摘要 |
A heating unit combining a block of thermal and electrical insulating material and an electrical resistance element in which the block contains a mass of ceramic fibers bound together and has an elongated slot with confronting walls rising to the surface of the block from opposite sides of a land, and the resistance element is in the form of a thin member constructed of a continuous resistance wire which is provided with opposite bends to form a serpentine shape, the bends being embedded in the opposite walls of the block to secure the electrical resistance element on the block, and the resistance element abutting the land of the slot between the walls thereof.
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