Mixer with Removable Spindle and Monitored Reservoir

Abstract

To provide a blender with a removable spindle and a monitored reservoir.SOLUTION: An economical blender includes: a removable, motor driven spindle assembly 30 to perform blending; a motor driven elevator 70 used to lift a cup 20 with food or beverage up to the spindle assembly and a liquid reservoir 60 which allows liquid to be inserted into the food or beverage during blending. The removable spindle assembly has a quick release coupler and a compression spring which connects the quick release coupler to a cup cover. Blending is accomplished by connecting a motor driven inner spindle drive shaft to a concentric outer spindle drive tube through cogged couplers. An outer spindle drive tube powers a blending tool 38 and, like the blending tool, is removable with the spindle assembly for cleaning.SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This non - provisional patent application claims priority under 35 U.S.C.§119(e) to U.S. Provisional Application No. 62 / 112,116, entitled "Blender With Removable Spindle and Monitored Reservoir", filed on February 4, 2015. The disclosure of the above - mentioned document is incorporated herein by reference in its entirety for all purposes.

[0002] (Field of the Invention) The present invention relates to food preparation machines, and more particularly to electric blenders for preparing smoothies, milkshakes, protein shakes, and other blended beverages.

Background Art

[0003] (Background of the Invention) Blended fruit smoothies, milkshakes, and protein shakes are becoming increasingly popular among health - conscious people. In these blended drinks, fresh fruits and / or vegetables are mixed, optionally with vitamin and protein supplements, to provide a convenient and portable form of fresh, nutritious food.

[0004] While it is advantageous to blend carefully selected ingredients at the peak of their freshness, this is often not practical. To have fresh fruits and vegetables available daily, for example, one may need to frequently go shopping to obtain such fruits / vegetables, allow time for the fruits / vegetables to ripen, and then ensure that they do not over - ripen. Additionally, working with fresh fruits and vegetables usually generates organic waste and often results in messes that necessarily require cleaning. This represents a significant amount of time and consideration.

[0005] In a rapidly changing society, there is a growing demand for fresh and nutritious blended beverages that can be quickly selected and prepared. More desirably, such fresh and blended beverages should be available at easily accessible locations such as convenience stores, restaurants, or at home.

[0006] F’Real Foods, LLC, a subsidiary of Rich Products Corporation, is engaged in the business of making fresh and nutritious smoothies and milkshakes available at easily accessible locations such as convenience stores. F’Real Foods starts with fresh ingredients such as fresh fruits and milk that are pre-blended into the smoothies and milkshakes. The pre-blended smoothies and milkshakes are then firmly frozen in sealed cups before being shipped to convenience stores in many different locations. The frozen and pre-blended smoothies and milkshakes are then stored in a freezer adjacent to a commercial-sized blender in the convenience store. When a convenience store consumer desires a fresh smoothie or milkshake, the consumer simply selects the desired frozen and pre-blended smoothie or milkshake from the convenience store freezer, peels the seal from the top of the smoothie / milkshake cup, and then places the smoothie / milkshake cup in the cup holder built into the blender. The consumer can then start the blender and mix the frozen smoothie / milkshake to the desired viscosity.

[0007] F’Real Foods, LLC has a number of U.S. patents and U.S. published patent applications covering its mixing machines and processes for preparing smoothies / milkshakes, including U.S. Patent Nos. 5,803,377, 5,962,060, 6,041,961, 6,326,047, 6,474,862, 6,465,034, 6,527,207, 7,144,150, 7,520,658, 7,520,662, 8,336,731, 8,735,515, and 8,902,626, as well as U.S. Published Patent Applications Nos. 2011 / 0088568, 2013 / 0341446, 2013 / 0344220, 2013 / 0341439, and 2013 / 0344221.

[0008] Regarding its convenience store market, F’Real constructs and supplies robust, stainless - steel, commercial - sized blenders that can withstand rough use by convenience store customers with little maintenance required. These robust blenders are typically installed on a public water supply to have an abundant supply of water for blending, cleaning, and automatic sanitization. After a milkshake or smoothie is blended and removed by a customer, the food - preparation chamber within a F’Real commercial - sized blender is sprayed with water, preferably heated water, to wash away any food residue and kill bacteria.

[0009] The popularity of F’Real Foods, LLC’s convenience store smoothies and milkshakes has led to a demand for making the same types of smoothies and milkshakes available for use in other settings such as at home or in a restaurant. In these other settings, commercial - sized blenders may be too expensive or dedicated access to a public water supply may not be available for the blender. In those cases, while it would still be important to prepare smoothies and milkshakes quickly and hygienically, it would be necessary to do so using a simpler, more affordably - purchased machine.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Means for Solving the Problems

[0011] (Brief Summary of the Invention) The present invention particularly targets an economical food or beverage mixer that is suitable for mixing frozen milkshakes and smoothies. The mixer features a removable motor-driven spindle assembly, a motor-driven elevator for lifting a cup with food or beverage to the spindle assembly, and a liquid reservoir / pump / heater combination where heated liquid can be inserted into the food or beverage during mixing. For safety reasons and to protect from damage, the motor, pump, and heater are located within the mixer housing. A pivotable spindle cover protrudes from the front to the mixer housing to prevent the spindle assembly mixing tool from injuring the user during the mixing process.

