Patent Application
20090017950
The present invention relates to bicycles, and particularly to a flexible bicycle chain, wherein the chain provides a greater flexibility to the bicycle so that in normal driving or in speed change, the bicycle can be operated smoothly.
In basic bicycle structure, a chain of a bicycle is engaged with gears for transferring driving power to the wheel so as to drive the bicycle to move. Furthermore, currently, most bicycles have speed change devices which have a plurality of gears so as to provide different speed levels to the bicycles. However in driving, even in the period of speed change, the chain will bend. If the flexibility of the chain of the bicycle is too low, the movement of the bicycle will not smooth.
In one improvement structure, the chain of the bicycle has roller units and connecting pins. The connecting pin is received in a receiving space of the roller unit. The roller unit is connected to the outer chain plate and inner chain plate. The structures are repeated and are connected one by one so as to form as a chain of a bicycle. In the improved structure, the pin is formed with a nose portion or a flange so that the pin is not completely adhered to an inner surface of the roller unit. As a result, the chain is a great margin as the chain is bent.
However the structure provides a greater flexibility than the prior art structure, but it still has some defects. In change speed, the roller unit will shift so that gaps are formed between the connecting pin and the roller unit. The gaps will make the roller unit is not effectively engaged to the connecting pin. Thus the action of the chain is not some efficient as desired. Furthermore, the contact areas of the connecting pin and roller unit suffer from greater stresses so as to have greater friction forces. Thus, for a long time, the roller unit and connecting pin are worn and can not work normally.
Accordingly, the primary object of the present invention is to provide a flexible bicycle chain, wherein the chain provides a greater flexibility to the bicycle so that in normal driving or in speed change, the bicycle can be operated smoothly.
To achieve above objects, the present invention provides a flexible bicycle chain comprising a plurality of chain unit, each chain unit including: two inner chain plates; each inner chain plate having a shape like an “8”, thus each inner chain plate having two inner holes; two outer chain plates; each outer chain plate having a shape like an “8”, each outer chain plate having two outer holes; a size of each outer hole of the outer chain plate being smaller than that of each inner hole of each outer chain plate; a roller unit having a receiving space; a connecting pin received in the receiving space of the roller unit; the connecting pin being longer that the roller unit; and wherein each roller unit includes a middle annular groove, two inclined annular surfaces; the middle annular groove is at a middle section of the roller unit and has a concave cambered shape; the two inclined annular surfaces are at two ends of the middle annular groove; each inclined annular surface is inclined with a small opening at an end near the middle annular groove and a large opening at an end far away from the middle annular groove.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.
In order that those skilled in the art can further understand the present invention, a description will be provided in the following in details. However, these descriptions and the appended drawings are only used to cause those skilled in the art to understand the objects, features, and characteristics of the present invention, but not to be used to confine the scope and spirit of the present invention defined in the appended claims.
Referring to
Two inner chain plates 13 are included. Each inner chain plate 13 has a shape like an “8”. Thus, each inner chain plate 13 has two inner holes 131.
Two outer chain plates 14 are included. Each outer chain plate 14 has a shape like an “8”. Thus, each outer chain plate 14 has two outer holes 141. A size of each outer hole 141 of the outer chain plate 14 is smaller than that of each inner hole 131 of each outer chain plate 14.
A roller unit 12 has a receiving space 121. Two ends of the roller unit 12 are reduced to have a diameter smaller than other portion of the roller unit 12. The diameter of the reduced portions of the roller unit 12 is approximately equal to the size of the inner hole 131 of the inner chain plate 13.
A connecting pin 11 is received in the receiving space 121 of the roller unit 12. The connecting pin 11 is longer than the roller unit 12. Two ends of the connecting pin 11 are reduced to have a small diameter than other portion of the connecting pin 11. The diameter of the reduced portions of the roller unit 12 is approximately equal to that of the outer hole 141 of the outer chain plate 14.
Referring to
Referring to
Referring to
Referring to
The present invention is thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
