Patent Application
20180167701
The present invention relates generally to power detection of bicycles, and more particularly to a power detection device for bicycles.
With the prevalence of leisure activities of cycling, bicycles have become a tool for leisure sports and not simply a transportation tool anymore. Therefore, a wide variety of bicycle accessories is developed in response to the trend. In order to understand the performance of cycling, bicycle computers are commonly mounted on bicycles to serve as the basis of the training. More advanced users may also install a power meter on their bicycles to check the pedaling strength at any moment or the overall riding condition.
The strain gauge of a conventional power meter is applied to an existing component of a bicycle, (e.g., mounting the strain gauge on the crank). However, the external power meter makes the appearance of the bicycle look more complicated. Furthermore, the strain gauge may be partially disengaged from the component of the bicycle (the crank, for example), and therefore cannot stably detect the deformation of the engaged component. As a result, the detection result of the strain gauge may be not accurate, so as to affect the power represented by the power meter.
In view of the above, the primary objective of the present invention is to provide a power detection device, of which the strain gauge could be secured and hidden.
The present invention provides a power detection device for a bicycle, wherein the power detection device is engaged with a rear hub of the bicycle. The power detection device includes at least one sprocket, a sprocket base, a strain gauge, a signal processing circuit, and a wireless signal transmitting circuit. Each of the at least one sprocket has a plurality of connection arms. The sprocket base is engaged with the sprocket to at least partially cover the connection arms. The strain gauge is embedded in the sprocket base. The signal processing circuit is electrically connected to the strain gauge, wherein the signal processing circuit is adapted to output an electrical signal according to an amount of deformation of the strain gauge. The wireless signal transmitting circuit is electrically connected to the signal processing circuit, wherein the wireless signal transmitting circuit receives the electrical signal outputted by the signal processing circuit, converts the received electrical signal into a wireless signal, and then sends out the wireless signal.
By using the strain gauge embedded in the sprocket base, the amount of deformation of the sprocket base could be accurately detected, so that the detected power would be more accurate. In addition, the strain gauge could be prevented from falling off from the sprocket base, and could be hidden therein. In other words, the user would not see the strain gauge from outside.
The present invention will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which
As shown in
The at least one sprocket 10 includes more than one sprocket 10 in the first embodiment, which are a first sprocket 102 and a second sprocket 104. The first sprocket 102 and the second sprocket 104 each has a plurality of connection arms 102a, 104a in an inner ring thereof. An outer diameter of the first sprocket 102 is greater than an outer diameter of the second sprocket 104, and the first sprocket 102 has more teeth than the second sprocket 104. In practice, the number of the at least one sprocket 10 could be more than two.
The sprocket base 12 is coupled to the first sprocket 102 and the second sprocket 104, wherein at least a portion of the connection arms 102a, 104a or the first sprocket 102 and the second sprocket 104 are coated by the sprocket base 12. An assembly hole 122 is provided at a center of the sprocket base 12, wherein the assembly hole 122 is adapted to fit around the sleeve. In the first embodiment, the sprocket base 12 is formed by placing the connected first sprocket 102 and second sprocket 104 in a mold (not shown), and injecting a plastic material (e.g., fiber-reinforced plastic) into the mold.
In addition, in the first embodiment, the detection modules 14 are placed in the mold together during the forming operation of the sprocket base 12, and are located at positions corresponding to the connection arms 102a, 104a. After that, the detection modules 14 are coated by the injected plastic, and therefore are embedded in the sprocket base 12 near the connection arms 102a, 104a. However, it must be noted that, since the detection modules 14 all have the same structure, one of the detection modules 14 is taken as an example in the following paragraphs.
Said detection module 14 includes a circuit board 16, a strain gauge 18 disposed on the circuit board 16, a signal processing circuit 20, a wireless signal transmitting circuit 22, and a power supply which is a battery 24 as an example, wherein the strain gauge 18 deforms along with the force exerted on the sprocket base 12. The signal processing circuit 20 is electrically connected to the strain gauge 18 and the wireless signal transmitting circuit 22, wherein the signal processing circuit 20 outputs an electrical signal according to an amount of deformation of the strain gauge 18. The wireless signal transmitting circuit 22 receives the electrical signal outputted by the signal processing circuit 20, converts it into a wireless signal, and then transmits the wireless signal to a receiving module 28 which is located outside. In this way, a display 282 of the receiving module 28 could correspondingly display the power detected by the strain gauge 18 for user's reference. The battery 24 is electrically connected to the signal processing circuit 20 and the wireless signal transmitting circuit 22, wherein the battery 24 is used to provide the required power to the signal processing circuit 20 and the wireless signal transmitting circuit 22.
Since the strain gauge 18, the signal processing circuit 20, the wireless signal transmitting circuit 22, and the battery 24 are firmly embedded in the sprocket base 12, the components in each of the detection modules 14 could be prevented from falling off while a rider is riding the bicycle. In addition, the strain gauge 18 is securely covered by the sprocket base 12, and therefore the strain gauge 18 could be deformed precisely in response to the force exerted on the sprocket base 12, whereby to get more accurate results for power detection.
A detection module 30 of a power detection device of a second embodiment of the present invention is illustrated in
A detection module 36 of a power detection device of a third embodiment of the present invention is illustrated in
A detection module 42 of a power detection device of a fourth embodiment of the present invention is illustrated in
In each of the aforementioned first to fourth embodiments, the detection module is hidden in the sprocket base. Therefore, the detection module could be effectively fixed, and would be not visible from outside.
A detection module 50 of a power detection device of a fifth embodiment of the present invention is illustrated in
A detection module 64 of a power detection device of a sixth embodiment of the present invention is illustrated in
A detection module 80 of a power detection device of a seventh embodiment of the present invention is illustrated in
With the aforementioned design that the strain gauge is embedded in a sprocket base, the strain gauge would be precisely deformed according to the force exerted on the sprocket base, whereby the detected power would be more accurate. Furthermore, the strain gauge could be effectively prevented from falling off from the sprocket base, and could be hidden therein, so that the strain gauge would not be visible from outside.
It must be pointed out that the embodiments described above are only some preferred embodiments of the present invention. All equivalent structures which employ the concepts disclosed in this specification and the appended claims should fall within the scope of the present invention.
