Frozen custard machine

FIELD OF THE INVENTION

The present invention generally relates to frozen custard machines or systems. More particularly, the present invention relates to the overall size and/or configuration of a frozen custard machine.

BACKGROUND OF THE INVENTION

Ice cream or frozen custard machines, as well as other systems for cooling or freezing food stuffs, condiments, or other materials, typically include an evaporator situated proximate the material being chilled. For example, in frozen custard machines, liquid custard (e.g., the mix) is typically inserted in a freezing chamber or barrel associated with the evaporator and is removed from the barrel as solid or semi-solid frozen custard. The evaporator removes heat from the freezing chamber as a liquid refrigerant, such as, FREON7, ammonia, R-404a, HP62, or other liquid having a low boiling point, changes to vapor in response to the heat from the liquid mix. Typically, the evaporator is partially filled with vapor as the liquid refrigerant boils (e.g., becomes vapor) in the evaporator.

Quick freezing of liquid mix and high capacity are desirous features of frozen custard machines. In addition, frozen custard quality and efficient manufacture of such custard are dependent upon maintaining a constant evaporator temperature (e.g., constant barrel temperature). The barrel temperature must be kept in a proper range for making frozen custard. If the custard is allowed to become too cold, the liquid mix in the evaporator becomes highly viscous and can block the travel of the frozen custard through the barrel. Blockage of the barrel in the freezing process is commonly known as “freeze up”. If the frozen custard is allowed to become warm, its texture is adversely affected.

Maintaining the temperature of the barrel at a constant level is particularly difficult as frozen custard flow rates through the machine vary and change the cooling load on the evaporator. For example, more heat dissipation is required as more frozen custard is produced (i.e., the flow rate is increased). Additionally, if the barrel temperature is too low, refrigerant flood-back problems can adversely affect the operation of the compressor. For example, if the refrigerant is not fully evaporated as it reaches the compressor, the liquid refrigerant can damage the compressor.

Problems associated with temperature consistency are exacerbated during periods of non-production (e.g., an idle mode, a period of slow sales, a hold mode, etc.). Generally, frozen custard machines can experience non-production modes, periods of little or low production operation or a “hold” mode. During this mode, liquid mix and frozen custard product remain in the barrel (the cooling chamber) awaiting to be processed. However, due to the low demand for frozen custard, frozen custard is not removed from the barrel. The frozen custard in the barrel can be subjected to temperature fluctuations during these periods of non-production due to heat infiltration.

Heretofore, frozen custard machines have required that the refrigeration system (the compressor) be cycled on and off to maintain the frozen custard in the barrel at the appropriate temperature. Such conventional systems have been unable to accurately maintain the barrel temperature at a proper and consistent temperature. For example, the fairly large compressors associated with the frozen custard machine cool (e.g., overcool) the barrel down and then allow it to warm back up before the compressor is engaged to cool the barrel. The temperature within the barrel fluctuates according to a sawtooth wave. The gradual freezing and thawing causes the product to break down such that texture of the product becomes more grainy and less desirable to the taste.

Further, conventional systems have allowed the liquid mix to have constant access to the barrel. Generally, conventional systems have included a liquid mix reservoir connected to the evaporator via an aperture. The allowance of liquid mix to enter the barrel during non-production times contributes to the warming of the frozen custard in the barrel, thereby affecting the quality of the frozen custard within the barrel when liquid mix is allowed to fill the barrel, the liquid mix can become frozen against the barrel, thereby reducing the freezing efficiency of the barrel.

Further, conventional systems have allowed the frozen custard product to be periodically and automatically mixed (i.e., beaten) in the evaporator during non-production modes or slow sales periods. Overbeating of the frozen custard product results in poor frozen custard texture and less desirable taste.

Further, conventional frozen custard machines are relatively large units that are supported directly by the ground or floor. The size of frozen custard machines is dictated at least in part by the components of the cooling system provided therein or operatively coupled thereto. Conventional cooling systems require a substantial amount of space and constitute a substantial amount of weight. Conventional frozen custard machines are known to be over 5 feet in height and to have weights in excess of 1000 pounds. Machines of such size are often difficult to deliver, move, clean around, and/or find space for within a store.

Thus, there is a need for a frozen custard machine which can operate in a hold mode and not allow the barrel temperature to fluctuate drastically. Further still, there is a need for a process and a machine which can more efficiently and more evenly cool frozen custard. Even further still, there is a need for a frozen custard machine which utilizes a barrel and maintains the frozen custard product at a consistent temperature.

Yet even further still, there is a need for a process or method which does not allow liquid mix to affect the temperature in the barrel while in a hold or non-production mode. Yet even further, there is a need for a frozen custard machine which does not allow the chamber wall to become coated with frozen custard. Further still, there is a need for an evaporator and a control system for a frozen custard machine which prevents breakdown of the frozen custard product during slow sales periods. Further, there is a need for a hold mode for a frozen custard machine which requires little or no bearing of the frozen custard product.

