CA2153738A1

CA2153738A1 - Microwave heating and vending machine for pizzas or the like

Info

Publication number: CA2153738A1
Application number: CA002153738A
Authority: CA
Inventors: William P. Davis, Jr.; Roland P. Swank
Original assignee: Individual
Current assignee: BUILTRIGHT PRODUCTS (INTERNATIONAL) Inc
Priority date: 1995-07-12
Filing date: 1995-07-12
Publication date: 1997-01-13

Abstract

A vending machine is disclosed which is adapted to house, and then automatically heat and dispense packaged frozen foods, such as boxed frozen pizzas and the like. A
microwave oven is provided within the vending machine to heat the frozen food product. The oven has an open bottom floor, and floor panel which is movable to retrieve food product, insert the retrieved food product into the microwave oven for heating, and then dispense the heated food product to an awaiting consumer. The floor panel and microwave are further constructed so that when food product is inserted in the microwave for heating, the floor panel closes and seals the microwave against radiation leakage without reliance on contact-to-contact seals.

Description

~15~73~
MICROWAVE HEATING AND VENDING MACHINE
FOR PIZZAS OR THE LIKE

SCOPE OF THE lNVh~ l lON
The present invention relates to vending machines having microwave ovens for heating food items, and more particularly and automated vending machine which internally moves food product which is to be heated or cooked, such as a frozen pre-prepared pizza, into the microwave oven for cooking, and then dispenses the heated product to a consumer.

BACKGROUND OF THE lNv~NllON

Vending machines for dispensing various food items are well known, and examples thereof include those shown in U.S. Patents 3,160,255, 4,482,078, 4,513,879, 3,416,429, 3,165,186, 2,890,644, 3,386,550, 3,534,676, 4,389,651, 4,671,425, 4,999,468 and British Patents 2,209,330, 2,209,331, and 2,209,332. Many of the prior patents disclose machines which incorporate microwave ovens for heating the food items, and many also disclose means for pushing the ready food items out an access tunnel where they are accessible to the customer.

One major disadvantage of prior art machines has been that to date, the microwave ovens which are used are overly large, making them particularly unsuitable for use in the confined space of a vending machine. Further, over time and repeated use, the microwave seals and latching mech~nisms on the microwave oven doors deteriorate, leading to leakage of microwave energy and possible health risks. This problem is particularly acute in the case of automatic vending machines which incorporate microwave ovens for cooking, where the microwave oven door may be opened and closed several hundred times each week.

One known pizza vending machine which incorporates a microwave cooking chamber is available from the American Pizza Company, a corporation of Nevada, (see Italian Patent No. 59465.B/86, which issued October 29, 1986 and related U.S.
Patent No. 4,999,468 to Paolo). This machine allows food to be placed on a rotary conveyor and moved through a series of microwave and infrared chambers for cooking. Maintenance of this machine is labour intensive, requiring it to be cleaned frequently and fresh ingredients added daily. Further, the use of the rotary conveyor to move food product through a fixed microwave chamber makes the manufacture and maintenance of effective microwave seals even more difficult.

Another pizza vending machine is available from Nouveau Vend International, Inc. of Palm, Pennsylvania and Nouveau Foods, International, Inc. of Spring City, Pennsylvania, which operate under the trademark PIZZA CHEF.
This vending machine has a large pizza storage 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, aligning the desired stack with an opening. The boxed pizza is then directed into a conventional microwave oven, cooked 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 contraction rates of the metals, the machine often jams. Loading this machine is also difficult as the cylinder or canister me~h~nism must be tilted forward, loaded with between one-hundred and twenty to one-hundred and fifty pounds of pizzas and then tilted back up and pushed back in. This is a difficult manoeuvre requiring more strength than many operators have. A further problem is that this machine uses round boxes which are exr~n-cive to make, difficult and eYp~ncive to seal food product therein, and must be a particular size to fit in the canister mech~niæm.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide an improved microwave oven which permits 23:s3738 repeated opening and closing of the oven door, without deterioration of a microwave seal, and which is particularly suited for extended commercial use, as for example, housed within a food heating and vending machine.

Another object of the invention is to provide a microwave oven having comparatively smaller dimensions so as to be readily installed in a compact space, while not adversely affecting oven operation.

Another object of the invention is to provide a vending machine which houses internally, and then cooks food product in a microwave oven which is effectively sealed during food heating without requiring a conventional metal-to-metal or contact seals between the microwave oven chamber and oven door.

Another object of the invention is to provide a modular product storage rack in a vending machine, which may be easily modified or adjusted to permit the stacking of a number of different sized and/or shaped products.

A further object of the present invention is to provide a vending machine which can handle square boxes of pizza, incorporates a freezer unit having as few moving parts as possible, is less likely to jam, and which quickly and efficiently cooks the pizzas and delivers them so they are accessible to the customer.

In accordance with at least some of the foregoing objects, the present invention provides an improved vending machine for heating and dispensing food products. The vending machine may include within its cabinet walls, a refrigeration or freezer unit for holding a plurality of stacks of boxed or packaged food product, and more preferably boxes of precooked frozen pizzas which are maintained at a temperature of approximately -10C. A microwave oven having a food or oven access opening and movable door is also housed within the machine for cooking or warming the food product.

Preferably the oven access opening is provided in the floor of the oven chamber as an open bottom, with a floor panel of the oven acting as the door and being movable towards and away from the oven access opening by the operation of a mec-h~nical transporter. The oven floor panel is attached to the mech~nical transporter which, in addition to moving the floor panel to open and close the oven access opening, moves the oven floor panel into the freezer unit to retrieve food product from a desired stack; removes the oven floor panel with the food product thereon from the freezer unit to position the food product directly beneath the open bottom of the oven; and raises the floor panel to move the food product up into the oven cavity, so that the floor panel seals the oven access opening to prevent the escape of microwaves.

After the food product has been sufficiently warmed or cooked in the microwave oven, the floor panel may then again be moved, positioning the food product to a delivery opening where it is ejected from the vending machine to a customer. Where cooked pizza is to be dispensed from the vending machine, the pizza is cooked from frozen to serving hot in about sixty seconds, with the entire cooking and vending operation taking about one and a half minutes.

More preferably, the microwave oven is constructed so that the oven door or floor panel effectively seals the oven cooking chamber to prevent microwave leakage, without reliance on a latching mech~nism or a door-to-oven contact seal. The microwave oven is thus constructed having a microwave choke, which by the physical construction of the oven walls and door cuts off the escape of microwaves between the oven door and a remainder of the oven. The choke may preferably incorporate a microwave sink which traps, internally reflects and dissipates microwaves harmlessly.

2~ ~3 73~, The microwave sink may be provided on either the door or the cooking chamber walls, but is most optimally provided about the oven access opening in a portion of the cooking chamber walls and is generally in the form of an elongated chamber which extends about the oven access opening.

