Abstract:
A liquid-activated lighted ice cube includes a battery-powered electrical circuit and LED housed in a hollow body that resembles an ice cube. The circuit includes electrodes exposed to the exterior of the hollow body that, when in contact with water or other liquid beverage, cause the circuit to turn on the LED and illuminate the beverage.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a division of application Ser. No. 10/720,737, filed on Nov. 24, 2003, now U.S. Pat. No. 7,049,766, which claims the benefit of Provisional Patent Application No. 60/428,391, filed Nov. 22, 2002, which application is hereby incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   This invention relates generally to artificial ice cubes and more particularly to artificial ice cubes with internal illumination. 
   A variety of objects have been configured to resemble an ice cube of the type customarily used to cool a beverage in a hand-held container such as a glass. Some have been intended to cool the beverage without diluting it, while others have been designed to generate light or sound effects. Examples of such objects may be found in the following patents: 
   
     
       
             
             
             
           
         
             
                 
             
             
               Patent No. 
               Inventor 
               Issue Date 
             
             
                 
             
           
           
             
                 740,847 
               Glebsattel 
               Oct. 6, 1903 
             
             
               4,325,230 
               Driscoll et al 
               Apr. 20, 1982 
             
             
               4,554,189 
               Marshall 
               Nov. 19, 1985 
             
             
               5,603,219 
               Kolb 
               Feb. 18, 1997 
             
             
               5,903,212 
               Rodgers 
               May 11, 1999 
             
             
                 
             
           
        
       
     
   
