Patent Application
20120047918
The subject matter disclosed herein relates to refrigeration, and more particularly to icemakers and the like.
It is now common practice in the art of refrigerators to provide an automatic icemaker. The icemaker is often disposed in the freezer compartment and ice is often dispensed through an opening in the access door of the freezer compartment. In this arrangement, ice is formed by freezing water with cold air in the freezer compartment.
As described herein, the exemplary embodiments of the present invention overcome one or more disadvantages known in the art.
One aspect of the present invention relates to an apparatus comprising a mold body with at least one cavity configured and dimensioned to receive water to be frozen into ice; and an ice discharge mechanism configured to cause the ice to be removed from the at least one cavity. The mold body has a plurality of natural frequencies of vibration. Also included is a vibration source mounted to the mold body at a location which is located near a region of high deflection at one of the first five natural frequencies of vibration of the mold body, which location is not a node at that particular one of the first five natural frequencies of vibration of the mold body.
Another aspect relates to a refrigerator comprising a body defining at least one cooled compartment; a mold body with at least one cavity configured and dimensioned to receive water to be frozen into ice, the mold body being in thermal communication with the at least one cooled compartment; and an ice discharge mechanism, mounted to the body of the refrigerator, which is configured to cause the ice to be removed from the at least one cavity. The mold body has a plurality of natural frequencies of vibration. Also included is a vibration source mounted to the mold body at a location which is located near a region of high deflection at one of the first five natural frequencies of vibration of the mold body, which location is not a node at that particular one of the first five natural frequencies of vibration of the mold body.
Still another aspect relates to an apparatus comprising a mold body with at least one cavity configured and dimensioned to receive water to be frozen into ice; and an ice discharge mechanism configured to cause the ice to be removed from the at least one cavity. Also included are a piezoelectric transducer mounted to the mold body and a controller configured to cause the ice discharge mechanism to cause the ice to be removed from the at least one cavity and to cause the piezoelectric transducer to vibrate the mold body.
Yet another aspect relates to a method comprising the steps of filling at least one cavity of a mold body with water to be frozen into ice; allowing the water to freeze into ice; and activating an ice discharge mechanism configured to cause the ice to be removed from the at least one cavity. The mold body has a plurality of natural frequencies of vibration. An additional step includes vibrating the mold body by applying a vibration source at a location which is located on the mold body near a region of high deflection at one of the first five natural frequencies of vibration of the mold body, the location not being a node that particular one of the first five natural frequencies of vibration of the mold body, the vibration source vibrating near that particular one of the first five natural frequencies of vibration of the mold body. The vibration is carried out to assist in the removal of the ice from the at least one cavity.
A further aspect relates to a method comprising the steps of carrying out at least one of modal analysis and prototype testing to determine at least one mode shape and at least one corresponding natural frequency of vibration of an ice mold body having at least one cavity for receiving water to be frozen into ice; specifying the at least one corresponding natural frequency as a target operating frequency for a vibration source; and specifying a location of the vibration source on the mold body near a region of high deflection at the at least one corresponding natural frequency of the mold body, the location not being a node at the natural frequency of vibration of the mold body, the location being determined from the at least one of modal analysis and prototype testing.
These and other aspects and advantages of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. Moreover, the drawings are not necessarily drawn to scale and, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
In the drawings:
Reference should initially be had to
The freezer compartment 108 and a fresh food compartment (not shown but also well known to the skilled artisan) are arranged in a side-by-side configuration where the freezer compartment 108 is disposed next to the fresh food compartment. The door closing the freezer compartment is omitted in
The fresh food compartment and the freezer compartment 108 are, in a well-known manner, contained within a main body including an outer case, which can be formed by folding a sheet of a suitable material, such as pre-painted steel, into a generally inverted U-shape to form a top and two sidewalls of the outer case. The outer case also has a bottom which connects the two sidewalk to each other at the bottom edges thereof, and a back. A mullion or divider connects the top and bottom to each other and separates the fresh food compartment from the freezer compartment 108. As is known in the art, a thermally insulating liner is affixed to the outer case.
Suitable racks or shelves 109 are provided within freezer compartment 108 to hold frozen foods or the like. In a preferred approach, an icemaker with a piezoelectric transducer is located in the freezer compartment door, as seen in
Thus, reference should now be had to
As best seen in
As best seen in
Water in mold body 104 must be chilled below the freezing point of water at ambient pressure; for example, by being located in freezer compartment 108 or a suitably cold auxiliary compartment 134 as described above. Ice in hopper 112 may be in or accessible from the door 110 of the freezer compartment 108 in a well known manner.
