Food transport fixture and method
This Application is a continuation of application Ser. No. 07/519,520 filed May 4, 1990, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to an apparatus and method for the transportation of food items. More particularly, the invention relates to an apparatus and method for receiving, transporting, depositing and retrieving a plurality of food items in a changeable predetermined array. 
     BACKGROUND OF THE INVENTION 
     In restaurants, especially quick service (fast food) restaurants, fast, consistent, efficient and safe food preparation is essential for a successful operation. One important task frequently required in the preparation of quick service food items is the simultaneous transferring of large numbers of food items to or from various food preparation stations. The simultaneous transfer of these items is typically labor intensive work which frequently requires a high degree of restaurant worker coordination, time and attention if the food items are to be quickly, safely and satisfactorily prepared. 
     The simultaneous preparation of a large number of hamburger sandwiches is one example of the demands made of workers in a quick service food environment. To perform this task, a worker must remove a large number of hamburger patties from a storage area, add the patties to a grill one at a time, remove the patties when each patty has been sufficiently and uniformly cooked, and place the patties on buns containing the appropriate condiments. Each of these tasks involves a transfer of food items which requires the worker&#39;s time and attention. Because many of these tasks simultaneously compete for the worker&#39;s time and attention, the worker may find it difficult to consistently produce a cooked product of uniformly high quality. 
     Even when a grill worker can consistently produce cooked items of uniformly high quality, the worker effort required to reach this result makes the process labor intensive. In areas where workers may be difficult to employ, or when labor resources are better used to perform other tasks, the multiple food transfers required in preparing food results in a labor intensive process. 
     Finally, the simultaneous preparation of a large number of food items raises potential safety and health issues for both the worker and the customer. First, an opportunity for worker injury may exist whenever a worker is required to transfer food items in close proximity to heated objects such as a grill or fry vat. Additionally, the sanitation concerns that are inherent to food service work generally are implicated each time a worker handles a food item during the preparation process. 
     Although quick service restaurants have existed for many years and now number in the tens of thousands, these establishments typically continue to use labor intensive, manual processes to prepare large numbers of food items. 
     Accordingly, a need exists for a commercially suitable food transfer system which reduces labor requirements and enhances the ability of the worker to safely and efficiently produce a product of consistently high quality. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a food transfer fixture is disclosed that is especially adapted for a fast food restaurant. The fixture is capable of receiving, transferring, discharging and retrieving food items between food processing stations. The food items could be virtually any product which requires frying, baking, thawing, or any other food preparation step or steps. The food items can be cooked or uncooked, frozen or non-frozen and have virtually any shape. The present invention is especially suited to transferring uncooked patty-shaped objects from a storage area to a grill for cooking, and then transferring the cooked products from the grill. 
     More specifically, in one embodiment of the invention, structure is included for horizontally surrounding at least one object to be transported, supporting the object from below, and moving the support structure relative to the surrounding structure to allow an object to be retained in or discharged from the fixture. Additional structure can be included for removably attaching additional surrounding and support structures below and in registry with the first surrounding and support structures to effect a second transfer. Also, structure may be included for depositing and retrieving a plurality of objects in a horizontal planar array to facilitate retrieving of the objects by another tool having a corresponding planar array. 
     In another embodiment of the invention, a food transfer fixture includes a hoop for surrounding at least one food object and a retractable spatula for selectively supporting the object within, or allowing the object to fall from the hoop by retracting the spatula. An extendable frame is used to horizontally retract or move the spatula from and to the hoop. Additional features can include a horizontal planar array of apertures in the first hoop for receiving and depositing food products in a specific array or geometric pattern, as well as a removably attached second hoop and second spatula subassembly in which the second hoop has a plurality of apertures vertically aligned with the first hoop apertures. This vertical alignment allows items deposited by the second hoop to be retrieved by the first hoop while maintaining the food items in the specific array or geometric pattern. Another feature of the invention can incorporate scoop mounted tracks for allowing the spatula to be slidably mounted relative to its respective hoop. 
