FIELD OF THE INVENTION

The present invention relates to equipment for dispensing arti¬ cles from stacks of articles. More particularly, it relates to equip¬ ment for removing the bottom box from a stack of boxes in a vending machine freezer. The invention is also concerned with vending machines having freezers for storing frozen food items and micro¬ wave ovens for heating those items. The invention more specifically relates to such machines used for handling boxes of frozen pre-pre- pared pizzas or the like. BACKGROUND OF THE INVENTION

Many vending machines for dispensing various food or other items are known, and examples thereof include those shown in U.S. Patents 2,790,379, 2,901,964, 3,160,255, 3,653,541, 4,482,078, 4,513,879, 3,343,479, 3,416,429, 3,165,186, 2,890,644, 3,338,155, 3,386,550, 3,534,676, 4,398,651, 4,428,280, 4,592,485, 4,598,810, 4,671,425, 4,677,278, 4,687,119, 4,944,218 and 5,011,042, British Pat¬ ents 2,209,330, 2,209,331 and 2,209,332, French publicatio ⁿ 2.589.607, Japanese publication 52-50794 and German publication DE.3738708.A1. (Each of these patents and publications and any other patents, applications or publications mentioned anywhere in this dis¬ closure are hereby incorporated by reference in their entireties.) Many of these patents or publications disclose machines which incor¬ porate microwave ovens for heating food items, and many disclose means for pushing the ready food items out an access tunnel to a posi¬ tion accessible to the customer.

One known pizza vending machine has been available from the American Pizza Company, a corporation of Nevada. See Italian Patent No. 59465.B/86, which issued October 29, 1986. This machine

allows the pizza toppings to be selected by the customer, placed on a fresh crust and baked in an infrared oven for three minutes or so. Maintenance of this machine is labor intensive, however, as it must be cleaned frequently and fresh ingredients added daily.

Referring to the May 13, 1991 edition of The Wall Street Jour¬ nal at page Bl, Cafe Quick Enterprises, Inc. of Irving Texas has apparently developed and placed orders on a device that cooks up french fries, pizza and chicken. Their machine reportedly thaws the interior of the food with microwaves, then blasts it with hot air jets, which leaves it "greaselessly" cooked in about a minute.

Another relatively recent pizza vending machine is that avail¬ able from Nouveau Vend International, Inc. of Palm, Pennsylvania and Nouveau Foods, International, Inc. of Spring City, Pennsylvania, under the mark PIZZA CHEF. See e.g., the January 14, 1991 edition of The Washington Post at page 6 of the Business Supplement. This vending machine has a large cylinder positioned in a freezer, and the cylinder in turn has round chambers into which small round pizza boxes are inserted. A selector button allows the cylinder to be rotated to align the desired stack with the opening. The boxed pizza, from the desired stack and passing out the opening, is then directed into a conventional microwave oven, cooked therein and pushed out to the customer. Unfortunately, this machine has a number of moving parts inside of the freezer, and because of differences in thermal expansion and con¬ traction rates of the metals of the machine parts, the machine appears susceptible to jamming. Loading this machine is also diffi¬ cult. The cylinder or canister mechanism has to be tilted forward, loaded with approximately one hundred and twenty to one hundred and fifty pounds of pizzas and then tilted baek up and pushed back in. This is a difficult maneuver requiring more strength than many opera¬ tors have. A further problem is that this machine uses round boxes which are expensive to make, difficult to load with pizzas and diffi¬ cult to cover with their round lids.

When frozen pizza or other similar food products are to be stored in a freezer and then heated in a microwave oven or the like while still in their carton, the construction of the cartons must be carefully chosen. The cartons first must be properly sealed and closed

to protect the pizza or other item during transportation and storage, and while in the freezer. On the other hand, the cartons should pref¬ erably allow for venting of steam therefrom both while in the oven and immediately after removal therefrom. The pizza, especially if it is frozen, contains a considerable amount of moisture. That moisture, under the rapid heating of a microwave oven, turns into steam vapor. If the vapor remains trapped in the carton it not only can cause the pizza to become moist and soggy but will also cause the carton or box to swell, which can cause the vending machine to jam. It is thus important to be able to easily and quickly form a steam vent in the carton after it has been removed from the freezer and before activat¬ ing the oven. This vent should be formed with minimal disturbance to the pizza or other frozen food content in the box. The vent will also be formed so as to be positionable in a securely opened position with little likelihood that it will accidentally close. In other words, the box must be constructed and designed so that the vent can be easily formed and easily manipulated later to an open position. Examples of cartons used for heating food products therein are disclosed in U.S. Patents 3,876,131 (Re. 29,185), 4,096,948, 4,260,060, 4,355,757 and 4,505,391. Containers which require a ventilating structure for venti¬ lating the contents thereof are also known for shipping other products such as cut flowers and the like. Examples of such shipping contain¬ ers are shown in U.S. Patents 4,176,745, 4,163,494, 4,331,235 and 4,339,036, and U.S. Patent 3,101,652 shows a prior art folded box construction.

As previously mentioned, a problem with at least one of the know machines is that the equipment used to remove the boxed pizza from the freezer can jam. An improved removal system having few movable components is thus desirable. U.S. Patent 3,819,087 shows a rather complicated apparatus for dispensing packages of cigarettes. Each stack of packs has its own T-shaped ejector for propelling the bottom item from the stack to the delivery port. The ejectors move on a carriage between rows within a stack. The ejector carriage is positioned under the row of stacks from which a selection is to be made, the ejector for the selected column is raised by a solenoid, and the array of ejectors is advanced to move the selected item forward

where it is dropped under force of gravity down to the delivery port. Other U.S. patents which are concerned with ejectors, dispensers and/ or vending machine handling equipment include 2,312,502, 2,946,482, 3,319,822 and 3,495,738.