Note that instead of a side-by-side configuration, the freezer compartment 108 and the fresh food compartment could be arranged in a configuration where the freezer compartment 108 is disposed beneath the fresh food compartment or on top of same.
Controller 197 activates motor 146 just long enough to move the assembly back and forth between the fill and dispense modes. Controller 197 also turns transducer 114 on and off at appropriate times.
It will thus be appreciated, with reference again to
Many alternative forms of ice mold bodies are possible, forming, for example, cubes or other conventional or novel ice shapes.
It will thus be appreciated that in one or more embodiments, an icemaker has a piezoelectric transducer 114 which causes vibration (and deformation) of mold body 104, to cause ice cubes to fall out of mold body 104; i.e., mold body 104 itself distorts under the action of transducer 114, rather than merely acting as a rigid body vibrating on its mountings. In a preferred but non-limiting approach, the frequency of the input signal to transducer 114 is deliberately selected to match (i.e., be at or close to) one of the natural frequencies of vibration of mold body 104, as will be discussed further below. This results in a relatively large displacement for a small power input to the transducer. In other instances, the frequency might be other than a natural frequency.
In a preferred but non-limiting approach, mold body 104 is coated with nano-ceramic coating or material exhibiting hydrophobicity and/or has a low friction surface to minimize bonding and/or friction between ice and mold body 104, thereby aiding in harvesting of the ice.
As alluded to above, it is desired to maximize the response of ice mold body 104 to the input from the piezoelectric transducer. Accordingly, in one or more embodiments, a modal analysis is performed on the ice mold to find where nodal points are located for given modes of vibration, to maximize response, the transducer should be located near points of maximum deflection and not near node points (such points of maximum deflection are also known as anti-nodal points).
For illustrative purposes,
Note that
In one or more embodiments, by locating the transducer 114 as described (away from nodes and at or near points of high deflection for a given natural frequency), and/or by exciting the transducer at or near such natural, only a relatively small piezoelectric input is needed to cause a significant vibrational response of mold 104, sufficient to loosen the ice for harvest (such that the ice falls out by gravity). This effect also advantageously can result in energy and/or cost savings as compared to arrangements employing harvest heaters, depending on transducer cost and power consumption.
In one or more embodiments, to locate one or more transducers 114 on ice mold body 104, first carry out a modal analysis using a finite element program such as the well-known ANSYS® software (registered mark) available from Ansys, Inc. Canonsburg, Pa., USA, to find natural frequencies and modes (or employ an analytical solution, if available for the shape of the ice mold in question). Then, on a prototype, carry out physical tests to verify the predicted natural frequencies and mode shapes, using, for example, solutions such as those available from LMS International N.V. of Leuven, Belgium. Locate one or more transducers away from nodal points at the natural frequency of interest and at anti-nodal points (points of maximum deflection). In one or more embodiments, it may be desirable to operate at the first natural frequency, or at least one of the lower natural frequencies, to minimize the number of nodal points and increase the vibrational response to the input from the transducer.
The ability to achieve sufficient vibrational response to help form clear ice and/or to assist in harvest, while using only a relatively small transducer or transducers, due to appropriate placement thereof and selection of appropriate drive frequencies therefor, is a significant aspect of one or more embodiments of the invention. Given the teachings herein, the skilled artisan can specify requirements for a piezoelectric transducer or other vibration source to a manufacturer of same and obtain an appropriate unit.
Again, for the avoidance of doubt, in one or more embodiments, the mold body 104 itself undergoes vibration in one or more of torsional, vertical flexure, and horizontal flexure modes and does not merely vibrate as a rigid mass on an elastic mount.
One or more embodiments thus provide an ice maker with a coupled source of vibration that allows the release of ice via the vibration produced by a piezoelectric transducer or similar vibration source device. The vibrations can also be used during the ice making process to stimulate the removal of air from the water and in this way produce clear ice. The vibration source is preferably coupled to an area of the mold and preferably, while the water freezes the transducer is energized to allow air to leave the water and produce clear ice. For harvesting, the mold preferably turns and the piezoelectric transducer is preferably energized. The vibration breaks the static friction between the mold and the ice and releases the cubes. One or more embodiments enable release of complex shapes without mechanical action on the mold and/or the ability to harvest ice that is not clouded or white in color due to trapped air and minerals. One or more embodiments provide an approach to ice making for unconventional shapes that can also be applied to the common crescent ice shape or other shapes.
One or more embodiments can be used with different kinds of icemakers; for example, so-called rake icemakers. The rake icemaker is known, for example, from US Patent Publication 2010/0154458, the complete disclosure of which is expressly incorporated herein by reference in its entirety for all purposes.
