Abstract:
A method and apparatus for an improved frozen vending machine having a glass front which provides the customer the opportunity to view the actual product they wish to purchase, while ensuring the maintenance of a freezing environment and utilizing a product conveyor system which reliably delivers a larger selection of frozen product to the customer than has been available in the past. The present invention also provides a method and kit for modifying existing vending machines into the frozen vending machine described herein.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is based on provisional application No. 60/067,754, filed Dec. 5, 1997. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to frozen product vending machines and, more particularly, to an improved frozen product vending machine having a glass front which provides the customer the opportunity to view the actual product they wish to purchase, while ensuring the maintenance of a frozen storage environment and utilizing a product conveyor system which reliably delivers a larger selection of frozen products to the customer than has been available in the past. The present invention also provides a method and kit for modifying existing vending machines into the frozen vending machine described herein. 
     2. Description of the Background 
     Frozen product vending machines are typically configured with an outer casing having a hinged front access door, a hinged inner barrier door, and a refrigerated inner section behind the barrier door containing a series of conveyors which carry frozen product and deliver the same to a particular opening in the access door for retrieval by a consumer. However, the methods in which the products are displayed to the consumer and the details of how the products are carried through the machine to the consumer vary widely. 
     Many frozen vending machines in the past have offered the consumer only a graphical depiction of the product they wish to purchase on a front access panel of the machine. The consumer inserts their coin into the machine and presses one of three selection buttons, in turn powering an electric motor to drive a vertical conveyor system just behind the panel depicting their desired product. The consumer then lifts the access panel, revealing the conveyor system, and slides their desired product out from between the panels of the vertical conveyor. Not only have these machines in the past resulted in excessive heat exchange both in reloading product and in operation by the consumer, but the consumer is often disappointed when the product they receive is either not quite as appealing as, or altogether different from, the one depicted on the access panel graphic. 
     Many current non-frozen product vending machines incorporate a glass front. The incorporation of a glass front in these machines vastly improved the commercial potential of standard vending machines, allowing consumers to view the products which they wished to purchase, thus ensuring confidence in the consumer that they were purchasing exactly what they thought they were purchasing. However, attempts to incorporate a glass front into frozen product vending machines have been less successful due to the need for maintaining a frozen environment behind a panel having a high rate of heat transfer. 
     More recent frozen product vending machines have attempted to incorporate a glass front to allow customers to view the products therein. However, such devices utilize traditional, horizontal, spiral product delivery mechanisms which make the preservation of a frozen environment difficult at best. The spiral product delivery mechanism requires that new product be placed in a precise orientation for proper machine operation and product delivery, thus increasing the amount of time it takes a delivery person to refill the machine with product. This additional period of heat exchange results in the melting and disconfiguration of the frozen product, and can even result in product spoilage. Further, the driving motors for the spiral product delivery mechanism are positioned inside of the frozen area, creating a harsh operating environment for the driving motors and an associated decrease in motor life and reliability. Likewise, the 22 gauge wire typically used to interconnect the motors with the electrical control system become brittle inside of the frozen compartment and are easily broken. 
     Other frozen vending machines display a non-saleable, artificial replica of the frozen products vended by the machine. After viewing the artificial products, a customer makes their selection by depressing the appropriate selection button, and a robotically controlled vacuum device retrieves the actual product from a chest freezer. In this configuration, the customer again is unable to view the actual product which they wish to purchase. 
     Both the spiral product delivery machines and the robotically controlled vacuum machines are complicated devices, the complexity of which vastly adds to the expense of these systems and increases the need for machine mechanics with more advanced technological skills, even for simple maintenance and troubleshooting. 
     Still other vending machines exist which vend other refrigerated products such as milk, soda, etc. Unfortunately, to date, no easy method exists of converting these machines into a more profitable frozen product vending machine. Thus, the typical vending machine owner of older or less profitable machines who desires to reap the profit potential of a frozen product vending machine is faced with either removing the machine from operation and losing the related income, or replacing the machine with a new vendor at large expense. 
