Spring chair

Abstract

A chair operable to change between an original shape and a plurality of different shapes is disclosed. The chair has a continuous surface, comprising a sheet of metal, which enables the chair to change shape without requiring the use of complex moving elements. The shape change is a reaction to the weight of a person seated in the chair, and creates an asymmetric rocking motion in reaction to shifts in the weight of the person.

1 . A chair, comprising: 
 a piece of metal formed into a continuous surface of a desired original shape that flexes to at least one different shape when supporting a person's weight and substantially returns to the original shape when not supporting the person.    
   
   
       2 . The chair of  claim 1 , wherein the continuous surface flexes to many different shapes as the person shifts his or her weight on the chair to provide an asymmetric rocking motion.  
   
   
       3 . The chair of  claim 2 , wherein said rocking motion is fluid.  
   
   
       4 . The chair of  claim 1 , wherein the degree and direction in which the continuous surface flexes are dependent upon the weight or size of the person.  
   
   
       5 . The chair of  claim 1 , wherein said metal is an alloy selected from the group consisting of aluminum, magnesium, silicon and combinations thereof.  
   
   
       6 . The chair of  claim 1 , the continuous surface comprising: 
 an upper seating portion and a lower ground-engaging portion.    
   
   
       7 . The chair of  claim 6 , wherein the upper seating portion shifts in proportion to the lower ground-engaging portion due to the person's weight.  
   
   
       8 . The chair of  claim 1 , wherein the piece of metal is made from a single sheet of metal.  
   
   
       9 . A chair, comprising: 
 a single piece of metal formed into a continuous surface of a desired original shape that flexes to at least one different shape when supporting a person and substantially returns to the original shape when not supporting the person, said chair flexing to many different shapes as the person shifts his or her weight on the chair to provide an asymmetric rocking motion.    
   
   
       10 . The chair of  claim 9 , wherein the degree and direction in which the continuous surface flexes are dependent upon the weight or size of the person.  
   
   
       11 . The chair of  claim 10 , wherein said rocking motion is fluid.  
   
   
       12 . The chair of  claim 9 , wherein said metal is an alloy selected from the group consisting of aluminum, magnesium, silicon and combinations thereof.  
   
   
       13 . The chair of  claim 9 , the continuous surface comprising: 
 an upper seating portion and a lower ground-engaging portion.    
   
   
       14 . The chair of  claim 13 , wherein the upper seating portion shifts in proportion to the lower ground-engaging portion due to the person's eight.  
   
   
       15 . A chair, comprising: 
 a single piece of metal formed into a continuous surface of a desired original shape that flexes to at least one different shape when supporting a person and substantially returns to the original shape when not supporting the person, said chair flexing to many different shapes as the person shifts his or her weight on the chair to provide an asymmetric rocking motion, wherein said metal is an alloy selected from the group consisting of aluminum, magnesium, silicon and combinations thereof.