Hydraulic reservoir and filter

Claim 1

FOR USE IN A RESERVOIR HAVING INLET AND EXHAUST PORTS AND A COVER REMOVABLY SECURED THERETO, AN IMPROVED EXTRACTABLE FILTERING DEVICE COMPRISING A SCREEN CLAMED BETWEEN THE RESERVOIR AND THE COVER, A SHELL ADJACENT SAID SCREEN HAVING A BASE AND A WALL PORTION DEPENDING DOWNWARDLY THEREFROM, A CONNECTING BOLT SECURING SAID SCREEN TO THE BASE OF SAID SHELL, A FIRST FILTER DISPOSED BETWEEN SAID SCREEN AND SAID BASE AND IN SEALING RELATION WITH SAID BASE, A CASING SECURED IN THE RESERVOIR BELOW AND IN SUBSTNATIAL VERTICAL ALIGNMENT WITH SAID FIRST FILTER, SAID CASING HAVING AN UPWARDLY PROJECTING WALL PORTION DISPOSED WITHIN SAID DOWNWARDLY DEPENDING SHELL WALL PORTION, A CUP ENGAGING THE UPPER END OF SAID CASING WALL PORTION, SAID CUP HAVING A FLANGE PORTION EXTENDING PERIPHERALLY THEREAROUND AND PROJECTING OUTWARDLY FROM SAID CASING WALL PORTION, A SECOND FILTER SECURED TO SAID CUP AND DISPOSED WITHIN SAID CASING, SAID CASING HAVING AN OPENING THEREIN COOPERATING WITH THE EXHAUST PORT, THE LOWER END OF SAID DOWNWARDLY DEPENDING SHELL WALL PORTION HAVING INWARDLY DIRECTED PROJECTIONS ENGAGEABLE WITH SAID FLANGE PORTION WHEN SAID SHELL IS MOVED VERTICALLY WITH RESPECT TO SAID CASING ENABLING SAID FIRST AND SECOND FILTERS TO BE SIMULTANEOUSLY REMOVED FROM THE RESERVOIR, AND SPRING MEANS SEATED AGAINST SAID CUP AND SAID SHELL BASE TO URGE SAID CUP INTO SEALING ENGAGEMENT WITH SAID CASING.