[0012] A preferred detachable spindle assembly has at its upper part a quick-release coupler that is mounted on a spindle support permanently attached within the mixer housing. The spindle assembly can be easily removed for cleaning by pivoting the quick-release coupler and then pulling the spindle assembly downward. Below the quick-release coupler is a compression spring that also connects to the cup cover. During mixing, the compression spring presses the cup cover against the top of the milkshake / smoothie or other frozen beverage cup during the mixing process, minimizing any overflowing milkshake / smoothie. Mixing is accomplished through a combination of an inner spindle drive shaft, a concentric outer spindle drive tube, a toothed coupler, and a mixing tool. In a preferred embodiment, the inner spindle drive shaft is permanently connected to the spindle motor through a combination of a pulley and a spindle drive belt. To operate the mixing tool attached to the outer spindle drive tube, the inner spindle drive shaft is inserted concentrically into the outer spindle drive tube and connected together through a toothed coupler. By engaging these toothed couplers, the inner spindle drive shaft and the outer spindle drive tube spin together when the spindle motor is activated. An important advantage of this spindle assembly design is that when the detachable portion of the spindle assembly is separated from the mixer, the entire spindle assembly surface that can come into contact with food can be removed and cleaned.

[0013] In a preferred embodiment, the liquid reservoir is connected to the mixer housing. A pump and a heater are connected to the reservoir and pour a predetermined amount of heated liquid from the reservoir into the frozen milkshake or smoothie during mixing. Removing the cap at the top of the reservoir allows the reservoir to be refilled. A fluid level sensor is provided to determine when the fluid level in the reservoir is low. The fluid level sensor may be, for example, a float, optical, ultrasonic, radio wave, capacitance, or inductive sensor. In some embodiments, the reservoir is detachable and can be removed for cleaning. In other embodiments, the reservoir is cleaned in place, for example, using a brush.

[0014] Operating the mixer of the present invention begins by moving the pivotable spindle cover upward and attaching a clean spindle assembly to the spindle support using a quick release coupler. The pivotable spindle cover is then pulled down to protect the user during the mixing process. The frozen milkshake or smoothie is inserted into the mixer cup holder and the start button on the mixer is pressed. The mixing process begins when a motorized elevator raises the cup holder to the point where the frozen milkshake or smoothie contacts the spindle assembly mixing tool. To minimize overflow, the spindle assembly automatically presses the cup cover against the top of the cup before and during mixing. The motorized elevator continues to move the frozen milkshake or smoothie up and down during mixing until the milkshake or smoothie is mixed to the desired viscosity. Fluid from the reservoir is added during the mixing process to facilitate mixing and improve viscosity. When mixing is complete, the motorized elevator lowers the cup and cup holder to the starting position so that the user can enjoy the fully mixed milkshake, smoothie, or other frozen mixed beverage. The present invention provides, for example, the following. (Item 1) A detachable spindle assembly for a mixer, A quick release coupler, and A container cover, a spring, a tube, wherein the tube is attached to a toothed coupler at its upper end and to a mixing tool at its lower end, and comprises a detachable spindle assembly in which the quick-release coupler, the spring, and the container cover are held concentrically around the tube and between the toothed coupler and the mixing tool. (Item 2) The mixing tool includes a rotary cutting edge, the detachable spindle assembly according to Item 1. (Item 3) The mixing tool includes a rotary cutting edge with one or more radially extendable cutting edges, the detachable spindle assembly according to Item 1. (Item 4) The detachable spindle assembly according to Item 1, further comprising a cup cover support at the lower end of the tube. (Item 5) The spring is interposed between the quick-release coupler and the container cover and presses against both of them, the detachable spindle assembly according to Item 1. (Item 6) The spindle assembly can be detached from the mixer by manually rotating and pulling away the quick-release coupler, the detachable spindle assembly according to Item 1. (Item 7) A mixing assembly, a spindle motor, an inner spindle drive shaft permanently coupled to the spindle motor, a spindle support for fixing the spindle motor and the inner spindle drive shaft within the mixer, and a spindle assembly detachably attached to the spindle support and comprises The spindle assembly includes a quick-release coupler, a container cover, a spring, and a tube. The tube is attached to a toothed coupler at its upper end and a mixing tool at its lower end. The quick-release coupler, spring, and container cover are concentrically held around the tube and between the toothed coupler and the mixing tool, which is a mixing assembly. (Item 8) The inner spindle drive shaft is concentrically inserted into the tube when the spindle assembly is attached to the spindle support, which is the mixing assembly according to Item 7. (Item 9) The mixing assembly according to Item 7 further includes a toothed coupler attached to the inner spindle drive shaft that connects to the toothed coupler attached to the tube and rotates the tube in conjunction with the inner spindle drive shaft. (Item 10) The toothed coupler has teeth that mesh together when the toothed coupler is connected, which is the mixing assembly according to Item 9. (Item 11) The mixing tool includes a rotary cutting blade with a radially extendable cutter, which is the mixing assembly according to Item 7. (Item 12) The spindle assembly can be detached from the spindle support by manually rotating and pulling away the quick-release coupler, which is the mixing assembly according to Item 7. (Item 13) The spring is interposed between and presses against the quick-release coupler and the container cover, which is the mixing assembly according to Item 7. (Item 14) A mixer for mixing food or beverage in a cup, a spindle motor connected to a detachable spindle assembly, a lift motor connected to a cup holder for holding a cup with food or beverage, a fluid reservoir and The food or beverage within the cup can be mixed when the elevator motor raises the cup holder to a point where the food or beverage contacts the mixing tool on the spindle assembly, and the spindle motor rotates the mixing tool while fluid is being added from the reservoir to the cup. (Item 15) The removable spindle assembly comprises a quick release coupler, a container cover, a spring, and a tube, the tube being attached at its upper end to a toothed coupler and at its lower end to a mixing tool, the quick release coupler, spring, and container cover being held concentrically around the tube and between the toothed coupler and the mixing tool, the mixer according to item 14. (Item 16) The spindle motor, elevator motor, and fluid reservoir are contained within a mixer housing, the mixer according to item 14. (Item 17) The mixer according to item 16, further comprising a pivotable cover attached to the mixer housing to prevent operator contact with the spindle assembly when the spindle motor is operating and to allow operator contact with the spindle assembly when the spindle motor is not operating. (Item 18) The pivotable cover pivots to a downward position when the spindle motor is operating and pivots to an upward position when the spindle motor is not operating, the mixer according to item 17. (Item 19) The mixer according to item 14, further comprising a microprocessor. (Item 20) The mixer according to item 19, further comprising a control panel operably engaged with the microprocessor. (Item 21) The mixer according to item 14, further comprising a level sensor within the reservoir for determining when the reservoir needs to be refilled with fluid. (Item 22) The mixer according to item 21, wherein the level sensor is a float sensor. (Item 23) The mixer according to item 21, wherein when the level sensor detects that the level of the fluid in the reservoir is too low, a visual or audible alert is issued. (Item 24) The mixer according to item 14, further comprising an inner spindle drive shaft permanently coupled to the spindle motor and a tube within the detachable spindle assembly operatively coupled therewith through a toothed coupler. (Item 25) A method for mixing food or beverage in a cup, comprising: selecting a mixer having a spindle motor connected to a detachable spindle assembly having mixing tools, a lift motor connected to a cup holder, and a fluid reservoir; placing a cup with food or beverage therein into the cup holder; activating the lift motor and lifting the cup holder until the food or beverage in the cup contacts the mixing tools of the spindle assembly; activating the spindle motor and rotating the mixing tools of the spindle assembly while adding fluid from the reservoir until the food or beverage in the cup is mixed. A method comprising the above steps. (Item 26) The method according to item 25, further comprising removing the detachable spindle assembly from the mixer for cleaning after the food or beverage is mixed. (Item 27) The method according to item 25, wherein the lift motor and the spindle motor of the mixer can be activated by the user pressing a start button on the control panel. (Item 28) The method according to item 27, wherein pressing the start button does not activate the elevator motor or the spindle motor until the microprocessor determines that the mixer can operate safely. (Item 29) The mixer according to item 14, further comprising a pump connected to the fluid reservoir for moving fluid between the reservoir and the cup. (Item 30) The mixer according to item 14, wherein the food or beverage is a frozen food or beverage. (Item 31) The mixer according to item 14, wherein the cup and the cup holder have a connecting anti-rotation mechanism for preventing them from rotating relative to each other during the mixing process. (Item 32) The mixing assembly according to item 7, further comprising a socket joint having a flexible socket connected to the inner spindle drive shaft and disposed within the tube. (Item 33) The mixer according to item 14, wherein the liquid reservoir is removable from the mixer. (Item 34) The mixer according to item 33, wherein the removable liquid reservoir is connected to a water coupler with a check valve when attached to the mixer. (Item 35) The mixer according to item 33, wherein water from a public water supply through a permanently piped water conduit automatically fills the reservoir. (Item 36) The mixer according to item 35, further comprising a float valve within the removable reservoir for shutting off the flow of water from the public water supply when the liquid in the reservoir reaches a predetermined height.

Brief Description of the Drawings

[0015]

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Best Mode for Carrying Out the Invention

[0016] (Detailed Description of the Invention) Figures 1 and 2 illustrate a preferred blender of the present invention as would be seen from the outside. The blender has a housing 12 (to protect its internal working components), an upper spindle cover 14, a pivotable lower spindle cover 16, a cup holder 18, a control panel 22, and a reservoir cap 28. The upper spindle cover 14 and the pivotable lower spindle cover 16 house a detachable spindle assembly 30 (Figure 2) that performs the blending. The cup holder 18 is used to hold a cup 20 containing the food or beverage to be blended. In one preferred embodiment, the food or beverage to be blended is a frozen milkshake or smoothie. The reservoir cap 28 covers a built-in fluid reservoir 60 (Figures 3A - B) behind the blender. To blend frozen foods or beverages, it is often advantageous to add a fluid such as heated water during the blending process to facilitate blending and achieve the desired viscosity. In the preferred blender of the present invention, the fluid is stored in the fluid reservoir 60. By removing the reservoir cap 28, the built-in fluid reservoir 60 can be refilled.

[0017] The control panel 22 near the upper part of the mixer housing 12 provides switches 24, 26 and indicator lights 29 that enable the operation of the mixer. For example, the mixing knob 24 enables the operator to set the desired viscosity for the mixed food or beverage, from a firm viscosity to a loose viscosity. The start button 26 enables the operator to start the mixing process. In a preferred embodiment, pressing the start button 26 will activate the mixer 10 only when the mixer 10 is ready for operation. The determination of whether the mixer 10 is ready for operation will preferably depend on factors such as whether the pivotable lower spindle cover 16 is in the lowered position and whether the cup holder 18 is in its basic starting position (as shown in FIG. 1). The indicator light 29 can be used to inform the operator whether there are problems that must be corrected before the mixer 10 can be operated. For example, the indicator light 29 can alert the operator to lower the pivotable lower spindle cover 16 for the operator's protection before the mixer 10 is started. The various functions of the control panel are managed by a suitable microprocessor (not shown).