     In still another embodiment of the invention, a food transfer fixture for transferring a plurality of food items includes a first hoop having multiple apertures located in a horizontal planar array for surrounding food items, a first spatula slidably mounted below the first hoop for supporting the food items, and an extendable frame for horizontally moving the first spatula relative to the first hoop to permit the food items to fall from the hoop when the spatula is moved horizontally to retract it from the hoop. The invention also includes a removably attached second hoop having multiple second apertures for partially surrounding food items, and a second spatula slidably mounted on the second hoop for supporting and discharging food items from the second hoop. An additional feature that can be included is a shuttle for transporting the second hoop and spatula to and from a food item dispensing station and for carrying second hoop and spatula release structure for removing the second hoop and spatula from the fixture. Another optional feature is a moveable arm system for the extendable frame that includes two moveable arms for allowing the spatulas to be moved a first distance and then a second additional distance horizontally from their respective hoops. 
     Finally, in accordance with another embodiment of the invention, a method for transporting food items from one food processing station to another is provided which includes the steps of loading food items into a food transfer item subassembly in a horizontal planar array, transferring the subassembly to a second food preparation area, depositing the food items in substantially the same horizontal planar array, and retrieving the food items in substantially the same planar array. Additional steps can include loading food items into a first subassembly for transferring and depositing and then retrieving the food items in the same array with a second subassembly for further processing. 
     In accordance with one aspect of the invention, a food transfer fixture is provided which permits the efficient transfer of a large number of food items from one processing station to another. 
     In accordance with another aspect of the invention, a food transfer system is provided which minimizes the need for manual handling of individual food items. 
     In accordance with yet another aspect of the invention, a food transfer fixture is provided which reduces food worker labor requirements. 
     In still another aspect of the invention, a food transfer fixture is provided which enhances the uniformity and quality of prepared food items. 
     In accordance with yet another embodiment of the invention, a food transfer fixture is provided which minimizes worker contact with food items and food preparation equipment, thereby minimizing the risk for worker injury and enhancing the sanitary handling of food items. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of one embodiment of the grill cell end-of-arm tool or food transport fixture showing the extendable fixture frame and the cooked patty subassembly. 
     FIG. 2 is a perspective view of additional components of the embodiment of the transport fixture of FIG. 1 showing the uncooked patty subassembly and the transfer shuttle. 
     FIG. 3 is a top plan view of the extendable fixture frame in its extended position with both the cooked and uncooked patty subassemblies attached. 
     FIG. 4 is a top plan view of the frame of FIG. 3 in the retracted position. 
     FIG. 5 is a fragmentary elevational view along lines 5--5 of FIG. 4 illustrating the operation of an uncooked hoop spring loaded finger. 
     FIG. 6 is a fragmentary elevational view along lines 6--6 of FIG. 4 of a transfer shuttle hoop guide pin and hoop guide aperture. 
     FIG. 7 is a perspective view of an automated food preparation system which employs the illustrated embodiment of the food transport fixture. 
     FIG. 8 is a top plan view of the system of FIG. 7 showing the relative location of various food preparation system components including a grill, a robot arm and an uncooked patty loading station. 
     FIG. 9 is a front elevational view of the system of FIG. 8 showing the patty dispensing station and the robot arm with the food transport fixture invention attached. 
     FIG. 10 is a side elevational view of the system of FIG. 8 illustrating the patty dispensing station shown in FIG. 9. 
     FIG. 11 is a top plan view of the uncooked patty dispensing station of FIG. 10 illustrating the operation of the patty dispensing rams. 
     FIGS. 12 and 13 are fragmentary side elevational views of the uncooked patty dispensing station of FIG. 11 which illustrate the filling of the uncooked patty subassembly. 
     FIGS. 14 through 26 are fragmentary side elevational views showing the movement and operation of the food transport fixture between the patty loading station, the grill and the automated food preparation system rack at various points in the automated food preparation cycle. 
