| 摘要 |
PURPOSE: A double coupling multi-speed bicycle is provided to enable low speed pedaling and high speed traveling by increasing the rear wheel number of rotation through the combination of speed-changing stages of 2×7×2×1. CONSTITUTION: A double coupling multi-speed bicycle is configured as follows. A second-stage drive sprocket of a pedal crank shaft(24) and one of multi-stage sprockets(8) for a shift function(B1-B7) are connected with a chain(16). One of the multi-stage sprockets for a transmitting function(C1) and a first-shift sprocket(42) of a cylindrical differential shaft(23) are connected with a chain(15). A semicircular division sprocket of plate shape is assembled to a second-stage sprocket of the cylindrical differential shaft and a flange type freewheel(9), and a single free sprocket(10) attached to a hub(27) of a rear wheel is connected thereto with a chain(14). A transmission(13) is connected through a "-" shaped cable to a gearshift. A second-stage drive sprocket transmission(11) of the pedal crank shaft and a second-stage sprocket transmission(12) of the cylindrical differential shaft are respectively to both upper ends of a "Y" shaped cable whose bottom is connected to the gearshift in order to link the transmissions. |
