US 9,814,100 B2
Heat treatment of helical springs or similarly shaped articles by electric resistance heating
Jerry G. Warner, Jackson, WI (US)
Assigned to Radyne Corporation, Milwaukee, WI (US)
Filed by Radyne Corporation, Milwaukee, WI (US)
Filed on Aug. 12, 2013, as Appl. No. 13/964,386.
Application 13/964,386 is a division of application No. 12/849,299, filed on Aug. 3, 2010, granted, now 8,506,732.
Claims priority of provisional application 61/232,058, filed on Aug. 7, 2009.
Prior Publication US 2013/0327743 A1, Dec. 12, 2013
Int. Cl. H05B 3/02 (2006.01); B21F 35/00 (2006.01); B21F 99/00 (2009.01); C21D 1/40 (2006.01); C21D 9/02 (2006.01)
CPC H05B 3/023 (2013.01) [B21F 35/00 (2013.01); B21F 99/00 (2013.01); C21D 1/40 (2013.01); C21D 9/02 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An electric resistance heat treatment apparatus for an elongated workpiece having opposing ends disposed at an angle to the axial length of the elongated workpiece, the electric resistance 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;
a complementary end insert contact for each one of the pair of end insert contacts, the complementary end insert contact having a complementary notch so that when the complementary end insert contact is positioned adjacent to one of the pair of end insert contacts the opposing ends of the elongated workpiece at least partially inserted into each one of the pair of end insert contacts is substantially enclosed by a combination of the seating notch in the one of the pair of end insert contacts and the complementary notch in the complementary end insert contact to form a pair of enclosed end insert contacts;
an electric power source for supplying an electric current to the pair of enclosed end insert contacts; and
an electrical conductor for connection of each one of the pair of enclosed end insert contacts to the electric power source to heat by Joule heating each one of the pair of enclosed end insert contacts to approximately a heat treatment temperature when the opposing ends of the elongated workpiece are at least partially inserted in the seating notches of the pair of enclosed end insert contacts.