The present invention further relates to systems for transport¬ ing boxed items controllably along three orthogonal axis within vend¬ ing machines. Examples of positioning or manipulating assemblies for manipulating work or tables are known. However, no system is known which positively controls in three dimensions the positioning of boxes within a vending machine, and particularly pizza boxes with respect to vending machine ovens. Examples of positioning tables in other environments are shown in U.S. Patents 3,124,018, 4,317,560, 4,378,709 and 4,672,859.

The present invention also is concerned with microwave oven designs, and particularly those adapted for heating pizzas or other flat food items and/or those used in vending machines. Many microwave oven designs are known and examples thereof shown in the U.S. patent art are discussed below. U.S. Patent 3,461,260 shows an oven design having nipple-like projections or protrusions on the interior oven wall faces which reflect, redistribute or disperse the microwave energy within the oven; the material to be heated in this oven is inserted on racks. U.S. Patent 3,965,325 shows a microwave oven using reflecting surfaces and a stirrer fan in the oven to distribute the microwave energy within the oven. U.S. Patent 4,831,224 shows a food container for microwave ovens incorporating reflective struc¬ ture in the container itself; the container includes a stepped platform to raise the material to be heated above the bottom of the container. U.S. Patent 4,833,285 ('285) discloses a high frequency cooking device including a waveguide having reflecting domes on the ceiling thereof. U.S. Patent 4,967,050, similar to the *285 patent, shows a microwave oven with a waveguide and a single reflecting dome in the ceiling of that waveguide. None of the ovens disclosed in these patents can efficiently and quickly heat pizzas or other similar flat targets. Flat targets such as pizzas tend to heat unevenly with the outer portions heating sooner and with the middle often not being heated sufficiently

or if heated sufficiently then the outer crust being heated to too great an extent or the heating process being inefficient. SUMMARY OF THE INVENTION

Accordingly, it is a principal object of the present invention to provide an improved apparatus for removing a single box from a stack of boxes in a vending machine freezer.

Another object is to provide an improved microwave heating and vending machine for frozen pizzas or the like. This machine can handle square boxes of pizza, has few, if any, relative moving parts in the freezer unit thereof, is unlikely to jam, quickly and efficiently cooks the pizzas and delivers them accessible to the customer, and is less susceptible to mischief and/or damage.

Directed to achieving these objects, an improved frozen pizza microwave heating and vending machine is herein disclosed. This machine includes within its cabinet walls a freezer unit, for storing a plurality - ^~ stacks of boxes of precooked frozen pizzas at approxi¬ mately five degrees Fahrenheit, and a microwave oven, for subse¬ quently cooking or heating these pizzas. The floor area of the oven is movable towards and away from the oven bottom opening by a three-dimensional mechanical transporter to which it is affixed. The transporter inserts the oven floor into the freezer unit where it retrieves the bottom box from the desired stack, removes the box from the freezer unit, positions it beneath the microwave oven and moves 't up so that the floor is sealed tight in the bottom opening of the microwave oven. After the pizza has been cooked in the micro¬ wave oven, the floor with the cooked pizza box thereon is moved towards a delivery opening of the machine and then is pushed by a motorized paddle through an access tunnel to the customer. When the oven is hooked up to a two hundred and twenty volt service, the pizza is cooked from frozen to serving hot in only about thirty seconds, and the entire cooking and vending operation takes less than a minute.

In other words, a vending machine having a freezer unit wherein at least first and second stacks of different types of packaged frozen foods, such as boxed frozen pizzas, are stored is herein pro¬ vided. The floor of the machine's microwave oven is mounted on a three-dimensional transporter. The floor is thereby controllably

movable into the freezer to retrieve the bottom box of pizza from the desired stack, position the box in the oven with the floor in a sealed tight arrangement with the oven bottom opening, and thereafter move the box with the heated pizza therein to a delivery position. A motorized paddle pushes the box from the delivery position out an access tunnel to the customer. Vertical movement of the floor, and thus the boxes, is not by gravity but by the transporter. This provides not only continuous positive control of the product but also flexibility in positioning, in three dimensions, of the components within the machine. The cooling compartment (refrigerator or freezer) thus need not be positioned higher than the oven which in turn need not be positioned higher than the delivery slot. This flexibility allows for taller pizza stacks (that is, more product stored in the vending machine) while still delivering the pizza to the customer at an acceptable height above the floor. The transporter maintains the box level and without rotation which could dislodge the pizza topping.

The frozen pizza, while in its box or carton, is thus loaded, stored, transported, heated and delivered to the customer. The cus¬ tomer can, by tearing open the top panel, eat the cooked pizza directly from the carton, if he so desires. This carton preferably has cooperating flaps on its top wall which normally close a carton top "opening" to prevent contamination of the frozen pizza during trans¬ port and storage of the boxed pizza, including while in the freezer. After the pizza box has been removed from the freezer and before being inserted in the oven, the box or carton is raised so that a fixed punch engages the flaps. (Alternatively, the carton can remain sta¬ tionary and the punch moved to engage it or they can both move together towards one another.)

The top flap or tab is formed on the carton top wall by perfora¬ tions or cuts along three of its sides and a fold line on its fourth. The bottom flap is hinged in the carton interior in a normal position cov¬ ering the cuts of the top tab and directly beneath the top tab. When the punch engages and pushes down on the top tab, it pushes the top flap down along its fold line, thereby forming the opening in the car¬ ton top wall. The top tab pushes against the bottom flap until they are both wedged securely against one another and preferably also

against the carton bottom wall. Steam emanating from the heated pizza can thereby vent out the opening. The carton is preferably con¬ figured and the steam vent positioned with respect thereto such that the flaps (flap and tab) and the punch never contact the pizza or other similarly shaped food item therein.

