Patent Description:
Documents <CIT> and <CIT> disclose a stand mixer and an ice cream maker fitting for a stand mixer; the ice cream maker fitting comprises an adapter element configured to cause a rotation of the ingredient processing blade coupled to it.

The invention provides a stand mixer as defined in claim <NUM>.

The present illustrated embodiments reside primarily in combinations apparatus components related to an ice cream maker assembly. Accordingly, the apparatus components have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Further, like numerals in the description and drawings represent like elements.

The terms "including," "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, article, or apparatus. An element proceeded by "comprises a. " does not, without more constraints, preclude the existence of additional identical elements in the process, article, or apparatus that comprises the element.

Referring to <FIG>, reference numeral <NUM> generally designates an ice cream making assembly. The ice cream making assembly <NUM> includes a mixing bowl <NUM> having an outer housing <NUM> with an arc-shaped outer cross-sectional profile <NUM> extending from an upper lip <NUM> toward a base <NUM> of the mixing bowl <NUM>. The mixing bowl <NUM> further includes an inner liner <NUM> disposed within the outer housing <NUM> to define a wall cavity <NUM> therebetween. The inner liner <NUM> defines a food-product receiving cavity <NUM> having an upper edge <NUM> spaced beneath and inset with respect to the lip <NUM> and a sidewall <NUM> extending downwardly and inwardly from the upper edge <NUM>. The inner liner <NUM> further defines an overflow area <NUM> positioned above the food-product receiving cavity <NUM> and extending outwardly from the upper edge <NUM> toward the lip <NUM>. The assembly <NUM> further includes a dasher <NUM> having a center axle <NUM> extending along an axis <NUM> from an input end <NUM> of the center axle <NUM> to an anchor end <NUM> contacting a central portion <NUM> of the inner liner <NUM> within the food-product receiving cavity <NUM>. The dasher <NUM> also has first and second mixing arms 46a,46b having side portions 50a,50b spaced outwardly from the center axle <NUM> to engage with the sidewall <NUM> of the food-product receiving cavity <NUM>.

As shown in <FIG>, the assembly <NUM> further includes a drive assembly <NUM> configured for transferring a torque applied generally along the axis <NUM> to the dasher <NUM> to cause rotation thereof about the axis <NUM>. As discussed further below the mixing bowl <NUM> further includes a radiator fin unit <NUM> (<FIG> and <FIG>) received within a portion of the wall cavity <NUM> and a phase-change medium <NUM> filling a further portion of the wall cavity <NUM> surrounding at least a portion of the radiator fin unit <NUM>. In this manner, the mixing bowl <NUM> is configured, as discussed further below, to be cooled (such as within a freezer) to cause the phase-change medium <NUM>, which is a liquid at room temperature, to freeze into a solid. A food-product in the general form of a liquid may be introduced to the food-product receiving cavity <NUM> such that the heat of the liquid food product is transferred by contact to the inner liner <NUM>, which may be of metal (e.g., aluminum or the like) or another heat-conducting material, and into the phase-change medium <NUM>. In one non-limiting example, the phase change medium can comprise urea and, in a further example, a solution including between about <NUM>% and <NUM>% or, more specifically between about <NUM>% and <NUM>% or about <NUM>% of urea. This process causes cooling of the food product to result in rapid freezing of the food product to form fine crystals at the contact interface between the inner liner <NUM> and the food product. Accordingly, the dasher <NUM> is configured to rotate with respect to the mixing bowl <NUM> to scrape the crystals from off of the inner liner <NUM> and to "churn" the food product to disperse the crystals within the entirety of the food product, to bring unfrozen portions of the food product into contact with the inner liner <NUM>, and to aerate the food product. As is generally known, this general process is useable with certain types of food products to generate distributed fine crystals of frozen liquid (e.g., water) and fine air bubbles that are densely packed, yet separated within other solid components of the food product mixture (e.g., lipids and other food solids).

