Abstract: A tiltable chair including a housing, a back support pivotally attached to the housing about a first horizontal axis and a seat support pivotally attached to the back support about a second horizontal axis and moveably supported by a curved track formed on the housing. A leaf spring includes a first end supported by the housing and a second end biasing the back support and seat support in an upward direction. Preferably, a fulcrum member, which includes a support surface having a curvilinear contour, is moveably supported in the housing and engages a bottom surface of the spring intermediate the first and second ends of the spring. Preferably, a linkage mechanism including a first and second link is adapted to adjust the position of the fulcrum. In another preferred embodiment, a gear housing is removably disposed in said housing and coupled to the fulcrum. In one preferred embodiment, rearward and forward tilt limiters are provided.

Abstract: A tilt assembly comprising a tilt housing, a body support member pivotally attached to said tilt housing about a first horizontal axis and a spring mounted to said tilt housing at a second horizontal axis. The body support member is moveable between a first and second position. The second horizontal axis is adjustably moveable relative to the first horizontal axis. The spring biases said body support member at a first location when the body support member is in the first position and at a second location when the body support member is in the second position, with the second location being a greater distance from the first horizontal axis than the first location. A method for supporting a chair body support member is also provided.