Chair

A chair comprising:

• a seat having a rear side;
• a backrest disposed behind the rear side of the seat and having
• a head portion disposed above the seat;
• a back portion formed below the head portion of the backrest, located behind the rear side of the seat, and having
• a front surface;
• a bottom;
• and
• a space formed through the back portion of the backrest and located above the bottom of the back portion;
• and
• a connecting rod formed between the head portion and the back portion of the backrest, and located above the space of the back portion;
• a lift structure disposed on the bottom of the back portion of the backrest;
• a back supporting structure disposed between the backrest and the lift structure, located in the space of the back portion, and having
• a front surface;
• a bending element connected with the connecting rod of the backrest and the lift structure, being elastic and bendable to deform, and having a top end;
• a bottom end;
• a front surface;
• two side surfaces;
• a top connecting portion disposed on the top end of the bending element and connected to the connecting rod of the backrest;
• and
• a bottom connecting portion disposed on the bottom end of the bending element and connected to the lift structure;
• and
• multiple supporting strips disposed on the front surface of the bending element at spaced intervals from the top end of the bending element to the bottom end of the bending element, and each supporting strip having
• a supporting element disposed on the front surface of the bending element, and having
• two sides;
• and
• two supporting portions respectively formed on the two sides of the supporting element and respectively extending out of the two side surfaces of the bending element;
• and
• a waist supporting structure in front of the front surface of the back supporting structure disposed on the seat, and having
• two pivoting bases disposed on the seat at a spaced interval;
• and
• a supporting plate pivoted between the two pivoting bases, abutting the front surface of the back supporting structure, selectively abutting the front surface of the back portion, and having
• a body disposed between the two pivoting bases and having two sides;
• and
• two pivoting portions respectively disposed on the two sides of the body and respectively pivoted into the two pivoting bases,
• wherein the bending element has
• a rear surface;
• multiple inner recesses formed on the front surface of the bending element at spaced intervals;
• and
• multiple outer recesses formed on the rear surface of the bending element at spaced intervals,
• wherein the inner recesses and the outer recesses are arranged in a staggered manner from the top end of the bending element to the bottom end of the bending element,
• wherein each one of the inner recesses and the outer recesses is selectively filled with a cushion block, and
• wherein a cross-section of each one of the inner recesses and the outer recesses is T-shaped, and each one of the inner recesses and the outer recesses is a T-shaped recess.