As can be appreciated, this is the general composition of ice cream, whereby the food product to which the above process is applied is sweetened or otherwise flavored cream or custard (with the food product further including other additives such as liquid or solid confections or fruit, for example). As is also further appreciated, the above process can be applied to other primarily-liquid food product mixtures to create other frozen desserts or the like, including but not limited to gelato, sorbet, sherbet, frozen yogurt, etc. In general, the above process is run until sufficient formation of ice crystals and aeration has been achieved. While acceptable end products can be achieved without fully solidifying the product (with such solidification being achieved through further subsequent chilling in, for example, a freezer), the end product can be improved by distributing relatively more ice crystals within the product during churning. The ability of a so-called ice cream maker to achieve this relatively higher distribution (and increased solidification) can be improved by increases in the efficiency with which the ice cream maker transfers heat away from the inner liner <NUM> during thawing of the phase-change medium <NUM> (as this is the phase when the medium absorbs heat more rapidly) and by maximizing scraping and agitation (or churning) of the food product to create an increased quantity of crystals at a minimum size with even distribution and minimal cohesion during the course of the phase-change medium <NUM> thawing.

The various aspects of the ice cream making assembly <NUM> disclosed herein can function alone or in various combinations to provide such improvements. In this respect, various specific aspects of the assembly <NUM> discussed herein can be applied to other forms, types, or configurations of ice cream makers to achieve similar improvements. In this manner, the present ice cream making assembly <NUM> is shown as an accessory/attachment for a stand mixer <NUM>, as shown in <FIG>. Although such mixers <NUM> can take a variety of forms, they generally include a drive head <NUM> (which may house a motor) and a stand <NUM>. As shown in <FIG>, the mixing bowl <NUM> is configured to be coupled with and generally supported by the stand <NUM>. In the example stand mixer <NUM> shown, this coupling is received through the base <NUM> of the mixing bowl <NUM>, which is fitted with a bayonet-fit structure and/or thread components. The present mixing bowl <NUM> is also configured to be supported by a bowl-lift mechanism included with other examples of stand mixers by the positioning and configuration of the depicted handles <NUM>, which are positioned to appropriately align with arms of such a lifting mechanism. Further, the handles <NUM> include at least one boss <NUM> (<FIG>) therein to receive pins positioned on the arms of the lifting mechanism (with the present example including two bosses <NUM> at different spacings to receive pins of lifting mechanisms of varying configurations). As further shown in <FIG>, and described further below, the dasher <NUM> is connected, by way of drive assembly <NUM> with the drive head <NUM> of the stand mixer <NUM> such that the stand mixer <NUM> can drive rotation of the dasher <NUM> within the mixing bowl <NUM>, as discussed above. In this manner, certain aspects for the drive assembly <NUM>, discussed below, are generally adapted to allow use of the ice cream making assembly <NUM> of the present disclosure to be used in connection with the stand mixer <NUM>. However, as would be understood, other aspects of the assembly <NUM> discussed herein can be adapted for use in a stand-alone appliance, including by various adaptations for driving rotation of the dasher <NUM> and/or in other variations where a bowl is rotated about a stationary dasher.

With reference to <FIG>, the coupling of the drive assembly <NUM> with the dasher <NUM> and, oppositely, with a hub <NUM> of the drive head <NUM> of the example stand mixer <NUM> are illustrated. In one example, the drive assembly <NUM> may be attached to the dasher <NUM> after the dasher <NUM> has been received within the food-product receiving cavity <NUM> (<FIG>), as discussed further below, although variations in the assembly process are contemplated. The drive assembly <NUM>, as shown in <FIG>, includes an input plate <NUM> that defines a channel <NUM> therein that is configured to engage with a gear housing <NUM> present on an output hub <NUM> of the stand mixer <NUM>. In general, such mixers <NUM>, as shown in the example of <FIG> often include a planetary output shaft <NUM> that rotates on its axis while the hub <NUM> itself rotates in an opposite direction about an axis that is disposed along the center of the drive head <NUM>. In this manner, the output shaft axis is offset from the drive head <NUM> axis such that attachment of the dasher <NUM> to the output shaft <NUM> is not desired. Rather, the dasher <NUM> is configured to be driven about the centered axis of the hub <NUM> with the axis <NUM> of axle <NUM> generally aligned therewith. Because the eccentric, planetary rotation of the output shaft <NUM> is driven by a gear assembly fitted within the hub <NUM>, such features will generally define the above-mentioned gear housing <NUM> that extends from the center of the hub <NUM> outwardly toward the output shaft <NUM>. In the example shown, the gear housing <NUM> is integrally formed within the hub <NUM> as a feature generally defining an elongate shoulder with flat faces. In this manner, the channel <NUM> in the input plate <NUM> of the drive assembly <NUM> can be configured to couple with the gear housing <NUM> in a press fit engagement that disregards the output shaft <NUM> of the mixer <NUM> and couples a central drive shaft <NUM> of the drive assembly <NUM> with the hub <NUM> for rotation about the fixed axis thereof.

