The present invention relates in general to a fluid filter incorporating a plastic shell and a replaceable fluid filter
cartridge. More specifically, the present invention relates to configuring the shell so that it will only accept, in terms of proper functioning, a cooperatively-configured replaceable fluid filter
cartridge. One of the
emerging technologies in terms of fluid filter construction is the enlargement of the threaded connection interface between the molded plastic shell and the fluid-delivery head, accompanied by the
elimination of the typical or traditional nutplate. In one embodiment of this design concept, the shell is molded out of plastic and the outer cylindrical surface of the shell adjacent the open end of the shell is externally threaded. This threaded surface of the shell is used to attach the shell, and in turn the fluid filter
assembly, to the head. This style of shell is configured for use with a spin-on style of
filtration system as part of a disposable fluid filter
assembly. Some end users of the type of
filtration systems described above enjoy the advantages gained from a replaceable fluid filter
cartridge. Therefore, it would be an advance in the state of the art to configure the molded plastic shell, generally as described above, but configured to accept a replaceable fluid filter cartridge. Related to the acceptance of a replaceable cartridge is the inability of the shell to accept a spin-on style of filter as part of a disposable, single-use
system. The fluid filter construction disclosed herein is directed to providing this capability by the design of a novel and unobvious fluid filter endplate with cooperative modifications to the upper exposed edge of the shell that defines the open end of the shell.