     It would therefore be advantageous to provide an improved frozen product vending machine which could securely maintain a frozen environment for storing the product while enabling the consumer to view the actual product they wish to purchase. It would also be advantageous to provide a kit and method for converting existing, unprofitable vending machines into a profitable frozen product vending machine using little technical expertise and little expense for upgrading and modifying components. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide an improved frozen product vending machine which displays the actual product being sold to the consumer through a glass front panel while maintaining an environmentally secure frozen storage environment. 
     It is another object of the present invention to provide an improved frozen product vending machine utilizing a product delivery system which maximizes the vending machine&#39;s product capacity while ensuring consistent product delivery and ease of reloading without excessive heat exchange or damage to the product. 
     It is still another object of the present invention to provide an improved frozen product vending machine that can be easily diagnosed and repaired in the event of a breakdown. 
     It is still another object of the present invention to provide a method and kit for converting existing, less profitable vending machines into frozen product vending machines having the features described herein at roughly half of the cost of purchasing an entirely new machine. 
     In accordance with the above objects, an improved frozen product vending machine is disclosed. The machine is provided with a hinged front panel having a traditional product selection panel, coin receiver, and access opening for retrieving vended product. The front panel is also provided with a central opening through which a consumer may view the interior frozen product storage compartment. 
     Inside of the machine and behind the hinged front panel is a freezer cabinet fitted with a steel enclosure fixedly attached to its front face. The steel enclosure is provided with an upper opening and a lower opening. The upper opening is fitted with a hinged, heated glass door which provides an environmentally secure frozen product storage environment within the machine&#39;s housing. The hinged, heated glass door is aligned with the central opening in the front panel and a refrigerated frozen product conveyor system within the frozen product storage compartment, such that a consumer may view from outside the actual products to be vended from the machine. The steel enclosure on the front face of the freezer cabinet is also equipped with a hinged access door which aligns with the access opening in the front panel and a frozen product receiving compartment within the frozen product storage compartment, allowing a consumer to retrieve their selected product by pushing open the hinged access door. 
     Lastly, the frozen product storage compartment is equipped with a multiple, horizontal conveyor frozen product delivery system comprising a series of electric motor-driven endless conveyor chains which carry a series of guide plates. The guide plates in turn cradle and transport the frozen products within the machine to a dropping point where the guide plates expel the frozen products to a frozen product receiving compartment. The guide plates comprise a three-dimensional elongate block having a top face, a bottom face, a back face, and one end face, the front face and opposing end face of the block remaining open to allow access to the product cradled by the guide plate. The guide plates thus cradle the product therein from both the top and the bottom, allowing product to be dispensed only when the front face of the guide plate is directed downward. This guide plate configuration offers an endless product conveyor delivery system having both an upper span and a lower span, vastly increasing the available storage capacity and selection choices over what has been available in past machines. 
     The motors are controlled by a central, commercially available motor controller which initiates a predesignated motor after a consumer has made a product selection. The controller directs a driving signal to the appropriate motor, driving that motor&#39;s associated conveyor until the frontmost product is dropped from the conveyor. In one embodiment of the present invention, as the product drops from its conveyor to the frozen product receiving compartment, it passes through a projected laser light beam to activate a diffuse photoelectric switch, which in turn activates a motor operation timer. The timer allows the driven motor to continue driving its particular conveyor for a predetermined amount of time, allowing the conveyor to advance the next guide plate and product to the delivery position, such that product may be immediately delivered from that conveyor upon selection by another consumer. 
