GB421714A - Improvements in trimming means for sewing machines - Google Patents

Abstract

421,714. Sewing machines. SPIELMAN, A., 440, South 56th Street, Philadelphia, U.S.A. July 31, 1934, No. 22366. [Class 112] A trimming mechanism for a sewing-machine comprises a driven rotary cutting wheel and an anvil disc, the cutting wheel being capable of radial adjustment with respect to the anvil disc. As the needle 5 of the machine reciprocates, oscillatory movement is imparted to the component 43 of the clutch 42 through the vibratory arm 63 and link 59, by means of the wedging action of the clutch rollers 47. The inclines 50 of the notches in the component 43 and the inner surface of the drum flange 48 of the component 44, causes the shaft 16 and hence the cutting wheel 17 to be intermittently turned in the direction of the arrow, Fig. V. As the cutting wheel 17 is firmly held in pressure contact with the freely revolving anvil disc 25 on the throat plate 3, the material is cut as it is fed forward. In the example shown, the zigzag periphery of the cutting wheel makes a correspondingly shaped edge 90, Fig. X. The wheel 17 may be shifted relatively to the needle by the thumb nut 39, Fig. 11, to vary the distance of the cut from the seam 89. The movements of the cutting wheel are adjusted to correspond with those of the feed dog by adjusting the stud 58 in the slot 37 of the clutch arm 56, and effecting a firm adjustment by the eccentric fulcrum pin 66.