Eccentric Bottom Bracket Assembly
AssigneeTrek Bicycle Corporation
InventorsTravis BRAUN, Andrew KRAUTBAUER, Michael LEIGHTON
Life of this patent
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Abstract
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.
Claims20
An eccentric bottom bracket assembly for use with a bicycle frame, comprising:
- a cylindrical insert having an off-centered opening adapted to receive a shaft connected to a pair of cranks of a bicycle crankset;
- and
- a worm gear arrangement operatively engaged with the cylindrical insert to rotate the cylindrical insert.
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;
- 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.
A method of adjusting tension of a flexible drive member of a bicycle drive train, comprising:
- rotating a worm that is engaged with a worm wheel to manipulate a position of an axis of rotation of a crankset relative to a bicycle frame.
Dependencies are inferred from the claim text.