As shown in <FIG> and <FIG>, the channel <NUM> in the input plate <NUM> can include a plurality of flexible and/or compressible thermoplastic elastomer ("TPE") inserts <NUM> extending inwardly thereinto and spaced along a length thereof. The inserts can be configured (in size and compressibility) to allow the input plate <NUM> to fit in a press-fit engagement with a range of differently-sized or otherwise configured gear housings <NUM> by absorbing size difference between such housings <NUM>, which may vary in size and configuration across a range of stand mixers <NUM>. In one example, the input plate <NUM> can be of a thermoplastic material, such as Polyamide A plastic (also referred to as Nylon plastic or "PA plastic") with the TPE inserts <NUM> overmolded to the PA plastic. The input plate <NUM> can include an alignment feature <NUM> on an interior of the channel <NUM> that can help a user to visually or physically assess the alignment of the drive shaft <NUM> with the center of the hub <NUM>. In one aspect, the channel <NUM> can be tapered to match a general taper of the range of gear housings <NUM> with which it is intended to fit. The input plate <NUM> can also include a notch <NUM> within the channel <NUM> to allow for clearance of the mixer <NUM> output shaft <NUM> and/or to facilitate alignment. As shown in <FIG>, in one implementation, the channel <NUM> can be aligned with the gear housing <NUM> and the input plate <NUM> can be pressed into assembly with the hub <NUM>. To facilitate such attachment, the drive head <NUM> can be tilted (if the mixer <NUM> facilitates tipping) or the drive assembly <NUM> can be assembled with the hub <NUM> prior to assembly of the mixing bowl <NUM> or with the mixing bowl <NUM> in a lowered position. In an alternative arrangement, the channel <NUM> can be somewhat widened such that a press-fit arrangement is not achieved, but rather a generally looser fit between the channel <NUM> and the gear housing <NUM> such that the drive assembly <NUM> can be coupled with the dasher <NUM> (when in place within the food-product receiving cavity <NUM>) prior to lowering of the drive head <NUM> or raising of the mixing bowl <NUM> to move the gear housing <NUM> into the channel <NUM> for operable engagement therebetween.

To facilitate assembly, the dasher <NUM>, as shown in <FIG>, includes a first clutch plate <NUM> at the input end <NUM> of the center axle <NUM>. As shown in <FIG> and <FIG>, the drive assembly <NUM> includes a second clutch plate <NUM> operably engageable with the first clutch plate <NUM> and mounted on an end of the drive shaft <NUM> opposite the input plate <NUM> such that the drive assembly <NUM> can cause rotation of the dasher <NUM> within the food-product receiving cavity <NUM>. In particular, the first and second clutch plates <NUM> and <NUM> are configured as clutch gears with respective sets of interengaging teeth <NUM>. As can be appreciated, the teeth <NUM> are generally of a similar configuration and arrangement (including the angles and phases thereof) between the first clutch plate <NUM> and the second clutch plate <NUM> such that the teeth <NUM> are oppositely arranged when the first and second clutch plates <NUM> and <NUM> are aligned for engagement. The teeth <NUM> include leading faces at a relatively high attack angle to facilitate driving of the dasher <NUM> with rotation of the drive assembly <NUM> and trailing faces at relatively low angles to allow mutual sliding for rotation of the drive assembly <NUM> relative to the dasher <NUM>. The second clutch plate <NUM> is movable along the drive shaft <NUM> and is biased away from the input plate <NUM> by a spring <NUM>. As shown in <FIG>, this allows the second clutch plate <NUM> to contact the first clutch plate <NUM> in initial assembly of the drive assembly <NUM> to the dasher <NUM> (regardless of the particular assembly sequence).