     FIGS. 27 through 31 are fragmentary side elevational views showing the detailed operation of the food transport fixture at several points in the food preparation cycle illustrated in FIGS. 14 through 26. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1-31 illustrate one embodiment of a food transport fixture invention which can be used to receive, transport, discharge and retrieve a plurality of food items between various food processing stations. Throughout these drawings, like reference numerals refer to like parts. The illustrated embodiment is adapted for use as part of an automated food preparation system intended for use in a quick service restaurant which is disclosed in U.S. patent application Ser. No. 07/519,387, filed concurrently herewith entitled &#34;Food Preparation System and Method. 
     As will be explained later, the described embodiment is an end-of-arm tool for use with a robot arm. The tool can accept a plurality of uncooked hamburger patties from a patty dispenser station, deliver and deposit the patties on a grill, remove the cooked patties from the grill, and deposit the cooked patties on a tray or on bun crowns, heels or on other desired items. Although this embodiment is designed for use in hamburger grilling, it will be obvious from the following discussion that the invention can be adapted to any of a variety of manual or automatic food transport tasks which require the movement of fresh, frozen, uncooked or cooked food items to or from food processing stations. For example, another embodiment of the invention might be used to transfer uncooked pizza pies from a storage area to a cooking oven and then subsequently used to transfer the cooked items out of the oven for cooling, packaging or serving. 
     FIGS. 1 and 2 illustrate the basic components of a hamburger grilling embodiment of the food transport fixture invention. In FIG. 1, a food transport fixture 40 includes an extendable fixture frame 42 which supports a cooked patty subassembly 43. Subassembly 43 includes a cooked patty hoop 44 having a plurality of hoop apertures 46 and a cooked patty spatula 48. Apertures 46 fix the location of individual cooked hamburger patties when cooked patty spatula 48 is inserted under or withdrawn from under hoop 44 by the action of extendable frame 42 as will be discussed in detail in conjunction with FIG. 3. Hoop 44 and its apertures 46 represent an important aspect of the invention because they allow patties HP to be discharged from or retrieved by fixture 40 in a horizontal planar array substantially identical to the horizontal planar array 49 of apertures 46 in hoop 44. The regular pattern of array 49 permits the subsequent retrieval of the patties by any fixture or utensil having a similar planar array aperture pattern. 
     Cooked patty hoop 44 is attached to frame 42 by inserting four upwardly-directed cooked patty hoop threaded studs 50 through four frame stud apertures 52 located in frame 42. Four cooked patty hoop retaining nuts 54 are then affixed to studs 50. In the preferred embodiment, nuts 54 consist of knurled knobs which can be easily removed for fixture disassembly and cleaning. Frame 42 also includes a pair of attachment nuts or bolts 55 which allow the tool to be gripped for raising by a robot arm as will be discussed in conjunction with FIGS. 7-9. 
     Cooked patty spatula 48 includes a pair of tracks 56 which allow spatula 48 to be slidably mounted on hoop 44. Spatula 48 is attached to frame 42 by pushing frame spatula stud 58 through a spatula stud aperture 60 and attaching a spatula securing nut 62. Preferably, nut 62 is also knurled to allow for easy disassembly. 
     Other major components of fixture 40 are illustrated in FIG. 2. An uncooked patty subassembly 63 includes an uncooked patty hoop 64 having a plurality of uncooked patty hoop apertures 66. Apertures 66 have a shape useful for depositing a plurality of hamburger patties on a grill in the horizontal planar array 49 pattern of hoop 44 as shown in FIG. 8. Apertures 66 are in vertical alignment with apertures 46, thereby permitting patties deposited in planar array 49 by uncooked subassembly 63 to be successfully reacquired by cooked subassembly 43. The use of separate cooked and uncooked subassemblies prevents the possible spread of bacteria from uncooked to cooked food. 
     Subassembly 63 also includes an uncooked patty spatula 68 which is slidably mounted to hoop 64 by a pair of uncooked patty spatula tracks 70. Tracks 70 permit spatula 68 to slide back and forth on hoop 64 to allow patties to be discharged from or reacquired by subassembly 63. Hoop 64 and spatula 68 can rest on a patty shuttle 72 for movement to and from an uncooked patty dispenser (see FIG. 9), and for removing uncooked subassembly 63 from fixture 40 as described in the following paragraph. 
