Seat frame for a vehicle seat

Claim 1

In a vehicle seat of the type including a seat frame, a pair of spaced slider rails to permit the vehicle seat to be reciprocally movable between forward and rearward positions and vertical adjustment means connecting said seat frame to said pair of slider rails for permitting said seat frame to be vertically adjustable relative to said slider rails, the improvement wherein said vertical adjustment means comprises: right and left link mechanisms associated with a respective one of said pair of slide rails, each said right and left link mechanisms including, (a) front and rear brackets vertically extending above and rigidly fixed to said respective one of said pair of slide rails, (b) a front link member pivotally connected at one end thereof to said front bracket by means of a first pivot shaft, and being pivotally connected at the other end thereof to an adjacent side portion of said seat frame by means of a second pivot shaft, (c) a segment gear connected to said front link member by means of said second pivot shaft and also connected to said front link member by means of an intermediate pivot shaft such that said segment gear is coupled to said front link member so as to be immovable relative thereto, said first, intermediate and second pivot shafts being colinearly positioned along said front link member, (d) a rear link member pivotally connected at one end thereof to said rear bracket by means of a third pivot shaft and pivotally connected at the other end thereof to said adjacent side portion of said seat frame by means of a fourth pivot shaft; (e) link rod means pivotally connected to said segment gear and to said rear link member for responsively transferring pivotal movement of said segment member to said rear link member; and (f) a center gear in meshed relationship with said segment gear, wherein said vertical adjustment means further comprises support shaft means for interconnecting said center gears of said right and left link mechanisms; and wherein said vertical adjustment means further comprises support operation means connected to shaft means for selectively rotating said shaft means, and thus said center gears, in a first rotational direction, said center gears, in turn, responsively causing said segment gears to move and rotate the front link members in a second direction, opposite to said first direction, wherein movement of said segment gears responsively causes a force to be exerted at said second pivot shaft to cause said front link member to rotate in said second direction about said first pivot shaft by virtue of said immovable coupling between said front link member and said segment gear to responsively vertically displace said second pivot shaft, and thus said seat frame, relative to said first pivot shaft whereby said seat frame is vertically adjusted relative to said slide rails.