WO2008056957A2

WO2008056957A2 - Ice maker and ice tray thereof

Info

Publication number: WO2008056957A2
Application number: PCT/KR2007/005646
Authority: WO
Inventors: Jin Sung Park; Dong Hoon Lee; Wook Yong Lee
Original assignee: Lg Electronics Inc.
Priority date: 2006-11-10
Filing date: 2007-11-09
Publication date: 2008-05-15
Also published as: WO2008056957A3; KR20080042618A; KR100830461B1

Abstract

An ice tray having an enhanced thermal conductivity to achieve an enhancement in ice- making speed, a reduction in ice-making time, and an increase in the amount of ice produced within a given time is disclosed. An ice maker equipped with the ice tray is also disclosed. The ice tray includes a body (110) including a plurality of cavities each defining a space to produce ice. The body (110) is made of a thermally non-conductive material and has a predetermined elasticity such that the body (110) can be twisted and then recovered. The ice tray also includes a thermal conductor partially or completely formed on at least one of inner and outer surfaces of the body (110), to achieve an enhancement in thermal conductivity. The thermal conductor has a structure including at least one layer.

Description

ICE MAKER AND ICE TRAY THEREOF

Technical Field

[1] The present invention relates to an ice tray and an ice maker with the same, and more particularly, to an ice tray having improved thermal transfer characteristics to achieve an enhancement in ice-making speed and an increase in the amount of ice produced within a given time, and an ice maker equipped with the ice tray. Background Art

[2] Generally, an appliance having an ice making function such as a refrigerator, a water purifier, or a vending machine (hereinafter, referred to as a refrigerator) uses an ice tray and an ice maker to produce ice by cooling water contained in a certain container below the freezing point of the water.

[3] Traditionally, the user obtains ice through a simple ice making method in which an ice tray containing water is positioned in a freezing compartment of the refrigerator where freezing is carried out below the freezing point of water, until ice is produced, and then the user directly takes the produced ice out of the freezing compartment. The raising of living standards and development of technologies have induced development of a system capable of automatically making ice and automatically separating ice without requiring a manual action.

[4] Recently, an ice maker using a new system has been developed. That is, the developed ice maker uses a system in which water is automatically supplied to an ice tray equipped in a refrigerator or the like, to make ice in the ice tray, and a heater is arranged adjacent to the ice tray, to heat the ice tray, and thus to separate the ice from the ice tray.

[5] Where the separation of ice is carried out by heating the ice tray using the heater, a large amount of water is produced during the separation of ice from the ice tray. As a result, pieces of the ice received in the ice maker may adhere to each other by the produced water. Otherwise, the produced water is gathered at the bottom of the ice maker.

[6] In order to solve such problems, a new system has recently been proposed. In the proposed system, the separation of ice from an ice tray is achieved by twisting the ice tray, without using a heater. The ice tray used in this system is referred to as a twist type ice tray.

[7] In the above-mentioned twist type ice tray, however, the material thereof is limited to a plastic material because the ice tray should have characteristics capable of being twisted and then recovered to an original state. In this case, there is a problem in that, since plastic generally exhibits very low thermal conductivity, the plastic ice tray exhibits a very low ice making speed and a long ice making time, so that it is impossible to produce a desired amount of ice or more within a given time.

[8] To this end, an attempt to implement an ice tray using a metal material exhibiting excellent thermal conductivity has also been made. However, the metal material is inferior to the plastic material in terms of elasticity. For this reason, in the case of a twist type ice tray made of a metal material, there is a problem in that a stress concentration phenomenon αxurs when the ice tray is twisted, so that the ice tray may be torn at a stress-concentrated portion thereof.

[9]

Disclosure of Invention Technical Problem

[10] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a twist type ice tray having an enhanced thermal conductivity to achieve an enhancement in ice-making speed, a reduction in ice-making time, and an increase in the amount of ice produced within a given time, and an ice maker equipped with the ice tray.

[H]

Technical Solution

[12] The object of the present invention can be achieved by providing an ice tray comprising: a body including a plurality of cavities each defining a space to produce ice, the body being made of a thermally non-conductive material and having a predetermined elasticity such that the body can be twisted and then recovered; and a thermal conductor partially or completely formed on at least one of inner and outer surfaces of the body, to achieve an enhancement in thermal conductivity, the thermal conductor comprising at least one layer.

