Electric cooking ovens

Claim 1

A heat storage electric oven, comprising a metal main frame, an oven box assembly supported on said main frame and including an oven liner fabricated in sheet metal which encloses an oven chamber, said oven liner having side walls, a top wall, a bottom wall and a back wall and open at the front, a heat-insulated closure door hinged on the main frame for closing the oven chamber front opening, external wall panels encasing said oven box assembly and main frame at the sides, top, bottom and back, heat insulating material interposed between said external wall panels and said oven box assembly, said oven box assembly further including upper and lower heat-conductive sole plates outside said oven liner above and below it and contiguous with its top and bottom surfaces, electrically-insulated electric heating elements assembled against the upper and lower surfaces of the upper and lower sole plates respectively, an electrical circuit for energizing said heating elements, electrically-insulating upper and lower refractory heat storage layers applied to said sole plates and covering said heating elements, upper and lower sheet metal trays containing said refractory layers, top and bottom cross beams clamping said trays to said sole plates and said sole plates to said oven liner, said cross beams having their ends projecting laterally beyond said over liner, and spring-loaded vertical tie rods connecting said top and bottom cross beams to one another at their laterally-projecting ends and allowing differential thermal expansion.