The ice mold body 211 also has a bottom wall 212 with its curved inner surface 213 extending generally longitudinally along the length of the ice mold body 211, and a plurality of partial partition walls 214 extending transversely across the ice mold body 211 to define a plurality of ice chambers 215. As is known in the art, ice cubes can be formed in these ice chambers 215. Each partial partition wall 214 preferably has a recessed upper edge portion (not shown) through which water flows successively from one ice chamber to the next to fill all of the ice chambers 215. The icemaker 202 can have a water inlet element 216 supported by the ice mold body 211 for directing water from the water supply conduit into the ice chambers 215 as is known in the art.
As clearly shown in
The icemaker 202 also has an ice stripper 221, which is disposed along the front side 2111 of the ice mold body 211 and partially covers the top openings 220. As clearly shown in
The icemaker 202 also has an ice rake or ejector 222 including a rotatable shaft 2221 disposed preferably slightly above the ice chambers 215 and at approximately midway between the frontal portions 2201 and the back portions 2202, and a plurality of rake fingers 2222 extending radially outwardly from the shaft 2221 and over the respective ice chambers 215. In this embodiment, each rake finger 2222 has a length so that it extends into the gap formed between the two respective adjacent stripper fingers 2211, but it does not touch the respective cover 2212 when the shaft 2221 rotates 360 degrees. One end of the shaft 2221 is connected to the axle 2101 of the motor 210. As is known in the art, when the motor 210 is activated, it rotates the shaft 2221, and the rake fingers 2222 move ice cubes from the respective ice chambers 215 to the ice stripper 221 during ice harvesting. In this embodiment, the motor 210 is an AC motor, and the shaft 2221 rotates approximately 360 degrees in a harvesting cycle. The icemaker 202 preferably has a heating element (not shown) which is used to heat ice mold body 211 when a harvest cycle begins in order to slightly melt ice cubes to allow the ice cubes to be more easily released from the ice chambers 215. In addition to or in lieu of the heating element, one or more piezoelectric transducers 114 can be provided in a suitable location, such as on mold body 211. The transducer(s) and motor 210 can be controlled, for example, by a controller such as 197 as described above.
One advantage that may be realized in the practice of some embodiments of the described systems and techniques is reduced energy use since only small piezoelectric input is needed to loosen ice for harvest. Another advantage that may be realized in the practice of some embodiments of the described systems and techniques is cost savings, again since only small piezoelectric input is needed to loosen ice for harvest. Still another advantage that may be realized in the practice of some embodiments of the described systems and techniques is increased ice clarity by avoiding trapped air and minerals. Yet another advantage that may be realized in the practice of some embodiments of the described systems and techniques is release of complex shapes without conventional mechanical action on the mold.
Given the discussion thus far, it will be appreciated that, in general terms, an exemplary apparatus, according to one aspect of the invention, includes a mold body 104 with at least one cavity 160 configured and dimensioned to receive water to be frozen into ice. The mold body has a plurality of natural frequencies of vibration (inherently, under whatever boundary (mounting) conditions it is subject to). Also included is an ice discharge mechanism configured to cause the ice to be removed from the at least one cavity. A non-limiting example is an actuation arrangement (e.g., motor 146 with gearing arrangement 148) which causes the mold body to transition between first and second positions, as shown in
Also included in the apparatus is a vibration source (piezoelectric transducer 114 is a non-limiting example) mounted to the mold body at a location which is located near a region of high deflection at one of the first five natural frequencies of vibration of the mold body; the location is also not a node at that particular one of the first five natural frequencies of vibration of the mold body.
In a preferred approach, a controller 197 is configured to cause the ice discharge mechanism to cause the ice to be removed from the at least one cavity and to cause the vibration source to vibrate near the particular one of the first five natural frequencies of vibration.
The mold body can have a variety of configurations; in one or more embodiments, a plurality of cavities 160 are configured and dimensioned to receive water to be frozen into ice.
As noted, in some instances, the ice discharge mechanism is an actuation arrangement which causes the mold body to transition between first and second positions; the controller is preferably configured to cause the actuation arrangement to transition the mold body between the first and second positions.
In one or more instances, controller 197 is further configured to cause the vibration source to vibrate near the particular one of the first five natural frequencies of vibration at a time when the mold body is in the second position and/or at a time just prior to when the mold body is in the second position.
Furthermore, in at least some cases, the controller is further configured to cause the vibration source to vibrate near the particular one of the first five natural frequencies of vibration while the water is freezing into the ice.
