Field of the Invention

The present invention relates to the field of a beverage-preparing device, and more particularly, the invention relates to a personal handheld rapid slushy drink maker.

Background of the Invention

Slushy drinks made of a specific liquid cooled close to the freezing point appeal to children and adults who enjoy consuming beverages such as iced coffee, slushy cocktails, frozen yogurts, and smooth ice cream.

Slushy generally has a semi-solid composition of ice crystals surrounded by liquid. Crystals are formed when heat is removed from a liquid at such conditions that total freezing is prevented.

Most slushy makers are expensive commercial machines. Typical home slushy makers are devices such as a blender that require the desired liquid to be mixed with ice cubes, which cools the liquid and contributes to the slushy texture of the finished product after the ice is crushed. This operation has two main disadvantages - the need for previously made ice cubes and the low-quality texture of crushed ice. In addition to that, a blender is usually heavy, noisy, and inconvenient to use. Other devices, which produce the slushy by cooling the liquid, are either large and therefore not portable or take a long time to prepare the slushy drink.

U.S. Patent Application Publication No. WO2021250682A1 discloses “a device for making slushy from a food substance contained within a container when the container and the device are exposed to ambient temperature below the freezing temperature of the food substance for a minimal time. The device comprises an operation casing attachable to a top portion of the container; at least one blade configured to extend from the bottom face of the operation casing; a motor accommodated within the operation casing and operatively connected to said blade, configured to rotate said blade at least throughout continuously said minimal time, and a DC power supply to supply power to the motor.” U.S. Patent Application Publication No. US4590852A discloses “a method and apparatus for cooling a frozen comestible plasticizer apparatus with a heat exchanger pan over a freezer, protecting the freezer from extraneous matter filling in, while providing a cool circulatable environment to cool the auger and cup of the apparatus to help avoid bacterial growth and minimize the need for cleaning of the apparatus.”

U.S. Patent Application Publication No. US2849868 discloses “an improved ice cream freezer, particularly a portable freezer for use in a home cold storage compartment, which is mounted on the cover of a top opening cold storage compartment. In said patent, an electric motor and reduction gearbox are secured to the top side of the compartment cover, and the container for the cream to be frozen is suspended from the underside of the cover. An agitator in the container is driven by a shaft passing through a hole in the cover. The prior arrangement is effective for its purpose. Still, it requires making a shaft hole in the compartment cover and constitutes a permanent attachment that cannot be conveniently removed when it is not in use. Also, its freezing speed is not as fast as desired because the cream container is exposed to the warmest stratum of air at the top of the refrigerated compartment. Therefore, the present invention's general objective is to provide a portable ice cream freezer readily inserted into and removed from a refrigerated compartment.”

U.K. Patent Application Publication No. GB2147983A discloses, “Improved heat exchange device for a frozen food product maker. The present invention involves the field of technology devices for making frozen food products in the freezing compartment of a refrigeration unit. More specifically, the invention is directed to an improved means for enhancing heat exchange between the contents of a mix canister associated with a frozen food product maker and the cold air generated by the evaporator of a refrigeration unit.”

It is an object of the present invention to provide a cost-effective home slushy maker that does not require the introduction of ice to produce a slushy drink of substantially uniform consistency.

The present invention's additional object is to provide a home slushy maker that can speedily produce a slushy drink. Another objective of the present invention is to provide a portable, handheld device that can easily be carried and used as a drinking cup.

Other objects and advantages of the invention will become apparent as the description proceeds.

Summary of the Invention

A home slushy maker comprises:

• An inner container made of heat-conducting material, such as aluminum, within which the desired liquid is introduced.

• The outer part of the container is built in a configuration of a ribbed heat exchanger.

• A bladed removable stirrer.

• An activation unit contains a microcontroller, the stirrer motor, a fan, and batteries.

Device activation at an ambient temperature below the freezing temperature of the ingredients (such as a home freezer) creates a flow of chilled air around the container. The heat is removed from the liquid by forced convection through the heat exchanger. This rapid cooling process of the liquid is controlled by a microcontroller and continues until the desired texture of the slushy drink is achieved.