Continued movement of the drive assembly <NUM> into engagement with the dasher <NUM>, such as by lowering of the drive head <NUM> or raising of the mixing bowl <NUM> can cause relative movement of the second clutch plate <NUM> toward the input plate <NUM> under compression of the spring <NUM> (<FIG>). This movement can allow for the second clutch plate <NUM> to engage with the first clutch plate <NUM> within a range of positions for the mixer hub <NUM> relative to the bowl <NUM> position, which may vary among mixers <NUM>. This arrangement can also allow for initial misalignment between the clutch plates <NUM> and <NUM> with the second clutch plate <NUM> being pushed toward the input plate <NUM> in such initial position by the engagement of the teeth <NUM> along the trailing surfaces thereof. In such an arrangement, initial rotation of the hub <NUM> can allow for proper engagement of the teeth <NUM> with the spring <NUM> biasing the second clutch plate <NUM> into full engagement with the first clutch plate <NUM>. Additionally, the compression of the spring <NUM> allows movement of the second clutch plate <NUM> in the vertical direction against the bias to selectively release from the first clutch plate <NUM> upon a torque between the drive shaft <NUM> and the center axle <NUM> sufficient to cause movement of the leading faces of the teeth <NUM> against each other and against the force of the spring <NUM>. This can prevent damage to either the drive assembly <NUM> or the dasher <NUM> due to jamming or other overtorque scenarios.

As further shown in <FIG>, the dasher <NUM> can further define a circular flange <NUM> surrounding the first clutch plate <NUM> and extending upwardly therefrom opposite the anchor end <NUM> of the center axle <NUM>. The second clutch plate <NUM> is operably receivable within the circular flange <NUM>, including prior to compression of the spring <NUM> (as shown in <FIG>). This arrangement can allow for feedback on mating of the clutch plates <NUM> and <NUM> during the above-described assembly process and can increase stability during such assembly. In a further aspect, the fitting of the second clutch plate <NUM> within the circular flange <NUM> can facilitate assembly of the drive assembly <NUM> with the dasher <NUM> prior to assembly of the drive assembly <NUM> with the hub <NUM>, as discussed above.

Turning now to <FIG> and <FIG>, various aspects of the dasher <NUM> configuration can improve usability of the disclosed ice cream making assembly <NUM> and can further improve performance thereof. In one aspect, the first and second mixing arms 46a,46b are supported with respect to the center axle <NUM> by direct connection therewith. As illustrated in <FIG>, the mixing arms 46a and 46b define support portions 48a and 48b that extend oppositely and laterally away from the center axle <NUM> (at a slight upward angle of, for example between about <NUM>° and <NUM>°, to match the lower surface <NUM> of the inner liner <NUM>) from near the anchor end <NUM>. The above-mentioned side portions 50a and 50b of the mixing arms 46a and 46b are defined by portions of the mixing arms 46a and 46b that extend upwardly away from the support portions 48a and 48b to generally follow the profile of the tapered inner surface <NUM> of the food-product receiving cavity <NUM>. Upper support arms 49a and 49b can separately extend from adjacent the input end <NUM> of the center axle <NUM> to respectively attach with the side portions 50a and 50b laterally adjacent the input end <NUM> to provide additional support and stability for mixing arms 46a and 46b. This arrangement can facilitate relatively easy removal of the dasher <NUM> from a frozen food-product created within the food-product receiving cavity <NUM> using the dasher <NUM>. The first and second mixing arms 46a and 46b can be configured to generally follow the interior profile of the inner liner <NUM>, which as shown in <FIG> can include the above-mentioned tapered inner surface <NUM>, along with a concave/conical lower surface <NUM>. This shape of the inner liner <NUM> can allow for easier access to the food-product receiving cavity <NUM> by the user and can generally follow the arc-shaped outer of the outer housing <NUM>. The dasher <NUM> can be of a thermoplastic such as Polyoxymethylene (also referred to as Acetal Plastic or "POM") to provide desired rigidity and temperature resistance.