Yet even further still, there is a need for a frozen custard machine that is sized to conveniently fit in a relatively small space within a store (e.g., a frozen custard shop or stand, etc.). Further still, there is a need for a frozen custard machine that is sized to fit on an elevated surface (e.g., a countertop, tabletop, shelf, etc.) rather than having to be supported by the floor. Further still, there is a need for a relatively compact frozen custard machine that can still output enough product for effective commercial use.

SUMMARY OF THE INVENTION

An exemplary embodiment relates to an ice cream making system. The ice cream making system includes an evaporator including a cooling chamber and at least one valve. The cooling chamber has an ice cream input and an ice cream output. The at least one valve is provided at the ice cream input and is capable of preventing ice cream from entering the cooling chamber.

Yet another embodiment relates to an evaporator for an ice cream making system. The evaporator includes an interior surface defining a cooling chamber for chilling a product, an evaporator chamber and a valve. The cooling chamber has an ice cream input and an ice cream output. The evaporator chamber surrounds the cooling chamber. The valve is in series with the ice cream input.

Yet another embodiment relates to a method of manufacturing ice cream. The method utilizes an ice cream machine having a cooling chamber. The method includes providing liquid ice cream contents into the cooling chamber through a valve. The valve prevents the cooling chamber from being more than 75% filled during a hold mode. The method also includes cooling the ice cream contents in the cooling chamber and removing frozen ice cream from the cooling chamber.

Still another embodiment relates to ice cream machine including an evaporator having a cooling chamber. The cooling chamber has an ice cream input and an ice cream output. The ice cream machine also includes means for restricting access through the ice cream input to the cooling chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:

FIG. 1 is a schematic diagram illustrating an advantageous ice cream making system according to an exemplary embodiment;

FIG. 2 is a schematic diagram illustrating another advantageous ice cream making system according to another exemplary embodiment;

FIG. 3 is a state diagram showing the operation of the systems illustrated in FIGS. 1 and 2;

FIG. 4 is a more detailed side cross-sectional view of an evaporator for use in the systems illustrated in FIGS. 1 and 2;

FIG. 5 is a more detailed side planar view of an alternative evaporator for use in the systems illustrated in FIGS. 1 and 2;

FIG. 6 is a more detailed side planar view of an alternative evaporator for use in the systems illustrated in FIGS. 1 and 2;

FIG. 7 is more detailed side planar view of an alternative evaporator for use in the systems illustrated in FIGS. 1 and 2;

FIG. 8 is a general block diagram of a gate, valve and auger control system for the ice cream machine systems illustrated in FIGS. 1 and 2;

FIG. 9 is a flow diagram showing exemplary operation of the systems illustrated in FIGS. 1 and 2;

FIG. 10 is a perspective view of a frozen custard machine according to an exemplary embodiment;

FIG. 11 is a side planar view of the frozen custard machine shown in FIG. 10;

FIG. 12 is a front planar view of the frozen custard machine shown in FIG. 10;

FIG. 13 is a top planar view of the frozen custard machine shown in FIG. 10; and

FIG. 14 is a schematic diagram illustrating a refrigeration or cooling system of the frozen custard machine of FIG. 10, shown according to an exemplary embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENT OF THE PRESENT INVENTION

A soft serve, frozen custard, or ice cream machine or making system 10 is diagrammatically shown in FIG. 1. Ice cream machine 10 includes a cooling or refrigeration system 12 and an evaporator 20. Refrigeration system 12 can include any number of components for providing and processing liquid refrigerant to and receiving and processing a vapor refrigerant from evaporator 20. For example only, system 12 can include an expansion device, such as, a valve, a shut-off device, such as, a solenoid valve, a sight glass, a filter, a condenser, a compressor, an accumulator, and a valve. Although not limited to such systems, system 12 can utilize any of the components or systems described in U.S. Pat. Nos. 6,119,472, 6,101,834, 5,755,106, and application Ser. No. 09/639,062.

Evaporator 20 can be a system including a number of components on a single integral unit. For example only, evaporator 20 can include a cylindrical cooling tank, a secondary evaporator, and an auxiliary tank. Evaporator 20 can have a design similar to any of the evaporators discussed in U.S. Pat. Nos. 6,119,472, 6,101,834, 5,755,106, and application Ser. No. 09/639,062. Evaporator 20 is modified to include a secondary evaporation or another jacket for maintaining the temperature within evaporator 20 during non-production modes.

Evaporator 20 includes a first refrigerant input 40, a first refrigerant output 42, a liquid ice cream input 44, and an ice cream output 46. Evaporator 20 further includes a second refrigerant input 41 and a second refrigerant output 43. Refrigeration system 12 utilizes refrigerant input 40 and refrigerant output 42 to provide primary cooling for ice cream making system 10. Refrigerant input 40 and output 42 are in fluid communication with an evaporator chamber which surrounds a cooling chamber between ice cream input 44 and ice cream output 46. Output 42 can also be coupled to an auxiliary evaporator tank as described below with reference to FIG. 4.

