Auger-type ice making apparatus with improved evaporator

Abstract

An improved evaporator is provided for an ice making apparatus of the auger-type. The evaporator employs an evaporator body having spiral grooves cut or milled into its outer cylindrical surface and a cylindrical jacket disposed over the spiral groove formed on the outer cylindrical surface of the evaporator body, with the jacket being in interference-fit engagement against the groove of the evaporator body. The interference fit is formed by thermal expansion of the jacket prior to it being telescopically slid over the body, followed by a cooling-down of the jacket, by which it shrinks or compresses radially inwardly, to tightly seal against the outer periphery of the grooves, creating a sealed path for refrigerant flow, from inlet to outlet of the evaporator.

What is claimed is:  
     
         1 . An ice making apparatus comprising: 
 (a) a generally cylindrical and hollow freezing chamber;    (b) a compacting head at an end of said freezing chamber;    (c) a rotatable ice auger sized to fit into said freezing chamber whereby said auger scrapes ice formed on the walls of said chamber and conveys the ice toward a discharge end of said auger and said compacting head;    (d) an evaporator comprising an evaporator body and a jacket;    (e) the evaporator body having a continuous generally spiral grove on its outer cylindrical surface, terminating in a radial outward edge; with the evaporator having a refrigerant inlet and refrigerant outlet.    (f) the evaporator jacket being telescopically disposed over the spiral groove of the evaporator body and being in interference fit against the outward edge of the spiral groove, sealingly engaging the evaporator jacket against the evaporator body, whereby refrigerant entering into the groove is sealingly trapped therein between a refrigerant inlet and a refrigerant outlet.    
     
     
         2 . The apparatus of  claim 1 , wherein the evaporator body includes a cylindrical groove at a lower end thereof and another cylindrical groove at an upper end thereof, with the cylindrical groove being in respective communication with the refrigerant inlet and refrigerant outlet.  
     
     
         3 . The apparatus of  claim 1  wherein the jacket is welded to the evaporator body at both upper and lower ends of the evaporator body.  
     
     
         4 . The apparatus of  claim 1 , wherein the spiral groove comprises a helical groove.  
     
     
         5 . The apparatus of  claim 1 , wherein the interference fit is obtained by a thermally expanded jacket that is subsequently cooled to effect the interference fit against the outward edge of the spiral groove.  
     
     
         6 . The apparatus of  claim 1 , wherein the compacting head is annular and is disposed normal to the axis of the freezing chamber.  
     
     
         7 . A method of making an ice making apparatus comprising: 
 (a) providing a generally cylindrical and hollow freezing chamber;    (b) providing a compacting head at an end of said freezing chamber;    (c) providing a rotatable ice auger sized to fit into said freezing chamber and disposing the auger in the freezing chamber whereby said auger scrapes ice formed on the walls of said chamber and conveys the ice toward a discharge end of said auger and said compacting head;    (d) providing an evaporator comprising an evaporator body and a jacket;    (e) providing on the evaporator body a continuous generally spiral grove on its outer cylindrical surface, terminating in a radial outward edge;    and providing to the evaporator with a refrigerant inlet and refrigerant outlet.    (f) telescopically disposing the evaporator jacket over the spiral groove of the evaporator body to be in interference fit against the outward edge of the spiral groove and thereby sealingly engaging the evaporator jacket against the evaporator body, whereby refrigerant entering into the groove is sealingly trapped therein between the refrigerant inlet and the refrigerant outlet.    
     
     
         8 . The method of  claim 7 , including providing the evaporator body with a cylindrical groove at a lower end thereof and another cylindrical groove at an upper end thereof, so that the cylindrical groove is in respective communication with the refrigerant inlet and refrigerant outlet.  
     
     
         9 . The method of  claim 7 , including the step of molding the jacket is welded to the evaporator body at both upper and lower ends of the evaporator body.  
     
     
         10 . The method of  claim 7 , wherein the step of providing the spiral groove comprises forming a helical groove.  
     
     
         11 . The method of  claim 7 , wherein the interference fit is obtained by thermally expanding the jacket and subsequently cooling the jacket to effect the interference fit against the outward edge of the spiral groove.  
     
     
         12 . The method of  claim 6 , wherein the step of providing a compacting head comprises the step of providing an annular compacting head, normal to the axis of the freezing chamber.