Patent ID: 8789673

Claim:
A hub assembly comprising: a hub having a first hole defined in one end thereof and an axle extending through the first hole, a first fixing portion defined in an inner periphery of the first hole and the first fixing portion being parallel to an axis of the hub; a tubular portion having a second hole in one end thereof and a slot defined in an inner periphery of the second hole, the slot being parallel to an axis of the tubular portion; an annular driving member having multiple teeth defined in an outer periphery thereof, the teeth located corresponding to the slot, the driving member having a cone-shaped first ratchet portion formed axially thereon, the cone-shaped first ratchet portion having a plurality of first and second triangular contact surfaces disposed in a conical arrangement about the axis of the tubular portion, the first and second triangular contact surfaces having different areas, the teeth of the driving member engaged with the slot to maintain the driving member movable linearly in the slot; an annular passive member having a second fixing portion located corresponding to the first fixing portion, the passive member having a cone-shaped second ratchet portion formed axially thereon, the second ratchet portion defining a plurality of contact surfaces disposed in a complementary conical arrangement about the axis of the hub to conically engage the first ratchet portion in radially opposed manner, the second fixing portion being fixed to the first fixing portion, and a returning member located between the tubular portion and the driving member.