As referred herein, "rapid cooling" means reaching the desired slushy texture from room temperature ingredients in less than 15 minutes. The device produces a slushy drink when the introduced liquid is subjected to rapid cooling by the chilled air. As referred to herein, a "slushy product" is one in which suspended ice crystals form in the introduced liquid or one, such as an ice cream product that has a smooth and creamy texture that is made from milk, cream, or yogurt with added ingredients for flavor and texture, whose viscosity is increased relative to that of the initially introduced liquid as a result of the rapid cooling.

Brief Description of the Drawings

In the drawings:

• Fig. 1A is a perspective of an embodiment of a home slushy maker when assembled with an activation unit. • Fig. IB is a perspective of an embodiment of a home slushy maker when assembled with a drinking cap.

• Fig. 2 is an exploded view of an activation unit used in conjunction with the home slushy maker of Fig. 1A.

• Fig. 3 is an explosive view schematic illustration of the activation unit circuitry used in conjunction with the activation unit of Fig. 2.

• Fig. 4 is a section view of the home slushy maker of Fig. 1A, cut along the longitudinal axis.

• Fig. 5 is a block diagram of the control circuitry components and function.

Detailed Description of the Invention

The home slushy maker is a portable, handheld, and cost-effective device that utilizes the cooling ability of a domestic freezer to produce a slushy drink. The dimensions of the home slushy maker are significantly smaller than those of a bulky commercial slushy maker, which requires a refrigerant as well as a compressor and condenser through which the refrigerant flows in a refrigeration cycle to generate the needed cold for preparing a slushy drink.

Despite the lack of a refrigeration system, the home slushy maker can speedily produce the slushy drink in a small fraction of an hour after the desired liquid, and other ingredients are introduced into an internal cavity outside the freezer. Then the slushy maker is placed in the freezer and activated. The speedy slushy production process is made possible using forced convection whereby cold air from the freezer interior is drawn into the internal cavity of the slushy maker and causes the introduced liquid to become significantly cooled.

Fig. 1A illustrates an embodiment of a home slushy maker 1000. The external structure of home slushy maker 1000 is shown to include two members, the first being the activation unit 100, and the second being a cylindrical cup 200 that is shown to be coupled with activation unit 100. The activation unit 100 can induce the forced convection generation for producing the slushy drink and output an indication when a slushy drink of substantially uniform consistency has been made. Fig. IB illustrates an embodiment of a home slushy maker 1000 with cap 400 coupled with cup 200. This configuration is used when the slushy drink is ready to be consumed directly from cup 200 after detaching the activation unit 100 and replacing it with cap 400.

Fig. 2 illustrates an exploded view of a home slushy maker 1000. As shown, stirrer 230 is coupled to motor 120 using output shaft 140 and adapter 150, the latter being frictionally engaged with a circular head plate 233 at the proximal end of stirrer 230. Stirrer 230, in turn, is received in the internal cavity defined by cylindrical inner cup 220, within which the desired liquid is also introducible and is rotatable about the longitudinal axis of inner cup 220. The outer wall of receiving inner cup 220 may be configured with a finned heat exchanger 221, which may be embodied by a plurality of axially extending and circumferentially spaced fins attached at one radial end to the outer wall of inner cup 220. Alternatively, or additionally, heat exchanger 221 may be embodied by a Peltier device, for example, attached to the outer wall of the inner cup 220. Cup casing 210 has a proximally located neck 213 of an enlarged radial dimension, encircles inner cup 220 to provide an air gap between, and is coupled with the outer wall of the activation unit casing 110 via neck 213 by threading 214 or by any other suitable coupling means well known to those skilled in the art. The activation unit casing 110 is fitted tightly inside the inner cup 220, and this coupling is sealed using O-ring 160.

