Unit area ratio accumulator with fail-safe means

Claim 1

IN COMBINATION, A HYDRAULIC UNIT HAVING A CYLINDRICAL RECESS IN ONE SURFACE THEREOF WITH A CYLINDRICAL BOSS OF REDUCED DIAMETER PROJECTING UPWARDLY INTO SAID RECESS, AN ACCUMULATOR COMPRISING A CYLINDRICAL HOUSING HAVING A CLOSED END AND AN OPEN END WITH AN ATTACHMENT FLANGE ABOUT SAID OPEN END, THE OUTSIDE DIAMETER OF SAID BOSS BEING SUBSTANTIALLY THE SAME AS THE INSIDE DIAMETER OF THE HOUSING, SAID OPEN END OF THE HOUSING BEING SLIDABLY POSITIONED OVER SAID BOSS, A CLAMPING RING FITTED WITHIN SAID RECESS ABOUT SAID HOUSING AND ABUTTING AGAINST SAID ATTACHMENT FLANGE, SAID CLAMPING RING THREADABLY ENGAGING THE WALL OF SAID RECESS TO POSITIVELY PREVENT THE DISENGAGEMENT OF THE HOUSING FROM THE BOSS, A FREE-FLOATING PISTON SLIDABLY SEALED WITHIN SAID HOUSING, SAID HYDRAULIC UNIT HAVING INLET AND OUTLET PASSAGEWAYS COMMUNICATING WITH THE END FACE OF SAID BOSS TO DIRECT PRESSURIZED FLUID INTO AND OUT OF A CHAMBER ON ONE SIDE OF THE PISTON, SAID PISTON BEING MAINTAINED AGAINST THE FLUID BY A PRESSURIZED GAS IN A CHAMBER ON THE OTHER SIDE OF THE PISTON, AND AN O-RING SEATED IN AN ANNULAR GROOVE IN THE CYLINDRICAL WALL OF SAID BOSS AND SLIDABLY SEALING AGAINST THE INNER CYLINDRICAL SURFACE OF SAID HOUSING.