Sofa bed iron frame mechanism

Abstract

A sofa bed iron frame mechanism has a side plate (16), a back plate (21), a first frame (1), a second frame (2), and connecting members (17); further includes a stabilizer rod assembly and an elastic connecting rod assembly. The first frame (1) is hinged to the second frame (2) by the stabilizer rod assembly, the second frame (2) is connected to the side plate (16) by the elastic connecting rod assembly, and the back plate (21) is disposed at a back side of the second frame (2). The first frame (1) and the second frame (2) are folded or unfolded through the stabilizer rod assembly, and the second frame (2) switches between a folded state and an unfolded state by inertia of the elastic connecting rod assembly. For this iron frame mechanism, there is no interference during folding.

1 . A sofa bed iron frame mechanism, comprising a side plate ( 16 ), a back plate ( 21 ), a first frame ( 1 ), a second frame ( 2 ), front support legs ( 13 ), middle support legs ( 14 ), and connecting members ( 17 ), wherein the first frame ( 1 ) and the second frame ( 2 ) are hinged to the connecting members ( 17 ), the first frame ( 1 ) is hinged to the front support legs ( 13 ), and the middle support legs ( 14 ) are fixed on the connecting members ( 17 ); and further comprising a stabilizer rod assembly and an elastic connecting rod assembly, wherein the first frame ( 1 ) is hinged to the second frame ( 2 ) by the stabilizer rod assembly, the second frame ( 2 ) is connected to the side plate ( 16 ) by the elastic connecting rod assembly, and the back plate ( 21 ) is disposed at a back side of the second frame ( 2 ); and the first frame ( 1 ) and the second frame ( 2 ) are folded or unfolded through the stabilizer rod assembly, and the second frame ( 2 ) switches between a folded state and an unfolded state by a tension of the elastic connecting rod assembly. 
     
     
         2 . The sofa bed iron frame mechanism according to  claim 1 , wherein the stabilizer rod assembly comprises a first connecting rod ( 4 ), a second connecting rod ( 5 ), the connecting member ( 17 ), and a mounting plate ( 15 ); the first frame ( 1 ) is hinged to the second frame ( 2 ) by the connecting members ( 17 ), one end of the first connecting rod ( 4 ) is hinged to the front support leg ( 13 ) and then is hinged to the first frame ( 1 ) by the front support leg ( 13 ), an other end of the first connecting rod ( 4 ) and one end of the second connecting rod ( 5 ) are jointly hinged to an extended iron sheet on the connecting member ( 17 ), an other end of the second connecting rod ( 5 ) is hinged to the mounting plate ( 15 ), and the mounting plate ( 15 ) is hinged to the second frame ( 2 ) and is fixed on the side plate ( 16 ); and in this manner, a connecting rod mechanism forms a stable structure and plays a role of guiding and limiting during relative rotation between the first frame ( 1 ) and the second frame ( 2 ). 
     
     
         3 . The sofa bed iron frame mechanism according to  claim 1 , wherein the elastic connecting rod assembly comprises a booster rod ( 7 ) and a booster spring ( 8 ); one end of the booster spring ( 8 ) is connected to the second frame ( 2 ), an other end is connected to an end portion of the booster rod ( 7 ), and the booster rod ( 7 ) is fixed on the side plate ( 16 ); and in this manner, when the second frame ( 2 ) rotates, an additional force is provided by the resilience of the booster spring ( 8 ) for the second frame ( 2 ) to switch between the folded state and the unfolded state. 
     
     
         4 . The sofa bed iron frame mechanism according to  claim 1 , wherein the elastic connecting rod assembly comprises a third connecting rod ( 23 ), a booster spring ( 24 ), a booster spring fixing sheet ( 25 ), and a hinge rod assembly ( 26 ); one end of the third connecting rod ( 23 ) is connected to the second frame ( 2 ), an other end of the third connecting rod ( 23 ) is connected to one end of the hinge rod assembly ( 26 ), an other end of the hinge rod assembly ( 26 ) is connected to the booster spring ( 24 ), and the booster spring ( 24 ) is connected to the side plate ( 16 ) by the booster spring fixing sheet ( 25 ); the booster spring fixing sheet ( 25 ) is disposed on an inner side of the side plate ( 16 ) and located below the second frame ( 2 ), and the hinge rod assembly ( 26 ) is disposed on the inner side of the side plate ( 16 ); and in this manner, when the second frame ( 2 ) rotates, the resilience of the booster spring ( 24 ) is transmitted to the second frame through the hinge rod assembly ( 26 ) and the third connecting rod ( 23 ) to provide an additional force for the second frame ( 2 ) to switch between the folded state and the unfolded state. 
     
