Patent Document

FIELD OF THE INVENTION 
     The present invention relates to the field of food handling and packaging, and, more particularly to an apparatus and method for stacking frozen food portions, such as hamburger patties or the like, in preparation for packaging, and without the need for human contact. 
     BACKGROUND OF THE INVENTION 
     Numerous advances have been made in the food processing and packaging industries over the last several decades. These advances, in large part, have been directed to automated handling and packaging systems for increasing the “assembly line” output, i.e., volume, of the food processing operation. Examples include machines for filling and sealing containers, stackers, sorters, and counters/measurement devices. Primary objectives of these systems have been cost reduction and accuracy. A large number of these systems have also been devised for use with final, processed, foods such as snacks, beverages, processed canned products, etc. 
     A different set of problems has evolved in recent years with respect to the handling and packaging of uncooked, or raw, food products, particularly meats. Concerns of tainted, or contaminated meat due to improper handling and processing of the raw meat products, such as ecoli, have given rise to increased governmental oversight. Additionally, concerns associated with human contact and the passage of human contamination during the cooking stage and service of food products have prompted higher workplace standards. One notable example is the passage of hepatitis. As fast food restaurants and the like have proliferated, so have the concerns over tainted food and incidents of food poisoning. Accordingly, product liability issues have arisen. Food processors and packagers are bearing high costs from the liabilities associated with human contact, and hence, contamination. 
     Yet, despite the advances made in automation and packaging, there has not heretofore been an effective, practical ways to eliminate human contact with raw meat products. At some point in the forming and packaging process, human contact with raw product has been necessary. Meat packers have, thus, found themselves increasingly culpable when cases of contamination arise, and have borne substantial losses over precautionary recalls of products when the source of the contamination has been indeterminate. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an apparatus for efficiently stacking predetermined numbers of food portions, such as frozen hamburger patties, received from bulk bins, or directly from a freezer, in preparation for subsequent packaging, and without the need for human contact. 
     In a preferred embodiment, the apparatus for stacking food patties includes a conveyor, counters, gates, and a stacking rake. In one embodiment, the conveyor comprises first and second conveying belts. The first, receiving conveying belt receives flat, frozen patties from a bulk bin, hopper, or freezer, at its first, or receiving, end. The belt is mechanically driven for moving patties along the length of the belt away from the bin or hopper and toward its second end. A first counter is desirably positioned above or below the first conveying belt so as to count patties passing a selected point along the first conveying belt. The first gate is positioned downstream of the counter for stopping and preventing further movement beyond a second selected point. The first counter and the first gate are electronically interconnected so that the first gate will open, or lift, when a preselected number of patties have passed by the counter. 
     When the first gate opens, the chain of patties are permitted to continue moving along the first conveying belt toward the second end of the first belt. A second counter is positioned near the end of the first belt for determining when a preselected number of patties have reached the end of the first belt and dropped onto the first end of the second conveying belt. 
     The second conveying belt is positioned with a first end slightly lower than the second end of the first conveying belt. The second conveying belt is started and stopped by the electronically interconnected second counter. A second gate is positioned just downstream of the first end of the second conveying belt and oriented so as to cause the initial patties arriving on the second conveying belt to shingle one upon the other. The second gate is a substantially flat lever that is pivotally mounted above the second conveying belt. In its initial position, the second gate forms a predetermined acute angle with respect to first end of the second conveying belt. 
     A stacking rake is positioned above and oriented along the longitudinal axis of the second conveyor belt for shuffling the patties into a horizontal stack and sliding the stack to the second end of the second conveying belt. 
     These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiments when considered in conjunction with the drawings. It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of the apparatus for stacking food patties constructed according to the present invention; 
     FIG. 2 is a top view of the apparatus of FIG. 1; 
     FIG. 3 is a perspective side view of the first conveying belt of the apparatus of FIG. 1; 
     FIG. 4 is a perspective side view of the second conveying belt of the apparatus of FIG  1 ; 
     FIG. 5 is a perspective view of the second conveying belt of FIG. 4, illustrating the action of the rake during the stacking step; and 
     FIGS. 6A through 6G illustrate the logic and steps of the stacking method. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in FIGS. 1 and 2, a first aspect of the present invention is directed to an apparatus, shown generally as  10 , for counting and stacking food patties, such as frozen hamburgers, into horizontal cylindrical stacks for subsequent packaging, and without requiring human intervention or contact. As those in the art will appreciate, the apparatus described in detail herein is not limited to use on frozen meat patties; rather, the apparatus  10  may be used with any type of food portion, including a patty or slice, meat or non-meat, frozen or unfrozen. Further, the apparatus is also not limited to the counting and stacking of food items, but could be used for counting and stacking other varieties of items where human contact and contamination are undesirable. 
     Generally, the apparatus  10  is comprised of a first conveying belt assembly  30 , a second conveying belt assembly  60 , a stacking mechanism  70 , and a stack receiver and transport assembly  80 . 