     Also provided is a method and kit for converting older, less profitable vending machines into frozen product vending machines of the instant invention. The present invention may be used to convert existing Rowe Model 487 Ice Cream Vendors and Rowe Model 495 Milk Vendors to the present invention, utilizing the existing outer cabinet and front panel hardware components. Thus, the current invention utilizes the simplistic, proven reliable technology of the Rowe Model 487 Ice Cream Vendors and Rowe Model 495 Milk Vendors to provide a frozen product vending machine with the added improvement of a glass front. As described in detail below, the hardware on the rear of the front panel may be relocated while maintaining all of the existing electrical connections, allowing the front panel itself to be reconfigured with the necessary openings for the present invention. Alternatively, the control mechanisms on the existing machines may be replaced with the motor controller described below in reference to the first stated embodiment of the present invention. Finally, either the existing motors or those described below in the first stated embodiment of the present invention may be mounted on a standard freezer cabinet, and the existing conveyors and guide plates modified to a horizontal configuration within the freezer cabinet. The freezer cabinet is then fitted with a steel enclosure to maintain a secure frozen environment, and the reconfigured assembly is able to provide both greater selection and product holding capacity than has been available in past machines, at a cost of approximately half of that of a new frozen product vending machine. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which: 
     FIG. 1 is a perspective view of the frozen product vending machine of the present invention. 
     FIG. 2A is a perspective view of the interior of the frozen product vending machine of the present invention. 
     FIG. 2B is a side view of the inner frozen product storage compartment. 
     FIG. 3 is a front perspective view of the inner frozen product storage compartment. 
     FIG. 4 is a perspective view of the rear of front panel  20  of the present invention. 
     FIG. 5 is a close-up perspective view of the modified chest freezer  50  of FIG.  3 . 
     FIG. 6 is a perspective view of the rear gear  55  and supporting structure therefor. 
     FIG. 7 is a perspective view of the rear bracket  53  of the present invention. 
     FIG. 8 is a side view of the conveyor assembly  70  of the present invention. 
     FIG. 9 is a close-up perspective view of the chain conveyor  71  and guide plates  72  of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 is a perspective view of a frozen product vending machine of the present invention. The machine outer body is comprised of a hollow, open-faced outer cabinet  10  and a front panel  20 . Front panel  20  is attached to outer cabinet  10  via hinges along one edge of front panel  20 , such that front panel  20  may be opened to allow access to the inner frozen product storage area and the front panel hardware (i.e., electronic selector switches, coin receiver, etc., discussed below). Front panel  20  is equipped with a selection panel  11  having a series of selector switches  12  which, when depressed, operate the appropriate internal electric motor (discussed below) to advance the selected frozen item to a frozen product receiving compartment behind a front panel access opening  15 . A suitable selection panel is commercially available from Coinco as Model 9302GX Keypad electronically coupled to a Model C-80 controller. After a product has been selected through depressing the appropriate selector switch  12 , the consumer simply reaches into front panel access opening  15 , pushing open a hinged access door  18  to reveal the vended product. 
     Front panel  20  is also equipped with a central opening  13  positioned in direct alignment with the display window of an interior frozen product compartment, such that a consumer may readily view the actual products within prior to purchase. Front panel  20  also incorporates a conventional vending machine locking mechanism  14  and conventional vending machine coin and dollar bill receiving and return slots  16  and  17 . 
     FIG. 2 shows the interior of outer cabinet  10 , in which is housed the inner frozen product storage compartment (shown generally at  40 ). Frozen product storage compartment  40  comprises a modified chest freezer  50  (described in detail below) which is placed within the hollow interior of outer cabinet  10 . The bottom of chest freezer  50  is placed on a simple 4 inch or other appropriately dimensioned wooden platform  42  to raise the chest freezer to the appropriate level for viewing through glass door  32  from outside the machine. In a second embodiment of the present invention, chest freezer  50  is slidably mounted to platform  42  using sliding rails (not shown) on the bottom of the freezer cabinet or, alternatively, on the inner sidewalls of outer cabinet  10 , enabling the entire frozen product storage compartment  40  to be slid outward from the interior of cabinet  10  to provide easy access to motors  51  for servicing. A suitable chest freezer is commercially available from Kelvinator as Model No. 1KG403, although any chest freezer having generally similar dimensions would suffice. 