If desired additional reflecting surfaces may also be provided to reflect microwave energy within the microwave chamber and increase the efficiency of the microwave heating.
Where the microwave oven has an open bottom, the reflecting surfaces of the microwave choke may be provided on the oven floor panel as an upwardly ex~en~;ng flange which extends inwardly into the oven cavity when the floor panel is positioned to seal the oven access opening. The flange may be constructed to extend as a continuous structure spaced towards a peripheral portion of the floor panel, and which is located a short distance from the microwave sink when the access opening is sealed. The reflecting flange on the floor panel and the microwave sink have a configuration which in operation of the microwave oven, act together as a wave guide to channel microwaves passing therebetween into the microwave sink. This construction thereby effectively completes the microwave seal as a choke to cut off microwave leakage, without the requirement of conventional seals, latching mech~n;~ms or door/microwave chamber contact.

The vending machine may also include as a divider assembly for the food product, removable rack guides which can be adjusted to facilitate dispensing of different sizes of packaged food products. For example, the freezer rack assembly may include a number of removable angle-bars which engage the corners of the packaged food product, and which are secured in place by tabs engaging complimentary sized slots formed in the freezer top and/or freezer bottom. By providing a number of spaced slots, the angle-bars may be repositioned so that different sizes and number of products can easily be accommodated within the freezer.

A modem may also be provided which allows remote monitoring of the vending machine to determine its status.
The modem may be coupled to either a hard wired or cellular telephone line. This feature allows operators to efficiently monitor one or more machines to assess product availability, sales, determine the amount of currency in the machine, and to react to current machine problems. In addition, a call-out feature could be incorporated to alert the operator to mechAn;cal failures or a security breech.

Accordingly in one aspect the present invention resides in a packaged food item heating and vending machine, comprising:
an oven having a floor opening;
an oven floor assembly movable with respect to said floor opening;
refrigeration means for storing at least one stack of refrigerated packaged food items;
access means for defining a customer access opening;
and mechAnical means for moving said oven floor assembly to obtain a package from the stack in said refrigeration means, moving said oven floor assembly with the package thereon to said floor opening and to a sealed arrangement such that the package is in a heating position in said oven, after the food item in the package has been heated by said oven, moving said oven floor assembly away from said floor opening to a delivery position, and pushing out the package with the heated food item therein from the delivery position to the customer via said customer access opening.

In another aspect the present invention resides in a microwave oven comprising, a cooking chamber having chamber walls defining a chamber cavity, an access opening into said chamber cavity, a microwave energy source for supplying microwave 21~73,8 nergy to said cooking chamber, cooking chamber door means movable between an open position permitting access into said chamber cavity via said access opening, and a closed position wherein said door means closes said access opening, the improvement wherein, said oven including microwave sink means for collecting and dissipating microwave energy, said microwave sink means located proximate a peripheral edge of said access opening and ext~n~;ng substantially thereabout, said door means comprising covering means for covering said access opening, and microwave reflecting means for assisting in reflecting microwave energy passing between the door means and a remainder of said oven into said microwave sink means when said door means is moved to said closed position.

In another aspect the present invention resides in a packaged food item microwave heating and vending machine, comprising:
a microwave oven comprising, a cooking chamber having chamber walls defining a chamber cavity, an oven access opening into said chamber cavity, a microwave energy source for supplying microwave energy into said chamber cavity, cooking chamber door means movable between an access position permitting access into said chamber cavity via said access opening, and a closed position wherein said door means closes said access opening, said chamber wall including microwave sink means for collecting and dissipating microwave energy, said microwave sink means located proximate a peripheral edge of said access opening and extending substantially thereabout, said door means including covering means for covering said access opening, and microwave reflecting means for assisting in reflecting microwaves passing between the - 8 - ~I~3738 door means and a remainder of the microwave oven into said microwave sink means when said door means is moved to said closed position, freezer means for storing at least one stack of said packages of food items in a frozen state;
access means for defining a customer access opening;
and mechanical means for moving said door means to said access position to obtain a package supported thereon from the stack in said freezer means, moving said door means with the package thereon to said oven access opening and said closed position such that the package is in a heating position within the chamber cavity, and after the food item in the package has been heated by said microwave energy, moving said door means away from said access opening to a delivery position for delivery of the package with the heated food item therein to the customer through said customer access opening, wherein said mech~;cal means provides continuous positive control of the package from the stack to the delivery position.

In a further aspect the invention resides in a packaged food item heating and vending machine, comprising:
a microwave oven comprising, a cooking chamber having chamber walls defining a chamber cavity and a bottom floor access opening into said chamber cavity, a microwave energy source for supplying microwave energy to said chamber cavity, a cooking floor assembly movable between an access position permitting access into said chamber cavity via said floor opening, and a closed position wherein said floor assembly closes said floor opening, said chamber walls including microwave sink means for collecting and dissipating microwave energy, said microwave sink means located proximate a peripheral edge of said floor opening and extending substantially thereabout, 21~3738 said floor assembly covering said access opening, and further including microwave reflecting means for assisting in reflecting microwaves passing between the floor assembly and the chamber wall into said microwave sink means when the floor assembly is moved to said closed position, freezer means for storing at least one stack of packages of frozen food items;
access means for defining a customer access opening;
and meçh~n;cal means for moving said oven floor assembly to said access position and to obtain a package from the stack in said freezer means, moving said oven floor assembly with the package thereon to said floor access opening and to the closed position with the package in a heating position in said chamber cavity, and after the food item in the package has been heated by said oven, moving said oven floor assembly away from said floor access opening to a delivery position for delivery of the package with the heated food item therein to the customer via said customer access opening.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the present invention will become more apparent to persons skilled in the art from the following description taken in conjunction with the accompanying drawings in which:

Figure 1 is a front schematic view of a vending machine of the present invention with the front access door thereof in the closed position;

Figure 2 is a schematic view of the machine of Figure 1 with the front access door in an open position;

Figure 3 is a schematic left side view of the internal components of the machine of Figure 1;

21.~3738 Figure 4 is a schematic front view showing the layout of the components of the machine of Figure l;

Figure 5 is a schematic top view of a microwave oven for use in the vending machine of Figure 1;

Figure 6 is a cross-sectional front view of the microwave oven of Figure 5, taken along line 6 - 6', with the oven door moved to an open position;

Figure 7 is a plan view of the oven door and transporter arm for use in the vending machine of Figure 1;

Figure 8 is a cross-sectional side view of the oven door and transporter arm of Figure 7, taken along line 8 - 8';

Figure 9 is an enlarged sectional view of a microwave choke assembly of the oven of Figure 5, taken along line 9 - 9', with the oven door moved to a closed position;

Figure 10 is an enlarged schematic view showing a food storage box being mech~n;cally retrieved from a storage rack housed within the freezer unit of the vending machine of Figure 1;

Figure 11 is a perspective top view of the bottom slide assembly of the storage rack of Figure 10;

Figure 12 is a perspective view of a guide rail for use in the storage rack of Figure 11;

Figure 13 is an enlarged schematic view showing the coupling of a front guide rail to the bottom slide assembly of Figure 11;

- 11 - 21 ~-~ 738 Figure 14 is a top plan view of an unpunched pizza box of the present invention and for use in the machine of Figure 1; and Figure 15 is a side view of the box of Figure 14 after being punched.