     FIG. 3 is a side perspective view of the first, or receiving, conveying belt assembly  30 . Conveying belt assembly  30  comprises a continuous belt  32  assembly that is moved by and across a series of rollers  33 . The belt assembly  30  is driven by a computer controlled electrical motor  34 ; however, a variety of motive drive systems, electrical and non-electrical, may be employed. As shown in FIG. 3, the belt moves in a clockwise direction, from a first, or receiving, end  32   a  to a second, or discharge, end  32   b . The first conveying belt assembly  30  is mounted on a frame  35  that is constructed to support the belt  32  and rollers  33 , the drive connections (not shown), and the electric motor  34 . The belt  32 , from the receiving end  32   a  to the discharge end  32   b , is approximately 36 inches long and approximately 5 inches wide. The belt  32  is a plastic link construction that comprises two spaced apart, parallel tracks, and is available from KVP, Inc. of Rancho Cordova, Calif. While a plastic link belt has been found suitable for the present invention, belts formed of other materials, such as flat fabric, whether as linked constructions or otherwise, may be equally suitable. This width of the belt  32  is slightly greater than the diameter of a frozen hamburger food patty; e.g., about 4.25 inches. First conveying belt end  32   a  of belt  32  is adapted to receive the frozen food patties from a hopper, or delivery belt  22 , as shown in FIG.  3 . 
     The frame  35  is preferably stainless steel or other similar metal that is easily cleaned and maintained sanitary. The electrical motor  34  that drives the first conveying belt assembly  30  is designed to repeatedly and intermittently start and stop belt  32 . In operation, the electric motor  34  is sized to move belt  32  at a constant speed of about 127 feet per minute. The electric motor is a ¼ horsepower motor supplied by Lenze of Lawrenceville, Ga., as Series VDE0530. The motor  34  is controlled by a programmed computer  25 . 
     Downstream of end  32   a  is a first counter  39 . This first counter  39  is desirably a diffused electronic eye that is so positioned as to detect and count each food patty intersecting the beam of the eye. One suitable diffused electronic eye is available from Banner Engineering of Minneapolis, Minn. as Model No. S185P6FF100C. The first counter  39  is mounted to a bracket (not shown) or other support that is secured to the frame  35  of the assembly  30 . Downstream of the first counter  39  is a first gate  43 . First gate  43  is mounted and supported by bracket  44  that is also affixed to the frame  35 . Gate  43  is pivotally attached to bracket  44  and comprises a pivotal attachment and a plurality of tines (forks)  43   a  that extend downward; however, the particular construction of gate  43  is not critical so long as it adequately prevents any further movement of patties along the belt. Gate  43  is electronically connected to and controlled by the first counter  39 . At the second, or discharge end  32   b , of belt  32 , is a second counter  48 , similar to the first counter  39 , that is held in place by a bracket  49 , also affixed to the frame  35  of the first conveying belt assembly  30 . 
     Turning now to FIG. 4, the second conveying belt assembly  60  comprises a belt  62  mounted on and moved by rollers  63  and driven by an electric motor  64  of the same type and rating as the first motor  34 . The motor  64  is controlled by the programmable computer  25 . The second conveying belt assembly  60  is constructed similar to assembly  30 , having a frame  65  that supports the belt  62 , rollers  63 , drive connections (not shown), electric motor  64 , and stacking mechanism  79 . Opposed, spaced walls  66  and  67  are affixed to the frame  65  for properly channeling patties moving along the length of the belt  62 . 
     Referring again to FIG. 1, it will be appreciated that the second conveying belt assembly  60 , and hence, the second belt  62 , is mounted at a slightly lower level (approximately 2.7 inches) than the first conveying belt assembly  30 . This assures that the patties dropping off the end of belt  32  at end  32   b  will properly shingle as they land and slide along belt  62  and onto the previous patties. For ease of reference, belt  62  also has a first, or receiving, end  62   a , and a second, or terminal, end  62   b . Just downstream of end  62   a  of the second conveying belt  62 , is a second gate  68 . This second gate  68  is supported by a bracket  69 , similar in construction to bracket  49 . Gate  68  is “ski”, or lever, shaped. In its initial position, gate  68  is pivotally attached to bracket  69  and slopes downward toward end  62   b  of belt  62 . The downward slope of gate  68  forms an acute angle between the gate  68  and the belt  62  of between about 15 and 20 degrees. This orientation assures consistently proper shingling of patties dropping onto the second belt  62 . That is, each patty overlaps about ⅔ of the previous patty. 
