NEEDLE THREAD SUPPLY DEVICE

PURPOSE:To reduce a slip of a needle thread while supplying efficiently the needle thread by disposing a plurality of driven rollers for clamping and sending the needle thread between a drive roller and the driven roller and controlling a yarn clamping means with respective driven roller controlling a yarn clamping means with a control means to independently rotate and stop the respective driven rollers. CONSTITUTION:A yarn drawing-out means 22 is constituted from a drive roller 25 and two drive rollers 26a, 26b. One driven roller 26a clamps a first upper yarn 27a between itself and the drive roller 25 and draws out this upper yarn by a predetermined amount from a yarn winding bobbin, and the other driven roller 26b clamps a second upper yarn 27b between itself and the drive roller 25 and draws out this upper yarn by a predetermined amount from the yarn winding bobbin. An electromagnet clamping mechanism of first and second yarn clamping means 23, 23' has an electromagnet 34 and a clamping plate 35. When the electromagnet 34 is excited and the clamping plate 35 is shifted toward a main body 34a, the upper yarn is clamped between the clamping plate and the end face of main body. When the clamping plate is separated from the main body the upper yarn is released. When a plurality of driven rollers are thus disposed in the direction of sending the upper yarn, the driven roller makes line contact with the drive roller 25 to increase the contact area so that a slip of the upper yarn is minimized.