US3824421A - Electric filament lamp - Google Patents

Abstract

The invention relates to an electric filament lamp, in particular a halogen twin lamp for motor-cars, in which an antidazzle cap is incorporated which partly screens one of the filaments and to which one or more current conductors are spotwelded. In the welding place, the screening cap comprises one or several ridges which are at least partly squeezed by the spotwelding operation.

Description

United States Patent Schuringa et al.

[ 51 July 16, 1974 ELECTRIC FILAMENT LAMP Inventors: Leffert Schuringa; Herman Albert Joannes Roefs, both of Eindhoven, Netherlands Assignee: U.S. Philips Corporation, New

York, NY.

Filed: Sept. 7, 1972 Appl. No.: 286,933

' Foreign Application Priority Data Sept. 9, 1971 Germany....; 12394 US. Cl 313/110, 29/475 R, 219/58, 313/117, 313/274 Int. Cl. H0lj 1/88 Field of Search 313/1 10, 274-278, 313/115, 117; 29/475; 219/80, 87, 86, 150

[56] References" Cited UNITED STATES PATENTS 974,891 11/1910 Lachman et a1. 219/58 2,745,045 5/1956 lngraham 29/475 UR X 2,795,722 6/1957 Burgener et a1. 313/115 X 2,869,011 1/1959 Verbeek 3,287,591 ll/l966 Sloan 313/275 X Primary Examiner-Alfred L. Brody Attorney, Agent, or Firm-Frank R. Trifari [57] ABSTRACT The invention relates to an electric filament lamp, in

particular a halogen twin lamp for motor-cars, in

which an anti-dazzle cap is incorporated which partly screens one of the filaments and to which one or more current conductors are spot-welded. 1n the welding 'place, the screening cap comprises one or several ridges which areat least partly squeezed by the spotwelding operation.

3 Claims, 1 Drawing Figure 1 ELECTRIC FILAMENT LAMP The invention relates to an electric filament lamp, in

In manufacturing this known filament lamp, the straight end of the filament or the conductor connected there to engages over a comparatively large length the flat part of the cap during the spot-welding operation. This produces a small contact resistance between the cap and the relevant end of the filament or the conductor, so that a high welding current is necessary. The

and a great detrition of the welding electrodes.

It is the object of the invention to avoid this drawback. For that purpose, in manufacturing the electric filament lamp according to the invention a cap is used the flat part of which comprises at least one ridge in the place where the relevant straight end of the conductor is welded to the cap. Said ridge extends transverse to the longitudinal direction of the end of the filament or the conductor which is forced into the ridge by the spot-welding operation. By using a cap having one or several ridges a larger contact resistance is formed as a result of which a lower energy consumption and a small detrition of the welding electrodes is achieved. Experiments have furthermore demonstrated that the spot-weld in a cap having a flat part with one or several ridges is considerably stronger than in the known cap.

The ridge is preferably in the form of a pleat in the material of the flat part of the cap, said pleat having a V-shaped cross-section.

The invention will be described in greater detail with reference to a drawing, in which a cap 1 of a filament according to the invention is shown. The helically wound anti-dazzle filament 2 extends approximately.

detrimental result hereof is a high energy consumption The sleeve 7 with the filament end 5 incorporated therein is connected as follows: First the sleeve 7 is moved to such a position relative to the flat edge 8, that the sleeve 7 engages the raised portion of the ridge. The contact surface between the ridge 9 and the sleeve 7 is substantially punctiform. The crossing of the ridge 9 and the sleeve 7 is then arranged between the electrodes of a spot-welding device, after which the spotwelding operation is carried out. As a result of this spot-welding operation, the sleeve 7 is forced into the ridge 9. The parts of the ridge 9 present on either side of the sleeves 7 are squeezed more or less.

In this example the ridge 9 has a V-shaped crosssection, as a result of which a very small contact surface exists between the ridge 9 and the sleeve 7 prior to the spot-welding operation.

Of course, the end 5 of the filament may also be spotwelded directly to the edge 8 so without the interposition of thesleeve 7.

The ridge 9 shown in the FIGURE extends over the full length of the edge 8, only locally interrupted by the spot-welding operation. Of course, a shorter ridge which covers only the area of the welding place will do. Furthermore, the edge 8 may also be constructed with two or more ridges which preferably extend in parallel and which extend throughout the length of the edge 8 or not.

What is claimed is:

' 1. In an electric filament lamp, in particular a halogen twin lamp for motor-cars, in which an anti-dazzle filament and a cap which partly screens said filament are arranged in the lamp envelope, the anti-dazzle filament being secured to a flat part of said cap with one of its straight ends connected thereto by means of a spot-welding operation, the improvement comprising that the flat part of the cap includes at least one ridge extending with its raised portion to the end of the filament and extends transverse thereto with its longitudinal direction, the said end of the filament being spotwelded to said ridge, said ridge including a deformation resulting from the spot-welding operation.

2. An electric filament lamp as claimed in claim 1 wherein the ridge is in the form of a pleat in the mate- 'rial of the flat part of the cap, said pleat having a V- shaped cross-section.

3. An electric filament as claimed in claim 1 wherein a tubular conductor is connected to one of the ends of the filament, the conductor being spot-welded to the ridge.

753 3 UNITED STATES PATENT OFFICE I CERTIFICATE OF CORRECTION 3,824,421 I Dated uly 16, 1974 @uten'z: No.

Inventor) Leffert Schuringa; Herman lbert ohannes Reefs It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

IN THE TITLE PAGE [30] Foreign Application riority Data Sept. 9,- 1971 Germany ..l2394" ept. 9, l97l.....The etherlands.-..7ll2394 Signed and sealed this 29th day of October 1974.

(SEAL) Attest:

C. MARSHALL DANN Commissioner of Patents McCOY M. GIBSON JR. Arresting Officer Po-ww "UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION j gtent No, Dated l6,

Inventor) Leffert Schuringa; Herman Albert Johannes Roefs It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

' IN THE TITLE PAGE [30] Foreign Application Priority Data Sept. 9, 1971 ermany .12394" should be [30] Foreign Application riority Data Sept. 9, l97l.....The Nether1ands--.-..7ll2394 Signed and sealed this 29th day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents

Claims (3)

1. In an electric filament lamp, in particular a halogen twin lamp for motor-cars, in which an anti-dazzle filament and a cap which partly screens said filament are arranged in the lamp envelope, the anti-dazzle filament being secured to a flat part of said cap with one of its straight ends connected thereto by means of a spot-welding operation, the improvement comprising that the flat part of the cap includes at least one ridge extending with its raised portion to the end of the filament and extends transverse thereto with its longitudinal direction, the said end of the filament being spot-welded to said ridge, said ridge including a deformation resulting from the spot-welding operation.

2. An electric filament lamp as claimed in claim 1 wherein the ridge is in the form of a pleat in the material of the flat part of the cap, said pleat having a V-shaped cross-section.

3. An electric filament as claimed in claim 1 wherein a tubular conductor is connected to one of the ends of the filament, the conductor being spot-welded to the ridge.

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