[0018] Figures 3A and 3B provide cutaway views of the blender 10 of the present invention, showing its internal working components. These components include a detachable spindle assembly 30, a spindle motor 50, a fluid reservoir 60, a fluid heater 61, a fluid pump 62, fluid tubes 64, 65, 66, a cup holder elevator 70, a cup holder carrier 74, an elevator drive gear 76, and an elevator drive belt 78. The detachable spindle assembly 30 is used to mix food or beverage within the cup 20. Through the combination of pulleys 52, 54 and belt 56 (Figure 4), the spindle motor 50 spins the mixing tool 38 of the detachable spindle assembly 30. To bring the mixing tool 38 into contact with the food or beverage, the elevator 70 is used to raise and lower the cup holder carrier 74 and the cup holder 18. The elevator 70 is powered by an elevator motor 72 through the elevator drive gear 76 and the elevator drive belt 78. The fluid reservoir 60 contains fluid to assist in the mixing process. The fluid pump 62 and fluid tubes 65, 66 are used to transfer fluid from the fluid reservoir 60 to the cup 20 during the mixing process. In an alternative embodiment, the fluid from the reservoir 60 can also be used for spray cleaning of the spindle assembly 30 after use.

[0019] The cup 20 and the cup holder 18 preferably have mating anti-rotation surfaces 17, 19 to prevent the cup 20 and the cup holder 18 from rotating relative to each other during the mixing process. Preferred anti-rotation surfaces 17, 19 are described in F’Real U.S. Patent Nos. 8,336,731 and 6,041,961, the disclosures of which are incorporated herein by reference.

[0020] Figure 4 illustrates how the detachable spindle assembly 30 is operably connected to the spindle motor 50. The detachable spindle assembly 30 is attached to the spindle support 33 of the mixer through a quick release coupler 32. After attachment, the spindle motor 50 rotates the spindle assembly mixing tool 38 by spinning the spindle motor pulley 52 and the spindle assembly pulley 54 through a connector belt 56.

[0021] Figures 5-6 illustrate the component parts of a preferred detachable spindle assembly embodiment 30. At the top of the spindle assembly 30 is a quick release coupler 32 for attaching the spindle assembly 30 to the mixer 10. At the base of the spindle assembly 30 are a cup cover 36 and a mixing tool 38. Between the quick release coupler 32 and the mixing tool 38 are an outer spindle drive tube 40 and a compression spring 34. A cup cover support 42 at the bottom of the outer spindle drive tube 40 is used to prevent the cup cover 36 from falling off the spindle assembly 30, and a toothed coupler 44 at the top of the outer spindle drive tube 40 is used to prevent the quick release coupler 32 from protruding from the top of the spindle assembly 30. The cup cover support 42 preferably has an upper planar surface 47 on which the cup cover 36 rests such that the cup cover 36 will be maintained in the same horizontal plane as the top of the cup 20 (Figs. 6 and 10B). To provide a permanent and secure attachment that prevents food particles from leaching out from inside the outer spindle drive tube 40, the outer spindle drive tube 40, the cup cover support 42, and the toothed coupler 44 are all preferably made of stainless steel, and both the cup cover support 42 and the toothed coupler 44 are abutted against the outer spindle drive tube 40. In this preferred embodiment, the compression spring 34 and the mixing tool 38 are also made of stainless steel. In contrast, the quick release coupler 32 and the cup cover 36 can be made of durable plastic. Alternatively, the cup cover 36 may be made of a combination of a rigid plastic base and a soft plastic or rubber seal. In this alternative embodiment, the rigid plastic base maintains an elastic shape for the cup.

[0022] In this preferred embodiment, the mixing tool 38 includes both a radially extendable cutting edge 39 and an internal cutting edge 41 (FIG. 6). The mixing tool 38 is preferably designed for both cutting food or beverage and aerating food or beverage. A preferred mixing tool embodiment including one or more radially extendable cutting edges 39 and internal cutting edges 41 is disclosed in U.S. Patent No. 6,527,207, the disclosure of which is incorporated herein by reference. The purpose of the radially extendable cutting edge 39 is to complement the internal cutting edge 41 by conforming to the cross-section of the cup 20 with different radii. For example, most cups are not completely cylindrical, but rather have a larger inner radius at their top than at their bottom. The cup 20 illustrated in FIG. 1 is such a tapered cup. By having one or more radially extendable cutting edges 39 that complement the internal cutting edge 41, the radially extendable cutting edge 39 can extend its mixing radius to the edge of the cup 20 even as the radius changes from the top of the cup to the bottom of the cup. The combination of the internal cutting edge 41 and the radially extendable cutting edge 39 is a preferred mixing tool 38 for the present invention, particularly when the food or beverage to be mixed is frozen, although those skilled in the art will recognize that other mixing tools, such as frothers, may also be used in appropriate situations.

