Foldable bed

Abstract

A foldable bed includes a bed frame unit that includes a first bed frame subunit and a second bed frame subunit, and that is foldable to a bed flat state, where the first bed frame subunit and the second bed frame subunit are arranged in a lengthwise direction. A backrest actuating mechanism includes a backrest connecting member and a backrest driving assembly. The backrest connecting member has a pivotal end and a connecting end. When the bed frame unit is in the bed flat state, the backrest actuating mechanism is operable to convert between a usage state, where a weight of the backrest driving assembly drives the connecting end to move away from the first bed frame, and a storage state, where the connecting end is adjacent to the first bed frame and the backrest driving assembly is moved closer to the backrest frame.

What is claimed is: 
     
         1 . A foldable bed comprising:
 a support unit;   a bed frame unit that is disposed on said support unit and that includes a first bed frame subunit and a second bed frame subunit connected to said first bed frame subunit, said second bed frame subunit being pivotable relative to said first bed frame subunit to fold said bed frame unit from a bed flat state, where said first bed frame subunit and said second bed frame subunit are arranged in a lengthwise direction, to a bed folded state, where said first bed frame subunit is stacked on top of said second bed frame subunit, said first bed frame subunit including a first bed frame that is connected to said support unit, and a backrest frame that is pivotable relative to said first bed frame; and   a driving unit that includes a backrest actuating mechanism connected to said first bed frame subunit, said backrest actuating mechanism including
 a backrest connecting member having a pivotal end that is pivotally connected to said first bed frame, and a connecting end that is opposite to said pivotal end, and 
 a backrest driving assembly pivotally connected between said backrest frame and said connecting end of said backrest connecting member, said backrest driving assembly being operable for driving said backrest frame to pivot relative to said first bed frame; 
   wherein, when said bed frame unit is in the bed flat state, said backrest actuating mechanism is operable to convert between a usage state, where a weight of said backrest driving assembly drives said connecting end of said backrest connecting member to pivot downwardly away from said first bed frame, and where said backrest driving assembly and said backrest frame cooperatively define a usage angle, and a storage state, where said connecting end of said backrest connecting member is pivoted to be adjacent to said first bed frame to move said backrest driving assembly closer to said backrest frame, and where said backrest driving assembly and said backrest frame cooperatively define a storage angle smaller than said usage angle.   
     
     
         2 . The foldable bed as claimed in  claim 1 , wherein said backrest connecting member is concave with a middle portion thereof being away from said first bed frame. 
     
     
         3 . The foldable bed as claimed in  claim 1 , wherein said backrest driving assembly includes:
 a backrest drive motor that is pivotally connected to said connecting end of said backrest connecting member; and   a backrest drive rod that telescopically extends from said backrest drive motor and that is pivotally connected to said backrest frame.   
     
     
         4 . The foldable bed as claimed in  claim 1 , wherein said backrest driving assembly has a gravity center that is located adjacent to said connecting end of said backrest connecting member. 
     
     
         5 . The foldable bed as claimed in  claim 1 , wherein:
 said backrest connecting member further has an abutting portion that is adjacent to said pivotal end; and   when said bed frame unit is in the bed flat state and said backrest actuating mechanism is in the usage state, said abutting portion of said backrest connecting member abuts against said first bed frame to limit downward pivoting movement of said connecting end of said backrest connecting member away from said first bed frame; and   when said backrest actuating mechanism is in the storage state, said abutting portion of said backrest connecting member is away from said first bed frame.   
     
     
         6 . The foldable bed as claimed in  claim 1 , wherein:
 said first bed frame subunit further includes a first fixing frame that is mounted to said first bed frame;   said backrest frame and said first fixing frame are arranged in the lengthwise direction; and   said backrest frame is connected to said first fixing frame, and is pivotable relative to said first fixing frame and said first bed frame.   
     
     
         7 . The foldable bed as claimed in  claim 1 , wherein:
 said second bed frame subunit includes a second bed frame that is disposed on said support unit,
 a second fixing frame that is mounted to said second bed frame, 
 a leg frame that is pivotally connected to said second fixing frame, and 
 a foot frame that is pivotally connected to said leg frame and that is opposite to said second fixing frame; and 
   when said bed frame unit is in the bed flat state, said second bed frame subunit is switchable between a flat state, where said second fixing frame, said leg frame, and said foot frame are flat in the lengthwise direction, and a bent state, where said leg frame is pivoted upwardly relative to said second fixing frame.   
     
     
         8 . The foldable bed as claimed in  claim 7 , wherein:
 said driving unit further includes a leg frame actuating mechanism that is connected to said second bed frame subunit, said leg frame actuating mechanism including a leg frame driving assembly that is pivotally connected between said second bed frame and said foot frame; and   when said bed frame unit is in the bed flat state, said leg frame driving assembly is operable to lift said foot frame, thereby driving said leg frame to pivot upwardly relative to said second fixing frame, and switching said second bed frame subunit to the bent state.   
     
     
         9 . The foldable bed as claimed in  claim 1 , wherein:
 when said bed frame unit is in the bed flat state and said backrest actuating mechanism is in the usage state, said backrest actuating mechanism has a usage height in a top-bottom direction perpendicular to the lengthwise direction;   when said backrest actuating mechanism is in the storage state, said backrest actuating mechanism has a storage height in the top-bottom direction perpendicular to the lengthwise direction; and   said usage height is greater than said storage height.   
     
     
         10 . The foldable bed as claimed in  claim 1 , wherein:
 when said bed frame unit is in the bed flat state and said backrest actuating mechanism is in the usage state, said backrest actuating mechanism protrudes outwardly from said first bed frame in a top-bottom direction perpendicular to the lengthwise direction; and   when said bed frame unit is in the bed folded state and said backrest actuating mechanism is in the storage state, said backrest actuating mechanism is disposed within a space defined by said first bed frame subunit and said second bed frame subunit.