Abstract: The invention is an electromechanical stretching apparatus of a convertible sofa, which consisting of a mechanical stretching apparatus and an electric actuator, the mechanical stretching apparatus being provided with an electrically-driven connecting rod, wherein, the electric actuator consists of a motor, a motor connecting tube, a motor movable slider, and a motor head fixing part, the motor adopted is a motor with a guide rail, the motor movable slider is installed on the guide rail of the motor, the motor head is rotationally connected through a second rotor shaft to the motor head fixing part fastened on the electrically-driven connecting rod, the motor connecting tube is connected to the motor movable slider through a first rotor shaft and the motor connecting tube is fastened on the mechanical stretching apparatus. The said motor connecting tube is fastened on a linkage part of the mechanical stretching apparatus. The said first rotor shaft and the second rotor shaft are both a bolt.

Abstract: The invention is directed to a movable backrest of an adjustable chair, which can include: a backrest assembly, a first backrest support, a first backrest connector, a second backrest support, a second backrest connector, and a backrest guiding apparatus; the backrest assembly is connected to the first backrest support through a first shaft, the backrest assembly is connected to the guiding apparatus through a seventh shaft, the first backrest support is connected to the first backrest connector through a second shaft, the backrest guiding apparatus is connected to the first backrest connector through a sixth shaft. The invention is simple, durable, and easy to operate, can help eliminate a gap between the backrest and the sitting pad when the adjustable chair is at different positions, reduce the friction feeling of a person's back and prevent the backrest from touching the well when the adjustable chair is at different positions.

Abstract: The invention is directed to a movable backrest of an adjustable chair, which can include: a backrest assembly, a first backrest support, a first backrest connector, a second backrest support, a second backrest connector, and a backrest guiding apparatus; the backrest assembly is connected to the first backrest support through a first shaft, the backrest assembly is connected to the guiding apparatus through a seventh shaft, the first backrest support is connected to the first backrest connector through a second shaft, the backrest guiding apparatus is connected to the first backrest connector through a sixth shaft. The invention is simple, durable, and easy to operate, can help eliminate a gap between the backrest and the sitting pad when the adjustable chair is at different positions, reduce the friction feeling of a person's back and prevent the backrest from touching the well when the adjustable chair is at different positions.