[0023] Figures 7 through 9C illustrate how the inner spindle drive shaft 46 cooperates with the concentric outer spindle drive tube 40 to transmit rotational energy from the spindle motor 50 to the mixing tool 38. Similar to the spindle motor 50 and pulleys 52, 54, the inner spindle drive shaft 46 is also permanently attached to the mixer 10. As the spindle assembly pulley 54 rotates, the inner spindle drive shaft 46, which is permanently attached to that pulley 54, rotates along with it. The problem facing the inventors was how to transmit the rotational movement of the inner spindle drive shaft 46 to the detachable spindle assembly mixing tool 38. The inventors solved this problem by permanently attaching the mixing tool 38 to the outer spindle drive tube 40. This outer spindle drive tube 40 has a circular cross-section in the preferred embodiment, although those skilled in the art will recognize that the outer spindle drive tube 40 can also have alternative cross-sectional shapes such as square, hexagonal, octagonal, etc. When the detachable spindle assembly 30 is attached to the mixer 10, the tip 59 of the inner spindle drive shaft 46 slides concentrically into the hollow central opening 45 of the toothed coupler 43 until the toothed coupler 43 of the outer spindle drive tube 40 meshes with the toothed coupler 48 of the inner spindle drive shaft 46 (see Figures 8D-F and 9C). To facilitate the meshing of the individual toothed couplers 43, 48, mating teeth 51 are provided on both sets of the toothed couplers 43, 48. These teeth 51 have inclined edges 55 and walled edges 57. As shown in Figures 8D-F, when the toothed couplers 43, 48 contact each other, the inclined tooth edges 55 bias the teeth 51 to engage firmly (see Figure 8E). This biasing is possible because the spindle assembly 30 and the inner spindle drive shaft 46 can rotate independently of each other until the toothed couplers 43, 48 are both locked together. Once the teeth 51 are thus firmly engaged and locked, the rotation of the inner spindle drive shaft 46 is efficiently converted into the rotation of the outer spindle drive shaft 40 and, in turn, the mixing tool 38.In other words, when the teeth 51 are securely engaged and locked, the inner spindle drive shaft 46 and the outer spindle drive tube 40 rotate in unison.

[0024] The use of the concentric drive shafts / tubes 40, 46 in the present invention has a number of advantages over conventional designs. The outer spindle drive tube 40 isolates the inner spindle drive shaft 46 so that it does not contact the food during the mixing process, eliminating the need to repeatedly clean the inner spindle drive shaft 46. This is important because the preferred inner spindle drive shaft 46 is permanently attached to the mixer 10 and thus cannot be easily transferred to and cleaned in a sink. In contrast, the outer spindle drive tube 40 is part of the detachable spindle assembly 30 and can be cleaned when the detachable spindle assembly 30 is removed from the mixer 10 for cleaning. As shown in FIGS. 11-14, the use of the concentric drive shafts / tubes 40, 46 also has further advantages when the permanently attached inner spindle drive shaft 46 acts as a guide during the process of reattaching the detachable spindle assembly 30 to the mixer 10. Once the free end 59 of the inner spindle drive shaft 46 is installed on the toothed coupler 43 and the upper part of the outer spindle drive tube 40, the reattachment of the detachable spindle assembly 30 to the mixer 10 generally then only involves sliding the outer spindle drive tube 40 onto the inner spindle drive shaft 46. Also, the toothed couplers 43, 48 are designed to allow the inner spindle drive shaft 46 to be firmly engaged with the outer spindle drive tube 40 during the mixing process but then to be easily separated when the spindle assembly 30 is removed from the mixer 10 for cleaning. A further advantage of the drive shaft / tube 46, 40 arrangement of the present invention is that by securing the inner drive shaft 46 at two separate ends of the outer drive shaft 40 (i.e., at the toothed coupler 43 and the cup cover support 42; see FIG. 9C), the wobbling or "runout" during operation of the spindle assembly 30 is minimized compared to a system where this is the only single point of contact.The use of an inner drive shaft 46, which is permanently attached to the mixer, and an outer spindle drive tube 40, which is part of the detachable spindle assembly 30, is a preferred embodiment of the present invention, but those skilled in the art will recognize that these components, even if interchanged, will still be able to create a functional mixer (i.e., the outer spindle drive tube is permanently attached to the mixer and the inner drive shaft is part of the detachable spindle assembly).

[0025] Figures 10A - H illustrate a preferred embodiment 100 of an alternative detachable spindle assembly. The preferred alternative embodiment is the same as the preferred embodiment 30 of the spindle assembly described above, but includes a socket joint 101, an O - ring 106, a screw 108, and an inner spindle drive shaft 103 with a shorter lower end 105. In the above - mentioned preferred embodiment, the tip 59 of the inner spindle drive shaft 46 automatically seats within a rigid hole 49 in the cup cover support 42 when the spindle assembly 30 is fully engaged and connected to the mixer 10 (see Figure 9C). Due to the rigidity of the hole, vibration of the inner spindle drive shaft 46 during operation of the spindle assembly 30 can cause fretting wear at the tip 59 of the inner spindle drive shaft 46, which can, over time, lead to increased wobbling and fretting wear. To address the fretting wear problem, the alternative spindle assembly 100 includes a socket joint 101 with a flexible socket 102. The socket joint 101 is preferably made of a rigid plastic such as polyethylene or polypropylene. Flexibility is incorporated into the socket 102 by including one or more longitudinal slots 104 within the socket 102. When the tip 59 of the inner spindle drive shaft 103 is inserted into the socket 102, the longitudinal slots 104 allow the socket 102 to expand to provide a snug conformal fit. The socket joint 101 has the additional advantage of allowing the lower end 105 of the inner spindle drive shaft 103 to be shorter than that in the preferred embodiment of the above - mentioned spindle assembly (see Figure 10D). The shorter lower end 105 allows for easier insertion into and removal from the outer spindle drive tube 40 of the inner spindle drive shaft 103.

[0026] To assemble the removable spindle assembly 100, the lower end of the outer spindle drive tube 40 is first welded to the upper portion of the cup cover support 42. An O-ring 106 is installed around the periphery of the socket joint 101, and the socket joint 101 is then slid into the inner annular space of the outer spindle drive tube 40 until its lower end rests on the upper portion of the cup cover support 42. A screw 108 is then inserted into the bottom of the socket joint 101 in much the same way that a screw locks a drywall anchor in place, expanding the socket joint 101 and locking it in position.

