Adjustable spring clip

In a base assembly for removeably mounting a rail on a support structure, said base assembly including a layer of resilient elastomer material disposed between and attaching to a base plate and a top plate, said base assembly having anchoring means adjacent each end for attaching said base assembly in a fixed position to said support structure, said rail being positioned on said top plate and being secured thereto by a pair of resilient rail clips disposed on opposite sides of said rail, said rail clips having an anchoring section and first and second bearing sections, said top plate having an elongated cut-out on opposite sides of said rail, the improvement comprising laterally adjustable rail clip fastening means, said fastening means including a pair of generally U-shaped sections of rigid material having an upper and lower leg, said upper leg being formed with a curved portion adjacent the closed end of said U-shape, one of said U-shaped sections being inserted within each of said elongated cut-outs in said top plate on opposite sides of said rail, said upper and lower legs being spaced apart a distance less than the thickness of said top plate and being forced apart upon insertion of said U-shaped sections within said elongated cut-outs to bear against said top plate, said U-shaped sections being laterally moveable along said elongated cut-outs to position said closed end in abutment with said rail, said upper and lower legs independently holding said U-shaped sections in abutment with said rail, whereby said anchoring section of each of said rail clips is inserted within said curved portion of said upper leg on each side of said rail to securely hold said rail clips in a position wherein said first bearing section contacts said rail and in cooperation with said U-shaped sections prevents movement of said rail relative to said base assembly.