DET~TT~n DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Figures 1 and 2 there is illustrated therein generally at 30 a microwave heating and vending machine in accordance with a preferred emho~iment of the present invention. The machine 30 is especially adapted for handling boxes 32 of prepared frozen pizzas, as for example is shown in Figure 3, however, other types of fresh or frozen prepared food products apparent to those skilled in the art could equally be used. Just some of the examples of other heatable and deliverable food products would include sandwiches, lasagnas, other pastas, soups and "TV dinners".

The machine 30 includes a sturdy box-like steel housing 34 supported either on four legs approximately six inches above a support surface or directly on the floor. An open front which can be closed by a hinged door 36 permits access into the machine 30. The door 36 is adapted to be locked in a known manner so that components of the machine 30 are protectively enclosed within the housing 34.

The Figures illustrate the layout or construction of the various machine components within the housing 34. Figure 2 shows best the machine 30 as including a freezer chamber 40 for storing boxed pizzas 32 to be dispensed. As will be described in greater detail hereafter with reference to Figures 10 to 13, a storage rack assembly 42 is housed within the freezer chamber 40 to maintain four stacks 44,46,48,50 of pizza boxes 32 in a square, vertically stacked relation. Two of the stacks 48,50 spaced closest towards an outer right - 12 - 21~3738 housing sidewall 52 extend vertically a distance further down than the inward two stacks 44,46. The freezer chamber 40 has a hinged front door panel 51 which may be swung open. The storage rack assembly 42 may be provided on a sliding carriage (not shown) within the freezer chamber 40 so that when the panel 51 is open, the stacks 44,46,48,50 may be slid forwardly out the freezer chamber 40 and housing 34 with the door 36 open, for restocking through open tops, but preferably the assembly 42 has fixed locating corners or angled brackets 150 allowing for convenient easy loading of product from the front.

A specially designed cooling evaporator 54 for the freezer 40 is shown within the freezer 40 behind stacks 44 and 48 and positioned near the top of the freezer 40. The cooling evaporator 54 is operable to maintain the desired temperature within the housing 40 and is equipped with a compatible powered defrost system to eliminate frost build-up on the coils. A freezer condenser and compressor assembly is also shown spaced below the stacks 44,46,48,50 positioned towards the right sidewall 52.

A novel microwave oven construction 60 is positioned about midway between the top and bottom of the housing 34, towards the left sidewall 58. The microwave oven construction 60 is shown best in Figures 5 to 9 as including a cooking chamber 62 and a door assembly 64. The microwave oven construction 60 has an overall shape which is more compact in size, as compared to conventional microwave ovens, and is adapted to heat the boxed pizza 32 which is positioned therein with optimum energy efficiency and minimal cooking time.
Further, the cooking chamber 62 and door assembly 64 are constructed so that the door assembly 64 may be moved between an open position permitting movement of a pizza box 32 into or out of the cooking chamber 62 and a closed position where the door assembly 64 prevents access and seals the cooking chamber 62 against microwave leakage.

~1S~3738 Figures 5 and 6 show the cooking chamber 62 best as including a chamber cavity 66 having an enlarged generally rectangular upper portion 68, which extends downwardly into a slightly smaller rectangular lower portion 69. The chamber cavity 66 is defined by two opposing pairs of generally parallel steel sidewalls 70 and a steel inner chamber end wall 72. The chamber sidewalls 70 are joined along their vertical edges with the chamber end wall 72 closing a top upper end of upper portion 68 of cavity 66. Food product access into the chamber cavity 66 is provided through a bottom floor opening 74 which is provided in the bottom of the chamber 62, opposite to the chamber end wall 72. The door assembly 64 function to close the cooking chamber 62 as a movable floor panel. In the embodiment shown, the bottom floor opening 74 is defined by each of the four chamber sidewalls 70 as a substantially open bottom floor. If desired, however, the floor opening 74 could also be provided as a smaller opening formed in a more pronounced bottom end wall which substantially closes a bottom lower end of the chamber 64 or through a side or top portion of the oven chamber 62.

It has been discovered that a preferable, more energy efficient microwave oven construction 60 may be achieved where the chamber configuration is matched with microwave transmission propagation waves for direct magnetron transmitter input into a tuned chamber for more energy efficient microwave oven construction 62. A preferred cavity 66 has an overall height of approximately 6 inches between the top end wall 72 and bottom floor opening 74, and the larger upper portion 68 of the oven cavity 66 has a width between each opposing pair of sidewalls 70 of between 9 and 10 inches.

The microwave oven construction 60 is provided with a microwave choke assembly 78 which substantially eliminates the leakage of the microwave energy from the cooking chamber 62 when the door assembly 64 is moved to the closed position.
Figure 9 shows best an enlarged sectional view of the - 14 - 21~3738 microwave choke assembly 78, as including a microwave sink 80 which is integrally formed in each of the chamber sidewalls 70, and a microwave reflecting wall or projection 81 provided as part of the door assembly 64.

The lower rectangular portion 69 of the cavity 66 is formed by a lower most end portion 83 of each of the chamber sidewall 70 adjacent the floor opening 74 projecting inwardly towards the opposing sidewall 70. The microwave sink 80 is provided in each inwardly projecting portion 83 of the sidewalls 70 as an open, smaller rectangular chamber 82 which extends horizontally the length of each chamber sidewall 70 about the opening 74. The chamber 82, seen best in Figures 6 and 9, has an overall cross-sectional vertical dimension of approximately one inch and a width of about one-half inch.
The chamber 82 includes a vertical inner sidewall 84 positioned towards and generally parallel to the opposing chamber sidewall 70, an outer sidewall 86 which is parallel to the inner sidewall 84 and spaced away from the opposing chamber sidewall 70; an inner end wall 88 spaced towards the chamber end wall 72 and which extends perpendicularly to and joins the inner sidewall 84 and outer sidewall 86; and a lower end wall 90 which is spaced from the inner end wall 88 away from the end wall 72. The lower end wall 90 projects perpendicularly from the outer sidewall 86 towards the inner sidewall 84 as the bottom edge of each respective chamber sidewall 70, and further defines the peripheral edge of the floor opening 74.

As seen best in Figure 6, the elongated chamber 82 is provided with an inverted "G" profile, with the inner sidewall 84 bent at 90 to form a flange 92 which extends perpendicularly towards the outer sidewall 86, and which further defines an elongated opening 94 between the flange 92 and the outer end wall 90 about one-third of an inch in height. The elongated opening 94 extends about the chamber cavity 66 immediately adjacent the peripheral edge of the 2li3738 floor opening 74. A number of parallel spaced slots 96 are also provided through the inner sidewall 84 ext~n~ing from the opening 94 vertically through the flange 92 and remainder of the sidewall 84 to the inner end wall 88. The slots 96 are spaced apart from each other by a distance which is equal to one-half the length of the microwave wave length produced by the oven 60.

