Sofa bed

Abstract

A sofa bed includes a seat portion, a backrest portion, a seat portion connecting rod, a backrest portion connecting rod, and two armrest frames. The seat portion connecting rod and the backrest portion connecting rod are connected at a locking mechanism and are pivotable relative to each other and lockable relative to each other. The two armrest frames are provided at both ends of the seat portion and the backrest portion in the longitudinal direction. Each of the armrest frames is provided with a sliding groove that opens toward the backrest portion and the seat portion and partially extends in the transverse direction. A rear end of the sliding groove is positioned lower than a front end of the sliding groove. An angle formed between the seat portion and the backrest portion can be locked to improve the reliability of the operation. A switching operation is quickly and easily achieved by allowing ta pin to slide in the sliding groove in an extension direction having a transverse component and a vertical component

1 . A sofa bed, comprising:
 a main body frame ( 100 ) comprising a seat portion ( 4 ) and a backrest portion ( 3 ) arranged adjacent to each other, the seat portion ( 4 ) and the backrest portion ( 3 ) being configured to be folded or unfolded about a locking mechanism ( 34 ), so that the main body frame ( 100 ) transitions between a bed configuration and a sofa configuration; and   an armrest frame ( 2 ) respectively disposed on both sides of the main body frame ( 100 ) in a longitudinal direction and connected to the main body frame ( 100 ) by the locking mechanism ( 34 ), wherein each of the armrest frames ( 2 ) is formed with a slideway ( 211 ) so that the movement of the locking mechanism ( 34 ) is guided by the slideway ( 211 ),   wherein, when the backrest portion ( 3 ) and the seat portion ( 4 ) pivot relative to each other about the locking mechanism ( 34 ), the sofa bed is configured to lock the backrest portion ( 3 ) relative to the seat portion ( 4 ) at a predetermined angle (α), allowing the locking mechanism ( 34 ) to be guided by the slideway ( 211 ) n a locked state to drive the main body frame ( 100 ) to displace.   
     
     
         2 . The sofa bed according to  claim 1 , wherein the locking mechanism ( 34 ) comprises:
 a seat portion connecting rod ( 41 ) attached to and extending along a transverse side edge of the seat portion ( 4 );   a backrest portion connecting rod ( 42 ) attached to a transverse side edge of the backrest portion ( 3 ) on the same side as the transverse side edge of the seat portion ( 4 ) and extending along the transverse side edge of the backrest portion ( 3 ); and   a pivot shaft connecting the seat portion connecting rod ( 41 ) with the backrest portion connecting rod ( 42 ), so that the backrest portion ( 3 ) and the seat portion ( 4 ) can pivot relative to each other.   
     
     
         3 . The sofa bed according to  claim 1 , wherein the main body frame ( 100 ) is configured to release the locking between the seat portion connecting rod ( 41 ) and the backrest portion connecting rod ( 31 ) when the seat portion ( 4 ) arranged in the locked stated is operated to pivot towards the backrest portion ( 3 ). 
     
     
         4 . The sofa bed according to  claim 3 , wherein one of the seat portion connecting rod ( 41 ) and the backrest portion connecting rod ( 31 ) is provided with a ratchet ( 342 ), the other of the seat portion connecting rod ( 41 ) and the backrest portion connecting rod ( 31 ) is provided with a pawl, and the ratchet ( 342 ) and the pawl engage with each other so that the backrest portion ( 3 ) is locked at a predetermined angle (α) with respect to the seat portion ( 4 ). 
     
     
         5 . The sofa bed according to  claim 4 , wherein an outer edge of the ratchet ( 342 ) is provided with a recessed portion that is recessed inward in a radial direction of the ratchet ( 342 ), the pawl is provided with a protruding portion corresponding to the recessed portion, and the protruding portion is configured to enable the protruding portion to engage with the recessed portion when the backrest portion ( 3 ) and the seat portion ( 4 ) form the predetermined angle (α), thereby locking the backrest portion ( 3 ) and the seat portion ( 4 ). 
     
     
         6 . The sofa bed according to  claim 1 , wherein both the seat portion ( 4 ) and the backrest portion ( 3 ) are formed as a rectangular structure. 
     
     
         7 . The sofa bed according to  claim 6 , wherein a side edge of the seat portion ( 4 ) extending in the longitudinal direction and a side edge of the backrest portion ( 3 ) extending in the longitudinal direction are arranged adjacent to each other. 
     
     
         8 . The sofa bed according to  claim 1 , wherein the main body frame ( 100 ) is configured such that the backrest portion ( 3 ) can be locked at a plurality of different predetermined angles relative to the seat portion ( 4 ). 
     
     
         9 . The sofa bed according to  claim 1 , wherein the main body frame ( 100 ) further comprises a driven beam ( 26 ), one end of which is pivotally connected to the armrest frame ( 2 ), and the other end of which is pivotally connected to the backrest portion ( 3 ). 
     
     
         10 . The sofa bed according to  claim 1 , wherein the armrest frame ( 2 ) comprises a substantially  -shaped armrest frame body ( 22 ) and a reinforcing transverse beam ( 21 ) connected between two legs of the armrest frame body ( 22 ), and wherein the slideway ( 211 ) is formed on the reinforcing transverse beam ( 21 ). 
     
     
         11 . The sofa bed according to  claim 10 , wherein the locking mechanism is provided with a pin ( 341 ) extending toward the outside of the main body frame ( 100 ), and the slideway ( 211 ) is a sliding groove formed on the reinforcing transverse beam, wherein one end ( 211   a ) of the slideway is positioned higher than the other end ( 211   b ) of the slideway, and the one end ( 211   a ) is opened toward an upper edge of the armrest frame ( 2 ) to receive the pin ( 341 ) of the locking mechanism ( 34 ). 
     
     
         12 . The sofa bed according to  claim 10 , wherein a sliding rod is provided on the reinforcing transverse beam, and the locking mechanism is provided with a sliding sleeve configured to journal on the sliding rod and slide along the sliding rod. 
     
     
         13 . The sofa bed according to  claim 10 , wherein a sliding rod is provided under the reinforcing transverse beam ( 21   b ), and the sliding rod and a lower edge of the reinforcing transverse beam jointly define a sliding groove ( 213 ). 
     
     
         14 . The sofa bed according to  claim 10 , wherein a cross section of the reinforcing transverse beam ( 21   c ) is in a shape of “ ”, and an outer end of the pin ( 341   c ) is provided with a protrusion having a shape that match with the “ ” shape. 
     
     
         15 . The sofa bed according to  claim 1 , wherein the sofa bed comprises a bottom supporting structure ( 24 ) that is disposed under the backrest portion ( 3 ) and the seat portion ( 4 ) and is fixedly connected to the two armrest frames ( 2 ).