     The open front face of chest freezer  50  is fitted with a steel enclosure panel  30 . Steel enclosure panel  30  is dimensioned to precisely mate with the front face of chest freezer  50  when the front door of freezer  50  is removed. As shown in the side view of chest freezer  50  and front enclosure panel  30  of FIG. 2B, the rectangular, rear open face of enclosure panel  30  mates directly with channel  46  on the front face of freezer cabinet  50 , and is affixed to the front face of freezer cabinet  50  using screws or similarly arranged fasteners. 
     Referring again to FIG. 2A, steel front enclosure panel  30  is provided with an upper opening  31  in direct interior alignment with the frozen product storage compartment  40 , and in direct exterior alignment with front panel central opening  13  when the front panel  20  is in its closed position. Upper opening  31  is closed with a heated, hinged glass door  32 . A suitable heated glass door is commercially available from Excellence as model number ELD-4. Glass door  32  allows easy access to the frozen product storage compartment  40 , allowing simple and efficient replacement of product with a minimum of heat exchange. A magnetic gasket seal is provided around the periphery of the underside of glass door  32 , sealing the gap between the rear surface of glass door  32  and front enclosure panel  30 , thus ensuring the maintenance of a frozen environment within the frozen product storage compartment. In this fashion, a serviceman may access frozen product storage compartment  40  simply by opening front panel  20  and opening glass door  32 . As traditional frozen product vending machines include a barrier door covering the full interior of outer cabinet  10 , minimizing the opening to glass window  32  vastly reduces the heat exchange that occurs during routine filling operations. Likewise, through this arrangement, a serviceman may access motors  51  for repair or maintenance without compromising the frozen environment within frozen product storage compartment  40 . 
     Steel front enclosure panel  30  is also provided with a lower hinged access door  18 , allowing a consumer to retrieve their purchased product after it has been dropped to a frozen product receiving compartment within the frozen product storage compartment. Hinged access door  18  is arranged such that when front panel  20  is in its closed position, hinged access door  18  is readily visible and accessible through front panel access opening  15 . 
     In an alternate embodiment of the present invention, and as shown in phantom in FIG. 2B, a laser operated switch  59  may be provided, mounted at the juncture of the front face of freezer cabinet  50  and the rear face of steel enclosure panel  30 . A suitable laser operated switch is a diffus photoelectric switch, and is commercially available from OMRON as model number E35-DS5E21. Laser  59  is positioned within the path of the product as it falls from the frozen product storage compartment  40  to open cavity  44  (FIG.  3 ), such that as the product falls, it interrupts the laser&#39;s projected beam and triggers the photoelectric switch. The photoelectric switch in turn triggers a timing device within a motor controller  18  (FIG. 4) mounted on the rear of front panel  20  and commercially available from OMRON as moto controller model number CPM-1A-CDRA. The motor controller then allows the driven motor to continue to rotate its respective conveyor for a predetermined amount of time to advance the conveyor to the next product delivery or “ready” position. 
     FIG. 3 shows the interior of inner frozen product storage compartment  40 . Access to frozen product storage compartment  40  is gained by opening hinged front panel  20  and glass door  32  on front enclosure  30 . Placed in the bottom of chest freezer  50  is a frozen product receiving compartment  43 , defining an open cavity  44  which a consumer may access through opening hinged door  18  (FIGS. 1 and 2) to retrieve the vended product. When a product is selected, it is dropped to the bottom of freezer cabinet  50  and comes to rest either in front of or just inside of open cavity  44 . When hinged door  18  is opened to retrieve the vended product, the consumer then has free access to open cavity  44 , while access to the frozen product storage compartment  40  is blocked by angled top plate  45 . Top plate  45  is configured to allow free rotation of hinged door  18  backwards until the back of door  18  butts against top plate  45 , allowing full access to open cavity  44  while denying access to frozen product storage compartment  40 . 
