Multi-layer coolant reservoir

Abstract

In various aspects of the invention a multi-layer pressurizable coolant reservoir includes an inner shell member shaped and configured to define at least one liquid storage chamber. An outer shell member is layered onto the inner shell member. The outer shell member is particularly adapted to provide structural stability and resist pressure deformation of the inner shell. The outer shell is isolated from the coolant by the inner layer. The material of the inner shell is selected for compatibility with the coolant.

1 . A multi-layer pressurizable coolant reservoir providing surge and overflow capacity to an engine cooling system, comprising:
 an inner shell member shaped and configured to define at least one liquid storage chamber for storing coolant therein, said chamber having at least one outer surface; and   an outer shell member layered onto at least a portion of said at least one outer surface, said outer shell member adapted to provide structural stability and resist pressure deformation of said inner layer;   wherein said outer shell comprises a higher strength material relative to said inner layer;   wherein said outer shell is isolated from said coolant by said inner layer; and   wherein material of said inner shell is selected for compatibility with said coolant.   
     
     
         2 . The coolant reservoir of  claim 1 , wherein
 said material of said inner shell is selected to be compatible with operating temperature and chemical compatibility with the coolant;   wherein said outer shell material is selected for strength and low cost to provide structural stability to said reservoir; and   wherein said coolant reservoir formed of said inner and outer shells is lower in weight or uses less material than a single layer reservoir.   
     
     
         3 . The coolant reservoir of  claim 1 , wherein
 said inner shell member comprises molded plastic material; and   wherein said outer shell member comprises a material different than said inner shell material.   
     
     
         4 . The coolant reservoir of  claim 3 , wherein said material of said outer shell comprises formed metal. 
     
     
         5 . The coolant reservoir of  claim 3 , wherein said inner shell member includes a molded plastic upper shell portion and a molded plastic lower shell portion, said upper and lower shell portions welded along mateable edge portions to form a one-piece inner shell member. 
     
     
         6 . The coolant reservoir of  claim 5 , wherein said outer shell member includes an upper shell portion and a lower shell portion, said outer shell upper and lower shell portions shaped and configured to substantially match the shape of and overlay onto respective ones of said inner shell portions. 
     
     
         7 . The coolant reservoir of  claim 6 , wherein
 said upper portions of said shells are molded as a unit using a two shot injection molding process; and   said lower portions of said shells are molded as a unit using a two shot injection molding process.   
     
     
         8 . The coolant reservoir of  claim 7 , further comprising:
 a substantially rigid skeletal shell member secured onto portions of the outer surface of the outer shell member, said skeletal shell member operative to provide further structural stability to said inner and outer shell members.   
     
     
         9 . The coolant reservoir of  claim 7 , wherein said material of said outer shell member comprises nylon or glass fibers, said fibers strengthening said outer shell member. 
     
     
         10 . The coolant reservoir of  claim 7 , wherein said inner layer material selected from the group including: polypropylene and polyethylene. 
     
     
         11 . The coolant reservoir of  claim 7 , wherein said outer shell material selected from the set consisting of: nylon, glass fiber filled polypropylene and metal. 
     
     
         12 . The coolant reservoir of  claim 7 , wherein said outer shell member forms ribs extending within said liquid storage chamber, said ribs encapsulated by rib encapsulating members of said inner shell member, said encapsulating members covering and isolating ribs of said outer shell member from said coolant.