Patent Description:
Machines for continuously freezing soft serve desserts are well known in the art. Most of these machines operate on a similar principle. A mixture of milk, sugar, gelatin, flavoring, coloring, nuts, fruits, syrups and sometimes eggs is fed into a metal cylinder or mixing chamber around which a compressed gas is expanded, making the metal surfaces of the mixing chamber very cold. Ice crystals form on the surface of the chamber and they are scraped off by sharp blades revolving around the interior of the chamber. Part of the scraping assembly is a beating arrangement that introduces air into the mixture, increasing its volume. The scraping assembly also moves the frozen dessert to the discharge spout associated with the door of the mixing chamber.

A frozen dessert stirring apparatus is disclosed in <CIT>.

In frozen dessert machines sold by Taylor Company, a division of Carrier Commercial Refrigeration, Inc. located in Rockton, IL, the scraping assembly is operatively associated with a cantilevered baffle that extends into the mixing chamber from the door of the freezer. In prior art soft serve dessert machines of this type, the cantilevered baffle is usually made from stainless steel and it has a threaded protrusion at its end that is used to affix the baffle to the interior surface of the freezer door, which made from a plastic material unlike the baffle.

This metal-to-plastic threaded interface exhibits high field failure rates when subjected to a typical daily heat treatment cycle, during which the dessert product remaining within the mixing chamber is pasteurized at a temperature of between <NUM> to <NUM> (<NUM> °F to <NUM> °F), and then cooled. This daily heat treatment cycle places stress on the threaded interface between the door and baffle, which tends to degrade the plastic door over time.

It would be beneficial therefore, to provide an interface between the door and baffle that could withstand the mechanical stress associated with a daily heat treatment cycle, and thereby effectively reduce or otherwise eliminate the high field failure rates that are currently being experienced in the marketplace. The subject invention provides such a solution.

The subject invention is directed to a novel mechanical interface assembly between a cantilevered baffle and the door of the frozen dessert machine to which it is affixed, which effectively reduces or otherwise eliminates the high field failure rates currently being experienced in frozen dessert machine in the marketplace.

The mechanical interface assembly of the subject invention includes a freezer door having opposed front and rear sides. At least one recessed mounting pocket is formed in the rear side of the freezer door, and the at least one mounting pocket has a cornice covering an upper portion thereof.

The interface assembly further includes at least one elongated baffle having opposed proximal and distal end portions. The proximal end portion of the at least one baffle includes a retention flange that is dimensioned and configured for detachable reception within the at least one mounting pocket of the freezer door behind the cornice covering the upper portion thereof, wherein the at least one baffle is formed from molded plastic material.

The at least one mounting pocket in the rear side of the freezer door may have a generally U-shaped configuration. The cornice that covers the upper portion of the at least one mounting pocket is preferably attached to the rear side of the freezer door by threaded fasteners, and a lower edge of the cornice is beveled. Alternatively, the cornice may be formed integral with the rear side of the freezer door.

The at least one baffle is formed from a molded plastic material, which is similar to the material from which the freezer door is formed. Preferably, the at least one baffle is formed from a self-lubricating thermoplastic material, such as the material sold under the registered trademark "Delrin" or a similar material.

The retention flange of the at least one baffle may have a generally U-shaped configuration that corresponds to the configuration of the at least one mounting pocket in the freezer door. Preferably, an upper edge of the retention flange of the at least one baffle is beveled to cooperate with the beveled lower edge the cornice covering the upper portion of the at least one mounting pocket in the freezer door.

The at least one baffle may have a central portion with a cross-sectional configuration that is adapted to enhance the blending of the dessert product by an associated rotatable beater. In one embodiment of the invention, the central portion has a generally cruciform cross-sectional configuration. In another embodiment of the invention, the central portion has a trilobular cross-sectional configuration. A generally cylindrical hub region is integrally formed on the proximal end portion of the at least one baffle for rotatably supporting the beater. An annular thrust bearing is also integrally formed on the proximal end portion of the at least one baffle between the cylindrical hub region and the retention flange for interacting with the beater. In addition, a generally cylindrical support region is integrally formed on the distal end portion of the at least one baffle for maintaining the concentricity of the baffle relative to the beater within a freezing cylinder.

