GB364891A - Thread cutting mechanism for sewing machines - Google Patents

Abstract

364,891. Sewing-machines. FAIRWEATHER, W., 65, Chancery Lane, London.-(Singer Manufacturing Co. ; Elizabeth, New Jersey, U.S.A.) Feb. 11, 1931, No. 4247. [Class 112.] A thread-cutting device arranged below the throat plate of a button sewing-machine comprises a pair of pointed blades one of which 64 detains the last needle loop drawn out of the shuttle 21 and the other subsequently deflects the work limb of the loop to the cutting blade 72. When the machine, which is described in Specification 118,672, [Class 112, Sewing &c.], is started by the lever 32, the blades 63, 64 are turned from the full to the dotted position, Fig. 5, by a linkage 80 where they remain for one or two revolutions of the main shaft 24 according to the number of stitches required. They then fall back to the position shown full and the blade 64 catches the last needle loop formed as the machine comes to rest. On lifting the presser foot by a treadle lever 18 the bobbin thread cutter bar 51 slides forward operated by linkage 55, 56, 57. The bar 51 displaces the blades 63, 64 and the detained needle loop is deflected by the curved edge 71 of the blade 63 to the cutting edge 72. The loop is severed simultaneously with the cutting of the bobbin thread by a knife 52. The blades 63, 64 are restored to the position shown in full by the recovery of a spring 83 when the presser foot is lowered.