GB423491A - Improvements in and relating to buttonhole sewing machines - Google Patents

Abstract

423,491. Sewing-machines. HUGHES, R. M., 72, Cannon Street, London.-(International Button Hole Sewing Machine Co. ; 502, Harrison Avenue, Boston, U.S.A.) Sept. 27, 1934, No. 27730. [Class 112] The needle-jogging mechanism of a buttonhole-sewing machine is provided with means for varying the amplitude of the jogging movement independent of means for varying the position of the needle thrusts at the buttonhole slit. The needle is mounted in a needle bar 6 which reciprocates in a head 7 on a stitch frame 8. The needle bar is reciprocated from a cam 9 on a cam shaft 10, the cam 9 having a path 11 receiving a follower 12 carried on the end of a lever 13 connected to the needle bar at 15. The needle bar extends through a sleeve 16 which in turn extends axially through a gear 17 by which the needle is turned when sewing round the end of a buttonhole. The hole through the gear is enlarged to permit the necessary freedom for jogging the needle bar. The sleeve 16 has two inclined grooves 19, and the gear 17 has two ears 20 each with a shoe 21 having a toe 22 occupying one of the grooves 19. The reciprocation of the needle causes the jog by reason of the inclined grooves 19 engaging the toes 22, thereby producing the slit thrusts and depth thrusts of the needle. The amplitude of the jogging movement of the needle is altered by shifting the pivot 37 in the slot 36 of the member 30 which reciprocates the sleeve 16 over the rod 29 and cam 23. The position of the slit thrusts relative to the buttonhole slit is varied by an adjustable connection between the rocker 31 and the arm 30, the relation between the two arms 30 and 32 being thus varied.