BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a perspective view of a hub assembly in accordance with the preferred embodiment of the present invention.
FIG. 2 is an exploded perspective view of the hub assembly as shown in FIG. 1.
FIG. 3 is a top view of the hub assembly for a bicycle as shown in FIG. 1.
FIG. 4 is a locally cross-sectional enlarged view of the hub assembly for a bicycle as shown in FIG. 3.
FIG. 5 is an exploded perspective assembly view of a hub assembly in accordance with another preferred embodiment of the present invention.
FIG. 6 is an exploded perspective assembly view of a hub assembly in accordance with another preferred embodiment of the present invention.
FIG. 7 is a perspective view of a conventional hub assembly in accordance with the prior art.
FIG. 8 is an exploded perspective view of the conventional hub assembly as shown in FIG. 7.
FIG. 9 is a top view of the conventional hub assembly for a bicycle as shown in FIG. 7.
FIG. 10 is a locally cross-sectional enlarged view of conventional the hub assembly for a bicycle as shown in FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings and initially to FIGS. 1 and 2, a hub assembly for a bicycle in accordance with the preferred embodiment of the present invention comprises a hub body 10 having a side provided with a mounting portion 11, a freewheel 20 slidably mounted on the mounting portion 11 of the hub body 10, and at least one retainer 30 mounted on the mounting portion 11 of the hub body 10 and rested on the freewheel 20 to retain the freewheel 20 on the mounting portion 11 of the hub body 10 to prevent the freewheel 20 from being detached from the mounting portion 11 of the hub body 10.
In the preferred embodiment of the present invention, the mounting portion 11 of the hub body 10 has a peripheral wall formed with a plurality of positioning grooves 13 which are equally spaced from each other. Each of the positioning grooves 13 is extended in the axial direction of the mounting portion 11 of the hub body 10 and through a whole length of the mounting portion 11 of the hub body 10. The mounting portion 11 of the hub body 10 has a distal end formed with at least one annular retaining groove 12 connected to the positioning grooves 13.
The freewheel 20 is slidable on the mounting portion 11 of the hub body 10 to translate along an axial direction of the mounting portion 11 of the hub body 10. The freewheel 20 has an inner wall formed with a plurality of radially and inwardly extending positioning ribs 22 each inserted into and positioned in a respective positioning groove 13 of the hub body 10 and an outer wall formed with a plurality of driven teeth 23. The positioning ribs 22 of the freewheel 20 are equally spaced from each other to correspond to the positioning grooves 13 of the hub body 10. Each of the positioning ribs 22 of the freewheel 20 is extended in an axial direction of the freewheel 20 and through a whole length of the inner wall of the freewheel 20. Each of the positioning ribs 22 of the freewheel 20 is slidable in a respective positioning groove 13 of the hub body 10. The inner wall of the freewheel 20 is formed with a mounting hole 21 mounted on the mounting portion 11 of the hub body 10.
The retainer 30 is preferably a substantially C-shaped snap ring. The retainer 30 is retained in the retaining groove 12 of the hub body 10.
In assembly, referring to FIG. 3, the hub assembly is mounted on a bicycle which comprises a bottom bracket axle 51, a crank 50, a chainwheel 52, a chain 40, a chain stay 53 and a wheel 54. The hub body 10 is rotatably mounted on the chain stay 53, the wheel 54 is mounted on the hub body 10, the chainwheel 52 is mounted on the bottom bracket axle 51, the crank 50 is mounted on the bottom bracket axle 51 to rotate the chainwheel 52, and the chain 40 intermeshes with the chainwheel 52 and the driven teeth 23 of the freewheel 20.
In operation, referring to FIGS. 1-3, when the crank 50 is rotated on the bottom bracket axle 51, the chainwheel 52 is rotated to drive the chain 40 which rotates the freewheel 20. At this time, the positioning ribs 22 of the freewheel 20 are positioned in the positioning grooves 13 of the hub body 10, so that the hub body 10 is rotated by the freewheel 20 to rotate the wheel 54 so as to move the bicycle forward.
