| 摘要 |
1301352 Electric hot plate GENERAL ELECTRIC CO 1 May 1970 [1 May 1969] 21044/70 Heading H5H A hot plate comprises a composite sheet 12 formed of a copper, aluminium, or silver core 14 of high thermal conductivity enclosed in a reinforcing skin 15, 16 of oxidation and corrosion resistant material, e.g. stainless steel nickel, or chromium, with an electric resistance heating element 18 secured to the underside of the composite sheet 12. The high conductivity core equalizes the temperature of the plate laterally across its surface. The composite sheet is preferably formed by explosive welding a copper sheet a two stainless steel sheets. The heating element 18 is a metal sheathed element braized to the underside of the composite sheet 12 to increase its strength. It may be of spiral or clover-leaf configuration. Further strength is imparted to the composite sheet 12 by providing a downturned peripheral flange 20 and by securing a reinforcing member to the underside. This reinforcing member shown has a central hub 24 and five spokes 22 braized to composite sheet 12. A liquid tight seal in the form of an asbestos gasket 32 is provided beneath flange 20 and the hot plate is secured to a reflector 35 by a J-bolt. The edge of reflector 35 is spaced from a cookertop 27 by spaced clips 37. In an alternative embodiment (Figs. 5 and 6, not shown) using a clover-leaf metal sheathed element, the reflector pan is integrally formed with the hot plate and has upwardly extending radial ribs which engage the underside of the composite sheet and obviate the need for a separate reinforcing member. The bottom surface of the composite sheet and heating element have a low emissivity. The reflector is sealed to the composite sheet and the space between them evacuated to prevent oxidation of the reflector. |
