Maximum energy absorbing hydraulic cushion

Claim 1

A HYDRAULIC CUSHION DEVICE FOR USE IN RAILWAY CARS AND ADAPTED FOR PROVIDING PROTECTION FOR LADING CARRIED THEREON FROM IMPACTS OF 12 M.P.H. AND UP COMPRISING A CYLINDER HAVING A CLOSED END AND AN OPEN END, A PISTON MEMBER TELESCOPICALLY DISPOSED IN SAID OPEN END OF SAID CYLINDER AND INCLUDING A HOLLOW PISTON ROD AND A PISTON HEAD FIXED TO ONE END THEREOF, AN INTERMEDIATE CYLINDER HEAD DISPOSED IN SAID CYLINDER BETWEEN SAID CLOSED AND OPEN ENDS THEREOF, SAID CYLINDER HEAD HAVING AN AXIAL OPENING THROUGH WHICH SAID PISTON ROD EXTENDS AND DEFINES THEREWITH AN ANNULAR OPENING, AN ORIFICE IN SAID PISTON HEAD, METERING PIN MEANS FIXED TO SAID CYLINDER CLOSED END AND EXTENDING THROUGH SAID ORIFICE INTO SAID HOLLOW PISTON ROD, A PORT MEANS IN SAID PISTON ROD ADJACENT SAID PISTON HEAD, A FLEXIBLE BOOT RESERVOIR FIXED AT ONE END TO SAID CYLINDER HEAD AND HAVING A REVERSLY TURNED PORTION AT ITS OTHER END FIXED TO SAID PISTON ROD OUTBOARD OF SAID CYLINDER HEAD, SAID BOOT BEING IN COMMUNICATION WITH SAID CYLINDER BY WAY OF SAID PORT MEANS, ANNULAR OPENING AND ORIFICE AND BEING EXPANDABLE TO SERVE AS A RESERVOIR FOR RECEIVING FLUID DISPLACED FROM SAID PISTON ROD BORE UPON RELATIVE TELESCOPIC MOVEMENT OF SAID PISTON MEMBER AND SAID CYLINDER, RESILIENT MEANS DISPOSED BETWEEN SAID PISTON MEMBER AND SAID CYLINDER, AND HYDRAULIC FLUID FILLING SAID CUSHION DEVICE, SAID CYLINDER HAVING A CYLINDER BORE OF MINIMUM DIAMETER AND A WALL OF MINIMUM THICKNESS FOR ACHIEVING THE REQUISITE LADING PROTECTION, AND SAID HOLLOW PISTON ROD BEING FORMED WITH THE TERMINAL END PORTION THEREOF REMOTE FROM SAID PISTON HEAD WITH AN OUTER DIAMETER LESS THAN THE OUTER DIAMETER OF THE CENTRAL PORTION OF SAID ROD AND THE END PORTION THEREOF ADJACENT SAID PISTON HEAD, SAID DIFFERENCE IN SAID OUTER DIAMETER OF SAID TERMINAL END PORTION AND THE OUTER DIAMETER OF SAID CENTRAL AND SAID END PORTION ADJACENT SAID PISTON HEAD BEING EQUAL TO OR EXCEEDING THE THICKNESS OF SAID REVERSELY TURNED PORTION OF SAID FLEXIBLE BOOT WHICH IS ATTACHED TO SAID TERMINAL END PORTION.