초록 ▼

An electric water heater has a body structure formed in a manner eliminating the need for a separate metal water storage tank therein. The body structure is formed from a coaxially and sealingly joined series of one-piece molded plastic body sections including opposite end sections having closed out

An electric water heater has a body structure formed in a manner eliminating the need for a separate metal water storage tank therein. The body structure is formed from a coaxially and sealingly joined series of one-piece molded plastic body sections including opposite end sections having closed outer ends. Each one piece molded plastic body section has tubular inner and outer shell portions that are coaxial with one another and radially separated by a circumferentially spaced series of radially extending ribs molded integrally therewith and defining therebetween a circumferentially extending series of arcuate insulation spaces. In the assembled body structure the inner shell portions entirely define in the water heater an internal water storage vessel portion that is outwardly enveloped by the insulation spaces and structurally reinforced, via the integral ribs, by the outer shell sections. Suitable inlet and outlet piping is operatively communicated with the interior of the body structure, and water disposed in the internal storage vessel portion thereof may be selectively heated by one or more electric resistance type heating elements operatively mounted on the water heater body structure.

대표청구항 ▼

Water storage apparatus comprising: a plurality of molded plastic one piece hollow tubular body sections positioned in a coaxial, end-to-end orientation in which there is at least one axially adjacent pair of body sections, and including first and second opposite end sections having closed outer end

Water storage apparatus comprising: a plurality of molded plastic one piece hollow tubular body sections positioned in a coaxial, end-to-end orientation in which there is at least one axially adjacent pair of body sections, and including first and second opposite end sections having closed outer ends, each of said body sections having at least one open end portion and further having: (1) a tubular inner shell section, (2) a tubular outer shell section coaxially circumscribing said tubular inner shell section and forming between said inner and outer shell sections an annular insulation space, and (3) a circumferentially spaced series of ribs extending radially across said annular insulation space and dividing said annular insulation space into circumferential segments, said ribs being integrally molded with said inner and outer shell sections, and said closed outer ends of said first and second opposite end sections being integrally molded with said first and second opposite end sections; and joining means for permanently and sealingly joining opposing contiguous open end portions of each axially adjacent pair of said plurality of body sections in a manner forming from said plurality of body sections a hollow water storage body structure having an internal water storage vessel portion defined entirely by said inner shell sections, outwardly enveloped by said annular insulation spaces and structurally reinforced, via said ribs, by said outer shell sections.