Patent ID: 7308841

Claim:
A speed adjustor device comprising: an input shaft to receive a first rotational velocity input in a first direction; a housing to receive a second rotational velocity input in a second direction, wherein the housing houses the input shaft and rotates relative to the input shaft; a first sprocket coupled to the input shaft proximate a first end of the housing to provide the first rotational velocity, the first sprocket defining an aperture disposed generally around the input shaft; and a second sprocket spaced apart from the first sprocket and coupled proximate the first end of the housing such that the second sprocket is generally disposed between the first sprocket and a middle portion of the housing, the second sprocket to provide the second rotational velocity input, and the second sprocket having substantially the same circumference as the first sprocket; an output shaft coupled to the input shaft and a second end of the housing to provide an output rotational velocity; the first sprocket and the second sprocket located on a coffesponding side of the housing opposing the output shaft such that the first and second sprocket are co-located proximate the input shaft and the second sprocket being spaced apart from the middle portion of the housing; and a first supporting base and a second supporting base being spaced apart from and situated at opposing ends of the housing, the first and second sprockets being disposed between the first supporting base and an end of the housing, and the first supporting base and the second supporting based disposed such that the rotational axes of the input shaft and the output shaft are substantially co-planar.