Patent ID: 7264312
Filing Date: 2007-09-04
Classification: A47C

Abstract:
1. A backrest adjusting mechanism, comprising: a main support being a hollow tubular member having a first end connected to a lower end of a backrest bracket mounted to a backrest of a chair; said main support being provided at a middle section on a lower surface thereof with a downward projected limiting element, and at the middle section on an upper surface thereof with an elastically upward protruded locating element; a sleeve member having a first end enclosing said main support and a second end opposite to the first end angularly extended to engage with two lateral sides of a seat bracket mounted below a seat of the chair; said sleeve member being provided at a lower surface of said first end with a lengthwise guide slot for said limiting element to upward extend thereinto to thereby guide said main support and said sleeve member to slide relative to one another; said sleeve member also being provided on an upper surface with a row of lengthwise arranged open-bottom locating recesses, so that said locating element protruded from the upper surface of said main support may elastically slide into one of said locating recesses to hold said main support in place in said sleeve member at an extended or a retracted position relative to said sleeve member; and a locating gear including a shaft having an outer end connected to a turning handle, and an inner end transversely extended through a middle section of said sleeve member; and at least one brake element mounted on a middle section of said shaft; and said brake element being provided at one side with a radially projected press lug; whereby when said shaft is turned via said turning handle, said press lug of said brake element is driven to firmly press against at least one lengthwise edge of said main support to firmly hold said main support in place at said extended or retracted position relative to said sleeve member.