Patent ID: 7445105

Claim:
A bicycle wheel hub assembly comprising: a wheel hub formed with a wheel hub shell disposed coaxially about a wheel mounting shaft, whereby said wheel hub shell is journaled for rotation about said wheel mounting shaft and a cylindrical annular hub cavity is defined therebetween, an annular power transmission sleeve disposed within said hub cavity and defining a cylindrical power transmission sleeve outer surface and a cylindrical power transmission sleeve inner surface that is eccentric relative to said power transmission sleeve outer surface, a sprocket having sprocket teeth projecting radially relative to a sprocket axis, with a central cylindrical wheel mounting shaft opening defined through said sprocket to receive said wheel mounting shaft coaxially therewithin, a drive sleeve projecting from said sprocket axially toward said hub and defining a cylindrical drive sleeve outer surface that is eccentric relative to said drive shaft opening, and said drive sleeve is disposed within said power transmission sleeve, and a drag mechanism mounted on said wheel mounting shaft to retard rotation of said power transmission sleeve relative to said drive sleeve, wherein said drive sleeve outer surface defines an outer drive sleeve cam lobe, and wherein said drive sleeve is provided with a backpedal safety stud at said drive sleeve outer surface, wherein said backpedal safety stud travels in a stud path of rotation about said wheel mounting shaft, and said power transmission sleeve outer surface defines a power transmission sleeve cam lobe, and said power transmission sleeve is provided with a backpedal catch tang that projects into said stud path of rotation, whereby rotation of said drive sleeve in one direction of rotation relative to said power transmission sleeve carries said stud away from said backpedal catch tang, thereby allowing said drag mechanism to operate to engage said drive sleeve, said power transmission sleeve, and said hub for rotation together when said power transmission sleeve cam lobe departs from diametric opposition relative to said drive sleeve cam lobe, and counterrotation of said drive sleeve brings said stud into abutment with said backpedal catch tang when a distance of separation exists between said power transmission sleeve outer surface and said hub.