It is preferred that a release coating be provided on the at least one cavity. A number of non-limiting examples have been discussed elsewhere; e.g., a nano-ceramic coating. Another non-limiting example is Thermolon® non-stick coating (registered mark of Thermolon Ltd., Kowloon, Hong Kong). Polytetrafluoroethylene (PTFE) or any other suitable non-stick coating could also be employed.
Furthermore, given the discussion thus far, it will be appreciated that, in general terms, an exemplary refrigerator according to still another aspect of the invention, includes a body defining at least one cooled compartment (e.g., 108, 134); and a mold body 104 with at least one cavity 160 configured and dimensioned to receive water to be frozen into ice. The mold body is in thermal communication with the at least one cooled compartment and has a plurality of natural frequencies of vibration. Also included is an ice discharge mechanism, such as that described above, mounted to the body of the refrigerator (for example, via bracket 196). As used herein, including the claims, mounting to the body includes direct attachment to the body or indirect attachment to the body, such as to a door hinged to the body or the like. As described above, in some instances, the actuation arrangement causes the mold body to transition between first and second positions (or causes the rake to rake the ice out of the mold, or the like). Also included is a vibration source, as described above (element 114 is a non-limiting example), mounted to the mold body at a location which is located near a region of high deflection at one of the first five natural frequencies of vibration of the mold body, the location not being a node at the particular one of the first five natural frequencies of vibration of the mold body.
The refrigerator can be provided with any of the additional components and/or features as described above with respect to the apparatus.
Still further, given the discussion thus far, it will be appreciated that, in general terms, another exemplary apparatus includes a mold body as described above, an ice discharge mechanism as described above, a piezoelectric transducer mounted to the mold body; and a controller configured to cause the ice discharge mechanism to cause the ice to be removed from the at least one cavity and to cause the piezoelectric transducer to vibrate the mold body. In this aspect, the piezoelectric transducer may be provided in a variety of locations which may or may not conform to the general philosophy of locating near a region of high deflection at a natural frequency of vibration of the mold body which is also not a node at the natural frequency of vibration of the mold body.
Yet further, given the discussion thus far, it will be appreciated that, in general terms, a exemplary method includes the steps of filling at least one cavity of a mold body with water to be frozen into ice (in at least some instances, while the mold body is in an upright position, as in
In at least some instances, the ice discharge mechanism is an actuation arrangement as described above and the vibrating step is carried out at a time when the mold body is in the second position and/or a time just prior to when the mold body is in the second position.
In at least some embodiments, the vibrating step is further carried out while the water is freezing into the ice.
Even further, given the discussion thus far, it will be appreciated that, in general terms, another exemplary method includes the steps of carrying out at least one of modal analysis and prototype testing to determine at least one mode shape and at least one corresponding natural frequency of vibration of an ice mold body 104 having at least one cavity 106 for receiving water to be frozen into ice; specifying the at least one corresponding natural frequency as a target operating frequency for a vibration source (transducer 114 is a non-limiting example); and specifying a location of the vibration source on the mold body near a region of high deflection at the at least one corresponding natural frequency of the mold body (the location is not a node at the natural frequency of vibration of the mold body). The location is determined from the aforementioned modal analysis and/or prototype testing, for example, as described with respect to
Software includes but is not limited to firmware, resident software, microcode, etc. As is known in the art, part or all of one or more aspects of the methods and apparatus discussed herein may be distributed as an article of manufacture that itself comprises a tangible computer readable recordable storage medium having computer readable code means embodied thereon. The computer readable program code means is operable, in conjunction with a computer system or microprocessor, to carry out all or some of the steps to perform the methods or create the apparatuses discussed herein. A computer-usable medium may, in general, be a recordable medium (e.g., floppy disks, hard drives, compact disks, EEPROMs, or memory cards) or may be a transmission medium (e.g., a network comprising fiber-optics, the world-wide web, cables, or a wireless channel using time-division multiple access, code-division multiple access, or other radio-frequency channel). Any medium known or developed that can store information suitable for use with a computer system may be used. The computer-readable code means is any mechanism for allowing a computer or processor to read instructions and data, such as magnetic variations on a magnetic medium or height variations on the surface of a compact disk. The medium can be distributed on multiple physical devices (or over multiple networks). As used herein, a tangible computer-readable recordable storage medium is intended to encompass a recordable medium, examples of which are set forth above, but is not intended to encompass a transmission medium or disembodied signal. A processor may include and/or be coupled to a suitable memory. A processor with suitable software and/or firmware instructions may be used to implement controller 197. Other types of controls, such as electromechanical controls, could also be used.
Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to exemplary embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. Moreover, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Furthermore, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