[0027] Figures 11 - 14 illustrate the progression of steps for attaching the removable spindle assembly 30 to the mixer when it is first installed or after removal and cleaning. To begin the process, the pivotable lower spindle cover 16 should first be tilted upward to allow for easier insertion of the removable spindle assembly 30. In some embodiments, this may involve pressing a switch or latch to release the cover 16 from its locked position. Preferably, as soon as the cover 16 is lifted upward, the spindle motor 50 and the elevator motor 72 are deactivated so as not to operate. This deactivation can be performed by a "kill switch" connected to the cover 16. As shown in Figures 11 - 12, the removable spindle assembly 30 should then be inserted into the front of the mixer 10 such that its quick release coupler 32 is below the lower tip 59 of the inner spindle drive shaft 46 and its cup cover 36 is above the upper portion of the cup holder 18. After the removable spindle assembly 30 has been inserted into this space, the lower tip 59 of the inner spindle drive shaft 46 should be aligned so that it can be inserted into the internal opening 45 of the toothed coupler 43. As shown in Figures 13 - 14, once the inner spindle drive shaft 46 has been inserted into the internal opening 45 of the toothed coupler 43, the removable spindle assembly 30 can slide upward until its quick release coupler 32 contacts the spindle support coupler 31 to which it is permanently attached.

[0028] In a preferred embodiment, once the quick release coupler 32 contacts the spindle support coupler 31, the two couplers can be locked together simply by turning the quick release coupler 32 to the left. Conversely, to unlock the quick release coupler 32 and disengage the detachable spindle assembly 30, the quick release coupler 32 would be turned to the right. One mechanism for attaching the spindle assembly 30 to the mixer is shown, but those skilled in the art will recognize that other mechanisms can also be used to attach the spindle assembly 30 to the mixer 10. For example, in an alternative embodiment, instead of manually turning the quick release coupler 32 by hand to attach the spindle assembly 30, a rotatable release lever (not shown) can be slid from one side to the other (e.g., from left to right) and engaged with the quick release coupler 32. In a further alternative embodiment, a button (not shown) can be pressed to lock or unlock the quick release coupler to the spindle support coupler 31. After the detachable spindle assembly 30 is properly attached to the mixer 10 as shown in FIGS. 11-14, the pivotable lower spindle cover 16 should be pivoted downward to its lowered operating position as shown in FIG. 1. Prior to operation, being in this lowered position prevents the user's finger from inadvertently contacting the rotating mixing tool 38 while mixing is occurring.

[0029] Figures 1 and 15 - 17 illustrate how a food or beverage product can be mixed once the removable spindle assembly 30 is properly attached to the mixer 10. As shown in Figure 1, the process begins with placing a cup 20 containing food or beverage into the cup holder 18. The operator can then rotate the mixing knob 24 on the control panel 22 to select the desired viscosity and press the start button 26 on the control panel 22, indicating that the operator is ready to start the mixing process. At that point, a microprocessor (not shown) within the mixer will preferably check that the machine is ready for mixing before activating the elevator motor 72 and then the spindle motor 50. For example, the microprocessor will confirm that the pivotable lower spindle cover 16 is in the lowered position as shown in Figure 1 and that the cup holder 18 is in its bottom starting position. Once these checks are made, the elevator motor 72 is activated to lift the cup holder 18 and cup 20 upward towards the spindle assembly 30. As shown in Figure 15, after the upper portion of the cup 20 passes through the bottom 19 of the pivotable lower spindle cover 16, the spindle assembly cup cover 36 is pressed onto the upper portion of the cup 20 by the compression spring 34. As previously mentioned, the purpose of the cup cover 36 is to prevent the food or beverage from overflowing out of the cup 20 during mixing. In addition to preventing overflow, the use of the compression spring 34 also presses more firmly to engage the anti - rotation mechanisms 17, 19 (Figure 3A) to prevent the cup 20 from spinning during the mixing process. In a preferred embodiment, the mixing tool 38 on the spindle assembly 30 is not allowed to start rotating until (1) the upper portion of the cup 20 has passed through the bottom 19 of the pivotable lower spindle cover 16, (2) the cup cover 36 has been pressed onto the upper portion of the cup 20, and (3) the mixing tool 38 is in contact with, or about to contact, the food or beverage within the cup 20 (see Figure 16). Sensors such as an optical sensor or current sensing (not shown) can be used to ensure that these conditions are met before the microprocessor activates the spindle motor 50.

[0030] Figures 16 and 17 illustrate the operation of the mixing tool 38 for mixing food or beverage within the cup 20. In the preferred mixer 10, the mixing tool 38 remains at a constant predetermined height while the cup holder 18 moves up and down. As the elevator assembly 70 moves the cup holder 18 up and down, the mixing tool 38 operates at different levels of the food or beverage within the cup 20. For example, in the position shown in FIG. 16, the mixing tool 38 begins by mixing the food or beverage at the top of the cup 20. As the elevator 70 continues to raise the cup 20, the mixing tool 38 mixes the food or beverage at progressively lower levels within the cup 20 until the mixing tool 38 reaches the bottom of the cup 20 as shown in FIG. 17. To achieve uniform mixing and good viscosity, the mixing tool 38 should act at all levels of the food or beverage present within the cup 20. When the cup holder 18 is subsequently lowered, the mixing tool 38 continues to mix but now mixes at progressively higher levels of the food or beverage within the cup 20. To obtain optimal mixing and viscosity, the cup holder 18 is preferably raised and lowered a plurality of times while the mixing tool 38 spins. The mixing process preferably ends with a "shake-down" after the cup is partially lowered such that the food or beverage is cleared from the mixing tool 38. Once the mixing process is complete, the elevator assembly 70 lowers the cup holder 18 and the cup 20 to the bottom starting position shown in FIG. 1. The mixer operator can then remove the cup 20 from the cup holder 18 so that the user can enjoy the fully mixed food or beverage. In the present invention, it is preferred that the mixing tool remains stationary and the cup / cup holder moves up and down during the mixing process, but the present invention could alternatively be implemented such that the cup / cup holder remains stationary and the mixing tool moves up and down. This alternative embodiment would allow a cup / cup holder rotating rack to be used to accelerate the preparation of multiple milkshakes / smoothies.

