GB289686A - Improvements in a supporting frame for a sewing machine - Google Patents

Abstract

289,686. Armstrong, J. J. V., (Union Special Machine Co.). Aug. 24, 1927. Frames.-The upper portion of a. sewing machine frame has a laterally projecting portion to which different sewing heads may be attached in order that machines for making different seams may be built on the same frame. The application to a machine of the suspended work-supporting arm type for felling, or for flat seam work in connection with knit goods is described. The part 2 of the frame which houses the main shaft 4 by which all of the upper parts are actuated, has a lateral extension 6 provided with lugs or crossbars 7, 7<1>. The detachable sewing heads 36 have corresponding lugs 22, 23, by which they may be secured to the frame lugs by screws 24 or otherwise. The work supporting arm is supplied with the proper co-operating elements according to the head selected. Needles, driving; governing needle thread.-In the sewing-head shown, the needle-bar 37 carries three needles and is actuated by a double-armed lever 11 secured to a rock-shaft 10 and connected by a link 12 to a crank on the main shaft 4. When the sewing-head 36 is changed, the link 15 in the needle-drive is disconnected. The shaft 10 may also be changed if the auxiliary devices require it. An arm 69 having needle thread guides is secured to a shaft 70 which is positioned. in accordance with the thickness of the work by a bar 74 fixed to a sleeve 75 on the presser-bar 42. Co-operating with the needles 38 are cross thread laying fingers 39, 40, which are actuated from a vertical rock-shaft 54 by levers 61, 68. The shaft is rocked by a link 58 connected to a ball crank 57 on the end of the cross-shaft 10. Trimming.-A movable trimming blade 41 is carried by a bracket 48 fixed to a sleeve 47 which is mounted to oscillate on the presser-bar 42. The sleeve is oscillated by a link connection 51 with the rock-shaft 54, and the blade 41 cooperates with a fixed blade on the presser-foot. Presser-bar lifting device.-The presser-bar 42, which is prevented from rotating by a collar 53, is lifted by a hand or treadle-operated rod 27. The connecting link 44 is readily detachable to facilitate changing of the sewing head.