BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a bicycle, and more particularly to a bicycle with an auxiliary power system to help rider cycling.
2. Description of the Related Art
In early days, bicycles were just an economic vehicle for workers and students, until motorcycles and automobiles gradually replaced bicycles and became the main transportation. Recently, the world has a lack of energy supply, and cycling has an advantage of helping to reduce the production of carbon dioxide. Now bicycles are a popular transportation in many cities.
As a transportation tool to school or work, bicycles should help riders to arrive at the destinations in a faster and easier way. For reaching this goal, bicycles are equipped with a transmission system with which riders may shift to a low gear when riding from a stop point or riding uphill; and shift to a high gear when riding downhill. When bicycle is switched to lower gear, rider exerts the bicycle with less strength but the bicycle goes slowly. On the contrary, when bicycle is switched to high gear, it may speed up the bicycle but rider has to exert the bicycle with greater strength.
Years ago, a power bike, which is equipped with a battery and a motor, was presented in the market. Such bike may function like a normal bike, driven by the rider, but the battery and motor may also take over and drive the bike moving when necessary. Such power bike in the market is huge and heavy because of the battery and motor, and when the battery is out, rider has to exert the bike with much greater strength than an ordinary bike.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to provide a bicycle with an auxiliary power for driving the bicycle moving at specific moments.
According to the objective of the present invention, a bicycle is equipped with an auxiliary power system, which includes a base fixed to a frame of the bicycle, a power storage device connected to the base, and a ratchet device connecting the power storage device and a main transmission system of the bicycle. When paddles of the bicycle are turned in a forward direction, it may drive the bicycle moving forward but not the power storage device through the ratchet device. When the paddles are turned in a rearward direction, it may drive the power storage device through the ratchet device to store power in the power storage device. The power stored in the power storage device can be released by the biker when necessary to drive the bicycle moving forward through the ratchet device and the main transmission system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a first preferred embodiment of the present invention;
FIG. 2 is an exploded view of the auxiliary power system of the first preferred embodiment of the present invention;
FIG. 3 is a perspective view of the auxiliary power system of the first preferred embodiment of the present invention;
FIG. 4 is a front view of the auxiliary power system of the first preferred embodiment of the present invention;
FIG. 5 is a sectional view of the auxiliary power system of the first preferred embodiment of the present invention;
FIG. 6 is a sketch diagram, showing that gear disc is not driven by the paw when the front sprocket is turned in the forward direction;
FIG. 7 is a sketch diagram, showing that gear disc is driven by the paw when the front sprocket is turned in the rearward direction;
FIG. 8 is a sketch diagram, showing that the front sprocket is driven by the paw when the gear disc is turned in the rearward direction;
FIG. 9 is a front view of a second preferred embodiment of the present invention; and
FIG. 10 is a perspective view of the auxiliary power system of the second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the present invention provides a normal bicycle mounted with an auxiliary power system. The bicycle includes a frame 10, two wheels 12, 14 pivotally mounted on the frame 10, and a main transmission system. The main transmission system includes a pair of cranks 16 with paddles 18, a crank axle 20 connecting the cranks 16, a front sprocket 22 connected to the crank axle 20, a rear hub 26 connected to the rear wheel 14, a rear sprocket 24 connected to the rear hub 26, and a chain 28 connecting the front sprocket 22 and the rear sprocket 24. The front sprocket 22 and the rear sprocket 24 may be cassettes, and a derailleur (not shown) may be provided to shift the chain 28. Above elements are the same as a normal bicycle so we do not describe the details here.