[0031] After each cup of food or beverage has been mixed, the mixing tool 38 should be raised to remove any food or beverage that has not yet been shaken off of the mixing tool 38. Preferably, the spindle assembly 30 is removed from the mixer and rinsed (similar to the cleaning of an ice cream scoop) either at a faucet or in a water container. The spindle assembly 30, or a spare spindle assembly that has already been rinsed, cleaned, and / or disinfected, is then attached to the mixer 10 before preparing a subsequent cup of food or beverage. Periodically, the spindle assembly 30 should be removed for more thorough cleaning of all of its parts. In a preferred embodiment, the spindle assembly 30 is removed for complete cleaning and disinfection at least once every four hours.

[0032] Figure 18 illustrates a preferred built-in reservoir 60 used to store a fluid such as water within the mixer 10. In order to mix frozen milkshakes or smoothies, the inventors have found it useful to insert a heated fluid into the cup 20 during the mixing process to achieve the desired viscosity. Under the control of a microprocessor, this fluid is pumped by a pump 62 through tubes 65, 66 into the cup 20 (see FIG. 3). In an alternative embodiment, the fluid from the reservoir 60 can also be used to rinse the mixing tool 38 or the entire spindle assembly 30 after each mixing process. The reservoir 60 is preferably made of stainless steel or a durable food-safe plastic.

[0033] In the embodiment shown in FIG. 18, the built-in reservoir 60 is manually filled by opening the reservoir cap 28 and pouring fluid into the upper portion of the reservoir 60. In an alternative embodiment, the reservoir 60 can be connected to a permanently piped water supply and automatically filled. To prevent the reservoir from inadvertently running dry, a level sensor 80 is preferably built into the bottom of the reservoir 60. In a preferred embodiment, the level sensor is a float sensor 80 as illustrated in FIGS. 19-20. When the fluid level is high, the float 82 will rise as shown in FIG. 19 until it reaches the upper stop 86. When the fluid level is low, the float 82 will drop as shown in FIG. 20 until the float reaches the lower stop 88. When the float 82 drops to this point, the mixer operator will be alerted by either a light 29, an audible noise, or both on the control panel 22 that the reservoir 60 needs to be refilled. In the alternative embodiment shown in FIG. 21, the level sensor 90 can utilize an optical beam, radio wave, capacitance, ultrasonic, or inductive sensing. For a through-beam optical sensor, an optical beam (visible or infrared) is passed through the liquid and the intensity is measured by a receiving sensor. The presence of the fluid will attenuate the light intensity recognized by the receiving sensor. A radio wave sensor operates in a similar manner. In a reflected optical beam configuration, a beam of light is reflected at the fluid / air interface within the reservoir and the angle of the reflected light varies with the fluid level. Again, a light receiving sensor measures the angle and determines the fluid level. If sufficient fluid is present within the reservoir, an alert signal is not transmitted. If it is determined that the fluid level is too low, an alert signal is generated. In a capacitance sensor, the presence of the fluid can act as a dielectric layer. The presence (or absence) of fluid between the capacitance plates modifies the electrical characteristics of the system. Similarly, an inductive system will detect changes in the permeability of the fluid or air and determine the water level. As shown in FIG. 21, the ideal sensor 90 will not contact the fluid for sanitary reasons and thus will not be located within the reservoir 60 itself.

[0034] Periodically, the built-in reservoir 60 should be cleaned. In the embodiment shown in FIG. 18, the cleaning can be accomplished by opening the cap 28 and preferably brushing the inner wall of the reservoir 60 with a mild chemical cleaning agent. A drain (not shown) is provided at the bottom of the reservoir 60 to remove any chemical cleaning agent and rinse water before the reservoir is refilled. For the purpose of cleaning, the use of an optical beam, radio wave, capacitance, ultrasonic, or inductive level indicator has advantages over the float indicator 80 of the preferred embodiment because these alternative optical beam or radio wave level indicators operate from outside the reservoir 60 and thus do not introduce additional internal surfaces that need to be cleaned.

[0035] As shown in FIGS. 22-25, a removable reservoir 112 can alternatively be used. In the embodiment shown in FIGS. 22-25, the removable reservoir 112 is built into the side of the mixer 110 and has a handle 114 for easy removal and reinsertion. In the illustrated embodiment, the reservoir 112 is removed (see FIG. 22) by depressing the snap-type flex latch 116 with one hand while pulling the reservoir handle 114 with the other hand. The removable reservoir 112 is then slid outwardly on the rail 119 until it is removed from the remainder of the mixer (FIG. 24). At that point, the top 113 of the reservoir 112 can be removed to allow the inside of the reservoir 112 to be cleaned. The cleaning can be accomplished by placing the removable reservoir 112 in a dishwasher or by manually cleaning the inside of the reservoir 112 using soap and potable water with a brush. Reinserting the removable reservoir 112 into the mixer 110 simply involves reversing the order of the steps. It begins by replacing the top 113 onto the filled or refilled reservoir 112, aligning the bottom of the reservoir on the rail 119, and sliding the reservoir 112 on the rail 119 until the snap-type flex latch 116 locks to return the reservoir 112 to its fixed position.

