| 摘要 |
PURPOSE: A drive unit of a bicycle is provided to reduce manufacturing and maintenance costs by simplifying the structure and reducing the weight of the unit. CONSTITUTION: A drive unit of a bicycle comprises a pair of freewheel sprockets(12,12'), a pair of drive bars(26,26') and a spring fixing bracket(38). A pair of freewheel sprockets are independently installed on both sides of the rear wheel spindle of the bicycle. A pair of drive bars is located on corresponding ends of pedals(14,14'). Chain fixing pins(16,16') are located on the corresponding rear ends of the drive bars. A pair of drive bars is fixed on the middle of drive bar support brackets(24,24') which enable rotation. Extension springs(32,32') are fixed on the both ends of the spring fixing bracket. |
