GB956122A - Lock stitch sewing machine - Google Patents

Abstract

956,122. Sewing machines. SINGER CO. Feb. 19,1963 [March 5,1962], No. 6593/63. Heading D1G. In a sewing machine in which a bobbin journalled in a looptaker is wound in situ with thread drawn from the needle, the needle bar is disconnected from its drive during the bobbin-winding operation. As shown, the arrangement is a modification of the machine described in Specification 931, 214, in which rotation of a control dial journalled in the machine standard moves a vertical link downwardly, the lower end of the link being pivoted to a lever adapted to initiate the bobbin-winding operation, and the upper end of the link being pivoted to a lever adapted to release the thread tension. The latter lever carries a flexible section 64 pivoted to the upper end of a bar 34 slidably mounted in the head of the machine. A lug 37 at the lower end of bar 34 underlies one arm 38 of a bell crank lever, the other arm 39 of which abuts the tension-release pin 41 of a thread tensioner 40. Upon actuation of said control dial, bar 34 is raised, whereby arm 39 shifts pin 41 to release the thread tension. The needle bar 43 is connected by a link 44 to a crank pin 45 on a crank disc 46 journalled on the upper arm shaft 14. A latch lever 52, pivoted at 53 on the crank disc 46, has at one end a detent 51 biased into engagement with a slot 50 in shaft 14 by a spring 55 acting on the other end 54 of lever 52. A pin 60 on bar 34 is engaged in a slot in one arm 61 of a bell crank lever pivoted at 63, whereby, when bar 34 is raised, the bell crank lever is pivoted, against the bias of a spring 65, to position its other arm 62 in the path of movement of end 54. Detent 51 is thereby withdrawn from slot 50 to immobilize the needle bar.