In the first preferred embodiment of the present invention, we provide the auxiliary power system mounted on the crank axle 20 behind the front sprocket 22. As shown in FIG. 2 to FIG. 5, the auxiliary power system includes a base 30, a gear disc 32, a power storage device 34, a paw 36, and a release controller 38. The base 30 is a disc fixed to the frame 10. The base 30 has an opening at center for the crank axle 20 to pass through. A bearing 40, which is a sleeve bearing, is mounted in the opening of the base 10 that the crank axle 20 is free for rotation relative to the base 30. Bearings 41 are mounted on the crank axle 20 to mount the crank axle 20 on the frame 10. The base 30 has a protrusion 42, which has two gaps 44 thereon. The base 30 is provided with several bores 46 to fix the base 30 on different frames. The gear disc 32 is a ring, which means it has an opening at a center. The gear disc 32 has several recesses 47 on a sidewall of the opening and teeth 48 on a circumference. The gear disc 32 is provided with three rollers 50, each of which has two plates 52 at opposite ends. Diameters of the plates 52 are greater than the roller 50 and a distance between the plates 52 is slightly greater than a thickness of the base 30 that the rollers 50 are engaged with a circumference of the base 30 to connect the gear disc 32 to the base 30 and allow the gear disc 32 rotating relative to the base 30. The power storage device 34 is a spring with opposite ends inserted into the gap 44 of the base 30 and the recess 47 of the gear disc 32. The paw 36 is pivoted on the front sprocket 22, and a spring 54 is provided to urge the paw 36 that the paw 36 is normally engaged with the teeth 48 of the gear disc 32. The paw 36 works as a ratchet device between the front sprocket 22 and the gear disc 32. As shown in FIG. 6, while the front sprocket 22 is turning in a forward direction, which is counterclockwise shown in FIG. 6, such turning may drive the bicycle moving forward, but not the gear disc 32. On the contrary, while the front sprocket 22 is turning in a rearward direction, which is clockwise shown in FIG. 7, the gear disc 32 is driven by the front sprocket 22. While the gear disc 32 is driven by the power storage device 34 for rotation in the forward direction, which is clockwise shown in FIG. 8, the front sprocket 22 will be driven for rotation. The release controller 38 has a frame 56 fixed to the base 30, a paw 58 pivoted on the frame 56, a spring 60 urging the paw 58 and making it normally engaged with the teeth 48 of the gear disc 32, and a cord 62 with an end connected to the paw 58 and the other end connected to a controller (not shown). Rider may operate the controller to disengage the paw 58 with the gear disc 32. While the paw 58 is engaged with the gear disc 32, the gear disc 32 is restricted to rotation in the rearward direction, not forward direction. A thickness of the paw 58 is about a half of the gear disc 32, so as the paw 36, that both of the paws 36 and 58 may be engaged with half of the teeth 48 of the gear disc 32 without interference.
When a rider rides the bicycle of the present invention and steps on the paddles 18 in a forward rotation, the bicycle of the present invention, like a normal bicycle, will moving forward, and the gear disc 32 will not be driven because of the paw 36. When the rider steps on the paddles 18 in a rearward rotation, the front sprocket 22 is turned in the rearward direction to drive the gear disc 32 for rotating in the rearward direction via the paw 36, which will wind up the spring 34. After that, the paw 58 of the release controller 38 will stop the gear disc 32 when the rider stops stepping or steps forward, and when the paw 58 is disengaged with the gear disc 32, the spring 34 will turn the gear disc 32 in the forward direction that the gear disc 32 may drive the front sprocket 22 via the paw 36 to provide extra power for moving the bicycle forward. After the power stored in the spring 34 is run out, rider may step the paddles 18 reversely again to store power in the spring 34 and release it by rider's control when necessary.
In cycling, rider has no need to step the bicycle when riding downhill or in high speed. On the contrary, rider has to step with more strength when cycling uphill or from a stop point. In riding the bicycle of the present invention, the rider may step the paddles reversely to store energy in the auxiliary power system, and then, rider may release it by operating the release controller when cycling uphill or from a stop point to give the bicycle extra power for moving forward. The auxiliary power system of the present invention gives extra power that may help rider to ride the bicycle more easily. The auxiliary power system of the present invention may be mounted on any kind of bicycles. In practice, rider may just take the original crank set off, and mount the auxiliary power system of the present invention that the auxiliary power system may work in the bicycle.
FIG. 9 and FIG. 10 show a second preferred embodiment of the present invention, in which an auxiliary power system is mounted on the rear hub 26. The auxiliary power system mounted on the rear hub 26 has the same structure as the first preferred embodiment, including a base 70 fixed to a rear fork of the frame 10 behind the rear sprocket 24, a gear disc 72 is pivotally mounted on the base 70 via several rollers 74, a spring 76 with opposite ends connected to the base 70 and the gear disc 72, a paw 78 mounted on an inner side of the rear sprocket 24, normally engaged with the gear disc 72, and a release controller 80 mounted on the base 70, normally engaged with the gear disc 72.
The function and operation of the auxiliary power system mounted on the rear hub 26 are the same as the auxiliary power system mounted on the crank axle 20. When rider steps the paddles 18 for driving the bicycle forward, it will drive the rear wheel 14 turning through the front sprocket 22, chain 28, and the rear sprocket 24, the same as a normal bicycle. When the rider steps the paddles 18 reversely, it will turn the rear sprocket 24 reversely to drive the gear disc 72 reversely turning through the paw 78 that the spring 76 is wound up to store power. When the rider operates the release controller to disengage a paw with the gear disc 72, the spring may drive the rear sprocket 24 turning via the paw 78 to give the bicycle extra power for moving forward.