| 摘要 |
<p>The derailleur gear for a bicycle has a gear changing mechanism with a jockey arm carrying a chain sprocket (3) which is swung inwards or outwards to change the chain from one drive sprocket to the other. This arm consists of three links (5, 6, 7) attached to each other by hinge pins (13, 15). The middle arm (6) also swings about a central pivot pin (14). The two outer arms (5, 7) are each slotted at their outer ends, to fit over corresponding hinge pins (12, 16) attached to a sheet member (8) which acts as a support and also a protective casing. The whole is attached to a support bracket (17).</p> |
