Expandable support frame for flexible sleeping mattresses

Claim 1

An expandable support frame suitable for providing supportive confinement for variously sized flexible mattresses, said frame comprising: a support member suitable for positioning on a supporting surface and defining a top disposed at a preselected location spaced from said supporting surface; an expandable mattress housing mounted on said top of said support member said housing including interlocking housing segments, each housing segment including a horizontal base element and vertical side element such that said housing segments form a supportive base bounded by four vertical sides for retaining a flexible mattress; at least one removable housing expansion segment of a size substantially less than each of said housing segments which expansion segment includes a horizontal base element and a vertical side element, said expansion segment combining with said interlocking housing segments to expand at least one of the length and width dimensions of said housing and thus the effective size of said housing; and a plurality of detachable joining members for releasably interlocking said housing segments and said expansion segment thereby providing means for fixedly assembling said housing segments and expansion segment into a single unit having a continuous horizontal surface and vertical sides.