In other words, a box or carton for shipping, storing and micro¬ wave heating therein frozen pizzas or the like is also herein provided. A punch down tab is formed on the carton top panel and a flap is hinged in the carton directly beneath the tab. After the carton con¬ taining a frozen precooked pizza or the like has been removed from the freezer, a punch is pushed down on the tab or the carton is pushed up against a punch thereby punching the hinged tab down. The tab pushes against the flap so that both of them become securely wedged against each other, or against each other and the carton bottom wall. / steam vent in the top of the carton is thereby formed. Steam from the frozen pizza, when it is microwave or otherwise heated, can escape from the carton out this vent. This carton with its punch down steam vent construction can be used for items other than frozen pizzas. The items need not be frozen or even chilled, however, or even be food items. The carton need not be used in a vending machine or other environment where an automatic or mechanical punch is employed. In fact, the vent can be manually opened as with the handle end of a fork or similar kitchen utensil. Thus, the carton can be used in commercial or residential kitchens where the cook removes the carton from the refrigerator or freezer, punches the vent open and places the carton in the microwave or other oven. No protective wrap for the carton may even be needed. With a tear open top the cooked pizza or other item can be consumed directly from box without dirtying any dishes, making it ideal for quick snacks or those living alone.

Other objects and advantages of the present invention will become more apparent to those persons having ordinary skill in the art to which the present invention pertains from the foregoing description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a front elevational view of a machine of the present invention with the door thereof in the closed position.

Figure 2 is a perspective view of the machine of Figure 1 with the door in an open position and illustrating a relative positioning of the machine parts.

Figure 3 is a left side elevational view of the internal compo¬ nents of the machine of Figure 1 and illustrating the delivery tunnel thereof.

Figure 4 is a front elevational view showing the layout of the components of the machine of Figure 1.

Figure 5 is a perspective view of the three-axis transporter of the machine of Figure 1 and shown in isolation.

Figure 6 is an enlarged elevational view showing a pizza box of the present invention being mechanically and automatically retrieved from the freezer of the machine of Figure 1.

Figure 7 is a top plan view of a first unpunched pizza box of the present invention and for use in the machine of Figure 1.

Figure 8 is a side view of the box of Figure 7 after having been punched.

Figure 9 is a plan view of a (paperboard) blank used to form a second pizza box or carton of the present invention.

Figure 10 is a perspective view of the blank of Figure 9 shown partially assembled into the box or carton and in an unpunched condition.

Figure 11 is a perspective view of a corner of the assembled carton of Figure 10 showing the punch opening or forming the steam vent.

Figure 12 is a view similar to that of Figure 11 showing the vent in a punched and wedged open position.

Figure 13 is a perspective view of the carton of Figure 10 after the vent has been punched open and the pizza therein cooked in the vending machine microwave oven, and illustrating the carton top being torn away to provide access to the heated pizza therein.

Figure 14 is a perspective view showing in isolation an alterna¬ tive floor assembly of the present invention.

Figure 15 is a perspective view of the floor assembly of Figure 14 shown positioned for removing the bottom box from a stack of boxes in the freezer of a vending machine of the present invention.

Figure 16 is a cross-sectional view through the bottom portion of the microwave oven of Figure(s) 1 (or 21 or 22) showing a variation of the floor assembly of Figure 14 in an inserted position in the bot¬ tom opening of the oven and with a pizza box supported thereon.

Figure 17 is a perspective view of a three axis transporter of the present invention shown in isolation, and being an alternative to that of Figure 5.

Figure 18 is a side elevational view taken on circle 18 of Figure 17.

Figure 19 is a view similar to Figure 2 illustrating therein the floor assembly of Figure 14 and the three axis transporter of Figure 17.

Figure 20 is a view similar to Figure 4 illustrating therein, sim¬ ilar to Figure 19, the floor assembly of Figure 14 and the three axis transporter of Figure 17.

Figure 21 is a cross-sectional view of a first alternative micro¬ wave oven of the present invention for use in the machine of Figure 1.

Figure 22 is a cross-sectional view of a second alternative microwave oven of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, there is illustrated therein generally at 30 a microwave heating and vending machine of the present inven¬ tion. Although it is especially adapted for handling cartons or boxes 32 of prepared frozen pizzas, other types of frozen prepared foods items as would be apparent to those skilled in the art can be used. Examples of such other heatable and deliverable products are lasagnas, other pastas, fajitas and "TV dinners". The machine 30 includes a sturdy box-like housing 34 supported on four legs 36 approximately six inches above the support surface or floor and with an open front which can be closed when the door 36 hinged thereto is shut and locked. All of the components of the machine 30 are thereby protectively enclosed within this housing 34.

Figures 2-4 and 6 illustrate schematically the layout of the various machine components within the housing 34. It is seen in Fig¬ ure 2 that the machine 30 includes a freezer chamber 40 enclosing therewithin stacking rails 42 for four stacks 44, 46, 48, 50 of pizza boxes in a square relation and with the outer two stacks 48, 50 extending a distance further down than the inward two stacks 44, 46. The pizza stacks can be slid forward generally out the housing 34 with the door open for restocking, through their open tops, with approxi¬ mately two hundred and forty boxes of pizza. The filtration and cool¬ ing evaporator for the freezer unit 40 is shown at the bottom of the stack to the left at 54, and the condenser and compressor assembly is shown to the right at 56. A novel microwave oven construction 60 is positioned about midway up the left hand wall and has an open bot¬ tom. The oven 60 is preferably ten inches wide and long and six to ten inches high. The oven floor assembly 64 (as shown for example in Figure 4) is then movable by a robotic three-axis transporter as shown generally at 66 controllably within the machine housing 34, and as shown in isolation in Figure 5.

