Replaceable filter cartridge with support element and liquid filter with such a filter cartridge

Abstract

A replaceable filter cartridge assembly for a liquid filter and a liquid filter in which such a filter cartridge is installed. The filter cartridge 10 is provided with a support element 15, and a seat 20 for a sealing membrane 19 is provided on the support element 15. The sealing membrane seals the inlet 22 of the housing via a sealing edge 21 that acts as a return flow barrier over the inlet. The sealing membrane 19 also has a radial sealing surface 23 to provide a seal between the support element 15 and the outlet port 24 of the filter. This permits the filter cartridge to be manufactured in a particularly cost-effective manner and assures simple mounting within the housing. Since only the filter cartridge, which can be pushed onto the support element 15, needs to be exchanged, very little material has to be disposed of when the filter is replaced, which further increases the cost-effectiveness of the filter in use.

What is claimed is:  
     
         1 . An exchangeable filter cartridge assembly for a liquid filter comprising an annular filter medium with sealed end faces; a support element mounted interiorly of the annular filter medium for supporting the filter medium, said support element having a seat in an end area for a sealing membrane which serves as a return flow barrier, said sealing membrane having a sealing edge for support inside the liquid filter and for sealing a filter inlet, and an additional sealing surface to provide a radial seal between the support element and a filter housing.  
     
     
         2 . A filter cartridge assembly according to  claim 1 , wherein said annular filter medium comprises a pleated filter paper.  
     
     
         3 . A filter cartridge assembly according to  claim 1 , wherein the sealing membrane which serves as a return flow barrier is permanently connected to the end area of the support element.  
     
     
         4 . A filter cartridge assembly according to  claim 1 , wherein the end area of the support element is provided with an interlocking configuration to create a form-fit connection with the sealing membrane.  
     
     
         5 . A filter cartridge assembly according to  claim 1 , wherein the end area of the support element extends axially beyond an adjacent end face of the filter medium.  
     
     
         6 . A filter cartridge assembly according to  claim 1 , wherein the filter medium is replaceably disposed on the support element.  
     
     
         7 . A filter cartridge assembly according to  claim 1 , wherein at least one end face of the filter medium is connected with an end disk for forming a seal.  
     
     
         8 . A filter cartridge assembly according to  claim 7 , wherein said end disk is made of nitrile-butadiene rubber.  
     
     
         9 . A filter cartridge assembly according to  claim 1 , wherein the support element is constructed as one piece.  
     
     
         10 . A filter cartridge assembly according to  claim 1 , wherein the additional sealing surface of the sealing membrane forms a radial seal between the support element and an outlet port of the filter housing.  
     
     
         11 . A liquid filter comprising an openable housing with an inlet and an outlet, and an annular filter cartridge disposed on a central support element in said housing, an elastic sealing membrane connected to a seat provided on one end of said support element, said sealing membrane having a sealing edge which is supported inside the housing in such a way that it forms a return flow barrier over the inlet.  
     
     
         12 . A liquid filter according to  claim 11 , wherein said housing comprises a base plate and a screw-on cover, and said support element is detachably connected to the housing cover by a snap connection.  
     
     
         13 . A liquid filter according to  claim 11 , wherein the housing has a substantially cylindrical shape, and the inlet and outlet are accommodated in a base plate of the housing, said the base plate comprising a threaded socket for attaching the liquid filter at an intended installation site, and wherein sealing rings are provided to seal the housing relative to the environment and to provide a seal between the inlet and the outlet.  
     
     
         14 . A liquid filter according to  claim 11 , wherein said filter is an oil filter for lubricating oil of an internal combustion engine.