Abstract
A sprocket wheel for a bicycle is provided with a plurality of first teeth; a plurality of second teeth alternating with the first teeth; and a plurality of recesses on one side, each recess extending from one first tooth to the adjacent first tooth via the second tooth between the two first teeth.
Claims
1. A sprocket wheel for a bicycle, comprising: a plurality of first teeth; a plurality of second teeth alternating with the first teeth; and a plurality of recesses on one side, each recess extending from one first tooth to the adjacent first tooth via the second tooth between the two first teeth.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of a portion of a conventional bicycle sprocket wheel;
[0010] FIG. 2 is a top view showing the first and second teeth of the sprocket wheel engaging the inner and outer links of a chain respectively;
[0011] FIG. 3 is a perspective view of a bicycle sprocket wheel according to the invention taken from one side;
[0012] FIG. 4 is a top view of the sprocket wheel;
[0013] FIG. 5 is an exploded view of the first and second teeth of the sprocket wheel;
[0014] FIG. 6 is a side view showing two sprocket wheels mounted with a crank;
[0015] FIG. 7 is a top view showing the first and second teeth of the sprocket wheel engaging the inner and outer links of a chain respectively;
[0016] FIG. 8 is a top view of the sprocket wheel of another configuration;
[0017] FIG. 9 is an exploded view of the first and second teeth of the sprocket wheel of FIG. 8; and
[0018] FIG. 10 is a top view showing the first and second teeth of the sprocket wheel of FIG. 8 engaging the inner and outer links of the chain respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to FIGS. 3 to 7, a sprocket wheel 1 of the invention is mounted with a crank 3 of a bicycle. The sprocket wheel 1 comprises a plurality of first teeth 11, a plurality of second teeth 12 alternating with the first teeth 11, and a plurality of recesses 13 on one side, each recess 13 extending from one first tooth 11 to the adjacent first tooth 11 via the second tooth 12 between the two first teeth 11. A chain 2 comprises a plurality of inner links 21 engaging the first teeth 11, and a plurality of outer links 22 engaging the second teeth 12. It is envisaged by the invention that after a predetermined number of derailing operations of the sprocket wheels, wear of the sprocket wheels 1 is less than that of the conventional art.
[0020] Referring to FIGS. 8 to 10, another configuration of sprocket wheel is shown. The characteristic is that the teeth sequence is a first teeth 11, a second teeth 12 at one side, another first teeth 11, another second teeth 12 at the other side and so on.
[0021] While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims.
