Filter element assembly

Claim 2

A filter cartridge, wherein the improvement comprises: an annular filter element; one end cap closing one end of said element; another annular end cap closing the other end of said element and having an axially inwardly offset inner peripheral portion, a substantially flat retaining ring forming with said inner peripheral portion an inwardly open annular channel, and annular elastic sealing means arranged in said channel.

Claim 3

The filter cartridge of claim 1 wherein said one end cap has an axially outwardly extending central tubular neck adapted to be inserted through and compress the sealing means of another filter cartridge corresponding to said sealing means to form a fluid tight seal therewith.

Claim 4

The filter cartridge of claim 2 wherein said neck is closed by a cap having an annular axial flange provided with an inwardly open annular recess, and annular elastic sealing means arranged in said recess and compressed by said neck to form a fluid tight seal therewith.

Claim 5

A filter assembly including, in combination, a housing having an inlet for fluid to be filtered and an outlet for discharging filtered fluid from said housing; and at least one filter cartridge arranged in said housing, wherein the improvement comprises: said cartridge including an annular filter element; one end cap closing one end of said element; another annular end cap closing the other end of said element and having an axially inwardly offset inner peripheral portion, a substantially flat retaining ring forming with said inner peripheral portion an inwardly open channel, and annular elastic sealing means arranged in said channel; said one end cap being closed to one of said inlet and outlet; and the other of said inlet and outlet including a tubular extension projecting axially inwardly through and compressing said sealing means to form a fluid tight seal therewith.

Claim 6

A filter assembly including, in combination, a housing having an inlet for fluid to be filtered and an outlet for discharging filtered fluid from said housing; and at least one filter cartridge arranged in said housing, wherein the improvement comprises: said cartridge including an annular filter element; one end cap closing one end of said element; another annular end cap closing the other end of said element and having an axially inwardly offset inner peripheral portion, a substantially flat retaining ring forming with said inner peripheral portion an inwardly open channel, and annular elastic sealing means arranged in said channel; said one end cap being closed to one of said inlet and outlet; and the other of said inlet and outlet including a tubular extension projecting axially inwardly through and compressing said sealing means to form a fluid tight seal therewith.

Claim 7

The filter assembly of claim 4 wherein said one end cap has an axially outwardly extending central tubular neck closed by a cap having an annular axial flange provided with an inwardly open annular recess, and annular elastic sealing means arranged in said recess and compressed by said neck to form a fluid tight seal therewith.

Claim 8

A filter assembly including, in combination, a housing having an inlet for fluid to be filtered and an outlet for discharging filtered fluid from said housing; and at least two filter cartridges arranged in stacked relationship in said housing, wherein the improvement comprises: each of said cartridges including an annular filter element; one end cap closing one end of said element; another annular end cap closing the other end of said element and having an axially inwardly offset inner peripheral portion, a substantially flat retaining ring forming with said inner peripheral portion an inwardly open annular channel, and annular elastic sealing means arranged in said channel; said one end cap of one of said cartridges having an axially outwardly extending central tubular neck inserted through and compressing said sealing means of the other of said cartridges to form a fluid tight seal therewith; said one end cap of said other cartridge being closed to one of said inlet and outlet; and the other of said inlet and outlet including a tubular extension projecting axially inwardly through and compressing said sealing means of said one cartridge to form a fluid tight seal therewith.

Claim 9

A filter assembly including, in combination, a housing having an inlet for fluid to be filtered and an outlet for discharging filtered fluid from said housing; and at least two filter cartridges arranged in stacked relationship in said housing, wherein the improvement comprises: each of said cartridges including an annular filter element; one end cap closing one end of said element; another annular end cap closing the other end of said element and having an axially inwardly offset inner peripheral portion, a substantially flat retaining ring forming with said inner peripheral portion an inwardly open annular channel, and annular elastic sealing means arranged in said channel; said one end cap of one of said cartridges having an axially outwardly extending central tubular neck inserted through and compressing said sealing means of the other of said cartridges to form a fluid tight seal therewith; said one end cap of said other cartridge being closed to one of said inlet and outlet; and the other of said inlet and outlet including a tubular extension projecting axially inwardly through and compressing said sealing means of said one cartridge to form a fluid tight seal therewith.

Claim 10

The filter assembly of claim 6 wherein said one end cap of each of said cartridges has said neck, with said neck of said one end cap of said other cartridge being closed by a cap having an annular axial flange provided with an inwardly open annular recess, and annular elastic sealing means arranged in said recess and compressed by said neck of said one end cap of said other cartridge to form a fluid tight seal therewith.