All machine actions, such as movement of the oven floor assembly 64 via the transporter 66, varying of cooking times (to adjust for different voltage levels), product selection, coinage control, and maintenance diagnostic and telemetry are controlled from a central computer control shown in the upper left hand corner of Figure 2. The controller 68 though depicted as being larger will preferably be only the size of a routine small computer card. The program of the controller 68 monitors the line voltage so that the cooking times are adjusted dependent upon the available energy. A transformer power unit 70 (Figure 2) for the machine is positioned beneath the computer control. The boxed pizza 32, after it has been cooked in the oven 60, is moved away from it on the oven floor assembly 64 and then pushed out by a motorized paddle 72 (Figure 3) accessible to the customer through the tunnel 74 which communicates with the opening 76 in the door 36, as shown in Figures 1 and 2.

Referring to Figure 1, the solid steel front machine door 36 is shown having centrally disposed thereon a brick oven shaped cutout 78 for advertising and/or explanatory graphics or the like. It is

anticipated that lighting (not shown) would be provided around the perimeter of the cutout 78 both for ornamentation and for ease of reading the graphics therewithin. At the top left of the door 36 is the dollar bill acceptor 80, and the units directly below are the select buttons 82, 84 for selecting the different desired pizza type, such as cheese or pepperoni. Generally on the left and below the cutout 78 is the slot 76 out through which the boxed cooked pizzas 32 are deliv¬ ered by the paddle 72. The coin handler 86 is positioned at the top, at the right of the cutout area 78, and the lock 88 for opening the machine, servicing it and subsequently relocking it is directly therebeneath. The double square at the bottom right is the customer coin return 90.

The four stacks of pizzas 44, 46, 48, 50 can be independently targeted to serve one kind of pizza or another; by setting a switch, the controller 68 is advised which kind of pizza is in each stack. For example, two of the stacks can be cheese pizzas and the other two pepperoni, or three can be pepperoni and one cheese. As previously mentioned, the leftmost stacks 44, 46 are shorter than (or raised higher than) the rightmost stacks 48, 50 since pizzas are removed from the bottom of the freezer unit 40 and the small offset 94 thereby defined allows for the (boxed) pizzas to be removed from the bottom of both the left and right stacks. Knock down, spring loaded doors 95 (Figure 6) are provided at the bottom inside corners of each of the stacks. The oven floor 64, when its movement is so directed by the controller 68, is moved by the transporter 66 in through the door 95 to retrieve the bottom box of pizza from the proper stack. The oven floor 68 has a small fence 96 along its forwardmost (rightmost) edge which is raised up behind the bottom pizza box and drags the box off the bottom of the stack (44, 46, 48 or 50) as the oven floor 64 is moved inward or to the left.

A three-quarter inch thick plastic shelf 98, on which the pizza box 32 sits and which is invisible to microwave radiation, and a steel plug 99, which on sealing presents an even floor surface thus tuning the oven cavity and acting to entrap microwave radiation, are mounted on top of the oven floor. Floor member 100 is about eight and a half inches square. Between the member 100 and the plastic

spacer 98 are the radiation seal and the oven floor. The metal plug 99 in the oven floor cutout allows the oven floor 100 to be seen by the oven magnetron 62 as a flat surface and as not having any indenta¬ tions. The plug 99 is essentially twice as thick as the oven floor — one thickness allows for it to be presented as a flat floor and the other allows for space for the radiation seal. Thus, any radiation try¬ ing to escape from the oven 60 must make two right angle turns. The pizza thereon appears, to the magnetron 62 of the oven 60, to be sus¬ pended three-quarters of an inch off of the oven floor 99. Referring to Figure 4, the magnetron 62 is seen to comprise a cooling fin assem¬ bly block 62a on the oven, a smaller penthouse rectangle 62b extend¬ ing down into the interior of the oven, a three-quarter inch magnetron dome 62c. Thus, the plastic spacer 98 raises the boxed pizza up off the metal floor portion 100 (Figure 6) so that the micro¬ wave energy sees it better and reduces the likelihood of hot spots being produced. The plastic spacer 98 comprises a polycarbonate slab that has been milled to have a small back or fence 96 to it, which then positions the boxed pizza approximately three-quarter inch off of the metal oven floor plug 99. The block has the one-half inch high fence 96 in back and one-quarter inch fences on two sides thereof.

The movement of the pizza box 32 thus is that it is first pulled out of the freezer 40 and moved back until it is lined up side-by-side as viewed from the front of the machine 30, then it is moved back until it is positioned under the steam vent punch pin 61 mounted in front of the oven 60. It is then raised up to punch the self -locking steam box vent in the pizza box 32, as will be explained in detail later. It is then moved down and back, and then raised up into the oven 60. When in position in the oven floor opening, the floor is sealed by a wire mesh type of seal relative to the oven 60 to prevent the microwave energy from escaping from the oven. After the boxed pizza has been cooked, the oven floor 64 is lowered, moved toward the front of the machine 30 and raised to a delivery position. At the delivery position the boxed pizza is pushed by the motorized rotary paddle 72 out through the tunnel 74 and accessible to the customer through slot opening 76.