With reference to FIG. 3, system 10 can manufacture ice cream or other frozen or semi-frozen food stuff in an operational mode 61. Ice cream can be manufactured utilizing a quick draw gate which creates ice cream whenever gate 52 is opened. During the manufacture of ice cream in mode 61, system 10 uses the primary cooling loop associated with input 40 and output 42. Alternatively, both the primary evaporator chamber and the secondary evaporator chamber (the secondary loop associated with input 41 and output 43) can be utilized.

When demand ceases, system 10 operates in a non-production mode 62. When demand returns, such as, when gate 52 is opened, system 10 returns to mode 61. Various sub-states or intervening states may occur between modes 61 and 62. For example, system 10 may not reach a non-production mode until the temperature within evaporator 20 reaches a particular level. Further, system 10 may be maintained in mode 61 until ice cream is not demanded for a period of time or until the temperature within evaporator 20 falls below a predetermined level after gate 52 is closed.

Advantageously, when system 10 operates in a non-production mode 62, it maintains the contents within evaporator 20 at a consistent temperature. Non-production mode 62, such as, an idle mode, or hold mode, refers to any period of time at which system 10 is not allowing ice cream to exit outputs 46 and yet ice cream product, whether or not completed or partially completed, remains in the freezing chamber of evaporator 20. The non-production mode can be utilized during periods of slow sales, when system 10 is idling between business hours (system 10 is idle for the night), etc.

In mode 62, refrigeration system 12 (FIG. 1), second refrigerant input 41 and second refrigerant output 43 maintain the interior cooling chamber of evaporator 20 at a consistent temperature. A secondary evaporator chamber is in fluid communication with input 41 and output 43. The secondary evaporator can encompass the primary evaporator chamber associated with input 40 and output 42.

The secondary evaporator preferably cools refrigerant trapped within the primary evaporator chamber, thereby acting as a second loop for cooling the primary refrigeration loop, (the primary evaporator chamber). The trapped refrigerant within the primary evaporator surrounding the interior freezing chamber provides a stabilizing effect to hold and transfer temperature into the ice cream product held within the interior cooling chamber.

The refrigeration system 12 can utilize a primary compressor system and/or a secondary compressor system to provide refrigerant to the secondary evaporator. The secondary evaporator can be any or any combination of wrapped tubing, refrigeration jackets, and/or chambers. By maintaining the temperature at a more consistent temperature via refrigerant input 41 and refrigerant output 43, fluctuations in product temperature that can break down the ice cream and cause poor tasting ice cream are reduced. Further, product which has been left in the interior chamber for prolonged period of time is not wasted.

In one embodiment in which system 10 is configured as a soft serve ice cream machine, ice cream can be stored in the interior chamber within the barrel to keep it at the appropriate temperature between draws (e.g., servings). This advantageously allows ice cream to be served directly from evaporator 20 and eliminates the need for a dipping cabinet or other refrigeration unit for storing post manufactured ice cream. In this way, ice cream directly from the machine can be immediately served.

Applicant has found that by using a secondary cooling loop (e.g., secondary evaporator between input 41 and output 43), a consistent temperature can be provided in the interior chamber for long periods of time, such as, 60 hours. Accordingly, over long periods of time in non-production mode 62, the contents of the interior chamber do not need to be emptied and discarded due to on/off cycling. Rather, the contents can remain in evaporator 20 and be served accordingly. Further, since ice cream is not discarded, the interior chamber does not need to be cleaned after each entry into non-production mode 62.

According to one embodiment, at least one non-positive shutting control valve can be provided at input 40 to the primary evaporator. Liquid refrigerant is allowed to enter through the control valve to evaporator 20 (to the first cooling loop of evaporator 20). Allowing liquid refrigerant through input 40 in a metered but continuous fashion allows the liquid in the first stage loop to become saturated and subcooled. The liquid refrigerant completely fills the first stage loop and its presence acts as a stabilizing effect on temperature swings by means of thermal mass and thermal transfer.

According to another preferred embodiment, machine 10 can control auger 56 at different speeds during different periods of production. During production of ice cream (mode 61), machine 10 allows auger 56 to spin at a first speed (slow rpm) for production. When gate 52 is open, auger 56 spins at a second speed (a faster rpm) for discharging product through output 46. Various speeds can be chosen in accordance with design criteria to achieve highest production and optimal discharge rates.

System 10 further includes an advantageous ice cream transport control system. Ice cream is provided at ice cream output when a gate 52 is opened. Gate 52 is preferably linked to a valve 54 at ice cream input 44. Accordingly, when gate 52 is opened and closed, valve 54 is also open and closed. A delay for opening and closing valve 54 after gate 52 is opened can also be implemented by a control mechanism. In one embodiment, once opened, valve 54 can remain open until a particular capacity is reached in the cooling chamber.

Valve 54 can be controlled by mechanical linkage coupled to gate 52. Alternatively, an electronic control system can be utilized to control the opening of valve 54 with respect to gate 52.

