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US 4,877,944 AGranted
Self regulating heater
AssigneeMetcal, Inc.
InventorsMark J. Cowell, Kevin Ladd, Philip S. Carter, Jr.
Life of this patent
Estimating the term…
Abstract
A self regulating heater comprises a non-conductive, magnetic core having a coil wound about it and providing pole pieces extending into contact or very near contact with a surrounding ferromagnetic member which in turn may be surrounded by and in intimate contact with a non-magnetic low resistance member; the magnetic member having an effective Curie temperature at the temperature to be maintained.
Claims6
A heater comprising:
- a conductive member,
- a ferromagnetic material lining a surface of said conductive member,
- a magnetic core of a material having a higher electrical resistivity and Curie temperature than said ferromagnetic material and located internally of said ferromagnetic material,
- a coil wound on said core,
- said core being located and shaped to tightly couple flux in said core to said ferromagnetic material, and
- means adapted to connect said coil to a constant, alternating current source of sufficient amplitude to heat said ferromagnetic material to a temperature approaching its Curie temperature.
3 more elements
A heater structure comprising,
- a core of high permeability, low conductivity material,
- a coil wound on said core,
- a hollow member having a high permeability disposed about said core and having a Curie temperature lower than the Curie temperature of said core for determining maximum temperature of said heater,
- said hollow member providing a low reluctance path through said core and said hollow member.
1 more element
Dependencies are inferred from the claim text.