GB241433A - Improvements in sewing machines - Google Patents

Abstract

241,433. Armstrong, J. J. V., (Union Special Machine Co.). Feb. 4, 1925. Seming-machines; loop-stitching; needles, driving. - In an over-edge sewing-machine a threaded looper mounted above the cloth plate co-operates with the needle and with a threaded looper below the cloth plate, the first-named looper deriving its movements from a single eccentric carried beneath the work-support. The needle-bar 2 is reciprocated by mechanism comprising a link 9, lever 8, eccentric strap 15 and eccentric 14 on the main shaft 12. The under looper 22 is mounted in an arm secured to a shaft 28 oscillated so as to give the looper two strokes for every needle stroke through mechanism comprising a toggle linkage 34, 35 and a link 33 pivoted to the lever 8. The upper looper 37, which has an over-edge motion and concentrates its thread with those of the needle and under looper, is mounted on a carrier 40 secured to a shaft 42 mounted in bearings 43, 44 carried by the outer end of a sleeve 46 which is rocked by an eccentric device 51, 52 on the shaft 12 and an arm 48. An arm 53 on the upper end of the shaft 42 is connected by a ball-ended link 54 to a fixed bracket 56b so that as rising and falling movements are communicated to the looper by the eccentric and its connections it is also constrained to move to and from the needle and under looper. Work supports; presser-feet.-The cloth plate 21 is supported by a bracket 29 which carries the upper looper mechanism and by a post 61. It is provided with slots for a main and auxiliary feed-dog and has a usual type of stitch finger. A presser-foot 74 is hinged to a presser-bar of usual type and is pressed against the work by a spring 77. The presser-foot has a plate provided with a stitch-finger above that on thecloth plate and this plate is cut away to provide space for a trimming mechanism. Frames.-A cover-plate 82 associated with the cloth plate and hinged on a vertical pin 89 is curved inward at 87<a> to provide a space into which material may be brought in stitching small tubular articles. The cover plate is held in position by a spring bolt 90.