Ice making assembly and method of operating the same

Abstract

An ice making assembly includes a central hub rotatably mounted within a chilled chamber. A mold assembly is attached to the central hub and includes an ice mold that is pivotally coupled to a yoke and defines a mold cavity for receiving water. A drive mechanism rotates the central hub by accelerating the central hub until the rotation speed reaches a target speed and periodically reducing the rotation speed of the central hub to a reduced speed before accelerating back to the target speed until an ice billet is formed.

What is claimed is: 
     
         1 . An ice making assembly comprising:
 a chilled chamber;   a central hub rotatably mounted within the chilled chamber;   a mold assembly mechanically coupled to the central hub, the mold assembly defining a mold cavity configured for receiving water;   a drive mechanism operably coupled to the central hub for selectively rotating the central hub at a rotation speed; and   a controller operably coupled to the drive mechanism, the controller being configured for:
 accelerating the central hub until the rotation speed reaches a target speed; and 
 periodically reducing the rotation speed of the central hub to a reduced speed before accelerating back to the target speed. 
   
     
     
         2 . The ice making assembly of  claim 1 , wherein the reduced speed is less than 20% of the target speed. 
     
     
         3 . The ice making assembly of  claim 1 , wherein the target speed is between about 600 and 2000 revolutions per minute. 
     
     
         4 . The ice making assembly of  claim 1 , wherein the reduced speed is between about 0% and 50% of the target speed. 
     
     
         5 . The ice making assembly of  claim 1 , wherein periodically reducing the rotation speed of the central hub comprises:
 (a) accelerating the central hub until the rotation speed reaches the target speed;   (b) maintaining the rotation speed of the central hub at the target speed for a spin time;   (c) reducing the rotation speed of the central hub to the reduced speed for a dwell time; and   (d) repeating steps (a)-(c) until the water in the mold cavity forms a billet of ice.   
     
     
         6 . The ice making assembly of  claim 5 , wherein a spin ratio of the spin time over a total time equal to the spin time plus the dwell time is between about 0.8 and 0.99. 
     
     
         7 . The ice making assembly of  claim 6 , wherein the spin ratio is between about 0.9 and 0.99. 
     
     
         8 . The ice making assembly of  claim 5 , wherein the spin time is between about 2 and 15 minutes. 
     
     
         9 . The ice making assembly of  claim 5 , wherein the dwell time is between about 5 seconds and 5 minutes. 
     
     
         10 . The ice making assembly of  claim 1 , wherein the mold assembly comprises:
 a yoke;   an ice mold defining the mold cavity and an opening to the mold cavity, the ice mold being pivotally mounted to the yoke such that the opening faces upward during a filling process and pivots toward a lateral direction when the central hub is rotated.   
     
     
         11 . The ice making assembly of  claim 10 , wherein the mold assembly comprises:
 a top cap positioned over the opening in the ice mold, wherein the top cap is insulated.   
     
     
         12 . The ice making assembly of  claim 10 , wherein the mold assembly comprises:
 a vibration device operably coupled to the ice mold for selectively vibrating the ice mold.   
     
     
         13 . The ice making assembly of  claim 10 , wherein the mold assembly comprises:
 a heating element in thermal communication with the ice mold for selectively heating the ice mold.   
     
     
         14 . The ice making assembly of  claim 10 , wherein the ice mold comprises a cylindrical sidewall, and wherein insulation surrounds the cylindrical sidewall. 
     
     
         15 . The ice making assembly of  claim 10 , wherein the ice mold comprises:
 one or more heat sinks mounted to a bottom wall of the ice mold to facilitate directional freezing.   
     
     
         16 . The ice making assembly of  claim 10 , wherein the ice mold is constructed from aluminum. 
     
     
         17 . The ice making assembly of  claim 1 , wherein the central hub is cylindrical and defines an inner surface, the mold assembly being mounted on the inner surface. 
     
     
         18 . The ice making assembly of  claim 1 , wherein the drive mechanism comprises an electric motor mounted below the central hub. 
     
     
         19 . A method of operating an ice making assembly, the ice making assembly comprises a central hub rotatably mounted within a chilled chamber and a mold assembly mechanically coupled to the central hub and defining a mold cavity configured for receiving water, the method comprising:
 accelerating the central hub until a rotation speed reaches a target speed; and   periodically reducing the rotation speed of the central hub to a reduced speed before accelerating back to the target speed.   
     
     
         20 . The method of  claim 19 , wherein periodically reducing the rotation speed of the central hub comprises:
 (a) accelerating the central hub until the rotation speed reaches the target speed;   (b) maintaining the rotation speed of the central hub at the target speed for a spin time;   (c) reducing the rotation speed of the central hub to the reduced speed for a dwell time; and   (d) repeating steps (a)-(c) until water in the mold cavity forms a billet of ice.