Seat adjusting mechanism

Claim 1

An adjustable vehicle seat, comprising stationary rail means adapted to extend generally horizontally of a vehicle, a carriage assembly slidable longitudinally on said rail means, seat elevating means on said carriage assembly including bell cranks pivoted to the front and rear edges of said carriage assembly rotatable about axes adapted to extend transversely of the vehicle, a seat connected to said bell cranks, said bell cranks each having a lift arm extending forwardly and downwardly from its pivot axis when the seat is in lowered position and swingable upwardly to raise said seat, and an actuating arm extending downwardly and rearwardly from its pivotal axis and swingable forwardly to raise said seat, a rigid link connecting longitudinally aligned actuating arms of said bell cranks, resilient counterbalance means extending generally parallel to said rail means, said counterbalance means comprising a tension spring having its forward end fixed with respect to the vehicle and its rear end attached to the actuating arm of a bell crank at the rear of said carriage assembly to apply simultaneously a forward bias to said carriage assembly and a torque to said bell cranks in a direction to rotate said bell cranks in a direction to elevate said seat.