As further shown in <FIG> and <FIG>, the first mixing arm 46a defines, in a cross-sectional profile thereof, a scraping portion <NUM> having a leading face <NUM> with an edge <NUM> positionable in contact with the inner surface <NUM> of the food-product receiving cavity <NUM>, as defined by the inner liner <NUM>. The scraping portion <NUM> extends at an acute angle α<NUM> (e.g. of about <NUM>°) with respect to a tangent τ of the contact point of the edge <NUM> along the inner surface <NUM>. The leading face <NUM> is positioned at about <NUM>° with respect to the tangent τ. In this arrangement, the mixing arm 46a is configured such that the leading edge <NUM> is positioned forward of the scraping portion <NUM> under rotation of the dasher <NUM> in direction R, as implemented by the direction in which the mixer hub <NUM> rotates. Such rotation brings the leading edge <NUM> into contact with ice crystals, with the acute angle defined between the scraping portion <NUM> and the leading face <NUM> promoting scraping of such ice crystals from off of the inner surface <NUM> of inner liner <NUM>. The leading face <NUM> also serves to direct inward the scraped crystals, along with the surrounding medium. The cross-sectional profile further has an agitation rib <NUM> extending from the scraping portion <NUM> away from the inner surface <NUM> at an obtuse angle α<NUM> (e.g. of about <NUM>°) with respect to the tangent τ. The illustrated cross-sectional profile can be generally consistent between the support portion 40a and the side portion 50a. An alternative dasher that is, effectively, a mirror image of the depicted dasher <NUM> can be used with a stand mixer <NUM>, for example, with the hub <NUM> that rotates in a direction opposite the depicted direction of rotation R.

As shown in <FIG>, the second mixing arm 46b is generally a mirror image of the first mixing arm 46a such that, under rotation of the dasher <NUM> in direction R, different portions of the mixing arm 46b move over the inner surface <NUM>, compared to the first mixing arm 46a. In particular, the edge <NUM> of the second mixing arm 46b is, effectively, a trailing edge <NUM> that trails the scraping portion <NUM> during rotation with an outer face <NUM> directing crystals along the inner surface <NUM> and compressing the food-product between outer face <NUM> and the inner surface <NUM> with a portion of the food-product moving inward past agitation rib <NUM>. As the face <NUM> of the second mixing arm 46b does not provide any scraping effect, the face <NUM> can be positioned generally normal to the tangent τ. The different movement and scraping and circulation actions provided, thusly, by the first and second mixing arms 46a and 46b can provide improved processing and texture of the resulting product, as discussed above. Each mixing arm 46a and 46b can include a grip flange <NUM> along the upper portions thereof to afford a portion of the dasher <NUM> that a user can easily grasp to remove the dasher <NUM> from the food-product receiving cavity <NUM> and any frozen or semi-frozen food product therein.

Turning to <FIG>, aspects of the mixing bowl <NUM> are discussed in greater detail. As shown in <FIG>, and generally discussed above, the mixing bowl <NUM> includes the above-mentioned outer housing <NUM>, along with the radiator fin unit <NUM> received in the outer housing <NUM>. The inner liner <NUM> is also received within the outer housing <NUM> to enclose the radiator fin unit <NUM> within the wall cavity <NUM> defined between the outer housing <NUM> and the inner liner <NUM>. The above-mentioned phase-change medium <NUM> is also received within the wall cavity <NUM> and surrounds the radiator fin unit <NUM> to varying degrees at least partially depending on the phase state of the medium <NUM>. By way of example, the wall cavity <NUM> can contain about <NUM> oz. (by weight, +/- <NUM> oz. ) of the phase-change medium <NUM>. In one aspect, the wall cavity <NUM> is tapered from a wider cross section (<FIG>) toward the upper lip <NUM> of the mixing bowl <NUM> to a narrower cross section toward the lower portion of the mixing bowl <NUM>. This tapered structure can provide an improved distribution of the phase-change material around the food-product receiving cavity <NUM>, including a greater amount thereof around the open top portion of the mixing bowl <NUM> and a lesser amount around the enclosed inner portion. Further, such a taper can allow for retention of the phase-change medium <NUM> toward the upper portion of the food-product receiving cavity <NUM> during melting of the medium <NUM>, which occurs over a time interval. As also mentioned above, the tapered arrangement can also provide easier access to the food-product receiving cavity <NUM> for the user, including during introduction of the liquid food-product or various additional ingredients thereto and the removal of the finished, frozen food-product therefrom. In various examples, the outer housing <NUM> can be of PC-ABS or ABS plastic at a thickness of about <NUM> and can include various decorative features to improve aesthetic appeal, while hiding material defects and providing strength to the outer housing <NUM>. As discussed above, the handles <NUM> with integrated pin-receiving bosses <NUM> can be integrally formed in the outer housing <NUM>.