Liquid ice cream is not allowed to enter the interior chamber and warm the contents of interior chamber when gate 52 is closed and system 10 is in a hold or non-production mode 62 (FIG. 3). In this way, valve 54 only allows an appropriate amount of mix to be in the interior chamber according to dry barrel technology. Further still, applicants have found that by limiting the quantity of material within the interior chamber, system 10 operating as a direct draw machine produces higher quality fresh ice cream having a superior taste. Product is produced with low overrun, thereby operating with results similar to a standard machine.

In another preferred embodiment, machine 10 utilizes valve 54 to meter and limit the amount of product stored in evaporator 20. By eliminating the amount of products stored in evaporator 20, the surface area available for production of product is increased, thereby increasing the speed at which ice cream is frozen. Faster freezing generally results in a better ice cream product texture.

As discussed above, since the amount of custard stored in the barrel of evaporator 20 is minimized (the heat exchange area is maximized), a more effective surface area for production is achieved. This is a significant advantage over conventional soft serve ice cream machines in which liquid ice cream product fills evaporator 20 (e.g., the freezing chamber is flooded). With such conventional systems, the inner wall of the chamber is coated with frozen product and becomes less effective for freezing the remaining product in the chamber of new product.

According to another embodiment, the dry barrel technology discussed above can be implemented via valve 54. Valve 54 can be a metering valve controlled by an actuator. An electric control circuit coupled to a sensor can ensure that actuator restricts the chamber to be less than half-filled during non-production modes. Preferably, the freezing chamber in evaporator 20 is 25% to 50% filled with pre-made product. A conventional machine typically allows of the chamber to be 75 to 100% filled with pre-made product. The metering valve is controlled to be positively shut when gate 52 is shut and ice cream is not drawn from evaporator 20. This allows the barrel to store pre-made product but only have 25-50% of the barrel full of pre-made product, thereby resulting in faster freezing of new product.

In addition, a control circuit or system is preferably provided which prevents an auger 56 within the interior chamber from overbeating the contents of interior chamber when gate 52 is closed. Embodiments of control systems mechanisms and schemes for system 10 are described with reference to FIG. 8. The control schemes monitor the operation of auger 56 and valve 54.

With reference to FIG. 2, an ice cream making system 100 is substantially similar to ice cream making system 10. However, refrigeration system 12 of FIG. 1 includes a primary refrigeration system 112 and a secondary refrigeration 114. Systems 112 and 114 can share components. Preferably, systems 112 and 114 have separate compressors. Alternatively, system 100 can include three or more refrigeration systems if three or more evaporator chambers or coils are utilized by evaporator 20.

Although evaporator 20 is shown as having four separate interfaces (inputs 40 and 41 and outputs 42 and 43) in FIGS. 1 and 2, the interfaces can be integrated together and/or separately divided within evaporator 20. For example, a gate or valve can be used to divert refrigerant from a single supply line to input 40 and input 41 located within evaporator 20. Similar systems can be designed for outputs 42 and 43.

Primary refrigeration system 112 preferably includes a relatively large compressor for use in making ice cream during normal operating temperatures. A smaller compressor can be utilized in secondary refrigeration system 114. The smaller compressor can more efficiently provide limited amounts of refrigerant to evaporator 20. Preferably, the secondary compressor is rated between ¼ and ¾ horsepower, depending on design. In a preferred embodiment, a ⅓ horsepower rating is utilized. The primary refrigeration system 112 can utilize a compressor with a 1½ to 3 horsepower or more rating. In a preferred embodiment, a compressor rated at a ½ horsepower rating is utilized. The use of the smaller compressor during mode 62 (FIG. 3) reduces energy consumption. Limiters may be used to make the capacity of a 1½ to 3 HP compressor act like smaller unit.

In an alternative embodiment, a separate condenser unit can also be provided for the secondary evaporation chamber and the hopper.

With,reference to FIGS. 4-7, more detailed drawings of alternative embodiments of evaporator 20 (FIGS. 1 and 2) are shown. Each of the embodiments provides for an evaporator with a primary evaporator chamber and a secondary evaporator chamber. The secondary evaporator chamber is used to advantageously maintain the interior chamber at an appropriate cooling temperature. In FIGS. 4-7, reference numerals having the same last two digits are substantially similar unless otherwise noted.

With reference to FIG. 4, an evaporator 124 includes an auxiliary evaporator tank 126, a primary evaporator chamber 128, and a secondary evaporator 130. Primary evaporator chamber 128 is provided about an interior cooling chamber 134 which can include an auger such as auger 56 (FIG. 1). Chamber 134 can be defined by a 0.125 inch thick stainless steel tube 135 having exemplary dimensions of a 4 inch outer diameter. Chamber 128 can be defined by a stainless steel tube 129 having exemplary dimensions of an inner diameter of 4.5 inches and a length of 18 inches-20.5 long.

