Lightweight waterbed assembly

Claim 1

A lightweight waterbed assembly comprising a fluid filled mattress and a substructure therefore, said substructure including, a pair of planar sheets for engaging and supporting the bottom of said mattress, a supporting frame comprising a lattice of interlocked members having upper edges positioned to support and engage said planar sheets in planes at an obtuse angle to one another, a retaining frame having sides and ends defining a rectangular wall, means supporting said retaining frame on said supporting frame with edges of said retaining frame extending above and other edges thereof extending at least partially below the outer edges of said planar sheets to define a cavity to receive said mattress with said cavity open at the top and with a non-uniformly deep bottom so that the maximum thickness of the mattress occurs in areas where maximum body support is required, said mattress being fabricated of upper and lower water impervious sheets sealed at their peripheries, each of said water impervious sheets having a width which is greater intermediate the ends than at the ends, said lower water impervious sheet conformed to the surfaces defined by said planar sheets and the walls of said retaining frame, said lattice of interlocked members include two sets of flat elongated members with each elongated member having parallel longitudinal edges and a plurality of slots in one of said edges, said sets positioned normal to one another with one set above the other and with said slots of one set aligned and interlocked with the slots of the other set.