Figures 7, 8 and 9 show best the microwave door assembly 64 and reflecting portion 81 which is sized to be inserted through the floor opening 74. The door assembly 64 includes a flat square steel base plate 100 which functions as the floor of the microwave chamber 62. The base plate has width of 9 x 9 inches between each opposing side so that when the door assembly 64 is moved to the closed position, the base plate 100 overlaps the bottom of all four of the chamber sidewalls 70, extenA;ng across an edge portion of each lower end wall 90 which defines the floor opening 72. A thin layer of Lexant~ 102 or other plastic or electrically insulating material is provided over the upper surface-of the base plate 100. The Lexan 102 acts as a spacer to ensure that when the door assembly 64 is moved to the closed position, no metal-to-metal contact occurs between the cooking chamber 62 and the base plate 100.

When the door assembly 64 is moved to the closed position, the door assembly 64 completes the microwave choke assembly 78 and substantially prevents the leakage of microwave energy from the chamber cavity 66.

The microwave reflecting portion 81 is formed as a square steel fence 104 ext~n~;ng perpendicularly upward from the upper surface of the Lexan layer 102. The reflecting fence 104 extends as an open square box with each of its opposing sides spaced apart a distance slightly less than the width of the floor opening 74. The fence 104 further extends upwardly from the Lexan layer 102 a height of about three-2~ r53738 quarters of an inch. The fence 104 is positioned so that whenthe door assembly 64 is moved to the closed position, the reflecting fence 104 extends a distance inwardly into the chamber cavity 66 with each of the sides of the fence 104 spaced from and parallel to part of an opposing inner sidewall 84 of a portion of the sink 80 which is provided in the adjacent chamber sidewall 70.

Although not essential, a three-quarter inch thick plastic shelf 107 may be provided on the Lexan layer 102 centered within the reflecting fence 104. The shelf 107 is sized to securely support the pizza box 32 sitting thereon and is invisible to microwave radiation. On moving the door assembly 64 to the closed position, a boxed pizza 32 thereon appears to the magnetron of the oven 60 to be suspended three-quarters of an inch off of the oven floor 100. The plastic shelf 107 may, for example, comprise a polycarbonate slab that has been milled to fit within the fence 104 so that a boxed pizza 32 rests evenly thereon.

As will be described hereafter, the door assembly further includes a small plastic back or tab 105 which extends upwardly from the reflecting fence 104. As will be described hereafter the tab 105 is used to position a boxed pizza 32 on the base plate 100. If desired additional peripherally extending fences 106 may be provided on one or more of the remaining sides of the reflecting fence 104. It has been found that the fences 105,106 advantageously act to maintain the proper position of a box 32 on the door assembly 64, and limit box lift when retrieving pizza boxes 32 from the storage rack assembly 42.

The microwave chamber 62 may further be provided with a plastic shield 108 ext~nAing downwardly over the inner sidewall 88 of the microwave sink 80. The plastic shield 108 advantageously ensures that no metal-to-metal contact occurs between the microwave sink 80 and the reflecting fence 104 - 17 - 21~3738 when the door assembly 64 is moved to the closed position, while permitting the passage of microwave energy therethrough.

A magnetron 76 is provided to produce microwave energy for heating boxed pizza 32 positioned within the chamber cavity 66. Preferably the magnetron 76 is selected to deliver between about 3,400 and 4,000 watts of heating energy during operation, so as to fully heat a frozen pizza in a pre-set heating time of between 25 to 50 seconds.

Referring to Figure 4 the magnetron 76 is seen to include a cooling fin assembly block 114 on the oven, a smaller penthouse rectangle 116 on top of the block 114, and protruding down into the interior of the oven is a three-quarter inch magnetron dome 118. Thus, the Lexan sheet 102 and spacer 107 raises the boxed pizza 32 up off the metal floor portion 100 so that the microwave energy sees it better and reduces the likelihood of hot spots being produced.

The magnetron 76 is positioned in the top corner of the oven 60 and extends down with dome 118 projecting through the oven ceiling into the interior of the oven cavity 66. The magnetron 76 located in the corner of the inner end 72 of the oven chamber 62 is oriented with respect to the boxed pizza 32 so that the pizza cooks uniformly. No waveguide is nec~scAry as is found in conventional microwave ovens, as a result of the unique configuration of the sidewall spacing and magnetron 76 location in the chamber 62. To further improve the heating efficiency, the geometry of the inside of the oven chamber 62 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.

With the microwave oven construction 60 of the present invention, when the door assembly 64 is moved to the closed position shown in Figure 9 the chamber cavity 66 is effectively sealed against microwave leakage, without reliance ~f ~3738 on contact seals or latching mec~nicms. With the door assembly 64 closed in the manner shown in Figure 9, the base plate 100 is positioned overlapping the ends of the chamber sidewalls 70 so that the Lexan layer 102 is positioned against the lower end wall 90. Further, in this position, the reflecting fence 104 extends part-way into the chamber cavity 66 so as to be spaced in parallel juxtaposition with a portion of the inner sidewall 84 ext~n~;ng between the opening 94 and upper end wall 88.

When the magnetron 76 is activated, any microwaves which move between the portion of the chamber sidewalls 70 which form microwave sink 80 and the portion of the door assembly 64 which forms the reflecting fence 104 are reflected into the elongated chamber 82 via the opening 94. Microwaves which are reflected into the chamber 82, thereafter continue to be reflected internally until they harmlessly dissipate.
The slots 96 have been found to advantageously act to neutralize (null) the microwave wave energy while segmenting and neutralizing the high captured and conducted wall energy that is created.

Figure 8 shows best the door assembly 64 as being mounted on an aluminum U-shaped conveyor assembly 122 which is oriented so as to open sideways. In other words, the conveyor assembly 122 comprises spaced horizontal upper and lower members 123a,123b which are joined by a vertical member 125 at one edge. As will be described later, the shape of the conveyor 122 advantageously permits insertion of the door assembly 64 within the interior of the freezer chamber 40 to selectively remove and transport a pizza box 32 for heating in the oven chamber cavity 66.

The U-shaped conveyor 122 is movable by a robotic three-axis transporter as shown generally at 124 in Figure 4.
The transporter 124 is controlled by microprocessor 132 and includes three continuous rails 126a,126b,126c, each having a 21~373~

corresponding trolley 128a,128b,128c thereon. Each rail 126 extends in a mutually perpendicular direction aligned with a respective "X", "Y" and "Z" axis. Each of the trolleys 128 are belt driven by an individual stepper motor 129a,129b,129c therein that respectively move the trolley 128a on rail 126a horizontally left to right in an "X" direction between the right sidewall 52 and left sidewall 58; the trolley 128b on rail 126b horizontally front to back in a "Y" direction normal to the "X" direction; and the trolley 128c on rail 126c vertically up and down in the "Z" direction.

