Heater plug for diesel engines
AssigneeW. C. Heraeus GmbH
InventorsFranz Sperner, Fritz Aldinger, Wilhelm Zwergel
Life of this patent
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Abstract
A heater plug comprising a heater coil connected to a terminal pin, said terminal pin maintained in gas-tight manner at least in part within and insulated from a plug shell, at least the surface of said heater coil formed by a metal or a base alloy of a metal of the platinum group said heater coil supported by heat resistant electrically insulating rod-like or tubular supporting body heater coil surrounded by a protective tube. The heater plug is useful as a starting aid for diesel engines and other internal combustion engines, especially those without spark ignitions.
Claims27
A heater plug comprising an electrically conductive heater coil connected to an electrically conductive terminal pin, said terminal pin maintained in gas-tight manner at least in part within and insulated from an electrically conductive plug shell, at least the surface of said heater coil formed of a metal of the platinum group, said heater coil supported by a heat resistant electrically insulating rod-like supporting body attached to said terminal pin, said heater coil being surrounded by a heat resistant electrically conductive protective tube made of metal and electrically connected at its other end to the end of said electrically conductive protective tube, said protective tube having openings over its circumference of number and size sufficient to permit fuel and air to pass to said heater coil, said protective tube having an opening at one end, said electrically conductive heater coil being electrically insulated along said protective tube, except for the terminal connecting portion, the wire of said heater coil comprising a core over which there is disposed a cladding, said cladding having a thickness of from 5 to about 50.mu. and said core having a diameter of 150 to 400.mu..
A heater plug comprising an electrically conductive heater coil connected to an electrically conductive terminal pin, said terminal pin maintained in gas-tight manner at least in part within and insulated from an electrically conductive plug shell, at least the surface of the heater coil formed of a metal of the platinum group, said heater coil supported by a heat-resistant, electrically insulating, tubular supporting body attached to said terminal pin, said heater coil being surrounded by a heat-resistant, electrically conductive protective tube made of a metal and electrically connected at its other end to the end of said electrically conductive protective tube, said protective tube having openings over its circumference of number and size sufficient to permit fuel and air to pass to said heater coil, said protective tube having an opening at one end, said electrically conductive heater coil being electrically insulated along said protective tube, except for the terminal connecting portion, the wire of said heater coil comprising a core over which there is disposed a cladding, said cladding having a thickness of from 5 to about 50.mu. and said core having a diameter of 150 to 400.mu..
A heater plug comprising an electrically conductive heater coil connected to an electrically conductive terminal pin, said heater coil being composed of a wire having a diameter of 200 to 400.mu. which wire comprises a core over which is disposed a cladding, said cladding having a thickness of from 5 to 50.mu. and being formed of a composition comprising a platinum group metal, said core having a diameter of 150 to 400.mu. and being made of a composition containing a metal selected from the group consisting of molybdenum and tungsten, said core having a cross-sectional area of about 0.02 to 0.10 mm.sup.2, said terminal pin maintained in gas-tight manner at least in part within and insulated from an electrically conductive plug shell, at least the surface of said heater coil being formed of a metal of the platinum group, said heater coil supported by a heat resistant electrically insulating rod-like supporting body attached to said terminal pin, said heater coil being surrounded by a heat-resistant, electrically conductive protective tube made of a metal and electrically connected at its other end to the end of said electrically conductive protective tube, said protective tube having openings over its circumference of number and size sufficient to permit fuel and air to pass to said heater coil, said protective tube having an opening end, said electrically conductive heater coil being electrically insulated along said protective tube, except for the terminal connecting portion.
A heater plug comprising an electrically conductive heater coil connected to an electrically conductive terminal pin, said terminal pin maintained in gas-tight manner at least in part within and insulated from an electrically conductive plug shell, at least the surface of said heater coil formed of a metal of the platinum group, said heater coil supported by a heat resistant electrically insulating rod-like supporting body attached to said terminal pin, said heater coil being surrounded by a heat resistant electrically conductive protective tube made of a metal and electrically connected at its other end to the end of said electrically conductive protective tube, said protective tube having openings over its circumference of number and size sufficient to permit fuel and air to pass to said heater coil, said protective tube having an opening at one end, said electrically conductive heater coil being electrically insulated along said protective tube, except for the terminal connecting portion, said heater coil being in the form of a strip which strip comprises a core and a cladding, the core having a cross-sectional area of about 0.02 to 0.10 mm.sup.2 and the cladding a thickness of 5 to 50.mu..
Dependencies are inferred from the claim text.