Patent ID: 7303233

Claim:
A height adjustable chair with rocking function comprising: a seat frame which is supported with a leg support extended and contracted by a cylinder internally fitted to, a back frame which is rotatably fitted to the seat frame at the forward end side thereof, and an resilient member for rocking which is interposed between the seat frame and the back frame; wherein a joint part of a joint member having an arm piece protruded on the joint part is rotatably assembled to the seat frame with a vertical shaft; wherein a rocking member whose base part is rockably fitted to the joint part with a horizontal shaft is assembled, wherein an operation lever whose tip is led to the outside of the seat frame is equipped at one end of the rocking member to make the operation lever rotatable in vertical and lateral directions with the vertical and horizontal shaft and a pressing piece which always positions over a button for rod advancing and retreating of the cylinder and touches and leaves thereof is provided at the other end of the rocking member to enable the extension and contraction of the leg support by vertically moving operation of the operation lever; wherein a regulating member which moves according to the rotation of the tip of the arm piece is provided in the seat frame, whereby the regulating member enable to move by the laterally moving operation of the operation lever and the rotation control of the back frame is adjustable by moving the regulating member; and wherein the back frame is fixed to a back frame board, the back frame board is rotatably fitted to the seat frame at the forward end side thereof, a cushion block as the rocking resilient member for supporting the rear end side of the back frame board is assembled to the seat frame, an engaging pin is provided on the tip of the arm piece, a movable plate which is engaged with the engaging pin so as to enable to move forward and backward is provided on the upper face of the seat frame as the regulating member, a protruded part protruding upward is formed on the upper face of the movable plate which is the regulating member, a downwardly protruded part whose lower end positions at directly near the upper surface of the protruded part when the movable plate positions at the forward position or backward position is provided on the under surface of the back frame board.