In an embodiment of the invention, the freezer door includes a pair of recessed mounting pockets formed in the rear side thereof, and each mounting pocket has a cornice covering an upper portion thereof, and an elongated baffle is detachably associated with each recessed mounting pocket formed in the rear side of the freezer door.

These and other features of the subject invention will become more readily apparent to those having ordinary skill in the art to which the subject invention appertains from the detailed description of the preferred embodiments taken in conjunction with the following brief description of the drawings.

So that those skilled in the art will readily understand how to make and use the subject invention without undue experimentation, preferred embodiments thereof and examples for a better understanding thereof will be described in detail herein below with reference to the figures:.

Referring now to the drawings wherein like reference numerals identify similar structural elements and features of the subject invention, there is illustrated in <FIG> and <FIG>, two different versions of soft serve dessert machines manufactured and sold by Taylor Company, a division of Carrier Commercial Refrigeration, Inc. located in Rockton, IL. These are examples of the type of machines for which the door and baffle interface assembly of the subject invention was specifically designed.

More particularly, <FIG> shows a soft serve dessert machine designated generally by reference numeral <NUM> that includes a single spout freezer door <NUM> and a single mixing chamber <NUM> for blending a dessert product. Similarly, <FIG> shows a soft serve desert machine designated generally by reference numeral <NUM> that includes a three spout door freezer door <NUM> and two mixing chambers 212a and 212b for two different flavors of frozen dessert product. These two machines <NUM>, <NUM> are merely exemplary of the dessert machines that are manufactured and sold by Taylor Company, and should not be viewed in anyway as limiting the scope of the subject disclosure.

These soft serve dessert machines require scheduled cleaning and sanitizing, often governed by statute and local regulatory agencies. Indeed, many of the soft serve dessert machines manufactured and sold by Taylor Company, such as the machines <NUM> and <NUM> illustrated in <FIG> and <FIG>, provide a daily heat treatment cycle to safely maintain dairy products contained therein up to two weeks, before a complete disassembly of the machine is required.

During the heat treatment cycle, the dessert product remaining within the mixing chambers of the machines is pasteurized at a temperature of between <NUM> to <NUM> (<NUM> °F to <NUM> °F), and then cooled. This treatment method increases efficiency, decreases labor time and costs and reduces product waste. However, as explained in more detail below, repeated daily heat treatment cycles can cause certain critical components in these machines to undergo a significant amount of stress and fatigue, which can result in mechanical failures, taking the machines out of service until they can be repaired.

Referring now to <FIG>, there is illustrated the soft serve dessert machine <NUM> with certain prior art component parts separated from the dessert machine for ease of illustration. More particularly, <FIG> illustrates the mechanical components that are associated with the single spout freezer door <NUM> of dessert machine <NUM>. These components include an elongated cantilevered baffle <NUM> which is affixed to the rear surface of the freezer door <NUM>, an annular door gasket <NUM> for sealing the freezer door relative to the freezing chamber <NUM>, and a cylindrical bearing <NUM> which slides over the baffle <NUM> to rotatably support the front end portion of a helical beater <NUM>. The helical beater <NUM> includes a plurality of scraper blades <NUM>. The blades <NUM> are configured to scrape frozen dessert product from the interior surfaces of the freezing cylinder <NUM> and move that product toward the spout <NUM> on freezer door <NUM>.

The mechanical components associated with freezer door <NUM> further include a beater drive shaft <NUM> and a drive shaft seal <NUM> that seals the end of the drive shaft <NUM> to the rear of the freezing cylinder or chamber <NUM>. The beater drive shaft <NUM> has a rectangular head portion <NUM> that is dimensioned and configured to fit within a correspondingly shaped hole <NUM> on the rear end of the beater <NUM>, to engage the two components together. In use, the beater drive shaft <NUM> transfers torque and rotational motion to the beater <NUM> from a motor housed within the dessert machine <NUM>.

