Injectable aerator mixing rod and method for manufacturing the same

Abstract

To provide an aerator mixing rod that can be manufactured at low cost. [Solution] The aerator mixing rod includes a body having a first end, a second opposite end, and an outer surface extending between the ends. The body defines a longitudinal axis extending through the ends. The aerator mixing rod also includes teeth extending radially outward from the outer surface, having a first tooth row and a second tooth row spaced apart from the first tooth row along the longitudinal axis. A first passage is formed between adjacent teeth of the first row, and a second passage is formed between adjacent teeth of the second row. The first passage is at least partially offset from the second passage in a direction parallel to the longitudinal axis such that the first and second passages form a winding path for fluid flowing along the outer surface of the body. The aerator mixing rod is formed from an injection-molded material by an injection molding process.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims priority to U.S. Provisional Patent Application No. 63 / 025,283, filed on May 15, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to an aerator mixing rod, and more particularly to an injection - molded aerator mixing rod.

Background Art

[0003] An aerator mixing rod is a static mixing rod that mixes and aerates a liquid product as the liquid product flows over or through the mixing rod. Such an aerator mixing rod can be incorporated into food product dispensers such as whipped product (e.g., whipped cream or other aerated emulsions) dispensers. A typical whipped product dispenser can include a product reservoir that stores the liquid product to be whipped, a whipping assembly (including the aerator mixing rod), and a drive mechanism configured to move the product from the product reservoir through the whipping assembly to form a whipped product. The whipped product is then dispensed through a nozzle for use.

[0004] To emulsify the liquid product and form whipped cream with the whipping assembly, the drive mechanism forces the liquid product through passages formed between teeth on the outer surface of the aerator mixing rod. As the liquid product moves through the passages on the aerator mixing rod, air / pressurized gas mixes with the liquid product to form a foamy, airy substance.

[0005] Due to their complex shapes, known aerator mixing rods are manufactured using either CNC machining, electrical discharge machining (EDM), or investment casting. However, these conventional methods have proven costly and time-consuming when manufacturing aerator mixing rods on an industrial scale. In addition, these methods can result in aerator mixing rods with dimensional inconsistencies or overall unsatisfactory surface finishes, leading to waste and increased overall costs. [Overview of the Initiative]

[0006] This disclosure provides, in a first embodiment, an aerator mixing rod comprising a body having a first end, a second end opposite to the first end, and an outer surface extending between the first and second ends. The body defines a longitudinal axis extending through the first and second ends. The aerator mixing rod also comprises a plurality of teeth extending radially outward from the outer surface of the body, having a first tooth row and a second tooth row spaced apart from the first tooth row along the longitudinal axis. A first passage is formed between adjacent teeth of the first tooth row, and a second passage is formed between adjacent teeth of the second tooth row. The first passage is at least partially offset from the second passage in a direction parallel to the longitudinal axis such that the first and second passages are configured to at least partially form a winding path for a fluid flowing along the outer surface of the body. The aerator mixing rod is formed from a material that is injection moldable by an injection molding process.

[0007] In some embodiments, each tooth of a plurality of teeth includes a first side and a second side substantially opposite the first side, and the first and second sides converge radially outward in the aerator mixing rod.

[0008] In some embodiments, the first side and the second side are axially oriented sides.

[0009] In some embodiments, the first side and the second side are sides facing the circumferential direction.

[0010] In some embodiments, each tooth of a plurality of teeth includes an inner width and an outer width. The inner width is defined adjacent to the outer surface of the body, and the inner width is greater than the outer width.

[0011] In some embodiments, the inner width is at least 5% greater than the outer width.

[0012] In some embodiments, each tooth of a group of teeth includes an outermost point. The outermost points of the group of teeth collectively define a first diameter, and the body defines a second diameter, which is 10% to 95% of the first diameter.

[0013] In some embodiments, the injection-molded material is a plastic material.

[0014] In some embodiments, the plastic material includes an acetal homopolymer.

[0015] In some embodiments, the first and second sets of teeth each contain eight teeth.

[0016] In some embodiments, the aerator mixing rod includes a core and an outer shell, the outer shell being molded on the core and the outer shell containing a plurality of teeth.

[0017] In a second aspect, the disclosure provides a food product dispenser comprising a drive unit and a dispensing unit coupled to the drive unit. The dispensing unit includes a product transfer assembly comprising a product reservoir configured to contain a food product, a dispensing nozzle, and an aerator mixing rod. The product transfer assembly is configured to be driven by the drive unit to transport the food product from the product reservoir along the aerator mixing rod to the dispensing nozzle, the aerator mixing rod being formed from a material that can be injection molded by an injection molding process.

[0018] In some embodiments, the aerator mixing rod has a thermal conductivity of 0.1 to 0.5 watts / meter Kelvin.

[0019] In some embodiments, the aerator mixing rod includes a first portion and a second portion arranged side by side within the product transfer assembly.

[0020] In some embodiments, the aerator mixing rod includes a first portion and a second portion arranged concentrically within the product transfer assembly.

[0021] In some embodiments, the injection-molded material is a plastic material.

[0022] In some embodiments, the injection-molded material includes an acetal homopolymer.