In one aspect, the inner liner <NUM> extends outwardly along an upper surface <NUM> from the food-product receiving cavity <NUM> to mate with and extend over an upper rim <NUM> of the outer housing <NUM> at an outer ridge <NUM> thereof that defines the upper lip <NUM> of the mixing bowl <NUM> and can capture a sealing member <NUM> above the rim <NUM> of the outer housing <NUM> to enclose the wall cavity <NUM>. The inner surface <NUM> of the food-product receiving cavity <NUM> defines an inner diameter <NUM> at an intersection with the upper surface <NUM> of the interior liner <NUM> of about <NUM>. The upper lip <NUM> defines a diameter <NUM> of about <NUM>. In other variations, the diameter <NUM> can be between about <NUM>% and <NUM>% greater than diameter <NUM>, with such wider outer diameter <NUM> further providing the above-mentioned improved access to the food-product receiving cavity <NUM>. Additionally, the area defined between the upper surface <NUM> and the ridge <NUM> can act as an overflow area to contain the food-product as its volume expands due to freezing and aeration. The inner liner <NUM> may be of a metallic or other conductive material, including Aluminum (and, more particularly, <NUM>-H32 Aluminum) at a thickness of, for example, <NUM> (+/- <NUM>). The inner liner <NUM> may be sized and configured such that the food-product receiving cavity <NUM> has a capacity of at least about <NUM> qt (quarter gallon), corresponding to about <NUM> I (litre). Additionally, the above-described overflow area can be structured to provide an additional capacity of at least about <NUM> qt (quarter gallon), corresponding to about <NUM> I (litre).

As shown in <FIG>, the structure of the radiator fin unit <NUM> generally matches that of the wall cavity <NUM> to provide an increased surface area thereof in contact with a generally optimized volume of the phase-change medium <NUM>. In this respect, the radiator fin unit <NUM> comprises a generally thin sheet of metal, such as Aluminum or the like (including <NUM>-H32 Aluminum) at a thickness of about <NUM> (+/- <NUM>). The metal material is cut and bent into the depicted shape, wherein a plurality of fins <NUM> extend outwardly from a plurality of inner connectors <NUM> and outer connectors <NUM> that maintain the fins <NUM> in the unitary structure of the radiator fin unit <NUM>. Such structure maintains the inner connectors <NUM> along a generally frustoconical profile <NUM> that matches the angled profile <NUM> of the inner liner <NUM>. When assembled, the inner connectors <NUM> are in at least partial contact with the interior liner <NUM> to provide for direct conduction of heat from the inner liner <NUM> to the radiator fin unit <NUM>. The fins <NUM> extend from the inner connectors <NUM> to further conduct heat away from the inner connectors <NUM> and inward within the phase-change medium <NUM> by conductive contact therewith. This arrangement allows for a more complete and rapid thawing of the phase-change medium <NUM> and corresponding rapid and thorough crystal formation within the food product. The fins <NUM> are spaced apart by the inner and outer connectors <NUM> and <NUM> at a distance <NUM> of about <NUM> (+/-<NUM>) to receive an appreciable amount of the phase-change medium <NUM> therebetween (<FIG>). As further shown in <FIG> and <FIG>, the outer profile <NUM> of the radiator fin unit <NUM> is partially defined by the outer connectors <NUM> and is angled to generally match the corresponding portion of the outer housing <NUM> to maximize the surface are of the fins <NUM> as they extend within the wall cavity <NUM>. As discussed above, the fins <NUM> extend downward past the outer connectors <NUM> along a chamfered portion <NUM> of the radiator fin unit <NUM> that allows for further maximizing of the fin <NUM> surface area within the wall cavity <NUM>.

As further shown in <FIG>, the outer housing <NUM> of the mixing bowl <NUM> can have a plurality of vertically-oriented ribs <NUM> formed integrally therein so as to define a plurality of corresponding channels <NUM> therebetween. As shown, the ribs <NUM> and channels <NUM> can extend through a majority of the outer profile <NUM> of the outer housing <NUM> and, thusly, can provide structural support for the outer housing <NUM>, including through the lower portion of the arced profile <NUM>. This structural support can allow for a decreased material thickness for the outer housing <NUM>, while providing resistance to potential adverse effects related to expansion and contraction of the phase-change medium <NUM> during freezing and thawing thereof, as well as of repeated assembly and disassembly with the mixer <NUM>. The relative spacing between the ribs <NUM> can vary, as can the height between the outer extent of the ribs <NUM> and the innermost portions of the channels <NUM> to provide the desired strength of the housing <NUM>, including for a desired material thickness. The cross-sectional profile and end portions of the ribs <NUM> and channels <NUM> are visible on the exterior of mixing bowl <NUM> and, accordingly, can also be adjusted to provide a desired aesthetic effect in addition to the above-described structural support.