     FIG. 4 shows the back of front panel  20 . As in traditional vending machines, front panel  20  is equipped with conventional coin and dollar bill receiving and return slots  16  and  17 , and selection panel  11 . Selection panel  11  in turn is electrically coupled to motor controller  18 . Selection panel  11  comprises a keypad which is commercially available from Coinco as model number 9302 GX, and model C-80 keypad controller. Likewise, motor controller  18  is commercially available from OMRON as model number CPM-1A-CDRA. As explained above, front panel  20  is provided with a central opening  13 . Central opening  13  is positioned in front panel  20  such that opening  13  is positioned in direct alignment with the display window of an interior frozen product compartment when front panel  20  is closed. Likewise, front panel  20  is provided with front panel access opening  15 , allowing a consumer access to the vended product via hinged access door  18 . 
     FIG. 5 shows a chest freezer cabinet  50  which has been equipped with a series of four vending motors  51  running vertically along both sides of the exterior of freezer cabinet  50 . Suitable vending motors are commercially available from Oriental as model number SMK216A-GN. Vending motors  51  are used to drive front gears  54  which, in combination with rear gears  55 , carry conveyor assembly  70  (see FIG.  8 ). Front and rear gears  54  and  55  are commercially available from Oriental as gear head model number 2GN15KA. The teeth of gears  54  and  55  engage the links of the frozen product conveyor assembly  70  (FIG. 8) to advance product to frozen product receiving compartment  43  in the bottom of chest freezer  50  (FIG.  3 ). 
     Front gears  54  are supported and held in place by the driving axes of vending motors  51 . The axles of front gears  54  pass through front brackets  52  and engage the ends of the driving axes of vending motors  51 . Vending motors  51  are bolted or otherwise fastened to both sides of the exterior of freezer cabinet  50 , slightly behind the front opening of freezer cabinet  50 . Likewise, rear gears  55  are supported and held in place by rear sprocket support plates  65  (See FIG.  6 ). Rear sprocket support plates  65  are in turn held by rear brackets  53  which are bolted or otherwise fastened to both sides of the interior of freezer cabinet  50 , slightly in front of the rear surface of the interior of cabinet  50 . Rear sprocket support plates  65  rotatably support the axes of rear gears  55 , and slidably engage notched sections of the sidewalls of rear brackets  53  (See FIG.  7 ). A horizontal extension plate extends outward from the rear sprocket support plate  65 , and a vertical flange extends upward from the horizontal extension plate and engages the opposite end of rear gear  55 . 
     As in conventional conveyor driven vending machines, an adjustable-length tension rod  59  extends between front and rear gears  54  and  55 . As shown in FIG. 6, tension rod  59  is hollow at its rear end such that it slides over an extension rod  100  of the rear sprocket assembly. Likewise, the front sprocket assembly is provided with an identical extension rod  100  which in turn is affixed to a tension bolt  101  (FIG.  6 ), which is hollowed to receive the front end of tension rod  59 . When tension bolt  101  is turned, tension rod  59  is pushed farther from the front sprocket assembly, in turn moving rear sprocket  55  further towards the rear of cabinet  50 , thus removing slack from the conveyor assembly  70  such that the upper and lower sections of conveyor assembly  70  run in parallel to one another and to the upper and lower surfaces of cabinet  50 . 
