GB463534A - Rotary hook and thread case devices for sewing machines - Google Patents

Abstract

463,534. Sewing - machines. FAIRWEATHER, W. C. (Singer Manufacturing Co.) Oct. 10, 1936, No. 27509. [Class 112] A horizontal axis rotary hook has a barrier spaced from and disposed at the loop-castoff side of the hook to limit the flying-off movement of the take-up limb of the thread loop. The hook 8 is carried on the shaft 9 and performs the usual two rotations for each complete reciprocation of the needle 7. The beak 12 of the hook is in close proximity with the needle guard 13. When the beak 12 seizes the needle thread loop passing between the needle 7 and work-limb of the needle thread loop, the lower end of the thread loop is caught by the spur 20 of the thread case carrier bearing-rib 16. The thread loop then passes under the hook-body rim under the hook body across the gap 21, about the spur 20 and along the inner face of the bearing rib, about the thread 12<1> and over the work free of the hook body to the needle. At high speeds the take-up thread limb flies so violently from the hook that it becomes jammed in the feed dog slots. This limb is confined between the inner face of the bobbin carrier 17 and the base of the hook body, and between a stop finger 23 and dog arm 36, so that in the flying-off action, the thread limb engages the arm 27 and avoids jamming. The arm 27 also serves as a stop for the bobbin carrier.