GB551925A - Trimmer mechanism for sewing machines - Google Patents

Abstract

551,925. Sewing-machines. FAIRWEATHER, W. C. (Singer Manufacturing Co.). Sept. 12, 1941, No. 11726. [Class 112] An independently driven knife bar, inclined to the needle-bar, is driven from an eccentric on a transverse shaft through toggle links that can be broken and straightened during running. The knife-bar and mechanism can be detached as a unit. The knifebar 18 is mounted in an arm 13 of a bracket 12 secured to the machine arm and the transverse shaft 42, carrying the operating eccentric 45, is mounted in a bracket 36 secured to the bracket 72. The pitman between the eccentric 45 and the knife-bar is provided by a toggle 32, 47, Fig. 5, and a clip 54 holds the parts resiliently in line. The link 32 is pivoted on a projection from the knife-bar which slides in a slot 27. A spring 34 raises 'the knife-bar when the toggle is broken. The pivot pin 50 reciprocates idly in a slot in a lever 59 and the toggle is broken when this lever is turned by a finger lever 55 engaging a pin 58. The toggle is straightened by means of a tip 55<SP>1</SP> on the lever 55 when.it is pressed on to a plunger 62 mounted above a spring 64 in the hollow knife-bar. The shaft 42 carries two belt pulleys and is driven from an electric motor mounted on the machine arm.