Turning to <FIG>, in an variation of the above-described dasher <NUM> (wherein similar features are designated with like reference numerals increased by <NUM> such that features not specifically discussed herein are generally similar to those described above), the first and second mixing arms 246a,246b can be cantilevered with respect to the center axle <NUM> at the anchor end <NUM>. In other words, the mixing arms 246a and 246b, in the illustrated variation, are only attached with the center axle <NUM> at the anchor end <NUM> and are otherwise unsupported by structural ribs or other features extending between the center axle <NUM> and, for example the side portions 256a,256b of the mixing arms 246a,246b. This arrangement can allow for easier removal of the dasher <NUM> from a frozen food product created within the food-product receiving cavity <NUM> using the dasher <NUM>. Even further, such an arrangement can allow for the removal of a substantial portion of the finished frozen food product from the mixing bowl <NUM> without removal of the dasher <NUM>. Such shape can also allow for the mixing arms 246a,246b to fit against the inner liner <NUM> under compression, with the side portions 250a and 250b of the mixing arms 246a and 246b tapering outwardly from the support portions 248a and 248b at a draft angle δ of between about <NUM>° and <NUM>°. In this manner, the side portions 250a and 250b can compress inward with assembly of the dasher <NUM> against the inner liner <NUM> by between about <NUM>° and <NUM>°. This compression can cause the side portions 250a and 250b to contact the inner liner <NUM> under pressure, which can improve the scraping of ice crystals from the inner liner <NUM>, including by scraping smaller crystals. Such compression may be balanced against the generation of noise by such scraping and to minimize heat generated by friction between components.

Further, in the illustrated example of the dasher <NUM>, the first and second mixing arms 246a,246b each define, in a cross-sectional profile thereof, a scraping portion <NUM> having a leading edge <NUM> positionable in contact with the inner surface <NUM> of the food-product receiving cavity <NUM>, in a similar manner to that which is discussed above with reference to <FIG>. The scraping portion <NUM> extends at an acute angle with respect to a tangent of the leading edge <NUM> along the inner surface <NUM>. The cross-sectional profile further has an agitation rib <NUM> extending from the scraping portion <NUM> away from the inner surface <NUM> at an obtuse angle with respect to the tangent. Notably, the first and second mixing arms 246a and 246b are mirror images of each other such that, under rotation of the dasher <NUM>, different portions of the respective mixing arms move over the inner surface <NUM> causing scraping of the inner surface <NUM> in different ways and different agitation of the food product by the different mixing arms 246a and 246b. In one example, the mixing arm 246a is configured such that leading edge <NUM> is positioned forward of the scraping portion <NUM> with ice crystals contacting the leading edge <NUM> along with the front face <NUM> of the scraping portion <NUM>. The front face <NUM> is positioned generally normal to the tangent such that crystals, along with the surrounding medium are directed inward from the inner surface <NUM>, along the interior of the scraping portion <NUM> and further inward by the agitation rib <NUM>. Conversely, the leading edge <NUM> of the second mixing arm 246b trails the scraping portion <NUM> during rotation with an outer face <NUM> directing crystals along the inner surface <NUM> and compressing the food product between the outer face <NUM> and the inner surface <NUM> with a portion of the food product moving inward past the agitation rib <NUM>. The different movement and scraping and circulation actions provided, thusly, by the first and second mixing arms 246a and 246b can provide improved processing and texture of the resulting product, as discussed above. The present example, in which the mixing arms 246a and 246b are mirror images of one another, results in the dasher <NUM> that provides the same functionality regardless of the particular direction in which the hub <NUM> of the stand mixer <NUM> rotates.

Additional aspects of the present disclosure are described in the following paragraphs and all possible combinations thereof.

