GB688957A - Improvements in and relating to sewing machines - Google Patents

Abstract

688,957. Sewing machines. DœRKOPPWERKE AKT.-GES. June 20, 1951 [June 20, 1950], No. 14606/51. Class 112. [Also in Group XXVI] Feed, regulating and reversing.-Eccentric means adjustable during operation to vary the extent and direction of the feed movement comprises a cylinder 6, with a bore inclined to its axis to receive a shaft 7, and a ring 8, bored obliquely in accordance with the inclination of the cylinder to the shaft, mounted on the cylinder; the cylinder is slotted longitudinally to receive a pin 10 held in the shaft, so that it is movable axially of the shaft but not rotatable thereon while the ring 8 is movable only in a radial plane, being held against rotation on the cylinder and movement therealong by the pin 10. In the form shown, the ring 8 produces the feed movement of the dog 16 through a pitman 9 and feed-rocker 12 connected to the feed-bar 14, which slides in a member 17 mounted on a feed-lift crank-pin 7' on the shaft 7 by means of an eccentric bush providing vertical adjustment of the dog. The cylinder 6 is moved axially by connection to a sliding bush 5 to which is secured a bar 4 with a lug engaged by the end 3 of a manually-operable lever; a spring 11 normally holds the parts in position for forward feed. The length of stitch is determined by a pin 19 on the bar 4 engaging a stop member 22 adjustable laterally of the bar by a screw 21, a second pin being provided on the bar to engage the member 22 when the bar is shifted for reverse feed; the member 22 may be symmetrically shaped to give equal backward and forward feeds, or its sides may be made different to give any other desired relation between the feeds in the two directions. An adjustable stop may be provided against which the handlever 3 may be held to give a predetermined shorter stitch when required, for example at the beginning and end of a seam.