Eccentric bottom bracket assembly

摘要

A bottom bracket assembly of a bicycle that cooperates in an eccentric or off-center manner with a bottom bracket shell of a bicycle frame. The eccentric bottom bracket assembly has a cylindrical insert with an off-centered opening for receiving a spindle that connects to cranks of the crankset. Rotating the cylindrical insert repositions the off-centered opening relative to at least the longitudinal direction of the bicycle and thus can be used to adjust the tension in the flexible drive member of the bicycle. A worm gear arrangement provides controlled manipulation of the position of the insert relative to the bicycle frame.

主权项

1. A drive system for a bicycle, comprising:
a crankset that includes a set of pedals; a first sprocket connected to the crankset and rotatable with revolution of the set of pedals; a second sprocket adapted to drive a wheel of the bicycle; a flexible drive member extending between the first and the second sprockets; an eccentric bottom bracket assembly that is engaged with the crankset, the eccentric bottom bracket assembly including an outer shell having an inner surface and defining an opening; a worm wheel positioned in the opening and connected to the eccentric bottom bracket assembly, wherein the crankset is offset from a center of the worm wheel; and a worm engaged with the worm wheel such that rotation of the worm manipulates a position of the crankset relative to the outer shell thereby adjusting tension in the flexible drive member; wherein the worm wheel includes a removable curvilinear track that is fastened to the circumference of the worm wheel, the worm wheel includes a cylindrical body having an outer surface with a groove formed therein; the track lies in the groove that is engaged with the worm; and the track comprises a plurality of notches formed radially through the track.