     Uncooked subassembly 63 is designed to be removably attached beneath cooked patty subassembly 43 as can be seen in FIG. 25. Structures included for this purpose which are illustrated in FIG. 1 include cooked patty hoop guide apertures 74, cooked patty spatula guide apertures 76 and uncooked patty hoop pivotable spring loaded fingers 80 (also illustrated in FIG. 2). Additional attaching structures illustrated in FIG. 2 include uncooked patty hoop guide apertures 81, uncooked patty spatula guide apertures 82, uncooked patty spatula spring loaded fingers 84, shuttle hoop guide pins 86, shuttle spatula guide pins 88, pivotable spring finger release levers 90 (see FIG. 5), and spring finger lever cylinders 92. The cooperative action of the uncooked patty subassembly attaching components listed above will be described later in conjunction with FIGS. 5 and 6. 
     When uncooked patty subassembly 63 is attached to cooked patty subassembly 43, cooked patty spatula 48 and uncooked patty spatula 68 are slidably moveable from their respective hoops 44 and 64 by the horizontal movement of extendable frame 42. As shown in FIG. 1, spatula 48 is directly attached to frame 42 and therefore moves when frame 42 moves. Because spatula 68 is attached to spatula 48 by spring loaded fingers 80 and 84, spatula 68 moves whenever frame 42 moves spatula 48. 
     Frame 42 moves between a retracted position R shown in FIG. 4 and an extended position E shown from above in FIG. 3. When frame 42 is in retracted position R, cooked patty spatula 48 and uncooked patty spatula 68 (shown by dashed line US) is directly beneath cooked patty hoop 44 and uncooked patty hoop 64 (shown by dashed line UH), respectively, as shown in FIG. 27. This allows uncooked hamburger patties to be held within hoop apertures 66 and supported from beneath by spatula 68 for transport to a grill. When frame 42 is moved to extended position E, spatulas 48 and 68 are no longer beneath hoops 44 and 64, and uncooked patties supported on spatula 68 will fall to the grill in the horizontal planar array 49 of FIG. 8 as shown in FIG. 28. As previously discussed, this permits retrieval of cooked patties by the similarly arrayed apertures of cooked patty hoop 44, shown in FIGS. 29 and 30. 
     It should be noted that uncooked hoop apertures 66 can be of a different form than cooked hoop apertures 46. This is because uncooked apertures 66 need only fix the location of hamburger patties when spatula 68 is withdrawn or moved to the extended position. Therefore, apertures 66 need only be semicircular shaped at the trailing edge of the hamburger, which permits a longer portion of hoop 64 to be cut away so that it is lighter. In contrast, hoop 44 must fix the position of patties during withdrawal and insertion of spatula 48, and therefore must be semicircular on both the leading and trailing edges of the hamburger patties to fix their position. 
     The components responsible for the horizontal movement of frame 42 are shown in FIG. 3. Extendable frame 42 includes a fixed frame member 94 to which is mounted a pair of outer cylinders 96. Cylinders 96 each have an outer cylinder rod 98 having its distal end attached to a moveable frame member 100. Frame 42 also includes an inner cylinder 102 affixed to frame member 100 which has an inner cylinder rod 104 attached to cooked patty spatula 48 by nut 62. When frame 42 is in extended position E, cylinder rods 98 and 104 are fully extended from cylinders 96 and 102 respectively. Preferably, cylinders 96 and 102 are hydraulic cylinders to provide smooth cylinder action. It is also preferred that the hydraulic fluid used to drive cylinders 96 and 102 be water or some equally food-compatible substance to prevent food contamination in the event of cylinder leakage. 