The paddle 72 pushes the pizza box 32 entirely through the tunnel 74 so the rear door 104 (Figure 3) thereof closes before the front door 106 opens. This denies the customer and other unautho¬ rized persons access to the interior of the machine 30. In other words, the paddle 72 pushes the box 32 clear of the back door 104 before it opens the front door 106, and then the paddle is withdrawn, the back door closes and the customer pulls the box from the machine 30. When the box 32 is clear of the front door 106, the front door closes. Even if the front door 106 is jammed open, the back door 104 would be closed, thereby denying the customer or other unauthorized persons access to the interior of the machine 30. The box 32, with the heated pizza therein and when in a delivery position, extends out of the machine 30 a couple of inches, readily accessible to the cus¬ tomer, who then never has to penetrate the machine, not even with his finger tips.

Figure 4 illustrates the door mechanisms for retrieving the pizza boxes 32 out of the stacks 44, 46, 48, 50. The outside edges of the stacks are shown by the four vertical rectangles which represent four angled rails 42. The pizza boxes 32 are loaded from the top of these rails 42, as previously mentioned. The oven floor assembly 64 is illustrated in Figure 4 in position to retrieve the bottom box of pizza from a rightmost stack 50. The oven floor assembly 64 comprises the thin horizontal wide steel member 100, the steel plug 99, and the polycarbonate shelf 98 with the fence 96 in the back or on the right of Figure 4. The pizza boxes 32 are held only at their corners by the bent rails 42, and the areas between the corners are generally clear or open. The floor 64 is pushed into the freezer 40 and then it raises up about a one-half inch so that the bo*tom of the pizza stack assembly is in contact with the shelf 98 and the fence 96 is immediately behind the bottom pizza box. The fence 96 works between the rails 42 hold¬ ing up the edges of the box 32 and slides one of them, and only one of them, out and onto the shelf 98.

As soon as the box 32 has been withdrawn from the freezer 40, it is moved all the way over (to the left-hand side of Figure 4), so that it is even with the microwave oven 60, as seen in Figure 4, directly in the left to right sense under the oven. The oven floor assembly 64 is

then moved back (into the page of Figure 4) until it is positioned below the bottom opening 62 of the oven 60. It then travels up thereby placing the boxed pizza (32) in the oven 60 and sealing the bottom of the oven with a radio frequency (R.F.) seal. The bottom of the oven 60 is thereby sealed against radiation leakage and the boxed pizza is enclosed within the oven. The two thousand watt magnetron 62 is actuated, and the pizza is heated.

The magnetron 62 is positioned in the top eorner of the oven 60 and extends down with dome 62c through the oven ceiling into the interior of the oven. The magnetron 62 located in the corner of the roof or ceiling of the oven 60 is oriented with respect to the pizza so that the pizza cooks uniformly. No waveguide as is typically provided in a conventional microwave oven is thus needed with this design. To further improve the heating efficiency, the geometry of the inside of the oven 60 can be adjusted, reflectors added, the location of the magnetron or the pizza altered as would be apparent to those skilled in the art from this disclosure.

The preferred power supply for the oven 60 is a two hundred and twenty volt service which can heat the pizzas in thirty seconds or less. If a thirty amp, one hundred and ten volt service is used then the pizza is cooked in forty-five to fifty seconds. A typical wall power supply of one hundred and ten volts and twenty amps requires about one and a half minutes to cook the pizza. The length of time to cook the pizza is directly related to the amount of energy provided to the magnetron 62. The microwave oven 60, since it is cooking pre¬ cisely the same item (a seven inch diameter pizza which is approxi¬ mately 0.650 inch high) each time, can be advantageously precisely tuned. These pizzas have been fully cooked at the bakery, boxed and frozen, and thus all the microwave oven 60 is doing is warming them up, that is, bringing them to a hot consumption temperature.

The doors 95 to the freezer 40 are spring loaded, knock down doors hinged by hinges 112 at the bottoms thereof and which are pushed open when the oven floor assembly 64 is inserted into the freezer 40 and which spring shut after the oven floor and pizza box 32 thereon have been removed from it. The freezer 40 is surrounded by insulation 114. The oven floor assembly 64 is secured to upper

member 122 by glue and/or screws. The assembly portion 120 of the transporter 66 — the portion which holds the oven floor assembly 64 — is shaped like a U lying on its side when viewed from the machine front and as can be seen in Figures 4 and 6. In other words, the assembly 120 comprises spaced horizontal upper and lower members 123a, 123b and a left vertical member 126 connecting them. This U shaped configuration allows the oven floor 64 to retrieve pizzas from any of the four stacks 44, 46, 48, 50 including the raised inside ones 44, 46. Thus, the assembly 120 is free to move front and back, left and right, and up and down, that is, in each of the X, Y and Z directions.

The transporter 66, which essentially comprises three linear actuators, is shown in isolation in Figure 5 wherein the three riding rails systems shown generally at 122, 124 and 126 for each of the directions are illustrated. For the up and down movement two rails 122a and 122b are provided since they must carry the weight of the assembly 120 including that of a pizza box 32, the transporter axes 124, 126 and the associated motors 132, 134, 136. The double rail 122 moves the assembly 120 up and down in a Z direction; the X direction extends out of the page; and the Y direction runs along the page. The assembly 120 is mounted on a small four inch block 130 as shown in Figure 5, and the U-shaped assembly opens towards the right hand side of the page. The individual stepper motors 132, 134, 136 move this biock along each of the axes or rails. They thus eliminate the different linkages apparently needed when DC actuator motors are used in most prior art vending machines.

