Three-quarter fold chair

Claim 1

A chair comprising a base having a ball recess; a ball within a portion of said recess; a seat having a lower portion provided with a ball support defining a recess receiving another portion of said ball to provide a pivot between the base and seat, said lower portion of the seat having a spring actuator arm extending inwardly below said pivot ball; a tail lock member providing a spring housing and enclosing said actuator arm and provided at its bottom with an outwardly extending spacer arm located in a normal position directly beneath said spring actuator arm of said lower portion of said seat, said seat being in a three-quarters raised position when said actuator arm and said spacer arm are thus aligned, said spacer arm bearing against said seat base; bolt means securing said tail lock to said base; and a coil spring within said housing having first and second spring ends located respectively on either side of said spacer arm and said actuator; whereby said seat may be further raised to a fully raised position wherein said actuator arm is rotated in one direction to engage said first end of said spring and apply torsion thereto, said second end of said spring being restrained by said space arm of said tail lock, or said seat may be lowered to a horizontal position wherein said actuator arm is rotated in a direction opposite to said first direction to engage said second end of said spring and apply torsion thereto, said first end of said spring being restrained by said spacer arm; said seat assuming said three-quarters raised position when not otherwise urged.