     The movement of frame 42 from extended position E to retracted position R is a two step process. First, outer cylinders 96 and inner cylinder 102 is actuated to pull frame member 100 inward a first distance D1. Outer cylinders 96 move first because of lower operating pressure requirements. Cylinders 96 and 102 move simultaneously once cylinder 102 begins moving. Spatula 48 moves inward the same distance as it is pulled inward by retracting inner cylinder rod 104 which is affixed to frame member 100. Frame 42 is then moved to its fully retracted position R by cylinders 96 and 102 to retract frame 42 a second distance D2. This pulls spatula 48 to a position directly beneath hoop 44. To extend frame 42 to its fully extended position, cylinders 96 and 102 are extended. 
     The cooperation of the components involved in attaching and removing uncooked patty subassembly 63 from cooked patty subassembly 43 is best described in conjunction with FIGS. 5 and 6. FIG. 5, which is representative of the operation of spatula spring loaded fingers 84 as well as hoop spring loaded fingers 80, shows uncooked patty hoop 64 stacked between patty shuttle 72 and cooked hoop 44. Hoop spring loaded finger 80 is shown in the attached position. Fixture 40 has been lowered onto shuttle 72 so that uncooked patty subassembly 63 can be removed from transport fixture 40 by releasing spring finger 80. In this attached condition, spring finger lever 90 is shown in an initial upright position and spring finger lever cylinder 92 is shown in an initial retracted position. To remove uncooked patty subassembly 63 from cooked patty subassembly 43, lever cylinder 92 is actuated. This causes cylinder rod 106 to move to an extended position (shown in dashed lines). Finger release lever 90 then pivots about lever pivot point LPP, which in turn causes spring finger 80 to pivot about finger pivot point FPP. This pushes the lower end of finger 80 inward, causing spring finger 80 to move outward at its upper end to provide sufficient clearance between finger 80 and hoop 44 for hoop 44 to be moved upward past retracted finger 80. 
     Subassembly 63 can be attached to subassembly 43 in a similar manner. Hoop 64 is first lowered over a shuttle hoop guide pin 86 passing through guide apertures 81 (as seen in FIG. 6). As the bottom edge of hoop 64 bears down on finger 80, the top of finger 80 pivots inwardly, thereby securing subassembly 63 to subassembly 43. 
     As previously noted, the illustrated embodiment of fixture 40 is adapted for use in an automated food preparation system. The operation of fixture 40 in this application will now be discussed in connection with FIGS. 7-29. 
     First referring to FIGS. 7, 8 and 9, fixture 40 is moved about an automated food preparation system 108 by a robot arm 110 capable of gripping grippable frame members 55 (illustrated in FIG. 3). FIG. 7 is a perspective view of preparation system 108 showing the physical arrangement of a patty dispensing station 112, a grill 114 and robot arm 110 with fixture 40 attached and sitting in a &#34;home&#34; position H. As can be seen from FIG. 9, uncooked subassembly 63 moves back and forth in the direction of double arrow A to load patties from dispensing station 112 and moves back and forth in the direction of double arrow B in FIG. 8 to deposit uncooked patties on grill 114. Similarly, cooked patty hoop 44 and spatula 48 move back and forth in the direction of double arrow B to pick up cooked patties from grill 114. 
     Turning now to FIG. 9, preparation system 108 includes a rack 116 for supporting various system components and a shuttle transfer system 118 for moving shuttle 72 and uncooked subassembly 63 to and from patty dispensing station 112 in the directions of double arrow A (also shown in FIG. 2). The cooking cycle begins when transfer system 118 moves shuttle 72 into patty dispensing station 112 in response to an order to cook patties. Transfer system 118 next positions shuttle 72 beneath three patty hoppers 120 as shown in FIG. 10. Each hopper 120 employs a cylinder operated patty dispensing ram 122 including a moveable patty push arm 123 to push a hamburger patty HP from the bottom of each hopper from a first position indicated by dotted elements 123&#39; and HP&#39; through an uncooked patty dispensing aperture 124 to the position indicated by elements 123 and HP as shown in FIG. 11. 