The rectangle in the back with the motor mounted on top and the two rails on the sides move the assembly up and down and are positioned against the left side of the machine. Less than halfway up, the X member is mounted and it runs from the front of the machine ⁺ o the back, that is from left to right; its motor 136 is at the right . ide. The Y direction is positioned towards the right side of the X member, its motor 134 is back against the X member, and it moves the block 130 from the motor end to the floor end where it enters into the backmost freezer. The transporter 66 thus allows the oven floor assembly 64 to be precisely positioned where necessary inside of the

cabinet or housing 34 including covering the oven floor cutout or bot¬ tom opening. In other words, the oven floor assembly 64 can be directed to enter the freezer 40, retrieve a boxed pizza 32, bring it back, up and into the pizza oven 60, and thereafter bring it down and forward to the delivery tunnel 74. To direct the oven floor 64 to the raised left stacks 44, 46 the transporter 66 raises the oven floor above the level needed for the right stacks 45, 50, that is, above step 94.

The construction and operation of both the freezer door 95 and the U-shaped assembly 120 are better depicted in Figure 6. The four inch block 130 that sits on the Y axis is shown and on top of that is mounted the U-shaped assembly 120. The U-shaped assembly 120 travels over and under the lower insulation layer 114 into the freezer 40. As the oven floor assembly 64 is inserted into the freezer 40 it impacts the door 95, which is folded down about hinge 112 into the area provided by the insulation cutoff triangle shown at 140 (Figure 6). The door 110 is illustrated in the down or open position in Figure 6. As the U-shaped assembly 120 with the oven floor 64 secured thereon is pushed further into the freezer 40 (or to the right of Figure 6) and the small fence 96 is clear of the stacked pizza boxes, the U-shaped assembly 120 raises up about one-half inch thereby position¬ ing the fence behind the boxes. The boxes 32 are each about three- quarters inch thick or high, and the bottom half inch of the box will thus then have the fence 96 behind it. The U-shaped assembly 120 is then withdrawn from the freezer 40, or to the left of Figure 6, and when it clears the door 95, the door is spring biased closed thereby closing the freezer. Thus, there are advantageously no relative mov¬ ing parts of the U-shaped assembly 120 inside of the freezer 40 and the oven floor assembly 64 can be positioned within two ten-thousands of an inch of the desired location. As can be appreciated, this is con¬ siderably greater accuracy than is needed.

To prevent steam from forming in the box 32 as the pizza is being heated in the oven 60 which would thereby soften the pizza and distort the box, a steam vent 148 is punched in the box after it has been removed from the freezer 40 and before it is inserted in the oven 60. Referring to Figure 7, an unpunched vent member 150 is formed in one corner of the box 32 during the box formation. The

member 150 has three of its edges 152 cut and the fourth edge 154 only scored to prevent accidental opening. The front of the box 32 is folded up and glued, and attached to it is a protruding tab 158. It also has a score line 160 and when folded up it is directly under the cutout. When the member 150 is punched from the top, the cut 152 on the three sides opens downward until it catches in the score 160 whereby it locks itself, thereby forming the self-locking steam vent 148, as shown in Figure 7. Thus, immediately before the boxed pizza 32 enters the oven 60, the oven floor assembly 64 moves over under the puncher 61 (the small nipple member under the oven) and raises up, punches the vent member 150, travels down and then travels under and into the oven as shown by the arrows in Figure 4. The score 160 on the bottom flap 158 thus effects the locking action by engaging the forward edge of the top flap member 150.

Figures 9-13 illustrate generally at 180 an alternative preferred pizza box or heat-in carton of the present invention. This carton 180 is illustrated in a laid flat orientation in Figure 9, and comprises a blank 182 formed of paperboard or other material suitable for con¬ taining a frozen food item in the freezer 40 and for containing it as it is heated subsequently in the microwave oven 60. The blank 182 com¬ prises essentially a continuous sheet of paperboard cut, scored and perforated as shown and with an adhesive layer or glue strip 186 along the end panel 188 as shown on the right side of Figure 9. The blank 182 is formed with fold lines 190, 191, 192, 193, 194, 195, 196 and 197 to define top and bottom panels 200, 202, side panels 203, 204, 205 and 206 and closure tabs 208, 210, 212 and 214. The blank 182 is folded in a conventional manner to form a rectangular box as shown in Figure 10 with the panels 216 and 218 folding up underneath into the interior 219 of the carton 180 and the panel 203 folding on and adhering to the adhesive layer 186.

Referring to Figure 9, it is seen that a flap 220 is formed hinged along line 221 to the end wall 188 and extending out there¬ from. Similarly, a tab 222 is formed on the top panel 200 with through-cuts along three sides 224, 226, 228 and a fold line 230 along the fourth. Fold line 230 is a half-cut line, cut half way through the top of the top panel 200. A pair of perforations are provided on side

226 (the side opposite to the fold line 230) to prevent accidental open¬ ing of the tab 222. When the carton 180 is assembled as shown in Fig¬ ure 10 the flap 220 is directly underneath and generally against the tab 222 as can be understood from Figure 11. With the pizza or other food item in the assembled carton 180 and the ends and sides securely closed, the pizza 223 (Figure 13) is enclosed and protected from con¬ tamination during shipping and storage. The flap 220 provides a sec¬ ondary protection as it covers the cut lines 224, 226, 228 of the tab 222.

