Vehicle-seat suspension

Claim 1

A SEATING ASSEMBLY FOR A VEHICLE SUBJECT TO JOLTING, COMPRISING A BASE; A SEAT SUPPORT MOUNTED ON SAID BASE FOR PIVOTAL MOVEMENT ABOUT A HORIZONTAL AXIS; RESILIENT MEANS ANCHORED TO SAID BASE AND TO SAID SEAT SUPPORT FOR COUNTERACTING THE WEIGHT OF THE LATTER; HYDRAULIC DAMPING MEANS ON SAID BASE, SAID DAMPING MEANS INCLUDING A PISTON CYLINDER AND PISTON MEANS POSITIVELY CONNECTING CYLINDER; AND TRANSMISSION MEANS POSITIVELY CONNECTING SAID SEAT SUPPORT WITH SAID PISTON MEANS; SAID PISTON MEANS COMPRISING A PAIR OF AXIALLY SPACED HEADS FORMING CHANNELS FOR THE PASSAGE OF A HYDRAULIC FLUID IN GENERALLY AXIAL DIRECTION WITHIN SAID CYLINDER, A FIRST VALVE ON ONE OF SAID HEADS SPRING-URGED INTO A NORMAL POSITION BLOCKING THE PASSAGE OF SAID FLUID IN ONE AXIAL DIRECTION WHILE BEING YIELDABLE TO A PREDETERMINED FLUID PRESSURE IN THE OPPOSITE AXIAL DIRECTION, SAID ONE OF SAID HEADS BEING PROVIDED WITH AN ORIFICE OF A WIDTH UNAFFECTED BY THE POSITION OF THE SAID FIRST VALVE AND INDEPENDENT OF THE PRESSURE DIFFERENTIAL ACROSS SAID ORIFICE FOR ENABLING THE PASSAGE OF A RESTRICTED FLUID FLOW THERETHROUGH, A SECOND VALVE ON THE OTHER OF SASID HEADS SPRING-URGED INTO A NORMAL POSITION BLOCKING THE PASSAGE OF SAID FLUID IN SAID OPPOSITE AXIAL DIRECTION WHILE BEING YIELDABLE TO A PREDETERMINED FLUID PRESSURE IN SAID ONE DIRECTION, AND A THIRD VALVE ON SAID OTHER OF SAID HEADS SPRING-URGED INTO A NORMAL POSITION BLOCKING THE PASSAGE OF SAID FLUID IN SAID ONE DIRECTION WHILE BEING YIELDABLE TO A PREDETERMINED FLUID PRESSURE IN SAID OPPOSITE DIRECTION, SAID THIRD VALVE BEING PROVIDED WITH A PORT OBSTRUCTED IN ITS NORMAL POSITION AND EXPOSED UPON YIELDING FOR PERMITTING ONLY A RESTRICTED FLOW OF SAID FLUID THROUGH SAID OTHER OF SAID HEADS IN SAID OPPOSITE DIRECTION.