Patent ID: 8672085

Claim:
A variable ratio transmission mechanism adapted for use in an automobile steering system, the automobile steering system including coaxially-disposed first and second steering shafts that extend along a first direction, said variable ratio transmission mechanism comprising: a securing unit connected co-rotatably to the first steering shaft about a first axis that extends in the first direction; a connecting unit connected co-rotatably to the second steering shaft about the first axis; a motor including a main body that is connected to one of said securing unit and said connecting unit and that is co-rotatable with the one of said securing unit and said connecting unit about the first axis, and a revolving shaft that extends along a second axis extending in a second direction different from the first direction and that is revolvable relative to said main body; and a transmitting unit including a first transmitting component that is provided on the other one of said securing unit and said connecting unit, and a second transmitting component that is provided on said revolving shaft of said motor and that meshes with said first transmitting component; wherein, when the first steering shaft rotates about the first axis by a selected rotational angle without a revolving movement of said revolving shaft, said first and second transmitting components are angularly positioned relative to each other, and the second steering shaft is rotated about the first axis by the selected rotational angle; wherein, when the first steering shaft rotates about the first axis by a selected rotational angle with the revolving movement of said revolving shaft about the second axis, the second steering shaft is rotated about the first axis by a different rotational angle; wherein said main body of said motor is connected co-rotatably to said securing unit, and said first transmitting component is provided on said connecting unit; and wherein said second transmitting component is configured as a worm, said first transmitting component being configured as a worm gear.