[0023] In a third aspect, the disclosure provides a method for manufacturing an aerator mixing rod using injection molding. The method comprises arranging a plurality of mold parts in a mold assembly structure, the mold assembly structure defining a mold cavity shaped to form an aerator mixing rod, thereby including a body having a first end, a second end opposite the first end, and an outer surface extending between the first and second ends. The body defines a longitudinal axis extending through the first and second ends. A plurality of teeth extend radially outward from the outer surface of the body, and the plurality of teeth include a first tooth row and a second tooth row spaced apart from the first tooth row along the longitudinal axis. A first passage is formed between adjacent teeth of the first tooth row, and a second passage is formed between adjacent teeth of the second tooth row. The first passage is at least partially offset from the second passage in a direction parallel to the longitudinal axis, such that the first and second passages form at least partially a winding path for a fluid flowing along the outer surface of the body. The method further includes heating an injection-molded material, injecting the injection-molded material into a mold assembly structure to form an aerator mixing rod, and, after a cooling period, removing the aerator mixing rod from the mold assembly structure by separating a plurality of mold parts from the aerator mixing rod.

[0024] In some embodiments, arranging a plurality of mold components to form a mold assembly structure involves selecting between a plurality of different mold release configurations to prevent undercuts.

[0025] In some embodiments, at least one of the mold release configurations is a symmetric configuration that includes a plurality of parting lines that intersect at the center of the mold cavity, and separating the plurality of mold components includes separating the mold components along the parting lines.

[0026] In some embodiments, at least one of the mold release configurations is an asymmetric configuration that includes four parting lines, and separating the plurality of mold components includes separating the mold components along the parting lines.

[0027] Other features and aspects of the present disclosure will become apparent by considering the following detailed description and the accompanying drawings. Any feature described herein with respect to one embodiment or implementation may be combined with any other feature described herein with respect to any other embodiment or implementation, where appropriate and applicable.

Brief Description of the Drawings

[0028] [Figure 1] A perspective view of an aerator mixing rod according to an embodiment of the present disclosure. [Figure 2] A longitudinal cross-sectional view of the aerator mixing rod of FIG. 1. [Figure 3A] An enlarged side view showing a portion of the aerator mixing rod of FIG. 1. [Figure 3B] An enlarged perspective view showing a portion of the aerator mixing rod of FIG. 1. [Figure 4] A cross-sectional view of the aerator mixing rod of FIG. 1. [Figure 5A] A molding assembly having a symmetric mold release configuration that can be used to mold an aerator mixing rod such as the aerator mixing rod of FIG. 1 is shown. [Figure 5B]Figure 1 shows a molded assembly having an asymmetrical demolding configuration that can be used to mold an aerator mixing rod, such as the aerator mixing rod shown in Figure 1. [Figure 6A] This is an end view of an aerator mixing rod showing an asymmetrical release configuration that results in undercutting. [Figure 6B] This is an end view of the aerator mixing rod in Figure 6A, showing a symmetrical release configuration that eliminates the undercut in Figure 6A. [Figure 7A] This is an end view of an aerator mixing rod having a first tooth profile. [Figure 7B] This is an end view of an aerator mixing rod having a second tooth profile. [Figure 8] This is a perspective view of an aerator mixing rod according to another embodiment. [Figure 9A] This is a perspective view showing a portion of an aerator mixing rod according to another embodiment. [Figure 9B] An enlarged side view showing a portion of an aerator mixing rod according to another embodiment. [Figure 9C] An enlarged side view showing a portion of an aerator mixing rod according to another embodiment. [Figure 10] This is a perspective view of a food product dispenser incorporating an aerator mixing rod. [Figure 11] Figure 10 is a perspective view of the food product dispenser, showing the dispensing unit separated from the drive unit of the food product dispenser. [Figure 12] Figure 11 is a cross-sectional view of the dispensing unit, showing the product flow path through the dispensing unit. [Figure 13] This is a cross-sectional view showing a portion of a dispensing unit incorporating an aerator mixing rod, according to another embodiment. [Modes for carrying out the invention]

[0029] Before any embodiment of this disclosure is described in detail, it should be understood that in its application, this disclosure is not limited to the details of the configuration and component arrangements described in the following description or illustrated in the following drawings. Other embodiments of this disclosure are possible and can be implemented or performed in various ways.

[0030] Figures 1 to 4 show an aerator mixing rod 10 according to one embodiment. The aerator mixing rod 10 (which may also be called the "aerator rod," "mixing rod," or "static mixing rod") includes an elongated body 12 having a first end 13 and a second end 14 opposite the first end 13 (Figure 1). The body 12 defines a longitudinal axis 15 extending to the center through the first end 13 and the second end 14. In the illustrated embodiment, the body 12 has a substantially cylindrical shape, but in other embodiments, the body 12 may have a different shape.

[0031] Referring to Figures 3A and 3B, the illustrated aerator mixing rod 10 includes a plurality of teeth 20 projecting radially from the outer surface 21 of the mixing rod 10. In the illustrated embodiment, the teeth 20 are arranged in a plurality of first rows 22A and a plurality of second rows 22B. The first rows 22A and the second rows 22B are staggered along the longitudinal axis 15 of the aerator mixing rod 10.

[0032] Each first row 22A of the teeth 20 defines a first set of passages 30 between adjacent teeth 20 in the first row 22A, and each second row 22B of the teeth 20 defines a second set of passages 32 between adjacent teeth 20 in the second row 22B. Since each first row 22A and the second row 22B of the teeth 20 are spaced apart axially by the interlattice distance G (Figure 3A), an axial gap is defined between the rows 22A and 22B of the teeth 20.

