Abstract: A method of establishing coil dimensional stability by thermally stress relieving the tungsten filament prior to mounting in a lamp. The filament is manipulated into the desired position by coiling it first around a primary mandrel, then a retractable secondary mandrel. After the secondary mandrel is removed, the filament is held in place by a pair of electrical contacts. A current is passed through the primary coil, which heats the tungsten and causes it to recrystallize. The recrystallization provides the desired dimensional stability.

Abstract: A method and apparatus for more precisely centering lamp leads (32, 34) uses a support mechanism (50) for radially aligning the leads. The support mechanism is a helical member having first and second helical portions (52, 54). The first helical portion has a diameter slightly less than the inner diameter of the lamp envelope to maintain a filament (30) on axis. The second helical portion has an outside diameter less than the outside diameter of the first helical portion for securing the support mechanism to a mounting mechanism (60). Here, the mounting mechanism is preferably defined by first and second flattened portions (62, 64) integrally formed on the lead that axially positions the support mechanism in place.