Although the distal end of inner cup 220 is solid to retain the introduced liquid and the slushy drink to be produced within its internal cavity, the distal end of cup casing 210 is configured with a plurality of air discharge openings 211, each of which is defined by two adjacent circumferentially spaced and axially extending rod elements 212 that distally extend from a surface in contact with the distal end of inner cup 220. Rod elements 212 may restrict the passage of foreign particles and ice from the freezer into the cup casing 210.

Activation unit casing 110 may be configured with an extension 115 that radially protrudes from one circumferential region of its outer wall. Extension 115, attached to or integrally formed with the outer wall of activation unit casing 110, houses the control circuitry 300 needed to perform a slushy-making operation. Activation unit casing 110 and extension 115 are sufficiently isolated to prevent damage to the control circuitry 300 if the home slushy maker inadvertently remains in the freezer for an extended period. Alternatively, extension 115 can be avoided, and in such case, the control circuitry will be in a control circuitry chamber 117 inside the activation unit casing 110.

Stirrer 230 is an elongated member that is adapted to extend substantially throughout the interior of inner cup 220 axially. In one embodiment, stirrer 230 is configured with three blades 231 angularly separated by 130 degrees, which radially extend from central stirrer shaft 234 with an axial length significantly less than blades 231, for example, one-half of their size, without radially protruding from head plate 233. Each blade 231 is configured with a plurality of apertures 232 throughout its length, through which formed ice crystals can pass when being agitated so as not to accumulate along the wall of inner cup 220 and reduce the temperature of the slushy drink below the desired value. The apertures 232 across the blade’s surface can have various shapes, sizes, and distributions.

Fan 170 is shown to be surrounded by a perforated cylindrical casing 171 that has a plurality of circumferentially spaced openings 172 to direct the drawn freezer air in specific radial directions. Fan 170 is covered by grille 180 to prevent injury to the user in case the home slushy maker has been inadvertently activated when repositioned.

Fig. 3 illustrates an exploded view of various components of activation unit 100, which are retained within activation unit casing 110. As shown, activation unit 100 comprises a fan 170, generally an axial fan, but which can be a radial fan or any other suitable type of fan having a built-in motor for generating airflow from the freezer interior through an annular passageway 111 along the inner side of activation unit casing 110, in a direction that is generally parallel to the fan axis. Fan 170 is covered by grille 180 to prevent injury to the user if the home slushy maker has been inadvertently activated when repositioning. Electric motor 120, provided with gearbox 130, configured with reduction gearing, is housed within a motor chamber 116 inside activation unit casing 110. Motor chamber 116 is axially spaced from another section where fan 170 is housed. The motor chamber has an end plate 112, formed with an aperture 113 through which the motor output shaft 140 axially extends. The output shaft 140 is connected to adapter 150, which is adapted to be coupled with the stirrer and may be fluted. An exemplary axial fan has a fan DC motor provided with dimensions of 70mm X 20mm and an average speed of 3800 RPM, generates an average volumetric airflow of 35 CFM, and requires a power supply of 12V (DC) and 0.5A, usually using one or more batteries. The fan motor is preferably configured with speed control to control the flow rate of the chilled air. An exemplary stirrer motor has a high torque gearbox that outputs 50 RPM, is equipped with a Hall encoder with speed measurement, a driver by which the speed is controlled, and requires a power supply of 12V (DC), usually using one or more batteries. Both the fan motor and the stirrer motor are preferably configured with a current sensor for determining the instantaneous load.

Fig. 4 illustrates a cross-sectional view of home slushy maker 1000 when adapter 150 is coupled with the motor output shaft 140 and stirrer 230 during a slushy-making operation. Stirrer 230 may be conveniently detached from motor output shaft 140. The stirrer 230 is detached from the device when it is desired to replace one type of stirrer with a different kind, depending on the selected slushy drink that is to be prepared, or when the slushy drink is ready, and the cup 200 is used as a drinking cup or when cleaning is needed.