After the box 180 containing a frozen pizza has been removed from the freezer 40 on the oven floor assembly 64, it is brought up so that the punch 61 punches down and impacts the tab 222, as best shown in Figure 11. The tab 222 and thereby the flap 220 are forced downward and wedged against not only each other but also the bottom panel 202 as shown in Figure 12. When the plunger 61 is pushed down onto the top panel, the hinges of the tab 222 and flap 220 work at opposing angles (are positioned at right angles) and wedge each other open. There is with this design little if any chance that the steam vent shown generally at 234 thereby formed will accidentally close during the operation of the vending machine. Since fold line 230 is a half-cut line and adjacent (lower) paperboard fibers are ruptured dur¬ ing the punching procedure, the punched tab 222 advantageously has little, if any, "springiness" urging it to close back up. Additionally, by positioning the steam vent 234 in a corner of the square top panel of the carton 180 none of the tab 222, flap 220 or plunger 61 ever con¬ tacts the round pizza 223.

With the steam vent 234 open, the pizza containing carton 180 is inserted in the microwave oven 60, microwave heated, removed from the oven and delivered to the customer, as previously described. The steam formed in the carton 180 from the heated frozen pizza 223 can then efficiently vent out through the steam vent 234 preventing the pizza 223 from becoming soggy and the carton from becoming distorted as the expanding steam thereby created attempts to escape. After the pizza 223 has been heated and delivered in the carton 180 to the customer, the customer can easily access and remove the pizza by tearing up on the tear tab 240, in a motion as shown in Figure 13 and

tearing along the tear lines, weakened portions or double cut lines 242, 244 of the top panel. Double cut lines are preferred over perfo¬ rations, since contaminants may be able to enter the carton through perforations. The customer if he so chooses can conveniently con¬ sume the cooked pizza 223 directly from the carton 180. This carton has uses aside from those in vending machines as would be appreci¬ ated by those skilled in the art. For example, the vent can be manu¬ ally punched open with generally any punch tool. The cook in a resi¬ dential or commercial setting can manually remove the carton from a reezer, punch the vent open and insert the carton into an oven, such as a countertop microwave oven.

An alternative floor-fence assembly of the invention, which can be used in lieu of the oven floor assembly 64, is illustrated in Fig¬ ures 14 and 15 generally at 280. Assembly 280 includes a metal floor 282, a metal plug 284, a polycarbonate slab or plate 286 and a T-shaped fence 288 secured at one end of the floor or slab by non- metallic screws 290. The previously-described fence 96 is basically rectangular in shape which limits the length of the bottom lips or flanges 294, 296 (Figure 15) of the pizza stack support rails. T-shaped fence 288, on the other hand, allows for the lips 294, 296 to be made longer, as shown in Figure 15, and thus to better support the stack of pizza boxes 298. T-shaped fence 288 does not work entirely in the gap 300 formed between the end of the lips 294, 296, rather the top (horizontal) extension part 302 of the T pulls (or pushes) the bottom box 304 from the stack 298 and passes over the lips 294, 296. The shaft 306 of the fence 288 works between the lips 294, 296 in the gap 300. The T shape thus enables the gap 300 to be made narrower, the flanges 294, 296 extended and the box stack 298 thereby better sup¬ ported. Furthermore, the pulling force exerted on the box 304 by the fence 288 is directed more toward the reinforced edge of the box. The assembly 280 thus moves from outside the freezer to the selected stack, drags the bottommost box 304 off the stack 298, moves outside the freezer where the steam vent is punch formed, moves up to form the oven floor, and moves to the delivery port where the box (180) is pushed off of the slab 286 (from the right side of Figure 14) through the delivery chute to the customer. No movement of the box relies

solely on gravity. Although a second fence at the opposite end of the slab 286 and facing fence 288 can be provided, it is not needed, since the slab is maintained stable and level throughout its transit. It is also within the scope of this invention to form grooves on the top of the slab 286 to provide for moisture drainage.

Figure 16 shows a cross-section of the floor assembly 280 in the oven floor opening or cutout. The floor can be provided with upturned flanges 310, 312 to effect a more secure fit with the oven sides and provide an extra ninety degree bend around which radiation must negotiate to escape from the oven. Seal 314 comprising a wire mesh with a silicone center extends around the bottom of the oven to prevent microwave leakage. These seals though can fatigue fail and the adhesive becomes unstuck. Thus, an alternative seal comprises a ferrite strip or choke 316 positioned around the bottom sides of the oven at the flanges and as shown in Figure 16 and/or at the bottom surface where the mesh seal is shown.

A transport system such as shown in Figure 5 or in Figure 17 generally at 320 transports the pizza box in an XYZ orthogonal sys¬ tem. The floor assembly (280) is held on a trolley 322 which moves on the X axis, along the arm 324 extending out to the right in Figure 17. The X axis is movable along the vertical Z axis, and the X and Z axis together with the trolley 322 are movable along the Y axis, which extends from the lower left to the upper right as can be seen in Fig¬ ure 17. These three axes move independently as in the embodiment of Figure 5. The longest or heaviest axis, the Y axis, is fixed to a back plate 330 of the vending machine cabinet, in the Figure 17 embodi¬ ment. This reduces the driving motor loads as it does not have to move; there is no need for a separate Y axis frame in other words. Further, this back panel 330 can be removed by simply loosening the screws 332, which allows the transporter 320 to be conveniently removed on the vending machine cabinet plate for installation, ser¬ vicing or replacement. Separate stepper motors 336, 338, 340 drive their respective drive screws 342 (X axis), 344 (Z axis), 346 (Y axis) and thereby cause movement along the axes. A fourth motor then drives the pusher paddle 72.

The oven 60 of Figures 3 and 4 heats the pizza relatively quickly and uniformly. The magnetron antenna (62c) extends down through the ceiling of the oven into the oven interior, and the micro¬ wave radiation emanates radially out from the antenna — some directly to the pizza (223) below it but most of the energy indirectly, dispersing and reflecting off of the walls to the pizza. The energy thereby to becoming more homogenous before it impacts the pizza and also tending to heat the edges of the pizza to a greater extent than the center thereof. In contrast, the oven designs shown gener¬ ally at 360 and 362 in Figures 21 and 22 more efficiently and quickly heat the pizzas and esDecially the centers thereof as explained below.

