Slow release coolant filter

Abstract

A coolant filter for use in filtering a coolant solution which flows through the coolant filter includes a filter housing assembly which is made up of an outer housing which is crimped to a nutplate which defines an internally threaded flow outlet. A generally cylindrical filter element is positioned inside of the filter housing assembly and a first endplate is bonded to the end of the filter element which is adjacent to the nutplate. An endplate member is provided for attachment to the opposite end of the filter element and is configured in such a way so as to define an interior chamber where supplemental coolant additive pellets are stored. A closing plate is applied across the open end of the interior chamber so as to create an enclosed chamber for the supplemental coolant additive pellets. A slow release mechanism is provided for controlling the rate of release of the supplemental coolant additive from the enclosed chamber into the coolant solution. In one embodiment of the present invention, the slow release mechanism includes a diffusion tube which defines a diffusion orifice. In another embodiment of the present invention, the slow release mechanism includes a semipermeable (or osmotic) membrane wafer. In both instances, the slow release mechanism is positioned between the source of supplemental coolant additive and the flow outlet in the nutplate.

What is claimed is:  
     
       1. A coolant filter for use in filtering a coolant solution which flows through the coolant filter and being designed for the release of a supplemental coolant additive into said coolant solution, said coolant filter comprising: 
       a filter housing assembly defining a flow outlet and flow inlet means;  
       a filter element positioned inside said filter housing assembly;  
       an endplate member which is configured with an interior chamber and having a first end wall, an opposite second end wall, a first substantially cylindrical wall portion disposed between said first and second end walls and having a first diameter, a second substantially cylindrical wall portion disposed between the first and second end walls and having a second diameter greater than the first diameter and a radially extending shelf therebetween to bear against the filter element, said endplate member in cooperation with said filter element defining  defines an interior space for receiving filtered coolant solution ;  
       a source of supplemental coolant additive positioned within said interior chamber; and  
       slow release means disposed between said source of supplemental coolant additive and said flow outlet for permitting a portion of said filtered  coolant solution from said interior space to enter said interior chamber  to dissolve said supplemental coolant additive and for controlling the rate of release of said supplemental coolant additive from said interior chamber into said filtered coolant solution in said interior space .  
     
     
       2. The coolant filter of claim  1  wherein said source of supplemental coolant additive includes a plurality of soluble supplemental coolant additive pellets. 
     
     
       3. The coolant filter of claim  2  wherein said plurality of soluble supplemental coolant additive pellets are coated with an outer coating consisting essentially of a polymeric material including a polyvinyl acetate material. 
     
     
       4. The coolant filter of claim  3  wherein said slow release means includes a diffusion tube defining a diffusion orifice. 
     
     
       5. The coolant filter of claim  4  wherein said diffusion tube and said diffusion orifice are tapered. 
     
     
       6. The coolant filter of claim  3  wherein said slow release means includes a semipermeable membrane wafer. 
     
     
       7. The coolant filter of claim  6  wherein said semipermeable membrane wafer is fabricated out of a microporous polypropylene material. 
     
     
       8. A coolant filter for use in filtering a coolant solution which flows through the coolant filter and being designed for the release of a supplemental coolant additive into said coolant solution, said coolant filter comprising: 
       a filter housing assembly defining a flow outlet and flow inlet means;  
       a filter element positioned inside said filter housing assembly;  
       an endplate member which is configured with an interior chamber, said endplate member in cooperation with said filter element defining an interior space for receiving filtered coolant solution;  
       a source of supplemental coolant additive positioned within said interior chamber; and  
       a diffusion tube comprising part of said endplate member and defining a diffusion orifice which is disposed between said source of supplemental coolant additive and said flow outlet for permitting a portion of said filtered coolant solution from said interior space to enter said interior chamber to dissolve said supplemental coolant additive and for controlling the rate of release of said supplemental coolant additive from said interior chamber into said filtered coolant solution in said interior space.  
     
     
       9. The coolant filter of claim  8  wherein said diffusion tube and said diffusion orifice are tapered. 
     
     
       10. The coolant filter of claim  9  wherein said source of supplemental coolant additive includes a plurality of soluble supplemental coolant additive pellets. 
     
     
       11. The coolant filter of claim  10  wherein said plurality of soluble supplemental coolant additive pellets are coated with a polyvinyl acetate material. 
     
     
       12. The coolant filter of claim  8  wherein said source of supplemental coolant additive includes a plurality of soluble supplemental coolant additive pellets. 
     
     
       13. The coolant filter of claim  12  wherein said plurality of soluble supplemental coolant additive pellets are coated with a polyvinyl acetate material. 
     
     
       14. A coolant filter for use in filtering a coolant solution which flows through the coolant filter and being designed for the release of a supplemental coolant additive into said coolant solution, said coolant filter comprising: 
       a filter housing assembly defining a flow outlet and flow inlet means;  
       a filter element positioned inside said filter housing assembly;  
       an endplate member which is configured with an interior chamber, said endplate member in cooperation with said filter element defining an interior space for receiving filtered coolant solution;  
       a source of supplemental coolant additive positioned within said interior chamber; and  
       a semipermeable membrane wafer assembled to said endplate member and disposed between said source of supplemental coolant additive and said flow outlet for permitting a portion of said filtered coolant solution from said interior space to enter said interior chamber to dissolve said supplemental coolant additive and for controlling the rate of release of said supplemental coolant additive from said interior chamber into said filtered coolant solution in said interior space.  
     