     
         5 . The sofa bed iron frame mechanism according to  claim 2 , wherein the first frame ( 1 ), the connecting member ( 17 ), and the second frame ( 2 ) are sequentially hinged, so that the first frame ( 1 ) and the second frame ( 2 ) do not interfere with each other in the folded state; and the connecting member ( 17 ) is made of channel steel, having a limiting function to prevent the first frame ( 1 ) and the second frame ( 2 ) from continuing to overturn after reaching the unfolded state. 
     
     
         6 . The sofa bed iron frame mechanism according to  claim 1 , further comprising a backrest frame ( 3 ) and an overturning mechanism, wherein the overturning mechanism is connected to the backrest frame ( 3 ) and the side plate ( 16 ) or the back plate ( 21 ), so that the backrest frame ( 3 ) is overturned and is switched between an overlapped state and an independent folded state with the second frame ( 2 ) through the overturning mechanism. 
     
     
         7 . The sofa bed iron frame mechanism according to  claim 6 , wherein the overturning mechanism comprises a third connecting rod ( 6 ), a locking spring ( 9 ), a support plate ( 10 ), a first support rod ( 11 ), a second support rod ( 12 ), and a back plate connecting member ( 20 ), the support plate ( 10 ) is fixed on the side plate ( 16 ), one end of the third connecting rod ( 6 ) is hinged to the support plate ( 10 ), an other end of the third connecting rod ( 6 ) is sequentially hinged to the back plate connecting member ( 20 ), the second support rod ( 12 ), and the first support rod ( 11 ), one end of the first support rod ( 11 ) is hinged to the support plate ( 10 ), and in this manner, the backrest frame ( 3 ) is disposed on the back plate connecting member ( 20 ), and the locking spring ( 9 ) is disposed between the first support rod ( 11 ) and the second support rod ( 12 ), so that the backrest frame ( 3 ) is overturned around the support plate ( 10 ) through the first support rod ( 11 ), the second support rod ( 12 ), and the back plate connecting member ( 20 ), and the backrest frame ( 3 ) is enabled to have a tension through the locking spring ( 9 ) during overturning. 
     
     
         8 . The sofa bed iron frame mechanism according to  claim 6 , wherein the overturning mechanism comprises hinges ( 22 ), a hinge support plate ( 28 ), and an overturnable backrest ( 29 ), a recess is provided at a lower side of the overturnable backrest ( 29 ) and is fitted with the hinge support plate ( 28 ) to enable surfaces on which the hinges ( 22 ) are mounted to be on the same plane, and the overturnable backrest ( 29 ) rotates around the hinges ( 22 ) to a horizontal position to overlap with the second frame ( 2 ). 
     
     
         9 . The sofa bed iron frame mechanism according to  claim 7 , wherein a limiting structure is provided on an inner side of the support plate ( 10 ), the backrest frame ( 3 ) is overturned around the support plate ( 10 ) through the first support rod ( 11 ), the second support rod ( 12 ), and the back plate connecting member ( 20 ), and the backrest frame ( 3 ) overlaps with the second frame ( 2 ) and the support plate ( 10 ) when the backrest frame ( 3 ) is overturned to a horizontal position. 
     
     
         10 . The sofa bed iron frame mechanism according to  claim 7 , wherein a limiting block ( 30 ) for limiting the third connecting rod ( 6 ) in the folded state is disposed on the support plate ( 10 ), and the limiting block ( 30 ) limits the first support rod ( 11 ) when the backrest frame ( 3 ) is overturned upward from a horizontal position. 
     
     
         11 . The sofa bed iron frame mechanism according to  claim 7 , wherein a limiting plate ( 18 ) is disposed on an end portion of the first support rod ( 11 ) or the second support rod ( 12 ), to limit the first support rod ( 11 ) and the second support rod ( 12 ) and prevent further rotation when the first support rod ( 11 ) and the second support rod ( 12 ) rotate relative to each other to a linear position. 
     
     
         12 . The sofa bed iron frame mechanism according to  claim 2 , wherein the booster spring fixing sheet ( 25 ) and the mounting plate ( 15 ) are the same component. 
     
     
         13 . The sofa bed iron frame mechanism according to  claim 9 , wherein a limiting and supporting groove ( 19 ) is provided on the support plate ( 10 ) and configured to limit and support the backrest frame ( 3 ). 
     
