Buffers and draw-gear for railways, tramways and like vehicles

Claim 1

A HYDRAULIC BUFFER OR DRAW-GEAR FOR RAILWAY, TRAMWAY OR LIKE VEHICLES COMPRISING A CYLINDER, PLUNGER MEANS MOVABLY MOUNTED WITHIN SAID CYLINDER TO FORM A UNIT INCORPORATING RESILIENT MEANS TO PROVIDE RESISTANCE AND RECOIL, A LIQUID CHAMBER HAVING LIQUID THEREIN DISPOSED IN SAID UNIT, RESERVOIR MEANS DISPOSED IN SAID UNIT, PASSAGE MEANS INTERCONNECTING SAID LIQUID CHAMBER AND SAID RESERVOIR MEANS, SAID PASSAGE MEANS INCLUDING AN ENERGY ABSORBING ORIFICE IN SAID PASSAGE MEANS SO THAT WHEN A LOAD IS APPLIED TO SAID PLUNGER MEANS LIQUID IS DISPLACED FROM SAID LIQUID CHAMBER INTO SAID RESERVOIR MEANS THROUGH SAID PASSAGE MEANS AND ENERGY ABSORBING ORIFICE, AND PRESSURE OPERATED VALVE MEANS DISPOSED IN SAID PASSAGE MEANS CLOSING SAID PASSAGE MEANS TO PREVENT ANY FLOW OF LIQUID FROM SAID LIQUID CHAMBER TO SAID RESERVOIR MEANS UNTIL A PREDETERMINED LIQUID PRESSURE HAS BEEN ATTAINED IN THE LIQUID CHAMBER WHEREUPON SAID VALVE MEANS OPENS AND PERMITS LIQUID FLOW AT A CONTROLLED PRESSURE, THE ACTION OF SAID VALVE MEANS BEING TO RAISE THE FORCE REQUIRED TO MOVE THE PLUNGER MEANS INWARDLY ABOVE THE RECOIL FORCE PROVIDED BY THE RESILIENT MEANS.