Heat treatment of helical springs or similarly shaped articles by electric resistance heating
AssigneeRadyne Corporation
InventorJerry G. Warner
Life of this patent
Estimating the term…
Abstract
Apparatus and method are provided for metallurgical heat treatment of coil springs, or similarly shaped workpieces and articles of manufacture, by electric resistance heating along the entire length of the workpiece so that the ends of the workpiece can be heat treated to the same degree and quality as the section of the workpiece between its two ends.
Claims12
A method of heat treating an elongated workpiece having opposing ends disposed at an angle to the axial length of the elongated workpiece, the method comprising the steps of:
- inserting each one of the opposing ends of the elongated workpiece at least partially in a seating notch in one of a pair of end insert contacts;
- and
- applying an electric potential across the pair of end insert contacts to establish an electric current flow through the pair of end insert contacts and the elongated workpiece to resistance heat the elongated workpiece to one or more heat treatment temperatures over a heat treatment time period while the pair of end insert contacts are resistance heated to approximately one or more heat treatment temperatures for each one of the opposing ends of the elongated workpiece at least partially inserted in the seating notch of each one of the pair of end insert contacts.
A method of heat treating an elongated workpiece having opposing ends disposed at an angle to the axial length of the elongated workpiece, the method comprising the steps of:
- inserting each one of the opposing ends of the elongated workpiece at least partially in a seating notch in one of a pair of end insert contacts;
- applying an electric potential across the pair of end insert contacts to establish an electric current flow through the pair of end insert contacts and the elongated workpiece to resistance heat the elongated workpiece to one or more heat treatment temperatures over a heat treatment time period while the pair of end insert contacts are resistance heated to approximately one or more heat treatment temperatures for each one of the opposing ends of the elongated workpiece at least partially inserted in the seating notch of each one of the pair of end insert contacts;
- and
- applying a compression force to an exposed surface area of at least one of the opposing ends of the elongated workpiece at least partially inserted in the seating notch of at least one of the end insert contacts to force the surface area of the at least one of the opposing ends of the elongated workpiece at least partially inserted into the seating notch against the interior surface area of the seating notch during the electric current flow.
A method of heat treating an elongated workpiece having opposing ends disposed at an angle to the axial length of the elongated workpiece, the method comprising the steps of:
- inserting each one of the opposing ends of the elongated workpiece at least partially in a seating notch in one of a pair of end insert contacts;
- positioning one of a pair of complementary end insert contacts adjacent to each one of the pair of end insert contacts to substantially enclose the opposing ends of the elongated workpiece at least partially inserted in the seating notch in each one of the pair of end insert contacts;
- applying an electric potential across the pair of end insert contacts to establish an electric current flow through the pair of end insert contacts and the elongated workpiece to resistance heat the elongated workpiece to one or more heat treatment temperatures over a heat treatment time period while the pair of end insert contacts are resistance heated to approximately one or more heat treatment temperatures for each one of the opposing ends of the elongated workpiece at least partially inserted in the seating notch of each one of the pair of end insert contacts;
- and
- applying the electric potential across the pair of complementary end insert contacts to establish a complementary electric current flow through the pair of complementary end insert contacts and the elongated workpiece in combination with the electric current flow through the pair of end insert contacts and the elongated workpiece.
A method of heat treating a coil spring having opposing spring ends disposed at an angle to the axial length of the coil spring, the method comprising the steps of:
- inserting each one of the opposing spring ends at least partially in a seating notch in one of a pair of end insert contacts;
- and
- applying an electric potential across the pair of end insert contacts to establish an electric current flow through the pair of end insert contacts and the coil spring to resistance heat the coil spring to one or more heat treatment temperatures over a heat treatment time period while the pair of end insert contacts are resistance heated to approximately one or more heat treatment temperatures for each one of the opposing spring ends at least partially inserted in the seating notch of each one of the pair of end insert contacts.
Dependencies are inferred from the claim text.