   SUMMARY OF THE INVENTION 
   The present invention provides a liquid-activated lighted artificial ice cube having a low-power, self-contained light circuit. In one embodiment the circuit includes a battery, one or more LEDs, an integrated circuit and a pair of spaced electrodes or contacts that are exposed to the exterior of the cube. When the artificial ice cube is immersed in water or other liquid beverage in the manner of an ordinary ice cube, the liquid completes the circuit between the exposed electrodes and thereby triggers the IC which then supplies power to the LED(s). 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top plan view of a preferred embodiment of a liquid-activated lighted ice cube according to the present invention. 
       FIG. 2  is a bottom plan view of the ice cube of  FIG. 1 . 
       FIG. 3  is a cross-sectional view of the ice cube of  FIG. 1 , taken along plane  3 - 3  of  FIG. 2  and viewed in the direction of the arrows. 
       FIG. 4  is a cross-sectional view of the ice cube of  FIG. 1 , taken along plane  4 - 4  of  FIG. 3  and viewed in the direction of the arrows. 
       FIG. 5  is an electrical schematic of a light circuit contained within the ice cube of  FIG. 1 . 
       FIG. 6  is a cross-sectional view of another embodiment of a liquid-activated lighted ice cube according to the present invention, similar to the view of  FIG. 3 . 
       FIG. 7  is a cross-sectional view of the ice cube of  FIG. 6 , taken along lines  7 - 7 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
   Referring to  FIGS. 1-4 , one embodiment of a liquid-activated lighted artificial ice cube  10  of the present invention includes a hollow body  12  that is generally in the shape of a cube, but can be made in other shapes that are suggestive of a piece of ice used to cool beverages. Preferably, hollow body  12  is constructed of a transparent or translucent thermosetting plastic material that can be molded to the desired shape, and includes a first portion  14  mating with a second portion  16 . First and second portions  14  and  16  are preferably welded or cemented together to form an hermetically sealed enclosed space  18  which contains a light circuit  20  to be described below. 
   For convenience and to provide a consistent frame of reference for description purposes, various directional terms, e.g., horizontal, vertical, bottom, top, side, upward, downward and the like, will be used to describe the orientation of various components of ice cube  10  relative to each other. The invention is not restricted to the described orientation. Unless described otherwise, the ice cube  10  can be used in any orientation in the same manner as a real ice cube. 
   First portion  14  of hollow body  12  includes a bottom wall  22  and four side walls  24  that are substantially perpendicular to bottom wall  22  and extend upward therefrom. The four side walls  24  are integrally joined together at four vertical corners and are integrally joined to the bottom wall  22  about the periphery thereof to form an open-topped box or cubic container having walls that surround the substantially cubic hollow space  18  on five sides. 
   Extending upward from bottom wall  22  within hollow space  18  is a battery holder  26  comprising four posts or standoffs  28  sized to hold three stacked button cells  30  and having a height approximately one half the vertical height of enclosed space  18 . Each post includes an arcuate inner surface  36  and an arcuate outer surface  38  as best shown in  FIG. 2 . The ice cube also includes a pair of spaced, upwardly tapered standoffs  42  which are integral with bottom wall  22  and extend therefrom in cantilever fashion. Standoffs  42  each have a height approximately equal to that of battery holder  26 . They are spaced from side walls  24  and from battery holder  26  as shown in  FIG. 2  and are approximately centered in adjacent quadrants of bottom wall  22 . 
   Second portion  16  of hollow body  12  includes a top wall  44  having a thickness substantially equal to that of side walls  24  and sized to mate with and close the open-topped cubic container formed by bottom wall  22  and side walls  24 , thereby fully enclosing space  18 . In one embodiment, the bottom surface  46  of top wall  44  is substantially planar to mate flatly against planar top surface  48  of side walls  24 , and a perimetrical lip  50  extends downwardly from bottom surface  46  and fits inside of side walls  24  to assure alignment of portions  14  and  16  of ice cube body  12 . The interface between portions  14  and  16  defined by surfaces  46  and  48  is sealed by thermal or chemical welding of the plastic material, or by use of cement, to hermetically seal enclosed space  18 . In another embodiment, the top wall is ultrasonically welded to the side walls. Top wall  44  has no lip  50  in this embodiment, and the interface defined by surfaces  46  and  48  is provided with a weld bead to facilitate ultrasonic welding. For example, one of the surfaces may be grooved and the other surface provided with a mating ridge. 
   A pair of spaced standoffs  52  is integral with and extends downward from top wall  44  in cantilever fashion, in vertical alignment with the pair of standoffs  42  on bottom wall  22  as illustrated in  FIG. 4 . The length of standoffs  52  is selected to leave a small gap between the lower ends thereof and the top ends of standoffs  42  when ice cube  10  is assembled. The gap is just wide enough to accommodate the thickness of a printed circuit board  54  sandwiched between standoffs  52  and standoffs  42 . 
   Printed circuit board  54  is sized and shaped to fit within enclosed space  18  while disposed substantially parallel to bottom wall  22  of first portion  14 . Printed circuit board  54  is substantially constrained against vertical downward movement by battery holder  26  and standoffs  42  upon which printed circuit board  54  rests. Standoffs  52  substantially constrain circuit board  54  against vertical upward movement, and side walls  24  provide substantial constraint against horizontal movement. 
   Referring to  FIG. 5 , one embodiment of a light circuit  20  suitable for use within the ice cube includes an integrated circuit IC 1 , resistors R 1  and R 2 , transistor Q 1 , LED 1  and battery power source B 1  interconnected as shown in the schematic and as further described herein. Also included is a pair of spaced electrodes  56  imbedded in bottom wall  22  and exposed to the exterior of hollow body  12  as switch contacts. A suitable LED is commercially available from Chi Ban Electronics Company Limited, Shenzhen, China, as part number 5X3VC, where the letter “X” designates the color, e.g., “R” for red, “G” for green, and “W” for white. The IC is preferably in die form and may be an AP3761-03 IC commercially available from Advanced Microelectronic Products, Inc., Taiwan. It is mounted on the circuit board along with transistor Q 1  and resistors R 1  and R 2 , and its power supply input is connected to the emitter of Q 1  which thereby controls the supply of power to the IC. The IC has an output connected to the cathode of the LED as shown. Resistor R 1  controls the clock frequency of the IC and resistor R 2  is a pull-down resistor provided to hold the transistor off when the base thereof is open. Electrodes  56  are preferably constructed of a corrosion-resistant metal alloy such as brass or stainless steel, as they are intended to contact water, ethyl alcohol and other liquids and substances commonly found in beverages. Nickel-plated copper is particularly suitable. A pair of wires  58  connects electrodes  56  to the battery positive terminal and to the base of transistor Q 1 . Thus, when a conductive liquid path is provided between the electrodes such as from immersion of the ice cube in a drink, it completes a circuit between the battery and the base of the transistor and thereby causes the transistor to turn on and supply power to the IC. 
   The IC may be wire bonded to operate in a “Lever Hold” mode whereby the LED output is held low, and the LED is thereby held on, whenever the switch defined by electrodes  56  is closed. When the switch is opened, power is immediately removed from the IC and the LED is thus turned off, whereby the circuit is completely deenergized. The IC is immediately retriggered and the LED turned on when the switch is closed again. 
   The AP3761-03 IC may alternatively be wire bonded to operate in astable mode, thereby causing continuous flashing of the LED, whenever the switch is closed. 
   In a less preferred alternative embodiment, the IC is continually supplied with power and a transistor is provided between the switch and a trigger input of the IC, which is configured to operate in a retriggerable one-shot mode such that it is triggered when the switch first closes upon contact with liquid and is retriggered as long as the ice cube remains wet. The one-shot times out, and thus the LED turns off, a set period of time after the switch is opened, that is, a set period of time after the drink is finished or the ice cube is removed from the glass. 
   In another embodiment, the LED is a UV LED and the plastic body of the ice cube is made fluorescent, either by means of a fluorescent pigment mixed into the plastic resin prior to formation of the cube or by means of a fluorescent coating applied to the inner surface and/or outer surface thereof. The LED preferably has a peak wavelength of 400 nm±10 nm. A suitable LED with such a wavelength is the DL50PLDW503 UV LED from Shue Kwong Optic Electronic Company, Shenzhen, China. The fluorescent pigment may be one of the following pigments commercially available from Wen Lee Plastic Pigment Company, Tungguong, China: P/N 61113 (green), P/N 31461 (blue), P/N 238 (red), and P/N 2600(yellow). The pigment may be mixed into the plastic with a mix ratio of about 1-2 grams pigment per one kilogram of plastic. The plastic body of the cube may be formed of polycarbonate mixed with such a pigment and injection molded. Alternatively, the cube may be formed of polystyrene, PVC, ABS or acrylic. 
   It will be appreciated by those skilled in the art that the weight of the batteries in the lower half of the ice cube tends to keep the LED side up and also tends to keep the electrodes wet, and thereby keep the LED on, when the ice cube is floating in a glass. 
   Referring to  FIGS. 6 and 7 , an alternative embodiment is shown that is substantially the same as the embodiment of  FIGS. 1-5 , except for the addition of a weight  70 . For a description of the other components of the embodiment of  FIGS. 6 and 7 , indicated by like primed reference numerals, reference should be made to the description above of the embodiment of  FIGS. 1-5 . Weight  70  can be made of iron or steel or other suitably dense material, and is shaped generally as a square flat plate, or stack of plates, having a generally square opening  72  in the center. Posts  28 ′ protrude through opening  72 . Two corners of the opening  72  include cutouts  74  to provide clearance for standoffs  42 ′. The mass of weight  70  is selected such that, in combination with the weight of the batteries, the artificial ice cube tends to float substantially submerged, with the top of the ice cube approximately level with the surface of the liquid in which it is immersed, much like the floating characteristics of a real ice cube 
   While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.