[13] The body may be made of a polypropylene-based plastic material or a polyethylene-based plastic material.

[14] The thermal conductor may be made of a metal or a thermally-conductive non- metal, and may be coated on at least one of the inner and outer surfaces of the body in the form of at least one layer.

[15] The thermal conductor may be made of a thermally-conductive coating material, and may be coated on at least one of the inner and outer surfaces of the body in the form of at least one layer.

[16] The ice tray may further comprise a plurality of fins provided around the cavities or formed directly on the body, to promote a thermal transfer to the cavities.

[17] The fins may be made of a thermally -conductive metal or non-metal.

[18] In another aspect of the present invention, an ice tray comprises: a body including a plurality of cavities each defining a space to produce ice; and a plurality of fins provided around the cavities or formed directly on the body, to promote a thermal transfer to the cavities.

[19] In another aspect of the present invention, an ice maker comprises: an ice tray comprising a body including a plurality of cavities each defining a space to produce ice, the body being made of a thermally non-conductive material and having a predetermined elasticity such that the body can be twisted and then recovered, and a thermal conductor partially or completely formed on at least one of inner and outer surfaces of the body, to achieve an enhancement in thermal conductivity, the thermal conductor comprising at least one layer; and a twister coupled to opposite ends of the ice tray, to twist the ice tray by a predetermined angle, for separation of ice from the ice tray.

[20] The thermal conductor may be made of a metal or a thermally-conductive non- metal, and may be coated on at least one of the inner and outer surfaces of the body in the form of at least one layer.

[21] The thermal conductor may be made of a thermally-conductive coating material, and may be coated on at least one of the inner and outer surfaces of the body in the form of at least one layer.

[22] The ice maker may further comprise a plurality of fins provided around the cavities or formed directly on the body, to promote a thermal transfer to the cavities.

[23] The twister may comprise a drive motor coupled to one end of the ice tray, to rotate the ice tray, and a rotation restrainer coupled to the other end of the ice tray, to prevent the ice tray from rotating over a predetermined angle so that the ice tray is twisted.

[24] In still another aspect of the present invention, an ice maker comprises: a case defined with a space for receiving ice, and opened at a top of the case; and an ice tray mounted to the top of the case, the ice tray comprising a body including a plurality of cavities each defining a space to produce ice, and a plurality of fins provided around the cavities or formed directly on the body, to promote a thermal transfer to the cavities. [25]

Advantageous Effects

[26] The ice tray according to the present invention and the ice maker equipped with the ice tray can achieve an enhancement in ice-making speed and a reduction in ice- making time, and can produce a sufficient amount of ice within a short period of time because the ice tray is of a twist type having improved thermal transfer characteristics.

[27]

Brief Description of the Drawings

[28] The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention.

[29] In the drawings:

[30] FIG. 1 is a view illustrating an ice tray according to the present invention and an embodiment of an ice maker equipped with the ice tray;

[31] FIGs. 2 to 4 are views illustrating operations of the ice tray of FIG. 1 according to the present invention and the ice maker equipped with the ice tray;

[32] FIG. 5 is a view illustrating an ice tray according to a first embodiment of the present invention; and

[33] FIG. 6 is a view illustrating an ice tray according to a second embodiment of the present invention.

[34]

Best Mode for Carrying Out the Invention

[35] Reference will now be made in detail to the preferred embodiments of the present invention associated with an ice tray and an ice maker equipped with the ice tray, examples of which are illustrated in the acompanying drawings.

[36] FIG. 1 is a view illustrating an ice tray according to the present invention and an embodiment of an ice maker equipped with the ice tray. FIGs. 2 to 4 are views illustrating operations of the ice tray of FIG. 1 according to the present invention and the ice maker equipped with the ice tray. FIG. 5 is a view illustrating an ice tray according to a first embodiment of the present invention. FIG. 6 is a view illustrating an ice tray according to a second embodiment of the present invention.

[37] As shown in FIG. 1, the ice maker aaaording to the present invention includes a case 400 defined with a space having a certain size to receive ice, an ice tray 100 mounted to the top of the case 400, and a twister mounted to opposite ends of the ice tray 100, to cause the ice tray 100 to be twisted.