According to one such aspect of the present disclosure, an ice cream making assembly includes a mixing bowl, having an outer housing and an inner liner defining a wall cavity therebetween. The inner liner further defines a food-product receiving cavity therein. The mixing bowl further includes a radiator fin unit received within a portion of the wall cavity and a phase-change medium filling a further portion of the wall cavity surrounding at least a portion of the radiator fin unit. The outer housing defines an arc-shaped outer cross-sectional profile of the wall cavity, and the inner liner defines an angled inner cross-sectional profile of the wall cavity. The radiator fin unit defines an outer chamfer extending generally along the outer cross-sectional profile and a tapered inner profile extending along inner cross-sectional profile of the wall cavity and in at least partial contact with the inner liner. The assembly further includes a dasher having a center axle extending along an axis from an input end of the center axle to an anchor end contacting a central portion of the inner liner, the dasher further including first and second mixing arms including support portions extending outwardly from the anchor end of the axle and side portions extending upwardly and outwardly from the support portions to generally follow an angled inner profile of the food-product receiving cavity.

The input end of the center axle may define a first clutch plate and the assembly may further comprise a drive assembly including a second clutch plate operably engageable with the first clutch plate such that the drive assembly can cause rotation of the dasher within the food-product receiving cavity. The second clutch plate may further be biased against the first clutch plate and movable against the bias to selectively release from the first clutch plate.

The dasher may further define a circular flange surrounding the first clutch plate and extending upwardly therefrom opposite the anchor end of the center axle, and the second clutch plate may be operably receivable within the circular flange.

The drive assembly may further define an input plate with a channel configured to engage with a gear housing on an output of a mixing appliance.

The first and second mixing arms may be cantilevered with respect to the center axle at the anchor end.

The first and second mixing arms may each define, in a cross-sectional profile thereof, a scraping portion having a leading edge positionable in contact with an inner surface of the food-product receiving cavity with the scraping section extending at an acute angle with respect to a tangent of the leading edge along the inner surface. The cross-sectional profile may further have an agitation rib extending from the scraping portion away from the inner surface at an obtuse angle with respect to the tangent.

The outer bowl may include first and second handles extending from opposite sides thereof. The handles may each define a respective boss for receiving a retention pin of a bowl lift mechanism associated with a stand mixer.

Claim 1:
A stand mixer (<NUM>) comprising an ice cream making assembly (<NUM>), the ice cream making assembly (<NUM>) comprising:
a mixing bowl (<NUM>) including:
an outer housing (<NUM>) having an arc-shaped outer cross-sectional profile (<NUM>) extending from an upper lip (<NUM>) toward a base (<NUM>) of the mixing bowl (<NUM>), wherein the base (<NUM>) is configured to couple with a base of the stand mixer (<NUM>); and
an inner liner (<NUM>) disposed within the outer housing (<NUM>) to define a wall cavity (<NUM>) therebetween, the inner liner (<NUM>) defining a food-product receiving cavity (<NUM>) having an upper edge (<NUM>) spaced beneath and inset with respect to the upper lip (<NUM>) and a sidewall (<NUM>) extending downwardly and inwardly from the upper edge (<NUM>), the inner liner (<NUM>) further defining an overflow area (<NUM>) positioned above the food-product receiving cavity (<NUM>) and extending outwardly from the upper edge (<NUM>) toward the upper lip (<NUM>);
a dasher (<NUM>) including a center axle (<NUM>) extending along an axis (<NUM>) from an input end (<NUM>) of the center axle (<NUM>) to an anchor end (<NUM>) contacting a central portion (<NUM>) of the inner liner (<NUM>) within the food-product receiving cavity (<NUM>), the dasher (<NUM>) further including first and second mixing arms (46a, 46b) having side portions (50a, 50b) spaced outwardly from the center axle (<NUM>) to engage with the sidewall (<NUM>) of the food-product receiving cavity (<NUM>); and
a drive assembly (<NUM>) configured for transferring a torque applied generally along the axis (<NUM>) to the dasher (<NUM>) to cause rotation thereof about the axis (<NUM>),
characterized in that the drive assembly (<NUM>) defines an input plate (<NUM>) defining a channel (<NUM>) configured to engage with a gear housing (<NUM>) on an output (<NUM>) of the stand mixer (<NUM>).