HEATING ELEMENT FOR AN AIR FLOW HEATER

摘要

A heating element for an air flow comprises a channel shaped bracket including a base and side walls at right angles thereto within which is mounted a pair of mica sheets arranged parallel to the base and at right angles to the sides and c onnected to the sides by ribs longitudinally of the sides with transverse slots within wh ich the sheets slide. Each sheet is wrapped with a heating wire formed into helical coil s so that each side of the sheet carries a plurality of parallel helical coil portions wit h connecting portions wrapped over the edges of the sheet. The sheets are symmetrical and one is inverted relative to the other. Each sheet carries at ends thereof a male and a female connector of the blade and receptacle type so that the blade of one sheet engage s into the receptacle of the other sheet. The connectors thus provide mechanical suppor t to hold the sheet in spaced position and in addition provide electrical connection across the sheets so that electrical energy from supply wires is connected in parallel acro ss the wires of the two sheets. The structure is simple to manufacture and provides a structurally rigid arrangement with high wire density leading to reduced wire temperature.