The assembly 122 is mounted to the trolley 128a as shown in Figure 4 and the U-assembly would be open towards the right hand sidewall 52. The individual stepper motors 129a,129b,129c move the trolleys 128a,128b,128c along each of the respective axes on rails 126a,126b,126c. The stepper motors 129a,129b,129c advantageously eliminate the different linkages apparently needed when D.C. actuator motors are used in known vending machines. The transporter 124 thus allows the oven floor assembly 64 to be precisely positioned where necessary inside of the cabinet or housing 34, including in position covering the oven floor opening 74. In other words, the oven floor assembly 64 can be directed to enter the freezer 40, retrieve a boxed pizza 32, move it up and into the oven cavity 66 for cooking, and thereafter bring it down and forward for delivery to a customer. Further, as will be described hereafter the transporter 124 further may be used to direct the oven floor assembly 64 into the desired stacks 44,46,48,50 to retrieve a desired type of pizza.

All machine actions, such as movement of the oven floor assembly 64 via the transporter 124, varying of cooking times (to adjust for different voltage levels), product selection, coinage control, and maintenance diagnostic and telemetry are controlled from the central computer control 132 shown in the upper left hand corner of Figure 2. The controller 132 will preferably be only the size of a routine 21~373~

small computer card. The controller 132 program monitors the line voltage so that the cooking times are adjusted dependent upon the available energy. A transformer power unit 134 (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 thereaway on the oven floor assembly 64 and then pushed out by a motorized paddle 172 (Figure 3) accessible to the customer through a tunnel 138 which communicates with a slot access opening 140 in the door 36 shown in Figures 1 and 2. As seen best in Figure 3 inner and outer tunnel doors 141,142 are provided at each end of the tunnel 138. The doors 141,142 are spaced apart by a distance selected so that a box 32 may be positioned therebetween. In this manner the inner door 141 is permitted to close prior to the removal of the box 32 from the tunnel 138.

The four stacks of pizzas 44,46,48,50 can be independently targeted to serve one or different kinds of pizza. By setting a switch, the controller 132 is advised which kind of pizza is in each stack, and may thus be used to actuate the transporter 124 to select the desired pizza type.
For example, two of the stacks can be cheese pizzas and the other two pepperoni, or three pepperoni and one cheese. As previously mentioned, the two stacks 44,46 closest to the oven assembly 60 are raised higher than the two stacks 48,50 closest sidewall 52 in a two tier arrangement.

It is the small offset defined by the different height between the stacks 44,46 and 48,50 which allows for the pizzas 32 to be removed from the bottom of both the rearward pair of stacks 44,48 and the forward stacks 46,50. Knock down, spring loaded doors 144 shown best in Figure 10 are positioned at the bottom of the freezer chamber 40, adjacent the lower inside corner of each stack 44,46,48,50 closest to sidewall 58. The doors 144 to the freezer chamber 40 are spring loaded, and hingely coupled to the freezer 40 by a bottom hinge 145. The doors 144 are configured to be pushed 2~3738 open from the closed position shown in solid lines in Figure 10, to the open position shown in phantom, when the oven floor assembly 64 is inserted into the freezer chamber 40. The springs bias the doors 144 shut after the oven floor assembly 64 and pizza box 32 thereon have been removed from the interior of the freezer 40. To maintain cooling efficiency the freezer is preferably surrounded by a layer of semi-rigid insulation 147 which has a thickness selected less than the innermost distance between upper and lower members 123a,123b.

The construction and operation of both the freezer door 144 and the U-shaped conveyor 122 are best depicted in Figures 4 and 10. The trolley 128a that sits on the rail 126a oriented along the "X" axis is shown coupled to the underside of the U-ehAre~ conveyor 122. The U-shaped conveyor 122 then travels along the rail 126a, moving over and under the lower insulation layer 147a of the freezer chamber 40. As the oven floor assembly 64 is inserted into the freezer chamber 40 in the direction of arrow 200, it impacts the door 144, which then folds down about hinge 145 into a recessed area provided as a cutout 148 formed in the insulation, positioning the door 144 in the down or open position in Figure 10. As the U-shaped conveyor 122 with the oven floor 64 secured thereon is pushed further into the freezer chamber 40, or to the right of Figure 10, the extension tab 105 is moved inwardly clear of the stack pizza boxes 32. The U-shaped conveyor 122 is then raised up in the direction of arrow 202 about one-half inch to position the fence extension tab 105 behind the lowermost box 32. The pizza boxes 32 are loaded from the top of the rack assembly 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 pizza boxes 32 are held only at their corners by the bent rails 150 and the areas between the corners are generally clear. In the manner previously disclosed, once the fence 104 is positioned under the pizza box 32 in the slide 21S37~

assembly 146, and the door assembly is raised up in the "Z"
direction, the extension tab 105 moves between the brackets 156a,156b engaging the rear side of the lowermost box 32 sliding it outwardly from the slide assembly 146 onto the Lexan layer 102. The boxes 32 are each about 1.2 inches thick or high and the bottom half inch of the box 32a will thus then have the extension 105 engagingly behind it. The U-shaped conveyor 122 is then withdrawn from the freezer chamber 40 in the direction of arrow 204, or to the left of Figure 10 moving the lowermost pizza box 32a therewith. When the door assembly 64 clears the door 144, the spring bias of the door 144 thereby returns it to a closed position, closing the freezer chamber 40. With the foregoing construction there are no relative moving parts of the U-shaped conveyor 122 inside of the freezer chamber 40 and the oven floor assembly 64 can be accurately positioned within three-thousandths of an inch, considerably greater than the accuracy required.

In each subsequent operation the oven floor 64 is directed in its movement by the controller 132, which actuates the transporter 124 to move the door assembly 64 through a desired door 144 to retrieve the bottom box of pizza 32 from a lowermost box slide assembly 146 provided at the bottom of the desired stack 44,46,48,50. It is to be understood that the trolleys 128a,128b,128c moved along the respective rails 126a,126b,126c a sufficient distance to move the door assembly 64 to each stack 44,46,48,50 in the freezer chamber 40 and move the plastic extension tab 105 on the reflecting fence 104 past the innermost end of the box 32 contained in any one slide assembly 146. Once fully moved into the freezer chamber 40, the trolleys 126 again move door assembly 64 up to slide the extension 105 h~h;~ the end of the pizza box 32 and drag it off the slide assembly 146 as the oven floor 64 is moved out of the freezer 40 towards the left sidewall 58.

Figures 10 to 13 illustrate best part of the storage rack assembly 42 used to form the stacks 44,46,48,50, with the 21~3738 vertical sides of each stack defined by four angled rails 150.
For clarity Figure 11 shows the lower portion of the rack assembly 42 used to form stack 44 together with the slide assembly 146 of stack 46, the remaining portions of assembly 42 being substantially identical. Figure 11 shows the rails 150 of each stack 44,46,48,50 as being mounted to the slide assembly 146 provided at the bottom of each stack. The slide assembly 146 includes a steel top wall 152 having a rectangular opening 154 which is sized to permit the downward movement of a boxed pizza 32 therethrough. A pair of angled brackets 156a,156b extend downwardly and inwardly from the top wall 152 on each side of the opening 154. The brackets 156a,156b define a slot 158 therebetween which extends generally parallel to the "X" axis, open towards the freezer door 144. The slot 158 has a size selected so that a boxed pizza 32 which moves downwardly from an associated stack 44,46,48,50 is retained on the brackets 156a,156b while permitting the movement of the extension tab 105 on the door assembly 64 therebetween to extract a boxed pizza.