Chamber 134 includes a liquid ice cream input 142 which can be controlled by a valve and an ice cream output 144 which can be controlled by a gate. Preferably, chamber 134 has a volume of approximately 226 cubic inches.

Evaporator chamber 128 includes a refrigerant input 152 corresponding to refrigerant input 40 and a refrigerant output 154 corresponding to refrigerant output 42 (FIGS. 1 and 2). Preferably, evaporator chamber 128 has a volume of approximately 60 cubic inches (e.g., length of 18 inches and a jacket width of 0.25 inches).

Auxiliary tank 126 includes a refrigerant output 156 which can be coupled to refrigeration system 12. Tank 126 operates as an accumulator similar to the accumulator described in U.S. Pat. Nos. 6,119,472 and 5,755,106. Tank 126 should not be confused with secondary evaporator 130 which operates in parallel with evaporator chamber 128, rather than in series with chamber 128 as tank 126 operates. Secondary evaporator 130 includes a refrigerant input 158 corresponding to refrigerant input 41 (FIGS. 1 and 2) and a refrigerant output 160 corresponding to refrigerant output 43. Preferably, secondary evaporator 130 is comprised of copper tubing wrapped completely around the barrel associated with evaporator chamber 128.

The tubing associated with secondary evaporator 130 can be 3/8 copper tubing. The tubing is closely wrapped in a single layer from end-to-end of evaporator chamber 128. Alternatively, other wrapping configurations and tubing materials and sizes can be utilized. Evaporator 130 can include two or more layers of tubing.

With reference to FIG. 5, an evaporator 224 is substantially similar to evaporator 124 including a refrigerant input 252 and a refrigerant output 254. Output 254 can be coupled to system 12 (FIG. 1) or system 112 (FIG. 2). Evaporator 224 does not include an auxiliary evaporator tank such as evaporator tank 126 in FIG. 4.

With reference to FIG. 6, evaporator 324 includes a secondary evaporator 350. Secondary evaporator 350 is defined by an outer barrel 355, and an inner barrel 360. A primary evaporator chamber 328 is defined by an intermediate barrel 360 and an inner barrel 365. Secondary evaporator 350 includes a refrigerant input 370 and a refrigerant output 380. Evaporator 324 can also include an auxiliary evaporator tank such as tank 126 (FIG. 4). Inner barrel 365 defines interior cooling chamber 334. In a preferred embodiment, inner barrel 365 has an outer diameter of 4 inches and a length of 18 inches. Barrel 360 has an outer diameter of 4.76 inches and a length of 18 inches, and barrel 355 has an outer diameter of 5.25 inches and a length of 18 inches. Barrels 355, 360, and 365 can be 0.125 inches thick and manufactured from stainless steel.

With reference to FIG. 7, evaporator 424 includes secondary evaporator 452 including a double wrap of copper tubes. A first wrap 480 is provided about a second wrap 482. Second wrap 482 is provided about evaporator chamber 450. Chamber 450 includes a refrigerant input and a refrigerant to output similar to refrigerant input 352 and 354 (FIG. 6). Wraps 480 and 482 are provided from end-to-end of chamber 450.

Second wrap 482 includes a refrigerant input 490 and a refrigerant output 492. First wrap 480 includes a refrigerant input 494 and a refrigerant output 496. Refrigerant input 490 and refrigerant output 492 can be coupled to a separate refrigeration system than that used for wrap 480 and chamber 450. Similarly, refrigerant input 494 and output 496 can be utilized with a different compressor or refrigeration system than that used for wrap 482 and chamber 450. Preferably, wraps 480 and 482 are provided on top of each other.

With reference to FIG. 8, a control system 500 is provided to more accurately control the temperature and consistency of product within interior chamber 134 during non-production mode 62. For example, control system 500 can include electronics or mechanical devices to ensure that valve 54 is open and closed simultaneously with gate 52. Alternatively, a delay can be utilized between opening and closing gate 52 with respect to valve 54.

Auger 56 is controlled by control system 500 to ensure auger 56 stops when the interior cooling chamber within evaporator 20 reaches an appropriate temperature. By sensing the amperage being provided through the motor associated with auger 56, the consistency of the contents within interior chamber 134 can be determined. The consistency can represent the appropriate temperature associated with the contents in evaporator 20. When the amperage is at the appropriate level, control system 500 can turn off the motor which drives auger 56, thereby preventing overbeating of the contents in evaporator 20.

Once gate 52 is opened, the motor can be reset and allowed to run until gate 52 is closed. After gate 52 is closed, the motor will continue to run until current sensed through the motor indicates that the appropriate temperature in interior chamber 134 is reached. Alternatively, control schemes can be utilized to stop auger 56 appropriately. For example, system 500 can utilize a temperature sensor situated in chamber 502 or chamber 134. Preferably, control system 500 includes a micro switch or other device for sensing when gate 46 is opened to re-engage the motor which drives auger 56.

