Chair frame and casual chair

A chair frame, comprising a frame mechanism, a connecting rod system disposed on the frame mechanism and a seat mechanism disposed on the connecting rod system, wherein the connecting rod system comprises a basic component fixed to the frame mechanism;

• a first front arm pivotally connected to a front end of the basic component;
• a first rear arm pivotally connected to a rear end of the basic component;
• a first transverse arm pivotally connected to the first front arm and the first rear arm;
• a second transverse arm pivotally connected to the first front arm;
• a second rear arm pivotally connected to the first rear arm and the second transverse arm;
• a second front arm pivotally connected to the second transverse arm;
• and
• a lifting component pivotally connected to the second front arm and the second rear arm, and
• the seat mechanism comprising a hip-leg supporting component, a front rocker arm and a rear rocker arm, wherein the hip-leg supporting component is suspended over the basic component, the front rocker arm is pivotally connected to the hip-leg supporting component and the lifting component, and the rear rocker arm is pivotally connected to the hip-leg supporting component and the lifting component, wherein a first planar four-rod mechanism is defined by the first front arm, the first rear arm, the first transverse arm and the basic component surrounding, a second planar four-rod mechanism is defined by the second front arm, the second rear arm, the second transverse arm and the lifting component surrounding, and a plane defined by the first planar four-rod mechanism is parallel to a plane defined by the second planar four-rod mechanism.