Patent Treuhand Gesellschaft Fur Elektrische Gluhlampen Mbh

Rupert Muhlberger

Karl Stadler

Rudiger Klam

To permit easy attachment of a coiled filament, and especially a coiled-c or double-twist filament, to the current supply leads within a lamp bulb, in which the current supply leads are made of tungsten, each current supply lead is flattened to form a plate-like flattened surface in the vicinity of the terminal end of the current supply lead. The secondary coiling of a coiled-coil filament--or the single coil of a single-coiled filament--is then slipped over the end portion of the lead-in to extend over and about the flattened portion and with a few turns adjacent the flattened portion and therebeyond on the end portion (15) of the current lead-in, thereby retaining the end portion in position due to the additional width of the flattened portion while providing a reliable electrical contact. The greatest width of the flattened portion is slightly greater than the inner diameter of the secondary coiling of the filament (13), for example about 5% to 20% wider.

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Ingolstadt, Germany

Rupert Muhlberger