Referring now to <FIG>, the prior art cantilevered baffle <NUM> includes a cylindrical hub portion <NUM> and an elongated U-shaped rod portion <NUM>. A threaded protrusion or post <NUM> extends from the front end of hub portion <NUM> for threaded engagement with a corresponding threaded bore <NUM> formed in the rear surface of freezer door <NUM>. The baffle <NUM> is made from stainless steel, while the freezer door <NUM> to which it is affixed, is made from plastic. This metal-to-plastic threaded interface between the plastic door <NUM> and the metal baffle <NUM> exhibits high field failure rates when subjected to a daily heat treatment cycle described above. The subject invention was developed to overcome this problem, as explained in more detail below.

Referring back to <FIG> in conjunction with <FIG>, the cylindrical bearing <NUM> is dimensioned and configured to fit over the hub portion <NUM> of the baffle <NUM>, and it includes a front flange that acts as a thrust bearing between the freezer door <NUM> and the front end of the helical beater <NUM>, which will tend to exert a force against the freezer door <NUM> when the dessert machine <NUM> is in operation.

Referring now to <FIG>, there is illustrated the soft serve desert machine <NUM> with certain prior art component parts thereof separated for ease of illustration. More particularly, <FIG> illustrates two sets of common mechanical components that are associated with the three spout freezer door <NUM> of dessert machine <NUM>. For the sake of brevity, these components include cantilevered baffles 216a, 216b affixed to three spout freezer door <NUM>, annular door gaskets 218a, 218b for sealing the freezer door <NUM> with respect to the mixing chambers 242a, 242b, cylindrical bearings 220a, 220b (with front flanges 246a, 246b) for rotatably supporting and interacting with the helical beaters 222a, 222b (with scraper blades 224a, 224b), beater drive shafts 226a, 226b which engage and drive the beaters 226a, 226b, and associated drive shaft seals 228a, 228b that sealingly interact with the rear of the freezing cylinders 242a, 242b.

Referring to <FIG>, each of the cantilevered baffles 216a, 216b of dessert machine <NUM> includes a cylindrical hub portion 234a, 234b and an elongated U-shaped rod portion 236a, 236b. A threaded protrusion or post 238a, 238b extends from each hub portion 234a, 234b for threaded engagement with corresponding threaded bores 240a, 240b formed in the rear surface of the freezer door <NUM>. These baffles 216a, 216b are made from stainless steel, while the freezer door <NUM> to which they are threadably affixed is made from plastic. Once again, this metal-to-plastic threaded interface exhibits high field failure rates when subjected to a daily heat treatment cycle.

Referring now to <FIG>, there is illustrated a single spout freezer door constructed in accordance with a preferred embodiment of the subject invention and designated generally by reference numeral <NUM>. Freezer door <NUM> is designed for use with dessert machine <NUM> shown in <FIG>, and it is similar to the single spout freezer door <NUM> shown in <FIG>, except that freezer door <NUM> has a generally U-shaped recessed mounting pocket <NUM> formed in the interior or rear surface thereof.

The recessed mounting pocket <NUM> is located within the periphery of annular groove <NUM> that accommodates the door gasket <NUM>, which is shown in <FIG>. A cornice <NUM> covers an upper portion of the mounting pocket <NUM>. The cornice <NUM> is attached to the rear side of the freezer door <NUM> by a pair of threaded fasteners <NUM>, as shown. Alternatively, the cornice may be formed integral with the rear side of the freezer door <NUM>, as described in more detail below with reference to <FIG> and <FIG>.

Referring to <FIG>, there is illustrated a cantilevered baffle constructed in accordance with a preferred embodiment of the subject invention and designated generally by reference numeral <NUM>. Unlike the prior art baffle <NUM> described above and shown in <FIG>, baffle <NUM> is molded from a plastic material, not stainless steel. Preferably, the baffle <NUM> is formed from a self-lubricating thermoplastic material, such as, for example, the material sold under the registered trademark "Delrin", which exhibits high stiffness, low friction and dimensional stability when subjected to heat.

The baffle <NUM> has a one-piece integral construction that includes a cylindrical front hub portion <NUM> having, an annular thrust bearing <NUM>, an elongated central portion <NUM> and a generally cylindrical support region <NUM>. The central potion <NUM> of the baffle <NUM> has a generally cruciform cross-sectional configuration, which is best seen in <FIG>. The cruciform shape aids in mixing dessert product within the core of the beater <NUM>, and is an enhancement over the U-shaped portion <NUM> of prior art baffle <NUM>. In an alternative embodiment of the baffle <NUM>, the elongated central portion <NUM> has a generally trilobular cross-sectional configuration, as illustrated in <FIG>, which is also an enhancement over the prior art baffle <NUM>.