     Referring to FIG. 5, positioned above the second conveying belt assembly  60  is the stacking mechanism  70 . The stacking mechanism  70  comprises an elongate rake  72 , a mounting mechanism  74 , and servo drive mechanism  76 . The stacking mechanism  70  is so configured that the mounting mechanism  74  pivots downward from above the second end of the second conveying belt  62 . The relative position and operation of the stacking mechanism  70  is best seen in FIG.  5 . This places the stacking rake behind the last patty received on the second conveying belt  62 . The servo drive mechanism  76  then causes the stacking rake  72  to move axially toward the second end  62   b  of belt  62 . The servo drive mechanism  76  is a linear servo, available from Linmont of Zurich, Switzerland as Model No. PS01-37X240. As the rake  72  begins to retract toward the second end  62   b  of the belt, belt  62  begins moving. Rake  72 , however, moves at a faster speed, causing the shingled patties to shuffle into a vertical orientation with respect to one another to form a horizontal cylinder of patties. By the time the rake  72  reaches the second end  62   b  of the second belt, the patties are all vertically-oriented and are pulled into a first receiving bucket  82 . 
     At the discharge end  62   b  of belt  62  is the stack receiver and transport assembly  80 . The stack receiver and transport assembly  80  consists of a first receiving bucket  82 , an intermediate transport bucket  84 , and a plurality of transport buckets  86 . A drive assembly  88  moves the transport buckets  86  to a packing apparatus conventionally known in the art for packaging cylindrical stacks of food items. 
     Referring now to FIGS. 6A through 6G, the operation and steps of the shingling and stacking process will be described in detail. As will be appreciated by those skilled in the art, a conventional programmable logic controller (PLC) is employed to control the sequence and timing of the operation of the present invention. 
     The operation begins as frozen patties  100  such as hamburgers, are moved from a freezer or hopper, or the like, along a delivery conveyer  22  and onto the receiving end  32   a  of belt  32 . Belt  32  moves continuously throughout the entire shingling and stacking cycle. The patties  100  move along belt  32  towards the opposite end  32   b , each patty passing under or by counter  39  (FIG.  6 A). Gate  43 , located downstream of counter  39 , and initially in a down, or closed, position. 
     As the patties move along belt  32 , they are prevented from forward movement until a predetermined number of the patties, e.g., three (3) have passed counter  39  (FIG.  6 B). When counter  39  counts the predetermined number, gate  43 , which is electrically interconnected to counter  39 , will open and allow the patties to move along toward the discharge end  32   b  of belt  32 . 
     Belt  62  of the second conveying belt assembly  60  is initially not moving and is ready to receive the first patties. Gate  43  is initially in a down, or closed, orientation. As the first patty arrives and drops onto belt  62 , it slides forward due to the delivery speed of belt  32  until it is stopped by gate  68 . The angle of the gate with respect to the belt causes each succeeding patty (numbers  2  and  3 ) to shingle atop one another (FIG.  6 C). 
     When counter  48  detects that the third patty has passed beneath it, it electronically communicates with gate  68  to raise, allowing the patties to move forward (FIG.  6 D). As each succeeding patty passes under counter  48 , belt  62  is caused to advance a length sufficient for the shingling of that patty, and so on with each patty, until approximately 25 patties have been shingled in a single row along belt  62 . When counter  48  detects that the twenty-fifth patty has passed, belt  62  advances to shingle that patty, and stacking rake  72  is placed in operation. Rake  72  has an elongate portion  72   a  and a rake projection  72   b  that extends downward. The rake  72  is caused to extend downward behind the trailing edge of the twenty-fifth patty (FIG.  6 F). 
     After extending downward, rake  72  moves axially toward the terminal end  62   b . This action causes the last, i.e., the twenty-fifth and each preceding patty, to be shuffled vertically together, much like a deck of cards. As rake  72  moves axially towards  62 , the patties are all shuffled into a horizontal cylindrical stack that is approximately 8.5 inches long. Rake  72  moves the horizontal cylindrical stack until the stack is pushed into an awaiting empty first receiving bucket  82  (FIG.  6 G). 
     The first receiving bucket  82  has an open top, substantially flat side walls, and a round, or triangular-shaped trough, or bottom, portion. The axial length of bucket  82  approximates the length of the cylindrical stack of twenty-five patties. As soon as rake  72  has deposited the first cylindrical stack of patties into bucket  82 , the rake  72  retracts and the entire shingling and stacking cycle begins again. Bucket  82 , which is pivotally mounted at its ends, rotates about its long axis to dump the stack of patties into the intermediate bucket  84 . A plurality of transport buckets  86  are spaced apart along a continuous chain drive  87 , positioned below intermediate bucket  84 , at intervals sufficient to match the cycle of each counting and stacking cycle. Thus, after receiving bucket  82  deposits the first stack of patties into the intermediate bucket  84 , that stack is synchronized for deposit into the next transport bucket  86  along the chain drive  87 . Transport buckets  86  move along the chain drive  87  where they are ultimately received at a packaging point (not shown). The entire counting, shingling, stacking, and transport process has been completed without human contact. 
     Although the present invention has been described with a preferred embodiment, it is to be understood that modifications and variations may be utilized without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims and their equivalents.

Technology Category: b