As shown, neck 213 of cup casing 210 is coupled to the distal end of the outer wall of activation unit casing 110, and neck 222 of inner cup 220 is connected to the distal end of inner wall 114 of activation unit casing 110. An O-ring 160, or any other suitable sealing element, may be provided at the inner wall distal end of activation unit casing 110 to prevent seepage of the slushy drink to annular passageway 111 or motor 120. Neck 222 of inner cup 220 may also be coupled to a rotatable sealing element.

The forced convection induced by the rotation of the blades of fan 170 draws the cold freezer air 510, e.g., at a set temperature of -18°C and at a high volumetric flow, e.g., at a rate of 1 m ³ /min, through grille 180, annular passageway 111 formed in activation unit casing 110, between the fins of the heat exchanger 221, and through discharge openings 211. The air 520 temperature after being discharged from openings 211 is slightly higher than that at the inlet of grille 180, e.g., -15°C. An additional cooling cycle is initiated within the freezer compartment to maintain the set temperature once the detected air temperature rises above a predetermined threshold. This forced convection arrangement optimally chills the liquid that has been introduced within the cavity of inner cup 220 by supercooling and facilitates the formation of tiny ice crystals that are characteristic of a slushy drink without having to deal with the bother of preparing ice cubes, handling them and introducing them into the internal cavity together with the desired liquid.

The flow of cold freezer air 510 across the wall of inner cup 220 provides a relatively high heat transfer rate from the introduced liquid and would generally cause the fluid to freeze to a solid block. The mechanical agitation from stirrer 230 causes the liquid temperature within the cup interior to be more uniform. Consequently, it inhibits crystal growth that would otherwise occur at the wall of inner cup 220, where heat is typically transferred out of the liquid. The tiny crystals that have already been formed remain suspended in the agitated liquid and produce the slush. Another cause for a reduction in the heat transfer rate from the introduced fluid is the presence of the heat sink. After home slushy maker 1000 has been repositioned from outside to inside the freezer, the heat sink is approximately equal to room temperature, reducing the heat transfer rate from the introduced liquid. Also, the presence of sugar within the introduced liquid reduces the initial freezing point of the liquid. It mitigates the bonding of water molecules that generally promote the formation of larger crystals and, eventually, solid ice. Since a sugar molecule is not integrated into the crystalline structure, the concentration of sugar in the remaining liquid increases as the percentage of the tiny crystal formations likewise increases, thus further reducing the freezing point of the remaining liquid.

Fig. 5 illustrates the control circuitry 300, which comprises a microcontroller 310 to command the fan and the stirrer. Microcontroller 310, which has a processor that is factory programmed or is programmed using a dedicated application 531 running on a computerized device 530 such as a smartphone, selectively transmits command signals C to the fan motor 173 and the stirrer motor 120 upon demand, whether wirelessly or through a wired connection. A battery 320 power microcontroller 310, fan motor 173, and stirrer motor 120. The battery 320 may be rechargeable, and the activation circuitry may also comprise a battery charger.

When a slushy-making operation is performed in conjunction with a current sensor 330 and a speed sensor 340, the values detected by these sensors, as well as by temperature sensor 350 for detecting the temperature of the introduced liquid and temperature sensor 350 for determining the temperature of the incoming surrounding air, generally freezer air, are continually monitored throughout the slushy making operation to determine whether the predetermined consistency has been produced. For purposes of troubleshooting, the current of the fan motor may be monitored throughout the slushy-making process to determine whether the fan motor has become overloaded, for example, due to blockage of the air outlet at discharge openings 211 that would seriously reduce the effectiveness of the forced convection and the slushy making operation. Before the commencement of a slushy-making operation, the battery's state of charge may be acquired to determine whether the battery is sufficiently charged to power the slushy-making process.

Upon determining that the slushy drink is ready to be consumed by a combination of various factors as defined in instructions stored in the microcontroller, including a predetermined temperature depending on the type of slushy drink that is being prepared and its sugar concentration and on the predetermined consistency of the slushy drink that is being produced, the microcontroller transmits a command to adjust the fan speed, depending on whether the slushy temperature increases or decreases.

