GB1061704A - Sewing machines having bobbin thread replenishing means - Google Patents

Abstract

1,061,704. Sewing machines. SINGER CO. May 4, 1965 [May 6, 1964], No. 18691/65. Heading DIG. A bobbin journalled in the rotary looptaker of a lock stitch sewing machine is wound with thread seized by the looptaker beak from a source separate and distinct from the source of the needle thread. The arrangement is a modification of the clamp-feed, group-stitch sewing machine described in Specification 906,397 and in which, during the last revolution of the looptaker, the remant of thread in the bobbin is extracted, while subsequent raising of the work clamp serves to severe the needle and bobbin threads, and re-starting the machine serves initially to re-wind the bobbin with needle thread. During the last revolution of the looptaker in the present arrangement when the needle is raised, a shaft 271 is moved axially, when a follower (294), Fig. 5, not shown, engages a cam (290) on the main rotary cam disc 81, to position adjacent the looptaker an arm 270 which is rigid with shaft 271 and is formed at its free end with an eye carrying thread from a separate spool (300), Fig. 4, not shown, mounted on the sub-base 24 of the machine. This thread is thereby seized by the looptaker beak (50), Fig. 11A, not shown, and is then clamped to the latter by an extension (76) of the rotary bobbin winder (70) which moves into operative engagement with the bobbin (62) when a cam follower (97), Fig. 5, engages a cam (80) on disc 81. A cam (222) then engages a follower (223) to stop the machine. On re-starting the machine, a bellcrank lever 317 is swung by a connection with the cam disc 81, to separate a driving clutch disc 311 on the divided arm shaft 34 from a driven clutch disc 310 to immobilise the needle bar. Bobbin winding continues until follower 97 is disengaged from cam 80 and lever 317 is released to permit a spring 315 to re-engage the clutch discs 310, 311.