     Patties fill uncooked subassembly 63 one row at a time. As patties HP are ejected from hoppers 120 by ram 122, they fall through uncooked patty dispensing apertures 124 (see FIGS. 11, 12 and 13). After a first row of uncooked hoop apertures 66 has been filled with a desired number of patties (see FIG. 12) transfer system 118 indexes shuttle 72 one aperture row at a time (see FIG. 13) until subassembly 63 has been filled with the desired number of patties (1-9 patties in the illustrated embodiment). System 118 then moves shuttle 72 beneath arm 110 and attached cooked patty subassembly 43 at home position H as shown in FIG. 9. 
     Arm 110, which can be a rodless air cylinder or an electric cylinder, for example, is next lowered in the direction of arrow C in FIG. 7 to engage and clamp uncooked patty subassembly 63. After clamping, arm 110 is raised and positioned over grill 114 as in FIGS. 16 and 27 and moveable frame 42 is moved to its extended position E as shown in FIGS. 17 and 28. This moves uncooked spatula 68 from beneath uncooked hoop 64, and causes patties HP to fall to grill 114 in the horizontal planar array 49 previously described. Frame 42 is then retracted and arm 110 moves fixture 40 back to home position H as shown in FIG. 18. 
     Empty uncooked patty subassembly 63 must now be returned to dispensing station 112 for refilling. To accomplish this, arm 110 lowers subassembly 63 onto shuttle 72 from home position H as shown in FIG. 26. Spring finger lever cylinders 92 are activated, causing subassembly 63 to be released from fixture 40 as already discussed in conjunction with FIG. 5. Transfer system 118 then returns shuttle 72 to station 112 for refilling. 
     After patties HP have been cooked on grill 114, fixture 40 must be returned to grill 114 to remove patties HP. This is accomplished by moving arm 110 back over grill 114 and extending frame 42, which moves cooked patty spatula 48 from beneath cooked patty hoop 44 as shown in FIGS. 21 and 29. Arm 110 is then lowered so that spatula 48 is horizontally aligned with the portion of grill 114 on which patties HP rest. Frame 42 is then returned to its retracted position causing spatula 48 to pass between patties HP and grill 114, scooping patties HP into fixture 40 as shown in FIGS. 29 and 30. Arm 110 then re filled fixture 40 to home position H shown in FIG. 23. 
     Sandwiches are prepared from cooked patties HP by the steps shown in FIGS. 20-25 and 31. First, while patties HP are cooking on grill 114, a moveable bun tray 126 loaded with bun crowns BC is attached to rack 116 as illustrated in FIG. 20. Bun tray 126 fits into a slot 127 on moveable bun tray frame 129 (part of rack 116) as shown in FIG. 31. Bun tray frame 129 is driven by an air cylinder, not shown, on bun tray track 131 which allows movement of bun tray 126 from an extended position as shown in FIG. 20 to a retracted position under fixture 40 to receive cooked patties HP as shown in FIG. 31. Bun tray 126 can include a cooked patty spatula wiper 128 as illustrated in FIGS. 22 and 23. Fixture 40 then returns to grill 114 with cooked patty spatula 48 extended as shown in FIG. 21, and is lowered to grill 114 as shown in FIG. 22. Spatula 48 is retracted, thereby retrieving cooked patties HP from grill 114. Fixture 40 then returns cooked patties HP to home position H (see FIG. 23) and bun tray 126 is moved under fixture 40 on track 131. This positions crowns BC beneath cooked patties HP and causes wiper 128 to clean the bottom of spatula 48 as tray 126 is moved from the position shown in FIG. 23 to the position shown in FIG. 24. Frame 42 is then extended, which moves cooked patty spatula 48 from beneath hoop 44, causing patties HP to fall on crowns BC as shown in FIGS. 25 and 31. Tray 126 is then extended by movement of bun tray frame 129 along track 131 in the direction of arrow B&#39; in FIG. 31 and bun heels BH are added by a restaurant worker to complete the sandwiches as shown in FIG. 26. 
     While the invention has been described with respect to the illustrated embodiment, it is to be understood that the invention is capable of numerous changes, modifications and rearrangements without departing from the invention as defined in the following claims.