Figures 12 and 13 illustrate the rails 150 used to form the corners of the stacks 44,46,48,50. The rails 150 each are formed as a rectangular length of steel, bent at a 90 angle to engage the corners of the pizza box 32. The bottom of the rails 150 are attached to the top 152 of a corresponding slide assembly 146 by the engagement of tabs 160 provided on the outer sides of the rails 150 within complimentary sized slots 162 formed in the top 152. The pair of rails 150a positioned closest to the freezer door 144 have essentially the identical construction as the pair of rails 150b spaced furthest therefrom, with the exception that the tabs 160 on the rails 150b are positioned further from the lower end of the rails 150b, with the result that the rails 150b extend downwardly through the opening 154 whereas the rails 150a do not.

215373~

It is to be appreciated that by varying the length and size of the tabs 160, the configuration of the racks 44,46,48,50 may be adjusted to store product of different sizes. Further, for greater flexibility, a number of slots may be provided through the slide assembly top 152 to permit the placement of the rails 150 on the slide assembly 146 to be varied.

As soon as the box 32 has been withdrawn from the freezer chamber 40 it is moved along the "X" direction axis in the direction of arrow 209 towards the sidewall 58 all the way over to the left-hand side of Figure 4, and into lateral alignment with the microwave oven assembly 60. The oven floor assembly 64 is then moved either forward or back in the "Y"
direction until the box 32 is positioned directly below the bottom opening 74 of the oven cooking chamber 62. The door assembly is then moved upwardly vertically in the "Z"
direction of arrow 208 shown in Figure 3, thereby placing the boxed pizza in the oven cavity 66 and sealing the bottom opening 74 of the oven with a non-contact seal. The bottom of the oven chamber 64 is thereby sealed against radiation leakage and the boxed pizza 34 is enclosed within the oven cavity 66. The two thousand watt magnetron 76 is actuated, and the pizza is heated.

In a more preferred embodiment, following its first removal out of the freezer chamber 40, the pizza box 32 on the door assembly 64 is first moved until it is positioned under a steam vent punch pin 164 mounted in front of the oven assembly 60. The door assembly 64 is then raised up to punch a self-locking steam box vent 210 provided in the pizza box 32, as will be explained in detail later. Following the punching of the vent 210, the door assembly 64 is then moved down, position under the floor opening 74, and then raised up into the oven cavity 66.

- 25 - ~I S3 738 After the boxed pizza 32 has been cooked, the oven floor assembly 64 is lowered in a direction opposite to arrow 208 and, moved forwardly in the "Y" and "Z" directions of arrows 212,213 toward the front of the machine 30, the transporter 124 repositioning the box 32 cont~;ning the cooked pizza in a delivery position rearward of an exit tunnel 138.
At the delivery position the pizza box 32 is pushed by the motorized paddle 172 out through the tunnel 138 and accessible to the customer through slot opening 140. If desired the tunnel 138 may be configured so that the pizza box 32 is pushed into the tunnel 138 so that a rear tunnel door (not shown) thereof closes before a front tunnel door opens. This denies people access to the interior of the machine 30, as in such a configuration the paddle 172 pushes the box 32 clear of the back door before it opens the front door. Alternately, when delivered the box 32 with the heated pizza therein may stick out of the machine 30 a couple of inches to be readily accessible to the customer who does not have to reach into the machine.

The preferred power supply for the machine 30 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 between forty-five and fifty seconds. A typical wall power supply of one hundred and ten volts and twenty amps, requires about a one and a half minutes to cook the pizza. The length of time to cook the pizza or other product is related to the amount of energy provided to the magnetron 76 and the weight of the product being heated. Since the microwave oven assembly 60 is cooking approximately the same content and shaped items, a 6 to 7 inch diameter pizza or other product 0.65 to 1.0 inches high, the tuned oven 62 can uniformly distribute the microwave energy and each product can be properly heated by adjustment of the cooking time. The pizzas have been fully cooked at the bakery, boxed and frozen so that all the microwave oven 60 is doing is heating them to a hot consumption temperature.

~53738 Referring to Figure 1 the front of the machine door 36 is shown having centrally disposed cutout 178 for advertising and/or explanatory graphics or the like. It is anticipated that lighting would be provided around the perimeter of the cutout 178 both for ornamentation and for ease of reading the graphics therewithin. At the top left is the dollar bill acceptor 180, and the two units shown directly below are the select buttons 182,184 for selecting two or more possible selections of pizza including cheese, pepperoni, vegetable, sausage or other types. Generally on the left and below the select button 184 is the access opening 140 out through which the boxed cooked pizzas 32 are delivered by the paddle 172. The coin handler 186 is positioned at the top at the right of the cutout area 178 and the lock 188 for opening the machine, servicing it and subsequently locking it is directly therebeneath. The double square at the bottom right is the customer coin return 189.

A preferred pizza box 32 for use with the present invention is shown in Figures 14 and 15. To prevent steam from forming in the box 32 as the pizza is heated in the oven cavity 66 and thereby soften the pizza, the steam vent 210 is punched in the box after it has been removed from the freezer chamber 40 and before it is inserted in the oven 60.
Referring to Figure 14, an unpunched vent member 214 is formed in one corner of the box 32 during the box formation. The member 214 has three of its edges 216 cut and the fourth edge 218 only scored to prevent accidental opening. The front of the box 32 is folded and glued, and attached to it is a tab 220 which sticks out. It also has a score line 222 and when folded up it is directly under the cutout. When the member 214 is punched from the top, the cut 216 on the three sides opens downward until it catches in the score 222 whereby it locks itself, thereby forming the self-locking steam vent 210, as shown in Figure 15. Thus, just before the boxed pizza 32 enters the oven cavity 66, the oven floor assembly 64 moves over under the puncher 164 (the smaller nipple member under 215373g the oven) and raises up, punches the vent member 214, travels down and then travels under and into the oven 60. The score 222 on the bottom flap 220 thus effects the locking action by engaging the forward edge of the top flap member 214. If desired, the box 32 may further be lined with microwave absorbing paper (not shown) which produces heat in the microwave 60, and browns the boxed food product as it is cooked.

In summary, the pizzas are pre-prepared, cooked, frozen and boxed. The boxes 32 are stacked according to pizza type in separate stacks in a freezer chamber 40. A three-axis movement mec-h~nicm or transporter 124 with the oven floor assembly 64 of the microwave oven chamber 62 secured thereto enters the freezer chamber 40 through door 144, extracts the bottom pizza box 32 from the desired stack 44,46,48, or 50 and accurately positions the oven floor assembly 64 in a sealed tight relation in the bottom opening 74 of the oven chamber 74, with the box 32 on the oven floor assembly 64 and positioned in the cavity 66. No relative moving parts of the transporter mech~n;cm 124 need enter the freezer chamber 40.
The pizza is then rapidly, accurately and consistently heated in the high intensity microwave oven assembly 60, following which the oven floor assembly 64 is lowered and moved away from the oven chamber 62 and the box 32 of heated pizza pushed by paddle 172 out a delivery tunnel 138 to a customer. All activities of the machine 30 are accurately and reliably controlled, adjusted and monitored from the central computer control 132.

