Thread feeding device of a sewing machine

A thread feeding device of a sewing machine for feeding upper and lower threads to a fabric, the lower thread being supplied from a lower thread bobbin, said thread feeding device comprising:

• a needle bar driven to move in an up-and-down direction between an upper position and a lower position to pull the upper thread through the fabric, said needle bar being movable in a left-and-right direction which is perpendicular to the up-and-down direction between a left terminal position and a right terminal position, said needle bar defining an imaginary plane to which said needle bar is normal and which extends in a front-and-rear direction that is perpendicular to both the up-and-down direction and the left-and-right direction, the imaginary plane including a left boundary line which extends in the front-and-rear direction and passes through the left terminal position, and a right boundary line which extends in the front-and-rear direction and passes through the right terminal position;
• and
• an inner rotary hook disposed below the fabric, said inner rotary hook including a hook base wall, a hook surrounding wall which surrounds said hook base wall to cooperatively define an accommodation chamber with an upwardly facing opening, and a thread tensing unit which is disposed on said hook surrounding wall;
• the lower thread bobbin being disposed in said accommodation chamber to supply the lower thread such that the lower thread is pulled out from the lower thread bobbin and passes through said thread tensing unit to reach the fabric, said thread tensing unit being provided with at least one thread abutting point where the lower thread abuts against and is tensed, said at least one thread abutting point including a final abutting point where the lower thread passes through said thread tensing unit immediately before the lower thread reaches the fabric, said final abutting point being projected on the imaginary plane in the up-and-down direction at a projected point, the projected point being interposed between the left boundary line and the right boundary line.