[0033] Continuing to refer to Figures 3A and 3B, the first passage 30 is at least partially axially offset from the second passage 32 (i.e., the first passage 30 is offset from the second passage 32 in the circumferential direction of the aerator mixing rod 10), defining a meandering or winding flow path through passages 30 and 32 along the outside of the aerator mixing rod 10 (see, for example, Figure 3B). In other words, there is no direct axial flow path that would allow the liquid product to flow directly through the first passage 30 and the second passage 32 without colliding with the teeth 20.

[0034] Referring to Figures 3A and 3B, the first row 22A and the second row 22B of the tooth 20 can be configured to have 4, 6, or 8 teeth in each row 22A, 22B. For example, each first row 22A of the tooth 20 may have 4 teeth 20, and each second row 22B of the tooth 20 may have 8 teeth 20. In the illustrated embodiment, the first row 22A and the second row 22B each have the same number of teeth 20. For example, the first row 22A and the second row 22B each may contain 8 teeth (Figure 4).

[0035] In some embodiments, the aerator mixing rod 10 may include 20 or more rows of teeth 20 (e.g., 10 rows in the first row 22A and 10 rows in the second row 22B). In other embodiments, the aerator mixing rod 10 may include 30 or more rows of teeth 20 (e.g., 15 rows in the first row 22A and 15 rows in the second row 22B). In yet another embodiment, the aerator mixing rod 10 may include 40 or more rows of teeth (e.g., 21 rows 22A and 22 rows 22B). In yet another embodiment, the aerator mixing rod 10 may include a larger number of unique rows (e.g., 3, 4, or more) arranged in various repeating patterns to provide a winding flow path with desired properties suitable for a particular product or application.

[0036] During operation, the aerator mixing rod 10 is positioned within a fluid passage such as a pipe. The liquid product is moved through the fluid passage (e.g., by a pump, pressurized gas source, or any other means). When the liquid product encounters the aerator mixing rod 10, it is pushed through the passages 30, 32 between the teeth 20. As the liquid product travels the length of the aerator mixing rod 10, it is sheared by the teeth 20, effectively mixing the liquid product, and in some embodiments, aerating and foaming the liquid product, creating a foamy, airy substance. The meandering flow pattern (Figure 3B) facilitates the production of a suitable foamed product, resulting in an overall desirable appearance and consistency.

[0037] For food product frothing applications, the aerator mixing rod 10 is formed within a mold assembly from a food-safe, non-porous, injection-molded material. In the illustrated embodiment, the aerator mixing rod 10 is formed from an injection-molded thermoplastic material, more specifically, an engineering thermoplastic such as Delrin® acetal homopolymer, to provide the aerator mixing rod 10 with sufficient strength and dimensional stability. The aerator mixing rod 10 may alternatively be made from other injection-molded materials, including but not limited to aluminum or stainless steel (e.g., via metal injection molding), ceramics, other plastics (e.g., PBT, PET, PTT, PLA, PP, ABS, ASA, PEI), cellulosic materials or other biomaterials, silicone compounds, or foaming materials (e.g., polyurethane, expanded polystyrene).

[0038] In some embodiments, the aerator mixing rod 10 may be formed from a combination of materials through a plurality of molding and / or coating operations. For example, referring to Figures 2 and 4, the illustrated aerator mixing rod 10 includes a core 40 and an outer shell 42 surrounding the core 40. The core 40 may be formed through a first molding operation, and the outer shell 42 may then be molded around the core 40 in a second molding operation. In the illustrated embodiment, the teeth 20 are formed as part of the outer shell 42.

[0039] Forming the aerator mixing rod 10 using a multi-stage molding process offers advantages including reducing the molding volume with each molding stage, which in turn improves dimensional stability by reducing shrinkage that occurs during solidification and cooling. The multi-stage molding process also allows the aerator mixing rod 10 to be formed from multiple different materials, optionally. For example, in some embodiments, the core 40 may be formed from a foamed material, and the outer shell 42 may be formed from a thermoplastic material. Such embodiments may allow the aerator mixing rod 10 to be lighter and to have other properties that may be desirable in certain applications, such as low thermal conductivity.

[0040] Figures 5A and 5B show exemplary mold assemblies 200 and 250 that may be used to form the aerator mixing rod 10. Each of the illustrated mold assemblies 200 and 250 includes a plurality of movable mold parts having different demolding configurations. For example, the illustrated mold assembly 200 has a symmetrical demolding configuration having four segmented mold parts 210 configured to abut each other at their respective cut lines 215a and 215b (Figure 5A). In the illustrated embodiment, the cut lines 215a and 215b are transverse and intersect at the center of the mold cavity formed by the mold parts 210 (corresponding to the center of the aerator mixing rod 10). The symmetrical configuration of the mold assembly 200 allows all of the mold parts 210 to be demolded radially from their respective cut lines 215 in the pulling direction 220.

[0041] Thus, a method for manufacturing an aerator mixing rod 10 using injection molding may include placing mold parts 210 in a mold assembly structure 200 that defines a mold cavity shaped to form the aerator mixing rod 10. The method may further include heating an injection-molded material, injecting the injection-molded material into the mold assembly structure 200 to form the aerator mixing rod 10, and, after a cooling period, removing the aerator mixing rod 10 from the mold assembly structure 200 by separating the mold parts 210 from the aerator mixing rod 10 along the mold split lines 215. The mold parts 210 move in a radial draw direction 220 during separation.

