Dual valve, dual element fluid filter assembly

Claim 1

A TWO-STAGE FLUID FILTER ASSEMBLY COMPRISING A HEAD SECTION WITH AN INLET PASSAGE AND AN OUTLET PASSAGE FORMED THEREIN, A BOWL SECTION REMOVABLY ATTACHED TO SAID HEAD SECTION, PRIMARY FILTER MEANS REMOVABLY DISPOSED IN SAID BOWL SECTION TO DEFINE A FIRST ANNULAR SPACE BETWEEN AN INTERIOR WALL OF SAID BOWL SECTION AND AN EXTERIOR SURFACE OF SAID PRIMARY FILTER MEANS, SECONDARY FILTER MEANS CONCENTRICALLY POSITIONED WITHIN SAID PRIMARY FILTER MEANS AND REMOVABLY DISPOSED IN SAID BOWL SECTION TO DEFINE A SECOND ANNULAR SPACE BETWEEN AN INTERIOR SURFACE OF SAID PRIMARY FILTER MEANS AND AN EXTERIOR SURFACE OF SAID SECONDARY FILTER MEANS, SAID SECONDARY FILTER MEANS HAVING AN INTERNAL THIRD SPACE, FIRST INTERNAL PASSAGE MEANS FORMED IN SAID HEAD SECTION FOR ALLOWING THE PASSAGE OF FLUID FROM SAID INLET PASSAGE INTO SAID FIRST ANNULAR SPACE, FIRST BY-PASS VALVE MEANS POSITIONED IN SAID HEAD SECTION AND INTERCONNECTING SAID FIRST ANNULAR SPACE WITH SAID SECOND ANNULAR SPACE, SAID FIRST BY-PASS VALVE MEANS BEING ACTUATED BY A PREDETERMINED FLUID PRESSURE DIFFERENTIAL ACROSS SAID PRIMARY FILTER MEANS TO BY-PASS FLUID FLOW AROUND SAID PRIMARY FILTER MEANS, SECOND BY-PASS VALVE MEANS POSITIONED IN SAID HEAD SECTION AND INTERCONNECTING SAID SECOND ANNULAR SPACE WITH SAID THIRD SPACE, SAID SECOND BY-PASS VALVE MEANS BEING RESPONSIVE TO A GREATER PREDETERMINED FLUID PRESSURE DIFFERENTIAL THAN SAID FIRST BY-PASS VALVE MEANS TO BYPASS FLUID FLOW AROUND SAID SECONDARY FILTER MEANS,