| 摘要 |
<p>This invention concerns an improved device for controlling the feeding of an elastic tape in sewing machines. It includes a tensioning roller (4) and a first pressing means (7) having inserted therebetween a tape (8) pulled by the sewing machine forwarding means (3), said roller (4) being connected to the shaft (5) of an electric motor (6) which is rotated according to the tension which is desired to be provided in the tape; a slackening roller (13) mounted between the tensioning roller (4) and the source of supply (10) of the elastic tape (8); a second means (15) adapted to press the tape (8) against the slackening roller (13); and a sensor (23) adapted to detect the tape position within the span between the tensioning roller (4) and the slackening roller (13), and being connected to a motor (28) which rotates the slackening roller (13) in either direction respectively withdrawing tape from said source (10) of supply or paying it out thereto in order to constantly maintain a slack tape loop within said span, whereby the tape is supplied tension-free to the tensioning roller.</p> |
