Narrow backrest electric seat mechanical extension device

A narrow backrest electric seat mechanical extension device, comprises the two mechanical extension units arranged in a bilateral symmetry, a back drive piece, and a front drive piece, wherein each of the two mechanical extension units comprise a leg assembly, a back assembly, and a seat panel, and the back assembly is provided with an eleventh connector, a front support piece, a tenth connector, a ninth connector, an eighth connector, a seventh connector, a sixth connector, a fifth connector, a fourth connector, a third connector, a second connector, a first connector, a backrest support plate, a backrest fixing plate, a back support piece, and a backrest return spring, the backrest fixing plate is fixedly connected to the seat panel, the backrest support plate is hinged with the backrest fixing plate through a first pin, the backrest support plate is hinged with the first connector through a second pin, the first connector is hinged with the second connector through a third pin, the second connector is hinged with the third connector through a fourth pin four, the second connector is mounted on the seat panel through a twenty-fifth pin, the third connector is hinged with the sixth connector through a fifth pin, the sixth connector is hinged with the eighth connector through a sixth pin, the fifth connector is hinged with the seventh connector through an eleventh pin, the seventh connector is hinged with the ninth connector through a twenty-third pin, the eighth connector is hinged with the ninth connector and the tenth connector through a seventh pin, the ninth connector is hinged with the tenth connector through a twenty-fourth pin, the tenth connector is hinged with the front support piece through an eighth pin, the front support piece is hinged with the seat panel through a ninth pin, the eleventh connector is hinged with the leg assembly, the back support piece is hinged with the seat panel through a thirteenth pin, the back support piece and the eleventh connector are hinged through a fourteenth pin, the back support piece is hinged with the tenth connector through a fifteenth pin, a first end of a driving device is hinged with the back drive piece, and the back drive piece is fixedly connected to the sixth connector;

• a second end of the driving device is hinged with the front drive piece, the front drive piece is connected to the leg assembly, and the backrest return spring is installed between the tenth connector and the third connector.