Patent ID: 7766143
Filing Date: 2010-08-03
Classification: B60B

Abstract:
1. A rear hub for a bicycle, comprising: a mandrel having a first end provided with a primary mounting portion which has a primary threaded section and a second end provided with a secondary mounting portion which has a diameter smaller than that of the primary mounting portion and has a secondary threaded section; a hub body rotatably mounted on the mandrel; a first locking nut screwed onto the primary threaded section of the primary mounting portion of the mandrel and rested on a first end of the hub body; a freewheel rotatably mounted on the secondary mounting portion of the mandrel and having a first end combined with a second end of the hub body to rotate the hub body; an auxiliary threaded post screwed onto the secondary threaded section of the secondary mounting portion of the mandrel to limit a second end of the freewheel and having an outer diameter equal to that of the primary mounting portion of the mandrel; a second locking nut screwed onto the auxiliary threaded post; wherein the auxiliary threaded post has an end portion formed as one piece with an enlarged limit flange to stop the second locking nut; the limit flange of the auxiliary threaded post has a side formed with a protruding resting edge directed toward the freewheel to limit the second end of the freewheel; the second end of the freewheel is provided with a driven gear; the hub body is located between the primary mounting portion and the secondary mounting portion of the mandrel; the hub body has an inside formed with a shaft hole to allow passage of the mandrel; the second end of the hub body is formed with a plurality of ratchet teeth; the first end of the freewheel is provided with a oneway ratchet wheel meshing with the ratchet teeth of the hub body to rotate the hub body in a oneway direction only.