With reference to FIG. 9, the various modes associated with systems 10 and 100 described with references to FIGS. 1 and 2 are discussed. In a first mode, or production mode 602, manufacture of an ice cream product can begin. Generally, the production mode operates auger 56 and uses a primary evaporator associated with refrigeration input 40 and refrigeration output 42. An operator can open gate 46 and remove ice cream from evaporator 20 in an operational mode 604. When gate 52 is open, valve 54 is open, thereby allowing liquid ice cream into evaporator 20. After gate 46 is closed and valve 44 is closed, system 10 can enter a non-production mode 606.

Non-production mode 606 can occur once the temperature within evaporator 20 reaches a particular temperature. In mode 606, the primary evaporator and auger are utilized. Similarly, as ice cream is removed, the auger and primary evaporator are utilized. In mode 606, the secondary evaporator is utilized and the auger is stopped to prevent overbeating of the ice cream.

Referring to FIGS. 10 through 14, a frozen custard machine or ice making system 700 is shown according to an exemplary embodiment. Unlike conventional frozen custard machines, frozen custard machine 700 is not a standalone or floor model system, but rather is a relatively compact system designed to be supported by an elevated surface such as a counter, table, cabinet, or any other suitable worksurface. The height at which frozen custard machine 700 is supported from the ground or floor may vary depending on the particular application, but preferably it is supported at a height that is convenient for an operator to use. For example, it may be desirable to support frozen custard machine 700 at a height above 24 inches from the floor, and preferably at a height ranging between approximately 30 inches and approximately 40 inches from the floor.

Referring to FIGS. 10 through 13 in particular, the components of frozen custard machine 700 are contained within a housing 702. Housing 702 is shown as a substantially rectangular structure having a width 704, a height 706, and a depth 708. According to an exemplary embodiment, width 704 is between approximately 15 inches and approximately 30 inches, height 706 is between approximately 20 inches and approximately 50 inches, and depth 708 is between approximately 18 inches and approximately 35 inches. According to a preferred embodiment, width 704 is approximately 20 inches, height 706 is approximately 35 inches, and depth 708 is approximately 25 inches. Providing housing 702 within such dimensions advantageously allows frozen custard machine 700 to conveniently fit on a preexisting elevated worksurface. According to various alternative embodiments, housing 702 may be configured in any of a variety of shapes, having any of a number of dimensions, which provide for a machine that can be readily supported by an elevated surface.

Housing 702 is preferably formed of an internal frame structure (not shown) made of a rigid material, such as steel, which is covered by one or more panels 710. The frame structure is configured to support the various components of frozen custard machine 700, while panels 710 are configured to conceal the components supported within the frame structure. According to the embodiment illustrated, housing 702 includes a front panel 712, a pair of side panels 714, a top panel 716, and a rear panel 718. Preferably, panels 710 are formed of a relatively rigid material that is resistant to corrosion and is relatively easy to clean or sanitize. According to one embodiment, panels 710 are formed of stainless steel and a welded to the frame structure and/or the other panels. According to another embodiment, panels 710 are covered with a coating and are coupled to the frame structure using one or more fasteners (e.g., rivets, bolts, etc.). Such an embodiment may provide sufficient cost savings since the welding process and finishing process (e.g., grinding, etc.) may be eliminated.

Preferably, frozen custard machine 700 has an overall weight that allows it to be placed upon a worksurface without having to modify (e.g., reinforce, etc.) the worksurface. The overall weight of frozen custard machine 700 is significantly less than the overall weight of conventional frozen custard machines (i.e., standalone machines configured to be supported by the floor). According to an exemplary embodiment, frozen custard machine 700 has an overall weight (without custard and/or the liquid mix) between approximately 200 pounds and approximately 400 pounds. According to various alternative embodiments, frozen custard machine 700 may have an overall weight which is greater or less than the range provided.

Frozen custard machine 700 is diagrammatically shown in FIG. 14. Frozen custard product is formed within a first evaporator 720 from a liquid mix provided to first evaporator 720 from a second evaporator 750. First evaporator 720 can have any of a number of configurations, including, but not limited to, those discussed above and those discussed in U.S. Pat. Nos. 6,119,472, 6,101,834, 5,755,106, and application Ser. No. 09/639,062. According to the embodiment illustrated, first evaporator 720 includes a primary refrigeration loop having a first refrigerant input 722 and a first refrigerant output 724, a secondary refrigeration loop having a second refrigerant input 730 and a second refrigerant, output 732, a liquid mix input 726, and a frozen custard output 728.

Frozen custard machine 700 utilizes first refrigerant input 722 and first refrigerant output to provide primary cooling of a cooling chamber 734 wherein the liquid mix is transformed into frozen custard. First refrigerant input 722 and first refrigerant output 724 are in fluid communication with an evaporator chamber 736 which surrounds cooling chamber 734. According to the embodiment illustrated, an auxiliary evaporator tank 736 is provided between evaporator-chamber 736 and first refrigerant output 724. Auxiliary evaporator tank 736 may have any of a variety of configurations including, but not limited to, those discussed in U.S. Pat. No. 6,119,472.

