Patent ID: 6012404
Filing Date: 2000-01-11
Classification: D05B

Abstract:
A zigzag pattern changing device for use in a sewing machine, said device comprising:a sewing machine frame;a sewing machine main shaft;a cam drive shaft (11) supported in said sewing machine frame in such a manner that it can be rotated deceleratingly in linking with said sewing machine main shaft;a needle swing cam (13) supported on said cam drive shaft and including at least two cams which are spaced apart from each other in the axial direction of said needle swing cam and respectively correspond to different needle swing patterns;a needle swing drive shaft (20) disposed in parallel to said cam drive shaft, supported in said sewing machine frame wherein the needle swing drive shaft makes swing motions about the axis thereof, and connected to a needle mechanism so that the needle swing drive shaft moves a needle in a direction at right angles to a cloth feeding direction due to said swing motion;a cam body (50) including a pair of contact bodies separately engageable with and removable from said two cams, for transmitting swing motions of said contact body due to one of said needle swing cams to be engaged to said needle swing drive shaft, and supported on said needle swing drive shaft in such a manner that said cam body is movable in the axial direction of said needle swing drive shaft;switching means (59) connected to said cam body for moving said cam body in the axial direction of said needle swing drive shaft to one position where one contact member is engagable with one cam groove and to another position where the other contact member is engagable with the other cam groove;a guiding member disposed in parallel to the axial direction of said needle swing drive shaft; and,a guided member to be guided engageable with said guiding member and relatively movable in the axial direction of said needle swing drive shaft.