Containers for liquids

Claim 1

A MEANS INCREASING THE EFFECTIVE CAPACITY AND FOR INDICATING THE LEVEL OF FLUID IN A RESERVOIR FOR A MASTER CYLINDER OF AN HYDRAULIC BRAKING SYSTEM OF WHICH SAID RESERVIOR IS OPEN AT ITS UPPER END WITHOUT SAID END BEING SURROUNDED BY A FLAT ANNULAR EDGE AND PROVIDED AT THAT END WITH AN EXTERNAL SCREW-THREADED PORTION, COMPRISING A HOLLOW TUBULAR EXTENSION MEMBER OF WHICH AS LEAST PART OF ITS WALL IS OF TRANSPARENT OR TRANSLUCENT MATERIAL, AN AXIALLY EXTENSING SPIGOT PORTION AT THE LOWER END OF SAID EXTENSION MEMBER RECEIVED WITHIN THE OPENING AT THE UPPER END OF THE RESERVIOR, AN OUTWARDLY EXTENDING RADIAL FLANGE INTERGRAL WITH SAID EXTENSION MEMBER AND SEATED AGAINST THE UPPER END OF SAID RESERVIOR, AN ANNULAR SEALING WASHER INTERPOSED BETWEEN SAID RADIAL FLANGE AND SAID ANNULAR EDGE OF SAID CONTAINER, AN INTERNALLY SCREWTHREADED RING CLAMPING SAID EXTENSION MEMBER AT ITS LOWER END TO SAID RESERVIOR AND FITTING OVER SAID RADIAL FLANGE AND ANGAGING WITH SAID EXTERNAL SCREW-THREADED PORTION ON THE UPPER END OF SAID RESERVIOR, SAID SEALING WASHER HAVING AN EXTERNAL DIAMETER SUBSTANTIALLY EQUAL TO THE INTERNAL DIAMETER OF SAID CLAMPING MEMBER WHEREBY SAID CLAMPING MEMBER ENGAGE SAID WASHER TO RESTRICT ITS RADIAL EXPANSION UNDER CLAMPING PRESSURE, AND A DETACHABLE CLOSURE CAP AT THE UPPER END OF SAID EXTENSION MEMBER.