| 摘要 |
1,163,862. Sewing machines. SINGER CO. 20 April, 1967 [25 April, 1966], No. 18128/67. Heading DIG. A lock stitch machine comprises a rotary looptaker body having a needle thread loopseizing beak, a bobbin case journalled relatively to the looptaker body, means for restraining the bobbin case from circular movement with the looptaker body, and means for shifting said restraining means from a first to a second position, whereby, when the bobbin case is in said first position needle thread loops are carried completely therearound, and when the bobbin case is in said second position the needle thread loops serve to replenish thread on a bobbin journalled in the bobbin case. A shuttle 22 is journalled in a raceway formed in a fixed housing 20, and is held in position by a retainer 23 capable of limited angular movement about studs 24, 25 projecting from housing 20 through arcuate slots 26, 27. The shuttle is rotated by a driver 52 located in a notch 51, one side of which is formed as a loop-siezing beak 54. A bobbin case 33 is journalled on a post projecting from the shuttle and is secured thereto by a screw 32. Thread from a bobbin, journalled within the bobbin case, leaves the latter by a radial slot 40 and is tensioned by a leaf spring 41 secured at 42 to the bobbin case. A finger 34 extends from the latter between abutments 35, 36 on retainer 23. For stitch formation, a tongue 105, engaging a slot 106 in retainer 23, shifts the latter to the end position shown, when slot 40 is positioned above the point of tangential engagement of the seized loop with the bobbin case. For bobbin replenishment, the limb of the seized loop extending to the work is clamped to the shuttle adjacent beak 54, and tongue 105 is simultaneously moved clockwise to shift retainer 23 to its other end position. Slot 40 is then positioned at said point of tangential engagement, and successive seized thread limbs extending to the needle 18 thereby pass through slot 40 and are wound on the bobbin. |
