Expandable filter assembly

Claim 1

A filter assembly comprising: A) a filter media unit that includes (1) a body having side edges, end edges, corners formed at the intersection of said side edges and said end edges, a length dimension measured between said end edges and a width dimension measured between said side edges, (2) a plurality of fastener-receiving holes defined through said body adjacent to each body corner, (3) two support strip elements fixed to said body adjacent to each body end edge, and (4) snap fastener socket elements mounted in said support strips in position to co-operate with each fastener-receiving hole; and B) an expandable and contractible frame unit that includes (1) a plurality of crossed legs, (2) pivot fastener elements connecting adjacent legs together in a manner that permits said frame unit to expand and to contract, four of said legs having free ends that are not connected to other legs, and (3) a snap fastener ball element mounted on each leg free end, each snap fastener ball element being sized and adapted to extend through said filter media unit body and to fit into a snap fastener socket element to releasably attach said frame unit to said filter media unit.