[0042] Referring to Figure 5B, the illustrated mold assembly 250 has an asymmetrical demolding configuration including two first mold parts 260 defining the respective mold split lines 265a and 265b, and two second mold parts 270 defining the respective mold split lines 285a and 285b. Referring to the orientation shown in Figure 5B, the mold assembly 250 allows the first mold parts 260 to be demolded perpendicularly (in the direction of arrow 280) from the mold split lines 265a and 265b. Simultaneously or sequentially, the second mold parts 270 can be demolded horizontally (in the direction of arrow 275) from the mold split lines 285a and 285b.

[0043] Thus, a method for manufacturing an aerator mixing rod 10 using injection molding may include placing mold parts 260, 270 within a mold assembly structure 250 that defines a mold cavity shaped to form the aerator mixing rod 10. The method may then further include heating an injection-molded material, injecting the injection-molded material into the mold assembly structure 250 to form the aerator mixing rod 10, and removing the aerator mixing rod 10 from the mold assembly structure 250 by separating mold part 260 in a pull-out direction 280 along the mold split lines 265a, 265b and mold part 270 in a pull-out direction 275 along the mold split lines 285a, 285b.

[0044] As shown in Figures 5A and 5B, the symmetrical mold assembly 200 includes two mold splitters 215a, 215b, while the asymmetrical mold assembly 250 includes four mold splitters 265a, 265b, 285a, 285b. In other embodiments, other demolding configurations may be used. That is, the aerator mixing rod 10 may be formed using a mold assembly having a different number and / or configuration of mold parts to facilitate different structures of the aerator mixing rod 10. As will be described in more detail below, the mold assembly used to form the aerator mixing rod is configured to prevent undercuts that would hinder the demolding of the mold parts (e.g., 210, 260, 270) from the aerator mixing rod 10 after molding. An undercut is any surface of a mold part that is not visible when viewed from the tensile direction. If an undercut feature is formed, the mold part may catch on the undercut, preventing the mold part from retracting after molding.

[0045] For example, Figure 6A shows an example of an aerator mixing rod 10A, which cannot be molded using the asymmetric mold assembly 250 of Figure 5B without forming undercuts. More specifically, the geometric shape of the aerator mixing rod 10A shown in Figure 6A results in several undercuts 300 that prevent the first mold part (not shown) from retracting in the direction of arrow 280. To avoid the undercuts 300, the same aerator mixing rod 10A can be molded using the symmetric mold assembly 200 of Figure 5A. That is, the aerator mixing rod 10A can be molded without undercuts 300 by radially demolding the mold part (not shown) in the direction of arrow 220.

[0046] The minimum number of mold parts for forming an aerator mixing rod, such as the aerator mixing rod 10, may be proportional to the maximum number of teeth 20 in each of the rows 22A and 22B. For example, in embodiments where rows 22A and 22B each have up to four teeth 20, two mold parts arranged to separate from a single mold line may be used to form the desired structure of the aerator mixing rod 10. In embodiments where rows 22A and 22B each have up to six teeth 20, three mold parts may be used to form the desired structure of the aerator mixing rod 10, and in embodiments where rows 22A and 22B each have up to eight teeth 20, four mold parts may be used to form the desired structure of the aerator mixing rod 10. Thus, in some embodiments, the number of mold parts in the mold assembly may be equal to twice the maximum number of teeth 20 in any given row along the aerator mixing rod 10. Each of the examples described herein includes an even number of teeth 20 in each row 22A, 22B, but in other embodiments, the aerator mixing rod 10 may be configured to have an odd number of teeth 20 in one or both rows 22A, 22B.

[0047] The aerator mixing rod 10 can be formed with teeth 20 of various geometric shapes. For example, Figures 7A and 7B show aerator mixing rods 10B and 10C having different tooth shapes. The outer contour 310 of the tooth 20 defines a first diameter D1 (i.e., from tip to tip), and the inner contour or base 320 of the tooth 20 defines a second diameter (i.e., from base to base) D2. Thus, the height of the tooth 20 can be expressed as the ratio of the first diameter D1 to the second diameter D2.

[0048] Referring to Figures 7A and 7B, the geometric shape of each tooth 20 can be further defined by a series of angles, all measured with respect to a radial reference line or axis 300 extending through the center of the tooth 20. Figures 7A and 7B show a first angle α (alpha) defined between the axis 300 and the inner edge of an adjacent tooth 20, a second angle γ (gamma) defined between the axis 300 and the inner edge of the tooth 20, and a third angle β (beta) defined between the axis 300 and the outer edge of the tooth 20. Finally, referring to Figure 3A, each tooth 20 defines an axial thickness T (i.e., parallel to the axis 15 of the aerator mixing rod 10).

[0049] The thickness T and inter-grid distance G (Figure 3A), as well as the angles α, γ, β and diameters D1, D2 (Figures 7A and 7B), can be optimized for a desired mixing application or material. For example, changing the angle α changes the offset distance between adjacent teeth 20, thereby changing the area of ​​each passage 30, 32 between adjacent teeth 20. In addition, by changing the diameters D1, D2 and / or angles α, γ, β, it is possible to optimize the overlap between rows of teeth 20, 22 for a specific mixing material or application. For example, increasing β increases the width of each tooth in the outer contour 310, resulting in an increased amount of tooth overlap between multiple teeth 20 on the aerator mixing rod 10. Greater tooth overlap can provide more winding paths between rows 22A, 22B of teeth 20, potentially producing a greater mixing and / or aeration effect. The angle γ may be increased to make the tooth 20 more V-shaped (e.g., Figure 7B), or decreased to make the tooth 20 more rectangular (e.g., Figure 7A).

