Composite chair

Abstract

A composite chair adapted for permitting a user to sit thereon. The composite chair includes a base unit and a seat unit. The seat unit includes a seat body that is mounted on the base unit and that is adapted for supporting the user's buttocks, and a pushing member that is fixedly mounted on a rear end of the seat body. The seat body is pivotable relative to the base unit for inclining the pushing member to push the user' s waist forward.

What is claimed is: 
     
         1 . A composite chair adapted for permitting a user to sit thereon, said composite chair comprising:
 a base unit; and   a seat unit including
 a seat body that is mounted on said base unit and that is adapted for supporting the user's buttocks, and 
 a pushing member that is fixedly mounted on a rear end of said seat body, said seat body being pivotable relative to said base unit for inclining said pushing member to push the user's waist forward. 
   
     
     
         2 . The composite chair as claimed in  claim 1 , further comprising a shifting device that is mounted on said base unit, that is disposed in front of said seat unit, and that includes two support units adapted for respectively supporting the user's thighs and movable relative to said base unit between a retracted position, where said support units are close to each other, and an expanded position, where said support units are away from each other. 
     
     
         3 . The composite chair as claimed in  claim 1 , further comprising a backrest unit that is mounted on said base unit and that is pivotable in a front-rear direction relative to said base unit for moving the user's back. 
     
     
         4 . The composite chair as claimed in  claim 3 , further comprising an inflatable unit that is mounted on aside of said backrest unit, that faces the user, and that is inflatable for supporting the user's back. 
     
     
         5 . The composite chair as claimed in  claim 4 , further comprising an armrest unit that is mounted on said backrest unit, that is vertically movable relative to said backrest unit and that is adapted for supporting the user's arms. 
     
     
         6 . The composite chair as claimed in  claim 5 , wherein said armrest unit includes
 a connecting member that is mounted on said backrest unit and that is vertically movable relative to said backrest unit, and   two armrest members that are respectively and pivotally connected to left and right ends of said connecting member and that are horizontally pivotable relative to said connecting member.   
     
     
         7 . The composite chair as claimed in  claim 1 , wherein:
 said base unit includes
 two front legs that are spacedly disposed, 
 two rear legs that are spacedly disposed, and 
 a connecting plate that interconnects said front and rear legs and that is disposed below said seat body of said seat unit; and 
   said seat unit further including a driving member mounted on said connecting plate for driving a pivoting motion of said seat body, and a power source mounted on said connecting plate for providing power to said driving member.   
     
     
         8 . The composite chair as claimed in  claim 2 , wherein said base unit further includes a top board interconnecting said front legs and disposed below said shifting device, said top board being formed with two arcuate slide grooves that are spaced apart from each other, each of said support units of said shifting device including a support plate, and a limiting member that protrudes downward from said support plate for engaging slidably a respective one of said slide grooves, such that said support units are movable relative to said base unit between the retracted position and the expanded position. 
     
     
         9 . The composite chair as claimed in  claim 3 , wherein said backrest unit includes
 a driving member that is pivotally mounted between said rear legs,   a back board that is mounted on said driving member, and   a power source that is mounted on said base unit for providing power to said driving member.   
     
     
         10 . The composite chair as claimed in  claim 6 , wherein said armrest unit further includes
 two driving members spacedly mounted on said back board of said backrest unit for controlling movement of said connecting member in a top-bottom direction, and   a power source for providing power to said driving members.   
     
     
         11 . The composite chair as claimed in  claim 10 , wherein said back board of said backrest unit is formed with two concave receiving portions facing the user's back, said inflatable unit including two inflatable members, each of which is received in a respective one of said receiving portions, and an inflating-deflating component which is mounted on said back board for inflating/deflating said inflatable members. 
     
     
         12 . The composite chair as claimed in  claim 1 , wherein said pushing member of said seat unit has an inverted trapezoid shape