Patent ID: 7513572

Claim:
A bracket angle adjustment mechanism comprising: a first bracket including an external-tooth gear; a second bracket including an internal-tooth gear which has a larger number of internal teeth than that of external teeth of the external-tooth gear; a pair of wedge members fitted in an eccentric space which is defined between a large-diameter hole formed in a central region of the external-tooth gear and a small-diameter shank constituting a central portion of the internal-tooth gear, in a state when the external-tooth gear and the internal-tooth gear are partly engaged with one another; a spring member applying a biasing force to each of the pair of wedge members in a wedging direction; and a wedged-state release member disposed between respective wedging-directional leading edges of the pair of wedge members, the wedged-state release member being operable, when rotated by a control shaft associated therewith, to move the pair of wedge members together with the spring member in a wedged-state release direction circularly in the eccentric space, whereby the small-diameter shank is eccentrically moved relative to the large-diameter hole to allow an engagement position of the internal-tooth gear relative to the external-tooth gear to be changed so as to adjust an angle of the second bracket relative to the first bracket, wherein each of the pair of wedge members has an inner surface and an outer surface each formed into an arc-shape capable of reducing shock to be given to the wedge; and wherein the arc-shaped outer surface of each of the wedge members is formed with a cutout portion, wherein the wedged-state release member is designed to be brought into contact with the cutout portion.