US2045512A - Electric incandescent lamp - Google Patents

Description

June 23, 1936. J BERGMANS 2,045,512

ELECTRIC INCANDESCENT LAMP Filed June 18, 1934' [VI EN 'TUR LIA-2v BER QMANS H75 7'' THRIVE Y Patented June 23, 1936 y r 2,045.512 nnsc'rarc INCANDESCENT LAMP I Jan Ber Eindhoven, Netherlanda assignor gmans, to General Electric (Jompany, a corporation of New York Application'June 18, 1934, Serial No. 731,148 In the Netherlands June 24, 1933 50mins. (01.17649 My invention relates to electric incandescent lamps and more particularly to lamps for use in vehicle headlamps.

It is desirable that the light beam projected when the lamp is used with a .reflectorwithout a configurated lens. The flutes are also arranged so as to make the bulb easy-to manufacture.

Further features and advantages of my inven- 20 tion will appear from the following description of a species thereof.

In the drawing Fig, 1 is a somewhat diagrammaticperspective view of a lamp comprising my invention; Fig. 2 is a front view of the bulb;

5 Fig. 3 is a partial plan view of the bulb with a partial section therein at the horizontal plane through the bulb axis; and Fig. 4 is a diagrammatic representation of beams producedby the lamps made accordingto my invention.

30 Referringto Fig. 1, the lamp comprises a base It and a-bulb l I having a pair of filaments l2, l3 sealed therein and located substantially in the longitudinal axis IA of the lamp. The filament I2 is disposed at the focus of the usual paraboloidal 35 reflector of a headlamp to provide the main driving beam. An internal reflector I5 is located below the forwardly disposed filament: It to direct the rays from said filament against the upper half of the paraboloidal reflector of the headlamp 40 to provide a depressed beam.

The upper surface of the bulb II is provided with flutes it which are located in vertical planes I1 which have a common line of intersection i8 45 which is perpendicular to the horizontal plane iii. The line I8 is tangent to the tip 20 of the bulb ll through which the longitudinal axis l4 passes. The flutes l6 extend on each side of the bulb to planes 2| which form angles preferably of from 95 to 105 degrees with the vertical plane 22 which also intersects the line l8. That is, the angles 23- between the planes 2| and the horizontal plane is are of the magnitude of from to 15 degrees. As many flutes are provided as 55 the manufacture of the bulb permits; for ex- -planes having ample, six per cm. of bulb periphery, measured at the horizontal plane. I g I The lower part of the bulb is also preferably provided with fluted portions 24, 25 (Fig. 2). The flutes in the portion 24 are located in planes 5 which have a common line of intersection 20-26 which is tangent to the bulb ii at the point 20 and makes an angle 21 of from 5 to 15 degrees with the vertical plane 22. The flutes in portion 25 are locateddn planes which have a common line of intersection 20-28 which is also tangent to the bulb H at 20 and makes an angle 29 of from 5 to degrees with the vertical plane 22.

A smooth strip 30 is preferably lefton the bulb between the upper and lower fluted portions for 15 purposes of adjust-ing the position of the internal reflector l5 and the filaments with respect to the bulb.

The full line pattern in Fig. 4 illustrates a crosssection of a dumb-bell" shaped driving beam obtained when thefllament i2 is energized. The dotted lines indicate a beam pattern which might be termed ideal, the ends thereof being depressed below those of the full line pattern.

What I claim as new and desire to secure by Letters Patent in the United States is:

1. An electric incandescent lamp comprising a bulb having a plurality of flutes on the suface thereof for spreading the light transmitted therethrough, said flutes being located in planes having a common line of intersection which is tangent t0 the bulb.

2. An electric incandescent lamp comprising a bulb having a plurality of flutes/{on the upper portion of the surface thereof located in vertical a common line of intersection which is tangent to the tip of the bulb and perpendicular to the longitudinal axis thereof.

3. An electric incandescent lamp comprising a bulb having a plurality of flutes on the upper 40 portion of the surface thereof lccated in vertical planes having a common line of intersection which is tangent to the tip of the bulb and perpendicular to the longitudinal axis thereof, and a plurality of flutes on the lower portion of the surface of .said bulb when horizontally placed, the flutes on each side of said lower surface being located in planes having a common line of intersection which is tangent to the said tip of said bulb and forms an angle with the vertical plane 5 through the bulb axis.

4. An electric incandescent lamp comprising a bulb having a pair of filaments disposed substantially in the longitudinal axis thereof and a concave reflector disposed below one of said fllaments, said bulb when horizontally placed hav ing a. plurality oi. flutes on the upper portion 01' the surface thereof located in vertical planes-having a common line of intersection which is tangent to the tip .01 thebulb and perpendicular to the longitudinal axis thereof.

5. An electric incandescent'lamp comprising a bulb having .a pair of filaments disposed substantially. in the longitudinal axis thereof and a concave reflector disposed below one or said Illa-' ments, said bulb when horizontally placed having a plurality'oi' flutes on the upper portion 01" said bulb, the flutes on each side of surface being. in planes having a common line- .oi' intersection which is tangent to the said tip of the surface thereof located in vertical planes having a common line of intersection which is tangent to the tip of the bulb and perpendicular to the longitudinal axis thereof, and a plurality of flutes on the lower portion of the surface of said lower;

said bulb and forms an angle with the vertical plane through the bulb axis.

v JAN BERGMANS.

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