Emerson Electric Company

Robert D Shirey

Alben C Boggs

Joseph L Lohman

A resistor with a heat sink, particularly adapted for use as a current limiter in an electrical system, such as a power transmission system. The resistor comprises a hollow tube formed of metal which offers resistance to the passage of electrical current, the tube being of a length sufficient to provide the electrical resistance for a given application. The heat sink comprises a material having a high specific heat, the material being contained within the tube and adapted to absorb heat generated by the resistance of the tube to passage of electrical current.

Resistors with heat sink

Screw plug mounting for an electric immersion heater

Our invention relates to electric heating elements for heating liquid within a tank, and particularly to heating elements for use in domestic commercial water tanks, wherein the element comprises a metal mounting member secured to the wall of the tank and a sheath portion carried by the mounting member and extending through a hole in the tank wall for immersion in the water in the tank. The sheath portion contains a resistance conductor and insulation which electrically insulates the conductor from the sheath, so that water in the tank is heated when the resistance conductor is electrically connected to a source of electrical energy. Our invention provides means for protecting the electric heating element from damage which may otherwise be caused by a sudden surge of high voltage, such as that which may be caused by lightning disturbances in the immediate vicinity.

Electric heating elements

The method of providing a corrosion-resistant coating on the aluminum sheath of an electric immersion heater, comprising the steps of treating the sheath with a nitric acid solution to put a uniform layer of oxide on the exterior sheath surface, then treating the sheath with a caustic tin-bearing solution to strip all oxide from said exterior surface and replace it with a uniform layer of tin, then depositing a uniform layer of bronze over the tin layer, and finally depositing a layer of tin over the bronze coating.

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Pittsburgh, PA, United States of America

Robert D Shirey