GB1135830A - Sewing machine - Google Patents

Abstract

1,135,830. Sewing machines. DOUGHBOY INDUSTRIES Inc. 23 Nov., 1966 [26 Sept., 1966], No. 52459/66. Heading DIG. A two-thread chain stitching machine for closing filled bags comprises combined needle and continuous work feed. A vertical shaft 27a, driven by a pulley 27, drives looper mechanism 21, and is connected both by a belt 40a to a shaft 41 driving a needle bar 44, and also by gearing 28 to a shaft 28a driving wheel and belt work feed. A feed wheel 29, rigid with shaft 28a, has a knurled centre portion 29a co-operating with a knurled presser wheel 32 carried by a block 33 rigid with a spring- biased presser bar 33b. Outer toothed portions 29b of wheel 29 drive feed belts 31a, 31b supported by an idler pulley 36. The belts bear against a fixed plate 37 and are supported in grooves formed in a throat plate 38 having an elongated needle aperture 38a. The mouth of a filled bag B first passes between the belts and a presser foot 39 which has an elongated needle aperture 39b and is rigid with block 33, and then passes between wheels 29 and 32. A crank 41b on shaft 41 is connected by a link 42 to needle bar 44 for reciprocating the latter. Needle bar 44, which carries a needle thread take-up finger, slides in universal joints provided at its outer end and in a transverselyslidable block 46. A cam 49 on shaft 41 acts on one arm of lever 50, the other arm of which is coupled to block 46 for reciprocating the latter to impart work-feed movements to the needle bar. A threaded looper 52 is carried by a crank arm 53 on a shaft 53a reciprocated axially via linkage 57a, 58, 59 from an eccentric 57 on shaft 27a. A yoke 55 on shaft 53a embraces a cylindrical eccentric 56 on shaft 27a for oscillating shaft 53a. A bag approaching presser foot 39 displaces a plate 61 carried by pivoted and spring-biassed bars 61a, 62 whereby bar 62 actuates a microswitch to start the driving motor. The sewn mouth after passing wheels 29, 32 is deflected by an inclined surface 64b of a fixed block 64. Surface 64b is formed with a notch 67, the outer end of which is traversed by a knife blade 69 pivoted at 70 to block 64 and oscillated continuously via a link 69b from eccentric 57. The arrangement is thereby such that the thread chain extending from the sewn bag enters notch 67 and is severed by blade 69 adjacent the bag. The front of the machine frame 16 is provided with a first cover which is detachably secured by a thumb screw and supports the guides and tensioners for the needle and looper threads, and with a second cover which encloses the looper mechanism and is detachably secured by magnetic catches.