Seating furniture chassis

A seating furniture chassis, comprising:

• a seat surface frame;
• a lever mechanism;
• a footrest connected to the seat surface frame by the lever mechanism, the footrest being convertible between a folded-in state in which the footrest is arranged below the seat surface frame and a folded-out state in which the footrest forms an obtuse angle with the seat surface frame;
• a first guide element arranged laterally next to a first end of the seat surface frame and rigidly connected to the seat surface frame;
• a first guide rail arranged laterally next to the first end of the seat surface frame and having a curved shape comprising a front end, a rear end, and a central region arranged between the front and rear ends, wherein the front and rear ends are arranged lower than the central region;
• a second guide element arranged laterally next to a second end of the seat surface frame;
• a second guide rail arranged laterally next to the second end of the seat surface frame;
• a third guide element arranged laterally next to the first end of the seat surface frame;
• a third guide rail having a curved shape and arranged laterally next to the first end of the seat surface frame;
• a fourth guide element arranged laterally next to the second end of the seat surface frame;
• and
• a fourth guide rail having a curved shape and arranged laterally next to the second end of the seat surface frame, wherein:
• when the footrest is converted between the folded-out and folded-in states, the first guide element is guided in the first guide rail,
• when the footrest is converted between the folded-in and folded-out states, the third guide element is guided in the third guide rail and the fourth guide element is guided in the fourth guide rail,
• during guidance in the third and fourth guide rails, respectively, the third and fourth guide elements are guided only horizontally and downwards when the footrest is converted from the folded-in state to the folded-out state,
• the lever mechanism comprises an elongated lever having an upper portion that is directly connected rotatably to the seat surface frame, a lower portion, and a longitudinal axis extending from the upper portion to the lower portion, and
• the longitudinal axis of the lever extends in a forward and downward direction from the seat surface frame in the folded-in state of the footrest.