[0050] In addition to determining the tooth overlap to ensure proper mixing, reference angles α, γ, and β control the axial surface area of ​​each tooth 20. The shear force acting on the liquid product flowing along the aerator mixing rod 10 depends on the surface area of ​​the teeth 20. A larger surface area of ​​the teeth 20 can also increase flow resistance and the corresponding pressure drop across the aerator mixing rod 10.

[0051] Consequently, the geometry of the aerator mixing rod is complex, and each of the above dimensions and angles affects the performance of the aerator mixing rod in a specific application. Through extensive testing and analysis, it has been found that the following ranges and ratios provide optimal performance when using the aerator mixing rod 10 to produce whipped cream products (including both dairy and non-dairy based creams).

[0052] More specifically, in some embodiments, the D1:D2 ratio can be 10:1 to 20:19, such that D2 is between 10% and 95% of D1. In other embodiments, the D1:D2 ratio can be 5:1 to 20:19, such that D2 is between 20% and 95% of D1. In yet another embodiment, the D1:D2 ratio can be 3:1 to 10:9, such that D2 is between 33% and 90% of D1. In embodiments where the aerator mixing rod 10 is used to whip cream, it has been found that the D1:D2 ratio is 14:10 to 14:13, such that it is particularly advantageous for D2 to be about 71% to about 93% of D1.

[0053] In some embodiments, the thickness T of each tooth 20 may be equal to the interstitial distance G between rows 22A and 22B of the teeth 20. In other embodiments, the ratio of the thickness T of each tooth 20 to the interstitial distance G may be 0.5:1 to 1:2. In other words, the interstitial distance G may be half to twice the thickness T of each tooth 20. This range of the ratio of thickness T to interstitial distance G has been found to be particularly advantageous for whipping cream.

[0054] In some embodiments, angle γ is 12° or greater. For example, angle γ can be 12°, 16°, 20°, 22.5°, or other angles. In some embodiments, angle β can be any angle between 0° and 20°. For example, angle β can be 5°, 11.25°, 15°, or other angles. In some embodiments, angle β can be any angle between 0° and 11.25°. These values ​​and ranges of angles γ and β have been found to be particularly advantageous for whipping cream.

[0055] Importantly, angles α, γ, and β affect not only the aeration / texture of the final foamed product, but also whether the aerator mixing rod 10 is injection moldable. First, referring to Figure 7B, angle γ must be greater than angle β so that the inner width of the teeth 20 is greater than the outer width. In other words, the teeth 20 are radially tapered. This makes it possible to avoid undercuts. In some embodiments, angle γ is at least 0.5° greater than angle β. In some embodiments, angle γ is at least 2° greater than angle β. In some embodiments, angle γ is at least 5% greater than angle β. In some embodiments, angle γ is at least 10% greater than angle β.

[0056] In some embodiments, the teeth 20 of the aerator mixing rod 10 may include a draft angle to allow the aerator mixing rod 10 to be removed more easily from the mold assembly. For example, Figure 9B shows an aerator mixing rod 10F in which the axial faces of each tooth 20 define a draft angle with respect to an axis that crosses the longitudinal axis 15 of the aerator mixing rod 10F. In the illustrated embodiments, each draft angle is greater than 0° (e.g., 1° or more) to facilitate demolding the mixing rod 10 from the mold assembly. In some embodiments, the draft angles of each axial side 20s of the teeth 20 may be the same or different.

[0057] Typically, parts manufactured using CNC machining have a zero-degree draft angle because CNC machining utilizes cutting tools to shape specific feature parts of a part, rather than having molten plastic (or other injection-molded material) injected into a mold and then demolded and removed from the mold. When a part is removed from a mold, friction exists between the mold and the part, which can tear or deform the part. With a draft angle, the tapered "V" shape of the part reduces the friction. In some embodiments, the draft angle can be proportional to the tooth height H (Figure 9B). For example, the greater the tooth height H of multiple teeth 20, the greater the draft angle.

[0058] Referring to Figure 8, in some embodiments, the aerator mixing rod 10 can be formed from multiple longitudinal segments. For example, Figure 8 shows an aerator mixing rod 10D divided into a first portion 60 and a second portion 70 configured to be joined together to form the entire length of the aerator mixing rod 10D. Since each portion 60, 70 is only half the length of the aerator mixing rod 10D, molding the first portion 60 and the second portion 70 separately may result in fewer stacked tolerances, thus leading to higher dimensional accuracy and / or lower precision requirements for the molded assembly. In some embodiments, the first portion 60 and the second portion 70 may include cooperating mounting features 65, 68 (e.g., a protrusion 65 on the first portion 60 and a corresponding recess 68 on the second portion 70, or vice versa) to facilitate joining the first portion 60 to the second portion 70. In other embodiments, the first portion 60 and the second portion 70 may be separate injection-molded parts arranged side by side, rather than being joined axially.

[0059] In some embodiments, the aerator mixing rod 10 may include relief gaps between adjacent teeth. For example, Figure 9A shows an aerator mixing rod 10E that includes relief gaps 400 between circumferentially adjacent teeth 20. In other words, the teeth 20 in each row 22A, 22B are not continuously connected. Rather, a portion of the outer surface 21 of the body 12 of the aerator mixing rod 10E extends between adjacent teeth 20. In other embodiments, the diameter of the relief gap 400 and the diameter of the outer surface 21 of the aerator mixing rod 10, measured from the center of the aerator mixing rod 10, can form a ratio between 1:1 and 12:9. That is, in some embodiments, circumferentially adjacent teeth may be interconnected by a raised wall (not shown) extending across the relief gap 400.