     FIG. 8 shows a detailed view of conveyor assembly  70 . As particularly shown in FIGS. 8 and 9, conveyor assembly  70  consists of chain conveyor  71  and guide plates  72 . As may be seen more clearly in FIG. 9, chain conveyor  71  comprises a series of parallel nylon chain links  75 . Each link is pivotally connected at both of its ends to another link using pins  76  as with any standard chain assembly. However, pins  76  are provided sufficient length such that a portion of each pin  76  extends outward from the flat face of link  75 . Guide plates  72  are configured with a nearly vertical back panel  80 , bottom panel  81 , top panel  82 , and end panel  83 , such that a frozen product is cradled in each support tray as it advances along the conveyor assembly. Guide plates  72  are also provided with a downward flange  84  having holes  85  therein which receive the exposed portion of pins  76 , thus providing a snap connection for snapping guide plates  72  onto nylon chain  75 . Thus, guide plates  72  may be easily removed to accommodate frozen products of varied sizes. In operation, the tines of front and rear gear heads  54  and  55  engage links  75  to advance the conveyor assembly such that the next available frozen product is dropped into frozen product receiving compartment  43  (FIG.  3 ). 
     Referring back to FIG. 9, it may be seen that the configuration of the conveyor assembly  70  will allow frozen product to be loaded and carried by the chain conveyor  71  and guide plates  72  along both the upper and lower spans of conveyor assembly  70 . While bottom plate  81  supports the frozen products from below as they are carried across the top span of the conveyor assembly, top plate  82  supports the frozen products from below as they are carried across the bottom span of the conveyor assembly. Likewise, top plate  82 , bottom plate  81 , and rear plate  80  all serve together to cradle the frozen product as it is carried around the rearward turn of the conveyor assembly to the upper span. Thus, the present invention nearly doubles the frozen product storage capacity for a horizontal frozen product conveyor assembly. 
     Thus, by utilizing a horizontal conveyor assembly, the present invention is able to offer a wider selection of frozen products to the consumer than have been available in the past with traditional vertical conveyor system vending machines, while being capable of carrying nearly the same amount of product as was available in those traditional machines for each product that is offered. Finally, by incorporating a compact, horizontal conveyor assembly system into a frozen product vending machine, the present invention allows a frozen product vending machine to be equipped with a glass front, such that consumers may view the actual product they wish to purchase, as opposed to a “mock-up” or graphical depiction of the product. 
     Retrofit of Existing Vending Machines 
     While the present invention may be entirely manufactured as a new unit, a particular feature of this invention is the ability to convert existing, unprofitable vending machines into frozen product vending machines which offer a larger and more aesthetically appealing variety of product than has been available from frozen product vending machines in the past. Thus, a vending machine owner may be presented with the option of converting an existing machine into a frozen product vending machine of the present invention at approximately half the cost of purchasing an entirely new machine. 
     To convert an existing vending machine into the present invention, the first step is to select a freezer cabinet to fit within the outer cabinet  10  of the existing vending machine, leaving a clearance of at least six inches on either side of the freezer cabinet to safely receive vending motors  51 . To convert existing frozen and refrigerated product vending machines, namely, Rowe Model 487 Ice Cream Vendors and Rowe Model 495 Milk Vendors, a suitable freezer cabinet is commercially available from Kelvinator as model number iKG403. An opening is cut in the rear of the existing outer cabinet  10  using a circular saw equipped with a steel blade. The opening is dimensioned to snugly receive the rear section of freezer cabinet  50 , and is finished with steel trim. The original gasket from the front door of freezer cabinet  50  is removed, and the front door of freezer cabinet  50  is discarded. 
     To prepare the existing vending machine, the existing conveyor assembly and existing compressor are removed from the interior of cabinet  10 , leaving behind the original wiring. Freezer cabinet  50  is then equipped with the OMRON motor and horizontal conveyor assembly fully described above in the following manner. 
     Front brackets  52  receive the axles of front sprockets  54 . Assembled front brackets  52  are then bolted to the interior side walls of freezer cabinet  50  towards the front opening of the freezer cabinet, and rear brackets  53  are adhesively attached to the interior side walls of freezer cabinet  50  towards the rear wall of the freezer cabinet. Vending motors  51  (Oriental model number CPM-1A-CDRA) are then mounted on the exterior sidewalls of freezer cabinet  50 , having their driving axes placed through the sidewalls of freezer cabinet  50  to engage an end of the axles of front sprockets  54 , and the motors are bolted in place. Next, the rear sprockets  55  are slid into the slots in rear brackets  53 . The completed conveyor assembly  70  (comprising nylon chain conveyor  71  and guide plates  72  as described above) is then placed over the front and rear sprockets  54  and  55 , and a tension rod is affixed to the extension rods  100  of each sprocket assembly. The tension rod length is then adjusted to remove any slack in the upper or lower spans of the conveyor assembly  70 . 
