Chain stitch machine

In a chain stitch sewing machine that include a needle bar movement mechanism having a pivoting needle bar drive lever that includes a needle bar attachment end, a pivot bushing disposed in a central portion thereof, and a hand wheel end that is mechanically linked to a drive motor through a crank shaft assembly;

• and wherein the pivoting needle bar drive lever pivots on the pivot bushing through which a uniform diameter pivot pin is inserted;
• the improvement comprising:
• replacing the uniform diameter pivot pin with an improved hinge shaft;
• and
• providing an operator activated hinge shaft angular orientation mechanism mechanically linked to the improved hinge shaft;
• the improved hinge shaft having two concentrically oriented end sections connected by an off-center bushing contact section that is dimensioned such that, when the improved hinge shaft is oriented at a first orientation by the operator activated hinge shaft angular orientation mechanism, the needle bar attachment end of the pivoting needle bar drive lever reciprocates between a normal upper and a normal lower position that causes the chain stitch sewing machine to form a chain stitch during each cycle of operation;
• and that, when the improved hinge shaft is oriented at a second orientation by the operator activated hinge shaft angular orientation mechanism, the needle bar attachment end of the pivoting needle bar drive lever reciprocates between a raised upper and a raised lower position that causes the chain stitch sewing machine to skip a chain stitch during each cycle of operation.