     
         14 . The sofa bed iron frame mechanism according to  claim 2 , further comprising a backrest frame ( 3 ) and an overturning mechanism, wherein the overturning mechanism is connected to the backrest frame ( 3 ) and the side plate ( 16 ) or the back plate ( 21 ), so that the backrest frame ( 3 ) is overturned and is switched between an overlapped state and an independent folded state with the second frame ( 2 ) through the overturning mechanism. 
     
     
         15 . The sofa bed iron frame mechanism according to  claim 3 , further comprising a backrest frame ( 3 ) and an overturning mechanism, wherein the overturning mechanism is connected to the backrest frame ( 3 ) and the side plate ( 16 ) or the back plate ( 21 ), so that the backrest frame ( 3 ) is overturned and is switched between an overlapped state and an independent folded state with the second frame ( 2 ) through the overturning mechanism. 
     
     
         16 . The sofa bed iron frame mechanism according to  claim 4 , further comprising a backrest frame ( 3 ) and an overturning mechanism, wherein the overturning mechanism is connected to the backrest frame ( 3 ) and the side plate ( 16 ) or the back plate ( 21 ), so that the backrest frame ( 3 ) is overturned and is switched between an overlapped state and an independent folded state with the second frame ( 2 ) through the overturning mechanism. 
     
     
         17 . The sofa bed iron frame mechanism according to  claim 14 , wherein the overturning mechanism comprises a third connecting rod ( 6 ), a locking spring ( 9 ), a support plate ( 10 ), a first support rod ( 11 ), a second support rod ( 12 ), and a back plate connecting member ( 20 ), the support plate ( 10 ) is fixed on the side plate ( 16 ), one end of the third connecting rod ( 6 ) is hinged to the support plate ( 10 ), an other end of the third connecting rod ( 6 ) is sequentially hinged to the back plate connecting member ( 20 ), the second support rod ( 12 ), and the first support rod ( 11 ), one end of the first support rod ( 11 ) is hinged to the support plate ( 10 ), and in this manner, the backrest frame ( 3 ) is disposed on the back plate connecting member ( 20 ), and the locking spring ( 9 ) is disposed between the first support rod ( 11 ) and the second support rod ( 12 ), so that the backrest frame ( 3 ) is overturned around the support plate ( 10 ) through the first support rod ( 11 ), the second support rod ( 12 ), and the back plate connecting member ( 20 ), and the backrest frame ( 3 ) is enabled to have a tension through the locking spring ( 9 ) during overturning. 
     
     
         18 . The sofa bed iron frame mechanism according to  claim 15 , wherein the overturning mechanism comprises a third connecting rod ( 6 ), a locking spring ( 9 ), a support plate ( 10 ), a first support rod ( 11 ), a second support rod ( 12 ), and a back plate connecting member ( 20 ), the support plate ( 10 ) is fixed on the side plate ( 16 ), one end of the third connecting rod ( 6 ) is hinged to the support plate ( 10 ), an other end of the third connecting rod ( 6 ) is sequentially hinged to the back plate connecting member ( 20 ), the second support rod ( 12 ), and the first support rod ( 11 ), one end of the first support rod ( 11 ) is hinged to the support plate ( 10 ), and in this manner, the backrest frame ( 3 ) is disposed on the back plate connecting member ( 20 ), and the locking spring ( 9 ) is disposed between the first support rod ( 11 ) and the second support rod ( 12 ), so that the backrest frame ( 3 ) is overturned around the support plate ( 10 ) through the first support rod ( 11 ), the second support rod ( 12 ), and the back plate connecting member ( 20 ), and the backrest frame ( 3 ) is enabled to have a tension through the locking spring ( 9 ) during overturning. 
     
     
         19 . The sofa bed iron frame mechanism according to  claim 14 , wherein the overturning mechanism comprises hinges ( 22 ), a hinge support plate ( 28 ), and an overturnable backrest ( 29 ), a recess is provided at a lower side of the overturnable backrest ( 29 ) and is fitted with the hinge support plate ( 28 ) to enable surfaces on which the hinges ( 22 ) are mounted to be on the same plane, and the overturnable backrest ( 29 ) rotates around the hinges ( 22 ) to a horizontal position to overlap with the second frame ( 2 ). 
     
     
         20 . The sofa bed iron frame mechanism according to  claim 15 , wherein the overturning mechanism comprises hinges ( 22 ), a hinge support plate ( 28 ), and an overturnable backrest ( 29 ), a recess is provided at a lower side of the overturnable backrest ( 29 ) and is fitted with the hinge support plate ( 28 ) to enable surfaces on which the hinges ( 22 ) are mounted to be on the same plane, and the overturnable backrest ( 29 ) rotates around the hinges ( 22 ) to a horizontal position to overlap with the second frame ( 2 ).