GB506631A - Zigzag sewing machine - Google Patents

Abstract

506,631. Eccentrics. FAIRWEATHER W. C. (Singer Manufacturing Co.). Dec. 21, 1938, No. 37104. [Class 122 (i)] [Also in Groups VII and XXV] Co-operating parts of a sewing-machine are actuated by two adjustable eccentrics which are connected together for simultaneous adjustment by a single means. A disc 21 fixed to the shaft 20 by set-screws 20<1> has pivoted to it at 221 on one face a plate 22 formed with one eccentric 23 and at 26 on the other face a plate 27 formed with the other eccentric 28; the eccentric rods 183, 184 are omitted in Fig. 6. The plates 22, 27 are slotted at their centres so that they can swing about their pivots 221, 26 across the shaft 20 to vary the throw of the eccentrics, and are held against the disc 21 by pins and slots 24, 29 respectively. A link 44, cranked to pass through a large notch in the disc 21, and recessed into the faces of the disc 21 at its ends, is pivoted to the plate 22 at 45 and to the plate 27 at 46, so that the plates are forced to move in unison about their pivots and the throws of the eccentrics are adjusted simultaneously and equally. The plate 22 is pressed towards the position in which the throw of the eccentric 23 is zero by a spring-pressed pin 41 bearing against the shaft 20, the movement being limited by a stop-screw 39 ; the plate 27 is similarly pressed towards the zerothrow position by a spring-pressed pin 36, but the stop-screw 33 in this case passes through a hole in the shaft 20 to abut against the bevelled end of a pin 49 sliding in an axial bore in the shaft and secured to an adjusting screw 53, whereby the throw of both eccentrics is determined. The pin 49 is prevented from rotation in the shaft by a screw 51 engaging a slot ; a leaf-spring 55 secured to the screw 53 holds this screw frictionally in its adjusted position.