Lumbar support mechanism and head tilt mechanism and adjustable bed therewith

An adjustable bed, comprising:

• a frame structure having a back frame and a foot frame;
• a plurality of platforms disposed on the frame structure, the plurality of platforms comprising at least a back platform having an opening;
• and
• a lifting mechanism positioned between the frame structure and the plurality of platforms for operably adjusting positions of at least one of the plurality of platforms so as to adjust the adjustable bed at a desired position;
• and
• a lumbar support mechanism received in the opening of and secured to the back platform for operably providing lumbar support, wherein the lumbar support mechanism comprises:
• a lumbar support member;
• first, second, third and fourth support legs, each support leg having an upper end and a lower end;
• a linkage member having a first end and an opposite, second end;
• first and second lumbar support brackets attached to the back platform,
• wherein the upper ends of the first and second support legs are pivotally connected to the lumbar support member, and the lower ends of the first and second support legs are pivotally connected to the first and second ends of the linkage member, respectively;
• and the upper ends of the third and fourth support legs are pivotally connected to the first and second support legs, respectively, and the lower ends of the third and fourth support legs are pivotally connected to the first and second lumbar support brackets, respectively, such that a distance between the lumbar support member and the linkage member is changeable between minimal and maximal distances when the linkage member moves between first and second positions;
• and
• a lumbar support actuator for operably moving the linkage member between the first and second positions.