| 摘要 |
<p>1,234,285. Furnace roofs. DRESSER INDUSTRIES Inc. 27 Aug., 1968 [19 Sept., 1967], No. 40977/68. Heading F4B. A downwardly opening dome-type roof for an electric furnace comprises a number of outer concentric rings 1-11 of metal cased basic refractory bricks, and a number of inner rings 12-19 of uncased basic refractory bricks, all contained within an annular roof band, and a flexible, articulated contour-controlling holddown mantle located over the encased bricks. The mantle may be formed from enlinked circular chain segments 30-33 secured to radial chain spokes 41 which are connected to the periphery of the roof band, or from linked eyelet bar members or linked slotted bar members (not shown). Ports 22-24 for the furnace electrodes are provided. Means to allow their expansion may be located between the metal cased bricks. Reference has been directed by the Comptroller to Specification 1,119,322.</p> |
