Patent ID: 7293309

Claim:
A bed, comprising: a support frame; a first frame having a first portion pivotally mounted on a first portion of the support frame; a first drive cylinder having a first portion pivotally mounted on the support frame and a second portion provided with a retractable first drive rod pivotally mounted on a second portion of the first frame; a second frame having a first portion pivotally mounted on a second portion of the support frame; a second drive cylinder having a first portion pivotally mounted on the support frame and a second portion provided with a retractable second drive rod pivotally mounted on the second frame; an auxiliary frame having a first portion pivotally mounted on a second portion of the second frame and a second portion provided with two rollers; a cushion enclosed around the first frame, the support frame, the second frame and the auxiliary frame; wherein the second frame has two opposite sides each provided with a downward extending resting portion rested on the cushion to stretch the cushion; the resting portion of the second frame is provided with a push bar extending toward the auxiliary frame and movable to rest on a bottom of the auxiliary frame when the auxiliary frame is pivoted downward relative to the second frame; the first drive rod of the first drive cylinder is expandable outwardly to push the first frame to pivot upward, so that the first frame is pivoted upward relative to the support frame to lift and bend a front portion of the cushion, the second drive rod of the second drive cylinder is expandable outwardly to push the second frame to pivot upward, so that the second frame is pivoted upward relative to the support frame to lift and bend a mediate portion of the cushion, and the auxiliary frame is pivoted downward and forward relative to the second frame simultaneously when the second frame is pivoted upward relative to the support frame to lower and bend a rear portion of the cushion; the auxiliary frame is pivoted downward and forward relative to the second frame until the push bar of the second frame is rested on the bottom of the auxiliary frame, so that the auxiliary frame is supported by the push bar of the second frame and disposed at an inclined state; when the second frame is pivoted upward successively relative to the support frame, the auxiliary frame is pushed by the push bar of the second frame to move upward and backward relative to the support frame until the auxiliary frame is disposed at a horizontal state.