Fatigue rated glass filled plastic filter assembly incorporating a coreless plastic filter element with integral seal

Abstract

A filter assembly for filtering fluids which may be readily disassembled includes a perforated center tube assembly which is fluid-tightly connected at one end to an injection molded plastic head and is closed at its other end; an injection molded plastic bowl having one open end and a semi-closed second end; a disposable cylindrical plastic filter element adapted to fit within the plastic bowl and slip over the perforated center tube assembly in close proximity thereto but with no physical retention means between the plastic filter element and the center tube assembly. The assembly includes a releasable seal between the plastic filter element and the center tube assembly. The plastic head further includes an annular base provided with injection molded threaded fittings whereby it can be attached to a fluid supply and unfiltered fluid can flow into the plastic bowl and filtered fluid can flow out of the plastic bowl. The plastic head assembly further includes a mechanism for releasable engagement with the open end of the plastic bowl.

1 . A filter element for filtering a fluid, said filter element comprising: 
 a cylindrical filtration medium having a top end and a bottom end; and    a first end cap coupled to said top end, wherein the end cap is a poly-elastomeric annular disc with a lower surface and an upper surface, and wherein the lower surface forms a seal with the filtration medium's top end so as to be integral therewith, the upper surface has first and second radial, axially-extending protrusions to form a recessed pocket therebetween, and the pocket is configured to form a fluid-tight seal with a first external, mating knife edge.    
   
   
       2 . The filter element of  claim 1 , wherein the poly-elastomeric annular disc is made from a viscoelastic polyurethane to form a viscoelastic-knife edge seal (VEKE-Seal).  
   
   
       3 . The filter element of  claim 1 , wherein the filtration medium defines a longitudinal hollow center portion therethrough, the filter element being adapted to receive a center tube assembly (CTA) within said center portion, and said CTA including a base and a central flow passage.  
   
   
       4 . The filter element of  claim 3 , wherein the filter element is configured to be contained in a housing, and the CTA's base includes a radial seal for sealingly engaging a radially outer surface of said CTA with said housing.  
   
   
       5 . The filter element of  claim 1 , wherein the filtration medium is a pleated membrane.  
   
   
       6 . The filter element of  claim 5 , wherein the poly-elastomeric annular disc is formed from a poly-elastomeric compound in a molding operation in which the compound attaches to the pleats of the membrane so as to become integral with the membrane.  
   
   
       7 . The filter element of  claim 1 , further including a second end cap coupled to said bottom end, wherein the second end cap is a poly-elastomeric annular disc.  
   
   
       8 . The filter element of  claim 7 , wherein the second end cap has a lower surface and an upper surface, said second end cap's upper surface forming a seal with the filtration medium's bottom end so as to be integral therewith.  
   
   
       9 . The filter element of  claim 8 , wherein the second end cap's lower surface includes first and second radial, axially-extending protrusions to form a recessed pocket therebetween, and the pocket is configured to form a fluid-tight seal with a second external, mating knife edge.  
   
   
       10 . The filter element of  claim 9 , wherein the filter element is configured to be contained in a housing, and said second external, mating knife edge is unitary with said housing.  
   
   
       11 . A filter element for filtering a fluid, said filter element comprising: 
 a cylindrical pleated membrane having a top end and a bottom end;    a first end cap coupled to said top end, wherein the end cap has a lower surface and an upper surface, and wherein the lower surface forms a seal with the membrane's top end so as to be integral therewith, the upper surface has first and second radial, axially-extending protrusions to form a recessed pocket therebetween, and the pocket is configured to form a fluid-tight seal with a first external, mating knife edge; and    a second end cap coupled to the membrane's bottom end, wherein the second end cap has a lower surface and an upper surface, and wherein said second end cap's upper surface forms a seal with the membrane's bottom end so as to be integral therewith, the second end cap's lower surface includes first and second radial, axially-extending protrusions to form a recessed pocket therebetween, and the pocket is configured to form a fluid-tight seal with a second external, mating knife edge.    
   
   
       12 . The filter element of  claim 11 , wherein the filter element is configured to be contained in a housing adapted to be coupled to a head member, and wherein said first external, mating knife edge is unitary with said head member, and said second external, mating knife edge is unitary with said housing.  
   
   
       13 . The filter element of  claim 11 , wherein each of the end caps is a poly-elastomeric annular disc.  
   
   
       14 . The filter element of  claim 13 , wherein each disc is made from a viscoelastic polyurethane to form a viscoelastic-knife edge seal (VEKE-Seal).  
   
   
       15 . The filter element of  claim 13 , wherein each poly-elastomeric annular disc is formed from a poly-elastomeric compound in a molding operation in which the compound attaches to the pleats of the membrane so as to become integral with the membrane.