Means for checking hydraulic installations

Claim 1

A RATE OF FLOW METER ADAPTED FOR USE IN A FILTER HOUSING OF THE AXIALLY MOVABLE FILTER CARTIDGE TYPE PROVIDED WITH AN INTERIORLY FORMED CYLINDER AT THE OUTLET END OF SAID HOUSING, THE OPPOSITE END BEING OPEN FOR THE RECEPTION OF THE FILTER CARTIDGE, SAID HOUSING HAVING MEANS FOR INDICATING MOVEMENT OF SAID CARTRIDGE, IN SAID HOUSING, SAID FLOW METER BEING INSERTABLE WITHIN SAID HOUSING IN PLACE OF THE FILTER CARTIDGE AND COMPRISING A CLOSURE PLATE FOR THE OPEN END OF SAID HOUSING, A SHAFT EXTENDING THROUGH SAID CLOSURE PLATE AND AXIALLY OF SAID HOUSING, A METER CARTRIDGE MOUNTED FOR AXIAL MOVEMENT UPON SAID SHAFT AND INCLUDING A PISTON AT ONE END FOR SLIDABLE RECEPTION IN SAID CYLINDER OF THE HOUSING, SPRING BIAS MEANS FOR MAINTAINING THE METER CARTRIDGE AGAINST THE CLOSURE PLATE, SAID PISTON BEING THE METER CARTRIDGE WITHIN THE HOUSING SO THAT MOVEMENT OF SAID CARTRIDGE WILL BE TRANSMITTED TO THE SAME MEANS FOR INDICATING MOVEMENT OF THE FILTER CARTRIDGE SO AS TO INDICATE MOVEMENT OF SAID METER CARTRIDGE AGAINST SAID SPRING BIAS MEANS, AND MEANS CARRIED BY SAID CLOSURE PLATE TO ROTATE SAID SHAFT AND ACTUATE SAID VALVE AND TO INDICATE THE CONDITION OF SAID VALVE AND THE RATE OF FLUID FLOW THERETHROUGH FOR A PREDETERMINED MOVEMENT OF SAID METER CARTRIDGE.