In addition, the hub body 10 has an inside containing a oneway ratchet wheel (not shown) and a bearing (not shown). Thus, when the freewheel 20 stops rotating (when the crank 50 stops rotating) or when the rotation speed of the wheel 54 is greater than that of the freewheel 20 (when the bicycle is moved on the downward slope), the rotation speed of the ratchet wheel is greater than that of the freewheel 20, so that the ratchet wheel is rotatable relative to the freewheel 20 to rotate the hub body 10 and the wheel 54 so as to move the bicycle forward successively by the clutch action of the ratchet wheel. Thus, the ratchet wheel is rotatable relative to the freewheel 20 and is not rotated by the freewheel 20 so that the freewheel 20 performs an idling rotation. Thus, the ratchet wheel and the hub body 10 are not rotated by the freewheel 20 and will not interfere with rotation of the freewheel 20 and the crank 50. When the rotation speed of the freewheel 20 is greater than that of the wheel, the ratchet wheel and the hub body 10 are rotated by the freewheel 20 again.
As shown in FIGS. 3 and 4, when the bicycle is provided with a bottom bracket axle 51 having different sizes and specification due to necessity of racing or performance, the position of the chainwheel 52 is changed to correspond to different positions of the bottom bracket axle 51 and the crank 50. At this time, the freewheel 20 is slidable on the mounting portion 11 of the hub body 10 as shown in FIG. 4 to change the position of the freewheel 20 relative to the chainwheel 52, so that the freewheel 20 is in line with the chainwheel 52, and the chain 40 is perpendicular to the hub body 10 constantly without incurring deflection. In addition, the freewheel 20 is tensioned by the chain 40 and the chainwheel 52 after adjustment of the position of the freewheel 20, so that the freewheel 20 cannot translate freely on the mounting portion 11 of the hub body 10, so that the hub body 10 is operated at the horizontal state.
Accordingly, the freewheel 20 is slidable on the mounting portion 11 of the hub body 10 to change the position of the freewheel 20 relative to the chainwheel 52, so that the freewheel 20 is in line with the chainwheel 52, and the chain 40 is perpendicular to the hub body 10 constantly without incurring deflection. In addition, the chain 40 is perpendicular to the hub body 10 constantly without incurring deflection, so that the force applied by the chain 40 on the hub body 10 is distributed evenly and smoothly, thereby facilitating the normal operation of the hub body 10, and thereby enhancing the lifetime of the hub body 10.
As shown in FIG. 5, the hub assembly comprises two retainers 30 mounted on the mounting portion 11 of the hub body 10, and the freewheel 20 is located between the two retainers 30 to prevent the freewheel 20 from being detached from the mounting portion 11 of the hub body 10. The mounting portion 11 of the hub body 10 is formed with a plurality of annular retaining grooves 12 which are equally spaced from each other and connected to the positioning grooves 13, and each of the two retainers 30 is retained in a respective retaining groove 12 of the hub body 10.
As shown in FIG. 6, the freewheel 20 has an inner wall formed with a plurality of positioning grooves 24 which are equally spaced from each other. Each of the positioning grooves 24 is extended in an axial direction of the freewheel 20 and through a whole length of the inner wall of the freewheel 20. The mounting portion 11 of the hub body 10 has a peripheral wall formed with a plurality of radially and outwardly extending positioning ribs 14 each inserted into and positioned in a respective positioning groove 24 of the freewheel 20. The positioning ribs 14 of the hub body 10 are equally spaced from each other to correspond to the positioning grooves 24 of the freewheel 20. Each of the positioning ribs 14 of the hub body 10 is extended in an axial direction of the mounting portion 11 of the hub body 10 and through a whole length of the mounting portion 11 of the hub body 10. Each of the positioning ribs 14 of the hub body 10 is slidable in a respective positioning groove 24 of the freewheel 20 when the freewheel 20 is slidable on the mounting portion 11 of the hub body 10.
Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.
Patent Application
20070254758