[38] The case 400 is opened at the top thereof, to allow ice made in the ice tray 100 to be introduced into the case 400 after being separated from the ice tray 100. The ice tray 100 includes rotating shafts 113 rotatably coupled to the top of the case 400 at opposite ends of the case 400, respectively. An outlet 420 is formed through the bottom of the case 400 at one side of the case 400, to allow the ice received in the case 400 to be discharged out of the case 400.

[39] Cavities 120 having a certain size are formed in the ice tray 100, to contain water and thus to form ice in the form of ice cubes. Details of the ice tray 100 will be described later with reference to FIGs. 5 and 6.

[40] As shown in FIG. 1, the twister includes a drive motor 200 coupled to one end of the ice tray 100, and a rotation restrainer 300 coupled to the other end of the ice tray 100. Although the twister has been illustrated as including the drive motor 200 and rotation restrainer 300, it may be configured by other constituent elements, in place of the drive motor 200 and rotation restrainer 300. For example, motors, which are rotatable in the same direction by different angles, may be coupled to the opposite ends of the ice tray, respectively.

[41] The rotation restrainer 300 may be configured by any means, as long as the means has a function capable of preventing the rotating shaft 113 at the other end of the ice tray 100 from rotating over a predetermined angle. That is, when the ice tray 100 rotates by the drive motor 200, the rotation restrainer 300 allows the rotating shaft 113 at the other end of the ice tray 100 to rotate by the predetermined angle, but restrains a rotation of the rotating shaft 113 over the predetermined angle. On the other hand, the drive motor 200 rotates over the predetermined angle, thereby causing the ice tray 100 to be twisted. As a result, ice present in the cavities 120 is separated from the ice tray 100, and is then introduced into the case 400.

[42] As in the example of FIG. 1, the rotation restrainer 300 may comprise a motor rotating by a predetermined angle in the same direction as the drive motor 200. In this case, the ice tray 100 is twisted as the drive motor 200 and rotation restrainer 300 rotate in the same direction. Alternatively, a stopper (not shown) may be provided at the rotating shaft 113 coupled to the other end of the ice tray 100. In this case, a step (not shown) is provided at an inside of the rotation restrainer 300 such that the stopper is engaged with the step as the rotating shaft 113 rotates, thereby restraining the rotation of the rotating shaft 113. On the other hand, a stopper (not shown) may be provided at the rotation restrainer 300, and a step (not shown) may be provided at an outer surface of the case 400. In this case, as the rotation restrainer 300 rotates together with the associated rotating shaft 113, it is engaged with the step, thereby restraining the rotation of the rotating shaft 113.

[43] It may be possible to restrain the rotation of the other end of the ice tray 100, without using the rotation restrainer 300. That is, a stopper (not shown) may be provided at one side of the ice tray 100, and a step (not shown) is formed at an inner surface of the case 400 adjacent to the other end of the ice tray 100. In this case, as the ice tray 100 rotates, the stopper is engaged with the step, thereby restraining the rotation of the ice tray 100.

[44] Meanwhile, in an exemplary embodiment of the present invention, as shown in

FIG. 1, an ice feeder 520 is arranged in the case 400. An ice processor 530 is also arranged at one end of the ice feeder 520. A driver 510 for driving the ice feeder 520 and ice processor 530 is arranged at the outside of the case 400. An opening/closing member 540 is also provided to open or close the outlet 420. This configuration is only for an illustrative purpose. The ice maker according to the present invention may have any configuration, as long as it includes the ice tray 100 and twister.

[45] Hereinafter, operation of the ice maker according to the present invention will be described with reference to FIGs. 2 to 4.

[46] In a process for making ice, the cavities 200 of the ice tray 100 are maintained to be upwardly directed, as shown in FIG. 2. When water is supplied to the cavities 120, it is frozen to produce ice. Thereafter, the drive motor 200 operates to rotate the ice tray 100.

[47] When the ice tray 100 rotates by a predetermined angle, as shown in FIG. 3, the other end of the ice tray 100 cannot further rotate by the rotation restrainer 300. However, one end of the ice tray 100 is continuously rotated by the drive motor 200.

