Low profile resilient suspension for vehicle seat

摘要

Low profile resilient suspension utilizes a pair of horizontally positioned, adjustably tensioned springs to support the weight of a seat occupant. The springs are mounted to one of the movable or fixed seat frame members so as to be completely independent of the linkages, such as scissors links, which guide the movable seat frame member for generally vertical parallel movement relative to the base frame member and floor. The tension of the springs can be adjusted by weight adjustment control members fixed to one of their ends to accommodate occupants of differing weights. The adjustment can be made when the seat is either occupied or unoccupied. The weight adjustment control members remain fixed relative to the seat frame as the suspension oscillates vertically. The opposite ends of the springs are mounted to the ends of the short arms on a pair of connected bellcrank levers which are pivoted to one of the seat frame members. The long arms of the bellcrank levers have a predetermined cam shape along one edge that engages a cam follower that is fixed during operation relative to the other of the seat frame members. The cam is shaped to provide any desired load deflection characteristic for the suspension seat and preferably either a straight line characteristic or one in which the springs would offer greater resistance to bottoming of the suspension at the end of its ride stroke. In a preferred embodiment, a height adjustment mechanism is provided for moving the movable seat frame and cam follower to a plurality of selected vertical positions which each permit the suspension to move within its entire "ride zone.