The present invention relates to bicycled, and more particularly to an effort-saving bicycle using extended links connected cranks of a conventional bicycle so as to allow effort-saving bicycling.
Since the invention of bicycles, the improvements have been focused on derailleurs but not pedaling efficiency due to the limitation of cranks' structural length. Hence, there is a need to improve pedaling efficiency and allow more effort-saving bicycling.
For breaking through the structural limitation of existing bicycles, the present invention provides an effort-saving bicycle. It moves the transmission gear from below the feet as arranged traditionally to the upper rear of the rear wheel, and uses an extended link that has one end connect to a crank and an opposite end provide with a pedal. When a force exerted through the pedal, the link acts as a lever, so as to allow effort-saving bicycling based on the level rule.
According to the present invention, the bicycle comprises a wheel. The wheel is centrality provided with a shaft gear at its rim. The shaft gear is connected to a chain. The chain is connected to a transmission gear. The transmission gear has a shaft connected to one end of a first crank. The first crank has an opposite end acting as a first crank joint. The first crank joint is connected to one end of a link at the link's inner side. The link has its opposite end provided with a pedal. The first crank joint of the link has its outer side connected to one end of a second crank through a second crank joint. The second crank has an opposite end connected to a second crank-frame joint, and the second crank-frame joint is connected to a frame. The frame has a roughly U-like shape and flanks two sides of the wheel. The link, the first crank, the second crank, and the pedal form a set and each of two sides of the wheel is provided with one side set. The transmission gear is located at one side and the upper rear of the wheel.
The present invention provides the following advantages:
In the present invention, the specially located transmission gear working with the extended link that connects two cranks allows effort-saving bicycling based on the lever rule.
Referring to
With the configuration described above, the link 2 shifts parallelly. When the pedal 6 at the opposite end of the link 2 is pedaled downward, the second crank-frame joint 13 acts as a fulcrum and an action based on the lever rule is activated to rotate the transmission gear 1 and then drive the chain 7 to roll the wheel 8 forward, thereby realizing effort-saving bicycling.