[48] The ice tray 100 reaches a state shown in FIG. 4 in accordance with the above- described process. That is, the ice tray 100 is twisted, thereby separating ice received in the cavities 120 from being separated from the ice tray 100. The separated ice is introduced into the case 400.

[49] Hereinafter, the ice tray according to the present invention will be described with reference to FIGs. 5 and 6.

[50] In accordance with the first embodiment of the present invention shown in FIG. 5, the ice tray 100 includes a body 110 formed with cavities 120, and thermal conductors 130 formed over an inner surface 111 of the body 110 and/or an outer surface 112 of the body 110. [51] The body 110 of the ice tray 100 is made of a thermally non-conductive material.

In particular, the body 110 is made of a plastic material exhibiting superior properties in terms of twisting and recovering after the twisting.

[52] Preferably, the body 110 is made of a polypropylene (PP)-based plastic material or a polyethylene (PE)-based plastic material. This is because the polypropylene (PP)-based plastic material or polyethylene (PE)-based plastic material is advantageous in terms of environment in that it has excellent moldability and requires no addition of a plastϋzer (producing an environmental hormone) for softening the material in a molding process. These materials are also advantageous in that they exhibit no or little stress concentration phenomenon and excellent recovery after being twisted.

[53] Meanwhile, the thermal conductors 130 contain a metal or non-metal material having a thermal conductivity higher than the material of the body 110. The thermal conductors 130 may be formed by coating a metal or non-metal having an excellent thermal conductivity over at least one of the inner and outer surfaces 111 and 112 of the body 110, or coating a thermally -conductive paint, a powder paint containing thermally-conductive particles, a thermally-conductive paste containing metal powder, or a silver paste containing silver powder.

[54] Each thermal conductor 130 may have a multilayer structure. Although FIG. 5 illustrates the case in which the thermal conductors 130 are formed over the inner and outer surfaces 111 and 112, respectively, such that each of the thermal conductors 130 has a single layer structure, the thermal conductors 130 may be formed such that the thermal conductor 130 formed over the inner surface 111 has a multilayer structure, and the thermal conductor 130 formed over the outer surface 112 has a single layer structure. Also, one thermal conductor 130 having a multilayer structure is formed only over the inner surface 111. Alternatively, thermal conductors 130, each having a multilayer structure, may be formed over the inner and outer surfaces 111 and 112, respectively. When each thermal conductor 130 has a multilayer structure, it exhibits enhanced thermal conductivity, but may have problems in that the manufacturing costs increase, and the thermal conductor 130 may be damaged during the twisting process. To this end, each thermal conductor 130 must have a multilayer structure having an appropriate number of layers, taking into consideration the above-described problems.

[55] When the thermal conductors 130 are formed using a coating process, electroplating, electroless plating, physical vacuum deposition, chemical vacuum deposition, etc. may be used for the coating process. [56] In the electroplating process, electrical energy is externally supplied to the body

110, which is made of a plastic material, under the condition in which the body 110 is dipped in a metal salt solution or the like, such that a metal coating is plated over the inner surface 111 and/or outer surface 112 of the body 110. In the electroless plating process, the body 110 is dipped in a metal salt solution. A reducing agent is used to reduce metal ions contained in the metal salt solution in a self -catalyzing manner, thereby plating a metal coating over the inner surface 111 and/or outer surface 112 of the body 110.

[57] The electroless plating process is more preferable than the electroplating process.

This is because the conductors 130 formed by the electroless plating process have an increased density and a more uniform thickness, as compared to those formed by the electroplating process.

[58] As described above, the thermal conductors 130 may be formed using a physical vacuum deposition process or a chemical vacuum deposition process. In this case, the body 110 is exposed to a gas containing metal ions. The gas is deposited in a solid phase over the inner and outer surfaces 111 and 112 of the body 110 in aoaordance with a physical or chemical change thereof, thereby forming a desired coating.

[59] Metal nano particles may be nano-coated over the body 110, to implement a twist type ice tray having a high thermal conductivity.

[6D] In place of coating the thermally high-conductivity material, the conductors 130 may be formed by coating a coating material (a paint or a paste) having a high thermal conductivity.