More preferably a bar code reader 190 which identifies the particular product going through the machine is provided adjacent the tunnel 138. This feature allows the accumulation of product sales information (times and quantities). Alternately, a bar code reader could be provided adjacent the microwave oven assembly 60 to permit the heating time to be set for each product as it is processed, and allow 21S3~38 the oven to be disabled in the event unauthorized product is being used in the machine 30.

A modem card 192 which allows remote monitoring of the machine 30 to determine its status is coupled to either a hardwired or cellular telephone line and preferably provided in the computer controller 132. The modem card 192 is operable to notify operators of possible trouble. This feature allows the operators to efficiently manage a group of machines 30, maintain product availability, to monitor sales and assess the amount of currency in the machines, and to react to current machine problems. In addition, the call-out feature can alert the operator to potential problems that may cause a loss of product and also to alert a monitoring station if there is a security breech.

Figures 1 and 2 show a vending machine 30 in which four stacks 44,46,48,50 of food products are housed in a frozen state to one side of the microwave oven assembly 60, provided in a two tiered arrangement. It is to be appreciated, however, that additional stacks provided in a 3,4 or more tiered arrangement could also be used. If desired the microwave oven assembly 60 could be positioned between both stacks and freezer units which are positioned within the machine housing 34 on each side of the microwave oven 60. In such a configuration the conveyor 122 would preferably also be adapted for 180 rotational movement on rail 126a.

Although the microwave oven assembly 60 is disclosed for use in a packaged food product heating and vending machine 30, the invention is not so limited. With minor modification, the microwave oven assembly shown in Figures 5 to 8 may equally be used outside of a vending machine, as for example, as a stand-alone commercial or residential oven. Similarly, while a smaller sized rectangular oven assembly is desirable for use housed within a vending machine 30, larger sized and/or different shaped ovens are also possible and will now become apparent.

Figures 8 and 9 illustrate a square microwave reflecting fence 104 provided on the microwave door assembly 64 as the microwave reflecting projection 81, other microwave reflecting structures are also envisioned and will now become apparent.

While the detailed description discloses a transporter 124 which incorporates stepper motor driven trolleys 128 which are movable along rails 126a,126b,126c, persons skilled will readily appreciate other transporter constructions, including screw gear and belt drive mech~n;sms may also be used.

From the foregoing detailed description, it will be evident that there are 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. However, it is intended that all such variations not departing from the spirit of the invention be considered as within the scope thereof. For a definition of the invention reference may be had to the appended claims.

Claims

1. A microwave oven comprising, a cooking chamber having chamber walls defining a chamber cavity, an access opening into said chamber cavity a microwave energy source for supplying microwave energy to said cooking chamber, cooking chamber door means movable between an open position permitting access into said chamber cavity via said access opening, and a closed position wherein said door means closes said access opening, the improvement wherein, said oven including microwave sink means for collecting and dissipating microwave energy, said microwave sink means located proximate a peripheral edge of said access opening and extending substantially thereabout, said door means comprising covering means for covering said access opening, and microwave reflecting means for assisting in reflecting microwave energy passing between the door means and a remainder of said oven into said microwave sink means when said door means is moved to said closed position.

2. A microwave oven as claimed in claim 1 wherein said chamber walls include an inner chamber end wall remote from said access opening and chamber sidewalls, said chamber sidewalls extending from said chamber end wall outwardly therefrom towards said access opening, said covering means comprising a generally planar member having a size selected so that when said door means is moved to said closed position, said planar member overlaps a portion of said chamber walls adjacent said access opening, and said microwave reflecting means extends generally perpendicularly from a peripheral portion of said planar member, wherein when said door means is moved to said closed position said microwave reflecting means projects inwardly into said chamber cavity.

3. A microwave oven as claimed in claim 2 wherein said chamber sidewalls define said access opening, said microwave sink means being provided in a portion of said chamber sidewalls adjacent said access opening, said microwave sink means comprising a generally box-shaped chamber extending about said access opening, the box-shaped chamber having a generally rectangular profile and including, an inner sidewall spaced towards an opposing chamber sidewalls, an outer sidewall generally parallel to the inner sidewall and spaced therefrom away from said opposing chamber sidewall, an inner end wall extending perpendicularly from said inner sidewall to outer sidewall, an outer end wall extending perpendicularly from said outer sidewall towards said inner sidewall, said outer end wall spaced outwardly from said inner end wall away from said chamber end wall, and an elongate opening formed through said inner sidewall adjacent said outer end wall, the elongate opening extending about said access opening.

4. A microwave oven as claimed in claim 3 wherein said inner sidewall further includes an inwardly projecting flange extending from a portion of said inner sidewall adjacent said elongate opening perpendicularly towards said outer sidewall.

5. A microwave oven as claimed in claim 3 wherein said inner sidewall further includes a plurality of generally parallel slots which extend substantially from said elongate opening to said inner end wall.

6. A microwave oven as claimed in claim 5 wherein said slots are spaced apart by a distance which is selected to be approximately one-quarter of an overall length of the microwaves supplied by said microwave energy source.

7. A microwave oven as claimed in claim 1, wherein said oven is for use in a packaged food item heating and vending machine, said vending machine including a storage assembly for storing packaged food items to be dispensed, said access opening being provided in the floor of said oven, said cooking chamber door means provided as part of a carriage assembly which is operable to retrieve a packaged food item from said storage assembly and move said retrieved food item into said cooking chamber for heating, wherein said door means supports said retrieved food item during cooking as a floor of said microwave oven.

8. A packaged food item microwave heating and vending machine, comprising:
a microwave oven comprising, a cooking chamber having chamber walls defining a chamber cavity, an oven access opening into said chamber cavity, a microwave energy source for supplying microwave energy into said chamber cavity, cooking chamber door means movable between an access position permitting access into said chamber cavity via said access opening, and a closed position wherein said door means closes said access opening, said chamber wall including microwave sink means for collecting and dissipating microwave energy, said microwave sink means located proximate a peripheral edge of said access opening and extending substantially thereabout, said door means including covering means for covering said access opening, and microwave reflecting means for assisting in reflecting microwaves passing between the door means and a remainder of the microwave oven into said microwave sink means when said door means is moved to said closed position, freezer means for storing at least one stack of said packages of food items in a frozen state;
access means for defining a customer access opening;
and mechanical means for moving said door means to said access position to obtain a package supported thereon from the stack in said freezer means, moving said door means with the package thereon to said oven access opening and said closed position such that the package is in a heating position within the chamber cavity, and after the food item in the package has been heated by said microwave energy, moving said door means away from said access opening to a delivery position for delivery of the package with the heated food item therein to the customer through said customer access opening, wherein said mechanical means provides continuous positive control of the package from the stack to the delivery position.