[0060] In some embodiments, the teeth 20 of the aerator mixing rod 10 may have a variable height. For example, Figure 9C shows an aerator mixing rod 10G having teeth 20 configured such that the outer surface 800 of each tooth 20 is angled with respect to the longitudinal axis 15 of the aerator mixing rod 10G. The teeth 20 thereby form a raised edge 810 that defines the maximum height H of the tooth. The angled surface 800 can create greater turbulence in the liquid product as the product flows through the teeth 20, thereby advantageously enhancing the mixing of certain products. In some embodiments, the angled surface 800 may be oriented at an angle of 1 to 45 degrees with respect to the longitudinal axis 15. In other embodiments, the angled surface 800 may be oriented at an angle of 5 to 30 degrees with respect to the longitudinal axis 15.

[0061] Figure 10 shows a food product dispenser 100. The food product dispenser 100 may be configured to utilize an injection-molded aerator mixing rod, such as an aerator mixing rod 10. The illustrated food product dispenser 100 includes a drive unit 114 and a dispensing unit or module 118 detachably coupled to the drive unit 114. The dispensing unit 118 includes a product reservoir 120 for holding the liquid product to be frothed, a dispensing nozzle 122, and a product transfer assembly or frothing assembly 126 configured to be powered by the drive unit 114 to move the product from the reservoir 120 to the dispensing nozzle 122.

[0062] Referring to Figure 11, the illustrated drive unit 114 includes a drive shaft 130 configured to engage with a drive socket 132 on the whisking assembly 126 when the dispensing unit 118 is coupled to the drive unit 114. The drive shaft 130 is driven by a motor (not shown) housed within the drive unit 114 and provides rotational input to the whisking assembly 126.

[0063] The foaming assembly 126 includes an aerator in fluid communication with the product reservoir 120 to draw the product from the product reservoir 120 and push the product through the aerator to form an aerated or "foamed" product, and a pump assembly 146 (e.g., a gear pump, wiper pump, etc.) driven by a motor (via a drive shaft 130 and a drive socket 132). The aerator is in communication with a dispensing nozzle 122 configured to dispense the foamed product.

[0064] In some embodiments, the dispensing unit 118 may include a motor. In such embodiments, the drive shaft 130 and drive socket 132 may be replaced by electrical connectors. In other embodiments, the drive unit 114 may include a pressurized gas source, such as a refillable and / or replaceable pressurized gas canister, and / or a compressor operable to produce pressurized gas on demand. In such embodiments, the drive shaft 130 and drive socket 132 may be replaced by pneumatic connectors, preferably quick-release pneumatic connectors such as bayonet fittings. The drive unit 114 may then supply pressurized gas to the dispensing unit 118 so that the liquid product is pushed out of the product reservoir 120 through the aerator (for example, by pressurizing the product reservoir 120). Alternatively, the pump may include a rotating impeller, and the pressurized gas may drive the rotating impeller to operate the pump. In yet another embodiment, the pressurized gas may be directed through a venturi to create suction and draw the liquid product out of the product reservoir. The liquid product can then be carried along by the flow of pressurized gas and directed through an aerator.

[0065] Referring to Figure 11, the dispensing unit 118, including the product reservoir 120, the foaming assembly 126, and the dispensing nozzle 122, can be quickly detached from the drive unit 114 as a single, self-contained assembly. This allows the user to remove the dispensing unit 118 when not in use and store it in a refrigerator. The product and all downstream components that come into contact with the product can therefore be maintained at a safe temperature without requiring a dedicated cooling system. This is advantageous in that it reduces the size, cost, complexity, energy requirements, and operating noise of the dispenser 100 compared to existing dispensers with onboard cooling systems.

[0066] The product reservoir 120 of the dispensing unit 118 is preferably insulated to keep the product contained therein suitably cold for extended periods when the dispensing unit is outside the refrigerator. For example, the product reservoir 120 may be a double-walled vacuum-insulated canister. The product reservoir 120 may be made of any other insulating food-safe material, including but not limited to stainless steel or plastic material. In some embodiments, the product reservoir 120 may include a heat conduction area that contacts the inner wall of the product reservoir 120 to enhance the cooling of the product in the reservoir 120 when the dispensing unit 118 is placed in the refrigerator. In such embodiments, an insulating cover may be provided to cover the heat conduction area when the product reservoir 120 is removed from the refrigerator for use. In some embodiments, the heat conduction area may be cooled by ice or a cooling device (such as a thermoelectric cooler) while the dispensing unit 118 is coupled to the drive unit 114.

[0067] In some embodiments, the product reservoir 120 may be a disposable product package such as a sterile brick pack, a plastic or metal foil pouch, or a bag-in-box assembly. Disposable product packaging can facilitate the replacement of the type of product dispensed by the dispensing unit 118 without the need to clean the product reservoir 120. In any such embodiment, the product reservoir 120 may optionally be insertable into an insulating sleeve or casing.

[0068] Referring to Figure 12, the foaming assembly 126 includes a housing 152 detachably coupled to the product reservoir 20, and the aerator housing portion 170 extends into the product reservoir 120. The aerator housing portion 170 includes a first chamber 172 and a second chamber 174 separated by a longitudinally extending dividing wall 175. The second chamber 174 is in fluid communication with the first chamber 172 via a transfer passage 176 extending through the dividing wall 175.