Both of these oven designs include a launcher or waveguide 364, 366 extending through the ceiling 368, 370 of the microwave oven down a distance into the oven cavity, 372, 374. The magnetrons 376, 378 of . both are mounted to the sides of their respective waveguides 364, 366, external to the oven cavity with their antennas 380, 382 extending perpendicularly into the waveguides such that the microwave energy emanating radially from the antennas is directed efficiently along the length of the waveguide. The magnetrons 376, 378 can be off-the-shelf components, such as the Richardson Elec¬ tronic 1950 Watt Magnetron Model No. NL10250. The boxed pizzas are supported on the bottom plate 384, 386 of the oven floor, and the waveguides 364, 366 are directed to the centers of the pizzas 390, 392, thereby directing and focusing the energy at the center of the frozen pizza where it is needed the most. Reflectors are provided in both designs to reflect the microwave energy passing through the centers of the pizzas, and not thereby initially absorbed, to the outer portions of the pizzas or pizza crusts.

There are significant differences between these two designs, however. The oven 360 of Figure 21 has its waveguide 364 vertically disposed and centered above the pizza 390. The microwave energy passing through the p za and thereby not absorbed by it is then reflected off of a spheueal dome reflector 396 positioned below the pizza and below the bottom support plate for the pizza and up through the bottom of the pizza to the edges thereof. In other words, in the oven 360, the waveguide 364 directs the energy through the middle of

the pizza where the dome 396 reflects the unabsorbed energy to the outside of the pizza. Since the perimeter of the pizza tends to heat more readily than the center, this reflection strategy works well for pizzas or other flat targets. It would be less effective, however, for lumpier targets. The oven 360 being easier to fabricate is preferred over the oven 362 of Figure 22.

The oven 362 has its waveguide 366 mounted in a top corner and directed at angle towards the center of the pizza 392 resting on the oven bottom plate. Those microwaves not absorbed by the pizza and thereby passing through the center of the pizza are reflected off the bottom plate at an angle towards the opposite wall 398 and off of a number of reflective surfaces including reflectors 400, 402 and 404 as well as the sidewall 398 and the ceiling 370 and back down to the pizza 392 and particularly to the edges thereof. That is, the edges of the pizza 392 in this oven 362 are heated primarily from waves reflected down to it while those in the oven 360 of Figure 21 are heated by waves reflected up to it. The bottom plate 384 of Figure 21 differs from the bottom plate 388 of Figure 22 in that with the excep¬ tion of the reflector it is fabricated of polycarbonate or other mate¬ rial invisible to microwave radiation so that the waves can pass through it. The bottom plates of both are made of stainless steel or sheet metal and painted with enamel to keep them from rusting.

That is, with both ovens 360, 362 the microwave energy is directed through a waveguide 364, 366 to the center of the pizza and the radiation that is not absorbed by the center, which is significant, is dispersed and reflected to the outside. With oven 360 the energy is directed straight to the center of the pizza, most of which passes through the center, and is then reflected by a dome reflector 396 underneath up to the edges of the pizza. Oven 362 has a number of reflectors 400, 402, 404 carefully positioned, and the energy is directed at an angle to the pizza center and then it bounces off the reflectors down to the edges of the pizza. Thus, in contrast to the oven of Figures 4 and 5 where the energy is bounced generally ran¬ domly off the walls and becomes more or less homogeneous before it eventually impacts the pizza, the ovens 360, 362 provide more directed and coherent energy.

In summary, the pizzas are pre-prepared, cooked, frozen and boxed. The boxes 32 or 180 are stacked according to pizza type in separate stacks in the vending machine freezer 40. A three-axis movement mechanism or transporter 66 or 320, with the oven floor assembly 64 or 280 of the microwave oven 60 or 360 or 362 secured thereto, enters the freezer 40 through door 95, extracts the bottom pizza box 32 or 180 from the desired stack 44, 46, 48 or 50 and accu¬ rately positions the oven floor assembly 64 or 280 in a sealed tight relation in the bottom opening of the oven with the box on the oven floor assembly and in the oven, and after the steam vent 148 or 234 has been punched open. No relative moving parts of the mechanism 66 enter the freezer 40. The pizza 223, 390 or 392 is then rapidly, accurately and consistently heated in the high intensity microwave oven 60, 360 or 362. The oven floor assembly 64 or 280 is thereafter moved down and away from the oven 60 and the box of heated pizza pushed by paddle 72 out a delivery tunnel 74 without customer assis¬ tance or the need for the customer to penetrate the machine 30. All activities of the machine 30 are accurately and reliably controlled, adjusted and monitored from the central computer control 68. The vending machine is extremely quick with a total cycle time of less than a minute possible, and the actual cooking or heating time in the microwave oven is only around thirty seconds. In contrast, a known vending machine using an infrared oven (which is slower than a microwave oven) has a cycle time of around three minutes.

From the foregoing detailed description, it will be evident that there a number of changes, adaptations and modifications of the present invention which come within the province of those skilled in the art. For example, the present vending machine can be adapted to handle heatable and deliverable products other than boxes of pre-prepared frozen pizzas, and/or the boxes or cartons can be used with different food items and/or with different ovens. Of course, if an infrared oven system were used, the food item would need to be removed from the cardboard box before cooking. However, it is intended that all such variations not departing from the spirit of the invention be considered as within the scope thereof is limited solely by claims appended hereto.