9. A heating and vending machine as claimed in claim 8 wherein said chamber walls include an inner chamber end wall remote from said access opening, and chamber sidewalls, said chamber sidewalls extending outwardly from said chamber end wall to define said oven access opening, said covering means comprising a generally planar member having a size selected so that when said door means is moved to said closed position, said planar member overlaps a portion of said chamber walls adjacent said oven access opening, and said microwave reflecting means extends generally perpendicularly from said planar member, wherein when said door means is moved to said closed position said microwave reflecting means projects inwardly into said chamber cavity.

10. A heating and vending machine as claimed in claim 9 wherein said microwave sink means comprises a generally box-shaped chamber extend about said access opening, the box-shaped chamber having a generally rectangular profile and including, an inner sidewall spaced towards an opposite side of said cooking chamber, an outer sidewall generally parallel to the inner sidewall and spaced therefrom in a direction away from said opposite side of said cooking chamber, an inner end wall extending perpendicularly from said inner sidewall to outer sidewall, an outer end wall extending perpendicularly from said outer sidewall towards said inner sidewall, said outer end wall spaced outwardly from inner end wall away from said chamber end wall, an elongate opening formed through said inner sidewall adjacent said outer end wall, the elongate opening extending substantially about said oven access opening.

11. A heating and vending machine as claimed in claim 10 wherein said mechanical means comprises motor means for controllably transporting said door means in both horizontal and vertical directions.

12. A heating and vending machine as claimed in claim 8 wherein said mechanical means further moves a package with a heated pizza therein a distance from its position on said door means to a customer delivery position adjacent the customer access opening.

13. A heating and vending machine as claimed in claim 12 further comprising tunnel means for defining a tunnel communicating at its exit end with said customer access opening, and delivery means for delivering the box with heated pizza therein from said delivery position along said tunnel to the customer.

14. A heating and vending machine as claimed in claim 13 wherein said delivery means comprises pushing means for pushing the box off of said door means, along said tunnel to an accessible position at the customer access opening.

15. A heating and vending machine as claimed in claim 13 wherein said tunnel includes an inner door at an inner end thereof, and an outer door at an outer end thereof, the inner door spaced from the outer door such that the box can be positioned generally therebetween following said inner door to close prior to removal of said box from the tunnel.

16. A heating and vending machine as claimed in claim 8 wherein said mechanical means includes a support member movable in both horizontal and vertical directions and a support assembly mounted to said support member, movable therewith, said door means mounted to said support assembly.

17. A heating and vending machine as claimed in claim 16 wherein said oven access opening is provided through a bottom of the oven, and said door means is positioned directly above said support member for use as an oven floor assembly.

18. A heating and vending machine as claimed in claim 16 wherein said support assembly comprises vertically spaced upper and lower members and a vertical end connector therebetween.

19. A heating and vending machine as claimed in claim 18 wherein said oven floor assembly is mounted on said upper member and said lower member is mounted on said support member.

20. A heating and vending machine as claimed in claim 18 wherein when said moving means is positioned to retrieve a boxed pizza from the stack, said lower member is positioned outside and below said freezer means and said upper member is positioned at least partially in said freezer means.

21. A packaged food item heating and vending machine, comprising:
a microwave oven comprising, a cooking chamber having chamber walls defining a chamber cavity and a bottom floor access opening into said chamber cavity, a microwave energy source for supplying microwave energy to said chamber cavity, a cooking floor assembly movable between an access position permitting access into said chamber cavity via said floor opening, and a closed position wherein said floor assembly closes said floor opening, said chamber wall including microwave sink means for collecting and dissipating microwave energy, said microwave sink means located proximate a peripheral edge of said floor opening and extending substantially thereabout, said floor assembly covering said access opening, and further including microwave reflecting means for assisting in reflecting microwaves passing between the floor assembly and the chamber walls into said microwave sink means when the floor assembly is moved to said closed position, freezer means for storing at least one stack of packages of frozen food items;
access means for defining a customer access opening;
and mechanical means for moving said oven floor assembly to said access position and to obtain a package from the stack in said freezer means, moving said oven floor assembly with the package thereon to said floor access opening and to the closed position with the package in a heating position in said chamber cavity, and after the food item in the package has been heated by said oven, moving said oven floor assembly away from said floor access opening to a delivery position for delivery of the package with the heated food item therein to the customer via said customer access opening.

22. A heating and vending machine as claimed in claim 21 wherein said covering means comprises a generally planar member having a size selected so that when said door means is moved to said closed position, said planar member extends beyond said floor access opening across adjacent portions of said chamber walls, and said microwave reflecting means extends generally perpendicularly from said planar member, wherein when said floor assembly is moved to said closed position said microwave reflecting means projects inwardly into said chamber cavity.

23. A heating and vending machine as claimed in claim 22 wherein said microwave sink means comprises a generally box-shaped chamber extending substantially about said floor access opening, said box-shaped chamber having a generally rectangular profile and including, an inner sidewall spaced towards an opposite side of said cooking chamber, an outer sidewall generally parallel to the inner sidewall and spaced therefrom in a direction away from said opposite side of said cooking chamber, an inner end wall extending perpendicularly from said inner sidewall to outer sidewall, an outer end wall extending perpendicularly from said outer sidewall towards said inner sidewall, said outer end wall spaced outwardly from said inner end wall, and an elongate opening formed through said inner sidewall extending about the periphery of said access opening.

24. A heating and vending machine as claimed in claim 23 wherein said mechanical means includes, a support member movable in both horizontal and vertical directions, and a support assembly mounted to said support member, said support assembly comprising vertically spaced upper and lower members and a vertical end connector therebetween, said floor assembly being mounted on said upper member and said lower member being mounted on said support member, wherein when said floor assembly is positioned to retrieve a package from the stack, said lower member is positioned outside and below said freezer means and said upper member is positioned at least partially in said freezer means.

25. A packaged food item heating and vending machine, comprising:
an oven having a floor opening;
an oven floor assembly movable with respect to said floor opening;
refrigeration means for storing at least one stack of refrigerated packaged food items;
access means for defining a customer access opening;
and mechanical means for moving said oven floor assembly to obtain a package from the stack in said refrigeration means, moving said oven floor assembly with the package thereon to said floor opening and to a sealed arrangement such that the package is in a heating position in said oven, after the food item in the package has been heated by said oven, moving said oven floor assembly away from said floor opening to a delivery position, and pushing out the package with the heated food item therein from the delivery position to the customer via said customer access opening.

26. A heating and vending machine as claimed in claim 25 wherein the oven comprises a microwave oven including, a cooking chamber having chamber walls defining a cooking cavity and said floor opening, and a microwave energy source for supplying microwave energy to said cooking cavity, said oven floor assembly movable between an open position permitting access into said cooking cavity via said floor opening, and a closed position wherein said oven floor assembly closes said floor opening in said sealed arrangement, said chamber walls further including microwave sink means for collecting and dissipating microwave energy, said microwave sink means located proximate a peripheral edge of said floor opening and extending substantially thereabout, said floor assembly comprising covering means for covering said floor opening, and microwave reflecting means for assisting in reflecting microwaves passing between the door means and the chamber walls into said microwave sink means when said floor assembly is moved to said closed position.