Patent ID: 7232186

Claim:
A depth-adjustable device for a chair being located between a chair body and a chair foot, comprising: a rail base, a supporting board, several clipping blocks and a locating pin, wherein: the rail base is provided with several railways, and in the bottom of each railway is formed a V-shaped concave, a locating block and a blocking rod are fixed on both ends of each railway, respectively, and a long through hole is defined in a side of one railway, and a rack is disposed beside the long through hole; each side of the supporting board is disposed with clipping blocks that are slid into the railways of the rail base respectively, and the clipping blocks are formed with V-shaped convexes for mating with the V-shaped concaves, and a rack is formed in the supporting board corresponding to the side of the long through hole, and formed on two sides of a tooth groove of the rack are inward inclined surfaces; and the locating pin is mounted on the rack of the rail base together with a spring, and a handle is formed on the outer end of the locating pin, and on the other end is formed with a protruded button that is inserted into the long through hole, and the protruded button end is positioned in the tooth groove of the supporting board corresponding to an inward inclined surface, and the protruded button end is formed with an inward inclined surface for mating with the inward inclined surfaces at both sides of the tooth groove.