Patent ID: 7363869

Claim:
A sewing machine comprising: a main frame containing therein a transmission mechanism, the main frame having a top forming a head portion and a bottom forming a base; a retainer mounted to the base of the main frame, the retainer defining a bore receiving therein a first gear transmission assembly, a rocker arm retaining disk assembly mounted on the bore, the first gear transmission assembly being in driving coupling with the transmission mechanism of the main frame and extending through the rocker arm retaining disk assembly; a rocker arm assembly comprising a rocker arm body which forms a plurality of bent sections, a second gear transmission assembly being arranged in the rocker arm body and in driving coupling with the first gear transmission assembly of the retainer, the second gear transmission assembly driving a thread engaging device arranged on the rocker arm body, the thread engaging device comprising a needle plate, the rocker arm body forming a pivot connection at a front side thereof, the pivot connection being fit over the rocker arm retaining disk assembly, the rocker arm body that forms a plurality of bent sections being configured to have the thread engaging device opposing the main frame; a wire assembly extending from opposite sides of the needle plate of the thread engaging device through the thread engaging device, the rocker arm body, and the rocker arm retaining disk assembly for driving the needle plate so as to maintain a fixed position of the needle plate when the rocker arm assembly reciprocally rotates; and a platform mounted to the base of the main frame.