-speed packaging equipment to bag hamburger rolls, hot dog rolls, and other bread products (collectively, “buns”). Typically, the buns are packaged in arrays of one or more layers; for example, a sixteen bun package may package the buns in a four-by-four array and a 32 bun package may package the buns in two four-by-four layers.  
         [0007]     In order to arrange the rolls in an array, a bun laner is used. The bun laner takes randomly arranged buns on a conveyer and aligns the buns into rows or “lanes”. When a sufficient number of buns are in each lane, a group is transported to a packaging machine.  
         [0008]     Unfortunately, the randomly arranged buns do not evenly fill the lanes under normal circumstances. If a certain lane is not being filled as quickly as the other lanes, then the packaging machine must wait, slowing the packing process. Accordingly, the bun laner generally requires human intervention to direct the buns to the lanes evenly. Manual supervision of the machines, of course, increases the cost of packaging the buns and wastes human resources on a tedious chore.  
         [0009]     Therefore, a need has arisen for a bun laner that does not require human supervision.  
       BRIEF SUMMARY OF THE INVENTION  
       [0010]     In the present invention, a bun laner comprises a staging area for holding a plurality of buns and a predetermined number of lanes into which buns from the staging area are sorted. A bun detection unit detects each lane that has at least a predetermined number of buns and, responsive to a detection, a vacuum selectively closing one or more of the lanes.  
         [0011]     The present invention provides significant advantages over the prior art. First, full lanes can be blocked using an uncomplicated vacuum mechanism. Second, the lanes are blocked without causing damage to the buns.  
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0012]     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:  
         [0013]      FIG. 1  illustrates a general block diagram of a bun laner;  
         [0014]      FIG. 2  illustrates a detailed top view of a bun laner;  
         [0015]      FIG. 3  illustrates a front view of a vacuum unit in conjunction with a front cross-sectional view of the bun laner;  
         [0016]      FIG. 4  illustrates a top view of a lane impeder unit.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]     The present invention is best understood in relation to  FIGS. 1-4  of the drawings, like numerals being used for like elements of the various drawings.  
         [0018]      FIG. 1  illustrates a basic diagram of a bun laner  10 . Buns enter the laner  10  in staging area  12  after cooling an de-panning. Sorting mechanism  14  aids in directing buns  16  from the staging area  12  into one of the lanes  18 . Bun detection unit  20  detects when the number of buns in a lane have reached a predetermined point in the lane. Lane impeder  22  can impede bun movement into one or more selected lanes, responsive to a signal from bun detection unit  20 . A packaging device  24  receives buns from the lanes  18   a - d  and packages the buns  16 .  
         [0019]     In operation, the staging area  16  includes a conveyor belt which transports the buns towards the sorting mechanism  14 . The sorting mechanism could use, for example, moving guides as shown in  FIGS. 2-4 . The purpose of the sorting mechanism is to direct randomly placed buns  16  into a lane  18 . Bun detection unit  20  could be implemented using an optical detector which senses the presence of a bun for a predetermined time (such as two seconds) or other optical, electrical, mechanical or electromechanical device which senses the presence of a bun for a predetermined amount of time or otherwise senses the non-movement of a bun. The purpose of the bun detection unit  20  is to signal the lane impeder whenever buns in a lane  18  have reached a certain point in the lane. Under control of the bun detection unit  20 , the lane impeder  22  temporarily stops buns from entering the filled lane(s). By impeding buns in one or more lanes, the remaining buns in the staging area  12  will be forced to enter an unfilled lane  18 . The lane impeder  22  selectively provides a vacuum at the bottom of the filled lanes, as shown in greater detail in connection with  FIG. 3 .  
         [0020]     For purposes of illustration, the lane impeder  22  is shown close to the bun detector  20 ; however, in an actual implementation, there would be several feet between these two units. Accordingly, by the time a filled lane is detected, there are likely to be additional buns behind the bun directly beneath the bun detector.  
         [0021]     To illustrate the benefits of the bun laner  10  of  FIG. 1 , it is assumed that the packaging device  24  is bagging buns in an array of 4×4, although any size array (or multiple arrays, such as a stack of two 4×4 arrays) could be accommodated by the bun laner  10 . In the case of a 4×4 array, the packaging device  24  cannot receive buns  16  from the laner  10  until each of the four lanes  18   a - d  hold at least four buns. If, for example, the middle lanes  18   b - c  are filling faster than the outside lanes  18   a  and  18   d , the packaging device  24  will be delayed in its operation. In the present invention, once a predetermined number of buns are in a lane  18  (for example, twelve buns), that lane will be impeded by lane impeder  22 , which prevents further buns from entering the impeded lane(s). Hence, in this example, as soon as lane detector  20  detects twelve buns in lane  18   b , a vacuum is applied to that lane and further buns are stopped at the sorting mechanism  14 . The buns  16  in the staging area  12  will thus be directed to the other lanes. When there are enough buns  16  in lanes  18  for packaging, the buns  16  will be released to the packaging device  24 ; the release of the buns may or may not cause the impeded lanes to be re-opened, depending upon the number of buns behind the bun detection unit  20  at the time that the lane was closed.  