[0069] In the illustrated embodiment, the transfer passage 176 includes a first rounded bore 176a and a second rounded bore 176b intersecting the first rounded bore 176a. The rounded bores 176a, 176b may have a substantially spherical contour. In some embodiments, the first rounded bore 176a is formed by inserting a ball end mill into the first chamber 172 through the bottom end of the aerator housing portion 170 until the ball end mill engages with the dividing wall 175 and removes the material from the dividing wall 175. Similarly, the second rounded bore 176b is formed by inserting a ball end mill into the second chamber 174 through the bottom end of the aerator housing until the ball end mill engages with the dividing wall 175 on the opposite side of the first rounded bore 176a and removes the material. By machining the transfer passage 176 in this manner, it is advantageous that the transfer passage 176 can be formed without requiring additional access openings, for example, to drill transversely through the division wall 175 using a straight drill bit. In addition, the rounded bores 176a, 176b lack sharp corners and 90-degree interface angles, which prevents the product from clogging the transfer passage 176, thereby facilitating cleaning. In some embodiments, the transfer passage 176 (including the rounded bores 176a, 176b) can be formed by other methods, including but not limited to injection molding or 3D printing.

[0070] Continuing to refer to Figure 12, the first mixing rod 178 is supported in the first chamber 172, and the second mixing rod 180 is supported in the second chamber 174. In the illustrated embodiment, the first mixing rod 178 and the second mixing rod 180 are stationary labyrinth mixing rods, such as the aerator mixing rod 10 described above. Thus, the mixing rods 178, 180 have teeth 20 and passages 30, 32 (Figures 3A and 3B) that define winding flow paths along the outside of the mixing rods 178, 180. In other embodiments, one or more mixing rods of other types or geometric shapes may be used. In the illustrated embodiment, each of the mixing rods 178, 180 is made of plastic, but in other embodiments, the mixing rods 178, 180 may be made of other materials.

[0071] During use, the drive unit 114 drives the pump assembly 146, which pushes a mixture of air and product into the first chamber 172 of the aerator housing portion 170. The mixture of air and product then flows along the first mixing rod 178 in a first direction (i.e., in the direction of arrow A in Figure 12), partially aerating the product. Upon reaching the end of the first mixing rod 178, the partially aerated product flows through the transfer passage 176 in a second direction. In the illustrated embodiment, the second direction is roughly transverse to the first direction. The partially aerated product then flows over the second mixing rod 180 in a third direction (i.e., in the direction of arrow B), which is roughly opposite to the first direction. This completes the aeration of the product, and the aerated or frothed product is discharged from the second chamber 174 through the dispensing nozzle 122.

[0072] By providing the two mixing rods 178 and 180 in separate compartments, the overall height of the assembly is reduced, thereby minimizing the overall size of the dispensing unit 118. In addition, the relatively short length of each rod 178 and 180 (compared to a single-piece rod having a length equal to the combined length of the rods 178 and 180) results in a smaller stack of tolerances, thus reducing the manufacturing tolerances of the mixing rods 178 and 180. However, in other embodiments, other mixing rod configurations may be used, including a single-piece mixing rod or any other number of mixing rods.

[0073] During operation, the shear of the product mixture as it flows over the mixing rods 178, 180 generates heat. Since the mixing rods 178, 180 are made of a material with low thermal conductivity (e.g., plastic in the illustrated embodiment), a minimal amount of heat is absorbed by the mixing rods 178, 180. Rather, the generated heat is carried away with the product. In the illustrated embodiment, the mixing rods 178, 180 have a thermal conductivity of 0.1 to 0.5 watts / meter Kelvin. In contrast, conventional mixing rods, typically made of metals such as stainless steel, can have a thermal conductivity of 10 to 20 watts / meter Kelvin or more. This means that conventional mixing rods can have a thermal conductivity at least 50 to 100 times greater than that of the mixing rods 178, 180, and as a result, more heat is absorbed by the mixing rods. The low thermal conductivity of the mixing rods 178 and 180 in the illustrated embodiment is particularly advantageous when the housing portion 170 is submerged in the product contained within the product reservoir 120, thereby minimizing the heating of the product in the product reservoir 120.

[0074] Figure 13 shows a dispenser 100'' according to another embodiment. Dispenser 100'' is similar to dispenser 100 described above with reference to Figures 10 to 12, but includes an aerator mixing rod 10'' which is housed in a housing 170'' and has a nested configuration. In particular, the aerator mixing rod 10'' includes a first portion 60'' and a second portion 70'' which surrounds the first portion 60'' and is arranged concentrically with respect to the first portion 60''. The second portion 70'' includes a plurality of teeth (such as teeth 20) located both inside 71'' and outside 72'' of the second portion 70''. In some embodiments, the teeth on the outside 72'' of the second portion 70'' may alternatively be located on the inner wall of the housing 170''. In some embodiments, the teeth on the inside 71'' of the second portion 70'' may alternatively be located on the outside 62'' of the first portion 60''.

[0075] During operation, the liquid product is pushed out through a winding path defined between the first section 60'' and the second section 70''. Upon reaching the bottom end 171'' of the housing 170'', the partially foamed product is redirected outwards from the second section 70''. The product then flows in the opposite direction through a winding path between the outside 72'' of the second section 70'' and the inner wall of the housing 170''. This completes the aeration of the product, which is then discharged through the dispensing nozzle 122''.

