Patent-Treuhand-Gesellschaft F. Elektrische Gluehlampen Mbh

Patent-Treuhand-Gesellschaft Fuer Elektrische Gluehlampen Mbh

Juergen Eder

Hans Liermann

Helmut Berger

Peter Schmidt

Hans-Juergen Streppel

Reinhard Sprenger

A method for producing helically wound filament elements, and filament elnts produced according to this method. The method is distinguished in that a thermal treatment of the incandescent wire at temperatures of over 1200.degree. C. takes place already before the winding of the incandescent wire, so that, after separation, the coil springs open and can easily be detached from the core wire.

Method for producing helically wound filament elements, and filament

To eliminate the necessity of a separate base for a pinch-sealed lamp having a glass bulb, a sleeve (11) made of the same material as the bulb (1) of the lamp, is formed on an extension of the pinch seal (6), the sleeve retaining a contact element (13) secured in the sleeve, for example by molten glass. The contact element (13) extends essentially transverse to a longitudinal axis (A) of the lamp, is recessed within the interior of the sleeve (11) and preferably has a circumference, which is spaced from said axis (A) by circumferentially different distances, optionally in accordance with a mathematical function which, further optionally, is a periodic function, wherein the minimum spacing of the circumference of said contact element from the axis (A) is less than the inner radius of the sleeve (11).

Double-based, double-ended, pinch-sealed electric lamp with integral base

To positively locate a filament (5, 22) in position within a bulb (2) of a halogen incandescent lamp, the walls of the bulb are deformed at selected points along the length of the filament within the bulb to define at least three inwardly projecting dimples which just barely engage, or engage, the filament. Preferably, the filament is formed with a connecting portion (7) in the region of engagement, which connecting portion is either straight, coiled with a very steep pitch, or, if the filament is double-coiled, only single-coiled. The connecting portion (7) may be electrically short-circuited by a core pin (39). If the bulb is single-ended (FIG. 3), a return lead (29) along the wall of the bulb, can be pinched between adjacent walls (45) of adjacent dimples. The dimples, looked at from the outside of the lamp, are essentially funnel-shaped and, in cross section, may be circular, or if space between adjacent dimples is insufficient, may be elliptical.

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Cologne, Germany

Juergen Eder