Frozen custard machine 700 utilizes second refrigerant input 730 and second refrigerant output 732 to provide cooling of cooling chamber 734 during a non-production mode (e.g., an idle mode, a hold mode, etc.) in which frozen custard machine 700 is not allowing frozen custard to exit frozen custard output 728 and yet frozen custard product (whether or not completed or partially completed) remains in cooling chamber 734. Second refrigerant input 730 and second refrigerant output 732 are in fluid communication with a secondary evaporator chamber 738. Secondary evaporator chamber 738 may be provided under, over, and/or adjacent to evaporator chamber 736. Preferably, secondary evaporator chamber 738 cools refrigerant trapped within evaporator chamber 736. According to an alternative embodiment, the secondary refrigeration loop may utilize the same chamber as the primary refrigeration loop using a series of valves or other control systems.

First evaporator 720 further comprises a structure, shown as a barrel 740, having an interior surface, wall or tube 742 which defines cooling chamber 734. Tube 742 of barrel 740 may be formed of a variety of suitable materials, such as stainless steel. According to an exemplary embodiment, barrel 740 is a cylindrical member having an overall length between approximately 8 inches and approximately 20 inches and an inner diameter between approximately 3 inches and approximately 6 inches. According to a preferred embodiment, barrel 740 has an overall length of approximately 12 inches and an inner diameter of approximately 4 inches. Utilizing a barrel of this size, advantageously allows frozen custard machine 700 to be configured as a relatively compact unit. The efficiency of the refrigeration system discussed above advantageously allows a shorter barrel 740 to be used for frozen custard machine 700. According to various exemplary embodiments, barrel 740 may have dimensions greater or less than those provided so long as barrel 740 can fit within a frozen custard machine configured to be supported by an elevated surface (such as a counter). One or more barrels 740 may be supported within housing 702. Providing more than one barrel 740 may allow frozen custard machine 700 to simultaneously produce more than one favor of frozen custard product.

Supported within barrel 740 is an auger 744. Auger 744 is provided to mix or otherwise agitate the liquid mix and/or frozen custard product within barrel 740. Auger 744 generally comprises a shaft upon which one or more paddles or blades are supported. The blades are preferably shaped and sized to facilitate the mixing of the liquid mix within barrel 740, the scraping of frozen custard product from tube 742, and the movement of frozen custard product out of barrel 740. The blades are preferably formed of a low friction material, such as Delrin, but may be formed of any of a variety of suitable materials. A first end of the shaft is operatively coupled to a motor 746 configured to provide rotational movement to the shaft and subsequently the blades. Operation of motor 746 is preferably coupled to a control system (as discussed above) and/or a user interface allowing for manual control. Motor 746 is supported within housing 702 of frozen custard machine 700.

As mentioned above, liquid mix is provided to first evaporator 720 from second evaporator 750. Second evaporator 750 can have any of a number of configurations. According to the embodiment illustrated, second evaporator 750 includes a refrigerant input 752 and a refrigerant output 754, a liquid mix input 756, and a liquid mix output 758. Frozen custard machine 700 utilizes refrigerant input 752 and refrigerant output 754 to provide cooling of the liquid mix before the liquid mix is provided to first evaporator 720. Preferably, the liquid mix is maintained in second evaporator 750 at approximately 34 degrees Fahrenheit, but any of a variety of temperatures may be maintained for a particular application if desired.

Refrigerant input 752 and refrigerant output 754 are in fluid communication with an evaporator chamber 760 which surrounds a receptacle, shown as a hopper 762, configured to retain the liquid mix until the liquid mix is provided to first evaporator 720. Hopper 762 has a substantially open top which constitutes liquid mix input 756. The open top configuration advantageously allows the liquid mix to be added easily to hopper 762 by simply pouring the liquid mix into the open top of hopper 762. Referring back to FIG. 10, housing 702 includes a movable and/or removable portion (shown as a lid 717) in top panel 716 which covers the open top of hopper 762. An operator may selectively move lid 717 to gain access to the open top of hopper 762.

Referring again to FIG. 14 and according to the embodiment illustrated, hopper 762 is supported above first evaporator 720 within housing 702. Liquid mix retained in hopper 762 is added to barrel 740 as needed (e.g., as frozen custard product is dispensed from frozen custard output 728, etc.). Supporting hopper 762 above first evaporator 720 advantageously allows the liquid mix to be added to barrel 740 without the use of a pump. In such a embodiment, frozen custard machine 700 relies on gravity to feed the liquid mix into barrel 740. Not requiring a pump for the liquid mix may save space within the compact system. According to various exemplary embodiments, hopper 762 may be supported in any of a number of positions relative to first evaporator 720 and a pump may be provided to pump the liquid mix into barrel 740. Preferably, a valve (not shown) is provided between liquid mix output 758 and liquid mix input 726 of first evaporator 720. Such a valve controls the rate at which the liquid mix is added to barrel 740.

