Patent ID: 7240628

Claim:
A sewing machine, comprising: a needle which is provided with an upper thread; a loop taker which houses a bobbin for a bottom thread; a drive member which drives the needle to perform a reciprocating movement, wherein the needle during its movement and in cooperation with the loop taker executes stitches on a sewing material, which is advanced between the upper thread and the bottom thread, wherein a lever arm in each stitch pulls tight a knot being formed in the sewing material from the upper thread and the bottom thread in cooperation; a thread transfer member which supplies the needle with upper thread utilizing a thread portioner or a friction braking assembly for braking the upper thread; a switch for switching between thread feed utilizing the thread portioner or the friction braking assembly; a control unit which controls the thread supply of the thread transfer member utilizing either the thread portioner or the friction braking assembly.