| 摘要 |
The heating element (3) is fitted on a base (2) of insulating material and surrounded by an edge (1), likewise of insulating material. Together, these parts form a heating unit. The element (3) consists of a metallic strip which is corrugated to meander form, which in turn is formed into an Archimedes spiral. - The element ends (5, 6) are each connected to an electrical connection, with the one in this case being located in the centre of the heating unit. The corrugated strip has three tops and three valleys and one of its broad sides faces the base with the limiting surfaces for the tops and valleys located in planes which are not parallel with one another. |