[0076] The aerator mixing rods described and illustrated herein can be used to produce different product mixtures, such as air and water, oil and air, and solute and solvent. In addition to food product dispensers, it should be understood that injection-molded aerator mixing rods can be advantageously used in a wide variety of applications. Finally, while the aerator mixing rods described and illustrated herein are preferably manufactured by injection molding, in other embodiments the aerator mixing rods may be manufactured by other methods, including but not limited to 3D printing or other additive manufacturing processes. Manufacturing aerator mixing rods using such alternative methods may be suitable for small-scale production.

[0077] While this disclosure is described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent embodiments of this disclosure as described.

[0078] Various features and aspects of this disclosure are described in the following claims.

Claims

1. Aerosol mixing rod, A body having a first end, a second end opposite to the first end, and an outer surface extending between the first end and the second end, wherein the body defines a longitudinal axis extending through the first end and the second end, A plurality of teeth extending radially outward from the outer surface of the main body, wherein the plurality of teeth include a first tooth row and a second tooth row spaced apart from the first tooth row along the longitudinal axis, A first passage is formed between adjacent teeth in the first dental arch, and a second passage is formed between adjacent teeth in the second dental arch. The first passage is at least partially offset from the second passage in a direction parallel to the longitudinal axis, such that the first passage and the second passage form at least partially a winding path for fluid flowing along the outer surface of the body. An aerator mixing rod wherein the aerator mixing rod is formed from a material that can be injection molded by an injection molding process.

2. The aerator mixing rod according to claim 1, wherein each of the plurality of teeth includes a first side and a second side substantially opposite to the first side, and the first side and the second side converge in a radially outward direction of the aerator mixing rod.

3. The aerator mixing rod according to claim 2, wherein the first side and the second side are sides facing in the axial direction.

4. The aerator mixing rod according to claim 2, wherein the first side and the second side are sides facing in the circumferential direction.

5. The aerator mixing rod according to claim 1, wherein each of the plurality of teeth includes an inner width and an outer width, the inner width is defined adjacent to the outer surface of the body, and the inner width is greater than the outer width.

6. The aerator mixing rod according to claim 5, wherein the inner width is at least 5% larger than the outer width.

7. The aerator mixing rod according to claim 1, wherein each of the plurality of teeth includes the outermost point, the outermost points of the plurality of teeth collectively define a first diameter, the body defines a second diameter, and the second diameter is 10% to 95% of the first diameter.

8. The aerator mixing rod according to claim 1, wherein the injection-molded material is a plastic material.

9. The aerator mixing rod according to claim 8, wherein the plastic material comprises an acetal homopolymer.

10. The aerator mixing rod according to claim 1, wherein the first tooth row and the second tooth row each include eight teeth.

11. The aerator mixing rod according to claim 1, wherein the aerator mixing rod includes a core and an outer shell, the outer shell is molded on the core, and the outer shell includes the plurality of teeth.

12. A food product dispenser, Drive unit and A dispensing unit coupled to the aforementioned drive unit, A product reservoir configured to store food products, Dispensing nozzle and The system comprises a product transfer assembly including an aerator mixing rod, and a dispensing unit, The product transfer assembly is configured to be driven by the drive unit to transport the food product from the product reservoir along the aerator mixing rod to the dispensing nozzle. A food product dispenser in which the aerator mixing rod is formed from a material that can be injection molded by an injection molding process.

13. The food product dispenser according to claim 12, wherein the aerator mixing rod has a thermal conductivity of 0.1 to 0.5 watts / meter Kelvin.

14. The food product dispenser according to claim 12, wherein the aerator mixing rod includes a first portion and a second portion arranged side by side within the product transfer assembly.

15. The food product dispenser according to claim 12, wherein the aerator mixing rod includes a first portion and a second portion arranged concentrically within the product transfer assembly.

16. The food product dispenser according to claim 12, wherein the injection-molded material is a plastic material.

17. The food product dispenser according to claim 16, wherein the injection-molded material comprises an acetal homopolymer.

18. A method for manufacturing an aerator mixing rod using injection molding, The process involves arranging multiple mold parts to form a mold assembly structure, wherein the mold assembly structure includes the aerator mixing rod, A body having a first end, a second end opposite to the first end, and an outer surface extending between the first end and the second end, wherein the body defines a longitudinal axis extending through the first end and the second end, A molded assembly structure that defines a molded cavity shaped to form the aerator mixing rod, comprising a plurality of teeth extending radially outward from the outer surface of the main body, wherein the plurality of teeth include a first tooth row and a second tooth row spaced apart from the first tooth row along the longitudinal axis, with a first passage formed between adjacent teeth of the first tooth row and a second passage formed between adjacent teeth of the second row, and the first passage includes a plurality of teeth that are at least partially offset from the second passage in a direction parallel to the longitudinal axis such that the first passage and the second passage form at least partially winding paths for fluid flowing along the outer surface of the main body, Heating an injection-molded material, The injection-molded material is injected into the mold assembly structure in order to form the aerator mixing rod. A method comprising removing the aerator mixing rod from the mold assembly structure by separating the plurality of mold components from the aerator mixing rod after a cooling period.

19. The method according to claim 18, wherein arranging the plurality of mold components to form the mold assembly structure includes selecting from a plurality of different demolding configurations to prevent undercuts.

20. The method according to claim 19, wherein at least one of the demolding configurations is a symmetrical configuration including a plurality of mold splitters that intersect at the center of the mold cavity, and separating the plurality of mold parts includes separating the mold parts along the mold splitters.

21. The method according to claim 19, wherein at least one of the demolding configurations is an asymmetric configuration including four mold dividers, and separating the plurality of mold parts includes separating the mold parts along the mold dividers.

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