Selecting mechanism of a double-function sewing machine

A selecting mechanism for a double-function sewing machine which is provided with two stitching mechanisms for different sewing operations within a single machine frame, the selecting mechanism comprising a drive shaft (6) which is rotatably supported on the machine frame and is connected at one end with an axially movable flywheel and is driven by a drive source via a belt wheel body;

• a first belt wheel (29) which is idle rotatably on the drive shaft and is operatively connected to a first stitching mechanism;
• an upper shaft belt wheel (11) which is secured on an upper shaft (9) of a second stitching mechanism, said upper shaft being rotatably supported in the machine frame and being coaxial with the drive shaft and having a rotation transmitting part;
• a slider (26) provided on said drive shaft between said upper shaft belt wheel (11) and said first belt wheel (29), said slider having a rotation transmitting part for selectively engaging either of the belt wheels, said slider being rotation-fixed with the drive shaft and movable in an axial direction of the drive shaft;
• a switching shaft (30) which is rotatably supported in the machine frame and is rotated by an external switching operation;
• moving means for moving the slider so as to connect the slider to the switching shaft;
• rotation checking means checking the rotation of for the switching shaft;
• and a release device which releases the rotation checking means by axially moving the flywheel.