Adjustable bed with internalized, non-protrusive lumbar-support mechanism

An adjustable bed, comprising:

• a frame structure comprising a base frame and an uplifted structure disposed on the base frame;
• a back lifting bracket having a first end pivotally connected to the base frame;
• a plurality of platforms comprising a back platform disposed on the back lifting bracket and a seat platform disposed on the uplifted structure;
• a back lifting actuator having a first end connected to the base frame and a second end connected to the back lifting bracket, wherein the back lifting actuator is configured to drive the back lifting bracket to pivot, thereby moving the back platform among a plurality of positions including a horizontal position;
• and
• a lumbar support mechanism comprising a first lumbar support unit comprising a first lumbar support member positioned above the seat platform;
• and a first lumbar lifting assembly positioned below a bottom side of the seat platform and operatively connected to the first lumbar support member, wherein the first lumbar lifting assembly is configured to drive the first lumbar support member to extend above or retract flush with the seat platform,
• wherein the uplifted structure is configured to elevate the seat platform to provide a vertical space within an elevated profile of the frame structure to accommodate the lumbar support mechanism entirely within the vertical space, thereby preventing outward protrusion.