According to the embodiment illustrated, hopper 762 is supported entirely within housing 702. To provide for this configuration, hopper 762 has a reduced capacity. According to an exemplary, hopper 762 is configured to hold between approximately 1 gallon of liquid mix and approximately 5 gallons of liquid mix. According to a preferred embodiment, hopper 762 is configured to hold approximately 3 gallons of liquid mix. According to various alternative embodiments, hopper 762 may extend at least partially out of housing 702 and/or may be configured to hold more or less liquid mix than the amounts provided herein by way of example.

Referring further to FIG. 18, frozen custard machine 700 is further shown as including a compressor 770 and a condenser 772. Compressor 770 and condenser 772 are each supported within housing 702. Compressor 770 provides high pressure vapor refrigerant to condenser 772, which in turn provides high pressure liquid refrigerant through a sight glass 774 to a manifold 776 comprising one or more expansion devices. Sight glass 774 allows an operator to determine visually if the level of high pressure liquid refrigerant in first evaporator 720 and/or second evaporator 750 is low, requiring additional refrigerant to be added to the system.

Frozen custard machine 700 preferably utilizes a relatively small compressor 770 to operate first evaporator 720 (comprising two refrigeration loops) and second evaporator 750. The use of a smaller compressor 770 reduces the space occupied by compressor 770 within housing 702 and reduces the overall weight of compressor 770. Reducing both factors enables frozen custard machine 770 to be sized to fit on an elevated surface. Further, using a smaller compressor may also reduce energy consumption. According to an exemplary embodiment, compressor 770 has a rating of less than 3 horsepower. According to a preferred embodiment, compressor 770 has a rating of approximately 1 horsepower.

According to the embodiment illustrated, manifold 776 includes a single input 778 coming from condenser 772 and three outputs (a first liquid refrigerant output 780, a second liquid refrigerant output 782, and a third liquid refrigerant output 784). First liquid refrigerant output 780 is in fluid communication with first refrigerant input 722 of first evaporator 720, second liquid refrigerant output 782 is in fluid communication with second refrigerant input 730 of first evaporator 720, and third liquid refrigerant output 784 is in fluid communication with refrigerant input 752 of second evaporator 750. An expansion device, shown as an expansion valve 786, is provided at each of the three liquid refrigerant outputs. Expansion valves 786 establish a relatively low pressure level for the liquid refrigerant passing into first refrigerant input 722, second refrigerant input 730, and refrigerant input 752 respectively.

Similar to the embodiments discussed above, frozen custard machine 700 is configured to operate between a production mode and a non-production mode. Frozen custard machine 700 may incorporate any of the above discussed control systems for determining when to operate in a particular mode or may incorporate any other suitable system for this function. In the production mode, frozen custard machine 700 is configured to provide a continuous stream of frozen custard product. While the output rate of frozen custard product will vary depending upon the particular liquid mix, frozen custard machine is configured to output between approximately 3 gallons and approximately 6 gallons per hour during a typical production mode. According to various alternative embodiments, frozen custard machine 700 may be configured to output more or less frozen custard product than the rates provided herein.

According to the embodiment illustrated, a ribbon of frozen custard product is directed by a chute 703 (shown as outwardly extending at front panel 712 in FIG. 10) or other structure as it passes through frozen custard output 728. A cut off gate may be provided at frozen custard output 728 to cut or other stop the flow of frozen custard product. An optional dipping cabinet 705 may be provided below chute 703 to collect and store the frozen custard product. Frozen custard product may then be hand dipped from dipping cabinet 705 for serving to customers. According to various alternative embodiments, frozen custard machine 700 may be a direct draw machine wherein frozen custard product is taken directly from the machine for serving to the customers.

The term “coupled”, as used in the present application, does not necessarily mean directly attached or connected. Rather, the term “coupled” in the present application means in fluid or electrical communication there with. Two components may be coupled together through intermediate devices. For example, the evaporator input is coupled to the condenser output even though the expansion valve, accumulator/heat exchanger, and sight glass are situated between the evaporator input and the condenser output.

It is understood that, while the detailed drawings and specific examples given to describe the preferred exemplary embodiment of the present invention, they are for the purpose of illustration only. The apparatus of the invention is not limited to the precise details and conditions disclosed. For example, although food stuffs and frozen custard are mentioned, the invention may be utilized in a variety of refrigeration or cooling systems. Further, single lines for carrying liquid refrigerant can represent multiple tubes. Additionally, although a particular valve, accumulator, compressor, condenser, and filter configuration is shown, the advantageous machine can be arranged in other configurations. Further still, the evaporator barrel and freezer can have any number of shapes, volumes, or sizes. Various changes can be made to the details disclosed without departing from the spirit of the invention, which is defined by the following claims.

	Number	Date	Country
Parent	10654371	Sep 2003	US
Child	11337209	Jan 2006	US
Parent	10075089	Feb 2002	US
Child	10654371	Sep 2003	US

	Number	Date	Country
Parent	11337209	Jan 2006	US
Child	11354566	Feb 2006	US

Frozen custard machine

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