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.
Claims16
A heat treatment apparatus for an elongated workpiece having opposing ends disposed at an angle to the axial length of the elongated workpiece, the heat treatment apparatus comprising:
- a pair of end insert contacts, each one of the pair of end insert contacts formed from a solid electrically conductive material and having a seating notch, the pair of end insert contacts spaced apart from each other so that the opposing ends of the elongated workpiece can be at least partially inserted in the seating notches of the pair of end insert contacts;
- an electric power source for supplying an electric current to the pair of end insert contacts;
- and
- an electrical conductor for connection of each one of the pair of end insert contacts to the electric power source.
A method of heat treating an elongated workpiece having opposing ends disposed at an angle to the axial length of the 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.
An apparatus for selectively heat treating a plurality of diverse coil springs, the apparatus comprising:
- a pair of end insert contacts for each one of the plurality of diverse coil springs, each one of the pair of end insert contacts formed from a solid electrically conductive material and having a seating notch, the pair of end insert contacts spaced apart from each other so that the opposing ends of each one of the plurality of coil springs can be at least partially inserted in the notches of the pair of end insert contacts, the seating notches in at least one of the pair of end insert contacts having a different cross sectional shape from the seating notches in at least one other of the pair of end insert contacts to accommodate the plurality of diverse coil springs;
- a pair of spaced apart opposing plates for mounting each one of the pair of end insert contacts;
- a drive for rotating the pair of spaced apart opposing plates to position each one of the pair of end insert contacts at a coil spring insertion and removal station;
- and
- an electric power source for supplying current to the pair of end insert contacts located at the coil spring insertion and removal station.
A coil spring metallurgically heat treated by electric resistance heating whereby the opposing ends of the coil spring are each at least partially disposed in a separate end insert contact and an electrical current is supplied to the separate end insert contacts to resistance heat the separate end insert contacts and the coil spring to a heat treatment temperature.
Dependencies are inferred from the claim text.