Bobbin housing assembly in a sewing machine having at least one hook

摘要

A sewing machine has at least one rotating top thread hook, the hook enclosing a bobbin housing which accommodates a bottom thread. A spring bar is mounted in the base of the sewing machine and has a free end for bearing against the bobbin housing. The free end of the spring bar is displaceable by the top thread as it is being looped. To prevent unwanted displacement or oscillation of the spring bar, a cam is disposed in the base closely adjacent to the free end of the spring bar. The cam prevents displacement of the free end beyond a predetermined range of displacement.