     Finally, the front opening of freezer cabinet  50  is fitted with a steel enclosure panel  30  including a heated, hingedly attached front glass window  32  and a lower hinged access door  18 , as described in detail above. 
     The completed adapted freezer cabinet  50  is then placed in the outer cabinet  10 , and fixed in place with wood frame  41 . Alternatively, sliding rails may be mounted on the interior sidewalls of cabinet  10  to position freezer cabinet at any desired height. 
     After freezer cabinet  50  has been affixed to the interior of outer cabinet  10 , barrier door  30  is removed from the outer cabinet  10  and discarded. Next, the interior of front panel  20  may be modified as necessary to reposition the existing hardware and to provide the necessary openings. When converting a Rowe Model 487 Ice Cream Vendor to a frozen product vending machine of the present invention, the original vend door assembly and push button selection assembly are removed from front panel  20 . The original vend door assembly is discarded, and a central opening  13  is cut so as to provide an opening in direct alignment with the glass door assembly  32  on barrier door  30 , opening  13  being slightly smaller than glass door assembly  32 . Thus, a consumer may readily view the contents of the machine through glass door  32 . The original push button assembly is then disassembled and reconfigured in a new push button mounting box to provide the multiple selection buttons mounted vertically alongside of opening  13 . Alternatively, an existing push button assembly from a Rowe Model 495 Milk Vendor may be substituted. 
     When converting a Rowe Model 495 Milk Vendor to a frozen product vending machine of the present invention, the original push button assembly is likewise removed from front panel  20 , and the original front panel  20  is cut with a central opening  13  in direct alignment with the glass door assembly  32  on barrier door  30 , opening  13  being slightly smaller than glass door assembly  32 . The original push button assembly is then again mounted vertically alongside of opening  13 . 
     Following the reconfiguration of front panel  20 , the electrical connections may be made using the identical wiring from the original machine that was left in the interior of outer cabinet  10  when the conveyor assemblies were removed. Because all of the original selection hardware remains on front panel  20 , the connections in the interior of outer cabinet  10  are made by simply attaching the appropriate selector lead wires to their respective vending motors  51 . 
     In the above described processes for retrofitting existing frozen product vending machines with the improvements of the instant invention, a machine owner is able to easily upgrade an existing, less profitable machine to a glass front frozen product vending machine for the cost of the assembled freezer cabinet. The entirety of the remaining structure is salvaged from the earlier machine, thus vastly reducing the cost of upgrading the machine. However, instead of using the existing control hardware, the owner may alternately replace the existing control hardware with the OMRON motor controller described above, providing the machine with the added improvements of reversible motors for assisting in the reloading of frozen product, and multiple product price settings for any single conveyor system. In such event, the machine owner is still able to salvage the entirety of the original machine&#39;s outer cabinet, once again vastly reducing the cost of upgrading a less profitable machine to one including the benefits of the instant invention. 
     While the present invention is preferably used to convert existing frozen and refrigerated product vending machines, namely, Rowe Model 487 Ice Cream Vendors and Rowe Model 495 Milk Vendors, it may be used to convert any existing vending machine which utilizes a 115 Volt delivery mechanism, including traditional canned soda machines. In these alternate machines, the vend signal again may be directed to the appropriate vending motor  51  of the present invention, and the appropriate openings may be made in front panels  20  and barrier doors  30  so as to provide a consumer with visual access to the interior of the frozen product storage compartment. 
     Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth herein.