Filter assembly with telescopic elements

Claim 1

A filter assembly comprising a plurality of telescopically disposed separate filter elements, each of said filter elements comprising a separate tubular screen having a plurality of longitudinally extending and uninterrupted ribs secured in a circumferentially spaced relationship therearound and wherein a first filter element of each adjacent pair of filter elements is telescopically disposed within a second filter element of said pair of filter elements with each rib of said first filter element being disposed in aligned relationship with a respective rib of said second filter element throughout the lengths thereof to space the screens of said pair of filter elements radially from each other to define a flow passage between circumferentially adjacent pairs of said ribs whereby a series of circumferentially disposed and isolated flow passages are defined throughout the length of said filter assembly, said pair of filter elements defining a first flow passage of said flow passages therebetween communicating directly with an inlet of said filter assembly disposed at a first end of said filter assembly and wherein another filter element spaced radially inwardly from said first filter element and said first filter element define a second flow passage of said flow passages therebetween communicating directly with an outlet of said filter assembly whereby fluid flow ingressing into the first flow passage of said filter assembly from said inlet will be forced through one of the filter elements of said pair of filter elements prior to its egress into said second flow passage and to said outlet.