GB898326A - Improvements in or relating to material trimming devices of sewing machines - Google Patents

Abstract

898,326. Sewing-machines. PFAFF A.G., G.M. March 15, 1961 [April 4, 1960], No. 9403/61. Class 112 [Also in Group XXIV] The work-trimming knife of a sewing-machine is connected by a rod 18 to one arm 14 of a bellcrank lever 13, oscillated about an axis 12 by an eccentric 5 on the arm-shaft of the machine, by means including a hinge joint 17 which is slidable with respect to a guide pin 26 secured to a control shaft 27. The shaft is rotatable by an operating lever 44 so that the axis of the hinge joint may be moved into alignment with the axis of oscillation 12 to render the knife inoperative, or to the shown position, when the knife reciprocates. The operating lever 44 is connected by a link 42 to a pin 32 on an operating member 33 journalled on the shaft 27, the pin 32 extending into a slot 31 in a lock member 28 secured to the shaft 27. In the position shown the member 28, and thus the shaft 27, is secured in position by a spring urged locking lever 37 pivoted to the machine frame and engaging a notch 30 in the member 28. As the lever 44 is rotated the operating member 33 is moved clockwise about the shaft 27 and the locking lever is withdrawn from the notch 30 by the engagement of a pin 35 on that lever with the cam edge of the member 33. Meanwhile the operating pin 32 has moved to the other end of the slot 31 and further movement displaces the member 28 clockwise to rotate the shaft 27 and swing the hinge joint 17 into alignment with the axis 12, the lever 37 then engaging a notch 29 in the lock member.