Improvements in and relating to spring suspensions for vehicle seats

Claim 1

A spring suspension for a vehicle seat, the suspension comprising a seat frame and a base frame interconnected by a scissor-action linkage arm system, the system including two pairs of scissor-action linkage arms spaced apart on a common pivot axis, said arms having pivotal interconnections at their opposite ends with said frames, to permit the frames to move towards and away from one another, each pivotal connection on one pair of arms being coaxial with a corresponding pivotal connection on the other pair of arms, and a biassing spring connected between parts of the suspension which pivot relatively to one another during relative movement of the frames towards or away from each other, to bias the two frames away from one another, characterised by all of the pivotal connections between one of said frames (11,12) and the adjacent ends of the linkage arms (13,14) connected thereto being displaceable connections extending in a common direction to permit both relative pivotal movement between the linkage arms of each pair and relative translational movement between all the linkage arms and said one frame (11), and a motion limiting resilient coupling (40,46,50,51) including an anchoring spring (46) of limited expansion and contraction connected between said one frame (11) and the linkage arm system to permit relative translational movement along said common direction between the whole linkage arm system and said one frame within the limits of expansion and contraction of the spring thereby reducing the transmission of vibration in said common direction between the base frame and the seat frame.