Foldable beds

Abstract

A foldable bed including first and second support structures pivotally connected to each other; a plurality of bed boards comprising a back board and a first seat board hinged to the back board and fixed on the first support structure; a back lifting assembly comprising a back lifting bracket pivotally connected to the first support structure and abutting against the back board, and a back lifting actuator pivotally connected between the back lifting bracket and the first support structure to drive the back lifting bracket to pivotally move in an upward or downward rotating direction relative to the first support structure, which in turn drives the back board to rotate in a desired position. When the first and second support structures are folded, the plurality of bed boards are folded at the same time, thereby folding the foldable bed in a folded state.

What is claimed is: 
     
         1 . A foldable bed, comprising:
 a support assembly comprising a first support structure and a second support structure pivotally connected to each other;   a plurality of bed boards disposed on the support assembly, comprising a back board and a first seat board hinged to the back board and fixed on the first support structure;   a back lifting assembly comprising a back lifting bracket pivotally connected to the first support structure and abutting against the back board, and a back lifting actuator pivotally connected between the back lifting bracket and the first support structure,   wherein in operation, the back lifting actuator drives the back lifting bracket to pivotally move in an upward rotating direction or a downward rotating direction relative to the first support structure, which in turn drives the back board to flip along the hinged end with the first seat board so as to adjust the back board in desired positions; and   wherein when the first support structure and the second support structure are folded, the plurality of bed boards are folded at the same time, thereby folding the foldable bed in a folded state.   
     
     
         2 . The foldable bed of  claim 1 , wherein the first support structure comprises a pair of first side rails transversely spaced and longitudinally aligned, an upper rail fixedly connected to the pair of first side rails at their upper ends, and a connecting mechanism comprising a connecting rod having a first end fixed to the upper rail and an opposite, second end fixed to the first seat board, and a connecting structure pivotally connecting the back lifting bracket to the connecting rod. 
     
     
         3 . The foldable bed of  claim 2 , wherein the back lifting bracket comprises a middle bar pivotally mounted to the connecting rod and the pair of first side rails of the first support structure, and a pair of swing arms transversely spaced and longitudinally aligned, and rigidly connected to the middle bar. 
     
     
         4 . The foldable bed of  claim 3 , wherein each of the pair of swing arms is equipped with at least one wheel. 
     
     
         5 . The foldable bed of  claim 3 , wherein the swing arms are in an arc-shaped design. 
     
     
         6 . The foldable bed of  claim 3 , wherein the back lifting actuator comprises a motor member, an outer tube extending from the motor member, and an activation rod having a first end portion received in the outer tube and an opposite, second end portion, wherein the activation rod is engaged with the motor member and configured to be telescopically movable relative to the outer tube according to a direction of motor rotation, wherein the motor member is pivotally connected to the upper rail of the first support structure and the second end portion of the activation rod pivotally connected to the middle bar of the back lifting bracket via a mounting bracket, or wherein the motor member is pivotally connected to the middle bar of the back lifting bracket via the mounting bracket and the second end portion of the activation rod pivotally connected to the upper rail of the first support structure, such that when the activation rod telescopically moves, it drives the middle bar, thereby the pair of swing arms, of the back lifting bracket to rotate accordingly. 
     
     
         7 . The foldable bed of  claim 3 , wherein the connecting structure comprises a clamping member sleeved on the middle bar of the back lifting bracket, and a fixing bracket fixing the clamping member to the connecting rod. 
     
     
         8 . The foldable bed of  claim 7 , wherein the connecting rod has a notch formed between the first and second ends for accommodating the clamping member therein. 
     
     
         9 . The foldable bed of  claim 2 , wherein the second support structure comprises a lower rail and a pair of second side rails transversely spaced and longitudinally aligned, wherein the pair of second side rails has lower ends fixedly connected to two ends of the lower rail and upper ends respectively hinged to lower ends of the pair of first side rails of the first support structure by a pair of hingers. 
     
     
         10 . The foldable bed of claim  10 , wherein a length of the lower rail of the second support structure is longer than that of the upper rail of the first support structure, wherein each first sider rail is hinged to the inner side of a corresponding second side rail such that when the first support structure and the second support structure are folded, the first support structure is stored inside the second support structure. 
     
     
         11 . The foldable bed of  claim 9 , wherein the plurality of bed boards further comprises a second seat board fixed on the second support structure, and a leg board hinged to the second seat board. 
     
     
         12 . The foldable bed of  claim 11 , further comprising:
 a leg lifting assembly comprising a leg lifting bracket pivotally connected to the second support structure and abutting against the leg board, and a leg lifting actuator pivotally connected between the leg lifting bracket and the second support structure,   wherein in operation, the leg lifting actuator drives the leg lifting bracket to pivotally move in an upward rotating direction or a downward rotating direction relative to the second support structure, which in turn drives the leg board to flip along the hinged end with the second seat board so as to adjust the leg board in desired positions.   
     
     
         13 . The foldable bed of  claim 12 , wherein the leg lifting bracket comprises a middle bar pivotally mounted to the pair of second side rails of the second support structure, and a pair of swing arms transversely spaced and longitudinally aligned, and rigidly connected to the middle bar. 
     
     
         14 . The foldable bed of  claim 13 , wherein each of the pair of swing arms is equipped with at least one wheel. 
     
     
         15 . The foldable bed of  claim 13 , wherein the leg lifting actuator comprises a motor member, an outer tube extending from the motor member, and an activation rod having a first end portion received in the outer tube and an opposite, second end portion, wherein the activation rod is engaged with the motor member and configured to be telescopically movable relative to the outer tube according to a direction of motor rotation, wherein the motor member is pivotally connected to the lower rail of the second support structure and the second end portion of the activation rod pivotally connected to the middle bar of the leg lifting bracket via a mounting bracket, or wherein the motor member is pivotally connected to the middle bar of the leg lifting bracket via the mounting bracket and the second end portion of the activation rod pivotally connected to the lower rail of the second support structure, such that when the activation rod telescopically moves, it drives the middle bar, thereby the pair of swing arms, of the leg lifting bracket to rotate accordingly. 
     
     
         16 . The foldable bed of  claim 15 , wherein the leg board comprises a thigh board and a lower leg board, wherein one end of the thigh board is hinged to the second seat board and the other end of the thigh board is hinged to one end of the lower leg board, and wherein the leg lifting bracket abuts against the thigh board such that the movement of the leg lifting bracket in the upward rotating direction or the downward rotating direction results in the position of the thigh board to be adjusted. 
     
     
         17 . The foldable bed of  claim 16 , wherein the second support structure further comprises at least one support bar having a first end hinged to the pair of the second side rails of the second support structure, and a second end hinged to the lower leg board, such that when the position of the thigh board is adjusted, the position of the lower leg board is adjusted accordingly. 
     
     
         18 . The foldable bed of  claim 9 , wherein the second support structure further comprises a connecting mechanism comprising a connecting rod having a first end fixed to the lower rail and an opposite, second end fixed to the second seat board, and a connecting structure pivotally connecting the leg lifting bracket to the connecting rod. 
     
     
         19 . The foldable bed of  claim 1 , wherein the back board has an opening defined to avoid interference when the back lifting assembly drives the back board to flip.