[0036] The water coupler with check valve 120 allows water to flow between reservoir 112 and mixer 110 when reservoir 112 is fully attached to mixer 110. The same water coupler with check valve 120 prevents water from flowing when reservoir 112 is not attached to mixer 110. In one embodiment, reservoir 112 can be manually filled by removing upper portion 113 and pouring water. In an alternative embodiment, a detachable reservoir is automatically filled by attaching it to a public water supply with a water pipe permanently piped through port 124. The water coupler with check valve may also be used within port 124 to ensure that water flows into reservoir 112 only when the reservoir is fully attached to mixer 110. When the reservoir is automatically filled from a public water supply, a float valve 122 can be used to detect the amount of water in the reservoir and automatically shut off the flow of water into reservoir 112 when the water level reaches a predetermined height.

[0037] In the foregoing specification, the invention has been described with reference to specific preferred embodiments and methods. However, it will be apparent to those skilled in the art that various modifications and changes may be made without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a limiting sense. That is, the invention is limited only by the appended claims.

Claims

**Claim 1**: A mixer, wherein the mixer comprises: a spindle support; a spindle motor fixed to the spindle support; an inner spindle drive shaft coupled to the spindle motor; a spindle assembly removably coupled to the spindle support and, the spindle assembly comprises: a quick release coupler; a tube; a mixing tool fixed for co-rotation with the tube, the mixing tool including a plurality of blades; The inner spindle drive shaft extends into the tube and is drivingly coupled to the tube such that when the spindle assembly is coupled to the spindle support, rotational energy is transmitted from the spindle motor through the tube to the mixing tool. **Claim 2**: The mixer according to claim 1, wherein the mixing tool is fixed to an end of the tube, and the quick release coupler is disposed around a coupling end of the tube opposite the end of the tube to which the mixing tool is fixed. **Claim 3**: The mixer according to claim 1 or claim 2, wherein the quick release coupler is a driven coupler, and the inner spindle drive shaft includes a drive coupler configured to be coupled to the driven coupler. **Claim 4**: The mixer according to claim 3, wherein the drive coupler is centrally disposed along the length of the inner spindle drive shaft. **Claim 5**: The mixer according to claim 3, wherein the drive coupler is coupled to the driven coupler, and the drive coupler transmits rotational energy to the driven coupler in a first rotational direction and does not transmit rotational energy to the driven coupler in a second rotational direction opposite the first rotational direction. **Claim 6**: The mixer according to claim 5, wherein the drive coupler includes a first plurality of teeth, and the driven coupler includes a second plurality of teeth, the second plurality of teeth being configured to engage the first plurality of teeth to transmit rotation from the drive coupler to the driven coupler. **Claim 7**: The mixer according to claim 6, wherein each tooth of the first plurality of teeth and each tooth of the second plurality of teeth include an inclined edge and a walled edge. **Claim 8**: A mixer, wherein the mixer comprises: a spindle support; a spindle motor fixed to the spindle support; an inner spindle drive shaft driven by the spindle motor; A spindle assembly and comprising, wherein the spindle assembly is a tube, and a mixing tool fixed for co-rotation with the tube, the mixing tool including a plurality of blades, the mixing tool and including, wherein the inner spindle drive shaft extends into the tube and is drivingly coupled to the tube so as to transmit rotational energy from the spindle motor to the mixing tool through the tube, a mixer. **Claim 9**: The mixer according to claim 8, wherein the tube is cylindrical. **Claim 10**: The mixer according to claim 8, wherein the inner spindle drive shaft includes a first coupler, and the first coupler is configured to engage a second coupler on the tube so as to transmit rotational energy from the inner spindle drive shaft to the tube. **Claim 11**: The mixer according to claim 10, wherein the second coupler includes an internal opening such that the inner spindle drive shaft extends through the second coupler. **Claim 12**: The mixer according to claim 10, wherein the first coupler includes a first plurality of teeth, and the second coupler includes a corresponding second plurality of teeth configured to engage the first plurality of teeth. **Claim 13**: The mixer according to any one of claims 8 to 12, wherein the tube isolates the inner spindle drive shaft from contact with food during operation of the mixer. **Claim 14**: The mixer according to any one of claims 8 to 12, wherein the inner spindle drive shaft and the tube are concentric. **Claim 15**: A mixer, the mixer comprising a spindle support, a spindle motor fixed to the spindle support, an inner spindle drive shaft driven by the spindle motor, a spindle assembly removably coupled to the spindle support and comprising, wherein the spindle assembly is a tube, and a mixing tool fixed for co-rotation with the tube and including, wherein the inner spindle drive shaft extends into the tube and is drivingly coupled to the tube so that the tube co-rotates with the inner spindle drive shaft, the tube isolating the inner spindle drive shaft from contact with food during operation of the mixer. **Claim 16**: The mixer according to claim 15, wherein the tube has a non-circular cross-sectional shape.

17. The mixer according to claim 15, wherein the inner spindle drive shaft is drivably coupled to the tube in only one rotational direction.

18. The mixer according to any one of claims 15 to 17, further comprising a cup cover supported by the tube.

19. The mixer according to any one of claims 15 to 17, wherein the inner spindle drive shaft and the tube are concentric.

20. The mixer according to any one of claims 15 to 17, wherein the mixing tool includes a cutter that can extend in the radial direction.

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