         [0022]     Accordingly, with the lane impeder  22  controlled responsive to detection by the bun detection unit  20 , buns  16  are directed to under-filled lanes without human intervention.  
         [0023]      FIG. 2  illustrates a more detailed top view of the bun laner  10  (in conjunction with the packaging device  24 . In staging area  12 , a first conveyor belt  30  transports buns  16  to the sorting mechanism  14 . Barriers  32  funnel the buns from to the center of the conveyor belt  30 , towards the lanes  18   a - d . The sorting mechanism  14 , shown in greater detail in connection with  FIG. 4 , has five guides  34  which oscillate back and forth (in parallel) to align the buns  16  with the lanes  18 . Wheel  36  controls the movement of the guides  34  at it is rotated by a motor (not shown). Lane impeder  22  includes a perforated grate that is sloped slightly downward such that buns  16  slide over lane impeder  22  onto conveyor belt  37  when a vacuum is not being applied.  
         [0024]     Once a bun has passed ever lane impeder  22 , it is transported down its lane by conveyor belt  37 . As the buns  16  are transported down a lane, they pass under bun detection unit  20 . If the bun detection unit  20  senses that a bun directly below the detection unit  20  is stationary, the bun detection unit  20  sends a signal to the lane impeder  22  indicating that the lane is full. At this point, buns may have already passed by the lane impeder  22 , so it is not necessarily the case that a bun underneath the bun detection unit is the last bun in the lane  18 .  
         [0025]     A second bun detection unit  38  detects when all of the lanes have a sufficient number of buns  16  for passing to the packaging device  24 . Second bun detection unit  38  works in conjunction with bun holder  40  to release a predetermined number of buns from the laner  10  to the packaging device  24  and or a bun slicing device. The packaging device  24  may be of any standard design. Because the bun laner  10  provides a more even distribution of buns through the lanes, it may lessen the amount of pressure needed to mechanically hold a bun in place, since the necessary pressure is related to the number of buns in line being pushed forward by conveyor belt  37 .  
         [0026]      FIG. 3  illustrates the lane impeder  22  (for a six lane unit). A vacuum unit  50  provides suction through hose  52 . The suction from hose  52  is diverted into six pipes  54 , each having a respective valve  56 . Each valve  56  is controlled by a respective sensor  58  on the detection unit  20 . Each valve is coupled to its respective lane  18 .  
         [0027]     The valves  56  control whether a bun is allowed to pass or is held in place by the vacuum created by vacuum unit  50 . When a valve  56  is open, the vacuum from vacuum unit  50  holds the bun over the valve in place.  
         [0028]     By selectively applying a vacuum to full lanes, the buns are held in place without damage to the bun and without a complicated mechanical structure to selectively shut of lanes.  
         [0029]      FIG. 4  illustrates detailed top view of the sorting mechanism  14 . Wheel  36  is constantly rotated by a motor (not shown). A bar  60  has one end that is pivotally attached to the perimeter of wheel  36  and a second end which is pivotally coupled to sliding bar  62 . Sliding bar  62  is slideably engaged in carrier  64 . Responsive to the rotation of wheel  36 , the sliding bar  62  move back and forth in carrier  64 . Sliding bar  62  is coupled to the guides  34 , such that as sliding bar  62  oscillates back and forth, guides  34  oscillate back and forth as well.  
         [0030]     In an alternative embodiment, a vibratory conveyor is used in the staging area  12  in place of conveyor belt  30  and sorting mechanism  22 . A vibratory conveyor is generally made of a smooth metal, such as stainless steel, and vibrates to move the food product, i.e., the buns  16 , forward towards the lanes. Because the staging area  12  with a metal surface is much smoother than a conveyor belt, there is less friction with the buns in staging area  12 , and the buns freely move around one another when one or more lanes are impeded by the vacuum.  
         [0031]     Although the Detailed Description of the invention has been directed to certain exemplary embodiments, various modifications of these embodiments, as well as alternative embodiments, will be suggested to those skilled in the art. The invention encompasses any modifications or alternative embodiments that fall within the scope of the claims.