Sofa bed

Abstract

A sofa bed comprises a mattress and a guard member having a vertically opened tube-shaped configuration so as to surround an entire circumference of the mattress. The mattress comprises a head side mattress part and a leg side mattress part which can be folded into two so as to meet their upper surfaces. The guard member comprises a head side guard part and a leg side guard part which can be folded into two in the same direction as the mattress so as to meet their upper surfaces. The form of bed is provided when the mattress and the guard member are extended, and the form of sofa is provided when they are folded into two. The folded guard member forms a pair of armrest parts and a backrest part.

1 . A sofa bed comprising: 
 a mattress which can be folded into two so as to meet its upper surfaces; and    a guard member which surrounds an entire circumference of said mattress and can be folded into two in the same direction as said mattress so as to meet its upper surfaces, wherein    said mattress and said guard member take the form of bed when they are extended, and said mattress and said guard member take the form of sofa when they are folded into two.    
     
     
         2 . The sofa bed according to  claim 1 , wherein folded parts of said mattress and said guard member are positioned at the center so as to be at the same distance from their head side ends and their leg side ends.  
     
     
         3 . The sofa bed according to  claim 1 , wherein said mattress and said guard member have hinge parts on their upper surfaces to be folded into two.  
     
     
         4 . The sofa bed according to  claim 1 , wherein the upper surface of said mattress is declined from its head side to its leg side.  
     
     
         5 . The sofa bed according to  claim 1 , wherein a head side region and a leg side region of the mattress have symmetrical semicircular configurations, and a head side region and a leg side region of said guard member have symmetrical semicircular configurations so as to follow the configurations of said mattress.