[61] The coating material, which has a high thermal conductivity, may include a paint or a powder paint containing metal powder or particles, a metal paste containing metal particles, or the like.

[62] FIG. 6 illustrates the ice tray 100 according to the second embodiment of the present invention. The ice tray 100 includes a body 110 formed with cavities 120, and fins 140 provided at an outer surface 112 of the body 110 around the cavities 120, to enhance a thermal conductivity of the cavities 120, and thus to achieve an enhancement in ice-making speed. The fins 140 are made of a metal or non-metal material having a high thermal conductivity.

[63] The fins 140 may be formed directly on the body 110, which is made of a plastic material. However, the fins 140 may also be formed on the outer surface 112 of the ice tray on which the conductor 130 shown in FIG. 5 is formed. In this case, it is possible to obtain a higher thermal conductivity. [64] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

[65]

[66]

[67]

Industrial Applicability

[68] The ice tray according to the present invention and the ice maker equipped with the ice tray have an industrial applicability in that it is possible to improve the thermal conductivity of the ice tray, and thus to achieve an enhancement in ice-making speed, a reduction in ice-making time, and an increase in the amount of ice produced within a given time.

[69]

[70]

[71]

Claims

[1] An ice tray comprising: a body including a plurality of cavities each defining a space to produce ice, the body being made of a thermally non-conductive material and having a pre determined elasticity such that the body can be twisted and then recovered; and a thermal conductor partially or completely formed on at least one of inner and outer surfaces of the body, to achieve an enhancement in thermal conductivity, the thermal conductor comprising at least one layer.

[2] The ice tray according to claim 1, wherein the body is made of a polypropylene- based plastic material or a polyethylene-based plastic material.

[3] The ice tray according to claim 1 or 2, wherein the thermal conductor is made of a metal or a thermally-conductive non-metal, and is coated on at least one of the inner and outer surfaces of the body in the form of at least one layer.

[4] The ice tray according to claim 1 or 2, wherein the thermal conductor is made of a thermally-conductive coating material, and is coated on at least one of the inner and outer surfaces of the body in the form of at least one layer.

[5] The ice tray according to claim 1, further comprising: a plurality of fins provided around the cavities or formed directly on the body, to promote a thermal transfer to the cavities.

[6] The ice tray aaoording to claim 5, wherein the fins are made of a thermally- conductive metal or non-metal.

[7] An ice tray comprising: a body including a plurality of cavities each defining a space to produce ice; and a plurality of fins provided around the cavities or formed directly on the body, to promote a thermal transfer to the cavities.

[8] An ice maker comprising: an ice tray comprising a body including a plurality of cavities each defining a space to produce ice, the body being made of a thermally non-conductive material and having a predetermined elasticity such that the body can be twisted and then recovered, and a thermal conductor partially or completely formed on at least one of inner and outer surfaces of the body, to achieve an enhancement in thermal conductivity, the thermal conductor comprising at least one layer; and a twister coupled to opposite ends of the ice tray, to twist the ice tray by a predetermined angle, for separation of ice from the ice tray.

[9] The ice maker according to claim 8, wherein the thermal oonductor is made of a metal or a thermally-conductive non-metal, and is coated on at least one of the inner and outer surfaces of the body in the form of at least one layer.

[10] The ice maker aocording to claim 8, wherein the thermal conductor is made of a thermally-conductive coating material, and is coated on at least one of the inner and outer surfaces of the body in the form of at least one layer.

[11] The ice maker according to claim 8, further comprising: a plurality of fins provided around the cavities or formed directly on the body, to promote a thermal transfer to the cavities.

[12] The ice maker according to any one of claims 8 to 11, wherein the twister comprises: a drive motor coupled to one end of the ice tray, to rotate the ice tray; and a rotation restrainer coupled to the other end of the ice tray, to prevent the ice tray from rotating over a predetermined angle so that the ice tray is twisted.

[13] An ice maker comprising: a case defined with a space for receiving ice, and opened at a top of the case; and an ice tray mounted to the top of the case, the ice tray comprising a body including a plurality of cavities each defining a space to produce ice, and a plurality of fins provided around the cavities or formed directly on the body, to promote a thermal transfer to the cavities.