The front hub portion <NUM> of baffle <NUM> supports rotation of the front end of the helical beater <NUM> and the integral thrust bearing <NUM> provides a bearing surface between the front end portion of the beater <NUM> and the freezer door <NUM>. The cylindrical support region <NUM> of baffle <NUM> interacts with the beater drive shaft <NUM> to aid in keeping the baffle <NUM> concentric with the beater <NUM> and the freezing cylinder <NUM>. By integrating these mechanical features into the one-piece baffle <NUM>, there is a reduction in component parts relative to the prior art mechanical assembly shown in <FIG>.

With continuing reference to <FIG>, the front end of the baffle <NUM> is formed with a retention flange <NUM> that has a generally U-shaped configuration, which corresponds to the U-shaped configuration of the recessed mounting pocket <NUM> in the freezer door <NUM> shown in <FIG>. More particularly, the retention flange <NUM> is dimensioned and configured for reception within the mounting pocket <NUM> of the freezer door <NUM> behind the cornice <NUM>, as best seen in <FIG>. It should be appreciated that an upper edge <NUM> of the retention flange <NUM> of baffle <NUM> is rounded or beveled, and a lower edge <NUM> of the cornice <NUM> covering the upper portion of mounting pocket <NUM> in freezer door <NUM> is angled or beveled (see <FIG>). This eases the engagement of the retention flange <NUM> behind the cornice <NUM> of the mounting pocket <NUM>, which will be described in more detail below with reference to <FIG> below.

The U-shaped interface between the retention flange <NUM> of baffle <NUM> and the mounting pocket <NUM> of freezer door <NUM>, prevents the baffle <NUM> from rotating relative to the freezer door <NUM> when the beater <NUM> is in motion during machine operation. Moreover, this plastic-to-plastic interface, which is shown in <FIG>, is not susceptible to the stress and fatigue that has impacted the metal-to-plastic threaded interface of the prior art metal baffle <NUM> and plastic freezer door <NUM>, as a result of repeated heat treatment cycles.

<FIG> illustrates the same mechanical interface described above as to <FIG>, but for a three spout freezer door <NUM> designed for use with dessert machine <NUM> shown in <FIG>, which supports two of cantilevered baffles 360a, 360b. Here, the freezer door <NUM> of the subject invention has two generally U-shaped mounting pockets 450a, 450b formed in the interior or rear surface thereof. The mounting pockets 450a, 450b corresponding to freezing cylinders 242a, <NUM> be of frozen dessert machine <NUM>. As an alternative to the separate cornice <NUM> shown in <FIG>, the embodiment of <FIG> provides integrally formed cornices 454a, 454b covering the upper portions of mounting pockets 450a, 450b.

Referring now to <FIG>, there are illustrated a series of side elevational views, in cross-section, that illustrate the method of affixing the cantilevered baffle <NUM> to the freezer door <NUM> of frozen dessert machine <NUM>, in accordance with a preferred embodiment of the subject invention. More particularly, <FIG> shows the initial positioning of the beveled upper edge <NUM> of the retention flange <NUM> of baffle <NUM> below the beveled lower edge <NUM> of the cornice <NUM> of mounting pocket <NUM> of the freezer door <NUM>.

Claim 1:
An interface for a frozen dessert machine comprising:
a) a freezer door (<NUM>, <NUM>) having opposed front and rear sides and including at least one recessed mounting pocket (<NUM>) formed in the rear side thereof, the at least one mounting pocket (<NUM>) having a cornice (<NUM>) covering an upper portion thereof, wherein the freezer door is made from plastic; and
b) at least one elongated baffle (<NUM>) having opposed proximal and distal end portions, the proximal end portion of the at least one baffle (<NUM>) including a retention flange (<NUM>) that is dimensioned and configured for detachable reception within the at least one mounting pocket (<NUM>) of the freezer door (<NUM>, <NUM>) behind the cornice (<NUM>) covering the upper portion thereof, wherein the at least one baffle (<NUM>) is formed from molded plastic material.