     
       15. The coolant filter of claim  14  wherein said semipermeable membrane wafer is fabricated out of a microporous polypropylene material. 
     
     
       16. The coolant filter of claim  15  wherein said source of supplemental coolant additive includes a plurality of soluble supplemental coolant additive pellets. 
     
     
       17. The coolant filter of claim  16  wherein said plurality of soluble supplemental coolant additive pellets are coated with a polyvinyl acetate material. 
     
     
       18. The coolant filter of claim  14  wherein said source of supplemental coolant additive includes a plurality of soluble supplemental coolant additive pellets. 
     
     
       19. The coolant filter of claim  18  wherein said plurality of soluble supplemental coolant additive pellets are coated with a polyvinyl acetate material. 
     
     
       20. The coolant filter of claim  19  which further includes a retainer plate held in position by said endplate member and sandwiching said wafer between a portion of said endplate member and said retainer plate. 
     
     
       21. A coolant filter cartridge for installing into a filter housing assembly for the filtering of a coolant solution, said coolant filter cartridge being designed for the release of a supplemental coolant additive into said coolant solution, said coolant filter cartridge comprising: 
       a filter element having a first end and opposite thereto a second end;  
       a first endplate bonded to the first end of said filter element;  
       a second endplate bonded to the second end of said filter element, said second endplate configured so as to define an interior chamber, said second endplate member in cooperation with said filter element defining an interior space for receiving filtered coolant solution;  
       a source of supplemental coolant additive positioned within said interior chamber;  
       a closing member assembled to said second endplate so as to enclose said interior chamber; and  
       slow release means disposed between said source of supplemental coolant additive and said flow outlet for permitting a portion of said filtered coolant solution from said interior space to enter said interior chamber to dissolve said supplemental coolant additive and for controlling the rate of release of said supplemental coolant additive from said interior chamber into said filtered coolant solution in said interior space.  
     
     
       22. The coolant filter cartridge of claim  21  wherein said source of supplemental coolant additive includes a plurality of soluble supplemental coolant additive pellets. 
     
     
       23. The coolant filter cartridge of claim  22  wherein said plurality of soluble supplemental coolant additive pellets are coated with a polyvinyl acetate material. 
     
     
       24. The coolant filter cartridge of claim  23  wherein said slow release means includes a diffusion tube defining a diffusion orifice. 
     
     
       25. The coolant filter cartridge of claim  24  wherein said diffusion tube and said diffusion orifice are tapered. 
     
     
       26. The coolant filter cartridge of claim  23  wherein said slow release means includes a semipermeable membrane wafer. 
     
     
       27. The coolant filter cartridge of claim  26  wherein said semipermeable membrane wafer is fabricated out of a microporous polypropylene material. 
     
     
       28. The coolant filter of claim  1  comprising an outer coating consisting essentially of a polymeric material substantially encasing the supplemental coolant additive. 
     
     
       29. The coolant filter of claim  28  wherein said outer coating includes a material formed of polyvinyl acetate or polyvinylidene chloride. 
     
     
       30. A coolant filter for use in filtering a coolant solution which flows through the coolant filter and being designed for the release of a supplemental coolant additive into said coolant solution, said coolant filter comprising: 
       
         a filter housing assembly defining a flow outlet and flow inlet means;  
       
       
         a filter element positioned inside said filter housing assembly;  
       
       
         an endplate member which is configured with an interior chamber and having a first end wall, an opposite second end wall, a first substantially cylindrical wall portion disposed between said first and second end walls and having a first diameter, a second substantially cylindrical wall portion disposed between the first and second end walls and having a second diameter greater than the first diameter and a radially extending shelf therebetween to bear against the filter element, said endplate member in cooperation with said filter element defining an interior space;  
       
       
         a source of supplemental coolant additive positioned within said interior chamber said source of supplemental coolant additive including a supplemental coolant additive having an outer coating; and  
       
       
         slow release means for controlling the rate of release of said supplemental coolant additive. 
       
     
     
       31. The coolant filter of claim  30  wherein said slow release means includes a diffusion tube defining a diffusion orifice. 
     
     
       32. The coolant filter of claim  30  wherein said slow release means includes a semipermeable membrane wafer. 
     
     
       33. The coolant filter of claim  30  wherein said outer coating consists essentially of a polymeric material substantially encasing the supplemental coolant additive. 
     
     
       34. A coolant filter for use in filtering a coolant solution which flows through the coolant filter and being designed for the release of a supplemental coolant additive into said coolant solution, said coolant filter comprising: 
       
         a filter housing assembly defining a flow outlet and flow inlet means;  
       
       
         a filter element positioned inside said filter housing assembly;  
       
       
         an endplate member which is configured with an interior chamber, said endplate member in cooperation with said filter element defining an interior space;  
       
       
         a source of supplemental coolant additive positioned within said interior chamber, said supplemental coolant additive substantially encased within an outer coating consisting essentially of a polymeric material, wherein the outer coating retards release of the supplemental coolant additive. 
       
     
     
       35. The coolant filter of claim  1  wherein the first end wall includes a diffusion orifice. 
     
     
       36. The coolant filter of claim  34  wherein the endplate member comprises a diffusion orifice. 
     
     
       37. The coolant filter of claim  34  wherein the endplate member comprising a semipermeable membrane.