Adjustment device for a vehicle seat

An adjustment device for use in a vehicle seat comprising fixed-side means, a rod journaled by said fixed-side means, a pair of link members each having an arc-shaped slit and each being fixed to said rod, free ends of said link members being connected to a movable side member, a crankshaft having a pair of bent portions on substantially 180.degree. opposing sides thereof being provided on said fixed-side means, said bent portions of said crankshaft being respectively inserted through and engaged with said slits in said link members, wherein said fixed-side means comprises a pair of side brackets respectively fixed to a pair of right and left side rails, said moveable-side member is a cushion frame, said rod is rotatably journaled between the front ends of said pair of brackets, and the free ends of said pair of link members fixed to said rod are rotatably mounted on opposite sides of said cushion frame, respectively, whereby said crank shaft is rotated to rotate said link members so as to move or adjust said moveable-side member relative to said fixed-side means.

An adjustment device for use in a vehicle seat comprising fixed-side means, a rod journaled by said fixed-side means, a pair of link members each having an arc-shaped slit and each being fixed to said rod, free ends of said link members being connected to a moveable side member, a crankshaft having a pair of bent portions on substantially 180.degree. opposing sides thereof being provided on fixedside means, said bent portions of said crankshaft being respectively inserted through and engaged with said slits in said link members, wherein said fixed-side means comprises a pair of side brackets respectively fixed to a pair of right and left side rails, and said moveable-side member is a cushion frame, and wherein the rear ends of said side brackets are connected to said cushion frame by means of links, whereby said crankshaft is rotated to rotate said link members so as to move or adjust said moveable-side member relative to said fixed-side means.

An adjustment device for use in a vehicle seat comprising fixed-side means, a rod journaled by said fixed-side means, a pair of link members each having an arc-shaped slit and each being fixed to said rod, free ends of said link members being connected to a moveable side member, a crankshaft having a pair of bent portions on substantially 180.degree. opposing sides thereof being provided on said fixed-side means, said bent portions of said crankshaft being respectively inserted through and engaged with said slits in said link members, wherein two removable preventive members are respectively fitted over the two end portions of said crankshaft, and two torsional coil springs are respectively compressed and interposed between grooves formed in said removal preventive members and projections provided in the lower portions of the outer surfaces of a pair of side brackets, respectively fixed to a pair of right and left side rails, whereby said crankshaft is being always pushed up by the biasing forces of said torsional coil springs so that the two end portions thereof are pressed against elongated holes formed in said side brackets and said bent portions thereof are pressed against the terminal edges of said slits in said two link members.