Murphy Bed

Overview

A Murphy bed, or wall bed, stows a full mattress vertically inside a cabinet so a room can serve another purpose during the day. The Cabinet Surround surround frames the folded bed and anchors the mechanism, while the Bed Frame is a welded steel frame whose slat platform holds the mattress through every position. The link between them is the Pivot Mechanism, which swings the bed down from vertical to horizontal.

Because a queen mattress and frame are heavy, the bed is sprung and balanced so a person can raise or lower it by hand. Torsion springs in the pivot offset most of the weight, a Counterbalance evens out the effort and dampens the ends of travel, Fold-Down Leg legs support the foot end, a Latch holds it closed, and a Wall Anchor fixes the whole assembly to the building.

How it works

When the Latch is released, the Pivot Mechanism lets the bed rotate down about a fixed axis carried on heavy brackets bolted to the cabinet base. Four torsion springs, wound through pivot arms, push against the swing, they are tensioned so their lifting torque roughly cancels the mattress weight, which is why the bed feels light. A Spring Adjuster sets that preload to match the actual mattress.

Spring force alone would make the bed slam or fly open, so the Counterbalance routes the load through links and adds gas dampers that slow the last stage of opening and closing, with stop blocks defining the end positions. Once horizontal, the Fold-Down Leg legs swing out to carry the foot end on the floor while the head end stays on the pivot.

All of this only works because the cabinet is tied to the wall. The Wall Anchor brackets and lag bolts fasten the Cabinet Surround into framing studs, so the reaction torque from the springs and the bed's weight is carried by the building rather than tipping the cabinet. A retention strap on the Bed Frame keeps the mattress in place while the bed is vertical.