Seat adjuster with compensating link

A seat adjustment mechanism for longitudinal motion of a seat bracket, having a seat disposed therewith in use, in relation to a stationary riser of a vehicle, the seat adjuster mechanism comprising a linkage system moveable to establish limits of motion of the seat to and from a predetermined number of positions, the linkage system including at least two primary links each having two ends and having disposed proximate each end a pivot opening, the at least two links both being connected either to the stationary riser or to the seat bracket proximate one of said ends thereof and having substantially arcuate motion, wherein the at least two links provide as they move with respect to the stationary riser the longitudinal motion of the seat bracket in relation to the stationary riser, the linkage system further including a compensating link to compensate for the substantially arcuate motion of the at least two primary links of the mechanism during the movement of the seat to and from said predetermined number of positions, the compensating link having at least three pivot openings and connecting to the opposite of the stationary riser or the seat bracket with respect to said at least two links at one pivot opening and being connected to both of the at least two links at the remaining pivot openings rendering a final longitudinal motion of the seat as substantially linear within the limits of motion of the seat.

A system for providing linear movement of a vehicle seat to alternate comfort positions comprising a seat bracket having a seat disposed therewith in use, the seat bracket being moveably affixed to a riser, each of the seat bracket and the riser having a front and rear, top and bottom;

• the seat bracket being located substantially on top of said riser in use;
• at least two first links pivotally engaged with said seat bracket, one of said at least two first links being connected proximate the front of the seat bracket and the other of said at least two first links being connected proximate the rear of said seat bracket;
• at least two second longer links, being longer than said first links, and pivotally engaged with said seat bracket, one of said at least two second links being pivotally connected proximate the front of said seat bracket, the pivot connection of said one of said second links and said seat bracket being offset towards the front and towards the top of the seat bracket in relation to the pivot connection of the first link and said seat bracket, and the other of said at least two second links being pivotally connected proximate the rear of said seat bracket, the pivot connection of said other of said second links and said seat bracket being offset towards the front and towards the top of the seat bracket in relation to the pivot connection of the first link and said seat bracket, said at least two first and two second links each respectively being pivotally interconnected with at least two compensating third links pivotably connected proximate the front and rear of the riser and having a free end remote from the riser and a pivoting end proximate the riser, the at least two first links each being interconnected with a respective one of the at least two compensating third links proximate the free end of the at least two compensating third links respectively, the at least two second links each being interconnected with a respective one of the at least two compensating third links respectively intermediate the free end and the pivoting end of each of the at least two compensating third links, the at least two first and two second links providing longitudinal fore and aft motion of the seat bracket in relation to the riser, the at least two compensating third links compensating for arcuate motion of the at least two first and two second links maintaining the movement of the seat bracket along an axis which is substantially parallel with respect to the riser throughout the movement of said seat bracket.