Abstract: A bed assembly (10a) is disclosed. The bed assembly (10a) includes an air mattress (32a) for supporting a human body in a generally prone position. The air mattress (32a) has an overall firmness determined by the amount of air in the air mattress. A port for admitting and releasing air to and from the air mattress (32a) is formed through the air mattress (32a). A box spring support structure (12a) holds the air mattress above a surface. A mechanism (44a) is provided for adjusting the overall firmness of the air mattress (32a) by adjusting the amount of air pressure in the air mattress (32a). The adjusting mechanism (44a) includes a bladder or balloon (48a-54a) for containing a quantity of air and a mechanism (56a) for transferring air between the air mattress (32a) and the bladder (48a-54a) to adjust the relative volume of the air mattress and the bladder.

Abstract: A bed assembly is disclosed. The bed assembly includes an air mattress for supporting a human body in a generally prone position. The air mattress has an overall firmness determined by the amount of air in the air mattress. A port for admitting and releasing air to and from the air mattress is formed through the air mattress. A platform supports the air mattress above a surface. A mechanism is provided for adjusting the overall firmness of the air mattress by adjusting the amount of air in the air mattress. The adjusting mechanism includes a bladder or balloon for containing a quantity of air and a mechanism for transferring air between the air mattress and the bladder to adjust the relative quantity of air in the air mattress and in the bladder. The adjusting mechanism sets the internal volume of the bladder at a desired volume in order to set the relative quantity of air between the air mattress and the bladder.