When factory programmed, microcontroller 310 may be activated by a manually activated activation switch 360, for example, when pressed for longer than a predetermined duration. After that, the control signal C is transmitted. A first control signal for activating the fan and stirrer may be transmitted following the activation of microcontroller 310. A second control signal for deactivating the fan and stirrer may be sent following a second predetermined duration after activation of microcontroller 310. If so desired, more than one activation switch 360 may be provided and indicated accordingly to select a slushy-making function for one of a plurality of predefined liquids, the duration of each process generally being different. The period of the slushy-making operation is generally the average time to prepare a slushy drink for the volume of the given liquid that can be introduced within the internal cavity, based on the fan motor's speed and the stirrer motor. For example, the typical duration of a slushy-making operation will be no more than fifteen minutes for a liquid mixture provided with a concentration of % milk and % water for the preparation of iced coffee from the time the home slushy maker containing this liquid mixture has been removed from the refrigerator at which it has been cooled to a temperature of 4°C until the liquid mixture has been converted to iced coffee with a slushy consistency. A LED light 370 may illuminate, and an enunciator 380 may emit a distinctive sound after the duration of the slushy-making operation.

Alternatively, the duration of a slushy-making operation may be determined electronically by monitoring the instantaneous speed and electric current associated with the stirrer motor as indicative of the mechanical resistance of the introduced liquid to agitation. The motor speed may be determined by a speed sensor 340 that detects the shaft speed and the direction of rotation or using pulse width modulation, whereby the duty cycle is varied. A current sensor 330 may be used to detect the current in the motor. In addition, microcontroller 310 is programmed to transmit a deactivation signal C when one or both speed sensor 340 and current sensor 330 detect a predetermined high value indicative of a corresponding slushy consistency and output one or more indications upon completion of the slushy-making operation.

The fan motor and stirrer motor may be controlled separately. For example, when the predetermined high value indicative of a slushy consistency is sensed by the current sensor of the stirrer motor, the speed of the stirrer is first decreased. Then the fan speed is reduced to prevent the transformation of the desired liquid into a single ice block.

When the dedicated application 531 is used, the entire slushy-making operation may be monitored through interaction with the application. Using application 531, the user can transmit an input signal IN that is indicative of the type of liquid that has been introduced and an activation signal ACT to initiate the slushy-making operation and is also able to receive an indication upon completion of the slushy-making process in conjunction with one or both of speed sensor 340 and current sensor 330. This completion indication COM received by the application may be in addition to or instead of an indication provided by LED light 370 and enunciator 380. Input signal IN, activation signal ACT, and completion indication signal COM can be remotely transmitted by Bluetooth module 311 or by a WIFI module 312.

Application 531 may be provided with instructions for preparing slushy drinks with one or more liquids and facilitates ordering various beverages or other edible items when inventory is low. The microcontroller 310 sometimes determines that the slushy drink has achieved the predetermined set temperature and consistency when the incoming surrounding air is equal to room temperature. Yet, the slushy drink remains contained within the home slushy maker after being removed from the freezer. Under these conditions, stirrer motor 120 is commanded to be intermittently deactivated and activated to maintain the achieved consistency until the slushy drink is ready to be consumed. Also, the fan motor is deactivated to prevent influx to the annular passageway of room temperature air that will melt the formed ice crystals of the slushy drink.

When the preparation process ends, the device goes into standby mode to maintain the desired texture of the slushy. In this mode, the fan reduces its operational performance, so the cooling effect is reduced, and freezing of the slushy is avoided.

Once the slushy drink is ready to be consumed, a completion indication is sent to the application in addition to the emitted visual or audible signal. A dedicated isolating cover may be used to cover the inner cup 220. Alternatively, the ready slushy drink can be emptied from the cup and transferred to another vessel. An additional slushy-making operation can be performed once the cup is washed.

While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried out with many modifications, variations, and adaptations and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without exceeding the scope of the claims.