Electric Hot Plate with a Cast-In Element: Jordan & Schneider, 1935

In a cast cooking plate the heating coils sit, insulated, inside tubes, and the tubes are cast into the plate. Friedrich Jordan and Paul Schneider of Voigt & Haeffner, Frankfurt, patented a better way in 1935, US 1,998,764: embed each tube only to about half its circumference, or a little more. Casting metal round the whole tube needs core models, costs material and spreads the heat unevenly, while the exposed underside loses little heat because air conducts far worse than metal. To hold the coil firmly while the iron is poured, holding strips or notched webs are fixed to its turns and cast into the plate with it. The centre of the plate may be made thicker to even out the heat.

متقدم

Foundry process

التعليمات

Coil the element

Coil the tubular heating element, the heating wire inside an insulated tube, into a spiral.

المواد لهذه الخطوة:

عنصر تسخين1 قطعة

Fix holding strips

Weld holding strips of sheet metal or wire across the turns of the spiral, or slide the turns into notched webs and bend the webs' tongues round them so they cannot come loose during casting.

المواد لهذه الخطوة:

شرائط تثبيت عنصر التسخين1 as required

الأدوات المطلوبة:

آلة لحام قوسي

زرّادية عادية

Cast the plate

Set the coil in the mould and cast the cooking plate in cast iron, so the tubes are embedded to about half their circumference, or a little more, and the strips or webs are cast in with them. The rest of each tube stays exposed on the underside. The plate may be made thicker at the centre.

المواد لهذه الخطوة: