| 摘要 |
<p>A needle mounted on a friction-free ruby bearing has its head resting on the yarn at a point before it enters the twisting spindle. The degree of twist imposed causes a pre-twisting effect on the yarn and as the needle rests in the groove of the twist, this is converted into an angular measurement by the needle on its pivot. The counterweight end of the needle affects the signal generated by two photo-electric cells, this signal being passed through a rheostat to correct the current to the motor driving the twisting spindle, to keep the degree of twist.</p> |
